Electronic Control Unit

Abstract

To expand a contact area with a bracket and improve assemblability.SOLUTION: In a state that a bracket 20 is assembled to a housing 2, a recessed part of a first facing surface part provided at the housing 2 and a protruding part of a second facing surface part provided at the bracket 20 come in close contact with each other in a fitting state. The structure can create a structure having a large contact area, and thus contact thermal resistance between the housing 2 and the bracket 20 can be reduced. Therefore, heat of a control unit can be efficiently transferred to the bracket 20.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electronic control device. [Background technology]

[0002] For example, as on-board electronic control devices installed in vehicles become smaller, the control unit, which is a heat generating body, is becoming increasingly hot, and so a structure capable of efficiently dissipating heat is required. A typical heat dissipation structure is a structure in which a heat dissipation member is interposed between the control unit and the housing, and the heat from the control unit is efficiently dissipated to the housing via the heat dissipation member. On the other hand, as the trend of high heat generation due to the miniaturization of the control unit becomes even stronger, not only the conventional heat dissipation structure but also the ability to effectively dissipate heat from the housing to the outside is now required.

[0003] Generally, an on-board electronic control unit is fixed to the vehicle body with bolts via a metal bracket. The bracket has a large heat dissipation area, so if heat can be efficiently transferred to the bracket, it can be effectively dissipated to the external space where the on-board electronic control unit is installed.

[0004] In the conventional structure, the mounting part of the housing and the fixed member are fixed with screws to dissipate heat from the on-board electronic control device to the bracket, but the only heat dissipation paths are through the bolt and the mounting part located around the bolt. In this case, since the contact area between the bolt and the mounting part is small, the heat from the on-board electronic control device cannot be efficiently dissipated to the bracket, and it is difficult to say that this structure can sufficiently dissipate heat from the housing to the outside. For the reasons mentioned above, it is desirable to provide a heat dissipation structure that improves the heat dissipation capability of the bracket. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-208005 A Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 proposes a fixing structure that can increase the contact area between a bracket and a heat dissipation target. In Patent Document 1, the mounting surface of the fixed member, which is fixed by tightening a bolt into a screw hole, is formed in a curved convex shape, and by tightening the bolts at two points, the mounting surface of the fixed member is pressed against the heat dissipation target surface and deformed by the pressure from the bolt head. As a result, the area located between the two screw tightening points in the curved convex shape comes into close contact with the heat dissipation target surface, so that the contact area with the heat dissipation target surface can be increased compared to when the mounting surface of the fixed member has a flat shape before tightening the bolts.

[0007] However, in the above-mentioned conventional technology, the contact area that can be secured is limited to the range of the curved convex shape between the screw holes, which causes problems such as insufficient heat dissipation to the fixed member when further miniaturization or high heat generation is required.In addition, since the mounting surface of the fixed member has a curved convex shape, there is a risk of it shifting left and right or swinging when screwed, which deteriorates the ease of assembly.

[0008] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an electronic control device which can increase the contact area with a bracket and improve the ease of assembly. [Means for solving the problem]

[0009] According to the invention of claim 1, a first opposing surface portion (19, 32) having a plurality of concave portions (19a, 32a) is provided on one of the opposing surfaces where the housing (2) and the bracket (20) face each other. Meanwhile, a second opposing surface portion (26, 34) having a plurality of convex portions (26a, 34a) corresponding to the plurality of concave portions is provided on the other opposing surface where the housing and the bracket face each other. When the bracket is assembled to the housing, the concave portions of the first opposing surface portion and the convex portions of the second opposing surface portion are fitted together and come into close contact with each other, thereby increasing the contact area with the bracket and improving the ease of assembly. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of an engine ECU showing an assembled state of a bracket according to a first embodiment; [Diagram 2] Perspective view of engine ECU [Diagram 3] Exploded perspective view of engine ECU [Figure 4] Top view of the cover [Diagram 5] A-A cross section of Figure 4 [Figure 6] Cross section B-B of Figure 5 [Figure 7] Bracket top view [Figure 8] A-A cross section of Figure 7 [Figure 9] Bracket bottom view [Figure 10] FIG. 13 is a perspective view of an engine ECU showing an assembled state of a bracket according to a second embodiment; [Figure 11] Perspective view of engine ECU [Figure 12] Top view of the cover [Figure 13] Section AA of Figure 12 [Figure 14] Bracket top view [Figure 15] Section AA of Figure 14 [Figure 16] Bracket bottom view DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a number of embodiments will be described with reference to the drawings. In the multiple embodiments, the same reference numerals may be used to designate functionally or structurally corresponding parts.

