Disclosed are a method and device for controlling the state switching of a fluid torque converter, a vehicle and a storage medium, the method including: obtaining a target instruction when the torque converter of the vehicle is in a locked state, the target instruction triggering a change in the torque transmission direction of a transmission system of the vehicle; obtaining a state parameter, and determining whether the current vehicle is in a target operating condition according to the state parameter; and if the current vehicle is in the target operating condition, switching the fluid torque converter to an open state, and switching the torque converter back to the locked state after maintaining the open state for a preset period of time.

Disclosed are a method and device for controlling the state switching of a fluid torque converter, a vehicle and a storage medium, the method including: obtaining a target instruction when the torque converter of the vehicle is in a locked state, the target instruction triggering a change in the torque transmission direction of a transmission system of the vehicle; obtaining a state parameter, and determining whether the current vehicle is in a target operating condition according to the state parameter; and if the current vehicle is in the target operating condition, switching the fluid torque converter to an open state, and switching the torque converter back to the locked state after maintaining the open state for a preset period of time.

An oil pressure estimation device for calculating an estimated differential pressure that is an estimated value of a differential pressure between two oil chambers generated in a torque converter including the two oil chambers and a lockup clutch includes a storage device and an execution device. The storage device stores mapping data defining a mapping, the mapping outputting as an output variable an estimated differential pressure variable indicating the estimated differential pressure, in response to input of an input variable, and the mapping having been trained by machine learning. The mapping includes an instruction differential pressure variable indicating the instruction differential pressure as one of a plurality of the input variables. The execution device executes an acquisition process of acquiring a value of the input variable and a calculation process of inputting the value of the input variable into the mapping to calculate a value of the output variable.

A transmission, includes a transmission mechanism including a torque converter having a lock-up clutch; an oil pump configured to discharge an oil to be supplied to the transmission mechanism; a lock-up oil pressure control valve configured to adjust a pressure of the oil discharged from the oil pump and supply the oil to the lock-up clutch; a lubricating oil pressure control valve configured to adjust the pressure of the oil discharged from the oil pump and supply the oil to a portion to be lubricated of the transmission mechanism; and a controller configured to control the lock-up oil pressure control valve. The controller controls the lock-up oil pressure control valve so that a precharge time when a lubricating oil pressure which is an oil pressure supplied from the lubricating oil pressure control valve is a first lubricating oil pressure becomes shorter than another precharge time when the lubricating oil pressure is a second lubricating oil pressure which is lower than the first lubricating oil pressure when performing a precharge of supplying the oil to the lock-up clutch.

A transmission, includes a transmission mechanism including a torque converter having a lock-up clutch; an oil pump configured to discharge an oil to be supplied to the transmission mechanism; a lock-up oil pressure control valve configured to adjust a pressure of the oil discharged from the oil pump and supply the oil to the lock-up clutch; a lubricating oil pressure control valve configured to adjust the pressure of the oil discharged from the oil pump and supply the oil to a portion to be lubricated of the transmission mechanism; and a controller configured to control the lock-up oil pressure control valve. The controller controls the lock-up oil pressure control valve so that a precharge time when a lubricating oil pressure which is an oil pressure supplied from the lubricating oil pressure control valve is a first lubricating oil pressure becomes shorter than another precharge time when the lubricating oil pressure is a second lubricating oil pressure which is lower than the first lubricating oil pressure when performing a precharge of supplying the oil to the lock-up clutch.

An apparatus for diagnosing an automatic transmission for detecting abnormality during driving of a vehicle includes a G-sensor configured to measure a vibration signal including a longitudinal vibration signal, a status detection unit configured to obtain the vibration signal of the G-sensor and status data of transmission and engine sensors of the vehicle, and a controller configured to check an operational element for each shifting operation by using a current shift-stage, a target shift-stage, and a shifting time detected as the status data, measure the longitudinal vibration signal of the G-sensor to calculate fluctuation level of the longitudinal vibration signal for each operational element, and determine a shift shock event when a longitudinal vibration signal value after adjustment based on driving acceleration of the vehicle exceeds a reference value.

A hydraulic control device that includes a primary pressure control valve that has a first valve element and that regulates the primary pressure by varying a position of the first valve element in accordance with operation of a first electromagnetic actuator; a secondary pressure control valve that has a second valve element and that regulates the secondary pressure by varying a position of the second valve element in accordance with operation of a second electromagnetic actuator; and a fail-safe valve that varies the position of the first valve element such that the primary pressure is reduced when the first electromagnetic actuator and the second electromagnetic actuator become inoperable.

A hydraulic control device that includes a primary pressure control valve that has a first valve element and that regulates the primary pressure by varying a position of the first valve element in accordance with operation of a first electromagnetic actuator; a secondary pressure control valve that has a second valve element and that regulates the secondary pressure by varying a position of the second valve element in accordance with operation of a second electromagnetic actuator; and a fail-safe valve that varies the position of the first valve element such that the primary pressure is reduced when the first electromagnetic actuator and the second electromagnetic actuator become inoperable.

The controller starts an output of an engagement instruction of the lockup clutch when a vehicle speed becomes a lockup start vehicle speed under a state where the lockup clutch is disengaged. When the vehicle speed, which is obtained a predetermined time after the output of the engagement instruction is started due to the vehicle speed becoming the lockup start vehicle speed, has reached a predetermined vehicle speed, the controller continues the output of the engagement instruction. When the vehicle speed has not reached the predetermined vehicle speed, the controller stops the output of the engagement instruction and restarts the output of the engagement instruction when the vehicle speed reaches a lockup restart vehicle speed which is set to a vehicle speed higher than the lockup start vehicle speed while the output is stopped.

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.