Title of Invention

"INTAKE HEATING DEVICE FOR INTERNAL COMBUSTION ENGINE"

Abstract

[Object] To provide an intake heating device for an internal combustion engine in which an additional heating device for exclusively heating intake air under utilization of the motorcycle starter mechanism is not required, a substantial reduction of cost is attained and a superior idling performance can be assured. [Solving Means] An intake heating device for an internal combustion engine comprising a carburettor 28, an electrical motorcycle starter mechanism 40 installed at the carburettor 28 so as to adjust mixture gas during an idling operation of the internal combustion engine and an intake pipe 27 connecting the carburettor 28 with a main body of the internal combustion engine, wherein a resistor heating element 60 is connected to a control circuit for the electrical motorcycle starter mechanism 40 and the resistor heating element 60 is fixed to the intake pipe 27.

Full Text

[Detailed Description of the Invention] [0001] [Technical Field of the Invention] This invention relates to a device for heating intake when an internal combustion engine is started to operate at a low temperature. [0002] [Prior Art] There is provided a certain example in which a motorcycle starter mechanism exclusively used for the starting operation is assembled in a carburettor to supply rich fuel at the time of starting to facilitate its starting operation in the case that an internal combustion engine is started to operate at a low temperature because there is a possibility that- fuel is supplied to a combustion chamber of a main body of the internal combustion engine under a state in which a gasification of fuel supplied to the internal combustion is insufficient and the fuel is not sufficiently atomized not to cause its starting operation to be smoothly carried out. [0003] However, the rich fuel supplied to the internal combustion engine at the time of starting operation is still kept at its poor gasification state to cause its combustion to be unstable, resulting in that its starting time extended or an amount of carbon monoxide and hydrocarbon contained in exhaust gas is increased or a drivability of the engine after its starting at a low temperature is deteriorated. [0004] In view of the foregoing, there is already provided in the prior art to arrange an intake heating heater in an intake passage in the internal combustion engine and an example shown in the gazette of the Japanese Patent Laid-Open No. Sho 6-257523 discloses a system in which a PTC heater {a positive characteristic thermistor element) is fixed to an inner surface of an inlet port of an intake hole of the internal combustion engine. [0005] At the time of starting operation of the internal combustion engine, idling performance is improved by a method wherein heat is generated by this PTC heater under an electrical energization of a battery to heat intake air so as to improve a gasification characteristic of fuel, the starting operation is smoothly performed and harmful substances contained in the exhaust gas are reduced. Then, the PTC heater shows that its resistance becomes a limitless high value when its temperature is increased to a certain degree so as to cause its electrical energization to be turned off, heating of the intake is completed and then the engine can keep its normal operating state. [0006] [Problems to be Solved by the Invention] However, the PTC heater is an exclusive element for use in heating intake air and an exclusive heating control device for controlling an operation of the PTC heater must be additionally installed, resulting in that its number of component parts is increased, its cost becomes high and concurrently the PTC heater is constructed to be stored at the inner surface of the inlet port of the intake hole to cause a manufacturing cost of the intake pipe itself to be increased. [0007] The present invention has been completed in view of the foregoing, and it is an object of the present invention to provide an intake heating device of an internal combustion engine in which a bi-starter mechanism is utilized to make a substantial reduction of cost without requiring any additional heating control device exclusively used for heating intake air and a superior intake performance can be assured. [0008] [Means for Solving the Problems, and Actions and Effects] In order to attain the aforesaid object, the present invention provides an intake heating device for an internal combustion engine comprising a carburettor, an electrical motorcycle starter