Title of Invention	FUEL INJECTION DEVICE FOR A MULTI-CYLINDER INTERNAL COMBUSTION ENGINE
Abstract	The fuel injection device has a high-pressure pump (10) and an injector (12) respectively for each cylinder of the internal combustion engine, the injector (12) being at least indirectly connected to the high-pressure pump (10) by a hydraulic pipe (26;27). Each injector (12) is connected to the high-pressure pump (10) and/or to the injector (12) of another cylinder of the internal combustion engine by a hydraulic pipe (26;27). A high-pressure accumulator that is usually provided between the high-pressure pump (10) and injectors (12) can be dispensed with in this manner.

Title of Invention

FUEL INJECTION DEVICE FOR A MULTI-CYLINDER INTERNAL COMBUSTION ENGINE

Abstract

The fuel injection device has a high-pressure pump (10) and an injector (12) respectively for each cylinder of the internal combustion engine, the injector (12) being at least indirectly connected to the high-pressure pump (10) by a hydraulic pipe (26;27). Each injector (12) is connected to the high-pressure pump (10) and/or to the injector (12) of another cylinder of the internal combustion engine by a hydraulic pipe (26;27). A high-pressure accumulator that is usually provided between the high-pressure pump (10) and injectors (12) can be dispensed with in this manner.

