EP2516839B1 - Fuel injector apparatus - Google Patents

Description

State of the art

The invention relates to a fuel injection device for internal combustion engines. Specifically, the invention relates to the field of fuel assemblies for air compressing auto-ignition internal combustion engines.

From the DE 10 2006 040 248 A1 a fuel injection device for a multi-cylinder internal combustion engine is known. The known fuel injection device has a high-pressure pump and in each case an injector for each cylinder of the internal combustion engine, which is connected at least indirectly via a hydraulic line to the high-pressure pump. The high-pressure pump is connected to a distributor element. Several of the injectors are connected in series via hydraulic lines. A first injector and a last injector of the series of injectors are connected in each case via a hydraulic line directly to the distributor element. On the housing of an injector two high-pressure connections are provided, is supplied via the high-pressure fuel to the injector or is continued by this. The high-pressure connections are in this case connected to a space of the injector, in which an actuator is arranged. In addition, the high-pressure ports are connected to the fuel injection valve through the space to supply the fuel necessary for the fuel injection thereto. The space forms a high-pressure accumulator, from which the fuel is taken for injection. The space has a sufficiently large volume in order to store the fuel volume required for the fuel injection can.

The from the DE 10 2006 040 248 A1 known fuel injection has the disadvantage that pressure pulsations occur during operation. This leads to vibrations in the fuel injection device. This has an unfavorable effect on the injection behavior of the individual injectors.

Disclosure of the invention

The fuel injection device according to the invention with the features of claim 1 has the advantage that pressure pulsations are reduced and in particular a cost-effective and low-vibration system can be created.

The measures listed in the dependent claims advantageous developments of the fuel injection device specified in claim 1 are possible.

It is advantageous that the fuel from the high pressure input via an additional volume for receiving fuel to the first fuel injection valve is feasible. The additional volume allows additional damping. Furthermore, it is advantageous that the additional volume is greater than a total fuel volume of a fuel injection valve. As a result, an advantageous vibration damping can be achieved. In addition, this can also be a reliable vibration damping when using cost fuel injectors, such as solenoid valves with relatively long switching times done. As a result, a robust and cost-effective design of the fuel injection device is possible. Specifically, it is advantageous in this case that the additional volume is at least approximately equal to a sum of the total fuel volume of the fuel injection valves. As a result, a fuel injection device can be provided which has very low pressure fluctuations due to the injection of the fuel injection valves.

It is also advantageous that the additional volume is connected via a line to the first fuel injection valve and via a further line to a second fuel injection valve. In this case, it is also advantageous that at least one further fuel injection valve is provided in addition to the first fuel injection valve and the second fuel injection valve and that the fuel injection valves and the additional volume are connected to each other via two lines corresponding to a closed series connection. This arrangement minimizes pressure oscillations and improves tolerance behavior. It is advantageous here, too, that the lines are at least approximately the same length. In order to allow this to optimize the line lengths, the fuel injectors may be connected to each other according to their arrangement so that there is always a connection to the next but one fuel injector. As a result, the vibration behavior can be further improved. Depending on the configuration of the internal combustion engine but also individual short or longer lines can be used.

It is advantageous that the fuel space is designed as a contiguous fuel space. This provides a relatively large volume for pressure damping available.

Alternatively, it is also advantageous that the partial volume for fuel injection and the additional partial volume for enabling the damping via at least one throttle are connected to each other. As a result, any vibrations occurring can be decoupled from the partial volume for fuel injection.

Particularly advantageous is the use of a 1-piston high pressure pump, which has only one delivery line, which is connected to the high pressure input. This allows a very cost-effective and low-vibration system can be achieved.

