JPH11159413A - Fuel injector used for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injector which requires no many valve devices and a large constituent space, and besides, can avoid a capacity that lowers the efficiency of a converter. SOLUTION: This device is equipped with a fuel high pressure pump 1 by which fuel is fed under pressure from a low pressure chamber 5 to a fuel injection valve 7 through a high pressure pipeline 3 and a hydraulic converter 13 arranged between these fuel high pressure pump 1 and fuel injection valve 7; the converter 13 has a stepped piston 19 which can slide in a hole 15; both the end surfaces of the stepped piston 19 partition each one pressure chamber; a larger first end surface 21 partitions a first pressure chamber 23 connected to a part on the pump side of the high pressure pipeline 3; a smaller second end surface 25 partitions a second pressure chamber 27 connected to a part on the injection valve side of the high pressure pipeline 3; and a supply passage is arranged in this device, which fills the second pressure chamber 27 with fuel, has a pressure valve and is brought out from the first pressure chamber 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device used for an internal combustion engine, which is provided with a fuel high pressure pump for pumping fuel from a low pressure chamber to a fuel injection valve through a high pressure pipe. A hydraulic conversion device is provided between the fuel high-pressure pump and the fuel injection valve, the conversion device having a stepped piston slidable in the hole, and both ends of the stepped piston. Surfaces each partition one pressure chamber, the larger first end surface partitioning a first pressure chamber connected to the pump-side portion of the high pressure line;
A second end face, which is located on the side opposite to the end face of the high pressure pipe, separates a second pressure chamber connected to the injection valve side portion of the high pressure line, and further has a second pressure chamber. Of a type provided with a supply passage having a pressure valve for filling the fuel with fuel.

[0002]

2. Description of the Related Art A fuel injection device of this type is known from DE-A-4 118 237. In this known fuel injection device, fuel is pumped from a low pressure chamber to a fuel injection valve via a high pressure pipe by a high pressure pump. In this case, a hydraulic converter is provided between the high-pressure pump and the fuel injector in order to increase the pressure in the fuel injector. The hydraulic conversion device has a stepped piston slidable in a hole, and both end faces of the stepped piston partition one pressure chamber. In this case, the larger first end surface partitions the first pressure chamber on the pump side,
The smaller second end surface partitions a second pressure chamber on the injection valve side. The hydraulic pressure conversion in this converter is related to the area ratio of both end faces of the stepped piston acting as a pump piston adjacent to both pressure chambers, in which case the operation of the stepped piston is This is done by supplying high fuel pressure to the larger end face.

[0003] The filling of the second pressure chamber on the side of the injection valve, which is delimited by the smaller second end face of the stepped piston of the hydraulic converter, is carried out via the valve device through the fuel circulation of the fuel injection device. Done from the road. The return movement of the stepped piston takes place also hydraulically via the fuel circuit and a corresponding valve arrangement provided in the supply line leading to the return chamber.

[0004] Known fuel injectors used in internal combustion engines have the disadvantage that a large number of actuating valves are required, which leads to a complicated structure. Furthermore, known fuel injection systems are based on complex valve controls and require a large amount of space, which cannot often be provided in modern internal combustion engines.

Another disadvantage of the hydraulic converters of the known fuel injectors is that they are located in the return chamber,
It is a large capacity that must be displaced. Such a large capacity significantly reduces the efficiency of the converter.

[0006]

SUMMARY OF THE INVENTION The object of the invention is to improve a fuel injection system of the type mentioned at the outset, to avoid the disadvantages described above, without the need for a large number of valve units and large construction space, and It is an object of the present invention to provide a fuel injection device in which the disadvantageous capacity of reducing the efficiency of the converter is avoided.

[0007]

In order to solve this problem, in the configuration of the present invention, the supply passage opening to the second pressure chamber is led out of the first pressure chamber.

