VEHICLE RUNNING CONTROL DEVICE

摘要

PURPOSE:To compensate an accidental trouble of a control circuit in the case that a vehicle speed is higher than a slow speed, by forcibly selecting an auxiliary transmission to a speed range where engine brake is effected, irrespective of an output from the control circuit. CONSTITUTION:A vehicle running control device 31 includes a high-speed range selecting circuit 32 for detecting that acceleration is off and a vehicle speed is higher than a slow speed and for forcibly engaging a hydraulic clutch 3b in an auxiliary transmission 3. An output from the circuit 32 together with an output from a control circuit 8 is supplied through an OR gate circuit 33 to a solenoid driver circuit 18. The circuit 32 is connected to a throttle opening sensor 9 and a vehicle speed sensor 11. The throttle opening sensor 9 detects that a throttle valve is fully closed by acceleration off, and thereby in the case that a vehicle speed is higher than a slow speed, the device 31 operates to select the auxiliary transmission 3 to a high-speed range irrespective of an output from a control circuit8.