| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an automatic parking brake state by a simple structure without consuming power. <P>SOLUTION: A holding tube 51 holding a plurality of lock elements 52 is arranged continuously with the rear part of a parking piston 103 enabling the provision of the parking brake state by an advancing operation according to the action of a control hydraulic pressure for parking, and energized to advance according to the advancement of the parking piston 103. An insert shaft 53 movably inserted into the holding tube 51 so as to hold the lock elements 52 in the clearance thereof from the inner surface of a casing 102 is coaxially arranged continuously with the front end of a lock pin 104 retreating according to the action of a control hydraulic pressure for releasing parking, and at least the portion of the outer peripheral surface of the insert shaft 53 in contact with the lock elements 52 is formed as a tapered surface 53a which is gradually reduced in diameter toward the front. Since the generated hydraulic pressure of a hydraulic pressure generating source is controlled by a hydraulic pressure control means, the control hydraulic pressure for parking and the control hydraulic pressure for releasing parking can be provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
