JP5910313B2 - Fuel pressure control device - Google Patents

Description

  The present invention relates to a fuel pressure control device, and more particularly to a fuel pressure control device that controls the pressure of fuel supplied to a fuel injection valve of an internal combustion engine mounted on a vehicle or the like.

  2. Description of the Related Art Conventionally, as a fuel pressure control device mounted on a vehicle such as an automobile, a motor-integrated fuel pump that sucks fuel in a fuel tank and pumps this fuel to a delivery pipe through a supply passage, and branches from the supply passage A recirculation passage for recirculating part of the fuel flowing in the supply passage to the fuel tank, and a recirculation passage for adjusting the fuel discharged from the fuel pump to a predetermined pressure, and for surplus fuel to the fuel tank What is provided with the fuel pressure control valve which returns is known.

  By the way, at the time of starting the vehicle, it is necessary to close the electromagnetic pressure control valve so that the fuel is not recirculated from the recirculation passage to the fuel tank in order to increase the pressure increase performance of the fuel pump.

  Therefore, as an electromagnetic pressure control valve, when the voltage is not applied, the valve body is separated from the valve seat by the urging force of the urging member to open the return passage, and against the urging force of the urging member when the voltage is applied. It is conceivable to provide an electromagnetic pressure control valve that varies the pressure of fuel pumped from the fuel pump by closing the return passage by seating the valve body on the valve seat.

  However, the electromagnetic pressure control valve generates an operating noise because the valve body is seated on the valve seat when the valve body is closed when the voltage is applied and the valve body is attracted by electromagnetic force. When the internal combustion engine is in an operating state, the ambient noise level (background noise) is high, and the operating sound at the time of sitting is not particularly recognized as noise, but before the internal combustion engine is started, that is, Since the ambient noise level is low during the start-up waiting period of the internal combustion engine until the cranking after the ignition switch is switched from the off state to the on state, the operating noise causes discomfort to the passenger.

  Conventionally, it is possible to prevent the passenger from feeling uncomfortable due to the operation sound of the electromagnetic pressure control valve when starting the internal combustion engine. For example, the control of the fuel injection device for an internal combustion engine described in Patent Document 1 is described below. The device is known.

  The control device for a fuel injection device for an internal combustion engine keeps the electromagnetic pressure control valve in one of the fully opened state and fully closed state in response to the ignition switch being switched from OFF to ON. Thereafter, by opening and closing the electromagnetic pressure control valve at the timing when the starter switch is switched from OFF to ON, the operation sound of the electromagnetic pressure control valve can be made inconspicuous due to noise during cranking.

JP 2002-31014 A

  However, in such a conventional control device for a fuel injection device for an internal combustion engine, the electromagnetic pressure control valve is opened and closed at the timing when the starter switch is switched from OFF to ON. When the starter motor is driven during the ranking operation, current consumption increases and a battery voltage drop occurs.

For this reason, the voltage applied to the electromagnetic pressure control valve decreases, and it is necessary to enlarge the electromagnetic pressure control valve in order to operate the electromagnetic pressure control valve at a low voltage.
Specifically, the normally open type electromagnetic pressure control valve needs to attract the valve body by electromagnetic force to be seated on the valve seat. Therefore, if the voltage applied to the electromagnetic pressure control valve is low, the valve body The suction power will be reduced.

  Therefore, in order to increase the attractive force of the valve body with a low applied voltage, for example, it is necessary to increase the number of turns of the electromagnetic coil of the electromagnetic pressure control valve. The problem that it will enlarge will occur.

  The present invention has been made to solve the above-described conventional problems, and suppresses an increase in the size of the electromagnetic pressure control valve, while the valve body is seated on the valve seat when the internal combustion engine is started. An object of the present invention is to provide a fuel pressure control device that can prevent a passenger from feeling uncomfortable due to an operating sound.

  In order to achieve the above object, a fuel pressure control device according to the present invention (1) pumps fuel stored in a fuel tank to a delivery pipe to which a fuel injection valve of an internal combustion engine is connected via a supply passage. A fuel pump capable of changing the amount of fuel to be pumped, a recirculation passage for recirculating a part of the fuel that branches from the supply passage and flows in the supply passage to the fuel tank, and the recirculation passage. When the voltage is not applied, the valve body is separated from the valve seat by the urging force of the urging member to open the return passage, and when the voltage is applied, the valve body is moved against the urging force of the urging member. A normally-open electromagnetic pressure control valve that varies the pressure of the fuel pumped from the fuel pump by closing the return passage while seated on a seat, and a control means for controlling opening and closing of the electromagnetic pressure control valve Prepared fuel A pressure control device, wherein the control means starts the operation of the electromagnetic pressure control valve before the start of the cranking operation of the starter device for cranking the internal combustion engine, and the cranking operation of the starter device It is comprised from what controls the action | operation of the said electromagnetic pressure control valve so that the said valve body may seat on the said valve seat.

  This fuel pressure control device starts the operation of the electromagnetic pressure control valve until the cranking operation is started, and controls the operation of the electromagnetic pressure control valve so that the valve body is seated on the valve seat during the cranking operation. Therefore, the operation of the electromagnetic pressure control valve can be started before the battery voltage drop occurs due to the cranking operation of the starter device. For this reason, the applied voltage of sufficient magnitude | size for attracting | sucking a valve body can be given to an electromagnetic pressure control valve, and it can prevent that an electromagnetic pressure control valve enlarges.

  In addition, since the electromagnetic pressure control valve can be closed before the cranking operation start time, high-pressure fuel can be supplied to the delivery pipe by the fuel pump, and fuel can be boosted quickly.