installed at the carburettor so as to adjust mixture gas during an idling operation of the internal combustion engine and an intake pipe connecting the carburettor with a main body of the internal combustion engine characterized in that a resistor heating element is connected to a control circuit for said electrical bi-starter mechanism and the resistor heating element is fixed to said intake pipe. [0009] Since the electrical motorcycle starter mechanism is utilized and a resistor heater for heating an intake pipe is connected to its control circuit, resulting in that it is possible to perform a heating of intake air only for an appropriate time required at the time of starting operation without providing any additional circuit for controlling the operation of the resistor heater. Accordingly, it is possible to make a substantial reduction of cost, perform a smooth starting operation, keep a superior idling performance, reduce an amount of harmful substances contained in the exhaust gas and improve a drivability of the engine after its starting at a low temperature. [0010] The control circuit for the aforesaid electrical motorcycle starter mechanism is a control circuit comprised of a positive characteristic thermistor element and the aforesaid resistor heater is connected in series with this positive characteristic thermistor element so as to constitute the intake heating device for the internal combustion engine defined in Claim 1, thereby the resistor placed- in the control circuit of the electrical bi-starter mechanism in the prior art is applied as the heating resistor so as to heat intake air, resulting in that the exclusive heater for use in heating intake air can be eliminated, its cost is low, its operation is cooperated with the operation of the bi-starter mechanism and its superior idling performance can be kept. [0011] The aforesaid resistor heater is provided as an intake heating device for an internal combustion engine as defined in Claim 1 or Claim 2 fixed to an outer wall of the intake pipe, thereby its structure is simplified, its assembling is easily carried out, a changing of the characteristic of the control circuit in the motorcycle starter mechanism can be easily performed by replacing the resistor heater, it can be constituted with a simple resistor, its durability or reliability and inspection as well as maintenance characteristic are substantially improved. Accordingly the present invention relates to an intake heating device for an internal combustion engine comprising a carburettor, an electrical motorcycle starter installed at the carburettor so as to adjust mixture gas during an. idling operation of the internal combustion engine and an intake pipe connecting the carburettor with a main body of the internal combustion engine characterized in that a resistor heating element is connected to a control circuit for said electrical bi-starter mechanism and the resistor heating element is fixed to said intake pipe. [Brief Description of the Accompanying Drawings] [Fig. 1] This is a side elevational view for showing a scooter type motorcycle having a unit-swing type internal combustion engine of one preferred embodiment of the present invention. [Fig. 2] This is a top plan view for showing a front part of the swing unit with its part being eliminated. [Fig. 3] This is a sectional view for showing a motorcycle starter mechanism. [Fig. 4] This is a rear view for showing an intake pipe. [Fig. 5] This is a rear view for showing a state in which a resistor heater is fixed to the intake pipe. [Fig. 6] This is a front elevational view for showing a resistor heater. [Fig. 7] This is a top plan view of Pig. 6 with a part broken away. [Fig. 8] This is a side elevational view of Fig. 6. [Fig. 9] This is a bottom view of Fig. 6. [Fig. 10] This is a perspective view for showing a substantial part of a wired state in a control circuit with a part being eliminated. [Fig. 11] This is a control circuit diagram for showing a motorcycle starter mechanism. [0012] [Preferred Embodiment of the Invention] Referring now to Figs. 1 to 11, one preferred embodiment of the present invention will be illustrated there and described. Fig. 1 is a side elevational view for showing a scooter type motorcycle 1 provided with an unit swing type internal combustion engine of the preferred embodiment. [0013] A body front part 2 and a body rear part 3 are connected to each other through a low floor part 4, a body frame 5 forming a body skeleton is constructed such that it is lowered at the body front part, branched into tow