4-WHEEL DRIVE SWITCHING CONTROLLER FOR PART-TIME 4-WHEEL DRIVE CAR

摘要

PURPOSE:To improve the travelability over coarse road by providing a vertical acceleration sensor for converting the vertical acceleration into an electrical signal and detecting the coarse road condition then automatically switching to 4-wheel drive mode. CONSTITUTION:The voltage signal A from a vertical acceleration sensor 1 is passed through threshold voltage setting circuit 2 to feed only higher signal than the threshold voltage Vs to an integrating circuit 3. Integrated level for predetermined time interval (t) is fed to a comparator 4 and if it is higher than a setting level, an output is produced. The output of the circuit 4 is held by a holding circuit 5 to function a 4-wheel drive switching actuator 7 through an amplifier 6 thus to switch automatically to 4-wheel drive. Once switched automatically to 4-wheel drive mode on the basis of the output from the circuit 4, it is held for predetermined time even if there is no output from the circuit 5.