  Further, since the valve body can be seated on the valve seat during the cranking operation, the operating sound when the valve body is seated on the valve seat can be made inconspicuous by the sound during the cranking operation. It is possible to prevent the passenger from feeling uncomfortable due to the operation sound when the body is seated on the valve seat.

  (2) In the fuel pressure control device according to (1), (2) the control means is configured to seat the valve body from the start of operation of the electromagnetic pressure control valve based on the applied voltage until the valve body is seated on the valve seat. Obtaining time, on the condition that the start signal is input, set the seating time so that the valve body is seated on the valve seat after the start time of cranking operation of the starter device for cranking the internal combustion engine, The operation of the electromagnetic pressure control valve is started before the seating time and before the cranking operation start time with respect to the seating time.

  This fuel pressure control device sets the seating time so that the valve body is seated on the valve seat after the start of the cranking operation of the starter device, and is the time when the cranking operation starts before the seating time. Since the operation of the electromagnetic pressure control valve is started before the operation, the operation of the electromagnetic pressure control valve can be started before the battery voltage drop is generated by the cranking operation of the starter device. For this reason, the applied voltage of sufficient magnitude | size for attracting | sucking a valve body can be given to an electromagnetic pressure control valve.

  Further, since the valve body can be seated on the valve seat during the cranking operation, the operation sound when the valve body is seated on the valve seat can be made inconspicuous by the sound during the cranking operation.

  In the fuel pressure control device described in (2) above, (3) the starter device includes a starter motor that cranks the internal combustion engine when a voltage is applied from a battery. As a ranking operation start timing, the ranking operation start timing is set to a timing at which application of voltage from the battery to the starter motor is started.

  In this fuel pressure control device, the control means sets the seating time so that the valve body is seated on the valve seat after the time when the voltage is applied from the battery to the starter motor, and the seating time is equal to the seating time. Since the operation of the electromagnetic pressure control valve is started before and before the cranking operation start time, before the voltage drop is generated by the cranking operation by the starter motor, the valve body is sucked into the electromagnetic pressure control valve. A sufficiently large applied voltage can be applied. As a result, it is possible to more reliably prevent the electromagnetic pressure control valve from increasing in size.

  Also, the operating noise when the valve element is seated on the valve seat can be made inconspicuous due to the background noise caused by the cranking operation of the starter motor. It is possible to prevent the user from feeling uncomfortable.

  (4) In the fuel pressure control device according to (3), (4) the control unit is configured to calculate a time from when the start signal is input to when a voltage is started to be applied to the starter motor. Has been.

  In this fuel pressure control apparatus, since the control means calculates the time from when the start signal is input until the start of voltage application to the starter motor, the voltage is applied to the starter motor after the start signal is input. The operation start timing of the electromagnetic pressure control valve can be easily calculated based on the time until the start and the seating time.

  (5) In the fuel pressure control device described in (1) to (4) above, (5) the fuel pump is driven at an applied voltage that is equal to or higher than a lower limit voltage capable of maintaining driving even when foreign matter is caught in the sliding portion. And the electromagnetic pressure control valve according to the internal combustion engine depending on the fuel discharge amount of the fuel pump when the fuel pump is driven at the lower limit voltage and the operating state of the internal combustion engine. It has a function as a reduction valve for returning the difference fuel with the required fuel consumption required for the engine to the fuel tank.

  In this fuel pressure control device, since the fuel pump is driven with an applied voltage that is equal to or higher than the lower limit voltage, the fuel pump stops driving even when foreign matter is caught in the sliding portion of the fuel pump. Can be prevented.

  On the other hand, if the drive region of the fuel pump is set to a region equal to or higher than the lower limit voltage, the fuel discharge amount supplied into the delivery pipe is limited to the minimum fuel discharge amount corresponding to the predetermined lower limit voltage.

  For this reason, such an electric fuel pump cannot realize a fuel discharge amount lower than the minimum fuel discharge amount. Therefore, in the fuel pressure control device provided with such a fuel pump, there is a possibility that the fuel injection amount injected from the fuel injection valve cannot be less than the minimum fuel discharge amount corresponding to the lower limit voltage.

  On the other hand, in the fuel pressure control device of the present invention, the electromagnetic pressure control valve returns the difference fuel between the fuel discharge amount of the fuel pump and the required fuel consumption when the fuel pump is driven at the lower limit voltage to the fuel tank. Therefore, the required fuel consumption can be made less than the minimum fuel discharge amount corresponding to the lower limit voltage while maintaining the applied voltage of the fuel pump at the lower limit voltage or higher. Therefore, excessive fuel consumption can be suppressed, and fuel consumption can be improved.

  According to the present invention, while preventing the electromagnetic pressure control valve from becoming large, it is possible to prevent the passenger from feeling uncomfortable due to the operation sound when the valve body is seated on the valve seat when the internal combustion engine is started. It is possible to provide a fuel pressure control device capable of

1 is a diagram illustrating an embodiment of a fuel pressure control device according to the present invention, and is a schematic configuration diagram of a vehicle including a fuel pressure control device. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows one Embodiment of the fuel pressure control apparatus which concerns on this invention, is a block diagram of a fuel pressure control apparatus, The state at the time of valve opening of the fuel pressure control apparatus of (a), (b) is fuel The state at the time of valve closing of a pressure control device is shown. It is a figure which shows one Embodiment of the fuel pressure control apparatus which concerns on this invention, and is a block diagram of a starter apparatus. It is a figure which shows one Embodiment of the fuel pressure control apparatus which concerns on this invention, and is a figure which shows the control system of a fuel pressure control apparatus. It is a figure which shows one Embodiment of the fuel pressure control apparatus which concerns on this invention, and is a flowchart of cranking control. It is a figure which shows one Embodiment of the fuel pressure control apparatus which concerns on this invention, and is a figure which shows the timing chart of cranking control. It is a figure which shows one Embodiment of the fuel pressure control apparatus which concerns on this invention, and is a timing chart of cranking control when a valve body seats on the valve seat before the cranking operation | movement used for the comparison. It is a figure which shows one Embodiment of the fuel pressure control apparatus which concerns on this invention, and is a timing chart of cranking control in case a valve body seats on the valve seat after completion | finish of the cranking operation | movement used for the comparison.

