JP3786002B2 - High pressure fuel supply device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-pressure fuel supply device for an internal combustion engine.
[0002]
[Prior art]
Injecting fuel directly into a cylinder of an internal combustion engine requires supplying high-pressure fuel to each fuel injection valve, and a high-pressure fuel supply device for this purpose is known.
[0003]
A typical high-pressure fuel supply apparatus includes a delivery pipe that communicates with each fuel injection valve. The delivery pipe is provided with a relief valve to prevent the fuel pressure in the delivery pipe from rising abnormally higher than the desired high fuel pressure, which is the fuel injection pressure during engine operation. In JP-A-11-351088, the valve opening pressure of the relief valve is set not lower than the abnormal high fuel pressure but lower than the desired high fuel pressure, and when the engine is operating, more than flowing out from the delivery pipe via the relief valve. It has been proposed to maintain a desired high fuel pressure in the delivery pipe by pumping an amount of fuel into the delivery pipe with a high pressure pump.
[0004]
In this prior art, when the fuel pressure feeding into the delivery pipe by the high-pressure pump is stopped when the engine is stopped, the fuel pressure in the delivery pipe immediately becomes the opening pressure of the relief valve lower than the desired high fuel pressure. As a result, even when the engine is restarted immediately after the engine is stopped, the fuel pressure in the delivery pipe is not high, and it is not necessary to open the fuel injection valve against this high pressure. Although the driving force at the time of opening the fuel injection valve is reduced, the fuel injection valve can be sufficiently opened by this reduced driving force.
[0005]
[Problems to be solved by the invention]
By the way, it is common to perform fuel cut during engine deceleration. Fuel cut is intended to reduce the engine speed at an early stage. However, if the engine speed is reduced too much, it becomes difficult to resume operation. Even if it continues further, the fuel injection is resumed and the fuel cut is resumed. In the high-pressure fuel supply device in general and the above-described prior art, the fuel pressure in the delivery pipe is maintained at the desired high fuel injection even during fuel cut. As a result, a relatively large amount of fuel is injected even when the opening time of the fuel injection valve is minimized when the fuel cut is restored, and a relatively large engine output is suddenly generated when the fuel cut is restored, resulting in a large torque shock.
[0006]
Accordingly, an object of the present invention is to provide a high-pressure fuel supply device for an internal combustion engine that can prevent occurrence of a large torque shock at the time of fuel cut recovery during engine deceleration.
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a high-pressure fuel supply device for an internal combustion engine comprising: a delivery pipe communicating with each fuel injection valve; a high-pressure pump connected to the delivery pipe; and a leak passage connected to the delivery pipe. The leak passage is configured so that the fuel pressure in the delivery pipe does not cause a large torque shock when the fuel injection amount during the minimum valve opening time of the fuel injection valve is restored at the time of fuel cut recovery during engine deceleration. The high-pressure pump pumps more fuel into the delivery pipe than the leak pipe through the leak passage during engine operation. it can, stops fuel pumping into the delivery pipe during the fuel cut, the leak passage, the A high-pressure passage communicating with the pressure pump and the delivery pipe is shared, and fuel is leaked from the delivery pipe through the high-pressure pump, and only the fuel flow from the high-pressure pump to the delivery pipe is allowed in the high-pressure passage. A check valve is disposed, and a communication passage that always communicates the upstream side and the downstream side of the check valve is formed in the valve body itself of the check valve or the seat part of the valve body, thereby the high pressure The passage is also made to function as the leak passage .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic view showing an embodiment of a high-pressure fuel supply apparatus according to the present invention. In the figure, reference numeral 1 denotes a fuel injection valve, for example, for injecting fuel directly into each cylinder of an internal combustion engine. Reference numeral 2 denotes a delivery pipe for supplying high-pressure fuel to each fuel injection valve 1. Reference numeral 3 denotes a fuel tank, and a low pressure pump 4 is disposed in the fuel tank 3. The low pressure pump 4 is an electric pump driven by a battery, and has a rated discharge pressure of 0.3 MPa, for example. The low pressure pump 4 is operated simultaneously with the start signal of the starter switch. On the suction side of the low-pressure pump 4, a filter 6 is provided for removing foreign matters when fuel is sucked from the fuel tank 3.
