Title of Invention	A METHOD OF ASSISTING IGNITION OF FUEL WITHIN A COMBUSTION CHAMBER OF AN INTERNAL COMBUSTION ENGINE
Abstract	The present invention discloses a glow member (54), preferably in the shape of a ring, to assist ignition and combustion of a fuel used in an internal combustion engine. A fuel injection valve (56) injects a plurality of fuel jets (58) directly into a combustion chamber during operation of the engine so that the fuel jets (58) are aimed to the proximity of the glow member (54) such that ignition of fuel in each fuel jet is assisted by the glow member (54). The glow member (54) is made from high temperature materials and can include catalytic materials to further promote combustion. The glow member (54) can be actively heated, for example by an electric current, in addition to being passively heated by the heat generated within the combustion chamber (60) by the combustion of the fuel therein.

Title of Invention

A METHOD OF ASSISTING IGNITION OF FUEL WITHIN A COMBUSTION CHAMBER OF AN INTERNAL COMBUSTION ENGINE

Abstract

The present invention discloses a glow member (54), preferably in the shape of a ring, to assist ignition and combustion of a fuel used in an internal combustion engine. A fuel injection valve (56) injects a plurality of fuel jets (58) directly into a combustion chamber during operation of the engine so that the fuel jets (58) are aimed to the proximity of the glow member (54) such that ignition of fuel in each fuel jet is assisted by the glow member (54). The glow member (54) is made from high temperature materials and can include catalytic materials to further promote combustion. The glow member (54) can be actively heated, for example by an electric current, in addition to being passively heated by the heat generated within the combustion chamber (60) by the combustion of the fuel therein.

