JP2008255980A - Fuel feed control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel feed control device capable of suppressing noises due to the opening/closing operation of an opening/closing means in a high pressure fuel force-feed means with a forcing means for pressurizing a fuel, which is arranged on the downstream side of a low pressure fuel force-feed means for force-feeding the fuel to a fuel injection device, and the opening/closing means for opening/closing the feeding flow passage of the fuel fed to the forcing means. <P>SOLUTION: This fuel feed control device controls the high pressure fuel force-feed means 1 provided with the forcing means 1p for forcing the fuel force-fed by the low pressure fuel force-feed means, which is arranged on downstream of the low pressure fuel force-feed means for force-feeding the fuel to the fuel injection device, and the opening/closing means 1s for opening/closing the feeding flow path of the fuel fed to the pressurizing means. When the operating conditions of an internal combustion engine satisfy preset prescribed conditions, the opening/closing means is stopped in an open state, and the fuel is fed to the fuel injection device by the low pressure fuel force-feed means without an increase in pressure of the fuel by the forcing means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel supply control device, and more particularly to a low-pressure fuel pumping means provided on the downstream side in the fuel flow direction relative to a low-pressure fuel pumping means that boosts the pressure of fuel and pumps it toward a fuel injection device of an internal combustion engine. Controls the high-pressure fuel pumping means comprising a boosting means for increasing the pressure of the fuel pumped toward the fuel injection device, and an opening / closing means for opening and closing a supply passage for the fuel supplied from the low-pressure fuel pumping means to the boosting means. The present invention relates to a fuel supply control device.

  As a fuel supply device for supplying fuel to an internal combustion engine, a feed pump (low pressure fuel pumping means) that pumps fuel at a relatively low pressure, and a high pressure pump that pumps the fuel after the pressure of the fuel pumped by the feed pump is increased ( High-pressure fuel pumping means).

  Control of the fuel discharge amount in the high-pressure pump is performed by, for example, opening and closing a metering valve (opening / closing means) provided in the high-pressure pump. When the metering valve opens and closes, an operating noise is generated with the opening and closing operation. When the sound generated from the internal combustion engine itself is relatively low, such as when the rotational speed of the internal combustion engine is low, the operation sound of the metering valve may be felt as noise.

JP 2002-213326 A JP 2000-8917 A JP 2000-249020 A

  It is provided downstream of the low-pressure fuel pumping means for increasing the pressure of the fuel and pumping it toward the fuel injection device of the internal combustion engine, and the fuel pumped toward the fuel injection device by the low-pressure fuel pumping means. In a high-pressure fuel pumping means comprising a pressure-increasing means for increasing pressure and an opening / closing means for opening and closing a supply passage of fuel supplied from the low-pressure fuel pumping means to the pressure-increasing means, it is hoped that noise associated with the opening / closing operation of the opening / closing means can be suppressed. It is rare.

  Japanese Patent Laid-Open No. 2002-213326 (Patent Document 1) is configured to include a plurality of high-pressure fuel pumps that are associated with opening and closing operations of electromagnetic valves, and the operation sound of the high-pressure fuel pump that accompanies opening and closing operations of the solenoid valves. A fuel supply device for an internal combustion engine that can be reduced is disclosed.

  The fuel supply device for an internal combustion engine described in Patent Document 1 is operated by the opening / closing control of an electromagnetic valve, and the high-pressure fuel pump in which the amount of fuel discharged to the high-pressure fuel pipe is adjusted through the opening / closing control of the electromagnetic valve. In the fuel supply apparatus for an internal combustion engine comprising a plurality of, the electromagnetic valve so as to reduce the number of operations of the plurality of high-pressure fuel pumps in a predetermined period according to the required fuel amount of the internal combustion engine when the required fuel amount is small The control means for controlling is provided.

  In the fuel supply device for an internal combustion engine described in Patent Document 1, when the required fuel amount of the internal combustion engine is small, the operation of the high-pressure fuel pump is stopped while maintaining the operation of at least one high-pressure fuel pump. The Although the operating noise of the high-pressure fuel pump is reduced, the operating noise associated with the opening / closing operation of the solenoid valve is still occurring in the operating high-pressure fuel pump.

  An object of the present invention is to be provided downstream of the low-pressure fuel pumping means for increasing the pressure of the fuel and pumping the fuel pressure toward the fuel injection apparatus of the internal combustion engine. In the high pressure fuel pumping means, comprising a boosting means for increasing the pressure of the fuel to be pumped and an opening / closing means for opening / closing a supply flow path of the fuel supplied from the low pressure fuel pumping means to the boosting means. To provide a fuel supply control device capable of suppressing noise.

