| 摘要 |
PURPOSE:To prevent quick change in the speed change shock reducing effect because of line pressure control by varying the line pressure via the values before and after changing-over at the time of changing-over caused by oil temp. variation of the speed changing line pressure control characteristic. CONSTITUTION:An automatic transmission performs speed changing by engaging selectively friction elements with line pressure, and during this speed changing a speed changing line pressure control means controls the line pressure by reference to the line pressure control characteristic corresponding to the working oil temp. sensed by an oil temp. sensor. Thus speed change shocks are reduced. When the line pressure control characteristics are altered according to the working oil temp., a line pressure transient control means varies for ex. the line pressure continuously via value between before and after alteration of the characteristic in compliance with signals from a sensing means which senses such alteration of line pressure control characteristic, and thus abrupt change in the line pressure is suppressed. Thus abrupt change of the speed change shock reducing effect due to line pressure control is prevented at the time of changing-over the speed changing line pressure control characteristic resulting from oil temp. variation to contribute to elimination of uncomfortable sense. |
