WO2020004673A1

WO2020004673A1 - Vehicle control device

Info

Publication number: WO2020004673A1
Application number: PCT/JP2019/026198
Authority: WO
Inventors: 優至木野村; 恵光尾関; 淳次石村
Original assignee: 株式会社アドヴィックス
Priority date: 2018-06-29
Filing date: 2019-07-01
Publication date: 2020-01-02
Also published as: JP2020001587A; JP7047635B2

Abstract

The present invention pertains to a vehicle control device which causes an electromagnetic valve 501 to be in an opened state by applying to the electromagnetic valve 501 a control current having a current value larger than a switching current value which is a current value set on the basis of the magnitude of the differential pressure between input and output ports of the electromagnetic valve 501. This vehicle control device is provided with: a control unit 11 that executes, in order to switch the electromagnetic valve 501 to the opened state from a closed state, valve-opening control for increasing the current value of the control current by a first current gradient up to a current value which is smaller than the switching current value by a first prescribed amount, and then increasing the current value of the control current by a second current gradient smaller than the first current gradient up until at least the current value of the control current exceeds the switching current value; and a setting unit 12 that sets the second current gradient to be smaller as the target change gradient of the differential pressure becomes larger.

Description

Vehicle control device

The present invention relates to a vehicle control device.

The vehicle control device is a device that controls the opening and closing of a solenoid valve provided in a hydraulic circuit of the vehicle braking device. For example, in the vehicle control device described in Japanese Patent Application Laid-Open No. 2015-199456, control is performed to reduce the gradient of the control current in order to suppress the tapping sound when the solenoid valve is opened and closed. The electromagnetic valve to be controlled is an electromagnetic valve capable of linearly controlling the fluid pressure, and a current value serving as a reference for switching between opening and closing is determined by a differential pressure between input and output ports. The solenoid valve includes a valve seat and a valve element (for example, a plunger) driven according to a control current. A state in which the valve body is seated on the valve seat is a closed state, and a state in which the valve body is separated from the valve seat is an open state.

JP-A-2015-456

Here, in the above-described vehicle control device, a tapping sound when the valve body and the valve seat come into contact is considered, but a self-excited vibration of the valve body which may occur when the solenoid valve opens is also considered. Not. Self-excited vibration of the valve element causes abnormal noise. As described above, the vehicle control device has room for improvement in terms of suppressing abnormal noise.

The present invention has been made in view of such circumstances, and has as its object to provide a vehicle control device capable of suppressing generation of abnormal noise due to self-excited vibration of a valve body of an electromagnetic valve.

A vehicle control device according to a first aspect of the present invention provides a vehicle brake including a normally closed solenoid valve provided in a hydraulic circuit for controlling a braking force applied to a vehicle and closed when power is not supplied. A current applied to the device, which is a reference current value at which the normally closed solenoid valve switches from a closed state to an open state, and a current set based on a magnitude of a differential pressure between input and output ports of the normally closed solenoid valve. A switching current value that is a value, a vehicle control device that opens the normally-closed solenoid valve by applying a control current having a larger current value to the normally-closed solenoid valve. In the opening state, the current value of the control current is increased at a first current gradient to a current value smaller by a first predetermined amount than the switching current value, and then at least A control unit that performs valve-opening control to increase the current value of the control current with a second current gradient smaller than the first current gradient until the current value of the control current becomes larger than the switching current value; A setting unit that reduces the second current gradient as the target change gradient increases.

A vehicle control device according to a second aspect of the present invention provides a vehicle brake including a normally open solenoid valve provided in a hydraulic circuit for controlling a braking force applied to a vehicle and opened when power is not supplied. A current applied to the device, which is a reference current value at which the normally open solenoid valve switches from a closed state to an open state, and a current set based on a magnitude of a differential pressure between input and output ports of the normally open solenoid valve. A switching current value that is a value, a vehicle control device that opens the normally open solenoid valve by applying a control current of a smaller current value to the normally open solenoid valve, wherein the normally open solenoid valve is closed from the closed state. In the opening state, the current value of the control current is reduced by a first current gradient to a current value larger by a first predetermined amount than the switching current value, A control unit that performs valve-opening control to reduce the current value of the control current with a second current gradient smaller than the first current gradient until the current value of the control current becomes smaller than the switching current value; A setting unit that reduces the second current gradient as the target change gradient increases.