  The fuel supply control device according to the present invention is provided on the downstream side in the fuel flow direction with respect to the low pressure fuel pumping means for increasing the pressure of the fuel and pumping it toward the fuel injection device of the internal combustion engine. High-pressure fuel pressure feed comprising pressure-increasing means for increasing the pressure of the fuel pressure-fed toward the fuel injection device, and opening / closing means for opening and closing the supply passage for the fuel supplied from the low-pressure fuel pressure-feeding means to the pressure-increasing means. A fuel supply control device for controlling the means, wherein when the operating condition of the internal combustion engine satisfies a predetermined condition, the opening / closing means is stopped in an open state, and the pressure of the fuel is increased by the pressure increasing means. The fuel is supplied to the fuel injection device by the low-pressure fuel pumping means without being increased, and the operating status of the internal combustion engine includes the rotational speed of the internal combustion engine and the fuel injection device. Against it characterized to include at least one of the command value of the injection quantity of the fuel.

  In the fuel supply control device of the present invention, the operating status of the internal combustion engine further includes an in-cylinder pressure of the internal combustion engine.

  In the fuel supply control device of the present invention, when the fuel is supplied to the fuel injection device by the low pressure fuel pumping means without increasing the pressure of the fuel by the pressure increasing means, the fuel injection device causes the internal combustion engine to The time when the fuel is supplied to the engine is set to the intake stroke of the internal combustion engine.

  In the fuel supply control device of the present invention, when the fuel is supplied to the fuel injection device by the low-pressure fuel pumping unit without increasing the pressure of the fuel by the boosting unit, Compared to the case where the fuel is supplied to the fuel injection device by the low-pressure fuel pumping means without increasing the pressure, the pressure at which the low-pressure fuel pumping means pumps the fuel is set to a large value. Features.

  The fuel supply control apparatus according to the present invention further includes a travel environment detection unit that detects a travel environment of a vehicle on which the internal combustion engine is mounted, and the travel environment detection is performed when the operation state of the internal combustion engine satisfies the predetermined condition. Based on the traveling environment detected by the means, the opening / closing means is stopped in the open state, and the fuel is supplied to the fuel injection device by the low pressure fuel pumping means without increasing the pressure of the fuel by the pressure raising means. It is characterized by determining whether to execute the supplied specific control.

  In the fuel supply control apparatus of the present invention, the traveling environment detection means detects or estimates a noise level outside the vehicle, and the detected or estimated noise level is a predetermined noise level. The specific control is executed when the value is smaller than the threshold value.

  In the fuel supply control apparatus of the present invention, the traveling environment detection means detects or estimates a gradient at a current position of the traveling path of the vehicle, and the detected or estimated gradient is an uphill gradient, The specific control is not executed when a predetermined gradient threshold value is exceeded.

  In the fuel supply control apparatus of the present invention, the traveling environment detection means detects or estimates a degree of congestion of road conditions at the current position of the vehicle, and the detected or estimated degree of congestion is determined in advance. The specific control is not executed when the congestion degree threshold value is exceeded.

  According to the fuel supply control device of the present invention, the fuel supply control device is provided on the downstream side in the fuel flow direction with respect to the low pressure fuel pumping means for increasing the fuel pressure and pumping the fuel pressure toward the fuel injection device of the internal combustion engine. In the high-pressure fuel pumping means, comprising a boosting means for increasing the pressure of the fuel pumped toward the fuel injection device, and an opening / closing means for opening and closing a supply passage for the fuel supplied from the low-pressure fuel pumping means to the boosting means. Noise associated with the opening / closing operation is suppressed.

  Hereinafter, an embodiment of a fuel supply control device of the present invention will be described in detail with reference to the drawings.

(First embodiment)
The first embodiment will be described with reference to FIGS. 1 to 6. The present embodiment is provided on the downstream side of the fuel flow direction with respect to the low pressure fuel pumping means for increasing the pressure of the fuel and pumping it toward the fuel injection apparatus of the internal combustion engine, and is directed toward the fuel injection apparatus by the low pressure fuel pumping means. The present invention relates to a fuel supply control device that controls a high-pressure fuel pumping unit that includes a booster that raises the pressure of fuel to be pumped and an opening / closing unit that opens and closes a supply flow path of fuel supplied from the low-pressure fuel pumper to the booster.

  In this embodiment, fuel is injected into the cylinder of the internal combustion engine. In order to inject fuel into a cylinder that becomes high pressure, the pressure of the fuel needs to be high. Therefore, as a fuel supply device, a feed pump (low pressure fuel pumping means, see reference numeral 3 in FIG. 1) and a high pressure pump (high pressure fuel pumping means, FIG. 1) for further increasing the pressure of fuel pumped by the feed pump 3 are used. (See reference numeral 1). The fuel boosted by the high-pressure pump 1 is supplied to an injector (a fuel injection device, see reference numeral 7 in FIG. 1) through a high-pressure pipe (see reference numeral 5 in FIG. 1) and a delivery pipe (see reference numeral 6 in FIG. 1). .

  The high-pressure pump 1 is provided with a spill valve (opening / closing means, see reference numeral 1s in FIG. 2) for controlling the fuel discharge amount. The spill valve 1s is opened and closed to control the fuel discharge amount. Depending on the operating condition of the internal combustion engine, the operation sound accompanying the opening / closing operation of the spill valve 1s may be felt as noise. In the present embodiment, when the required amount of fuel can be injected with the fuel pressure pumped by the feed pump 3 according to the operating state of the internal combustion engine, the operation of the spill valve 1s is stopped in the open state. . Thereby, generation | occurrence | production of the noise by the opening / closing operation | movement of spill valve 1s is suppressed.

