JP2002213326A - Fuel supply device for internal combustion engine - Google Patents

Abstract

(57) Abstract: An internal combustion engine capable of reducing the operating noise of a high-pressure fuel pump associated with the opening and closing operation of an electromagnetic valve in a configuration including a plurality of high-pressure fuel pumps associated with the opening and closing operation of an electromagnetic valve. An engine fuel supply device is provided. Two high-pressure fuel pumps are respectively operated by opening / closing control of an electromagnetic spill valve, and the amount of fuel discharged to a high-pressure fuel pipe is adjusted through the opening / closing control. When the required fuel amount of the internal combustion engine is small, the ECU 40
The opening and closing of the electromagnetic spill valve 35 of each pump 30 is controlled so as to stop the operation of one of the pumps, the number of operations of the entire high-pressure fuel pump in a predetermined period is reduced, and the operating frequency of the electromagnetic spill valve 35 is reduced. The operation noise of the high-pressure fuel pump 30 accompanying the opening / closing operation is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system for an internal combustion engine, and more particularly to a system having a plurality of high-pressure fuel pumps.

[0002]

2. Description of the Related Art In a fuel supply system for an internal combustion engine, such as a direct injection type internal combustion engine, which requires a high fuel pressure for a fuel supplied to an injector, as disclosed in Japanese Patent Application Laid-Open No. 10-252593, A high-pressure fuel pump for pressurizing the fuel supplied from the tank and discharging the fuel to a high-pressure fuel pipe (delivery pipe) is provided. As the high-pressure fuel pump, a pump that is operated by opening and closing control of an electromagnetic valve and that adjusts a discharge amount of fuel to a high-pressure fuel pipe through the opening and closing control is adopted.

[0003] For example, a high pressure fuel pump of the spill valve type has an electromagnetic spill valve as the electromagnetic valve. The electromagnetic spill valve is configured to overflow fuel without discharging it to the high-pressure fuel pipe in accordance with the opening and closing operation of the high-pressure fuel pump during the pressurization process. The discharge amount of fuel to the high-pressure fuel pipe is adjusted by controlling the opening and closing timing of the electromagnetic spill valve in the pressurizing process.

In the high-pressure fuel pump of the suction metering valve type, a suction metering valve for permitting / prohibiting the intake of fuel in accordance with the opening / closing operation in the suction stroke of the pump is provided as the electromagnetic valve. By controlling the opening / closing timing of the suction metering valve during the suction stroke, the amount of fuel discharged to the high-pressure fuel pipe is adjusted.

In any case, the operation of such a high-pressure fuel pump involves an opening and closing operation of an electromagnetic valve.

[0006]

In a fuel supply device having such a high-pressure fuel pump, the high-pressure fuel pump generates an operating sound in accordance with the opening / closing operation of the solenoid valve, and is applied to a vehicle-mounted internal combustion engine. In some cases, the operation sound may give a feeling of strangeness to the occupant of the vehicle. When such a fuel supply device is applied to an internal combustion engine having a large required fuel amount, such as an eight-cylinder direct injection internal combustion engine,
As disclosed in Japanese Patent Application Laid-Open No. 11-44276, there is a case where a plurality of such high-pressure fuel pumps are provided. In this case, as the number of pumps increases, the operation frequency of the high-pressure fuel pump in the entire fuel supply device increases, and the operation noise of the high-pressure fuel pump accompanying the opening / closing operation of the solenoid valve increases.

In the high-pressure fuel pump of the type in which the discharge amount is adjusted by controlling the opening and closing of the solenoid valve as described above, the discharge amount is increased or decreased, and the solenoid valve is opened and closed each time the pump is operated. For this reason, even when the discharge amount is small, even when the discharge amount is large, the magnitude of the operation sound does not change so much. Therefore, the operating sound of the high-pressure fuel pump becomes particularly prominent in a low-load low-rotation region such as during idling when the sound generated by the entire internal combustion engine is low.

