JP2005127289A - Fuel injection device for internal combustion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection device for an internal combustion engine capable of eliminating waste of fuel supplied to an internal combustion engine and eliminating unnecessary friction of the internal combustion engine. <P>SOLUTION: This fuel injection device for an internal combustion engine is provided with a high-pressure fuel injection valve for injecting high-pressure fuel, which is low-pressure fuel pressurized by a low-pressure pump, discharged and supplied to a high-pressure pump 5, and further pressurized by the high-pressure pump 5 to be discharged therefrom, and a low-pressure fuel injection valve for injecting low-pressure fuel pressurized by the low-pressure pump and discharged therefrom. The fuel injection device comprises an actuator 6 as a discharge suppressing means for setting the high-pressure fuel discharging amount of the high-pressure pump 5 to approximately 0 when the high-pressure fuel injection valve is not operated. When the high-pressure fuel injection valve is not operated, a connection between the high pressure pump 5 and a pump drive cam 12 as a drive source for driving the high-pressure pump 5 is released by the actuator 6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fuel injection device for an internal combustion engine, and more particularly to a fuel injection device for an internal combustion engine that supplies fuel to the internal combustion engine from a low pressure fuel injection valve and a high pressure fuel injection valve.

  As a method of supplying fuel to an internal combustion engine such as a gasoline engine or a diesel engine mounted on a vehicle such as a passenger car or a truck, direct injection that directly injects fuel into the cylinder of the internal combustion engine, and in the cylinder of the internal combustion engine There are a port injection in which fuel is injected into an intake port for supplying air and a direct injection / port injection in which the above two methods are combined, that is, direct injection and port injection are switched according to the operating state of the internal combustion engine.

  An example of a fuel injection device for an internal combustion engine that performs direct injection / port injection in accordance with the operating state of the internal combustion engine is disclosed in Patent Document 1. The fuel injection device for an internal combustion engine includes a high pressure fuel injection valve (main fuel injection valve) that injects fuel into a combustion chamber of the internal combustion engine, and a low pressure fuel injection valve (auxiliary fuel injection valve) that injects fuel into an intake passage. Prepare. The low-pressure fuel pressurized and discharged by the low-pressure pump (low-pressure fuel pump) is supplied to the low-pressure fuel injection valve via the fuel supply pipe, and is injected from the low-pressure fuel injection valve into the intake passage. On the other hand, the low-pressure fuel pressurized and discharged by the low-pressure pump is supplied to the high-pressure pump through the fuel pipe and the fuel filter. The high-pressure fuel further pressurized and discharged by the high-pressure pump is supplied to the high-pressure fuel injection valve, and is injected from the high-pressure fuel injection valve into the combustion chamber of the internal combustion engine.

  This fuel injection device for an internal combustion engine is based on a map created based on the operating state of the internal combustion engine, for example, engine speed (engine speed), intake air amount, accelerator opening (throttle opening), cooling water temperature, and the like. The injection of the high-pressure fuel injection valve and the low-pressure fuel injection valve (the valve opening corresponding to the injection timing and the injection amount) is controlled. Specifically, the map is divided into a direct injection region that includes only the high pressure fuel injection valve, a direct injection / port injection region that includes both the high pressure fuel injection valve and the low pressure fuel injection valve, and a port injection region that includes only the low pressure fuel injection valve. The control device for the fuel injection device of the internal combustion engine controls the injection of the high pressure fuel injection valve and the low pressure fuel injection valve according to the operating state of the internal combustion engine.

JP 11-351043 A

  By the way, the conventional fuel injection device for an internal combustion engine includes a high-pressure pump for supplying high-pressure fuel to the high-pressure fuel injection valve as described above. The high-pressure pump is driven by rotation of a pump drive cam attached to the intake camshaft or the exhaust camshaft. That is, as the pump drive cam rotates, the plunger provided in the high-pressure pump reciprocates to further pressurize the low-pressure fuel pressurized by the low-pressure pump supplied to the high-pressure pump. Here, since the control device of the fuel injection device of the internal combustion engine is controlled not to inject high pressure fuel from the high pressure fuel injection valve, that is, even when the high pressure fuel injection valve is not operated, the pump drive cam rotates. This high-pressure pump continues to drive. Therefore, the high-pressure pump has a problem of wastefully supplying the high-pressure fuel pressurized by the high-pressure pump to the high-pressure fuel injection valve even when the high-pressure fuel pressurized by the high-pressure pump is not required in the high-pressure fuel injection valve. .

The high-pressure pump obtains a force necessary for further pressurizing the low-pressure fuel pressurized by the low-pressure pump by the plunger from a pump drive cam that is a drive source. The intake shaft or the exhaust camshaft to which the pump drive cam is fixed is rotated by transmitting the rotation of the crankshaft of the internal combustion engine via the timing chain. Therefore, even when the high-pressure fuel pressurized by the high-pressure pump is not required in the high-pressure fuel injection valve, the high-pressure pump provides the force necessary for further pressurizing the low-pressure fuel pressurized by the low-pressure pump. There is also a problem that this becomes useless friction of the internal combustion engine.

