| 摘要 |
PURPOSE: To construct a line pressure control device whereby a line pressure in a V belt type continuously variable transmission can be properly controlled even at no-load time of a prime mover. CONSTITUTION: In a controller 17, a target input rotational speed Ni is obtained from input information, to correspondingly operate a valve 21 through a link 22 by a step motor 23. In the valve 21, a control pressure Ps is regulated to perform a stepless speed change of transmission ratio between pulleys 1, 2 to ratio corresponding to the target input rotational speed Ni. In the case of controlling a line pressure PL which is the original pressure, the controller 17, including no-load time with a throttle opening TVO 0, based on a torque converter performance curve and an engine performance curve, estimates input torque, to obtain a required line pressure corresponding to this input torque, to command the corresponding duty D to a solenoid 14, and to control the line pressure PL to the required line pressure corresponding to the input torque. |
