JP2001114085A - Hydraulic pressure control device for brake system - Google Patents

Abstract

(57) [Problem] To provide a hydraulic pressure control device for a brake system capable of reducing and preventing a liquid hammering noise and a decrease in hydraulic pressure control accuracy when an electromagnetic valve is opened. SOLUTION: A power hydraulic pressure source having a low pressure pump and a high pressure pump, an electromagnetic control valve for increasing and decreasing pressure are provided between a reservoir and a wheel cylinder, and a hydraulic pressure of a wheel cylinder is controlled by the power hydraulic pressure source and the electromagnetic control valve. Increase, decrease, and maintain.
Since the pressure-increasing electromagnetic control valve is closed when the pressure is reduced, the hydraulic fluid remains in a pressurized state between the pressure-increasing electromagnetic control valve and the power hydraulic pressure source, and a pressure difference may occur before and after the pressure-increasing electromagnetic control valve. When the pressure-increasing electromagnetic control valve is opened at the time of pressure increase, the supply current is gradually increased if the braking is not sudden and the differential pressure exceeds 0.5 MPa. Open at a lower speed to prevent the occurrence of liquid hammering noise. When the differential pressure becomes 0.5 MPa or less, the pressure-increasing electromagnetic control valve is opened at a stretch to reduce a delay in increasing the wheel cylinder fluid pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pressure control device for a brake system, and more particularly to an opening of a control valve in a hydraulic pressure control device having a control valve for permitting or shutting off communication of a liquid passage. It is.

[0002]

2. Description of the Related Art A hydraulic pressure control device for a brake system, which includes a control valve and permits or shuts off the communication of a liquid passage, includes, for example,
Although it has not been disclosed yet, Japanese Patent Application No.
0-270172. This hydraulic pressure control device includes a pump capable of controlling a discharge hydraulic pressure in response to a braking request, and a pump shutoff valve which is an electromagnetic valve provided in a liquid passage connecting the pump and a brake cylinder. The pump shutoff valve is provided for each of the plurality of brake cylinders, and is closed by supplying current and opened by shutting off current. This pump shutoff valve
It is opened when the hydraulic pressure of the brake cylinder is increased during the antilock control, and is closed when the hydraulic pressure of the brake cylinder is kept constant or reduced when the hydraulic pressure of the brake cylinder is reduced.

However, in this hydraulic pressure control device, if the hydraulic fluid remains in a pressurized state between the pump and the pump shutoff valve when the pump shutoff valve is closed, the hydraulic pressure control device is then operated to increase the pressure. When the pump shut-off valve is opened, a liquid hammering sound is generated. When the valve is opened, the pump cutoff valve is fully opened.However, since the pump cutoff valve is opened at once by supplying the current required to keep the pump cutoff valve in the fully open state, the hydraulic pressure of the pump side hydraulic fluid is reduced Acting at once, a sudden change in hydraulic pressure occurs and a liquid hammering sound is generated. Or,
When the hydraulic pressure of the hydraulic fluid on the pump side acts on the hydraulic fluid on the brake cylinder at once, pulsation occurs, and the hydraulic pressure control accuracy may be reduced.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to a hydraulic pressure control device for a brake system having a control valve, which is provided with a control valve, when the control valve is opened. An object of the present invention is to provide a hydraulic control device for a brake system in which at least one of a shooting sound and a decrease in hydraulic control accuracy is reduced or prevented. A hydraulic control device for the system is obtained. As in the case of the claims, each aspect is divided into sections, each section is numbered, and if necessary, the other sections are cited in a form in which the numbers are cited. This is for the purpose of facilitating the understanding of the present invention and should not be construed as limiting the technical features and combinations thereof described in the present specification to those described in the following sections. . Further, when a plurality of items are described in one section, the plurality of items need not always be adopted together. It is also possible to select and adopt only some of the items. (1) For a brake system including a solenoid valve provided in a liquid passage for guiding hydraulic fluid of a brake system and capable of taking a state of communicating with and shutting off the liquid passage, and a valve control device for controlling the solenoid valve A fluid pressure control device, comprising: a valve opening speed control unit that opens the solenoid valve at a smaller speed when the pressure difference before and after the solenoid valve is large. The solenoid valve may be, for example, a pressure increasing valve for increasing the hydraulic pressure of the brake cylinder or a pressure reducing valve for decreasing the hydraulic pressure of the brake cylinder. Further, the solenoid valve may be a valve that is in a communicating state by supplying current, or a valve that is in a shut-off state by supplying current. The hydraulic fluid is led to the hydraulic fluid by various members and devices constituting the brake system, such as a brake cylinder, a reservoir, and another solenoid valve. When the differential pressure before and after the solenoid valve is large, if the solenoid valve is opened at a smaller speed than when the differential pressure is small, the hydraulic pressure of the hydraulic fluid in front of the solenoid valve is higher than that of the hydraulic fluid behind the solenoid valve. The high hydraulic pressure gradually acts on the hydraulic fluid behind the solenoid valve, and the hydraulic pressure is not suddenly changed,
The liquid hammering noise is reduced or prevented from being generated. Alternatively, the pulsation of the hydraulic pressure is reduced or prevented, so that the decrease in the hydraulic control accuracy is reduced or prevented. If the valve opening speed is reduced in this way, the occurrence of a liquid hammering sound and the like can be prevented or reduced, but in some cases, a delay may occur in the hydraulic pressure control that the hydraulic pressure control device should originally perform. . Therefore, it is desirable that the valve opening speed be set in consideration of both prevention and reduction of generation of liquid hammering noise and reduction of control accuracy and prevention and reduction of control delay.
The hydraulic pressure of the hydraulic fluid on the front side of the solenoid valve decreases by acting on the hydraulic fluid on the rear side, and when the valve opening is large, the hydraulic pressure difference is small, so that liquid hammering noise and pulsation occur. Never. The features after (3) can be applied to the hydraulic control device of this section. In that case, the "pressure boosting valve" shall be read as "electromagnetic valve". The valve opening speed may be reduced stepwise according to the magnitude of the differential pressure, or may be reduced steplessly. In the latter case, the size may be reduced linearly, may be reduced in a curved line, or may be reduced in a combination thereof. Further, the solenoid valve may be continuously opened to the required opening degree, may be opened while repeatedly increasing the opening degree and maintaining the opening degree, or may be opened while repeatedly opening and closing the valve. Good. (2) For a brake system including a pump capable of controlling a discharge hydraulic pressure in response to a braking request, and a booster valve provided in a liquid passage connecting the pump and a brake cylinder and opened when a booster pressure is requested. In the hydraulic pressure control device, when the residual pressure in the portion of the liquid passage between the pump and the pressure increasing valve at the time of the pressure increasing request is large, the pressure increasing valve is opened at a smaller speed when the residual pressure is small. A hydraulic control device provided with a valve opening speed control unit (Claim 2). The braking request can be acquired by, for example, a brake operation member and an operation amount sensor that detects a brake operation amount that is an operation amount such as an operation force and an operation stroke of the brake operation member. In this case, the braking request represents the driver's braking intention. If the hydraulic pressure is automatically increased or decreased, the braking request is made automatically. In addition, a pump device capable of controlling the discharge hydraulic pressure in response to a braking request includes, for example, a pump and a discharge hydraulic pressure of the pump detected by a brake operation amount detected by the operation amount sensor, a change gradient thereof, and the like. And a pump control device that performs control in response to a braking request. The pressure increasing valve is a control valve that is provided in a liquid passage that connects the pump device and a brake cylinder that operates a brake that suppresses rotation of the wheel, and that can take a communication state in which the liquid passage is shut off and a communication state in which the communication is established. For example, an electromagnetic on-off valve that simply opens and closes according to the supply and cutoff of current, and a linear hydraulic pressure control valve that can control the output hydraulic pressure to a size corresponding to the supply current can be used. In a state where the pump is operated according to the braking request, the booster valve is opened and the hydraulic pressure is supplied to the brake cylinder, if the booster valve is closed to shut off the supply of the hydraulic fluid to the brake cylinder, A large hydraulic pressure may remain in a portion of the liquid passage between the pump and the booster valve. If the booster valve is opened in this state, the residual pressure acts on the hydraulic fluid on the brake cylinder side, but if the residual pressure is large, the booster valve is opened at a lower speed than when the residual pressure is small, The residual pressure acts gradually to reduce or prevent the occurrence of the fluid hammering noise, or to reduce or prevent the decrease in hydraulic pressure control accuracy of the brake cylinder. (3) The hydraulic pressure control device for a brake system according to (2), wherein the residual pressure includes a differential pressure acquisition unit that acquires a difference between hydraulic pressures before and after the pressure increasing valve in the liquid passage. (4) The hydraulic pressure control device for a brake system according to the above mode (3), wherein the differential pressure acquisition unit has a differential pressure detection unit that actually detects the differential pressure. (5) The hydraulic pressure control device for a brake system according to the above mode (3) or (4), wherein the differential pressure acquiring section includes a differential pressure estimating section for estimating the differential pressure. The estimation of the differential pressure is performed by estimating at least one of the hydraulic pressure before and after the pressure increasing valve. For example, the hydraulic pressure on the brake cylinder side with respect to the pressure increasing valve is estimated to be equal to the target hydraulic pressure of the brake cylinder. The target hydraulic pressure of the brake cylinder is set, for example, based on the operation amount of the brake operating member, and is controlled by controlling the pump and the pressure increasing valve so that the hydraulic pressure of the brake cylinder becomes the target hydraulic pressure. Therefore, the hydraulic pressure of the brake cylinder may be estimated to be the target hydraulic pressure. Also,
The hydraulic pressure on the pump side of the booster valve is estimated based on the operation amount of the brake operating member, for example, if the hydraulic pressure of the brake cylinder is controlled by the pump, and if the pump is fully activated, it is fully activated. The discharge fluid pressure at that time is estimated to be the fluid pressure on the pump side from the pressure increasing valve. The case where one of the hydraulic pressures before and after the pressure increasing valve is not estimated is the case where one of the hydraulic pressures is always fixed or the case where the hydraulic pressure is detected by the hydraulic pressure sensor. In these cases, the estimation of the differential pressure is based on a fixed or detected hydraulic pressure,
This is performed based on the estimated hydraulic pressure. If the differential pressure is estimated, for example, the number of hydraulic pressure sensors for acquiring the differential pressure can be reduced, and the configuration of the device can be simplified. When this section is dependent on the section (4), the differential pressure acquiring section has both the differential pressure detecting section and the differential pressure estimating section. For example, it is possible to detect a failure of the differential pressure detecting unit by comparing the detected differential pressure with the estimated differential pressure. (6) During the valve opening speed control by the valve opening speed control unit, when the differential pressure acquired by the differential pressure acquiring unit falls below a set differential pressure, the speed control by the valve opening speed control unit is stopped. The hydraulic pressure control device for a brake system according to item (3), including a valve opening speed control suspension unit (claim 4). By stopping the valve opening speed control, the pressure increasing valve is opened at a higher speed than during the valve opening speed control. As a result, the hydraulic pressure supplied to the brake cylinder is no longer suppressed due to insufficient valve opening, and the delay in raising the hydraulic pressure of the brake cylinder can be reduced. If the differential pressure is equal to or lower than the set differential pressure, the hydraulic pressure fluctuation of the hydraulic fluid on the brake cylinder side can be small, and there is little possibility of generating liquid hammering noise and pulsation without reducing the valve opening speed. The brake cylinder hydraulic pressure can be increased with a small delay while preventing the occurrence of hydraulic pressure control and the occurrence of hydraulic pressure control. (7) A pump starting unit that starts the pump in response to the pressure increase request, and the valve opening speed control unit controls the valve opening speed so that the valve opening speed control ends before the pump starts up. The hydraulic pressure control device for a brake system according to any one of (2) to (6), which controls the hydraulic pressure control device for a brake system.
“Starting of the pump” refers to a time after the pump is started to operate until the pump almost reaches a steady operating state or until it reaches an operating state where the required pressure increase gradient can be satisfied.
The valve opening speed control may end when the booster valve is opened to the opening required for control of the brake cylinder. May be terminated in an open state to an opening at which there is no fear of a decrease in the pressure. If the valve opening speed control is performed even after the pump is started, the flow of the hydraulic fluid is obstructed by the pressure increasing valve, and a rise in the hydraulic pressure of the brake cylinder is delayed. On the other hand, if the valve opening speed control is completed before the pump starts, the supply of the pump discharge hydraulic pressure to the brake cylinder is not disturbed, and the occurrence of the liquid hammering noise and the like is prevented. Operation delay can be avoided. (8) The valve opening speed controlled by the valve opening speed control unit is made larger when the required braking force increasing gradient required by the braking request is large than when the required braking force increasing gradient is small. The hydraulic pressure control device for a brake system according to any one of the above modes (2) to (7) including a part (claim 5). If the valve opening speed of the booster valve is reduced, the supply of the hydraulic pressure to the brake cylinder may be delayed accordingly, but if the required braking force increase gradient is added, the required braking force increases, for example, during emergency braking. When the gradient is large, the pressure-intensifying valve is quickly opened, the delay in supplying the hydraulic pressure to the brake cylinder is reduced, and the braking force according to the request can be quickly obtained. Reduction of liquid hammering noise,
The booster valve can be opened in consideration of both the reduction of the decrease in the hydraulic control accuracy and the avoidance of the braking delay. (9)
The aspect described in the paragraph is an aspect in which the valve opening speed is maximized, and the operation delay of the brake cylinder can be minimized. (9) When the required braking force increasing gradient is equal to or greater than the set increasing gradient, the required braking force increasing gradient adding unit invalidates the valve opening speed control by the valve opening speed control unit. The hydraulic pressure control device for a brake system according to the above mode (8). The valve opening speed control disabling unit is for preventing the control command of the valve opening speed control unit from being supplied to the drive circuit of the pressure increasing valve, for example, even if the valve opening speed control unit is disabled. It is only necessary that as a result, the pressure increasing valve is not controlled by the valve opening speed control unit. (10) The pressure-intensifying valve includes a seat valve in a shut-off state in which the valve is seated on a valve seat to shut off the liquid passage, and an electromagnetic drive device that causes the valve to move relative to the valve seat, In addition, the hydraulic pressure control device includes a current initial value determination unit that determines an initial value of the supply current to the electromagnetic drive device based on a hydraulic pressure difference before and after the pressure increasing valve (2) to (9). A hydraulic pressure control device according to any one of the preceding claims. The differential pressure acting force based on the hydraulic pressure difference before and after the pressure increasing valve acts on the valve element, and the acting direction depends on the arrangement state of the pressure increasing valve. For example, (12)
As in the hydraulic pressure control device described in the section, the pressure increasing valve may be disposed in a state where the differential pressure acting force acts in a direction to separate the valve element from the valve seat, or You may arrange | position in the state which acts on the direction which makes a child sit on a valve seat. In the former case, the differential pressure acting force helps the pressure intensifier valve open, and the larger the differential pressure acting force, the smaller the current supplied to the electromagnetic drive for opening the pressure intensifying valve. In the latter case, the differential pressure acting force helps the intensifier valve close, and the greater the differential pressure acting force, the greater the current supplied to the electromagnetic drive. Therefore, if the initial value of the supply current is determined irrespective of the hydraulic pressure difference, there may be a delay in valve opening. For example, in the hydraulic pressure control device according to the item (12), when the initial value is always a constant value, even if the hydraulic pressure difference is large, the booster valve is not greatly opened by the supply of the initial current. In addition, the initial value is determined to be small, and when the hydraulic pressure difference is small, the time required from the start of current supply to the start of opening of the pressure-intensifying valve becomes long, and the valve opening is delayed. On the other hand, if the initial value of the supply current to the booster valve is determined based on the hydraulic pressure difference, for example,
If the initial value of the supply current is set to a value immediately before the booster valve opens, the booster valve can be opened without delay even if the hydraulic pressure difference is large or small. (11) The hydraulic pressure control device according to the mode (10), wherein the valve opening speed control unit includes a current gradually changing unit that gradually changes a supply current to the electromagnetic drive device. The supply current to the electromagnetic drive device may be changed continuously or stepwise. In the former case, the change may be made at a constant gradient, or the change gradient may be changed according to an increase in the supply current. If the pressure-intensifying valve is configured to be in a communication state by the supply of the current and to be in a cut-off state by the interruption of the current, the current gradual change unit may be configured to gradually increase the supply current to the electromagnetic drive device. Increased If the pressure-intensifying valve is configured to be cut off by the supply of the current and to be in the communication state by the cut-off of the current, the current gradual change unit may be configured to gradually reduce the current supplied to the electromagnetic drive device. It is regarded as reduced. (12) The pressure-intensifying valve is arranged such that a differential pressure acting force based on a hydraulic pressure difference before and after the pressure-increasing valve acts in a direction to separate the valve element from the valve seat (10) or (10). The hydraulic pressure control device according to the item 11). In this aspect, the initial value of the supply current to the electromagnetic drive device is set to a smaller value as the hydraulic pressure difference is larger. (13) The hydraulic pressure control device according to any one of the above modes (10) to (12), wherein the electromagnetic drive device includes a solenoid. A force motor that operates by the interaction of the magnetic fields of two magnets can be used as the electromagnetic driving device. However, if a solenoid that operates by the magnetic attraction of the magnet is used, the configuration of the electromagnetic driving force device can be simplified. can do.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A hydraulic brake device according to an embodiment of the present invention will be described with reference to FIGS. In FIG. 1, reference numerals 10 and 12 indicate a left front wheel and a right front wheel, respectively, and reference numerals 14 and 16 indicate a left rear wheel and a right rear wheel, respectively. The front wheels 10 and 12 are provided with brakes having front wheel cylinders (wheel cylinders are abbreviated as W / C as necessary) 20 and 22 as brake cylinders.
22 is operated by supplying hydraulic pressure to the front wheel 1.
A braking torque is applied to 0,12. Similarly, the rear wheels 14, 16 are provided with brakes having rear W / Cs 24, 26 as brake cylinders. Front W / C2
The hydraulic pressure of the manual hydraulic pressure source 30 and the hydraulic pressure of the power hydraulic pressure source 32 are alternatively supplied to 0, 22 and the rear W / C 24,
The hydraulic pressure of the power hydraulic pressure source 32 is always supplied to 26.

