Patent ID: 6196642
Filing Date: 2001-03-06
Classification: B60T

Abstract:
A brake fluid pressure controller comprising:a tandem master cylinder;a control valve having a control valve main body and connected to the tandem master cylinder via a first input port;a diaphragm piston inside the control valve main body;a diaphragm inside the control valve main body, wherein an outer circumference of the diaphragm is secured to the control valve main body; anda first output port for outputting hydraulic pressure proportional to pressure in the tandem master cylinder,wherein a flexible portion of the diaphragm is adapted to contact an end surface of the diaphragm piston;wherein a wall thickness of the diaphragm decreases from a center portion of the diaphragm to the outer circumference of the diaphragm;a first cylinder in the control valve main body;a pilot piston slidably arranged within the first cylinder and having a stepped shape including a large diameter portion and a small diameter portion;a first hydraulic chamber, a second hydraulic chamber and a third hydraulic chamber arranged within the first cylinder and sectioned by the pilot piston;a second output port in the control valve main body; anda third output port in the control valve main body,wherein the first hydraulic chamber communicates with a first hydraulic pressure chamber of the tandem master cylinder via the first input port,wherein the first hydraulic chamber communicates with the first output port of the control valve,wherein the second hydraulic chamber communicates with the third output port,wherein the third hydraulic chamber communicates with the second input port of the control valve main body, andwherein the third hydraulic chamber communicates with the second output port.