| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To attain an automatic parking brake state with simple structure without consuming electric power. <P>SOLUTION: The parking brake state of a wheel brake 2A is obtained by advance actuation of a parking piston 44 faced with a control hydraulic chamber 47 for parking on the back surface side to be slidably engaged with a casing 23. The advanced state of the parking piston 44 is mechanically locked by push-up by ball elements 58 due to advance of the parking piston 44. In an inner surface of a large diameter hole 38, and inner surfaces of a regulation step part 42 and a small diameter hole 39, a plurality of guide grooves 126 for the ball elements 58 to be respectively engaged to be capable of rolling are provided to have cross sectional form in inwardly recessed curvature to be extended in the axial direction of an insertion shaft 59. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