[0008]

The fuel injection device according to the present invention has the following advantages. That is, the injection pressure in the fuel injection valve is increased without significantly increasing the construction space compared to a fuel injection system without a hydraulic conversion device, and the injection energy and the supplied work of the entire fuel injection device are increased. And the hydraulic efficiency as a ratio can be improved. In addition to this, the fuel injection device according to the invention has the advantage that, compared to known fuel injection devices with a converter, due to their simple structure, the construction and assembly labor is significantly reduced. ing. This is possible in particular because the filling of the second pressure chamber on the side of the injection valve takes place directly from the high-pressure range between the fuel high-pressure pump and the converter. Thus, an additional supply line from the low pressure range of the system can be dispensed with. In this case, the filling of the second pressure chamber on the side of the injection valve is provided parallel to the stepped piston as a pressure valve in a connection pipe or a supply pipe between the high-pressure pipe and the second pressure chamber. It is particularly advantageous if this takes place via a dedicated filling valve. In this case, the supply line for filling the second pressure chamber on the injection valve side may be formed as a bypass line. Forming the supply line as a bypass line in this way has the advantage that the converter can be easily manufactured, since the stepped piston can be formed from two parts. Such a bypass line, which preferably runs parallel to the stepped piston, has no problem in terms of function and can be manufactured without strict tight tolerances. Another possibility of the supply line is to provide the supply line directly as a through hole in the stepped piston. This has the advantage that the hydraulic converter has a very small structure. This makes it possible to retrofit hydraulic converters to existing injection lines in known injection systems, for example dispensing pumps, pump-line-nozzle systems or common-rail systems. . In this case, the filling valve inserted in the supply line is formed as a pressure valve, preferably a check valve,
The opening pressure of this check valve is adjustable via a valve spring.
The stepped piston of the hydraulic converter is arranged in the guide hole with as long a sliding surface as possible, so that a very small amount of fuel is released from both pressure chambers via the play between the stepped piston and the guide hole. This is advantageous because only spills can occur. As a result, hydraulic converters have very little leakage loss. The hydraulic conversion ratio in the stepped piston is advantageously between 1 and 3 as the ratio of the larger first end face to the smaller second end face. In this case, a conversion ratio of 1.5 to 2.2 is particularly suitable. This is because at a conversion ratio of 1.5 to 2.2, the hydraulic efficiency is significantly improved without a significant increase in the required displacement of the fuel high-pressure pump.

[0009] Such an improvement in efficiency is more important than a pure pressure increase in the fuel injection valve in terms of energetics. This is because, together with the reduced drive energy required, the heat load of the pump and, consequently, the tendency of the pump to "sease" is reduced. As a result, a smaller play between the piston or distributor shaft and the bush of the distributor shaft can be realized, so that the efficiency can be further improved based on a smaller leakage.

Another advantage is obtained by incorporating a dust filter as a fuel filter in the supply passage leading to the pressure chamber on the injection valve side. This is because the dead volume in the high-pressure range on the injection valve side, that is, the dead volume can be further reduced.

The volume displaced by the stepped piston at the piston annular end face of the spring chamber is advantageous because it is released to the low-pressure circuit with as little back pressure as possible. Thereby, the hydraulic loss or hydraulic pressure loss in the hydraulic converter can be kept as small as possible. Further, in order to obtain a reliable function, a throttle portion is provided inside the supply pipe leading to the second pressure chamber on the side of the injection valve. This throttle portion is formed large enough to guarantee refilling during the return stroke of the stepped piston, and at the same time, rapidly operates the check valve during the pressure conversion stroke of the stepped piston, that is, during the pressure increase stroke. It is designed to be small enough to create a closing pressure differential. If a dust filter having a gap formed so as to perform the required restriction is inserted in front of the check valve, such a separate restriction part can be eliminated.

The return of the stepped piston of the hydraulic converter is advantageously effected by a return spring.
This eliminates the need for additional hydraulic or hydraulic return forces. Therefore, additional control lines and control valves can be dispensed with, which further simplifies the construction of the hydraulic converter.

