| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve resistance on secondary and third failures in a hydraulic pressure control unit for an automatic transmission realizing a skip shift function, and also to improve shift shocks at the time of running at a failure mode. <P>SOLUTION: The hydraulic pressure control unit for an automatic transmission comprises: an one-way valve and first orifice for blocking an oil flow to an exhaust port side respectively arranged in parallel at an exhaust port side of a specified solenoid valve controlling hydraulic pressure supplied to a frictional connection element of the hydraulic pressure control unit for an automatic transmission; and an one-way valve and second orifice for blocking an oil flow from a supply port side respectively arranged in parallel at a supply port side of the solenoid valve. When detecting a failure, a fixed shift pattern is provided for forming an oil passage supplying hydraulic pressure of a hydraulic pressure source on an exhaust port of the specified solenoid valve via a shift valve and a specified forward gearshift, and the hydraulic pressure is thereby supplied and exhausted via the first and second orifices, and a suitably arranged accumulator. <P>COPYRIGHT: (C)2007,JPO&INPIT |
