| 摘要 |
<p>PROBLEM TO BE SOLVED: To form the whole of a hydraulic pressure master cylinder light and compact. SOLUTION: A bulkhead 12 is firmly provided in a hollow space liquidtight, and a main hydraulic pressure chamber 15 is provided on the opening side of a cylinder hole. An auxiliary piston 16 is internally inserted between the bulkhead 12 and a bottom wall 3d liquidlight and free to move, and an auxiliary hydraulic pressure chamber 18 is provided between the auxiliary piston 16 and the bottom wall 3d. A main piston 8 and the auxiliary piston 16 are energized in a direction of the opening part of the cylinder hole by return springs 19, 20. A small diametrical shaft 8a is projectively provided on the bottom wall side of the cylinder hole of the main piston 8, and it is projected and arranged to the opening side of the cylinder hole of the auxiliary piston 16 from the bulkhead 12. A clearance C is set between a head end surface 8b of a small diametrical shaft 8a and the auxiliary piston 16 so that the head end surface 8b of the small diametrical shaft 8a comes in contact with the auxiliary piston 16 and pushes the auxiliary piston 16 to move in the bottom wall direction of the cylinder hole at the time when working liquid quantity supplied to a caliper body 7 increases more than specified.</p> |
