JP2023157225A - High pressure fuel pump control device - Google Patents

Abstract

The present invention provides a control device for a high-pressure fuel pump that avoids pulsations in fuel pressure due to interference between two controls: discharge amount control based on current start timing and noise reduction control based on current value. [Solution] An ECU (112) that controls a high-pressure fuel pump (103) is provided with a fuel pressure sensor (401), a plunger phase measurement section (402), a plunger operation determination section (801), and a fuel pressure increase The amount of fuel discharged is determined by controlling the timing to start applying current to the solenoid (205) based on the fuel pressure measured by the evaluation unit (802), the valve closing determination unit (803), and the fuel pressure sensor (401) and the target fuel pressure. The discharge amount control section (804) determines the control gain of the current application start timing based on the determination result of the valve closing determination section (803). [Selection diagram] Figure 8

Description

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

Internal combustion engines for automobiles are required to have high efficiency, low emissions, and high output. Direct-injection internal combustion engines have been popular for a long time as a means to solve these problems in a well-balanced manner. Automobile manufacturers and suppliers have been making constant efforts to improve the value of their products, and one of the important issues is making high-pressure fuel pumps quieter.

In order to make a high-pressure fuel pump quieter, it is sufficient to reduce the current that drives the pump. However, if the pressure is reduced too much, the high pressure fuel pump will not be able to discharge fuel. The optimum amount of current to be applied for noise reduction varies depending on the individual high-pressure fuel pump.

In conventional high-pressure fuel pump noise reduction control, control is performed as in Patent Document 1 in order to check the minimum amount of current applied to each high-pressure fuel pump within a range that does not cause failure in fuel discharge. The technique disclosed in Patent Document 1 achieves quietness by reducing the current (second current). On the other hand, if the current is reduced too much, the valve closing operation will be insufficient, so when the actual fuel pressure in the pressure accumulator container falls below the target fuel pressure by a predetermined value or more, the current is increased to eliminate the insufficient valve closing operation.

JP2017-53247A

Incidentally, regardless of whether noise reduction control is performed or not, the discharge amount of the high-pressure fuel pump is controlled so that the fuel pressure follows the target value. In a high-pressure fuel pump, the discharge amount is controlled by controlling the start time of the current applied to the solenoid. Therefore, in a high-pressure fuel pump compatible with noise reduction control, two types of control are performed in parallel: discharge amount control based on current start timing and noise reduction control based on current value.

The problem here is that two controls are performed by comparing the measured value of the fuel pressure and the target fuel pressure, and that the two controls interfere.

In Patent Document 1, when the measured value of the fuel pressure becomes lower than the target fuel pressure, it is determined that the valve closing operation is insufficient, and the second current value is increased. On the other hand, in the discharge amount control, when the measured value of the fuel pressure becomes lower than the target fuel pressure, the current application start timing is advanced in order to increase the discharge amount. Two values are controlled without determining whether the cause of the measured value of the fuel pressure being lower than the target fuel pressure is the current value or the timing of starting the current application.

Further, when a valve closing malfunction occurs, the fuel pressure becomes lower than the target value. In this case, the current application start timing becomes early even though the current application start timing can realize a sufficient ejection amount. This early start timing of current application causes unnecessary fuel pressure pulsations.

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-pressure fuel pump control device that avoids pulsations in fuel pressure caused by interference between two controls: discharge amount control based on current start timing and noise reduction control based on current value.

A high-pressure fuel pump control device according to one aspect of the present invention is arranged between both pipes to pressurize and discharge fuel in the low-pressure pipe to the high-pressure pipe, and arranged between the low-pressure pipe and the pressurizing chamber. A control device for controlling a high-pressure fuel pump including at least an intake valve, a solenoid for controlling opening and closing of the intake valve, and a plunger for compressing fuel in the pressurizing chamber, the high-pressure piping having a fuel pressure sensor. is arranged, a plunger phase measuring section for measuring a phase angle of the plunger is provided near the plunger, a plunger operation determining section for determining that the plunger is rising based on the phase angle of the plunger; a fuel pressure increase evaluation section that evaluates the increase in fuel pressure during the period in which the plunger is determined to be rising by the plunger operation determination section; and a determination of success or failure in closing the intake valve based on the evaluation result of the fuel pressure increase evaluation section. and a discharge amount control section that controls the amount of fuel discharged by controlling the timing to start applying current to the solenoid based on the fuel pressure measured by the fuel pressure sensor and the target fuel pressure. The discharge amount control section determines a control gain for the current application start timing based on the determination result of the valve closing determination section.

According to the present invention, it is possible to provide a high-pressure fuel pump control device that avoids fuel pressure pulsation due to interference between two controls: discharge amount control based on current start timing and noise reduction control based on current value.