In normal control, the change rate of the electromagnetic force applied to the valve body of the solenoid valve increases as the target change gradient of the differential pressure increases, and the acceleration of the valve body also increases. Theoretically, when the acceleration of the valve body increases, self-excited vibration is likely to occur. However, according to the present invention, in the valve opening control, the current gradient (that is, the second current gradient) when the current value of the control current crosses the switching current value decreases as the target change gradient of the differential pressure increases. Thereby, depending on the situation, it is possible to suppress an increase in the acceleration of the valve body when the valve is opened and to suppress the occurrence of self-excited vibration.

1 is a configuration diagram of a vehicle braking device according to a first embodiment. It is a conceptual diagram which shows the structure of a solenoid valve. 5 is a time chart for explaining valve opening control of the first embodiment. It is a block diagram of the vehicle braking device of 2nd Embodiment. It is a time chart for explaining valve opening control of a 2nd embodiment. It is a lineblock diagram of a vehicle control device of a third embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, portions that are the same or equivalent are denoted by the same reference numerals in the drawings. Each drawing used in the description is a conceptual diagram. For example, hatching in cross sections is omitted in FIGS. 1, 2, and 4.

<First embodiment>
As shown in FIG. 1, the vehicle control device 1 of the first embodiment includes a pressure reducing valve (“normal”) that is closed when power is not supplied to a hydraulic circuit 6 for controlling a braking force applied to a vehicle. (Corresponding to "close solenoid valve") 501, 502, 503, 504. In detail, the vehicle braking device 9 includes a cylinder mechanism 2, a reservoir 3, a stroke simulator 4, a hydraulic control mechanism 5, a hydraulic circuit 6 for connecting each member with a flow path,

wheel cylinders

71 and 72, 73 and 74 and the vehicle control device 1.

The cylinder mechanism 2 includes a master cylinder 21,

master pistons

22 and 23 that are driven according to the operation of the brake operation member 29 by the driver,

master chambers

24 and 25, and a stroke sensor 26. The

master pistons

22 and 23 define

master chambers

24 and 25 in the master cylinder 21. As the

master pistons

22, 23 advance, the fluid pressures in the master chambers 24, 25 (hereinafter, referred to as master pressures) increase. The operation amount of the brake operation member 29 (hereinafter, also referred to as a stroke) is detected by the stroke sensor 26. The

master pistons

22 and 23 are urged toward an initial position by a spring (not shown).

The reservoir 3 is a tank (at atmospheric pressure) opened to the outside air, and stores the hydraulic fluid. The reservoir 3 is connected to the master cylinder 21, the pressure reducing valves 501 to 504, and the pump 513. The flow path between the reservoir 3 and the

master chambers

24, 25 communicates when the

master pistons

22, 23 are at the initial position, and is shut off when the

master pistons

22, 23 advance by a predetermined amount.

The stroke simulator 4 is a device that applies a reaction force to the brake operation member 29. The stroke simulator 4 is connected to the master chamber 24 via a simulator cut valve 41. Note that the simulator cut valve 41 is a normally closed solenoid valve that is closed when no power is supplied, and opens when the brake operation is started.

The hydraulic pressure control mechanism 5 is a device that controls the hydraulic pressure of the wheel cylinders 71 to 74 (hereinafter, referred to as wheel pressure) based on a command from the vehicle control device 1. The hydraulic control mechanism 5 includes pressure reducing valves 501 to 504,

pressure increasing valves

505, 506, 507, 508,

master cut valves

509, 510, an accumulator 511, a motor 512, a pump 513, and pressure sensors 514 to 520. And Each part is connected by a hydraulic circuit 6. The hydraulic circuit 6 includes a plurality of flow paths through which the working fluid can flow.

