Disclosed is a method of controlling a damper clutch through learning. A controller determines whether a driving condition of a vehicle is a condition where a predetermined selected fluid pressure value is desired. When necessary learning conditions are satisfied, the controller applies a control current for realizing a relevant fluid pressure to the solenoid valve. The controller updates the control current of the solenoid valve to an appropriate value based on response of the damper clutch. Thereafter, the controller controls the solenoid valve based on the updated control current.

A controller and a control strategy for a hybrid electric vehicle having a traction motor between an engine and an automatic transmission include maintaining a bypass clutch of a torque converter in an engaged position and applying a motor torque from a traction motor to the torque converter such that slip of the torque converter does not otherwise reach zero while the bypass clutch is maintained in the engaged position.

An electronic control unit starts shift initial oil pressure control after the completion of lockup initial oil pressure control when shift control is performed during the performance of lockup control, the electronic control unit starts shift initial oil pressure control after the completion of lockup initial oil pressure control. Besides, the electronic control unit places priority on the shift control and starts the lockup initial oil pressure control after the completion of the shift initial oil pressure control, when the lockup control is performed during the performance of the shift control. Therefore, the shift initial oil pressure control and the lockup initial oil pressure control are prevented from occurring at the same time when the shift control and the lockup control are performed at the same time.

A method and system are provided for operating a lockup clutch of a torque converter of a motor vehicle. The torque converter includes a pump rotatably driven by a drive unit, a rotatable turbine fluidly coupled to the pump and configured to drive an input shaft of a transmission, and a lockup clutch selectively engageable to non-fluidically couple the pump to the turbine to transmit torque from the drive unit to the transmission. The operation of the lockup clutch is controlled by the system in response to detecting that the motor vehicle is coasting.

A hydraulic control system for an automatic transmission with a torque converter includes two regulator valves controlled by a single variable force solenoid (VFS). A bypass clutch regulator valve increases the pressure to a bypass clutch apply chamber as the VFS pressure increases. A converter charge regulator valve decreases the pressure in a converter charge circuit as the VFS pressure increases. The converter charge circuit is in series with a lubrication circuit. An orifice restricts the flow through these circuits such that they can be supplied from the line pressure circuit rather than a lower priority circuit. In one embodiment, an on/off solenoid opens a flow control valve to bypass the orifice when additional flow is required. In another embodiment, an electric pump supplements the flow in these circuits when required. This later embodiment includes a switch valve such that the electric pump also supports stop/start operation.

A hydraulic control system for an automatic transmission with a torque converter includes two regulator valves controlled by a single variable force solenoid (VFS). A bypass clutch regulator valve increases the pressure to a bypass clutch apply chamber as the VFS pressure increases. A converter charge regulator valve decreases the pressure in a converter charge circuit as the VFS pressure increases. The converter charge circuit is in series with a lubrication circuit. An orifice restricts the flow through these circuits such that they can be supplied from the line pressure circuit rather than a lower priority circuit. In one embodiment, an on/off solenoid opens a flow control valve to bypass the orifice when additional flow is required. In another embodiment, an electric pump supplements the flow in these circuits when required. This later embodiment includes a switch valve such that the electric pump also supports stop/start operation.

A CPU of a control device is configured to perform a specific cylinder fuel cutoff process of causing an internal combustion engine to operate such that supply of fuel to some cylinders out of a plurality of cylinders is stopped and supply of fuel to the other cylinders is maintained and a fastening force decreasing process of decreasing a fastening force of a lockup clutch of a torque converter. The CPU is configured to start the specific cylinder fuel cutoff process in a state in which the fastening force has been decreased through the fastening force decreasing process when the specific cylinder fuel cutoff process is performed in a state in which the internal combustion engine operates with a load.

A torque converter having a shell formed by a front cover assembly and a rear cover. The front cover assembly further includes a front cover and a front boss, with the front boss being fixedly mounted to the front cover. The torque converter further including an impeller, a turbine located within the shell, a lock-up clutch and a piston. The piston being axially moveable relative to the front cover assembly along a central axis of the torque converter. A leaf spring, positioned between the piston and the front cover assembly, connects the piston to the front cover assembly.

A method of evaluating a thermal effect of torque converter clutch slip speed calibration settings on a torque converter includes estimating values of a plurality of vehicle operating parameters with a drive simulation model on a computer. The drive simulation model uses drive cycle inputs of a test drive cycle, and a slip speed calibration table to estimate values of the plurality of vehicle operating parameters over a pre-defined period of time for the test drive cycle. The temperature of each of a plurality of discrete regions of the torque converter are estimated with a temperature model on the computer. The temperature model uses the estimated values of the vehicle operating parameters to estimate the temperature of each discrete region of the torque converter at different times during the pre-defined period of time of the test drive cycle.

In a transmission with a lockup clutch, in a case where zero-slip control of the lockup clutch is not established (converged) within a predetermined time, a sweep increase of a lockup clutch hydraulic pressure starts at an increase rate smaller than a normal increase rate in a case where the zero-slip control is established within the predetermined time, the increase rate until the end of the sweep increase is set to be equal to or less than the normal increase rate, and in addition, a hydraulic pressure at the time of the end of the sweep increase is set to be equal to or greater than a hydraulic pressure in a case where the zero-slip control is established within the predetermined time. With such control, in a case where the zero-slip state is not brought, suppressing the occurrence of shock when complete engagement is carried out.