JP6121879B2 - Controller unit - Google Patents

Description

  The present invention relates to an electronic control device mounted on, for example, an automobile.

  In recent years, the automobile industry has been required to reduce the size and weight of mounted components in order to improve the fuel efficiency of automobiles. A vehicle is provided with a control unit for controlling an engine, a transmission, and the like, and these control units are also required to be further reduced in size and weight. As an example, the control unit has been made of resin in a metal casing.

  On the other hand, the board mounted in the control unit needs to be grounded by electrically connecting the ground pattern of the circuit board and the metal base from the viewpoint of improving noise resistance.

  As background art of the present invention, there is JP-A-2003-258451 (Patent Document 1). This publication states that "the circuit board may be fixed by being sandwiched between the base and the cover" (refer to the detailed description of the invention). Moreover, there exists Unexamined-Japanese-Patent No. 2012-199451 (patent document 2). This publication states that “the circuit board 3 has four corners of the outer peripheral edge thereof fixed to a circuit board support portion 11 (described later) of the case 5 by screws 18” (implementing the invention). For example).

JP 2003-258451 A JP 2012-199451 A

  The circuit board in the background art described above may have a case ground for noise countermeasures. In these control units, for example, the circuit board, the metal base, and the cover are in contact with each other, and the cover and the base are firmly tightened with screws or the like to hold the circuit board so that the ground pattern and the metal base are May be designed to ensure grounding by electrical connection.

  At this time, if the design is such that the substrate can be sandwiched between the cover and the base, a gap is generated between the cover flange portion and the base. When this is firmly fixed, a high stress is generated at the base of the flange portion of the cover. Therefore, in the prior art, a material that can withstand the stress generated in the cover flange portion, such as a steel plate cover, is employed. When this is a resin cover, the stress generated around the base of the cover flange portion exceeds the proof stress of the resin, so that it is difficult to take a structure that is sandwiched between the base and the cover. Therefore, when a resin cover is used and a case ground is taken, screws are fastened from the upper surface of the substrate to the base.

  On the other hand, the resin cover may be designed so that the cover and the connector are integrated. The connector-integrated cover is more advantageous than a design in which the connector and the cover are separated from each other in terms of reducing the number of parts and reducing the amount of waterproof sealant applied. However, in the structure in which the cover and the connector are integrated, it is difficult to screw the board to the base from the upper surface side of the board, so that the case grounding cannot be taken with the screwing technique.

  As shown in Patent Document 1, the control unit, which is made of a cover resin to reduce the size and weight of the control unit, employs a structure in which the substrate is sandwiched between the cover and the base, and the stress generated in the cover flange portion. Need to relax.

In order to solve the above problems, the configuration described in the claims is adopted.
The present application includes a plurality of means for solving the above-described problems. For example, a circuit board covered with a metal base, a resin cover, the metal base and the resin cover, and mounted with an electronic component. The metal base includes a first abutting portion with which one surface of the circuit board abuts, and the resin cover has a second surface with which the other surface of the circuit board abuts. An abutting portion, wherein the first abutting portion and the second abutting portion sandwich the circuit board, and the second abutting portion is inclined on a surface facing the circuit board side. A control unit characterized by comprising:

The present application realizes a structure in which a substrate is sandwiched between a resin cover and a metal base, and a screw for fixing the substrate is eliminated, thereby reducing the cost and size and weight of the control unit.

Electronic control unit Cross section of electronic control unit I Exploded view of electronic control unit Sectional view IV of cover contact portion and cover contact portion of Example 1 IV Sectional view IV of cover contact portion and cover contact portion of Example 1 IV Sectional view IV of cover contact portion and cover contact portion of Example 2 Sectional view IV of cover contact portion and cover contact portion of Example 3 Sectional view IV of cover contact portion and cover contact portion of Example 4

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
Here, FIGS. 1 to 3 are described by taking the engine control unit 1 for automobiles as an example, and the first embodiment is shown in FIGS. 4 and 5. FIG. Here, FIG. 2 is a cross-sectional view of I in FIG. 1, and FIG. 3 is an exploded view of the engine control unit 1.

  Reference numeral 10 denotes a base constituting the engine control unit 1, and the base 10 is made of a metal material such as aluminum, and is integrally formed as a substantially square bottomed box-like body. As shown in FIGS. 1 to 3, the base 10 includes a base bottom portion 11, peripheral walls 12 </ b> A, 12 </ b> B, 12 </ b> C, 12 </ b> D, and a bracket portion 13.

  Reference numeral 11 denotes a base bottom of the base 10, and the base bottom 11 is formed in a flat plate shape. For example, the base bottom 11 has a substantially rectangular shape, and base peripheral walls 12A to 12D are erected on four sides.