(4) The pressure reducing valves 501 to 504 are normally closed type solenoid valves that are closed when power is not supplied. The pressure reducing valve 501 is provided in a flow path connecting the wheel cylinder 71 and the reservoir 3. Similarly, a pressure reducing valve 502 is provided in a flow path connecting the wheel cylinder 72 and the reservoir 3, a pressure reducing valve 503 is provided in a flow path connecting the wheel cylinder 73 and the reservoir 3, and a pressure reducing valve 504 is provided in the flow path connecting the wheel cylinder 74 and the reservoir 3. 3 is provided in the flow path connecting the first and second channels. By opening the pressure reducing valves 501 to 504, the wheel pressure can be reduced.

(4) The pressure-intensifying valves 505 to 508 are normally closed solenoid valves that are closed when power is not supplied. The pressure increasing valve 505 is provided in a flow path connecting the wheel cylinder 71 and the accumulator 511. Similarly, a pressure increasing valve 506 is provided in a flow path connecting the wheel cylinder 72 and the accumulator 511, a pressure increasing valve 507 is provided in a flow path connecting the wheel cylinder 73 and the accumulator 511, and the pressure increasing valve 508 is provided in the wheel cylinder 74 and the accumulator 511. 511 is provided in the flow path. The ports on the accumulator 511 side of the pressure increasing valves 505 to 508 are connected to each other by a flow path. The wheel pressure can be increased by opening the pressure increasing valves 505 to 508.

The master cut

valves

509 and 510 are normally open solenoid valves that are opened when power is not supplied. The master cut valve 509 is provided in a flow path that connects a port on the wheel cylinder 71 side of the pressure increasing valve 505 and the master chamber 25. The master cut valve 510 is provided in a flow path connecting the port on the wheel cylinder 74 side of the pressure increasing valve 508 and the master chamber 24. The master cut

valves

509 and 510 are valves for cutting off the supply of the master pressure to the downstream as necessary.

The accumulator 511 is a pressure accumulator that stores a high-pressure hydraulic fluid. The motor 512 is an electric motor and drives the pump 513. The pump 513 has a suction port connected to the reservoir 3 and a discharge port connected to the accumulator 511. The hydraulic pressure of the accumulator 511 (hereinafter, referred to as accumulator pressure) is maintained at a high pressure by driving the pump 513.

The pressure sensor 514 detects the hydraulic pressure (master pressure) in the master chamber 25. The pressure sensor 515 detects the hydraulic pressure (master pressure) of the master chamber 24. Pressure sensor 516 detects the accumulator pressure.

Pressure sensors

517, 518, 519, and 520 detect wheel pressures of corresponding wheel cylinders 71 to 74. Each wheel is provided with a wheel speed sensor S. The wheel pressure may be estimated (calculated) from, for example, the master pressure and the control state. In this case, the pressure sensors 517 to 520 can be omitted.

The vehicle control device 1 is an electronic control unit (ECU) including a CPU, a memory, and the like, and is a device that controls the simulator cut valve 41 and the hydraulic control mechanism 5 based on information from the various sensors described above. The vehicle control device 1 determines a target deceleration of the vehicle according to the stroke, and determines a target wheel pressure based on the target deceleration. The vehicle control device 1 controls opening and closing of each of the

solenoid valves

41, 501 to 510 and driving of the motor 512 based on the target wheel pressure. The change per unit time of the target wheel pressure becomes the target change gradient of the wheel pressure.

