Electronic control unit

Abstract

To provide en electronic control device having high cooling performance, and capable of restricting radiation of electromagnetic noise occurring in electronic components to the outside.SOLUTION: An electronic control device comprises: a substrate where electronic components are to be mounted; a housing that stores the substrate; a heat dissipation member that is thermally connected to the electronic component through a heat conduction material to dissipate heat transmitted from the electronic component, to the outside; and a fan that generates a flow of cooling air for cooling the heat dissipation member. The substrate has a high temperature region where high heat generating components are to be mounted and a low temperature region where no components are to be mounted. The housing is provided with an opening part facing the high temperature region. The heat dissipation part has a heat dissipation part for diffusing the heat from the high heat generating components, and a radiation fin protruding from the heat dissipation part to the outside through the opening part. The heat dissipation part comprises: a fin base to which the high heat generating components are to be connected and on which the radiation fin is installed; and an extension part that extends from the fin base along the substrate, and thermally connected to a low temperature region facing part facing the low temperature region of the housing through an intermediate member.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] Electronic control devices used in vehicles and other applications are becoming smaller and more powerful, but the amount of heat they generate and the amount of electromagnetic noise (high-frequency noise) they generate are also increasing. In recent years, operating frequencies have increased from the MHz range to the GHz range, and as a result, communication speeds between electronic control devices and external devices have also increased. The increase in operating frequency has required electronic control devices to have greater cooling performance. Furthermore, the increase in communication speed requires greater suppression of electromagnetic noise emissions to the outside and electromagnetic noise intrusion from the outside.

[0003] Conventionally, a technique for cooling an electronic control device using cooling air has been known (see Patent Document 1). Patent Document 1 discloses a cooling element that is composed of a substrate on one side of which electronic components that generate heat are mounted, and fins that are mounted on the other side of the substrate, and that cools the electronic components by sending cooling air to the fins. Patent Document 1 discloses a cooling element in which fins that are approximately the same length as the substrate and fins that are half that length are arranged alternately at a predetermined interval. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-208116 Summary of the Invention [Problem to be solved by the invention]

[0005] When incorporating the cooling element described in Patent Document 1 into the housing of an electronic control device, it is assumed that the electronic components are housed inside the housing and only the fins are exposed to the outside. However, the cooling element described in Patent Document 1 has fins with a length approximately equal to the length of the board, which requires the formation of a large opening in the housing that is approximately the same size as the board that supports the fins. The larger the opening, the more difficult it becomes to suppress the radiation of electromagnetic noise generated by the electronic components inside the housing to the outside of the housing.

[0006] An object of the present invention is to provide an electronic control device that has high cooling performance and is capable of suppressing external radiation of electromagnetic noise generated in electronic components. [Means for solving the problem]

[0007] According to one aspect of the present invention, an electronic control device includes a substrate on which electronic components are mounted, a housing that houses the substrate, a heat dissipation member that is separate from the housing and thermally connected to the electronic components via a thermally conductive material and that dissipates heat transferred from the electronic components to the outside of the housing, and a fan that generates a flow of cooling air to cool the heat dissipation member. The substrate has a high-temperature region in which high-heat-generating components that generate a heat value exceeding a predetermined value are mounted, and a low-temperature region in which the high-heat-generating components are not mounted. The housing has an opening that faces the high-temperature region, and the heat dissipation member has a thermal diffusion section that diffuses heat from the high-heat-generating components and heat dissipation fins that protrude from the thermal diffusion section to the outside of the housing through the opening. The thermal diffusion section has a fin base that is thermally connected to the high-heat-generating components and on which the heat dissipation fins are mounted, and an extension section that extends from the fin base along the substrate and is thermally connected via an intermediate member to a low-temperature region-facing section of the housing that faces the low-temperature region. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an electronic control device that has high cooling performance and is capable of suppressing external radiation of electromagnetic noise generated in electronic components. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an external perspective view of an electronic control device according to a first embodiment. [Figure 2] FIG. 2 is a plan view of the electronic control device according to the first embodiment. [Figure 3] FIG. 3 is a perspective view of the electronic control device according to the first embodiment, with the cover not shown. [Figure 4] FIG. 4 is a plan view of the electronic control device according to the first embodiment, with the cover not shown. [Figure 5] FIG. 5 is a schematic cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a diagram illustrating the flow of cooling air generated by the cooling fan and the flow of heat generated by the high heat generating components. [Figure 7] FIG. 7 is a plan view of the electronic control device according to the second embodiment, with the cover not shown. [Figure 8] FIG. 8 is a schematic cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a partially enlarged plan view of an electronic control device according to a third embodiment, with the cover omitted. [Figure 10] FIG. 10 is a plan view of the electronic control device according to the fourth embodiment, with the cover not shown. [Figure 11] FIG. 11 is a plan view of the electronic control device according to the fifth embodiment, with the cover not shown. [Figure 12] FIG. 12 is a schematic cross-sectional view taken along line XII-XII in FIG. [Figure 13] FIG. 13 is a plan view of the electronic control device according to the sixth embodiment, with the cover not shown. [Figure 14] FIG. 14 is a schematic cross-sectional view taken along line XIV-XIV in FIG. [Figure 15] FIG. 15 is an external perspective view of an electronic control device according to the first modification. [Figure 16] 16 is a side view of the electronic control device as seen from the XVI direction in FIG. [Figure 17]FIG. 17 is a plan view of the electronic control device according to the second modification, with the cover not shown. [Figure 18] FIG. 18 is a diagram illustrating the flow of cooling air when the central cooling fan of the electronic control device according to the second modification is stopped. [Figure 19] FIG. 19 is a diagram showing an example in which the heat dissipation base and the heat dissipation fins are separate bodies. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and some omissions and simplifications have been made as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0011] The position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings. Note that the electronic control device described below is preferably an electronic control device mounted on an automobile, but may also be applied to other electronic control devices.

[0012] First Embodiment An electronic control device 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG. 1 is an external perspective view of the electronic control device 100 according to the first embodiment of the present invention, and FIG. 2 is a plan view of the electronic control device 100. In this embodiment, for convenience of explanation, up / down, left / right, and front / rear directions are defined as shown in the drawings. The directions shown in the drawings are defined for the purpose of explanation and do not define the installation direction or use direction of the electronic control device 100. As shown in FIGS. 1 and 2, the electronic control device 100 includes a housing 110 that houses a circuit board 140 (see FIG. 5), which will be described later, a cover 120 that is arranged to cover the top of the housing 110, and a plurality of cooling fans 130 that send air into the space between the housing 110 and the cover 120.

