| 摘要 |
PROBLEM TO BE SOLVED: To restrict the over-returning when driving an electric motor in a release direction.SOLUTION: A revolution direct-acting conversion mechanism 43 includes: a base nut 44 to which the rotary motion of an electric motor 66 is transmitted; and a direct-acting member 50 being screw-fitted to the base nut 44 so as to move a piston 39 by the relative displacement relative to the base nut 44 in an axial direction. The base nut 44 is provided with a revolution side projection part 44D and the direct-acting member 50 (a cylindrical retainer 58) is provided with a direct-acting side projection part 58E, and the revolution side projection part 44D and the direct-acting side projection part 58E are disposed at a position where the revolution side projection part 44D and the direct-acting side projection part 58E come in contact with each other when the direct-acting member 50 approaches the retraction limit. A parking brake control device 19 detects an electric current when the revolution side projection part 44D and the direct-acting side projection part 58E are relatively rotating while being in contact with each other so as to stop electricity supply to the electric motor 66.SELECTED DRAWING: Figure 5 |
