VEHICLE BRAKE DEVICE

摘要

A vehicle brake device includes a hydraulic pressure generating device, a valve device, a pump and an accumulation section forming an accumulation chamber connected to a fluid passage between the valve device and the hydraulic pressure generating device or to a master chamber. A dead band is set in which the change of force of the magnitude corresponding to the hydraulic pressure in the master chamber does not substantially act on a brake operating member. A characteristic representing the relation between the pressure and the brake fluid quantity in the accumulation chamber is set based on a characteristic representing the relation between the pressure and the brake fluid quantity in a wheel cylinder and the dead band so that, when brake fluid is flowing into and from the accumulation chamber, a force of the magnitude corresponding to the master chamber hydraulic pressure does not act on the brake operating member.

主权项

1. A vehicle brake device comprising:
a hydraulic pressure generating device in which with an operation on a brake operating member, a master piston is slid relative to a master cylinder to generate a hydraulic pressure corresponding to the operation on the brake operating member in a master chamber; a valve device that is provided on a flow passage for brake fluid between the hydraulic pressure generating device and a wheel cylinder and that controls the flow of the brake fluid between the hydraulic pressure generating device and the wheel cylinder; a pump that discharges the brake fluid on the hydraulic pressure generating device side with respect to the valve device toward the wheel cylinder side with respect to the valve device; and an accumulation section that forms an accumulation chamber connected to a portion between the valve device and the hydraulic pressure generating device of the fluid passage for the brake fluid or to the master chamber; wherein a dead band is set that, when the change of the hydraulic pressure in the master chamber acting on the master piston is smaller than a predetermined value, makes the change of an operating force on the brake operating member relative to the change of the hydraulic pressure in the master chamber not act substantially on the brake operating member; and wherein a characteristic representing the relation between the hydraulic pressure and the fluid quantity of the brake fluid in the accumulation chamber is set based on a characteristic representing the relation between the hydraulic pressure and the fluid quantity of the brake fluid in the wheel cylinder and the dead band so that, when brake fluid is flowing into or from the accumulation chamber, a force of the magnitude corresponding to the hydraulic pressure in the master chamber acting on the master piston does not act on the brake operating member.