Vehicle brake device and vehicle brake device control method

摘要

In a BBW type vehicle brake device, first and second fluid paths that are connected to each other are both connected to a slave cylinder with a simple structure that is equipped with a single fluid pressure chamber, thereby enabling wheel cylinders having two lines to be operated and eliminating the need for a complicated tandem type slave cylinder. When the slave cylinder becomes inoperable due to malfunction of the power supply, by opening first and second master cut valves and closing the communication control valve, braking is carried out by means of brake fluid pressure generated by a master cylinder. In this process, since the interconnection between the first and second fluid paths is blocked by closing the communication control valve, even if the wheel cylinder of one of the brake lines suffers from a liquid leakage malfunction, the other remained brake line is enabled to ensure a braking force.

主权项

1. A vehicle brake device comprising:
a master cylinder that is operated by a brake pedal to generate brake fluid pressure for two fluid supply lines, a stroke simulator that is connected to at least one output port of the master cylinder and into which is introduced a brake fluid from the master cylinder, a first fluid path that provides a connection between a first fluid pressure chamber of the master cylinder and a wheel cylinder of a first one of said fluid supply lines, a second fluid path that provides a connection between a second fluid pressure chamber of the master cylinder and a wheel cylinder of a second one of said fluid supply lines, a slave cylinder that is connected to the first fluid path and generates a brake fluid pressure by means of the driving force of an actuator, first and second master cut valves that are provided in the first and second fluid paths respectively on an upstream side relative to the slave cylinder and can block communication between the master cylinder and the wheel cylinders of the first and second lines, a third fluid path that provides communication between the first and second fluid paths on a downstream side relative to the first and second master cut valves, and a communication control valve that is provided in the third fluid path and, when closed, blocks fluid communication between the first and second fluid paths via the third fluid path, wherein the communication control valve is placed in communication with the slave cylinder at all times via only one of the first and second fluid paths.