초록 ▼

A fail-safe arrangement for an electrical power steering system is directed to providing a control arrangement for a power steering motor which will prevent abnormal operation from having adverse impact. The control system detects the welding or sticking together of closed relay contacs and function

A fail-safe arrangement for an electrical power steering system is directed to providing a control arrangement for a power steering motor which will prevent abnormal operation from having adverse impact. The control system detects the welding or sticking together of closed relay contacs and functions to prevent such a situation by monitoring the motor terminal voltage so as to cut off power above a predetermined value regardless of position of the relay contacts.

대표청구항 ▼

A fail-safe means for an electrical power steering device comprising: torque detecting means for sensing a steering torque applied to a steering wheel; a motor for generating auxiliary torque so as to decrease the steering torque detected by the torque detecting means; an electro-magnetic clutch for

A fail-safe means for an electrical power steering device comprising: torque detecting means for sensing a steering torque applied to a steering wheel; a motor for generating auxiliary torque so as to decrease the steering torque detected by the torque detecting means; an electro-magnetic clutch for intermittently engaging with said motor to connect said motor to said steering wheel; a clutch driving circuit for controlling the intermittent engagement of said clutch with said motor; a motor driving circuit for controlling power flowing to said motor so as to optimize the steering torque sensed by the detecting means; a relay having contacts in series with said motor which controls current flow through said motor; opening instruction means for instructing said relay to open; voltage detecting means for sensing voltage at connections with said motor and comparing said voltage to a desired voltage and including short circuit detecting means for detecting a short circuit in said relay; and power cut-off instruction means for instructing said motor driving circuit to stop supply of current to said motor when said opening instruction means orders the relay contact to be opened and said voltage detecting means senses any voltage in disparity with said desired voltage and for instructing said clutch driving circuit to disengage said clutch from said motor.