[0014]
7 is a high pressure pump for maintaining the fuel pressure in the delivery pipe 2 in the vicinity of the target high fuel pressure. The high-pressure pump 7 is of an engine drive type that is driven by a cam 7e interlocked with a crankshaft. The high-pressure pump 7 discharges the fuel sucked into the cylinder 7d through the suction port 7b from the discharge port 7c, and has a plunger 7a that slides in the cylinder 7d for this purpose. The suction port 7 b is connected to the discharge side of the low-pressure pump 4 via the low-pressure pipe 8, and the discharge port 7 c is connected to the delivery pipe 2 via the high-pressure pipe 11. The low-pressure pipe 8 is also provided with a filter 10 for removing foreign matters in the fuel.
[0015]
The plunger 7a is moved to expand the space in the cylinder 7d by a spring 7f as a suction stroke, and is moved to reduce the space in the cylinder 7d by a cam 7e as a discharge stroke. Reference numeral 16 denotes a valve body for opening and closing the suction port 7b, and is always urged in the valve opening direction by a spring 16b. 16a is a solenoid for biasing the valve body 16 in the valve closing direction against the spring 16b. The solenoid 16a is de-energized in the suction stroke of the high-pressure pump 7, and the valve body 16 is opened by the spring 16b, so that fuel is sucked into the cylinder 7d from the low-pressure pipe 8 through the suction port 7b. Since this fuel has been pressurized to 0.3 MPa by the low pressure pump 4 as described above, fuel vapor accompanying negative pressure is not generated in the low pressure pipe 8 during the intake stroke.
[0016]
On the other hand, in the discharge stroke of the high-pressure pump 7, the solenoid 16a is energized at a desired time, and the valve body 16 is closed. The fuel in the cylinder 7d is returned to the low-pressure pump 4 through the low-pressure pipe 8 without being fed into the high-pressure delivery pipe 2 before the valve body 16 is closed, but after the valve body 16 is closed. It is pumped into the delivery pipe 2. In this high-pressure fuel supply device, the discharge stroke of the high-pressure pump 7 is provided for each fuel injection of two cylinders, and the valve closing timing of the valve body 16 is controlled to inject fuel into these two cylinders. It is possible to maintain the inside of the delivery pipe 2 in the vicinity of the target high fuel pressure by metering the amount of fuel used in this step and pumping the fuel into the delivery pipe 2.
[0017]
The high-pressure pipe 11 is provided with a check valve 12 that opens with a slight pressure difference in order to prevent fuel from flowing backward due to pressure pulsation generated by the high-pressure pump 7. Reference numeral 21 denotes a pressure sensor for monitoring the fuel pressure in the delivery pipe 2.
[0018]
Thus, unnecessary fuel out of all the fuel discharged by the plunger 7a is returned to the fuel tank 3 through the low-pressure pipe 8, and at this time, the high-pressure fuel flows back through the low-pressure pump 4. It will be. In order to prevent this reverse flow, the low pressure pipe 8 may be communicated with the fuel tank 3 through a safety valve that opens at a pressure slightly exceeding the rated discharge pressure of the low pressure pump 4.
[0019]
Since the high-pressure pump 7 operates satisfactorily during engine operation, the intended fuel discharge can be performed and the inside of the delivery pipe 2 can be maintained near the target high fuel pressure. Fuel injection becomes possible. The target high fuel pressure may be fixed to the first target high fuel pressure, such as 12 MPa, regardless of the fuel injection amount. However, when the fuel injection amount is small, such as at low engine load, the fuel injection amount Since the valve opening time becomes very short and it becomes difficult to accurately control the fuel injection amount, a second target high fuel pressure such as 8 MPa may be provided for this time. Of course, three or more target high fuel pressures may be set according to the engine load or the engine operating state.
[0020]
22 is a relief pipe that communicates between the delivery pipe 2 and the fuel tank 3, and a relief valve 23 that is opened at a pressure slightly higher than the first target high fuel pressure is disposed, and the fuel pressure in the delivery pipe 2 is caused by some factor. This prevents the first target high fuel pressure from being increased abnormally.
[0021]
By the way, at the time of engine deceleration, for the purpose of reducing fuel consumption and early deceleration, fuel injection from each fuel injection valve 1 is stopped, that is, fuel cut is performed. As a result, the engine speed decreases relatively rapidly. If the engine deceleration time is relatively long and the engine speed is still reduced even if the engine speed is reduced to a predetermined engine speed, for example, the idling engine speed, fuel injection is performed to ensure reliable restart of operation. Is resumed and the fuel cut is resumed.
