| 摘要 |
PURPOSE:To permit stable constant-speed traveling by installing a negative- pressure sensor for detecting the negative-pressure in an intake manifold and a constant-speed traveling controlling circuit for constant-speed traveling. CONSTITUTION:A car-speed sensor 90 detects a car speed and a throttle actuator 20 controls the opening degree of an accelerator. An overdrive stop solenoid 60 operates a speed change mechanism to switch a gear ratio. A negative-pressure sensor 40 for detecting the negative-pressure in an intake manifold is installed. In a constant-speed traveling controlling circuit 1, traveling with the highest gear ratio is suspended as the car speed reduces, and traveling is carried-out through speed change to the lower gear ratio. When the negative-pressure sensor detects that the pressure in the intake manifold rises over a prescribed value as the car speed is restored, traveling with the highest gear ratio is restored. Thus, stable constant-speed traveling is permitted even on a slope having a long rising gradient. |