The present invention has been made in view of the above circumstances, and has as its object to provide a configuration including a plurality of high-pressure fuel pumps whose operation involves opening and closing an electromagnetic valve. An object of the present invention is to provide a fuel supply device for an internal combustion engine that can reduce the operating noise of the high-pressure fuel pump.

[0009]

The means for achieving the above object and the operation and effect thereof will be described below. According to the first aspect of the present invention, a fuel supply system for an internal combustion engine includes a plurality of high-pressure fuel pumps that are operated by opening / closing control of a solenoid valve and that adjust a discharge amount of fuel to a high-pressure fuel pipe through opening / closing control of the solenoid valve. A control means for controlling the solenoid valve so as to reduce the number of operations of the plurality of high-pressure fuel pumps in a predetermined period when the required fuel amount is small, in accordance with the required fuel amount of the internal combustion engine. It is.

According to a second aspect of the present invention, in the fuel supply device for an internal combustion engine according to the first aspect, the control means includes:
The electromagnetic valve is controlled so that each of the plurality of high-pressure fuel pumps operates intermittently, so that the number of times of operation of the plurality of high-pressure fuel pumps as a whole is reduced.

According to a third aspect of the present invention, in the fuel supply device for an internal combustion engine according to the first aspect, the control means includes:
The electromagnetic valve is controlled so as to stop the operation of a part of the plurality of high-pressure fuel pumps, thereby reducing the number of times of operation of the plurality of high-pressure fuel pumps as a whole.

In each of the above constructions, the high-pressure fuel pump is operated by controlling the opening and closing of the solenoid valve, and regulates the amount of fuel discharged to the high-pressure fuel pipe through the opening and closing control. Operation will be involved.

In the fuel supply system for an internal combustion engine having a plurality of such high pressure fuel pumps, in each of the above-described configurations, when the required fuel amount of the internal combustion engine decreases, the number of times of operation of the plurality of high pressure fuel pumps in a predetermined period, that is, the operation frequency Has been reduced. If it is a high-pressure fuel pump that adjusts the discharge amount of fuel to the high-pressure fuel pipe through opening and closing control of the solenoid valve,
If the required fuel amount is small, even if the number of operations is reduced, the amount of fuel required for each operation can be secured by increasing the amount of fuel discharged for each operation. Then, at this time, the frequency of the opening / closing operation of the solenoid valve is reduced in accordance with the reduction in the operation frequency of the entire high-pressure fuel pump. Therefore, according to each of the above configurations, it is possible to reduce the operating noise of the high-pressure fuel pump accompanying the opening and closing operation of the solenoid valve.

The decrease in the number of times of operation of the plurality of high-pressure fuel pumps in a predetermined period can be achieved by controlling the solenoid valves so that each of the plurality of high-pressure fuel pumps operates intermittently. Alternatively, it can be realized by controlling the solenoid valve so as to stop the operation of a part of the plurality of high-pressure fuel pumps. In particular, if the solenoid valve is controlled as described in claim 3, it is possible to omit or simplify the operation noise countermeasures for a part of the high-pressure fuel pump that is stopped in such a situation, Costs can also be reduced.

Here, the required fuel amount of the internal combustion engine refers to a required amount of fuel discharge from the entire plurality of high-pressure fuel pumps to the high-pressure fuel pipe, or a control amount corresponding thereto. For example, in a fuel supply device configured to calculate a target value of the fuel discharge amount of the entire high-pressure fuel pump and control the fuel discharge amount of each high-pressure fuel pump based on the target value, the target value is used as the required fuel amount. be able to.
The required fuel amount can also be roughly estimated from the operating state of the internal combustion engine such as the rotation speed, the engine load, and the fuel injection amount.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied as a fuel supply device applied to an in-cylinder in-cylinder internal combustion engine will be described below with reference to FIGS.