[0022]
In a general high-pressure fuel supply system, even if the fuel pressure feed to the delivery pipe by the high-pressure pump is stopped simultaneously with the fuel cut, the fuel pressure in the delivery pipe when the fuel cut is restored will be delivered by the fuel cut. Since there is no fuel consumption in the pipe, this is the value immediately before engine deceleration, that is, the fuel pressure during normal operation. Immediately before engine deceleration, high-load operation is often performed, and as described above, this fuel pressure is in the vicinity of the first target high fuel pressure on the high side even when there are two target high fuel pressures. In many cases.
[0023]
When returning to the fuel cut, if the delivery pipe is at such a high fuel pressure, a relatively large amount of fuel will be supplied into the cylinder even if the fuel injection valve is opened with the minimum valve opening time. Output is generated. As a result, a large torque shock is caused at the time of fuel cut recovery during engine deceleration, and the driver feels uncomfortable.
[0024]
Of course, instead of returning from fuel cut while the engine is decelerating, the driver suddenly compares the case when the engine decelerates and the accelerator pedal is depressed to return from the fuel cut to accelerate the engine. Although a large engine output is generated and a similar torque shock is caused, this is the intention of the driver, and the driver does not feel uncomfortable.
[0025]
An object of the present embodiment is to prevent occurrence of torque shock at the time of fuel cut recovery during engine deceleration. For this purpose, the check valve 12 arranged in the high-pressure pipe 11 has a structure as shown in FIG. A general check valve has a spherical valve body and a spring that biases the valve body against a seat portion. The check valve 12 arranged in the high-pressure pipe 11 of the present embodiment is provided with a notch A in a part of an annular seat portion 12b with which the valve body 12 abuts. Thereby, even if the valve body 12a is urged | biased with respect to the sheet | seat part 12b by the spring 12c, the upstream and downstream of the non-return valve 12 are always connected by the notch A. That is, the notch A constitutes a communication path that always communicates the upstream side and the downstream side of the check valve 12.
[0026]
In the present embodiment, the fuel pumping of the high pressure pump 7 is stopped during the fuel cut, that is, the solenoid 16a is not energized in the discharge stroke of the high pressure pump 7, and the valve body 16 is kept open. As a result, the fuel in the delivery pipe 2 leaks through the notch A in the seat portion 12 b of the check valve 12 during the fuel cut, and is returned to the fuel tank 3 through the high-pressure pump 7.
[0027]
Thus, when the engine speed is reduced to the predetermined speed during the engine deceleration and returned from the fuel cut, the fuel pressure in the delivery pipe 2 is such that the fuel pressure at the start of the fuel cut is close to the first target high fuel pressure. Even if it exists, it is lower than the second target high fuel pressure due to fuel leakage during fuel cut. Thereby, the fuel injection amount at the minimum valve opening time of the fuel injection valve at the time of fuel cut return can be made smaller than the fuel injection amount at the time of idling, for example, and the generated engine output is very small, resulting in a large torque shock. Will not bring.
[0028]
In the present embodiment, the size of the notch in the seal portion 12b of the check valve 12 is selected so that, for example, a fuel leak that reduces the fuel pressure in the delivery pipe by about 1 MPa per second occurs. This fuel leak amount is 1/10 or less of the fuel pumping amount in the cranking of a normal high pressure pump. As a result, this fuel leak occurs even during normal operation. However, the fuel leak is offset by slightly increasing the amount of fuel pumped by the high-pressure pump, and the first target high fuel pressure in the delivery pipe 2 is offset. Alternatively, the second target high fuel pressure can be sufficiently maintained.
[0029]
In the present embodiment, the leak passage is made common to the high pressure passage communicating the high pressure pump 7 and the delivery pipe 2 by the above-described check valve structure, and the fuel leaks from the delivery pipe through the high pressure pump. . Thereby, in the discharge stroke of the high-pressure pump 7 during normal operation, the fuel pressure in the cylinder 7d of the high-pressure pump 7 is higher than the fuel pressure in the delivery pipe 2, so that fuel leakage from the delivery pipe 2 does not occur. Of course, the leak passage may directly connect the delivery pipe 2 and the fuel tank, but according to the leak passage of the present embodiment, the amount of fuel leak during engine operation can be reduced as described above. Therefore, it is possible to reduce the load of the high-pressure pump 7 by reducing the amount of fuel fed by the high-pressure pump 7 accordingly.