[0013] The housing 110 has a lower housing 112 constituting a lower housing member and an upper housing 111 constituting an upper housing member. The upper housing 111 is formed in the shape of a rectangular box with an open bottom. The upper housing 111 has a rectangular top plate 116, a front plate 117a which is a side wall provided on the front edge of the top plate 116, a rear plate 117b provided on the rear edge of the top plate 116, a left plate 117c provided on the left short side of the top plate 116, and a right plate 117d provided on the right edge of the top plate 116. The front plate 117a and the rear plate 117b are arranged opposite each other. The left plate 117c and the right plate 117d are arranged opposite each other.

[0014] Lower housing 112 is formed in the shape of a rectangular flat plate and covers the opening on the bottom surface of upper housing 111. Upper housing 111 and lower housing 112 are connected by fastening members such as screws (not shown). Upper housing 111 and lower housing 112 connected to each other form an internal space that houses circuit board 140 (see FIG. 5).

[0015] Upper housing 111 is made of a metal material with excellent thermal conductivity, such as aluminum (e.g., aluminum die-casting) or iron. Upper housing 111 may also be made of a non-metal material, such as a resin material. It is preferable to use a material that can dissipate heat by thermal radiation or the like, as the resin material. Lower housing 112 and cover 120, like upper housing 111, are made of a metal material with excellent thermal conductivity, such as aluminum, or a non-metal material, such as a resin material.

[0016] Openings 113 such as holes or notches are formed in the left and right plates 117c and 117d of the housing 110 for inserting connectors 149 provided on a circuit board 140 (see FIG. 5). The connectors 149 are connected to a wiring pattern (not shown) formed on the circuit board 140. Power is supplied and control signals are sent and received between the external device and the electronic control device 100 via the connectors 149.

[0017] The cover 120 is formed in a box shape, and an opening on the bottom surface is closed by the top plate 116 of the upper housing 111. The cover 120 has a fan mounting portion 121 and a duct 122. The fan mounting portion 121 is provided near the front plate 117a of the housing 110 in a plan view. The fan mounting portion 121 is provided with three mounting openings 123 to which three air-cooling fans 130 are respectively attached. The duct 122 extends from the front plate 117a toward the rear plate 117b of the housing 110. An exhaust port 122a for discharging air is provided at the rear end of the duct 122.

[0018] Fig. 3 is a perspective view of the electronic control device 100 without illustrating the cover 120, and Fig. 4 is a plan view of the electronic control device 100 without illustrating the cover 120. As shown in Figs. 3 and 4, two rectangular openings 114 are provided in the upper housing 111. Heat dissipation fins 162 of a heat dissipation member 160, which will be described later, protrude from the openings 114.

[0019] Fig. 5 is a schematic cross-sectional view taken along line VV in Fig. 4. As shown in Fig. 5, a circuit board 140 is disposed inside the housing 110. A plurality of mounting bosses 115 are provided on the outer periphery of the upper housing 111. The mounting bosses 115 are provided so as to protrude downward from the top plate 116 of the upper housing 111. The circuit board 140 is attached to the mounting bosses 115 with screws (not shown).

[0020] The circuit board 140 is formed of an organic material such as epoxy resin. The circuit board 140 may also be made of a metal material such as a metal core board. The circuit board 140 may also be a single-layer board or a multi-layer board.

[0021] A plurality of electronic components are mounted on the circuit board 140. The circuit board 140 also has a wiring pattern formed thereon that connects the plurality of electronic components to one another or to a connector 149. The electronic components include computing devices such as a central processing unit (CPU), a graphics processing unit (GPU), a system on a chip (SoC), or a system in a package (SiP), storage devices such as a DDR SDRAM, a power supply IC, a coil, and a capacitor. The electronic components may also be Flip Chip Ball Grid Array (FCBGA)-type semiconductor elements that generate heat. Hereinafter, among the plurality of electronic components, an electronic component that generates more than a predetermined heat value W0 [W] is defined as a high-heat component 141.

[0022] The circuit board 140 has a high temperature region Ra, which is a region where at least the high heat generating component 141 is mounted, and a low temperature region Rb, which is a region where the high heat generating component 141 is not mounted. In the first embodiment, no electronic components are mounted in the low temperature region Rb. In the first embodiment, the region on the right side of the circuit board 140 in the figure, from the inner end (front end) of the high heat generating component 141 to the outer end, is defined as the high temperature region Ra, and the other region on the left side in the figure is defined as the low temperature region Rb. In the first embodiment, the low temperature region Rb has a larger area than the high temperature region Ra.

[0023] The electronic control device 100 includes a heat dissipation member 160 attached to the top plate 116 of the housing 110, an intermediate member 170 provided between the heat dissipation member 160 and the top plate 116, and a thermally conductive material 151 provided between the heat dissipation member 160 and the high heat-generating component 141. In this embodiment, two high heat-generating components 141 are mounted on the circuit board 140. Therefore, the two high heat-generating components 141 are cooled by the two heat dissipation members 160. The left-side heat dissipation member 160A and the right-side heat dissipation member 160B shown in FIG. 4 have the same configuration, and therefore will be collectively referred to as the heat dissipation member 160.

[0024] 5, the heat dissipation member 160 is configured as a separate member from the housing 110, and is connected to the top plate 116 with fastening members such as screws. The heat dissipation member 160 is thermally connected to the high heat generating component 141 via the thermal conductive material 151, and dissipates the heat transferred from the high heat generating component 141 to the outside of the housing 110.

[0025] There are various types of thermally conductive material 151, such as grease, gel, and sheet. Commonly used thermally conductive material 151 is a grease-like material known as thermal grease, and examples of such materials include adhesive thermosetting resins and low-elastic semi-cured resins. Thermally conductive material 151 contains fillers made of highly thermally conductive materials such as metal, carbon, and ceramic. Thermally conductive material 151 preferably has flexibility that allows it to deform in response to thermal deformation, vibration, and manufacturing tolerances of circuit board 140. For example, thermally conductive material 151 is preferably a semi-cured resin made of a silicon-based resin containing ceramic fillers.

[0026] The heat dissipation member 160 has a rectangular, flat heat dissipation base 161 and a plurality of heat dissipation fins 162 that protrude from the heat dissipation base 161 to the outside of the housing 110 through an opening 114 in the top plate 116 of the upper housing 111. The heat dissipation base 161 is a plate-like member made of a metal material with excellent thermal conductivity, such as aluminum or copper. The heat dissipation fins 162, like the heat dissipation base 161, are also plate-like members made of a metal material with excellent thermal conductivity, such as aluminum or copper. The heat dissipation fins 162 are arranged perpendicular to the heat dissipation base 161.

[0027] The multiple heat dissipation fins 162 extend in a strip shape in the left-right direction in Figure 5. The length of the heat dissipation fins 162 in the longitudinal direction (extension direction) is longer than the protruding height of the heat dissipation fins 162. The multiple heat dissipation fins 162 are arranged parallel to one another at a predetermined pitch. Each of the multiple heat dissipation fins 162 has the same shape.

