JP2003184696A - High pressure fuel supply system for internal combustion engine - Google Patents

Abstract

(57) [Problem] To provide a high-pressure fuel supply device for an internal combustion engine that can shorten the engine start time as compared with the related art. SOLUTION: A delivery pipe 2 communicating with each fuel injection valve.
And a discharge passage 22 connected to the delivery pipe, and an opening / closing valve 23 disposed in the discharge passage. When the engine is started, the pumping of fuel into the delivery pipe is started, and when a set time has elapsed or when the delivery pipe When the internal fuel pressure rises to the set pressure, the on-off valve is opened to discharge gas from inside the delivery pipe, and then the on-off valve is closed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a high pressure fuel supply system for an internal combustion engine.

[0002]

2. Description of the Related Art In order to directly inject fuel into a cylinder of an internal combustion engine, it is necessary to supply high-pressure fuel to each fuel injection valve, and a high-pressure fuel supply device therefor is known.

A general high-pressure fuel supply system includes a delivery pipe leading to each fuel injection valve, a high-pressure pump for pumping high-pressure fuel to the delivery pipe, and a high-pressure pump for ensuring fuel suction into the high-pressure pump. And a low-pressure pump connected to the suction side of the. Generally, the high pressure pump is engine driven and the low pressure pump is electrically driven. During the engine operation, the inside of the delivery pipe is maintained near the target high fuel pressure by the fuel supplied by the high pressure pump, and the high pressure fuel can be injected through each fuel injection valve.

When the engine is stopped, the fuel injection through the fuel injection valve is stopped, and the high pressure pump and the low pressure pump are also stopped so that the fuel is not supplied. Therefore, a predetermined pressure is applied in the delivery pipe. The fuel of will be sealed. The fuel temperature in the delivery pipe is lower than the engine temperature when the engine is stopped, but rises to the engine temperature after the engine is stopped, and then gradually decreases with the engine temperature.

As the temperature decreases, the fuel contracts by heat, so that the fuel pressure in the delivery pipe decreases. At this time, since the coefficient of thermal expansion of the fuel is not so small, the decrease in the fuel pressure with the decrease in temperature becomes relatively rapid. As a result, when the fuel temperature drops to a certain temperature, the fuel pressure in the delivery pipe becomes lower than the saturated vapor pressure at this temperature, and fuel vapor is generated in the delivery pipe. When a space is formed in the delivery pipe by the fuel vapor, the pressure in the delivery pipe then shifts near the saturated vapor pressure at each temperature as the temperature decreases, and the fuel vapor in the delivery pipe gradually increases. The space becomes larger.

When a space is formed by the fuel vapor in the delivery pipe in this way, the air dissolved in the fuel gradually precipitates in this space, so that the engine is stopped when the engine is stopped as in a normal start. If the time is relatively long, a relatively large amount of air is contained in the space of the delivery pipe.

When the engine is started, the fuel pressure in the delivery pipe, which is almost atmospheric pressure, is increased to the desired fuel pressure to start fuel injection. However, a space due to fuel vapor and deposition air is formed in the delivery pipe. Once formed,
Unless a large amount of fuel is pumped into the delivery pipe, the inside of the delivery pipe cannot be boosted to the desired fuel pressure, and a long time is required before starting the engine.

In Japanese Unexamined Patent Publication (Kokai) No. 7-77119, a delivery pipe and a fuel tank are communicated with each other through a discharge passage in which an on-off valve is arranged. First, the concept of discharging the gas in the space inside the delivery pipe through the discharge passage is disclosed.

[0009]

According to the above-mentioned prior art, it is possible to raise the pressure in the delivery pipe to the desired fuel pressure at the time of engine start, faster than the space in the delivery pipe is compressed. However, a relatively long engine start-up time is still required to expel all the gas in the delivery pipe before raising the pressure in the delivery pipe to the desired fuel pressure.

Therefore, an object of the present invention is to provide a high-pressure fuel supply system for an internal combustion engine which can shorten the engine starting time as compared with the prior art.