Brief description of the drawings

• Fig. 1 eine Brennstoffeinspritzeinrichtung in einer schematischen Darstellung entsprechend einem ersten Ausführungsbeispiel;
• Fig. 2 eine Brennstoffeinspritzeinrichtung in einem schematischen Darstellung entsprechend einem zweiten Ausführungsbeispiel;
• Fig.3 eine Brennstoffeinspritzeinrichtung in einer schematischen Darstellung entsprechend einem dritten Ausführungsbeispiel;
• Fig. 4 eine Brennstoffeinspritzeinrichtung in einer schematischen Darstellung entsprechend einem vierten Ausführungsbeispiel;
• Fig. 5 ein Brennstoffeinspritzventil für eine Brennstoffeinspritzeinrichtung entsprechend einer möglichen Ausgestaltung in einer nicht erfindungsgemäßen, auszugsweisen und schematischen Schnittdarstellung und
• Fig. 6 ein Brennstoffeinspritzventil einer Brennstoffeinspritzeinrichtung entsprechend einer erfindungsgemäßen Ausgestaltung in einer auszugsweisen, schematischen Schnittdarstellung.

Partial aspects of the invention are explained in more detail in the following description with reference to the accompanying drawings, in which corresponding elements are provided with corresponding reference numerals. The FIGS. 1 to 5 show fuel injectors, each of which constitute aspects of the invention and not show all the features of the invention. In detail shows

• Fig. 1 a fuel injection device in a schematic representation according to a first embodiment;
• Fig. 2 a fuel injection device in a schematic representation according to a second embodiment;
• Figure 3 a fuel injection device in a schematic representation according to a third embodiment;
• Fig. 4 a fuel injection device in a schematic representation according to a fourth embodiment;
• Fig. 5 a fuel injection valve for a fuel injector according to a possible embodiment in a non-inventive, excerpted and schematic sectional view and
• Fig. 6 a fuel injection valve of a fuel injection device according to an embodiment of the invention in an excerpt, schematic sectional view.

Partial embodiments of the invention

Fig. 1 shows a first embodiment of a fuel injector 1 with fuel injectors 2, 3, 4, 5 and a high-pressure pump 6. The fuel injector 1 is used for an internal combustion engine, in particular an air-compressing, self-igniting internal combustion engine. The fuel injection valves 2 to 5 can serve as injectors for such an internal combustion engine. A preferred use of the fuel injection device 1 is for commercial vehicles or passenger cars. However, the fuel injector 1 of the invention is also suitable for other applications.

Compliance with the pollutant limit values has high priority in the development of internal combustion engines. With a common-rail injection system, a significant contribution to the reduction of pollutants can be made. The advantage of such an injection system lies in the independence of the injection pressure of speed and load. Here, a common rail is available, to which all injectors are connected. The fuel pressure is held in the central common rail and distributed from there to the individual injectors. In this case, the common rail should have approximately the length,) which are the injectors spaced apart in the installed state, to allow short connecting lines. Nevertheless, unwanted pressure oscillations occur between the common rail and the injectors.

The fuel injection device 1 of the first embodiment allows a linear connection of the fuel injection valves 2 to 5 via lines 7, 8, 9. In addition, a line 10 is provided, via which the fuel injection valve 5 is connected to the high-pressure pump 6. An output 11 of the high pressure pump 6 is in this case connected to a high pressure input 12. The high-pressure input 12 is provided on the line 10 in this embodiment. The high pressure input 12 is for the fuel injectors 2 to 5 to supply fuel to the fuel injection valves 2 to 5. The fuel injection valves 2 to 5 are connected in series. In addition, an additional component 13 is provided, which is connected via a line 14 to the fuel injection valve 2. The additional component 13 is connected to the last fuel injection valve 2 of the series and can be configured for example as a pressure regulating valve or pressure sensor. The additional component 13 may be arranged in a separate functional body, as shown in the Fig. 1 is illustrated, or may be arranged directly on the fuel injection valve 2. Thus, all the fuel injection valves 2 to 5 are also traversed by the necessary standard fuel. One additional accumulator in the form of a common rail or the like is not required.

The fuel injection valve 5 has two high pressure ports 15, 16. Here, the line 10 is connected to the high-pressure port 15 of the fuel injection valve 5. In this embodiment, a throttle 17 is arranged in the conduit 10 to allow a throttled supply of fuel. As an alternative to two separate high-pressure connections 15, 16, a distributor adapter may also be provided at a common high-pressure connection. The connection of the line 10 to the high-pressure port 15 of the fuel injection valve 5 takes place at the beginning of the row or injector chain.

