Electronic Control Devices

Abstract

The present invention provides an electronic control device capable of improving the cooling performance achieved by air cooling. The electronic control device includes a circuit board 6 (circuit board); a heat generating component 7 (heat generating body) mounted on the circuit board 6; a heat dissipation component 12 (heat conducting component) in contact with the heat generating component 7 and capable of conducting the heat of the heat generating component 7; a fin-integrated shell 3 (shell) in contact with the heat dissipation component 12 and covering the circuit board 6; and a cover 1 covering the fin-integrated shell 3. The cover 1 has a hole (2) 8 and a hole (3) 9 as an air intake hole and a hole (1) 2 as an air exhaust hole. Compared with the hole (2) 8 and the hole (3) 9, the hole (1) 2 is formed at a position close to the heat generating component 7. Compared with the hole (1) 2, the hole (2) 8 and the hole (3) 9 are formed at a position away from the heat generating component 7.

Description

Technical Field

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

[0002] As a method for cooling an electronic control device equipped with high-heat generating components, for example, a method using an electric fan or electric circulating cooling water is known (see, for example, Patent Document 1).

[0003] Patent Document 1 describes a cooling system that uses a vapor chamber and water cooling in an electronic control device. A vapor chamber is used as a radiator, and a housing is provided on the top thereof as a cover for passing cooling water.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-113227 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the technology disclosed in Patent Document 1, the electronic control device is cooled by water cooling. An object of the present invention is to provide an electronic control device capable of improving the cooling performance achieved by air cooling.

[0009] Technical solutions to solve problems

[0010] In order to achieve the above-mentioned purpose, the electronic control device of the present invention includes: a circuit board; a heating element mounted on the circuit board; a heat-conducting component in contact with the heating element and capable of conducting heat from the heating element; a shell in contact with the heat-conducting component and covering the circuit board; and a cover covering the shell, the cover having an air intake hole and an exhaust hole, the exhaust hole being formed at a position closer to the heating element than the air intake hole, and being formed at a position farther away from the heating element than the exhaust hole.

[0011] Effects of the Invention

[0012] According to the present invention, the cooling performance by air cooling can be improved. Other problems, structures and effects than those described above will be explained through the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is an overall view showing an electronic control device according to a first embodiment of the present invention.

[0014] Figure 2 It is an exploded view of the electronic control device according to the first embodiment of the present invention.

[0015] Figure 3 This is a schematic diagram of a cover of the electronic control device according to the first embodiment of the present invention.

[0016] Figure 4A It is a top view of the electronic control device according to the first embodiment of the present invention.

[0017] Figure 4B It is a top view of an electronic control device according to a modified example of the first embodiment of the present invention.

[0018] Figure 5 It is a schematic diagram of a cross-sectional view of an electronic control device according to a first embodiment of the present invention.

[0019] Figure 6 It is a schematic diagram of a cross-sectional view of an electronic control device according to a first embodiment of the present invention.

[0020] Figure 7 It is a schematic diagram of a cross section of an electronic control device according to a second embodiment of the present invention.

[0021] Figure 8 This is a table showing the results of thermal flow analysis showing the effects of the electronic control device according to the second embodiment of the present invention.

[0022] Fig. 9 It is a bottom view of a cover of an electronic control device according to a third embodiment of the present invention.

[0023] Fig.10 It is an overall view of an electronic control device according to a fourth embodiment of the present invention.

[0024] Fig.11 It is a bottom view of an electronic control device according to a fourth embodiment of the present invention and an enlarged view of the air intake holes of a cover.

[0025] Fig.12 It is a schematic diagram of a casing of an electronic control device according to a fifth embodiment of the present invention.

[0026] Fig.13 Schematic diagram showing various dimensions around a cover of an electronic control device according to a sixth embodiment of the present invention.

