| 摘要 |
PURPOSE:To avoid a shift-out speed change by controlling line pressure for increment as much as the specified value irrespective of inertia phase time at the speed change in the case where it is carried out with such line pressure as causing the shift-out speed change. CONSTITUTION:An inertial phase time measuring means B measures such a time when a gear ratio of a speed change gear mechanism A is varied, namely, inertial phase time during a speed change on the basis of a signal out of input and output speed sensors S1 and S2, and it controls the extent of the line pressure so as to cause it to become the desired value E by a line pressure regulating means C. On the other hand, A total shift time measuring means F measures the total time ranging from change indication of a friction element to completion of a variation in the gear ratio, and when it exceeds the reference value, there is such a possibility that a shift-out speed change has occurred, so that a shift-out speed change avoiding means D makes the line pressure regulating means C perform such control as increasing the line pressure during the speed change as much as the specified value irrespective of the inertia phase time in the speed change. Thus, the shift-out speed change is avoided, and the occurrence of a large shift shock and the lowering of service life in the friction element are preventable. |