segments, extends below the floor part 4 to a rearward direction and then it extends above the body rear part 3 in a rearward direction. [0014] A seat 6 is installed at an upper part of the body rear part 3, and a steering head 8 provided with a handle 7 is mounted at an upper part of the forward body front part 2. A front wheel 10 is suspended at the body front part 2 through a front fork 9 and this wheel is steered by the handle 7. [0015] Then, a bracket 11 is projected from a cross member arranged between right and left slant segments rising in a slant upward direction at the rear part of the body frame 5 (see Fig. 10). A pair of right and left hanger brackets 17 projected upward at a front part of the unit swing case 16 are pivotally supported at a pivot shaft 12 supported at the bracket 11 to cause the swing unit 15 can be oscillated upward or downward and concurrently a rear cushion 19 is installed between it and the body frame 5 at a rear location of the pivot shaft 12. [0016] An internal combustion engine 20 is integrally assembled at a front part of the swing unit 15, a rear wheel 21 is pivotally supported at a rear part of the swing unit and a power of the internal combustion engine 20 is transmitted to the rear wheel 21 through a belt transmitting mechanism 22 having an automatic transmission function. A fuel tank 23 is fixed to a lower part of the floor part 4 and mounted on the body frame. [0017] The internal combustion engine 20 is a two-cycle internal combustion engine, wherein a cylinder 25 is projected forward from a front part of the unit swing case 16 in a slight upward direction and the cylinder 25 is placed below the pivot shaft 12 and passes between the right and left body frames 5. [0018] In addition, the internal combustion engine 20 has a crank case reed valve system in which a reed valve is arranged at the crank case, and as shown in Fig. 2, the intake pipe 27 is extended from the upper part of the crank case of the unit swing case 16, extended in a left rear direction while avoiding the rear wheel 21 and connected to a carburettor 28. Air is fed from an air cleaner 29 mounted at the rear part of the unit swing case 16 into the carburettor 28. [0019] An exhaust pipe 30 extending downward from the lower part of the cylinder 25 of the internal combustion engine 20 is connected to a muffler 31 bypassed below the crank case 16a in a rearward and rightward direction, and a right end of the crank shaft of the internal combustion engine 20 is provided with an AC generator 32. [0020] The aforesaid carburettor 28 is integrally constructed with an electrical automatic motorcycle starter mechanism 40 having an air passage 41 for the motorcycle starter separate from the usual venturi air passage between the intake air inlet 28a to be connected to the air cleaner 29 and the mixture gas outlet 28b. [0021] Fig. 3 is a sectional view for showing, the automatic motorcycle starter mechanism 40, wherein a cylindrical valve 43 is fitted between an intake air feeding passage 41a and a mixture gas feeding-out passage 41b in such a manner that it nay be slid in a vertical direction, a motorcycle starter needle 44 of the cylindrical valve 43 is slidably inserted in the air passage 43a formed at the side wall of it in a crossed state, and the motorcycle starter needle 44 is passed with its extremity end being directed downwardly and further inserted into an opening of a fuel supplying passage 45 communicating from below it. [0022] A sleeve 46 is biased upwardly by a spring 47 and arranged above the valve 43 in such a manner that it may be ascended or descended, and an engaging projection 46b projected from the lower part of the sleeve 46 has its extremity end inserted into the valve 43. A piston 47 sliding in an upward or a downward direction by a thermo-wax 48 arranged above the sleeve 46 is integrally fitted to the sleeve 46, the thermo-wax 48 is heated by a PTC heater 49 acting as a positive characteristic thermistor element arranged at its upper part. To the PTC heater 49 is connected a cord 50 of an electrical power line, [0023] The automatic bi-starter mechanism 40 has such a structure as described above, wherein the valve 43 is kept open at a low temperature where no heating with the PTC heater 49 is carried out, and when the PTC heater 49 is electrically energized to generate heat and the thermo-wax 48 is heated, the thermo-wax 48 is expanded to cause the piston 47 to be pushed down together with the sleeve 46 against the spring 47. When it is lowered by a desired distance, the engaging projection 46a of