Control unit and electric power steering device employing control unit

Patent metadata

Field	Value
Publication number	US-2018233992-A1
Application number	US-201415516430-A
Country	US
Kind code	A1
Filing date	Nov 13, 2014
Priority date	Nov 13, 2014
Publication date	Aug 16, 2018
Grant date	—

Abstract

A frame has upper and lower surfaces that extend in a perpendicular direction to a motor output shaft, donut-shaped conductive plates are mounted respectively on the upper and lower surfaces, and the conductive plates both include connection-forming terminal portions provided on inner and outer peripheral sides thereof. An inverter circuit is constituted by a power module formed from a plurality of switching elements, a power supply terminal is provided on one side of a package forming the power module, while an output terminal connected to a winding terminal for supplying power to a motor and a control terminal connected to a control signal are provided on an opposing side. The terminal portions on the inner peripheral sides of the conductive plates are connected to the power supply terminal of the power module, and the control board is connected to the control terminal of the power module.

First claim

1 . A control unit for controlling driving of a motor, the control unit being formed integrally with the motor so as to be coaxial with a motor output shaft of the motor, and comprising:
a control board that is housed in the interior of a housing forming an outer covering of the control unit, and that calculates a control signal for the motor and outputs the calculated control signal; an inverter circuit that supplies power to the motor in accordance with the control signal; and a frame that serves as an intermediate member provided between the control board and the inverter circuit, wherein the frame has upper and lower surfaces that extend in a perpendicular direction to the motor output shaft, donut-shaped conductive plates are mounted respectively on the upper and lower surfaces, and the conductive plates both include connection-forming terminal portions provided on inner and outer peripheral sides thereof, the inverter circuit is constituted by a power module formed from a plurality of switching elements, a power supply terminal is provided on one side of a package forming the power module, while an output terminal connected to a winding terminal for supplying power to the motor and a control terminal connected to the control signal are provided on an opposing side, and the terminal portions on the inner peripheral sides of the conductive plates are connected to the power supply terminal of the power module, and the control board is connected to the control terminal of the power module.

2 . The control unit according to claim 1 , wherein the power supply terminal of the power modules is constituted by + and − terminals,
the terminal portions of the conductive plates mounted on the frame project in a parallel direction to the motor output shaft,
the terminal portions projecting from respective surfaces of the conductive plates are all oriented in an identical direction,
the terminal portions of one of the conductive plates pass through the frame and project up to the terminal portions of the other conductive plate so as to form pairs therewith, and
the terminal portions formed on the inner peripheral sides of the conductive plates connect terminals forming the pairs on the respective surfaces of the conductive plates to the power supply terminals of the power module.

3 . The control unit according to claim 1 , wherein a leg portion of at least one of a capacitor and a coil installed in the control unit and the terminal portions formed on the outer peripheral sides of the conductive plates are connected to each other, and resulting connection portions are disposed on an identical side of the frame to connection portions connecting the terminal portions formed on the inner peripheral sides of the conductive plates to the power supply terminals of the power module.

4 . The control unit according to claim 1 , wherein a terminal of a connector for supplying power to the control unit is connected to the conductive plates on the frame in a position between the plurality of terminal portions.

5 . The control unit according to claim 1 , wherein a large-diameter hole through which the motor output shaft passes is formed in a central portion of the frame, and the terminal portions on the inner peripheral sides of the conductive plates are disposed discretely on a periphery of the hole,
a group of small holes for the control signal terminal of the power module is disposed near an outer periphery of the frame, and the terminal portions formed on the outer peripheral sides of the conductive plates are positioned on the inner peripheral side of the group of small holes.

6 . The control unit according to claim 1 , wherein one surface of the frame is provided with:
a partition for positioning at least one of a capacitor and a coil installed in the control unit; a column for fixing the control board while maintaining a distance to the control board; and a guide portion for extending a hole used for the control signal terminal of the power module.

7 . The control unit according to claim 1 , wherein the motor, the control board, the frame, and the power module are disposed coaxially in that order on an output side of the motor output shaft.

8 . The control unit according to claim 1 , wherein the motor, the power module, the frame, and the control board are disposed coaxially in that order on an anti-output side of the motor output shaft.

9 . An electric power steering device constituted by the control unit according to claim 1 and the motor, and generating auxiliary steering torque using the motor.

Assignees

• Mitsubishi Electric Corp

Inventors

• Takeuchi Kensuke
• Okanoue Takahiro
• Tanigawa Masaaki
• Kaneko Akira

Classifications

• H02K11/33

  Drive circuits, e.g. power electronics (H02K11/38 takes precedence) · CPC title

• H02P27/06

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title

• H02K2211/03

  Machines characterised by circuit boards, e.g. pcb · CPC title

• H02K5/225

  Terminal boxes or connection arrangements (specially adapted for submersible motors H02K5/132) · CPC title

• B62D5/0463

  calculating assisting torque from the motor based on driver input · CPC title