| 摘要 |
PURPOSE:To prevent the occurrence of an engine stall, by a method wherein deceleration is made in a state in which a hydraulic closing circuit is completely closed by means of a direct coupling clutch valve, and when a car speed or the number of revolutions of an engine is decreased to a value lower than a given value, the hydraulic closing circuit is released from shut off. CONSTITUTION:An ECU 100 performs control of the volume of a hydraulic motor M through first and second servo valves 30 and 50, and when a car speed is increased along with an increase in engine rotation in a minimum change gear ratio, the hydraulic closing circuit between a hydraulic pump P and the hydraulic motor is shut off by means of a direct coupling clutch DC. With this state, a car speed or the number of revolutions of an engine is de creased to a value lower than a given value due to deceleration of a vehicle, the direct coupling clutch DC is shifted to an OFF state, and when brake action is effected, deceleration is shifted on the high car speed side compared with a case in which a brake is inoperative. This method enables prevention of the occurrence of an engine stall since engine rotation is too low during rapid brake.
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