JPH11245793A - Vehicular brake hydraulic pressure control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake hydraulic pressure control device being applicable to antiskid control, traction control, sideslip preventive control or the like by properly sucking a brake fluid stored in a reservoir by a hydraulic pump. SOLUTION: This brake hydraulic pressure control device is equipped with reservoirs RS1 and RS2 storing a brake fluid exhausted out of a wheel cylinder via modulators PC1 to PC8, hydraulic pumps HP1, HP2, selector valves SC1 and 2, S11 and 12 selectively connecting a master cylinder to the modulators or each inlet side of the hydraulic pumps, and first check valves CV5 and 8 being disposed between the reservoir and a first junction J1 connecting the master cylinder to the inlet side of the hydraulic pump via the selector valve, and allowing only a flow of the brake fluid to the hydraulic pump side, respectively. Moreover, second check valves CV7 and 10 allowing only the brake fluid flowing into the hydraulic pump side are installed in space between the selector valve and the first junction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake fluid for supplying brake fluid of a master cylinder to a wheel cylinder via a modulator by a hydraulic pump and storing brake fluid of the wheel cylinder in a reservoir via a modulator. The pressure control device is particularly applicable to anti-skid control, traction control, side slip prevention control for preventing a vehicle from skidding, and the like.

[0002]

2. Description of the Related Art As this kind of prior art, for example, the one disclosed in Japanese Patent Application Laid-Open No. 5-116609 is known. This device performs traction control using a hydraulic pump for anti-skid control.

[0003] More specifically, a brake is provided in a main hydraulic pressure path connecting a master cylinder to a wheel cylinder, and controls a brake fluid pressure of the wheel cylinder, and a brake discharged from the wheel cylinder via the modulator. A reservoir for storing fluid, a suction side connected to the reservoir, and a discharge side connected to a main hydraulic pressure passage between the modulator and the master cylinder. The brake fluid in the reservoir is sucked and pressurized, and the pressurized brake fluid is passed through the modulator. And a hydraulic pump for discharging to a wheel cylinder. A normally open first on-off valve is provided in the main hydraulic path between the master cylinder and the modulator, and a normally closed type open / close valve is connected to the auxiliary hydraulic path connecting the master cylinder to the suction side of the hydraulic pump. The second on-off valve is provided, so that traction control can be performed. Further, a check valve is provided between the connection point of the auxiliary hydraulic passage with the hydraulic pump suction side and the reservoir, which allows the flow of the brake fluid to the hydraulic pump side and prevents the flow in the reverse direction, Thus, it is possible to prevent the pressurized brake fluid of the master cylinder from flowing into the reservoir while the second on-off valve is open.

[0004]

In the above apparatus, the hydraulic pump is driven, and the first on-off valve is in the closed position and the second on-off valve is in the second position.
Each of the on-off valves is switched to the open position, and the modulator is controlled, whereby traction control is performed. That is, the brake fluid of the master cylinder is supplied to the wheel cylinder by the hydraulic pump, and the brake fluid pressure of the wheel cylinder is adjusted by the modulator. When the brake pedal is operated in this state, the output hydraulic pressure of the master cylinder rises and becomes higher than the hydraulic pressure of the reservoir. In addition, since the check valve exists between the connection point of the auxiliary hydraulic pressure path and the reservoir, it becomes a resistance when the hydraulic pump sucks the brake fluid in the reservoir. For this reason, the hydraulic pump preferentially sucks the brake fluid in the master cylinder, and as a result, the brake fluid stored in the reservoir can hardly be sucked, and the reservoir may be full. Therefore, for example, when shifting to the anti-skid control, it may be difficult to perform the predetermined pressure reducing operation. This problem also occurs when the present invention is applied to a vehicle side slip prevention device.

Therefore, according to the present invention, the brake pedal is operated, and the hydraulic fluid pump supplies the brake fluid of the master cylinder to the wheel cylinder via the modulator.
When adjusting the brake fluid pressure of the wheel cylinder,
It is an object of the present invention to provide a vehicle brake hydraulic pressure control device capable of appropriately sucking brake fluid stored in a reservoir by a hydraulic pump.