The manual hydraulic pressure source 30 includes a master cylinder (abbreviated as M / C as necessary) 38 for generating a hydraulic pressure corresponding to an operation force which is an operation amount of a brake pedal 36 as a brake operation member. I have. The M / C 38 is of a tandem type and generates the same amount of hydraulic pressure in two independent pressurizing chambers. M / C 38 has a master reservoir 39
Is provided. When the brake pedal 36 is in the non-braking position and the pressurizing piston in the M / C 38 is at the retreat end position, the two pressurizing chambers of the M / C 38 communicate with the master reservoir 39 and the pressurizing piston Is slightly advanced from the retreat end position, the pressurizing chamber is shut off from the master reservoir 39. One pressurizing chamber is connected to the front W / C 20 by a liquid passage 40, and the other pressurizing chamber is connected to the front W / C 22 by a liquid passage 42. Liquid passage 40,
M / C cut valves (master cylinder cut valves) 44 and 46 each comprising a normally open electromagnetic on-off valve are provided at 42, and the front W / C 20 and 22 sides of the M / C cut valves 44 and 46 are provided. Hydraulic pressure is W / C hydraulic pressure sensor 50,5
2 and the hydraulic pressure on the M / C 38 side is detected by the M / C hydraulic pressure sensor 54.

[0007] A stroke simulator 55 is provided between the brake pedal 36 and the M / C 38.
A stroke simulator 56 is also connected to a portion of the liquid passage 42 closer to the M / C 38 than the M / C cut valve 46.
Further, the stroke of the brake pedal 36 is detected by the stroke sensor 58. The stepping stroke is
The stroke sensor 58 is an operation stroke sensor that is a type of a brake operation amount sensor.

The stroke simulator 55 is a purely mechanical device that includes an elastic member such as a spring and allows a predetermined amount of relative movement of the brake pedal 36 with respect to the M / C 38 by elastic deformation of the elastic member. The two stroke simulators allow the hydraulic fluid to be discharged from the M / C 38 by storing the hydraulic fluid while increasing the hydraulic pressure while the M / C cut valves 44 and 46 are closed. 55 and 56 cooperate to give the driver a feeling similar to a brake operation in a normal hydraulic brake device without the power hydraulic pressure source 32.

The power hydraulic pressure source 32 is
A low pressure pump 64 and a high pressure pump 66 driven by 0, 62 are provided. The low pressure pump 64 and the high pressure pump 66 are gear pumps. The high pressure pump 66
The discharge pressure is higher than the low-pressure pump 64 and the discharge flow rate is smaller. These low pressure pumps 6
4. The high-pressure pump 66 is a pump whose discharge fluid pressure can be controlled according to a braking request. Further, the electric motors 60 and 62
Is a DC motor in the present embodiment.

A liquid passage for supplying the hydraulic fluid discharged from the low-pressure pump 64 to the W / Cs 20 to 26 on each discharge side of the low-pressure pump 64 and the high-pressure pump 66;
Non-return valves 68 and 70 are provided on the low pressure pump 64 side and the high pressure pump 66 side, respectively, rather than at a portion where a hydraulic passage for supplying the hydraulic fluid discharged from 6 to the W / Cs 20 to 26 merges. The check valve 68 prevents the high discharge liquid pressure of the high-pressure pump 66 from acting on the low-pressure pump 64 when the high-pressure pump 66 is operated.
4 prevents leakage of the working fluid, and prevents the low-pressure pump 64 from being reversed by the high-pressure working fluid discharged from the high-pressure pump 66. The high-pressure hydraulic fluid discharged from the high-pressure pump 66 allows the low-pressure pump 6
It is not necessary to apply a holding torque to the electric motor 60 in order to prevent the hydraulic fluid 4 from being reversed and the hydraulic fluid from returning to the master reservoir 39. Also, the check valve 70
Prevents the hydraulic fluid from leaking from the high-pressure pump 66, which is a gear pump, and when only the low-pressure pump 64 operates, the high-pressure pump 66 is rotated in the reverse direction based on the discharge fluid pressure of the low-pressure pump 64, The return of the hydraulic fluid to the master reservoir 39 is avoided. When the low-pressure pump 64 is operating and the high-pressure pump 66 is not operating, the reverse rotation of the high-pressure pump 66 can be prevented without applying a holding torque to the electric motor 62 that drives the high-pressure pump 66. is there.