  FIG. 1 is a schematic configuration diagram of an apparatus according to the present embodiment. In FIG. 1, the code | symbol 1 shows a high pressure pump. Details of the structure and operation of the high-pressure pump 1 will be described later. The fuel tank 2 is provided with a feed pump 3. The high pressure pump 1 is connected to the feed pump 3 through a low pressure pipe 4. The feed pump 3 sucks the fuel in the fuel tank 2, raises the fuel pressure to the feed pressure, and pumps the fuel toward the high-pressure pump 1.

  The high-pressure pump 1 is connected to a delivery pipe 6 through a high-pressure pipe 5. The fuel whose pressure has been increased by the high-pressure pump 1 flows into the delivery pipe 6 through the high-pressure pipe 5 and is accumulated in the delivery pipe 6. The delivery pipe 6 includes a first delivery pipe 6a and a second delivery pipe 6b. The first delivery pipe 6a and the second delivery pipe 6b are connected by a connection pipe 6c.

  The delivery pipe 6 is provided with an injector 7. The fuel supplied from the delivery pipe 6 is injected into the cylinder of the internal combustion engine by the injector 7.

  The delivery pipe 6 is provided with a pressure sensor 8 and a relief valve 9. The pressure sensor 8 detects the fuel pressure (fuel pressure) in the delivery pipe 6. When the fuel pressure in the delivery pipe 6 exceeds the set pressure (relief pressure) of the relief valve 9, the relief valve 9 opens. In this case, the fuel in the delivery pipe 6 is returned from the relief valve 9 to the fuel tank 2 through the relief passage 11. Thereby, it is suppressed that the fuel pressure in the delivery pipe 6 becomes higher than the relief pressure.

  FIG. 2 is an enlarged view of the vicinity of the high-pressure pump 1 in FIG. The high-pressure pump 1 includes a cylinder 1y, a spill valve 1s, a plunger (pressure increasing means) 1p, and a check valve 1c. A pressurizing chamber 15 is formed above the plunger 1p in the cylinder 1y. The high-pressure pump 1 is driven by a pump cam 14 provided on a camshaft 13 of the internal combustion engine. When the plunger 1p is driven by the pump cam 14 to reciprocate, the fuel is sucked into the pressurizing chamber 15 and the fuel in the pressurizing chamber 15 is pressurized. The discharge amount of the pressurized fuel to the delivery pipe 6 (see FIG. 1) is controlled by the opening / closing operation of the spill valve 1s.

  FIG. 2 shows a state in which the spill valve 1s is opened and the plunger 1p is stroked to the suction side as indicated by reference numeral Y10. In this case, fuel is sucked into the pressurizing chamber 15 from the low pressure pipe 4.

  FIG. 3 shows a state where the spill valve 1s is opened and the plunger 1p is stroked to the discharge side as indicated by reference numeral Y11. In this state, since the spill valve 1 s is open, the fuel in the pressurizing chamber 15 is pushed out to the low pressure pipe 4.

  FIG. 4 shows a state where the spill valve 1s is closed and the plunger 1p is stroked to the discharge side as indicated by reference numeral Y12. In this state, since the spill valve 1s is closed, the pressure in the pressurizing chamber 15 increases and becomes higher than the valve opening pressure of the check valve 1c. Thereby, the check valve 1c is opened, and the fuel in the pressurizing chamber 15 is discharged to the high-pressure pipe 5. The fuel discharged to the high pressure pipe 5 is pumped to the delivery pipe 6.

  As shown in FIG. 1, a vehicle (not shown) is provided with a vehicle control unit 20 having an ECU (Electronic Control Unit) that controls each part of the vehicle. The pressure sensor 8 is connected to the vehicle control unit 20, and the measurement result by the pressure sensor 8 is input to the vehicle control unit 20. The spill valve 1s of the high-pressure pump 1 is connected to the vehicle control unit 20, and the spill valve 1s is controlled by the vehicle control unit 20.

  During steady operation, the vehicle control unit 20 controls the discharge amount of the high-pressure pump 1 so that the fuel pressure in the delivery pipe 6 becomes the target pressure. More specifically, based on the detection result of the pressure sensor 8, the set value of the discharge amount of the high-pressure pump 1 required to set the pressure in the delivery pipe 6 as the target pressure is calculated. Based on the calculated set value of the discharge amount, the valve opening timing and the valve opening period of the spill valve 1s are controlled.

  When fuel is supplied to the delivery pipe 6 as described above, an operating noise is generated with the opening and closing of the spill valve 1s.

  In this embodiment, as will be described below, when the required amount of fuel can be injected at the feed pressure, the operation of the spill valve 1s is stopped.