[0011]

According to a first aspect of the present invention, there is provided a high pressure fuel supply system for an internal combustion engine, a delivery pipe communicating with each fuel injection valve, a discharge passage connected to the delivery pipe, and the discharge. An on-off valve disposed in the passage, and starts the pressure feeding of fuel into the delivery pipe at the time of engine startup, and opens and closes when a set time has elapsed or when the fuel pressure in the delivery pipe has risen to a set pressure. It is characterized in that the valve is opened to discharge the gas from the delivery pipe, and then the on-off valve is closed.

A high pressure fuel supply system for an internal combustion engine according to a second aspect of the present invention is the high pressure fuel supply system for an internal combustion engine according to the first aspect, wherein the on-off valve is intentionally opened at the time of engine startup. Valve and can be closed,
It is characterized in that it also functions as a safety valve that automatically opens when the fuel pressure in the delivery pipe reaches a set high fuel pressure.

According to a third aspect of the present invention, there is provided the high pressure fuel supply system for an internal combustion engine according to the first aspect, wherein the fuel pressure in the delivery pipe is during operation of the engine. In the above, the high pressure pump raises the fuel pressure to a desired high fuel pressure, and when the fuel pressure in the delivery pipe is intentionally reduced, the on-off valve is opened in synchronization with the discharge stroke of the high pressure pump. To do.

[0014]

1 is a schematic view showing an embodiment of a high-pressure fuel supply device according to the present invention. In the figure, 1
Is a fuel injection valve, for example, for directly injecting fuel into each cylinder of the internal combustion engine. Reference numeral 2 is 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 arranged in the fuel tank 3. The low-pressure pump 4 is an electric pump driven by a battery, for example, 0.3M
It has a rated discharge pressure of Pa. The low-pressure pump 4 is operated at the same time as the starter switch ON signal. A filter 6 is provided on the suction side of the low-pressure pump 4 to remove foreign matter when sucking fuel from the fuel tank 3.

Reference numeral 7 is a high-pressure pump for maintaining the fuel pressure in the delivery pipe 2 near the target high fuel pressure. This high-pressure pump 7 includes a cam 7 that works with a crankshaft.
It is an engine drive type driven by e. 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 7b is connected to the discharge side of the low pressure pump 4 via a low pressure pipe 8, and the discharge port 7c is connected to the delivery pipe 2 via a high pressure pipe 11. A filter 10 for removing foreign matter in the fuel is also arranged in the low-pressure pipe 8.

The plunger 7a has a spring 7 as an intake stroke.
It is moved by f so as to enlarge the space inside the cylinder 7d, and is moved so as to reduce the space inside the cylinder 7d by the cam 7e as the discharge stroke. 16 is a suction port 7b
Is a valve element for opening and closing, and is always biased in the valve opening direction by a spring 16b. 16a is a valve body 16 spring 1
6b is a solenoid for urging in the valve closing direction against 6b. 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. Therefore, the low-pressure pipe 8 is opened via the suction port 7b.
Fuel is sucked into the cylinder 7d from. Since this fuel has been boosted to 0.3 MPa by the low-pressure pump 4 as described above, fuel vapor due to negative pressure is not generated in the low-pressure pipe 8 during the intake stroke.

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 1
6 is closed. The fuel in the cylinder 7d is returned to the low pressure pump 4 via the low pressure pipe 8 without being pumped 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 the two cylinders, and the valve closing timing of the valve element 16 is controlled,
By adjusting the amount of fuel used for fuel injection into these two cylinders and pumping the fuel into the delivery pipe 2, the inside of the delivery pipe 2 can be maintained near the target high fuel pressure.

A check valve 12 that opens at a set pressure is arranged in the high-pressure pipe 11 in order to prevent the fuel from flowing backward due to the pressure pulsation generated by the high-pressure pump 7. Reference numeral 21 is a pressure sensor for monitoring the fuel pressure in the delivery pipe 2. Further, the delivery pipe 2 is communicated with the fuel tank 3 by a discharge pipe 22, and an opening / closing valve 23 is arranged in the discharge pipe 22. The on-off valve 23 is
The valve element 2 biased in the valve closing direction by the spring 23a
3b, the discharge pipe 22 is normally closed. However, a solenoid 23c for attracting and opening the valve body 23b against the spring 23a is provided,
If necessary, the opening / closing valve 23 can be opened to open the discharge pipe 22.