Full Text	A METHOD OF ASSISTING IGNITION OF FUEL WITHIN A COMBUSTION CHAMBER OF AN INTERNAL COMBUSTION ENGINE Field of the Invention [0001] The present disclosure relates to a method and an apparatus for assisting ignition of fuel within a combustion chamber of an internal combustion engine. Background of the Invention [0002] Fuel alternatives to diesel, including gaseous fuel such as natural gas, hydrogen, ethane, and blends of such gaseous fuels, when used to power internal combustion engines, can significantly reduce emissions of pollutants when compared to the same engines fuelled by diesel. Emissions of pollutants such as nitrogen oxides (NOk), particulate matter (PM) and carbon dioxide (CO:) can be reduced when gaseous fuels are used to fuel diesel engines. The amount of such reductions depends on the fuel chosen amongst other variables. Further, diesel engines can be fuelled by gaseous fuel and still maintain the performance found when diesel fuel is used. For example, gaseous fuel directly injected under high pressure into the combustion chamber of a diesel engine can deliver performance that matches its diesel-fuelled counterpart. [0003] Many gaseous fuels and some non-diesel liquid fuels are less auto-ignitable than diesel fuel. As such, conditions within the cylinder may not provide the necessary environment for auto- ignition when the same environment can auto-ignite diesel. Therefore, a method of assisting ignition is needed to ensure the gaseous fuel is ignited. [0004] Injecting a pilot fuel is one method of initiating ignition of a directly injected quantity of gaseous fuel such as natural gas. Typically, a small amount of diesel fuel is added to a compressed intake charge within the combustion chamber when the piston is near top dead center. The diesel fuel auto-ignites. A main quantity of gaseous fuel is then injected. This quantity is ignited by the burning quantity of pilot fuel. [0005] This method requires a source of a second, more auto- ignitable fuel. Therefore, such a system requires separate pilot fuel storage, and specialized fuel injection valve design and piping to manage pilot diesel fuel flow in addition to main fuel flow. Burning diesel fuel in the combustion chamber generates diesel emissions resulting in higher NOx, CO2 and PM levels than would otherwise be present if no pilot diesel fuel is employed. [0006] Alternatively, hot surface or glow plug ignition can be employed to initiate ignition of a gaseous fuel that is directly injected into a compressed intake charge. Here, in general, a glow plug protrudes from the fire deck, a small distance into the combustion chamber. One of several fuel jets injected into the combustion chamber can be directed at the glow plug to initiate combustion of this fuel jet. In turn, this fuel jet, once ignited, will propagate a flame through the combustion chamber in an effort to ignite the other fuel jets. [0007] One of the problems with this method is that the glow plug is a point source of heat within the combustion chamber. Therefore, it takes time for a first ignited fuel jet to propagate a flame throughout the combustion chamber. Additional turbulence may help but can be imperfect. Gas furthest removed from the glow plug may not ignite or may not burn incompletely. As such, the engine may run less efficiently, delivering less power because of incomplete combustion. Also, a higher percentage of unburned fuel can result in increased hydrocarbon (HC) emissions, see : Mueller, C. J. and Musculus, M. P., "Glow Plug Assisted Ignition and Combustion of methanol in an Optical DI Diesel Engine", SAE paper 2001-01-2004. Spark ignition can also be used, however, like glow plugs, spark ignition ignites a flame at one point within the combustion chamber that propogates throughout the chamber. Therefore, combustion can be incomplete with this method too. There is a need to address the problems noted above to improve engine efficiency and to reduce engine emissions. Summary Accordingly, the present invention provides a method of assisting ignition of a fuel within a combustion chamber of an internal combustion engine, said method comprising : a. introducing an intake charge into said combustion chamber during an intake stroke of a piston, said piston partially defining said combustion chamber, b. compressing said intake charge during a compression stroke of said piston, c. injecting a plurality of spatially distinct fuel jets of said fuel directly into said combustion chamber, d. directing at least two of said plurality of spatially distinct fuel jets proximate to a glow member, said glow member igniting said fuel at at least two locations within said combustion chamber, each of said at least two locations corresponding to each of said at least two of said plurality of spatially distinct fuel jets, e. igniting and burning said fuel within said combustion chamber. The invention further provides an apparatus for assisting combustion of a fuel within a combustion chamber of an internal combustion engine, said apparatus comprising a glow member, which has a heatable surface that is positionable within said combustion chamber where a plurality of spatially distinct fuel jets are directly injected, to ignite at least two of said plurality of spatially distinct fuel jets at at least two locations within said combustion chamber, each of said at least two locations corresponding to each of said at least two of said plurality of spatially distinct fuel jets. The invention further provides an internal combustion engine comprising : a. a combustion chamber defined by : a cylinder; a piston disposed in said cylinder, said piston oscillating between top dead center and bottom dead center within said cylinder during operation of said engine; a fire deck covering one end of said cylinder opposite to said piston, b. a fuel injection valve, said fuel injection valve capable of injecting a plurality of spatially distinct fuel jets of a fuel directly into said combustion chamber, c. a glow member comprising a hot surface positioned relative to said fuel injection valve such that said fuel from at least two of said plurality of fuel jets is heatable by said glow member at at least two locations within said combustion chamber, each of said at least two locations corresponding to each of said at least two of said plurality of spatially distinct fuel jets. The present disclosure introduces a glow member within the combustion chamber that assists in ignition of gaseous fuel and other fuels with a relatively high auto-ignition temperature, compared to diesel fuel. The glow member either initiates combustion or assists in initiating combustion by providing an ignition assist for each of the fuel jets rather than one fuel jet or one region of the chamber. This helps to achieve complete combustion throughout the combustion chamber. A method is provided for assisting ignition of a fuel within a combustion chamber of an internal combustion engine. The method comprises introducing an intake charge into the combustion chamber during an intake stroke of a piston and compressing the intake charge during a compression stroke of the piston. A plurality of spatially distinct fuel jets is introduced directly into the combustion chamber. At least two distinct fuel jets are directed near or onto a glow member with a surface that is heatable to assist with ignition of the fuel. That is, the at least a portion of the fuel introduced by each one of the fuel jets is directed to respective location within the combustion chamber that is proximate to the heated surface of the glow member so that the heat provided by the glow member assists with the ignition of the fuel, which is burned within the combustion chamber. In a preferred method, the glow member with the hot surface can be in the shape of a ring. [0012] The glow member can be heated by the heat of combustion alone or with additional heat provided by a heating element, powered, for example, by an electric current. A preferred method comprises heating the glow member to a temperature of at least 1200°C. [0013] The method may further comprise stepping down the voltage of said engine's electrical system so that a lower voltage is applied to the heating circuit for the glow member. For example, and engine's electrical system typically operates with a voltage of at least 12 volts, but in a preferred method the voltage applied to the circuit for the heating element of the glow member can be stepped down to less than or equal to 2 volts. An advantage of using a lower voltage is that it allows a material with a lower electrical resistivity to be employed, which can provide more flexibility in selecting heating element materials or to have higher thermal mass, which can result in reduced temperature fluctuations during the course of an engine's operation. A heating element with a larger mass can also be more robust in the severe operating conditions that are normally present within an engine's combustion chamber. In a preferred arrangement, for an engine with a plurality of combustion chambers and a glow member in each combustion chamber, a step down transformer is provided for each glow member and the heating element forms the secondary circuit of the respective step down transformer. [0014] A catalytic coating can be put on the glow member to create conditions where the fuel is ignitable at a lower temperature, compared to the conditions where there is no catalyst present. An advantage of this approach is that heating the glow member, which may comprise a ring, to a lower temperature can improve the durability of the glow member. [0015] A preferred apparatus comprises a glow member disposed within a combustion chamber of an internal combustion engine for assisting combustion of a fuel therein. The glow member provides a beatable surface positioned to assist with the ignition of a plurality of spatially distinct fuel jets injected directly into the combustion chamber. A preferred shape for the glow member is a circular ring. [0016] The glow member can have a surface comprising a catalytic material. The catalytic material can comprise a precious metal. By way of preferred example, the precious metal can be platinum. [0017] The glow member can be connected to a current source for directing an electric current through the glow member. The electric current is capable of heating the glow member. The apparatus can further comprise a transformer for reducing the voltage that is applied to the heating circuit. Vehicles typically use electrical systems based upon a voltage of at least 12 volts. The voltage applied to the glow member heating circuit, could be reduced, for example to less than or equal to 2 volts. By reducing the voltage, the electrical resistance can also be reduced, allowing thicker, more robust heating elements that have a larger thermal mass or the selection of a material with a lower resistivity. The glow member can be subjected to cooling during the engine cycle, for example, when the relatively cool intake charge is introduced into the combustion chamber. A larger thermal mass allows the glow member to retain more heat so there is less variation in the surface temperature of the glow member. In a preferred arrangement of this embodiment, for engines with a plurality of combustion chambers with a glow member in each combustitin chamber, a step down transformer is provided for each glow member and the heating element for each glow member is the secondary circuit for the step down transformer. [0018] In some embodiments, the glow member can be capable of being heated to a temperature of at least 1200°C. [0019] A further aspect of the invention provides an internal combustion engine comprising a combustion chamber defined by a cylinder, a piston disposed in the cylinder, the piston oscillating between top dead center and bottom dead center within the cylinder during operation of the engine and a fire deck covering one end of the cylinder opposite to the piston. The engine further includes a fuel injection valve, which is capable of injecting a plurality of spatially distinct fuel jets directly into the combustion chamber. Also, a glow member provides a hot surface that is positioned relative to the fuel injection valve such that a quantity of the fuel from each one of the plurality of fuel jets is heatable by the glow member. [0020] The glow member hot surface can be provided in the shape of a ring. [0021] The engine can be configured so that each one of the plurality of fuel jets impact directly on the glow member. [0022] The glow member can comprise a catalytic material. The catalytic material can comprise a precious metal and in a preferred embodiment, that precious metal can be platinum. [0023] The glow member can comprise an anode and a cathode capable of providing an electric current for heating the glow member. The engine can further comprise a transformer for stepping down the voltage of the electric current from the voltage provided by the engine's electrical system to a lower voltage that can be applied to the glow member. As in previously described embodiments, the voltage applied to the glow member may be less than or equal to 2 volts. [0024] The glow member can further define an orifice and a reservoir. The orifice allows a quantity of the intake charge to flow into and out of the reservoir. When the engine is running, a portion of the intake charge can flow into the reservoir and accumulating therein during a compression stroke. The glow member heats the portion of the intake charge that is held within the reservoir, and during the power stroke the heated portion of the intake charge can flow from the reservoir through the orifices and back into the combustion chamber as a heated "charge jet". [0025] In some embodiments the engine further comprises a barrier disposed within the combustion chamber between the fuel injection valve and the glow member. In this embodiment at least a portion of the fuel that is introduced into the combustion chamber by the plurality of fuel jets impacts on the barrier to generate fuel eddies and the glow member is positioned in a space where the fuel eddies are generated when the engine is operating. The velocity of the fuel in the fuel jets is greater closer to the fuel injection valve, and if the glow member is positioned closer to the fuel injection valve it can be desirable to slow down the fuel that is directed to the glow member so that it has a greater opportunity to ignite. An advantage of this arrangement is that the barrier acts to slow down the fuel and the fuel in the eddies can remain proximate to the glow member for a longer period of time. The barrier is attached to the fire deck. In one embodiment, the barrier can be a spring clip. The glow member can be attached to the barrier for structural support. [0026] The engine can comprise an injection valve sleeve defining an opening for receiving and supporting the fuel injection valve, which is mountable therein. The barrier can be a portion of the sleeve that extends beyond the fire deck so that it protrudes into the combustion chamber. In another embodiment, the barrier