FIG. 1 is a schematic configuration diagram showing an internal combustion engine according to a first embodiment. FIG. 2 is a schematic configuration diagram showing the high-pressure fuel pump according to the first embodiment. FIG. 3 is a time chart showing the operation of the high-pressure fuel pump according to the first embodiment. FIG. 4 is a block diagram showing the high-pressure fuel pump according to the first embodiment. FIG. 5A is an explanatory diagram showing the operation of the valve body when the valve closes successfully according to the first embodiment. FIG. 5B is an explanatory diagram showing the operation of the valve body when the valve fails to close according to the first embodiment. FIG. 6 is a conceptual diagram showing a method of identifying success or failure of valve closing from the increase in fuel pressure in synchronization with the rise of the plunger according to the first embodiment. FIG. 7 is an explanatory diagram showing changes in fuel pressure when the present invention is not applied. FIG. 8 is a block diagram showing the high-pressure fuel pump and each control section of the ECU according to the first embodiment. FIG. 9 is a flowchart showing the noise reduction control (current application amount control) executed every 2 ms according to the first embodiment. FIG. 10 is a flowchart showing ejection amount control executed every 10 ms according to the first embodiment. FIG. 11 is an explanatory diagram showing how pressure pulsation is reduced according to the first embodiment. FIG. 12 is a block diagram showing a high-pressure fuel pump according to the second embodiment. FIG. 13 is an explanatory diagram showing a map showing the correlation between target fuel pressure and current application timing according to the second embodiment. FIG. 14 is a flowchart showing interference reduction control between discharge amount control and noise reduction control (first current application amount control) according to the operating state of the internal combustion engine according to the second embodiment. FIG. 15 is a block diagram showing a high-pressure fuel pump according to a fourth embodiment. FIG. 16 is an explanatory diagram showing a map for adjusting the correlation between the current application timing and the current application amount stored in the current parameter memory according to the fourth embodiment by learning for each individual. FIG. 17 is a flowchart showing interference reduction control between discharge amount control and noise reduction control (first current application amount control) according to the learning state of the internal combustion engine according to the fourth embodiment.

Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the embodiments described below, and the technical idea of the present invention may be realized by combining other known components. Note that in each figure, the same elements are denoted by the same reference numerals, and redundant explanations will be omitted. Further, in each figure, the U direction is upward, the D direction is downward, the R direction is rightward, and the L direction is leftward.

<First embodiment>
In this embodiment, the valve body is open when no current is applied to the solenoid. Then, when current is applied to the solenoid, the valve body closes, and this valve closing prevents the fuel compressed by the rise of the plunger from returning to the low-pressure piping side, and discharges the fuel to the high-pressure piping side. A normally open type pump that operates in this manner will be described. However, this embodiment can also be applied to a normally closed type pump by replacing the closed valve with the opened valve.

<<Overview of internal combustion engine 100>>
FIG. 1 is a schematic configuration diagram showing an internal combustion engine 100 according to the present embodiment. FIG. 1 schematically shows a direct injection internal combustion engine as an internal combustion engine 100. In the internal combustion engine 100, fuel stored in a fuel tank 101 is pressurized to about 0.4 MPa by a feed pump 102, and further pressurized to several tens of MPa by a high-pressure fuel pump 103 via a low-pressure pipe 111. The pressurized fuel is injected from the direct injector 105 into the cylinder 106 of the internal combustion engine 100 via the high pressure pipe 104 .

The injected fuel is mixed with air taken into the cylinder 106 by the operation of the piston 107. This air-fuel mixture is ignited by the spark generated by the spark plug 108 and explodes. The heat generated by the explosion causes the air-fuel mixture in cylinder 106 to expand, pushing piston 107 down. The force pushing down the piston 107 rotates the crankshaft 110 via the link mechanism 109. The rotation of the crankshaft 110 is transmitted to the wheels through the transmission and becomes the force that moves the vehicle.

Such an internal combustion engine 100 is controlled by an ECU (engine control unit) 112 that is a control device. The ECU 112 is a microcontroller that comprehensively controls the operation of the internal combustion engine 100 using electrical auxiliary devices. For example, the ECU 112 constitutes a functional unit formed by cooperation of a program and an arithmetic unit. ECU 112 is a control device that controls high-pressure fuel pump 103.

The internal combustion engine 100 is mainly required to have low fuel consumption, high output, and exhaust purification, but is also required to reduce noise and vibration as added value. In the high-pressure fuel pump 103, noise is generated due to collision between the valve body or the anchor 204 and the stopper 208 when the suction valve 203 is opened or closed. Each automobile manufacturer and supplier is making a lot of effort to reduce noise.

<<Configuration of high pressure fuel pump 103>>
FIG. 2 is a schematic configuration diagram showing the high-pressure fuel pump 103 according to this embodiment. FIG. 2 shows the structure of the high-pressure fuel pump 103. The high-pressure fuel pump 103 includes a plunger 202 that moves up and down as a cam 201 attached to the crankshaft 110 of the internal combustion engine 100 rotates. Plunger 202 compresses fuel within pressurizing chamber 211 .

The high-pressure fuel pump 103 includes an intake valve 203 that opens and closes in synchronization with the vertical movement of the plunger 202. The suction valve 203 is disposed between the low-pressure pipe 111 and the pressurizing chamber 211 among both pipes in order to pressurize and discharge the fuel in the low-pressure pipe 111 to the high-pressure pipe 104.

High-pressure fuel pump 103 includes a solenoid 205 that controls the opening and closing operation of intake valve 203. The high-pressure fuel pump 103 includes an anchor 204 that is attracted by electromagnetic force generated by a solenoid 205 and controls the operation of the suction valve 203 .

The high-pressure fuel pump 103 is surrounded by a casing 223 and has a pressurized chamber 211 formed therein. Fuel flows into the pressurizing chamber 211 from the low pressure pipe 111 side through the inlet 225 and the communication port 221. The fuel that has flowed into the pressurizing chamber 211 passes through the outlet 222 and is discharged to the high pressure pipe 104 side. Outlet 222 is opened and closed by discharge valve 210. The discharge valve 210 is always biased by a spring portion 226 in a direction to close the outlet port 222, and when the pressure in the pressurized chamber 211 overcomes the spring force of the spring portion 226, the outlet port 222 opens and fuel is injected. be done.