  FIG. 5 is a flowchart showing the operation of the present embodiment. First, in step S10, it is determined whether or not the rotational speed of the internal combustion engine is equal to or less than a predetermined rotational speed. In step S10 and the next step S20, it is determined whether or not the required amount of fuel can be injected at the feed pressure. The rotational speed of the internal combustion engine is detected by a rotational speed sensor (not shown). When fuel is injected at the feed pressure, the fuel pressure is low, so the injection amount per unit time from the injector 7 is a small value. In this case, there is a possibility that the required amount of fuel cannot be injected within the stroke of the internal combustion engine. However, when the rotational speed of the internal combustion engine is low, the stroke time becomes a large value, so that a required amount of fuel can be injected within the stroke. The predetermined number of rotations can be set to 1,000 rpm, for example.

  As a result of the determination in step S10, when it is determined that the rotation speed of the internal combustion engine is equal to or less than the predetermined rotation speed (Yes in step S10), the process proceeds to step S20.

  In step S20, it is determined whether or not the required injection amount (injection amount command value) for the injector 7 is equal to or less than a predetermined injection amount. When the required injection amount is a small value, the required amount of fuel can be injected even at the feed pressure. The determination is made based on, for example, the load on the internal combustion engine. In this case, it is determined whether or not the ratio of the load of the internal combustion engine to the total load is equal to or less than a predetermined ratio. The predetermined ratio can be set to 20%, for example.

  As a result of the determination in step S20, when it is determined that the required injection amount is equal to or less than the predetermined injection amount (Yes in step S20), the process proceeds to step S30. In step S30, the fuel pumping by the high-pressure pump 1 is stopped. In this case, as shown in FIG. 3, the operation is stopped with the spill valve 1s opened. Thereby, the fuel injection by the feed pressure is started as described below.

  Although the reciprocating motion of the plunger 1p is continuously performed, the fuel is not pressurized because the spill valve 1s remains open. Since the pressure in the high-pressure pipe 5 is higher than the pressure in the pressurizing chamber 15, the check valve 1c is not opened. For this reason, high pressure fuel is not discharged to the high pressure pipe 5.

  When supply of high-pressure fuel to the high-pressure pipe 5 is not performed, the amount of fuel accumulated in the delivery pipe 6 decreases each time fuel is injected. For this reason, the pressure in the delivery pipe 6 and the high-pressure pipe 5 decreases. When the pressure in the high-pressure pipe 5 decreases to a value substantially equal to the feed pressure, the check valve 1c opens as shown in FIG. In this case, the fuel at the feed pressure is supplied to the delivery pipe 6 via the high-pressure pipe 5, and the fuel is injected at the feed pressure. When step S30 is executed, this control flow is reset.

  As a result of the determination in step S10 in FIG. 5, when it is determined that the rotational speed of the internal combustion engine is greater than the predetermined rotational speed (No in step S10), or as a result of the determination in step S20, the required injection amount is When it is determined that the injection amount is larger than the predetermined injection amount (No at Step S20), the process proceeds to Step S40. In step S40, the operation of the spill valve 1s is not stopped, and the fuel is pumped by the high-pressure pump 1. When step S40 is executed, this control flow is reset.

  In the following description, a fuel supply state in which fuel is supplied to the delivery pipe 6 at a feed pressure is referred to as a feed pressure supply. When the feed pressure is supplied, the fuel pressure is lower than when the fuel is pumped by the high pressure pump 1. For this reason, when fuel injection is performed at a time when the in-cylinder pressure such as the compression stroke becomes high, the differential pressure across the injector 7 may decrease, making it difficult to supply the required amount of fuel. In the present embodiment, fuel is injected during the intake stroke when the feed pressure is supplied. In the intake stroke, the in-cylinder pressure is approximately equal to or lower than the atmospheric pressure, so that a necessary amount of fuel can be injected even if the fuel pressure is about the feed pressure.

  Note that when the in-cylinder pressure is higher than the atmospheric pressure in the intake stroke, such as when supercharging is performed, it may be difficult to supply the required injection amount of fuel. For this reason, a condition that the in-cylinder pressure in the intake stroke is equal to or lower than the atmospheric pressure may be added to the condition described with reference to FIG. 5 (Yes in Step S10, Yes in Step S20) as a condition for shifting to the feed pressure supply. it can.

  Hereinafter, the effect of this embodiment will be described. According to this embodiment, when the rotational speed of the internal combustion engine is a low speed equal to or lower than the predetermined rotational speed (Yes at Step S10) and the required injection amount is a value equal to or lower than the predetermined injection amount (Yes at Step S20). Feed pressure is supplied. By stopping the operation of the spill valve 1s, the generation of the operation sound of the spill valve 1s is suppressed. When the sound generated from the internal combustion engine itself is relatively low, such as when the rotational speed of the internal combustion engine is low, the operating sound of the spill valve 1s may be felt as noise. According to the present embodiment, since the operation of the spill valve 1s is stopped in the operating state of the internal combustion engine in which the operation sound of the spill valve 1s is likely to be felt particularly loud, noise is effectively suppressed.