  The present invention has been made in view of the above, and provides a fuel injection device for an internal combustion engine that eliminates waste of fuel supplied to the internal combustion engine and eliminates waste of friction of the internal combustion engine. It is for the purpose.

  In order to solve the above-described problems and achieve the object, the present invention pressurizes with a low-pressure pump, supplies the discharged low-pressure fuel to the high-pressure pump, further pressurizes the low-pressure fuel with the high-pressure pump, and discharges the high-pressure A fuel injection device for an internal combustion engine comprising a high-pressure fuel injection valve that injects fuel and a low-pressure fuel injection valve that pressurizes and discharges low-pressure fuel that is pressurized by a low-pressure pump. Discharge suppression means for reducing the high-pressure fuel discharge amount to approximately 0 is provided.

  According to the present invention, in the fuel injection device for an internal combustion engine, the discharge suppression means releases the connection between the high-pressure pump and the drive source that drives the high-pressure pump.

  In the fuel injection device for an internal combustion engine according to the present invention, the discharge suppression means does not supply low-pressure fuel to the high-pressure pump.

  In the fuel injection device for an internal combustion engine according to the present invention, when the high-pressure fuel pressurized by the high-pressure pump is not required in the high-pressure fuel injection valve, that is, when the high-pressure fuel injection valve is not operated, By releasing the connection with the drive source that drives the pump, or by not supplying the low-pressure fuel to the high-pressure pump, the high-pressure fuel discharge amount of the high-pressure pump is made substantially zero. Therefore, it is possible to eliminate the waste of fuel supplied to the internal combustion engine and to eliminate the wasteful friction of the internal combustion engine.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the best mode for carrying out the invention. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same. Here, the fuel injection device described below is a device that supplies fuel to an engine that is an internal combustion engine such as a gasoline engine or a diesel engine mounted on a vehicle such as a passenger car or a truck.

FIG. 1 is a diagram illustrating a configuration example of a fuel injection device for an internal combustion engine according to a first embodiment. FIG. 2 is a diagram illustrating a configuration example of the internal combustion engine. FIG. 3A is a diagram of a configuration example of the high-pressure pump of the fuel injection device for the internal combustion engine according to the first embodiment. FIG. 3-2 is an operation explanatory diagram of the high-pressure pump. FIG. 4A is a diagram of a configuration example of the discharge suppression unit of the fuel injection device for the internal combustion engine according to the first embodiment. FIG. 4B is an enlarged perspective view of a portion A in FIG. FIG. 4-3 is a diagram for explaining the operation of the discharge suppression unit of the fuel injection device for the internal combustion engine according to the first embodiment. As shown in FIGS. 1 and 4-1, a fuel injection device 1 for an internal combustion engine according to the present invention includes a port injection fuel injection valve 2 which is a low pressure fuel injection valve and a direct injection fuel which is a high pressure fuel injection valve. The injection valve 3, the low-pressure pump 4, the high-pressure pump 5, and the actuator 6 that is a discharge suppression means are configured.

  As shown in FIGS. 1 and 2, a port injection fuel injection valve 2 that is a low pressure fuel injection valve and a direct injection fuel injection valve 3 that is a high pressure fuel injection valve are provided for each cylinder 20 of an in-line four-cylinder internal combustion engine. It is provided for each. The port injection fuel injection valve 2 and the direct injection fuel injection valve 3 are electromagnetic valves, and the injection timing and the injection amount are controlled by an injection signal from a control device 7 to be described later. The plurality of port injection fuel injection valves 2 are supplied with low-pressure fuel discharged from a low-pressure pump 4 described later via a low-pressure delivery pipe 2a. On the other hand, the direct injection fuel injection valve 3 is supplied with high-pressure fuel discharged from a high-pressure pump 5 to be described later via a high-pressure delivery pipe 3a. Reference numeral 3b denotes a pressure sensor for detecting the pressure of the high-pressure fuel supplied to the direct injection fuel injection valve 3. Here, the number of cylinders of the internal combustion engine is not limited to four cylinders. Therefore, for example, in the case of a 6-cylinder internal combustion engine, the fuel injection device 1 of the internal combustion engine includes six port injection fuel injection valves 2 and six direct injection fuel injection valves 3.