In the high-pressure fuel pump 103, the operation of the anchor 204 in the axial direction (left-right direction in FIG. 2) is controlled by controlling the on/off state of energization of the solenoid 205. When the solenoid 205 is de-energized, the anchor 204 is constantly biased in the valve-opening direction by the first spring 209 to maintain the suction valve 203 in the open position. Such a high-pressure fuel pump 103 is called a normally open type high-pressure fuel pump, and in this embodiment, the normally open type will be described. However, the high-pressure fuel pump 103 can also be applied to a normally closed type high-pressure fuel pump by replacing the opening and closing valves.

When the solenoid 205 is energized, an electromagnetic attractive force is generated between the fixed part (magnetic core) 206 and the anchor 204. As a result, the anchor 204 provided on the base end side of the suction valve 203 is attracted in the valve opening direction (left direction L in FIG. 2) against the spring force of the first spring 209. When the anchor 204 is attracted to the fixed part 206, the suction valve 203 becomes a check valve that opens and closes based on the differential pressure between the upstream side and the downstream side and the biasing force of the second spring 215. Therefore, as the pressure on the downstream side of the suction valve 203 increases, the suction valve 203 moves in the valve closing direction. When the suction valve 203 moves by the set lift amount in the valve closing direction, it is seated on the seat portion 207, the suction valve 203 is closed, and the fuel in the pressurizing chamber 211 cannot flow back to the low pressure pipe 111 side.

<<Operation time chart of high pressure fuel pump 103>>
FIG. 3 is a time chart showing the operation of the high-pressure fuel pump 103 according to this embodiment. The suction valve 203 detects the rotation angle of a cam 201 attached to the crankshaft 110 so that it opens and closes in synchronization with the up and down movements of the plunger 202, and detects the rotation angle determined from, for example, Top Dead Center (TDC). After the crankshaft 110 has rotated through an angle (P-ON timing), voltage V starts to be applied to both ends of the solenoid 205 (timing t1). Due to this voltage V, the current I flowing through the solenoid 205 is
LdI/dt=V-RI...(Formula 1)
increase according to Here, L and R are the inductance and resistance of the solenoid 205 and wiring, respectively. As the current I increases, the magnetic attraction force Fmag by which the fixed part (magnetic core) 206 attracts the anchor 204 also increases.

When the magnetic attraction force Fmag becomes larger than the force Fsp of the first spring 209, the anchor 204, which has been held down by the spring force Fsp, starts to move toward the fixed part 206 (timing t2). When the anchor 204 moves, the suction valve 203 also follows the anchor 204 and moves toward the fixed part 206, being pushed by the pressurized fuel due to the rise of the plunger 202.

Then, the current I decreases (timing t3). Between timing t2 and timing t3, there is a period Th during which the current I is applied at its maximum value.

Eventually, the protrusion of the suction valve 203 collides with the seat portion 207 and sits on it. Due to this collision, the fuel flow path (dotted line in FIG. 2) is blocked, and the fuel pressurized by the rise of the plunger 202 cannot return to the low pressure pipe 111 side, and the pressure in the pressurizing chamber 211 increases (timing t4 ).

When the pressure in the pressurizing chamber 211 becomes greater than the spring force Fsp_out that suppresses the discharge valve 210, the discharge valve 210 opens and the fuel pressurized by the rise of the plunger 202 is discharged to the high pressure pipe 104. Thereafter, when the drive pulse is turned off at timing t5, a reverse voltage is applied to the solenoid 205, thereby cutting off the holding current supplied to the solenoid 205.

When the cam angle passes the top dead center and the plunger 202 starts descending (timing t6), the fuel pressure in the pressurizing chamber 211 decreases, and when the fuel pressure becomes smaller than the spring force Fsp_out, the discharge valve 210 closes and the discharge of fuel ends. do.

Furthermore, due to the decrease in fuel pressure in the pressurizing chamber 211, the anchor 204 moves together with the suction valve 203 from the valve closed position to the valve open position (timing t7 to t8).

Through this operation, the high-pressure fuel pump 103 sends fuel from the low-pressure pipe 111 to the high-pressure pipe 104. In this process, the anchor 204 collides with the fixed part 206 to complete the valve closing (timing t4 in FIG. 3), and the anchor 204 and the intake valve 203 collide with the stopper 208 to complete the valve opening (timing t8 in FIG. 3). ), noise is generated when This noise can be unpleasant for drivers, especially when idling, and automobile manufacturers and suppliers of the high-pressure fuel pump 103 are competing to reduce this noise. This embodiment aims to reduce noise when the anchor 204 and suction valve 203 are completely closed.

<<Peak current and holding current>>
The current that drives the high-pressure fuel pump 103 is roughly divided into two. They are the peak current (the diagonal line part of the current waveform in FIG. 3) and the holding current (the horizontal line part of the current waveform in FIG. 3). The peak current applies momentum to close the suction valve 203 and the anchor 204, which are pressed by the first spring 209 and are stationary at the valve open position. On the other hand, the holding current attracts the anchor 204 approaching the fixed part 206 until it collides with the fixed part 206. After the anchor 204 collides with the fixed part 206, the contact state is maintained. If the peak current application amount is reduced, the force of closing the suction valve 203 and the anchor 204 will be weakened, and noise can be reduced. However, if the peak current application amount is reduced too much, the suction valve 203 and the anchor 204 will fail to close. Therefore, it is desirable to reduce the peak current application amount as much as possible within the range in which the suction valve 203 and the anchor 204 are closed. Note that, as shown in FIG. 3, the maximum current value of the peak current is Im, and the maximum current value of the holding current is Ik.

