Patent ID: 8589039
Filing Date: 2013-11-19
Classification: F16H,Y10T

Abstract:
1. A control device for controlling an automatic transmission including: a mechanical oil pump which is drivable by having rotation of an engine transmitted thereto; a suction passage in which hydraulic oil sucked into the mechanical oil pump is configured to flow; a discharge passage in which the hydraulic oil discharged from the mechanical oil pump is configured to flow, wherein the discharge passage includes a narrow part; a communicating passage which allows communication between the suction passage and a part of the discharge passage upstream of the narrow part in a flowing direction of the hydraulic oil while bypassing the mechanical oil pump; and a flow control mechanism which includes a spool configured to set the communicating passage in a communicating state when a differential pressure between a hydraulic pressure upstream of the narrow part and that downstream of the narrow part in the flowing direction of the hydraulic oil is larger than a predetermined value and configured to set the communicating passage in a non-communicating state when the differential pressure is equal to or smaller than the predetermined value; wherein the control device, comprises: an oil temperature detection unit configured to detect oil temperature of the hydraulic oil; an engine torque calculation unit configured to calculate an engine torque; a line pressure setting unit configured to set a higher line pressure as the engine torque increases; a first rotation speed detection unit configured to detect a rotation speed of an output shaft side of the automatic transmission; and a line pressure correction unit configured to increase line pressure as the rotation speed of the output shaft side increases when the oil temperature is equal to or higher than a predetermined oil temperature at which the communicating passage is switched from the communicating state to the non-communicating state due to air mixed into the hydraulic oil and the engine torque is equal to or lower than a predetermined engine torque at which the communicating passage is switched from the communicating state to the non-communicating state due to the air mixed into the hydraulic oil.