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, so that the high-pressure fuel flows back through the low-pressure pump 4 at this time. Becomes In order to prevent this backflow, the low-pressure pipe 8 is connected to the fuel tank 3 via a safety valve that opens at a pressure slightly exceeding the rated discharge pressure of the low-pressure pump 4.
You may make it communicate with.

Since the high-pressure pump 7 operates well during engine operation, the intended fuel discharge is possible and the inside of the delivery pipe 2 can be maintained near the target high fuel pressure.
Good fuel injection is possible via the fuel injection valve 1. The target high fuel pressure is, for example, 1 regardless of the fuel injection amount.
It may be fixed to the first target high fuel pressure such as 2 MPa, but when the fuel injection amount is small such as when the engine load is low,
Since the valve opening time of the fuel injection valve becomes very short and it becomes difficult to control the accurate fuel injection amount, even if the second target high fuel pressure such as 8 MPa is provided for this time, for example. good. Of course, the target high fuel pressure may be set in multiple stages depending on the engine load or the engine operating state.

By the way, when the engine is stopped, the fuel injection valve 1
The fuel injection via the
Since the low-pressure pump 4 is also stopped and the fuel is not supplied, the fuel having the target high fuel pressure is sealed in the delivery pipe 2. The fuel temperature in the delivery pipe when the engine is stopped is lower than the engine temperature because the fuel having a relatively low temperature is continuously supplied from the fuel tank 3 during engine operation. Is increased to the engine temperature because the fuel supply at a relatively low temperature is lost, and then gradually decreases with the engine temperature.

Although the delivery pipe 2 and the fuel are thermally contracted as the temperature decreases, the thermal expansion coefficient of the fuel is larger than that of the metal delivery pipe 2, and as a result, the fuel in the delivery pipe 2 is reduced. The pressure drops. Since the fuel pressure drop relative to the fuel temperature drop is relatively rapid, in many cases, the fuel pressure becomes saturated vapor pressure before the fuel temperature drops to the outside air temperature, and the fuel in the delivery pipe is vaporized. Begins to turn.

After the space formed by the fuel vapor is formed in the delivery pipe 2 in this manner, the fuel pressure in the delivery pipe 2 thereafter changes in the vicinity of the saturated vapor pressure at each temperature as the temperature decreases, and the delivery pipe 2 Inside, the space for fuel vapor gradually increases. Thus, a large space is often formed in the delivery pipe 2 when the engine is started.

Since the internal combustion engine to which the present high-pressure fuel supply device is attached is of the cylinder injection type, the homogeneous combustion that forms a homogeneous mixture in the cylinder by the fuel injection in the intake stroke and the fuel injection in the compression stroke are performed. It is possible to carry out stratified combustion in which a combustible mixture is formed only in the vicinity of the spark plug. Generally, homogeneous combustion is performed on the high load side, and stratified combustion is performed on the low load side. Since it is difficult to make the fuel pressure in the delivery pipe 2 that has decreased to near atmospheric pressure to the target high fuel pressure at the time of engine start, homogeneous combustion that enables fuel injection in the intake stroke with low in-cylinder pressure is performed. Be implemented.

However, even 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 at the highest possible pressure. Thereby, in general, in addition to the pressurization by the low pressure pump 4, the high pressure pump 7 also pressurizes the inside of the delivery pipe 2 to a predetermined pressure higher than the rated discharge pressure of the low pressure pump 4 for fuel injection. It is supposed to start.

In the present embodiment, when the engine is started, the low pressure pump 4 is operated at the same time as or before or after the start of cranking. Thereby, the discharge pressure of the low-pressure pump 4 acts on the delivery pipe 2. At this time, preferably, the solenoid 16a of the high-pressure pump 7 continues to be in a non-excited state, whereby the valve body 16 remains open regardless of the discharge stroke and the suction stroke of the high-pressure pump 7, and the low-pressure pump 4 Thus, the fuel is continuously pumped into the delivery pipe 2 via the high pressure pump 7.