  As shown in FIG. 2, each cylinder 20 of the internal combustion engine has a cylinder block 21, a piston 22, a cylinder head 23 fixed to the cylinder block 21, and a combustion formed between the piston 22 and the cylinder head 23. The chamber 24, the intake valve 25, the exhaust valve 26, the intake port 27, the exhaust port 28, and the spark plug 29 are configured. The port injection fuel injection valve 2 is provided so as to inject low pressure fuel into an intake port 27 communicating with an intake passage (not shown). The direct injection fuel injection valve 3 is fixed to the cylinder head 23 and is provided so that high pressure fuel can be directly injected into the combustion chamber 24. In addition, 22a is a recessed part for guide | inducing the fuel injected from the direct-injection fuel injection valve 3 to the ignition plug 29 vicinity. The port injection fuel injection valve 2 may inject low-pressure fuel into an intake passage (not shown) or a surge tank (not shown) provided upstream of the intake passage to supply the internal combustion engine with fuel. .

  As shown in FIG. 1, the low-pressure pump 4 is driven by a drive signal from a control device 7 described later, and pressurizes the fuel stored in the fuel tank 8 to a predetermined pressure (for example, a low pressure of about 0.4 MPa). An electric pump that discharges low-pressure fuel into the low-pressure passage 9. The low-pressure fuel discharged from the low-pressure pump 4 is supplied to the plurality of port injection fuel injection valves 2 via the low-pressure passage 9 and the low-pressure delivery pipe 2a, and is branched from the middle of the low-pressure passage 9. Is supplied to the high-pressure pump 5. 4a returns a part of the low pressure fuel discharged from the low pressure pump 4 to the fuel tank 8 when the pressure of the low pressure fuel in the low pressure passage 9 becomes higher than a predetermined pressure (low pressure). This is a regulator that keeps the pressure of the low pressure fuel supplied to the inside, that is, the port injection fuel injection valve 2 and the high pressure pump 5 constant.

  As shown in FIGS. 1 and 3-1, the high pressure pump 5 is pressurized by the low pressure pump 4 via the low pressure passage 9 and the branch passage 10, and further pressurizes the discharged low pressure fuel. The pressurized high-pressure fuel is discharged and supplied to the plurality of direct injection fuel injection valves 3 through the high-pressure passage 11 and the high-pressure delivery pipe 3a. The high pressure pump 5 includes a low pressure fuel port 5a, a high pressure fuel port 5b, a solenoid valve 5c, a pressurizing chamber 5d, and a plunger 5e. 5f is a check valve that opens when the fuel in the pressurizing chamber 5d reaches a predetermined pressure (for example, a high pressure of about 12 MPa) and discharges the high-pressure fuel to the high-pressure passage 11. As shown in FIGS. 4A and 4B, the high-pressure pump 5 is fixed to an intake camshaft 13 that is rotatably supported in the cylinder head 23 and a cylinder head cover 30 that covers the exhaust camshaft. .

The low-pressure fuel port 5 a communicates with the branch passage 10 shown in FIG. 1 and supplies pressurized low-pressure fuel discharged by the low-pressure pump 4 to the high-pressure pump 5. This low pressure fuel port 5
One end of a communicates with the pressurizing chamber 5d. The low pressure fuel supplied to the low pressure fuel port 5a is supplied to the pressurizing chamber 5d via the electromagnetic valve 5c. The electromagnetic valve 5c is opened / closed by an opening signal from the control device 7 to be described later, and controls the amount of low-pressure fuel supplied into the pressurizing chamber 5d. The valve opening degree of the electromagnetic valve 5c is based on the pressure of the high-pressure fuel so that the pressure of the high-pressure fuel in the high-pressure delivery pipe 3a detected from the pressure sensor 3b shown in FIG. Dudey controlled. The pressurizing chamber 5d communicates with the high pressure fuel port 5b through the check valve 5f. The high pressure fuel pressurized in the pressurizing chamber 5d is discharged into the high pressure passage 11. In the pressurizing chamber 5d, the plunger 5e is supported so as to be able to reciprocate in the direction of arrow B, and the low pressure fuel supplied to the pressurizing chamber 5d is pressurized by the reciprocating motion of the plunger 5e. The plunger 5e is fixed to the lifter 5g. The lifter 5g is supported so as to be movable up and down in the direction of arrow B in the lifter guide 5h. The lifter 5g is always in contact with a pump drive cam 12 that is a drive source of the high-pressure pump 5 by a biasing force of a spring (not shown).

  Here, as shown in FIGS. 4A and 4B, the pump drive cam 12 includes a cam small-diameter portion 12a and a cam portion 12b formed so as to be continuous with the cam small-diameter portion 12a. ing. The pump drive cam 12 is fixed to an intake camshaft 13. The intake camshaft 13 is connected to a crankshaft 14 on which a piston 22 of each cylinder 20 shown in FIG. 2 is rotatably supported via a timing chain (not shown). That is, the rotation of the crankshaft 14 of the internal combustion engine is transmitted to the intake camshaft 13 via the timing chain, and rotates in the same direction as the rotation direction of the crankshaft 14, that is, in the direction of arrow C. Further, as shown in the figure, the intake camshaft 13 has a plurality of valve drive cams 13a corresponding to the cylinders 20 fixed thereto. The valve drive cam 13a is always in contact with the intake valve 25 of each cylinder 20 by a biasing force of a spring (not shown), and the intake shaft 13 rotates in the direction of arrow C, whereby the intake valve 25 is repeatedly opened and closed. Is called.