The cylinder arrangement of the internal combustion engine to which the present invention is applied has four cylinders in each of the first and second banks.
It has a V-type eight-cylinder arrangement with two cylinders. In the following description, components common to the first bank and the second bank are denoted by the same reference numerals, and the components of the first bank are suffixed with “a”, and the components of the second bank are denoted by “a”. The components are distinguished by adding "b" at the end. If there is no particular need to distinguish between the two, only the number is displayed as a code.

As shown in FIG. 1, the fuel supply system for an internal combustion engine includes a feed pump 11 and a high-pressure fuel pump 30. The feed pump 11 pumps up the fuel stored in the fuel tank 10, and the high-pressure fuel pump 30 pressurizes and pumps out the pumped-up fuel. The high-pressure fuel delivered from the high-pressure fuel pump 30 is pressure-fed to a high-pressure fuel pipe (delivery pipe) 17. The high-pressure fuel sent to the high-pressure fuel pipe 17 is stored therein while maintaining the required pressure, and is distributed to the injectors 22 provided for each cylinder of the internal combustion engine. Then, the required amount of fuel is injected and supplied to the internal combustion engine at a required timing by the injector 22.

In this internal combustion engine, both banks are each provided with one high-pressure fuel pipe 17a, 17b, and each high-pressure fuel pipe 17a, 17b has four injectors 22 for one bank. Are connected respectively. Two high-pressure fuel pumps 30a, 30b are provided, one for each high-pressure fuel pipe 17a, 17b.
b. Incidentally, in this internal combustion engine, the two high-pressure fuel pipes 17a and 17b are connected through a connection pipe 18, and substantially function as an integrated high-pressure fuel pipe.

The fuel pumped by the feed pump 11 in the fuel supply apparatus is sent to the two high-pressure fuel pumps 30 through the low-pressure fuel passage 12. In the middle of the low-pressure fuel passage 12, a filter 13 for filtering fuel and a pressure regulator 14 are provided from the feed pump 11 side. The pressure regulator 14 returns the fuel in the low-pressure fuel passage 12 to the fuel tank 10 when the fuel pressure in the low-pressure fuel passage 12 becomes equal to or higher than a predetermined pressure (for example, 0.4 MPa).
The fuel pressure in 2 is kept below a predetermined pressure.

At that point, the low-pressure fuel passage 12 is branched into two toward each of the high-pressure fuel pumps 30a and 30b.
The branched passages 12 are connected to the gallery 31 of the high-pressure fuel pump 30 of each bank via the pulsation damper 15.
Connected to each other. The pulsation damper 15 suppresses fuel pressure pulsation in the low-pressure fuel passage 12 when the high-pressure fuel pump 30 operates.

On the other hand, the high-pressure fuel pump 30 of each bank
Through the high-pressure fuel passage 16, the high-pressure fuel pipe 1 of the bank
The high-pressure fuel is pressurized to the high-pressure fuel pipe 17.
A check valve 19 is provided in the middle of the high-pressure fuel passage 16, and the high-pressure fuel pump 30
Backflow of the fuel to the sides a and 30b is prevented.

One of the high-pressure fuel pipes 17 (in FIG.
A drain passage 21 is connected to the high-pressure fuel pipe 17a) of the bank via a relief valve 20. The relief valve 20 opens when the fuel pressure P in the high-pressure fuel pipe 17 becomes equal to or higher than a predetermined pressure (for example, 14 to 14.5 MPa).
Part of the fuel stored in the pipe 17 is transferred to the drain passage 2
1 to the fuel tank 10. This allows
Excessive increase of the fuel pressure in the high-pressure fuel pipe 17 is prevented.

The two high-pressure fuel pumps 30 (30a, 30b) provided in the present fuel supply device have a cylinder 32 and a plunger 33 therein. The plunger 33 is disposed so as to be able to reciprocate in the cylinder 32, and is reciprocated by rotation of a pump cam 24 provided on a cam shaft 23 for an intake valve or an exhaust valve of the internal combustion engine.