The lines 7, 8, 9 preferably have the same length. Furthermore, it is advantageous that the line 10 is designed to be relatively short. Optionally, connecting pieces may also be provided for the integration of control components.

The fuel injection valve 5 has a fuel chamber 18. A total fuel volume of the fuel chamber 18 for receiving fuel is divided into a partial volume 19 and an additional partial volume 20. The total fuel volume of the fuel chamber 18 allows damping of pressure pulsations. In this case, the additional partial volume 20 is available in addition to the partial volume 19 in order to allow such damping. In this exemplary embodiment, the partial volumes 19, 20 are connected to one another via a throttle 21.

In this embodiment, the partial volume 19 is already made relatively large. Thus, the partial volume 19 also contributes to the damping of pressure pulsations.

The fuel injection valve 5 has a valve element 22 which serves to open and close the injection cross section. Further, a valve unit 23 is provided, which serves to control the injection.

The fuel chamber 18 of the fuel injection valve 5 is connected via the line 7 to the fuel chamber 24 of the fuel injection valve 4. Through the lines 8 and 9 there is also a connection to the fuel spaces 25, 26 of the fuel injection valves 2, 3. Thus, all the fuel chambers 18, 24, 25, 26 of the fuel injection valves 2 to 5 via the lines 7, 8, 9 are interconnected. There is no additional memory in the system.

The high-pressure pump 6 is configured as a 1-piston high-pressure pump 6. Here, the high-pressure pump 6 is designed with volume control. The high-pressure pump 6 delivers via the line 10 under high pressure fuel to the first fuel injection valve 5 of the series.

Specifically, the fuel injectors 2 to 5 may be configured as injectors with servo-controlled nozzle needle 22 and with solenoid valve 23. For example, the fuel injection valve 5 may have a servo control chamber 27 into which the nozzle needle 22 protrudes. The control of the nozzle needle 22 via the control of the pressure in the servo control chamber 27 by means of the solenoid valve 23. The nozzle needle 22 extends through the fuel chamber 18th

By the total fuel volume of the fuel chamber 18 with the proposed throttle 21, the line vibrations of the linear, formed by the lines 7, 8, 9 injector compound are attenuated, so that a cost-effective and low-vibration system.

Depending on the configuration of the fuel injection valves 2 to 5, one or more returns to the fuel injection valves 2 to 5 may be provided. Furthermore, the high-pressure pump 6 has a low-pressure circuit for regulating the filling. System components required for this, for example for pressure regulation or function monitoring, can be attached to the high-pressure pump 6 or to additional adapter pieces.

Advantageously, the fuel injector 5 thus comprises a total integrated volume of fuel and a long valve member 22 which extends through the fuel space 18 and forms a servo-controlled nozzle needle. As a result, the closing throttle provided for tuning can be arranged on the input side of the partial volume 19. In this way, the throttle 21 can take over both the function of the closing throttle and the function of the damping throttle for damping line vibrations. In conjunction with the designed as a 1-stamp high-pressure pump high-pressure pump 6, which has only one formed by the line 10 conveying line, a very cost-effective and low-vibration system can be realized.

The design of the fuel injection valves 2, 3, 4 results according to the described embodiment of the fuel injection valve. 5

Fig. 2 shows a fuel injector 1 in a schematic representation according to a second embodiment. In this embodiment, the fuel injection valve 2 is connected via a line 30 with an adapter piece 31. The adapter piece 31 is connected via the line 10 to the output 11 of the high-pressure pump 6. In addition, the fuel injection valve 3 is connected via a line 32 to the adapter piece 31. The adapter piece 31 divides the fuel flow to the fuel injection valves 2, 3. In addition, the additional component 13 is attached to the adapter piece 31 in this embodiment, which is configured for example as a pressure control valve.