<<Discharge amount control>>
FIG. 4 is a block diagram showing the high pressure fuel pump 103 according to the first embodiment. The role of the high-pressure fuel pump 103 is to compress the fuel in the low-pressure pipe 111 and discharge it to the high-pressure pipe 104 so as to maintain the fuel pressure in the high-pressure pipe 104 at a target value. For this purpose, the fuel pressure in the high pressure pipe 104 is measured by the fuel pressure sensor 401, and the current application start timing (P-ON timing) is adjusted according to the block diagram shown in FIG. 4 so that the fuel pressure measurement value follows the target fuel pressure. It is controlled by a discharge amount control section 403. Controlling the current application start timing (P-ON timing) is discharge amount control. In the discharge amount control, if the fuel pressure measurement value is lower than the target fuel pressure, the P-ON timing is advanced in order to increase the discharge amount delivered to the high pressure pipe 104. In the discharge amount control, if the fuel pressure measurement value is higher than the target fuel pressure, the P-ON timing is delayed in order to reduce the discharge amount delivered to the high pressure pipe 104. PID control is generally applied to discharge amount control.

Note that the cam 201 near the plunger 202 may be provided with a plunger phase measuring section 402 that measures the phase angle of the plunger 202.

<<Quiet control (current application amount control)>>
FIG. 5A is an explanatory diagram showing the operation of the valve body when the valve closes successfully according to the present embodiment, and FIG. 5B is an explanatory diagram showing the operation of the valve body when the valve close according to the present embodiment fails. As described in the previous <<Peak current and holding current>>, reducing the peak current application amount reduces the speed at which the valve element of the suction valve 203 closes, achieving quieter operation.

The noise can be made quieter by reducing the peak current, but if the peak current is reduced too much, the suction valve 203 and anchor 204 will fail to close. If a sufficient peak current is applied, the valve body of the suction valve 203 moves as shown in FIG. 5A. However, if an insufficient peak current is applied, the valve body of the suction valve 203 fails to close due to the spring force of the first spring 209, as shown in FIG. 5B.

FIG. 6 is a conceptual diagram illustrating a method for determining whether the intake valve 203 has been successfully closed based on the rise in fuel pressure that is synchronized with the rise in the plunger 202 according to the present embodiment. When the suction valve 203 is successfully closed, the valve body of the suction valve 203 closes the flow path from the pressurizing chamber 211 to the low-pressure pipe 111, and the pressure increase due to the rise of the plunger 202 propagates to the high-pressure pipe 104. As a result, in synchronization with the rise of the plunger 202, the pressure in the high-pressure pipe 104 rises as shown by the hatched area upward to the right in FIG. On the other hand, if the suction valve 203 fails to close, even if the plunger 202 rises, the fuel in the pressurizing chamber 211 will escape to the low-pressure pipe 111, and the pressure in the high-pressure pipe 104 will be reduced as shown by the diagonal line downward to the right in FIG. does not rise.

This difference is identified based on the measured value of the fuel pressure sensor placed in the high pressure pipe 104 or the common rail, and if the suction valve 203 fails to close, the amount of current applied is increased, and if the suction valve 203 closes successfully, the amount of current applied is increased. Repeat this process to reduce the

In this way, the success or failure of closing the suction valve 203 is determined based on the fuel pressure fluctuations synchronized with the vertical movement of the plunger 202, and the amount of current applied is increased or decreased, thereby realizing the closing of the suction valve 203. The current can be controlled near the minimum amount of current applied. Control of this current is noise reduction control. The noise reduction control can reduce the noise when the high-pressure fuel pump 103 closes.

<<Interference between noise reduction control and discharge amount control>>
FIG. 7 is an explanatory diagram showing changes in fuel pressure when the present invention is not applied. FIG. 7 shows the relationship among the fuel pressure in the high-pressure pipe 104, the current application start timing P-ON, and the amount of current application when discharge amount control and noise reduction control are applied to the high-pressure fuel pump 103.

In FIG. 7, the fuel pressure pulsates at a period of 37.5 ms until around 150 ms. The reason why this pulsation occurs is that when the suction valve 203 is successfully closed, the pressure increase due to the rise of the plunger 202 is transmitted to the high-pressure pipe 104, while the pressure in the high-pressure pipe 104 decreases due to fuel injection from the direct injection injector 105. This is because what you do is repeated.

However, at 187.5 ms, which is 37.5 ms after 150 ms, no increase in fuel pressure is observed. This is because the suction valve 203 fails to close and the fuel pressure increase due to the rise of the plunger 202 escapes to the low pressure pipe 11 side and is not transmitted to the high pressure pipe 104. By observing such changes, it is determined whether or not the suction valve 203 has been successfully closed.

The amount of current applied at this time is gradually reduced while the suction valve 203 is successfully closed for up to 150 ms. However, the amount of current applied increases in the cycle from 150 ms to 187.5 ms because a failure in closing the suction valve 203 was detected.

On the other hand, it can be seen that the current application start timing becomes rapidly early around 200 ms. This is because the discharge amount control determines that the fuel pressure has decreased because the current application amount has been reduced too much and the suction valve 203 has failed to close, but the fuel pressure has decreased because the current application start timing is late. . This is because the discharge amount control advances the current application start timing to compensate for the decrease in fuel pressure.

Such a phenomenon is called interference between noise reduction control and discharge amount control, and this embodiment provides a solution to this interference.