The cam 24 for the pump has a camshaft 23
Two cam ridges are formed at an angle of 180 ° about the rotation axis of, and the plunger 33 reciprocates according to the cam ridges. On the other hand, the camshaft 23 makes one rotation every two rotations of a crankshaft (not shown) of the internal combustion engine. For this reason, the plunger 33 of the high-pressure fuel pump 30
Is reciprocated four times in one cycle of the internal combustion engine, that is, while the crankshaft is rotated twice. Incidentally, in this embodiment, the pump cams 24 of the high-pressure fuel pumps 30a and 30b of both banks
Cam ridges are formed with a phase difference of 0 °. For this reason, the plungers 33 of the high-pressure fuel pumps 30a and 30b of both banks are alternately reciprocated at equal intervals (45 ° CA).

On the other hand, inside each high pressure fuel pump 30,
Partitioned by a cylinder 32 and a plunger 33,
A pressure chamber 34 is formed. The pressurizing chamber 34 can communicate with the gallery 31 connected to the low-pressure fuel passage 12, is connected to the high-pressure fuel passage 16, and is connected to the high-pressure fuel pipe 17 via the passage 16 and the check valve 19. Have been.

The volume of the pressurizing chamber 34 changes according to the reciprocating motion of the plunger 33. During the suction stroke of the high-pressure fuel pump 30 in which the volume of the pressurizing chamber 34 is expanded by the reciprocating motion of the plunger 33, the low-pressure fuel passage 12
Inhaling fuel inside. Also, during the pressurization stroke of the high-pressure fuel pump 30 in which the volume of the pressurization chamber 34 is reduced, the fuel sucked into the pressurization chamber 34 during the suction stroke can be discharged to the high-pressure fuel pipe 17 through the high-pressure fuel passage 16. Has become.

An electromagnetic spill valve 35 is provided inside the high-pressure fuel pump 30. The electromagnetic spill valve 35 is an electromagnetic valve that opens and closes by controlling the energization of an electromagnetic solenoid, thereby shutting off communication between the gallery 31 and the pressurizing chamber 34. Here, the electromagnetic spill valve 35 is
The valve is opened when the power supply to the electromagnetic solenoid is stopped to connect the gallery 31 and the pressurizing chamber 34, and the valve is closed according to the power supply to the electromagnetic solenoid to shut off the communication.

Therefore, if the electromagnetic spill valve 35 is opened during the suction stroke, the low pressure fuel passage 12
Fuel from the side is sucked into the pressurizing chamber 34 via the gallery 31. Here, when the pressurizing process is started while the electromagnetic spill valve 35 is open, the fuel sucked into the pressurizing chamber 34 in the suction process overflows to the gallery 31. At this time, the fuel is returned from the gallery 31 to the low-pressure fuel passage 12 side without being pressure-fed to the high-pressure fuel pipe 17. Therefore, if the electromagnetic spill valve 35 is kept open from the start to the end of the pressurization process, the fuel will not be pumped to the high-pressure fuel pipe 17 and the high-pressure fuel pump 3
Zero operation can be stopped.

On the other hand, when the gallery 31 and the pressurizing chamber 34 are shut off by closing the electromagnetic spill valve 35 during the pressurizing process, when the volume of the pressurizing chamber 34 is reduced by the plunger 33, the pressurizing is performed. The fuel in the chamber 34 is pressurized. When the fuel pressure in the pressurizing chamber 34 exceeds a predetermined pressure, the check valve 1
9 is pushed open, and the fuel is pumped to the high-pressure fuel pipe 17.

In the high-pressure fuel pump 30, as described above, the electromagnetic spill valve 35 is closed during the pressurization process,
The fuel is pressurized and discharged to the high-pressure fuel pipe 17. By controlling the closing timing of the electromagnetic spill valve 35 during the pressurizing process, the amount of fuel discharged to the high-pressure fuel pipe 17 is adjusted. That is, in the fuel pump 30, fuel is discharged from the pressurizing chamber 34 to the high-pressure fuel pipe 17 only during a period during which the electromagnetic spill valve 35 in the pressurizing process is closed. Therefore, if the valve closing timing of the electromagnetic spill valve 35 during the pressurizing process is advanced to prolong the valve closing period during the pressurizing process, the amount of fuel discharged to the high-pressure fuel pipe 17 increases, and the valve closing timing is delayed. To shorten the valve closing period,
The amount of discharged fuel is reduced.