In a further advantageous embodiment of the fuel injection device according to the invention, a stepped piston is provided in a guide bush, which itself is inserted into a tube piece. In this case, the guide bush has a longitudinal slit through which the connecting element, preferably a clamp, passes, which acts radially on the reduced diameter part of the stepped piston. doing. On the radial outside of the guide bush, a return spring of the stepped piston acts, which is guided into the annular chamber between the guide bush and the inner wall of the tube piece. Such a spring device,
It allows a large winding diameter of the return spring and thus a large spring stroke. Furthermore, each component of the hydraulic converter can be easily manufactured as a rotationally symmetric component. This considerably reduces the production effort and the required construction space. In this case, it is advantageous if the bypass passage is integrated in the guide bush. In this case, the throttle portion is arranged in front of the pressure valve that opens in the direction of the second pressure chamber on the side of the injection valve. The bypass passage is formed as a simple longitudinal hole provided in the guide bush, and opens to each pressure chamber through an enlarged portion of the guide hole provided in the guide bush for accommodating the stepped piston. . The stepped piston may be formed in one piece, as in the embodiment shown, but it is more advantageous to form the stepped piston in two parts because of its simpler manufacture. This is possible without changing the structure shown.

A further advantage of the fuel injection device according to the invention is obtained by arranging the hydraulic conversion device as close as possible to the fuel injection valve. This makes it possible to limit the range with very high fuel pressure to the very small range of pipes where such high pressures are actually required. This makes it possible to reduce the undesired volume in the high-pressure injection range and thus to reduce hydraulic losses or hydraulic losses.
In the other pump-side fuel line areas, the pressure remains reduced, so that in this area the load on each component is reduced, so that these components can be further maintained while maintaining the same length of life. Small dimensions can be set.

The hydraulic converters of the individual fuel injectors can be connected to one another, and the connection to the high-pressure fuel pump can be made via one common line.

Further advantages and further advantageous configurations of the present invention are described in detail in the embodiments of the invention.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

The fuel injection device used for the internal combustion engine shown in FIG. The fuel high-pressure pump 1 pumps fuel from a low-pressure chamber 5, preferably a fuel tank, to a fuel injection valve 7 via a high-pressure line 3. In order to control the high-pressure supply of fuel to the fuel injection valve 7, in the exemplary embodiment shown, a control valve 9, preferably a solenoid valve, is connected to a bypass line 11 that branches off from the high-pressure line 3. This bypass pipe 11 opens to the low-pressure chamber 5 as a return pipe. In this case, a check valve 12 that opens in the direction of the low-pressure chamber 5 is downstream of the control valve 9. Through this check valve 12, the reference pressure (Standruck) remaining in the bypass line 11 and the high-pressure line 3 can be adjusted. In this case, the control valve 9 is switched so that the fuel pumped by the high-pressure fuel pump 1 flows into the fuel injection valve 7 when the control valve 9 is closed, or is pumped by the high-pressure fuel pump 1. Is switched back to the low pressure chamber 5 via the bypass line 11 by the open control valve 9 (short circuit). In this case, the check valve 12 arranged in the bypass line 11 maintains a specified reference pressure in the system.