Hereinafter, embodiments of a fuel pressure control device according to the present invention will be described with reference to the drawings.
FIGS. 1-8 is a figure which shows one Embodiment of the fuel pressure control apparatus based on this invention.
First, the configuration will be described.
In FIG. 1, the vehicle 1 includes an engine 10, a fuel supply mechanism 20, a starter device 50, a battery 70, and an ECU (Electronic Control Unit) 100.

  The engine 10 is configured as an internal combustion engine capable of outputting power using a hydrocarbon fuel such as gasoline or light oil. The fuel used for the engine 10 may be an alcohol fuel obtained by mixing alcohol such as ethanol and gasoline.

  In the present embodiment, the engine 10 is a so-called in-line 4-cylinder gasoline engine in which four cylinders 11 are arranged in series as indicated by # 1, # 2, # 3, and # 4.

  The engine 10 is not limited to an in-line four-cylinder engine, and is configured by various types of engines such as an in-line six-cylinder engine, a V-type six-cylinder engine, a V-type 12-cylinder engine, or a horizontally opposed six-cylinder engine. Also good.

  Further, in the present embodiment, the engine 10 is constituted by a four-cycle gasoline engine that performs a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke while a piston (not shown) reciprocates twice. Explain that it is.

  Furthermore, each of the four cylinders 11 indicated by # 1, # 2, # 3, and # 4 in the engine 10 is provided with an intake port 12 respectively. The engine 10 also includes a port injector 13 for injecting fuel into the intake port 12.

  The port injector 13 includes a solenoid coil controlled by an injection command signal Iq from the ECU 100, a needle valve, and a nozzle part. The port injector 13 is supplied with fuel at a predetermined pressure.

  When the solenoid coil is energized by the ECU 100, the port injector 13 opens the needle valve and injects fuel into the intake port 12. The port injector 13 in the present embodiment constitutes a fuel injection valve.

  The fuel supply mechanism 20 includes a fuel pump 21 that pressurizes and pumps fuel from the fuel tank 30, and a delivery pipe 23 that introduces the fuel pumped by the fuel pump 21 through the fuel pipe 22. A supply passage 22 a for supplying fuel from the fuel pump 21 to the delivery pipe 23 is formed in the fuel pipe 22.

  With this configuration, the fuel supply mechanism 20 supplies fuel to the plurality of port injectors 13 that respectively inject fuel into the plurality of intake ports 12 corresponding to the plurality of cylinders 11 in the intake passage 15 of the engine 10. It has become.

  The fuel pump 21 is an electric fuel pump that is driven in accordance with a control signal output from the ECU 100. The fuel pump 21 pumps up the fuel stored in the fuel tank 30 and passes it through a supply passage 22 a in the fuel pipe 22. Thus, the pressure is fed to the delivery pipe 23 to which the port injector 13 is connected.

  Specifically, the fuel pump 21 has a motor whose rotational speed changes according to the applied voltage from the battery 70 in accordance with a control signal output by the ECU 100, and an impeller that rotates by the rotational force of this motor. .

  The fuel pump 21 pressurizes and pumps fuel from the fuel tank 30 by rotating the impeller. Therefore, in the fuel pump 21, the rotational force of the motor is adjusted according to the magnitude of the applied voltage applied to the motor, and the fuel discharge amount of the discharged fuel is variable.

  In addition, the fuel pump 21 is an integrated filter that has both a function of a suction filter that removes relatively large foreign matters contained in the fuel and a function of a fuel filter that removes relatively small foreign matters and motor foreign matters contained in the fuel. I have.

  The delivery pipe 23 is connected to the fuel pipe 22 at one end side in the series arrangement direction of the plurality of cylinders 11 and is configured to supply fuel to the plurality of port injectors 13 independently. The delivery pipe 23 is provided with a fuel pressure sensor 25 that detects the pressure of the fuel in the delivery pipe 23 (hereinafter referred to as fuel pressure).

  Further, the fuel supply mechanism 20 includes a first return pipe formed inside each of return passages 26 a and 27 a that branch from the fuel pipe 22 and return a part of the fuel flowing in the fuel pipe 22 to the fuel tank 30. 26 and a second return pipe 27 are provided.

  The first return pipe 26 is a mechanical type that returns fuel from the fuel pipe 22 to the fuel tank 30 when the fuel pressure of the fuel pipe 22 exceeds a predetermined fuel pressure (for example, several hundred kPa). A relief valve 28 is provided. The relief valve 28 is provided to prevent an abnormal increase in the fuel pressure of the fuel pipe 22. The relief valve 28 may be provided in the fuel pipe 22.

The second return pipe 27 is provided with an electromagnetic reduction valve 29 as an electromagnetic pressure control valve. The reduction valve 29 is switched between a valve opening state and a valve closing state by applying a voltage from the battery 70 in response to a command signal from the ECU 100. In the present embodiment, the reduction valve 29 constitutes a reduction valve.
When the reduction valve 29 is opened, a part of the fuel flowing in the fuel pipe 22, for example, surplus fuel is returned to the fuel tank 30 through the second return pipe 27 as described later.