(Second Embodiment)
A second embodiment will be described with reference to FIG. In the second embodiment, only differences from the first embodiment will be described.

  In the first embodiment, the feed pressure is supplied when the rotational speed of the internal combustion engine is low and the required injection amount is a small value. In the present embodiment, in addition to this, when the feed pressure is supplied, the feed pressure is set to a larger value than when the feed pressure is not supplied. As a result, it is possible to inject the required amount of fuel more reliably when the feed pressure is supplied.

  FIG. 7 is a schematic configuration diagram of an apparatus according to the present embodiment. A first relief passage 21 and a second relief passage 24 are connected to the low-pressure pipe 4. The low pressure pipe 4 and the fuel tank 2 are communicated with each other by the first relief passage 21 and the second relief passage 24. The first relief passage 21 is provided with an opening / closing valve 22 for opening and closing the first relief passage 21. A first relief valve 23 is provided closer to the fuel tank 2 than the installation position of the on-off valve 22 in the first relief passage 21.

  A second relief valve 25 is provided in the second relief passage 24. The first relief valve 23 and the second relief valve 25 are opened when the fuel pressure in the low-pressure pipe 4 reaches a predetermined pressure (relief pressure). The relief pressure P1 of the first relief valve 23 is set to a value smaller than the relief pressure P2 of the second relief valve 25.

  Instead of the vehicle control unit 20 of the first embodiment, a vehicle control unit 30 is provided. The on-off valve 22 is connected to the vehicle control unit 30 and is controlled by the vehicle control unit 30.

  Except when the feed pressure is supplied, the on-off valve 22 is open. When the fuel pressure in the low pressure pipe 4 rises and exceeds the relief pressure P1 of the first relief valve 23, the first relief valve 23 is opened. Thereby, the fuel in the low pressure pipe 4 is released to the fuel tank 2 through the first relief passage 21. As a result, the fuel pressure in the low pressure pipe 4 is reduced, so that the fuel pressure in the low pressure pipe 4 is prevented from exceeding the relief pressure P1 of the first relief valve 23.

  When supplying the feed pressure, the on-off valve 22 is closed. In this case, the low pressure pipe 4 and the first relief valve 23 are blocked. Therefore, the fuel pressure in the low pressure pipe 4 exceeds the relief pressure P1 of the first relief valve 23 and rises to the relief pressure P2 of the second relief valve 25. When the fuel pressure in the low pressure pipe 4 exceeds the relief pressure P2 of the second relief valve 25, the second relief valve 25 is opened. Thereby, the fuel in the low-pressure pipe 4 is released to the fuel tank 2 through the second relief passage 24.

  As described above, when the feed pressure is supplied, the feed pressure is larger than when the feed pressure is not supplied. As a result, the fuel injection pressure is increased, so that the required amount of fuel can be supplied to the internal combustion engine more reliably. Further, by increasing the feed pressure, the time required to inject the same amount of fuel can be shortened, and the fuel can be injected into a higher pressure cylinder. As a result, the required amount of fuel can be injected with the feed pressure even in the region where the rotational speed of the internal combustion engine is higher and the load is higher. Therefore, the operation of the spill valve 1s is stopped in a region where the rotational speed of the internal combustion engine is higher and the load is higher, and noise can be suppressed.

  In this embodiment, two relief valves (23, 25) and an on-off valve 22 are provided as a method for increasing the feed pressure when supplying the feed pressure, and the relief pressure is switched by opening and closing the on-off valve 22. Alternatively, the feed pressure can be increased by increasing the discharge pressure of the feed pump 3 when the feed pressure is supplied compared to when the feed pressure is not supplied. For example, when the feed pump 3 is electric, the supply voltage can be increased when the feed pressure is supplied to increase the feed pressure.

(Third embodiment)
A third embodiment will be described with reference to FIGS. 8 and 9. In the third embodiment, only differences from the above embodiments will be described.

  In each of the above-described embodiments (FIG. 5), whether or not to perform control (feed pressure supply) for stopping the operation of the spill valve 1s is determined based on the operating state (the number of revolutions and the required injection amount) of the internal combustion engine. . In this embodiment, when it is determined that the feed pressure supply is performed based on the operating state of the internal combustion engine, it is further determined whether the feed pressure supply is actually executed based on the traveling environment. This is due to the following reason.

  When feed pressure supply is performed and fuel is injected at a low pressure (feed pressure), the degree of fuel atomization is lower than when the high-pressure pump 1 is operated and fuel is injected at a high pressure. . Thereby, combustion deteriorates due to a decrease in the homogeneity of the fuel (air-fuel mixture), and there is a possibility that idle stability may be reduced or idle vibration may occur. Therefore, it is desirable that the feed pressure supply is executed only when the noise suppression effect due to the supply of the feed pressure is high. In the present embodiment, the feed pressure supply is allowed to be executed only in an environment in which the operation sound of the spill valve 1s accompanying the operation of the high pressure pump 1 is particularly worrisome.

