US 6,607,254 B2Granted

Hydraulic brake device

AssigneeAisin Seiki Kabushiki Kaisha

InventorHaruo Arakawa

Life of this patent

Estimating the term…

Loading patent…

Abstract

A hydraulic brake device which enables an accurate increase in the braking force after reaching the boosting limit of a brake booster includes a cylinder, a master piston, a floating piston, a master pressure chamber defined by the cylinder, the master piston and the floating piston, a brake pressure chamber defined by the cylinder and the floating piston, and a valve disposed in the master piston for establishing and interrupting a communication between the master pressure chamber and a reservoir tank. In addition, a valve actuating member is movable relative to the output member for opening the valve when moved by a predetermined amount relative to the output member in accordance with operation of the brake operation member, and a moving amount controlling mechanism reduces the relative movement of the valve actuating member in accordance with the increase of the operation force by the brake operating member.

Claims15

Dependent claims

A hydraulic brake device comprising:

a cylinder;
a master piston movable in the cylinder in response to operation of an output member of a brake booster in accordance with operation of a brake operation member;
a floating piston having a smaller diameter than the master piston, the floating piston being engaged with the master piston and movable relative to the master piston;
a master pressure chamber defined by the cylinder, the master piston and the floating piston;
a brake pressure chamber defined by the cylinder and the floating piston;
a valve disposed in the master piston for establishing and interrupting communication between the master pressure chamber and a reservoir tank;
a valve actuating member movable relative to the output member for opening the valve when the valve actuating member is moved by a predetermined amount relative to the output member in accordance with operation of the brake operation member;
and
a moving amount controlling mechanism reducing the relative movement of the valve actuating member with respect to the output member in accordance with an increase of the operation force by the brake operating member.

6 more elements

A hydraulic brake device comprising:

a vacuum booster which boosts an operation force applied to a brake operation member, the vacuum booster having an output member and a deformable reaction disk mounted in the output member;
a cylinder;
a master piston movable in the cylinder in response to operation of the output member of the vacuum booster, the master piston having a diameter;
a floating piston positioned in the cylinder and engaged with the master piston, the floating piston having a diameter that is smaller than the diameter of the master piston and being movable relative to the master piston;
a master pressure chamber defined by the cylinder, the master piston and the floating piston;
a brake pressure chamber defined by the cylinder and the floating piston;
a valve disposed in the master piston and adapted to be open to permit communication between the master pressure chamber and a reservoir tank and adapted to be closed to prevent communication between the master pressure chamber and the reservoir tank;
a projecting pin movable relative to the output member in accordance with operation of the brake operation member to open the valve when the valve projecting pin is moved by a predetermined amount relative to the output member in accordance with operation of the brake operation member;
and
a space provided between the output member and an outer periphery of the reaction disk, the space receiving a portion of the reaction disk when the reaction disk is deformed during increased operation force by the brake operating member to reduce movement of the projecting pin relative to the output member.

7 more elements

Dependencies are inferred from the claim text.