Here, the configuration of the pressure reducing valves 501 to 504 to be controlled by the vehicle control device 1 will be described using the pressure reducing valve 501 as an example. The pressure reducing valve 501 is not an on / off valve (binary control valve) but an electromagnetic valve that can be linearly controlled, and has a known configuration of a normally closed type. As shown in FIG. 2, the pressure reducing valve 501 includes a plunger 5011 that is a valve body (movable core) driven by application of a control current, a valve seat 5012 on which the plunger 5011 is seated in a closed state, and a valve seat 5012 And a solenoid mechanism 5014 for urging the actuator in the direction of. When a control current is applied to the solenoid unit 5014, an electromagnetic force is applied to the plunger 5011 in a direction away from the valve seat 5012 (that is, a direction against the spring force) according to the current value. When the sum of the electromagnetic force and the fluid force due to the differential pressure between the input /

output ports

501a and 501b exceeds the sum of the spring force and the friction force, the plunger 5011 is separated from the valve seat 5012, and the pressure reducing valve 501 is opened. It becomes. The current value of the control current at which the state of the pressure reducing valve 501 switches from the closed state to the open state is referred to as a “switching current value”.

The switching current value is a reference current value at which the normally closed pressure reducing valves 501 to 504 switch from a closed state to an open state, and a differential pressure between the input / output ports of the pressure reducing valves 501 to 504 (hereinafter referred to as “first pressure reducing valve”). (Referred to as "differential pressure"). The vehicle control device 1 opens the pressure reducing valve 501 by supplying a control current having a current value larger than the switching current value to the pressure reducing valves 501 to 504.

The vehicle control device 1 includes a control unit 11 and a setting unit 12 as functions when opening the pressure reducing valves 501 to 504. As shown in FIG. 3, the control unit 11 changes the normally closed pressure reducing valves 501 to 504 from the closed state to the open state with a first current gradient up to a current value smaller by a first predetermined amount than the switching current value. Valve opening control for increasing the current value of the control current and subsequently increasing the current value of the control current at a second current gradient smaller than the first current gradient until at least the current value of the control current becomes larger than the switching current value It is configured to perform.

The control unit 11 executes the current increase with the second current gradient, for example, until the current value of the control current becomes the valve-opening holding current value larger than the switching current value. The valve opening holding current value is a value that is larger by a second predetermined amount than the switching current value.

The setting unit 12 is configured to reduce the second current gradient as the target change gradient of the first differential pressure increases. In the first embodiment, the first differential pressure is the difference between the wheel pressure and the atmospheric pressure (the pressure of the reservoir 3), and has the same value as the wheel pressure in calculation. Therefore, the target change gradient of the first differential pressure is the same as the target change gradient of the wheel pressure. That is, the setting unit 12 sets the second current gradient based on the target change gradient of the wheel pressure (change gradient of the target wheel pressure). The decreasing change of the second current gradient with respect to the increase of the target changing gradient of the first differential pressure may be stepwise, linear, or quadratic. For example, the setting unit 12 sets a predetermined threshold value for the target change gradient of the first differential pressure, and when the target change gradient of the first differential pressure at the start of the valve opening control is equal to or larger than the predetermined threshold value, the second current gradient May be set to be small (see “second current gradient before change” and “second current gradient after change” in FIG. 3). A plurality of the predetermined thresholds may be set. The valve opening control can also be referred to as current gradient limiting control.

として As an example of the flow up to the execution of the valve opening control, when the driver releases the operation of the brake operation member 29, it is determined whether or not the wheel pressure is equal to or higher than a predetermined pressure. If the wheel pressure is equal to or higher than the predetermined pressure, it is determined whether or not the switching current value is larger than the current value of the control current currently applied to the pressure reducing valves 501 to 504. Then, when the switching current value is larger than the current value of the control current, the above-described valve opening control is executed.

において In the first embodiment, a situation where the target change gradient of the first differential pressure is large means a situation where the target pressure reduction gradient of the wheel pressure is large because the control target is the pressure reducing valves 501 to 504. Conventionally, in a situation where the target pressure reduction gradient is large, from the viewpoint of responsiveness, there has been a tendency to perform control to increase the control current to the pressure reduction valves 501 to 504 at once. However, as the increasing gradient of the control current increases, the increasing gradient of the electromagnetic force applied to the plunger 5011 increases, and the acceleration of the movement of the plunger 5011 increases. This is one cause of the self-excited vibration of the plunger 5011.