Reference numeral 13 denotes, for example, two bracket portions provided on the outer surface side of the base 10. Each bracket portion 13 protrudes left and right from the base bottom portion 11 or the base peripheral wall 12A to D, and attaches the engine control unit to a vehicle body such as an automobile. Is.
A base abutting portion 14A that abuts on the circuit board 40 is provided on the base bottom 11 inside the base 10 surrounded by the base peripheral walls 12A to 12D.

  14B is a base-side contact surface where the base contact portion 14A and the circuit board 40 come into contact with each other.

  Reference numeral 15 denotes a screw hole into which the attachment screw 30 is screwed.

  Reference numeral 20 denotes a cover attached to the base 10 using an attachment screw 30. The cover 20 is formed by, for example, resin injection molding.

  The cover 20 is formed in a box shape that opens downward. For example, the cover 20 has a substantially rectangular box shape, and includes a lid portion 21 that covers the electronic component 41 and the like of the circuit board 40, cover peripheral walls 22 </ b> A to 22 </ b> D that are erected on the four sides of the lid portion 21, and the like. Furthermore, the flange part 23 is formed so that it may protrude outside from the end surface of the said cover surrounding walls 22A-D. Here, the flange portion 23 faces the peripheral walls 12 </ b> A to 12 </ b> D of the base 10, and a plurality of insertion holes 24 into which the collars 29 are fitted are provided.

  A cover contact portion 25 </ b> A that contacts the circuit board 40 is provided inside the cover 20 surrounded by the cover peripheral walls 22 </ b> A to 22 </ b> D.

  Reference numeral 25B denotes a cover-side contact surface where the cover contact portion 25A and the circuit board 40 contact each other.

  The cover 20 is attached to the base 10 by being screwed into the screw holes 15 of the base 10 via the collars 29 with the respective mounting screws 30, and at the same time, between the cover contact portion 25A and the base contact portion 14A. The circuit board 40 is sandwiched.

  Here, reference numeral 26 denotes a connector formed integrally with the cover 20, and the connector 26 includes a connector housing 27 and terminal pins 28 as shown in FIGS. 1 to 3.

  The connector 26 is connected to various sensors, actuators and the like provided on the vehicle side, whereby the control unit 1 controls the engine.

  Reference numeral 27 denotes a connector housing which forms the outer shape of the connector 26, and is integrally molded from the cover peripheral walls 22A to D of the cover 20 as, for example, a substantially rectangular frame extending in the front-rear direction. 27D, and a partition wall 27E that partitions a midway portion in the front-rear direction.

  Reference numeral 28 denotes a plurality of terminal pins implanted in the partition wall 27E of the connector housing 27. Each terminal pin 28 protrudes downward from the connector housing 27 and is connected to the circuit board 40 by means of soldering or the like. , Has been fixed. Further, the distal end side of each terminal pin 28 protrudes outward from the connector housing 27 and is connected to the harness-side connector.

  40 is a circuit board disposed inside the peripheral wall of the cover. As shown in FIGS. 2 and 3, the circuit board 40 is formed, for example, as an approximately square plate by an insulating resin material. A wiring pattern is provided on the upper surface and the lower surface, and a plurality of electronic components 41 made of, for example, capacitors, coils, transistors, semiconductor ICs, and the like are mounted.

  For example, the four corners of the circuit board are supported by the cover contact portion 25A and the base contact portion 14A.

The engine control unit according to the present embodiment has the above-described configuration.

  4 and 5 show a first embodiment of the present invention and are sectional views taken along line II shown in FIG. IV is a partial cross-sectional view of the cover contact portion 25A.

  In this embodiment, the electronic control device is composed of a metal base 10, a resin cover 20, and a circuit board 40. The resin cover 20 is a connector-integrated resin cover in which a connector 26 is provided on a peripheral wall 22B.

  The flange portion 23 of the resin cover 20 is provided with an insertion hole 24 for a collar 29, and is firmly fixed to the base 10 with a mounting screw 30 using a metal collar 29. In addition, the cover 20 includes a cover contact portion 25A on which one surface of the circuit board 40 contacts, and the base 10 includes a base contact portion 14 on which the other surface of the circuit board 40 contacts. The circuit board 40 is supported by the base contact portion 14A, and the cover contact portion 25A and the base contact portion 14A sandwich the circuit board 40 by fixing the cover 20 to the base 10.

  The cover abutting portion 25A is provided with an inclination or a curved surface on a part or the whole of the cover side contact surface 25B facing the circuit board 40, and the resin cover 20 is provided with an inclined surface in the direction of the fixing portion. 20, the deformation around the flange portion 23 is allowed, and the stress generated at the root of the flange portion 23 is relieved.

