| 摘要 |
<p>A control for shifting from an off-going speed range to an on-coming speed range comprises an off-going range releasing stage, an on-coming range void-stroke-clearing stage, an on-coming range engaging stage and an on-coming range final stage. During the off-going range releasing stage, an off-going engaging element is released in response to a shift command signal. During the on-coming range void-stroke-clearing stage, the engagement-actuation pressure of the on-coming engaging element is set at a predetermined high-pressure for a predetermined time period after the shift command signal is generated, whereby the void stroke of the on-coming engaging element is cleared. During the on-coming range engaging stage, after the completion of the on-coming range void-stroke-clearing stage, the on-coming engaging element is engaged. During the on-coming range final stage, following the on-coming range engaging stage, the on-coming engaging element is engaged completely. In this control, the predetermined time period for the on-coming range void-stroke-clearing stage is corrected for a next shift operation, based on the condition of the engaging operation of the on-coming engaging element. As shown in the left part of the figure maximum value is given during a first time period Tm(1), and the pressure of the on-coming engaging element is rapidly increased to clear the void stroke. After the completion of this stage, the clearing of the void stroke, the command value is lowered. When the on-coming engaging element starts engaging the input/output rotational speed ratio e starts changing. Here, a calculation is made of the rate of change alpha (1) of the input/output rotational speed ratio e over a predetermined value DELTA e of change. This rate of change alpha (1) is compared with a standard rate of change alpha S, and the time period Tm for clearing the void stroke is corrected for a next shift operation on the basis of the result of this comparison.</p> |
