JP2009068462A - Fuel supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel supply device capable of achieving at least either one of restriction of deterioration in emissions and improvement of fuel economy. <P>SOLUTION: This fuel supply device is furnished with a relief valve 7 provided between a low pressure fuel system to which fuel pressurized by a low pressure pump is supplied and a high pressure fuel system to which fuel further pressurized by a high pressure pump is supplied, to open by valve opening force in the valve opening direction by fuel pressure of the fuel of the high pressure fuel system of more than opening valve fuel pressure and to return the fuel of the high pressure fuel system to the low pressure fuel system. The relief valve 7 has a return spring 73 to generate valve closing force in the valve closing direction and a hiss mechanism 74 to mechanically close the valve by the return spring 73. The hiss mechanism 74 is constituted so that a click member 74b and a recessed part 74a are engaged with each other by a pressure spring 74c when the valve opens and the click member 74b and the recessed part 74a are disengaged by valve-closing force when it becomes less than the valve-closing fuel pressure. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel supply device, and more particularly, to a fuel supply device including a relief valve that returns a high-pressure fuel system fuel to a low-pressure fuel system.

  A fuel supply device that supplies 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 performs in-cylinder injection that directly injects fuel into a combustion chamber in a cylinder of the internal combustion engine. There is.

  In a fuel supply device that performs in-cylinder injection, it is necessary to increase the fuel pressure of the fuel. Therefore, the fuel supply device that performs in-cylinder injection includes a high-pressure pump that further pressurizes the low-pressure fuel fuel pressurized by the low-pressure pump. The high-pressure fuel fuel pressurized by the high-pressure pump is directly injected into the combustion chamber in the cylinder by the injector. Here, a relief valve is provided between the high-pressure fuel system and the low-pressure fuel system. In the relief valve, the valve opening force generated by the fuel pressure of the high-pressure fuel system and the valve closing force in the valve closing direction opposite to the valve opening direction by the spring act on the valve body. The valve opening force moves the valve body in the valve opening direction against the valve closing force when the fuel pressure of the fuel in the high-pressure fuel system becomes equal to or higher than the valve opening fuel pressure. As a result, the valve body is separated from the valve main body, the relief valve is opened, and the high-pressure fuel system fuel is returned to the low-pressure fuel system.

  In the fuel supply device that performs in-cylinder injection, as shown in Patent Document 1, in order to suppress a decrease in the fuel pressure of the fuel in the high-pressure fuel system at the time of restart, the high-pressure pump is operated when the internal combustion engine is stopped, A technique for boosting the pressure of the system fuel has been proposed. Further, as shown in Patent Document 2, in order to suppress the sticking of the members constituting the relief valve, the high-pressure pump is operated when the internal combustion engine is stopped to increase the fuel of the high-pressure fuel system above the valve opening fuel pressure, A technique for opening a relief valve has been proposed.

  In the prior arts disclosed in Patent Documents 1 and 2 described above, when the internal combustion engine is stopped, the fuel of the high-pressure fuel system is increased to about the valve opening fuel pressure at which the relief valve opens. Here, the valve opening fuel pressure is set higher than the fuel pressure at which in-cylinder injection can be performed. Therefore, in the prior arts disclosed in Patent Documents 1 and 2, the fuel pressure of the high-pressure fuel system becomes high when the internal combustion engine is stopped. Here, if the fuel pressure of the high-pressure fuel system is high when the internal combustion engine is stopped, there is a risk of fuel leakage from the injector even if the sealing performance of the injector is improved. In other words, if the fuel pressure of the high-pressure fuel system is high when the internal combustion engine is stopped, there is a problem that the fuel leakage from the injector cannot be suppressed and the emission deteriorates.

  Therefore, in order to suppress the deterioration of emissions, it is important to lower the fuel pressure of the high-pressure fuel system when the internal combustion engine is stopped. The fuel supply device that performs in-cylinder injection shown in Patent Document 3 includes a relief valve having an actuator that is forcibly opened by electromagnetic force, and forcibly opens the relief valve by the actuator when the internal combustion engine is stopped. Therefore, the fuel pressure of the high-pressure fuel system is lowered.

JP 2001-317389 A JP-A-6-249101 JP-A-9-42109

  As described above, in order to forcibly open the relief valve by the actuator, it is necessary to counter the valve closing force. Here, the valve opening force due to the fuel pressure of the high-pressure fuel system fuel acts on the valve body. Therefore, the electromagnetic force for forcibly opening the relief valve by the actuator reduces the fuel pressure of the high-pressure fuel system fuel. Increase with. In general, the engine speed is low because the engine is idling immediately before the internal combustion engine is stopped. Here, the discharge capacity of the high-pressure pump changes in the internal combustion engine based on the engine speed. Therefore, immediately before the internal combustion engine is stopped, the fuel pressure of the fuel of the high-pressure fuel system is often low, and there is a possibility that the electromagnetic force for forcibly opening the relief valve by the actuator at the time of stop increases. As a result, when the relief valve is forcibly opened by the actuator at the time of stoppage, there is a problem that a large amount of electric power is consumed by the actuator and fuel consumption deteriorates.

  The present invention has been made in view of the above, and an object of the present invention is to provide a fuel supply device for an internal combustion engine that can achieve at least one of suppression of deterioration of emission and improvement of fuel consumption. is there.

  In order to solve the above-described problems and achieve the object, in the present invention, a low-pressure pump that pressurizes fuel in a fuel storage chamber, a high-pressure pump that further pressurizes fuel pressurized by the low-pressure pump, and the high-pressure pump An injector for injecting further pressurized fuel into the internal combustion engine, a low-pressure fuel system on the low-pressure pump side relative to the high-pressure pump, a high-pressure fuel system on the injector side relative to the high-pressure pump, and the high-pressure fuel system; The high-pressure fuel system is opened with a valve opening force in the valve-opening direction by the fuel pressure of the high-pressure fuel system that is provided between the low-pressure fuel system and the fuel pressure of the high-pressure fuel system is equal to or higher than the valve-opening fuel pressure. A relief valve for returning, wherein the relief valve has a valve closing means for generating a valve closing force in a valve closing direction opposite to the valve opening direction, and a valve closing lower than the valve opening fuel pressure Below fuel pressure , And having a hysteresis mechanism which is closed by mechanically the closed unit.