can be attached to the injection valve sleeve. [0027] The barrier can comprise a catalytic material that helps to ignite the fuel at a lower temperature, compared to the temperature that would be necessary to ignite the fuel without the presence of the catalytic material. The catalytic material can comprise a precious metal and in a preferred embodiment, the precious metal is platinum. [0028] A further aspect of the invention provides an internal combustion engine comprising a cylinder, a piston disposed within the cylinder where the piston oscillates between top dead center and bottom dead center within the cylinder during operation of the engine. A fire deck covers one end of the cylinder opposite to the piston. The cylinder, the piston and the fire deck substantially define a combustion chamber. The engine includes a fuel injection valve and the fuel injection valve comprises a plurality of orifices, which are provided through a nozzle of the fuel injection valve. The nozzle projects from the fire deck to allow each one of the orifices to direct a fuel into the combustion chamber in a spatially distinct fuel jet. A glow member is positioned suspended from the fire deck and positioned relative to fuel injection valve such that each one of the plurality of fuel jets will impact on the glow member when it is directed into the combustion chamber. [0029] Yet another embodiment of the invention provides an engine comprising a cylinder, a piston disposed in the cylinder where the piston oscillates between top dead center and bottom dead center within the cylinder during operation of the engine. Also, a fire deck is included. The cylinder, the piston and the fire deck substantially define a combustion chamber. Also a fuel injection valve is included where the fuel injection valve comprises at least two orifices. A valve sleeve is included defining a support space and a first end, the first end projected from the fire deck into the combustion chamber. The injection valve is disposed in the support space wherein each of the orifices is capable of directing a fuel jet past the sleeve into the combustion chamber. A glow member is fixed around a clip. The clip is fixed to the first end and positioned on the first end such that a portion of the fuel jets will impact on the clip when injected into the combustion chamber resulting in fuel eddies. The glow member is positioned on the clip such that the eddies impact the glow member. [0030] In preferred embodiments, the fuel that is introduced into the combustion chamber is a gaseous fuel. [0031] Further aspects of the invention and features of specific embodiments of the invention are discussed below. Brief Description of the Accompanying Drawings [0032] In drawings which illustrate non-limiting embodiments of the invention: [0033] FIGURES la and lb show two views of the combustion chamber of a first embodiment wherein a glow member is affixed to the fire deck of the combustion chamber. FIGURE la shows a top view of the combustion chamber demonstrating a preferred position for the subject glow member. FIG. lb shows a cross-sectional side view of the combustion chamber across line A-A shown in FIG. la, illustrating the glow member attached to the fire deck. [0034] FIGURES 2a and 2b show a second embodiment wherein a glow member is affixed to a piston. FIG. 2a shows a top view of the second embodiment and FIG. 2b shows a cross-sectional side view of the second embodiment across line B-B shown in FIG. 2a. [0035] FIGURES 3a, 3b and 3c show three views of a third embodiment of a glow member. FIG. 3a shows a cross sectional side view of the ring attached to a clip, which in turn is attached to an injector sleeve, which houses a fuel injection valve. FIG. 3b shows a close up of the circled portion of FIG. 3a with the outline of a fuel jet stream being ejected from the fuel injection valve. FIG. 3c shows an exploded view of the glow member and clip. Detailed Description [0036] A glow member is provided that assists in ignition and combustion of fuels that are difficult to auto-ignite under the conditions typically found within a compression ignition diesel-fuelled engine. The disclosed method and apparatus help to burn more of the fuel within the combustion chamber. [0037] In the embodiments discussed herein, the combustion chamber has accumulated an intake charge through the piston's intake stroke and has compressed that charge through the piston's compression stroke. The embodiments are demonstrated when the piston is at or near top dead center at the commencement of a power stroke. By way of example, a gaseous fuel is injected into the compressed intake charge within the combustion chamber at about this point in the cycle of the engine. Amongst a number of considerations, the injection should be timed to allow the fuel to ignite and burn to drive the power stroke. [0038] Referring to FIGS, la and lb, ring-shaped glow member 54 is shown attached to fire deck 63. [0039] The first embodiment of the subject disclosure is shown with intake valves 50 and exhaust valves 52 outlined in the top view. Glow member 54, and the nozzle of fuel injection valve 56 are disposed within combustion chamber 60. Dashed lines outline the general shape of fuel jets 58. In FIG. lb, piston 62 is at or near top dead center within combustion chamber 60. The side view of FIG. lb also shows fire deck 63 along with posts 65, from which glow member 54 is supported. [0040] Note that fuel jets 58 are shown demonstrating a typical spray pattern within the combustion chamber. FIGs. la and lb show how fuel jets 58 can be directed to the proximity of glow member 54 so that at least a portion of the fuel in fuel jets 58 is heatable by the glow member to assist with igniting the fuel. [0041] Referring to FIG. lb, glow member 54 is shown affixed to fire deck 63. Glow member 54 is provided in this first embodiment at a distance from fire deck 63 and with a circumference that provides a hot surface area, which assists with ignition and combustion of each fuel jet 58. That is, preferably each fuel jet 58, shortly after being injected into the combustion chamber from fuel injection valve 56, will impact on the upper surface of glow member 54. In turn, glow member 54 imparts heat to at least some of the fuel provided by fuel jets 58 helping to initiate ignition of these fuel jets. That is, as glow member 54 is preferably approximately centered on the fuel injection valve, each fuel jet interacts, and preferably impacts, glow member 54 allowing it to ignite more easily. Combustion is less reliant on flame propagation to ignite and burn all fuel. Therefore, more complete combustion can be achieved. [0042] The disclosure contemplates a fuel injection valve that directs at least two spatially distinct fuel jets into a combustion chamber. That is, the fuel injection valve has a plurality of nozzle orifices, with each orifice providing a point of origin for a fuel jet to direct fuel into the combustion chamber. Each nozzle orifice can direct a fuel jet that is spatially distinct from the fuel jets originating from other respective nozzle orifices. Typically, fuel jets are dispersed from the injection valve tip to various different parts of the combustion chamber to provide fuel to all parts of combustion chamber to help use as much of the intake charge as possible. [0043] The preferred glow member arrangement in the shape of a ring centered on the injection valve allows each fuel jet to impact on the glow member at approximately the same time assuming the injection pressure and injection valve nozzle orifice sizes are the same and symmetry of the fuel jet pattern around the injection valve tip is approximately equal. However, the dimension of the ring can be varied to deal with asymmetric jet patterns. That is, it is preferred, more generally, that the ring be positioned, shaped and dimension such that it would be in the path of each fuel jet directed from the injection valve. [0044] By way of example, the range of dimensioning for the geometry of glow member 54 can be provided by: D = (0.2-0.35)B d = (0.1-0.25)B h = (0.01-0.1)*B where D is the outer diameter of the ring and d the inner diameter of the ring, h is height of the supporting posts, and B is the diameter of the cylinder. [0045] In preferred embodiments, the diameter of the ring and distance of the ring from the fire deck are selected to help ensure that the glow member is exposed to the combustion environment to help the glow member to accumulate heat during combustion events within the chamber. At the same time, glow member 54 is positioned close enough to the fuel jet that ignition can be assisted. [0046] As would be understood by a person skilled in the art, care should taken to ensure that a glow member with a larger diameter be clear of intake valves 50 and exhaust valves 52, allowing these valves to open as required during operation of the engine. [0047] This first embodiment of the glow member can be "passively" or "actively" heated. As defined herein, a passively heated glow member is made of materials that retain heat between engine cycles. The temperature within the combustion chamber fluctuates during engine operation. For example the temperature drops when the relatively cool intake charge is introduced during the intake stroke, and the temperature increases during the compression stroke and the temperature rises even more during the power stroke when the fuel is burned. A passively heated glow member is made from a material that acts as a "thermal absorber". After being warmed during the first few cycles after start-up, a passively heated glow member can maintain a temperature within a desired range between subsequent combustion events as determined by, amongst other things, the thermal retention and absorption properties of the material and the combustion environment. That is, the combustion environment of a particular fuel will warm the combustion chamber and the passively heated glow member. The heat retained by the glow member allows it to maintain a surface temperature that is hot enough to assist with the ignition of at least a portion of fuel jets 58, which impacts on glow member 54. In this arrangement, the fuel will either ignite and burn as a result of impacting the glow member or ignite and burn more easily than would be the case otherwise. In the later case, another ignition assist strategy can be used in addition to the disclosed glow member, but with less energy being required to ignite the fuel. [0048] A glow member that is only passively heated will be cold if the engine has been shut down for an extended period of time. Therefore, a passively heated glow member requires additional ignition assistance at times when the glow member cannot provide heat to assist with ignition. Therefore, by way of example, a start-up ignition assist such as a glow plug, spark plug or pilot fuel can be used to help initiate ignition of the gaseous fuel until the combustion chamber, and the glow member, is warmed. However, once the engine is "warm", the glow member will impart some heat to the fuel jets. Depending upon the temperature within the combustion chamber and the type of fuel being burned, the amount of assistance from other ignition assistance devices can be reduced or eliminated. [0049] An engine controller may monitor such things as the hydrocarbon emissions, cycle-to-cycle combustion variability and load to help ensure ignition of the fuel, complete combustion of the fuel and a reduction or elimination of a start-up ignition assist such as pilot fuel or a conventional glow plug. [0050] The preferred materials to make glow member 54 are generally high temperature materials of suitable durability to withstand the environment within the combustion chamber. Glow member 54 is made from a material that can withstand the thermal conditions and tresses within the combustion chamber. By way of example, some mitable materials include those considered for glow plugs and glow plug shields. These materials can be coated with catalytic materials such as platinum or other precious metals. U.S. Patent 6,076,493 teaches use and preparation of such materials for a glow plug shield for use in a combustion chamber. [0051] In the disclosed embodiments, ignition assistance is preferably provided by a glow member that can, between cycles, retain a temperature above that found within a given charge at that point near the completion of the compression stroke or the commencement of the power stroke at which time fuel is injected into the combustion chamber. [0052] Note that the shape of the illustrated piston bowl is demonstrative of typical piston bowl designs. Such a design, developed for diesel-fueled engines, is directed at promoting turbulence within the combustion chamber. In the case of glow plug ignition assisted engines, turbulence helps promote the propagation of combustion throughout the combustion chamber. As there is less need for flame propagation within the combustion chamber where the subject teaching is used, such turbulence enhancement geometry within the combustion chamber may be less important than would otherwise be the case. [0053] As already noted, the glow member shown in FIGs. la and lb can also be actively heated. An actively heated glow member is defined as a glow member that does not rely entirely on the absorption of heat from within the combustion chamber for storing heat energy. By way of example, the glow member can be heated by running an electric current through the glow member itself or through an electric heating circuit provided within the glow member. [00541 As an additional feature, any one of the embodiments of the glow member described herein can further comprise one or a plurality of reservoirs provided within the body of a passively or actively heated glow member. Orifices can provide communication between the glow member reservoir(s) and the combustion chamber. A portion of the intake charge that is introduced into the combustion chamber during an intake stroke can accumulate within such, reservoir(s) during the intake stroke and the subsequent compression stroke. The intake charge that flows into such reservoir(s) is surrounded by the warmed glow member. Upon commencement of the power stroke, the warmed charge would be expelled into the combustion chamber by the expansion of the combustion chamber, with the warmed charge and the turbulence caused by its re-introduction into the combustion chamber providing further ignition assistance to the fuel. [0055] Known methods can be employed for mounting the glow member within the combustion chamber. For example, in each embodiment it would be appropriate to attach the glow member using appropriate screws, bolts, welding or other known methods, as would be understood by a person skilled in the art. [0056] Referring to FIGS. 2a and 2b, a second embodiment is provided. In this embodiment, passive glow member 92 is affixed to piston 90 by posts 93. Again fuel jet 94 is outlined being injected into combustion chamber 96, which is partially defined by piston 90. FIG. 2a shows the location of intake valves 98 and exhaust