Full Text	FUEL INJECTION DEVICE FOR A MULTI-CYLINDER INTERNAL COMBUSTION ENGINE Prior Art The invention emanates from a fuel injection device for a multi-cylinder internal combustion engine in accordance with the genre of Claim 1. This type of fuel injection device is established in EP 0 299 337 A. This fuel injection device has a high-pressure pump through which fuel that is in a high-pressure accumulator, a so-called rail, is conveyed. An injector is provided for each cylinder of the internal combustion engine, whereby each injector is connected to the high-pressure accumulator by a hydraulic pipe that is attached to the high-pressure connection of the injector. The disadvantage in the case of this fuel injection device is the magnitude of the manufacture and assembly complexity that is brought about by the high-pressure accumulator located between the high-pressure pump and the injectors. The high-pressure accumulator must exhibit great stability owing to the high pressure that prevails in the same. Over and above this, the installation space required on account of the high-pressure accumulator in the vicinity of the internal combustion engine for the fuel-injection device is increased. Advantages of the Invention The fuel-injection device, in accordance with the invention, with features according to Claim 1 on the other hand has the advantage of not requiring a high-pressure accumulator, whereby its manufacture and assembly is simplified and its installation space requirement is reduced. Beneficial designs and further development of the fuel-injection device in accordance with the invention are specified in the dependent claims. Drawing Several exemplary embodiments of the invention are described in greater detail in the drawings and in the subsequent description. Figure 1 presents a fuel-injection device for an internal combustion engine in a simplified drawing in accordance with a first embodiment. Figure 2 is an enlargement of the injector of the fuel-injection device and Figures 3 to 10 illustrate the fuel-injection device in accordance with other exemplary embodiments. Description of the Exemplary Embodiments Figures 1 to 10 present a fuel-injection device for a multi-cylinder internal combustion engine, that is preferably a self-igniting internal combustion engine of a motor vehicle. The fuel-injection device has a high-pressure pump 10 through which fuel is conveyed under high pressure. An injector 12 is located at each cylinder of the internal combustion engine through which fuel can be injected into the combustion chamber of the cylinder. Only a few of the injectors 12 are illustrated in Figures 1 to 10 in the process, whereby other injectors, except for the last injector 12d, are indicated by dots. Injector 12 has a fuel-injection valve 14, as illustrated in Figure 2, through which fuel is injected into the combustion chamber of the cylinder and has an electrically operated actuator 16. The opening and closing movement of an injection valve element 15 of the fuel-injection valve 14 is controlled by the actuator 16. The actuator 16 is preferably a piezo-electric actuator whose size changes subject to the electrical voltage supplied to the same. A switching function can be achieved through this change in size, by means of which the injection valve element 15 can be opened and closed respectively. Actuator 16 is controlled by electronic controlling equipment 18. Actuator 16 is located in a fuel-filled chamber 20 in a casing 22 of the injector 12. The actuator 16 can, for example, act upon a piston 17 which restricts a buncher space 19, whereby the injection valve element 15 is loaded by pressure prevailing in the buncher space 19 in the closing direction. Piston 17 is held in position at the actuator 16 by a preloaded spring 21. Apart from this, the injection valve element 15 is loaded in the closing direction by a pre-loaded spring 23. If an electrical voltage is applied to the actuator 16 by the controlling equipment 18, the same expands and presses the piston 17 into the buncher space 19 in which a higher pressure consequently prevails, as a result of which the injection valve element 15 is held in its closed position so that fuel injection does not takes place. If no electrical voltage is applied by the controlling equipment 18 to the actuator 16, the same reduces its expansion so that piston 17 is moved out of the buncher space 19 by the spring 21 due to which the pressure in the buncher space 19 sinks. The injection valve element 15 is then moved into its opening position by high pressure acting upon the same in the opening direction against the lower pressure prevailing in buncher space 19 and against spring 23 force, so that fuel is injected. Two high-pressure connections 24 are provided at casing 22 of injector 12 through which fuel that is under high-pressure is fed to the injector 12 and/or conveyed onwards from the same. High-pressure connections 24 are connected to chamber 20 in which the actuator 16 is located. Apart from this, the high-pressure connections 24 are connected to the fuel-injection valve 14 via chamber 20 in order to supply the same with fuel required for the injection of fuel. Chamber 20 thereby forms a high-pressure accumulator from which fuel is extracted for injection. Chamber 20 thus has a volume that is large enough to store fuel quantities required for fuel injection. The volumes of chamber 20 can range between 1 and 5 cm3, approximately 2 cm3, for example. In the case of a first exemplary embodiment of the fuel injection device presented in Figure 1, only a first injector 12a of injectors 12 is connected to the high-pressure pump 10, whereby a hydraulic pipe 26 leading away from the high-pressure connection of the high-pressure pump 10 is connected to the high-pressure connector 24 of injector 12a. The first injector 12a that is connected to the high-pressure pump 10 is preferably the injector of the internal combustion engine that is the one located next to the high-pressure pump 10. The cylinders of the internal combustion engine and therewith also the injectors 12 allocated to the same are located in a row. A hydraulic pipe 27 is connected to the other high-pressure connection 24 of the first injector 12a, this pipe leading to another injector 12b and