[0028] The heat dissipation base 161 has a fin base 161a to which the high heat-generating component 141 is thermally connected via a thermally conductive material 151 and on which the heat dissipation fins 162 are provided, and an extension portion 161b that extends from the fin base 161a along the circuit board 140. The extension portion 161b is thermally connected via an intermediate member 170 to a low-temperature region facing portion 116b of the top plate 116 of the upper housing 111 that faces the low-temperature region Rb of the circuit board 140.

[0029] Intermediate member 170 is disposed so as to seal at least the gap between the periphery of opening 114 in top plate 116 and heat dissipation base 161. Intermediate member 170 is a sealing member made of, for example, a liquid gasket (FIPG), a rubber material, or the like. By providing intermediate member 170 in the gap between the periphery of opening 114 in top plate 116 and heat dissipation base 161, foreign matter (dust, liquid, etc.) is prevented from entering the inside of housing 110 through opening 114.

[0030] It is preferable to select a material with high thermal conductivity for the intermediate member 170 not only for its sealing performance but also for efficiently transferring heat from the extension portion 161b, which is in contact with its lower surface, to the low-temperature region facing portion 116b, which is in contact with its upper surface. Therefore, it is preferable that the thermal conductivity of the intermediate member 170 be equal to or higher than that of the thermally conductive material 151. If the thermal conductivity of the intermediate member 170 is lower than that of the housing 110, the thickness of the intermediate member 170 can be reduced to effectively transfer heat from the heat dissipation base 161 to the top plate 116. It is preferable that the thickness of the intermediate member 170 be smaller than the thicknesses of the heat dissipation base 161, the top plate 116, and the thermally conductive material 151.

[0031] Furthermore, the intermediate member 170 contains a conductive material. In other words, the intermediate member 170 is a conductive member that has conductivity. It is preferable to use a flexible intermediate member 170, but it may also be a plate member made of metal. By using a conductive member for the intermediate member 170, it is possible to effectively prevent electromagnetic noise from entering the housing 110 through the gap between the housing 110 and the heat dissipation member 160. It is also possible to effectively prevent electromagnetic noise generated by electronic components mounted on the circuit board 140 from being emitted to the outside of the housing 110 through the gap between the housing 110 and the heat dissipation member 160.

[0032] The air-cooling fan 130 generates a flow of cooling air that cools the top plate 116 of the housing 110 and the heat dissipation member 160. The air-cooling fan 130 is arranged on the low-temperature region Rb side of the circuit board 140. The air-cooling fan 130 is an axial fan. The rotation center axis CL of the air-cooling fan 130 is parallel to the vertical direction. The air-cooling fan 130 is arranged so that the rotation center axis CL is perpendicular to the plate-shaped low-temperature region facing portion 116b. The outlet of the air-cooling fan 130 faces downward. In this embodiment, the low-temperature region facing portion 116b of the housing 110, the intermediate member 170, and the extension portion 161b of the heat dissipation member 160 are stacked on the rotation center axis CL of the air-cooling fan 130.

[0033] In this embodiment, the extension 161b of the left heat dissipation member 160A (see FIG. 4) is disposed on the rotation center axis CL of the left air-cooling fan 130 (see FIG. 2), and the extension 161b of the right heat dissipation member 160B (see FIG. 4) is disposed on the rotation center axis CL of the right air-cooling fan 130 (see FIG. 2). The rotation center axis CL of the central air-cooling fan 130 (see FIG. 2) is disposed between the extension 161b of the left heat dissipation member 160A (see FIG. 4) and the extension 161b of the right heat dissipation member 160B (see FIG. 4).

[0034] In this embodiment, the high-temperature region Ra of the circuit board 140, the high-heat-generating component 141, the thermally conductive material 151, the fin base 161a, and the heat dissipation fins 162 are stacked in the vertical direction. That is, the housing 110 is provided with an opening 114 facing the high-temperature region Ra of the circuit board 140, and the heat dissipation fins 162 are arranged within this opening 114.

[0035] The opening 114 is formed to have a size that allows the heat dissipation fins 162 to pass through, and to have as small an opening area as possible. In this embodiment, the heat dissipation fins 162 are not formed over the entire area of ​​the heat dissipation base 161. The heat dissipation fins 162 are formed only in the portion of the heat dissipation base 161 that comes into contact with the high-heat-generating component 141 and around that portion. In this embodiment, the length in the front-rear direction of the fin base 161a is shorter than the length in the front-rear direction of the extension portion 161b. The length in the front-rear direction (total length) of the heat dissipation fin 162 is shorter than half the length in the front-rear direction (total length) of the heat dissipation base 161.

[0036] The opening 114 is closed by the heat dissipation base 161. The gap between the periphery of the opening 114 and the heat dissipation base 161 is sealed by the intermediate member 170. This effectively prevents foreign matter such as liquid and dust from entering the housing 110 from the outside to the inside through the opening 114, which exposes the heat dissipation fins 162 to the outside of the housing 110. The heat dissipation base 161 and the housing 110 are formed of a conductive material. This prevents electromagnetic noise generated by electronic components such as the high-heat-generating component 141 housed inside the housing 110 from radiating outside the housing 110. This also prevents electromagnetic noise that could affect electronic components such as the high-heat-generating component 141 from entering the inside of the housing 110 from the outside.

[0037] If the heat dissipation fins 162 were provided over the entire area of ​​the heat dissipation base 161, the opening 114 would become large. This configuration increases the risk of electromagnetic noise radiation and intrusion, and the risk of foreign matter intrusion. In contrast, in this embodiment, the heat dissipation fins 162 are provided only at the thermal connection portion between the heat dissipation base 161 and the high heat-generating component 141 and its surroundings, so the opening 114 can be made small. As a result, the risk of electromagnetic noise radiation and intrusion, and the risk of foreign matter intrusion can be reduced.

[0038] 6 is a diagram illustrating the flow of cooling air generated by the air-cooling fan 130 and the flow of heat generated by the high-heat-generating component 141. In Fig. 6, the cooling air flows Fc1 and Fc2 are schematically indicated by white arrows, and the heat flows Fh1, Fh2, and Fh3 are schematically indicated by bold black arrows.

[0039] As shown in FIG. 6, the air-cooling fan 130 draws in air from above and discharges it downward. The air discharged from the air-cooling fan 130 flows as cooling air through a space defined by the top plate 116 and the duct 122. The cooling air discharged downward from the air-cooling fan 130 hits the low-temperature region-facing portion 116b of the top plate 116 of the housing 110 and changes direction by 90 degrees. Here, the air-cooling fan 130 is provided at the front end of the electronic control device 100, and an exhaust port 122a is provided at the rear end of the electronic control device 100. Therefore, the cooling air discharged downward from the air-cooling fan 130 changes direction mainly toward the rear of the electronic control device 100 and flows toward the heat dissipation fins 162, as indicated by arrow Fc1 in the figure.

