摘要 |
This toroidal continuous variable transmission detects a deviation of the spool valve from its neutral position and performs a feedback control to prevent the transmission ratio from converging on other than the target transmission ratio or the speed change sequence from being started again. Further, the toroidal continuous variable transmission performs control so that as the actual transmission ratio approaches the target transmission ratio, the transmission speed decreases in order to prevent an overshoot of the speed change control. When the difference between the actual transmission ratio and the target transmission ratio is smaller than a specified value, the output signals to the solenoid valves are controlled so that the pressure difference between the pilot pressures acting on the ends of the spool valves is proportional to the difference between the actual transmission ratio and the target transmission ratio. When the difference between the actual transmission ratio and the target transmission ratio exceeds the specified value, the target transmission speed is set according to the difference and the output signals to the solenoid valves are controlled so that the pressure difference between the pilot pressures acting on the ends of the spools is proportional to the difference between the actual transmission speed and the target transmission speed.
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