The fuel injection valve 2 is connected via the line 8 to the fuel injection valve 4. Further, the fuel injection valve 4 is connected via the line 9 to the fuel injection valve 5. The fuel injection valve 5 is in turn connected via the line 7 to the fuel injection valve 3. This results in a closed series connection of the fuel injection valves 2 to 5. This closed series connection does not necessarily connect the fuel injection valves 2 to 5 in the form of a ring, since the fuel injection valve 3 is skipped by the conduit 8 and the fuel injection valve 4 is skipped by the conduit 7. This makes it possible that the lines 7, 8, 9 are configured at least approximately the same length.

In the fuel injector 1 of the second embodiment, large fuel spaces 18, 24, 25, 26 are formed in the fuel injection valves 2 to 5. An additional storage for fuel is not provided.

The high-pressure pump 6 delivers fuel via the line 10 to the adapter piece 31. The adapter piece 31 can be used here at any point in the closed chain of the fuel injectors 2 to 5. Here, the two lines 30, 32, which are connected to the adapter piece 31, be the same length or different lengths configured. Furthermore, it is possible that the adapter piece 31 is arranged directly on one of the fuel injection valves 2 to 5. The adapter piece 31 is spatially arranged in the vicinity of the lines 7, 8, 9. The additional component 13, in particular a pressure regulating valve and / or a pressure sensor, can also be arranged directly on the high-pressure pump 6, in particular on the outlet 11.

In the Fig. 2 an arrangement of the fuel injection valves 2 to 5 is illustrated, as it can be used in a four-cylinder inline engine. Leave here can be realized by the special interconnection of the fuel injection valves 2 to 5, in which the line 7, the fuel injector 4 bridges and the line 8 bridges the injection valve 3, substantially equal length connections 7, 8, 9 realize. This can also take place in the case of a different number of fuel injection valves, in which at least part of the fuel injection valves is bridged, and thus the second-but-one fuel injection valve is connected starting from a fuel injection valve.

Alternatively, it is also possible that the fuel injection valves 2 to 5 are connected according to their arrangement with the adjacent fuel injection valves and the two outermost fuel injection valves 2, 5 are connected via lines to the adapter piece 31: Specifically, in an internal combustion engine with at most four cylinders, this can be an expedient Be alternative.

It is also an annular connection of the fuel injection valves possible, for example, in an internal combustion engine with six cylinders in V-arrangement.

Fig. 3 shows a fuel injector 1 in a schematic representation according to a third embodiment. In this embodiment, the high-pressure pump 6 is connected via two lines 10, 10 'to a memory 40. Here, the high-pressure pump 6 outputs 11, 11 ', on which the lines 10, 10' are mounted. The high pressure input 12 is formed in this embodiment on the two lines 10, 10 '. Through the memory 40, an additional volume 41 is provided. The memory 40 has throttled outputs 42, 43. At the throttled output 42, the line 30 is attached. The conduit 30 connects the fuel injector 2 to the reservoir 40. The conduit 32 is attached to the throttled outlet 43. The line 32 connects the fuel injection valve 5 to the memory 40. In addition, the fuel injection valve 2 is connected via the line 9 to the fuel injection valve 3 in this embodiment. Further, the fuel injection valve 3 is connected via the line 8 to the fuel injection valve 4. The fuel injection valve 4 is in turn connected to the fuel injection valve 5 via the conduit 7, so that a closed chain is formed in the form of a ring. In this embodiment, the accumulator 40 thus initially distributes the fuel to the fuel injection valves 2, 5. In this case, the fuel supplied from the high-pressure pump 6 is guided via the additional volume 41 to the fuel injection valves 2 to 5. The additional volume 41 allows a further damping, which acts in addition to the fuel chambers 18, 24, 25, 26 of the fuel injection valves 2 to 5 vibration reducing.

In this example, the partial volume 19 for fuel injection and the additional partial volume 20 for enabling the damping are not separated, which is not according to the invention. The total fuel volume of the fuel chamber 18 in this case depends without a throttle connection or the like. The fuel chamber 18 of the fuel injection valve 5 is designed as a large fuel chamber 18. The fuel injection valve 5 includes the valve element 22 for opening and closing the injection cross section and the valve unit 23 for controlling the injection.