  According to the present invention, in the fuel supply device, the relief valve closes when a valve body is seated on a valve body, and the His mechanism closes the valve body when the valve body is opened. It is characterized by restricting movement in the direction.

  According to the present invention, in the fuel supply apparatus, the His mechanism includes a recess formed in the valve body, a claw member that is supported so as to be able to fit into the recess when the valve is opened, and a recess in the claw member. The claw member and the recess are fitted by the pressing means when the valve is opened, and the claw member and the recess are fitted when the fuel pressure is equal to or lower than the valve closing fuel pressure. It is characterized by being released by the closing force.

  According to the present invention, in the fuel supply apparatus, the His mechanism includes a first magnet member provided on the valve body and a second magnet member provided on the valve body, wherein the first magnet member The relative distance between the second magnet member and the second magnet member is smaller when the valve is opened than when the valve is closed, and the mutual attractive force is increased.

  In the fuel supply apparatus according to the present invention, the His mechanism adjusts at least a valve closing speed to a speed at which the valve closing means closes the valve closing fuel pressure.

  According to the present invention, in the fuel supply device, the relief valve is closed when a valve body is seated on the valve body, and the hysteresis mechanism is connected to the valve body and the valve body. The cylinder mechanism reduces the moving speed of the valve body in the valve closing direction when the fuel flows in.

  In the fuel supply apparatus according to the present invention, when the internal combustion engine is stopped, the fuel pressure of the fuel in the high-pressure fuel system is increased to the valve opening fuel pressure, and then the high-pressure pump is stopped.

  According to the present invention, in the fuel supply apparatus, the relief valve further includes an actuator for forcibly opening the valve. When the internal valve engine stops, the actuator is operated to The valve is opened automatically.

  According to the present invention, in the fuel supply device, the forced valve opening condition is that the fuel pressure in the high-pressure fuel system cannot be increased to the valve-opening fuel pressure, or the fuel pressure in the high-pressure fuel system is lower than the valve closing fuel pressure. It is characterized in that it is at least one of the cases.

  In the present invention, the relief valve is opened when the fuel pressure of the high-pressure fuel system is equal to or higher than the open fuel pressure, and the fuel pressure of the high-pressure fuel system is decreased by returning the high-pressure fuel system fuel to the low-pressure fuel system. When the valve-closing fuel pressure is reached, the valve-opening state maintained by the His mechanism is shifted to the valve-closing state by the valve-closing means. Therefore, when the internal combustion engine is stopped, the fuel pressure of the high-pressure fuel system can be lowered, and fuel leakage from the injector can be suppressed. Thereby, there exists an effect that the deterioration of an emission can be suppressed.

  Further, in the present invention, there is provided a hysteresis mechanism that mechanically adjusts the valve closing speed with the valve closing fuel pressure to be closed by the valve closing means by restricting the movement of the valve body in the valve closing direction when the valve is opened. When the fuel pressure of the fuel of the high pressure fuel system becomes the valve closing fuel pressure, the relief valve is closed by the valve closing means. Therefore, when the internal combustion engine is stopped, power consumption can be suppressed as compared with a case where the relief valve is forcibly opened by the actuator. Thereby, there exists an effect that a fuel consumption can be improved.

  Further, in the present invention, an actuator that forcibly opens the relief valve when the fuel pressure in the high-pressure fuel system cannot be increased to the valve-opening fuel pressure or when the fuel pressure in the high-pressure fuel system is made lower than the valve-closing fuel pressure. Is provided. Therefore, the relief valve can be reliably opened even in the case of an abnormality in the high pressure pump, an abnormality in the His mechanism, a sudden engine stop of the internal combustion engine, etc., and the fuel pressure of the fuel in the high pressure fuel system can be lowered. . In addition, even when the temperature of the internal combustion engine or the fuel of the high-pressure fuel system is high and the high-pressure fuel system is abnormally boosted after the internal combustion engine is stopped, the relief valve can be reliably opened. As a result, it is possible to reliably suppress the deterioration of emission and to improve the fuel efficiency reliably.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. 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 supply device described below is a device that supplies 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. Further, in the following embodiment, a fuel supply device in a V-type six-cylinder internal combustion engine having three cylinders as one cylinder group will be described, but the present invention is not limited to this, and four cylinders are provided. The present invention can also be used for a V-type 8-cylinder internal combustion engine that forms one cylinder group, an in-line 4-cylinder internal combustion engine that includes four cylinders in series, an in-line 6-cylinder internal combustion engine, and the like.

[Embodiment 1]
FIG. 1 is a diagram showing a configuration example of a fuel supply apparatus according to the present invention. FIG. 2 is a diagram illustrating a relief valve (when the valve is closed) of the fuel supply apparatus according to the first embodiment. FIG. 3 is a diagram illustrating a relief valve (when the valve is opened) of the fuel supply apparatus according to the first embodiment. As shown in FIG. 1, the fuel supply device 1 according to the first embodiment includes a low pressure pump 2, a low pressure fuel system 3, a high pressure pump 4, a high pressure fuel system 5, an injector 6, and a relief valve 7. It is configured. Reference numeral 8 denotes a fuel tank that is a fuel storage chamber for storing fuel to be supplied to the internal combustion engine 100. Reference numeral 9 denotes an ECU that controls the operating state of the internal combustion engine 100. Reference numeral 10 denotes a fuel pressure sensor that detects the fuel pressure of the fuel in the high-pressure fuel system 5 and outputs it to the ECU 9. Reference numeral 11 denotes a relief pipe that connects the low pressure fuel system 3 and the high pressure fuel system 5.

