WO2023026514A1

WO2023026514A1 - Solenoid valve control device

Info

Publication number: WO2023026514A1
Application number: PCT/JP2022/002727
Authority: WO
Inventors: 裕貴中居; 修向原; 史博板羽
Original assignee: 日立Astemo株式会社
Priority date: 2021-08-23
Filing date: 2022-01-25
Publication date: 2023-03-02

Abstract

The purpose of the present invention is to provide a solenoid valve control device that is able to achieve silencing of a solenoid valve without failing to close the solenoid valve in a subsequent discharge operation of a fuel pump. To this end, in this solenoid valve control device 109 for controlling the opening/closing of a solenoid valve 300 in an internal combustion engine system, the success or failure of closing the solenoid valve 300 in a subsequent discharge operation of a fuel pump 125 is determined on the basis of a fuel pressure change inside a fuel rail 129, said change being produced by the current discharge operation of the fuel pump 125 and a discharge operation one or more cycles before the current discharge operation.

Description

Solenoid valve controller

The present invention relates to a solenoid valve control device that controls the opening and closing of solenoid valves.

High efficiency, low emissions, and high output are required for automobile internal combustion engines. In-cylinder direct-injection internal combustion engines are widely used as means for solving these demands in a well-balanced manner. A cylinder direct injection internal combustion engine is an internal combustion engine that injects fuel pressurized by a high-pressure fuel pump directly into a cylinder from a fuel injection valve. In recent years, regulations on exhaust gas performance of internal combustion engines have been strengthened on a global scale. As countermeasures against this problem, various technologies have been devised and put into practical use for in-cylinder direct-injection internal combustion engines that can improve homogeneity and reduce the amount of unburned fuel.

As a technology for improving homogeneity, for example, there is a technique that increases the pressure of the fuel injected into the cylinder to promote atomization of the fuel. In a high-pressure fuel pump, in order to increase the pressure of the fuel, a return spring corresponding to the fluid force of the fuel that has been increased in pressure is required. However, if the return spring is strengthened, the operational responsiveness will deteriorate, so additional mechanisms and component improvements will be required to satisfy high fuel pressure and responsiveness. If the high-pressure fuel pump has a complicated structure, there is a risk that the noise that accompanies driving will increase or that the number of times the noise will occur will increase.

Conventional pump silent control has means for judging whether or not the solenoid valve has closed successfully. A method of applying only the amount of current is known. Here, as a method for judging the success or failure of the solenoid valve, a method using at least one of a change in the current flowing through the solenoid portion, a change in the voltage applied to the solenoid portion, the amount of displacement of the valve body, and vibration of the control valve; There are two methods of using fuel pressure in the common rail. The former requires the addition of special circuits such as a low-pass filter circuit and an operational amplifier circuit to the existing control circuit, resulting in increased cost and longer lead time. Therefore, the development of the latter, which can be manufactured at low cost and in a short period of time, is being actively carried out these days.

For example, in Patent Document 1, in a method for controlling a fuel injection device for an internal combustion engine, the fuel injection device includes a high-pressure pump, and a quantity control valve provided with an electromagnetic valve electromagnetically operable by a coil for supplying fuel. A quantity control valve associated with the high pressure pump controls the amount of fuel supplied by the high pressure pump and a coil of the solenoid valve is energized with a first current value to close the solenoid valve for supplying fuel to the high pressure pump. and the first current value is reduced to the second current value when closing the solenoid valve such that the audible sound emission produced when the solenoid valve closes during operation of the internal combustion engine is at least partially reduced. A method is disclosed.

Japanese Patent Publication No. 2010-533820

In the high-pressure pump control device described in Patent Document 1, the fuel pressure in the common rail is compared with a threshold, and if the fuel pressure is greater than the threshold, that is, if the solenoid valve has successfully closed, apply When the current value is decreased and the fuel pressure becomes smaller than the threshold value, that is, when the solenoid valve fails to close, the applied current is increased and the control is terminated. Therefore, when this control is used, the fuel pressure falls below the threshold once before the end of the control, that is, the solenoid valve once fails to close. If the solenoid valve fails to close, the fuel pressure controllability deteriorates when the present invention is used for online control while the vehicle is in operation. Since the responsiveness of the control is deteriorated and the valve is closed or not closed depending on the cycle, problems such as deterioration of NV due to intermittent noise occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to reduce the noise of the solenoid valve without failing to close the solenoid valve in the next discharge operation of the fuel pump. A solenoid valve control device will be provided.

In order to achieve the above object, the present invention provides a plunger that moves up and down as a pump drive cam rotates to increase or decrease the volume of a pressurization chamber, an electromagnetic valve for sucking fuel into the pressurization chamber, A solenoid valve for controlling the opening and closing of the solenoid valve in an internal combustion engine system comprising a fuel pump having a discharge valve for discharging fuel from the pressurizing chamber, and a fuel rail for accumulating the fuel discharged by the fuel pump In the control device, the solenoid valve is closed in the next discharge operation of the fuel pump based on the fuel pressure change in the fuel rail caused by the current discharge operation of the fuel pump and the discharge operation one cycle or more before the current discharge operation. It shall judge the success or failure of the valve.

According to the present invention configured as described above, when the determination result of the closing success or failure of the solenoid valve in the next discharge operation of the fuel pump is positive, the current set value of the solenoid valve is decreased, and when the determination result is negative, By maintaining the current set value at that time, it is possible to reduce the noise of the solenoid valve without failing to close the solenoid valve.

According to the present invention, when the determination result of the closing success or failure of the solenoid valve in the next discharge operation of the fuel pump is positive, the current set value of the solenoid valve is decreased, and when the determination result is negative, the current set value at that time. By maintaining , it becomes possible to realize the noise reduction of the solenoid valve without failing to close the solenoid valve.

As a result, compared to conventional methods, it is possible to improve fuel pressure controllability, shorten feedback control response time, and improve NV.

Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiment.

1 is an overall configuration diagram showing a basic configuration example of an internal combustion engine equipped with a fuel injection control device according to a first embodiment of the present invention; FIG. 1 is a schematic configuration diagram of an ECU according to a first embodiment of the invention; FIG. 1 is an overall configuration diagram of a fuel system according to a first embodiment of the present invention; FIG. FIG. 4 is a diagram showing a time chart of the operation of the high-pressure fuel pump according to the first embodiment of the invention; FIG. 4 is a diagram showing variations in individual characteristics of high-pressure fuel pumps; FIG. 4 is a diagram showing the relationship between the driving current value of the high-pressure fuel pump and the noise level; FIG. 3 is a diagram showing the relationship between fuel discharge from a high-pressure fuel pump, fuel injection from a fuel injection valve, and fuel pressure from a common rail; 4 is a flow chart of electromagnetic valve control in a high-pressure fuel pump; FIG. 5 is a diagram showing an example of a filter used for fuel pressure data; FIG. 3 is a diagram showing the relationship between fuel discharge from a high-pressure fuel pump, fuel injection from a fuel injection valve, fuel pressure from a common rail, and fuel pressure after filtering. 4 is a flow chart of electromagnetic valve control using a valve closing success/failure determination for the next cycle in the high-pressure fuel pump according to the first embodiment of the present invention; FIG. 7 is a diagram showing a method of determining whether the solenoid valve is closed successfully in the next cycle using fuel pressure filter values from the start of control to the present according to the first embodiment of the present invention; FIG. 5 is a diagram showing a method of determining whether the solenoid valve is closed in the next cycle using a preset value and a fuel pressure filter value from the start of control to the present according to the first embodiment of the present invention; . FIG. 4 is a diagram showing a method of setting a threshold when determining success or failure of closing an electromagnetic valve in the next cycle according to the first embodiment of the present invention; FIG. 4 is a diagram showing the relationship between solenoid valve control and fuel pressure feedback control according to the first embodiment of the present invention; FIG. 5 is a diagram showing a method of setting a threshold value when judging success or failure of closing the solenoid valve in the next cycle based on solenoid valve control and fuel pressure feedback control according to the first embodiment of the present invention; FIG. 5 is a diagram showing a method of using the slope of the fuel pressure filter value in setting the drive current correction amount during electromagnetic valve control in the high-pressure fuel pump according to the first embodiment of the present invention; FIG. 4 is a diagram showing a method of using a fuel pressure filter value in setting a drive current correction amount during electromagnetic valve control in the high-pressure fuel pump according to the first embodiment of the present invention; FIG. 5 is a diagram showing a method of using a drive current value in setting a drive current correction amount during electromagnetic valve control in the high-pressure fuel pump according to the first embodiment of the present invention; FIG. 5 is a diagram showing a method of using the number of cycles from the start of learning in setting a drive current correction amount during electromagnetic valve control in the high-pressure fuel pump according to the first embodiment of the present invention; 4 is a flowchart of electromagnetic valve control using determination of the amount of discharge for the next cycle in the high-pressure fuel pump according to the first embodiment of the present invention; 8 is a flow chart of electromagnetic valve control in a high-pressure fuel pump according to a second embodiment of the present invention; FIG. 7 is a diagram showing the relationship among fuel discharge from a high-pressure fuel pump, fuel injection from a fuel injection valve, fuel pressure from a common rail, and fuel pressure after filtering according to a second embodiment of the present invention; It is a flow chart of fuel injection valve control according to a third embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, constituent elements having substantially the same function or configuration are denoted by the same reference numerals, and overlapping descriptions are omitted.

A solenoid valve control device according to a first embodiment of the present invention will be described.
[Internal combustion engine system]
First, the configuration of an internal combustion engine system in which the solenoid valve control device according to this embodiment is mounted will be described. FIG. 1 is an overall configuration diagram of an internal combustion engine system equipped with a fuel injection control device according to this embodiment.

An internal combustion engine (engine) 101 shown in FIG. 1 is a four-cycle engine that repeats four strokes of an intake stroke, a compression stroke, a combustion (expansion) stroke, and an exhaust stroke. is the engine. Note that the number of cylinders that the internal combustion engine 101 has is not limited to four, and may have three, six, or eight or more cylinders.