[0006]

In order to solve the above technical problems, a vehicle brake fluid pressure control apparatus according to the present invention is provided with a wheel cylinder mounted on wheels of a vehicle to apply a braking force, and a brake pedal. A master cylinder that generates a hydraulic pressure in accordance with the operation of the above, a main hydraulic path that connects the master cylinder to the wheel cylinder, and a modulator that is disposed in the main hydraulic path and that controls brake hydraulic pressure of the wheel cylinder. A reservoir for storing brake fluid discharged from the wheel cylinder via the modulator;
A suction side is connected to the reservoir, and a discharge side is connected to the main hydraulic path between the modulator and the master cylinder. The brake fluid in the reservoir is suctioned and pressurized, and the pressurized brake fluid is passed through the modulator. A hydraulic pump for discharging to the wheel cylinder, switching valve means for selectively connecting the master cylinder to the modulator or the suction side of the hydraulic pump, and a hydraulic pump for connecting the master cylinder through the switching valve means. A first check valve disposed between a first connection point connected to a suction side of a pump and the reservoir, and allowing a flow of brake fluid to the hydraulic pump side and preventing a flow in a reverse direction; In the brake fluid pressure control device for a vehicle provided with, between the switching valve means and the first connection point, the flow of the brake fluid to the hydraulic pump side is allowed to flow in the opposite direction. In which is disposed a second check valve that stop.

According to the first aspect of the present invention, the hydraulic pump is provided between the connection point (first connection point) connecting the master cylinder to the suction side of the hydraulic pump via the switching valve means and the switching valve means. A check valve (second check valve) that allows only the flow of brake fluid to the side is provided, so that it becomes a resistance when the hydraulic pump sucks the brake fluid of the master cylinder, but the brake fluid in the reservoir It does not become a resistance when inhaling. As a result, when the brake pedal is operated and the hydraulic fluid pump supplies the brake fluid of the master cylinder to the wheel cylinder via the modulator to adjust the brake fluid pressure of the wheel cylinder, the brake fluid stored in the reservoir is adjusted. The liquid can be appropriately sucked by a hydraulic pump. Therefore,
It can suppress that the inside of a reservoir becomes full.

Further, the first check valve can be used as a pump suction valve for a reservoir, and the second check valve can be used as a pump suction valve for a master cylinder. As a result, the suction resistance of the hydraulic pump can be minimized. Can be.

According to a first aspect of the present invention, a first orifice is disposed between the first connection point and the reservoir, and a first orifice is provided between the switching valve means and the connection point. It is preferable to arrange the second orifice in the second orifice. According to this configuration, when the brake pedal is operated and the brake fluid of the master cylinder is supplied to the wheel cylinder via the modulator by the hydraulic pump and the brake fluid pressure of the wheel cylinder is adjusted, the hydraulic pump is Thus, the brake fluid can be reliably sucked from both the master cylinder and the reservoir. Further, for example, when the suction pressure of the hydraulic pump temporarily becomes zero, it is possible to prevent a rapid inflow of brake fluid to the suction side of the hydraulic pump.

According to a second aspect of the present invention, it is preferable that the throttle area of the first orifice is smaller than the throttle area of the second orifice. According to this configuration, the resistance when the hydraulic pump sucks the brake fluid in the reservoir may be smaller than the resistance when the brake pump sucks the brake fluid in the master cylinder. Therefore, when the brake pedal is operated and the hydraulic fluid pump supplies the brake fluid of the master cylinder to the wheel cylinders via the modulator to adjust the brake fluid pressure of the wheel cylinders, the brake fluid stored in the reservoir is adjusted. Can be reliably sucked by the hydraulic pump.

According to a first aspect of the present invention, the flow of the brake fluid to the hydraulic pump is allowed between the first connection point and the suction side of the hydraulic pump. A third check valve for preventing the flow in the reverse direction may be provided.

