JP6436046B2 - Fuel pump control device - Google Patents

Description

  The present invention relates to a control device for a fuel pump.

  2. Description of the Related Art Conventionally, for example, as a fuel supply system for a diesel engine, a high pressure pump that makes high pressure low pressure fuel pumped from a fuel tank and a pressure accumulation chamber that stores high pressure fuel discharged from the high pressure pump are provided. An accumulator fuel supply system that injects fuel into an engine cylinder from an injection valve is known. The high-pressure pump is configured to be rotationally driven by the operation of the engine, and the plunger reciprocates in synchronization with the rotation of the engine, and fuel is pressurized in the pressurizing chamber with the reciprocation. The high-pressure pump is provided with a metering valve that opens and closes the suction port of the pressurizing chamber. By changing the valve closing instruction angle of the metering valve, the amount of fuel discharged from the pressurizing chamber is set to the required value. I try to control it.

  In the technique described in Patent Document 1, the controllable range of the energization timing is learned and corrected based on the control behavior of the energization timing of the metering valve during operation of the fuel pump. Specifically, a retard angle side guard value and an advance angle side guard value of energization timing are determined. Even if the energization timing is guarded with the retarded guard value, the retarded guard value is set to the retarded side when the actual fuel pressure continues to be higher than the target fuel pressure. I am trying to correct learning. Also, if the current fuel pressure is lower than the target fuel pressure by more than the specified value even though the energization time is guarded with the advance side guard value, the advance side guard value is I am trying to correct the learning on the side.

JP 2003-322048 A

  However, regarding the advance side guard, even if the actual fuel pressure is lower than the target fuel pressure by a predetermined amount or more, the peak value of the pump discharge characteristic is not always on the advance side. In other words, whether the advance side guard value is deviated to the advance side or the retard side, with respect to the actual pump discharge characteristics, the actual fuel pressure is in the state of the advance side guard. A state that is lower than a predetermined level with respect to the target fuel pressure is continued. In this case, in an actual fuel pump, both the advance side guard value and the retard side can occur with respect to the pump discharge characteristics. There is room for improvement in the update process.

  The present invention has been made in view of the above circumstances, and a main purpose thereof is a high-pressure pump capable of appropriately setting an advance side guard value with respect to pump discharge characteristics, and thus capable of performing appropriate discharge amount control. It is to provide a control device.

  The pump control apparatus according to the present invention is applied to a fuel pump (13) that sucks and pumps fuel in the pressurizing chamber (35) by reciprocating movement of the plunger (32), and in a pumping period in which the volume of the pressurizing chamber decreases. A pump control device (60) for controlling a fuel discharge amount by adjusting a closing timing of a suction passage (36) by a metering valve (38), and a guard angle on an advance side in a valve closing instruction angle of the metering valve When the advance angle side guard value is determined and the valve closing command angle of the metering valve is the advance side guard value, the valve closing command angle of the metering valve is changed to the retard side and the change is made The first determination unit that determines whether or not the fuel discharge amount has increased due to the above, and when the valve closing instruction angle of the metering valve is the advance side guard value, the valve closing instruction angle of the metering valve is set to the advance side A second determination for determining whether or not the fuel discharge amount has increased due to the change When the first determination unit determines that the fuel discharge amount has increased, the advance side guard value is updated to the retard side, and when the second determination unit determines that the fuel discharge amount has increased, An update unit that updates the advance side guard value to the advance side.

  In the fuel pump, if the valve closing timing of the intake passage by the metering valve shifts too far to the advance side, the fuel discharge amount may change from an increase to a decrease, resulting in a decrease in the fuel discharge amount. A guard value is defined. This advance side guard value is determined at or near the peak value at which the fuel discharge amount is maximum with respect to the rotation angle of the pump output shaft (pump rotation angle). In such a case, if there are variations in the pump discharge characteristics due to manufacturing variations of the fuel pump or changes over time, it is possible that the setting of the advance side guard value for the pump discharge characteristics becomes inappropriate.

