ELECTRONIC CONTROL DEVICE

• US 20130058044A1
• Filed: 09/07/2012
• Published: 03/07/2013
• Est. Priority Date: 09/07/2011
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Watanabe, Hirofumi, Nakano, Kazuhiko, Yasukawa, Daisuke
• Granted Patent: US 8,929,079 B2
• Time in Patent Office: Days
• US Class Current: 361/714
• CPC Class Codes: H05K 5/006 characterized by features for holding the PCB within the housing
• CPC Class Codes: H05K 7/20854 Heat transfer by conduction from internal heat source to heat radiating structure H05K7/20863 takes precedence

Abstract

An electronic control device comprises a circuit board having a heat generating part mounted thereon; a case for installing therein the circuit board, the case having a heat receiving portion that is in contact with the heat generating part; at least two first fixing units that are constructed and arranged to fix a peripheral portion of the circuit board to the case; and at least one second fixing unit that is arranged to fix a given area of the circuit board to the case while pressing the given area against the heat receiving portion through the heat generating part, the given area being an area where the heat generating part is placed.

Claims

1. An electronic control device comprising:

a circuit board having a heat generating part mounted thereon;

a case for installing therein the circuit board, the case having a heat receiving portion that is in contact with the heat generating part;

at least two first fixing units that are constructed and arranged to fix a peripheral portion of the circuit board to the case; and

at least one second fixing unit that is arranged to fix a given area of the circuit board to the case while pressing the given area against the heat receiving portion through the heat generating part, the given area being an area where the heat generating part is placed.

2. An electronic control device as claimed in claim 1, in which the heat receiving portion is a flat portion that is projected from a bottom wall of the case toward the heat generating part and in which the second fixing unit is arranged on the projected flat portion.

3. An electronic control device as claimed in claim 1, in which the circuit board is provided with an electric plug unit that projects toward the bottom wall of the case and in which the second fixing unit is arranged between the electric plug unit and the heat generating part.

4. An electronic control device as claimed in claim 3, in which the electric plug unit is arranged beside a side wall of the projected flat portion of the case.

5. An electronic control device as claimed in claim 3, in which the electric plug unit includes terminals through which a drive current is fed to an electric actuator to which the case is connected.

6. An electronic control device as claimed in claim 1, in which a plurality of second fixing units are arranged at both sides of the given area of the circuit board where the heat generating part is placed.

7. An electronic control device as claimed in claim 1, in which the circuit board is equipped with a tubular electric connector through which an electric power is fed to electric elements mounted on the circuit board, and in which a plurality of second fixing units are arranged along an axial direction of the tubular electric connector.

8. An electronic control device as claimed in claim 1, in which the heat generating part comprises three pairs of heat generating elements that are arranged adjacent to one another and in which at least two second fixing units are provided at the given area where the three pairs of heat generating elements are arranged.

9. An electronic control device as claimed in claim 1, in which the circuit board is provided with a tubular electric connector, and in which a plurality of second fixing units are aligned in a direction perpendicular to an axial direction of the tubular electric connector.

10. An electronic control device as claimed in claim 1, in which the heat generating part comprises three pairs of heat generating elements that are arranged adjacent to one another and in which at least two second fixing units are arranged on an imaginary line that extends along a line passing through the two heat generating elements that constitute one pair.

11. An electronic control device as claimed in claim 1, in which the circuit board is equipped with a tubular electric connector, a noise filtering circuit and an electric plug unit that projects toward the bottom wall of the case for feeding an electric actuator with a drive current, and in which the heat generating part and the electric plug unit are placed between the tubular electric to connector and at least one part of the noise filtering circuit.

12. An electronic control device as claimed in claim 1, in which the circuit board is equipped with a tubular electric connector and a noise filtering circuit, and in which the at least one second is fixing unit is placed between the tubular electric connector and at least one part of the noise filtering circuit.

13. An electronic control device as claimed in claim 1, in which the first fixing unit comprises:

a connecting hole formed in the peripheral portion of the circuit board, and

a connecting bolt that passes through the connecting hole to be engaged with a threaded opening provided by the case.

14. An electronic control device as claimed in claim 1, in which the second fixing unit comprises:

a connecting hole formed in the given area of the circuit board, and

a connecting bolt that passes through the connecting hole to be engaged with a threaded opening provided by the heat receiving portion of the case.

15. An electronic control device as claimed in claim 1, further comprising:

a second circuit board that is mounted over the circuit board; and

a plurality of resiliently deformable holding poles that are provided on the circuit board and projected toward the second circuit board, each pole having a pawl that is able to catch a peripheral portion of the second circuit board.

16. An electronic control device comprising:

a first circuit board having a heat generating part mounted thereon;

a second circuit board mounted over the first circuit board through a plurality of snap-fit units formed on the second first is circuit board;

a case for installing therein the first and second circuit boards, the case having a raised portion of which flat top surface faces a major surface of the heat generating part of the first circuit board; and

inside connecting bolts that secure the first circuit board to the case in such a manner that the major surface of the heat generating part intimately contact to the flat top surface of the raised portion, each inside connecting bolt being engaged with a threaded opening formed at the flat top surface of the raised portion of the case after passing through an inside connecting hole formed in the first circuit board; and

outside connecting bolts that secure the first circuit board to the case, each outside connecting bolt being engaged with a threaded opening formed at a peripheral portion of the case after passing through an outside connecting hole formed in the first circuit board.

17. An electronic control device as claimed in claim 16, in which the inside connecting bolts are arranged to surround the heat generating part of the first circuit board.

18. An electronic control device as claimed in claim 17, in which the heat generating part is a group of switching elements mounted to a circuit board printed on a lower surface of the first circuit board.

19. An electronic control device as claimed in claim 18, in which the flat top surface of the raised portion of the case is rectangular in shape.