Oil pump control device for automatic transmission

摘要

A speed ratio control operation of an automatic transmission for a vehicle is controlled by using an oil pressure supplied from a oil pump (16). At least a circuit (22) which sets a rotation speed of the oil pump (16) to a first pump rotation speed in order to maintain a necessary minimum line pressure to control a variable mechanism, a stationary vehicle condition determination circuit (24) which determines that the vehicle is operating under the conditions that the brake is operated and vehicle speed is below a fixed value, and a circuit (23) which sets a second pump rotation speed which is lower than the first pump rotation speed when stationary vehicle conditions are met are provided. The rotation speed is lowered to the second pump rotation speed when the vehicle stationary conditions are met which results in reduced energy consumption and reduced noise pollution.