<<Interference reduction control>>
The ECU 112 performs cooperative control of the discharge amount control and noise reduction control (hereinafter referred to as interference reduction control) in order to reduce the interference between the discharge amount control and the noise reduction control described above. Here, the discharge amount control is performed at a cycle of 10 ms. The noise reduction control is performed at a 2ms cycle. Although it is not necessarily limited to this period, since the noise reduction control needs to detect the pulsation of the fuel pressure that is synchronized with the rise of the plunger 202, the period must be short enough to detect this pulsation. Must not be. Further, the cycle of the discharge amount control does not need to be as short as the cycle of the noise reduction control. Although the cycle of the discharge amount control may be matched with the cycle of the noise reduction control in order to simplify the software, it is necessary to take into account that the calculation load will increase.

FIG. 8 is a block diagram showing the high-pressure fuel pump 103 and each control section of the ECU 112 according to the present embodiment. High pressure fuel pump 103 is controlled by ECU 112.

The fuel pressure sensor 401 is arranged in the high pressure pipe 104. A plunger phase measuring section 402 that measures the phase angle of the plunger 202 is provided on the cam 201 near the plunger 202 . The plunger phase measurement unit 402 is a rotation angle sensor that detects the rotation angle of the cam 201, and measures the phase of the plunger 202 from the rotation angle of the cam 201.

The ECU 112 includes a plunger operation determination unit 801 that determines that the plunger 202 is rising based on the phase angle of the plunger 202. The ECU 112 includes a fuel pressure increase evaluation section 802 that evaluates an increase in fuel pressure during a period in which the plunger operation determination section 801 determines that the plunger 202 is rising. The ECU 112 includes a valve closing determination section 803 that determines whether or not the intake valve 203 has been closed based on the evaluation result of the fuel pressure increase evaluation section 802.

The ECU 112 includes a discharge amount control unit 804 that controls the amount of fuel discharged by controlling the timing at which current is applied to the solenoid 205 based on the fuel pressure measured by the fuel pressure sensor 401 and the target fuel pressure. The discharge amount control unit 804 determines a control gain for the current application start timing based on the determination result of the valve closing determination unit 803. That is, the discharge amount control unit 804 reduces the control gain of the current application start timing when the determination result of the valve closing determination unit 803 is a failure in closing the valve.

Specifically, when the determination result of the valve closing determination unit 803 is that the valve has failed to close, the discharge amount control unit 804 determines the current application start timing based on a predetermined relationship between the fuel pressure and the current application start timing. Control to speed up. In other words, the discharge amount control section 804 controls the control gain of the current application start timing based on the determination result of the valve closing determination section 803 in the immediately previous control cycle when the current application amount control section 805 controls the amount of current applied to the solenoid. control to speed up the process.

The ECU 112 includes a current application amount control section 805 that controls the amount of current applied to the solenoid 205 based on the determination result of the valve closing determination section 803.

<<Processing flow of interference reduction control>>
<<Processing flow of noise reduction control>>
FIG. 9 is a flowchart showing the noise reduction control executed every 2 ms according to this embodiment.

First, when a 2 ms period interrupt occurs, the ECU 112 uses the plunger phase measuring unit 402 to detect high pressure based on the crank angle calculated from the crank angle sensor and the phase difference between the cam angle and crank angle from the variable valve mechanism control device. The phase angle of the plunger 202 of the fuel pump 103 is calculated (step 901).

The plunger operation determination unit 801 of the ECU 112 determines whether the plunger phase angle reaches a preset starting angle of a fuel pressure change calculation range (step 902). In step 902, if the plunger phase angle has reached the preset start angle of the fuel pressure change calculation range, the process proceeds to step 903. In step 902, if the plunger phase angle has not reached the preset start angle of the fuel pressure change calculation range, the process proceeds to step 904.

The fuel pressure increase evaluation unit 802 of the ECU 112 sets the fuel pressure measurement value to the fuel pressure at the time when the increase starts (step 903). After the processing in step 903, wait for the next 2ms interrupt.

On the other hand, the plunger operation determination unit 801 of the ECU 112 determines whether the phase angle of the plunger 202 has reached the end angle of the preset fuel pressure change calculation range (step 904). In step 904, if the plunger phase angle has reached the end angle of the preset fuel pressure change calculation range, the process proceeds to step 905. In step 904, if the plunger phase angle has not reached the end angle of the preset fuel pressure change calculation range, after the process in step 904, the ECU 112 waits for the next 2 ms interrupt.

The fuel pressure increase evaluation unit 802 of the ECU 112 sets the fuel pressure measurement value to the fuel pressure at the end of the increase (step 905).

After the process in step 905, the fuel pressure increase evaluation unit 802 of the ECU 112 calculates a fuel pressure increase value by subtracting the fuel pressure at the start of the increase set in steps 903 and 905 from the fuel pressure at the end of the increase (step 906).

The valve closing determination unit 803 of the ECU 112 determines whether the fuel pressure increase value calculated in step 906 is greater than a threshold value (step 907). In step 907, if the fuel pressure increase value is larger than the threshold value, the process proceeds to step 908, and it is determined that the valve closing has been successful (step 908). After the process in step 908, the process proceeds to step 910. In step 907, if the fuel pressure increase value is not larger than the threshold value, the process proceeds to step 909, and it is determined that the valve closing has failed (step 909). After the process in step 909, the process proceeds to step 911.

The current application amount control unit 805 of the ECU 112 reduces the current application amount in the case of successful valve closing in step 908 (step 910). In the case of valve closing failure, which has proceeded to step 909, the amount of current applied is increased (step 911). After the processing in step 910 and step 911, the ECU 112 waits for the next 2 ms interrupt.