[0030]
Further, the check valve 12 is provided with a communication passage so that the high-pressure passage and the leak passage are common, so that the communication passage of the check valve 12 has a reverse direction when fuel is fed by the high-pressure pump 7 and when fuel leaks. Therefore, the fuel does not flow, and the foreign matter is not stuck in the notch A constituting the communication path.
[0031]
FIG. 3 shows another structure of the check valve for sharing the leak passage with the high-pressure passage 11 communicating with the high-pressure pump 7 and the delivery pipe 2. In this check valve 12 ′, A groove B serving as a communication path that connects the upstream side and the downstream side of the valve 12 ′ is formed in the valve body 12a ′. Of course, even with such a configuration, the same effect as described above can be obtained.
[0032]
In the present embodiment, a communication passage is formed in the check valve 12 disposed in the high pressure passage 11 and the leak passage is shared with the high pressure passage 11. However, the same communication is provided not in the check valve 12 but in the relief valve 23. If a passage is formed, the leak passage can be shared with the relief passage 22.
[0033]
FIG. 4 is a schematic view showing another embodiment of the high-pressure fuel supply apparatus according to the present invention. Only differences from the above-described embodiment will be described below. In the present embodiment, the check valve 12 disposed in the high-pressure pipe 11 is a general one in which no communication passage is formed in the valve body and the seat portion. The fuel leak passage 24 is formed so as to communicate the high-pressure pipe 11 and the low-pressure pipe 8. Of course, the delivery pipe 2 and the low-pressure pipe 8 may be communicated with each other. In the leak passage 24, a narrowed portion 25 having a narrow passage section is formed, and if the fuel pumping by the high-pressure pump is stopped during the fuel cut, the leak passage 24 is formed in the same manner as the leak passage in the embodiment of FIG. The fuel pressure in the delivery pipe 2 is reduced by, for example, 1 MPa per second due to the fuel leak.
[0034]
With such a configuration, in the high-pressure fuel supply device of this embodiment as well, in the delivery pipe 2 due to fuel leak through the leak passage 24 at the time of fuel cut recovery during engine deceleration, as in the embodiment of FIG. The fuel pressure can be made sufficiently low, and a small amount of fuel can be injected by the fuel injection valve, so that a large torque shock does not occur.
[0035]
By the way, when the engine is started, the fuel pressure in the delivery pipe 2 that has dropped to almost atmospheric pressure must be increased immediately. Since the low pressure pump 4 is electrically driven, a relatively large amount of fuel can be pumped from the beginning of cranking. However, since the high pressure pump 7 is engine driven, the discharge stroke can be maximized. Only a small amount of fuel can be pumped at the cranking engine speed. In the present embodiment, since the low pressure pipe and the high pressure pipe are communicated by the leak passage 24, the fuel is pumped into the delivery pipe 2 by the high pressure pump during the discharge stroke of the high pressure pump 7 at the time of engine start. During the intake stroke of the high-pressure pump 7, the fuel is pumped into the delivery pipe 2 by the low-pressure pump 4 through the leak passage 24. Thereby, when fuel injection is started with the fuel pressure in the delivery pipe 2 set to the rated discharge pressure of the low-pressure pump 4 or a desired pressure higher than that, the time until the start of fuel injection can be shortened.
[0036]
In the present embodiment, the check valve of FIG. 2 or 3 may be arranged in the leak passage 24 instead of the throttle portion 25. As a result, the fuel discharged from the low-pressure pump 4 is easily pumped into the delivery pipe 2 by opening the check valve during the intake stroke of the high-pressure pump 7 when the engine is started. Time can be shortened. Further, in this way, the fuel flows in the reverse direction at the time of engine start and at the time of fuel leak in the communication path of the check valve 12 arranged in the leak path 24, and the notch constituting the communication path is clogged with foreign matter. There is no such thing as to remain.