  In this regard, if the valve closing instruction angle of the metering valve is the advance side guard value, the valve closing instruction angle of the metering valve is changed to the retard side, and if the fuel discharge amount increases as a result of the change, the advance angle The side guard value has been updated to the retard side. If the valve closing command angle of the metering valve is the advance side guard value, the valve closing command angle of the metering valve is changed to the advanced side. Updated the guard value to advance. As a result, the advance side guard value can be set appropriately with respect to the pump discharge characteristics, and as a result, appropriate discharge amount control can be performed.

The block diagram which shows the outline | summary of a common rail type fuel injection system. The figure for demonstrating the structure and operation | movement of a high pressure pump. The figure which shows a pump discharge characteristic. The flowchart which shows the process sequence of learning update of an advance angle side guard value. The time chart which shows the aspect of the retard process or advance process of an advance side guard value. The figure which shows the advance side guard value defined supposing the most retarded angle characteristic.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. The present embodiment embodies the present invention as a common rail fuel injection system for a vehicle diesel engine, and a detailed configuration thereof will be described below.

  FIG. 1 is a configuration diagram showing an outline of a common rail fuel injection system. In FIG. 1, a multi-cylinder diesel engine (hereinafter referred to as an engine) 10 is provided with an electromagnetic injector 11 for each cylinder, and these injectors 11 are connected to a common rail (pressure accumulation pipe) 12 common to each cylinder. A high pressure pump 13 as a fuel supply pump is connected to the common rail 12. The high-pressure pump 13 sucks and pressurizes low-pressure fuel pumped from the fuel tank 16 by the feed pump 15 through the low-pressure passage 36 and discharges it to the common rail 12 through the high-pressure passage 41. As a result, the high pressure fuel is accumulated in the common rail 12.

  Next, the structure and operation of the high-pressure pump 13 will be described with reference to FIG. The high-pressure pump 13 is provided with a cylinder 31 in the pump body, and a plunger 32 is accommodated in the cylinder 31 so as to be able to reciprocate. One end of the plunger 32 is in contact with the cam 33. The cam 33 is fixed to a camshaft 34 connected to the crankshaft, and rotates due to the rotation of the crankshaft accompanying the engine drive. As the cam 33 rotates, the plunger 32 reciprocates.

  A pressure chamber 35 is provided in the cylinder 31 adjacent to the plunger 32. A low pressure passage 36 and a high pressure passage 41 are connected to the pressurizing chamber 35. The fuel in the low pressure passage 36 is sucked in accordance with the movement of the plunger 32, and the sucked fuel is pressurized and fed from the pressurizing chamber 35.

  A metering valve 38 is provided on the low pressure passage 36 side of the high pressure pump 13. The metering valve 38 is, for example, an electromagnetic flow control valve (PCV), and is configured as a normally open valve that opens when not energized. The metering valve 38 is not limited to an electromagnetic flow control valve, and may be a piezoelectric flow control valve. The metering valve 38 is closed when energized during the pumping period. The metering valve 38 is energized for a predetermined time, and then the energization is interrupted.

  A discharge valve 42 is provided on the high pressure passage 41 side of the high pressure pump 13. The discharge valve 42 is configured by a known check valve, and only allows the fuel to flow out from the pressurizing chamber 35 in accordance with the fuel pressure in the pressurizing chamber 35, and the fuel from the common rail 12 to the pressurizing chamber 35. Regulate the inflow.

  During the intake period in which the volume in the pressurizing chamber 35 increases, the energization of the metering valve 38 is interrupted, so that the metering valve 38 is opened. That is, the pressurizing chamber 35 and the low pressure passage 36 are in communication. At this time, the plunger 32 moves from the top dead center to the bottom dead center with the metering valve 38 opened, and the volume of the pressurizing chamber 35 increases. Then, the low pressure fuel pumped up from the feed pump 15 is sucked into the pressurizing chamber 35.