In this way, by executing the noise reduction control at a 2 ms cycle, the amount of current applied is controlled near the minimum value that allows successful valve closing, and noise reduction is achieved.

<<Processing flow of discharge amount control>>
FIG. 10 is a flowchart showing ejection amount control executed every 10 ms according to this embodiment. The discharge amount control is performed at a cycle of 10 ms.

When a 10 ms cycle interrupt occurs, the discharge amount control unit 804 of the ECU 112 determines whether or not the most recent valve closing determination in the noise reduction control performed at a 2 ms cycle has been determined to be successful (step 1001). The discharge amount control unit 804 of the ECU 112 selects the fuel pressure feedback gain depending on whether or not it is determined that the valve has closed successfully in step 1001.

If the discharge amount control unit 804 of the ECU 112 determines in step 1001 that the valve has been successfully closed, the process proceeds to step 1002. The discharge amount control unit 804 of the ECU 112 selects a feedback gain for success (step 1002).

If the discharge amount control unit 804 of the ECU 112 determines in step 1001 that the valve has failed to close, the process proceeds to step 1003. The discharge amount control unit 804 of the ECU 112 selects a failure feedback gain that is smaller than the success feedback gain in order to prevent the current application start timing from being excessively advanced even though there is no problem with the discharge amount control. (step 1003).

Next, the discharge amount control unit 804 of the ECU 112 reads a fuel pressure sensor signal representing the fuel pressure from the fuel pressure sensor 401 (step 1004). After the process in step 1004, the ECU 112 advances the process to step 1005.

Then, the discharge amount control unit 804 of the ECU 112 controls the current application start timing, for example, by PID control, using the gain determined earlier according to the difference between the fuel pressure read in step 1004 and the target fuel pressure (step 1005). . After the process in step 1005, the ECU 112 waits for a 10ms interrupt.

<<Effects of this embodiment>>
FIG. 11 is an explanatory diagram showing how pressure pulsation is reduced according to this embodiment. According to this embodiment, it is possible to reduce the feedback gain of the discharge amount control when the valve fails to close. Thereby, it is possible to prevent the current application start timing from becoming too early. FIG. 11 shows an example of fuel pressure, current application amount, and current application start timing when this control is applied. When compared with FIG. 7 before application of this embodiment, the current application start timing is suppressed from becoming too early 187.5 ms after the valve closing failure is detected. This shows that the non-pulsation of the fuel pressure can be reduced.

<<Second embodiment: Silent pump during idling>>
In this embodiment, noise reduction limited to when the operating state of the internal combustion engine 100 is idling will be described. When the internal combustion engine 100 is in an idle state, noise from components other than the high-pressure fuel pump 103 is small. Therefore, the operating noise of the high-pressure fuel pump 103 is noticeable. For this reason, there is a need to perform noise reduction control only when the operating state is idling. Therefore, the amount of current applied to the solenoid 205 is controlled only when the operating state of the internal combustion engine 100 is determined to be the idle state.

<<Noise reduction control when the operating state of the internal combustion engine 100 is in the idle state>>
FIG. 12 is a block diagram showing the high-pressure fuel pump 103 according to this embodiment. The ECU 112 controls a first current application amount control unit (current application amount control unit in the first embodiment) 1201 that controls the amount of current applied to the solenoid 205 only when the operating state of the internal combustion engine 100 is determined to be an idle state. Be prepared. Specifically, the first current application amount control unit 1201 executes first current control to control the amount of current applied to the solenoid 205 based on the determination result of the valve closing determination unit 803. ECU 112 includes a second current application amount control unit 1202 that executes second current control that controls the amount of current applied to solenoid 205 based on the relationship between a predetermined target fuel pressure and current application start timing. The ECU 112 includes an idle determination unit 1203 that determines whether the operating state of the internal combustion engine 100 is an idle state. When it is determined that the operating state of internal combustion engine 100 is in the idle state, ECU 112 executes noise reduction control (first current control) by first current application amount control section 1201. When it is determined that the operating state of internal combustion engine 100 is not the idle state, ECU 112 causes second current application amount control section 1202 to perform second current control.

The configuration of this embodiment is such that an idle determination unit 1203 that determines whether the operating state of the internal combustion engine 100 is in an idle state is added to the configuration shown in FIG. Further, when the operating state of the internal combustion engine 100 is other than the idle state, the current parameter of the second current application amount control unit 1202 is used to control the current application amount using a predetermined current parameter without performing noise reduction control. A current parameter memory 1204 is added that stores the current parameter memory 1204.

<<Current parameter memory 1204>>
FIG. 13 is an explanatory diagram showing a map showing the correlation between target fuel pressure and current application timing according to the second embodiment. The current parameter map shown in FIG. 13 is a map showing the correlation between the target fuel pressure and the current application timing obtained in advance through experiments, etc., and is stored in the current parameter memory 1204.

The current parameter map shows a tendency that when the target fuel pressure is high, the current application start timing is early, and when the target fuel pressure is low, the current application start timing is late. As a second current control, the second current application amount control unit 1202 of the ECU 112 determines the current application start timing according to the target fuel pressure using a map of current parameters. In the current parameter map, when the measured value of the fuel pressure is lower than the target fuel pressure, the current application start timing is controlled to be early, and when it is higher than the target fuel pressure, it is controlled to be delayed.

<<Processing flow of interference reduction control>>
FIG. 14 is a flowchart showing interference reduction control between discharge amount control and noise reduction control (first current application amount control) according to the operating state of the internal combustion engine according to the present embodiment.