valves 100. While the illustrated embodiment employs a four-valve arrangement (two intake valves and two exhaust valves), glow member 92 can be employed with a different number of intake or exhaust valves. Also shown by the illustrated embodiment is a combustion chamber with centrally positioned fuel injection valve 102 from which fuel jets 94 originate. [0057] The second embodiment works in generally the same way as the first embodiment. However, as this second embodiment shows the glow member attached to piston 90 instead of fire deck 105, glow member 92 will only come into direct contact with fuel jets 58 when the piston is at or near top dead center. Therefore, it is preferred, for this embodiment, that the fuel be injected near top dead center. [0058] Further, this embodiment has less flexibility adapting an actively heated system to the glow member. It is more difficult to provide the power necessary to an active system because the glow member is attached to the piston. [0059] Referring to FIG. 3, a third embodiment is provided wherein an active glow member is shown. Glow member 200 is attached to support member 202, which is, in turn, attached to injection valve sleeve 204. Fuel injection valve 206 is shown mounted inside injection valve sleeve 204. Injection valve nozzle orifices 208 are shown with fuel jets 210. Fuel eddies 212 are shown generated near and beyond support member 202 which acts as a barrier in the path of at least a portion of the fuel jet. Positive and negative power leads 214 and 216 are shown as well. Fire deck 218 defines one boundary of the combustion chamber from which protrudes injection valve 206. [0060] In this preferred embodiment of actively heated glow member 200, support member 202 is attached to an end of injection valve sleeve 204 that extends below fire deck 218 and that projects into the combustion chamber. Glow member 200 is attached to support member 202 as shown, and support member 202 also projects into the combustion chamber. When a controller commands fuel injection valve 206 to open, a quantity of fuel is injected into the combustion chamber, and at least a portion of fuel jets 210 impact on support member 202 to generate fuel eddies 212, which recirculate around support member 202 in the vicinity of glow member 200. Actively heated glow member 200 is heated by an electric current through leads 214 and 216. Therefore, shortly after the fuel eddies are heated by being in the proximity of glow member 200, ignition results. Due to the ring shape of glow member 200 and support member 202, each one of jets 210 from each one of nozzle orifices 208 will generate fuel eddies 212 which can bring fuel close to glow member 200 resulting in ignition of each fuel jet from each eddy. Combustion from the fuel contained in each fuel jet is, likewise, assisted. Further, glow member 200 is relatively small which results in reduced power requirements to heat glow member 200 compared to a larger active glow member. [0061] While it is possible to remove support member 202 and position glow member 200 in the path of fuel jets 210, positioning the glow member directly in the path of fuel jets 210 can inhibit combustion. As fuel jets 210 are driven from fuel injection valve 206 at very high velocity, the fuel can be driven past glow member 200 without igniting. Therefore, support member 202, allows an eddy of fuel to form. It is directed at a relatively low velocity towards the glow member and is allowed to ignite and propagate a flame through to each fuel jet 210. [0062] For this embodiment, the ring should be made of a material capable of being electrically heated to temperatures within the range of 900°C to 1700°C, with the preferred temperature range between 900°C and 1200°C. Materials that are able to withstand the conditions found within the combustion chamber are known. For example, suitable materials include Si3N4 composites. Likewise, support member 202 can be used as a thermal catalyst to promote ignition. It could be made of a thermally absorbing material, such as those discussed above in regards to the passive glow members of the first and second embodiments. When support member 202 is employed as a passive glow member, once heated, it can help reduce the load on active glow member 200. [0063] The disclosed passively and actively heated glow member embodiments can be employed with four-stroke and two-stroke engines. [0064] Conventional glow plugs use a hot surface at a point within the combustion chamber to assist with ignition of a fuel. The present apparatus and method employs a glow member that provides a hot surface that provides ignition and combustion assistance to more than one area of the combustion chamber in cooperation with the fuel injection pattern dictated by fuel injection valve design. Therefore, hot surface geometry that provides ignition and combustion assistance to a plurality of spatially distinct fuel jets also falls within the disclosure. A ring-shaped glow member is a convenient embodiment as many fuel injection valves provide a relatively uniform spray pattern to many regions of a generally cylindrical combustion chamber. However, where the fuel injection valve provides a variation on this spray pattern, the hot surface or "glow element" shape and positioning can be adapted. Therefore, as would be understood by a person skilled in the art, the glow member may be "C"-shaped, oval shaped, or may have other shapes to match the fuel injection valve design. [0065] For the purposes of this disclosure, gaseous fuels are contemplated as the fuel used to drive the engine. However, as suggested above, many fuels that are more difficult to auto-ignite than diesel can, in general, be adapted and are contemplated within the subject disclosure, as would be understood by a person skilled in the art. Therefore, where gaseous fuels are referenced, the disclosure contemplates such fuels as natural gas, methane, ethane, butane, propane and other gaseous hydrocarbon fuels as well as hydrogen and other fuels that contain one or more of these gaseous fuels. Also, some liquid fuels, such as methanol, that can require ignition assistance, depending on engine design, can also benefit. Most such fuels will benefit to some extent from the presence of the disclosed glow member or, more generally, hot surface geometry found in the combustion chamber. [0066] Rate shaping can also be used in the context of this disclosure to help ignite fuel. Greater exposure of a fuel to the glow member, in essence priming the fuel prior to ignition, can help ignition when required during or at the commencement of the power stroke. [0067] While particular elements, embodiments and applications of the present disclosure have been shown and described, it will be understood, of course, that the disclosure is not limited thereto since modifications can be made by those skilled in the art without departing from the scope of the present disclosure, particularly in light of the foregoing teachings. WE CLAIM : 1. A method of assisting ignition of a fuel within a combustion chamber of an internal combustion engine, said method comprising : a. introducing an intake charge into said combustion chamber during an intake stroke of a piston, said piston partially defining said combustion chamber, b. compressing said intake charge during a compression stroke of said piston, c. injecting a plurality of spatially distinct jets of said fuel directly into said combustion chamber, d. directing at least two of said plurality of spatially distinct fuel jets proximate to a glow member, said glow member igniting said fuel at at least two locations within said combustion chamber, each of said at least two locations corresponding to each of said at least two of said plurality of spatially distinct fuel jets, e. igniting and burning said fuel within said combustion chamber. 2. The method as claimed in claim 1, wherein said glow member is in the shape of a ring. 3. The method as claimed in claim 1, wherein said glow member is heated by an electric current. 4. The method as claimed in claim 3, which involves heating said glow member to a temperature of at least 1200°C. 5. The method as claimed in claim 3, which involves stepping down the voltage of said engine's electrical system so that a lower voltage is applied to said glow member. 6. The method as claimed in claim 5, wherein the voltage applied to said glow member is less than or equal to 2 volts. 7. The method as claimed in claim 1, which involves coating said glow member with a catalytic coating. 8. An apparatus for assisting combustion of a fuel within a combustion chamber of an internal combustion engine, said apparatus comprising a glow member, which has a heatable surface that is positionable within said combustion chamber where a plurality of spatially distinct fuel jets are directly injected, to ignite at least two of said plurality of spatially distinct fuel jets at at least two locations within said combustion chamber, each of said at least two locations corresponding to each of said at least two of said plurality of spatially distinct fuel jets. 9. The apparatus as claimed in claim 8, wherein said glow member is in the shape of a ring. 10. The apparatus as claimed in claim 8, having a catalytic material disposed on a surface of said glow member. 11. The apparatus as claimed in claim 10, wherein said catalytic material is a precious metal. 12. The apparatus as claimed in claim 11, wherein said precious metal is platinum. 13. The apparatus as claimed in claim 8, having first and second electrodes for directing an electric current through said glow member, said electric current capable of heating said glow member. 14. The apparatus as claimed in claim 13, wherein a surface of said glow member is capable of being heated to a temperature of at least 1200°C. 15. The apparatus as claimed in claim 13, having a transformer for stepping down the voltage of said engine's electrical system so that a lower voltage can be applied to said glow member. 16. The apparatus as claimed in claim 15, wherein said transformer is capable of stepping down the voltage applied to said glow member to less than or equal to 2 volts. 17. The apparatus as claimed in claim 15, wherein a heating element for said glow member is employed as a secondary circuit for said transformer. 18. An internal combustion engine comprising : a. a combustion chamber defined by : a cylinder; a piston disposed in said cylinder, said piston oscillating between top dead center and bottom dead center within said cylinder during operation of said engine; a fire deck covering one end of said cylinder opposite to said piston, b. a fuel injection valve, said fuel injection valve capable of injecting a plurality of spatially distinct fuel jets of a fuel directly into said combustion chamber, c. a glow member comprising a hot surface positioned relative to said fuel injection valve such that said fuel from at least two of said plurality of fuel jets is heatable by said glow member at at least two locations within said combustion chamber, each of said at least two locations corresponding to each of said at least two of said plurality of spatially distinct fuel jets. 19. The engine as claimed in claim 18, wherein said glow member is in the shape of a ring. 20. The engine as claimed in claim 18, wherein said plurality of fuel jets impact directly on said glow member. 21. The engine as claimed in claim 18, wherein said glow member comprises a catalytic material. 22. The engine as claimed in claim 21, wherein said catalytic material is a precious metal. 23. The engine as claimed in claim 22, wherein said precious metal is platinum. 24. The engine as claimed in claim 18, wherein said glow member comprises an anode and a cathode capable of providing an electric current for heating said glow member. 25. The engine as claimed in claim 24, having a transformer for stepping down the voltage of the electric current from said engine's electrical system so that a lower voltage can be applied to said glow member. 26. The engine as claimed in claim 25, wherein said transformer is capable of stepping down the voltage applied to said glow member to less than or equal to 2 volts. 27. The engine as claimed in claim 25, wherein a heating circuit for said glow member is employed as a secondary circuit for said transformer. 28. The engine as claimed in any one of claims 18 and 24, wherein said glow member defines an orifice and a reservoir, said reservoir capable of accumulating and heating a quantity of intake charge during a compression stroke, and said orifice is capable of directing a charge jet of said quantity from said orifice into said combustion chamber during a power stroke. 29. The engine as claimed in any one of claims 18 and 24, having a barrier disposed within said combustion chamber between said fuel injection valve and said glow member whereby at least a portion of said fuel introduced into said combustion chamber by said plurality of fuel jets impacts on said barrier to generate fuel eddies, wherein said glow member is positioned in the space where said fuel eddies are generated when said engine is operating. 30. The engine as claimed in claim 29, wherein said barrier is attached to said fire deck. 31. The engine as claimed in claim 29, wherein said barrier is a spring clip. 32. The engine as claimed in claim 29, wherein said glow member is attachable to said barrier for structural support. 33. The engine as claimed in claim 29, having an injection valve sleeve defining an opening for receiving and supporting said fuel injection valve, which is mountable therein, wherein said barrier is attachable to said injection valve sleeve. 34. The engine as claimed in claim 29, wherein said barrier comprises a catalytic material. 35. The engine as claimed in claim 34, wherein said catalytic material is a precious metal. 36. The engine as claimed in claim 35, wherein said precious metal is platinum. 37. The engine as claimed in claim 29, having an injection valve sleeve defining an operating for receiving and supporting said fuel injection valve, which is mountable therein, wherein said barrier is provided by a sleeve end that extends beyond said fire deck and into said combustion chamber. 38. The engine as claimed in any one of claims 18 through 37, wherein said fuel is a gaseous fuel. The present invention discloses a glow member (54), preferably in the shape of a ring, to assist ignition and combustion of a fuel used in an internal combustion engine. A fuel injection valve (56) injects a plurality of fuel jets (58) directly into a combustion chamber during operation of the engine so that the fuel jets (58) are aimed to the proximity of the glow member (54) such that ignition of fuel in each fuel jet is assisted by the glow member (54). The glow member (54) is made from high temperature materials and can include catalytic materials to further promote combustion. The glow member (54) can be actively heated, for example by an electric current, in addition to being passively heated by the heat generated within the combustion chamber (60) by the combustion of the fuel therein.