  More specifically, when the noise level outside (around) the vehicle is estimated to be smaller than a predetermined noise level threshold based on the current position of the vehicle (running environment), the feed It is allowed to supply pressure. Here, the traveling environment in which the noise level outside the vehicle is estimated to be smaller than the noise level threshold is, for example, in a parking lot, a residential area, particularly a night residential area.

  The operation sound of the spill valve 1s is particularly worrisome because the feed pressure supply is permitted only when a driving environment in which the noise level outside the vehicle is estimated to be lower than the noise level threshold is detected. The operation of the spill valve 1s can be stopped only in the situation. Thereby, generation | occurrence | production of the problem accompanying the fall of the degree of fuel atomization can be suppressed, suppressing the noise accompanying operation | movement of 1 spill valve. Below, the case where the propriety of feed pressure supply is determined based on whether the vehicle is in parking is demonstrated.

  FIG. 8 is a schematic configuration diagram of an apparatus according to the present embodiment. In addition to the device of the first embodiment (FIG. 1), a navigation system device (running environment detection means) 40 is provided. Further, a vehicle control unit 50 is provided instead of the vehicle control unit 20.

  The navigation system device 40 has a basic function of guiding the host vehicle to a predetermined destination, and includes an arithmetic processing device and information (map, straight road, curve, uphill / downhill, highway) necessary for traveling the vehicle. Etc.), a first information detection device including a geomagnetic sensor, a gyrocompass, and a steering sensor, and a current position of the vehicle by radio navigation. It is for detecting a position, road conditions, etc., and is provided with a second information detection device including a GPS antenna and a GPS receiver.

  The operation of this embodiment will be described with reference to FIG.

First, in step S110, the vehicle control unit 50
(1) The rotation speed of the internal combustion engine is less than a predetermined rotation speed N (2) The vehicle speed is less than a predetermined vehicle speed V (3) A predetermined air volume Q with a predetermined intake air volume It is determined whether or not three conditions are satisfied. Here, the intake air amount is a value corresponding to the required injection amount (injection amount command value) for the injector 7 in each of the above embodiments.

  The reason why the vehicle speed is added as a condition for determining whether or not to supply the feed pressure is to avoid a problem that may occur when the feed pressure is supplied at a high vehicle speed as described below. As a case where the above conditions (1) and (3) are satisfied and the vehicle speed is equal to or higher than the predetermined vehicle speed V, for example, the internal combustion engine is temporarily operated after the accelerator is turned off during traveling and then accelerated again. It is conceivable that the engine speed and the required injection amount are reduced. In such a situation, when the feed pressure supply is started regardless of the vehicle speed, re-acceleration is performed immediately after the feed pressure supply is started, and the feed pressure supply is likely to return. In this case, the air-fuel ratio may be deteriorated due to a change in fuel pressure. In the present embodiment, when the vehicle speed is equal to or higher than the predetermined vehicle speed V, the feed pressure supply is prohibited, so that the air-fuel ratio is prevented from becoming rough.

  As a result of the determination in step S110, if it is determined that the above three conditions (1) to (3) are satisfied (Yes in step S110), the process proceeds to step S120, and if not (No in step S110). This control flow is reset.

  In step S120, the vehicle control unit 50 determines whether or not the vehicle is in parking. The vehicle control unit 50 performs the determination in step S120 based on the current position information and the map information output from the navigation system device 40. Parking is an area that includes a parking spot of a vehicle and a runway for moving to the parking spot. SA (service area), PA (parking area), and other parking lots on a motorway such as an expressway Including.

  As a result of the determination in step S120, if it is determined that the vehicle is in the parking area (step S120 affirmative), the process proceeds to step S130. If not (NO in step S120), the control flow is reset.

  In step S <b> 130, the vehicle control unit 50 stops the fuel pumping by the high-pressure pump 1. The spill valve 1s is stopped in an open state, and feed pressure supply is started. When step S130 is executed, this control flow is reset.

  In this embodiment, as a method for determining whether or not the noise level outside the vehicle is smaller than the noise level threshold, the noise level outside the vehicle is based on information output from the navigation system device 40. Although estimated, instead of this, a noise level outside the vehicle may be detected by a sensor or the like.

(Fourth embodiment)
The fourth embodiment will be described with reference to FIG. In the fourth embodiment, only differences from the above embodiments will be described.

  In the said 3rd Embodiment (FIG. 9), the driving | running | working environment which permits feed pressure supply was set. Instead, in this embodiment, a travel environment that prohibits feed pressure supply is set. More specifically, when an uphill road is detected, feed pressure supply is prohibited. This is because, as will be described below, when feed pressure is supplied on an uphill road, torque shortage is likely to occur when starting or accelerating.

  As described above, when the feed pressure is being supplied, the degree of fuel atomization is lower than when the high-pressure pump 1 is operating, and thus combustion may be worsened. Further, even if the feed pressure is returned from the start or acceleration, a predetermined time (for example, several seconds) is required until the fuel pressure increases after the high pressure pump 1 starts to operate. Therefore, if the feed pressure is supplied when the vehicle is on an uphill road where a particularly large output torque is required at the time of starting or accelerating, the torque tends to be insufficient at the time of starting or accelerating.