The hydraulic pressure of the power hydraulic pressure source 32 is supplied to the W / Cs 20 to 26 through a hydraulic passage 72 and detected by a pump hydraulic pressure sensor 74. The pump hydraulic pressure sensor 74 is
Check valves 68 and 70 and pressure increasing electromagnetic control valves 76, 80 and 8
4, 88, and the power hydraulic pressure source 32
Detect the hydraulic pressure of The power hydraulic pressure source 32 is provided with a relief valve 75 for the high-pressure pump 66, which makes the maximum discharge hydraulic pressure scheduled for the high-pressure pump 66 a relief pressure.
As is clear from the above description, in the present embodiment, the power hydraulic pressure source 32 includes the electric motors 60 and 62, the low-pressure pump 64, the high-pressure pump 66, and the check valves 68 and 70,
It is constituted by a pump device including the relief valve 75. The discharge hydraulic pressure of the pump device is the hydraulic pressure of the power hydraulic pressure source 32.

An electromagnetic pressure increasing electromagnetic control valve 76 and a pressure decreasing electromagnetic control valve 78, and a pressure increasing electromagnetic control valve 80 and a pressure decreasing electromagnetic control valve 82 are provided corresponding to the front W / Cs 20 and 22, respectively. I have. These have the structure schematically shown in FIG. 2 and are both normally closed seat valves. Rear W /
A pressure increasing electromagnetic control valve 84 and a pressure reducing electromagnetic control valve 86, and a pressure increasing electromagnetic control valve 88 and a pressure reducing electromagnetic control valve 90 are provided corresponding to C24 and C26. As shown in FIG. 3, the pressure increasing electromagnetic control valves 84 and 88 are normally closed seat valves, while the pressure reducing electromagnetic control valves 86 and 90 are normally open seat valves. The hydraulic pressures of the rear W / Cs 24 and 26 are respectively W / C hydraulic pressure sensors 9
2,94.

The pressure-increasing electromagnetic control valve 76 and the pressure-reducing electromagnetic control valve 78 on the front wheels 10 and 12 have the structure schematically shown in FIG. The pressure increasing electromagnetic control valve 76 is connected to the valve seat 13.
A seat valve 134 comprising a valve element 132 and a valve element 132 which can be seated and separated therefrom is provided. The valve element 132 is urged in a seating direction by a spring 136 as an urging device. A movable core 138 is provided integrally with the valve 132, and a fixed core 140 is provided opposite to the movable core 138. The two cores 138 and 140 are separated from each other by the spring 136, but are magnetized by supplying a current to the coil 142, and the movable core 138 is fixed to the fixed core 140.
Sucked on the side. As a result, the valve 132 is moved to the valve seat 130.
And the seat valve 134 is opened to open the liquid passage 7.
A communication state is established in which the two are communicated. Pressure increasing solenoid control valve 76
Is connected to the power hydraulic pressure source 32 and the front W / C 20 in a state in which a differential pressure acting force based on a hydraulic pressure difference before and after itself acts in a direction to separate the valve 132 from the valve seat 130. Therefore, the valve 132 is provided with a differential pressure acting force based on the hydraulic pressure difference between the front and rear of the seat valve 134 and the solenoid 1 including the movable core 138, the fixed core 140 and the coil 142.
The sum of the electromagnetic driving force of the spring 44 and the sum of the electromagnetic driving force of the spring 44 stops at a position where the sum of the electromagnetic driving force and the spring 136 is balanced. Can be. The opening degree of the pressure increasing electromagnetic control valve 76 can be controlled, whereby the flow rate of the working fluid, that is, the pressure increasing rate of the front W / C 20 can be controlled. The power hydraulic pressure source 32
When the difference between the hydraulic pressure of the front W / C 20 and the hydraulic pressure of the front W / C 20 becomes small, and the sum of the differential pressure acting force and the electromagnetic driving force becomes slightly smaller than the urging force of the spring 136, the valve element 132 moves to the valve seat 130.
And the seat valve 134 is closed to shut off the liquid passage 72, so that the difference between the hydraulic pressure of the power hydraulic pressure source 32 and the hydraulic pressure of the front W / C 20 is controlled by controlling the supply current to the coil 142. Can be controlled. The pressure-increasing electromagnetic control valves 76, 80, 84, and 88 are linear control valves capable of controlling the output hydraulic pressure to a size corresponding to the supply current. In this embodiment, the solenoid 144 constitutes an electromagnetic drive device. ing.

Since the structure of the pressure reducing electromagnetic control valve 78 is the same as that of the pressure increasing electromagnetic control valve 76, the corresponding components are denoted by the same reference numerals and description thereof will be omitted. However, the pressure reducing electromagnetic control valve 78 has a direction in which the differential pressure acting force based on the difference between the hydraulic pressure of the front W / C 20 and the hydraulic pressure of the master reservoir 39 acts in a direction in which the valve 132 is separated from the valve seat 130. The liquid passage 40 and the liquid passage 146 are connected to the front W / C 20 and the master reservoir 39. Therefore, by controlling the supply current to the coil 142, the pressure reduction speed of the front W / C 20 and the differential pressure between the front W / C 20 and the master reservoir 39 can be controlled. Since the hydraulic pressure of the master reservoir 39 can be substantially regarded as the atmospheric pressure, the control of the pressure difference between the front W / C 20 and the master reservoir 39 is the hydraulic pressure control of the front W / C 20 as it is.

The pressure-increasing electromagnetic control valves 84 and 88 on the rear W / Cs 24 and 26 are the same as the pressure-increasing electromagnetic control valves 76 and 80 on the front W / Cs 20 and 22, and therefore correspond to each other in FIG. The constituent elements are denoted by the same reference numerals, and the description is omitted. On the other hand, the pressure reducing electromagnetic control valves 86 and 90
Is a normally open seat valve, and its structure is slightly different. Valve seat 13
In the same manner, a seat valve 134 comprising a valve 132 and a valve 132 is provided.
It is urged away from zero. Seat valve 134
Are disposed in such a direction that a differential pressure acting force based on a differential pressure between the rear W / C 24 and the master reservoir 39 acts in a direction to separate the valve element 132 from the valve seat 130. The rear end of the valve 132 extends through a through hole formed in the center of the fixed core 152, protrudes from the fixed core 152, and is provided integrally with the movable core 154.
When a current is supplied to the coil 156, the fixed core 152 and the movable core 154 are magnetized, and the movable core 154 is attracted to the fixed core 152 side, so that an electromagnetic driving force is applied to the valve 132. Fixed core 152, movable core 15
4 and a coil 156, the electromagnetic driving force of the solenoid 158 causes the valve 132 to move the valve seat 1 against the differential pressure acting force.
It acts in the direction of sitting on 30. The urging force of the spring 150 may be large enough to keep the valve 132 away from the valve seat 130 in a state where neither the differential pressure acting force nor the electromagnetic driving force acts. You can ignore it when considering the match.

The components described above are connected to a control device 170 shown in FIG. The control device 170 includes a hydraulic control computer 172, and the hydraulic control computer 172 includes a PU (processing unit) 174,
A ROM 176, a RAM 178, and an I / O port 180 are provided. Various detectors including the stroke sensor 58 are connected to the I / O port 180, and various actuators including the electric motor 60 are connected via drive circuits 184.
The control device 170 is constituted by the drive circuit 184 and the hydraulic control computer 172. I /
A wheel slip state monitoring computer 186 is connected to the O port 180, and the ROM 176 is represented in the flowcharts of FIGS. A hydraulic pressure control program. PU
Reference numeral 174 denotes information from various detectors including the stroke sensor 58 and the wheel slip state monitoring computer 1.
Based on the information from the CPU 86, a hydraulic control program is executed using the RAM 178 to control the hydraulic pressure of the W / Cs 20 to 26. It should be noted that the hydraulic control computer 17
2 and the wheel slip state monitoring computer 186 may be constituted by one computer. For example,
The wheel slip state monitoring program is also stored in the ROM of the computer that executes control programs such as the main routine and the hydraulic control program, and is executed in a time-division manner.

At the time of normal braking that does not require antilock control, a normal braking hydraulic pressure control program shown in the flowchart of FIG. 5 is executed. During normal braking,
The hydraulic pressures of the W / Cs 20 to 26 are controlled to be equal to each other. When increasing the pressure, first, W is controlled by the low pressure pump 64.
/ C20, etc., and if insufficient, the operation of the high pressure pump 66 and the control by the electromagnetic control valves 76, 80, 84, 88 are performed in addition to the operation of the low pressure pump 64,
Alternatively, the low pressure pump 64 is stopped and the high pressure pump 6
6 and control by the electromagnetic control valves 76, 80, 84, 88 is performed. This is because the power hydraulic pressure source 32 (pump device) has the following properties. When the target hydraulic pressure of the W / Cs 20 to 26 is relatively small, the demand can be satisfied only by the low-pressure pump 64. However, when the target W / C hydraulic pressure increases, the demand can be satisfied only by the high-pressure pump 66. Further, when the target pressure increasing speed is relatively small, it can be realized by the discharge flow rate of only the low pressure pump 64.
It is necessary to operate both the low pressure pump 64 and the high pressure pump 66. Further, in both the low-pressure pump 64 and the high-pressure pump 66, if the target W / C hydraulic pressure is close to the limit of each discharge hydraulic pressure, it is difficult to control the discharge hydraulic pressure. In addition, the brake system requires a large flow of hydraulic fluid in order to eliminate the brake clearance at the beginning of operation and to elastically deform the seal member, etc. Of the working fluid.

As a result, as shown in FIG. 7, in this embodiment, the target W / C hydraulic pressure, which is the target W / C hydraulic pressure, is equal to or less than a threshold value, for example, 4 MPa, and the target pressure In the first region where the speed is below a threshold value, for example, 20 MPa / sec,
The target W / C hydraulic pressure and the target pressure increasing speed are controlled only by the low pressure pump 64, and in the second region where the target W / C hydraulic pressure is greater than 4 MPa, the low pressure pump is independent of the target pressure increasing speed. 64 is stopped, the high-pressure pump 66 is fully operated by the maximum current, the target W / C hydraulic pressure is 4 MPa or less, and the target pressure increasing speed is higher than 20 MPa / sec.
In the region, both low pressure pump 64 and high pressure pump 66 are fully operated at maximum current. Therefore, the first
In the region, the electromagnetic control valves 76, 80, 84, 88 are fully opened, and in the second and third regions, the hydraulic control of the W / C 20, etc. is performed by the electromagnetic control valves 76, 80, 84, 88.
The threshold values of the target W / C hydraulic pressure and the target pressure increasing speed, which determine the operation modes of the low-pressure pump 64 and the high-pressure pump 66, are not limited to 4 MPa and 20 MPa / sec, respectively. Another value may be set accordingly.

When the pressure of the W / C 20 or the like is reduced, the low pressure pump 6
4 and the high-pressure pump 66 are both stopped, and the pressure-increasing electromagnetic control valves 76, 80, 84, 88 are fully closed,
By controlling the pressure reducing electromagnetic control valves 78, 82, 86, and 90, the hydraulic pressure of the W / C 20, etc., is reduced. W / C20
The same applies when the hydraulic pressure is maintained. A pump performance table that defines the operation modes of the low-pressure pump 64 and the high-pressure pump 66 based on the target W / C hydraulic pressure and the target pressure increasing speed shown in FIG. 7 is stored in the ROM 176 of the hydraulic control computer 172. Pressure increasing electromagnetic control valves 76, 80, 84, 88
Is opened, and when the W / C hydraulic pressure is increased by the hydraulic fluid supplied from the power hydraulic pressure source 32, the power hydraulic pressure source 3
The hydraulic pressure and the pressure increasing speed of No. 2 may be regarded as the hydraulic pressure and the pressure increasing speed of W / C. The pump performance table indicates that the low pressure and the high pressure Pump 64,
66 are configured to determine the operating mode.