[0040] As shown by arrow Fc2 in the figure, the cooling air passes between the multiple heat dissipation fins 162 and is discharged from the exhaust port 122a to the outside of the electronic control device 100. Because the multiple heat dissipation fins 162 are arranged on the downstream side of the duct 122, the cross-sectional area of ​​the flow path of the cooling air is smaller on the downstream side than on the upstream side. Therefore, the flow velocity of the cooling air is greater on the downstream side of the duct 122.

[0041] As shown by arrow Fh1 in the figure, heat generated by high heat-generating component 141 is transferred to fin base 161a of heat dissipation base 161 via thermally conductive material 151. The heat transferred to fin base 161a is transferred to heat dissipation fins 162, and then transferred from heat dissipation fins 162 to the cooling air. As described above, the flow rate of the cooling air flowing between heat dissipation fins 162 is greater than the flow rate of the cooling air before it is introduced between heat dissipation fins 162. Therefore, most of the heat generated by high heat-generating component 141 is absorbed by the cooling air from heat dissipation fins 162 and is discharged together with the cooling air to the outside of electronic control device 100 through exhaust port 122a.

[0042] Furthermore, the heat transferred from the high-heat-generating component 141 to the heat dissipation base 161 is diffused within the components of the heat dissipation base 161. That is, the heat transferred to the fin base 161a is also transferred to the extension 161b, as indicated by the arrow Fh2 in the figure. The heat transferred to the extension 161b is transferred to the top plate 116 of the housing 110 via the intermediate member 170, as indicated by the arrow Fh3 in the figure. The heat transferred to the top plate 116 is absorbed by the cooling air flowing above the top plate 116 and is discharged together with the cooling air from the exhaust port 122a to the outside of the electronic control device 100.

[0043] According to the above-described embodiment, the following advantageous effects are achieved.

[0044] (1) As shown in Fig. 5, electronic control device 100 includes circuit board (substrate) 140 on which electronic components such as high-heat-generating component 141 are mounted, housing 110 that houses circuit board 140, heat dissipation member 160 that is configured separately from housing 110 and is thermally connected to high-heat-generating component 141 via thermally conductive material 151 and that dissipates heat transferred from high-heat-generating component 141 to the outside of housing 110, and air-cooling fan (fan) 130 that generates cooling air flows Fc1 and Fc2 (see Fig. 6) that cool heat dissipation member 160. Circuit board 140 has a high-temperature region Ra on which high-heat-generating component 141, an electronic component that generates more than a predetermined amount of heat, is mounted, and a low-temperature region Rb on which high-heat-generating component 141 is not mounted. Housing 110 has opening 114 that faces high-temperature region Ra. The heat dissipation member 160 has a heat dissipation base 161 as a thermal diffusion part that diffuses heat from the high heat-generating component 141, and heat dissipation fins 162 that protrude from the heat dissipation base 161 to the outside of the housing 110 through the opening 114. The heat dissipation base 161 has a fin base 161a to which the high heat-generating component 141 is thermally connected and to which the heat dissipation fins 162 are provided, and an extension 161b that extends from the fin base 161a along the circuit board 140 and is thermally connected via an intermediate member 170 to a low-temperature region facing portion 116b that faces the low-temperature region Rb of the housing 110.

[0045] According to this configuration, it is possible to provide an electronic control device 100 that has high cooling performance and is capable of suppressing the intrusion of electromagnetic noise from the outside and the radiation of electromagnetic noise generated by electronic components to the outside.

[0046] (2) The air-cooling fan 130 is disposed on the low-temperature region Rb side of the circuit board 140. In other words, the air-cooling fan 130 is disposed at a position closer to the low-temperature region Rb than to the high-temperature region Ra of the circuit board 140. The air-cooling fan 130 is a push-type axial fan, and the cooling air generated by the air-cooling fan 130 flows from the low-temperature region-facing portion 116b of the top panel 116 toward the heat dissipation fins 162.

[0047] When the air-cooling fan 130 is an axial fan, the flow rate of the cooling air is low in the area around the rotation center axis CL. In this embodiment, the air-cooling fan 130 and the heat dissipation fins 162 are arranged offset in the front-to-rear direction. This increases the flow rate of the cooling air passing through the heat dissipation fins 162 compared to when the heat dissipation fins 162 are arranged directly below the air-cooling fan 130, thereby effectively cooling the high-heat-generating component 141. Furthermore, by configuring the cooling air to flow from the low-temperature region of the heat dissipation member 160 to the high-temperature region, the cooling air that absorbs heat from the high-temperature region does not affect the low-temperature region. This increases the temperature difference between the thermal connection portion (high-temperature portion) of the heat dissipation base 161 with the high-heat-generating component 141 and the extension portion (low-temperature portion) 161b of the heat dissipation base 161. As a result, heat is efficiently transported from the thermal connection portion with the high-heat-generating component 141 to the extension portion 161b in the heat dissipation base 161, improving the cooling performance of the electronic control device 100.

[0048] (3) In this embodiment, the low-temperature region facing portion 116b of the housing 110, the intermediate member 170, and the extension portion 161b of the heat dissipation member 160 are stacked on the rotation center axis CL of the air-cooling fan 130. Because the extension portion 161b is sufficiently long, the contact area between the extension portion 161b and the intermediate member 170 and the contact area between the intermediate member 170 and the low-temperature region facing portion 116b can be sufficiently wide. This allows efficient heat transfer from the low-temperature region facing portion 116b to the cooling air. As a result, the temperature difference between the thermal connection portion (high-temperature portion) of the heat dissipation base 161 with the high-heat-generating component 141 and the extension portion (low-temperature portion) 161b of the heat dissipation base 161 can be sufficiently large.

[0049] (4) In this embodiment, high cooling performance can be achieved, thereby enabling the miniaturization of the electronic control device 100. Furthermore, the heat dissipation member 160 is fixed to the top plate 116 of the housing 110 with screws. This allows for resource conservation compared to conventional configurations using a backplate. A conventional configuration is known in which components are fixed by sandwiching the circuit board 140 between the heat dissipation member 160 and a backplate. This conventional configuration requires a backplate installed on the underside of the circuit board 140 and spring screws that penetrate the heat dissipation member 160, the circuit board 140, and the backplate. In contrast, this embodiment has a simple configuration in which the heat dissipation member 160 is fixed to the top plate 116 of the housing 110 with screws. As a result, in this embodiment, the backplate and springs can be omitted, and the length of the fixing screws can be shorter than in conventional configurations. Therefore, this embodiment allows for resource conservation and provides an environmentally friendly electronic control device 100.

