Screw Engagement Type Clamp Device, Clamping System, and Fluid Pressure Actuator

摘要

An annular piston ( 21 ) is inserted into a cylinder hole ( 20 ) of a housing ( 4 ) so as to be vertically movable and be prevented from rotating. Into a cylindrical hole ( 24 ) of the piston ( 21 ), a cylindrical rotating member ( 25 ) is inserted while prevented from moving vertically. A ball screw mechanism ( 28 ) is provided between the piston ( 21 ) and the rotating member ( 25 ). On an outer peripheral surface of the rotating member ( 25 ), a circulation passage ( 59 ) which communicatively connects a start end and a terminal end of a male spiral groove ( 56 ) is formed in a recessed manner. Into a guide hole ( 29 ) formed in an upper half of the housing ( 4 ), an output rod ( 30 ) is inserted rotatably and movably vertically. An input portion ( 41 ) of the output rod ( 30 ) is connected to the rotating member ( 25 ) so as to transmit rotation. By driving the piston ( 21 ) upward, a bolt ( 45 ) provided on an upper end portion of the output rod ( 30 ) is engaged with an internal threaded hole ( 12 ) of a work ( 10 ).