However, according to the first embodiment, in the valve opening control, the current gradient (that is, the second current gradient) when the current value of the control current crosses the switching current value is larger as the target change gradient of the first differential pressure is larger. Become smaller. Accordingly, it is possible to suppress an increase in the acceleration of the plunger 5011 when the valve is opened, and to suppress the occurrence of self-excited vibration depending on the situation. That is, according to the first embodiment, generation of abnormal noise due to self-excited vibration can be suppressed.

Further, in the first embodiment, the threshold value for reducing the second current gradient (the threshold value of the target change gradient) is determined in a specific situation, for example, sudden operation, ABS control (anti-skid control), ESC control (side skid prevention control), or It is set assuming a sudden pressure reduction in the automatic brake control. That is, at the time of pressure reduction in the normal operation, the second current gradient is relatively large, and the responsiveness is secured. The first predetermined amount is set to a minimum value in consideration of hardware variation and response delay. As a result, even in a specific situation, a decrease in responsiveness is minimized.

<Second embodiment>
The vehicle control device according to the second embodiment is different from the first embodiment in that the control target is a normally open solenoid valve. Hereinafter, different points will be mainly described. In the description of the second embodiment, the description of the first embodiment and the drawings can be appropriately referred to.

As shown in FIG. 4, the vehicle control device 10 of the second embodiment is a normally open type electromagnetic electromagnetic valve which is provided in a hydraulic circuit 6 for controlling a braking force applied to a vehicle and which is opened when power is not supplied. The present invention is applied to a vehicle braking device 91 having a valve (corresponding to a “normally open solenoid valve”) 81. The vehicle braking device 91 includes a cylinder mechanism 20, a reservoir 3, a stroke simulator 4, an actuator 5A, a hydraulic circuit 6 for connecting various parts with flow paths, wheel cylinders 71 to 74, a hydraulic pressure control mechanism 8, , A vehicle control device 10.

The cylinder mechanism 20 includes a master cylinder 201, an input piston 202 connected to the brake operating member 29, a master piston 203, an input chamber 204, a servo chamber 205, and a master chamber 206. The cylinder mechanism 20 has a by-wire structure in which the input piston 202 and the master piston 203 are separated from each other. When the brake operating member 29 is operated and the input piston 202 moves forward, the hydraulic fluid flows from the hydraulic pressure control mechanism 8 into the servo chamber 205 according to the stroke, and the hydraulic pressure in the servo chamber 205 (hereinafter, referred to as “servo pressure”). The master piston 203 moves forward. Then, the master pressure (the fluid pressure in the master chamber 206) increases. The master chamber 206 is connected to the

wheel cylinders

71 and 72 via the actuator 5A. The connection between the reservoir 3 and the master chamber 206 is cut off when the master piston 203 advances by a predetermined amount from the initial position. Although not shown, the stroke simulator 4 is connected to the cylinder mechanism 20 so as to generate a reaction force hydraulic pressure in a room in front of the input chamber 204 and the servo chamber 205.

The actuator 5A is a so-called ESC actuator, and is configured to be able to increase wheel pressure by a pump (not shown) and a solenoid valve (differential pressure control valve) that can be linearly controlled. However, in the second embodiment, based on a command from the vehicle control device 10, the actuator 5A does not perform the hydraulic pressure adjustment during a normal brake operation, but performs the hydraulic pressure adjustment at a specific time such as during ABS control or ESC control. .

The hydraulic control mechanism 8 includes an electromagnetic valve 81, a motor 82, and a pump 83. The solenoid valve 81 is a solenoid valve that can be linearly controlled, and has a known configuration of a normally open type. The solenoid valve 81 includes a plunger (valve element), a valve seat, a spring mechanism, and a solenoid, like the pressure reducing valves 501 to 504. That is, the electromagnetic valve 81 is an electromagnetic valve in which self-excited vibration may occur. The motor 82 is an electric motor that drives the pump 83.