this injector 12b is connected to a high-pressure connection 24. Injector 12b is preferably located adjacent to the first injector 12a. A hydraulic pipe 27 is connected to the other high-pressure connection 24 of injector 12b, this pipe in turn leading to another preferably adjacent injector 12 and this injector 12 is connected to a high-pressure . connection 24. The last injector 12d is connected to the preceding adjacent injector only by one hydraulic pipe 27 connected to the two high-pressure connections 24, while a pressure sensor 28 is located at its other high-pressure connection 24. The pressure sensor 28 can alternatively also be located at another injector 12 in one of the hydraulic pipes 27 between injectors 12, between the high-pressure pump 10 and the first injector 12a or at the high-pressure pump 10. Injectors 12 of the cylinders of the internal combustion engine are connected hydraulically in a line, whereby only the first injector 12a is directly connected to the high-pressure pump 10. The pressure sensor 28 is connected to controlling equipment 18 and provides the same with a signal regarding the pressure that is actually prevailing in injectors 12. A fuel measuring device 30 is located at the intake side of the high-pressure pump 10 which can modify the quantities of fuel sucked out from the high-pressure pump 10 and conveyed under high pressure. The alterable cross-section of the stream can, for example, be adjusted by the fuel measuring device 30 at the intake side of the high-pressure pump 10. Fuel is preferably conveyed from a storage tank 32 to the intake side of the high-pressure pump 10 by means of a feed pump 34, whereby the fuel measuring device 30 is located between the feed pump 34 and the high-pressure pump 10. The fuel measuring device 30 is controlled in such a manner by the controlling device 18 that the high-pressure pump 10 supplies injectors 12 with a fuel quantity under high pressure such as they require in order to maintain a pre-determined pressure in injectors 12 for the fuel injection. The high-pressure pump 10 can be designed to have only one single pump element, whereby a hydraulic pipe 26 leading to the first injector 12a is connected at the outlet of this pump element. In an alternate design, the high-pressure pump 10 can have several pump elements, one or three pump elements for example, whereby the outlets of the pump elements are merged into a common outlet at the high-pressure pump 10 to which the hydraulic pipe 26 leading to the first injector 12a is connected. The fuel-injection device in accordance with a second exemplary embodiment is presented in Figure 3 in which the basic structure is similar to that of the first exemplary embodiment. The deviation here, however, is that even the last injector 12d is connected directly to the high-pressure pump 10 by a hydraulic pipe 26. As in the first exemplary embodiment, the last injector 12d is, furthermore, connected to the adjacent injector by a hydraulic pipe 27. Two high-pressure outlets are hereby provided at the high-pressure pump 10 of which one is connected to the first injector 12a and the other to the last injector 12d. The pressure sensor 28 can be located at one of the injectors 12 or in a hydraulic pipe 27 between the injectors or in a hydraulic pipe 26 between the high-pressure pump 10 and one of injectors 12 or at the high-pressure pump 10. If the high-pressure pump 10 has only one pump element then two high-pressure connections must be provided at the same to connect the two to the hydraulic pipe 26 leading to injectors 12a and 12d. If the high-pressure pump 10 has two pump elements then the hydraulic pipe 26 is connected to the first injector 12a at the outlet of the one pump element and the hydraulic pipe 26 to the last injector 12d is connected at the outlet of the other pump element. If the high-pressure pump 10 has more than two pump elements then their outlets are merged into two high-pressure connections at the high-pressure pump 10, whereby a hydraulic pipe 26 leading to one injector 12a and 12d respectively is connected at each high-pressure connection. Figure 4 presents the fuel injection device in accordance with a third exemplary embodiment in which the cylinders of the internal combustion engine are located in a v-shape, whereby several cylinders are located one next to the other in each cylinder bank. Only the first injector 12a of the first cylinder bank is connected directly to the high-pressure pump 10 and the remaining injectors 12 are connected to one another in a row by the hydraulic pipe 27. The injectors 12 of the two cylinder banks that are respectively located the farthest from the high-pressure pump 10 are also connected to one another by a hydraulic pipe 27. Pressure sensor 28 is.located at injector 12d of the second cylinder bank, this injector being located next to the high-pressure pump 10. The pressure sensor 28 can also be located elsewhere as is specified in the case of the first exemplary embodiment. The design of the high-pressure pump 10 is the same as was described in the case of the first exemplary embodiment. Figure 5 is an illustration of the fuel injection device in accordance with a fourth exemplary embodiment that differentiates itself from the third exemplary embodiment only in that, in each case, the injector 12 of each cylinder bank located next to the high-pressure pump 10 is connected to the high-pressure pump 10 by a hydraulic pipe 26 respectively. The remaining injectors 12 are respectively interconnected in a row by hydraulic pipes 27. The design of the high-pressure pump 10 is the same as was described in the case of the second exemplary embodiment. Figure 6 presents the fuel injection device in accordance with a fifth exemplary embodiment in which the basic structure is the same as in the first exemplary embodiment. A pressure control valve 32 is provided in addition in the fuel injection device in accordance with the fifth exemplary embodiment, through which pressure prevailing in injectors 12 can be modified. The pressure control valve 32 can be located, for example, at the high-pressure pump 10. The pressure sensor 28 can be located at the last injector 12d. The pressure control valve 32 can alternatively also be located at the last