[0050] Second Embodiment Referring to FIGS. 7 and 8, the electronic control device 200 according to the second embodiment of the present invention will be described. Components that are the same as or corresponding to those described in the first embodiment are denoted by the same reference numerals, and differences will be mainly described. In the second embodiment, components different from those in the first embodiment are denoted by reference numerals in the 200 series. Also, in the second embodiment, components corresponding to those described in the first embodiment may be denoted by the same numbers in the units and tens places, and a different number "2" in the hundreds place.

[0051] FIG. 7 is a plan view of the electronic control device 200 according to the second embodiment, and FIG. 8 is a schematic cross-sectional view taken along line VIII-VIII of FIG. 7. As shown in FIGS. 7 and 8, the configuration of the housing 210 of the electronic control device 200 according to the second embodiment is different from that of the first embodiment. Specifically, the difference from the first embodiment is that a plurality of housing fins 218 are provided on the housing 210.

[0052] The plurality of housing fins 218 are each formed in a plate shape with the longitudinal direction along the front-rear direction of the electronic control device 200. The housing fins 218 project upward from the low-temperature region facing portion 116b. The plurality of housing fins 218 are arranged at a predetermined interval (also referred to as the first pitch) p1 in the left-right direction of the electronic control device 200. Similar to the first embodiment, the heat dissipation member 160 is provided with a plurality of heat dissipation fins 162 arranged at a predetermined interval (also referred to as the second pitch) p2 in the left-right direction of the electronic control device 200.

[0053] The second pitch p2, which is the dimension between adjacent heat dissipation fins 162, is narrower than the first pitch p1, which is the dimension between adjacent housing fins 218 (p2 < p1). The plurality of housing fins 218 and the plurality of heat dissipation fins 162 are all formed to be parallel in one direction (the front-rear direction of the electronic control device 200).

[0054] As in the first embodiment, the electronic control device 200 according to this embodiment is configured as a forced-air-cooled device in which air is forcibly introduced into the duct 122 by the air-cooling fan 130. This allows air to flow at a high flow rate through the flow paths between the housing fins 218 and the heat dissipation fins 162. In a natural-air-cooled configuration without the air-cooling fan 130, a small fin pitch makes it difficult for air to flow through the flow paths between the fins. In contrast, the forced-air-cooled configuration in this embodiment allows air to flow at a high flow rate through the flow paths between the fins even when the fin pitches p1 and p2 are small. In other words, according to this embodiment, the pitch p1 of the housing fins 218 and the pitch p2 of the heat dissipation fins 162 can be made smaller than in a natural-air-cooled configuration, thereby increasing the heat dissipation area (cooling area).

[0055] According to the second embodiment, in addition to the same effects as those of the first embodiment, the following effects are achieved.

[0056] 7 and 8, the housing 210 is provided with a plurality of housing fins 218 that protrude from the low-temperature region facing portion 116b toward the side opposite to the circuit board 140 (the upper side of the electronic control device 200). As in the first embodiment, the cooling air generated by the air-cooling fan 130 flows from the low-temperature region facing portion 116b toward the heat dissipation fins 162. In other words, the cooling air generated by the air-cooling fan 130 flows from the housing fins 218 toward the heat dissipation fins 162.

[0057] In the second embodiment, the provision of the housing fins 218 on the low-temperature region facing portion 116b promotes heat transfer from the housing 210 to the air. This makes it possible to increase the temperature difference between the thermal connection portion of the heat dissipation base 161 with the high-heat-generating component 141 and the extension portion 161b of the heat dissipation base 161 more than in the first embodiment. As a result, in the heat dissipation base 161, heat is more efficiently transported from the thermal connection portion with the high-heat-generating component 141 to the extension portion 161b, and the cooling performance of the electronic control device 200 can be improved.

[0058] (2) The housing 210 is provided with a plurality of housing fins 218. Therefore, compared to when a single housing fin 218 is provided on the housing 210, the heat dissipation area (cooling area) can be easily increased, and cooling performance can be improved.

[0059] (3) The air-cooling fan 130 is an axial fan and is disposed so that its central axis of rotation CL intersects with the low-temperature region facing portion 116b. Each of the multiple housing fins 218 is plate-shaped and rectifies the cooling air flowing toward the heat dissipation fins 162. With this configuration, turbulence in the cooling air discharged from the air-cooling fan 130 toward the low-temperature region facing portion 116b is rectified by the plate-shaped housing fins 218 and flows toward the heat dissipation fins 162. As a result, in the second embodiment, the heat dissipation performance of the heat dissipation fins 162 is improved compared to the first embodiment.

[0060] (4) The housing 210 is provided with a plurality of housing fins 218 arranged at a first pitch p1, and the heat dissipation member 160 is provided with a plurality of heat dissipation fins 162 arranged at a second pitch p2 narrower than the first pitch p1. By arranging the heat dissipation fins 162 at a narrow pitch on the fin base 161a connected to the high heat-generating component 141 via the thermal conductive material 151, a large heat dissipation area (cooling area) can be secured. In this embodiment, the total heat dissipation area of ​​the plurality of heat dissipation fins 162 is larger than the total heat dissipation area of ​​the plurality of housing fins 218 provided on the low-temperature region facing portion 116b. By ensuring a sufficient heat dissipation area of ​​the heat dissipation fins 162, heat generated by the high heat-generating component 141 can be effectively transferred from the heat dissipation fins 162 to the cooling air.

[0061] Third Embodiment An electronic control device 300 according to a third embodiment of the present invention will be described with reference to FIG. 9. Configurations that are the same as or equivalent to those described in the second embodiment will be given the same reference symbols, and differences will be mainly described. In the third embodiment, configurations that differ from those in the second embodiment will be given reference symbols in the 300 range. Also, in the third embodiment, configurations that correspond to those in the second embodiment may be given the same numbers in the ones and tens digits, with only a different number "3" given in the hundreds digit.

[0062] 9 is a partially enlarged plan view of an electronic control device 300 according to the third embodiment. As shown in FIG. 9, the electronic control device 300 according to the third embodiment differs from the second embodiment in the arrangement of the multiple housing fins 318 provided on the housing 310. In the second embodiment, the multiple housing fins 218 were provided parallel to one another (see FIG. 7). In contrast, the third embodiment differs from the second embodiment in that the distance between the multiple housing fins 318 decreases as they approach the heat dissipation fin 162.

[0063] The multiple housing fins 318 provided corresponding to the left heat dissipation member 160A and the multiple housing fins 318 provided corresponding to the right heat dissipation member 160B have the same arrangement. Therefore, the following will describe the multiple housing fins 318 provided corresponding to the left heat dissipation member 160A, and will omit a description of the multiple housing fins 318 provided corresponding to the right heat dissipation member 160B.