  The low pressure pump 2 sucks the fuel in the fuel tank 8 through a strainer 21 and a filter (not shown), pressurizes the sucked fuel, and discharges it as low pressure fuel. The discharged low pressure fuel is supplied to the low pressure fuel system 3. The low-pressure pump 2 is an electric type equipped with a motor (not shown), and the operation is controlled by the drive control of the motor being performed by the ECU 9.

  The low-pressure fuel system 3 constitutes the low-pressure pump 2 side of the high-pressure pump 4, that is, between the high-pressure pump 4 and the low-pressure pump 2. In the first embodiment, the low pressure fuel pipe 31 and the pressure regulator 32 are used. The low-pressure fuel pipe 31 connects the low-pressure pump 2 and the high-pressure pump 4. Therefore, the low pressure fuel discharged from the low pressure pump 2 is supplied to the high pressure pump 4 via the low pressure fuel pipe 31. The pressure regulator 32 is a check valve that returns the low-pressure fuel of the low-pressure fuel system 3 to the fuel tank 8 by opening the valve. The pressure regulator 32 opens when the fuel pressure of the low-pressure fuel in the low-pressure fuel system 3 exceeds a predetermined low pressure. Accordingly, the low-pressure fuel in the low-pressure fuel system 3 is maintained near the predetermined low pressure.

  The high-pressure pump 4 further pressurizes low-pressure fuel that is fuel pressurized by the low-pressure pump 2. In the high-pressure pump 4, the pump 42 connected to the intake-side or exhaust-side camshaft 101 of the internal combustion engine 100 rotates in conjunction with the rotation of a crankshaft (not shown) of the internal combustion engine 100, so that the plunger 42 reciprocates. Exercise. The high-pressure pump 4 sucks the low-pressure fuel of the low-pressure fuel system 3 into the pressurizing chamber 41 through the low-pressure fuel pipe 31 by the reciprocating motion of the plunger 42 in the pressurizing chamber 41. The high-pressure pump 4 further pressurizes the sucked low-pressure fuel in the pressurizing chamber 41 and discharges it as high-pressure fuel. The discharged high pressure fuel is supplied to the high pressure fuel system 5. In other words, the discharge capacity of the high-pressure pump 4 changes based on the engine speed of the internal combustion engine 100. Further, the high-pressure pump 4 has a metering valve 43. The metering valve 43 includes an actuator 43b that moves the valve element 43a by electromagnetic force, and the low pressure fuel flowing into the pressurizing chamber 41 is metered by the drive control of the actuator 43b by the ECU 9. . The ECU 9 controls the driving of the actuator 43b based on the fuel pressure of the high-pressure fuel that is the fuel in the high-pressure fuel system 5 detected by the fuel pressure sensor 10 so that the high-pressure fuel is adjusted to the first predetermined high pressure. The low-pressure fuel flowing into the pressurizing chamber 41 is metered by the valve 43.

  The high-pressure fuel system 5 constitutes the injector 6 side of the high-pressure pump 4, that is, between the injector 6 and the high-pressure pump 4. In the first embodiment, the high-pressure fuel pipe 51, the check valve 52, the first delivery pipe 53, the communication pipe 54, and the second delivery pipe 55 are configured. The high-pressure fuel pipe 51 connects the high-pressure pump 4 and the first delivery pipe 53. Accordingly, the high-pressure fuel discharged from the high-pressure pump 4 is supplied to the first delivery pipe 53 via the high-pressure fuel pipe 51. The check valve 52 is provided in the middle of the high-pressure fuel pipe 51, and supplies the high-pressure fuel discharged from the high-pressure pump 4 to the high-pressure fuel system 5 by opening the valve. The check valve 52 opens when the fuel pressure of the high-pressure fuel discharged from the high-pressure pump 4 becomes equal to or higher than a second predetermined high pressure (a value lower than the first predetermined high pressure), and the high-pressure fuel in the high-pressure fuel system 5 Returning to the high-pressure pump 4 is prohibited. The first delivery pipe 53 connects the high pressure fuel pipe 51 and the injector 6. Accordingly, the high-pressure fuel discharged from the high-pressure pump 4 is supplied to the injector 6 via the high-pressure fuel pipe 51 and the first delivery pipe 53. Here, the injectors 6 corresponding to the three cylinders are connected to the first delivery pipe 53. The communication pipe 54 connects the first delivery pipe 53 and the second delivery pipe 55. Accordingly, the high-pressure fuel discharged from the high-pressure pump 4 is supplied to the communication pipe 54 via the high-pressure fuel pipe 51 and the first delivery pipe 53. The second delivery pipe 55 connects the communication pipe 54 and the injector 6. Accordingly, the high-pressure fuel discharged from the high-pressure pump 4 is supplied to the injector 6 via the second delivery pipe 55. Here, the injector 6 corresponding to each of the three cylinders is connected to the second delivery pipe 55.

  The injector 6 injects high-pressure fuel, which is fuel further pressurized by the high-pressure pump 4, into the internal combustion engine 100. In the first embodiment, the injector 6 directly injects fuel into the fuel chamber of each cylinder (not shown) of the internal combustion engine 100. The injector 6 performs injection control such as fuel injection amount and fuel injection timing by the ECU 9.

  The relief valve 7 returns the high-pressure fuel from the high-pressure fuel system 5 to the low-pressure fuel system 3. The relief valve 7 is provided in the middle of the relief pipe 11, and is provided between the high pressure fuel system 5 and the low pressure fuel system 3. As shown in FIGS. 2 and 3, the relief valve 7 includes a valve body 71, a valve body 72, a return spring 73, and a hysteresis mechanism 74.