When the fuel pressure in the delivery pipe 2 reaches the set pressure in this way, the fuel vapor in the space of the delivery pipe 2 is sufficiently liquefied and the space in the delivery pipe is almost filled with air. Since the fuel vapor is easily liquefied by a slight pressure increase, it is not necessary to pump so much fuel into the delivery pipe 2 by the low-pressure pump 4 to raise the pressure to the set pressure. However, in order to further increase the pressure in the delivery pipe 2 to a predetermined pressure at which fuel can be injected, the air in the space does not dissolve in the fuel at this predetermined pressure, so a large amount of fuel is delivered in order to compress the air. It must be pumped into the pipe 2, which requires a long time.

In the present embodiment, when the pressure inside the delivery pipe 2 is raised to the set pressure by fuel pressure feeding by the low pressure pump 4, the opening / closing valve 23 of the discharge pipe 22 is opened by using the solenoid 23c. As a result, the air in the space of the delivery pipe 2 is discharged to the fuel tank 3 via the discharge pipe 22. After that, the open / close valve 23 is closed. On-off valve 2
The fuel pressure feeding of the low-pressure pump 4 is continued even during the opening / closing of the valve 3, and the fuel pressure in the delivery pipe 2 drops once below the set pressure due to the opening of the opening / closing valve 23. Since there is no space in the delivery pipe 2, the opening / closing valve 23 is closed to immediately increase the pressure to the rated discharge pressure higher than the set pressure.

At this point in time, the current crank angle is known, so that the valve body 16 is closed only during the discharge stroke of the high pressure pump 7 to enable the high pressure pump 7 to pump the maximum amount of fuel. . By this maximum fuel pressure feeding, the inside of the delivery pipe 2 is boosted to a predetermined pressure and fuel injection is started. In this way, the engine start time can be shortened sufficiently.

In this embodiment, the high pressure pipe 11 is connected to one end of the delivery pipe 2, and the discharge pipe 22 is connected to the other end of the delivery pipe 2. When the fuel discharged from the low-pressure pump 4 is supplied to one end of the delivery pipe 2 via the high-pressure pipe 11 at the time of starting the engine, the flow moves the space in the delivery pipe 2 to the other end of the delivery pipe 2. The fuel vapor is liquefied. As a result, when the on-off valve 23 is opened when the set pressure is reached, the air forming the space of the delivery pipe 2 is reliably discharged from the discharge pipe 22 connected to the other end of the delivery pipe 2 in a short time. . When a pipe having a check valve that allows only the fuel flow to the delivery pipe is arranged so as to connect the delivery pipe and the low-pressure pipe 8 to each other, the low-pressure pump 4 discharges the low-pressure pump 4 through the pipe when the engine is started. Fuel is delivery pipe 2
In order to be supplied to the delivery pipe 2, this pipe is preferably connected to one end side of the delivery pipe 2 instead of the high pressure pipe 11.

Since the gas space is formed above the delivery pipe 2, in order to further ensure the discharge of the gas, the discharge pipe 22 has the other end of the delivery pipe 2 as shown in FIG. It is preferably connected to the top on the side. Further, in order to surely move the space above the other end side of the delivery pipe 2, it is preferable that the pressure-fed fuel of the low-pressure pump 4 is supplied to the upper part of the delivery pipe 2 on one end side. Further, in order to make this movement more reliable, it is preferable that the upper portion of the inner wall of the delivery pipe 2 is not provided with irregularities, and further, the upper portion of the inner wall of the delivery pipe 2 is tilted so that the other end side faces upward. It is also preferable to

In the present embodiment, when the gas is discharged from the delivery pipe 2, the fuel pressure in the delivery pipe 2 is raised to the set pressure, so that the pressure difference between the delivery pipe 2 and the fuel tank 3 is increased. Is relatively large, and it is possible to reliably discharge air from the delivery pipe 2 in a short time not only at the connecting position of the discharge pipe 22 described above, but also by that.

In this embodiment, the opening / closing valve 2 is activated when the pressure inside the delivery pipe 2 is raised to the set pressure when the engine is started.
3 is opened to open the discharge pipe 22, but of course, the fuel pressure in the delivery pipe 2 at the time of starting the operation of the low pressure pump 4, the volume of the delivery pipe 2, and the unit time of the low pressure pump 4 Set the time until the inside of the delivery pipe 2 reaches the set pressure based on the discharge amount of
The discharge pipe 22 may be opened after the set time has elapsed.