[0037]
FIG. 5 is a cross-sectional view of a leak passage showing a modification of the embodiment of FIG. The leak passage 24 ′ of the present modification is provided with a throttle portion 25 similar to that of the embodiment of FIG. 4, and a pressure regulating valve 26 is disposed on the low pressure pipe side from the throttle portion 25 ′. The pressure regulating valve 26 includes a valve body 26a and a spring 26c that biases the valve body 26a toward the seat portion 26b. If the pressure difference between the high-pressure pipe and the low-pressure pipe is larger than the biasing force of the spring 26c, the valve body 26a. Is opened to allow fuel flow from the high pressure line to the low pressure line.
[0038]
The spring 26c changes the urging force acting on the valve body 26a depending on the temperature of the bimetal or shape memory alloy, and the urging force becomes smaller as the temperature is lower. Even with such a configuration, when returning from the fuel cut during engine deceleration, the pressure regulating valve 26 is opened by a relatively large differential pressure between the high-pressure pipe and the low-pressure pipe, and is the same as in the embodiment of FIG. In addition, the fuel pressure in the delivery pipe 2 can be made sufficiently low due to the fuel leak through the leak passage 24 ', and a small amount of fuel can be injected by the fuel injection valve. Absent.
[0039]
By the way, since the fuel pressure feeding into the delivery pipe 2 by the high-pressure pump 7 is stopped even when the engine is stopped, the fuel pressure in the delivery pipe 2 gradually decreases due to the fuel leak through the leak passage 24 '. . The fuel temperature in the delivery pipe 2 is lower than the temperature of the delivery pipe 2 due to the relatively low temperature fuel supplied from the fuel tank during engine operation. Since such fuel supply is lost, it becomes equal to the temperature of the delivery pipe 2 and then gradually decreases with the temperature of the delivery pipe 2.
[0040]
When the fuel temperature rises immediately after the engine stops, the urging force of the spring 26c becomes stronger, and when the fuel pressure in the delivery pipe 2 drops to a certain pressure, the pressure regulating valve 26 is closed and is connected via the leak passage 24 '. The fuel leak will not occur. Thereafter, as the fuel temperature decreases with the temperature of the delivery pipe 2, the urging force of the spring 26 c gradually decreases. Therefore, generation and stop of the fuel leak through the leak passage 24 ′ are repeated, and the delivery pipe is repeated. The higher the fuel temperature in 2, the higher the fuel pressure in the delivery pipe 2 can be maintained.
[0041]
The fuel has a saturated vapor pressure that increases as the temperature increases. In the pressure regulating valve 26 of this embodiment, the valve opening pressure with respect to the fuel temperature is set higher than the saturated vapor pressure with respect to the fuel temperature. Thus, after the engine is stopped, the fuel pressure in the delivery pipe 2 is prevented from becoming saturated vapor pressure at each fuel temperature, and fuel vapor is not generated in the delivery pipe 2.
[0042]
Since the internal combustion engine to which this high-pressure fuel supply device is attached is an in-cylinder injection type, in the vicinity of the spark plug by homogeneous combustion that forms a homogeneous mixture in the cylinder by fuel injection in the intake stroke and fuel injection in the compression stroke Only stratified combustion that forms a combustible mixture can be performed. In general, homogeneous combustion is performed on the high load side, and stratified combustion is performed on the low load side. When starting the engine, it is difficult to set the fuel pressure in the delivery pipe 2 that has dropped to the vicinity of the atmospheric pressure to the target high fuel pressure. Therefore, homogeneous combustion that allows fuel injection in the intake stroke with low in-cylinder pressure is performed. To be implemented.
[0043]
However, also in the intake stroke injection, the higher the injection pressure, the greater the frictional force with the intake air, and the vaporization of the injected fuel is promoted. Therefore, it is preferable to inject the fuel as high pressure as possible. At the time of starting the engine, only the low-pressure pump 4 or the low-pressure pump 4 and the high-pressure pump 7 pressurizes the inside of the delivery pipe 2 to a desired pressure and starts fuel injection. If it is formed, this space must first be compressed, and a long time is required until the pressure is increased to the desired pressure, so that the engine startability deteriorates. According to the present embodiment, since fuel vapor is not generated in the delivery pipe 2 while the engine is stopped, such deterioration of engine startability can be prevented.
[0044]
In the case where the leak passage is shared with the relief passage 22 as described above, the pressure regulating valve 26 according to the present embodiment may be arranged in the relief passage 22 on the downstream side of the relief valve 23. Generation of fuel vapor in the pipe 2 can be prevented.