  In the pressure-feeding period in which the volume in the pressurizing chamber 35 decreases, when the plunger 32 moves from the bottom dead center toward the top dead center, the metering valve 38 is not energized, and the valve-opening state is maintained. The fuel in 35 flows backward to the fuel tank 16 side. The period before the metering valve 38 is closed is the prestroke period.

  Thereafter, when the metering valve 38 is energized at a predetermined pump rotation angle to be closed, the pressure of the fuel in the pressurizing chamber 35 rises, and the high pressure fuel increased in pressure by the pressure rise causes the discharge valve 42 to be discharged. It is discharged to the common rail 12 via. The period during which the high-pressure fuel is discharged to the common rail 12 is the fuel discharge period.

  Therefore, in the high pressure pump 13, the discharge amount of the high pressure fuel discharged from the high pressure pump 13 to the common rail 12 can be controlled by controlling the energization start timing (valve closing instruction angle) of the metering valve 38. That is, the fuel discharge amount is increased by setting the valve closing instruction angle of the metering valve 38 to the advance side, and the fuel discharge amount is decreased by setting the valve closing instruction angle to the retard side.

  When the metering valve 38 is energized and closed to increase the pressure in the pressurizing chamber 35, the metering valve 38 is closed by the fuel pressure in the pressurizing chamber 35 even if the metering valve 38 is de-energized. Retained. Therefore, as shown in FIG. 2, the energization of the metering valve 38 is cut off before the plunger 32 reaches the top dead center.

  Returning to the description of FIG. 1, the common rail 12 is provided with a common rail pressure sensor 17, and the fuel pressure in the common rail 12 (hereinafter also referred to as an actual rail pressure) is detected by the common rail pressure sensor 17. Although not shown, the common rail 12 is provided with an electromagnetically driven (or mechanical) pressure reducing valve. When the common rail pressure rises excessively, the pressure reducing valve is opened to perform pressure reduction. It has become.

  The ECU 60 is an electronic control unit including a known microcomputer including a CPU, ROM, RAM, EEPROM, and the like. The ECU 60 detects a rotation speed of the engine 10 in addition to a detection signal of the common rail pressure sensor 17. Detection signals are sequentially input from various sensors such as a rotation speed sensor, an accelerator opening sensor that detects the amount of accelerator operation by the driver, a water temperature sensor that detects the temperature of engine cooling water, and a fuel temperature sensor that detects the fuel temperature in the common rail 12. Is done. Then, the ECU 60 determines an optimal fuel injection amount and injection timing based on engine operation information such as engine rotation speed and accelerator opening, and outputs an injection control signal corresponding to the fuel injection amount to the injector 11. Thus, fuel injection from the injector 11 to the combustion chamber is controlled in each cylinder.

  Further, the ECU 60 calculates a target value of the common rail pressure (injection pressure) based on the engine rotational speed and the fuel injection amount at that time, and sets the fuel discharge amount of the high-pressure pump 13 so that the actual rail pressure becomes the target rail pressure. Feedback control. Actually, the discharge start timing of the high-pressure pump 13 is set based on the deviation between the actual rail pressure and the target rail pressure, and the valve closing instruction angle to the metering valve 38 is set based on the discharge start timing. The valve closing instruction angle to the metering valve 38 is set in consideration of the valve closing response delay of the metering valve 38 from the discharge start timing.

