| 摘要 |
PURPOSE:To soften the engaging shock of a frictional element in the down-shift even in the operation of a retarder. CONSTITUTION:When the down-shift is detected on the basis of the signal supplied from an inhibitor switch 15, a control unit 13 sets the back-up pressure having the gentle starting-up inclination in the operation of a retarder device, according to the signal that a retarder device 7 related to a retarder driving device 16 is driven or not, and controls the back-up oil pressure for the frictional element in a transmission mechanism part through a hydrualic pressure control device 12. Accordingly, even if the reduction of the engine revolution is accelerated by the operation of the retarder device, and the coast torque is low, the engaging shock of the frictional element is softened, and the speed change feeling is improved. |