[0027] Fig.14 It is a cross-sectional view showing a hole in a cover of an electronic control device according to a seventh embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following is a description of the structure of the electronic control device of the first to seventh embodiments of the present invention using the accompanying drawings. In addition, in each figure, the same reference numeral represents the same part. In addition to the purpose of the above invention, the purpose of these embodiments is to provide a cooling system that expands the area in which the heat of the heat-generating component can be dissipated by natural convection without using power.

[0029] (First Embodiment)

[0030] Below, use Figure 1 to Figure 6 A first embodiment of the present invention will be described.

[0031] Figure 1 It is an overall view showing an electronic control device according to a first embodiment of the present invention. Figure 2 yes Figure 1 The electronic control device of the present invention is shown in an exploded view. The device is composed of a cover 1, a fin-integrated housing 3, a circuit board 6 on which a plurality of electronic components are mounted, and a lower housing 4.

[0032] The fin-integrated case 3 is covered by the cover 1 so as to cover the surface on which the fins are formed.

[0033] The cover 1 is provided with holes 2 on the top surface (a surface parallel to the surface of the fin-integrated housing 3 on which the fins are formed). Figure 3 The back side of the cover 1 with holes (the side opposite to the fin-integrated housing) is shown. Figure 4A It is a top view of the electronic control device 1 through the cover 1 .

[0034] Hole (1) 2, hole (2) 8 and hole (3) 9 are formed in the cover 1. The positions where hole (2) 8 and hole (3) 9 are formed are perpendicular to the extending direction of the fin of the fin integrated housing opposite to the cover 1 ( Figure 4A The side surface of the cover 1 is one side 10 of the fin integrated housing 3 (in the longitudinal direction). In addition, the cover 1 is made of aluminum, for example, and the hole (1) 2, the hole (2) 8 and the hole (3) 9 are formed by laser processing, for example.

[0035] Next, a phenomenon occurring due to the above structure will be described using a cross-sectional view.

[0036] Figure 5 Schematic diagram of a cross section of the electronic control device of the present invention parallel to the extending direction of the fins. Figure 6 Schematic diagram of a cross section perpendicular to the extending direction of the fins. Heat of the heat generating component 7 is dissipated to the fin-integrated housing 3 via the heat dissipating member 12 .

[0037] like Figure 5As shown, the electronic control device includes at least a circuit board 6 (circuit board); a heat generating component 7 (heat generating element) mounted on the circuit board 6; a heat dissipation component 12 (heat conducting component) in contact with the heat generating component 7 and conducting the heat of the heat generating component 7; a fin-integrated housing 3 (housing) in contact with the heat dissipation component 12 and covering the circuit board 6; and a cover 1 covering the fin-integrated housing 3, the details of which will be described later. The cover 1 has holes (2) 8 and (3) 9 as air intake holes, and hole (1) 2 as an exhaust hole. Compared with holes (2) 8 and (3) 9, hole (1) 2 is formed at a position close to the heat generating component 7 (heat generating element). Compared with holes (1) 2, holes (2) 8 and (3) 9 are formed at a position away from the heat generating component 7.

[0038] As a result, natural convection occurs in the space between the cover 1 and the fin-integrated housing 3 (housing). As a result, the cooling performance of the electronic control device can be improved. In addition, since the air intake holes (holes (2) 8 and (3) 9) and the air exhaust holes (holes (1) 2) are formed in the cover 1 (the same component), the holes can be processed at the same time, which can reduce the workload.

[0039] like Figure 6 As shown, a plurality of fins 5 are provided on the surface of the fin integrated case 3 (case) on the cover 1 side. This increases the surface area of ​​the fin integrated case 3 and can further improve the cooling performance.

[0040] like Figure 5 As shown, hole (1) 2 as an exhaust hole is formed on the top surface of the cover 1 opposite to the fin integrated shell 3 (shell), and hole (2) 8 and hole (3) 9 as an air intake hole are formed on the side surface of the cover 1. The air intake holes (hole (2) 8, hole (3) 9) are L-shaped. Figure 3 As shown, the inlet of the air intake hole (for example, the hole (3) 9) is located at the front end surface S1 of the side portion of the cover 1.