The internal combustion engine 101 has a piston 102 , an intake valve 103 and an exhaust valve 104 . Intake air (intake air) into the internal combustion engine 101 passes through an air flow meter (AFM) 120 that detects the amount of inflowing air, and the flow rate is adjusted by a throttle valve 119 . The air that has passed through the throttle valve 119 is sucked into the collector 115, which is a branch, and then enters the combustion chamber 121 of each cylinder via the intake pipe 110 and the intake valve 103 provided for each cylinder. supplied.

On the other hand, fuel is supplied from the fuel tank 123 by the low-pressure fuel pump 124 to a plurality of high-pressure fuel pumps 125, and is increased by each high-pressure fuel pump 125 to the pressure required for fuel injection. That is, the high-pressure fuel pump 125 moves up and down a plunger (described later with reference to FIG. 3) provided in the high-pressure fuel pump 125 by power transmitted from an exhaust camshaft (not shown) of the exhaust cam 128. to pressurize (boost) the fuel in the high-pressure fuel pump 125 .

An opening/closing valve (electromagnetic intake valve 300 described later) driven by a solenoid is provided at the intake port of the high-pressure fuel pump 125 . The solenoid is connected to an ECU (Engine Control Unit) 109 . The ECU 109 includes an electromagnetic valve control device that controls driving of the electromagnetic valves. The ECU 109 controls the solenoid to drive the open/close valve so that the pressure of the fuel discharged from the high-pressure fuel pump 125 (fuel pressure) becomes a desired pressure.

The fuel pressurized by the high-pressure fuel pump 125 is sent to the fuel injection valve 105 via the common rail 129 . A plurality of common rails 129 are provided corresponding to the plurality of high-pressure fuel pumps 125, and each pressure-accumulates the fuel discharged by the high-pressure fuel pumps 125. As shown in FIG.

The fuel injection valve 105 is of an in-cylinder direct injection type capable of injecting fuel into the combustion chamber 121 multiple times during one cycle. The fuel injection valve 105 operates a valve element to inject fuel, for example, by supplying (energizing) a drive current to an electromagnetic coil (solenoid). The fuel injection valve 105 receives a command (injection pulse) from the ECU 109 and injects fuel into the combustion chamber 121 by opening the valve for the time specified by the command.

Note that the total amount of fuel injected from the fuel injection valve 105 in one cycle (total fuel injection amount) can be determined in advance, and each value of the fuel injection amount of fuel injection performed a plurality of times (injection amount of each time) ) can also be predetermined.

Also, the internal combustion engine 101 is provided with a fuel pressure sensor 126 that measures the fuel pressure in the common rail 129 . The fuel pressure measured by the fuel pressure sensor 126 is the actual fuel pressure supplied to the fuel injection valve 105, that is, the actual fuel pressure. The ECU 109 sends a control command to the fuel injection valve 105 to set the fuel pressure in the common rail 129 to a desired pressure based on the measurement result of the fuel pressure sensor 126 . That is, the ECU 109 performs so-called feedback control to bring the fuel pressure in the common rail 129 to a desired pressure.

Further, each combustion chamber 121 of the internal combustion engine 101 is provided with an ignition plug 106, an ignition coil 107, and a water temperature sensor . The spark plug 106 exposes an electrode portion in the combustion chamber 121 and ignites a mixture of intake air and fuel in the combustion chamber 121 by electric discharge. Ignition coil 107 produces a high voltage for discharging at spark plug 106 . A water temperature sensor 108 measures the temperature of cooling water that cools the cylinders of the internal combustion engine 101 .

The ECU 109 controls energization of the ignition coil 107 and ignition control by the ignition plug 106 . A mixture of intake air and fuel in the combustion chamber 121 is combusted by sparks emitted from the spark plug 106, and the pressure pushes the piston 102 downward.

Exhaust gas generated by combustion is discharged to the exhaust pipe 111 through the exhaust valve 104 . A three-way catalyst 112 and an oxygen sensor 113 are provided in the exhaust pipe 111 . The three-way catalyst 112 purifies harmful substances such as nitrogen oxides (NOx) contained in the exhaust gas. The oxygen sensor 113 detects the concentration of oxygen contained in the exhaust gas and outputs the detection result to the ECU 109 . Based on the detection result of the oxygen sensor 113, the ECU 109 performs feedback control so that the fuel injection amount supplied from the fuel injection valve 105 becomes the target air-fuel ratio.

A crankshaft 131 is also connected to the piston 102 via a connecting rod 132 . The reciprocating motion of the piston 102 is converted into rotary motion by the crankshaft 131 . A crank angle sensor 116 is attached to the crankshaft 131 . Crank angle sensor 116 detects the rotation and phase of crankshaft 131 and outputs the detection result to ECU 109 . ECU 109 can detect the rotational speed of internal combustion engine 101 based on the output of crank angle sensor 116 .

The ECU 109 receives signals from the crank angle sensor 116, the air flow meter 120, the oxygen sensor 113, the accelerator opening sensor 122 that indicates the opening of the accelerator operated by the driver, the fuel pressure sensor 126, and the like.

Based on the signal supplied from the accelerator opening sensor 122, the ECU 109 calculates the required torque of the internal combustion engine 101 and determines whether or not the vehicle is in an idling state. The ECU 109 also calculates the amount of intake air required for the internal combustion engine 101 from the required torque and the like, and outputs an opening degree signal corresponding to the amount to the throttle valve 119 .

The ECU 109 uses the outputs of various sensors to calculate the fuel amount and the number of injections according to the intake air amount of each cylinder (combustion chamber 121). Then, the ECU 109 outputs a fuel injection signal to the fuel injection valve 105 according to the calculated fuel amount and the number of injections. Furthermore, the ECU 109 outputs an energization signal to the ignition coil 107 and an ignition signal to the ignition plug 106 .

The internal combustion engine 101 is mainly required to have low fuel consumption, high output, and clean exhaust gas, but as further added value, it is required to reduce noise and vibration. In the high-pressure fuel pump 125, when the electromagnetic intake valve is opened and closed, the valve body and the anchor collide with the stopper, causing noise.
[Configuration of ECU]
Next, the configuration of the ECU 109 shown in FIG. 1 will be described using FIG.

FIG. 2 is a schematic configuration diagram of the ECU 109. FIG.

The ECU 109 includes an input circuit 203 , an A/D converter 204 , a CPU (Central Processing Unit) 205 as a central processing unit, and an output circuit 210 . The CPU 205 implements a plurality of functions, which will be described later, by executing programs stored in advance.

The ECU may include a rewritable logic circuit, FPGA (Field Programmable Gate Array), or an application-specific integrated circuit, ASIC (Application Specific Integrated Circuit).

The input circuit 203 takes in signals output from the sensors 201 (oxygen sensor 113, crank angle sensor 116, air flow meter 120, accelerator opening sensor 122, etc.) as input signals 202. When the input signal 202 is an analog signal, the input circuit 203 removes noise components from the input signal 202 and outputs the noise-removed signal to the A/D converter 204 .

The A/D converter 204 converts the analog signal into a digital signal and outputs it to the CPU 205 . The CPU 205 takes in the digital signal output from the A/D conversion unit 204 and executes a pre-stored control logic (program) to perform various calculations, diagnosis, control, and the like.

The calculation result of the CPU 205 is output as a control signal 211 from the output circuit 210 to drive the actuators 212 provided in the intake valve 103, the exhaust valve 104, the fuel injection valve 105, the plurality of high pressure fuel pumps 125, and the like. On the other hand, when the input signal 202 is a digital signal, it is sent directly from the input circuit 203 to the CPU 205 via the signal line 206, and the CPU 205 executes necessary calculation, diagnosis, control, and the like.

Also, the CPU 205 and the A/D conversion unit 204 constitute a microcomputer (hereinafter referred to as “microcomputer”) 220 . The microcomputer 220 is a specific example of a control unit according to the present invention, and performs filter processing, electromagnetic valve diagnosis processing, and the like, which will be described later. The filtering process and the electromagnetic valve diagnosis process may be executed by hardware resources of the microcomputer 220, or may be executed using software.
[Configuration of high-pressure fuel pump]
Next, the configuration of the fuel system according to this embodiment will be described with reference to FIG.

FIG. 3 is an overall configuration diagram of the fuel system according to this embodiment.

As shown in FIG. 3 , the high-pressure fuel pump 125 pressurizes the fuel supplied from the fuel tank 123 and pumps it to the common rail 129 . Fuel is supplied from the fuel tank 123 to the low-pressure fuel pump 124 and led from the low-pressure fuel pump 124 to the fuel inlet of the high-pressure fuel pump 125 . At this time, the pressure of the fuel is adjusted to a constant pressure by the pressure regulator 152 .

The high-pressure fuel pump 125 has a casing 323. The casing 323 is provided with a communication port 321 , an outlet port 322 , an inlet port 325 and a pressure chamber 311 . The high-pressure fuel pump 125 includes a plunger 302 that moves up and down due to the rotation of a pump drive cam 301 attached to the camshaft of the internal combustion engine 101, an electromagnetic intake valve 300 that opens and closes in synchronization with the up-and-down movement of the plunger 302, and fuel. and a discharge valve 310 for discharging to the common rail 129 .

When the plunger 302 descends, the volume of the pressurization chamber 311 increases, and when the plunger 302 ascends, the volume of the pressurization chamber 311 decreases. That is, the plunger 302 is arranged to reciprocate in the direction of expanding and contracting the volume of the pressurizing chamber 311 . Discharge valve 310 opens and closes outlet 322 . The spring portion 326 biases the discharge valve 310 in the valve opening direction. That is, the discharge valve 310 is always biased in the direction to close the outflow port 322 . When the pressure of the fuel in the pressurization chamber 311 becomes greater than the biasing force of the spring portion 326, the outflow port 322 opens. As a result, the fuel in pressurization chamber 311 is discharged to common rail 129 .

The electromagnetic intake valve 300 is a normally open type electromagnetic valve, and a force acts in the valve opening direction when not energized, and a force acts in the valve closing direction when energized. The electromagnetic intake valve 300 includes a valve body 303, a first spring 309 that biases the valve body 303 in the valve-opening direction, a second spring 315 that biases the valve body 303 in the valve-closing direction, a solenoid 305, and an anchor. 304.