According to a first aspect of the present invention, there is provided an auxiliary hydraulic pressure path connecting the master cylinder to the first connection point, wherein the switching valve means is connected to a discharge side of the hydraulic pump. A first on-off valve for opening and closing the main hydraulic path between a second connection point connecting the main hydraulic path and the master cylinder, and a second on-off valve for opening and closing the auxiliary hydraulic path. Preferably, the second check valve is disposed in the auxiliary hydraulic pressure path.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a brake fluid pressure control device according to a first embodiment. In response to an operation of a brake pedal BP, a master cylinder MC is provided via a vacuum booster VB.
Is boosted, the brake fluid in the master reservoir LRS is boosted, and the master cylinder hydraulic pressure is output to the hydraulic system on the wheels FR, RL and the wheels FL, RR. That is, a so-called X pipe is configured. The master cylinder MC is a tandem type master cylinder, and two pressure chambers are connected to respective brake hydraulic systems. That is, the first pressure chamber MCa is connected to the brake hydraulic system on the wheels FR, RL side, and the second pressure chamber MCb is connected to the wheels F, RL.
It is connected to the brake hydraulic system on the L, RR side.

In the brake hydraulic system for the wheels FR and RL, the first pressure chamber MCa is connected to the wheel cylinders Wfr and Wrl via a main hydraulic pressure passage MF1 and its branch hydraulic pressure passages MFr and Mrl, respectively. I have. Branch hydraulic path MF
r and Mrl are normally open two-port two-position solenoid valves PC1 and PC2 (hereinafter simply referred to as valve PC1 and PC2, respectively).
2). Further, check valves CV1 and CV2 are arranged in parallel with these, respectively. Check valve CV
1 and CV2 allow only the flow of the brake fluid in the direction of the master cylinder MC. When the brake pedal BP is released, the wheel cylinders Wfr, CV1 and CV2, The brake fluid in the Wrl is returned to the master cylinder MC and eventually to the master cylinder reservoir LRS. Also,
Normally-closed two-port two-position solenoid on-off valves PC5 and PC6 (hereinafter simply referred to as on-off valves PC5 and PC6) are arranged on discharge-side branch hydraulic pressure paths RFr and Rrl that are connected to the wheel cylinders Wfr and Wrl. And the branch hydraulic path RF
The discharge hydraulic pressure path RF where r and Rrl merge is connected to the auxiliary reservoir RS1 at the connection point J3.

The auxiliary reservoir RS1 has a hydraulic pump HP
1 is connected to the suction side, and the discharge side is connected to the upstream side of the on-off valves PC1 and PC2 via a hydraulic path MFp.
The hydraulic pump HP1 is driven by a single electric motor M together with the hydraulic pump HP2, introduces brake fluid from the suction side, increases the pressure to a predetermined pressure, and outputs it from the discharge side. The auxiliary reservoir RS1 is provided independently of the master reservoir LRS of the master cylinder MC, and can be referred to as an accumulator. The auxiliary reservoir RS1 includes a piston and a spring, and is configured to store a predetermined volume of brake fluid. I have.

The connection point J2 of the hydraulic path MFp and the pressure chamber MC
A normally open two-port two-position electromagnetic on-off valve SC1 (which functions as a so-called cut-off valve, hereinafter simply referred to as on-off valve SC1) is disposed in the main hydraulic pressure path MF1 between a and b. Further, the first pressure chamber MCa is connected to the suction side of the hydraulic pump HP1 at the connection point J1 via the auxiliary hydraulic path MFc1. The auxiliary hydraulic passage MFc1 has two ports 2
A normally closed solenoid on-off valve SI1 is provided. The normally closed valve SI1 shuts off the communication between the master cylinder MC and the suction side of the hydraulic pump HP1 at the normally closed position shown in FIG. 1, and connects the master cylinder MC and the suction side of the hydraulic pump HP1 at the open position. Is switched to.