[0041] This makes it easier for a temperature difference to be generated between the air intake hole and the air exhaust hole.

[0042] Figure 5 , Figure 6 The heat dissipation component 12 shown is preferably made of a material with a thermal conductivity as high as possible. However, on the other hand, when the thermal conductivity is high, the heat dissipation component 12 is often made of a harder material, which affects the reliability of the joint between the heat dissipation component 7 and the circuit board. The heat dissipation component 12 selected here is preferably made of a material with a hardness level that does not affect the reliability of the joint between the heat dissipation component 7 and the circuit board.

[0043] Due to the heat of the heated fin-integrated housing 3, heat transfer occurs to the air 13 between the fin-integrated housing 3 and the cover 1. The density of the air 13 decreases due to the heating. As a result, the heated air 13 gradually flows out from the hole (1) 2 of the cover 1 to the outside air with a lower temperature. When the air 13 flows out to the outside air, relatively cold air from the outside is sucked in from the hole (2) 8 and the hole (3) 9. The hole (2) 8 and the hole (3) 9 serving as the suction port are sufficiently small relative to the environment outside the housing.

[0044] Therefore, according to Bernoulli's principle, near the entrances of holes (2) 8 and (3) 9, the pressure decreases and the air flow rate increases. Bernoulli's principle is [pressure + (weight of fluid) / (gravitational acceleration × 2) × flow rate 2 =constant] expressed by the law of conservation of energy about the fluid.

[0045] The cold air sucked in from the holes (2) 8 and (3) 9 passes through the holes and flows along the fins 5 between the cover 1 and the fin-integrated housing 3. It is then heated again by the heat of the heat generating component 7 and discharged from the hole (1) 2. Due to the continuous air flow of exhaust from the hole (1) 2 and intake from the holes (2) 8 and (3) 9, air convection occurs between the cover 1 and the fin-integrated housing 3. In addition, during the period of exhaust from the hole (1) 2, the cold air is continuously sucked in from the holes (2) 8 and (3) 9.

[0046] Here, the existing electronic control device is described. In the past, there was no cover 1, but it was composed of a fin-integrated shell, a circuit board equipped with electronic components, and a lower shell. The heat of the heat-generating component is dissipated to the fin-integrated shell via a heat dissipation component as an intermediate component. Furthermore, the heat dissipated to the fin-integrated shell diffuses in the in-plane direction of the shell through the fins. However, the heat diffused in the shell is only 1 to 2.5 times the contact area with the heat-generating component. It is difficult to diffuse the heat to the end of the shell, and it is difficult to reduce the temperature of the joint of the heat-generating component to below the maximum rated temperature. Therefore, forced air cooling is performed, for example, using a fan. The shell surface is cooled by using an electric fan. As a result, the heat dissipated from the heat-generating component to the shell via the heat dissipation component can be increased, thereby reducing the temperature of the joint of the heat-generating component.

[0047] However, fans have problems from the perspectives of cost, size, quietness, and reliability. For example, quietness is an important research item for electronic control devices installed in the car. No matter how small the sound of the fan motor and the sound of the propeller rotating are, they sound like noise to the human ear. In addition, fans have a lifespan. Generally speaking, the lifespan of a fan is 5 to 6 years.

[0048] Noise will start to be generated at an earlier stage than this. For this reason, fans are not recommended for automotive products and should be used with extreme caution.

[0049] According to this embodiment, the holes (1) 2, (2) 8, and (3) 9 provided in the cover 1 can be used to generate convection of the air 13 in the space between the fin-integrated housing 3 and the cover 1, thereby cooling the surface of the fin-integrated housing 3. During the period when the temperature of the air 13 heated by the fin-integrated housing 3 is higher than the temperature of the air outside the cover 1, natural convection continuously occurs between the fin-integrated housing 3 and the cover 1.

