| 摘要 |
A procedure for the control of ratio-change occurrences of an automatic transmission in a motor vehicle, which vehicle possesses a hydraulic system with at least two hydraulic pressure branches ( 3, 9 ) with different hydraulic pressures, wherein in a first hydraulic pressure branch ( 3 ) controllable pressure reducing valves ( 4, 5 ) can be found, by which the hydraulic users (S 1 , S 2 ) can be supplied with an activation pressure, wherein in the first hydraulic pressure branch ( 3 ), a pressure regulation valve ( 6 ) is placed, the exit port of which is connected to a line of the second hydraulic pressure branch ( 9 ), and wherein by the activation of the pressure regulation valve ( 6 ) the pressure in the first hydraulic circuit ( 3 ) is adjustable, and whereby in the first hydraulic pressure branch ( 3 ) a hydraulic pressure is provided, which represents the highest, necessary operational pressure of the hydraulic users (S 1 , S 2, 11 ) plus an offset pressure. Further, provision is made that in certain operational conditions of the motor vehicle, one of the pressure reducing valves ( 4, 5 ) of, respectively, one of the two ratio-changing organs (S 1 , S 2 ) remains fully open and the offset-pressure becomes reduced to the value of zero, or to nearly zero, and upon the removal of said certain operational condition the off-set pressure is once again increased and the pressure reducing valve ( 5 ) resumes its function of pressure reduction.
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