CENTER VALVE TYPE MASTER CYLINDER

摘要

PROBLEM TO BE SOLVED: To provide a center valve type master cylinder capable of preventing a return delay in a piston at brake operation releasing time by a driver by sufficiently securing clearance between the piston and an annular support member for supporting a piston member being one constitutive element of a center valve mechanism. SOLUTION: Inside clearance G1 formed between an inner diameter of an annular support member 21 and an outer diameter of a piston 3 is set larger than outside clearance G2 formed between a cylinder hole 2 and a maximum outer diameter of the annular support tmember 21 to sufficiently secure clearance as a liquid passage between the annular support member 21 and the piston 3. An outer peripheral surface of the annular support member 21 is partially cut out to form clearance G2' larger than the outside clearance G2 to sufficiently secure the passage area of a hydraulic fluid flowing between the outside clearance G2 and the cylinder hole 2.