When a time interrupt (typically 10 ms) occurs, the idle determination unit 1203 of the ECU 112 determines whether or not the internal combustion engine 100 is in an idle state based on the idle signal from the ECU 112, the rotation speed of the internal combustion engine, the load, etc. (step 1401). If the determination result in step 1401 is that the device is in an idle state, the process proceeds to step 1402. If the determination result in step 1401 is other than the idle state, the process proceeds to step 1403.

If the determination result in step 1401 is the idle state, the noise reduction control in the first current application amount control unit 1201 shown in FIG. 9 is performed at a 2 ms cycle (step 1402), and the discharge amount control shown in FIG. is performed at a period of 10 ms (step 1403). The flow of this process is the same as in the first embodiment, so noise reduction control is performed based on the valve closure detection result, and the gain of the discharge amount control is suppressed when the valve is closed.

If the determination result in step 1401 is other than the idle state, the discharge amount control is performed every 10 ms (step 1403). On the other hand, the second current application amount control unit 1202 performs second current control (step 1404). Here, the noise reduction control is not performed, the second current application amount control is performed based on the current parameter memory 1204, and the feedback control based on the fuel pressure when the plunger 202 rises is not performed.

<<Effects of this embodiment>>
According to this embodiment, the noise reduction control can be executed only when the operating state of the internal combustion engine 100 is the idle state. When performing noise reduction control, valve closing failure occurs with a certain frequency. However, failure to close the valve causes fuel pressure pulsations. When the internal combustion engine 100 is in an idling operating state, the influence of fuel pressure pulsations is reduced. Therefore, by limiting implementation of the noise reduction control when the operating state of the internal combustion engine 100 is in the idle state, the influence of pulsation can be suppressed to an acceptable level.

<<Third Embodiment>>
In the first embodiment, the discharge amount control unit 804 reduces the feedback gain when it is determined that the valve has failed to close. This prevents the current application start timing from being unnecessarily advanced due to a decrease in fuel pressure due to a failure in valve closing due to excessively restricting the current for noise reduction control.

In the present embodiment, instead of this, when a valve closing failure is recognized, the current application start timing is held as a map of the target fuel pressure. And, fuel pressure feedback is not performed.

<<Effects of this embodiment>>
According to this embodiment, when a valve closing failure is recognized, the current application start timing is held as a target fuel pressure map, and fuel pressure feedback is not performed. Therefore, when it is recognized that the valve has failed to close, control is performed using a simple map, and it is possible to suppress excessive advance of the current application start timing and reduce fuel pressure pulsation.

<<Fourth embodiment>>
In the first embodiment, valve closing is detected based on an increase in fuel pressure in synchronization with the plunger 202, and the amount of current applied is gradually reduced while the valve is successfully closed, and the amount of current applied is increased when the valve fails to close. Then, the amount of current applied was adapted to each individual. In the method of the first embodiment, the amount of current applied is maintained near the minimum amount of current applied for each individual by intentionally causing the valve to fail to close at a certain frequency. However, there are cases where fuel pressure pulsations due to valve closing failure using the method of the first embodiment cannot be tolerated.

In such a case, the pump learns the minimum current application amount to close the pump when the key is turned on, controls the pump with the minimum current value based on this learning, and if the valve fails to close due to disturbances such as fuel pressure fluctuations, It is desirable to change the feedback gain so that the current application start timing P-ON does not become earlier than necessary.

<<Quiet control based on learning period>>
FIG. 15 is a block diagram showing the high-pressure fuel pump 103 according to this embodiment. The ECU 112 controls a first current application amount control section (current control in the first embodiment) that executes noise reduction control (first current control) that controls the amount of current applied to the solenoid 205 based on the determination result of the valve closing determination section 803. (application amount control unit) 1201. The ECU 112 includes a third current application amount control unit 1501 that executes third current control that controls the amount of current applied to the solenoid 205 based on the relationship between the predetermined current application start timing and the amount of current application. The third current control is a control in which the current application amount is determined according to the current application start timing using the current parameter map in the current parameter memory 1503 without performing feedback control based on the fuel pressure when the plunger 202 rises. The ECU 112 includes a learning period determination unit 1502 that determines whether or not it is a learning period for learning the minimum current application amount for valve closing of the high-pressure fuel pump 103. During the learning period, the ECU 112 executes noise reduction control by the first current application amount control section 1201. The ECU 112 acquires the determination result of the valve closing determination section 803 at predetermined intervals other than the learning period, and executes the third current control by the third current application amount control section 1501 based on the acquired determination result.

The configuration of this embodiment adds a learning period determination unit 1502 that determines whether the operating state of the internal combustion engine 100 is in the learning period to the configuration of FIG. Additionally, a current parameter memory 1503 stores current parameters of the third current application amount control section 1501 for controlling the current application amount using predetermined current parameters without performing noise reduction control during periods other than the learning period. is added.

<<Current parameter memory 1503>>
FIG. 16 is an explanatory diagram showing a map for adjusting the correlation between the current application start timing and the current application amount stored in the current parameter memory 1503 according to the present embodiment by learning for each individual. The current parameter map shown in FIG. 16 is a map that adjusts the correlation between the current application start timing and the current application amount obtained in advance through experiments etc. by learning for each individual, and is stored in the current parameter memory 1503. .

The current parameter map shows a plurality of characteristic lines showing a tendency that when the current application start timing is high, the current application amount is low, and when the current application start timing is low, the current application amount timing tends to be high. A plurality of characteristic lines showing this tendency are used by moving them mainly in the direction of the magnitude of the applied current according to the learning for each individual. The third current application amount control unit 1501 of the ECU 112 determines the current application amount according to the current application start timing as third current control using a current parameter map.