[0064] The multiple housing fins 318 provided corresponding to the heat dissipation member 160A are arranged symmetrically with respect to the left-right central axis of the heat dissipation member 160A. A pair of housing fins 318a provided near the left-right center of the heat dissipation member 160A have a dimension p10a between their front ends and a dimension p10b between their rear ends. p10a and p10b are equal (p10a=p10b).

[0065] Housing fins 318b, 318c, and 318d arranged on the left and right outer sides of the pair of housing fins 318a are inclined so as to approach the left-right central axis of heat dissipation member 160A from the front end to the rear end. In other words, the multiple housing fins 318 provided corresponding to heat dissipation member 160A are arranged so as to collect cooling air into the group of heat dissipation fins of heat dissipation member 160A.

[0066] Of the pair of housing fins 318a, the dimension between the front ends of the right-hand housing fin 318a and its adjacent housing fin 318b to the right is p11a, and the dimension between their rear ends is p11b, which is shorter than p11a (p11a>p11b). The dimension between the front ends of the housing fin 318b and its adjacent housing fin 318c to the right is p12a, and the dimension between their rear ends is p12b, which is shorter than p12a (p12a>p12b). The dimension between the front ends of the housing fin 318c and its adjacent housing fin 318d to the right is p13a, and the dimension between their rear ends is p13b, which is shorter than p13a (p13a>p13b).

[0067] As described above, in the electronic control device 300 according to the third embodiment, some of the multiple housing fins 318 are arranged so that the distance between adjacent housing fins 318 decreases from the front end to the rear end. On the other hand, none of the multiple housing fins 318 are arranged so that the distance between adjacent housing fins 318 increases from the front end to the rear end. In the illustrated example, a pair of housing fins 318a at the center in the left-right direction are arranged parallel to each other, but the pair of housing fins 318a may also be arranged so that the distance between them decreases from the front end to the rear end.

[0068] According to the third embodiment, in addition to the same effects as those of the first embodiment, the following effects are achieved.

[0069] As described above, in the third embodiment, the multiple housing fins 318 are arranged to guide the cooling air toward the heat dissipation fins 162. This allows the cooling air discharged from the air-cooling fan 130 to reach the heat dissipation fins 162 without waste, thereby improving the heat dissipation performance of the heat dissipation fins 162.

[0070] Furthermore, in the third embodiment, the cross-sectional area of ​​the cooling air flow path formed between the multiple housing fins 318 becomes smaller toward the downstream side of the cooling air. This rectifies the cooling air, and allows cooling air with a high flow rate to be introduced into the flow path between the heat dissipation fins 162. This also improves the heat dissipation performance of the heat dissipation fins 162.

[0071] <Fourth embodiment> An electronic control device 400 according to a fourth embodiment of the present invention will be described with reference to FIG. 10. Note that components that are the same as or equivalent to those described in the second embodiment will be given the same reference symbols, and differences will be mainly described. In the fourth embodiment, components that differ from those in the second embodiment will be given reference symbols in the 400 range. Also, in the fourth embodiment, components that correspond to those in the second embodiment may be given the same numbers in the ones and tens digits, with only a different number "4" in the hundreds digit.

[0072] In the second embodiment, an example was described in which a heat dissipation member 160 is provided for each of two high heat-generating components 141. However, only one heat dissipation member may be provided in the electronic control device. FIG. 10 is a plan view of an electronic control device 400 according to a fourth embodiment. As shown in FIG. 10, the electronic control device 400 according to the fourth embodiment is provided with a single heat dissipation member 460. Multiple high heat-generating components 141 (two high heat-generating components 141 in the illustrated example) are thermally connected to the heat dissipation member 460. Even with this configuration, the same effects as those of the second embodiment can be achieved. Note that in the fourth embodiment, the heat dissipation area (cooling area) of the heat dissipation fins 162 and the contact area of ​​the heat dissipation member 460 with the housing 210 can be increased compared to the second embodiment, thereby further improving cooling performance.

[0073] Fifth Embodiment An electronic control device 500 according to a fifth embodiment of the present invention will be described with reference to Figures 11 and 12. Note that configurations that are the same as or equivalent to those described in the second embodiment will be given the same reference symbols, and differences will be mainly described. In the fifth embodiment, configurations that differ from those in the second embodiment will be given reference symbols in the 500s. Also, in the fifth embodiment, configurations that correspond to those in the second embodiment may be given the same numbers in the ones and tens digits, with only a different number "5" in the hundreds digit.

[0074] In the second embodiment, no electronic components are mounted in the low temperature region Rb of the circuit board 140. However, electronic components may be mounted in the low temperature region Rb. Fig. 11 is a plan view of an electronic control device 500 according to a fifth embodiment, and Fig. 12 is a schematic cross-sectional view taken along line XII-XII in Fig. 11.

[0075] A low heat generating component 542, which is an electronic component that does not exceed a predetermined heat generation amount W0 [W], is mounted in the low temperature region Rb of the circuit board 540. The low heat generating component 542 is thermally connected to the extension portion 161b of the heat dissipation base (thermal diffusion portion) 161 via a thermal conductive material 552. The intermediate member 170 is provided between the low temperature region facing portion 116b of the housing 110 and the low heat generating component 542.

[0076] In other words, the low heat generating component 542, the thermally conductive material 552, the extension 161b of the heat dissipation base 161, the intermediate member 170, and the low-temperature region facing portion 116b of the top plate 116 of the housing 110 are stacked on an imaginary axis extending in the vertical direction. With this configuration, heat generated in the low heat generating component 542 is transferred to the heat dissipation base (thermal diffusion portion) 161 via the thermally conductive material 552, and then from the heat dissipation base 161 to the housing 110 via the intermediate member 170. The heat transferred to the housing 110 is transferred to the cooling air via the housing fins 218. By filling the intermediate member 170 not only around the periphery of the opening 114 but also directly above the low heat generating component 542, the thermal resistance between the heat dissipation base 161 and the low-temperature region facing portion 116b of the housing 110 is reduced, thereby improving heat dissipation.

[0077] Sixth Embodiment An electronic control device 600 according to a sixth embodiment of the present invention will be described with reference to Figures 13 and 14. Note that components that are the same as or equivalent to those described in the second embodiment will be given the same reference symbols, and differences will be mainly described. In the sixth embodiment, components that differ from those in the second embodiment will be given reference symbols in the 600 range. Also, in the sixth embodiment, components that correspond to those in the second embodiment may be given the same numbers in the ones and tens digits, with only a different number "6" in the hundreds digit.

[0078] In the second embodiment, each of the housing fins 218 was formed in a plate shape (see FIGS. 7 and 8). However, various shapes can be adopted for the housing fins. Fig. 13 is a plan view of an electronic control device 600 according to a sixth embodiment, and Fig. 14 is a schematic cross-sectional view taken along line XIV-XIV in Fig. 13.