In the present hydraulic brake system, when an abnormality occurs in any of the power hydraulic pressure source 32, the electromagnetic control valves 76 to 90, and the control device 170, the M / C cut valve 4
4 and 46 are kept open, and the hydraulic pressure of the M / C 38 is supplied to the front W / Cs 20 and 22. Power hydraulic pressure source 32
In the event of a failure, etc., the brakes on the front wheels 10, 12 are operated in the same manner as the manual brake.

On the other hand, if the brake pedal 36 starts to be depressed while the power hydraulic pressure source 32, the electromagnetic control valves 76 to 90 and the control device 170 are normal, the M / C cut valves 44 and 46 are closed. , M / C38 and front W / C
Communication with 20, 22 is interrupted. Therefore, as long as the power hydraulic pressure source 32 and the like are normal, the hydraulic fluid from the power hydraulic pressure source 32 is supplied to the W / Cs 20 to 26 with the pressure increasing electromagnetic control valves 76 and 8.
0,84,88. The start of depression of the brake pedal 36 can be detected by a conventionally used stop lamp switch, but in the present embodiment, the stroke sensor 5 is used.
8 or the detection value of the M / C hydraulic pressure sensor 54 is detected from the fact that the increase has started. Both sensors 5
When the values 8 and 54 are both normal, the detection value of the stroke sensor 58 starts increasing before the detection value of the M / C hydraulic pressure sensor 54 starts increasing. Brake pedal 36 based on start
When the stroke sensor 58 fails, the start of depression of the brake pedal 36 is detected based on the start of the increase in the detection value of the M / C hydraulic pressure sensor 54. This is for fail safe, and it is also possible to detect the start of depression of the brake pedal 36 based on the start of increase of the detection value of one of the stroke sensor 58 and the M / C hydraulic pressure sensor 54. is there.

In the normal state, W / C 20 to 26
Is controlled according to the flowchart of FIG. In step 1 of FIG. 5 (hereinafter referred to as S1; the same applies to other steps), a target value of the W / C hydraulic pressure is calculated. In this calculation, the target value of the W / C hydraulic pressure is M
The operation is performed in proportion to the M / C hydraulic pressure detected by the / C hydraulic pressure sensor 54. This is performed in consideration of the depression stroke of the brake pedal 36. In the present embodiment,
The target W / C hydraulic pressure P _WCNM which is the target value of the W / C hydraulic pressure is M /
P _WCNM = γ between the C hydraulic pressure P _MC and the depression stroke S
It is determined so that the relationship of (t) · P _MC + δ (t) · S is established. Here, the coefficient γ (t) increases as the elapsed time t from the start of depression of the brake pedal 36 increases, and the coefficient δ (t) decreases as the elapsed time t increases. However, not limited to the above formula, generally _{P WCNM = f (t, S} , P MC) can be made to be determined based on a function of.

In S2, a deviation of the actual W / C hydraulic pressure, which is the actual W / C hydraulic pressure, from the target W / C hydraulic pressure is calculated. The actual W / C hydraulic pressure is determined by the W / C hydraulic pressure sensors 50, 52,
92 and 94 are detected. During normal braking,
Although the actual W / C hydraulic pressures of the W / Cs 20 to 26 should be essentially equal to each other, the actual W / C hydraulic pressures of the W / Cs 20 to 26 are actually different due to individual differences of the pressure increasing electromagnetic control valve 76 and the like. Minute variations occur. Therefore, in S2, deviations of the actual W / C hydraulic pressures of all the W / Cs 20 to 26 from the target W / C hydraulic pressures are obtained. Then, in S3, it is determined whether or not any of the above-mentioned deviations requires an increase in the W / C hydraulic pressure, that is, whether the actual W / C hydraulic pressure of any of the W / Cs is equal to the target W / C hydraulic pressure. It is determined whether the pressure is smaller than the pressure.

If the result of determination in S3 is YES, that is, if it is determined that the pressure needs to be increased in one or more W / Cs, pump control is performed in S4. In S4, for pump control, only the low-pressure pump 64 is operated in order to achieve the target W / C hydraulic pressure and the target pressure increasing speed as the required braking force increasing gradient in accordance with the pump performance table stored in the ROM 176. High pressure pump 6
It is determined whether to operate only 6 or to operate both the low-pressure pump 64 and the high-pressure pump 66. The target pressure increase speed is determined by the previous target W / C hydraulic pressure and the current target W / C
It is determined as the difference from the C hydraulic pressure. Target W / C fluid pressure is 4MP
a, and when the target pressure increasing speed is 20 MPa / sec or less, the electric motor 60 is controlled so that the target W / C hydraulic pressure and the target pressure increasing speed can be obtained by controlling the discharge hydraulic pressure of the low-pressure pump 64. Is determined. The electric motor 60 is set so that the actual W / C hydraulic pressure is equal to the target W / C hydraulic pressure for the wheels whose actual W / C hydraulic pressure is lower than the target W / C hydraulic pressure.
The electric current supplied to the electric motor 6 is increased.
In this embodiment, the increment ΔI of the current to 0 is expressed by the equation Δ
I = C ₁ · (P _WCNM -P _WCAC ) + C ₂ · ΔP _WCNM ΔP _WCNM is the target pressure increase rate, and P _WCAC
Is the actual W / C hydraulic pressure. C ₁ and C ₂ are constants determined based on the discharge characteristics and the like of the pump. Target W / C fluid pressure is 4
If the pressure is greater than MPa, the low pressure pump 64 is stopped, and the high current is supplied to the high pressure pump 66 to be fully operated. If the target W / C hydraulic pressure is 4 MPa or less but the target pressure increase gradient is larger than 20 MPa / sec, the maximum current is supplied to the low-pressure pump 64 and the high-pressure pump 66, respectively. Is fully activated. In S4, the pressure reducing electromagnetic control valve 7 is also provided.
8, 82, 86, 90 are closed. The target pressure increasing speed is obtained as the difference between the previous target W / C hydraulic pressure and the current target W / C hydraulic pressure as described above. The comparison with 20 MPa / sec) is performed using both units. Also in the determination of the next step S5, in the figure, the target pressure increasing speed is shown as it is to be compared with the set pressure increasing speed of 20 MPa / sec in order to facilitate understanding. Be compared.

Next, S5 to S15 are executed, and the pressure increasing electromagnetic control valves 76, 80, 84, 88 are operated. If this operation is roughly explained, the target W / C hydraulic pressure is 4 MPa.
If the target pressure increasing speed is 20 MPa / sec or less, the pressure increasing electromagnetic control valves 76, 80, 84, and 88 are fully opened, the target W / C hydraulic pressure is 4 MPa or less, and When the target pressure increasing speed is higher than 20 MPa / sec or when the target W / C hydraulic pressure is higher than 4 MPa, the W / C hydraulic pressure is controlled by the pressure increasing electromagnetic control valves 76, 80, 84, 88. At this time, when the valve opening speed control execution condition is satisfied, the pressure increasing electromagnetic control valves 76, 80, 84, 88
, The valve opening speed control is performed.

In the present embodiment, the conditions for executing the valve opening speed control are that the target pressure increasing speed is 20 MPa / sec or less, and that the discharge hydraulic pressure of the pump device (power hydraulic pressure source 32) is equal to the actual W / C hydraulic pressure. Pressure is greater than 0.5 MPa. When rapid braking is required, if valve opening speed control is performed, there is a large delay in increasing the W / C hydraulic pressure. Therefore, valve opening speed control is not performed. 7
It is a condition that 6,80,84,88 is opened at a stretch. Also, the pressure difference between the power hydraulic pressure source 32 and the W / C hydraulic pressure, that is, the pressure increasing electromagnetic control valves 76, 80, 84, 88
If the pressure difference before and after the pressure is larger than 0.5 MPa, the pressure increasing solenoid control valves 76, 80, 84, 88 are opened all at once to generate a liquid hammering sound. It is said that. Note that 20 MPa / sec is also a threshold value that determines the operation mode of the pressure-increasing electromagnetic control valves 76, 80, 84, and 88, and the valve opening speed depends on whether the target pressure-increasing speed is 20 MPa / sec or less. Whether or not one of the control execution conditions is satisfied, and the pressure-intensifying electromagnetic control valves 76, 80, and 8
The determination of the operation mode of 4,88 is performed simultaneously. If the condition for executing the valve opening speed control is not satisfied once, the valve opening speed control is not performed even if the condition for executing the valve opening speed control is satisfied, and the target W / C hydraulic pressure and the target increase Pressure increasing electromagnetic control valve 7 in a manner determined by the pressure speed
6,80,84,88 are activated. It should be noted that the target pressure increasing speed for determining sudden braking and the pressure increasing electromagnetic control valve 7
The target pressure increasing speed for determining the operation mode of 6, 80, 84, 88 may be different from the target pressure increasing speed.

In S5, it is determined whether or not the target pressure increase speed is equal to or less than a set pressure increase speed at which the set pressure increase gradient is equal to, for example, 20 MPa / sec. It is determined whether or not sudden braking is required, and the pressure increasing electromagnetic control valves 76, 80, 84,
The determination of the operation mode of 88 is performed. If the target pressure increasing speed is larger than 20 MPa / sec, the determination result of S5 is N
Become O to S12 is executed, the flag F ₁ is set. Flag F ₁ is not shown, is provided on the RAM178 of the hydraulic pressure control computer 172, by the set, the target increase圧速degree is exceeded 20 MPa / sec, that sudden braking is requested Remember.

[0028] Then, S13 is executed, along with the flag F ₂ is reset, intensifying the electromagnetic control valve 76,8
The W / C hydraulic pressure is controlled by 0, 84, 88. If the target pressure increase speed is greater than 20 MPa / sec, both the low pressure pump 64 and the high pressure pump 66 are fully operated,
The pressure-intensifying electromagnetic control valve 76 corresponding to the W / C requiring pressure increasing,
A predetermined current is supplied to 80, 84, 88, and the W / C hydraulic pressure is controlled by the pressure increasing electromagnetic control valves 76, 80, 84, 88. The magnitude of this current is determined based on the discharge hydraulic pressure detected by the pump hydraulic pressure sensor 74 and the target W / C hydraulic pressure. Based on the discharge hydraulic pressure and the target W / C hydraulic pressure, a differential pressure acting force when the W / C hydraulic pressure reaches the target W / C hydraulic pressure is calculated.
The magnitude is determined to be necessary to generate an electromagnetic driving force of a magnitude subtracted from the biasing force of No. 6. The larger the difference between the current (actual) differential pressure between the discharge hydraulic pressure and the W / C hydraulic pressure and the target differential pressure, that is, the differential pressure when the W / C hydraulic pressure becomes the target W / C hydraulic pressure, Then, the pressure-intensifying electromagnetic control valve opens widely, and the actual differential pressure quickly catches up with the target differential pressure. Here, in order to facilitate understanding, the control of the pressure-increasing electromagnetic control valves 76, 80, 84, and 88 is performed by simple proportional control considering only the proportional component. It is also possible to perform control in consideration of at least one of the integral and the integral component. A solenoid drive command signal is output so that the determined supply current is supplied to the solenoid 144. The current having the determined magnitude is supplied to the pressure-increasing electromagnetic control valves 76, 80, 84, and 88 at once, and the pressure-increasing electromagnetic control valves 76, 80, 84, and 88 are opened at a stretch. The valve opening speed at this time is higher than the valve opening speed at the time when the valve opening speed control described later is executed, and the W / C hydraulic pressure is increased without delay in response to a request for rapid braking. After execution of S13, S18 and S19 are executed, and an end process is performed, which will be described later.