[0050] Therefore, the heat dissipated from the heat generating element to the fin-integrated housing 3 via the heat dissipation component 12 is cooled by the convection of the air 13, and the temperature of the joint of the heat generating element does not continue to rise. That is, because the cover 1 has a hole, a cooling system that does not require power is realized. As a result, an electronic control device that does not require power consumption for cooling and is small and capable of installing high-heat generating components is realized. Furthermore, compared with an expensive vehicle-mounted fan, the cover with holes can be manufactured at a low cost, thereby realizing an electronic control device with a low-cost cooling system.

[0051] In addition, in this embodiment, the fin 5 is plate-shaped. Figure 4B As shown, the hole (2) serving as the exhaust hole, and the hole (2) 8 and the hole (3) 9 serving as the intake hole are formed at positions along the grooves between adjacent fins 5. In detail, the exhaust hole is located above the grooves between adjacent fins 5, and the center lines of the intake hole and the exhaust hole are contained in a plane S2. Thus, the air flow from the intake hole to the exhaust hole is improved. The fins 5 are arranged along the length direction of the fin integrated shell 3 (shell). Thus, the fins 5 are cooled by air supplied from the intake holes (holes (2) 8, holes (3) 9) away from the heat generating component 7 (heat generating element).

[0052] (Second Embodiment)

[0053] Figure 7 FIG. 2 is a schematic diagram of a cross section of an electronic control device according to a second embodiment of the present invention. Figures 1 to 6 The fin-integrated housing in the first embodiment has a heat spreader formed inside, which is the fin-integrated heat spreader 14. In other words, the fin-integrated housing (housing) has a heat spreader.

[0054] A vapor chamber is a heat sink with a working fluid sealed inside. Due to the slight temperature difference within the surface, the working fluid repeatedly changes phase between liquid and gas, allowing the heat to be diffused over a wide area.

[0055] It is known that the performance of the heat spreader is high. For example, when evaluated by the thermal conductivity index, it has a thermal conductivity that is two orders of magnitude higher than that of copper and aluminum. This can quickly reduce the temperature of the joint of the heating element, and it has been used as a heat sink component in personal computers and smartphones for more than 10 years.

[0056] The material of the heat spreader shell includes aluminum, copper, stainless steel, resin, etc. The basic structure is a shell formed by joining the outer peripheries of two overlapping plates and injecting a working fluid into the space between the plates. The working fluid is, for example, water or alcohol. The working fluid varies depending on the material of the shell.

[0057] The manufacturing method of the heat spreader housing is, for example, to produce two plates by die casting using a mold when the housing is made of aluminum. Alternatively, it can be produced by pressing, and the fin portion can be produced by extrusion.

[0058] One of the issues when using it in a vehicle is the strength of the heat spreader shell itself. In order to be a device that can withstand the difference in air pressure and temperature, the heat spreader shell needs to be thick to a certain extent. Alternatively, the strength can be maintained by providing reinforcement columns in the space inside the heat spreader. In addition, the strength of the joint between the two plates of the heat spreader is also one of the issues. When the joint strength is low, the internal working fluid leaks and can no longer function. Therefore, a high-strength joint is obtained, for example, by brazing or laser welding, friction stir welding, etc.

[0059] Here, the characteristics of the subject of the heat spreader are explained. In order to continuously maintain the high heat diffusion capacity of the heat spreader, it is important to continuously ensure a small temperature difference in the in-plane direction of the heat spreader. In the case of a control device equipped with a high-heat generating component, when heat flows in that exceeds the maximum heat capacity of the heat spreader, the temperature of the entire heat spreader becomes uniform.