  Next, the operation of the high pressure pump 5 will be described. When the internal combustion engine is in an operating state, the crankshaft 14 is rotating, so that the intake camshaft 13 rotates in the direction of arrow C similarly to the crankshaft 14. As the intake camshaft 13 rotates in the direction of arrow C, the protrusion 12c of the cam portion 12b of the pump drive cam 12 and the lifter 5g of the high-pressure pump 5 begin to contact each other. Thereby, the lifter 5 starts to move upward in the lifter guide 5h, and the plunger 5e starts to move upward in the pressurizing chamber 5d. The electromagnetic valve 5c is opened in advance by an opening signal from the control device 7, and low pressure fuel is supplied from the low pressure fuel port 5a to the pressurizing chamber 5d as indicated by an arrow D.

  Then, the control device 7 starts the movement of the plunger 5e upward in the pressurizing chamber 5d, that is, in the direction of pressurizing the low-pressure fuel in the pressurizing chamber 5d, and at the same time, the opening degree signal output to the electromagnetic valve 5c. To stop. As a result, the solenoid valve 5c moves in the direction of arrow E by the urging force of a spring (not shown), that is, the communication between the low pressure fuel port 5a and the pressurizing chamber 5d is interrupted. Inflow from the port 5a into the branch passage 10 is prevented. When the plunger 5e moves upward in the pressurizing chamber 5d, the low-pressure fuel in the pressurizing chamber 5d is suddenly pressurized and becomes high-pressure fuel having a predetermined pressure (high pressure). Since the check valve 5f is set to open when the high-pressure fuel reaches a predetermined pressure (high pressure) or higher, the high-pressure fuel in the pressurizing chamber 5d is indicated by an arrow F in FIG. It passes through the high pressure fuel port 5b via the check valve 5f and is discharged into the high pressure passage 11.

After passing the apex (not shown) of the protrusion 12c of the cam portion 12b (the point where the distance from the center of the cam portion 12b is the longest), the plunger 5e and the lifter 5g are moved into the pressurizing chamber 5d and by the urging force of the spring (not shown). It starts to move downward in the lifter guide 5h. At this time,
The control device 7 outputs an opening degree signal to the electromagnetic valve 5c, opens the electromagnetic valve 5c, and sucks low pressure fuel from the low pressure fuel port 5a. By repeating the above, the high pressure pump 5 further pressurizes the low pressure fuel pressurized by the low pressure pump 4 and discharges it to the high pressure passage 11 as high pressure fuel.

  As shown in FIG. 1, the high-pressure fuel discharged from the high-pressure pump 5 to the high-pressure passage 11 is supplied to the plurality of direct injection fuel injection valves 3 via the high-pressure passage 11 and the high-pressure delivery pipe 3a. Reference numeral 15 denotes a high pressure in the high pressure delivery pipe 3a by returning a part of the high pressure fuel in the high pressure delivery pipe 3a to the fuel tank 8 when the pressure of the high pressure fuel in the high pressure delivery pipe 3a is excessively increased. This is a relief valve that keeps the fuel pressure constant.

  The actuator 6 is a discharge suppression means, and is a hydraulic or electric actuator. As shown in FIG. 4A, the actuator 6 is disposed at one end of the intake camshaft 13, and moves the intake camshaft 13 in the direction of arrow G by a drive signal from the control device 7 described later. It is.

  As shown in FIG. 2, the control device 7 includes sensors attached to various parts of the internal combustion engine, for example, an angle sensor 41 attached to the crankshaft 14 for detecting the engine speed, and an accelerator opening for detecting the accelerator opening. The engine speed, the accelerator opening, the intake air amount, and the like are input as input signals from the sensor 42, the flow sensor 43 that detects the intake air amount of air taken into the internal combustion engine, and the like. Further, based on this input signal and various maps stored in the storage unit 7c, the injection control for controlling the injection timing and the injection amount of the port injection fuel injection valve 2 and the direct injection fuel injection valve 3, the low pressure pump 7 Output signals for performing drive control, opening / closing control of the electromagnetic valve 5c of the high-pressure pump 5, drive control of the actuator 6, and the like are output. Specifically, an interface unit 7a that inputs and outputs the input signal and output signal, and a processing unit 7b that calculates the injection timing and the injection amount of the port injection fuel injection valve 2 and the direct injection fuel injection valve 3; The storage unit 7c stores the map and the like. The control device 7 may be realized by dedicated hardware. The processing unit 7b includes a memory and a CPU (Central Processing Unit), and loads and executes a program based on the injection control method for the port injection fuel injection valve 2 and the direct injection fuel injection valve 3 in the memory. Thus, an injection control method or the like may be realized. Further, the control device 7 may be incorporated in an ECU (Engine Control Unit) that controls the internal combustion engine. Further, the storage unit 7c is a non-volatile memory such as a flash memory, a volatile memory such as a ROM (Read Only Memory) or a volatile memory such as a RAM (Random Access Memory) that can be read and written. The memory can be configured by a combination of these.