If the target pressure increase speed is 20 MPa / sec or less, no rapid braking is required, and the result of the determination in S5 is YE
At S, S6 is executed, and the pressure increasing electromagnetic control valves 76, 8
It is determined whether or not the differential pressure, which is the hydraulic pressure difference before and after 0, 84, 88, is equal to or less than the set differential pressure. Pressure increasing solenoid control valve 7
The hydraulic pressure before 6, 80, 84, 88 is the hydraulic pressure on the power hydraulic pressure source 32 side, is the discharge hydraulic pressure of the pump device, and is detected by the pump hydraulic pressure sensor 74. The hydraulic pressure after the pressure-intensifying electromagnetic control valves 76, 80, 84, 88, that is, the W / C from the pressure-increasing electromagnetic control valves 76, 80, 84, 88
It is determined whether or not a value obtained by subtracting the actual W / C hydraulic pressure, which is the hydraulic pressure on the 20-26 side, is equal to or less than a set differential pressure, for example, 0.5 MPa. In addition, hydraulic pressure sensors 50, 52, 92, and 94 are provided for each of the W / Cs 20 to 26, and
/ C hydraulic pressure is detected, so in S6, four W
The minimum hydraulic pressure of the / C hydraulic pressure is used as the actual W / C hydraulic pressure. The average value of the four W / C hydraulic pressures may be used as the actual W / C hydraulic pressure. The pressure increasing electromagnetic control valves 76, 80, 84,
When the power supply 88 is closed, the power hydraulic pressure source 32 (the check valve 68,
70) and the pressure-increasing electromagnetic control valves 76, 80, 84, 88, the hydraulic fluid is confined. In this case, the pump hydraulic pressure sensor 74 detects the confining pressure which is the hydraulic pressure of the confined hydraulic fluid. Is detected, and the differential pressure is the hydraulic pressure difference between the confinement pressure and the actual W / C hydraulic pressure.

If the differential pressure is equal to or less than 0.5 MPa, the result of the determination in S6 is YES, and S14 is executed to set the target W / C.
It is determined whether or not the hydraulic pressure is 4 MPa or less. If the target W / C hydraulic pressure is below 4 MPa, S14 of the determination result of S15 it is being performed is to YES, together with the flag F ₂ is reset, intensifying the electromagnetic control valve 76,80,8
4,88 is fully opened. At the time of execution of S15, the target pressure increasing speed is 20 MPa / sec or less and the target W / C
Since the hydraulic pressure is 4 MPa or less and the W / C hydraulic pressure is controlled by controlling the discharge hydraulic pressure of the low-pressure pump 64, the pressure-increasing electromagnetic control valves 76, 80, 84, and 88 are fully opened. The solenoid drive command signal is output so that the current for full opening is supplied to the solenoid valve. As a result, the solenoids 144 of the pressure-intensifying electromagnetic control valves 76, 80, 84, 88 are provided to the pressure-increasing electromagnetic control valves 76, 80, 84,
The current necessary to keep 88 fully open is supplied at once, and the pressure-intensifying electromagnetic control valves 76, 80, 84, 88 are opened at a stretch.

If the target W / C hydraulic pressure is greater than 4 MPa,
The determination result in S14 is NO, and S13 is executed.
In this case, the target W / C hydraulic pressure is greater than 4 MPa, the high-pressure pump 66 is fully operated at the maximum current, and the W / C hydraulic pressure is controlled by the pressure-intensifying electromagnetic control valves 76, 80, 84, and 88. In this case, the pressure increasing electromagnetic control valves 76, 80, 8
The current necessary for controlling the W / C hydraulic pressure is supplied to the solenoids 144, 88, and the solenoids for pressure increase 76, 80,
84 and 88 are opened.

If the differential pressure is greater than 0.5 MPa, S
The determination result at 6 is NO, and S7 to S11 are executed.
The valve opening speeds of the pressure increasing electromagnetic control valves 76, 80, 84, 88 are controlled. In S7, the flag F ₁ is the determination of whether it is set is performed. It has sudden braking is requested, if the flag F ₁ is set, S7
Is YES, and S14 is executed. Even if sudden braking is required and the target pressure increasing speed is higher than 20 MPa, the target pressure increasing speed is 20 MPa / sec or less and the differential pressure sometimes exceeds the set differential pressure, if sudden braking is requested, the request is stored by a set of flags F _1, the valve opening speed control is what is prevented is performed. When the differential pressure is equal to or lower than the set differential pressure, the W / C hydraulic pressure is controlled by the low pressure pump 64 or the W / C hydraulic pressure is controlled by the pressure increasing electromagnetic control valves 76, 80, 84, 88.
In the state where the / C hydraulic pressure is controlled, the differential pressure does not become larger than the set differential pressure, and S1 to S6, S14, S1
5 or S1 to S6, S14, and S13 are repeatedly executed. The valve opening speed control is performed when the pressure is increased from the state in which the W / C is substantially reduced or maintained. Note that, just in case, a flag is set when the differential pressure has become equal to or less than the set differential pressure, and once the differential pressure has become equal to or less than the set differential pressure, the differential pressure may exceed the set differential pressure. Even if there is, the valve opening speed control may not be performed.

If rapid braking is not requested, the flag F
₁ has not been set, the judgment result of S7, S8 becomes NO is executed, the flag F ₂ it is determined whether or not has been set is performed. Flag F ₂ is not shown, provided in the RAM 178, set by, intensifying the electromagnetic control valve for performing opening speed control if the differential pressure is greater than 0.5 MPa 76,80,84,88 It stores that the initial value of the supply current for opening the valve has been determined. Flag F ₂ is reset in such initialization of the main routine, not S13 and shown, when the first S8 is executed the determination result of S7 is turned to NO are reset, the determination result of S8, becomes NO S9 Is executed,
An initial value I _i0 of a valve opening current Ii, which is a supply current for opening the pressure increasing electromagnetic control valves 76, 80, 84, 88, is calculated.

The initial value I _i0 of the valve opening current Ii is calculated based on the differential pressure across the pressure-increasing electromagnetic control valves 76, 80, 84, 88. The differential pressure is determined by the pressure increasing solenoid control valves 76, 80, 8
4,88 differs depending on the discharge hydraulic pressure and the W / C hydraulic pressure at the time of opening. When the W / C hydraulic pressure is reduced or maintained, the pressure-intensifying electromagnetic control valves 76, 80, 84, and 88 are closed, whereby the power hydraulic pressure source 32 (the check valves 68, 7) is closed.
0) and the hydraulic fluid are confined between the pressure increasing electromagnetic control valves 76, 80, 84, 88, and the confining pressure is equal to the discharge fluid pressure when the valve is closed. Then, the depression of the brake pedal 36 is loosened and the pressure is reduced, so that the target W / C hydraulic pressure decreases and the actual W / C hydraulic pressure decreases. However, before the depression of the brake pedal 36 is released, the target W / C hydraulic pressure is reduced again. If you step in,
The target W / C hydraulic pressure and the actual W / C hydraulic pressure start increasing. As shown in FIG. 8A, if the mode is changed from the pressure reduction mode to the pressure increase mode in a state where the pressure reduction amount is small, the differential pressure is small, and FIG.
As shown in (2), if the mode is switched from the pressure reduction mode to the pressure increase mode in a state where the pressure reduction amount is large, the differential pressure increases.

Then, between the differential pressure and the initial value I _i0 ,
As shown in FIG. 9, there is a relationship in which the larger the differential pressure, the smaller the initial value I _i0 . This is because the pressure increasing electromagnetic control valves 76, 8
0, 84, 88, as described above, the differential pressure acting force is the valve 1
32 are disposed in a state of acting in a direction away from the valve seat 130, and as the differential pressure increases, the pressure-increasing electromagnetic control valve 7 increases.
6, 80, 84 and 88 are easy to open, and the initial current is small. In the present embodiment, the initial value I _i0 of the valve opening current Ii is set to a value immediately before the pressure-increasing electromagnetic control valves 76, 80, 84, 88 are opened. The relation between the differential pressure and the initial current shown in FIG. 9 is tabulated and stored in the ROM 176 of the hydraulic pressure control computer 172, and the initial value I _i0 is calculated (acquired) based on this table and the differential pressure. It is stored in a valve opening current memory (not shown) provided in the RAM 178. Also in S9, the flag F ₂ is set, the acquisition of the initial value I _i0 is stored. Then S1
0 is executed, and the initial value I _i0 acquired in S8 is changed to the solenoid 1 of the pressure increasing electromagnetic control valves 76, 80, 84, 88.
A solenoid drive command signal is output so as to be supplied to 44 (coil 142).

[0036] Since the flag F ₂ is set, the next time the S8 is executed, the judgment result is S11 becomes YES is performed, the pressure increase solenoid control valve 76,80,8
The 4,88 valve opening currents Ii are increased by a set amount. In the present embodiment, the amount of increase is set to a constant value, for example, 0.1 A regardless of the size of the differential pressure.
By executing S11, the valve opening current Ii is increased by 0.1A. 0.1 A is added to the value stored in the valve opening current memory. Then, in S9, the coil 14
A solenoid drive command signal is output to increase the supply current to 2 by 0.1 A.

The target pressure increasing speed is 20 MPa / sec or less,
While the differential pressure is greater than 0.5 MPa, S1 to S8, S11,
S10 is repeatedly executed, and the pressure increasing electromagnetic control valves 76, 8
The supply current to 0, 84, 88 is increased by 0.1 A each time S11 is executed, and is increased substantially in a straight line. Thereby, the pressure increasing electromagnetic control valves 76, 8
0, 84, 88 are, as shown in FIGS. 10 and 11,
The target pressure increasing speed is larger than 20MPa / sec or smaller than the case where the differential pressure is 0.5MPa or less. Is prevented, and the hydraulic pressure control is performed with high accuracy.

As shown in FIG. 8, when the pressure of the wheel cylinder is being increased, the depression of the brake pedal 36 is relaxed, and the pressure increasing electromagnetic control valve 7 is operated to reduce the pressure.
When the hydraulic fluid 6, 80, 84, 88 is closed, the hydraulic fluid is confined between the pressure increasing electromagnetic control valves 76, 80, 84, 88 and the power hydraulic pressure source 32 in a pressurized state. For this reason, if the depression amount of the brake pedal 36 is large and the differential pressure between the confined pressure, which is the hydraulic pressure of the confined hydraulic fluid, and the actual W / C hydraulic pressure is large and exceeds the set differential pressure, the pressure is increased. When the pressure-increasing electromagnetic control valves 76, 80, 84, 88 are opened at a stretch, the confining pressure is increased at a stretch to W / C 20-26.
Acting on the hydraulic fluid on the side, a sudden change in hydraulic pressure occurs as shown in FIG. 12 to generate a liquid hammering sound or a pulsation in hydraulic pressure. For example, as shown by an arrow in FIG.
Are fully operated, and the pressure increasing electromagnetic control valves 76, 80, 8
From the state where the W / C hydraulic pressure is controlled by 4,88,
The pressure is reduced and the pressure increasing electromagnetic control valves 76, 80, 84, 8
8 is closed, a differential pressure is generated. From this state, the W / C hydraulic pressure is controlled by the low-pressure pump 64. When the pressure-increasing electromagnetic control valves 76, 80, 84, 88 are fully opened, a liquid hammering sound is generated. And hydraulic pressure pulsations occur.