the sleeve 46 strikes against the head part of the motorcycle starter needle 44 to push down the motorcycle starter needle 44 together with the valve 43 so as to reduce a supplying amount of fuel and finally the supplying of fuel is terminated and concurrently the valve 43 is closed. [0024] The PTC heater 43 has a characteristic in which it may generate heat when an electrical energization is carried out and when its value exceeds a certain degree, the electrical energization is . automatically terminated. In the case that the electrical energization is terminated, the internal combustion engine is out of its cold temperature., state, the automatic bi-starter mechanism 40 may keep the valve 43 in its closed state and the carburettor 28 may act its original action not depending upon the automatic bi-starter mechanism 40. [0025] As described above, the automatic motorcycle starter mechanism 40 opens the valve 43 when an internal combustion engine starts to operate at a low temperature to supply fuel, wherein its starting is easily carried out with the fuel supplied to the internal combustion engine being rich and in turn when the engine is out of its cold temperature state, the valve 43 is automatically closed and then the supplying of fuel with the automatic bi-starter mechanism 40 is stopped. [0026] Since the intake pipe 27 connected to the mixture gas outlet 28b of the carburettor 28 having such automatic motorcycle starter mechanism 40 assembled as above is extended out upwardly from the upper part of the crank case as described above, bent to extend in a relative long distance at a left rear side in a substantial horizontal state and connected to the carburettor 28, this structure is hardly heated, gas is liquefied and easily accumulated there, so that in the preferred embodiment of the present invention, the resistor heater 60 is fixed to the intake pipe 27 from outside with a bolt 65 (see Fig. 2). [0027] An inverse T-shaped flat surface 27a is formed at a rear side surface of the intake pipe 27 as shown in Pig. 4 and a fixing hole 27b for the bolt 65 is arranged at a part of the surface. In turn, the resistor heater 60 is constructed such that a steel case 61 of an inverse T-shaped form as seen in its top plan view is formed by a rectangular box 61a extending longitudinally in a lateral direction and a bracket 61b with its central part being bulged out along its opening plane, and a nichrome wire 63 is buried in heat-resistant cement filled in the rectangular box 61a. [0028] One end of the nichrome wire 63 is fixed to the case 61 and the other end of it is connected to the cord 64 and extended outwardly from a bottom wall of the rectangular box 61a. A bolt hole 61c is punched at the bracket 61b, and the heat-resistant cement 62 having the nichrome wire 63 buried therein forms a flat plane at the opening of the rectangular box 61a. [0029] Such a resistor heater 60 as above is fixed in such a nanner that its aforesaid flat surface is contacted with and abutted against the inverse T-shaped flat plane 27a of the aforesaid intake pipe 27 and the bolt 65 is threadbly inserted while the bolt hole 61c is aligned with the fixing hole 27b (see Fig. 5). Accordingly, when the nichrome wire 63 is electrically energized, the wire generates heat and then the intake pipe 27 is heated through the heat-resistant cement 62. [0030] As shown in Fig. 10, the cord 64 extending out of the resistor heater 60 and the cord 50 extending out of the aforesaid automatic motorcycle starter mechanism 40 extend upwardly and are connected by a connecting part 36 of a wire harness 35 located at a slant part of the left side body frame 5. To the wire harness 35 is connected a cord 33 extending from the AC generator 32 through a connector 34. [0031] In Fig. 11 is shown a control circuit- for the automatic bi-starter mechanism 40 and the resistor heater 60. The AC generator 32 is constructed such that the cord 33 connected to the power generating coil is connected to a cord 50a extending from one end of the PTC heater 49 of the automatic bi-starter mechanism 40 through the connector 34, the wire harness 35 and the connecting part 36, and the cord 50b connected to the other end of the PTC heater 49 is connected to the cord 64 extending from the nichrome wire 63 of the resistor heater 60 through the connecting part 36 and further the other end of the nichrome wire 63 is contacted with the vehicle body through the case 61. That is, the PTC heater 49 and the nichrome wire 63 are connected in series with a power supply for the AC generator 32. [0032] As