injector 12d as in the case of a variant illustrated in Figure 7 and the pressure sensor 28 can be located between the injectors 12 in one of the hydraulic pipes 27. The pressure control valve 32 and the pressure sensor 28 can also be placed at any other location. The pressure control valve 32 is connected to controlling equipment 18 and is controlled by the same in order to adjust the pressure prevailing in injectors 12 to a pre-determined value. Very quick modification of the pressure prevailing in injectors 12 can be achieved by controlling the pressure control valve 32 through the controlling equipment 18. Controlling the fuel measuring device 30 through the controlling equipment 18 accomplishes the purpose of the high-pressure pump 10, at least essentially, only discharging fuel quantities under high pressure required for fuel injection to injectors 12, whereby the driving power can be minimised for the high-pressure pump 10. Figure 8 presents a fuel injection device in accordance with a sixth exemplary embodiment that essentially has the same design as the third exemplary embodiment with a v-shape formation of the cylinders of the internal combustion engine and in which the pressure control valve 32 is provided in addition. The connection of injectors 12 to the high-pressure pump 10 via the hydraulic pipe 26 and among themselves through the hydraulic pipes 27 is the same as in the third exemplary embodiment so that only the first injector 12a is connected directly to the high-pressure pump 10. The pressure control valve 32 is located, for example, at the high-pressure pump 10 and the pressure sensor 28 is located at the last injector 12d. The pressure control valve 32 can alternatively also be located at the last injector 12d as is illustrated in Figure 9 and the pressure sensor 28 can be located in one of the hydraulic pipes 27 between the injectors 12. The pressure control valve 32 and the pressure sensor 28 can also be positioned at any other location. Figure 10 presents the fuel injection device in accordance with a seventh exemplary embodiment in which, deviating from the sixth exemplary embodiment, the injector 12 of the two cylinder banks respectively, located next to the high-pressure pump 10, is connected to the high-pressure pump 10 by a hydraulic pipe 26. Injectors 12d of the two cylinder banks that are located farthest from the high-pressure pump 10 are not connected to one another but a pressure control valve 32 is instead located at the two respectively. A pressure sensor 28 is located in one of the hydraulic pipes 27 between the injectors 12 of the two cylinder banks. The pressure control valve 32 and the pressure sensor 28 of both cylinder banks could also be positioned at any other location. Separated high-pressure branches for injectors 12 of both cylinder banks of the internal combustion engine with own pressure control valve 32 and pressure sensor 28 are thus present in the seventh exemplary embodiment. Claims 1. Fuel injection device for a multi-cylinder internal combustion engine with a high-pressure pump (10) and with an injector (12) respectively for each cylinder of the internal combustion engine that is at least indirectly connected to the high-pressure pump (10) by a hydraulic pipe (26;27), characterised in that, each injector (12) is connected by a hydraulic pipe (26;27) to the high-pressure pump (10) and/or to the injector (12) of another cylinder of the internal combustion engine. 2. Fuel injection device in accordance with Claim 1, characterised in that, each cylinder (12) has at least one buncher space (20), which is connected to the hydraulic pipes (26;27). 3. Fuel injection device in accordance with Claims 1 or 2, characterised in that, each injector (12) has two high-pressure connections (24) for the hydraulic pipes (26;27). 4. Fuel injection device in accordance with one of Claims 1 to 3, characterised in that, injectors (12) are connected to one another in a row by the hydraulic pipes (26;27) and that only the first of the injectors (12a) is directly connected to the high-pressure pump (10). 5. Fuel injection device in accordance with one of Claims 1 to 3, characterised in that, the injectors (12) are connected in a row to one another by the hydraulic pipes (26;27) and that a first and last injector (12a, 12d) are connected directly to the high-pressure pump (10). 6. Fuel injection device in accordance with one of the preceding Claims, characterised in that, at least one pressure sensor (28) is located at the high-pressure pump (10), at one of the injectors (12), in a hydraulic pipe (27) between the injectors (12) or in a hydraulic pipe (26) between the high-pressure pump (10) and in one of the injectors (12). 7. Fuel injection device in accordance with Claim 6, characterised in that, the at least one pressure sensor (28) is connected to an electrical controlling equipment (18) and that a fuel measuring device (30) that is controlled by the controlling equipment (18), subject to pressure registered by the pressure sensor (28), is connected upstream from the high-pressure pump (10). 8. Fuel injection device in accordance with one of the preceding Claims, characterised in that, at least one pressure control valve (32) that is controlled by an electrical controlling unit (18) is located at the high- pressure pump (10), at one of the injectors (12), in a hydraulic pipe (27) between the injectors (12) or in a hydraulic pipe (26) between the high- pressure pumps (10) and in one of the injectors (12). 9. Fuel injection device in accordance with one of the preceding Claims, characterised in that, the high-pressure pump (10) has one single pump element to which at least one of injectors (12) is connected by a hydraulic pipe (26). 10. Fuel injection device in accordance with one of Claims 1 to 8, characterised in that, the high-pressure pump (10) has several pump elements that are connected to a common high-pressure connection of the high-pressure pump (10) to which one of the injectors (12) is connected by a hydraulic pipe (26). 11. Fuel injection device in accordance with one of Claims 1 to 8, characterised in that, the high-pressure pump (10) has two pump elements to which one of the injectors (12) respectively is connected by one hydraulic pipe (26) respectively.