Full Text

A METHOD OF ASSISTING IGNITION OF FUEL WITHIN A COMBUSTION CHAMBER
OF AN INTERNAL COMBUSTION ENGINE
Field of the Invention
[0001] The present disclosure relates to a method and an apparatus for assisting ignition of
fuel within a combustion chamber of an internal combustion engine.
Background of the Invention
[0002] Fuel alternatives to diesel, including gaseous fuel such as natural gas, hydrogen,
ethane, and blends of such gaseous fuels, when used to power internal combustion engines, can
significantly reduce emissions of pollutants when compared to the same engines fuelled by diesel.
Emissions of pollutants such as nitrogen oxides (NOk), particulate matter (PM) and carbon dioxide
(CO:) can be reduced when gaseous fuels are used to fuel diesel engines. The amount of such
reductions depends on the fuel chosen amongst other variables. Further, diesel engines can be fuelled
by gaseous fuel and still maintain the performance found when diesel fuel is used. For example,
gaseous fuel directly injected under high pressure into the combustion chamber of a diesel engine can
deliver performance that matches its diesel-fuelled counterpart.
[0003] Many gaseous fuels and some non-diesel liquid fuels are less auto-ignitable than diesel
fuel. As such, conditions within the cylinder may not provide the necessary environment for auto-
ignition
when the same environment can auto-ignite diesel. Therefore, a method
of assisting ignition is needed to ensure the gaseous fuel is ignited.
[0004] Injecting a pilot fuel is one method of initiating ignition of a
directly injected quantity of gaseous fuel such as natural gas. Typically,
a small amount of diesel fuel is added to a compressed intake charge
within the combustion chamber when the piston is near top dead center.
The diesel fuel auto-ignites. A main quantity of gaseous fuel is then
injected. This quantity is ignited by the burning quantity of pilot fuel.
[0005] This method requires a source of a second, more auto-
ignitable fuel. Therefore, such a system requires separate pilot fuel
storage, and specialized fuel injection valve design and piping to manage
pilot diesel fuel flow in addition to main fuel flow. Burning diesel fuel
in the combustion chamber generates diesel emissions resulting in higher
NOx, CO2 and PM levels than would otherwise be present if no pilot
diesel fuel is employed.
[0006] Alternatively, hot surface or glow plug ignition can be
employed to initiate ignition of a gaseous fuel that is directly injected
into a compressed intake charge. Here, in general, a glow plug protrudes
from the fire deck, a small distance into the combustion chamber. One of
several fuel jets injected into the combustion chamber can be directed at
the glow plug to initiate combustion of this fuel jet. In turn, this fuel jet,
once ignited, will propagate a flame through the combustion chamber in
an effort to ignite the other fuel jets.
[0007] One of the problems with this method is that the glow plug
is a point source of heat within the combustion chamber. Therefore, it
takes time for a first ignited fuel jet to propagate a flame throughout the
combustion chamber. Additional turbulence may help but can be imperfect. Gas furthest removed
from the glow plug may not ignite or may not burn incompletely. As such, the engine may run less
efficiently, delivering less power because of incomplete combustion. Also, a higher percentage of
unburned fuel can result in increased hydrocarbon (HC) emissions, see : Mueller, C. J. and Musculus,
M. P., "Glow Plug Assisted Ignition and Combustion of methanol in an Optical DI Diesel Engine",
SAE paper 2001-01-2004.
Spark ignition can also be used, however, like glow plugs, spark ignition ignites a flame at
one point within the combustion chamber that propogates throughout the chamber. Therefore,
combustion can be incomplete with this method too.
There is a need to address the problems noted above to improve engine efficiency and to
reduce engine emissions.
Summary
Accordingly, the present invention provides a method of assisting ignition of a fuel within a
combustion chamber of an internal combustion engine, said method comprising :
a. introducing an intake charge into said combustion chamber during an intake stroke of
a piston, said piston partially defining said combustion chamber,
b. compressing said intake charge during a compression stroke of said piston,
c. injecting a plurality of spatially distinct fuel jets of said fuel directly into said
combustion chamber,
d. directing at least two of said plurality of spatially distinct fuel jets proximate to a
glow member, said glow member igniting said fuel at at least two locations within said
combustion chamber, each of said at least two locations corresponding to each of said
at least two of said plurality of spatially distinct fuel jets,
e. igniting and burning said fuel within said combustion chamber.
The invention further provides an apparatus for assisting combustion of a fuel within a
combustion chamber of an internal combustion engine, said apparatus comprising a glow member,
which has a heatable surface that is positionable within said combustion chamber where a plurality of
spatially distinct fuel jets are directly injected, to ignite at least two of said plurality of spatially
distinct fuel jets at at least two locations within said combustion chamber, each of said at least two
locations corresponding to each of said at least two of said plurality of spatially distinct fuel jets.
The invention further provides an internal combustion engine comprising :
a. a combustion chamber defined by :
a cylinder;
a piston disposed in said cylinder, said piston oscillating between top dead
center and bottom dead center within said cylinder during operation of said engine;
a fire deck covering one end of said cylinder opposite to said piston,
b. a fuel injection valve, said fuel injection valve capable of injecting a plurality of
spatially distinct fuel jets of a fuel directly into said combustion chamber,
c. a glow member comprising a hot surface positioned relative to said fuel injection
valve such that said fuel from at least two of said plurality of fuel jets is heatable by said glow
member at at least two locations within said combustion chamber, each of said at least two locations
corresponding to each of said at least two of said plurality of spatially distinct fuel jets.
The present disclosure introduces a glow member within the combustion chamber that assists
in ignition of gaseous fuel and other fuels with a relatively high auto-ignition temperature, compared
to diesel fuel. The glow member either initiates combustion or assists in initiating combustion by
providing an ignition assist for each of the fuel jets rather than one fuel jet or one region of the
chamber. This helps to achieve complete combustion throughout the combustion chamber.
A method is provided for assisting ignition of a fuel within a combustion chamber of an
internal combustion engine. The method comprises introducing an intake charge into the combustion
chamber
during an intake stroke of a piston and compressing the intake charge
during a compression stroke of the piston. A plurality of spatially
distinct fuel jets is introduced directly into the combustion chamber. At
least two distinct fuel jets are directed near or onto a glow member with a
surface that is heatable to assist with ignition of the fuel. That is, the at
least a portion of the fuel introduced by each one of the fuel jets is
directed to respective location within the combustion chamber that is
proximate to the heated surface of the glow member so that the heat
provided by the glow member assists with the ignition of the fuel, which
is burned within the combustion chamber. In a preferred method, the
glow member with the hot surface can be in the shape of a ring.
[0012] The glow member can be heated by the heat of combustion
alone or with additional heat provided by a heating element, powered, for
example, by an electric current. A preferred method comprises heating
the glow member to a temperature of at least 1200°C.
[0013] The method may further comprise stepping down the
voltage of said engine's electrical system so that a lower voltage is
applied to the heating circuit for the glow member. For example, and
engine's electrical system typically operates with a voltage of at least 12
volts, but in a preferred method the voltage applied to the circuit for the
heating element of the glow member can be stepped down to less than or
equal to 2 volts. An advantage of using a lower voltage is that it allows a
material with a lower electrical resistivity to be employed, which can
provide more flexibility in selecting heating element materials or to have
higher thermal mass, which can result in reduced temperature
fluctuations during the course of an engine's operation. A heating
element with a larger mass can also be more robust in the severe
operating conditions that are normally present within an engine's
combustion chamber. In a preferred arrangement, for an engine with a
plurality of combustion chambers and a glow member in each
combustion chamber, a step down transformer is provided for each glow
member and the heating element forms the secondary circuit of the
respective step down transformer.
[0014] A catalytic coating can be put on the glow member to create
conditions where the fuel is ignitable at a lower temperature, compared to
the conditions where there is no catalyst present. An advantage of this
approach is that heating the glow member, which may comprise a ring, to
a lower temperature can improve the durability of the glow member.
[0015] A preferred apparatus comprises a glow member disposed
within a combustion chamber of an internal combustion engine for
assisting combustion of a fuel therein. The glow member provides a
beatable surface positioned to assist with the ignition of a plurality of
spatially distinct fuel jets injected directly into the combustion chamber.
A preferred shape for the glow member is a circular ring.
[0016] The glow member can have a surface comprising a catalytic
material. The catalytic material can comprise a precious metal. By way of
preferred example, the precious metal can be platinum.
[0017] The glow member can be connected to a current source for
directing an electric current through the glow member. The electric
current is capable of heating the glow member. The apparatus can
further comprise a transformer for reducing the voltage that is applied to
the heating circuit. Vehicles typically use electrical systems based upon
a voltage of at least 12 volts. The voltage applied to the glow member
heating circuit, could be reduced, for example to less than or equal to 2
volts. By reducing the voltage, the electrical resistance can also be
reduced, allowing thicker, more robust heating elements that have a
larger thermal mass or the selection of a material with a lower resistivity.
The glow member can be subjected to cooling during the engine cycle,
for example, when the relatively cool intake charge is introduced into the
combustion chamber. A larger thermal mass allows the glow member to
retain more heat so there is less variation in the surface temperature of
the glow member. In a preferred arrangement of this embodiment, for
engines with a plurality of combustion chambers with a glow member in
each combustitin chamber, a step down transformer is provided for each
glow member and the heating element for each glow member is the
secondary circuit for the step down transformer.
[0018] In some embodiments, the glow member can be capable of
being heated to a temperature of at least 1200°C.
[0019] A further aspect of the invention provides an internal
combustion engine comprising a combustion chamber defined by a
cylinder, a piston disposed in the cylinder, the piston oscillating between
top dead center and bottom dead center within the cylinder during
operation of the engine and a fire deck covering one end of the cylinder
opposite to the piston. The engine further includes a fuel injection valve,
which is capable of injecting a plurality of spatially distinct fuel jets
directly into the combustion chamber. Also, a glow member provides a
hot surface that is positioned relative to the fuel injection valve such that a
quantity of the fuel from each one of the plurality of fuel jets is heatable by
the glow member.
[0020] The glow member hot surface can be provided in the shape
of a ring.
[0021] The engine can be configured so that each one of the
plurality of fuel jets impact directly on the glow member.
[0022] The glow member can comprise a catalytic material. The
catalytic material can comprise a precious metal and in a preferred
embodiment, that precious metal can be platinum.
[0023] The glow member can comprise an anode and a cathode
capable of providing an electric current for heating the glow member.
The engine can further comprise a transformer for stepping down the
voltage of the electric current from the voltage provided by the engine's
electrical system to a lower voltage that can be applied to the glow
member. As in previously described embodiments, the voltage applied to
the glow member may be less than or equal to 2 volts.
[0024] The glow member can further define an orifice and a
reservoir. The orifice allows a quantity of the intake charge to flow into
and out of the reservoir. When the engine is running, a portion of the
intake charge can flow into the reservoir and accumulating therein during
a compression stroke. The glow member heats the portion of the intake
charge that is held within the reservoir, and during the power stroke the
heated portion of the intake charge can flow from the reservoir through
the orifices and back into the combustion chamber as a heated "charge
jet".