In order to increase the injection pressure at the fuel injection valve 7, a hydraulic converter 13, particularly a pressure booster, is inserted between the fuel high-pressure pump 1 and the fuel injection valve 7 in the high-pressure line 3. I have. The hydraulic conversion device 13 includes a guide hole 15 provided in a housing 17.
It has a stepped piston 19 guided axially therein. Both axial end faces of the stepped piston 19 partition one pressure chamber in a guide hole 15 provided in the housing 17 of the conversion device 13. In this case, the larger first end face 21 of the stepped piston 19 partitions a first pressure chamber 23, which in turn communicates with the high-pressure fuel pump 1 in the high-pressure line 3. Connected to the part. The smaller second end face 25 of the stepped piston 19 partitions a second pressure chamber 27 in the housing 17 of the converter 13, which is separate from the first pressure chamber 23. High pressure line 3 located on the opposite side
, Is connected to a second portion connected to the fuel injection valve 7. The integral stepped piston 19 illustrated in the first embodiment has an annular collar 29 at the cross section transition from the large diameter D1 to the small diameter D2. This annular collar 29
Project beyond the large diameter D1. The annular end face 31 of the annular collar 29 opposite the large diameter range of the stepped piston 19 delimits a spring chamber 33 in the direction of the second pressure chamber 27. On the other hand, the spring chamber 33 is separated from the second pressure chamber 27 by a sleeve 35 pressed into the guide hole 15 of the housing 17. In this case, the small diameter D of the stepped piston 19 of the sleeve 35
An inner wall surface which guides the portion having 2 in the axial direction partitions a second pressure chamber 27 on the injection valve side. Further, the annular end face of the sleeve 35 that partitions the spring chamber 33 is provided with the spring chamber 3.
Acts as a spring receiving surface for a return spring 37 clamped in 3. The return spring 37 acts on the annular end face 31 of the annular collar 29 of the stepped piston 19, and the stepped piston 19 is applied to the housing fixed hole step 39 provided in the guide hole 15 by the annular collar 29. I have. Spring chamber 3
From 3, preferably two pressure relief lines 41 are led out. These pressure relief conduits 41 are open to the low pressure chamber 5.
In order to fill the second pressure chamber 27 on the injection valve side with fuel, the stepped piston 19 is provided with an axial through hole 43. This through-hole 43 opens from the first pressure chamber 23 to the second pressure chamber 27. In this case, a check valve 45 serving as a filling control valve is inserted into the through hole 43. The valve member 49 of the check valve 45 is a valve spring 4
7 in the direction of the second pressure chamber 27 against the closing force of the valve seat 5.
Can be lifted from 1. Further, a fuel filter 57 formed as a dust filter is inserted into a region of the through hole 43 of the stepped piston 19 adjacent to the first pressure chamber 23. The filter gap of the fuel filter 57 is set so that the filtering necessary for the function of the converter 13 is performed together with the filtering of the fuel, that is, the filtering.

The conversion ratio of the stepped piston 19, which is determined based on the ratio of the diameter D1 set on the first end face 21 to the diameter D2 set on the second end face 25, is in a value range of 1 to 3. Yes, advantageously a value between 1.5 and 2.2.

The fuel injection device according to the present invention operates as follows.

Prior to the start of the high-pressure injection in the fuel injection valve 7, the second pressure chamber 27 is filled with fuel via a supply line formed by a through hole 43 provided in the stepped piston 19. In this case, the filling of the second pressure chamber 27 takes place until a pressure compensation takes place between the two connected pressure chambers 23, 27 and the check valve 45 closes the supply line. In order to start the injection in the fuel injection valve 7, the control valve 9 closes the bypass line 11, and the high-pressure fuel pump 1 pumps the fuel to the high-pressure line 3 toward the fuel injection valve 7. As a result, the high fuel pressure first flows into the first pressure chamber 23 provided in the stepped piston 19 of the hydraulic conversion device 13 and moves the stepped piston 19 in the direction of the small second pressure chamber 27. Move. At this time, the two annular end faces 2 of the stepped piston 19 having different sizes from each other.
Based on 1 and 25, the pressure in the second pressure chamber 27 is increased compared to the fuel pressure generated by the high-pressure fuel pump 1. This increased fuel pressure flows into the fuel injection valve 7 via the second part of the high-pressure line 3, and at an injection opening provided in the fuel injection valve 7, the combustion chamber of the internal combustion engine to be supplied with fuel. Injected to. At this time, the fuel present in the spring chamber 33 is displaced without significant back pressure through the pressure relief conduit 41, and hardly reduces the efficiency of the converter 13.
At this time, the check valve 45 has a combined force formed by the pressing force applied from the second pressure chamber 27 and the spring force of the valve spring 47 greater than the pressing force applied from the first pressure chamber 21. Due to its formation, it is kept closed by this combined force. As a result, the check valve 45 remains closed during the working process of the stepped piston 19.

