摘要 |
A control apparatus for a power transmission of vehicles such as construction machine having at least one work implement actuated by a hydraulic cylinder unit, a transmission gear with hydraulically operated speed-change clutch, and a torque converter interposed between an engine and the transmission gear so as to transmit rotational power of the engine and having a hydraulically operated stator clutch. The control apparatus has two solenoid actuated clutch pressure control valves respectively provided in two hydraulic circuits which connect a hydraulic fluid supply source with the speed-change clutch and the stator clutch, respectively, so as to change the hydraulic pressure in the hydraulic circuits by the operation of a controller to which respective solenoids of the clutch pressure control valves are connected on its output part and an engine rotation sensor, a pressure sensor for detecting the pressure in the hydraulic cylinder unit of the work implement and a speed-change lever position sensor for detecting the shift of the lever to its first speed position are connected on its input part. |