  Next, pump discharge characteristics will be described with reference to FIG. FIG. 3 is a graph showing the pump discharge characteristics, and shows the fuel discharge amount with respect to the valve closing instruction angle. FIG. 3A is a graph showing pump discharge characteristics when the feed pressure of the low-pressure fuel is high, and FIG. 3B is a pump when the feed pressure of the low-pressure fuel is low. It is a graph which shows a discharge characteristic. When the feed pressure of the low-pressure fuel is a high feed pressure, as shown in FIG. 3A, the valve closing instruction angle at which the fuel discharge amount becomes maximum exists over a predetermined angle region (full discharge flat region). . On the other hand, when the feed pressure of the low-pressure fuel is a low feed pressure, as shown in FIG. 3B, there is no full discharge flat region in the pump discharge characteristics, and the fuel discharge amount becomes maximum. There is a drop in the fuel discharge amount on both the retard side and the advance side of the valve closing instruction angle. For this reason, there is a peak at which the fuel discharge amount becomes maximum in the graph showing the pump discharge characteristics. Further, the drop in the fuel discharge amount on the advance side is larger than the drop in the fuel discharge amount on the retard side.

  Here, when the valve closing instruction angle is changed to the advance side with respect to the peak of the pump discharge characteristic, it is conceivable that the fuel discharge amount significantly decreases. In this case, there is a concern that the fuel discharge amount is insufficient with respect to the required discharge amount. For this reason, the advance side guard value is set in advance at the valve closing instruction angle, and the valve closing instruction angle is limited to the retard side with respect to the advance side guard value. The advance side guard value is determined at or near the peak position of the pump discharge characteristic, as shown by the broken line in FIG.

  However, if there are variations in the pump discharge characteristics due to manufacturing variations of fuel pumps or changes over time, it may be considered that the setting of the advance side guard value for the pump discharge characteristics becomes inappropriate. That is, it is conceivable that the actual pump discharge characteristic is shifted to the advance side or the retard side with respect to the advance side guard value. In this case, for example, it is conceivable that the valve closing instruction angle is the advance side guard value and the actual rail pressure is lower than the target rail pressure.

  Therefore, in the present embodiment, the valve closing instruction angle of the metering valve 38 is learned when the actual rail pressure is lower than the target rail pressure with the valve closing instruction angle being the advance side guard value. Update. Specifically, when the valve closing instruction angle of the metering valve 38 is the advance side guard value and the actual rail pressure is lower than the target rail pressure, the valve closing instruction angle of the metering valve 38 is delayed. If the fuel discharge amount increases due to the change to the corner side, the advance side guard value is updated to the retard side. Further, when the valve closing instruction angle of the metering valve 38 is the advance side guard value and the actual rail pressure is lower than the target rail pressure, the valve closing instruction angle of the metering valve 38 is set to the advance side. If the fuel discharge amount increases due to the change, the advance side guard value is updated to the advance side. Then, the updated advance side guard value is stored as a learning value in a backup memory (EEPROM or the like).

  Next, a processing procedure for learning of the advance side guard value performed by the ECU 60 will be described with reference to the flowchart of FIG. This process is repeatedly executed by the ECU 60 at a predetermined cycle.

  First, in step S10, it is determined whether a learning update condition for the advance side guard value is satisfied. Here, the learning update condition is satisfied when the valve closing instruction angle of the metering valve 38 is the advance side guard value and the state where the actual rail pressure is lower than the target rail pressure continues for a predetermined time or more. Is determined.

  If “YES” in the step S10, the process proceeds to a step S11 to determine whether or not the shift direction of the pump discharge characteristic is confirmed by changing the advance side guard value to the retard side. If NO in step S11, the process proceeds to step S12, and the valve closing instruction angle is changed to the retard side by a predetermined amount θ1. In a succeeding step S13, it is determined whether or not the peak position of the pump discharge characteristic is shifted to the retard side with respect to the advance side guard value. Here, as shown at time t1 in FIG. 5 (a), when the valve closing instruction angle is changed to the retarded side by a predetermined amount θ1, the fuel discharge amount after the retard is equal to the fuel discharge amount before the retard. The actual rail pressure after retarding increases with respect to the actual rail pressure before retarding. For this reason, when the actual rail pressure is increased by changing the valve closing instruction angle to the retard side, it is determined that the peak position of the pump discharge characteristic is shifted to the retard side with respect to the advance side guard position. .