In order to terminate the high-pressure fuel injection in the fuel injection valve 7, the control valve 9 opens the bypass line 11 again, so that the high-pressure line 3 is connected to the low-pressure chamber 5 via the bypass line 11. And the fuel pressure existing in the high pressure line 3
As a result, the high fuel pressure present in the converter 13 is released toward the low-pressure chamber 5 to a predetermined adjustable reference pressure.
At this time, the residual reference pressure remaining in the high-pressure fuel line 3 that can be adjusted through the check valve 12 provided in the bypass line 11 is set higher than the opening pressure of the check valve 45, During the return movement of the stepped piston 19, the second pressure chamber 27 is again filled with fuel from the first pressure chamber 23 via the through hole 43. In this case, the return movement of the stepped piston 19 is mainly performed by the spring force of the return spring 37. The return spring 37 pushes the annular collar 29 of the stepped piston 19 back until it comes into contact with the hole fixed portion 39 fixed to the housing, that is, pushes the stepped piston 19 back to the starting position or the initial position. At this time, when the fuel flows from the first pressure chamber 23 to the second pressure chamber 27, the fuel is filtered by the fuel filter 57 formed as a dust filter.

The second embodiment of the fuel injection device according to the present invention used in an internal combustion engine shown in FIGS. 2 and 3 is different from the first embodiment in the structure of a hydraulic converter 13 provided in the high-pressure line 3. Only the third embodiment differs from the first embodiment. Therefore, FIGS. 2 and 3 show the converter 13 according to the second embodiment.
Only that is shown. FIG. 2 is a cross-sectional view of the conversion device 13 according to the second embodiment, and FIG. 3 is a view of the conversion device 13 shown in FIG. 2 when rotated by 90 °. .

The converter 13 according to the second embodiment includes a first pressure chamber 23 on the pump side and a second pressure chamber 27 on the injection valve side.
Supply line to the stepped piston 19 consisting of two parts
Is different from the conversion device 13 according to the first embodiment shown in FIG. In the second embodiment, the second
The supply or filling passage for the pressure chamber 27 is formed as a bypass line. This bypass line is arranged in the housing 17 of the hydraulic converter 13 parallel to the stepped piston 19. This bypass line is formed by a first lateral hole 59 derived from the first pressure chamber 23 and a second lateral hole 61 derived from the second pressure chamber 27. Both lateral holes 59,
61 are connected to each other by longitudinal holes 63,
Advantageously, this longitudinal bore 63 extends axially parallel to the stepped piston 19. In this longitudinal hole 63,
As in the case of the through hole 43 provided in the stepped piston 19 in the first embodiment, the check valve 45 and the fuel filter 57 are provided.
And have been inserted.

The hydraulic converter 13 shown in FIGS. 2 and 3 operates similarly to the converter 13 shown in FIG. 1 of the fuel injection device according to the present invention. The conversion ratio in the conversion device 13 is also determined by the area ratio of both end faces 21 and 25 provided on the stepped piston 19, and
3, preferably in the range from 1.5 to 2.2.

In the third embodiment shown in FIGS. 4 and 5,
The stepped piston 19 is slidably guided in a guide hole 65 provided in the guide bush 67. The guide bush 67 itself is inserted into the pipe piece 69. The larger first end face 21 of the stepped piston 19 is
, And the smaller second end face 25 of the stepped piston 19 partitions the second pressure chamber 27 on the injection valve side. The first pressure chamber 23 is in this case arranged, in part, in a correspondingly enlarged section of the guide bore 65, that is to say in an enlarged section, and partially in the adjacent tube piece 6.
The second pressure chamber 27 is provided in a through hole provided in the connection pipe piece 73. The connecting pipe piece 73 is screwed into the pipe piece 69 on the injection valve side, and tightens the guide bush 67 in the axial direction toward the step portion 75 of the pipe piece 69. In the third embodiment, the connection pipe piece 73
The valve holder 77 of the fuel injection valve 7 is screwed into the end opposite to the pipe piece 69, in which case a tight fit is ensured via the conical filler 79. I have. The filler 79 is tightened in the axial direction between the valve holder 77 and the connecting pipe 73 and has an axial through-opening.