Full Text

FUEL INJECTION DEVICE FOR A MULTI-CYLINDER INTERNAL COMBUSTION ENGINE
Prior Art
The invention emanates from a fuel injection device for a multi-cylinder internal combustion engine in accordance with the genre of Claim 1.
This type of fuel injection device is established in EP 0 299 337 A. This fuel injection device has a high-pressure pump through which fuel that is in a high-pressure accumulator, a so-called rail, is conveyed. An injector is provided for each cylinder of the internal combustion engine, whereby each injector is connected to the high-pressure accumulator by a hydraulic pipe that is attached to the high-pressure connection of the injector. The disadvantage in the case of this fuel injection device is the magnitude of the manufacture and assembly complexity that is brought about by the high-pressure accumulator located between the high-pressure pump and the injectors. The high-pressure accumulator must exhibit great stability owing to the high pressure that prevails in the same. Over and above this, the installation space required on account of the high-pressure accumulator in the vicinity of the internal combustion engine for the fuel-injection device is increased.
Advantages of the Invention
The fuel-injection device, in accordance with the invention, with features according to Claim 1 on the other hand has the advantage of not requiring a

high-pressure accumulator, whereby its manufacture and assembly is simplified and its installation space requirement is reduced.
Beneficial designs and further development of the fuel-injection device in accordance with the invention are specified in the dependent claims.
Drawing
Several exemplary embodiments of the invention are described in greater detail in the drawings and in the subsequent description. Figure 1 presents a fuel-injection device for an internal combustion engine in a simplified drawing in accordance with a first embodiment. Figure 2 is an enlargement of the injector of the fuel-injection device and Figures 3 to 10 illustrate the fuel-injection device in accordance with other exemplary embodiments.
Description of the Exemplary Embodiments
Figures 1 to 10 present a fuel-injection device for a multi-cylinder internal combustion engine, that is preferably a self-igniting internal combustion engine of a motor vehicle. The fuel-injection device has a high-pressure pump 10 through which fuel is conveyed under high pressure. An injector 12 is located at each cylinder of the internal combustion engine through which fuel can be injected into the combustion chamber of the cylinder. Only a few of the injectors 12 are illustrated in Figures 1 to 10 in the process, whereby other injectors, except for the last injector 12d, are indicated by dots. Injector 12 has a fuel-injection valve 14, as illustrated in Figure 2, through which fuel is injected into the combustion chamber of the cylinder and has an electrically operated

actuator 16. The opening and closing movement of an injection valve element
15 of the fuel-injection valve 14 is controlled by the actuator 16. The actuator
16 is preferably a piezo-electric actuator whose size changes subject to the electrical voltage supplied to the same. A switching function can be achieved through this change in size, by means of which the injection valve element 15 can be opened and closed respectively. Actuator 16 is controlled by electronic controlling equipment 18. Actuator 16 is located in a fuel-filled chamber 20 in a casing 22 of the injector 12. The actuator 16 can, for example, act upon a piston 17 which restricts a buncher space 19, whereby the injection valve element 15 is loaded by pressure prevailing in the buncher space 19 in the closing direction. Piston 17 is held in position at the actuator 16 by a preloaded spring 21. Apart from this, the injection valve element 15 is loaded in the closing direction by a pre-loaded spring 23. If an electrical voltage is applied to the actuator 16 by the controlling equipment 18, the same expands and presses the piston 17 into the buncher space 19 in which a higher pressure consequently prevails, as a result of which the injection valve element 15 is held in its closed position so that fuel injection does not takes place. If no electrical voltage is applied by the controlling equipment 18 to the actuator 16, the same reduces its expansion so that piston 17 is moved out of the buncher space 19 by the spring 21 due to which the pressure in the buncher space 19 sinks. The injection valve element 15 is then moved into its opening position by high pressure acting upon the same in the opening direction against the lower pressure prevailing in buncher space 19 and against spring 23 force, so that fuel is injected.
Two high-pressure connections 24 are provided at casing 22 of injector 12 through which fuel that is under high-pressure is fed to the injector 12 and/or conveyed onwards from the same. High-pressure connections 24 are connected to chamber 20 in which the actuator 16 is located. Apart from this, the high-pressure connections 24 are connected to the fuel-injection valve 14 via chamber 20 in order to supply the same with fuel required for the injection

