Brake fluid pressure controller for vehicle

Abstract

A brake fluid pressure controller for a vehicle having a brake system, a brake operation element and a master cylinder, the brake system including: a pump configured for being activated and increasing brake fluid pressure to provide braking force to a wheel brake of the other brake system in which the brake operation element is not operated; a cutoff valve which blocks an output fluid pressure passage leading from a master cylinder-side to a wheel brake-side when the pump is operated; a brake fluid pool disposed downstream of the cutoff valve and upstream of the pump; and a pressure member configured for being slidably moved by a brake fluid pressure generated on the master cylinder-side relative to the cutoff valve by an operation of the brake operation element and for providing pressure to a fluid pressure passage leading to the wheel brake.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The various aspects, other advantages and further features of the present invention will become more apparent by describing in detail illustrative, non-limiting embodiments thereof with reference to the accompanying drawings.

FIG. 1 is a brake fluid pressure circuit diagram to be used for a brake fluid pressure controller for a vehicle according to a first embodiment of the present invention.

FIG. 2 is a brake fluid pressure circuit diagram showing a state of the brake fluid pressure controller for a vehicle when an ignition is off.

FIG. 3 is a brake fluid pressure circuit diagram showing a state of the brake fluid pressure controller for a vehicle during regular braking.

FIG. 4 is a brake fluid pressure circuit diagram showing a state of the brake fluid pressure controller for a vehicle during interlocking braking.

FIG. 5 is a brake fluid pressure circuit diagram to be used for a brake fluid pressure controller for a vehicle according to a second embodiment of the present invention.

FIG. 6 is a modified example of a brake fluid pressure circuit diagram to be used for a brake fluid pressure controller for a vehicle according to the second embodiment of the present invention.

Claims

1. A brake fluid pressure controller for a vehicle having first and second brake systems and a brake operation element and a master cylinder for each brake system, each brake system comprising a pump configured for, when the brake operation element of one of the first and second brake systems is operated, being activated and increasing a brake fluid pressure to provide a braking force to a wheel brake of the other brake system in which the brake operation element is not operated, whereinat least one of the first and second brake systems comprises:a cutoff valve which is disposed upstream of the pump and blocks an output fluid pressure passage leading from a master cylinder-side to a wheel brake-side when the pump is operated;a brake fluid pool disposed downstream of the cutoff valve and upstream of the pump; anda pressure member configured for being slidably moved by a brake fluid pressure generated on the master cylinder-side relative to the cutoff valve by an operation of the brake operation element and for providing pressure to a fluid pressure passage leading to the wheel brake of the at least one of the brake systems.

2. The brake fluid pressure controller according to claim 1, wherein the pressure member applies a pressure through the pump to a discharged fluid pressure passage extending from the pump, by applying a pressure to a sucked fluid pressure passage leading to the pump when the pump is operated.

3. The brake fluid pressure controller according to claim 1, wherein the pressure member comprises: a cylinder chamber; and a pressure piston which is slidably disposed in the cylinder chamber and partitions the cylinder chamber into a pool chamber and a pressure chamber, and the pressure member is configured such that:a brake fluid flows into and is stored in the pool chamber when the brake operation element is not operated;a brake fluid pressure of the master cylinder-side relative to the cutoff valve is applied to the pressure chamber, andthe pressure piston is allowed to slidably move by the brake fluid pressure generated by the operation of the brake operation element to discharge the brake fluid stored in the pool chamber.

4. The brake fluid pressure controller according to claim 2, wherein the pressure member comprises: a cylinder chamber; and a pressure piston which is slidably disposed in the cylinder chamber and partitions the cylinder chamber into a pool chamber and a pressure chamber, and the pressure member is configured such that:a brake fluid flows into and is stored in the pool chamber when the brake operation element is not operated;a brake fluid pressure of the master cylinder-side relative to the cutoff valve is applied to the pressure chamber, andthe pressure piston is allowed to slidably move by the brake fluid pressure generated by the operation of the brake operation element to discharge the brake fluid stored in the pool chamber.

5. The brake fluid pressure controller according to claim 3, wherein the pressure member has a regulating member that regulates an amount of slide movement of the pressure piston to a predetermined amount.

6. The brake fluid pressure controller according to claim 4, wherein the pressure member has a regulating member that regulates an amount of slide movement of the pressure piston to a predetermined amount.

7. The brake fluid pressure controller according to claim 3, wherein the cylinder chamber of the pressure member has a pressing member that presses the pressure piston to a pressure chamber-side.

8. The brake fluid pressure controller according to claim 4, wherein the cylinder chamber of the pressure member has a pressing member that presses the pressure piston to a pressure chamber-side.

9. The brake fluid pressure controller according to claim 1, wherein the brake system comprising the pressure member is a brake system of a front wheel-side.