  For example, when starting from a state where the vehicle is stopped on an uphill road (vehicle speed is 0), the driver greatly depresses the accelerator compared to when the driver is on a flat road. At this time, if the feed pressure is supplied and the fuel pressure is low, the required injection amount may not be satisfied. For this reason, a difference may occur between the output torque expected by the driver and the actual output torque, which may give the driver a sense of discomfort. Therefore, in the present embodiment, when an uphill road having a gradient exceeding a predetermined value (gradient threshold) is detected, feed pressure supply is prohibited. As a result, the occurrence of torque shortage at the time of start or acceleration is suppressed, and drivability is improved.

  The operation of this embodiment will be described with reference to FIG.

In step S210, the vehicle control unit 50
(1) The rotation speed of the internal combustion engine is less than a predetermined rotation speed N (2) The vehicle speed is less than a predetermined vehicle speed V (3) A predetermined air volume Q with a predetermined intake air volume It is determined whether or not three conditions are satisfied. As a result of the determination, if it is determined that the above three conditions (1) to (3) are satisfied (Yes at Step S210), the process proceeds to Step S220. If not (No at Step S210). This control flow is reset.

  In step S220, the vehicle control unit 50 determines whether the current location is an uphill road (uphill) and the vehicle speed is zero. The vehicle control unit 50 determines whether the current location is an uphill road having a gradient exceeding the predetermined value based on the current position information, map information, gradient information, and the like output from the navigation system device 40. As a result of the determination in step S220, if it is not determined that the current location is an uphill road and the vehicle speed is 0 (No in step S220), the process proceeds to step S230. If not (Yes in step S220), the control flow is reset. Is done.

  In step S230, the vehicle control unit 50 stops the fuel pumping by the high-pressure pump 1. The spill valve 1s is stopped in an open state, and feed pressure supply is started. When step S230 is executed, this control flow is reset.

  In this embodiment, the current position is an uphill road and the vehicle speed is 0 as a condition for prohibiting feed pressure supply. Instead, the current position is an uphill road regardless of the vehicle speed. The feed pressure supply may be prohibited.

(Modification of the fourth embodiment)
A modification of the fourth embodiment will be described.

  In the fourth embodiment, the uphill road is detected based on the information of the navigation system device 40, but the uphill road detection method is not limited to this. For example, the G sensor can be mounted on the vehicle, and the uphill road and the slope of the uphill road can be detected based on the detection result of the G sensor.

(Fifth embodiment)
The fifth embodiment will be described with reference to FIG. In the fifth embodiment, only differences from the above embodiments will be described.

  In the fourth embodiment (FIG. 10), the feed pressure supply is prohibited on the uphill road. Instead, in the present embodiment, the feed pressure supply is prohibited when there is a traffic jam. During a traffic jam, stop, low-speed running, and slow acceleration are repeated, and therefore, when it is determined whether or not the feed pressure can be supplied based only on the operating state of the internal combustion engine, the operation and stop of the high-pressure pump 1 are frequently repeated. Cheap. As a result, hunting of the fuel pressure occurs, the air-fuel ratio becomes rough, and the emission may be deteriorated (the emission amount of harmful substances increases). Therefore, in the present embodiment, fuel pressure hunting is suppressed by prohibiting feed pressure supply during traffic jams.

  The operation of this embodiment will be described with reference to FIG.

In step S310, the vehicle control unit 50
(1) The rotation speed of the internal combustion engine is less than a predetermined rotation speed N (2) The vehicle speed is less than a predetermined vehicle speed V (3) A predetermined air volume Q with a predetermined intake air volume It is determined whether or not three conditions are satisfied. As a result of the determination, if it is determined that the above three conditions (1) to (3) are satisfied (Yes at Step S310), the process proceeds to Step S320, and if not (No at Step S310). This control flow is reset.

  In step S320, the vehicle control unit 50 determines whether or not there is a traffic jam. The navigation system device 40 acquires information indicating road conditions, information indicating weather conditions, and the like via communication (including inter-vehicle communication and road-to-vehicle communication) with other vehicles and communication centers. The vehicle control unit 50 performs the determination in step S320 based on the information indicating the road situation output from the navigation system device 40. The vehicle control unit 50 determines that the vehicle is congested when the degree of congestion of the road situation at the current position exceeds a predetermined congestion degree threshold. As a result of the determination, if it is not determined that the vehicle is congested (No at Step S320), the process proceeds to Step S330. If not (Yes at Step S320), the control flow is reset.

  In step S330, the vehicle controller 50 stops the fuel pumping by the high-pressure pump 1. The spill valve 1s is stopped in an open state, and feed pressure supply is started. When step S330 is executed, this control flow is reset.

  In this embodiment, the degree of congestion of the road situation is acquired by the navigation system device 40. Instead, the degree of congestion of the road situation is detected based on the average value of the vehicle speed, the travel distance, etc. within a predetermined period. Or can be estimated.