A check valve CV5 and an orifice O1 are arranged between the connection point J1 of the auxiliary hydraulic pressure path MFc1 and the connection point J3 of the discharge hydraulic pressure path MF in order from the hydraulic pump HP1 side. The check valve CV5 blocks the flow of the brake fluid to the auxiliary reservoir RS1, and allows the flow in the reverse direction.
The suction valve for the auxiliary reservoir RS1 is also used. Also,
The orifice O1 prevents sudden inflow of brake fluid from the auxiliary reservoir RS1 to the suction side of the hydraulic pump HP1. In the hydraulic passage MFp on the discharge side of the hydraulic pump HP1, a check valve CV6 serving as a discharge valve and a damper DP1 for reducing discharge pulsation are arranged in order from the hydraulic pump HP1 side.

Auxiliary hydraulic passage MFc downstream of on-off valve SI1
Is provided with a check valve CV7 and an orifice O2 in this order from the hydraulic pump HP1 side. The check valve CV7 allows the flow of the brake fluid to the hydraulic pump HP1 side and prevents the flow in the reverse direction, and also serves as a suction valve for the master cylinder MC. The check valve CV7 is provided with an on-off valve SI1.
When the hydraulic pump HP1 is opened, the resistance when the hydraulic pump HP1 sucks the brake fluid of the master cylinder MC is, of course, not the resistance when the brake fluid of the auxiliary reservoir RS1 is sucked. The orifice O2 prevents the brake fluid from rapidly flowing from the master cylinder MC to the hydraulic pump HP1, and also serves as a resistance when the brake fluid of the master cylinder MC is sucked. Here, the throttle area of the orifice O2 is smaller than the throttle area of the orifice O1, and the suction resistance from the auxiliary reservoir RS1 side is smaller than the suction resistance from the master cylinder MC side.

A relief valve RV is connected in parallel with the on-off valve SC1.
1 and a check valve AV1. Relief valve RV
1 restricts the flow of the brake fluid from the master cylinder MC in the direction of the on-off valves PC1 and PC2, and controls the on-off valves PC1 and PC2.
When the brake fluid pressure on the second side becomes higher than the master cylinder fluid pressure by a predetermined set pressure or more, the brake fluid is allowed to flow in the direction of the master cylinder MC (a so-called relative pressure relief valve). It is possible to prevent the discharge brake fluid from the pressure pump HP1 from exceeding a predetermined pressure. Check valve AV1
Is for permitting the flow of the brake fluid in the direction of the wheel cylinders Wfr and Wrl and prohibiting the flow in the opposite direction. Due to the presence of the check valve AV1, the brake fluid pressure in the wheel cylinders Wfr and Wrl is increased when the brake pedal BP is depressed even when the on-off valve SC1 is in the closed position. The wheel cylinder Wrl on the rear wheel side
The proportioning valve PV1 is interposed in the hydraulic path leading to.

On the other hand, also in the brake fluid pressure system on the wheels FL and RR, similarly, the normally open solenoid on-off valves PC3 and PC3 are used.
4. Normally closed electromagnetic on / off valves PC7 and PC8, normally open electromagnetic on / off valve SC2, and normally closed electromagnetic on / off valve SI2 are provided, respectively. Also, check valves CV3, CV4, CV8 to CV10, relief valve RV2, check valve AV2, reservoir RS2, damper DP2 and proportioning valve P
V2 is also provided. The hydraulic pump HP2 is driven by the electric motor M together with the hydraulic pump HP1.

FIG. 2 shows a vehicle brake fluid pressure control device according to a second embodiment. This is a check valve that allows only the flow of the brake fluid to the hydraulic pump HP1 side between the connection point J1 and the hydraulic pump HP1 in the FR-RL hydraulic system in addition to the first embodiment. CV11 is newly established. In the FL-RR hydraulic system, a check valve CV12 is similarly newly provided. That is, these check valves CV11 and CV12 are common suction valves for the auxiliary reservoir RS and the master cylinder MC.

In this embodiment, two on-off valves SC
1, SI1 is employed, but a 3-port 2-position electromagnetic switching valve may be employed instead.