[0025] In some embodiments the engine further comprises a barrier
disposed within the combustion chamber between the fuel injection valve
and the glow member. In this embodiment at least a portion of the fuel
that is introduced into the combustion chamber by the plurality of fuel
jets impacts on the barrier to generate fuel eddies and the glow member is
positioned in a space where the fuel eddies are generated when the
engine is operating. The velocity of the fuel in the fuel jets is greater
closer to the fuel injection valve, and if the glow member is positioned
closer to the fuel injection valve it can be desirable to slow down the fuel
that is directed to the glow member so that it has a greater opportunity to
ignite. An advantage of this arrangement is that the barrier acts to slow
down the fuel and the fuel in the eddies can remain proximate to the glow
member for a longer period of time. The barrier is attached to the fire
deck. In one embodiment, the barrier can be a spring clip. The glow
member can be attached to the barrier for structural support.
[0026] The engine can comprise an injection valve sleeve defining
an opening for receiving and supporting the fuel injection valve, which is
mountable therein. The barrier can be a portion of the sleeve that
extends beyond the fire deck so that it protrudes into the combustion
chamber. In another embodiment, the barrier can be attached to the
injection valve sleeve.
[0027] The barrier can comprise a catalytic material that helps to
ignite the fuel at a lower temperature, compared to the temperature that
would be necessary to ignite the fuel without the presence of the catalytic
material. The catalytic material can comprise a precious metal and in a
preferred embodiment, the precious metal is platinum.
[0028] A further aspect of the invention provides an internal
combustion engine comprising a cylinder, a piston disposed within the
cylinder where the piston oscillates between top dead center and bottom
dead center within the cylinder during operation of the engine. A fire
deck covers one end of the cylinder opposite to the piston. The cylinder,
the piston and the fire deck substantially define a combustion chamber.
The engine includes a fuel injection valve and the fuel injection valve
comprises a plurality of orifices, which are provided through a nozzle of
the fuel injection valve. The nozzle projects from the fire deck to allow
each one of the orifices to direct a fuel into the combustion chamber in a
spatially distinct fuel jet. A glow member is positioned suspended from
the fire deck and positioned relative to fuel injection valve such that each
one of the plurality of fuel jets will impact on the glow member when it is
directed into the combustion chamber.
[0029] Yet another embodiment of the invention provides an engine
comprising a cylinder, a piston disposed in the cylinder where the piston
oscillates between top dead center and bottom dead center within the
cylinder during operation of the engine. Also, a fire deck is included.
The cylinder, the piston and the fire deck substantially define a
combustion chamber. Also a fuel injection valve is included where the
fuel injection valve comprises at least two orifices. A valve sleeve is
included defining a support space and a first end, the first end projected
from the fire deck into the combustion chamber. The injection valve is
disposed in the support space wherein each of the orifices is capable of
directing a fuel jet past the sleeve into the combustion chamber. A glow
member is fixed around a clip. The clip is fixed to the first end and
positioned on the first end such that a portion of the fuel jets will impact
on the clip when injected into the combustion chamber resulting in fuel
eddies. The glow member is positioned on the clip such that the eddies
impact the glow member.
[0030] In preferred embodiments, the fuel that is introduced into
the combustion chamber is a gaseous fuel.
[0031] Further aspects of the invention and features of specific
embodiments of the invention are discussed below.

Brief Description of the Accompanying Drawings
[0032] In drawings which illustrate non-limiting embodiments of
the invention:
[0033] FIGURES la and lb show two views of the combustion
chamber of a first embodiment wherein a glow member is affixed to the
fire deck of the combustion chamber. FIGURE la shows a top view of
the combustion chamber demonstrating a preferred position for the
subject glow member. FIG. lb shows a cross-sectional side view of the
combustion chamber across line A-A shown in FIG. la, illustrating the
glow member attached to the fire deck.
[0034] FIGURES 2a and 2b show a second embodiment wherein a
glow member is affixed to a piston. FIG. 2a shows a top view of the
second embodiment and FIG. 2b shows a cross-sectional side view of the
second embodiment across line B-B shown in FIG. 2a.
[0035] FIGURES 3a, 3b and 3c show three views of a third
embodiment of a glow member. FIG. 3a shows a cross sectional side
view of the ring attached to a clip, which in turn is attached to an injector
sleeve, which houses a fuel injection valve. FIG. 3b shows a close up of
the circled portion of FIG. 3a with the outline of a fuel jet stream being
ejected from the fuel injection valve. FIG. 3c shows an exploded view of
the glow member and clip.
Detailed Description
[0036] A glow member is provided that assists in ignition and
combustion of fuels that are difficult to auto-ignite under the conditions
typically found within a compression ignition diesel-fuelled engine. The
disclosed method and apparatus help to burn more of the fuel within the
combustion chamber.
[0037] In the embodiments discussed herein, the combustion
chamber has accumulated an intake charge through the piston's intake
stroke and has compressed that charge through the piston's compression
stroke. The embodiments are demonstrated when the piston is at or near
top dead center at the commencement of a power stroke. By way of
example, a gaseous fuel is injected into the compressed intake charge
within the combustion chamber at about this point in the cycle of the
engine. Amongst a number of considerations, the injection should be
timed to allow the fuel to ignite and burn to drive the power stroke.
[0038] Referring to FIGS, la and lb, ring-shaped glow member 54
is shown attached to fire deck 63.
[0039] The first embodiment of the subject disclosure is shown
with intake valves 50 and exhaust valves 52 outlined in the top view.
Glow member 54, and the nozzle of fuel injection valve 56 are disposed
within combustion chamber 60. Dashed lines outline the general shape
of fuel jets 58. In FIG. lb, piston 62 is at or near top dead center within
combustion chamber 60. The side view of FIG. lb also shows fire deck
63 along with posts 65, from which glow member 54 is supported.
[0040] Note that fuel jets 58 are shown demonstrating a typical
spray pattern within the combustion chamber. FIGs. la and lb show
how fuel jets 58 can be directed to the proximity of glow member 54 so
that at least a portion of the fuel in fuel jets 58 is heatable by the glow
member to assist with igniting the fuel.
[0041] Referring to FIG. lb, glow member 54 is shown affixed to
fire deck 63. Glow member 54 is provided in this first embodiment at a
distance from fire deck 63 and with a circumference that provides a hot
surface area, which assists with ignition and combustion of each fuel jet
58. That is, preferably each fuel jet 58, shortly after being injected into
the combustion chamber from fuel injection valve 56, will impact on the
upper surface of glow member 54. In turn, glow member 54 imparts heat
to at least some of the fuel provided by fuel jets 58 helping to initiate
ignition of these fuel jets. That is, as glow member 54 is preferably
approximately centered on the fuel injection valve, each fuel jet interacts,
and preferably impacts, glow member 54 allowing it to ignite more
easily. Combustion is less reliant on flame propagation to ignite and burn
all fuel. Therefore, more complete combustion can be achieved.
[0042] The disclosure contemplates a fuel injection valve that
directs at least two spatially distinct fuel jets into a combustion chamber.
That is, the fuel injection valve has a plurality of nozzle orifices, with
each orifice providing a point of origin for a fuel jet to direct fuel into the
combustion chamber. Each nozzle orifice can direct a fuel jet that is
spatially distinct from the fuel jets originating from other respective
nozzle orifices. Typically, fuel jets are dispersed from the injection valve
tip to various different parts of the combustion chamber to provide fuel
to all parts of combustion chamber to help use as much of the intake
charge as possible.
[0043] The preferred glow member arrangement in the shape of a
ring centered on the injection valve allows each fuel jet to impact on the
glow member at approximately the same time assuming the injection
pressure and injection valve nozzle orifice sizes are the same and
symmetry of the fuel jet pattern around the injection valve tip is
approximately equal. However, the dimension of the ring can be varied to
deal with asymmetric jet patterns. That is, it is preferred, more generally,
that the ring be positioned, shaped and dimension such that it would be in
the path of each fuel jet directed from the injection valve.
[0044] By way of example, the range of dimensioning for the
geometry of glow member 54 can be provided by:
D = (0.2-0.35)*B
d = (0.1-0.25)*B
h = (0.01-0.1)*B
where D is the outer diameter of the ring and d the inner diameter of the
ring, h is height of the supporting posts, and B is the diameter of the
cylinder.
[0045] In preferred embodiments, the diameter of the ring and
distance of the ring from the fire deck are selected to help ensure that the
glow member is exposed to the combustion environment to help the glow
member to accumulate heat during combustion events within the
chamber. At the same time, glow member 54 is positioned close enough
to the fuel jet that ignition can be assisted.
[0046] As would be understood by a person skilled in the art, care
should taken to ensure that a glow member with a larger diameter be
clear of intake valves 50 and exhaust valves 52, allowing these valves to
open as required during operation of the engine.
[0047] This first embodiment of the glow member can be
"passively" or "actively" heated. As defined herein, a passively heated
glow member is made of materials that retain heat between engine cycles.
The temperature within the combustion chamber fluctuates during
engine operation. For example the temperature drops when the relatively
cool intake charge is introduced during the intake stroke, and the
temperature increases during the compression stroke and the temperature
rises even more during the power stroke when the fuel is burned. A
passively heated glow member is made from a material that acts as a
"thermal absorber". After being warmed during the first few cycles after
start-up, a passively heated glow member can maintain a temperature
within a desired range between subsequent combustion events as
determined by, amongst other things, the thermal retention and
absorption properties of the material and the combustion environment.
That is, the combustion environment of a particular fuel will warm the
combustion chamber and the passively heated glow member. The heat
retained by the glow member allows it to maintain a surface temperature
that is hot enough to assist with the ignition of at least a portion of fuel
jets 58, which impacts on glow member 54. In this arrangement, the fuel
will either ignite and burn as a result of impacting the glow member or
ignite and burn more easily than would be the case otherwise. In the later
case, another ignition assist strategy can be used in addition to the
disclosed glow member, but with less energy being required to ignite the
fuel.
[0048] A glow member that is only passively heated will be cold if
the engine has been shut down for an extended period of time.
Therefore, a passively heated glow member requires additional ignition
assistance at times when the glow member cannot provide heat to assist
with ignition. Therefore, by way of example, a start-up ignition assist
such as a glow plug, spark plug or pilot fuel can be used to help initiate
ignition of the gaseous fuel until the combustion chamber, and the glow
member, is warmed. However, once the engine is "warm", the glow
member will impart some heat to the fuel jets. Depending upon the
temperature within the combustion chamber and the type of fuel being
burned, the amount of assistance from other ignition assistance devices
can be reduced or eliminated.
[0049] An engine controller may monitor such things as the
hydrocarbon emissions, cycle-to-cycle combustion variability and load to
help ensure ignition of the fuel, complete combustion of the fuel and a
reduction or elimination of a start-up ignition assist such as pilot fuel or a
conventional glow plug.
[0050] The preferred materials to make glow member 54 are
generally high temperature materials of suitable durability to withstand
the environment within the combustion chamber. Glow member 54 is
made from a material that can withstand the thermal conditions and
tresses within the combustion chamber. By way of example, some
mitable materials include those considered for glow plugs and glow plug
shields. These materials can be coated with catalytic materials such as
platinum or other precious metals. U.S. Patent 6,076,493 teaches use and
preparation of such materials for a glow plug shield for use in a
combustion chamber.
[0051] In the disclosed embodiments, ignition assistance is
preferably provided by a glow member that can, between cycles, retain a
temperature above that found within a given charge at that point near the
completion of the compression stroke or the commencement of the power
stroke at which time fuel is injected into the combustion chamber.
[0052] Note that the shape of the illustrated piston bowl is
demonstrative of typical piston bowl designs. Such a design, developed
for diesel-fueled engines, is directed at promoting turbulence within the
combustion chamber. In the case of glow plug ignition assisted engines,
turbulence helps promote the propagation of combustion throughout the
combustion chamber. As there is less need for flame propagation within
the combustion chamber where the subject teaching is used, such
turbulence enhancement geometry within the combustion chamber may
be less important than would otherwise be the case.
[0053] As already noted, the glow member shown in FIGs. la and
lb can also be actively heated. An actively heated glow member is
defined as a glow member that does not rely entirely on the absorption of
heat from within the combustion chamber for storing heat energy. By
way of example, the glow member can be heated by running an electric

