ELECTRIC POWER STEERING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an optimum electric current limiting method to protect a part being used from breakage and deterioration due to heat on an electric power steering device.

SOLUTION: This electric power steering device to assist steering of a steering system by controlling an electrified electric current to a motor 6 in accordance with steering information by providing the motor 6 to give steering assisting force to the steering system is constituted by furnishing a temperature assumption apparatus 7 to compute temperature of each portion of the electric power steering device from a calorific value 71 of the heating portion of the electric power steering device and a mathematic model 72 concerning heat movement of the electric power steering device and an upper limit electric current computer 8 to compute an upper limit value of the electrified electric current to the motor in accordance with the temperature computed by the temperature assumption apparatus 7.

COPYRIGHT: (C)2007,JPO&INPIT