The set pressure is preferably set to a pressure at which the amount of fuel vapor in the space of the delivery pipe 2 is completely vaporized when the engine is started, but the fuel pressure and the fuel injection in the delivery pipe 2 when the engine is started. May be set to an arbitrary pressure between the fuel pressure at which the fuel injection is started. As a result, at least a part of the fuel vapor in the space of the delivery pipe 2 can be liquefied by the time the opening / closing valve 23 is opened, and the gas in the delivery pipe 2 has a pressure difference when the opening / closing valve 23 is opened. Since the fuel can be discharged in a short time, the engine start time until the pressure inside the delivery pipe 2 is increased to the predetermined pressure for starting the fuel injection can be shortened. Similarly, when the on-off valve is opened after the set time elapses, from the start of pressure feeding of the low-pressure pump 4 to the time required to pressurize the inside of the delivery pipe 2 without opening the on-off valve 23. The open / close valve may be opened after an arbitrary time period.

In this embodiment, the fuel discharged from the low-pressure pump 4 is initially used to raise the pressure in the delivery pipe 2 to a predetermined pressure when the engine is started. However, the high-pressure pump 7 does not meter and pump the fuel as in the present embodiment. For example, the valve body 16 is a check valve without such a spill mechanism, and the high-pressure pump is always operated. When the fuel is pumped at the maximum discharge amount, the fuel is pumped into the delivery pipe 2 from the beginning by the high pressure pump. Of course, in this case as well, by opening the on-off valve as described above, it is possible to shorten the engine start time for raising the pressure in the delivery pipe 2 to the predetermined pressure.

As described above, the opening / closing valve 23 is normally closed by the spring 23a. By appropriately setting the biasing force of the spring 23a, the valve body 23b can be opened when the fuel pressure in the delivery pipe 2 becomes an abnormally high fuel pressure higher than the target high fuel pressure. In this way, the opening / closing valve 23 can function as a safety valve and the discharge pipe 22 can function as a relief passage.
Further, if the on-off valve 23 is opened at a pressure slightly higher than the target high fuel pressure, even if the fuel is constantly pumped at the maximum discharge amount without metering the fuel by the high pressure pump, that is, the spill mechanism is provided. Even if a high-pressure pump that does not operate is used, the inside of the delivery pipe 2 can be maintained at the target high fuel pressure.

By the way, when the fuel pressure in the delivery pipe during normal operation is changed in multiple stages,
When boosting is required, the fuel discharge amount of the high-pressure pump is adjusted to the increasing side. On the other hand, when the pressure reduction is required, it takes a long time to wait for the fuel pressure in the delivery pipe 2 to be consumed by the fuel injection by setting the fuel discharge amount of the high pressure pump to zero. Further, it is necessary to suppress the target fuel pressure in the delivery pipe 2 to a low level when the fuel cut is restored, but in this case, fuel consumption due to fuel injection cannot be expected.

In particular, when the engine is decelerated for a long period of time, it is difficult to restart the operation because the engine speed falls below the predetermined speed due to the fuel cut. Therefore, even when the engine speed reaches the predetermined speed even during the engine deceleration. The fuel injection is restarted to recover from the fuel cut. Since this is performed regardless of the driver's intention, when a large engine output is generated, the driver feels a torque shock. In order to prevent this, it is desirable to inject a smaller amount of fuel than during idling, for example, so as not to generate a large engine output when the fuel cut is restored during engine deceleration. Even if the opening time of the fuel injection valve is minimized, in order to realize this, the fuel pressure in the delivery pipe 2 must be sufficiently lower than the target fuel pressure during normal operation.

In this embodiment, when the fuel pressure in the delivery pipe 2 is lowered for the purpose of changing the target high fuel pressure to the depressurizing side or returning to the fuel cut, the open / close valve 23 is opened and the discharge pipe 22 is used in this embodiment. Then, the fuel in the delivery pipe 2 is discharged. The opening area of the valve portion 23a of the on-off valve 23 and the cross-sectional area of the discharge pipe 22 are made relatively large in order to discharge the gas in the delivery pipe 2 in a short time when the engine is started. As a result, if the on-off valve 23 is simply opened, the fuel pressure in the delivery pipe 2 will suddenly drop, exceed the target value, and be excessively reduced.