[0079] 13 and 14, a housing 610 of an electronic control device 600 according to the sixth embodiment is provided with a plurality of cylindrical housing fins 618 called pin fins. The plurality of housing fins 618 are arranged in a grid pattern. The pin fins may also be arranged in a staggered pattern instead of the grid pattern.

[0080] As described above, in the sixth embodiment, each of the plurality of housing fins 618 is cylindrical. Therefore, the heat dissipation area (cooling area) of the housing fins 618 can be made larger than that of the second embodiment. As a result, the heat dissipation performance of the housing fins 618 can be improved.

[0081] The following modified examples are also within the scope of the present invention, and it is possible to combine the configuration shown in the modified example with the configuration described in the above embodiment, to combine the configurations described in the different embodiments above, or to combine the configurations described in the different modified examples below.

[0082] <Variation 1> The configuration of the electronic control devices 100, 200, 300, 400, 500, and 600 is not limited to the examples described in the above embodiments. For example, in the electronic control device 100 of the first embodiment, a member that restricts the flow of cooling air may be disposed in the flow path space between the housing 110 and the cover 120. With reference to FIGS. 15 and 16, an example in which a restricting member 124 is provided in the electronic control device 100 of the first embodiment will be described. FIG. 15 is an external perspective view of the electronic control device 100 according to Modification 1, and FIG. 16 is a side view of the electronic control device 100 as viewed from the direction of arrow XVI in FIG. 15.

[0083] As shown in FIGS. 15 and 16 , in this modification, a downwardly protruding protrusion 124 is provided on the top plate of the cover 120 as a restricting member. The protrusion 124 is disposed between the heat dissipation fins 162 of the left heat dissipation member 160A and the heat dissipation fins 162 of the right heat dissipation member 160B. The protrusion 124 extends a predetermined length in the front-to-rear direction of the electronic control device 100. The front end of the protrusion 124 is located forward of the front end of the heat dissipation fins 162, and the rear end of the protrusion 124 is located rearward of the rear end of the heat dissipation fins 162. By providing the protrusion 124 between the pair of left and right heat dissipation fin groups in this manner, the flow rate of cooling air flowing through the heat dissipation fin groups can be increased, thereby improving cooling performance. Note that, although the example shown in FIGS. 15 and 16 describes an example in which the protrusion 124 is provided on the cover 120, a protrusion protruding upward may also be provided on the top plate 116 of the upper housing 111.

[0084] <Variation 2> In the above embodiment, an example has been described in which the air-cooling fan 130 is a push-type fan that draws in outside air and discharges it into the space between the housing 110 and the cover 120 (see FIG. 6). However, the air-cooling fan may also be a pull-type fan that draws in air from the space between the housing and the cover and discharges it to the outside.

[0085] FIG. 17 is a plan view of an electronic control device 700 according to Modification 2. The electronic control device 700 according to Modification 2 has the same configuration as the electronic control device 100 according to Modification 1 (see FIG. 15 ), except that the air-cooling fan 730 is a pull type. In FIG. 17 , the air-cooling fan 730 attached to the mounting opening 123 of the cover 120 and the protrusion 124 provided on the cover 120 are indicated by two-dot chain lines. In Modification 2, as shown in FIG. 17 , an opening at the rear end of the housing 110 functions as an air intake port 722a that takes in air into the space between the housing 110 and the cover 120. The air taken in through the air intake port 722a flows toward the front side of the electronic control device 700, as indicated by the arrow Fm in the figure, and is discharged from the air-cooling fan 730 to the outside of the electronic control device 700.

[0086] Note that an electronic control device 700 employing a pull-type air-cooling fan 730 has the following problem. If one of the multiple air-cooling fans 730 stops due to a malfunction or the like, the mounting opening 123 of the stopped air-cooling fan 730 functions as an air intake for the normal air-cooling fans 730. For example, as shown in FIG. 18 , if the central air-cooling fan 730 of three air-cooling fans 730 stops, a shortcut flow of air occurs from the mounting opening 123 of the stopped air-cooling fan 730 toward the normal air-cooling fan 730, as indicated by arrow Fs in the figure. When a shortcut flow occurs, the flow rate of air taken in through the air intake 722a and flowing along the heat dissipation member 160 (see arrow Fm) decreases. As a result, the cooling performance of the electronic control device 700 is significantly reduced.

[0087] In contrast, in an electronic control device 100 employing a push-type air-cooling fan 130 (see FIGS. 1 to 6, 15, etc.), even if one of the multiple air-cooling fans 130 stops due to a malfunction or other reason, much of the cooling air discharged from the air-cooling fan 130 flows toward the exhaust port 122a. By arranging the plate-shaped housing fins 218 (see FIGS. 7 and 8) described in the second embodiment directly below the air-cooling fan 130, it is possible to effectively prevent the occurrence of a shortcut flow of air from a normal air-cooling fan 130 toward the mounting opening 123 of the stopped air-cooling fan 130. Furthermore, by providing the housing fins (pin fins) 618 (see FIGS. 13 and 14) described in the sixth embodiment, even if one of the multiple air-cooling fans 130 stops due to a malfunction or other reason, the cooling air flows evenly (in all directions) between the housing fins 618. Therefore, the cooling air can also be sent toward the heat dissipation fins 162 near the failed air-cooling fan 130. Therefore, by employing the push-type cooling fan 130, even if one of the plurality of cooling fans 130 stops due to a malfunction or the like, the deterioration of the cooling performance of the electronic control devices 100, 200, 300, 400, 500, 600 can be suppressed.

[0088] <Variation 3> The boundary between the high temperature region Ra and the low temperature region Rb is not limited to the example described in the above embodiment. For example, in order to prevent heat from the high heat generating component 141 from being transferred to the low heat generating component 542, a recessed portion serving as a heat insulating function portion may be provided between the high heat generating component 141 and the low heat generating component 542 in the circuit board 540. In this case, with the heat insulating function portion as the boundary, the region on which the high heat generating component 141 is mounted may be defined as the high temperature region Ra, and the region on which the low heat generating component 542 is mounted may be defined as the low temperature region Rb.

[0089] <Variation 4> The heat dissipation base (thermal diffusion unit) 161 may be a vapor chamber. A vapor chamber is a hollow structure made of metal such as copper or aluminum. A cooling working fluid is sealed in the internal space of the vapor chamber. When heat generated by the high-heat-generating component 141 is transferred to the vapor chamber, the internal working fluid vaporizes and moves at high speed through the internal space toward the low-temperature section. The vaporized working fluid comes into contact with the outer wall of the low-temperature section, where it is cooled and liquefied. The liquefied working fluid returns to the high-temperature section due to capillary action. By repeating this process, the vapor chamber transports heat from the high-temperature section to the low-temperature section.

