Cooling structure for vehicle-mounted ecu

Abstract

To provide a cooling structure of an on-vehicle ECU capable of effectively cooling the ECU while improving space efficiency in a vehicle.SOLUTION: A cooling structure of an in-vehicle ECU includes a body part 10 constituting a part of a vehicle body, and an ECU40 attached to the body part 10, wherein the body part 10 has a heat sink 50 on a back surface of an attachment surface of the ECU40, and the body part 10 is an aluminum die-cast part 12 integrally molded together with the heat sink 50.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This specification discloses a cooling structure for an electronic control unit (hereinafter referred to as "ECU") mounted on a vehicle. [Background technology]

[0002] An ECU is a device that controls the operation of electronic components installed in a vehicle. Such an ECU is installed in an available space inside the vehicle. Typically, an ECU has a signal circuit and a power circuit, and heat is generated as the ECU operates. If the ECU becomes excessively hot, it will deteriorate or fail. Therefore, it has been proposed to attach a heat sink to the ECU in order to efficiently cool the ECU.

[0003] Patent Document 1 discloses a heat sink for improving heat dissipation performance. The heat sink in Patent Document 1 has a heat dissipation base and multiple heat dissipation fins rising from the surface of the heat dissipation base. The multiple heat dissipation fins are die-cast and integrated with the heat dissipation base. This heat sink improves the efficiency of heat transfer from the heat dissipation base to the heat dissipation fins, further improving heat dissipation performance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-039497 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the heat sink in Patent Document 1 is a separate component independent of both the vehicle body components and the ECU. Therefore, a dedicated process is required to manufacture the heat sink, and a dedicated space is required to place the heat sink. Furthermore, to improve the heat dissipation capacity of the heat sink, the surface area of ​​the heat sink needs to be increased. However, it is usually difficult to make the heat sink excessively large, and it is also difficult to increase the surface area sufficiently.

[0006] Therefore, this specification discloses a cooling structure for an in-vehicle ECU that can effectively cool the ECU while improving the space efficiency inside the vehicle. [Means for solving the problem]

[0007] The cooling structure for an on-vehicle ECU disclosed in this specification comprises a body part that constitutes part of the vehicle body, and an ECU that is attached to the body part, the body part having a heat sink on the back side of the attachment surface of the ECU, and the body part being an aluminum die-cast part that is integrally molded with the heat sink.

[0008] By molding the body part and the heat sink as a single unit, the heat from the ECU can be effectively cooled without the heat sink having to be excessively large. As a result, the ECU can be cooled effectively while improving the space efficiency inside the vehicle.

[0009] In this case, the heat sink may have a plurality of heat dissipation fins arranged parallel to one another, or a plurality of heat dissipation pins arranged in a two-dimensional array.

[0010] With this configuration, the surface area of ​​the heat sink is increased, and the heat dissipation effect of the heat sink can be improved.

[0011] The body part is an aluminum die-cast part integrally formed with a pair of side panels spaced apart in the vehicle width direction, wheel arch portions that bulge inward in the vehicle width direction from each of the pair of side panels, and a connecting panel that connects the pair of side panels, each of the pair of side panels including a cabin side portion that functions as a side wall of the cabin, the ECU is attached to the inner surface of the cabin side portion in the vehicle width direction, and the heat sink protrudes toward the outside of the vehicle from the opposite side of the ECU, with the side panels in between.

[0012] By installing the ECU on the side of the passenger compartment, the available space can be used effectively. In addition, by protruding the heat sink toward the outside of the vehicle, the heat from the ECU can be efficiently dissipated. This prevents the heat from the ECU from reaching the front seat passengers, maintaining their comfort.

[0013] Furthermore, the ECU may further include a resin cover that covers the ECU from the passenger compartment side, and the ECU may have an aluminum case that is screwed and fastened to the body part while being in contact with the body part.

