PROBLEM TO BE SOLVED: To provide a master cylinder capable of improving supply performance of a brake fluid.SOLUTION: A piston seal 45 disposed in a peripheral groove 32 comprises: an annular base part 101; an inner peripheral lip part 102 projecting from an inner peripheral side of the base part 101; an outer peripheral lip part 103 projecting from an outer peripheral side of the base part 101; and an intermediate projecting part 104 projecting from a space between the inner peripheral lip part 102 and the outer peripheral lip part 103 of the base part 101. On a wall face 89A on a supply path 48 side of the peripheral groove 32, a step part 93 which becomes hollow with respect to a face part 89a on a bottom face 88A side is formed on an opening side of the peripheral groove 32. The step part 93 extends into a range of thickness in a radial direction of the intermediate projecting part 104 of the piston seal 45, and is formed into an annular shape.
【課題】ブレーキ液の補給性能を向上させることができるマスタシリンダの提供。【解決手段】周溝32内に設けられるピストンシール45が、円環状の基部101と、基部101の内周側から突出する内周リップ部102と、基部101の外周側から突出する外周リップ部103と、基部101の内周リップ部102と外周リップ部103との間から突出する中間突出部104とを備え、周溝32の補給路48側の壁面89Aに、底面88A側の面部89aよりも凹む段差部93が周溝32の開口側に形成されており、段差部93は、ピストンシール45の中間突出部104の径方向厚さの範囲内まで延びて環状に形成されている。【選択図】図2
MASTER CYLINDER
マスタシリンダ
2015-11-05
Patent
Electronic Resource
Japanese