| 摘要 |
PURPOSE:To improve the shift operability in the title device by suppressing the rise in hydraulic pressure with a pressure supressing means when a hydraulic pressure line is selected on the retreat side and restricting power transmission until a control means reaches a defined operational position so as to enlarge the neutral range. CONSTITUTION:An intercommunicating passage 74 is formed between hydraulic pressure lines 63, 64 and, in an advance state that, when a motor shaft 26 is rotated on the right, a ball 75 is energized on the high pressure line side, to thereby form a check valve. A taper valve body 77 with a small leak hole 77a is energized on the low pressure line 64 side so that the line 64 and an intercommunicating passage 74 are intercommunicated to each other, to thereby form a pressure suppressing means. As a liquid pressure lines 63, 64 are selected on the retreat side, the rise in pressure of the line 64 is suppressed through the small hole 77a so that there exists a range where the power is not transmitted to a motor shaft 26, in the stage changed from the advance range to the retreat stage. |