  As shown in FIG. 2, the weight reduction valve 29 includes a housing 31. A plunger 32 as a valve body and a coil spring 33 that constitutes an urging member are built in the housing 31. An electromagnetic coil 34 is attached to the part.

  A communication portion 31a is formed at one end of the housing 31 so as to communicate with the upstream portion of the return passage 27a of the second return pipe 27, and the fuel is recirculated from the return passage 27a into the housing 31 through the communication portion 31a. It has become so.

  Further, a valve seat 31b is formed on the periphery of the communication portion 31a, and one end portion of the plunger 32 can be seated or separated with respect to the valve seat 31b. The coil spring 33 is interposed between one end portion of the housing 31 and one end portion of the plunger 32, and urges the plunger 32 so as to be separated from the valve seat 31b.

When the plunger 32 is separated from the valve seat 31b to open the return passage 27a of the second return pipe 27, the reduction valve 29 connects the return passage 27a and the fuel tank 30 to the fuel pipe 22. A part of the fuel flowing inside is returned to the fuel tank 30.
As described above, the weight reduction valve 29 of the present embodiment is constituted by the normally open type weight reduction valve 29.

  The electromagnetic coil 34 is excited by applying a voltage from the battery 70 in accordance with a command signal from the ECU 100. When the electromagnetic coil 34 is excited, the urging force of the coil spring 33 is applied. The plunger 32 is sucked against the valve seat 31b, and the plunger 32 is seated on the valve seat 31b.

  When the plunger 32 is seated on the valve seat 31b, the reduction valve 29 closes the recirculation passage 27a of the second return pipe 27, thereby blocking communication between the recirculation passage 27a and the fuel tank 30.

  As shown in FIG. 3, the starter device 50 includes a starter motor 51 that rotates when voltage is applied from a battery 70, and a pinion gear 52 is attached to a motor shaft 51 a that is a rotation shaft of the starter motor 51. It has been.

  The pinion gear 52 is meshed with a ring gear 53 of a flywheel fixed to a crankshaft (not shown), and the rotation of the starter motor 51 is transmitted to the crankshaft via the pinion gear 52 and the ring gear 53. The engine 10 is started.

  The lower end portion of the shift lever 54 is engaged with the pinion gear 52. When the shift lever 54 rotates counterclockwise about the fulcrum 54a, the pinion gear 52 is engaged with the ring gear 53 and rotates clockwise. Then, the pinion gear 52 is detached from the ring gear 53.

  The upper end portion of the shift lever 54 is attached to one end portion of the plunger 55 made of a magnetic material in the axial direction, and the shift lever 54 rotates as the plunger 55 moves in the axial direction.

  The plunger 55 is accommodated in the main body 56 so as to be capable of reciprocating in the axial direction, and a coil 57 is built in the main body 56. Note that only a part of the main body 56 is illustrated. The coil 57 is excited by closing the starter relay 58, and when the starter relay 58 is excited, the plunger 55 moves to the left in FIG.

  The starter relay 58 is turned on by an excitation signal of the ECU 100 when the driver turns the ignition switch to a start position (cranking start position) or pushes the starter switch to start. .

  A start signal is input to the ECU 100 when the ignition switch is turned to the start position or when the starter switch is pushed, and the starter relay 58 is excited when the start signal is input. Output a signal. Note that the pushing operation of the start switch is an operation in the push type start system, but in the present embodiment, the ignition switch 104 will be described as an example.

  A movable contact 59 is provided at the other end of the plunger 55. The plunger 55 is excited to the left in FIG. 3 by exciting a coil 57 built in the main body 56 by closing the starter relay 58. The pinion gear 52 is moved and connected to the ring gear 53, and the movable contact 59 is brought into contact with a pair of fixed contacts 60a and 60b provided facing the movable contact 59. In the starter device 50 of this embodiment, the plunger 55 and the coil 57 constitute a magnet switch 62.

  One contact 60 a of the pair of fixed contacts 60 a and 60 b is connected to the battery 70, and the other contact 60 b is grounded via the starter field coil 61 and the starter motor 51.

  Accordingly, when the movable contact 59 comes into contact with the fixed contacts 60 a and 60 b, the power of the battery 70 is applied to the starter motor 51, and the rotational force of the motor shaft 51 a of the starter motor 51 is transmitted to the ring gear 53 via the pinion gear 52. The cranking operation of the engine 10 is performed.

  On the other hand, the ECU 100 is configured to include, for example, a microcomputer including a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and signals according to a program stored in the ROM in advance. Processing is to be performed. Various control constants and various maps are stored in advance in the ROM.

  As shown in FIG. 4, the ECU 100 includes various sensors such as the fuel pressure sensor 25, the rotation speed sensor 101, the intake air amount sensor 102, the accelerator opening sensor 103, and the battery sensor 105 described above, and the port injection injector 13. The fuel pump 21, the weight reduction valve 29, the ignition switch 104, and the switch 106 are connected.

  The fuel pressure sensor 25 detects the fuel pressure in the delivery pipe 23. The rotational speed sensor 101 detects the engine rotational speed Ne of the engine 10. The intake air amount sensor 102 detects the intake air amount GA.

  The accelerator opening sensor 103 detects an accelerator operation amount ACC corresponding to the depression amount of the accelerator pedal. The battery sensor 105 detects the voltage value of the battery 70. Each of these sensors transmits a signal corresponding to the detection result to the ECU 100.

  The ECU 100 executes various calculations based on signals input from these various sensors, and executes various controls based on the calculation results.