  Next, the operation of the fuel injection device 1 for the internal combustion engine according to the first embodiment will be described. The processing unit 7 b of the control device 7 first outputs a drive signal to the low-pressure pump 4 to rotate the low-pressure pump 4. Thereby, the fuel in the fuel tank 8 pressurized by the low pressure pump 4 is supplied to the port injection fuel injection valve 2 and the high pressure pump 5 as low pressure fuel. Next, the processing unit 7b detects the pressure of the high-pressure fuel in the high-pressure delivery pump 3a detected by the pressure sensor 3b, the pressure of the high-pressure fuel stored in the storage unit 7c, and the valve of the electromagnetic valve 5c of the high-pressure pump 5. Based on the map that correlates the opening, an opening signal is output to the electromagnetic valve 5c of the high-pressure pump 5, and duty control of the electromagnetic valve 5c is performed. By opening and closing the electromagnetic valve 5c and the reciprocating motion of the plunger 5e by the pump drive cam 12 which is a drive source, the low pressure pump 4 pressurizes and discharges the low pressure fuel, and the direct injection fuel is used as the high pressure fuel. Supply to the injection valve 3.

Next, the processing unit 7b performs injection control of the port injection fuel injection valve 2 and the direct injection fuel injection valve 3 in accordance with the operating state of the internal combustion engine. Specifically, the processing unit 7b determines the operating state of the internal combustion engine from the engine speed, the accelerator opening, the intake air amount, etc. input to the control device 7, for example, the rotational range of the internal combustion engine is high or low. Whether the internal combustion engine load region is a high load region or a low load region, and whether the fuel of the internal combustion engine is a homogeneous fuel or a stratified fuel. Then, the processing unit 7b performs injection control of the port injection fuel injection valve 2 and the direct injection fuel injection valve 3 based on the operating state of the internal combustion engine and the map stored in the storage unit 7c. Here, the map stored in the storage unit 7c is the direct injection region by the direct injection fuel injection valve 3 alone, the direct injection / port injection by both the direct injection fuel injection valve 3 and the port injection fuel injection valve 2. The region is divided into a port injection region by only the fuel injection valve 2 for port injection.

  When determining that the injection region is the direct injection region from the operating state of the internal combustion engine, the processing unit 7b, for example, from the direct injection fuel injection valve 3 to the combustion chamber 24 of each cylinder 20 only once at the end of the compression process of each cylinder 20. An injection signal is output to the direct injection fuel injection valve 3 so that high pressure fuel is directly injected into the fuel injection valve 3. Further, when it is determined from the operating state of the internal combustion engine that the injection region is the direct injection / port injection region, for example, this port injection is performed so that fuel is injected into the intake port 27 only once at the beginning of the intake stroke of each cylinder 20. The injection signal is output to the fuel injection valve 2 and the high pressure fuel is directly injected into the combustion chamber 24 of each cylinder 20 from the direct injection fuel injection valve 3 only once at the end of the compression process of each cylinder 20. An injection signal is output to the direct injection fuel injection valve 3. Further, if it is determined from the operating state of the internal combustion engine that the injection region is the port injection region, for example, the fuel injection for port injection is performed so that fuel is injected into the intake port 27 only once in the initial stage of the intake stroke of each cylinder 20. An injection signal is output to the valve 2.

  Here, when the injection region is not the direct injection region or the direct injection / port injection region, that is, the processing unit 7b of the control device 7, that is, the injection region is the port injection region, and the direct injection fuel injection is a high pressure fuel injection valve. When it is determined that the valve 3 is not operating, a drive signal is output to the actuator 6. When a drive signal is output from the control device 7, the actuator 6 moves the intake camshaft 13 in the direction of arrow G as shown in FIG. When intake camshaft 13 moves in the direction of arrow G, as shown in FIG. 4-3, pump drive cam 12 that is the drive source of high-pressure pump 5 also moves in the direction of arrow G, and the cam portion of pump drive cam 12 12 and the lifter 5g of the high-pressure pump 5 are disconnected. That is, when the high-pressure fuel pressurized and discharged by the high-pressure pump 5 in the direct-injection fuel injection valve 3 is not required, the high-pressure pump 5 and the drive for driving the high-pressure pump 5 by the actuator 6 serving as discharge suppression means. The connection with the pump drive cam 12 as the source is released, and the drive of the high-pressure pump 5 is stopped. Therefore, the high-pressure fuel discharge amount of the high-pressure fuel discharged from the high-pressure pump 5 to the direct injection fuel injection valve 3 via the high-pressure passage 11 can be made substantially zero. As a result, the high-pressure fuel pressurized and discharged by the high-pressure pump 5 is not wastedly supplied to the direct injection fuel injection valve 3, and the waste of fuel supplied to the internal combustion engine can be eliminated. When the processing unit 7b determines that the injection region has changed from the direct injection region or the direct injection / port injection region to the port injection region, the processing unit 7b stops the drive signal output to the actuator 6. As a result, the intake camshaft 13 is moved in the direction opposite to the arrow G direction by a biasing force of a spring (not shown), and the pump drive cam 12 that is a drive source and the high-pressure pump are connected.