On the other hand, in the present embodiment, when the valve opening speed control execution condition is satisfied, the pressure increasing electromagnetic control valves 76, 80, 84, 88 are opened at a lower speed than when the condition is not satisfied. As described above, the confinement pressure gradually decreases, and gradually acts on the hydraulic fluid on the W / C 20 to 26 side, thereby preventing generation of a liquid hammering sound and a pulsation of the liquid pressure.

If the condition for executing the valve opening speed control is not satisfied while the valve opening speed control is being performed, for example, if the differential pressure becomes 0.5 MPa or less, the determination result in S6 becomes YES and S14 Is executed, and the pressure-increasing electromagnetic control valves 76, 80, 84, and 88 are operated in a manner corresponding to the target W / C hydraulic pressure (S13 to S15). The valve opening speed control is stopped, and the pressure increasing electromagnetic control valves 76, 80, 84, 8
8, the current necessary for controlling the W / C hydraulic pressure is supplied at once,
The valve is quickly opened at a higher speed than during the valve opening speed control. When the supply current is increased by 0.1 A, the opening is performed at a higher speed. For example, if the target W / C hydraulic pressure is 4 MPa or less and the pressure-increasing electromagnetic control valves 76, 80, 84, and 88 are fully opened, as shown in FIG. 84, 88 open quickly at a greater rate if the differential pressure exceeds 0.5 MPa. Also, if the target pressure increase speed exceeds 20 MPa / sec, S5
Is NO, and S12 and S13 are executed.
Sudden braking is performed.

In the determination in S3, all the wheels
It is determined that there is no need for pressure increase in W / C 20-26
In this case, the determination result of S3 is NO, and S16 is executed.
And the low pressure pump 64 and the high pressure pump 66 are stopped.
And the flag F ₁ , F_Two Was reset
Thereafter, S17 is executed, and valve linear control is performed.
This control is performed by all the pressure-intensifying electromagnetic control valves 76, 80, 8
Close 4,88, and for W / C which needs decompression, use for decompression
Open the solenoid control valve and depressurize W / C that needs to be held
This is control for closing the electromagnetic control valve. Electromagnetic control valve 7 for pressure reduction
The supply current when opening 8, 82 is based on the target W / C hydraulic pressure.
Is determined. In the pressure reducing electromagnetic control valves 78 and 82
Means that the differential pressure across the seat valve 134 is W / C
Equivalent to hydraulic pressure. Therefore, the valve 1
32 is calculated, and this differential pressure acting force and
The sum of the electromagnetic drive force of the solenoid 144 and the spring 136
The supply current to the coil 142 is determined to be equal to the power.
It is determined. The supply current determined in this way is
If the W / C hydraulic pressure is set at the target W / C
When the pressure becomes equal to the fluid pressure, the pressure-reducing electromagnetic control valve closes, and W /
The C hydraulic pressure is controlled to the target W / C hydraulic pressure. What
When holding or depressurizing, the low pressure pump 64
Even if at least one of the pressure pumps 66 is operated
Good. A state in which holding or depressurization is performed by this
When the pressure is suddenly increased due to sudden braking from
It is possible to prevent a delay in coming out.

Subsequent to the control of any of S10, S13, and S17 described above, in S18, it is determined whether or not the hydraulic control should be terminated. This determination may be made by detecting whether or not the depression of the brake pedal 36 is released by using a conventionally used stop lamp switch, but in the present embodiment,
The stroke sensor 58 detects that the brake pedal 36 has been depressed, and the M / C hydraulic pressure sensor 54 detects that the M / C hydraulic pressure has decreased to 0 (atmospheric pressure). A determination is made that the hydraulic control should be terminated. The determination may be made based on one of these, and a stop lamp switch may be used in addition to these.

If the decision result in the step S18 is NO, the execution of the program ends. On the other hand, if the determination result in S18 is YES, a termination process is performed in S19. Since the supply current to the electric motors 60 and 62 is set to 0, the supply current to the pressure-increasing and pressure-reducing electromagnetic control valves 76 to 90 is set to 0, and the M / C cut valves 44 and 46 are opened. is there. However, the supply currents of the pressure-increasing electromagnetic control valves 84 and 88 are set to 0 after being opened for a predetermined period of time. In the present embodiment, the rear wheels 14, 16
Since the pressure-decreasing electromagnetic control valves 86 and 90 are normally open, the hydraulic fluid on the power hydraulic pressure source 32 side receives the pressure-increasing electromagnetic control valve 8.
The pressure is returned to the master reservoir 39 through the solenoid valves 4 and 88 and the pressure reducing electromagnetic control valves 86 and 90, and the residual pressure of the power hydraulic pressure source 32 is completely released. Further, the rear W / Cs 24 and 26 pass through the pressure-reducing electromagnetic control valves 86 and 90 returned to the open state, and the front W / Cs 20 and 22 operate the M / C cut valves 44 and 46 returned to the open state. Through the master reservoir 39, any W / C 20
No hydraulic pressure remains in -26.

At the time of normal braking, W /
When the C hydraulic pressure is controlled to a magnitude proportional to the driver's depression force of the brake pedal 36, the W / C hydraulic pressure so controlled is excessively large in relation to the road surface friction coefficient. , Antilock control is performed. The control of the W / C hydraulic pressure in this case is performed by executing an antilock control hydraulic pressure control program shown in the flowchart of FIG. The execution of the anti-lock control hydraulic control program is started in response to an interrupt signal supplied from the wheel slip state monitoring computer 186 during the execution of the normal brake hydraulic control program.

The antilock control of the present embodiment will be schematically described. If only one of the four wheels needs pressure increase, pressure increase is performed on the W / C of the wheel. The pressure increase stops the low pressure pump 64 and the high pressure pump 66
Only the full operation is performed, and the W / C hydraulic pressure is controlled by the pressure increasing electromagnetic hydraulic control valves 76, 80, 84, 88. On this occasion,
As in the case of normal braking, if the valve opening speed control execution condition is satisfied, the valve opening speed control is performed and the pressure-increasing electromagnetic control valve 7 is controlled.
The valves 6, 80, 84, 88 are opened at a lower speed than when the valve opening speed control execution condition is not satisfied, and are quickly opened if the valve opening speed control execution condition is not satisfied.
Also, in addition to the wheels that need to be increased in W / C 20 to 26,
If there is a wheel that needs to be decompressed by / C20 to 26, valve linear control is performed on the wheel in the same manner as during depressurization during normal braking and during holding.

The wheel slip condition monitoring computer 186
While the ignition key switch of the vehicle is ON, the wheels 10, 12, 1
While monitoring the slip state of 4,16, when the slip state becomes a state that requires antilock control,
An interrupt signal is supplied to the hydraulic control computer 172, and the execution of the antilock control program is started. First,
In S31, target values of the W / C hydraulic pressures of the W / Cs 20, 22, 24, 26 corresponding to the wheels 10, 12, 14, 16 are calculated. The target value of the W / C hydraulic pressure is, for example, information on the slip state of the wheels 10, 12, 14, 16 supplied from the wheel slip state monitoring computer 186, that is, the slip ratio SR and its change rate dS.
R / dt and W / C hydraulic pressure sensors 50, 52, 92, 94
And the actual W / C hydraulic pressure detected by The slip ratio SR is determined by the moving speed of the vehicle body and each wheel 10, 12, 1
It is calculated by a well-known formula from the peripheral velocities of 4 and 16. The moving speed of the vehicle body may be detected by a Doppler type ground vehicle speed sensor or the like that detects the relative moving speed between the road surface and the vehicle body using the Doppler effect, and the maximum peripheral speed of the wheels 10, 12, 14, 16 It may be estimated in a known manner based on the thing. The target W / C hydraulic pressure of each W / C is, for example, each W / C
Real W / C hydraulic pressure obtained by adding the hydraulic pressure change amount [Delta] P _WC, hydraulic change amount [Delta] P _WC is a reference slip ratio SR _NM is a reference value predetermined slip ratio, the slip ratio SR of From the change rate of the slip ratio dSR / dt, Δ
P _WC = C ₆ · (SR-SR _NM ) + C ₇ · dSR / dt C ₆ and C ₇ are both negative constants. As the slip ratio SR is larger than the reference slip ratio SR _{NM and} the change rate dSR / dt of the slip ratio is larger, the fluid pressure change amount ΔP _WC is an absolute value. Becomes a large negative value. Therefore, the target W / C hydraulic pressure is determined to be smaller than the current actual W / C hydraulic pressure. Conversely, the slip rate SR is smaller than the reference slip rate SR _NM and the slip rate change rate d
When SR / dt is negative, the hydraulic pressure change amount ΔP _WC becomes a positive value, and the target W / C hydraulic pressure is determined to be larger than the current actual W / C hydraulic pressure. The calculation of the hydraulic pressure change amount ΔP _WC can be performed by an equation other than the above equation, and the slip rate SR and the rate of change d of the slip rate d can be calculated.
The relationship between SR / dt and the hydraulic pressure change amount ΔP _WC is tabulated in advance, and based on the table, the hydraulic pressure change amount ΔP _WC
May be determined. Further, it is also possible to use the slip amount instead of the slip ratio.

Steps S32 and S33 are performed in the same manner as in steps S2 and S3 of the normal brake hydraulic pressure control program. Actual W / C
If at least one wheel has a hydraulic pressure lower than the target W / C hydraulic pressure,
The decision result in S33 is YES, and S34 is executed,
The low pressure pump 64 is stopped. Then, S35 is executed, and the high-pressure pump 66 is fully operated. The supply current to the electric motor 62 is maximized, and the hydraulic pressure of the power hydraulic pressure source 32 is equal to the relief pressure of the relief valve 75 and is constant.

At the time of antilock control, W / C 20 to 2
Each hydraulic pressure of 6 is individually controlled. Therefore, S36 to S46 are executed for each of the four wheels 10 to 16. FIG. 6 representatively shows control for one wheel. Although not shown, S36 to S46 are similarly executed for the other three wheels.

In S36, it is determined whether the W / C hydraulic pressure is increased, reduced, or maintained. This determination is made based on the deviation calculated in S32. If the actual W / C hydraulic pressure is lower than the target W / C hydraulic pressure, the pressure is increased, and the determination result in S36 becomes YES and S
The following 37 steps are executed. If the actual W / C hydraulic pressure is equal to or higher than the target W / C hydraulic pressure, the W / C hydraulic pressure is reduced or maintained. This is executed in the same manner as S17 at the time of braking.

When increasing the W / C hydraulic pressure, the W / C hydraulic pressure is controlled by the pressure-increasing electromagnetic control valve, and the valve opening speed control is performed if the conditions for executing the valve opening speed control are satisfied. The conditions for executing the valve opening speed control are the same as those during the normal braking (S3
7, S38). Even during the antilock control, for example, when the friction coefficient of the road surface suddenly changes from a low state to a high state, the target W / C hydraulic pressure rapidly increases from a low state,
The target pressure increasing speed may exceed the set pressure increasing speed, for example, 20 MPa / sec. In such a case, the valve opening speed control is not performed, and the W / C hydraulic pressure is quickly controlled to the target value. It is being done. If the valve opening speed control execution condition is not satisfied, the W / C hydraulic pressure is controlled by the pressure-intensifying electromagnetic control valve regardless of the magnitude of the target W / C hydraulic pressure (S4).
5). Further, once the target pressure increasing speed exceeds 20 MPa / sec and sudden braking is performed, as in the case of normal braking,
The set of flags F _1, the valve opening speed control is prevented from being performed (S44).