  For example, the ECU 100 calculates the target fuel injection amount Q based on the intake air amount GA, the engine rotational speed Ne, the accelerator operation amount ACC, and the like. The ECU 100 sets a valve opening period of the port injector 13, that is, an injection period based on the fuel pressure so that the calculated target fuel injection amount Q can be realized. ECU 100 individually outputs a valve opening command to each port injector 13 according to the set injection period.

  As a result, an amount of fuel commensurate with the operating state of the engine 10 is injected from each port injector 13. At this time, the ECU 100 controls the applied voltage applied to the fuel pump 21 so as to adjust the fuel discharge amount of the fuel pump 21 so that fuel for the target fuel injection amount Q is injected from the port injector 13. It has become.

  In addition, the ECU 100 applies an applied voltage to the fuel pump 21 in accordance with the target fuel pressure so that the minimum discharge capacity necessary for securing the target fuel pressure (hereinafter referred to as the target fuel pressure) is obtained. To control. Here, the target fuel pressure is an optimum fuel pressure according to, for example, the operating state of the engine 10 and the fuel injection amount.

  More specifically, the ECU 100 controls the applied voltage at a predetermined lower limit voltage Vmin or higher. The predetermined lower limit voltage Vmin generates a driving torque capable of maintaining the driving of the fuel pump 21 even if foreign matter is caught in a sliding portion of the fuel pump 21, for example, a gap portion between the impeller and the pump cover. The voltage that can be used. Therefore, it is possible to prevent the fuel pump 21 from being stopped due to the above-mentioned foreign matter being caught.

  Here, since the fuel pump 21 is limited by the above-described lower limit voltage Vmin, it cannot be driven with an applied voltage lower than the lower limit voltage Vmin. In this case, the minimum fuel discharge amount of the fuel pump 21 is a fuel discharge amount corresponding to the lower limit voltage Vmin.

  Therefore, the fuel pump 21 cannot discharge fuel with a fuel discharge amount less than the minimum fuel discharge amount according to the lower limit voltage Vmin. For this reason, for example, when the required fuel injection amount is small, such as during idle operation, the above-mentioned minimum fuel discharge amount becomes larger than the target fuel injection amount Q, and the desired fuel injection amount is reduced. There is a problem that cannot be obtained. The required fuel consumption here is, for example, the fuel consumption consumed by the engine 10 to obtain the target fuel injection amount Q.

As a result, the actual fuel pressure in the delivery pipe 23 (hereinafter referred to as the actual fuel pressure) also rises above the target fuel pressure, and the actual fuel pressure cannot be maintained at the target fuel pressure.
Therefore, in the present embodiment, the above-described reduction valve 29 is provided in the fuel supply mechanism 20 in order to solve such a problem.

  Thus, when there is a difference fuel between the minimum fuel discharge amount when the fuel pump 21 is driven at the lower limit voltage Vmin and the required fuel consumption amount that is required according to the operating state of the engine 10, the reduction valve 29 By opening the valve, the differential fuel can be returned to the fuel tank 30. In the present embodiment, the fuel supply mechanism 20 and the ECU 100 constitute a fuel pressure control device.

  On the other hand, the ignition switch 104 can be switched to four positions of an off position, an accessory position, an on position, and a start position. When the ignition switch 104 is switched to the start position, the starter relay 58 is energized to start the relay. 58 turns on.

  The starter device 50 includes an accessory relay and a power relay that are closed when the ignition switch 104 is operated to the accessory position and the on position, respectively, but the accessory relay and the power relay are not shown.

  When the power relay is turned on, a voltage is applied from battery 70 to auxiliary equipment such as an air conditioner of engine 10. When the accessory relay is turned on, a voltage is applied from the battery 70 to an accessory device that is an electrical component such as audio. The ECU 100 is directly connected to the battery 70 so that a voltage is directly applied from the battery 70.

  When the ignition switch 104 is switched to the start position, a start signal is input to the ECU 100 from the ignition switch 104. When the start signal is input, the ECU 100 sends an excitation signal to the starter relay 58. Output.

  Further, when the ignition switch 104 is switched to the ON position, an ON signal is output from the battery 70 to the ECU 100, and auxiliary devices such as an air conditioner and a power window of the vehicle 1 are operable.

  Further, the ECU 100 determines that the plunger 32 is attached to the coil spring 33 from the start of energization of the electromagnetic coil 34, which is the start of operation of the reduction valve 29, based on the voltage applied from the battery 70 to the reduction valve 29, that is, the battery voltage. The seating time until seating on the valve seat 31b against the force is calculated.

  Regarding this calculation, the ROM of the ECU 100 stores an applied voltage from the battery 70, that is, a seating time map in which the battery voltage and the seating time are associated with each other. The ECU 100 uses the voltage value detected by the battery sensor 105. Based on this, the seating time is obtained from the ROM. The seating time is set shorter as the battery voltage increases.

  Further, the ECU 100 starts the operation of the reduction valve 29 until the start of the cranking operation of the starter device 50, and the reduction valve 29 so that the plunger 32 is seated on the valve seat 31b during the cranking operation of the starter device 50. The operation of is controlled.

  Specifically, the ECU 100 performs the cranking of the starter device 50 that performs cranking of the engine 10 on condition that a start signal is input from the ignition switch 104 when the ignition switch 104 is turned to the start position. The seating time is set so that the plunger 32 is seated on the valve seat 31b after the ranking operation start time.