  The valve body 71 is formed with a valve body hollow portion 71a and a His mechanism hollow portion 71b communicating with the valve body hollow portion 71a. The hollow part 71a for valve bodies is cylindrical shape, and the both ends of an axial direction are opened and formed. The hollow part 71a for valve bodies is connected with the relief piping 11, and one end part (right side end part of FIG. 2 and FIG. 3) is connected with the high-pressure fuel system 5 among the axial both ends, and the other Is connected to the low-pressure fuel system 3 (the left end in FIGS. 2 and 3). Further, a valve seat 71c is formed at one end of the valve body hollow portion 71a. The His mechanism hollow portion 71b is formed at a plurality of positions, for example, at equal intervals in the circumferential direction with respect to the valve body hollow portion 71a. Each His mechanism hollow portion 71b is formed to extend in the radial direction. The valve seat portion 71c is formed in a ring shape so as to face a contact portion 72a (described later) of the valve body 72 in the axial direction.

  The valve body 72 is seated on or separated from the valve body 71. The valve body 72 is inserted into the valve body hollow portion 71a so as to be movable in the axial direction. The valve body 72 has a contact portion 72a, a communication hollow portion 72b, a cutout portion 72c, and a communication hole 72d.

  The contact portion 72a is in contact with the valve seat portion 71c of the valve body 71, and is formed at one end portion (the left side in FIGS. 2 and 3) of both end portions in the axial direction of the valve body 72. . The contact part 72a is configured by a curved surface, for example, a hemispherical surface. The contact portion when the contact portion 72a and the valve seat portion 71c come into contact with each other is sealed in a ring shape, and the relief pipe 11 is blocked by blocking the valve body hollow portion 71a. That is, the valve body 72 is seated on the valve body 71 and the relief valve is closed (see FIG. 2). Further, when the contact portion 72a in contact with the valve seat portion 71c moves away from the valve seat portion 71c due to the valve body 72 moving in the valve opening direction, the shutoff of the valve body hollow portion 71a is released, and the relief pipe 11 is shut off. Is released. That is, the valve body 72 is separated from the valve body 71, and the relief valve is opened (see FIG. 3). The valve body 72 is subjected to a valve opening force F1 in the other axial direction, that is, the valve opening direction due to the fuel pressure of the high pressure fuel in the high pressure fuel system 5 flowing into the valve body hollow portion 71a of the valve body 71. . The valve opening force F1 increases as the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 increases.

  The communication hollow portion 72b has one end portion in the axial direction (the right side in FIGS. 2 and 3) closed by the contact portion 72a, and the other end portion (the left side in FIGS. 2 and 3) is the valve body hollow portion. It is a cylindrical shape opened to the low-pressure fuel system 3 side of 71a. The cutout portion 72c communicates the high-pressure fuel system 5 side of the valve body hollow portion 71a with the communication hole 72d. In the first embodiment, the cutout portions 72c are formed at a plurality of locations at regular intervals in the circumferential direction with respect to the valve body 72, for example. Each notch 72c has one end (right side in FIGS. 2 and 3) in the axial direction that opens to the high pressure fuel system 5 side of the valve body hollow portion 71a, and the other end (FIGS. 2 and 3). Are formed in the respective communication holes 72d. The communication hole 72d communicates the cutout portion 72c and the communication hollow portion 72b. In the first embodiment, the communication holes 72d are formed at a plurality of locations corresponding to the notches 72c with respect to the valve body 72, respectively. Each communication hole 72d is formed such that the radially outer side opens to each notch 72c, and the radially inner side opens to the communication hollow portion 72b. Therefore, when the relief valve 7 is opened, the valve body hollow portion 71a blocked by the valve body 72 is communicated by the notch portion 72c, the communication hole 72d, and the communication hollow portion 72b, and the high pressure fuel system 5 has a high pressure. The fuel is returned to the low pressure fuel system 3.

  The return spring 73 is a valve closing means, and generates a valve closing force F2 in one of the axial directions, that is, in a valve closing direction opposite to the valve opening direction. The return spring 73 is arranged in a state of being biased between the valve main body 71 and the valve body 72, and generates an inactive force as the valve closing force F2. The generated valve closing force F2 acts on the valve body 72. That is, a valve opening force F1 in the valve opening direction due to the fuel pressure of the high pressure fuel in the high pressure fuel system 5 and a valve closing force F2 in the valve closing direction due to the return spring 73 act on the valve body 72. Here, the return spring 73 is closed so that the valve body 72 cannot be moved in the valve opening direction by the valve opening force F1 acting on the valve body 72 when the fuel pressure of the high pressure fuel in the high pressure fuel system 5 is less than the valve opening fuel pressure. The valve force F2 is set to act on the valve body 72. Therefore, the valve body 72 is opened by the valve opening force F1 in the valve opening direction generated by the fuel pressure of the fuel of the high-pressure fuel system 5 equal to or higher than the valve opening fuel pressure, so that the relief valve 7 is opened.

  The hysteresis mechanism 74 is mechanically closed by the return spring 73 at a valve closing fuel pressure lower than the valve opening fuel pressure. In the first embodiment, the hysteresis mechanism 74 mechanically restricts the movement of the valve body 72 in the valve closing direction when the relief valve 7 is opened. The His mechanism 74 is provided at a plurality of locations corresponding to the respective His mechanism hollow portions 71b. The hysteresis mechanism 74 includes a recess 74a, a claw member 74b, and a pressing spring 74c.

