Control device for automatic transmission and control method therefor

A method of controlling an automatic transmission which includes a torque transmitter provided between an input shaft and an output shaft of a gear transmission, wherein the torque transmitter in at least one change gear stage is constituted by a friction clutch and in other change gear stages are constituted by synchromesh clutches, and when performing a change gear from one change gear stage to another change gear stage, the friction clutch is controlled, comprising detecting a torque capacity of the friction clutch when performing a change gear to a predetermined change gear stage, and determining a timing when releasing the respective synchromesh clutch into a neutral state based on the detection.

An automatic transmission comprising a torque transmitter provided between an input shaft and an output shaft of a gear transmission, wherein the torque transmitter in at least one change gear stage is constituted by a friction clutch and in other change gear stages are constituted by synchromesh clutches and when performing a change gear from one change gear stage to another change gear stage, the friction clutch is controlled, and wherein the mesh clutches are configured such that, when at a moment a transfer torque (Tcp) of the friction clutch, exceeds a calculated transfer torque (Tce) from the input shaft on one of the synchromesh clutches concerned at that moment, during a change gear to a predetermined change gear stage, the respective synchromesh clutch is released into a neutral state.

A control device for an automatic transmission, comprising a torque transmission operatively provided between an input shaft and an output shaft of a gear transmission, the torque transmission having a friction clutch in at least one change gear stage and a mesh clutch with synchromesh in other change gear stages, whereby the friction clutch is controlled when performing a change gear from one change gear stage to another change gear stage;

• a detector configured to detect or compute a transfer torque value of the friction clutch when performing a change gear to a predetermined change gear stage;
• and a clutch release timing determining device configured to determine a timing when releasing the respective mesh clutch into a neutral state based on the detected or computed value.

A method of controlling an automatic transmission which includes a torque transmission provided between an input shaft and an output shaft of a gear transmission having a friction clutch in at least one change gear stage and mesh clutches with synchromesh in other change gear stages whereby the friction clutch is controlled when performing a change gear from one change gear stage to another change gear stage, comprising detecting a transfer torque of the friction clutch when performing a change gear to a predetermined change gear stage, and determining a timing when releasing the respective mesh clutch into a neutral state based on the transfer torque detection.

An automatic transmission, comprising a torque transmission operatively provided between an input shaft and an output shaft of a gear transmission having a friction clutch in at least one change gear stage and mesh clutches with synchromesh in other change gear stages whereby the friction clutch is controlled when performing a change gear from one change gear stage to another change gear stage, and the respective mesh clutch is arranged to be released into a neutral state when at a moment a torque capacity (Tcp) of the friction clutch exceeds a calculated transfer torque (Tce) from the input shaft, on one of the mesh clutches concerned at the moment during a change gear to a predetermined change gear stage.