As described above, the high-pressure fuel pump 30
Is from the start of the suction stroke to the end of the pressurization stroke
It is operated as a cycle, and pressurizes and discharges fuel to the high-pressure fuel pipe 17.

Next, a control system of the fuel supply device for controlling the operation of the high-pressure fuel pump 30 will be described. As shown in FIG. 1, the control system of the present fuel supply device mainly includes an electronic control unit (ECU) 40. The ECU 40 controls the operation state of the internal combustion engine, such as the control of the fuel injection amount and the fuel injection timing by the control of the injector 22, and also performs the opening / closing control of the electromagnetic spill valve 35 as a part thereof.

The ECU 40 is configured as an arithmetic and logic operation circuit having a central processing unit (CPU), a memory, and the like, and has a port for inputting and outputting signals to and from external devices. Input ports of the ECU 40 include, for example, a crank angle sensor 41, an intake pressure sensor 42, an accelerator sensor 43
And the like, detection signals of various sensors for detecting the operating state of the internal combustion engine and the vehicle are input. ECU40
Is the required load KL based on the detection signals of these sensors.
Various parameters indicating the operating state of the engine, such as the engine speed and the rotational speed NE, are obtained. A fuel pressure sensor 44 attached to the high-pressure fuel pipe 17 is also connected to an input port of the ECU 40, and the ECU 40 obtains a fuel pressure P in the pipe 17 based on the detection signal. On the other hand, ECU4
A signal line to the injector 22, the electromagnetic spill valve 35, and the like is connected to the output port 0, and a command signal to these is output.

The ECU 40 configured as described above controls the high-pressure fuel pump 30 by controlling the opening and closing of the electromagnetic spill valve 35.
Is controlled. FIG. 2 shows a flowchart of a processing routine for controlling the operation of the high-pressure fuel pump 30. The processing of this routine is periodically executed by the ECU 40 at every predetermined crank angle.

In this embodiment, as shown in FIG.
In relation to the operation control of the high-pressure fuel pump 30, the operating region of the engine is divided into two regions based on the rotational speed NE and the required load KL of the internal combustion engine. The area A in FIG.
This is an operation region in which a sufficient amount of fuel supply required by the internal combustion engine can be ensured only by discharging fuel from the two high-pressure fuel pumps 30. That is, this area A is the high-pressure fuel pipe 17
The demand for fuel supply to a single high pressure fuel pump 3
This is an operation region where the fuel discharge amount is less than the maximum amount of zero fuel discharge. On the other hand, the region B in FIG.
That is, this is an operation region in which it is necessary to operate both of the two high-pressure fuel pumps 30a and 30b in order to secure the required fuel pumping amount.

In this embodiment, as shown in FIG. 2, when the operating range of the internal combustion engine is in the range B (S10: NO), the ECU 40 operates both of the two high-pressure fuel pumps 30a and 30b. Let the high pressure fuel pipe 17
The electromagnetic spill valves 35 of the high-pressure fuel pumps 30 are controlled to open and close so that the fuel is pumped (S20). That is,
As shown in FIG. 4, at this time, every time one of the two high-pressure fuel pumps 30a and 30b enters the pressurizing stroke, the ECU 40 sets the electromagnetic spill valve 35
Is closed at a necessary timing according to the operation state of the internal combustion engine, and the fuel is pressure-fed to the high-pressure fuel pipe 17.