The pump 83 has a suction port connected to the reservoir 3 and the output port of the solenoid valve 81, and a discharge port connected to the input port of the solenoid valve 81, the servo chamber 205, and the wheel cylinders 73 and 74 (via the actuator 5A). Pump. A part of the hydraulic circuit 6 forms an annular flow path 61 that connects the electromagnetic valve 81 and the pump 83 in an annular shape. The vehicle control device 10 normally controls the electromagnetic valve 81 and the motor 82 so that a small amount of hydraulic fluid flows through the annular flow path 61.

The vehicle control device 10 drives the pump 83 according to the target wheel pressure and adjusts the amount of restriction of the flow path by the solenoid valve 81, so that the pressure difference between the input and output ports of the solenoid valve 81 (hereinafter referred to as the “second Pressure). The hydraulic pressure at the output port side of the solenoid valve 81 is atmospheric pressure, and the change gradient of the target wheel pressure is the target change gradient of the second differential pressure. When the target wheel pressure increases, the target differential pressure increases, and the vehicle control device 10 increases the current value of the control current applied to the electromagnetic valve 81, and controls the electromagnetic valve 81 to a throttle amount corresponding to the target differential pressure. . The second differential pressure increases toward the target differential pressure by driving the pump 83 with the flow path narrowed. Then, the high-pressure hydraulic fluid is supplied to the

wheel cylinders

73 and 74 via the actuator 5A and also to the servo chamber 205. As a result, the master pressure increases, and high-pressure hydraulic fluid is also supplied to the

wheel cylinders

71 and 72 via the actuator 5A. At the time of pressure reduction, the vehicle control device 10 opens the solenoid valve 81 to reduce the second differential pressure.

When reducing the wheel pressure, the vehicle control device 10 opens the electromagnetic valve 81 by supplying a control current having a current value smaller than the switching current value to the electromagnetic valve 81. Specifically, as shown in FIG. 5, the control unit 11 of the vehicle control device 10 sets a current larger than the switching current value by a first predetermined amount when the normally open solenoid valve 81 is changed from the closed state to the open state. Value of the control current at the first current gradient until the current value of the control current decreases to at least the current value of the control current at least until the current value of the control current becomes smaller than the switching current value. It is configured to perform valve opening control for decreasing the value. As in the first embodiment, the setting unit 12 reduces the second current gradient as the target change gradient of the second differential pressure increases. Thereby, the same effect as in the first embodiment is exerted.

The vehicle braking device 91 according to the second embodiment performs control to close the electromagnetic valve 81 and stop the motor 82 in a limited state such as when the vehicle is stopped, from the viewpoint of suppressing motor operating noise and energy loss. It may be configured to be performed. In this case, the solenoid valve 81 is in the closed state and the second differential pressure is in a large state, and the possibility that self-excited vibration occurs in the plunger of the solenoid valve 81 with the opening is relatively high. Particularly in such a situation, the effect of the valve opening control is increased.

<Third embodiment>
The vehicle control device 100 of the third embodiment is applied to, for example, the vehicle braking device 9 of the first embodiment or the vehicle braking device 91 of the second embodiment, and is different from the first and second embodiments. The difference is that the temperature of the hydraulic fluid is reflected in the valve opening control. Therefore, different parts will be described. In the description of the third embodiment, the description of the first and second embodiments and the drawings can be appropriately referred to.

As shown in FIG. 6, the vehicle control device 100 includes a control unit 11, a setting unit 12, and a temperature calculation unit 13 as functions. The temperature calculation unit 13 is configured to calculate (estimate) the temperature of the working fluid filled in the hydraulic circuit 6 based on, for example, the outside air temperature and the control state. The temperature of the working fluid can be calculated by a known method. The vehicle is provided with a temperature sensor (not shown) for detecting the temperature of outside air, and the detection result can be used for temperature estimation. When a temperature sensor for directly measuring the temperature of the hydraulic fluid is provided in the hydraulic circuit 6, the temperature calculation unit 13 may calculate (determine) the temperature of the hydraulic fluid based on the detection result. Good.

