Patent ID: 6454073
Filing Date: 2002-09-24
Classification: F16D

Abstract:
An apparatus for hydraulically operating a clutch comprising:a clutch master cylinder for generating a pressure by depressing a clutch operating member; a clutch operating cylinder for switching said clutch from an engaged state to a disengaged state by a hydraulic pressure transmitted from said clutch master cylinder; a flow limiting device disposed between said clutch master cylinder and said clutch operating cylinder such that, in switching said clutch from the disengaged state to the engaged state by releasing the depression of said clutch operating member, a flow amount of an operating fluid to be pushed out of said clutch operating cylinder is reduced when said clutch attains a clutch-slipping state, said flow limiting device having a cylinder portion which comprises: a first fluid chamber on one axial side in communication with said clutch master cylinder; a second fluid chamber on an axially opposite side in communication with said clutch operating cylinder; and a piston for partitioning said first and second fluid chambers, characterized in: that said piston has on a circumference thereof: an annular groove in communication with said second fluid chamber through a passage inside said piston; and a land on the axially opposite side of said annular groove; that a first passage and a second passage are provided as passages to communicate said second fluid chamber and said clutch operating cylinder, said first passage opening into said cylinder portion in a position away in the axially opposite side relative to said land when said piston is in one stroke position at which said clutch is disengaged, said second passage opening into said cylinder portion at a position coinciding with a position of said annular groove when said piston is in said one stroke position, such that, in an axially intermediate stroke position of said piston at which said clutch attains the clutch-slipping state, an opening of said second passage is closed by said land; and that said first passage has interposed therein a one-way valve having an orifice, said one way valve having an easy flow direction in a direction toward said clutch operating cylinder.