The cranking operation start time is set to the time when the magnet switch 62 is turned on, and the voltage from the battery 70 is applied to the starter motor 51 in synchronization with the time when the magnet switch 62 is turned on, so that the starter motor 51 operates. When the starter motor 51 is started, current consumption increases, and a voltage drop of the battery 70 occurs.
Therefore, the time for starting the cranking operation is the time when the starter motor 51 starts to operate, and this time coincides with the time when the voltage drop of the battery 70 occurs.

Further, the time from when the start signal is input to when the starter motor 51 starts to operate is a fixed value, and this time is stored in the ROM of the ECU 100.
In addition, the ECU 100 outputs an excitation signal to the weight reduction valve 29 before the seating time of the seating time of the weight reduction valve 29 and before the time when the cranking operation is started to start the operation of the weight reduction valve 29. When the excitation signal is input to the weight reduction valve 29, the electromagnetic coil 34 starts to attract the plunger 32.

  When an excitation signal is output to the reduction valve 29, the switch 106 that opens and closes the battery 70 and the electromagnetic coil 34 is energized, the switch 106 is turned on, and a voltage is applied to the reduction valve 29 from the battery 70. Note that the ECU 100 in the present embodiment constitutes a control means.

Next, the cranking control of the engine 10 will be described with reference to FIGS.
FIG. 5 is a flowchart of cranking control executed by the ECU 100. This cranking control program is stored in the ROM of the ECU 100, and is executed by the CPU of the ECU 100.

First, the ECU 100 determines whether or not the ignition switch 104 has been turned to the on position by the driver (step S1).
ECU 100 determines that ignition switch 104 has been turned to the ON position when an ON signal is input from ignition switch 104, and acquires the voltage value of battery 70 based on detection information from battery sensor 105. The seating time corresponding to the voltage value is obtained from the seating time map stored in the ROM (step S2).

If ECU 100 determines that ignition switch 104 has not been turned to the ON position by the driver, ECU 100 ends the current process.
Next, the ECU 100 determines whether or not a start signal has been input from the ignition switch 104 (step S3). If it is determined that the start signal has not been input, the ECU 100 moves to step S1 and the start signal is If it is determined that the input has been made, the initial setting process of the reduction valve 29 is executed (step S4).

  In this initial setting process, the seating time is set so that the plunger 32 is seated on the valve seat 31b later than the start time of the cranking operation of the starter device 50, and the seating time is before the seating time of the weight reduction valve 29. And, the operation start time is set to the weight reduction valve 29 before the cranking operation start time. Thereafter, the ECU 100 executes a cranking process of the engine 10 (step S5) and ends the current process.

  In this cranking process, the ECU 100 outputs an excitation signal to the starter relay 58. When an excitation signal is output to the starter relay 58, the coil 57 is excited by closing the starter relay 58, the plunger 55 is magnetized, and moves to the left in FIG.

  When the plunger 55 is magnetized and moves leftward in FIG. 3, the pinion gear 52 is engaged with the ring gear 53 and the movable contact 59 is brought into contact with the pair of fixed contacts 60a and 60b.

  That is, the magnet switch 62 is turned on, the electric power of the battery 70 is applied to the starter motor 51, and the rotational force of the motor shaft 51 a of the starter motor 51 is transmitted to the ring gear 53 via the pinion gear 52 to crank the engine 10. Operation is performed.

  Further, the ECU 100 outputs an excitation signal to the electromagnetic coil 34 of the weight reduction valve 29 before the cranking operation of the engine 10 is performed. When an excitation signal is output to the electromagnetic coil 34, the switch 106 that opens and closes the battery 70 and the electromagnetic coil 34 is turned on, and a voltage is applied from the battery 70 to the weight reduction valve 29.

  At this time, the plunger 32 is attracted to the electromagnetic coil 34 against the biasing force of the coil spring 33, and the plunger 32 is seated on the valve seat 31b after the cranking operation start time and closes the valve seat 31b. The communication between the return passage 27a of the return pipe 27 and the fuel tank 30 is cut off.

Here, the cranking control will be described more specifically based on the timing chart of FIG.
The seating time T1 acquired by the ECU 100 is 20 ms, the time T2 from when the start signal is input from the ignition switch 104 until the starter relay 58 is turned on is 3 ms, and until the magnet switch 62 is turned on after the starter relay 58 is turned on. That is, it is assumed that the time T3 until the plunger 55 is excited is 15 ms.

  In this case, since the time T4 (T2 + T3) from when the start signal is input to when the magnet switch 62 is turned on is 18 ms, the seating time Te is 2 ms later than the cranking operation start time Tcs.

  That is, when the start signal is input from the ignition switch 104, the sitting time Te is later than the cranking operation start time Tcs, so that the ECU 100 starts the operation of the weight reduction valve 29 when the start signal is input from the ignition switch 104. Time Ts becomes the same time as the start signal input time.

  For this reason, the operation start time Ts of the weight reduction valve 29 is set before the voltage applied to the starter motor 51 increases the current consumed by the starter motor 51 and the battery voltage drop occurs.

  When the ECU 100 excites the electromagnetic coil 34 of the weight reduction valve 29 at the operation start time Ts, the plunger 32 is seated on the valve seat 31b at the seating time Te, so that the high pressure fuel is pumped from the fuel pump 21 to the delivery pipe 23 and the fuel is supplied. Boosted.

  In addition, when the seating time T1 acquired by the ECU 100 is shorter than T4, for example, 15 ms, when the excitation signal is output to the weight reduction valve 29 when the start signal is input, the sitting time Te starts the cranking operation. Before Te time.

