| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a structure which improves resistance to secondary and third failures in a hydraulic pressure control unit for an automatic transmission realizing a skip shift function, and selects a speed change gear in response to environments of a vehicle when generating a failure such as an open circuit. <P>SOLUTION: A hydraulic pressure control unit for an automatic transmission has a plurality of shift valves for forming an oil passage from a specified solenoid valve to a specified frictional connection element in response to an automatic gearshift pattern for separately controlling a necessary solenoid valve and a fixed gearshift pattern for forcibly fastening a necessary frictional connection element. The hydraulic pressure control unit comprises: a first latch circuit for retaining the state of the specified shift valve by output hydraulic pressure of the solenoid valve at a specified high speed gearshift formation; and a second latch circuit for retaining the state of the specified shift valve by output hydraulic pressure of the solenoid valve at a specified restarting gearshift formation. <P>COPYRIGHT: (C)2007,JPO&INPIT |
