Electric power steering apparatus
First Claim
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1. An electric power steering apparatus including an electric motor for generating 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 board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
a capacitor mounted on said power board for absorbing ripples of the electric current;
a control board at least having a microcomputer mounted thereon for generating a drive signal to control said bridge circuit based on steering torque of said steering wheel;
a power connector electrically connected to a battery of the vehicle;
a signal connector unit to and from which signals are input and output through external wiring;
motor terminals electrically connected to said electric motor;
a housing having a conductive plate constituting a wiring pattern and said motor terminals insert-molded of an insulation resin;
a connection member mounted on said power board and having a plurality of terminals built therein for electrically connecting said power board, said housing and said control board to one another; and
a heat sink disposed on said power board in surface contact therewith;
wherein said heat sink has a plurality of protrusions formed on its surface at a side opposite to said power board,wherein said capacitor is fixedly attached to said housing by means of an adhesive, andwherein said housing has a beam for reinforcement formed in the neighborhood of said capacitor, and said capacitor is fixedly attached to said beam.
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Accused Products
Abstract
An electric power steering apparatus can improve heat dissipation of a power board. A heat sink is mounted on the power board in surface contact therewith, on which power board there is mounted a bridge circuit including a plurality of semiconductor switching elements for switching an electric current supplied to an electric motor in accordance with torque assisting a steering wheel. The heat sink has a plurality of protrusions formed on a surface thereof at a side opposite to the power board.
85 Citations
17 Claims
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1. An electric power steering apparatus including an electric motor for generating 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 board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
a capacitor mounted on said power board for absorbing ripples of the electric current;
a control board at least having a microcomputer mounted thereon for generating a drive signal to control said bridge circuit based on steering torque of said steering wheel;
a power connector electrically connected to a battery of the vehicle;
a signal connector unit to and from which signals are input and output through external wiring;
motor terminals electrically connected to said electric motor;
a housing having a conductive plate constituting a wiring pattern and said motor terminals insert-molded of an insulation resin;
a connection member mounted on said power board and having a plurality of terminals built therein for electrically connecting said power board, said housing and said control board to one another; and
a heat sink disposed on said power board in surface contact therewith;wherein said heat sink has a plurality of protrusions formed on its surface at a side opposite to said power board, wherein said capacitor is fixedly attached to said housing by means of an adhesive, and wherein said housing has a beam for reinforcement formed in the neighborhood of said capacitor, and said capacitor is fixedly attached to said beam.
- a power board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
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2. An electric power steering apparatus including an electric motor for generating 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 board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
a capacitor mounted on said power board for absorbing ripples of the electric current;
a control board at least having a microcomputer mounted thereon for generating a drive signal to control said bridge circuit based on steering torque of said steering wheel;
a power connector electrically connected to a battery of the vehicle;
a signal connector unit to and from which signals are input and output through external wiring;
motor terminals electrically connected to said electric motor;
a housing having a conductive plate constituting a wiring pattern and said motor terminals insert-molded of an insulation resin;
a connection member mounted on said power board and having a plurality of terminals built therein for electrically connecting said power board, said housing and said control board to one another; and
a heat sink disposed on said power board in surface contact therewith;wherein said heat sink has a plurality of protrusions formed on its surface at a side opposite to said power board, wherein said power connector and said signal connector unit are disposed in an axial direction of said electric motor at a side opposite to said motor terminals with said connection member interposed therebetween.
- a power board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
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3. An electric power steering apparatus including an electric motor for generating 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 board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
a capacitor mounted on said power board for absorbing ripples of the electric current;
a control board at least having a microcomputer mounted thereon for generating a drive signal to control said bridge circuit based on steering torque of said steering wheel;
a power connector electrically connected to a battery of the vehicle;
a signal connector unit to and from which signals are input and output through external wiring;
motor terminals electrically connected to said electric motor;
a housing having a conductive plate constituting a wiring pattern and said motor terminals insert-molded of an insulation resin;
a connection member mounted on said power board and having a plurality of terminals built therein for electrically connecting said power board, said housing and said control board to one another; and
a heat sink disposed on said power board in surface contact therewith;wherein said heat sink has a plurality of protrusions formed on its surface at a side opposite to said power board, wherein said motor terminals are formed on one end of said conductive plate, and a switch for turning on and off the motor current supplied to said electric motor is disposed on an electric path including said conductive plate connected to at least one of said motor terminals, said switch being held by said housing. - View Dependent Claims (4, 5, 6, 7)
- a power board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
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8. An electric power steering apparatus including an electric motor for generating 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 board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
a capacitor mounted on said power board for absorbing ripples of the electric current;
a control board at least having a microcomputer mounted thereon for generating a drive signal to control said bridge circuit based on steering torque of said steering wheel;
a power connector electrically connected to a battery of the vehicle;
a signal connector unit to and from which signals are input and output through external wiring;
motor terminals electrically connected to said electric motor;
a housing having a conductive plate constituting a wiring pattern and said motor terminals insert-molded of an insulation resin;
