MOTORIZED POWER STEERING APPARATUS

• Main Authors: KOGE, SHINICHI, MORISHITA, MITSUHARU, NISHINO, KAZUHISA
• Format: Patent
• Language: English; Korean
• Published: 27.05.1994
• Edition: 5
• Subjects: LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS; MOTOR VEHICLES; PERFORMING OPERATIONS; TRAILERS; TRANSPORTING

A motorized power steering apparatus is equipped with a torque sensor (3) including a primary potentiometer (3d) for detecting a steering torque applied to the steering wheel (1) by a driver. The torque sensor (3) further includes an auxiliary potentiometer (3d) so as to detect variations in the output voltage of a constant voltage power supply to the potentiometers. When there is a difference between the outputs of the primary and auxiliary potentiometers which is greater than a prescribed level, a fail-safe relay (904) is turned off to nullify the power steering operation of a motor (7). When the output voltage of the power supply for supplying a constant voltage to the primary and auxiliary potentiometers drops below or rises above a predetermined level, the output voltage of the auxiliary potentiometer, which is not used for power steering control, is raised so as to increase the difference between the output voltages of the potentiometers to a detectable level, whereby a fail-safe operation is carried out to nullify the power steering operation of the electric motor. Thus, the steering wheel is prevented, in a reliable manner, being turned spontaneously or unintentionally against the driver's will due to variations in the neutral point of the torque sensor resulting from fluctuations in the voltage supplied thereto.