Lock-up clutch control device for a multi-speed automatic transmission
A lock-up clutch control device is described for a multi-speed automatic transmission. The automatic transmission has an input shaft, a speed changing gear mechanism including a sub-transmission unit and a main transmission unit operatively connected to the sub-transmission unit for outputting multiple transmission speeds. The sub-transmission unit outputs at least a low speed when in a lower speed mode and a high speed that is greater than the low speed when in a higher speed mode. The main transmission unit is shiftable between at first and second gears to assume at least first and second speed modes for outputting the multiple speeds with the sub-transmission unit, frictional engagement elements respectively and operatively associated with the main transmission unit and the sub-transmission unit, and a torque convertor having a lock-up clutch operatively connected between the input shaft and the speed gear changing mechanism for converting torque from the input shaft to drive the speed changing gear mechanism. The torque is converted directly from the input shaft to drive the speed changing gear mechanism via actuation of the lock-up clutch. The lock-up control device comprises: a lock-up operation means operatively connected to the frictional engagement elements of the main transmission unit and to the frictional engagement elements of the sub-transmission unit; a signal transmission means operatively connected to the lock-up control device for transmitting the control signal from the lock-up operation means; and a lock-up relay valve operatively connected to the signal transmission means and the lock-up clutch. The lock-up relay valve controls the lock-up clutch only when receiving the signal from the signal transmission means.
- Assignee:
- Toyota Jidosha Kabushiki Kaisha
- Patent Number(s):
- US 4697474
- OSTI ID:
- 5763136
- Country of Publication:
- United States
- Language:
- English
Similar Records
Torque converter disconnect and bypass clutch structure for automatic mechanical transmission
Method for controlling amt system including after transmission gear change fuel control