An annular chamber 71 is provided between the outer peripheral wall of the guide bush 67 and the inner peripheral wall of the pipe piece 69. In the third embodiment, the annular chamber 71 houses the return spring 37 of the stepped piston 19. In this case, the return spring 37 is fixedly supported on the end face of the connecting pipe piece 73, and on the other hand, the stepped piston 1
9 is loaded in the direction of the first pressure chamber 23. This clamp 81 is formed in a U-shape as shown in detail in FIG. This slit 8
The dimension 3 corresponds to the smaller diameter of the stepped piston 19 or to a receiving groove provided at the cross section transition of the stepped piston 19. Clamp 81
The guide bush 67 extends radially through a longitudinal slit (not shown) provided in the guide bush 67.
And is in contact with the reduced diameter portion of the stepped piston 19.

The stroke movement of the stepped piston 19 in the direction of the first pressure chamber 23 on the pump side is limited by an annular step 85 provided on the peripheral surface of the guide bush 67. In this case, the return spring 37 moves the stepped piston 19 to this starting position. The working stroke of the stepped piston 19 in the direction of the second pressure chamber 27 on the side of the injection valve is equal to the guide hole 6.
5 is limited by the stepped portion 91 provided in the step 5. This step 9
1 is in contact with a clamp 81 fixed to the stepped piston 19 (FIG. 4).

The filling of the second pressure chamber 27 is performed via a bypass pipe or a supply pipe derived from the first pressure chamber 23. This bypass line or supply line
An axial longitudinal hole 87 provided in the guide bush 67
Is formed by Depending on the position of the stepped piston 19, the passage of fuel is carried out directly to the two pressure chambers 23, 27 separated by both end faces of the guide bush 67, or the stepped piston 19 and the pipe piece 69 or This is performed through play remaining between the connecting pipe 73 and the wall of the through hole provided in the connecting pipe piece 73. A check valve 45, which opens in the direction of the second pressure chamber 27 on the injection valve side, is inserted into the longitudinal direction hole 87. Further, in front of the check valve 45 when viewed in the flow direction, a throttle portion is provided. 89 are arranged.

The mode of operation of the third embodiment is the same as the mode of operation of the first and second embodiments. FIG. 4 shows the position that the stepped piston 19 assumes when reaching the end position during the working stroke. FIG. 5 shows a position immediately before the stepped piston 19 reaches the starting position. In this case, before the stepped piston 19 reaches the starting position,
The supply passage formed along the play of the stepped piston 19 in the pipe piece 69, the longitudinal passage 87 and the check valve 4
5, a new fuel filling of the second pressure chamber 27 can be started.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention of a fuel injection device.

FIG. 2 is a sectional view of a conversion device according to a second embodiment.

FIG. 3 is a view of the conversion device shown in FIG. 2 in a state rotated by 90 °.

FIG. 4 is a sectional view showing a fuel injection device according to a third embodiment in a state where a stepped piston has reached a terminal position.

5 is a sectional view showing the fuel injection device shown in FIG. 4 in a state immediately before the stepped piston reaches a start position.

FIG. 6 is a schematic view of a clamp used in the third embodiment.

