| 摘要 |
PURPOSE:To prevent production of a shift shock by a method wherein through control to a running range, a signal pressure is fed to the back pressure regulat ing valve of an accumulator by a signal pressure switching valve, and when an oil pressure to a frictional engaging device is increased to a given value, a signal pressure is fed to a second pressure regulating valve. CONSTITUTION:When a car speed exceeds a predetermined decision reference value, a signal pressure Psol4 from a signal pressure generating means is fed through an oil passage 356 to a second pressure regulating valve by means of a signal pressure switching valve 350, and a second line oil pressure is re duced by a given value necessary enough to compensate for a centrifugal oil pressure. For a given period starting from a time when a shift lever is controlled to a running range, a signal pressure is fed through a signal pressure switching valve 350 to a back pressure regulating valve 170, and the back pressure of an accumulator 342 is regulated so that engagement of a frictional engaging device 72 is smoothly effected. This constitution improves durability of a trans mission belt, and enables prevention of production of a shift shock. |