The valve body 303 is formed in a substantially rod shape, and an anchor 304 is provided at one end in the axial direction. A contact piece 303 a is formed at the other end of the valve body 303 . The contact piece 303a contacts the seat portion 307 provided at the inflow port 325 when the valve is closed. Thereby, the valve body 303 closes the communicating portion between the inflow port 325 and the pressurizing chamber 311 .

One end of the first spring 309 is connected to the anchor 304. The other end of first spring 309 is connected to casing 323 . One end of the second spring 315 is connected to a stopper 308 arranged between the valve body 303 and the pressure chamber 311 . The other end of the second spring 315 is connected to the end of the valve body 303 opposite to the anchor 304 .

The solenoid 305 faces the anchor 304. When the solenoid 305 is energized, an electromagnetic force is generated between the solenoid 305 and the anchor 304 . As a result, the anchor 304 is pulled in the valve closing direction, which is the direction (left side in FIG. 3) that resists the spring force of the first spring 309 .

In the high-pressure fuel pump 125, the operation of the anchor 304 in the axial direction (horizontal direction in FIG. 3) is controlled by controlling ON/OFF of the energization of the solenoid 305. When the solenoid 305 is de-energized, the anchor 304 is constantly urged in the valve opening direction (to the right in FIG. 3) by the first spring 309 . Thereby, the valve body 303 is held at the valve open position.

When the solenoid 305 is energized, an electromagnetic attractive force is generated between the fixed portion 306 (magnetic core) and the anchor 304 . As a result, the anchor 304 is attracted in the valve closing direction (leftward in FIG. 3) against the spring force of the first spring 309 . When the anchor 304 is attracted to the fixed portion 306 , the valve body 303 functions as a check valve that opens and closes based on the pressure difference between the upstream side and the downstream side and the biasing force of the second spring 315 .

When the pressure on the downstream side of the valve body 303 rises, the valve body 303 moves in the valve closing direction. When the valve body 303 moves by the set lift amount in the valve closing direction, it is seated on the seat portion 307 . As a result, the electromagnetic suction valve 300 is closed, and the fuel in the pressurization chamber 311 cannot flow back to the low-pressure pipe side.

If the electromagnetic intake valve 300 is open when the plunger 302 descends, fuel flows into the pressurization chamber 311 from the inflow port 325 . Hereinafter, the stroke in which the plunger 302 descends will be referred to as a suction stroke. On the other hand, if the electromagnetic intake valve 300 is closed when the plunger 302 is raised, the pressure of the fuel in the pressurization chamber 311 is increased, and the fuel is pressure-fed to the common rail 129 through the discharge valve 310 (outflow port 322). be. Hereinafter, the stroke in which the plunger 302 rises will be referred to as a compression stroke.

If the electromagnetic intake valve 300 is closed during the compression stroke, the fuel sucked into the pressurization chamber 311 during the intake stroke is pressurized and discharged to the common rail 129 side. On the other hand, if the electromagnetic intake valve 300 is open during the compression stroke, the fuel in the pressurization chamber 311 is pushed back toward the inflow port 325 side and is not discharged toward the common rail 129 side. Thus, the discharge of fuel by the high-pressure fuel pump 125 is controlled by opening and closing the electromagnetic intake valve 300 . The opening and closing of the electromagnetic intake valve 300 is controlled by the electromagnetic valve control device 109 .

The common rail 129 accumulates fuel discharged from the high-pressure fuel pump 125 . A plurality of fuel injection valves 105 , a fuel pressure sensor 126 , and a pressure regulating valve (hereinafter referred to as “relief valve”) 355 are attached to the common rail 129 . The relief valve 355 opens when the fuel pressure in the common rail 129 exceeds a predetermined value to prevent damage to the piping. A plurality of fuel injection valves 105 are mounted according to the number of cylinders (combustion chambers 121), and inject fuel according to the drive current output from the ECU 109. FIG.

The fuel pressure sensor 126 outputs the detected pressure data to the ECU 109. The ECU 109 determines an appropriate injection fuel amount (target injection fuel amount) and an appropriate fuel pressure (target fuel pressure), etc.

Further, the ECU 109 controls driving of the high-pressure fuel pump 125 and the plurality of fuel injection valves 105 based on the calculation results. That is, the electromagnetic valve control device 109 has a pump control section that controls the high-pressure fuel pump 125 and an injection valve control section that controls the fuel injection valve 105 .
[Operation of high-pressure fuel pump]
Next, the operation of the high-pressure fuel pump according to this embodiment will be described with reference to FIG.

FIG. 4 is a time chart explaining the operation of the high-pressure fuel pump 125. FIG.

The electromagnetic intake valve 300 opens and closes in synchronization with the rise and fall of the plunger 302 . The electromagnetic valve control device 109 detects the rotation angle of the pump drive cam 301. For example, after the pump drive cam 301 rotates from the top dead center (TDC: Top Dead Center) to a predetermined angle (P_ON timing), A voltage V is applied across the solenoid 305 (timing t1).

The current I flowing through the solenoid 305 increases according to Equation (1). Note that L is the inductance between the solenoid 305 and the wiring, and R is the resistance between the solenoid 305 and the wiring.

As the current I increases, the magnetic attraction force Fmag with which the fixing part 306 (magnetic core) attracts the anchor 304 increases. When the magnetic attraction force Fmag becomes larger than the spring force Fsp of the first spring 309, the anchor 304 held down by the spring force Fsp starts moving toward the fixing portion 306 (timing t2).

When the anchor 304 moves toward the fixed portion 306 , the valve element 303 pushed by the fuel pressurized by the rise of the plunger 302 moves toward the fixed portion 306 following the anchor 304 . Then, the contact piece 303 a of the valve body 303 collides with the seat portion 307 . That is, the valve body 303 is seated on the seat portion 307 . As a result, the fuel passage (dotted line in FIG. 3) is blocked, and the fuel pressurized by the rise of the plunger 302 cannot return to the low-pressure pipe side. As a result, the fuel pressure in pressurization chamber 311 rises. (Timing t4).

When the fuel pressure in the pressurizing chamber 311 exceeds the spring force Fsp_out that biases the discharge valve 310, the discharge valve 310 opens. As a result, the fuel pressurized by the rise of plunger 302 is discharged to common rail 129 . After that, when the drive pulse is turned off at timing t5, a reverse voltage is applied to the solenoid 305 . As a result, the holding current supplied to the solenoid 305 is cut off.

When the cam angle passes the top dead center and the plunger 302 starts to descend (timing t6), the fuel pressure in the pressurizing chamber 311 decreases. Then, when the fuel pressure in the pressurizing chamber 311 becomes smaller than the spring force Fsp_out, the discharge valve 310 is closed. Thus, the discharge of fuel by the high-pressure fuel pump 125 ends. Further, the anchor 304 moves from the valve closed position to the valve open position together with the valve body 303 (timings t7 to t8) as the fuel pressure in the pressurizing chamber 311 decreases.

By such operation, the high-pressure fuel pump 125 sends fuel to the common rail 129 from the low-pressure piping. In this process, when the anchor 304 collides with the fixed portion 306 to complete the valve closing (timing t4 in FIG. 4), and when the anchor 304 and the valve body 303 collide with the stopper 308 to complete the valve opening (in FIG. 4). Noise occurs at timing t8). This noise can be annoying to the driver, especially at idle. In this embodiment, the noise at the time of completion of valve closing is reduced.
[Peak current and holding current]
Next, the peak current and holding current according to this embodiment will be described with reference to FIG.

The current that drives the high-pressure fuel pump 125 is roughly divided into two. That is, the drive current for the high-pressure fuel pump 125 is divided into a peak current (shaded portion of the current waveform in FIG. 4) and a holding current (horizontal line portion of the current waveform in FIG. 4). As shown in FIG. 4, the maximum current value of the peak current is Im, and the maximum current value of the holding current is Ik.

When the peak current flows, the valve body 303 and the anchor 304, which are urged by the first spring 309 and are stationary at the valve open position, are given momentum to close the valve. After that, when the holding current flows, the anchor 304 approaching the fixed part 306 is attracted until it collides with the fixed part 306 . Further, after the anchor 304 collides with the fixed portion 306, the contact state is maintained.

By reducing the amount of peak current applied, the momentum of closing the valve is weakened, so noise can be reduced. However, if the amount of applied peak current is reduced too much, the electromagnetic suction valve 300 will fail to close. Therefore, it is desirable to reduce the amount of applied peak current as much as possible within the range in which the electromagnetic suction valve 300 is closed.

Basically, the limit (minimum) amount of peak current applied at which the electromagnetic intake valve closes depends on the individual characteristics of the high-pressure fuel pump. FIG. 5 is a diagram showing variations in individual characteristics of high-pressure fuel pumps. FIG. 5 shows the average velocity v_ave (from the start of valve closing to closing) for the standard spring force Fsp, the upper limit spring force Fsp due to manufacturing variations, and the lower limit spring force Fsp due to manufacturing variations. average value until completion) and the peak current integral value II.

In the present embodiment, the applied amount of peak current is the integrated value of the current, but the applied amount of peak current may be replaced with the integrated value of the square of the current or the integrated value of the product of the current and the voltage. The individual characteristics of

From FIG. 5, it can be seen that the relationship between the peak current integral value II and the average speed v_ave varies depending on the spring force Fsp. That is, if the average speed required for a certain solenoid valve is indicated by a dashed line, the required peak current integral value II will vary greatly within the range of A to C due to individual differences.

If the valve closing limit current for the lower limit of the spring force Fsp is set to the upper limit of the spring force Fsp, the magnetic attraction force generated by the solenoid will be smaller than the spring force, and the electromagnetic intake valve will fail to close. Therefore, as the valve closing limit current, it is necessary to select the valve closing limit current for the upper limit product of the spring force Fsp. However, if the lower limit product of the spring force Fsp is controlled by the valve closing limit current for the upper limit product of the spring force Fsp, an excessive magnetic attraction force will be generated compared to the spring force. As a result, the electromagnetic intake valve closes faster than necessary.

