| 摘要 |
PURPOSE:To accelerate the activation of a catalyst immediately after the cold startup of an internal combustion engine so as to perform the purification of exhaust gas in an early stage by shifting the speed change timing to the high gear speed side onto the high vehicle speed side within a specified period immediately after the cold startup of the engine. CONSTITUTION:In the low throttle opening region of a throttle valve 14, the condition of upshift from the second gear speed where a rear clutch 27 is engaged with a kick-down brake 29 to the third gear speed where a front clutch 26, the rear clutch 27 and a four-speed clutch 28 are engaged, and the condition of upshift from this third gear speed to the fourth gear speed where the four- speed clutch 28 is engaged with the kick-down brake 29 are moved onto the higher vehicle speed side than the normal case on the basis of an upshift corresponding speed change region map stored in an electronic control unit 43. That is, the execution of speed change is made difficult even if the vehicle speed is increased in low throttle opening, so that the rotating speed of an engine 11 is forcibly increased to raise the temperature of exhaust gas and thereby to accelerate the temperature rise of a catalyst. |