  Further, when the direct fuel injection valve 3 which is a high pressure fuel injection valve is not operated, the high pressure pump 5 is disconnected from the pump drive cam 12 which is a drive source by an actuator 6 which is a discharge suppression means. It is not necessary to transmit a force necessary for further pressurizing the low-pressure fuel pressurized by the low-pressure pump 4 from the pump drive cam 12 to the plunger 5c through the lifter 5g. Therefore, no unnecessary friction is applied to the crankshaft 14 that rotates the intake camshaft 13 to which the pump drive cam 12 is fixed, so that unnecessary friction of the internal combustion engine can be eliminated.

Here, when the solenoid valve 5c of the high-pressure pump 5 is opened by the opening signal from the control device 7,
A pulsation occurs in the high-pressure pump 5, and the pulsation propagates to the branch passage 10 and the low-pressure passage 9. Due to this pulsation, there is a possibility that the injection amount of low pressure fuel to be injected from the port injection fuel injection valve 2 which is a low pressure fuel injection valve cannot be injected. However, when the direct injection fuel injection valve 3 which is a high pressure fuel injection valve is not operated, that is, at least when the port injection fuel injection valve 2 is operated, the driving of the high pressure pump 5 is stopped. Therefore, since the pulsation generated in the high pressure pump 5 is suppressed, the pulsation propagating to the branch passage 10 and the low pressure passage 9 is suppressed, and the low pressure fuel of the injection amount based on the injection signal from the control device 7 is used as the fuel for port injection. The fuel can be injected from the injection valve 2.

  FIG. 5A is a diagram of a configuration example of the discharge suppressing unit of the fuel injection device for the internal combustion engine according to the second embodiment. FIG. 5-2 is an explanatory diagram of the operation of the discharge suppression unit of the fuel injection device for the internal combustion engine according to the second embodiment. The fuel injection device 1 for the internal combustion engine according to the second embodiment differs from the fuel injection device 1 for the internal combustion engine according to the first embodiment in that the intake camshaft 13 is moved to move the high-pressure pump 5 and the pump that is the drive source. Discharge suppression means for releasing the connection between the high-pressure pump 5 and the pump drive cam 12 as a drive source by moving the high-pressure pump 5 instead of the actuator 6 as the discharge suppression means for releasing the connection with the drive cam 12. That is, the actuator 16 is provided. The basic configuration and basic operation of the internal combustion engine fuel injection device 1 according to the second embodiment are the same as the basic configuration and basic operation of the internal combustion engine fuel injection device 1 according to the first embodiment. The description is omitted.

  The actuator 16 is discharge suppression means and is a hydraulic actuator. As shown in FIG. 5A, the actuator 16 is fixed to the cylinder head cover 30 so as to cover the high pressure pump 5. The actuator includes an oil storage device 16a, a switching valve 16b, a hydraulic pump 16c, and a partition plate 16d. In the oil storage device 16a, the high-pressure pump 5 is supported by a partition plate 16d so as to be movable up and down. In the oil reservoir 16a, a first oil reservoir 16e and a second oil reservoir 16f are formed by the partition plate 16d.

  The switching valve 16b moves in the direction of the arrow H and switches the oil passage in response to a switching signal from the control device 7. When the switching valve 16b switches the oil passage, oil that is a working fluid supplied from a hydraulic pump 16c, which will be described later, is supplied to one of the first oil reservoir 16e and the second oil reservoir 16f. In response to a drive signal from the control device 7, the hydraulic pump 16c causes the oil stored in the oil tank 16g to pass through the oil passage and the switching valve 16b to the first oil storage portion 16e or the second oil in the oil storage device 16a. It supplies to either one of the storage parts 16f. The partition plate 16d is attached to the high-pressure pump 5, and suppresses the movement of oil between the first oil reservoir 16e and the second oil reservoir 16f. The hydraulic pump 16 may be an oil pump provided in the internal combustion engine.

