| 摘要 |
PURPOSE:To shorten the time necessary for speed change operation by bringing a shift valve into neutral position prior to switching of a changeover valve thereafter bringing the changeover valve to the switching position. CONSTITUTION:When changing from 1-speed to 2-speed, a hydraulic changeover valve 9 is left as it is while the shift valves 10, 11 are set respectively to the switching positions 10B, 11B. Upon finish of standby, said valve 9 is set to the switching position 9B. Consequently, a hydraulic changeover valve 3 is switched to the changeover position 3B to disengage a clutch 1 instantaneously through working oil pressure in a conduit 7a by means of an actuator 2. At the same time, pressure oil is fed to the shift valve 10, 11 to bring the shift lever to the position (nl) by means of a shift actuator 12.
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