[Explanation of symbols]

1 high-pressure fuel pump, 3 high-pressure line, 5 low-pressure chamber,
7 fuel injection valve, 9 control valve, 11 bypass line, 12 check valve, 13 conversion device, 15 guide hole, 17 housing, 19 stepped piston,
21 first end face, 23 first pressure chamber, 25 second end face, 27 second pressure chamber, 29 annular collar,
31 annular end face, 33 spring chamber, 35 sleeve, 37 return spring, 39 hole step, 41 relief line, 43 through hole, 45 check valve, 47 valve spring, 49 valve member, 51 valve seat, 57 fuel filter, 59 first transverse direction, 61 second transverse hole, 63 longitudinal hole, 65 guide hole, 67
Guide bush, 69 Pipe piece, 71 Annular chamber, 73
Connection pipe piece, 75 steps, 77 Valve holder, 79
Filling material, 81 clamp, 83 slit, 85
Annular step, 87 longitudinal hole, 89 throttle,
91 steps, D1, D2 diameter

 ──────────────────────────────────────────────────の Continued on the front page (72) Walter Eigler Inventor Gerlingen ai Henweg 8 (72) Inventor Jörg Schmidt Germany Stuttgart Farionstrasse 29

Claims (23)

[Claims] 1. A fuel injection device for use in an internal combustion engine, comprising: a high-pressure fuel pump (1) for pumping fuel from a low-pressure chamber (5) to a fuel injection valve (7) via a high-pressure pipe (3). A hydraulic converter (13) is provided between the high-pressure fuel pump (1) and the fuel injection valve (7), and the converter (13) is provided with a hole (15). A stepped piston (19) slidable therein, with both end faces of the stepped piston (19) each separating one pressure chamber and having a larger first end face (21). Partition a first pressure chamber (23) connected to the pump-side portion of the high-pressure line (3) and are located on the side opposite to the first end face (21), the smaller first pressure chamber (23). 2 end face (25)
A second pressure chamber (27) connected to the injection valve side portion of the high-pressure pipe (3) is partitioned, and a pressure valve for filling the second pressure chamber (27) with fuel is provided. An internal combustion engine, characterized in that the supply passage opening to the second pressure chamber (27) is led out of the first pressure chamber (23). A fuel injection device used for. 2. A stepped piston (1) of a hydraulic conversion device (13), wherein a pressure valve provided in the supply passage is provided.
2. The fuel injection device according to claim 1, wherein the fuel injection device is connected in parallel to (9). 3. The stepped piston according to claim 1, wherein the supply passage is a stepped piston.
The fuel injection device according to claim 1, wherein the fuel injection device is formed as a bypass passage that bypasses the fuel injection valve. 4. A stepped piston (19), wherein the supply passage is provided with a stepped piston (19).
The fuel injection device according to claim 3, wherein the fuel injection device is disposed in parallel with the fuel injection device. 5. The supply passage has lateral holes (59, 61) derived from a first pressure chamber (23) and a second pressure chamber (27), respectively, and both lateral holes (59, 61). 61) are formed by a longitudinal hole (63) connecting them to each other, said longitudinal hole (63) being a stepped piston (19).
5. The fuel injection device according to claim 4, wherein the fuel injection device is arranged axially parallel to the hole (15) for accommodating the fuel. 6. The stepped piston (19), wherein the supply passage is a stepped piston (19).
Formed by the through hole (43) provided in the
A pressure valve closing the supply passage is provided with a stepped piston (1).
The fuel injection device according to claim 1, wherein the fuel injection device is disposed inside of (9). 7. The pressure valve is formed as a check valve (45) that opens in the direction of the second pressure chamber (27), and the opening pressure of the check valve (45) is high. 2. The fuel injection device according to claim 1, wherein the fuel pressure is set to be lower than the reference pressure. 8. The stepped piston (19) is slidably guided in a bore (15) in a housing (17) of the hydraulic converter (13). 2. The fuel injection device according to claim 1. 9. The larger first stepped piston (19).
2. The fuel injection device according to claim 1, wherein the conversion ratio between the end face (21) and the smaller second end face (25) is a value between 1 and 3. 10. A fuel filter (57) in the supply passage.