FIG. 6 is a diagram showing the relationship between the driving current value of the high-pressure fuel pump and the noise level. As shown in FIG. 6, the noise level increases as the peak current integral value II increases. Further, as described with reference to FIG. 5, the value of the valve closing limit current must be set to a value (current value C) corresponding to the upper limit product of the spring force Fsp. However, the current value A is required for the product with the lower limit of the spring force Fsp. Therefore, the width of the double-headed arrow shown in FIG. 6 is the noise level variation. That is, if the current value applied to the lower limit product of the spring force Fsp can be reduced to the current value A, which is the originally required value, the noise level corresponding to the variation can be reduced.
[Valve closure detection using fuel rail pressure]
In order to apply to the solenoid valve a current value corresponding to the spring force Fsp, in other words, an appropriate current value corresponding to the individual difference of the pump, it is necessary to detect the individual difference of the pump. In this embodiment, the fuel rail pressure (fuel pressure in the common rail 129) is used as means for detecting individual differences.

The high-pressure fuel pump 125 and fuel injection valve 105 are connected to a common rail 129 having a pressure accumulation function. The behavior of each solenoid valve in the high-pressure fuel pump 125 and the fuel injection valve 105 is closely related to the fuel pressure within the common rail 129 . For example, when the electromagnetic intake valve 300 of the high-pressure fuel pump 125 is closed, the fuel pressure in the pressurization chamber 311 increases. As a result, the fuel in the pressurization chamber 311 is discharged from the discharge valve 310, and the fuel pressure in the common rail 129 increases. In other words, it can be said that the successful closing of the electromagnetic intake valve 300 is an increase in the fuel pressure within the common rail 129 .

On the other hand, when the solenoid valve of the fuel injection valve 105 opens, fuel is injected from the injection port of the fuel injection valve 105, so the fuel pressure in the common rail 129 decreases. In other words, it can be said that the successful opening of the solenoid valve in the fuel injection valve 105 is a decrease in the fuel pressure in the common rail 129 .

FIG. 7 is a diagram showing the relationship between the fuel discharge of the high-pressure fuel pump, the fuel injection of the fuel injection valve, and the fuel pressure of the common rail. In the high-pressure fuel pump 125, during the period from the completion of the closing of the electromagnetic intake valve 300 to TDC, fuel is supplied through the discharge valve 310 in accordance with the decrease in the volume of the pressurization chamber 311 due to the rise of the plunger 302 (increase in the cam lift amount 601). Fuel is discharged (high pressure pump fuel discharge 602).

In addition, the fuel injection valve 105 injects fuel based on an injection instruction from the ECU 109 (fuel injection 603 of the fuel injection valve). As a result, fuel pressure 604 in common rail 129 generally travels through four regions, regions A, B, C, and D.

Area A is an area affected by the fuel injection valve 105, and the fuel pressure 604 in the common rail 129 decreases according to the amount of fuel injected by the fuel injection valve 105. Region B, following region A, is the region where fuel pressure 604 in common rail 129 is maintained. In the region B, the high-pressure fuel pump 125 does not discharge fuel and the fuel injection valve 105 does not inject fuel. Therefore, the fuel pressure 604 in the common rail 129 is maintained at the decreased value in the region A.

A region C next to the region B is an area affected by the high-pressure fuel pump 125, and the fuel pressure 604 in the common rail 129 increases according to the amount of fuel discharged by the high-pressure fuel pump 125. A region D next to the region C is a region in which the fuel pressure in the common rail 129 is maintained. Also in this region, similarly to region B, fuel is not discharged by the high-pressure fuel pump 125 and fuel is not injected by the fuel injection valve 105 . Therefore, the fuel pressure 604 in the common rail 129 is maintained at the increased value in region C. Basically, the target fuel pressure of the system is achieved as the average fuel pressure by balancing the injection amount from the fuel injection valve 105 and the discharge amount from the high-pressure fuel pump 125 .

By detecting the fuel pressure in the common rail 129 from the relationship between the pump discharge, the fuel injection valve injection, and the rail fuel pressure, the valve behavior of the electromagnetic intake valve 300 and the fuel injection valve 105 of the high-pressure fuel pump 125 can be grasped. It turns out that it is possible to Specifically, by detecting the fuel pressure in the common rail 129, it is possible to detect whether the electromagnetic intake valve 300 and the fuel injection valve 105 are closed. Also, the fuel pressure in the common rail 129 can be easily detected from the value of a fuel pressure sensor mounted in a general direct injection system.

Thus, the only monitor value required in the present invention is the fuel pressure value within the common rail 129 that can be read from the existing fuel pressure sensor 126 . Therefore, according to the present invention, there is no need to develop a new circuit and control, and it is possible to implement the device at a shorter delivery time and at a lower cost than in the conventional case where a new circuit and control are developed. On the other hand, conventionally, current/voltage values are directly detected in order to detect whether or not the solenoid valve is closed. As a result, costs and lead times increase.
[Control of electromagnetic intake valve]
Next, control processing of the electromagnetic intake valve 300 will be described with reference to FIG.

FIG. 8 is a flow chart of solenoid valve control in the high-pressure fuel pump.
First, the solenoid valve control device 109 acquires fuel pressure data in the common rail 129 (step S101). In this process, fuel pressure data is acquired from the fuel pressure sensor 126 . It should be noted that a shorter sampling period is desirable. However, even with the conventionally set resolution of 1ms, 2ms, and 4ms, there is sufficient accuracy for this control in the low to medium speed range where engine noise is generally a problem. It is possible to secure

Next, the solenoid valve control device 109 performs filter processing according to the application on the acquired fuel pressure data (step S102). FIG. 9 is a diagram showing an example of a filter used for fuel pressure data. Filter 1 is calculated using Filter coefficients 801 . Filter 2 is calculated using Filter coefficients 802 . Filter 3 is calculated using Filter coefficients 803 . That is, Filter 1, Filter 2, and Filter 3 are calculated from Equations 2 to 4 below, respectively.

Filter1 to Filter3 are filters that cut the DC component and extract the difference. The peak of the gain of change is the sampling period for Filter1, twice the sampling period for Filter2, and three times the sampling period for Filter3. Therefore, it is preferable to set the filter at a well-balanced point from the viewpoint of detecting the sampling frequency and removing noise.

Next, the solenoid valve control device 109 compares the filtered pressure data (fuel pressure 901) with a preset threshold value 902 to determine whether or not the solenoid intake valve 300 is successfully closed (step S103). ). In the processing of step S103, it is determined that the valve has been successfully closed when the filtered fuel pressure data exceeds the threshold value. Further, when the filtered fuel pressure data is equal to or less than the threshold value, it is determined that the valve closing has failed.

FIG. 10 is a diagram showing the relationship between the fuel discharge of the high-pressure fuel pump, the fuel injection of the fuel injection valve, the fuel pressure of the common rail, and the fuel pressure after filtering. As shown in FIG. 10, when the filtered fuel pressure 901 exceeds the threshold value 902, it is considered that the fuel discharge amount has reached the target discharge amount. Therefore, it can be determined that the fuel in the pressure chamber 311 of the high-pressure fuel pump 125 has not returned to the inflow port 325 (see FIG. 3) and the valve has been successfully closed.

On the other hand, if the filtered fuel pressure 901 is less than or equal to the threshold value 902, it is considered that the fuel discharge amount has not reached the target discharge amount. Therefore, it can be determined that the fuel in the pressure chamber 311 of the high-pressure fuel pump 125 has returned to the inflow port 325 (see FIG. 3) and the valve closing has failed.

The threshold value 902 considers a value that does not cause erroneous detection after considering noise and detection accuracy as the lower limit. Further, the threshold value 902 considers a value that can reliably detect even the lower gain limit when the pump discharges, including variations as the upper limit side. Then, the threshold value 902 is set between the lower limit side and the upper limit side. If only the closed state of the electromagnetic intake valve 300 is detected, there is no problem with the concept of the lower limit side.

However, in a scene where precision in the discharge amount is required, although the electromagnetic intake valve 300 is closed, the responsiveness slows down, so it is conceivable that the precision of the discharge flow rate may become a problem. Therefore, when setting the lower limit of the threshold value, it is necessary to take into account the factor of the minimum required ejection flow rate, in addition to avoiding erroneous detection based on noise, detection accuracy, and the like. Also, the threshold value 902 may be a fixed value, but if there is more than one control scene, it must be set by MAP according to the fuel pressure, the discharge amount of the pump, etc., or set variably. There is

The conversion from the discharge flow rate to the pressure fluctuation can be calculated from the pressure, volume, fuel physical properties, etc. using the compressible fluid formula. Conversely, it is also possible to calculate the discharge flow rate of the high-pressure fuel pump from the amount of change in the measurement signal (pressure data after differential filtering). In the processing of step S103, the discharge flow rate of the high-pressure fuel pump may be calculated, and it may be determined from the calculated discharge flow rate whether the current set value should be corrected to a lower value or a higher value. For example, when the calculated discharge flow rate of the high-pressure fuel pump is larger than a predetermined value, the determination (YES determination) is the same as when the valve is successfully closed. On the other hand, when the calculated discharge flow rate of the high-pressure fuel pump is equal to or less than the predetermined value, the same determination (NO determination) as when the valve closing has failed is made.

Further, as shown in FIG. 10, a determination window 903 is set for each cam cycle so that the high-pressure fuel pump 125 can actually discharge fuel within a range from the bottom dead center to the top dead center of the plunger 302 that can discharge fuel. To surely cover the range in which is discharged. By limiting the determination window 903 to a necessary range, the risk of erroneous detection due to noise or the like can be reduced.

When it is determined in step S103 that the valve has been successfully closed (YES in step S103), the solenoid valve control device 109 determines that the current set value of current has a margin. Then, the solenoid valve control device 109 corrects the current set value to a value lower than the current set value (step S104). After that, the solenoid valve control device 109 acquires fuel pressure data again. That is, the solenoid valve control device 109 returns the process to step S101.

The finer the correction amount (feedback amount) of the current setting value in step S104, the higher the accuracy. However, the finer the correction amount of the current set value, the more susceptible it is to noise, and the more time it takes to make the determination. Therefore, the correction amount (feedback amount) of the current setting value in step S104 should be set based on both the time that can be allocated to this control and the required accuracy.

