| 摘要 |
PURPOSE:To dissolve speed change shocks by suppressing the flow of the operating oil fed to the first hydraulic actuator for a predetermined time during the travel at a low vehicle sped and a low throttle opening when switching from the second gear stage to the first gear stage. CONSTITUTION:The control oil pressure in a control chamber 122 is generated when a flow selector valve 128 is closed, thus a spool valve piece 118 is moved against a spring when this flow switching solenoid valve 128 is closed. Thereby, the connection between a pair or ports 114, 116 of a flow selector valve 104 is opened, the operating oil from the output port 96 of a shift valve 90 is quickly fed to the first hydraulic actuator 74' to set up a low speed gear stage. However, when the flow selector valve 128 is closed, the downstream side of an orifice 124 is discharged and the control chamber 122 is made the atmospheric pressure, and the communication between the ports 114, 116 is closed. Accordingly, the operating oil passes through the restriction 126 of the spool valve piece 118, thus the feed flow of the operating oil is restricted.
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