[0060] The heat spreader diffuses heat through the phase change of the working fluid caused by a small temperature difference, so if there is no temperature difference, the heat transfer capacity decreases. Therefore, in electronic control devices with very high heat generation, sometimes a heat spreader and a power such as an electric fan for dissipating the heat are used at the same time. However, as mentioned above, the use of a fan has problems such as quietness and mechanical reliability, so there are cases where it cannot be used.

[0061] According to the present embodiment, a heat spreader is built into the fin-integrated housing to form the fin-integrated heat spreader 14, and the fin-integrated heat spreader 14 is covered with a cover having holes, thereby realizing a high-power cooling system that utilizes the capability of the heat spreader without requiring power.

[0062] Figure 8The results of heat flow analysis of three cooling systems were performed to confirm the effect of the heat spreader on the heat generation of the heat generating components. The three modes refer to (i) the case where the fin-integrated heat spreader is used as the heat sink, i.e., the shell, (ii) the case where a fan is used in conjunction with the conventional fin-integrated shell, and (iii) the case where a cover with holes is used in conjunction with the fin-integrated heat spreader as the structure of the present invention.

[0063] In the case of (i) a heat spreader shell with fins, the temperature of the joint of the heat generating component B cannot be suppressed below the maximum rated temperature. On the other hand, the cooling effect of the conventional fin-integrated shell + fan of (ii) is relatively high, and the temperature of the joint of the heat generating component B can be sufficiently reduced relative to the maximum rated temperature. In the case of (iii) a fin-integrated heat spreader shell + a cover with holes as the structure of the present invention, although it is not as good as using a fan at the same time as (ii), the temperature of the joints of all heat generating components can be suppressed below the maximum rated temperature. This is because a heat spreader with high thermal conductivity and a cover with holes are used at the same time.

[0064] According to the embodiment of the present invention, a fin-integrated vapor chamber and a cover with holes are used simultaneously, thereby realizing a high cooling system.

[0065] The heat transferred from the heat generating component 7 to the fin-integrated heat spreader via the heat dissipating component 12 is diffused to a wider range in the in-plane direction of the heat spreader. The wider range refers to the entire fin-integrated heat spreader 14. Compared with the usual fin-integrated housing, the heat conduction area is greatly enlarged, so the heat dissipation from the heat generating component 7 is greatly increased.

[0066] Furthermore, due to the air convection generated between the cover 1 and the fin-integrated heat spreader due to the holes in the cover 1, the surface of the fin-integrated heat spreader is cooled. As a result, a temperature difference is generated in the in-plane direction of the heat spreader, and the heat diffusion capacity of the heat spreader can be maintained. As a result, the heat dissipation amount from the heat-generating component 7 can be increased, and the temperature of the joint of the heat-generating component 7 can be greatly reduced. That is, it is possible to provide an electronic control device having a higher level of cooling system than the electronic control device of the first embodiment.

[0067] As a result, the natural convection of air between the cover 1 and the fin-integrated heat spreader 14 promotes the phase change of the working fluid in the heat spreader, thereby ensuring the quietness of the electronic control device and further improving the cooling performance.

[0068] In addition, in the fin-integrated heat spreader 14, the fin-integrated housing and the heat spreader are integrated, so the cooling performance is good due to the synergistic effect of the fins and the heat spreader. In addition, the number of components can also be reduced.

[0069] (Third Embodiment)

[0070] It is conceivable that the hole of the cover 1 may be located at a plurality of positions. Fig. 9 This is a schematic diagram of the back side (the side opposite to the fin-integrated housing) of the cover in which the position of the hole is different from that of the first and second embodiments. In this embodiment, exhaust holes (15 or 16 or 17) and air intake holes (15 or 16 or 17) are formed on the same surface (here, the top surface) of the cover 1. The hole provided at a position closer to the heat source is the exhaust hole, and the hole provided at a position farther from the heat source is the air intake hole.