[0012] (First embodiment) The first embodiment will be described with reference to FIGS. 2 and 3, for example, an engine ECU 1 is composed of a housing 2 and a control unit 3 built into the housing 2. The housing 2 is composed of a base 4 and a cover 5, and when the base 4 is closed with the cover 5, an enclosed space is formed inside. The engine ECU 1 corresponds to an electronic control device.

[0013] The base 4 and cover 5 are manufactured by, for example, die-casting aluminum. The base 4 has a flat container shape, and a corner of a mounting board 7 is mounted in a positioned state on a pedestal 6 formed at a corner of the bottom surface. Various electronic components 8 and a connector 9 are mounted on the mounting board 7, and the control unit 3 is composed of the various electronic components 8 and the connector 9.

[0014] A protrusion 10 is provided on the bottom of the base 4, and the back side of the mounting board 7 mounted on the base 4 is in contact with the protrusion 10 via a heat transfer member 11 having high thermal conductivity, such as a heat dissipation sheet or heat dissipation gel. Heat generated from the control unit 3 is transferred to the base 4 via the heat transfer member 11 and the protrusion 10. The protrusion 10 and the heat transfer member 11 may be omitted.

[0015] A plurality of heat dissipation fins 12 and a connector storage section 13 are integrally formed on the surface of the cover 5, and the housing 2 is configured to include the heat dissipation fins 12 and the connector storage section 13. Screw holes 14 are formed in the base 4 and screw holes 15 are formed in the cover 5, and a sealed space is formed inside the housing 2 by screwing the cover 5 into the screw holes 14 in the base 4 through the screw holes 15. A connection portion 16 of the connector 9 faces the outside from this sealed space. A connection portion of a connector connected to a cable on the engine side to be controlled is connected to this connection portion 16. The surface of the cover 5 corresponds to the opposing surface. The engine ECU 1 having the above configuration is attached to the vehicle body by a bracket.

[0016] However, in the conventional technology, the contact area between the housing 2 and the bracket is equal to the mounting area, which causes a problem that the contact thermal resistance is large and heat cannot be efficiently transferred from the housing 2 to the bracket. For these reasons, in this embodiment, as described below, the opposing surfaces of the housing 2 and the bracket are made uneven to provide a contact area greater than or equal to the mounting area, thereby reducing the contact thermal resistance and enabling efficient heat transfer.

[0017] Of the multiple heat dissipation fins 12, the heat dissipation fins 12 located at both ends have opposing arms 17, which are additional structures, integrally formed on their sides in a direction parallel to the surface direction of the cover 5. The opposing arms 17 have multiple screw holes 18 formed therein. On the other hand, a first opposing surface portion 19 is formed on the surface of the cover 5 at a portion opposing the opposing arm portion 17 .

[0018] 4 to 6, the first opposing surface portion 19 is configured by a series of recessed portions 19a having a triangular cross section along a predetermined direction parallel to the surface of the housing 2. The predetermined direction is a direction perpendicular to the longitudinal direction of the bracket 20 attached to the housing 2 as shown in FIG. 1, that is, a direction perpendicular to the attachment direction of the bracket 20.

[0019] 7 to 9, the bracket 20 is composed of an assembly portion 21, an extension portion 22, and a mounting portion 23, and is bent between the assembly portion 21 and the extension portion 22 and between the extension portion 22 and the mounting portion 23 in order to adjust the mounting position of the engine ECU 1. A plurality of screw receiving portions 24 are formed on the surface of the assembly portion 21. The extension portion 22 is formed so as to become narrower from the assembly portion 21 to the mounting portion 23. A plurality of screw holes 25 are formed in the mounting portion 23.

[0020] A second opposing surface portion 26 is formed on the back surface of the mounting portion 21. The second opposing surface portion 26 is configured by continuing convex portions 26a having a triangular cross section along a predetermined direction. The predetermined direction is a direction perpendicular to the mounting direction of the bracket 20. The back surface of the mounting portion 21 corresponds to the opposing surface.

[0021] When the bracket 20 is attached to the housing 2, it is attached so that the first opposing surface portion 19 of the housing 2 and the second opposing surface portion 26 of the bracket 20 are in surface contact with each other. In this case, since the opposing arm portion 17 is provided on the housing 2 and the bracket 20 cannot be attached from above the housing 2, the bracket 20 is slid in a state in which the second opposing surface portion 26 of the bracket 20 and the first opposing surface portion 19 of the housing 2 are meshed with each other. In other words, since the concave portion 19a of the first opposing surface portion 19 and the convex portion 26a of the second opposing surface portion 26 have corresponding cross-sectional shapes, the bracket 20 can be smoothly guided to the assembly position of the housing 2 by sliding them in a state of meshing with each other.