Although the X pipe hydraulic circuit has been described, the present invention is also applicable to front and rear pipes.

[0025]

According to the present invention, the hydraulic pump side is provided between the connection point (first connection point) connecting the master cylinder to the suction side of the hydraulic pump via the switching valve means and the switching valve means. Check valve (second check valve) that allows only the flow of brake fluid to the brake pedal is operated, and the hydraulic fluid pump supplies the brake fluid of the master cylinder to the wheel cylinder via the modulator. When the brake fluid pressure of the wheel cylinder is being adjusted, the brake fluid stored in the reservoir can be appropriately sucked by the fluid pressure pump. Therefore, it is possible to suppress the reservoir from being full.

Further, the first check valve can be used as a pump suction valve for a reservoir, and the second check valve can be used as a pump suction valve for a master cylinder. As a result, the suction resistance of the hydraulic pump can be minimized. Can be.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle brake fluid pressure control device according to a first embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a vehicle brake fluid pressure control device according to a second embodiment of the present invention.

[Explanation of symbols]

 FR, FL, RR, RL Wheel Wfr, Wfl, Wrr, Wrl Wheel cylinder BP Brake pedal MC Master cylinder MF Main hydraulic pressure passage PC1-PC8 Open / close valve (modulator) RS1, RS2 Auxiliary reservoir (reservoir) HP1 Hydraulic pump SC1, SC2 On-off valve (switching valve means; first on-off valve) MFc Auxiliary hydraulic pressure path SI1, SI2 On-off valve (switching valve means; second on-off valve) CV5, CV8 Check valve (first check valve) CV7, CV8 Reverse Stop valve (second check valve) J1 connection point (first connection point) J2 connection point (second connection point) O1, O3 orifice (first orifice) O2, O4 orifice (second orifice)

Claims (5)

[Claims] 1. A wheel cylinder mounted on wheels of a vehicle for applying a braking force, a master cylinder for generating a hydraulic pressure in response to an operation of a brake pedal, and a main hydraulic passage connecting the master cylinder to the wheel cylinder. A modulator disposed in the main hydraulic path for controlling brake fluid pressure of the wheel cylinder; a reservoir for storing brake fluid discharged from the wheel cylinder via the modulator; and a suction side connected to the reservoir. And a discharge side connected to the main hydraulic pressure passage between the modulator and the master cylinder to suck and pressurize brake fluid in the reservoir, and discharge the pressurized brake fluid to the wheel cylinder via the modulator. Pressure pump and the master cylinder selectively on the suction side of the modulator or the hydraulic pump A switching valve means for connecting, and a first connection point for connecting the master cylinder to the suction side of the hydraulic pump via the switching valve means and the reservoir; A first check valve for permitting the flow of brake fluid and preventing the flow in the reverse direction, wherein the fluid is provided between the switching valve means and the first connection point. A brake fluid pressure control device for a vehicle, comprising a second check valve for allowing a flow of brake fluid to a pressure pump side and preventing a flow in a reverse direction. 2. The device according to claim 1, wherein a first orifice is provided between the first connection point and the reservoir, and a second orifice is provided between the switching valve means and the connection point. A brake fluid pressure control device for a vehicle, comprising: 3. The vehicle brake fluid pressure control device according to claim 2, wherein the throttle area of the first orifice is smaller than the throttle area of the second orifice. 4. The hydraulic pump according to claim 1, wherein a flow of the brake fluid to the hydraulic pump is allowed between the first connection point and a suction side of the hydraulic pump, and a flow in a reverse direction is prevented. A brake pressure control device for a vehicle, comprising a third check valve. 5. The hydraulic pump according to claim 1, further comprising an auxiliary hydraulic pressure path connecting the master cylinder to the first connection point, wherein the switching valve means connects a discharge side of the hydraulic pump to the main hydraulic pressure path. A first on-off valve for opening and closing the main hydraulic passage between the second connection point and the master cylinder, and a second on-off valve for opening and closing the auxiliary hydraulic passage. A brake pressure control device for a vehicle, wherein the second check valve is provided.