The setting unit 12 sets the second current gradient according to the temperature of the working fluid filled in the hydraulic circuit 6 (calculation result of the temperature calculation unit 13). The setting unit 12 reduces the second current gradient according to the temperature of the working fluid. An example of a setting example will be described. When the working fluid becomes lower than the first predetermined temperature, bubbles (air) start to be generated in the working fluid. Here, when air bubbles collect on the spring mechanism side of the plungers of the solenoid valves (501 to 504, 81), the resistance to the movement of the plunger when the valve is opened is reduced, and the plunger is easily moved. That is, the generation of air in the working fluid tends to increase the speed of the plunger when the valve is opened, and self-excited vibration is likely to occur.

Therefore, when performing the valve opening control, the setting unit 12 of the third embodiment reduces the second current gradient as the temperature of the working fluid decreases. The change in the second current gradient may be stepwise, linear, or quadratic in relation to a change in the temperature of the working fluid. For example, when the calculation result of the temperature calculation unit 13 is lower than the first predetermined temperature, the setting unit 12 reduces the second current gradient. Thereby, the control for suppressing the self-excited vibration can be performed in a form more suited to the situation.

As yet another example, focusing on the viscosity of the hydraulic fluid, the setting unit 12 may reduce the second current gradient as the temperature of the hydraulic fluid is higher. The higher the temperature of the hydraulic fluid, the lower its viscosity, and the lower the resistance to movement of the plunger when the valve is opened. Therefore, for example, when the calculation result of the temperature calculation unit 13 is equal to or higher than the second predetermined temperature, the setting unit 12 reduces the second current gradient. This also enables control according to the situation.

Further, for example, when the temperature of the hydraulic fluid is lower than the first predetermined temperature or higher than the second predetermined temperature (first predetermined temperature <second predetermined temperature), the setting unit 12 reduces the second current gradient. May be. The setting unit 12 stores a plurality of values of the second current gradient, for example, a normal gradient, a low temperature gradient, and / or a high temperature gradient (specific gradient), and selects a gradient value according to the temperature of the hydraulic fluid. Is also good. The valve opening control of the third embodiment can be applied to a normally closed solenoid valve and a normally open solenoid valve.

Further, in the third embodiment, the setting unit 12 may be configured to reduce at least one of the first predetermined amount and the second current gradient according to the temperature of the working fluid filled in the hydraulic circuit 6. Good. For example, depending on the temperature of the hydraulic fluid, when the setting unit 12 reduces the second current gradient, when it is highly possible that the setting unit 12 reduces the second current gradient, or when the viscosity of the hydraulic fluid is extremely high, etc. By setting the first predetermined amount smaller by the setting unit 12, the responsiveness can be improved.

<Others>
The present invention is not limited to the above embodiment. For example, from the viewpoint of maintaining responsiveness, the setting unit 12 may reduce the second current gradient and also reduce the first predetermined amount. That is, the setting unit 12 may reduce the first predetermined amount as the target change gradient of the differential pressure increases. The change in the first predetermined amount may be stepwise, linear, or quadratic with respect to the change in the target change gradient. Thereby, the deterioration of the responsiveness is further suppressed.

The setting unit 12 may be configured to decrease at least one of the first predetermined amount and the second current gradient as the actual first differential pressure or the second differential pressure increases. The relationship between these changes may be stepwise, linear, or quadratic, as described above. For example, when the first differential pressure or the second differential pressure during the valve opening control is equal to or greater than a predetermined differential pressure, the setting unit 12 reduces the second current gradient. As the actual pressure difference increases, the fluid pressure pushing the plunger toward the valve opening side increases, and self-excited vibration is more likely to occur. However, according to this configuration, valve opening control according to the situation can be performed. In addition, as the first differential pressure or the second differential pressure increases, the responsiveness can be improved by reducing the first predetermined amount.