On the other hand, if the operating region of the internal combustion engine is in the region A (S10: YE in FIG. 2)
S) One of the two high-pressure fuel pumps 30a, 30b
One of the high-pressure fuel pumps 30a, 30b so as to suspend the operation of one of them and operate only the other one.
5 is opened and closed. That is, as shown in FIG. 5, at this time, the ECU 40 holds the electromagnetic spill valve 35 of the high-pressure fuel pump (the pump 30 a in the first bank) to be stopped in the open state, and connects the high-pressure fuel pump 17 to the high-pressure fuel pipe 17. Stop pumping fuel. The ECU 40 also operates a high-pressure fuel pump (in this case, the pump 3 in the second bank).
Regarding 0b), every time the pump 30b enters the pressurization stroke, the electromagnetic spill valve 35 is closed at a necessary timing according to the operation state of the internal combustion engine.

At this time, the closing timing of the electromagnetic spill valve 35 of the high-pressure fuel pump 30b for maintaining the operation is set such that only one pump 30b can discharge the required amount of fuel. In other words, the amount of fuel discharged for each operation can be increased by an amount corresponding to the decrease in the number of high-pressure fuel pumps 30 to be operated, and the required amount of fuel discharged by operating only one high-pressure fuel pump 30 can be secured. Thus, the valve closing timing is set.

As described above, according to the present embodiment,
The following effects can be obtained. (1) In the present embodiment, when the required fuel amount of the internal combustion engine decreases, one of the two high-pressure fuel pumps 30a and 30b is stopped to reduce the number of times of operation of the entire high-pressure fuel pump during a predetermined period. That is, the operation frequency is reduced. As a result, the frequency of opening and closing operation of the electromagnetic spill valve 35 is reduced while securing the required fuel discharge amount during the predetermined period, and the operation of the high-pressure fuel pump 30 associated with such opening and closing operation of the electromagnetic spill valve 35 is performed. Sound can be reduced. In particular, for example, when the noise generated by the internal combustion engine itself is low, such as during idling, the high-pressure fuel pump 30
, The frequency of operation is reduced, so that the effect of reducing the operation noise becomes remarkable.

(2) According to the present embodiment, with respect to the high pressure fuel pump 30a of the first bank which is stopped when the required fuel amount of the internal combustion engine is small, the operation countermeasures are omitted or simplified. To be able to
The cost required for countermeasures for operating noise can also be reduced.

In the present embodiment, the high-pressure fuel pump 30b, which operates even when the required fuel amount of the internal combustion engine decreases, is located in the engine room of the vehicle.
Than the high-pressure fuel pump 30a that is stopped at that time,
It is located away from the cabin. That is, the high-pressure fuel pump 30b whose operation is maintained is disposed at a position where the occupant in the vehicle compartment hardly feels the operation noise, and the operation noise countermeasures of the pump 30b can be easily omitted or simplified. Has become.

Although the above embodiment has been described with respect to the configuration including the two high-pressure fuel pumps 30, the configuration including three or more high-pressure fuel pumps 30 can also be used to control the operation of the high-pressure fuel pump as in the present embodiment. By applying, the operating noise can be reduced. In this case, the operation control of the high-pressure fuel pump is as follows: When the required fuel amount of the internal combustion engine is small, the operation of one of the high-pressure fuel pumps is stopped. When the required fuel amount of the internal combustion engine is small, at least one
The operation of two or more high-pressure fuel pumps is stopped simultaneously while the operation of one or more high-pressure fuel pumps is maintained. -The operation of the high-pressure fuel pump is sequentially stopped one by one according to the decrease in the required fuel amount of the internal combustion engine. Variations such as are conceivable. In any case, when the required fuel amount of the internal combustion engine is small, if the operation of some of the plurality of high-pressure fuel pumps is stopped, the number of operations of the entire high-pressure fuel pump within a predetermined period is reduced. Thus, the operating noise of the pump can be reduced.

In the above embodiment, as shown in FIG. 4, whether the required fuel amount of the internal combustion engine is small or not is determined based on the operating range divided according to the rotational speed NE and the required load KL of the internal combustion engine. Is determined. Such a determination mode,
Alternatively, the calculation mode of the required fuel amount can be arbitrarily changed according to the control mode of the fuel discharge amount of the high-pressure fuel pump in the applied fuel supply device.