<<Processing flow of interference reduction control>>
FIG. 17 is a flowchart showing interference reduction control between the discharge amount control and the first current application control (silence control) according to the learning state of the internal combustion engine 100 according to the present embodiment.

When a time interrupt (typically 10 ms) occurs, the learning determination unit 1502 of the ECU 112 determines whether or not the internal combustion engine 100 is in the learning period based on the idle signal from the ECU 112, the rotation speed of the internal combustion engine 100, the load, etc. Determine (step 1701). If the determination result in step 1401 is that it is a learning period, the process proceeds to step 1702. If the determination result in step 1701 is that the period is other than the learning period, the process proceeds to step 1703.

If the determination result in step 1701 is the learning period, the noise reduction control (first current application amount control) in the first current application amount control unit 1201 shown in FIG. 9 is performed at a 2 ms cycle (step 1702), and , the discharge amount control shown in FIG. 10 is performed at a 10 ms cycle (step 1703). The flow of this process is the same as in the first embodiment, so noise reduction control is performed based on the valve closure detection result, and the gain of the discharge amount control is suppressed when the valve is closed.

If the determination result in step 1701 is that it is outside the learning period, the ejection amount control is performed every 10 ms (step 1703). On the other hand, the valve closing determination unit 803 of the ECU 112 performs a valve closing determination (step 1704). Here, the noise reduction control is not performed, the third current application amount control 1501 is performed based on the current parameter memory 1503, and the feedback control based on the fuel pressure when the plunger 202 rises is not performed.

Then, when controlling the discharge amount, as shown in FIG. 10, the gain of feedback control of the PON timing is changed based on whether the valve was successfully closed or failed in the most recent valve closing determination. This prevents excessive control from being misunderstood as a decrease in fuel pressure due to PON timing control due to a failure in valve closing.

<<Effects of this embodiment>>
According to this embodiment, even if the valve fails to close due to a sudden change in fuel pressure or the like, it is possible to prevent excessive PON control from occurring due to the fuel pressure fluctuation due to the valve closing failure.

Although the embodiments of the present invention have been described above, the above embodiments merely show a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. do not have.

100... Internal combustion engine, 101... Fuel tank, 102... Feed pump, 103... High pressure fuel pump, 104... High pressure piping, 105... Direct injection injector, 106... Cylinder, 107... Piston, 108... Spark plug, 109... Link mechanism, 110... Crankshaft, 111... Low pressure piping, 112... ECU, 200... Electromagnetic actuator, 201... Cam, 202... Plunger, 203... Suction valve, 204... Anchor, 205... Solenoid, 206... Fixed part, 207... Seat part, 208... Stopper, 209... First spring, 210... Discharge valve, 211... Pressurizing chamber, 212... Channel, 215... Second spring, 221... Communication port, 222... Outflow port, 223... Casing, 225... Inflow port , 226...Spring section, 401...Fuel pressure sensor, 402...Plunger phase measurement section, 403...Discharge amount control section, 801...Plunger operation determination section, 802...Fuel pressure increase evaluation section, 803...Valve closing determination section, 804...Discharge amount Control unit, 805... Current application amount control unit, 1201... First current application amount control unit, 1202... Second current application amount control unit, 1203... Idle determination unit, 1204... Current parameter memory, 1501... Third current application amount Control unit, 1502...Learning period determination unit, 1503...Current parameter memory.

Claims (5)

a suction valve disposed between the low pressure piping and the pressurizing chamber for pressurizing and discharging fuel in the low pressure piping to the high pressure piping; and a solenoid for controlling opening and closing of the suction valve. A control device for controlling a high-pressure fuel pump including at least a plunger that compresses fuel in the pressurizing chamber,
A fuel pressure sensor is arranged in the high pressure pipe,
A plunger phase measuring section for measuring a phase angle of the plunger is provided near the plunger,
a plunger operation determination unit that determines that the plunger is rising based on a phase angle of the plunger;
a fuel pressure increase evaluation unit that evaluates an increase in fuel pressure during a period in which the plunger is determined to be rising by the plunger operation determination unit;
a valve closing determination unit that determines success or failure of closing the intake valve based on the evaluation result of the fuel pressure increase evaluation unit;
a discharge amount control unit that controls the amount of fuel discharged by controlling the timing at which current is applied to the solenoid based on the fuel pressure measured by the fuel pressure sensor and the target fuel pressure;
Equipped with
The discharge amount control section is a high-pressure fuel pump control device that determines a control gain for the current application start timing based on the determination result of the valve closing determination section. The high pressure fuel pump control device according to claim 1,
A control device for a high-pressure fuel pump, further comprising a current application amount control section that controls an amount of current applied to the solenoid based on a determination result of the valve closing determination section. The high pressure fuel pump control device according to claim 1,
The discharge amount control unit is a high-pressure fuel pump control device that reduces a control gain of the current application start timing when the determination result of the valve closing determination unit is a failure in valve closing. The high pressure fuel pump control device according to claim 1,
The discharge amount control unit is configured to control a high-pressure current application start timing based on a predetermined relationship between a predetermined fuel pressure and a current application start timing when the determination result of the valve closing determination unit is a valve closing failure. Fuel pump control device. The high pressure fuel pump control device according to claim 2,
The current application amount control unit is a high-pressure fuel pump control device that controls the amount of current application to the solenoid only when the operating state of the internal combustion engine is determined to be an idle state.

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