When the seating time T1 is shorter than T4, the ECU 100 sets the seating time Te to a constant value, for example, 2 ms after the cranking operation start time Tcs, and sets the operation start time Ts to (T4 + 2ms) −T1. Then, the operation start time Ts is set to 5 ms from the time when the start signal is input from the ignition switch 104.
In addition, T1-T4, Ts, Te, and Tcs mentioned above are illustrations, Comprising: It is not limited to this.

  As described above, the ECU 100 of the fuel pressure control apparatus according to the present embodiment starts the operation of the weight reducing valve 29 until the start of the cranking operation of the starter device 50, and the plunger 32 is moved during the cranking operation of the starter device 50. The operation of the weight reduction valve 29 is controlled so as to be seated on the valve seat 31b.

  In particular, the ECU 100 according to the present embodiment has a timing when the voltage drop of the battery 70 occurs after the cranking operation start time Tcs of the starter device 50, that is, when the voltage is applied from the battery 70 to the starter motor 51. The seating time Te is set so that the plunger 32 is seated on the valve seat 31b after Tcs, and the operation of the weight reduction valve 29 is performed before the seating time T1 minutes before the seating time Te and before the cranking operation start time Tcs. Configured to start.

  Therefore, the operation of the weight reduction valve 29 can be started before the voltage drop of the battery 70 occurs due to the cranking operation of the starter device 50. For this reason, the applied voltage of sufficient magnitude | size for attracting | sucking the plunger 32 can be given to the weight reduction valve 29, and it can prevent that the weight reduction valve 29 enlarges.

  In particular, when the voltage value of the battery 70 is the end-of-discharge voltage value, the voltage applied to the weight reduction valve 29 when the voltage drop occurs is small, but before the voltage drop of the battery 70 occurs, the weight reduction valve 29 can be started, so that an applied voltage sufficiently large to suck the plunger 32 can be applied to the weight reduction valve 29.

Further, since the plunger 32 can be seated on the valve seat 31b during the cranking operation, the operating sound when the plunger 32 is seated on the valve seat 31b is made inconspicuous by the sound (dark noise) during the cranking operation. It is possible to prevent the passenger 32 from feeling uncomfortable due to the operation sound when the plunger 32 is seated on the valve seat 31b.
In FIG. 6, the battery voltage rises after the cranking operation ends because charging is started by the alternator.

  Here, for comparison, as shown in FIG. 7, when the seating time Te is set before the cranking operation start time Tcs, there is no voltage drop, so the reduction valve 29 is large. A voltage can be applied. However, in this case, since the background noise due to the cranking operation is not generated, the operation sound when the plunger 32 is seated on the valve seat 31b becomes noise.

  In addition, as shown in FIG. 8, when the seating time Te is set after the cranking operation end time Tce, the operating sound when the plunger 32 is seated on the valve seat 31b due to background noise due to the operation of the engine 10 is generated. It can be made inconspicuous.

  However, in this case, the weight reduction valve 29 is opened for a long time and the fuel is recirculated from the recirculation passage 27a of the second return pipe 27 to the fuel tank 30, so that it is not possible to boost the fuel early. .

  On the other hand, in the present embodiment, as shown in FIG. 6, the operation of the weight reduction valve 29 can be started before the voltage drop of the battery 70 occurs due to the cranking operation of the starter device 50. By closing the weight reduction valve 29, high pressure fuel can be supplied to the delivery pipe 23 by the fuel pump 21, and the fuel can be boosted quickly.

  Further, in the present embodiment, the ECU 100 calculates the time from when the start signal is input until the voltage is applied to the starter motor 51, so that the voltage is applied to the starter motor 51 after the start signal is input. The operation start timing Ts of the weight reduction valve 29 can be easily calculated based on the time until the voltage is applied, that is, the time from when the start signal is input until the voltage drop of the battery 70 occurs and the seating time Te. .

  In the present embodiment, the seating time Te is set after the cranking operation start time Tcs, but may be set at the same time as the cranking operation start time Tcs. In short, the seating time Te may be set after the cranking operation start time Tcs including the cranking operation start time Tcs.

  Note that the ECU 100 according to the present embodiment has the plunger 32 mounted on the valve seat after the start of the cranking operation of the starter device 50 that performs cranking of the engine 10 on the condition that a start signal is input from the ignition switch 104. Although the seating time is set so as to sit on 31b, it is not limited to this.

  For example, the ECU 100 sets the operation start time Ts so as to start the operation of the weight reduction valve 29 when a predetermined time elapses after the start signal is input from the ignition switch 104, and the plunger 32 is moved to the valve seat during the cranking operation. You may make it sit on 31b.

  In short, the operation of the reducing valve 29 is started before the cranking operation of the starter device 50 is started, and the operation of the reducing valve 29 is performed so that the plunger 32 is seated on the valve seat 31b during the cranking operation of the starter device 50. Any mode may be used as long as it is controlled.

Next, the operation of the reduction valve 29 after cranking will be described.
When the engine 10 is in a normal operation state other than when the operation is stopped or started, the voltage reducing valve 29 is maintained in an open state by the urging force of the coil spring 33 because no voltage is applied to the electromagnetic coil 34. Yes. At this time, the fuel discharge amount discharged from the fuel pump 21 is set to a discharge amount in consideration of the fuel amount returned to the fuel tank 30 via the reduction valve 29.

  Here, for example, when the engine 10 is in an idle operation state, the applied voltage of the fuel pump 21 is lowered to the lower limit voltage Vmin to reduce the fuel discharge amount to the minimum amount in order to reduce the fuel supplied to the engine 10. At this time, the required fuel consumption required for the engine 10 in the idle operation state is lower than the minimum fuel discharge amount corresponding to the lower limit voltage Vmin of the fuel pump 21.