[0022] With the first opposing surface portion 19 of the housing 2 and the second opposing surface portion 26 of the bracket 20 in surface contact as described above, the bolt 27 is screwed into the screw hole 18 of the opposing arm portion 17 as shown in Fig. 1. At this time, the tip of the bolt 27 presses the screw receiving portion 24 of the bracket 20, so that the bracket 20 is pressed against the housing 2, and the bracket 20 is fixed to the housing 2. At this time, the concave portion 19a of the first opposing surface portion 19 and the convex portion 26a of the second opposing surface portion 26 are in close contact with each other in a fitted state, so that the contact area between the first opposing surface portion 19 and the second opposing surface portion 26 can be increased.

[0023] Here, the height dimension of the convex portion 26a is set slightly larger than the height dimension of the concave portion 19a, so that when the concave portion 19a and the convex portion 26a are in close contact with each other in an engaged state, the back surface of the bracket 20 is slightly spaced from the surface of the housing 2.

[0024] As shown in FIG. 1, a screw hole 25 is formed in the mounting portion 23 of the bracket 20, so that the engine ECU 1 can be fixed to the vehicle body by screwing the screw into the vehicle body through the screw hole 25.

[0025] According to this embodiment, the following effects can be obtained. When the bracket 20 is attached to the housing 2, the concave portion 19a of the first opposing surface portion 19 provided on the housing 2 and the convex portion 26a of the second opposing surface portion 26 provided on the bracket 20 are fitted together and come into close contact with each other. This makes it possible to realize a structure with a large contact area, thereby reducing the contact thermal resistance between the housing 2 and the bracket 20 and allowing the heat of the control unit 3 to be efficiently transferred to the bracket 20. The concave portion 19a of the first opposing surface portion 19 and the convex portion 26a of the second opposing surface portion 26 also function as a positioning mechanism for the housing 2 and the bracket 20, thereby improving the ease of assembly.

[0026] Since the opposing arm 17, which is an additional structure, has the effect of increasing the heat dissipation capacity of the existing heat dissipation fin 12, providing the opposing arm 17 to the heat dissipation fin 12 can increase the heat dissipation capacity of the existing heat dissipation fin 12. In other words, the heat dissipation fin 12 is often provided directly above a heat generating body, and the heat transfer area is increased by the opposing arm 17, which is an additional structure, so that heat can be efficiently dissipated to the external space of the housing 2.

[0027] The height dimension of the convex portion 26a is set to be greater than the height dimension of the concave portion 19a, so that the contact area between the housing 2 and the bracket 20 can be reliably secured even if manufacturing variations occur. The first opposing surface portion 19 and the second opposing surface portion 26 have cross-sectional shapes along a direction perpendicular to the assembly direction of the bracket 20 to the housing 2 that are configured by repeating the same shape, thereby improving manufacturability and assembly ease.

[0028] The bracket 20 is pressed against the housing 2 by a bolt 27 screwed into the screw hole 18, so that the concave portion 19a and the convex portion 26a are fitted together and tightly fitted together, thereby increasing the contact area between the housing 2 and the bracket 20 and improving the heat dissipation capacity of the bracket 20.

[0029] Since the structure fixes bracket 20 to housing 2 by screwing bolt 27 into screw hole 18 of opposing arm 17, which is an additional structure, and pressing the tip of bolt 27 against bracket 20, there is no need to provide a screw hole in housing 2, and the area of ​​first opposing surface 19 of housing 2 and second opposing surface 26 of bracket 20 can be increased. Since the screw holes 18 are provided in the opposing arm portion 17 and the screw receiving portion 24 is provided on the surface of the bracket 20, the manufacture of the housing 2 is facilitated and the degree of freedom in the shape of the concave portion 19a and the convex portion 26a can be increased.

[0030] Second embodiment The second embodiment will be described with reference to Figures 10 to 16. The second embodiment is characterized in that the bracket is fixed directly to the housing 2.

[0031] 12 to 14, a plurality of screw holes 31 are formed on the surface of the cover 5. In this embodiment, the first opposing surface portion 32 is provided at a position away from the area surrounding the screw holes 31. In other words, the first opposing surface portion 32 is not provided in the area surrounding the screw holes 31, and the surface of the housing 2 is exposed as it is. Also, the opposing arm portion 17 provided in the first embodiment is omitted.

[0032] 14 to 16, a plurality of screw holes 33 are formed in the bracket 20. In this embodiment, the second opposing surface portion 34 is provided at a position away from the area surrounding the screw holes 33. In other words, the second opposing surface portion 34 is not provided in the area surrounding the screw holes 33, and the back surface of the bracket 20 is exposed as it is.