[0014] The resin cover improves the design and reduces the heat transfer from the ECU to the passengers. Also, by constructing the ECU case from aluminum or a material primarily composed of aluminum, which has high thermal conductivity, the ECU can be cooled more efficiently. [Effects of the Invention]

[0015] According to the technology disclosed in this specification, it is possible to improve the space efficiency inside the vehicle while effectively cooling the ECU. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 2 is a perspective view showing a vehicle body and a frame at the front of the vehicle. [Figure 2] FIG. 2 is a perspective view of a vehicle interior side portion as viewed from the outside in the vehicle width direction. [Figure 3]FIG. 2 is a cross-sectional view of the area surrounding the ECU mounting portion. [Figure 4] FIG. 10 is a perspective view showing another example of a heat sink. DETAILED DESCRIPTION OF THE INVENTION

[0017] The cooling structure of the ECU 40 will be described below with reference to the drawings. Fig. 1 is a perspective view showing a vehicle body and frame at the front of the vehicle. In each drawing, Fr, Up, and Rh indicate the front, upper, and right sides of the vehicle, respectively.

[0018] The vehicle shown in FIG. 1 is a four-wheel vehicle primarily used for transporting people. A body part 10 is disposed at the front of the vehicle. The body part 10 is a component that constitutes part of the vehicle body. In this example, the body part 10 is an aluminum die-cast part 12 that is integrally formed with a pair of side panels 14, a pair of wheel arch portions 16, and a connecting panel 20. Naturally, the aluminum die-cast part 12 is primarily composed of aluminum or an aluminum alloy and has high thermal conductivity. As is clear from FIG. 1, the aluminum die-cast part 12 is a large part that includes a pair of wheel arch portions 16. Such a large aluminum die-cast part 12 is manufactured using a large-scale die-casting technology known as gigacasting or megacasting.

[0019] The side panel 14 of the body part 10 (aluminum die-cast part 12) is a panel material that functions as a side wall of the vehicle. As shown in FIG. 1, a portion of the side panel 14 bulges inward in the vehicle width direction. This bulging portion functions as a wheel arch portion 16. A suspension tower 18 is connected to the wheel arch portion 16. This suspension tower 18 is also integrally formed with the wheel arch portion 16 and the like by aluminum die-casting.

[0020] A pair of left and right side panels 14 are connected by a connecting panel 20. The connecting panel 20 is a panel material extending in the vehicle width direction, and both ends of the connecting panel 20 in the vehicle width direction are connected to the side panels 14. A dash panel 34 (not shown in FIG. 1, see FIG. 3) is attached to this connecting panel 20. The dash panel 34 is a partition wall separating the passenger compartment 30 and the power unit compartment 32. Therefore, the space in front of the connecting panel 20 is the power unit compartment 32, and the space behind the dash panel 34 is the passenger compartment 30. The portion of the side panel 14 in front of the connecting panel 20 functions as a side wall of the power unit compartment 32. The portion of the side panel 14 behind the connecting panel 20 functions as a side wall of the passenger compartment 30. Hereinafter, this portion functioning as a side wall of the passenger compartment 30 will be referred to as a "compartment side portion 22."

[0021] Such a body component 10 is fixed to a frame member of a vehicle. In the example of Fig. 1, the vehicle has, as frame members, a pair of rockers 27 extending in the fore-and-aft direction of the vehicle and a cross member 28 connecting the pair of rockers 27. The body component 10 is fixed to the rockers 27 and the cross member 28.

[0022] As described above, the passenger compartment side portion 22 is a front side wall of the passenger compartment 30 and is located near the lower legs of an occupant seated in a front seat. In this example, the ECU 40 is attached to the passenger compartment side portion 22. The ECU 40 is a device that uses a microcomputer to process electrical signals input from various sensors mounted on the vehicle and controls the operation of various actuators mounted on the vehicle. The ECU 40 attached to the body component 10 may be an individual ECU (e.g., an engine ECU or a battery ECU) that controls the operation of a specific device, or may be an integrated ECU that integrates multiple ECUs mounted on the vehicle. In either case, the ECU 40 has a signal circuit for calculating the electrical signals, a power supply circuit for supplying power to the signal circuit, and an aluminum case 42 that houses these. When the ECU 40 is operated, current flows through electronic elements (e.g., semiconductor elements) incorporated in the signal circuit and power supply circuit, generating heat. If the ECU 40 becomes excessively hot due to this heat, it may cause damage or malfunction of the ECU 40. Furthermore, since the ECU 40 is located near the lower legs of the occupant, the ECU 40 becoming too hot may impair the comfort of the occupant.

[0023] Therefore, in this example, in order to more efficiently cool the ECU 40, the ECU 40 is attached to the body part 10, and a heat sink 50 is formed in the body part 10. This will be described below with reference to FIGS. 2 and 3.