  The recess 74 a is formed in the valve body 72. The recess 74a is formed on the outer peripheral surface of the valve body 72 at a position facing the respective his mechanism hollow portions 71b in the radial direction when the relief valve 7 is opened. The claw member 74b is supported so as to be able to fit into the recess 74a when the valve is opened. The claw member 74b is inserted into each of the His mechanism hollow portions 71b and supported so as to be movable in the radial direction. The pressing spring 74c is a pressing unit that presses the claw member 74b toward the concave portion 74a. The pressing spring 74c is inserted into each of the His mechanism hollow portions 71b and is arranged to be urged between the valve body 71 and the claw member 74b, so that an ineffective force acts on the claw member 74b, and the claw member 74b is recessed. Press to the 74a side. When the relief valve 7 is opened and the valve body 72 moves in the valve opening direction, when the concave portion 74a and the claw member 74b face each other in the radial direction, the claw member 74b is pressed toward the concave portion 74a by the pressing spring 74c. Yes. Therefore, when the relief valve is opened, the claw member 74b and the recess 74a are fitted (see FIG. 3). Accordingly, the hysteresis mechanism 74 can mechanically restrict the movement of the valve body 72 in the valve closing direction when the relief valve 7 is opened. Here, the pressing spring 74c is operated by the return spring 73 when the valve opening force F1 due to the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 that is lower than the valve closing fuel pressure lower than the valve opening fuel pressure is acting on the valve body 72. It is set so that the fitting between the claw member 74b and the recess 74a is released by the valve closing force F2 acting on the valve body 72. Therefore, when the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 becomes equal to or less than the valve closing fuel pressure, the valve body 72 tends to move in the valve closing direction due to the difference between the valve closing force F2 and the valve opening force F1, thereby The fitting between 74b and the recess 74a is released. That is, when the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 becomes equal to or less than the valve closing fuel pressure, the fitting between the claw member 74b and the recess 74a is released by the valve closing force, the valve body 72 moves in the valve closing direction, and the relief valve 7 The valve is closed (see FIG. 2).

  Next, the operation of the relief valve 7 according to the first embodiment when the internal combustion engine 100 is stopped will be described. First, the ECU 9 determines whether or not the internal combustion engine 100 is stopped. If the ECU 9 determines that the internal combustion engine 100 is stopped, the ECU 9 increases the fuel pressure of the high pressure fuel in the high pressure fuel system 5 to the valve opening fuel pressure. Here, the ECU 9 controls the driving of the actuator 43b, measures the low pressure fuel flowing into the pressurizing chamber 41 by the metering valve 43, and boosts the fuel pressure of the high pressure fuel in the high pressure fuel system 5 to the valve opening fuel pressure. The ECU 9 determines whether or not the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 detected by the fuel pressure sensor 10 is equal to or higher than the valve opening fuel pressure, and the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 is equal to or higher than the valve opening fuel pressure. If it is determined that, the high-pressure pump 4 is stopped. Here, the ECU 9 stops ignition of a spark plug (not shown) of the internal combustion engine 100 and stops fuel injection from the injector 6, thereby reducing the engine speed to 0 and stopping the high-pressure pump 4.

  When the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 becomes equal to or higher than the valve opening fuel pressure, the valve body 72 is separated from the valve body 71 and the relief valve 7 is opened as shown in FIG. When the relief valve 7 is opened, the recess 74a of the hysteresis mechanism 74 and the claw member 74b are fitted, and the hysteresis mechanism 74 restricts the valve body 72 from moving in the valve closing direction. When the relief valve 7 is opened, the shutoff of the valve body hollow portion 71 a is released, and the high-pressure fuel in the high-pressure fuel system 5 is returned to the low-pressure fuel system 3 through the valve body 72. As a result, the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 begins to decrease.

  When the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 is equal to or lower than the valve closing fuel pressure (for example, a predetermined low pressure at which the pressure regulator 32 opens), as shown in FIG. The joint is released by the valve closing force acting on the valve body 72, the valve body 72 moves in the valve closing direction, the valve body 72 is seated on the valve body 71, and the relief valve 7 is closed.

  As described above, the relief valve 7 is opened when the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 is equal to or higher than the valve-opening fuel pressure, and the fuel in the high-pressure fuel system 5 is returned to the low-pressure fuel system. When the fuel pressure of the fuel decreases and the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 becomes the valve closing fuel pressure, the valve opening state maintained by the hysteresis mechanism 74 is shifted to the valve closing state by the return spring 73. Therefore, when the internal combustion engine 100 is stopped, the fuel pressure of the fuel in the high-pressure fuel system 5 can be lowered, and fuel leakage from the injector can be suppressed. Thereby, the deterioration of emission can be suppressed.

  Further, when the relief valve 7 is opened, the movement of the valve body 72 in the valve closing direction is regulated by a mechanical mechanism 74 that mechanically engages the recess 74a and the claw member 74b. When the fuel pressure of the high pressure fuel becomes the valve closing fuel pressure, the relief valve 7 is closed by the return spring 73. Therefore, when the internal combustion engine 100 is stopped, power consumption can be suppressed as compared with the case where the relief valve 7 is forcibly opened by the actuator. Thereby, fuel consumption can be improved.

[Embodiment 2]
FIG. 4 is a diagram illustrating a relief valve (when the valve is closed) of the fuel supply apparatus according to the second embodiment. FIG. 5 is a diagram illustrating a relief valve (when the valve is opened) of the fuel supply apparatus according to the second embodiment. The difference between the second embodiment and the first embodiment is that the movement of the valve body 72 in the valve closing direction when the relief valve 7 is opened is mechanically controlled by fitting the recess 74a and the claw member 74b. This is not a hysteresis mechanism 74 but a hysteresis mechanism 75 which is mechanically performed by an attractive force generated by a magnet. Note that the basic configuration of the fuel supply apparatus according to the second embodiment is the same as the basic configuration of the fuel supply apparatus 1 according to the first embodiment, and a description thereof will be omitted.

  The His mechanism 75 is mechanically closed by the return spring 73 at a valve closing fuel pressure lower than the valve opening fuel pressure. In the second embodiment, the hysteresis mechanism 75 mechanically restricts the movement of the valve body 72 in the valve closing direction when the relief valve 7 is opened. The hysteresis mechanism 75 includes a first magnet member 75a and a second magnet member 75b.