current through the glow member itself or through an electric heating
circuit provided within the glow member.
[00541 As an additional feature, any one of the embodiments of the
glow member described herein can further comprise one or a plurality of
reservoirs provided within the body of a passively or actively heated
glow member. Orifices can provide communication between the glow
member reservoir(s) and the combustion chamber. A portion of the
intake charge that is introduced into the combustion chamber during an
intake stroke can accumulate within such, reservoir(s) during the intake
stroke and the subsequent compression stroke. The intake charge that
flows into such reservoir(s) is surrounded by the warmed glow member.
Upon commencement of the power stroke, the warmed charge would be
expelled into the combustion chamber by the expansion of the
combustion chamber, with the warmed charge and the turbulence caused
by its re-introduction into the combustion chamber providing further
ignition assistance to the fuel.
[0055] Known methods can be employed for mounting the glow
member within the combustion chamber. For example, in each
embodiment it would be appropriate to attach the glow member using
appropriate screws, bolts, welding or other known methods, as would be
understood by a person skilled in the art.
[0056] Referring to FIGS. 2a and 2b, a second embodiment is
provided. In this embodiment, passive glow member 92 is affixed to
piston 90 by posts 93. Again fuel jet 94 is outlined being injected into
combustion chamber 96, which is partially defined by piston 90. FIG. 2a
shows the location of intake valves 98 and exhaust valves 100. While
the illustrated embodiment employs a four-valve arrangement (two intake
valves and two exhaust valves), glow member 92 can be employed with a
different number of intake or exhaust valves. Also shown by the
illustrated embodiment is a combustion chamber with centrally
positioned fuel injection valve 102 from which fuel jets 94 originate.
[0057] The second embodiment works in generally the same way as
the first embodiment. However, as this second embodiment shows the
glow member attached to piston 90 instead of fire deck 105, glow
member 92 will only come into direct contact with fuel jets 58 when the
piston is at or near top dead center. Therefore, it is preferred, for this
embodiment, that the fuel be injected near top dead center.
[0058] Further, this embodiment has less flexibility adapting an
actively heated system to the glow member. It is more difficult to provide
the power necessary to an active system because the glow member is
attached to the piston.
[0059] Referring to FIG. 3, a third embodiment is provided wherein
an active glow member is shown. Glow member 200 is attached to
support member 202, which is, in turn, attached to injection valve sleeve
204. Fuel injection valve 206 is shown mounted inside injection valve
sleeve 204. Injection valve nozzle orifices 208 are shown with fuel jets
210. Fuel eddies 212 are shown generated near and beyond support
member 202 which acts as a barrier in the path of at least a portion of the
fuel jet. Positive and negative power leads 214 and 216 are shown as
well. Fire deck 218 defines one boundary of the combustion chamber
from which protrudes injection valve 206.
[0060] In this preferred embodiment of actively heated glow
member 200, support member 202 is attached to an end of injection valve
sleeve 204 that extends below fire deck 218 and that projects into the
combustion chamber. Glow member 200 is attached to support member
202 as shown, and support member 202 also projects into the combustion
chamber. When a controller commands fuel injection valve 206 to open,
a quantity of fuel is injected into the combustion chamber, and at least a
portion of fuel jets 210 impact on support member 202 to generate fuel
eddies 212, which recirculate around support member 202 in the vicinity
of glow member 200. Actively heated glow member 200 is heated by an
electric current through leads 214 and 216. Therefore, shortly after the
fuel eddies are heated by being in the proximity of glow member 200,
ignition results. Due to the ring shape of glow member 200 and support
member 202, each one of jets 210 from each one of nozzle orifices 208
will generate fuel eddies 212 which can bring fuel close to glow member
200 resulting in ignition of each fuel jet from each eddy. Combustion
from the fuel contained in each fuel jet is, likewise, assisted. Further,
glow member 200 is relatively small which results in reduced power
requirements to heat glow member 200 compared to a larger active glow
member.
[0061] While it is possible to remove support member 202 and
position glow member 200 in the path of fuel jets 210, positioning the
glow member directly in the path of fuel jets 210 can inhibit combustion.
As fuel jets 210 are driven from fuel injection valve 206 at very high
velocity, the fuel can be driven past glow member 200 without igniting.
Therefore, support member 202, allows an eddy of fuel to form. It is
directed at a relatively low velocity towards the glow member and is
allowed to ignite and propagate a flame through to each fuel jet 210.
[0062] For this embodiment, the ring should be made of a material
capable of being electrically heated to temperatures within the range of
900°C to 1700°C, with the preferred temperature range between 900°C
and 1200°C. Materials that are able to withstand the conditions found
within the combustion chamber are known. For example, suitable
materials include Si3N4 composites. Likewise, support member 202 can
be used as a thermal catalyst to promote ignition. It could be made of a
thermally absorbing material, such as those discussed above in regards to
the passive glow members of the first and second embodiments. When
support member 202 is employed as a passive glow member, once
heated, it can help reduce the load on active glow member 200.
[0063] The disclosed passively and actively heated glow member
embodiments can be employed with four-stroke and two-stroke engines.
[0064] Conventional glow plugs use a hot surface at a point within
the combustion chamber to assist with ignition of a fuel. The present
apparatus and method employs a glow member that provides a hot
surface that provides ignition and combustion assistance to more than
one area of the combustion chamber in cooperation with the fuel
injection pattern dictated by fuel injection valve design. Therefore, hot
surface geometry that provides ignition and combustion assistance to a
plurality of spatially distinct fuel jets also falls within the disclosure. A
ring-shaped glow member is a convenient embodiment as many fuel
injection valves provide a relatively uniform spray pattern to many
regions of a generally cylindrical combustion chamber. However, where
the fuel injection valve provides a variation on this spray pattern, the hot
surface or "glow element" shape and positioning can be adapted.
Therefore, as would be understood by a person skilled in the art, the glow
member may be "C"-shaped, oval shaped, or may have other shapes to
match the fuel injection valve design.
[0065] For the purposes of this disclosure, gaseous fuels are
contemplated as the fuel used to drive the engine. However, as suggested
above, many fuels that are more difficult to auto-ignite than diesel can, in
general, be adapted and are contemplated within the subject disclosure,
as would be understood by a person skilled in the art. Therefore, where
gaseous fuels are referenced, the disclosure contemplates such fuels as
natural gas, methane, ethane, butane, propane and other gaseous
hydrocarbon fuels as well as hydrogen and other fuels that contain one or
more of these gaseous fuels. Also, some liquid fuels, such as methanol,
that can require ignition assistance, depending on engine design, can also
benefit. Most such fuels will benefit to some extent from the presence of
the disclosed glow member or, more generally, hot surface geometry
found in the combustion chamber.
[0066] Rate shaping can also be used in the context of this
disclosure to help ignite fuel. Greater exposure of a fuel to the glow
member, in essence priming the fuel prior to ignition, can help ignition
when required during or at the commencement of the power stroke.
[0067] While particular elements, embodiments and applications of
the present disclosure have been shown and described, it will be
understood, of course, that the disclosure is not limited thereto since
modifications can be made by those skilled in the art without departing
from the scope of the present disclosure, particularly in light of the
foregoing teachings.
WE CLAIM :
1. A method of assisting ignition of a fuel within a combustion chamber of an internal
combustion engine, said method comprising :
a. introducing an intake charge into said combustion chamber during an intake stroke of
a piston, said piston partially defining said combustion chamber,
b. compressing said intake charge during a compression stroke of said piston,
c. injecting a plurality of spatially distinct jets of said fuel directly into said combustion
chamber,
d. directing at least two of said plurality of spatially distinct fuel jets proximate to a
glow member, said glow member igniting said fuel at at least two locations within said
combustion chamber, each of said at least two locations corresponding to each of said
at least two of said plurality of spatially distinct fuel jets,
e. igniting and burning said fuel within said combustion chamber.
2. The method as claimed in claim 1, wherein said glow member is in the shape of a ring.
3. The method as claimed in claim 1, wherein said glow member is heated by an electric current.
4. The method as claimed in claim 3, which involves heating said glow member to a temperature
of at least 1200°C.
5. The method as claimed in claim 3, which involves stepping down the voltage of said engine's
electrical system so that a lower voltage is applied to said glow member.
6. The method as claimed in claim 5, wherein the voltage applied to said glow member is less
than or equal to 2 volts.
7. The method as claimed in claim 1, which involves coating said glow member with a catalytic
coating.
8. An apparatus for assisting combustion of a fuel within a combustion chamber of an internal
combustion engine, said apparatus comprising a glow member, which has a heatable surface that is
positionable within said combustion chamber where a plurality of spatially distinct fuel jets are
directly injected, to ignite at least two of said plurality of spatially distinct fuel jets at at least two
locations within said combustion chamber, each of said at least two locations corresponding to each
of said at least two of said plurality of spatially distinct fuel jets.
9. The apparatus as claimed in claim 8, wherein said glow member is in the shape of a ring.
10. The apparatus as claimed in claim 8, having a catalytic material disposed on a surface of said
glow member.
11. The apparatus as claimed in claim 10, wherein said catalytic material is a precious metal.
12. The apparatus as claimed in claim 11, wherein said precious metal is platinum.
13. The apparatus as claimed in claim 8, having first and second electrodes for directing an
electric current through said glow member, said electric current capable of heating said glow
member.
14. The apparatus as claimed in claim 13, wherein a surface of said glow member is capable of
being heated to a temperature of at least 1200°C.
15. The apparatus as claimed in claim 13, having a transformer for stepping down the voltage of
said engine's electrical system so that a lower voltage can be applied to said glow member.
16. The apparatus as claimed in claim 15, wherein said transformer is capable of stepping down
the voltage applied to said glow member to less than or equal to 2 volts.
17. The apparatus as claimed in claim 15, wherein a heating element for said glow member is
employed as a secondary circuit for said transformer.
18. An internal combustion engine comprising :
a. a combustion chamber defined by :
a cylinder;
a piston disposed in said cylinder, said piston oscillating between top dead
center and bottom dead center within said cylinder during operation of said engine;
a fire deck covering one end of said cylinder opposite to said piston,
b. a fuel injection valve, said fuel injection valve capable of injecting a plurality of
spatially distinct fuel jets of a fuel directly into said combustion chamber,
c. a glow member comprising a hot surface positioned relative to said fuel injection
valve such that said fuel from at least two of said plurality of fuel jets is heatable by said glow
member at at least two locations within said combustion chamber, each of said at least two locations
corresponding to each of said at least two of said plurality of spatially distinct fuel jets.
19. The engine as claimed in claim 18, wherein said glow member is in the shape of a ring.
20. The engine as claimed in claim 18, wherein said plurality of fuel jets impact directly on said
glow member.
21. The engine as claimed in claim 18, wherein said glow member comprises a catalytic material.
22. The engine as claimed in claim 21, wherein said catalytic material is a precious metal.
23. The engine as claimed in claim 22, wherein said precious metal is platinum.
24. The engine as claimed in claim 18, wherein said glow member comprises an anode and a
cathode capable of providing an electric current for heating said glow member.
25. The engine as claimed in claim 24, having a transformer for stepping down the voltage of the
electric current from said engine's electrical system so that a lower voltage can be applied to said
glow member.
26. The engine as claimed in claim 25, wherein said transformer is capable of stepping down the
voltage applied to said glow member to less than or equal to 2 volts.
27. The engine as claimed in claim 25, wherein a heating circuit for said glow member is
employed as a secondary circuit for said transformer.
28. The engine as claimed in any one of claims 18 and 24, wherein said glow member defines an
orifice and a reservoir, said reservoir capable of accumulating and heating a quantity of intake charge
during a compression stroke, and said orifice is capable of directing a charge jet of said quantity from
said orifice into said combustion chamber during a power stroke.
29. The engine as claimed in any one of claims 18 and 24, having a barrier disposed within said
combustion chamber between said fuel injection valve and said glow member whereby at least a
portion of said fuel introduced into said combustion chamber by said plurality of fuel jets impacts on
said barrier to generate fuel eddies, wherein said glow member is positioned in the space where said
fuel eddies are generated when said engine is operating.
30. The engine as claimed in claim 29, wherein said barrier is attached to said fire deck.
31. The engine as claimed in claim 29, wherein said barrier is a spring clip.
32. The engine as claimed in claim 29, wherein said glow member is attachable to said barrier for
structural support.
33. The engine as claimed in claim 29, having an injection valve sleeve defining an opening for
receiving and supporting said fuel injection valve, which is mountable therein, wherein said barrier is
attachable to said injection valve sleeve.
34. The engine as claimed in claim 29, wherein said barrier comprises a catalytic material.
35. The engine as claimed in claim 34, wherein said catalytic material is a precious metal.
36. The engine as claimed in claim 35, wherein said precious metal is platinum.
37. The engine as claimed in claim 29, having an injection valve sleeve defining an operating for
receiving and supporting said fuel injection valve, which is mountable therein, wherein said barrier is
provided by a sleeve end that extends beyond said fire deck and into said combustion chamber.
38. The engine as claimed in any one of claims 18 through 37, wherein said fuel is a gaseous fuel.
The present invention discloses a glow member (54), preferably in the shape of a ring, to
assist ignition and combustion of a fuel used in an internal combustion engine. A fuel injection valve
(56) injects a plurality of fuel jets (58) directly into a combustion chamber during operation of the
engine so that the fuel jets (58) are aimed to the proximity of the glow member (54) such that ignition
of fuel in each fuel jet is assisted by the glow member (54). The glow member (54) is made from
high temperature materials and can include catalytic materials to further promote combustion. The
glow member (54) can be actively heated, for example by an electric current, in addition to being
passively heated by the heat generated within the combustion chamber (60) by the combustion of the
fuel therein.

