| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the deformation of a sleeve during operation of a brake, facilitate manufacturing of guide grooves, and eliminate any regulation of retreating limits of a primary piston and a secondary piston. SOLUTION: A master cylinder is so constituted that a cylinder housing 1 is composed of a body main body 2 and a cap 3, first and second pistons 4, 5 guided by sleeves fitted in the cylinder housing 1 are slidably provided, first and second pressure chambers 9, 10 are partitioned, and spring mechanisms 11, 12 are arranged therein so that the first and second pistons 4, 5 are energized thereby in the retreating direction, projecting ends 17c projecting in the radially outer direction are formed on a spring retainer 17 of a spring mechanism 11 for energizing the first piston 4, and trapezoidal guide grooves whose groove widths become wider toward their sleeve ends and which penetrate the outer circumferential surface of the sleeve 8 in the axial direction, where the projecting parts 17c are inserted and engaged, and locking parts 20a which are brought in contact with the projecting ends 17c in such positions as a little extended from the retreating limit are formed in the sleeve 8.</p> |