[0071] In this embodiment, the exhaust hole and the air intake hole are formed parallel to or at an angle with respect to the thickness direction of the cover 1. The air intake hole is formed on the top surface of the cover 1. Thus, for example, the exhaust hole and the air intake hole can be easily processed.

[0072] Between the cover 1 and the fin-integrated shell 3, the heated air 13 flows out from the exhaust hole, and gradually rises to the upper part (space) of the top surface of the cover 1 due to the rising airflow. Relatively speaking, the cold air is pushed out from the upper part of the top surface of the cover 1 and flows in from the air intake hole formed on the top surface of the cover 1. Through this series of cycles, natural convection of the air 13 occurs. Here, when the exhaust hole is not located directly above the heat-generating component that serves as the heat source but is offset therefrom, the convection of the air can more efficiently contact the shell surface directly above the heat-generating component, thereby improving the cooling effect.

[0073] According to this embodiment, even when outside air cannot be introduced from the bottom and side surfaces of the electronic control device, air can be exhausted and inhaled using only the top surface of the cover 1. Thus, an electronic control device without installation restrictions can be provided.

[0074] (Fourth Embodiment)

[0075] Fig.10 This is a schematic diagram showing an electronic control device according to a fourth embodiment of the present invention, in which the lengths of the surfaces 18 and 19 perpendicular to the extending direction of the fins of the integrated fin case 3 are extended in the -Z direction. Fig.11 Observed from the back side Fig.10 18 and 19. A schematic diagram of an electronic control device of the embodiment of the present invention, and an enlarged view of the front end portion of the surface 19. A plurality of holes serving as air intake holes are formed inside each of the surface 18 and the surface 19.

[0076] like Fig.10 As shown, the electronic control device includes a lower case 4 fitted with a fin-integrated case 3 (case), and the front end surface of the side surface of the cover 1 is farther from the top surface of the cover 1 than the bottom surface S3 of the lower case 4 .

[0077] According to this embodiment, by extending the inlet of the suction hole away from the housing, air at a lower temperature can be sucked in. In addition, since the temperature difference between the air in the suction hole and the exhaust hole is increased, the pressure difference is increased. According to the law of conservation of energy, the difference in the air flow velocity is also increased, and the convection velocity is increased. As a result, an electronic control device with a high cooling effect can be provided.

[0078] (Fifth Embodiment)

[0079] The shape of the fins of the fin-integrated housing 3 or the fin-integrated heat sink 14 may also be considered to be a shape other than the shape extending in a specified direction on a plane parallel to the cover. As Fig.12 shown, it may also be fins that extend in the vertical direction with respect to the top surface of the housing, such as needle-shaped fins. That is, the fins may also be columnar. Thereby, the surface area is further increased, and the cooling performance can be further improved. In addition, the shape of the needle is not limited to a cylinder or a prism, and various shapes can be adopted.

[0080] According to this embodiment, in the case of needle-shaped fins, the area of the fins in contact with the wind generated by natural convection of air is increased. As a result, an electronic control device with an improved heat dissipation effect can be provided.

[0081] (Sixth Embodiment)

[0082] Regarding the exhaust hole and the suction hole formed in the cover 1, it is difficult to improve the cooling effect if the hole diameter is too small or too large. As Fig.13 shown, when the diameter of the hole formed in the cover 1 is Z3, the distance between the cover and the fins is Z1, and the height of the fins is Z2, it is preferably satisfied that Z3 ≤ Z1 + Z2, and further 0 < Z3 ≤ Z1 + Z2. That is, the diameter of the hole is formed to be sufficiently small compared to the space outside the hole.

[0083] In other words, as Fig.13 shown, when the diameters of the holes (2) 8 and (3) 9 serving as suction holes are Z3, the distance between the cover 1 and the fins 5 is Z1, and the height of the fins 5 is Z2, at least the relationship of Z3 ≤ Z1 + Z2 is satisfied. In addition, it is preferably satisfied that 0 < Z3 ≤ Z1 + Z2.