  In the present embodiment, even in such a case, the reduction valve 29 is opened, so that the difference fuel between the minimum fuel discharge amount and the required fuel consumption amount causes the return passage 27a and the reduction valve 29 to flow. To the fuel tank 30. Thereby, the fuel consumption consumed by the engine 10 can be made into a desired required fuel consumption.

  Further, when the engine 10 is started, since the reduction valve 29 is closed as described above, the fuel pressure at the time of starting the engine 10 can be quickly increased, which contributes to improvement of startability. When the start of the engine 10 is completed, the energization of the electromagnetic coil 34 is released, and the reduction valve 29 is opened.

  In the present embodiment, an example in which the reduction valve 29 is opened when the engine 10 is in a normal operation state and is closed only at the time of starting has been described. However, the present invention is not limited to this example. ) The reduction valve 29 may be closed even during high load operation such as in a state. In this case, by closing the reduction valve 29, the amount of fuel supplied to the engine 10 can be increased at an early stage, and the driver's high load operation request can be responded with good response.

  As described above, in the fuel pressure control apparatus according to the present embodiment, the ECU 100 can maintain the drive of the fuel pump 21 even when the applied voltage applied to the fuel pump 21 causes foreign matter to be caught in the sliding portion of the fuel pump 21. Is controlled to be equal to or higher than the lower limit voltage Vmin for generating a sufficient driving torque. For this reason, it is possible to prevent the electric fuel pump 21 from being stopped due to the foreign object biting as described above.

  In addition, the fuel pressure control device according to the present embodiment has a minimum fuel discharge amount when the fuel pump 21 is driven at the lower limit voltage Vmin and a required fuel consumption amount that is required according to the operating state of the engine 10. When there is a differential fuel, the differential fuel is recirculated to the fuel tank 30 by opening the reduction valve 29.

  Therefore, while maintaining the applied voltage of the electric fuel pump 21 at or above the lower limit voltage Vmin, the fuel injection amount injected from the port injector 13 may be less than the minimum fuel discharge amount corresponding to the lower limit voltage Vmin. it can.

  In the present embodiment, the engine 10 is configured by an internal combustion engine that performs only port injection for injecting fuel into the intake port. However, the present invention is not limited to this, and a cylinder that directly injects fuel into the combustion chamber in the cylinder. You may comprise with the internal combustion engine of the dual injection system which uses together internal injection and port injection which injects a fuel in the intake port corresponding to a cylinder.

  As described above, the fuel pressure control device according to the present invention suppresses an increase in the size of the electromagnetic pressure control valve and allows the occupant to hear the operating sound when the valve body is seated on the valve seat when the internal combustion engine is started. It is effective as a fuel pressure control device for controlling the pressure of fuel supplied to a fuel injection valve of an internal combustion engine mounted on a vehicle, etc. .

10 Engine (Internal combustion engine)
13 port injector (fuel injection valve)
20 Fuel supply device (fuel pressure control device)
21 Fuel pump 22a Supply passage 23 Delivery pipe 27a Recirculation passage 29 Reduction valve (electromagnetic pressure control valve, reduction valve)
30 Fuel tank 31b Valve seat 32 Plunger (valve element)
33 Coil spring (biasing member)
50 starter device 51 starter motor 70 battery 100 ECU (control means)

Claims (5)

A fuel pump that pumps fuel stored in a fuel tank to a delivery pipe to which a fuel injection valve of an internal combustion engine is connected via a supply passage;
A return passage for branching off from the supply passage and returning a part of the fuel flowing in the supply passage to the fuel tank;
The return passage is provided in the return passage to open the return passage by separating the valve body from the valve seat by the biasing force of the biasing member when no voltage is applied, and resists the biasing force of the biasing member when the voltage is applied. A normally open electromagnetic pressure control valve that varies the pressure of fuel pumped from the fuel pump by closing the return passage by seating the valve body on the valve seat;
A fuel pressure control device comprising control means for performing opening / closing control of the electromagnetic pressure control valve,
The control means starts the operation of the electromagnetic pressure control valve until the start of the cranking operation of the starter device for cranking the internal combustion engine, and the valve body is moved during the cranking operation of the starter device. A fuel pressure control device for controlling an operation of the electromagnetic pressure control valve so as to be seated on a valve seat. The control means obtains a seating time from when the electromagnetic pressure control valve starts to operate until the valve body is seated on the valve seat based on an applied voltage;
On the condition that a start signal is input, a seating time machine is set so that the valve body is seated on the valve seat after the start time of cranking operation of the starter device, and the seating time before the seating time machine is set. 2. The fuel pressure control device according to claim 1, wherein the operation of the electromagnetic pressure control valve is started before the cranking operation start timing. The starter device has a starter motor that cranks the internal combustion engine when a voltage is applied from a battery;
The fuel pressure control apparatus according to claim 2, wherein the control means sets a time when the application of voltage from the battery to the starter motor is started as a time for starting a cranking operation.   4. The fuel pressure control apparatus according to claim 3, wherein the control unit calculates a time from when the start signal is input to when the start of application of voltage to the starter motor. 5. The fuel pump is composed of an electric fuel pump that is driven with an applied voltage equal to or higher than a lower limit voltage capable of maintaining driving even when foreign matter is caught in the sliding portion,
A fuel discharge amount of the fuel pump when the electromagnetic pressure control valve drives the fuel pump at the lower limit voltage, and a required fuel consumption amount required for the internal combustion engine according to an operating state of the internal combustion engine. The fuel pressure control device according to any one of claims 1 to 4, wherein the fuel pressure control device has a function as a reduction valve for returning the differential fuel to the fuel tank.

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