[0045]
The high-pressure pump 7 in the high-pressure fuel supply apparatus described so far is configured to meter and feed the necessary amount of fuel so as to maintain the inside of the delivery pipe 2 at a desired high fuel pressure during normal operation. It is not intended to limit the invention. For example, if the relief passage 22 is connected to the delivery pipe 2 and the relief pressure of the relief passage 22 is set to a desired high fuel pressure in the delivery pipe 2, the entire amount is always pumped without having a spill mechanism as a high-pressure pump. Things can also be used. In this case, the operation of the high-pressure pump may be stopped using a clutch or the like in order to stop the fuel pumping to the delivery pipe by the high-pressure pump during the fuel cut. Of course, if the engine driving force is transmitted through the clutch even in a metering type high-pressure pump, the clutch may be disconnected during fuel cut to stop the fuel pumping. Further, if the high-pressure pump is electrically driven, the power supply may be stopped to stop the fuel pumping.
[0046]
【The invention's effect】
According to the high pressure fuel supply apparatus for an internal combustion engine according to the present invention, the leak passage is connected to the delivery pipe, and the leak passage is configured to change the fuel pressure in the delivery pipe to a predetermined fuel pressure at the time of fuel cut recovery during engine deceleration. Can be reduced to During engine operation, the high-pressure pump can maintain the inside of the delivery pipe at a desired high fuel pressure in order to pump more fuel that leaks from inside the delivery pipe through the leak passage into the delivery pipe. . In addition, since the high-pressure pump stops the fuel pumping to the delivery pipe during the fuel cut, the fuel pressure in the delivery pipe is reduced to a predetermined pressure by the leak passage when the fuel cut is restored during engine deceleration. The fuel injection amount at the minimum valve opening time is a fuel injection amount that does not generate a large torque shock. Thereby, it is possible to prevent the occurrence of a large torque shock at the time of fuel cut return during engine deceleration. The leak passage is common to the high-pressure passage that connects the high-pressure pump and the delivery pipe, leaks fuel from the delivery pipe through the high-pressure pump, and allows only the fuel flow from the high-pressure pump to the delivery pipe through the high-pressure passage. A check valve is arranged, and a communication passage that always communicates the upstream side and the downstream side of the check valve is formed in the valve body of the check valve itself or in the seat portion of the check valve, thereby making the high-pressure passage a leak passage It is supposed to function as well.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a high-pressure fuel supply apparatus according to the present invention.
2 is a cross-sectional view showing the structure of a check valve of a high-pressure pipe in the high-pressure fuel supply apparatus of FIG.
3 is a cross-sectional view showing another structure of a check valve of a high-pressure pipe in the high-pressure fuel supply apparatus of FIG.
FIG. 4 is a schematic view showing another embodiment of the high-pressure fuel supply apparatus according to the present invention.
FIG. 5 is a cross-sectional view of a leak passage showing a modification of the embodiment of FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Fuel injection valve 2 ... Delivery pipe 4 ... Low pressure pump 7 ... High pressure pump 8 ... Low pressure piping 11 ... High pressure piping 12 ... Check valve 22 ... Relief passage 23 ... Relief valve 24, 24 '... Leak passage 25 ... Restriction part 26 ... Pressure adjustment valve

Claims (1)

A delivery pipe that communicates with each fuel injection valve; a high-pressure pump that is connected to the delivery pipe; and a leak passage that is connected to the delivery pipe. The high-pressure pump can reduce the fuel injection amount at the minimum valve opening time of the fuel injection valve to a predetermined fuel pressure such that the fuel injection amount does not generate a large torque shock when returning to the fuel cut during deceleration. may pumping fuel in the amount of more than leaks from within the delivery pipe via the leak passage during engine operation into the delivery pipe, stops fuel pumping into the delivery pipe during the fuel cut The leak passage is common with the high pressure passage communicating the high pressure pump and the delivery pipe. A check valve that leaks fuel from the delivery pipe through the high-pressure pump and allows only a fuel flow from the high-pressure pump to the delivery pipe is disposed in the high-pressure passage; An internal combustion mechanism characterized in that a communication passage that always communicates the upstream side and the downstream side of the check valve is formed in the body itself or the seat portion of the valve body, thereby causing the high-pressure passage to function as the leak passage. High pressure fuel supply system for engines.

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