of fuel. Chamber 20 thereby forms a high-pressure accumulator from which fuel is extracted for injection. Chamber 20 thus has a volume that is large enough to store fuel quantities required for fuel injection. The volumes of chamber 20 can range between 1 and 5 cm3, approximately 2 cm3, for example.
In the case of a first exemplary embodiment of the fuel injection device presented in Figure 1, only a first injector 12a of injectors 12 is connected to the high-pressure pump 10, whereby a hydraulic pipe 26 leading away from the high-pressure connection of the high-pressure pump 10 is connected to the high-pressure connector 24 of injector 12a. The first injector 12a that is connected to the high-pressure pump 10 is preferably the injector of the internal combustion engine that is the one located next to the high-pressure pump 10. The cylinders of the internal combustion engine and therewith also the injectors 12 allocated to the same are located in a row. A hydraulic pipe 27 is connected to the other high-pressure connection 24 of the first injector 12a, this pipe leading to another injector 12b and this injector 12b is connected to a high-pressure connection 24. Injector 12b is preferably located adjacent to the first injector 12a. A hydraulic pipe 27 is connected to the other high-pressure connection 24 of injector 12b, this pipe in turn leading to another preferably adjacent injector 12 and this injector 12 is connected to a high-pressure . connection 24. The last injector 12d is connected to the preceding adjacent injector only by one hydraulic pipe 27 connected to the two high-pressure connections 24, while a pressure sensor 28 is located at its other high-pressure connection 24. The pressure sensor 28 can alternatively also be located at another injector 12 in one of the hydraulic pipes 27 between injectors 12, between the high-pressure pump 10 and the first injector 12a or at the high-pressure pump 10. Injectors 12 of the cylinders of the internal combustion engine are connected hydraulically in a line, whereby only the first injector 12a is directly connected to the high-pressure pump 10.

The pressure sensor 28 is connected to controlling equipment 18 and provides the same with a signal regarding the pressure that is actually prevailing in injectors 12. A fuel measuring device 30 is located at the intake side of the high-pressure pump 10 which can modify the quantities of fuel sucked out from the high-pressure pump 10 and conveyed under high pressure. The alterable cross-section of the stream can, for example, be adjusted by the fuel measuring device 30 at the intake side of the high-pressure pump 10. Fuel is preferably conveyed from a storage tank 32 to the intake side of the high-pressure pump 10 by means of a feed pump 34, whereby the fuel measuring device 30 is located between the feed pump 34 and the high-pressure pump 10. The fuel measuring device 30 is controlled in such a manner by the controlling device 18 that the high-pressure pump 10 supplies injectors 12 with a fuel quantity under high pressure such as they require in order to maintain a pre-determined pressure in injectors 12 for the fuel injection.
The high-pressure pump 10 can be designed to have only one single pump element, whereby a hydraulic pipe 26 leading to the first injector 12a is connected at the outlet of this pump element. In an alternate design, the high-pressure pump 10 can have several pump elements, one or three pump elements for example, whereby the outlets of the pump elements are merged into a common outlet at the high-pressure pump 10 to which the hydraulic pipe 26 leading to the first injector 12a is connected.
The fuel-injection device in accordance with a second exemplary embodiment is presented in Figure 3 in which the basic structure is similar to that of the first exemplary embodiment. The deviation here, however, is that even the last injector 12d is connected directly to the high-pressure pump 10 by a hydraulic pipe 26. As in the first exemplary embodiment, the last injector 12d is, furthermore, connected to the adjacent injector by a hydraulic pipe 27. Two high-pressure outlets are hereby provided at the high-pressure pump 10 of

