| 摘要 |
PURPOSE:To prevent occurrence of slippage in a transmission, by shifting the transmission a load and speed reducing position automatically when it is detected that there is fear of causing slippage at a frictional power transmitting section of the transmission along with increasing of load. CONSTITUTION:The turning speed of an engine output shaft 27 is kept within a prescribed limited range by affording output signals of a first means 21 for detecting the operational conditions of a transmission, a second means 22 for detecting the turning speed of an output shaft 12 of the transmission 7, and a third means 23 for detecting the turning speed of the output shaft 27 of an engine E to a control unit 30. In this state, if the turning speed of the output shaft 12 of transmission 7 becomes lower than a specific range of speed preset in the first detecting means 21, the transmission 7 is shifted to a speed reducing position automatically and in a reversible manner by means of the control unit 30. In addition to the above, there is further provided an automatic control stopping unit 32 which stops automatic control of the transmission 7 by the control unit 30 on the basis of the output of a fourth means 24 for detecting the driving pressure of a motor M. |