The additional volume 41 of the memory 40 is preferably set greater than the total fuel volume of a single fuel chamber 18 of a fuel injector 5. It is also advantageous that the sum of the total fuel volume of the fuel chambers 18, 24, 25, 26 of the fuel injectors 2 to 5 at least approximately equal to Additional volume 41 of the memory 40 is. The additional volume 41 is integrated into the annular arrangement of the fuel chambers 18, 24, 25, 26. Thus, the additional volume 41 and the total fuel volume of the fuel chambers 18, 24, 25, 26 are annularly connected. The high-pressure pump 6 delivers fuel into the additional volume 41 and into the individual fuel chambers 18, 24, 25, 26.

For further damping of pressure oscillations, the throttled high-pressure ports 15, 16 are provided on the fuel injection valve 5. In this case, throttles 17, 44 are integrated into the high-pressure connections 15, 16. This applies correspondingly to the other fuel injection valves 2, 3, 4. This results in a fuel injection device 1, which is subject to very small pressure fluctuations due to the injection of the individual fuel injection valves 2 to 5.

Thus, injection tolerances which may occur due to pressure oscillations are prevented or at least reduced. This can be achieved, in particular, by the throttles 17, 44 of the fuel injection valve 5 acting as damper throttles and the further throttles provided on the remaining fuel injection valves 2 to 4. Thus, in the linear interconnected fuel injection valves 2 to 5 in an advantageous manner, an attenuation of the combination of the throttle effect and the storage volume, namely the fuel chambers 18, 24, 25, 26 and the additional volume 41, possible. As a result, vibrations are reduced and tolerances during injection between the individual fuel injection valves 2 to 5 can be kept low. The throttling effects of the throttled outputs 42 to 43 of the memory 40 also contribute to the damping effect.

It should be noted that the additional volume 41 can also be given approximately the same size as each individual total fuel volume of the fuel chambers 18 of the fuel injection valves 2 to 5. The additional volume 41 is, for example, approximately the same size as the volume of the fuel chamber 18. However, the additional volume 41 be chosen differently.

Fig. 4 shows a fuel injector 1 in a schematic representation according to a fourth embodiment. In this embodiment, the memory 40 has a throttled output 43 and an unthrottled output 42. In addition, the fuel injection valve 5 has a high pressure port 15, which is designed unthrottled. The throttled output 43 of the accumulator 40 is connected to the high-pressure port 15 of the fuel injection valve 5 via the line 32. In this case, a throttling action is given via the throttle 43 of the throttled output 43. In addition, the fuel injection valve 5, the high-pressure port 16 which is configured throttled or at which a throttle 44 is provided. Via the line 7, the fuel injection valve 5 is connected to the fuel injection valve 4. Here, the line 7 is attached on the one hand to the throttled high-pressure port 16 of the fuel injection valve 5 and on the other hand attached to an unthrottled high-pressure port 15 'of the fuel injection valve 4. The same applies to the connecting lines 8, 9, which serve to connect the fuel injection valves 2 to 4. The fuel injection valve 2 is connected via the line 30 with the throttled output 42 of the memory 40, wherein a throttle 45 is provided in the region of the fuel injection valve 1 to the line 30 and to the fuel injection valve 2.

Thus, the fuel injection valves 2 to 5 and the additional volume 41 are in turn connected annularly. In this case, damping throttles, in particular the damping throttles 43, 44, 45, are provided, which are arranged only on one side, symmetrically on the fuel injection valves 2 to 5 or the accumulator 40. Thus, each of the lines 7, 8, 9, 30, 32 is throttled at one end and at the other end unthrottled connected to the respective component.

The fuel injection valve 5 has a large fuel chamber 18. Here, the fuel injection valve 5 comprises a valve element 22 for opening and closing the injection cross-section. The valve element is controlled in this embodiment via the servo control chamber 27 and the valve unit 23 for controlling the pressure in the servo control chamber 27. Depending on the configuration of the fuel injection valve 5 can also be provided one or more returns to the fuel injection valve 5. The damper throttles provided on the fuel injection valves 2 to 5 and the accumulator 40 can be used for any number of cylinders and engine configurations.