  If “YES” in the step S13, the process proceeds to a step S14 to perform a retard process of the advance side guard value. Specifically, the valve closing instruction angle is retarded by a predetermined amount, and the advance side guard value is adjusted to the peak position of the pump discharge characteristic. At this time, as shown after time t1 in FIG. 5A, the advance side guard value is used as a reference value, the valve closing instruction angle is changed from the reference value to the retard side by a predetermined step amount, and then returned to the reference value. Repeat the process. At this time, the predetermined step amount is increased from the previous value.

  In a succeeding step S15, it is determined whether or not the advance side guard value is updated. At this time, in the retard processing, the advance guard value is updated when the step amount θ2 in which the increase in the actual rail pressure caused by the change to the retard side by a predetermined step amount is detected is detected. To do. Here, as shown in FIG. 5 (a), the current value of the increase width of the actual rail pressure caused by the change to the retard side by a predetermined step amount is compared with the previous value, and the current value is When the value is smaller than the value, the step amount when the previous value is obtained is detected as the step amount θ2.

  If YES in step S15, the process proceeds to step S16, where the advance side guard value is updated to a changed value that is retarded by the step amount θ2, and the updated advance side guard value is stored in the ECU 60 as a learned value. Then, this process ends.

  On the other hand, if “YES” in the step S11, the process proceeds to a step S17 to determine whether or not the retard process is being performed. If YES in step S17, the process proceeds to step S14 again. On the other hand, if “NO” in the step S17, the process proceeds to a step S18 to determine whether or not the shift direction of the pump discharge characteristic is confirmed by changing the advance side guard value to the advance side.

  If NO in step S18, the process proceeds to step S19, and the valve closing instruction angle is changed to the advance side by a predetermined amount θ3. In subsequent step S20, it is determined whether or not the peak position of the pump discharge characteristic is on the advance side with respect to the advance guard position. Here, as shown at time t2 in FIG. 5 (b), when the valve closing instruction angle is changed to the advance side by a predetermined amount θ3, the fuel discharge amount after the advance is smaller than the fuel discharge amount before the advance. The actual rail pressure after advance increases with respect to the actual rail pressure before advance. For this reason, when the actual rail pressure is increased by changing the valve closing instruction angle to the advance side, it is determined that the peak position of the pump discharge characteristic is shifted to the advance side with respect to the advance side guard position. .

  If “YES” in the step S20, the process proceeds to a step S21 to perform advance processing of the advance side guard value. Specifically, the valve closing instruction angle is advanced by a predetermined amount, and the advance side guard value is adjusted to the peak position of the pump discharge characteristic. At this time, as shown after time t2 in FIG. 5B, after changing the valve closing instruction angle to the advance side by a predetermined amount θ3, the advance side guard value is again set to the advance side guard value before advancement. Return to. Then, using the advance side guard value as a reference value, the valve closing instruction angle is changed from the reference value to the advance side by a predetermined step amount and then returned to the reference value. At this time, the predetermined step amount is increased from the previous time. Note that the step amount at the time of the retard processing and the step amount at the time of the advance processing may be set to different values.

  In a succeeding step S22, it is determined whether or not the advance side guard value is updated. At this time, in the advance processing, the advance side guard value is updated when the step amount θ4 at which the increase in the actual rail pressure caused by the change to the advance side by a predetermined step amount is detected is detected. To do. Here, as shown in FIG. 5B, the current value of the actual rail pressure increase caused by the change to the advance side by a predetermined step amount is compared with the previous value, and the current value is the previous value. When the value becomes smaller than that, the step amount when the previous value is obtained is detected as the step amount θ4.

  If YES in step S22, the process proceeds to step S23, where the advance side guard value is updated to a value changed to the advance side by the step amount θ4, and the updated advance side guard value is stored in the ECU 60 as a learning value. To end this process.