On the other hand, if it is determined in step S103 that the valve closing has failed (NO determination in step S103), the solenoid valve control device 109 determines that the current set value of current is low. Then, the solenoid valve control device 109 corrects the current set value to a value higher than the current set value (step S105). After that, the solenoid valve control device 109 determines that the current setting value corrected in the process of step S105 is the minimum necessary current value, and ends the control.

The correction amount (feedback amount) of the current set value in step S105 may be set to the current set value at which the valve was closed successfully last. However, it is desirable to set the correction amount (feedback amount) of the current setting value in step S105 after considering an appropriate safety factor in consideration of robustness. Further, the correction amount (feedback amount) of the current set value in steps S104 and S105 may be stored in the storage unit as a map value or set variably according to the driving scene.

In the control of the solenoid valve described above, the pressure fluctuation is filtered for each shot (each energization pulse of the solenoid valve) to determine whether the solenoid valve has closed successfully. Therefore, it is possible to detect whether the solenoid valve has been closed more accurately and directly, compared to the method of determining whether the solenoid valve has been closed simply based on whether the fuel pressure has decreased or increased.

In addition, by feeding back the closing success or failure of the solenoid valve to the drive current value, it is possible to drive the solenoid valve with the minimum current value, and it is possible to achieve significant noise reduction and power saving. Furthermore, since only the existing monitor value of the fuel rail fuel pressure value (fuel pressure data in the common rail 129) is used to detect the closing of the solenoid valve, there is no need to add a new control circuit. It is possible to detect the closing of the solenoid valve. As a result, the development period can be significantly shortened, and a significant cost reduction can be achieved.

On the other hand, the solenoid valve control based on FIG. 8 compares the fuel pressure in the common rail with a threshold, and if the fuel pressure is greater than the threshold, that is, if the solenoid valve has successfully closed, the applied current When the value is decreased and the fuel pressure becomes smaller than the threshold value, that is, when the solenoid valve fails to close, the applied current is increased and the control is terminated. Therefore, when this control is used, the fuel pressure falls below the threshold once before the end of the control, that is, the solenoid valve once fails to close. If the solenoid valve fails to close, when the present invention is used for on-line control during vehicle operation, fuel pressure controllability deteriorates due to the fuel pressure dropping once due to the failure to close the valve, and feedback control. In addition, since the valve is closed or not closed depending on the cycle, problems such as deterioration of NV due to intermittent noise occur.

Therefore, in order to solve the above problems, the method of realizing noise reduction of the solenoid valve by current feedback control without failing to close the valve will be explained below.

FIG. 11 is a flow chart of solenoid valve control in the high-pressure fuel pump according to the first embodiment.

The flow is the same as the electromagnetic valve control based on FIG. be. On the other hand, in the electromagnetic valve control according to the present embodiment, instead of the valve closing success/failure determination (step S103) shown in FIG. In the valve closing success/failure determination for the next cycle (step S1203), it is determined whether the solenoid valve has closed in the next cycle based on the fuel pressure change in the rail caused by the current discharge operation and the discharge operation one cycle or more before the current discharge operation. do.

When it is determined in step S1203 that the valve will be closed successfully in the next cycle (YES in step S1203), the solenoid valve control device 109 determines that the current set value of current has a margin. Then, the solenoid valve control device 109 corrects the current set value to a value lower than the current set value (step S1204). The current set value here is not limited to the maximum current value Im of the peak current and the maximum current value Ik of the holding current shown in FIG. After that, the solenoid valve control device 109 acquires fuel pressure data again. That is, the electromagnetic valve control device 109 returns the processing to step S1201.

On the other hand, when it is determined in step S1203 that the valve closing in the next cycle fails (determined as NO in step S1203), the solenoid valve control device 109 sets the current set value to a value lower than the current set value sufficiently low. , it is determined that the solenoid valve fails to close. Then, the solenoid valve control device 109 determines that the current set value of current is the minimum required current value, and terminates the control.

Next, the method for judging success or failure of valve closing in the next cycle described in step S1203 of FIG. 11 will be described. FIG. 12, for example, shows a method for judging success or failure of closing the solenoid valve in the next cycle. This is done by calculating the slope of the peak value of fuel pressure change based on the peak value of fuel pressure change for each discharge operation (cycle) from the start of control to the present, and calculating the peak value of fuel pressure change for the next cycle based on the slope. By estimating , it is predicted whether or not the solenoid valve will succeed in closing. As shown in FIG. 12, immediately after the start of the noise reduction control, even if the current setting value is lowered, the fuel pressure variation peak value does not change. The fuel pressure variation peak value becomes smaller after the cycle in which the value 1301 is measured. After that, when the fuel pressure variation peak value falls below a certain threshold value 1303, the solenoid valve fails to close. Here, for example, the slope 1304 is calculated from two points, the current value and the previous value, and the next value 1302 is estimated from the current value and the slope 1304 . By comparing the next value 1302 and a threshold value 1303, it is possible to determine whether or not the electromagnetic valve is closed successfully in the next cycle based on whether or not the threshold value 1302 is exceeded. Here, in this example, the slope is calculated using the current value and the previous value, but the previous value may be used. Alternatively, the slope may be calculated using values of two or more points. However, as the number of points used to calculate the inclination increases, the control becomes more complicated. Therefore, it is necessary to check the actual data of the common rail pressure and determine the method of calculating the inclination based on the required accuracy. The start point of this control may be the engine start timing, or may be specifically limited to a region where this noise reduction control is required. Moreover, it may be performed after the scene determination, the fuel injection effect determination, and the like described in the second embodiment are established.

The method of calculating the slope based on the fuel pressure change amount peak value for each discharge operation from the start of control to the present has been described with reference to FIG. is insufficient to calculate the slope. Therefore, in FIG. 13, a method of calculating the slope based on the fuel pressure change amount peak value for each discharge operation from the start of control to the present and a fuel pressure change amount peak value set in advance will be described. Reference numeral 1401 indicates the control start timing. With the method shown in FIG. 12, the slope cannot be calculated at 1402, which is the calculation timing of the first fuel pressure variation peak value. On the other hand, as shown in FIG. 13, by setting a value (1403) in advance as a value before the start of control, it is possible to calculate the slope immediately after the start of control. It becomes possible to determine whether or not the solenoid valve is closed. It is preferable that the preset value (1403) is adapted in advance from the operating range, the number of rotations, the discharge amount, and the like. If it is difficult to match, mask one cycle or several cycles from the start of control, and only calculate the fuel pressure peak value. Also good.

Next, the threshold value for judging whether the solenoid valve is closed will be explained. As shown in FIG. 14, the threshold value (1501) is obtained from the sum of the maximum value (1502) of variation in the fuel pressure pulsation peak value when there is no pump discharge and the maximum value (1503) of the valve closing success/failure determination error in the next cycle. should be set large. Also, these values must include the measurement error of the sensor. By setting such a value, it is possible to prevent the erroneous determination that the solenoid valve has closed successfully despite the fact that the valve has failed to close, even if there is variation. Note that the threshold value may be the maximum value of variation in consideration of all operating conditions, or may be variable according to the operating condition of the internal combustion engine system.

Next, the relationship between fuel pressure feedback control and solenoid valve noise reduction control according to the present invention will be described using FIG. First, by decreasing the current set value by the noise reduction control, the fuel pressure change amount peak value (1602) decreases with 1601 as a boundary. At that time, the fuel pressure in the common rail decreases, and if it falls below the fuel pressure target value by a predetermined value or more, fuel pressure feedback control advances the current application timing of the high-pressure fuel pump to increase the discharge amount. is executed. As a result, the fuel pressure variation peak value (1603) may increase even though the current set value is reduced by the noise reduction control. However, even if such a state occurs once, if the current setting value is further decreased in the next cycle and thereafter, the fuel pressure variation peak value (1604) will begin to decrease again. It is possible to determine whether or not the solenoid valve is closed in the next cycle based on the noise reduction control flow. However, it is necessary to consider the influence of the fuel pressure feedback control on the method of calculating the slope of the fuel pressure variation peak value and the method of setting the current value correction amount, which will be described later. As described above, even in a scene where fuel pressure feedback control is performed, the noise reduction control according to the present invention acts effectively. It is preferable to apply it in a scene where the difference is within a certain range.

Alternatively, as shown in FIG. 16, there is a method of setting a threshold value so that the noise reduction control can be completed in a region where the feedback of the fuel pressure feedback control is not executed. For example, a decrease in the fuel pressure variation peak value is synonymous with a decrease in the discharge amount, and a decrease in the discharge amount means a decrease in the pressure in the rail. Therefore, for example, in order to prevent the fuel pressure feedback control from being executed, the fuel pressure change amount peak value immediately after the start of the control is set to a value in the area (1701) where there is almost no fluctuation, and within a predetermined value (1702) in a smaller direction from there. A threshold value (1703) is provided for determining whether the solenoid valve is closed in the next cycle. Here, the predetermined value is set to a value within a certain range of the difference between the actual fuel pressure and the target fuel pressure so that the feedback of the fuel pressure feedback control is not executed. By setting such a value, it becomes possible to complete the noise reduction control in a region where the feedback of the fuel pressure feedback control is not executed. In this example, it is shown in the form of a threshold value, but for example, it is also possible to add to the control flow of FIG. effect can be expected.

Next, a method for setting the correction amount for the current set value when the result of the success/failure determination for closing the solenoid valve in the next cycle is YES will be described.

In FIG. 17, the correction amount of the current set value is increased based on the slope of the fuel pressure change peak value for each discharge operation, and is increased when the absolute value of the slope of the fuel pressure change peak value is less than or equal to a predetermined value. Shows how to reduce the amount of correction when it exceeds the value. As shown in FIG. 17, the fuel pressure variation peak value does not change significantly from the start of control to the timing of 1801, so the slope does not change significantly either. After that, when the current set value is further decreased, the fuel pressure variation peak value begins to decrease at the timing of 1802, and along with this, the absolute value of the slope also begins to increase. Since the slope exceeds the first predetermined value 1804 at timing 1802, the correction amount of the drive current set value is reduced. At timing 1803, the fuel pressure variation peak value continues to decrease and exceeds the second predetermined value 1805, so it can be seen that the current set value correction amount is further reduced. By gradually decreasing the correction amount of the current set value in this way, it is possible to prevent an erroneous determination that the valve will actually fail even though it is determined that the valve will be closed successfully in the next cycle by decreasing the current too much at once. It is possible to avoid. Further, by making the resolution of the correction amount finer in this way, it is possible to bring it closer to the minimum necessary current value necessary for closing the solenoid valve. In FIG. 17, the slope is treated as a positive absolute value, but it is treated as a negative value. may calculate a larger correction amount.