a connection member mounted on said power board and having a plurality of terminals built therein for electrically connecting said power board, said housing and said control board to one another; and
a heat sink disposed on said power board in surface contact therewith;wherein said heat sink has a plurality of protrusions formed on its surface at a side opposite to said power board, and wherein said power connector has terminals formed at one end of said conductive plate, and a coil for preventing noise generated upon switching operation of said bridge circuit from flowing out to the outside is disposed on electric paths including said conductive plate, said coil being held by said housing. - View Dependent Claims (9)
- a power board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
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10. An electric power steering apparatus including an electric motor for generating 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 board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
a capacitor mounted on said power board for absorbing ripples of the electric current;
a control board at least having a microcomputer mounted thereon for generating a drive signal to control said bridge circuit based on steering torque of said steering wheel;
a power connector electrically connected to a battery of the vehicle;
a signal connector unit to and from which signals are input and output through external wiring;
motor terminals electrically connected to said electric motor;
a housing having a conductive plate constituting a wiring pattern and said motor terminals insert-molded of an insulation resin;
a connection member mounted on said power board and having a plurality of terminals built therein for electrically connecting said power board, said housing and said control board to one another; and
a heat sink disposed on said power board in surface contact therewith;wherein said heat sink has a plurality of protrusions formed on its surface at a side opposite to said power board, and wherein said housing is formed at a side surface thereof with an engaging portion that has cut portions at opposite ends thereof, respectively, and a metal casing covering said control board, said housing and said power board to form an electromagnetic shield is fixedly secured to said housing by being inserted into said cut portions. - View Dependent Claims (11)
- a power board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
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12. An electric power steering apparatus including an electric motor for generating 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 board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
a capacitor mounted on said power board for absorbing ripples of the electric current;
a control board at least having a microcomputer mounted thereon for generating a drive signal to control said bridge circuit based on steering torque of said steering wheel;
a power connector electrically connected to a battery of the vehicle;
a signal connector unit to and from which signals are input and output through external wiring;
motor terminals electrically connected to said electric motor;
a housing having a conductive plate constituting a wiring pattern and said motor terminals insert-molded of an insulation resin;
a connection member mounted on said power board and having a plurality of terminals built therein for electrically connecting said power board, said housing and said control board to one another; and
a heat sink disposed on said power board in surface contact therewith;wherein said heat sink has a plurality of protrusions formed on its surface at a side opposite to said power board, and wherein said heat sink is formed with an opening through which said motor terminals are exposed to the outside, and a cap molded of an insulation resin and having through holes through which said motor terminals can extend is inserted into said opening, and said cap has its one end which is extended through said opening to be engaged with said housing. - View Dependent Claims (13)
- a power board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
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14. An electric power steering apparatus including an electric motor for generating 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 board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
a capacitor mounted on said power board for absorbing ripples of the electric current;
a control board at least having a microcomputer mounted thereon for generating a drive signal to control said bridge circuit based on steering torque of said steering wheel;
a power connector electrically connected to a battery of the vehicle;
a signal connector unit to and from which signals are input and output through external wiring;
motor terminals electrically connected to said electric motor;
a housing having a conductive plate constituting a wiring pattern and said motor terminals insert-molded of an insulation resin;
a connection member mounted on said power board and having a plurality of terminals built therein for electrically connecting said power board, said housing and said control board to one another; and
a heat sink disposed on said power board in surface contact therewith;wherein said heat sink has a plurality of protrusions formed on its surface at a side opposite to said power board, and wherein said control board is engaged by an engaging member formed on said housing at its opening end, and said engaging member has a fallout-preventing portion formed in a fallout direction of said control board for preventing fallout of said control board, and a positioning portion for positioning said control board in its surface direction. - View Dependent Claims (15)
- a power board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
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16. An electric power steering apparatus including an electric motor for generating 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 board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
a capacitor mounted on said power board for absorbing ripples of the electric current;
a control board at least having a microcomputer mounted thereon for generating a drive signal to control said bridge circuit based on steering torque of said steering wheel;
a power connector electrically connected to a battery of the vehicle;
a signal connector unit to and from which signals are input and output through external wiring;
motor terminals electrically connected to said electric motor;
a housing having a conductive plate constituting a wiring pattern and said motor terminals insert-molded of an insulation resin;
a connection member mounted on said power board and having a plurality of terminals built therein for electrically connecting said power board, said housing and said control board to one another; and
a heat sink disposed on said power board in surface contact therewith;wherein said heat sink has a plurality of protrusions formed on its surface at a side opposite to said power board, and wherein said housing is formed, on its side wall parallel to a row of terminals of said connection member, with a concave portion into which a convex portion of said signal connector unit is fitted. - View Dependent Claims (17)
- a power board having a bridge circuit mounted thereon which includes a plurality of semiconductor switching elements for switching an electric current supplied to said electric motor in accordance with the torque assisting the operation of said steering wheel;
Specification