[0024] FIG. 2 is a perspective view of the cabin side portion 22 to which the ECU 40 is attached, as seen from the outside in the vehicle width direction. FIG. 3 is a cross-sectional view of the vicinity of the attachment portion of the ECU 40. As shown in FIGS. 1 and 2, the ECU 40 is screwed to the surface of the cabin side portion 22 facing the cabin 30. A portion of the aluminum case 42 of the ECU 40 is in contact with the cabin side portion 22. Heat generated by the ECU 40 is efficiently transferred to the body component 10 through this contact portion. In this example, the ECU 40 is fastened using screws. However, the ECU 40 may be attached to the cabin side portion 22 by other methods as long as it is fixed in contact with the body component 10. For example, the ECU 40 may be fastened with clips, fitted, or attached with adhesive tape. The aluminum case 42 may be in direct contact with the cabin side portion 22, or another highly heat-conductive member may be interposed between the aluminum case 42 and the cabin side portion 22. For example, thermally conductive grease or a thermal pad may be placed between the aluminum case 42 and the vehicle interior side portion 22 to fill the gap between them. In addition, although the present example uses an aluminum case 42 whose main component is aluminum, the housing of the ECU 40 may have a different configuration as long as it can transfer heat generated by the ECU 40 to the outside.

[0025] A resin cover 44 is also attached to the passenger compartment side portion 22. The resin cover 44 is a box-shaped member made of resin that covers the ECU 40 from the passenger compartment 30 side. By providing this resin cover 44, heat directed from the ECU 40 toward the periphery of the occupant's lower legs is blocked. As a result, the temperature rise around the occupant's lower legs can be suppressed, improving the comfort of the occupant. Furthermore, by providing the resin cover 44, the ECU 40 is hidden, thereby improving the design of the passenger compartment.

[0026] A heat sink 50 is formed on the opposite side of the ECU 40 across the passenger compartment side portion 22. This heat sink 50 is integrally cast with the body component 10. This configuration eliminates the need for a separate dedicated process for forming and attaching the heat sink 50, thereby reducing the cost and effort required for installing the heat sink 50. Furthermore, by integrally casting the heat sink 50 with the body component 10, there is no seam between the mounting surface of the ECU 40 (i.e., the passenger compartment side portion 22) and the heat sink 50. This eliminates thermal resistance caused by the seam, improving the efficiency of heat transfer from the passenger compartment side portion 22 to the heat sink 50.

[0027] As shown in FIGS. 2 and 3 , the heat sink 50 includes a plurality of heat dissipation fins 52 arranged at intervals in the vertical direction. Each heat dissipation fin 52 is a substantially flat plate-shaped member extending from the cabin side portion 22 toward the outside in the vehicle width direction. In this example, the thickness direction of the heat dissipation fin 52 is substantially parallel to the vertical direction. The provision of a plurality of heat dissipation fins 52 increases the surface area of ​​the entire heat sink 50, improving heat dissipation efficiency. This allows the ECU 40 located on the opposite side of the heat sink 50 to be efficiently cooled.

[0028] As shown in FIGS. 2 and 3 , the body part 10 has folded portions 24 extending in the vehicle width direction at its upper and rear edges. Furthermore, multiple ribs 26 are formed on the outer surfaces of the body part 10 in the vehicle width direction. Providing these folded portions 24 and ribs 26 improves the section modulus of the body part 10 and, ultimately, the rigidity of the body part 10. The protruding dimension H1 of the heat dissipation fins 52 is smaller than the protruding dimension H2 of the folded portions 24 and some of the ribs 26. Therefore, providing the heat dissipation fins 52 does not increase the size of the body part 10. In other words, in this example, the heat sink 50 is formed in the dead space formed by the folded portions 24 and the ribs 26. Forming the heat sink 50 in this dead space prevents a decrease in space efficiency due to the installation of the heat sink 50.

[0029] As mentioned above, the heat sink 50 is integrally cast with the body component 10. Therefore, heat generated in the ECU 40 is transferred not only to the heat sink 50 but also to the body component 10. The body component 10 is primarily made of aluminum or an aluminum alloy, which has high thermal conductivity. The body component 10 is also very large and has a large surface area. Transferring heat to the body component 10 further improves the heat dissipation efficiency of the ECU 40.