Thus, in an advantageous manner, a connection via lines 7, 8, 9, 30, 32 with one-sided, symmetrically arranged damper throttles on the fuel injection valves 2 to 5 and the memory 40 take place. Thus, the pressure loss during injection can be reduced and still a good vibration damping can be achieved. In this case, each of the lines 7, 8, 9, 30, 32 has a throttled connection at one end. As a result, a number of parts and the associated costs are reduced. The pressure loss generated by the damper throttles is reduced and the system efficiency is increased.

Ideally, this one-way damping is applied in a system design with the reservoir 40 providing the additional volume 41, when the additional volume 41 is about as large as the integrated, serving as a storage volume fuel chambers 18, 24, 25, 26 of the fuel injection valves 2 to 5 In this case, a one-sided throttle 43 is also used on the additional volume 41. The high-pressure pump 6 promotes in the additional volume 41. This results in a very low-vibration system is achieved, in which each fuel injection valve 2 to 5 has the same connection conditions. In addition, possibly required additional components 47, 48, such as pressure control valve, pressure relief valve and sensors, are attached to the additional volume 41. For example, a pressure regulating valve 46 and a pressure limiting valve 47 are provided, which are connected via a return 48 to a tank or the like. From such a tank, the high-pressure pump 6 delivers fuel to the reservoir 40 via an inlet 49.

In the configuration of the fuel injector 1, separate piping ports may be formed on the respective case of the fuel injection valves 2 to 5, or a manifold member may be used. The throttles can in this case also be integrated into the housings (injector body) or into the distributor pieces or inserted as a separate insert part between the lines 7, 8, 9, 30, 32 and the respective connection.

Particularly advantageous is the vibration damping when using fuel injection valves 2 to 5, which have both a large fuel chamber 18, 24, 25, 26 and servo-controlled nozzle needles as valve elements 22, since the nozzle needle control via the servo circuit very sensitive to pressure oscillations responding. This is especially true when a control is carried out by a valve unit 23 having a solenoid valve, as by the relatively slow switching time a tolerance-sensitive injector vote is necessary. The fuel injector 1 can realize such a system with good tolerance behavior for such robust, inexpensive servo injectors 2 to 5.

The fuel injector 1 may therefore advantageously have leak-free fuel injection valves 2 to 5, which are also suitable for common rail applications. However, a common rail can be dispensed with in this case, resulting in a cost-effective configuration of the fuel injection device 1.

Fig. 5 shows a fuel injection valve 5 for a fuel injector 1 in a partial, schematic sectional view according to a possible embodiment. The fuel injection valve 5 has an injector body 55, in which the large fuel chamber 18 is formed. The fuel injection valve 5 has the valve element 22 for opening and closing the injection cross section and the valve unit 23 for controlling the injection. In addition, the fuel injection valve 5 has a return 56, which leads to a tank. Further, a servo control is provided to control the valve element 22 by means of the valve unit 23 having a solenoid valve. This takes place via the servo control chamber 27, which is delimited by an end face 57 of the valve element 22 protruding into the servo control chamber 27. The control of the valve element 22 via the control of the pressure in the servo control chamber 27. The injector behavior of the fuel injection valve 5 depends strongly on the injector pressure, whereby pressure fluctuations in the injector to changes in quantity during injection. Due to the large total fuel volume of the fuel chamber 18 damping is given in this regard. In addition, this attenuation, for example, by an additional volume 41, as shown in the Fig. 4 is shown supported. In addition, a designed as a 2-stamp high-pressure pump 6 high-pressure pump 6 via preferably two lines 10, 10 'initially in the additional volume 41 promote. In combination with the annular system arrangement of the fuel injection valves 2 to 5 and the additional volume 41, pressure oscillations are minimized and the tolerance behavior is improved. As a result, a relatively constant injection is achieved. Pressure fluctuations in the fuel injection valve 5 and thus quantity changes during injection are avoided.