  The first magnet member 75 a is provided on the valve body 72. In the second embodiment, the first magnet member 75a has a ring shape, and one end portion in the axial direction (right side in FIGS. 4 and 5) is the other end portion in the axial direction of the valve body 72 (see FIG. 4 and FIG. 5 is formed integrally with the valve body 72 so as to face the left side. Here, in the first magnet member 75a, one end portion (right side in FIGS. 4 and 5) in the axial direction is an N pole, and the other end portion (left side in FIGS. 4 and 5) is an S pole. It is configured. The second magnet member 75 b is provided on the valve body 71. In the second embodiment, the second magnet member 75 b has a ring shape and is inserted into the valve body hollow portion 71 a of the valve body 71. The second magnet member 75b has the other end portion (left side in FIGS. 4 and 5) in the axial direction and the other end portion (left side in FIGS. 4 and 5) in the axial direction of the valve body hollow portion 71a. Opposed to the valve body 71 is fixed. Therefore, the relative distance between the first magnet member 75a and the second magnet member 75b decreases when the relief valve 7 is opened (see FIG. 4) rather than when the relief valve 7 is closed (see FIG. 5). Here, as for the 2nd magnet member 75b, one edge part (right side in FIG. 4 and FIG. 5) of an axial direction becomes a north-pole, and the other edge part (left side in FIG. 4 and FIG. 5) becomes a south pole. It is configured. That is, the first magnet member 75a and the second magnet member 75b are disposed so that the S pole and the N pole face each other in the axial direction. Accordingly, the first magnet member 75a and the second magnet member 75b generate a suction force that attracts each other, and the suction force F3 is a force that moves the valve body 72 in the valve opening direction. Act on 72. Accordingly, the hysteresis mechanism 75 can mechanically restrict the movement of the valve body 72 in the valve closing direction when the relief valve 7 is opened. Note that the first magnet member 75a and the second magnet member 75b have an increased attractive force due to a decrease in relative distance. Here, in the first magnet member 75a and the second magnet member 75b, the valve opening force F1 due to the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 that is equal to or lower than the valve-closing fuel pressure lower than the valve-opening fuel pressure when the valve is opened is the valve body 72. , The valve body 72 is moved in the valve closing direction against the valve opening force F1 and the valve body suction force F3 by the valve closing force F2 acting on the valve body 72 by the return spring 73. In addition, a suction force is set. Therefore, when the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 becomes equal to or less than the valve closing fuel pressure, the valve body 72 moves in the valve closing direction due to the difference between the valve closing force F2, the valve opening force F1, and the valve body suction force F3. Then, the relief valve 7 is closed (see FIG. 4).

  Here, the return spring 73 according to the second embodiment includes a valve opening force F1 that acts on the valve body 72 when the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 is less than the valve opening fuel pressure, and a valve when the relief valve is closed. The valve closing force F2 that cannot move the valve body 72 in the valve opening direction with the body suction force F3 is set to act on the valve body 72. Therefore, the valve body 72 is opened by the valve opening force F1 in the valve opening direction generated by the fuel pressure of the fuel of the high-pressure fuel system 5 equal to or higher than the valve opening fuel pressure, so that the relief valve 7 is opened.

  Next, the operation of the relief valve 7 according to the second embodiment when the internal combustion engine 100 is stopped will be described. Since the operation of the relief valve 7 according to the second embodiment is substantially the same as the operation of the relief valve 7 according to the first embodiment, the same portions will be omitted or simplified for explanation. The ECU 9 causes the high-pressure pump 4 to set the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 to be equal to or higher than the valve opening fuel pressure.

  When the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 becomes equal to or higher than the valve opening fuel pressure, the valve body 72 is separated from the valve body 71 and the relief valve 7 is opened as shown in FIG. When the relief valve 7 is opened, the relative distance between the first magnet member 75a and the second magnet member 75b decreases, so that the mutual attraction force increases. Therefore, the valve body attraction force F3 increased compared to when the valve is closed. Acts on the valve body 72 and the His mechanism 75 restricts the valve body 72 from moving in the valve closing direction. When the relief valve 7 is opened, the fuel pressure of the high pressure fuel in the high pressure fuel system 5 begins to decrease.

  When the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 is equal to or lower than the valve closing fuel pressure (for example, a predetermined low pressure at which the pressure regulator 32 opens), the valve closing force acting on the valve body 72 by the return spring 73 as shown in FIG. F2 becomes larger than the sum of the valve body suction force F3 acting on the valve body 72 by the hysteresis mechanism 75 and the valve opening force F1 acting on the valve body 72 due to the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5, and the valve body 72 The valve body 72 moves in the valve closing direction, the valve body 72 is seated on the valve body 71, and the relief valve 7 is closed.

  As described above, the relief valve 7 is opened when the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 is equal to or higher than the valve-opening fuel pressure, and the fuel in the high-pressure fuel system 5 is returned to the low-pressure fuel system. When the fuel pressure of the fuel decreases and the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 becomes the valve-closing fuel pressure, the valve-opening state maintained by the hysteresis mechanism 75 is shifted to the valve-closing state by the return spring 73. Therefore, when the internal combustion engine 100 is stopped, the fuel pressure of the fuel in the high-pressure fuel system 5 can be lowered, and fuel leakage from the injector can be suppressed. Thereby, the deterioration of emission can be suppressed.

  Further, a His mechanism 75 is used which mechanically controls the movement of the valve body 72 in the valve closing direction when the relief valve 7 is opened by the attractive force generated by the first magnet member 75a and the second magnet member 75b. When the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 becomes the valve closing fuel pressure, the relief valve 7 is closed by the return spring 73. Therefore, when the internal combustion engine 100 is stopped, power consumption can be suppressed as compared with the case where the relief valve 7 is forcibly opened by the actuator. Thereby, fuel consumption can be improved.

[Embodiment 3]
FIG. 6 is a diagram illustrating a relief valve (when the valve is closed) of the fuel supply apparatus according to the third embodiment. FIG. 7 is a diagram illustrating a relief valve (when the valve is opened) of the fuel supply device according to the third embodiment. The third embodiment is different from the first embodiment in that the valve closing speed of the relief valve 7 is not the hysteresis mechanism 74 that restricts the movement of the valve body 72 in the valve closing direction when the relief valve 7 is opened. This is a hysteresis mechanism 76 that adjusts the valve closing fuel pressure to a speed at which the return spring 73 closes the valve. Note that the basic configuration of the fuel supply apparatus according to the third embodiment is the same as the basic configuration of the fuel supply apparatus 1 according to the first embodiment, and a description thereof will be omitted.