It is a schematic block diagram of the apparatus which concerns on 1st Embodiment of the fuel supply control apparatus of this invention. It is a figure for demonstrating the operation | movement at the time of the fuel attraction | suction of the high pressure pump in 1st Embodiment of the fuel-injection control apparatus of this invention. It is a figure for demonstrating the operation | movement at the time of fuel discharge of the high pressure pump in 1st Embodiment of the fuel-injection control apparatus of this invention. It is a figure for demonstrating the operation | movement at the time of the fuel discharge of the high pressure pump in 1st Embodiment of the fuel-injection control apparatus of this invention. It is a flowchart which shows operation | movement of 1st Embodiment of the fuel-injection control apparatus of this invention. It is a figure for demonstrating the operation | movement at the time of feed pressure supply in 1st Embodiment of the fuel-injection control apparatus of this invention. It is a schematic block diagram of the apparatus which concerns on 2nd Embodiment of the fuel supply control apparatus of this invention. It is a schematic block diagram of the apparatus which concerns on 3rd Embodiment of the fuel supply control apparatus of this invention. It is a flowchart which shows operation | movement of 3rd Embodiment of the fuel-injection control apparatus of this invention. It is a flowchart which shows operation | movement of 4th Embodiment of the fuel-injection control apparatus of this invention. It is a flowchart which shows operation | movement of 5th Embodiment of the fuel-injection control apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High pressure pump 1c Check valve 1p Plunger 1s Spill valve 1y Cylinder 2 Fuel tank 3 Feed pump 4 Low pressure piping 5 High pressure piping 6 Delivery pipe 7 Injector 8 Pressure sensor 9 Relief valve 11 Relief passage 13 Camshaft 14 Pump cam 15 Pressure chamber 20 Vehicle Control unit 21 First relief passage 22 On-off valve 23 First relief valve 24 Second relief passage 25 Second relief valve 30 Vehicle control unit 40 Navigation system device 50 Vehicle control unit

Claims (8)

It is provided downstream of the low-pressure fuel pumping means for increasing the pressure of the fuel and pumping it toward the fuel injection device of the internal combustion engine, and is pumped toward the fuel injection device by the low-pressure fuel pumping means. A fuel supply control device for controlling a high-pressure fuel pumping means, comprising: a pressure-increasing means for increasing the pressure of the fuel; There,
When the operating condition of the internal combustion engine satisfies a predetermined condition, the opening / closing means is stopped in an open state, and the pressure of the fuel is not increased by the pressure increasing means, and the low pressure fuel pressure feeding means Fuel is supplied to the fuel injector;
The operating condition of the internal combustion engine includes at least one of a rotational speed of the internal combustion engine and a command value of the fuel injection amount for the fuel injection device. The fuel supply control device according to claim 1,
The operating condition of the internal combustion engine further includes an in-cylinder pressure of the internal combustion engine. The fuel supply control device according to claim 1 or 2,
When the fuel is supplied to the fuel injection device by the low pressure fuel pumping means without increasing the pressure of the fuel by the boosting means, the timing at which the fuel is supplied to the internal combustion engine by the fuel injection device Is set to the intake stroke of the internal combustion engine. In the fuel supply control device according to any one of claims 1 to 3,
When the fuel is supplied to the fuel injection device by the low pressure fuel pumping means without increasing the pressure of the fuel by the pressure increasing means, the low pressure fuel is not increased by the pressure increasing means without increasing the pressure of the fuel. The fuel supply control device, wherein the pressure at which the low pressure fuel pumping unit pumps the fuel is set to a larger value than when the fuel is supplied to the fuel injection device by the pumping unit. In the fuel supply control device according to any one of claims 1 to 4,
A traveling environment detecting means for detecting a traveling environment of a vehicle on which the internal combustion engine is mounted;
When the operating condition of the internal combustion engine satisfies the predetermined condition, the opening / closing means is stopped in the open state based on the traveling environment detected by the traveling environment detecting means, and the boosting means A fuel supply control device that determines whether or not to execute a specific control in which the fuel is supplied to the fuel injection device by the low-pressure fuel pumping means without increasing the pressure. The fuel supply control device according to claim 5, wherein
The traveling environment detection means detects or estimates a noise level outside the vehicle, and the detected or estimated noise level is smaller than a predetermined noise level threshold value. The fuel supply control device characterized by executing the specific control. The fuel supply control device according to claim 5 or 6,
The traveling environment detection means detects or estimates a gradient at a current position of the traveling path of the vehicle, and the detected or estimated gradient is an upward gradient, and a predetermined gradient threshold value is set. If it exceeds, the specific control is not executed. The fuel supply control device according to any one of claims 5 to 7,
The travel environment detection means detects or estimates the degree of congestion of road conditions at the current position of the vehicle, and the detected or estimated degree of congestion exceeds a predetermined congestion degree threshold. Does not execute the specific control. A fuel supply control device, wherein:

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