The fuel injection device according to claim 1, wherein the fuel injection device is inserted. 11. An annular collar (29) is provided at the transition of the cross section of the stepped piston (19), said annular collar (2).
9) the annular end face of the stepped piston (19) facing the larger diameter portion (D1) of the stepped piston (19) forms a stop surface which cooperates with a hole step (39) provided in said hole (15). An annular end face (31) of said annular collar (29) facing the smaller diameter portion (D2) of the stepped piston (19).
2. The fuel injection device according to claim 1, wherein the partition partitions a spring chamber (33) provided in the hole (15). 12. A return spring (37), which coaxially surrounds the stepped piston (19), is tightened in the spring chamber (33), and the return spring (37) is attached to a fixed position support. The stepped piston (19) is loaded in the direction of the hole step (39) at the annular end face (31) of the annular collar (29) on the spring chamber side, and the return spring (37) is further supported. ) Are related to the reference pressure in the high-pressure pipe (3), the both end faces (21, 25) of the stepped piston (19), and the opening pressure of the pressure valve provided in the supply passage. The piston with pressure (19) is pressed against a step (39) serving as a stopper on the pump side when each injection stage is interrupted.
The fuel injection device according to claim 11. 13. A spring supporting surface having a fixed position is provided with said hole (1).
12. The fuel injection device according to claim 11, wherein the fuel injection device is provided on a sleeve (35) inserted therein. 14. The fuel injection device according to claim 11, wherein at least one pressure relief line (41) leads from the spring chamber (33) to a low-pressure chamber (5). 15. The stepped piston (19) is provided with a pipe piece (6).
The fuel injection device according to claim 1, wherein the fuel injection device is slidably guided in a guide hole (65) provided in a guide bush (67) inserted therein. 16. An annular chamber (71) is formed between said guide bush (67) and the inner wall of said tube piece (69), said annular chamber (71) being a stepped piston (19). 16. The fuel injection device according to claim 15, wherein the return spring (37) is accommodated. 17. An axial end face of said return spring (37), which is oriented in the direction of the smaller second end face (25) of the stepped piston (19), comes into contact with a position-fixed stopper. And the stepped piston (1) of the return spring (37).
9) the end face facing the larger first end face (21)
The connecting member is loaded, and the connecting member is provided on the stepped piston (19) through the guide bush (67) in a radial direction through a longitudinal slit provided in the guide bush (67). 2. The reduced diameter portion is in contact with the reduced diameter portion.
7. The fuel injection device according to 6. 18. The clamp according to claim 18, wherein the coupling member is a U-shaped clamp.
18. The fuel injection device according to claim 17, formed as 1). The supply passage for filling the second pressure chamber (27) on the injection valve side is provided with the guide bush (6).
7) is formed radially outside the guide hole (65) as a longitudinal hole (87) provided in the guide bush (67). The fuel injection device according to claim 15, wherein the fuel injection device opens to both the pressure chambers via a diameter expansion portion or a diameter expansion portion of the guide hole. 20. The guide bush (67) is axially attached to a step (75) provided on the pipe piece (69) by a connection pipe piece (73) screwable into the pipe piece (69). The fuel injection device according to claim 15, wherein the fuel injection device is tightened. 21. A first pressure chamber (23) on the pump side,
The pipe piece (69) is provided at a portion adjacent to the guide bush (67), and a second pressure chamber (27) on the injection valve side is provided inside the connection pipe piece (73). 21. The fuel injection device according to claim 20, wherein 22. A check valve (45) which opens in the direction of the second pressure chamber (27) on the side of the injection valve is inserted into the longitudinal hole (87), and the check valve is viewed in the flow direction. 20. The fuel injection device according to claim 19, wherein a throttle (89) is arranged before the valve (45). 23. Hydraulic converter (13)
2. The fuel injection device according to claim 1, wherein the fuel injection valve is spatially arranged near the fuel injection valve.