[0084] As a result, according to Bernoulli's law, the flow velocity near the entrance and exit of the hole can be increased, and the natural convection of the air 13 actively occurs. As a result, the cooling effect achieved by natural convection can be improved.

[0085] (Seventh Embodiment)

[0086] The shape of the hole formed in the cover 1 is as Fig.14As shown, it is preferably a circular or angular shape. In other words, the cross-sectional shape of the hole (1) 2 as the exhaust hole and the hole (2) 8 and the hole (3) 9 as the suction hole is circular or polygonal.

[0087] For example, in the case of a circular shape, there is no possibility of sound being generated when air passes through the hole, and it is possible to provide an electronic control device that maintains quietness.

[0088] On the other hand, when the shape of the hole is an angular shape, the convection of the air after passing through the hole becomes turbulent. In the turbulent flow of natural convection, the Reynolds number representing the viscosity of the fluid increases. The Reynolds number of turbulence is proportional to the Nusselt number representing the characteristics of the fluid. The Nusselt number is the ratio of the heat transfer coefficient to the thermal conductivity of the fluid, and is proportional to the heat transfer coefficient. Therefore, when the Reynolds number of natural convection increases and becomes turbulent, the heat transfer coefficient of the fluid increases. As a result, the amount of heat transferred from the surface of the fin-integrated housing 3 or the fin-integrated heat spreader 14 to the air increases, which can further improve the cooling effect.

[0089] In addition, the present invention is not limited to the above-mentioned embodiments, and includes various modified examples. For example, the above-mentioned embodiments are described in detail in order to explain the present invention in an easy-to-understand manner, and are not limited to all structures that must be described. In addition, a part of the structure of a certain embodiment can be replaced with the structure of other embodiments, and the structure of other embodiments can be added to the structure of a certain embodiment. In addition, for a part of the structure of each embodiment, other structures can be added, deleted, or replaced.

[0090] In addition, the present invention may be implemented in the following aspects.

[0091] (1) An electronic control device, comprising a heating element mounted on a circuit board, a shell in thermal contact with the heating element via an intermediate component, and a cover covering the shell, wherein the cover has an air intake hole and an air exhaust hole formed on the top surface or the side surface, the air exhaust hole is formed at a position close to a heat source, and the air intake hole is formed at a position far from the heat source.

[0092] (2) The electronic control device described in (1), wherein the housing is a fin-integrated housing having fins integrally formed on a surface facing the cover.

[0093] (3) In the electronic control device described in (1), the housing has a heat spreader formed integrally with the fins.

[0094] (4) In the electronic control device described in (1), (2) or (3), the hole of the cover is located on the top surface and the side surface of the cover, or only on the top surface of the cover.

[0095] (5) In the electronic control device described in (2) or (3), the fin shape of the fin-integrated housing is a shape extending in a predetermined direction parallel to the top surface of the housing, and the holes of the cover are formed at two or more different positions on the same extension line of the fin.

[0096] (6) In the electronic control device described in (2) or (3), the fin shape of the fin-integrated housing is a shape extending in the vertical direction relative to the top surface of the housing, and the hole of the cover is a part or all of it.

[0097] (7) In the electronic control device described in (2) or (3), when the diameter of the hole formed on the cover is Z3, the distance between the cover and the fin is Z1, and the height of the fin is Z2, the relationship Z3≤Z1+Z2 is satisfied.

[0098] (8) As described in (2) or (3) of the electronic control device, the diameter Z3 of the hole of the cover satisfies 0 <Z3≤Z1+Z2。

[0099] (9) In the electronic control device described in (1), (2) or (3), the hole of the cover has a circular or angular shape.

[0100] (10) In the electronic control device described in (1), (2) or (3), the hole of the cover is formed to be parallel to or at an angle with respect to the thickness direction of the cover.