  The His mechanism 76 is mechanically closed by the return spring 73 at a valve closing fuel pressure lower than the valve opening fuel pressure. In the third embodiment, the hysteresis mechanism 76 mechanically adjusts the valve closing speed of the relief valve 7 to a speed at which the valve is closed by the return spring 73 with the valve closing fuel pressure. The hysteresis mechanism 76 is a cylinder mechanism including a cylinder 76a and a piston 76b.

  The cylinder 76 a is provided on the valve body 72. In the third embodiment, the cylinder 76 a is disposed in the communication hollow portion 72 b of the valve body 72. The cylinder 76a is formed by opening the other end (the left end in FIGS. 6 and 7) in the axial direction. The piston 76 b is provided on the valve main body 71. In Embodiment 3, the piston 76b faces the cylinder 76a in the axial direction, and is disposed so as to be positioned in the piston 76b regardless of whether the relief valve 7 is closed or opened. Here, a gap 76c is formed between the cylinder 76a and the piston 76b. A resistance oil chamber 76d is formed between the cylinder 76a and the piston 76b. The fuel in the valve body hollow portion 71a of the valve body 71 can flow into and out of the resistance oil chamber 76d through the gap 76c. When the relief valve 7 opens, the valve body 72 moves in the valve opening direction, so that the fuel in the resistance oil chamber 76d flows out from the gap 76c into the valve body hollow portion 71a. Therefore, when the relief valve 7 shifts from the closed state to the open state, the fuel in the resistance oil chamber 76d flows out from the gap 76c into the valve body hollow portion 71a. It can be adjusted by reducing the moving speed of the valve body 72 in the valve opening direction with respect to the relief valve 7 not provided with the hysteresis mechanism 76. When the opened relief valve is closed, the valve body 72 moves in the valve opening direction, so that the fuel in the valve body hollow portion 71a flows into the resistance oil chamber 76d from the gap 76c. Therefore, when the relief valve 7 shifts from the open state to the closed state, the fuel in the valve body hollow portion 71a flows into the resistance oil chamber 76d from the gap 76c. It can be adjusted by reducing the moving speed of the valve body 72 in the valve closing direction with respect to the relief valve 7 not provided with the hysteresis mechanism 76. Here, the clearance 76c is set such that the valve closing speed of the relief valve, that is, the moving speed of the valve body 72 in the valve closing direction becomes the speed at which the return spring 73 is closed by the valve closing fuel pressure.

  Next, the operation of the relief valve 7 according to the third embodiment when the internal combustion engine 100 is stopped will be described. Since the operation of the relief valve 7 according to the third embodiment is substantially the same as the operation of the relief valve 7 according to the first embodiment, the same portions will be omitted or simplified for explanation. The ECU 9 causes the high-pressure pump 4 to set the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 to be equal to or higher than the valve opening fuel pressure.

  When the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 becomes equal to or higher than the valve opening fuel pressure, as shown in FIG. 7, the valve body 72 is separated from the valve body 71 and the valve body 72 moves in the valve opening direction by the valve opening force F1. As a result, the fuel in the resistance oil chamber 76d flows out from the gap 76c into the valve body hollow portion 71a, and the relief valve 7 is opened. When the relief valve 7 is opened, the fuel pressure of the high pressure fuel in the high pressure fuel system 5 begins to decrease.

  When the fuel pressure of the high pressure fuel in the high pressure fuel system 5 becomes less than the valve opening fuel pressure, the valve body 72 moves in the valve closing direction by the valve closing force F2, so that the fuel in the valve body hollow portion 71a flows from the gap 76c to the resistance oil. When flowing into the chamber 76d and the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 becomes the valve closing fuel pressure, the valve body 72 is seated on the valve body 71 and the relief valve 7 is closed as shown in FIG.

  As described above, the relief valve 7 is opened when the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 is equal to or higher than the valve-opening fuel pressure, and the fuel in the high-pressure fuel system 5 is returned to the low-pressure fuel system. When the fuel pressure of the fuel decreases and the fuel pressure of the high pressure fuel in the high pressure fuel system 5 becomes the valve closing fuel pressure, the valve opening state maintained by the hysteresis mechanism 76 is shifted to the valve closing state by the return spring 73. Therefore, when the internal combustion engine 100 is stopped, the fuel pressure of the fuel in the high-pressure fuel system 5 can be lowered, and fuel leakage from the injector can be suppressed. Thereby, the deterioration of emission can be suppressed.

  Further, the adjustment of the valve closing speed of the relief valve 7 to the speed at which the valve is closed by the return spring 73 is configured by the cylinder 76a and the piston 76b, and the resistance oil chamber 76d has a gap 76c to the valve body hollow portion 71a. The relief valve 7 is closed by the return spring 73 when the fuel pressure of the high-pressure fuel in the high-pressure fuel system 5 becomes the valve-closing fuel pressure using the mechanical mechanism 76 that is mechanically performed by the resistance when the fuel flows. Therefore, when the internal combustion engine 100 is stopped, power consumption can be suppressed as compared with the case where the relief valve 7 is forcibly opened by the actuator. Thereby, fuel consumption can be improved.

  In the first to third embodiments, an actuator (not shown) that forcibly opens the relief valve 7 may be provided. The actuator moves the valve body 72 in the valve opening direction by, for example, electromagnetic force, is connected to the ECU 9, and the operation is controlled by the ECU 9. The ECU 9 determines whether or not the forced valve opening condition is satisfied when the internal combustion engine 100 is stopped. If the forced valve opening condition is satisfied, the ECU 9 performs the drive control of the actuator to forcibly open the relief valve 7. May be. Here, the forced valve opening condition is at least one of the case where the fuel pressure in the high pressure fuel system 5 cannot be increased to the valve opening fuel pressure, or the case where the fuel pressure in the high pressure fuel system 5 is made lower than the valve closing fuel pressure. is there.

