Motor-driven power steering apparatus
AssigneesHitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.
InventorsHisatugu Ishikura, Nobuyoshi Onuma, Shigeki Saito, Hiroyosi Sakurai
Life of this patent
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Abstract
The present invention provides a controller for a power steering control system with a current limiter for limiting current to be fed to a power steering motor, in accordance with a power source voltage, whereby the power source is prevented from falling into an overdischarge state while a power steering function is performed. An additional feature of the present invention is an idle speed control device for increasing the engine idle speed when the current of the power steering motor reaches a predefined level.
Claims8
A motor-driven power steering apparatus comprising:
- an electric motor which assists in a control force of a steering wheel of an automobile,
- clutch means to transmit a torque of the electric motor to a driving shaft for moving tires,
- a power source which feeds electric power to the electric motor, and
- a controller which controls the power fed to the electric motor and the operation of the clutch means in accordance with an output signal of a torque sensor for detecting a deviation between a steering wheel shaft driven by the steering wheel and the tire driving shaft said controller including voltage detecting means to detect a voltage valve of said power source, and current limiting means to limit the current to be fed to said electric motor based on the detected voltage value.
Dependencies are inferred from the claim text.