described above, since the PTC heater 49 is operated such that its resistance becomes a limitless high value at a temperature more than a certain degree of temperature so as to turn off its electrical energization, the nichrome wire 63 also has no electrical energization at that time and the resistor heater 60 terminates its generating heat. [0033] Accordingly, the resistor heater 60 may generate heat only in the case that the internal combustion engine is kept at its cold state when the low temperature starting is performed and the aforesaid automatic motorcycle starter mechanism 40 is operated to supply rich fuel so as to heat the intake pipe 27 and also to heat the mixture gas passed in the intake pipe 27 and easily liquefied, resulting in that it is possible to keep a sufficient gasification of fuel. [0034] Accordingly, it is possible to perform a smooth starting of the internal combustion engine, increase an idling performance, reduce an amount of harmful substances contained in the exhaust gas and further improve a drivability of the engine after its starting at a low temperature. [0035] As described above, the control circuit for the motorcycle starter mechanism 40 in the preferred embodiment may also be used as a control circuit for the resistor heater 60 for use in heating the intake pipe 27 with the resistor connected in series with the PTC heater 49 being applied as the resistor heater 60. Accordingly, the heat generating member exclusively heating the special intake air and the control circuit can be eliminated, the number of component elements can be reduced, its structure can be simplified and a substantial cost reduction can be attained. [0036] In addition, since the resistor heater 60 is an external fixed structure which is fixed to an outer surface of the intake pipe 27, its structure is simplified and concurrently it is made of simple nihrome wire 63 so as to increase substantially its durability or reliability as well as an inspection or maintenance characteristic. [Description of the Reference Numbers] 1: scooter type motorcycle, 2: body front part, 3: body rear part, 4: floor part, 5: body frame, 6: seat, 7: handle, 8: steering head, 9: front fork, 10: front wheel, 11: bracket, 12: pivot shaft, 15: swing unit, 16: swing case, 17: hanger bracket, 19: rear cushion, 20: internal combustion engine, 21: rear wheel, 22: belt transmission mechanism, 23: fuel tank, 25: cylinder, 27: intake pipe, 28: carburettor, 30: exhaust pipe, 31: muffler, 32: AC generator, 33: cord, 34: connector, 35: wire harness 36: connecting part, 40: motorcycle starter mechanism, 41: air passage, 43: valve, 44: motorcycle starter needle, 45: fuel supplying passage, 46: sleeve, 47: spring, 48: thermo-wax, 49: PTC heater, 50: cord, 60: resistor heater, 61: case, 62: heat-resistant cement, 63: nichrome wire, 64: cord, 65: bolt WE CLAIM: 1. An intake heating device for an internal combustion engine [20] comprising a carburetor [28], an electrical motorcycle starter[40] installed at the carburetor[28] to adjust mixture gas during an idling operation of the internal combustion engine and an intake pipe[27] connecting the said carburetor[28] with a main body of the internal combustion engine characterized in that a resistor heating element[60]is connected to a control circuit for said electrical bi-starter mechanism|40] and the resistor heating element is fixed to said intake pipe[27|. 2. An intake heating device for an internal combustion engine as claimed in claim 1, wherein the control circuit for said electrical bi-starter mechanism[40] is a control circuit comprising a positive characteristic thermistor element and said resistor heating member[60] is connected in series with the positive characteristic thermistor. 3. An intake heating device for an internal combustion engine as claimed in claim 1 or claim 2 wherein said resistor heating member[60] is fixed to an outer wall of the said intake pipe [27]. 4. An intake heating device for an internal combustion engine substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Documents:

2990-del-1996-abstract.pdf

2990-del-1996-claims.pdf

2990-del-1996-correspondence-others.pdf

2990-del-1996-correspondence-po.pdf

2990-del-1996-description (complete).pdf

2990-del-1996-drawings.pdf

2990-del-1996-form-1.pdf

2990-del-1996-form-13.pdf

2990-del-1996-form-19.pdf

2990-del-1996-form-2.pdf

2990-del-1996-form-3.pdf

2990-del-1996-form-4.pdf

2990-del-1996-form-6.pdf

2990-del-1996-gpa.pdf

2990-del-1996-petition-137.pdf

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