MOTOR-DRIVEN POWER STEERING DEVICE

摘要

PURPOSE:To suppress power consumption of a battery by equipping a microprocessor as a main component element of a motor controlling device with a function to vary the duty ratio of the output voltage dependent upon car speed signal for restriction the max. value of the motor voltage. CONSTITUTION:In a motor-driven power steering device, a pinion 3 provided at the tip of a steering input shaft 2 coupled with a steering wheel H is meshed with a rack 6, whose ends are coupled with a knuckle arm 4 of wheel 1 through a side rod 5. The rack 6 is meshed with another pinion 8 rotated by a reversible motor M through a speed reduction machine 7. This motor M is controlled by a motor controlling device (a) which is fed with output signals from a torque sensor 9 and a car speed 10. This motor controlling device (a) is provided as main component element as a microprocessor having a function to vary the duty ratio of the output voltage dependent upon car speed signals and to restrict the max. value of the motor voltage.