Documents:

686-KOLNP-2005-CORRESPONDENCE.pdf

686-KOLNP-2005-FORM 27.pdf

686-KOLNP-2005-FORM-27.pdf

686-kolnp-2005-granted-abstract.pdf

686-kolnp-2005-granted-assignment.pdf

686-kolnp-2005-granted-claims.pdf

686-kolnp-2005-granted-correspondence.pdf

686-kolnp-2005-granted-description (complete).pdf

686-kolnp-2005-granted-drawings.pdf

686-kolnp-2005-granted-examination report.pdf

686-kolnp-2005-granted-form 1.pdf

686-kolnp-2005-granted-form 18.pdf

686-kolnp-2005-granted-form 3.pdf

686-kolnp-2005-granted-form 5.pdf

686-kolnp-2005-granted-form 6.pdf

686-kolnp-2005-granted-gpa.pdf

686-kolnp-2005-granted-reply to examination report.pdf

686-kolnp-2005-granted-specification.pdf

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Patent Number

224994

Indian Patent Application Number

686/KOLNP/2005

PG Journal Number

44/2008

Publication Date

31-Oct-2008

Grant Date

29-Oct-2008

Date of Filing

20-Apr-2005

Name of Patentee

WESTPORT POWER INC.

Applicant Address

101-1750 WEST 75TH AVENUE, VANCOUVER, BRITISH COLUMBIA V6P 6G2

Inventors:

#	Inventor's Name	Inventor's Address
1	ZHANG, DEHONG	703-121 WEST 44TH AVENUE, VANCOUVER BRITISH COLUMBIA V6M 5G5
2	HILL, PHILIP, G	2037 ALLISON ROAD, VANCOUVER, BRITISH COLUMBIA V6T 1T2
3	LI, GUOWEI	206-1251 WEST 71TH AVENUE, VANCOUVER BRITISH COLUMBIA V6P 3A9
4	WELCH, ALAN, B	2828 WEST 34TH AVENUE, VANCOUVER, BRITISH COLUMBIA V6N 2J6
5	DUNN, MARK, E	2263 REDBUD LANE, VANCOUVER, BRITISH COLUMBIA V6K 4V7

PCT International Classification Number

F02P 19/02

PCT International Application Number

PCT/CA2003/001437

PCT International Filing date

2003-10-02

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2,406,297	2002-10-02	Canada