| 摘要 |
<p>PURPOSE:To obtain an optimum shock countermeasure value by using an accumulator back pressure which is generated independently of the speed change position as the back up pressure of a frictional element reducing valve for reducing the line pressure supplied to the frictional element. CONSTITUTION:The discharge pressure of an oil pump 6 is adjusted to a line pressure corresponding to the throttle opening degree due to a solenoid 1 by a line pressure adjusting valve 2, and an accumulator back pressure is generated by an accumulator control valve 3, and the discharge pressure is adjusted to a pressure sensitive control pressure by a frictional element reducing valve 4, having the above-described accumulator back pressure as back up pressure, and a frictional element O/C is connected. In this case, the back-up pressure can be arbitrarily set by the change of the accumulator back pressure characteristics without varying the line pressure characteristics by properly selecting the spring 3a of the accumulator control valve 3. Thus, the operating pressure reduction control for the frictional element can be carried out in single form to obtain an optimum shock countermeasure value.</p> |