If the condition for executing the valve opening speed control is satisfied and the rapid braking is not requested, S40 to S43 are executed in the same manner as S8 to S11 of the normal braking control, and the valve opening speed is reduced. At the time of the antilock control, the high-pressure pump is fully operated, and the pressure increase, the holding, or the pressure reduction are alternately and repeatedly performed. Therefore, if the pressure-increasing electromagnetic control valve is closed to maintain or reduce the pressure from the pressure increase, a high-pressure discharge liquid pressure is confined between the power hydraulic pressure source 32 and the pressure-intensification electromagnetic control valve, and the differential pressure is reduced. Although the set pressure difference may be exceeded, if the condition for executing the valve opening speed control is satisfied, the valve opening speed is reduced, thereby preventing the occurrence of the liquid hammering sound or the pulsation of the liquid pressure and the anti-lock control. Is accurately controlled. If the differential pressure becomes 0.5 MPa or less by executing the valve opening speed control, the valve opening speed control is stopped, and the pressure increasing electromagnetic control valve is quickly opened. Note that S
If it is determined in S33 that there is no need to increase the pressure in the W / Cs 20 to 26 of all the wheels, the determination result in S33 is NO, and S47 and S48 are S16 and S17.
Is executed in the same way as

As is clear from the above description, in the present embodiment, the control device 170 constitutes a valve control device,
S5, S6, S9-S11, S37,
The part that executes S38 and S41 to S43 constitutes a valve opening speed control unit. The part of the control device 170 that executes S9 and S41 also constitutes a current initial value determination unit,
1, the part that executes S43 constitutes a current gradual increase unit that is a current gradual change unit. Further, the pump hydraulic pressure sensor 74, W /
C hydraulic pressure sensors 50, 52, 92, 94 and control device 1
The part performing S6 and S38 of 70 constitutes a differential pressure detecting unit which is a differential pressure acquiring unit, and S13 to S15 of the control device 170.
The part that executes S45 constitutes a valve opening speed control suspension part,
The part of the control device 170 that executes S5, S37, S13, and S45 constitutes a valve opening speed control invalidating unit that is a required braking force increase gradient adding unit. In the present embodiment, the valve opening speed control disabling unit is configured to prevent the valve opening speed control unit from operating.

When performing the valve opening speed control in the above embodiment, the valve opening speed is fixed irrespective of the magnitude of the differential pressure, but may be changed according to the differential pressure. Figure 1 shows an example
This will be described with reference to FIGS. The circuit configuration of the brake system of the present embodiment is the same as that of the above-described embodiment, and illustration and description are omitted.

In the present embodiment, the ROM of the hydraulic control computer constituting the control device of the brake system includes:
A table for determining the valve opening speed based on the differential pressure and the target pressure increase speed of the W / C hydraulic pressure is stored in addition to the programs such as the normal braking hydraulic pressure control program shown in the flowchart in FIG. As shown in FIG. 16, it is desirable that the valve opening speed is smaller as the differential pressure is larger. As shown in FIG. 17, as the required braking force represented by the target pressure increasing speed is larger,
It is desirable that the valve opening speed be high. The greater the differential pressure,
By opening the pressure-increasing electromagnetic control valve, liquid hammering sound is likely to occur
In order to gradually reduce the differential pressure, the valve opening speed is reduced. Also, as the target pressure increasing speed is higher, it is required to increase the W / C hydraulic pressure faster. Thus, the supply delay of the hydraulic pressure is reduced. A table for determining the valve opening speed is provided as shown in FIG. 18 to satisfy these requirements. The valve opening speed is
The larger the increment of the valve-opening current supplied to the pressure-increasing electromagnetic control valve is, the larger the value is. The valve-opening speed determination table specifically determines the increment of the valve-opening current.

The normal braking control will be described as a representative. S61 to S6 of the normal braking hydraulic pressure control program of the present embodiment
4, S77 and S78 correspond to S1 to S4 and S
16 and S17. Then, at the time of pressure increase, S65 to S76 are executed. The pressure increase control will be schematically described. First, the valve opening speed, that is, the increment ΔI of the valve opening current, is determined using the differential pressure, the target pressure increasing speed, and the valve opening speed determination table.
Is determined based on the differential pressure, and the initial value of the valve-opening current of the pressure-intensifying electromagnetic control valve is determined. The valve speed is obtained. When the current necessary for controlling the W / C hydraulic pressure is supplied to the pressure-increasing electromagnetic control valve and the valve is opened, the valve-opening current is maintained at the value at that time.

A specific description will be given. After the pump control is executed in S64, S65 is executed, the flag F ₄ it is determined whether or not has been set is performed. Flag F ₄
Stores that the electromagnetic pressure control valve for pressure increase is opened by supplying the current necessary for controlling the W / C hydraulic pressure. S65 the determination result is initially a NO, S66 is executed, the flag F ₃ it is determined whether or not has been set is performed. Flag F ₃ is set by, the initial value I _i0 opening current Ii of intensifying the electromagnetic control valve is determined,
And that the valve opening speed is determined. Initial value I
_{If i0} and the valve opening speed have not been determined,
The determination result in S66 is NO and S67 is executed, and the valve opening speed is determined using the differential pressure, the target pressure increasing speed, and the valve opening speed determination table. Specifically, as the valve opening speed,
An increment ΔI of the supply current to the pressure-intensifying electromagnetic control valve is determined.

[0057] Then S68 is executed, with the initial value I _i0 is determined, the flag F ₃ is set. The initial value I _i0 is determined in the same manner as in the above embodiment. And S
Step 69 is executed, and a solenoid drive command signal is output.

Subsequently, S71 to S74 are executed, and it is determined whether or not the pressure increasing electromagnetic control valve is opened according to the control mode of the pressure increasing electromagnetic control valve. As in the previous embodiment, the operation mode of the pressure-intensifying electromagnetic control valve depends on the target W / C
It is determined based on the hydraulic pressure and the target pressure increase speed, and the target W /
C fluid pressure is 4MPa or less and target pressure increase speed is 20MPa /
sec or less, the pressure-intensifying electromagnetic control valve is fully opened,
If the target W / C hydraulic pressure exceeds 4 MPa or the target pressure increasing speed exceeds 20 MPa / sec, the pressure-intensifying electromagnetic control valve is opened by supplying a current necessary for controlling the W / C hydraulic pressure. Therefore, the target W / C hydraulic pressure is larger than 4 MPa,
Alternatively, if the target pressure increasing speed exceeds 20 MPa / sec, the determination result of S71 or S72 becomes NO and S
Step 74 is executed to determine whether or not the pressure increasing electromagnetic control valve has been opened. This determination is made as to whether or not the actual supply current to the pressure-intensifying electromagnetic control valve has reached the supply current determined based on the discharge hydraulic pressure detected by the pump hydraulic pressure sensor and the target W / C hydraulic pressure. It is performed by

If the target W / C hydraulic pressure is 4 MPa or less and the target pressure increasing speed is 20 MPa / sec or less, S
The determination results in S71 and S72 are both YES and S7.
Step 3 is executed to determine whether the pressure-intensifying electromagnetic control valve is fully opened. The current required to fully open the pressure-intensifying electromagnetic control valve is known in advance, and it is determined whether the actual supply current to the pressure-intensifying electromagnetic control valve has reached the current for full opening. The pressure increasing solenoid control valve is not fully opened,
Alternatively, if it is not opened by the supply of the current necessary for controlling the W / C hydraulic pressure, S79 is executed. S79, S8
0 is executed in the same manner as S18 and S19 of the above embodiment.

[0060] If the initial value I _i0 of opening speed and the valve-opening current is determined, since the flag F ₃ is set, the next time the S66 is executed, the determination result is becomes YES S70 is And the supply current to the pressure-intensifying electromagnetic control valve is increased by the increment ΔI determined in S67.
At 69, a drive command signal is output to the solenoid drive circuit. Thereby, the pressure increasing electromagnetic control valve is opened at a speed corresponding to the differential pressure and the target pressure increasing speed. Then, intensifying the electromagnetic control valve is caused to fully open, or if opened by the supply of electric current necessary for the control of the W / C hydraulic pressure, S75 are being flag F ₄ is set is executed, intensifying the electromagnetic control valve Is stored. Therefore, the next time S65 is executed, the determination result becomes YES and S76 is executed, so that the supply current to the pressure-intensifying electromagnetic control valve is equal to the magnitude of maintaining the pressure-intensifying electromagnetic control valve in the fully open state or the target W. / C hydraulic pressure is maintained at a level that can be obtained.

In this embodiment, the valve opening speed is determined based on the differential pressure and the target pressure increasing speed. For example, if the target pressure increasing speed is high, the valve opening speed is increased. The control valve is opened quickly, and the occurrence of a braking delay is avoided. In addition, the valve opening speed is determined to be smaller as the differential pressure is larger, and the occurrence of liquid hammering noise and pulsation of the liquid pressure due to the opening of the pressure increasing electromagnetic control valve is prevented. In the present embodiment, the portion that executes S67 to S70 of the control device constitutes a valve opening speed control unit. Although illustration and explanation are omitted, also at the time of pressure increase in the antilock control, the valve opening speed is determined based on the differential pressure, the target pressure increasing speed and the valve opening speed determination table, and the pressure increasing electromagnetic control valve is opened. Valve speed control is performed. Instead of S37 to S45 of the antilock control program of the embodiment, S65 to S65
Steps S69 and S74 to S76 are executed.

In the embodiment shown in FIGS. 15 to 18, the normal brake hydraulic pressure control program is executed until the pressure-intensifying electromagnetic control valve is fully opened or the current required for controlling the W / C hydraulic pressure is supplied and opened. The valve opening speed may be determined each time the operation is performed. In addition, the valve opening speed control is performed until the pressure-increasing electromagnetic control valve is fully opened or the current required for controlling the W / C hydraulic pressure is supplied and opened. It may be. For example, S
If the increase in the supply current to the pressure-intensifying electromagnetic control valve performed in step 70 is performed a set number of times, the current is stopped at once and the pressure-intensifying electromagnetic control is opened at once, or the discharge is performed. If the differential pressure between the hydraulic pressure and the actual W / C hydraulic pressure becomes equal to or less than the set differential pressure, the operation is stopped.

In each of the above-described embodiments, the valve opening speed is different from the target pressure increasing speed in two stages depending on whether the target pressure increasing speed is equal to or lower than the set pressure increasing speed. The higher the speed was, the higher the speed was steplessly increased. In addition, for example, as shown in FIG. 19, when the target pressure increasing speed was equal to or less than the set pressure increasing speed, the pressure was kept constant.
As long as the set pressure increase speed is exceeded, the larger the set pressure increase speed, the larger it may be. Further, the valve opening speed with respect to the differential pressure is made different in two stages depending on whether the differential pressure is equal to or less than the set differential pressure and when the differential pressure exceeds the set differential pressure. However, as shown in FIG. 20, when the differential pressure exceeds the set differential pressure, the valve opening speed is kept constant, and when the differential pressure is equal to or lower than the set differential pressure, the valve opening speed increases as the differential pressure decreases. Alternatively, as shown in FIG. 21, when the differential pressure is equal to or less than the set differential pressure, the valve opening speed is kept constant. When the differential pressure exceeds the set differential pressure, the valve opening speed decreases as the differential pressure increases. You may make it become.

In the case where the valve opening speed is determined based on the differential pressure and the target pressure increasing speed, the relationship between the valve opening speed and the differential pressure and the relationship between the valve opening speed and the target pressure increasing speed described in each of the above embodiments are described. Any of these may be combined to determine the valve opening speed. When the valve opening speed can be changed with respect to the differential pressure or the target pressure increasing speed, the valve opening speed may be determined using a table. Instead of a table, for example, the valve opening speed may be determined using an equation.

