PURPOSE: To prevent a speed change the driver does not intend by limiting a down shift of a main speed change gear when it is detected that the operation position to determine the speed change range of an auxiliary speed change gear was shifted from a lower speed range position to a higher speed range position.
CONSTITUTION: When the driver shifts the operation position to determine the speed change range of an auxiliary speed change gear 16 from a lower speed range position to a higher speed range position by a pattern select switch 26, a CPU 36 controls an electromagnetic valve 48 to shift the auxiliary speed change gear 16 to a higher speed range through an oil pressure circuit 40. As a result, the car speed detected by a car speed sensor 32 is lowered, and in this case, the limiting device of the CPU 36 limits a down shift of a main speed change gear 14 regardless of the reduction of the car speed. Consequently, the generation of a speed change at the main speed change gear 14 that the driver does not intend is prevented, and an unpleasant feeling of the increase of engine rotation frequency and the generation of a speed chock can be avoided.
YOSHIZAWA KENICHI
YASUE HIDEKI
NISHIKAWA SEIICHI
AKASHI MITSUO
AISIN AW CO
| JPS5635850A | 1981-04-08 |
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