| 摘要 |
<p>PCT No. PCT/EP89/01243 Sec. 371 Date Apr. 25, 1991 Sec. 102(e) Date Apr. 25, 1991 PCT Filed Oct. 18, 1989 PCT Pub. No. WO90/04732 PCT Pub. Date Mar. 5, 1990.In an electronic-hydraulic control mechanism of an automatically shifting motorcar transmission, control valves (88, 70, 65, 67, 91 and 94) are coordinated with actuation devices (81 to 87) of hydraulically engageable and disengageable friction clutches or brakes (A to E1). The pressure level in one main pressure system of the control mechanism is regulated by a main pressure valve (29) while a control unit (72) designed as microprocessor controls the actuation devices via electrically actuated solenoid valves (41, 42 and 43) and pressure-control valves (38, 39 and 40) in accordance with operation parameters of the motorcar transmission and of a drive engine, the same as of a shift and/or travel program control. To provide an electronic-hydraulic control system in which the control operations develop under control, at low construction cost, the pressure control valves (38, 39 and 40) are situated in a first control system (36) of reduced pressure compared to the main pressure system (lines 25 and 34) through which they act with pilot control upon the control valves (65, 67, 70 and 94) and the main pressure valve (29) while the solenoid valves (41, 42, 43) are situated in a second control system (44) of likewise reduced pressure compared to the main pressure system, said solenoid valves (41, 42, 43) acting with pilot control upon shift valves (28, 30, 47) which control the feeding of pressurized fluid from the main pressure system to the pressure valves (65, 67, 70, 94).</p> |