  FIG. 6 shows a second embodiment of the present invention and is a cross-sectional view taken along the line II shown in FIG. IV is a partial cross-sectional view of the cover contact portion 25A. Compared to the first embodiment, the cover contact portion 25A is provided with a protrusion on the surface facing the circuit board 40, and a gap is provided in the cover fixing portion direction of the cover side contact surface 25B where the cover 20 and the circuit board 40 are in contact. Thus, deformation around the flange portion 23 in the resin cover 20 is allowed, and stress generated at the root of the flange portion 23 is relieved. In addition, it is possible to arrange electronic components 41 and wiring in the gap.

  FIG. 7 shows a third embodiment of the present invention and is a cross-sectional view taken along the line III shown in FIG. In contrast to the first embodiment, the outer edge portion of the circuit board 40 is held by providing the cover abutting portion long along the side of the substrate. In general, since the outer edge portion of the circuit board 40 is a forbidden band where the electronic component 41 cannot be mounted, the forbidden band newly increased due to the cover contact portion 25A can be suppressed. At this time, as in the first embodiment, the cover abutting portion 25A is provided with an inclination or a curved surface on a part or the whole of the cover side contact surface 25B facing the circuit board 40, and in the direction of the fixing portion of the resin cover 20. Due to the presence of the inclined surface, deformation around the flange portion 23 in the resin cover 20 is allowed, and stress generated at the root of the flange portion 23 is relieved.

  FIG. 8 shows a fourth embodiment of the present invention and is a cross-sectional view taken along the line III shown in FIG. In contrast to the first embodiment, a plurality of cover contact portions 25 </ b> A are arranged not only on the four corners of the circuit board 40 but also on the side of the circuit board 40, for example. At this time, the cover abutting portion 25A closer to the fixing portion between the cover 20 and the base 10 is made shorter and the clearance with the substrate is made larger, so that the stress generated at the base of the flange portion 23 is relieved. The cover side contact surface 25B is flat or the same as in the first or second embodiment. In the present embodiment, since the cover side contact surface 25B can be dispersed on the circuit board 40, for example, even when the area on the circuit board 40 occupied by the cover contact portion 25A in Example 1 cannot be secured sufficiently, This can be implemented by holding a plurality of narrow areas between electronic components.

  The fixing method of the base 10 and the cover 20 is not limited to screw fixing, and any fixing means such as snap fit, heat caulking, tapping screw, rivet, adhesive, press-fitting, etc. may be used.

The base 10 may be made of resin and the cover 20 may be made of metal. In this case, the base contact portion 14A is provided with the same structure as the cover contact portion 25A described in the first to fourth embodiments.

DESCRIPTION OF SYMBOLS 10 Base 11 Base bottom part 12A, 12B, 12B, 12D Base peripheral wall 13 Bracket part 14A Base contact part 14B Base side contact surface 15 Screw hole 20 Cover 21 Cover part 22A, 22B, 22B, 22D Cover peripheral wall 23 Flange part 24 Insertion hole 25A Cover contact portion 25B Cover side contact surface 26 Connector 27 Connector housing 27A Upper surface 27B Lower surface 27C Left side surface 27D Right side surface 27E Bulkhead 28 Terminal pin 29 Collar 30 Mounting screw 40 Circuit board 41 Electronic component

Claims (4)

A metal base,
A resin cover,
In a control unit comprising a circuit board covered with the metal base and the resin cover and mounted with electronic components,
The base includes a base abutting portion with which one surface of the circuit board abuts,
The cover includes a cover abutting portion with which the other surface of the circuit board abuts,
A plurality of the base contact portion and the cover contact portion;
The base contact portion and the cover contact portion sandwich the circuit board,
The cover contact portion includes an inclined surface on a surface facing the circuit board side ,
According to the shortest distance from the cover abutting portion to the portion where the metal base and the resin cover are fixed, the control unit is characterized in that the height of the cover abutting portion is lowered as the distance is shorter. The control unit according to claim 1, wherein
The control unit, wherein the cover contact portion includes a curved surface or an inclined surface on a surface facing the circuit board side. The control unit according to claim 1 or 2,
On the cover side contact surface where the cover contact portion contacts the circuit board,
The control unit, wherein the curved surface or the inclined surface is provided in a direction of a fixing portion between the cover and the base. The control unit according to any one of claims 1 to 3,
The base contact portion is in contact with the circuit board wiring pattern;
The control unit, wherein the wiring pattern and the metal base are electrically connected.