which one is connected to the first injector 12a and the other to the last injector 12d. The pressure sensor 28 can be located at one of the injectors 12 or in a hydraulic pipe 27 between the injectors or in a hydraulic pipe 26 between the high-pressure pump 10 and one of injectors 12 or at the high-pressure pump 10. If the high-pressure pump 10 has only one pump element then two high-pressure connections must be provided at the same to connect the two to the hydraulic pipe 26 leading to injectors 12a and 12d. If the high-pressure pump 10 has two pump elements then the hydraulic pipe 26 is connected to the first injector 12a at the outlet of the one pump element and the hydraulic pipe 26 to the last injector 12d is connected at the outlet of the other pump element. If the high-pressure pump 10 has more than two pump elements then their outlets are merged into two high-pressure connections at the high-pressure pump 10, whereby a hydraulic pipe 26 leading to one injector 12a and 12d respectively is connected at each high-pressure connection.
Figure 4 presents the fuel injection device in accordance with a third exemplary embodiment in which the cylinders of the internal combustion engine are located in a v-shape, whereby several cylinders are located one next to the other in each cylinder bank. Only the first injector 12a of the first cylinder bank is connected directly to the high-pressure pump 10 and the remaining injectors 12 are connected to one another in a row by the hydraulic pipe 27. The injectors 12 of the two cylinder banks that are respectively located the farthest from the high-pressure pump 10 are also connected to one another by a hydraulic pipe 27. Pressure sensor 28 is.located at injector 12d of the second cylinder bank, this injector being located next to the high-pressure pump 10. The pressure sensor 28 can also be located elsewhere as is specified in the case of the first exemplary embodiment. The design of the high-pressure pump 10 is the same as was described in the case of the first exemplary embodiment.

Figure 5 is an illustration of the fuel injection device in accordance with a fourth exemplary embodiment that differentiates itself from the third exemplary embodiment only in that, in each case, the injector 12 of each cylinder bank located next to the high-pressure pump 10 is connected to the high-pressure pump 10 by a hydraulic pipe 26 respectively. The remaining injectors 12 are respectively interconnected in a row by hydraulic pipes 27. The design of the high-pressure pump 10 is the same as was described in the case of the second exemplary embodiment.
Figure 6 presents the fuel injection device in accordance with a fifth exemplary embodiment in which the basic structure is the same as in the first exemplary embodiment. A pressure control valve 32 is provided in addition in the fuel injection device in accordance with the fifth exemplary embodiment, through which pressure prevailing in injectors 12 can be modified. The pressure control valve 32 can be located, for example, at the high-pressure pump 10. The pressure sensor 28 can be located at the last injector 12d. The pressure control valve 32 can alternatively also be located at the last injector 12d as in the case of a variant illustrated in Figure 7 and the pressure sensor 28 can be located between the injectors 12 in one of the hydraulic pipes 27. The pressure control valve 32 and the pressure sensor 28 can also be placed at any other location. The pressure control valve 32 is connected to controlling equipment 18 and is controlled by the same in order to adjust the pressure prevailing in injectors 12 to a pre-determined value. Very quick modification of the pressure prevailing in injectors 12 can be achieved by controlling the pressure control valve 32 through the controlling equipment 18. Controlling the fuel measuring device 30 through the controlling equipment 18 accomplishes the purpose of the high-pressure pump 10, at least essentially, only discharging fuel quantities under high pressure required for fuel injection to injectors 12, whereby the driving power can be minimised for the high-pressure pump 10.

Figure 8 presents a fuel injection device in accordance with a sixth exemplary embodiment that essentially has the same design as the third exemplary embodiment with a v-shape formation of the cylinders of the internal combustion engine and in which the pressure control valve 32 is provided in addition. The connection of injectors 12 to the high-pressure pump 10 via the hydraulic pipe 26 and among themselves through the hydraulic pipes 27 is the same as in the third exemplary embodiment so that only the first injector 12a is connected directly to the high-pressure pump 10. The pressure control valve 32 is located, for example, at the high-pressure pump 10 and the pressure sensor 28 is located at the last injector 12d. The pressure control valve 32 can alternatively also be located at the last injector 12d as is illustrated in Figure 9 and the pressure sensor 28 can be located in one of the hydraulic pipes 27 between the injectors 12. The pressure control valve 32 and the pressure sensor 28 can also be positioned at any other location.
Figure 10 presents the fuel injection device in accordance with a seventh exemplary embodiment in which, deviating from the sixth exemplary embodiment, the injector 12 of the two cylinder banks respectively, located next to the high-pressure pump 10, is connected to the high-pressure pump 10 by a hydraulic pipe 26. Injectors 12d of the two cylinder banks that are located farthest from the high-pressure pump 10 are not connected to one another but a pressure control valve 32 is instead located at the two respectively. A pressure sensor 28 is located in one of the hydraulic pipes 27 between the injectors 12 of the two cylinder banks.
The pressure control valve 32 and the pressure sensor 28 of both cylinder banks could also be positioned at any other location. Separated high-pressure branches for injectors 12 of both cylinder banks of the internal combustion engine with own pressure control valve 32 and pressure sensor 28 are thus present in the seventh exemplary embodiment.