In this embodiment, in order to prevent this,
When the fuel pressure in the delivery pipe 2 is reduced in order to change the target high fuel pressure on the pressure reducing side or to restore the fuel cut, the fuel discharge by the high pressure pump 7 is not stopped, that is, the valve body 16 of the high pressure pump 7 is In the discharge stroke, the valve is not continuously opened but closed, and the open / close valve 23 is opened only when the fuel is being discharged.

In this way, the inside of the delivery pipe 2 is depressurized to a target value by the difference between the fuel discharge amount per unit time by opening the open / close valve 23 and the fuel discharge amount per unit time by the high pressure pump. This difference is not so large that the fuel pressure in the delivery pipe 2 does not suddenly drop. The fuel discharge amount per unit time in the discharge stroke of the high-pressure pump 7 changes depending on the engine speed,
Further, the on-off valve 2 is controlled by the fuel pressure in the delivery pipe 2.
Since the fuel discharge amount per unit time when the valve 3 is opened changes, the timing for stopping the opening of the open / close valve 23 may be determined in consideration of these. Of course, if the time required for a single discharge stroke of the high-pressure pump is insufficient for the required decompression in the delivery pipe 2, the opening / closing valve 23 is closed at the same time as the end of this discharge stroke, and only the time required for the next discharge stroke is required. The valve body 16 of the high-pressure pump 7 is closed and the discharge pipe 22
The open / close valve 23 may be opened.

[0042]

According to the high-pressure fuel supply system for an internal combustion engine of the present invention, when the engine is started, the fuel is pumped into the delivery pipe, and when the set time elapses or the fuel pressure in the delivery pipe reaches the set pressure. When the pressure is increased, the opening / closing valve of the discharge passage connected to the delivery pipe is opened to discharge gas from the delivery pipe, and then the opening / closing valve is closed. As a result, the fuel pressure in the delivery pipe is raised or set to the set pressure as the set time elapses, and at least a part of the fuel vapor in the space of the delivery pipe is liquefied. Since fuel vapor easily liquefies even at low pressure, for this liquefaction,
It is not necessary to pump so much fuel into the delivery pipe, for this it is sufficient to pump the fuel for a short time. Then, the on-off valve is opened so that the remaining gas in the delivery pipe, mainly air, is discharged from the delivery pipe. The time required for this discharge is short because the pressure inside the delivery pipe is increased. When the on-off valve is closed after that, there is no space in the delivery pipe, and the pressure in the delivery pipe is immediately increased to the fuel injection pressure at the time of engine startup by the fuel pressure feeding. The time required so far is short, and thus engine start-up time can be shortened.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a high-pressure fuel supply device according to the present invention.

[Explanation of symbols]

1 ... Fuel injection valve 2… Delivery pipe 4 ... Low pressure pump 7 ... High-pressure pump 22 ... Discharge pipe 23 ... Open / close valve

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 37/20 F02M 37/20 Q 63/00 63/00 C 63/02 63/02 A F term (reference) ) 3G066 AA02 AB02 BA30 BA37 CB07U CB16 CE22 DA06 DB01 DC09 DC18

Claims (3)

[Claims] 1. A delivery pipe communicating with each fuel injection valve, a discharge passage connected to the delivery pipe, and an opening / closing valve arranged in the discharge passage, wherein fuel is introduced into the delivery pipe when the engine is started. When the set time has elapsed or the fuel pressure in the delivery pipe has risen to the set pressure, the on-off valve is opened to discharge gas from the delivery pipe, and then the on-off valve is opened. A high-pressure fuel supply device for an internal combustion engine, which is closed. 2. The safety valve, which can be opened and closed intentionally when the engine is started, and which is automatically opened when the fuel pressure in the delivery pipe reaches a set high fuel pressure. The high-pressure fuel supply system for an internal combustion engine according to claim 1, wherein the high-pressure fuel supply system also functions as: 3. The fuel pressure in the delivery pipe is increased to a desired high fuel pressure by a high pressure pump during engine operation, and when the fuel pressure in the delivery pipe is intentionally reduced, The opening / closing valve is opened in synchronization with a discharge stroke.
A high-pressure fuel supply system for an internal combustion engine as set forth in.