| 摘要 |
PURPOSE:To permit speed changing without shock of speed change by a method wherein the timing of shift valve switching and the same of releasing and engaging of a direct coupling clutch are corelatively controlled by an electronic controlling device and the direct coupling clutch is brought into a released condition upon changing the speed. CONSTITUTION:A direct coupling clutch 4 in an automatic speed change gear 1 and a clutch as well as a brake in a gear type speed change mechanism 7 are constituted so that a hydraulic pressure is supplied to them or the supplied hydraulic pressure is discharged selectively by an automatic speed change gear hydraulic pressure control system 32. Solenoids No.1(b), No.2(c), controlling the speed change gear 7, and the solenoid No.3(d), controlling the direct coupling clutch 4, are controlled corelatively by a computer 33 and are set so that the direct coupling clutch 4 is released prior to the switching of a speed change stage at first while it is re-engaged when the direct coupling clutch is in a condition that it may be engaged after a given time has elapsed from the finish of the speed changing. |