  As described above, when the fuel pressure in the high-pressure fuel system cannot be increased to the valve-opening fuel pressure, or when the fuel pressure in the high-pressure fuel system is made lower than the valve closing fuel pressure, the actuator that forcibly opens the relief valve Prepare. Therefore, the relief valve can be reliably opened even in the case of an abnormality in the high pressure pump, an abnormality in the His mechanism, a sudden engine stop of the internal combustion engine, etc., and the fuel pressure of the fuel in the high pressure fuel system can be lowered. . In addition, even when the temperature of the internal combustion engine or the fuel of the high-pressure fuel system is high and the high-pressure fuel system is abnormally boosted after the internal combustion engine is stopped, the relief valve can be reliably opened. As a result, it is possible to reliably suppress the deterioration of the emission and to improve the fuel consumption with certainty.

  As described above, the fuel supply apparatus according to the present invention is useful for a fuel supply apparatus that includes a relief valve that returns high-pressure fuel fuel to a low-pressure fuel system, and in particular, suppresses deterioration of emissions and improves fuel consumption. Suitable for

It is a figure which shows the structural example of the fuel supply apparatus concerning this invention. It is a figure which shows the relief valve (at the time of valve closing) of the fuel supply apparatus concerning Embodiment 1. FIG. It is a figure which shows the relief valve (at the time of valve opening) of the fuel supply apparatus concerning Embodiment 1. FIG. It is a figure which shows the relief valve (at the time of valve closing) of the fuel supply apparatus concerning Embodiment 2. FIG. It is a figure which shows the relief valve (at the time of valve opening) of the fuel supply apparatus concerning Embodiment 2. FIG. It is a figure which shows the relief valve (at the time of valve closing) of the fuel supply apparatus concerning Embodiment 3. FIG. FIG. 10 is a diagram illustrating a relief valve (when the valve is opened) of the fuel supply device according to the third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel supply apparatus 2 Low pressure pump 3 Low pressure fuel system 31 Low pressure fuel piping 32 Pressure regulator 4 High pressure pump 41 Pressurization chamber 42 Plunger 43 Metering valve 5 High pressure fuel system 51 High pressure fuel piping 52 Check valve 53 1st delivery piping 54 Communication Piping 55 Second delivery piping 6 Injector 7 Relief valve 71 Valve body 72 Valve body 73 Return spring (valve closing means)
74 His mechanism 74a Recess 74b Claw member 74c Pressing spring (pressing means)
75 His mechanism 75a First magnet member 75b Second magnet member 76 His mechanism 76a Cylinder 76b Piston 76c Clearance 76d Resistance oil chamber 8 Fuel tank 9 ECU
10 Fuel Pressure Sensor 11 Relief Piping 100 Internal Combustion Engine

Claims (9)

A low pressure pump for pressurizing fuel in the fuel storage chamber;
A high-pressure pump for further pressurizing the fuel pressurized by the low-pressure pump;
An injector that injects fuel further pressurized by the high-pressure pump into an internal combustion engine;
A low-pressure fuel system closer to the low-pressure pump than the high-pressure pump;
A high-pressure fuel system closer to the injector than the high-pressure pump;
The high-pressure fuel system is opened between the high-pressure fuel system and the low-pressure fuel system with a valve-opening force in the valve-opening direction by the fuel pressure of the fuel in the high-pressure fuel system that is equal to or higher than the valve-opening fuel pressure. A relief valve for returning to the low-pressure fuel system;
A fuel supply device comprising:
The relief valve is
Valve closing means for generating a valve closing force in a valve closing direction opposite to the valve opening direction;
A fuel supply device comprising: a His mechanism that mechanically closes the valve by a valve closing fuel pressure lower than the valve opening fuel pressure. The relief valve is a valve that closes when a valve element is seated on the valve body,
The fuel supply device according to claim 1, wherein the His mechanism regulates movement of the valve body in the valve closing direction when the valve is opened. The His mechanism is
A recess formed in the valve body;
A claw member supported so as to be able to fit into the recess when the valve is opened;
A pressing means for pressing the claw member toward the recess;
Consists of
The claw member and the concave portion are fitted by the pressing means when the valve is opened, and the fitting between the claw member and the concave portion is disengaged by the valve closing force when the pressure is equal to or lower than the valve closing fuel pressure. 2. The fuel supply device according to 2. The His mechanism is
A first magnet member provided on the valve body;
A second magnet member provided on the valve body;
Consists of
3. The fuel supply device according to claim 2, wherein the first magnet member and the second magnet member have a relative distance that is reduced when the valve is opened and a mutual attractive force is increased than when the valve is closed.   The fuel supply device according to claim 1, wherein the His mechanism adjusts at least a valve closing speed to a speed at which the valve closing means closes the valve closing fuel pressure. The relief valve is a valve that closes when a valve element is seated on the valve body,
The said hysteresis mechanism is a cylinder mechanism that is connected to the valve body and the valve body, and reduces the moving speed of the valve body in the valve closing direction when the fuel flows in. 5. The fuel supply device according to 5.   The fuel according to any one of claims 1 to 6, wherein when the internal combustion engine is stopped, the fuel pressure of the high-pressure fuel system is increased to a valve opening fuel pressure, and then the high-pressure pump is stopped. Feeding device. The relief valve further includes an actuator that forcibly opens the valve,
8. The fuel supply device according to claim 7, wherein when the condition for forced valve opening is satisfied when the internal combustion engine is stopped, the actuator is operated to forcibly open the valve.   The forced valve opening condition is at least one of a case where the fuel pressure in the high pressure fuel system cannot be increased to the valve opening fuel pressure, or a case where the fuel pressure in the high pressure fuel system is made lower than the valve closing fuel pressure. The fuel supply device according to claim 8.

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