For example, when the fuel discharge amount of the entire high-pressure fuel pump within a predetermined period is feedback-controlled based on the detection result of the fuel pressure P in the high-pressure fuel pipe 17 by the fuel pressure sensor 44, the fuel discharge amount The above-mentioned target value may be used as the required fuel amount of the internal combustion engine to control the operation of the high-pressure fuel pump related to the reduction of the operation noise as described above. In this case, it can be determined that the required fuel amount of the internal combustion engine is small when the target value of the fuel discharge amount is lower than the predetermined determination value. When the operation of one of the two high-pressure fuel pumps 30 is stopped as in the above embodiment, the determination value is set to a value smaller than the maximum value of the fuel discharge amount of one high-pressure fuel pump 30. By doing so, it is possible to preferably reduce the operating noise of the high-pressure fuel pump while securing the required fuel discharge amount of the entire high-pressure fuel pump.

(Other Embodiments) In the above embodiment,
By stopping the operation of one of the two high-pressure fuel pumps 30 when the required fuel amount of the internal combustion engine is small, the number of operations of the entire high-pressure fuel pump during a predetermined period is reduced. By the way, by controlling the opening and closing of the electromagnetic spill valves 35 so that each of the high-pressure fuel pumps 30 operates intermittently, the operation frequency of the entire high-pressure fuel pump can be reduced.

That is, for example, as shown in FIG. 6 showing an example of control of the high-pressure fuel pumps 30a and 30b, when the required fuel amount of the internal combustion engine is small, each of the high-pressure fuel pumps 30a and 30b
By controlling the opening and closing of the electromagnetic spill valve 35 so as to operate the respective 30b intermittently, the operation frequency of the entire high-pressure fuel pump can be reduced. In the example of FIG.
For each of the high-pressure fuel pumps 30a and 30b, the electromagnetic spill valve 35 is closed to discharge fuel to each of the pumps 30a and 30b only in one of the two pressurization steps. Thereby, the operation and the stop of each of the high-pressure fuel pumps 30a and 30b are switched every cycle. Also in this case, the number of operations of the entire high-pressure fuel pump within a predetermined period is reduced, and the operation sound of the high-pressure fuel pump 30 accompanying the opening and closing operation of the electromagnetic spill valve 35 is reduced.

The mode of the intermittent operation of each of the high-pressure fuel pumps 30 is arbitrary, and the interval of the pressurizing process for operating each pump 30 or the interval of the pressurizing process for stopping the operation thereof may be appropriately changed. good. Also, in a configuration including three or more high-pressure fuel pumps, similarly, each pump may be operated intermittently to reduce the number of times the entire pumps operate within a predetermined period. In any case, when the required fuel amount of the internal combustion engine is small, by controlling the opening and closing of the electromagnetic spill valve so as to intermittently operate each of the high-pressure fuel pumps, it is possible to secure the required fuel discharge amount, The operation noise of the high-pressure fuel pump accompanying the opening and closing operation of the valve can be reduced.

The embodiments described above may be modified as follows. In the above embodiments, the configuration including the high-pressure fuel pump of the spill valve type has been described, but the fuel supply device of the internal combustion engine including a plurality of the high-pressure fuel pumps of the suction metering valve type as described above also The operation control of the high-pressure fuel pump related to the reduction of the operation noise in a mode similar to or similar to the embodiment can be applied.

The point is that whether a high pressure fuel pump discharges fuel to a high pressure fuel pipe by operating its open / close control, whether it is an electromagnetic spill valve, the above-mentioned suction metering valve, or another electromagnetic valve, Is accompanied by the opening and closing operation of the solenoid valve, and an operating sound is generated due to the opening and closing operation.
In addition, if a plurality of high-pressure fuel pumps for adjusting the amount of fuel discharged to the high-pressure fuel pipe through opening and closing control of the solenoid valve are provided, if the required fuel amount of the internal combustion engine is small, the operation frequency of the entire pump is reduced. However, the required amount of fuel can be secured by increasing the fuel discharge amount for each operation. Thereby, the frequency of the opening / closing operation of the solenoid valve can be reduced, and the operating noise of the high-pressure fuel pump accompanying the opening / closing operation can be reduced appropriately.

