초록 ▼

A master cylinder realizes a stroke simulator function without the need to change the structure around a brake pedal and without impairing brake pedal feel, is easy to form by machining, and also facilitates a hydraulic fluid charging and air bleeding operation. A secondary piston is split to make t

A master cylinder realizes a stroke simulator function without the need to change the structure around a brake pedal and without impairing brake pedal feel, is easy to form by machining, and also facilitates a hydraulic fluid charging and air bleeding operation. A secondary piston is split to make the axial length thereof variable, thereby imparting the stroke simulator function to the secondary piston. By doing so, brake pedal feel is improved more than by separately adding a stroke simulator.

대표청구항 ▼

[ What is claimed is:] [1.]1. A master cylinder comprising:a cylinder having a cylinder bore, one end of which is closed to form a bottom, and a port communicated with a reservoir; andat least one piston slidably disposed in said cylinder bore for partially defining a fluid pressure generating chamb

[ What is claimed is:] [1.]1. A master cylinder comprising:a cylinder having a cylinder bore, one end of which is closed to form a bottom, and a port communicated with a reservoir; andat least one piston slidably disposed in said cylinder bore for partially defining a fluid pressure generating chamber which is connected to at least one wheel cylinder,wherein said piston includes:a front piece adjacent to said fluid pressure generating chamber;a rear piece on the side of the front piece remote from said fluid pressure generating chamber;seals supported by said front and rear pieces to define therebetween a fluid supply chamber for the fluid pressure generating chamber, the seal supported by said front piece separating said fluid pressure generating chamber from said fluid supply chamber; anda device for connecting said front and rear pieces so that it permits the distance between these pieces to be reduced upon application of an input force to said piston while exerting a reaction force and restores the original distance upon cancellation of the input force;wherein said port communicates with said fluid supply chamber so that fluid in said fluid supply chamber is not pressurized when said distance between said front and rear pieces is reduced.