[0101] (11) In the electronic control device described in (2) or (3), the hole of the cover is formed at a position that does not overlap with the protrusion of the fin in the side view and the top view.

[0102] According to (1) to (11), it is possible to provide high cooling performance by natural convection of air without using power such as circulating cooling water and electric fans. Natural convection occurs due to the air intake holes and exhaust holes formed in the cover provided in a manner covering the shell. Therefore, it is possible to pre-design the flow rate and flow velocity, and realize a highly reliable cooling system with very little change in cooling performance during use. In addition, since no power is used, problems such as failure and noise are solved, and miniaturization and cost reduction are further achieved.

[0103] Description of Reference Numerals

[0104] 1 Cover

[0105] 2 holes(1)

[0106] 3 fin integrated housing

[0107] 4 Lower housing

[0108] 5 Fins

[0109] 6 Circuit Board

[0110] 7 Heat generating components

[0111] 8 holes (2)

[0112] 9 holes (3)

[0113] 10 Perpendicular to the extension direction of the fin

[0114] 11 Parallel to the extension direction of the fin

[0115] 12 Heat sink

[0116] 13 Air

[0117] 14 fin integrated heat sink

[0118] 15 holes (4)

[0119] 16 holes (5)

[0120] 17 holes (6)

[0121] 18 A surface (1) perpendicular to the extending direction of the fins of the fin integrated housing 3

[0122] 19 A surface (2) perpendicular to the extending direction of the fins of the fin integrated housing 3

[0123] 20 holes (7).

Claims

1. An electronic control device, characterized in that: Comprising: A circuit board; A heating element mounted on the circuit board; A heat conducting component in contact with the heating element and capable of conducting the heat of the heating element; A housing covering the circuit board and in contact with the heat conducting component; And A cover covering the housing, The cover has an air intake hole and an air exhaust hole, Compared with the air intake hole, the air exhaust hole is formed at a position closer to the heating element on the top surface portion of the cover opposite to the housing; Compared with the air exhaust hole, the air intake hole is formed at a position farther from the heating element on the side surface portion or the top surface portion of the cover; A plurality of fins are formed on the surface of the housing on the cover side; The air exhaust hole and the air intake hole are formed at positions along the groove between adjacent fins.

2. The electronic control device according to claim 1, wherein: The housing has a heat spreader.

3. The electronic control device according to claim 1, wherein: The fins are plate-shaped.

4. The electronic control device according to claim 1, wherein: The fins are columnar.

5. The electronic control device according to claim 1, wherein: When the diameter of the air intake hole is Z3, the distance between the cover and the fins is Z1, and the height of the fins is Z2, the relationship Z3≤Z1 + Z2 is satisfied.

6. The electronic control device according to claim 1, wherein: When the diameter of the air intake hole is Z3, the distance between the cover and the fins is Z1, and the height of the fins is Z2, the relationship 0 < Z3≤Z1 + Z2 is satisfied.

7. The electronic control device according to claim 1, wherein: The cross-sectional shapes of the air exhaust hole and the air intake hole are circular or polygonal.

8. The electronic control device according to claim 1, wherein: The air exhaust hole and the air intake hole are formed parallel or at an angle with respect to the thickness direction of the cover.

9. The electronic control device according to claim 3, wherein: The air exhaust hole is located above the groove between adjacent fins, The center lines of the air intake hole and the air exhaust hole are included in one plane.

10. The electronic control device according to claim 1, wherein: The air intake hole is formed on the side surface portion of the cover, The entrance of the air intake hole is located on the front end surface of the side surface portion of the cover.

11. The electronic control device according to claim 3, wherein: The air intake hole is L-shaped.

12. The electronic control device according to claim 10, wherein: There is a lower housing fitted with the housing, The front end surface of the side surface portion of the cover is farther from the top surface portion of the cover than the bottom surface of the lower housing.

13. The electronic control device according to claim 3, wherein: The fins are arranged along the length direction of the housing.

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