Next, based on the fuel pressure change peak value for each discharge operation, the correction amount of the current set value is increased when the fuel pressure change peak value is greater than or equal to a predetermined value, and is decreased when less than or equal to the predetermined value. A method for calculating the amount is shown in FIG. As shown in FIG. 18, from the start of control to the timing of 1901, there is no significant change in the fuel pressure change amount peak value, and the correction amount of the drive current set value also does not change. After that, when the current set value is further decreased, the fuel pressure variation peak value begins to decrease at the timing of 1902 and falls below the predetermined value 1903, so the correction amount of the drive current set value is decreased. Even when the current correction amount is set based on the fuel pressure variation peak value in this way, it is possible to obtain the same effect as in the case described with reference to FIG.

Furthermore, a method for reducing the current correction amount according to the drive current value will be described. As shown in FIG. 19, the control is started, and the drive current setting value is decreased each time the valve closing success determination is made. As the drive current value decreases, the current value correction amount also decreases. . By doing so, it is possible to correct the current value with higher resolution as the required minimum current value is approached. As indicated by 2001, it is desirable to preset a minimum current value defined by the hardware and set the correction amount of the current value so as to asymptotically approach that value. Here, the control may be terminated when the minimum current value is sufficiently asymptotic and the correction amount becomes approximately zero.

Also, a method of setting the correction amount based on the number of times of learning (the number of discharge operations from the start of control of the high-pressure fuel pump 125) obtained by adaptation in advance will be described. As shown in FIG. 20, in this method, from the timing of control start 2101, the current set value is reduced according to the preset correction amount (2102, 2103, 2104, 2105) according to the number of times of learning. . It is preferable to set the correction amount by adaptation or the like. By setting a constant in advance, there is no need to calculate the main correction amount each time within the control cycle, so it is possible to reduce the calculation load. Also, the control configuration can be made simple. In this example, the current set value is reduced for each discharge operation of the high-pressure fuel pump 125, and the number of times of learning is set to the number of discharge operations from the start of control of the high-pressure fuel pump 125. However, the current set value does not need to be reduced for each ejection operation, and the number of times of learning may be the number of times of correcting the current set value.

Next, in FIG. 11, the control flow for judging whether the solenoid valve is closed in the next cycle has been described, but this control can also be applied to the discharge amount judgment in the next cycle. FIG. 21 shows a flow chart when the electromagnetic valve control according to this embodiment is applied to the discharge amount determination for the next cycle. The contents from the start of control to acquisition of rail pressure (step S2201) and filter processing (step S2202) are the same as those described in FIG. On the other hand, in FIG. 11, the next item is the valve closing success/failure determination for the next cycle (step S1203), whereas in FIG. It is characterized in that the judgment is made based on whether or not the required flow rate is discharged in the next cycle, not whether the valve is closed in the next cycle. Regarding the method of determining whether or not the flow rate is being discharged, since it is synonymous that the discharge amount decreases when the fuel pressure change amount peak value decreases, the concept of the threshold setting method (1502 + 1503 ), the necessary discharge amount is further added to set a threshold value, and the threshold value is compared with the fuel pressure variation peak value. As for other controls, the same concept as that for determining whether the valve is closed in the next cycle can be applied.

As described above, the control of the solenoid valve described above determines whether the solenoid valve is closed in the next cycle and corrects the current setting value, so that the valve is controlled to the minimum required current value without failing to close the valve even once. Is possible. Therefore, by adopting this solenoid valve, even if it is used for on-line control while the vehicle is running, the fuel pressure controllability deteriorates due to the fuel pressure dropping once due to a valve closing failure, and the responsiveness of the feedback control deteriorates. cannot occur. In addition, intermittent noise due to the valve closing and not closing depending on the cycle is not generated.

In addition, when the present invention is applied to the engine control of a hybrid (series hybrid) vehicle whose engine is dedicated to power generation, there are many scenes in which the engine is operated in a steady state. It is possible to further reduce the drive current value.

(summary)
In this embodiment, a plunger 302 that moves up and down as the pump drive cam rotates to increase or decrease the volume of the pressurizing chamber 311 , an electromagnetic valve 300 for sucking fuel into the pressurizing chamber 311 , and a pressurizing chamber 311 . A solenoid valve control for controlling the opening and closing of the solenoid valve 300 in an internal combustion engine system comprising a fuel pump 125 having a discharge valve 310 for discharging fuel and a fuel rail 129 storing the fuel discharged by the fuel pump 125 In the device 109, the solenoid valve is closed in the next discharge operation of the fuel pump 125 based on the change in the fuel pressure in the fuel rail 129 caused by the current discharge operation of the fuel pump 125 and the discharge operation one cycle or more before the current discharge operation. Judge success or failure.

According to the present embodiment constructed as described above, when the determination result of the closing success or failure of the solenoid valve 300 in the next discharge operation of the fuel pump 125 is positive, the current set value of the solenoid valve 300 is decreased, and the determination result is If not, by maintaining the current set value at that point in time, it becomes possible to realize the noise reduction of the solenoid valve 300 without failing to close the solenoid valve 300 .

Further, the solenoid valve control device 109 according to the present embodiment calculates the slope of the fuel pressure change amount peak value based on the fuel pressure change amount peak value for each discharge operation of the fuel pump 125 from the start of control to the present, An estimated fuel pressure change amount peak value, which is an estimated value of the fuel pressure change amount peak value in the next discharge operation, is calculated based on the fuel pressure change amount peak value in the current discharge operation and the slope, and the estimated fuel pressure change amount peak value and the threshold value are calculated. By comparing, it is determined whether or not the solenoid valve 300 is closed in the next discharge operation. As a result, it is possible to improve the accuracy of determining whether the solenoid valve 300 has been successfully closed.

Further, the electromagnetic valve control device 109 according to the present embodiment operates on the basis of the fuel pressure change amount peak value for each discharge operation of the fuel pump 125 from the start of control to the present and the fuel pressure change amount peak value set in advance. calculating the slope of the fuel pressure variation peak value, calculating an estimated fuel pressure variation peak value, which is an estimated value of the fuel pressure variation peak value in the next ejection operation, based on the fuel pressure variation peak value in the current ejection operation and the slope; By comparing the estimated fuel pressure variation peak value with a threshold value, it is determined whether or not the electromagnetic valve 300 has been successfully closed in the next discharge operation. This makes it possible to calculate the slope of the fuel pressure variation peak value immediately after the start of control. As a result, it is possible to determine whether or not the solenoid valve 300 is closed in the next cycle immediately after the start of control.

Further, the solenoid valve control device 109 according to the present embodiment calculates the threshold value based on the lower limit value that does not erroneously determine whether the solenoid valve 300 is closed or not, and the fuel pressure change amount corresponding to the required discharge amount of the fuel pump 125. do. This makes it possible to maintain the required discharge amount of the fuel pump 125 .

Also, the solenoid valve control device 109 according to this embodiment changes the threshold according to the operating state of the internal combustion engine system. As a result, regardless of the operating state of the internal combustion engine system, it is possible to maintain the accuracy of determining whether or not the solenoid valve 300 has been closed.

In addition, the solenoid valve control device 109 according to the present embodiment corrects the current set value of the solenoid valve 300 according to the determination result of whether or not the solenoid valve 300 is closed in the next discharge operation of the fuel pump 125 . As a result, in the next discharge operation of the fuel pump 125, the solenoid valve 300 does not fail to close and the noise of the solenoid valve 300 can be reduced.

Further, when the solenoid valve control device 109 according to the present embodiment determines that the closing of the solenoid valve 300 in the next discharge operation of the fuel pump 125 is successful, the solenoid valve control device 109 calculates a predetermined correction amount from the current setting value of the solenoid valve 300. Subtract. This makes it possible to suppress collision noise when the solenoid valve 300 is closed.

Further, the solenoid valve control device 109 according to the present embodiment operates based on at least one of the fuel pressure variation peak value for each discharge operation of the fuel pump 125, the current set value of the solenoid valve 300, and the number of discharge operations of the fuel pump 125. to calculate the amount of correction for the current set value. This makes it possible to reduce the drive current of the solenoid valve 300 while preventing the solenoid valve 300 from failing to close in the next discharge operation.

Further, the solenoid valve control device 109 according to the present embodiment controls the slope of the fuel pressure change amount peak value for each discharge operation of the fuel pump 125, the fuel pressure change amount peak value for each discharge operation of the fuel pump 125, and the current of the solenoid valve 300. A correction amount of the current setting value is calculated according to a comparison result between at least one of the setting values and a preset threshold value. This makes it possible to reduce the drive current of the solenoid valve 300 while preventing the solenoid valve 300 from failing to close in the next discharge operation.

Further, the solenoid valve control device 109 according to the present embodiment corrects the current set value of the solenoid valve 300 when the absolute value of the slope of the fuel pressure variation peak value for each discharge operation of the fuel pump 125 is equal to or less than a predetermined value. When it exceeds the predetermined value, the correction amount is decreased. As a result, it is possible to avoid an erroneous determination that the valve closing is actually unsuccessful in spite of the determination that the valve will be closed successfully in the next cycle. Further, by making the resolution of the correction amount finer in this way, it is possible to bring the value closer to the minimum required current value required for closing the solenoid valve 300 .

Further, the solenoid valve control device 109 according to the present embodiment increases the correction amount of the current set value of the solenoid valve 300 when the fuel pressure change amount peak value for each discharge operation of the fuel pump 125 is equal to or greater than a predetermined value. If the value is below the value, the correction amount is decreased. As a result, it is possible to avoid an erroneous determination that the valve closing is actually unsuccessful in spite of the determination that the valve will be closed successfully in the next cycle. Further, by making the resolution of the correction amount finer in this way, it is possible to bring the value closer to the minimum required current value required for closing the solenoid valve 300 .