  On the other hand, if NO in step S20, the process ends without updating the advance side guard value. Here, when the advance side guard value is at the peak position of the pump discharge characteristic, as shown in FIG. 5C, when the advance side guard value is changed to the retard side and when it is changed to the advance side In either case, the fuel discharge amount does not increase, so the actual rail pressure does not increase. For this reason, in both cases where the valve closing instruction angle is changed to the retarded angle side and to the advanced angle side, if the fuel discharge amount does not increase, the advance side guard value is the pump discharge characteristic. It is determined that the peak position is set, and this processing is terminated without updating the advance side guard value. At this time, if the actual rail pressure is lower than the target rail pressure even though the advance side guard value is at the peak position, it is considered that an abnormality has occurred in the high pressure pump 13. For this reason, abnormality determination may be performed and this processing may be terminated.

  As mentioned above, according to this embodiment explained in full detail, the following outstanding effects are acquired.

  If the valve closing instruction angle of the metering valve 38 is the advance side guard value, the valve closing instruction angle of the metering valve 38 is changed to the retard side, and if the actual rail pressure increases due to the change, the advance angle The side guard value has been updated to the retard side. If the valve closing instruction angle of the metering valve 38 is the advance side guard value, the valve closing instruction angle of the metering valve 38 is changed to the advance side, and if the actual rail pressure increases due to the change, Updated advance side guard value to advance side. As a result, the advance side guard value can be set appropriately with respect to the pump discharge characteristics, and as a result, appropriate discharge amount control can be performed.

  The valve closing instruction angle to the retard angle side was changed first, and when the fuel discharge amount did not increase in that state, the valve closing instruction angle to the advance angle side was changed. In this case, even if the valve closing instruction angle is changed to reduce the fuel discharge amount in the pump discharge characteristics, it is possible to suppress the fuel discharge amount from being insufficient.

  The predetermined step amount is increased from the previous time while repeating the process of returning the reference value after changing the valve closing instruction angle by a predetermined amount. In this case, since the step amount gradually increases, the peak position of the pump discharge characteristic can be accurately grasped.

(Other embodiments)
The above embodiment may be modified as follows, for example.

  When the valve closing instruction angle of the metering valve 38 is the advance side guard value, the delay angle is one of the change of the valve closing instruction angle to the retard angle side and the change of the valve closing instruction angle to the advance angle side. The valve closing instruction angle to the side is changed first, and when the actual rail pressure does not increase in that state, the valve closing instruction angle is changed to the advance side. It may be changed. That is, when the valve closing instruction angle of the metering valve 38 is the advance side guard value, the valve closing instruction angle is changed to the advance side first, and the actual rail pressure does not increase in that state. In this case, the valve closing instruction angle is changed to the retarded angle side.

  -When the valve closing instruction angle is gradually advanced from the reference value by a predetermined amount, the process of returning to the reference value is repeated each time. However, this may be changed. For example, the valve closing instruction angle from the reference value may be retarded or advanced by a predetermined amount without returning to the reference value. In this case, when the valve closing instruction angle is changed by a predetermined amount, the advance side guard value when the increase amount of the current value with respect to the previous value of the actual rail pressure changes from positive to negative may be used as the update value.

  ・ Determines whether the actual rail pressure has increased when the valve closing command angle is changed to the retarded angle side or the advanced angle side, and the actual rail pressure does not increase in any of these cases In addition, although it is configured to end without updating the advance side guard value, this may be changed. For example, when the actual rail pressure decreases in either the case where the valve closing instruction angle is changed to the retard side or the case where the valve closing instruction angle is changed to the advance side, the configuration may be completed without updating the advance side guard value. .

  The feed pump 15 may be a pump that can control the feed pressure of the fuel to the high-pressure pump 13 by the opening of an electromagnetic valve, such as a trochoid feed pump. Further, the feed pressure may be variably set by the ECU 60. In such a configuration, when the feed pressure of the fuel supplied to the high-pressure pump 13 is high, the full discharge flat region is considered to be larger than when the fuel feed pressure is low. In this case, for example, if the advance side guard value is in the full discharge flat area, the valve close instruction angle is changed to either the retard side or the advance side at any valve close instruction angle in the full discharge flat area. However, since the fuel discharge amount does not increase, the advance side guard value cannot be determined.

