Control of gear-change in vehicle automatic transmission for smooth action - has number of electrohydraulic actuators for gear changing that are controlled by computer to ensure that a smooth change is obtained.

摘要

An automatic transmission for use in a vehicle has IC engine (1) output coupled via a hydrodynamic converter (2) to the input (6) of the gearbox (3). The gearbox has various stages with electrohydraulic couplings and brake element (K1-B2). The output shaft (7) connects via a differential (4) with the drive wheels (ii). The gearchange system is controlled by a computer (12) that has inputs from a number of sensors (13-16). A change in gear requires a reduction in control pressure for one coupling which an increase is generated for a second coupling. The controller operates to maintain a smooth torque transition during changeover. ADVANTAGE - Maintains essentially constant torque during gear change.