MASTER CYLINDER DEVICE

摘要

A master cylinder device 110 according to the invention comprises: a housing 300 whose front side is closed and which has a separation wall for separating the inside of the housing into a front side chamber and a rear side chamber; a pressurizing piston 302 disposed in the front side chamber so as to define a pressurizing chamber R1 for pressurizing the brake fluid and an input chamber R3 into which a brake fluid from a high pressure source 118 is introduced; an input piston 306 disposed in the rear side chamber and moving forward by an operation force; and a transmission rod 340 which is through the separation wall, whose proximal end portion is fixed in one of the above pistons, and whose distal end portion is apart from the other of the above pistons in a state of no forward movement.