  In this regard, in step S10 of FIG. 4, it may be determined that the set value of the feed pressure of the feed pump 15 is lower than a predetermined threshold as the learning update condition on the advance side. In such a case, the full discharge flat area is reduced, and the advance side guard value is easily determined.

  ・ Assuming the most retarded angle characteristic that is the most retarded initial characteristic in the variation of the initial characteristic before the pump discharge characteristics change over time, the advance side guard value is determined based on the most retarded angle characteristic. Also good. In this case, as shown in FIG. 6, the peak position of the solid line graph showing the most retarded angle characteristic existing on the retard side with respect to the broken line graph showing the center characteristic which is the initial side characteristic in the variation of the initial characteristic. It is preferable that an advance side guard value is determined.

  DESCRIPTION OF SYMBOLS 13 ... High pressure pump (fuel pump), 32 ... Plunger, 35 ... Pressurizing chamber, 36 ... Low pressure passage (suction passage), 38 ... Metering valve, 60 ... ECU (pump control device).

Claims (5)

It is applied to a fuel pump (13) that sucks and pumps fuel in the pressurizing chamber (35) by reciprocating movement of the plunger (32). A fuel pump control device (60) for controlling a fuel discharge amount by adjusting a valve closing timing of a suction passage (36),
An advance side guard value that is an advance side guard angle is determined at the valve closing instruction angle of the metering valve,
When the valve closing instruction angle of the metering valve is the advance side guard value, the valve closing instruction angle of the metering valve is changed to the retard side, and whether or not the fuel discharge amount has increased due to the change is determined. A first determination unit for determining;
When the valve closing instruction angle of the metering valve is the advance side guard value, the valve closing instruction angle of the metering valve is changed to the advance side, and whether or not the fuel discharge amount has increased due to the change is determined. A second determination unit for determining;
When it is determined by the first determination unit that the fuel discharge amount has increased, the advance side guard value is updated to the retard side, and when the second determination unit determines that the fuel discharge amount has increased. An update unit for updating the advance side guard value to the advance side;
A fuel pump control device comprising:   When the valve closing instruction angle of the metering valve is the advance side guard value, the first determination unit among the first determination unit and the second determination unit closes the valve to the retard side. 2. The change in the valve closing instruction angle toward the advance angle by the second determination unit is performed when the change in the instruction angle is performed first and the fuel discharge amount does not increase in that state. Fuel pump control device.   The said 1st determination part and the said 2nd determination part change the valve closing instruction | indication angle of the said metering valve by predetermined amount, and it is determined whether the fuel discharge amount increased by the change. Fuel pump control device. Applied to a fuel supply system comprising a low pressure pump (15) for pumping fuel from a fuel tank (16) and supplying the fuel to the fuel pump at a predetermined supply pressure;
A setting unit for variably setting the supply pressure;
The said 1st determination part and the said 2nd determination part do not change the valve closing instruction | indication angle of the said metering valve, when the setting value of the said supply pressure is more than a predetermined threshold value. The fuel pump control device according to claim 1. Applied to a fuel supply system comprising a pressure accumulation chamber (12) for accumulating fuel discharged from the fuel pump in a high pressure state, and a pressure sensor (17) for detecting fuel pressure in the pressure accumulation chamber,
When the fuel pressure detected by the pressure sensor is increased due to the change of the valve closing instruction angle of the metering valve to the retard side, the first determination unit indicates that the fuel discharge amount has increased. Determine
When the fuel pressure detected by the pressure sensor is increased due to the change of the valve closing instruction angle of the metering valve to the advance side, the second determination unit indicates that the fuel discharge amount has increased. The fuel pump control device according to any one of claims 1 to 4, wherein:

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