초록 ▼

A control system for a torque converter includes a lock-up clutch provided in the torque converter for connecting input and output members of the torque converter directly, and a shift valve having first and second spools disposed in series in a sleeve for shifting an introduction of an engaging and

A control system for a torque converter includes a lock-up clutch provided in the torque converter for connecting input and output members of the torque converter directly, and a shift valve having first and second spools disposed in series in a sleeve for shifting an introduction of an engaging and releasing pressure acting on the lock-up clutch in accordance with positions of the first and second spools. The first spool is subjected to a first hydraulic pressure at one end thereof. The second spool is subjected to a second hydraulic pressure at one end thereof opposite to the one end of the first spool. The first and second spools are subjected to a third hydraulic pressure therebetween. The control system further has a first control device for controlling the first hydraulic pressure, and an adjusting valve for controlling the releasing pressure of the lock-up clutch. The shift valve provides the first and second spools with first, second and third positions corresponding to a converter condition, lock-up condition and slip condition, respectively. The shift valve is shifted between the second and third positions when the releasing pressure is relatively low so that the releasing pressure is continuously changed irrespective of the shifting action among the first, second and third positions of the shift valve. An abrupt change in the engaging force of the lock-up clutch is prevented.

대표청구항 ▼

A control system for a torque converter comprising: lock-up clutch means provided in said torque converter for connecting input and output members of the torque converter directly, means for generating a regulated line pressure, shift valve means having first and second spools disposed in series in

A control system for a torque converter comprising: lock-up clutch means provided in said torque converter for connecting input and output members of the torque converter directly, means for generating a regulated line pressure, shift valve means having first and second spools disposed in series in a sleeve for shifting introduction of said regulated line pressure to provide engaging and releasing pressures acting on the lock-up clutch means in accordance with positions of the first and second spools, said first spool being subjected to a first hydraulic pressure at one end thereof so that the engaging pressure is regulated according to introduction of said first hydraulic pressure, said second spool being subjected to a second hydraulic pressure at one end thereof opposite to said one end of the first spool so that the releasing pressure is regulated according to introduction of said second hydraulic pressure, said first and second spools being subjected to a third hydraulic pressure therebetween, first control means for controlling said first hydraulic pressure, and adjusting valve means for controlling said releasing pressure of the lock-up clutch means, said shift valve means providing the first and second spools with first, second and third positions corresponding to a converter condition, lock-up condition and slip condition, respectively, said adjusting valve means controlling the releasing pressure so that it gradually increases as the second hydraulic pressure decreases during a transition from the lock-up condition to the converter condition, in which the second hydraulic pressure is interrupted and the releasing pressure reaches a value approximately equal to said regulated line pressure.