Fig. 6 shows a fuel injection valve 5 in a schematic, partial sectional view according to another possible embodiment. In the injector body 55, a large partial volume 19 of the fuel chamber 18 is formed. The Valve element 22 extends through the partial volume 19 of the fuel chamber 18 and is guided in a valve piece 58. The valve piece 58 has an inlet throttle 59, via which fuel from the fuel chamber 18 into the servo control chamber 27 can be guided. Furthermore, the valve piece 58 has an outlet throttle 60 which can be opened and closed via the valve unit 23 in order to control the pressure in the servo control chamber 27.

In addition, a sealing element 61 is provided which divides the fuel chamber 18 into the partial volume 19 and the additional partial volume 20. The sealing element 61 is in this case arranged between the valve piece 58 and the injector body 55. The partial volume 19 and the additional partial volume 20 of the fuel chamber 18 are in this case connected to one another via a throttle 62 formed in the valve piece 58. The throttle 62 in this case has the function of a closing throttle. The additional partial volume 20 serves in this embodiment as an inlet chamber, which is connected via the throttle 62 with the partial volume 19 of the fuel chamber 18.

By using a servo control circuit and a relatively slow solenoid actuator for the valve unit 23, the fuel injector 5 is sensitive to pressure oscillations. Therefore, the proposed system structure for vibration reduction is particularly advantageous in such a fuel injection valve 5. The fuel injection valve 5 may have one or more returns 56. In order to optimize the injector tuning, a closing throttle close to the storage volume can additionally be used.

That in the Fig. 6 shown fuel injection valve 5 can in particular in the basis of the Fig. 1 described fuel injector 1 and the basis of the Fig. 4 described fuel injector 1 are used.

The invention is not limited to the described embodiments.

Claims (5)

1. Fuel injection apparatus (1), in particular for air-compressing, auto-ignition internal combustion engines, having at least one high-pressure inlet (12), having a first fuel injection valve (2 - 5) and having at least one further fuel injection valve (2 - 5), wherein, via the high-pressure inlet (12), fuel can be conducted at least indirectly into a fuel chamber (18) of the fuel injection valve (2 - 5), wherein the further fuel injection valve (2 - 5) is connected via at least one line (7, 8, 9) to the first fuel injection valve (2 - 5), and wherein, via the line (7, 8, 9), fuel can be conducted from the fuel chamber (18) of the first fuel injection valve (2 - 5) into a fuel chamber of the further fuel injection valve (2 - 5), wherein, for the purpose of damping pressure pulsations, the fuel chambers (18, 24, 25, 26) of the fuel injection valves (2 - 5) accommodate a total fuel volume which comprises a subvolume (19) for fuel injection and at least one additional subvolume (20) for permitting damping, wherein the fuel can be conducted from the high-pressure inlet (12) to the first fuel injection valve (2 - 5) via an auxiliary volume (41) for accommodating fuel,
   wherein
   the auxiliary volume (41) is larger than a total fuel volume of a fuel injection valve (2 - 5), and the auxiliary volume (41) is connected via a line (30, 32) to the first fuel injection valve (2 - 5) and via a further line (30, 32) to a second fuel injection valve (2 - 5), wherein, at least one further fuel injection valve (2 - 5) is provided in addition to the first fuel injection valve (2 - 5) and the second fuel injection valve (2 - 5), and wherein the fuel injection valves (2 - 5) and the auxiliary volume (41) are connected to one another in each case via two lines (7, 8, 9, 30, 32), correspondingly to a closed series circuit.
2. Fuel injection apparatus according to Claim 1, characterized in that the auxiliary volume (41) is at least approximately equal to a sum of the total fuel volumes of the fuel injection valves (2 - 5).
3. Fuel injection apparatus according to Claim 1, characterized in that the lines (7, 8, 9, 30, 32) are of at least approximately equal length.
4. Fuel injection apparatus according to one of Claims 1 to 3, characterized in that the subvolume (19) for fuel injection and the additional subvolume (20) for permitting damping are connected to one another via at least one throttle (21, 62).
5. Fuel injection apparatus according to one of Claims 1 to 4, characterized in that a single-plunger high-pressure pump (6) is provided, which is connected to the high-pressure inlet (12).

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