Electric power steering apparatus
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsTsutomu Tominaga, Tohru Hohtani, Yasushi Yamaguchi, Tadayuki Fujimoto
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Abstract
A control unit including a plurality of boards is formed of a single multilayer metal substrate, whereby an electric power steering apparatus can be obtained in which connection members for connecting between the boards are made unnecessary, so the size and cost of the apparatus can be reduced, and the reliability of bonding can be improved. In the electric power steering apparatus, a power main body (20a) and a control main body (20b) are mounted on a metal substrate (22), and the power main body (20a) and the control main body (20b) are electrically connected to each other by wiring patterns (26a through 26e) and metal columns 28a through 28d in the metal substrate 22.
Claims45
An electric power steering apparatus including an electric motor for outputting assist torque to a steering wheel of a vehicle, and a control unit for controlling the driving of said electric motor,
- said control unit comprising:
- a power main body that includes a bridge circuit composed of a plurality of semiconductor switching elements for switching a current supplied to said electric motor in accordance with torque assisting said steering wheel;
- a control main body that generates a drive signal to control said bridge circuit based on the steering torque of said steering wheel;
- a metal substrate that is composed of a plurality of insulating layers and a plurality of conductive layers having wiring patterns respectively formed thereon, said insulating layers and said conductive layers being alternately laminated one over another on a metal plate;
- and
- a heat sink with said metal substrate being fixedly attached thereto;
- wherein said power main body and said control main body are arranged on the same surface of said metal substrate, and said power main body and said control main body are electrically connected to each other through said metal substrate.
An electric power steering apparatus including an electric motor for outputting assist torque to a steering wheel of a vehicle, and a control unit for controlling the driving of said electric motor,
- said control unit comprising:
- a power main body including a bridge circuit composed of a plurality of semiconductor switching elements for switching a current supplied to said electric motor in accordance with torque assisting said steering wheel;
- a control main body that generates a drive signal to control said bridge circuit based on the steering torque of said steering wheel;
- a metal substrate that is composed of a plurality of insulating layers and a plurality of conductive layers having wiring patterns respectively formed thereon, said insulating layers and said conductive layers being alternately laminated one over another on a metal plate;
- a heat sink with said metal substrate being fixedly attached thereto;
- a power connector that is electrically connected to a power supply of said vehicle;
- and
- a signal connector to and from which a signal is input and output through external wiring;
- wherein said power connector and said signal connector are at least integrally formed with each other to provide one connector.
An electric power steering apparatus including an electric motor for outputting assist torque to a steering wheel of a vehicle, and a control unit for controlling the driving of said electric motor,
- said control unit comprising:
- a power main body including a bridge circuit composed of a plurality of semiconductor switching elements for switching a current supplied to said electric motor in accordance with torque assisting said steering wheel;
- a control main body that generates a drive signal to control said bridge circuit based on the steering torque of said steering wheel;
- a metal substrate that is composed of a plurality of insulating layers and a plurality of conductive layers having wiring patterns respectively formed thereon, said insulating layers and said conductive layers being alternately laminated one over another on a metal plate;
- a capacitor that is mounted on said metal substrate for absorbing ripples of said current;
- a heat sink with said metal substrate being fixedly attached thereto;
- and
- a cover that fastens to said heat sink for receiving therein said metal substrate and said capacitor;
- wherein said cover is made of a metallic material having high conductivity, and a high thermal conductive heat dissipation material is fitted between said cover and said capacitor.
An electric power steering apparatus including an electric motor for outputting assist torque to a steering wheel of a vehicle, and a control unit for controlling the driving of said electric motor,
- said electric motor having a motor housing;
- said control unit comprising:
- a power main body including a bridge circuit composed of a plurality of semiconductor switching elements for switching a current supplied to said electric motor in accordance with torque assisting said steering wheel:
- a control main body that generates a drive signal to control said bridge circuit based on the steering torque of said steering wheel:
- a metal substrate that is composed of a plurality of insulating layers and a plurality of conductive layers having wiring patterns respectively formed thereon, said insulating layers and said conductive layers being alternately laminated one over another on a metal plate:
- and
- a heat sink with said metal substrate being fixedly attached thereto;
- wherein said motor housing is integrally formed with said heat sink.
Dependencies are inferred from the claim text.