In the above embodiments, when controlling the valve opening speed of the pressure-increasing electromagnetic control valve, the supply current to the solenoid is increased linearly at a gradient determined by the increment of the supply current. May be increased. For example, as shown in FIG. 22, the supply current may be increased by repeatedly increasing the supply current and maintaining the current for a set time. Even if the supply current is changed stepwise, it is equivalent to a gradual change if the step is small. Opening) gradually increases. This is also a kind of valve opening speed control. The example shown in FIG. 23 supplies the intermediate current for a certain time before the supply of the final current, and is an extreme example of the valve opening speed control.

In the above embodiments, the valve opening speed of the pressure-intensifying electromagnetic control valve is determined so as to sufficiently prevent the occurrence of a liquid hammering sound when the pressure-increasing electromagnetic control valve is opened. It is desirable that the valve opening speed be determined so as not to prevent the pump from rising. However, it is not always necessary to determine the valve opening speed to a value that does not prevent the pump from rising.

Further, in each of the above-described embodiments, the valve opening speed control is performed when the brake pedal is depressed again, or when the pressure is increased by the anti-lock control. In addition to the antilock control, the valve opening speed control may be performed in a state where the depression of the brake pedal is not loosened. For example, if the load pressure based on at least one of the deceleration and the lateral acceleration of the vehicle reduces the hydraulic pressure of the wheel cylinder of at least one of the plurality of wheels as compared with the other,
The pressure difference before and after the booster valve provided for the wheel cylinder increases, and when the booster valve is opened, a liquid hammering sound or a pulsation of the hydraulic pressure may occur. For example, front / rear braking force distribution control that distributes the braking force of the front and rear wheels appropriately according to the vehicle traveling state, or left and right braking force distribution that controls the braking force of the left and right wheels for the purpose of ensuring vehicle stability during turning braking When performing control, if the wheel cylinder hydraulic pressure of each wheel is determined to be an optimum value according to deceleration, lateral acceleration, etc., for example, the wheel cylinder hydraulic pressure of the rear wheel becomes the wheel cylinder hydraulic pressure of the other wheels. A pressure difference that exceeds the set differential pressure becomes lower, and a liquid hammering sound and a pulsation of the liquid pressure may occur at the time of opening the pressure intensifying valve. By doing so, it is possible to prevent the occurrence of a liquid hammering sound and the like. In the traction control, for example, similarly to the antilock control of each of the above embodiments, if the discharge hydraulic pressure of the fully operated pump is controlled by the pressure-intensifying electromagnetic control valve and supplied to the wheel cylinder, the set differential pressure And a valve opening speed control may be performed.

Further, the pressure increasing valve may be an electromagnetic valve which simply opens and closes in response to supply and cutoff of current. in this case,
The valve opening speed is set to a value at which, for example, duty control of the current supply to the electromagnetic on-off valve reduces the liquid hammering noise or the pulsation of the hydraulic pressure or prevents the occurrence thereof. For example, if the followability with respect to the supply current of the solenoid on-off valve is not so high and the unit time of the duty control is relatively short, the next current is supplied before the solenoid on-off valve is closed by shutting off the current supply, The electromagnetic on-off valve can be considered to be continuously opened at a speed based on the current obtained by averaging the supply current per unit time of the duty control. The valve opening speed control unit outputs a duty ratio or an increase in the duty ratio to a drive circuit of the electromagnetic on / off valve, and the electromagnetic on / off valve is opened at a speed determined by the increase in the duty ratio. High follow-up to supply current of solenoid on-off valve,
In addition, when the unit time of the duty control is relatively long, the solenoid on-off valve opens and closes following the supply and cutoff of the current. The increase in the supply current due to the increase in the duty ratio increases the distance (opening) of the valve element from the valve seat in the pressure-intensifying electromagnetic control valve, and the electromagnetic on-off valve opens at a speed determined by the increase in the duty ratio. It is made to valve.

Further, in each of the above embodiments, the supply current is increased by a fixed amount by adding the set current to the currently supplied current. It may be increased by multiplying by a larger coefficient (for example, 1.1).

In each of the above embodiments, the low-pressure pump 64 and the high-pressure pump 66 are both gear pumps, but at least one of them may be a plunger pump. When at least one of the low pressure pump and the high pressure pump has a discharge valve such as a plunger pump,
At least one of the check valves 68 and 70 may be omitted.

Further, the present invention may be applied to a hydraulic control device for a brake system including only one pump, or a hydraulic system for a brake system not including a pump capable of controlling a discharge hydraulic pressure according to a braking request. It is also applicable to a pressure control device. For example, it is provided between a master cylinder in which a hydraulic pressure is generated in a pressurizing chamber based on an operation of a brake operating member and a brake cylinder of a brake operated by a hydraulic pressure supplied from the master cylinder to a brake cylinder. A hydraulic pressure control device that includes a booster valve as an electromagnetic valve and controls the hydraulic pressure supplied from the master cylinder to the brake cylinder by opening and closing the booster valve also requires that the hydraulic pressure control increase the hydraulic pressure difference before and after the booster valve. When the pressure-intensifying valve is opened, a liquid hammering sound or the like may be generated. By performing the valve opening speed control, it is possible to prevent and reduce a decrease in hydraulic pressure control accuracy due to the liquid hammering sound and the pulsation of the hydraulic pressure. . The present invention can be applied to any hydraulic pressure control device that includes an electromagnetic valve and in which a hydraulic pressure difference may occur before and after the electromagnetic valve due to hydraulic pressure control by the electromagnetic valve.

While some embodiments of the present invention have been described in detail above, these are merely examples, and the present invention is not limited to the above-mentioned [Problems to be Solved by the Invention, Means for Solving Problems and Effects]. The present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art, including the described embodiment.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a brake system including a brake system hydraulic pressure control device according to an embodiment of the present invention.

FIG. 2 is a front view (partial cross section) showing a pressure-increasing electromagnetic hydraulic pressure control valve and a pressure-decreasing electromagnetic hydraulic pressure control valve which constitute the brake system and are provided for front wheels.

FIG. 3 is a front view (partial cross section) showing a pressure-increasing electromagnetic hydraulic pressure control valve and a pressure-decreasing electromagnetic hydraulic pressure control valve provided for the rear wheel, which constitute the brake system.

FIG. 4 is a block diagram schematically showing a portion of the control device provided in the brake system that is relevant to the present invention.

FIG. 5 is a flowchart showing a normal braking hydraulic pressure control program stored in a ROM of a hydraulic control computer constituting the control device.

FIG. 6 is a flowchart showing an antilock control hydraulic control program stored in a ROM of the hydraulic control computer.

FIG. 7 is a diagram showing a pump performance table stored in a ROM of the hydraulic control computer.

FIG. 8 is a graph showing changes in a target W / C hydraulic pressure and an actual W / C hydraulic pressure and a differential pressure between a discharge hydraulic pressure and an actual W / C hydraulic pressure during braking in the brake system of the present embodiment.

FIG. 9 is a graph showing the relationship between the differential pressure and the initial value of the valve opening current of the pressure increasing electromagnetic control valve.

FIG. 10 is a graph showing a relationship between the differential pressure and the valve opening speed.

FIG. 11 is a graph showing a relationship between a target pressure increasing speed and a valve opening speed.

FIG. 12 is a graph showing changes in actual W / C hydraulic pressure and confinement pressure when the pressure increasing electromagnetic control valve is opened without performing valve opening speed control.

FIG. 13 is a graph showing changes in the actual W / C hydraulic pressure and the confinement pressure when the pressure-increasing electromagnetic control valve is opened while controlling the valve opening speed.

FIG. 14 is a graph showing changes in the confinement pressure and the degree of opening of the pressure-increasing electromagnetic control valve when the valve-opening speed control is performed, the control is stopped halfway, and the pressure-intensifying electromagnetic control valve is fully opened.

FIG. 15 is a computer RO of a control device of a brake system including a hydraulic control device according to another embodiment of the present invention.
4 is a flowchart illustrating a normal braking hydraulic pressure control program stored in M.

FIG. 16 is a graph showing the relationship between the differential pressure and the valve opening speed of the valve opening speed control executed in the program shown in FIG.

17 is a graph showing a relationship between a target pressure increasing speed and a valve opening speed of the valve opening speed control executed in the program shown in FIG.

FIG. 18 is a diagram showing a valve opening speed determination table set based on the relationship between the differential pressure, the target pressure increasing speed, and the valve opening speed shown in FIGS. 16 and 17.

FIG. 19 is a graph showing a relationship between a target pressure increasing speed and a valve opening speed for valve opening speed control in a hydraulic control device according to still another embodiment of the present invention.

FIG. 20 is a graph showing a relationship between a differential pressure for valve opening speed control and a valve opening speed in a hydraulic control device according to still another embodiment of the present invention.

FIG. 21 is a graph showing a relationship between a differential pressure for valve opening speed control and a valve opening speed in a hydraulic control device according to still another embodiment of the present invention.

FIG. 22 is a graph illustrating an increase in supply current to a pressure-intensifying electromagnetic control valve during valve-opening speed control in a hydraulic control device according to still another embodiment of the present invention.

FIG. 23 is a graph illustrating an increase in supply current to a pressure-intensifying electromagnetic control valve during valve-opening speed control in a hydraulic control device according to still another embodiment of the present invention.

[Description of Signs] 20, 22: Front wheel cylinder 24, 2
6: Rear wheel cylinder 50, 52: Wheel cylinder pressure sensor 64: Low pressure pump 66: High pressure pump 72: Liquid passage 74: Pump liquid pressure sensor
76, 80, 84, 88: Electromagnetic control valve for pressure increase 9
2, 94: wheel cylinder fluid pressure sensor 130: valve seat 132: valve 144: solenoid 170: control device 172: fluid pressure control computer

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (5)

[Claims] 1. A brake provided in a liquid passage for guiding hydraulic fluid of a brake system, the solenoid valve being capable of taking a state of communicating with the liquid passage and a state of being shut off, and a valve control device for controlling the electromagnetic valve. A hydraulic control device for a system, comprising: a valve opening speed control unit that opens an electromagnetic valve at a lower speed when the differential pressure across the electromagnetic valve is large when the differential pressure before and after the electromagnetic valve is small. . 2. A brake, comprising: a pump capable of controlling a discharge hydraulic pressure in response to a braking request; and a booster valve provided in a liquid passage connecting the pump and a brake cylinder, the valve being opened when a pressure increase is requested. In the system hydraulic pressure control device, when the residual pressure in the portion of the liquid passage between the pump and the pressure increasing valve at the time of the pressure increasing request is large, the pressure increasing valve is opened at a smaller speed when the residual pressure is small. A fluid pressure control device comprising a valve opening speed control unit for opening a valve. 3. The hydraulic pressure control device for a brake system according to claim 1, further comprising: a differential pressure obtaining unit that obtains a difference between hydraulic pressures before and after the pressure increasing valve in the hydraulic passage as the residual pressure. . 4. During the valve opening speed control by the valve opening speed control unit, if the differential pressure acquired by the differential pressure acquiring unit falls below a set differential pressure, the valve opening speed control unit controls the speed. The hydraulic pressure control device for a brake system according to claim 3, further comprising a valve opening speed control suspension unit that suspends the operation. 5. A required braking force increase in which the valve opening speed controlled by the valve opening speed control unit is made larger when the required braking force increasing gradient required by the braking request is large than when the required braking force increasing gradient is small. The hydraulic pressure control device for a brake system according to any one of claims 1 to 4, further comprising a gradient adding unit.