MASTER CYLINDER WITH INCREASED SAFETY AND PISTON FOR SUCH A MASTER CYLINDER

摘要

A master cylinder with improved safety and a piston for the master cylinder are provided to secure a simple design, to apply for any kinds of master cylinders having a valve and the piston, and to be appropriate for an electronic safety control system. A master cylinder with improved safety is composed of a body(2) having a bore(3) blocked by an end wall(5) at one end; at least one piston(8,10) mounted to the bore to slide in a sealed state; a hydraulic fluid supply chamber(26) formed as a longitudinal slot in the piston; an operating chamber connected to a brake and the supply chamber through a passage(36) formed in the piston; and a valve(18) for cutting off the passage in a braking state. The valve has a valve seat(20) supported by the piston and a shutter(22). The shutter is propped for a supporting element(42) fixed and mounted to the body of the master cylinder. The supporting element passes through the longitudinal slot. The distance for separating a first end of the slot far apart from the valve and a first end of the supporting element far from the end wall is shorter than the distance for separating a first end(34) of the piston close to the end wall and the end wall. The supporting element is a pin. The first end of the slot is formed like a circular arc with the diameter same as the diameter of the pin to distribute equally stress applied on the piston.