When the injection region is not the direct injection region or the direct injection / port injection region, that is, the processing unit 7b is in the port injection region, and the direct injection fuel injection valve 3 that is a high-pressure fuel injection valve is not operating. If it is determined that the switching signal is output to the switching valve 16b of the actuator 16, the output of the switching signal is stopped. When the output of the switching signal from the control device 7 is stopped, the switching valve 16b of the actuator 16 moves to the position shown in FIG. 5A by the biasing force of a spring (not shown). When the switching valve 16b moves to the position shown in the figure, the oil supplied from the hydraulic pump 16c to the first oil storage part 16e of the oil storage device 16a before the switching valve 16b moves to the position shown in the figure is The switching valve 16b supplies the second oil reservoir 16f of the oil reservoir 16a as shown in FIG. When oil is supplied to the second oil reservoir 16f, the oil stored in the first oil reservoir 16e is returned to the oil tank 16g by the switching valve 16b. Thereby, the high pressure pump 5 moves in the direction of arrow I in the oil storage device 16a as shown in FIG. When the high pressure pump 5 moves in the direction of arrow I, the connection between the cam portion 12 of the pump drive cam 12 and the lifter 5g of the high pressure pump 5 is released as shown in FIG. That is, when the high-pressure fuel pressurized and discharged by the high-pressure pump 5 in the direct-injection fuel injection valve 3 is not required, the high-pressure pump 5 and the drive for driving the high-pressure pump 5 by the actuator 16 serving as discharge suppression means. The connection with the pump drive cam 12 as the source is released, and the drive of the high-pressure pump 5 is stopped. As a result, as in the first embodiment, waste of fuel supplied to the internal combustion engine can be eliminated.

  When the processing unit 7b determines that the injection region has changed from the direct injection region or the direct injection / port injection region to the port injection region, it outputs a switching signal to the switching valve 16b of the actuator 16. As a result, the switching valve 16b moves in the direction of arrow H as shown in FIG. 5-1, and the second oil storage of the oil storage device 16a from the hydraulic pump 16c before the switching valve 16b moves in the direction of arrow H. The oil that has been supplied to the portion 16f is supplied to the first oil storage portion 16e of the oil storage device 16a by the switching valve 16b as shown in FIG. When oil is supplied to the first oil reservoir 16e, the oil stored in the second oil reservoir 16f is returned to the oil tank 16g by the switching valve 16b that has moved in the direction of arrow H. As a result, the high-pressure pump 5 moves in the oil storage device 16a in the direction opposite to the arrow I direction as shown in FIG. 5-2, and as shown in FIG. And a high-pressure pump are connected.

  Further, since the high-pressure pump 5 is disconnected from the pump drive cam 12 serving as a drive source by an actuator 16 serving as a discharge restraining means, the low-pressure pump 4 pressurizes the plunger 5c via the lifter 5g. It is not necessary to transmit the force required to further pressurize the fuel. Therefore, as in the first embodiment, useless friction of the internal combustion engine can be eliminated. Further, when the direct injection fuel injection valve 3 which is a high pressure fuel injection valve is not operated, that is, at least when the port injection fuel injection valve 2 is operated, the drive of the high pressure pump 5 is stopped. Further, the pulsation generated in the high-pressure pump 5 is suppressed, and an injection amount of low-pressure fuel based on the injection signal from the control device 7 can be injected from the port injection fuel injection valve 2.

  The fuel injection device 1 for the internal combustion engine according to the third embodiment is different from the fuel injection device 1 for the internal combustion engine according to the first embodiment in that the intake camshaft 13 is moved to move the high-pressure pump 5 and the pump as a drive source. Without providing the actuator 6 which is a discharge suppressing means for releasing the connection with the drive cam 12, so that the low pressure fuel is not supplied to the high pressure pump 5 when the direct injection fuel injection valve 3 which is a high pressure fuel injection valve is not operated. It is a point which became the discharge suppression means by controlling the solenoid valve 5c of the high-pressure pump 5. The basic configuration and basic operation of the internal combustion engine fuel injection device 1 according to the third embodiment are the same as the basic configuration and basic operation of the internal combustion engine fuel injection device 1 according to the first embodiment. The description is omitted.