[0030] 3, a front fender panel 62 is disposed outward in the vehicle width direction from the passenger compartment side portion 22. A front side door 64 is disposed behind the front fender panel 62. The heat sink 50 is surrounded by the front fender panel 62 and the front side door 64, and therefore cannot be seen from the outside. As a result, even with the heat sink 50, the vehicle's design can be maintained at a high level. Furthermore, the provision of the heat sink 50 improves the section modulus of the body component 10, further improving the rigidity of the body component 10.

[0031] As is clear from the above description, in this example, the ECU 40 is attached to the body part 10, and the heat sink 50 is integrally molded with the body part 10 and provided on the opposite side of the ECU 40. With this configuration, the ECU 40 can be effectively cooled while improving the space efficiency inside the vehicle.

[0032] However, the configuration described above is merely an example, and other configurations may be modified as long as the configuration described in claim 1 is included. For example, in the above description, the heat sink 50 has multiple heat dissipation fins 52 arranged vertically. However, the heat sink 50 may have other configurations as long as it is integrally molded with the body component 10. For example, the heat dissipation fins 52 of the heat sink 50 may be arranged in the front-to-rear direction rather than the up-to-down direction. In this case, each heat dissipation fin 52 is arranged with its thickness direction parallel to the front-to-rear direction. The heat dissipation fins 52 may also be arranged in a direction inclined relative to the front-to-rear and up-to-down directions. For example, if wind flows around the heat sink 50 during vehicle travel, the multiple heat dissipation fins 52 may be arranged in a direction inclined relative to the front-to-rear and up-to-down directions so that the heat dissipation fins 52 are parallel to the flow of the wind. Furthermore, as shown in FIG. 4, the heat sink 50 may have multiple heat dissipation pins 54 arranged in a two-dimensional array.

[0033] Furthermore, in the explanation so far, the body component 10 has been described as a large aluminum die-cast component 12 in which two wheel arch portions 16 are integrally formed. However, the body component 10 to which the heat sink 50 is attached may have other configurations as long as it is part of the vehicle body. For example, the body component 10 may be configured to be divided into left and right portions. In other words, the body component 10 may have one of the left and right wheel arch portions 16, but may not have the other wheel arch portion 16.

[0034] In addition, the above description has been given taking the example of the body part 10 disposed at the front of the vehicle as an example, but the ECU 40 and the heat sink 50 may be attached to the body part 10 at a location other than the front of the vehicle, for example, at the rear of the vehicle. [Explanation of symbols]

[0035] 10 Body parts, 12 Aluminum die-cast parts, 14 Side panels, 16 Wheel arch portions, 18 Suspension towers, 20 Connecting panels, 22 Passenger compartment side portions, 24 Fold-up portions, 26 Ribs, 27 Rockers, 28 Cross members, 30 Passenger compartments, 32 Power unit compartments, 34 Dash panels, 40 ECUs, 42 Aluminum cases, 44 Resin covers, 50 Heat sinks, 52 Heat dissipation fins, 54 Heat dissipation pins, 62 Front fender panels, 64 Front side doors.

Claims

1. a body part that constitutes a part of a vehicle body; an ECU attached to the body part; the body part has a heat sink on a back surface of the mounting surface of the ECU, The body part is an aluminum die-cast part integrally formed with the heat sink.

1. A cooling structure for an in-vehicle ECU.

2. The cooling structure for an on-vehicle ECU according to claim 1, The cooling structure for an in-vehicle ECU, wherein the heat sink has a plurality of heat dissipation fins arranged parallel to one another or a plurality of heat dissipation pins arranged in a two-dimensional array.

3. The cooling structure for an on-vehicle ECU according to claim 1, The body part is A pair of side panels arranged at an interval in the vehicle width direction; wheel arch portions each bulging inward in a vehicle width direction from the pair of side panels; a connecting panel that connects the pair of side panels; It is an aluminum die-cast part that is molded as a single unit. Each of the pair of side panels includes a vehicle compartment side portion that functions as a side wall of the vehicle compartment, The ECU is attached to an inner surface of the vehicle interior side portion in a vehicle width direction, The heat sink protrudes toward the outside of the vehicle from the opposite side of the side panel from the ECU.

1. A cooling structure for an in-vehicle ECU.

4. The cooling structure for an on-vehicle ECU according to claim 3, further comprising: a resin cover that covers the ECU from the vehicle interior side; The ECU has an aluminum case, and is screwed to the body part with the aluminum case in contact with the body part.

1. A cooling structure for an in-vehicle ECU.

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