[0033] The concave portion 32a of the first opposing surface portion 32 of the housing 2 and the convex portion 34a of the second opposing surface portion 34 of the bracket 20 are in the shape of a quadrangular pyramid, and are arranged two-dimensionally to form the first opposing surface portion 32 and the second opposing surface portion 34. As in the first embodiment, the height dimension of the convex portion 34a is set slightly larger than the height dimension of the concave portion 32a to prevent the influence of dimensional errors.

[0034] 11, bracket 20 is attached to housing 2 from above housing 2 with a screw into screw hole 31 of housing 2 via screw hole 33 of bracket 20 in a state in which first opposing surface portion 32 of housing 2 and second opposing surface portion 34 of bracket 20 are in surface contact with each other. In this case, bracket 20 is attached to housing 2 by pressing a head of a bolt against bracket 20.

[0035] As shown in FIG. 10, when the bracket 20 is attached to the housing 2, the concave portion 32a of the first opposing surface portion 32 and the convex portion 34a of the second opposing surface portion 34 are fitted together and come into close contact with each other, thereby increasing the contact area between the first opposing surface portion 32 and the second opposing surface portion 34.

[0036] According to this embodiment, the first opposing surface portion 32 and the second opposing surface portion 34 are provided at positions away from the areas surrounding the screw holes 31 and 33, respectively, and the bracket 20 is fixed to the housing 2 by screwing into the screw hole 31 via the screw hole 33. Therefore, even though the bracket 20 is directly screwed into the housing 2, it is possible to prevent the bracket 20 from being affected by dimensional errors in the concave portion 32a and the convex portion 34a.

[0037] (Other embodiments) In the first embodiment, the second opposing surface portion 26 may be provided on the housing 2, and the first opposing surface portion 32 may be provided on the bracket 20. The opposing arm portion 17 is not limited to being formed integrally with the heat dissipation fin 12, but may be provided directly on the surface of the cover 5 or may be a separate member that is later attached. The cross-sectional shapes of the concave and convex portions are not limited to triangular shapes, but may be rectangular or polygonal. In the second embodiment, the first opposing surface portion 32 and the second opposing surface portion 34 may be provided around the screw hole 31 and the screw hole 33. The screw receiving portion 24 may be omitted.

[0038] Although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also encompasses various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and concept of the present disclosure. [Explanation of symbols]

[0039] In the drawings, 1 is an engine ECU (electronic control unit), 2 is a housing, 3 is a control unit, 14 is a screw hole, 17 is an opposing arm portion, 19 and 32 are first opposing surface portions, 19a and 32a are concave portions, 20 is a bracket, 26 and 34 are second opposing surface portions, 26a and 34a are convex portions, 31 is a screw hole, and 33 is a screw hole.

Claims

1. A housing (2) that includes a control unit (3) and includes a base (4) and a cover (5) on which a plurality of heat dissipation fins (12) are formed; A bracket (20) attached to the cover; a first opposing surface portion (19, 32) provided on one of the opposing surfaces where the cover and the bracket face each other and having a plurality of concave portions (19a, 32a); a second opposing surface portion (26, 34) provided on the other of the opposing surfaces where the cover and the bracket face each other and having a plurality of convex portions (26a, 34a) corresponding to the plurality of concave portions; An opposing arm portion (17) provided on the housing and extending in a direction parallel to a surface of the cover; a screw hole (18) provided in the opposing arm portion and facing in a planar direction of the surface of the cover; the first opposing surface portion is provided at a portion of the surface of the cover different from a portion where the heat dissipation fins are formed, When the bracket is assembled to the cover, the concave portion of the first opposing surface and the convex portion of the second opposing surface are fitted together in a tight fit, and the bracket is fixed by screwing it into the screw hole and pressing it against the cover.

2. 2. The electronic control device according to claim 1, wherein a height dimension of the convex portion is set to be greater than a height dimension of the concave portion.

3. 3 . The electronic control device according to claim 1 , wherein the first opposing surface portion and the second opposing surface portion have a cross-sectional shape in a direction perpendicular to a direction in which the bracket is attached to the cover, the cross-sectional shape being configured by repeating the same shape.

4. A screw hole (31) provided on the surface of the cover; A screw hole (33) provided in the bracket, the first opposing surface portion and the second opposing surface portion are provided at positions away from the screw hole and a portion surrounding the screw hole, The electronic control device according to claim 2 , wherein the bracket is fixed to the cover by screwing a screw into the screw hole through the screw hole.

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