Vehicle brake system

Patent metadata

Field	Value
Publication number	US-10682999-B2
Application number	US-201815956917-A
Country	US
Kind code	B2
Filing date	Apr 19, 2018
Priority date	May 11, 2017
Publication date	Jun 16, 2020
Grant date	Jun 16, 2020

Abstract

A vehicle brake system including a hydraulic brake device having two systems and configured to generate a braking force, wherein, in a failure condition of one of the two systems, one of the following two operation modes of the hydraulic brake device is selectively established: (a) a two-wheel mode in which master shut-off valves shut respective master fluid passages and a braking force that depends on a pressure of a working fluid supplied from a master cylinder is generated for each of right and left wheels; and (b) a one-wheel mode in which one of the master shut-off valves corresponding to the other of the two systems shuts off the corresponding master fluid passage and a braking force that depends on the working fluid supplied by a controlled-pressure supply device is generated for only one of the right and left wheels that corresponds to the other of the two systems.

First claim

What is claimed is:

1. A brake system for a vehicle installed on the vehicle, the brake system comprising a brake operation member to be operated by a driver and a hydraulic brake device configured to generate a braking force that depends on a pressure of a working fluid in accordance with an operation of the brake operation member,
wherein the hydraulic brake device includes two systems respectively corresponding to a right wheel and a left wheel,
wherein the hydraulic brake device includes:
a pair of wheel brakes which are provided respectively for the right wheel and the left wheel and which are configured to generate the braking force in accordance with a pressure of the working fluid supplied thereto;

a master cylinder configured to pressurize the working fluid by a force applied to the brake operation member by the driver;
a pair of master fluid passages through which the working fluid pressurized by the master cylinder is supplied to the respective wheel brakes;
a pair of master shut-off valves which are provided respectively for the master fluid passages so as to shut off flows of the working fluid through the respective master fluid passages; and
a controlled-pressure supply device including a high-pressure source and configured to supply, to the wheel brakes, the working fluid from the high-pressure source while controlling the pressure of the working fluid,
wherein, in a normal condition, the master shut-off valves shut off the flows of the working fluid through the respective master fluid passages and the hydraulic brake device generates, for each of the right wheel and the left wheel, the braking force that depends on the working fluid supplied by the controlled-pressure supply device, and
wherein, in a failure condition of one of the two systems, one of the following two operation modes of the hydraulic brake device is selectively established: (a) a two-wheel mode in which the master shut-off valves allow the flows of the working fluid through the respective master fluid passages and the hydraulic brake device generates, for each of the right wheel and the left wheel, the braking force that depends on a pressure of the working fluid supplied from the master cylinder; and (b) a one-wheel mode in which one of the master shut-off valves that corresponds to the other of the two systems shuts off the flow of the working fluid through a corresponding one of the master fluid passages and the hydraulic brake device generates the braking force that depends on the working fluid supplied by the controlled-pressure supply device for only one of the right wheel and the left wheel that corresponds to the other of the two systems.

2. The vehicle brake system according to claim 1 ,
wherein, in the failure condition of the one of the two systems, the two-wheel mode is established when the driver operates the brake operation member while the one-wheel mode is established when a brake request not based on an intension of the driver is made.

3. The vehicle brake system according to claim 2 , wherein, when the driver operates the brake operation member in a state in which the one-wheel mode is established, the two-wheel mode is established in place of the one-wheel mode in an instance where a sum of the braking forces which would be generated for the right wheel and the left wheel in the two-wheel mode in accordance with the operation of the brake operation member is larger than the braking force which is being generated for the one of the right wheel and the left wheel in the one-wheel mode.

4. The vehicle brake system according to claim 1 ,
wherein the hydraulic brake device is provided for one of: front right and left wheels; and rear right and left wheels, and
wherein the vehicle brake system further comprises an electric brake device provided for the other of: the front right and left wheels; and the rear right and left wheels, the electric brake device being configured to generate, based on the operation of the brake operation member, a braking force that depends on a force generated by an electric motor.

5. The vehicle brake system according to claim 4 , wherein the hydraulic brake device is provided for the front right and left wheels, and the electric brake device is provided for the rear right and left wheels.

6. The vehicle brake system according to claim 4 , wherein a ratio between the braking force to be generated for the right wheel by the electric brake device and the braking force to be generated for the left wheel by the electric brake device is changed depending upon which one of the two-wheel mode and the one-wheel mode is being established.

7. The vehicle brake system according to claim 1 , wherein the hydraulic brake device includes a reservoir, as a low-pressure source, which stores the working fluid,
wherein the master cylinder is configured to pressurize the working fluid stored in the reservoir,
wherein the controlled-pressure supply device includes:
a reservoir fluid passage connected to the reservoir not via the master cylinder;
a pump device, as a high-pressure source, which is configured to pump up the working fluid stored in the reservoir via the reservoir fluid passage so as to pressurize the working fluid and to supply the pressurized working fluid to the wheel brakes;
a pair of return fluid passages each of which connects a corresponding one of the wheel brakes to the reservoir or the reservoir fluid passage; and
a pair of electromagnetic control valves which are provided respectively for the return fluid passages and each of which is configured to control a flow of the working fluid from a corresponding one of the wheel brakes to the reservoir in accordance with electric current supplied thereto.

Assignees

• Toyota Motor Co Ltd

Inventors

• Yamamoto Naoki

Classifications

• B60T8/4081 Primary

  Systems with stroke simulating devices for driver input (B60T8/4077 takes precedence) · CPC title

• B60T8/4059

  involving the rate of delivery · CPC title

• B60T8/94

  on a fluid pressure regulator · CPC title

• B60T13/741

  acting on an ultimate actuator · CPC title

• B60T17/18 Primary

  Safety devices; Monitoring · CPC title