[0090] <Variation 5> The heat dissipation fins 162 may be integrally formed with the heat dissipation base 161, or may be separate from the heat dissipation base 161. As shown in FIG. 19 , when the heat dissipation base 161 and the heat dissipation fins 162 are separate, the heat dissipation fins 162 are connected to the heat dissipation base 161 by brazing or adhesive. For example, a rectangular recess is formed in the plate-shaped heat dissipation base 161 by press processing or the like, and a fin base 862a on which the heat dissipation fins 162 are erected is fitted into the recess. The fin base 862a and the recess are connected by a connecting portion 863, such as a brazing portion formed by solidified brazing material or an adhesive portion formed by solidified adhesive. This configuration allows the heat dissipation base 161 and the heat dissipation fins 162 to be formed from different materials. Note that if the connecting portion 863 is a brazing portion, thermal resistance can be reduced, allowing heat to be effectively transferred from the heat dissipation base 161 to the heat dissipation fins 162. Note that the brazing material is preferably a highly thermally conductive material, such as aluminum or copper.

[0091] <Variation 6> Intermediate member 170 may be insulating heat dissipation grease or the like. By interposing heat dissipation grease as intermediate member 170 between top plate 116 of housing 110 and heat dissipation base 161 of heat dissipation member 160, heat from heat dissipation base 161 can be effectively transferred to top plate 116 while ensuring sealing. Furthermore, by reducing the gap between heat dissipation base 161 and top plate 116, it is possible to effectively suppress the intrusion and emission of electromagnetic noise.

[0092] <Variation 7> In the first embodiment, the housing fins 218 are not provided directly below the air-cooling fan 130. Therefore, by arranging the position of the air-cooling fan 130 closer to the top plate 116 of the housing 110, the height (vertical dimension) of the electronic control device 100 can be reduced.

[0093] <Variation 8> In the above embodiment, an example has been described in which the cooling fan 130 is provided at the front of the electronic control device. However, the cooling fan 130 may also be provided at the rear end of the electronic control device. For example, a push-type cooling fan 130 or a pull-type cooling fan 730 may be disposed in the opening serving as the exhaust port 122a in the first embodiment, and the opening serving as the mounting opening 123 in the first embodiment may function as an exhaust port or an intake port.

[0094] <Variation 9> In the above embodiment, an example has been described in which the air-cooling fan 130 is an axial fan. However, various types of fans can be used as the air-cooling fan 130. For example, the air-cooling fan 130 may be a centrifugal fan.

[0095] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments. [Explanation of symbols]

[0096] 100, 200, 300, 400, 500, 600, 700...Electronic control device, 110, 210, 310, 610...Housing, 111...Upper housing, 112...Lower housing, 114...Opening, 116...Top plate, 116b...Low temperature region facing portion, 120...Cover, 121...Fan mounting portion, 122...Duct, 122a...Exhaust port, 123...Mounting opening, 130, 730...Air-cooling fan (fan), 140, 540...Circuit board (board), 140A...First circuit board, 140B...Second circuit board Plate, 141...high heat generating component (electronic component), 151...thermal conductive material, 160, 460...heat dissipation component, 161...heat dissipation base (thermal diffusion portion), 161a...fin base, 161b...extension portion, 162...heat dissipation fin, 170...intermediate member, 218, 318, 618...casing fin, 542...low heat generating component (electronic component), 552...thermal conductive material, 722a...air intake port, 863...connection portion, CL...rotational center axis of air-cooled fan, p1...first pitch, p2...second pitch, Ra...high temperature region, Rb...low temperature region

Claims

1. An electronic control device comprising: a substrate on which electronic components are mounted; a housing that houses the substrate; a heat dissipation member that is formed separately from the housing and thermally connected to the electronic components via a thermally conductive material and that dissipates heat transferred from the electronic components to the outside of the housing; and a fan that generates a flow of cooling air that cools the heat dissipation member, the substrate has a high-temperature region in which a high-heat-generating component, which is the electronic component that generates a heat amount exceeding a predetermined value, is mounted, and a low-temperature region in which the high-heat-generating component is not mounted, The housing has an opening facing the high-temperature region, the heat dissipation member includes a thermal diffusion section that diffuses heat from the high heat generating component, and a heat dissipation fin that protrudes from the thermal diffusion section to the outside of the housing through the opening, The thermal diffusion unit has a fin base to which the high heat generating component is thermally connected and to which the heat dissipation fins are provided, and an extension portion that extends from the fin base along the substrate and is thermally connected via an intermediate member to a low temperature region facing portion of the housing that faces the low temperature region. Electronic control unit.

2. 2. The electronic control device according to claim 1, The fan is disposed on the low-temperature region side, The cooling air generated by the fan flows from the low-temperature region facing portion toward the heat dissipation fins. Electronic control unit.

3. 3. The electronic control device according to claim 2, the fan is an axial flow fan, The low-temperature region facing portion of the housing, the intermediate member, and the extension portion of the heat dissipation member are stacked on the central axis of rotation of the fan. Electronic control unit.

4. 4. The electronic control device according to claim 3, the housing is provided with housing fins that protrude from the low-temperature region facing portion toward an opposite side to the substrate side, The cooling air generated by the fan flows from the housing fins toward the heat dissipation fins. Electronic control unit.

5. 5. The electronic control device according to claim 4, The housing is provided with a plurality of housing fins, The plurality of housing fins are each plate-shaped and regulate the cooling air flowing from the fan toward the heat dissipation fins. Electronic control unit.

6. 6. The electronic control device according to claim 5, The plurality of housing fins are arranged to guide cooling air toward the heat dissipation fins. Electronic control unit.

7. 7. The electronic control device according to claim 6, The cross-sectional area of ​​the flow path of the cooling air formed between the plurality of housing fins becomes smaller toward the downstream side of the cooling air. Electronic control unit.

8. 5. The electronic control device according to claim 4, low-heat-generating components, which are electronic components whose heat generation amount does not exceed the predetermined amount, are mounted in the low-temperature region of the board; the low heat generating component is thermally connected to the extension of the thermal diffusion unit via a thermally conductive material; The intermediate member is provided between the low-temperature region facing portion of the housing and the low-heat-generating component. Electronic control unit.

9. 2. The electronic control device according to claim 1, The intermediate member is a conductive member having electrical conductivity. Electronic control unit.

10. 6. The electronic control device according to claim 5, the housing is provided with the plurality of housing fins arranged at a first pitch, The heat dissipation member is provided with a plurality of the heat dissipation fins arranged at a second pitch narrower than the first pitch. Electronic control unit.

11. 2. The electronic control device according to claim 1, The heat dissipation fins are formed separately from the thermal diffusion unit and are connected to the thermal diffusion unit by brazing. Electronic control unit.

12. 5. The electronic control device according to claim 4, The housing is provided with a plurality of housing fins, Each of the plurality of housing fins is cylindrical. Electronic control unit.

Images