| 摘要 |
PROBLEM TO BE SOLVED: To provide a master cylinder device that is applied to a longitudinally interlocking brake apparatus of a vehicle, thereby allowing feeling in operation of a brake pedal to be excellent.SOLUTION: A first piston 61 is inserted into a first cylinder bore, and a second piston 115 is inserted into a second cylinder bore and a third cylinder bore. The second piston is biased by a second coil spring. Inner diameters of the first cylinder bore and the third cylinder bore are substantially identical to each other. An inner diameter of the second cylinder bore is half of the inner diameter of the third cylinder bore. The interior of the first cylinder bore communicates with the interior of the second cylinder bore and the interior of the third cylinder bore through a connection pipe 56. Brake fluid pressure in the first cylinder bore is supplied into the third cylinder bore, thus causing the second piston to move against the bias of the second coil spring. The movement of the second piston cuts off the communication between the interior of the first cylinder bore and the interior of the second cylinder bore.SELECTED DRAWING: Figure 3 |