Claims
1. Fuel injection device for a multi-cylinder internal combustion engine with a high-pressure pump (10) and with an injector (12) respectively for each cylinder of the internal combustion engine that is at least indirectly connected to the high-pressure pump (10) by a hydraulic pipe (26;27), characterised in that, each injector (12) is connected by a hydraulic pipe (26;27) to the high-pressure pump (10) and/or to the injector (12) of another cylinder of the internal combustion engine.
2. Fuel injection device in accordance with Claim 1, characterised in that, each cylinder (12) has at least one buncher space (20), which is connected to the hydraulic pipes (26;27).
3. Fuel injection device in accordance with Claims 1 or 2, characterised in that, each injector (12) has two high-pressure connections (24) for the hydraulic pipes (26;27).
4. Fuel injection device in accordance with one of Claims 1 to 3, characterised in that, injectors (12) are connected to one another in a row by the hydraulic pipes (26;27) and that only the first of the injectors (12a) is directly connected to the high-pressure pump (10).
5. Fuel injection device in accordance with one of Claims 1 to 3, characterised in that, the injectors (12) are connected in a row to one another by the hydraulic pipes (26;27) and that a first and last injector (12a, 12d) are connected directly to the high-pressure pump (10).
6. Fuel injection device in accordance with one of the preceding Claims, characterised in that, at least one pressure sensor (28) is located at the high-pressure pump (10), at one of the injectors (12), in a hydraulic pipe (27) between the injectors (12) or in a hydraulic pipe (26) between the high-pressure pump (10) and in one of the injectors (12).

7. Fuel injection device in accordance with Claim 6, characterised in that,
the at least one pressure sensor (28) is connected to an electrical
controlling equipment (18) and that a fuel measuring device (30) that is
controlled by the controlling equipment (18), subject to pressure
registered by the pressure sensor (28), is connected upstream from the
high-pressure pump (10).
8. Fuel injection device in accordance with one of the preceding Claims,
characterised in that, at least one pressure control valve (32) that is
controlled by an electrical controlling unit (18) is located at the high-
pressure pump (10), at one of the injectors (12), in a hydraulic pipe (27)
between the injectors (12) or in a hydraulic pipe (26) between the high-
pressure pumps (10) and in one of the injectors (12).
9. Fuel injection device in accordance with one of the preceding Claims,
characterised in that, the high-pressure pump (10) has one single pump
element to which at least one of injectors (12) is connected by a
hydraulic pipe (26).
10. Fuel injection device in accordance with one of Claims 1 to 8,
characterised in that, the high-pressure pump (10) has several pump
elements that are connected to a common high-pressure connection of
the high-pressure pump (10) to which one of the injectors (12) is
connected by a hydraulic pipe (26).
11. Fuel injection device in accordance with one of Claims 1 to 8,
characterised in that, the high-pressure pump (10) has two pump
elements to which one of the injectors (12) respectively is connected by
one hydraulic pipe (26) respectively.

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Patent Number

268653

Indian Patent Application Number

4128/CHENP/2007

PG Journal Number

37/2015

Publication Date

11-Sep-2015

Grant Date

10-Sep-2015

Date of Filing

20-Sep-2007

Name of Patentee

ROBERT BOSCH GMBH

Applicant Address

POSTFACH 30 02 20, D-70442 STUTTGART, GERMANY.

Inventors:

#	Inventor's Name	Inventor's Address
1	PAUER, THOMAS	GROSSE AECKER 10, 71691 FREIBERG, GERMANY.

PCT International Classification Number

F02M 55/02

PCT International Application Number

PCT/EP06/50448

PCT International Filing date

2006-01-25

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	102005012928.5	2005-03-21	Germany