In the first to third embodiments, the control unit 11 increases the switching current value by a second predetermined amount in the case of the normally closed type in order to maintain the open state after the solenoid valve is opened. In the case of the normally open type, a control current of a value (valve-opening holding current value) smaller by a second predetermined amount is applied to the solenoid valve. Here, when the current gradient of the control current is the second current gradient in the valve opening control, and the first differential pressure or the second differential pressure is less than a predetermined value, the setting unit 12 sets the current gradient of the control current. May be configured to be larger than the second current gradient. That is, when the target differential pressure decreases due to the opening of the valve, the control unit 11 may change the control current with a current gradient larger than the second current gradient to quickly reach the valve opening holding current value. If the first pressure difference or the second pressure difference becomes smaller than a predetermined value due to the pressure reduction control, the possibility of the occurrence of self-excited vibration is almost eliminated, so that the current gradient is increased, for example, the original gradient (the first current gradient) is reduced. There is no problem to return to). However, the second current gradient may be left as it is. In particular, in a specific situation where the setting unit 12 is assumed to reduce the second current gradient, there is no problem even if the current gradient is not changed to the valve-opening holding current value. Also, the setting unit 12 may be configured to change the current gradient from the second current gradient when a predetermined amount has changed or a predetermined time has elapsed after the switching current value has been crossed.

Further, the setting unit 12 of the third embodiment does not reduce the second current gradient as the target change gradient of the differential pressure increases, but decreases the second current gradient in accordance with the temperature of the hydraulic fluid. May be done. Although not described, a check valve is appropriately disposed in the hydraulic circuit 6 such as a flow path connected to the discharge ports of the

pumps

513 and 83, for example.

Claims

Applied to a vehicle braking device having a normally closed solenoid valve that is closed when not energized provided in a hydraulic circuit for controlling a braking force applied to a vehicle,
A switching current that is a reference current value at which the normally closed solenoid valve switches from a closed state to an open state, and is a current value set based on the magnitude of a differential pressure between input and output ports of the normally closed solenoid valve. Value, a vehicle control device that opens the normally closed solenoid valve by applying a control current having a larger current value to the normally closed solenoid valve,
When the normally closed solenoid valve is changed from the closed state to the open state, the current value of the control current is increased at a first current gradient to a current value smaller than the switching current value by a first predetermined amount, and then at least the A control unit that performs valve-opening control to increase the current value of the control current with a second current gradient smaller than the first current gradient until the current value of the control current becomes larger than the switching current value;
A setting unit that reduces the second current gradient as the target change gradient of the differential pressure is greater;
A vehicle control device comprising:
The present invention is applied to a vehicle braking device having a normally open solenoid valve that is opened when power is not supplied provided to a hydraulic circuit for controlling a braking force applied to a vehicle,
A switching current that is a reference current value at which the normally open solenoid valve switches from a closed state to an open state, and is a current value set based on the magnitude of a differential pressure between input and output ports of the normally open solenoid valve. Value, a vehicle control device that opens the normally open solenoid valve by providing a control current having a smaller current value to the normally open solenoid valve,
In changing the normally open solenoid valve from the closed state to the open state, the control current is decreased at a first current gradient to a current value larger than the switching current value by a first predetermined amount, and then at least the A control unit that performs valve-opening control to reduce the current value of the control current with a second current gradient smaller than the first current gradient until the current value of the control current becomes smaller than the switching current value;
A setting unit that reduces the second current gradient as the target change gradient of the differential pressure is greater;
A vehicle control device comprising:
3. The vehicle control device according to claim 1, wherein the setting unit reduces at least one of the first predetermined amount and the second current gradient in accordance with a temperature of the hydraulic fluid filled in the hydraulic circuit. 4. .
The vehicle control device according to any one of claims 1 to 3, wherein the setting unit decreases the first predetermined amount as the target change gradient of the differential pressure increases.
The vehicle control device according to any one of claims 1 to 4, wherein the setting unit reduces at least one of the first predetermined amount and the second current gradient as the differential pressure increases.
When the differential pressure is less than a predetermined value when the current gradient of the control current is the second current gradient in the valve opening control, the setting unit sets the current gradient of the control current to the second current gradient. The vehicle control device according to any one of claims 1 to 5, wherein the vehicle control device is set to be larger than the gradient.