| 摘要 |
PURPOSE:To certainly prevent interlocking by letting an interlocking preventive valve cut off the communication between a solenoid valve and hydraulic oil pressure source by means of the working oil pressure of another hydraulic working means which engages and actuates when a specified hydraulic working engaging means is in a disengaged state. CONSTITUTION:In the relation between the operation of an interlock preventive valve 20 and the engaging operation of engaging means A, B, and C for every speed change range, in the case of the speed change range III, it is necessary to let the engaging means A be disengaged. Since in this speed change range, both the engaging means B and C are let to be engaged, a spool 21 is moved to the right to cut off the communication of a hydraulic oil pressure source 5 and oil passage 17 and to let the oil passage 17 communicate a drain. For this reason, even if a solenoid valve 10 is actuated, working oil is not supplied to the engaging means. Owing to this constitution, even if the solenoid valve 10 malfunctions with the engaging means B and C engaged, the engaging means A is engaged certainly preventing interlocking. |
