| 摘要 |
PURPOSE:To prevent generation of blow-up of an engine and a gear-change shock by connecting a solenoid valve to an oil passage communicating to a port which is closed when an oil temperature of an automatic transmission is less than predetermined. CONSTITUTION:This device is provided with a port 10b for putting in oil pressure so that a timing valve 10 works on a spool 10A in the direction opposed to engaging oil pressure to a high-speed side friction engaging element 14. To an oil passage L1 communicating to this port 10b, a solenoid valve 12 is connected which is closed by an electronic control means 13 when an oil temperature of an automatic transmission is less than a set value. By this, proper timing is maintained for engagement and release of the high-speed and low-speed side friction engaging elements at up-shift. Thus, blow-up of an engine or increase in gear-change shock due to generation of a lag in gear-change timing by drop in the oil temperature can be prevented. |