Further, the solenoid valve control device 109 according to the present embodiment reduces the correction amount of the current set value as the current set value of the solenoid valve 300 becomes smaller. Accordingly, as the current set value approaches the minimum required current value, the current value can be corrected with higher resolution.

Further, the correction amount according to this embodiment is set in advance based on the number of discharge operations of the fuel pump 125 . This eliminates the need to calculate the correction amount each time within the control cycle, so it is possible to reduce the computational load. Also, the control configuration can be made simple.

Further, the solenoid valve control device 109 according to the present embodiment does not correct the current setting value of the solenoid valve 300 when it is determined that the valve closing of the fuel pump 125 during the next discharge operation is successful or not. As a result, the current set value at the time when the solenoid valve 300 was finally successfully closed is maintained, so that it is possible to prevent the solenoid valve 300 from failing to close.

A solenoid valve control device 109 according to a second embodiment of the present invention will be described. A solenoid valve control device 109 according to the second embodiment of the present invention has the same configuration as the solenoid valve control device 109 according to the first embodiment described above. The electromagnetic valve control device 109 according to the second embodiment differs from the electromagnetic valve control device 109 according to the first embodiment in the control of the electromagnetic intake valve 300 . Therefore, the control of the electromagnetic intake valve 300 according to the second embodiment will be described here, and the description of the common configuration of the electromagnetic valve control device 109, the high-pressure fuel pump 125, the electromagnetic intake valve 300, etc. will be omitted.
[Control of electromagnetic intake valve]
Control processing of the electromagnetic intake valve 300 according to the second embodiment will be described with reference to FIG. 22 .

FIG. 22 is a flow chart of solenoid valve control according to the second embodiment.

First, the electromagnetic valve control device 109 performs scene determination (step S2301). In this process, it is determined from the driving scene whether or not to continue the feedback control (the process of feeding back the success or failure of closing of the electromagnetic intake valve to the drive current value). It is difficult to perform this feedback control in all driving scenes. For example, during transient operation, the required fuel pressure and the required discharge amount change from moment to moment, increasing disturbance. Therefore, it is desirable not to perform this feedback control during transient operation because there is a possibility that appropriate feedback will not be performed.

Specific scenes in which this feedback control is performed include during engine shipping tests, during maintenance, during no-load operation, or during steady-state operation. When this feedback control is performed at the time of the engine shipping test, it is possible to reduce the noise of the solenoid valve 300 initially (before reaching the user). When this feedback control is performed during maintenance, it is possible to adjust the current value again, assuming that the required current value has changed due to durability deterioration of the pump or the like. If this feedback control is performed during no-load operation (idling operation) or steady operation, noise during idling operation can be reduced. In addition, the current value can be fed back online.

If it is determined in step S2301 that the scene is not for feedback control (NO determination in step S2301), the solenoid valve control device 109 ends the control. As a result, this feedback control is not performed. On the other hand, when it is determined in step S2301 that it is the scene in which the feedback control is to be performed (YES in step S2301), the solenoid valve control device 109 determines the injection influence of the fuel injection valve 105. (Step S2302).

The discharge of fuel by the high-pressure fuel pump 125 and the fuel injection by the fuel injection valve 105 are large factors affecting the fuel pressure of the common rail 129 . Therefore, attention must be paid to this feedback control in a scene where the two overlap.

FIG. 23 is a diagram showing the relationship between the fuel discharge of the high-pressure fuel pump 125, the fuel injection of the fuel injection valve 105, the fuel pressure of the common rail 129, and the fuel pressure after filtering according to the second embodiment of the present invention. As shown in FIG. 23, when the fuel discharge 2402 of the high-pressure fuel pump 125 and the fuel injection 2403 of the fuel injection valve 105 are at the same timing, the increase in the fuel pressure due to the fuel discharge 2402 of the high-pressure fuel pump 125 is the fuel injection. It is canceled by the fuel pressure drop due to the fuel injection 2403 of the valve 105 . As a result, the fuel pressure 2404 in the common rail 129 does not change, making it impossible to detect closing of the electromagnetic intake valve 300 from pressure fluctuations. In this case, the electromagnetic valve control device 109 determines that the fuel injection 2403 by the fuel injection valve 105 affects this feedback control.

Since the fuel pressure 2404 in the common rail 129 has pulsation, a scene in which the timings of fuel discharge 2402 and fuel injection 2403 completely overlap as shown in FIG. 23 is not actually assumed. However, in a scene where ejection and injection overlap even a little, the applicability of this feedback control is examined by checking the actual pressure behavior and taking into consideration the settings of the threshold value, the detection window, and the like. The region in which the high-pressure fuel pump 125 can discharge fuel is only the range in which the plunger 302 is raised (from the bottom dead center of the cam to the top dead center). Therefore, if the fuel injection pulse overlaps even a little with the range in which the plunger 302 is raised, it may be determined that the fuel injection by the fuel injection valve 105 affects this feedback control.

If it is determined in step S2302 that the fuel injection by the fuel injection valve 105 affects this feedback control (YES in step S2302), the solenoid valve control device 109 ends the control. As a result, this feedback control is not performed.

On the other hand, if it is determined in step S2302 that the fuel injection by the fuel injection valve 105 does not affect the feedback control (YES in step S2302), the solenoid valve control device 109 performs steps S2303 to S2306. The processing of steps S2303-S2306 is the same as the processing of steps S1201-S1204 or steps S2201-S2204 of the electromagnetic valve control according to the first embodiment. Therefore, description of these processes is omitted here.

Also in the solenoid valve control according to the second embodiment, the above-described control of the solenoid valve 300 determines whether or not the solenoid valve is closed in the next cycle, and corrects the current set value. It is possible to control to the minimum required current value without failure. Therefore, by adopting this solenoid valve control, even if it is used as online control while the vehicle is in operation, the fuel pressure controllability deteriorates due to the fuel pressure dropping once due to a failure to close the valve, and the responsiveness of the feedback control. No deterioration can occur. In addition, intermittent noise due to the valve closing and not closing depending on the cycle is not generated.

Next, an electromagnetic valve control device 109 according to a third embodiment of the invention will be described. The electromagnetic valve control device 109 according to the third embodiment of the present invention has the same configuration as the electromagnetic valve control device 109 according to the first embodiment described above. The solenoid valve control device 109 according to the third embodiment differs from the solenoid valve control device 109 according to the first embodiment in that the solenoid valve control described in the first or second embodiment is applied to the fuel injection valve 105 applied to Here, the control of the fuel injection valve 105 according to the third embodiment will be explained, and the explanation of the common configuration of the solenoid valve control device 109, the fuel injection valve 105, etc. will be omitted.
[Control of fuel injection valve]
A control process for the fuel injection valve 105 according to the third embodiment will be described with reference to FIG.

FIG. 24 is a flow chart of solenoid valve control according to the third embodiment.

When the electromagnetic intake valve 300 of the high-pressure fuel pump 125 is successfully closed, the fuel pressure within the common rail 129 rises. On the other hand, when the fuel injection valve 105 is successfully opened, the fuel pressure in the common rail 129 drops. As described above, the electromagnetic intake valve 300 of the high-pressure fuel pump 125 and the fuel injection valve 105 are in a reverse relationship, so that part of the electromagnetic valve control is different.

First, the solenoid valve control device 109 performs scene determination (step S2501). In this process, it is determined from the driving scene whether or not to continue the feedback control (the process of feeding back the success or failure of opening of the fuel injection valve 105 to the driving current value). The driving scene is the same as in the second embodiment described above.

If it is determined in step S2501 that it is not the scene for performing this feedback control (NO in step S2501), the solenoid valve control device 109 ends the control. As a result, this feedback control is not performed. On the other hand, if it is determined in step S2501 that the current feedback control is to be performed (YES in step S2501), the electromagnetic valve control device 109 determines the influence of discharge of the high-pressure fuel pump 125 (step S2502).

As described above, when the fuel discharge from the high-pressure fuel pump 125 and the fuel injection from the fuel injection valve 105 are at the same timing, the increase in the fuel pressure due to the fuel discharge from the high-pressure fuel pump 125 is the same as the fuel injection from the fuel injection valve 105. is canceled by the fuel pressure drop due to As a result, the fuel pressure in the common rail 129 does not change, making it impossible to detect the opening of the fuel injection valve 105 from the pressure fluctuation. In this case, the solenoid valve control device 109 determines that fuel discharge by the high-pressure fuel pump 125 affects this feedback control. For example, if the fuel injection pulse overlaps the range from the cam top dead center to the bottom dead center even a little, it may be determined that fuel discharge by the high-pressure fuel pump 125 affects this feedback control.

If it is determined in step S2502 that fuel discharge by the high-pressure fuel pump 125 affects this feedback control (YES in step S2502), the solenoid valve control device 109 ends the control. As a result, this feedback control is not performed.

On the other hand, if it is determined in step S2502 that fuel discharge by the high-pressure fuel pump 125 does not affect the feedback control (YES in step S2502), the solenoid valve control device 109 performs steps S2503 and S2504. The processing of steps S2503 and S2504 is the same as the processing of steps S1201-S1202 or steps S2201-S2202 of the solenoid valve control according to the first embodiment. Therefore, the description of the processing in steps S2503 and S2504 is omitted here.

After the process of step S2504, the solenoid valve control device 109 compares the filtered pressure data with a preset threshold value to determine whether the fuel injection valve 105 is successfully opened in the next cycle (step S2505). ). If the fuel injection valve 105 succeeds in opening in the next cycle, the fuel pressure in the common rail 129 drops. Therefore, the threshold is set to a negative value, and it is determined that the valve has been successfully opened when the filtered fuel pressure is less than the threshold. Further, when the filtered fuel pressure data is equal to or greater than the threshold value, it is determined that the valve opening has failed.

When it is determined in step S2505 that the valve will be successfully opened in the next cycle (YES in step S2505), the solenoid valve control device 109 determines that the current set value of current has a margin. Then, the solenoid valve control device 109 corrects the current set value to a value lower than the current set value (step S2506). After that, the solenoid valve control device 109 acquires fuel pressure data again. That is, the solenoid valve control device 109 returns the processing to step S2503.

