| 主权项 |
1. A hydraulic pressure control system for a torque converter including a lock-up clutch operated according to pressure difference between an engagement side oil chamber and a disengagement side oil chamber, the control system comprising:
a first hydraulic line communicating with the disengagement side oil chamber, and second and third hydraulic lines communicating with the engagement side oil chamber; and a lock-up switch valve and a torque converter hydraulic pressure control valve which fluidly communicate with the first, second, and third hydraulic line, wherein the lock-up switch valve and the torque converter hydraulic pressure control valve communicating with the first, second, and third hydraulic lines generate pressure difference between the second line and the third hydraulic line which respectively communicate with the engagement side oil chamber so that fluid within the engagement side oil chamber is circulated in lock-up on state of the lock-up clutch, and the lock-up switch valve and the torque converter hydraulic pressure control valve generate pressure difference between the second hydraulic line and the third hydraulic line in slip state of the lock-up clutch higher than the pressure difference between the second hydraulic line and the third hydraulic line in the lock-up on state of the lock-up clutch so that fluid within the engagement side oil chamber is circulated; wherein the lock-up switch valve is a spool valve which is able to communicate hydraulic lines according to movement of a valve spool of the lock-up switch valve by control pressure of an on/off solenoid valve; wherein the torque converter hydraulic pressure control valve is a spool valve which is able to control exhausted hydraulic pressure through the lock-up switch valve according to movement of a spool valve of the hydraulic pressure control valve by control pressure of a proportional control solenoid valve; wherein the lock-up switch valve comprises a plurality of ports connecting the first hydraulic line communicating with the disengagement side oil chamber and the torque converter hydraulic pressure control valve, supplying drive pressure of a regulator valve to the second hydraulic line, and connecting the third hydraulic line communicating with the engagement side oil chamber and the torque converter hydraulic pressure control valve respectively; wherein a valve body of the lock-up switch valve comprises:
a first port of which the control pressure of the on/off solenoid valve is supplied thereto;a second port of which the drive pressure of the regulator valve is supplied thereto;a third port selectively supplying hydraulic pressure supplied to the second port to a cooler;a fourth port connected with the third hydraulic line;a fifth port selectively communicating with the fourth port;a sixth port of which the drive pressure of the regulator valve is supplied thereto;a seventh port connected with the second hydraulic line;an eighth port of which the drive pressure of the regulator valve is supplied thereto;a ninth port connected with the first hydraulic line; anda tenth port selectively communicating with the ninth port, wherein the torque converter hydraulic pressure control valve is able to exhaust the hydraulic pressure exhausted from the lock-up switch valve through two exit ports, wherein a valve body of the torque converter hydraulic pressure control valve comprises: a first port of which the drive pressure of the regulator valve is supplied thereto;
a second port communicating with the tenth port of the lock-up switch valve;a third port communicating with the fifth port of the lock-up switch valve;a fourth port communicating with the tenth port of the lock-up switch valve together with the second port;a fifth port of which the control pressure of the proportional control solenoid valve is supplied thereto;a first exhaust port exhausting hydraulic pressure supplied to the first port and leaked therefrom;a second exhaust port selectively communicating with the second port;a third exhaust port selectively communicating with the third port; anda fourth exhaust port selectively communicating with the third port, wherein the third exhaust port and the fourth exhaust port are provided with an orifice respectively, and wherein a cross section of the orifice disposed to the third exhaust port is smaller than a cross section of the orifice disposed to the fourth exhaust port. |