And, of course, the fuel supply device for an internal combustion engine according to the present invention can be applied to a fuel supply device of any configuration as long as it has a plurality of high pressure fuel pumps as described above. Further, the internal combustion engine to which the fuel supply device is applied is also all the internal combustion engines to which the fuel supply device including a plurality of such high-pressure fuel pumps is applied,
It is not limited to the internal combustion engine exemplified in the above embodiment.

The technical ideas grasped from the embodiments described above are described below. (A) The solenoid valve is configured to allow fuel to overflow without being discharged to the high-pressure fuel pipe in accordance with an opening / closing operation of the high-pressure fuel pump during a pressurization process. Fuel supply device for an internal combustion engine.

(B) The solenoid valve shuts off the flow of fuel into the high-pressure fuel pump according to the opening / closing operation of the high-pressure fuel pump during the suction stroke. A fuel supply device for an internal combustion engine according to the above.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the overall structure of an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation control procedure of the high-pressure fuel pump in the embodiment.

FIG. 3 is a graph showing an example of a setting mode of an operation region.

FIG. 4 is a timing chart showing an example of a control mode of the high-pressure fuel pump of the embodiment.

FIG. 5 is a timing chart showing an example of a control mode of the high-pressure fuel pump of the embodiment.

FIG. 6 is a timing chart showing an example of a control mode of a high-pressure fuel pump according to another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Fuel tank, 11 ... Feed pump, 12 ... Low pressure fuel passage, 13 ... Filter, 14 ... Pressure regulator, 15 ... Pulsation damper, 16 ... High pressure fuel passage, 17 (17a, 17b) ... High pressure fuel piping, 18 ... Connection pipe, 19: check valve, 20: relief valve, 21
... Drain valve, 22 ... Injector, 23 ... Cam shaft, 24 ... Cam for pump, 30 (30a, 30b) ... High pressure fuel pump, 31 ... Gallery, 32 ... Cylinder, 3
DESCRIPTION OF SYMBOLS 3 ... plunger, 34 ... pressurization chamber, 35 ... electromagnetic spill valve (electromagnetic valve), 40 ... electronic control unit (ECU: control means), 41 ... crank angle sensor, 42 ... intake pressure sensor,
43 ... accelerator sensor, 44 ... fuel pressure sensor.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F02M 59/46 F02M 59/46 Y F term (reference) 3G066 AA01 AA07 AB02 AC09 BA22 BA61 CA19 CE22 DC01 DC09 3G301 HA01 HA02 HA06 JA37 LB16 LC01 MA00 ND01 PA17A PB08A PE01A

Claims (3)

[Claims] 1. A fuel supply device for an internal combustion engine, comprising: a plurality of high-pressure fuel pumps that are operated by opening / closing control of an electromagnetic valve and that adjust a discharge amount of fuel to a high-pressure fuel pipe through opening / closing control of the electromagnetic valve. When the required fuel amount is small, the fuel for the internal combustion engine is provided with control means for controlling the solenoid valve so as to reduce the number of times of operation of the plurality of high-pressure fuel pumps in a predetermined period in accordance with the required fuel amount of the internal combustion engine. Feeding device. 2. The control means controls the solenoid valve so as to intermittently operate each of the plurality of high-pressure fuel pumps, thereby reducing the number of times of operation of the plurality of high-pressure fuel pumps as a whole. The fuel supply device for an internal combustion engine according to claim 1. 3. The control means controls the solenoid valve so as to stop the operation of a part of the plurality of high-pressure fuel pumps, thereby reducing the number of operations of the plurality of high-pressure fuel pumps as a whole. The fuel supply device for an internal combustion engine according to claim 1.