| 摘要 |
<p>A system for controlling oil pressure of an automatic vehicle transmission having a plurality of frictional engaging elements (K1, K2, K3, B1, B2) for establishing a gear, and a plurality of solenoid valves (SA and SE) at least one of which (SA) supplies pressurized oil to at least one of the frictional engaging elements (K1). The system also has a manual switching valve (20) whose spool moves in response to the selection of the shift lever for supplying the pressurized oil to the frictional engaging element (K1), bypassing the solenoid valve (SA), when the shift lever selects a gear range (1) in case of solenoid valve (SA) failure, and an underdrive engage control valve (30,96) placed between the frictional engaging element (K1) and the switching valve (SA) for regulating pressure of the pressurized oil supplied to the frictional engaging element (K1) in response to the pressurized oil outputted from the solenoid valve (SA) and in response to the pressurized oil supplied from the manual switching valve (20).</p> |
