| 摘要 |
A control device for a motor vehicle automatic gearbox is described, which has a main pressure control valve (1) for developing a main pressure as a function of the operating state for the actuation of shift elements of the gearbox and a solenoid control valve (2), which generates a control pressure, varying at least as a function of the load condition of the engine assigned to the motor vehicle, for acting on an active surface (6a) of the control piston (3) of the main pressure control valve (1). At the same time, the solenoid control valve (2) is designed to generate a control pressure increasing proportional to the load of the engine and the control pressure acts on an active surface (6a) of the control piston (3) of the main pressure control valve (1), loaded by the spring (11), against the main pressure acting on at least one counter-surface (6b; 7a). In order to be able to use a solenoid control valve of the simplest possible design and at the same time to be able to generate a sufficiently high main pressure by means of the main pressure control valve (1) in the event of a breakdown, that is should the solenoid control valve fail, it is proposed that a switch valve (15) be connected to the main pressure control valve on the inlet side, which switch valve ... a pressure admission space (12), assigned to the active surface (6a) of the control piston (3) of the main pressure control valve (1), to the control valve in a first position, with the control valve (2) operating, ... Original abstract incomplete. <IMAGE> |