Here, even if the injection region is the port injection region, the processing unit 7b outputs an opening degree signal to the electromagnetic valve 5c of the high-pressure pump 5 and performs duty control on the electromagnetic valve 5c. However, in the fuel injection device 1 for the internal combustion engine according to the third embodiment, the processing unit 7b is configured so that the injection region is not the direct injection region or the direct injection / port injection region, that is, the injection region is the port injection region. If it is determined that the direct injection fuel injection valve 3 that is the injection valve is not operating, the opening degree signal is not always output to the electromagnetic valve 5c of the high pressure pump 5. That is, even when the normal injection region is the port injection region, duty control of the electromagnetic valve 5c, which is performed, is not performed, and the electromagnetic valve 5c is always closed. Therefore, even if the plunger 5e of the high pressure pump 5 is reciprocated by the pump drive cam 12 which is a drive source, the low pressure fuel is not supplied from the low pressure fuel port 5a into the pressurizing chamber 5d. Therefore, the amount of high-pressure fuel discharged from the high-pressure pump 5 through the high-pressure passage 11 to the direct-injection fuel injection valve 3 can be made substantially zero. As a result, the high-pressure fuel pressurized and discharged by the high-pressure pump 5 is not wastedly supplied to the direct injection fuel injection valve 3, and the waste of fuel supplied to the internal combustion engine can be eliminated.

  Further, since the solenoid valve 5c of the high-pressure pump 5 serving as the discharge suppressing means does not supply the low-pressure fuel to the high-pressure pump 5, the pump drive cam 12 is pressurized by the low-pressure pump 4 to the plunger 5c via the lifter 5g. It is not necessary to transmit the force required to further pressurize the fuel. Therefore, as in the first embodiment, useless friction of the internal combustion engine can be eliminated. Further, when the direct injection fuel injection valve 3 which is a high pressure fuel injection valve is not operated, that is, at least when the port injection fuel injection valve 2 is operated, the electromagnetic valve 5c of the high pressure pump 5 which is a discharge suppressing means Since the pump 5 is not supplied, the pulsation generated in the high-pressure pump 5 is suppressed as in the first embodiment, and an injection amount of low-pressure fuel based on the injection signal from the control device 7 is supplied from the port injection fuel injection valve 2. Can be injected.

  In the above embodiment, the pump drive cam 12 that is the drive source of the high-pressure pump 5 is fixed to the intake camshaft 13, but the present invention is not limited to this, and the exhaust valve 26 shown in FIG. You may fix to the exhaust camshaft which opens and closes.

  As described above, the fuel injection device for an internal combustion engine according to the present invention is useful for a fuel injection device for an internal combustion engine that includes a high-pressure pump that is driven according to the operating state of the internal combustion engine. During operation, waste of fuel supplied to the internal combustion engine by the high-pressure pump and waste of fuel supplied to the internal combustion engine can be eliminated.

1 is a diagram illustrating a configuration example of a fuel injection device for an internal combustion engine according to a first embodiment; It is a figure which shows the structural example of an internal combustion engine. 1 is a diagram illustrating a configuration example of a high-pressure pump of a fuel injection device for an internal combustion engine according to Embodiment 1. FIG. It is operation | movement explanatory drawing of a high pressure pump. FIG. 3 is a diagram illustrating a configuration example of a discharge suppression unit of the fuel injection device for the internal combustion engine according to the first embodiment. FIG. 4 is an enlarged perspective view of a portion A in FIG. 4-1. FIG. 3 is an operation explanatory diagram of a discharge suppression unit of the fuel injection device for the internal combustion engine according to the first embodiment. FIG. 6 is a diagram illustrating a configuration example of a discharge suppression unit of a fuel injection device for an internal combustion engine according to a second embodiment. FIG. 6 is an operation explanatory view of a discharge suppressing means of a fuel injection device for an internal combustion engine according to a second embodiment.

Explanation of symbols

1 Fuel Injection Device 2 Port Injection Fuel Injection Valve (Low Pressure Fuel Injection Valve)
3. Fuel injection valve for direct injection (high pressure fuel injection valve)
4 Low pressure pump 5 High pressure pump 6 Actuator (Discharge suppression means)
7 Control Device 8 Fuel Tank 9 Low Pressure Passage 10 Branching Passage 11 High Pressure Passage 12 Pump Drive Cam 13 Intake Cam Shaft 14 Crankshaft 15 Relief Valve 16 Actuator (Discharge Suppression Unit)
20 cylinder 30 cylinder head cover

Claims (3)

Pressurizing with a low-pressure pump, supplying low-pressure fuel to be discharged to a high-pressure pump, further pressurizing the low-pressure fuel with a high-pressure pump, and pressurizing with a high-pressure fuel injection valve for injecting high-pressure fuel to be discharged; In a fuel injection device for an internal combustion engine comprising a low pressure fuel injection valve for injecting discharged low pressure fuel,
A fuel injection device for an internal combustion engine, comprising: a discharge suppressing means for reducing a high-pressure fuel discharge amount of the high-pressure pump to substantially zero when the high-pressure fuel injection valve is not operated.   2. The fuel injection device for an internal combustion engine according to claim 1, wherein the discharge suppression unit releases the connection between the high-pressure pump and a drive source that drives the high-pressure pump.   The fuel injection device for an internal combustion engine according to claim 1, wherein the discharge suppression means does not supply the low-pressure fuel to the high-pressure pump.

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