Apparatus for controlling pulley side-pressure of continuously variable transmission in vehicle having function of stopping engine idling

摘要

In an apparatus for controlling a pulley side-pressure of a belt type continuously variable transmission mechanism (5) provided, in series with a starting clutch (7), in a transmission of a vehicle having a function of stopping engine idling so that an engine (1) is automatically stopped, if the vehicle start-up is controlled from the state of engine stopping in an ordinary way in which the pulley side-pressure is determined by that belt transmission torque (TQBLTNOM) corresponding to an output torque of the engine (1) which is obtained by the rotational speed and the negative suction pressure of the engine (1), the pulley side-pressure becomes excessive by wrong judgement that the engine output torque is large, because the negative suction pressure is small at the beginning of the engine starting. The durability then deteriorates and the specific fuel consumption becomes poor. As a solution, at a vehicle start-up from the state of engine stopping, a belt transmission torque (TQBLTSC) corresponding to that transmission torque (TQSCX) of the starting clutch (7) which is obtained by the engaging force of the starting clutch (7) is compared with a belt transmission torque (TQBLTNORM) corresponding to the engine output. The pulley side-pressure (PDR, PDN) is each controlled based on that transmission torque (TQDR) of the drive pulley (50) corresponding to the smaller belt transmission torque and on the transmission torque (TQDN) of the driven pulley (51).