On the other hand, if it is determined in step S2505 that the valve opening will fail in the next cycle (NO determination in step S2505), the solenoid valve control device 109 may fail to open the valve if the current set value is lowered. judge there is. Then, the electromagnetic valve control device 109 holds the current set value as the current set value. After that, the solenoid valve control device 109 determines that the current set value of current is the minimum required current value, and ends the control.

In the above example, step S2505 describes the case where it is determined whether or not the valve has been successfully opened in the next cycle. Conversion from injection flow rate to pressure fluctuation can be calculated from pressure, volume, fuel physical properties, etc. using the formula of compressible fluid. Conversely, it is also possible to calculate the injection flow rate of the fuel injection valve from the amount of change in the measurement signal (pressure data after differential filtering). In the processing of step S2505, the injection flow rate of the fuel injection valve may be calculated, and it may be determined from the calculated injection flow rate whether the current set value should be corrected to a lower value or a higher value. For example, when the calculated injection flow rate of the fuel injection valve is less than a predetermined specific value, the determination (YES determination) is the same as when the valve is successfully opened in the next cycle. On the other hand, when the calculated injection flow rate of the fuel injection valve is equal to or greater than the specific value, the determination (NO determination) is the same as when the valve opening fails in the next cycle.

Also in the electromagnetic valve control according to the third embodiment, the above-described control of the electromagnetic valve determines whether the opening of the electromagnetic valve in the next cycle is successful or not, and corrects the current set value, so the valve opening fails even once. It is possible to control to the minimum required current value without any need. Therefore, by adopting this solenoid valve, even if it is used for on-line control while the vehicle is running, fuel pressure controllability deteriorates due to the fuel pressure rising once due to valve opening failure, and feedback control responsiveness deteriorates. cannot occur. In addition, intermittent noise due to the valve opening and non-opening depending on the cycle does not occur.

(summary)
In this embodiment, a plunger 302 that moves up and down as the pump drive cam rotates to increase or decrease the volume of the pressurizing chamber 311 , an electromagnetic valve for sucking fuel into the pressurizing chamber 311 , A fuel pump 125 having a discharge valve 310 for discharging fuel, a fuel rail 129 for accumulating the fuel discharged by the fuel pump 125, and a fuel rail 129 arranged downstream of the fuel rail 129 to supply fuel to the combustion chamber of the engine. In the electromagnetic valve control device 109 that controls the opening and closing of the fuel injection valve 105 in an internal combustion engine system including a fuel injection valve that injects, the current injection operation of the fuel pump 125 and the injection operation one cycle or more before the current injection operation. Based on the fuel pressure change in the fuel rail 129, it is determined whether or not the fuel injection valve 105 has opened in the next injection operation.

According to the present embodiment configured as described above, when the determination result of the valve opening success or failure of the fuel injection valve 105 in the next injection operation of the fuel injection valve 105 is positive, the current setting value of the fuel injection valve 105 is decreased, If the determination result is negative, the current set value at that time is maintained, so that the fuel injection valve 105 does not fail to open and the noise of the fuel injection valve 105 can be reduced.

(others)
The embodiment of the electromagnetic valve control device of the present invention has been described above, including its effects. However, the solenoid valve control device of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the invention described in the claims.

In addition, the above-described embodiments have been described in detail for easy-to-understand description of the present invention, and are not necessarily limited to those having all the described configurations. In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

For example, in the above-described embodiments (Embodiments 1 and 2), the solenoid valve is such that the valve body is open when no current is applied to the solenoid, and the valve body is closed when current is applied to the solenoid. Applied to normally open solenoid valves. However, the electronic valve control device according to the present invention is applied to a normally closed solenoid valve in which the valve body is opened when current is passed through the solenoid, and the valve body is closed when current is not passed through the solenoid. may

DESCRIPTION OF SYMBOLS 101... Internal combustion engine 102... Piston 103... Intake valve 104... Exhaust valve 105... Fuel injection valve 106... Ignition plug 107... Ignition coil 108... Water temperature sensor 109... Electromagnetic valve control device 110... Intake Pipe 111 Exhaust pipe 112 Three-way catalyst 113 Oxygen sensor 115 Collector 116 Crank angle sensor 119 Throttle valve 120 Air flow meter 121 Combustion chamber 122 Accelerator opening sensor , 123 fuel tank 124 low pressure fuel pump 125 high pressure fuel pump 126 fuel pressure sensor 128 exhaust cam 129 common rail (fuel rail) 131 crankshaft 132 connecting rod 152 pressure regulator , 201 Sensors 202 Input signal 203 Input circuit 204 A/D converter 205 CPU 206 Signal line 210 Output circuit 211 Control signal 212 Actuators 220 Microcomputer 300 Electromagnetic intake valve (solenoid valve) 301 Pump drive cam 302 Plunger 303 Valve element 303a Contact piece 304 Anchor 305 Solenoid 306 Fixed part 307 Seat part , 308... Stopper 309... First spring 310... Discharge valve 311... Pressure chamber 315... Second spring 321... Communication port 322... Outflow port 323... Casing 325... Inflow port 326... Spring Part, 355... Relief valve.

Claims

a plunger that moves up and down as the pump drive cam rotates to increase or decrease the volume of the pressurizing chamber;
a solenoid valve for sucking fuel into the pressurized chamber;
a fuel pump having a discharge valve for discharging fuel from the pressurizing chamber;
A solenoid valve control device for controlling opening and closing of the solenoid valve in an internal combustion engine system comprising a fuel rail for accumulating fuel discharged by the fuel pump,
Determines whether the solenoid valve is closed in the next discharge operation of the fuel pump based on the fuel pressure change in the fuel rail caused by the current discharge operation of the fuel pump and the discharge operation one cycle or more before the current discharge operation. A solenoid valve control device characterized by:
In the solenoid valve control device according to claim 1,
calculating a slope of the fuel pressure change amount peak value based on the fuel pressure change amount peak value for each discharge operation of the fuel pump from the start of control to the present,
calculating an estimated fuel pressure change amount peak value, which is an estimated value of the fuel pressure change amount peak value in the next discharge operation, based on the fuel pressure change amount peak value in the current discharge operation and the slope;
A solenoid valve control device that determines whether or not the solenoid valve is closed successfully in the next discharge operation by comparing the estimated fuel pressure variation peak value with a threshold value.
In the electromagnetic valve control device according to claim 2,
calculating a slope of the fuel pressure change amount peak value based on the fuel pressure change amount peak value for each discharge operation of the fuel pump from the start of control to the present and a preset fuel pressure change amount peak value;
calculating an estimated fuel pressure change amount peak value, which is an estimated value of the fuel pressure change amount peak value in the next discharge operation, based on the fuel pressure change amount peak value in the current discharge operation and the slope;
A solenoid valve control device that determines whether or not the solenoid valve is closed in the next discharge operation by comparing the estimated fuel pressure variation peak value with the threshold value.
In the solenoid valve control device according to claim 2 or 3,
The electromagnetic valve control device, wherein the threshold value is calculated based on a lower limit value that does not erroneously determine whether the electromagnetic valve is closed or not, and a fuel pressure change amount corresponding to a required discharge amount of the fuel pump.
In the solenoid valve control device according to claim 2 or 3,
An electromagnetic valve control device, wherein the threshold value is changed according to the operating state of the internal combustion engine system.
In the solenoid valve control device according to any one of claims 1 to 3,
A solenoid valve control device, wherein a current set value of the solenoid valve is corrected according to a determination result of success or failure of closing of the solenoid valve in the next discharge operation of the fuel pump.
In the solenoid valve control device according to claim 6,
A solenoid valve control device, wherein a predetermined correction amount is subtracted from the current set value when it is determined that the solenoid valve has closed successfully in the next discharge operation of the fuel pump.
In the solenoid valve control device according to claim 7,
The solenoid valve control device, wherein the correction amount is calculated based on at least one of a fuel pressure variation peak value for each discharge operation of the fuel pump, the current set value, and the number of learning times of the fuel pump.
In the solenoid valve control device according to claim 8,
Depending on the result of comparison between at least one of the slope of the fuel pressure change amount peak value for each discharge operation of the fuel pump, the fuel pressure change amount peak value for each discharge operation of the fuel pump, and the current set value and a predetermined value An electromagnetic valve control device, wherein the correction amount is calculated.
In the solenoid valve control device according to claim 9,
The correction amount is increased when the absolute value of the slope of the fuel pressure variation peak value for each discharge operation of the fuel pump is equal to or less than the predetermined value, and is decreased when the absolute value exceeds the predetermined value. Solenoid valve control device.
In the solenoid valve control device according to claim 9,
Solenoid valve control, wherein the correction amount is increased when the fuel pressure variation peak value for each discharge operation of the fuel pump is equal to or greater than the predetermined value, and the correction amount is decreased when the peak value is less than the predetermined value. Device.
In the solenoid valve control device according to claim 9,
A solenoid valve control device, wherein the correction amount is decreased as the current set value is decreased.
In the solenoid valve control device according to claim 9,
The electromagnetic valve control device, wherein the correction amount is set in advance based on the number of learning times of the fuel pump.
In the solenoid valve control device according to claim 6,
A solenoid valve control device, wherein the current set value is not corrected when it is determined that the valve is closed successfully or not during the next discharge operation of the fuel pump.
a plunger that moves up and down as the pump drive cam rotates to increase or decrease the volume of the pressurizing chamber;
a solenoid valve for sucking fuel into the pressurized chamber;
a fuel pump having a discharge valve for discharging fuel from the pressurizing chamber;
a fuel rail for accumulating fuel discharged by the fuel pump;
An electromagnetic valve control device for controlling opening and closing of the fuel injection valve in an internal combustion engine system including a fuel injection valve arranged downstream of the fuel rail and injecting fuel into a combustion chamber of the engine,
determining whether or not the fuel injection valve is successfully opened in the next injection operation based on changes in the fuel pressure in the fuel rail caused by the current injection operation of the fuel pump and the injection operation one cycle or more before the current injection operation. A solenoid valve control device characterized by: