JP2017001412A - Heat radiation structure of electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology which can reduce a size of a vehicle body while cooling an electronic component which is arranged in an engine room.SOLUTION: A heat radiation structure of an electronic component comprises: an exterior member 34 having a cover part 34b which covers an ECU 32 arranged in an engine room, and contacts with the ECU 32, and an insertion part 34c inserted into a heat radiation space which is defined as a space different from the engine room through an attachment hole which is formed at a wall for partitioning the engine room; a heat pipe 36 having a heat receiving part 36a which is thermally connected to the cover part 34b, and a heat radiation part which is thermally connected to the insertion part 34c, and transmitting heat which is received by the heat receiving part 36 to the heat radiation part; heat radiation fins 38 which are arranged at the insertion part 34c, and promote the radiation of the heat which is received from the heat radiation part toward a heat radiation space; and a protection member 46 which is interposed between the exterior member 34 and the attachment hole, and protects the exterior member 34 from contact with the attachment hole.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a heat dissipation structure for an electronic component for cooling an electronic component mounted in an engine room.

  In recent years, the downsizing turbocharged engine using a turbocharger has made it easy for the ambient temperature in the engine room to rise. Accordingly, electronic components such as an electronic control unit (hereinafter referred to as ECU) arranged in the engine room are easily exposed to severe thermal conditions, and protection from thermal damage is required.

  Patent Document 1 discloses a vehicle in which an electronic component is mounted on the rear side of a suspension tower in an engine room. In this vehicle, a cooling air passage for guiding cooling air from the front of the vehicle body to the rear of the suspension tower is provided. It is said that the electronic component is cooled by the cooling air guided to the electronic component through the cooling air passage, and the electronic component can be protected from heat damage.

JP 2001-234746 A

  By the way, in recent years, from the viewpoint of design, it is required to arrange the height position of the hood of the vehicle body at a low position. Under such a requirement, in the structure of Patent Document 1, since a duct for guiding cooling air from the front of the vehicle body to the rear of the suspension tower is provided, it is necessary to secure an extra space for the duct in the vehicle body. Accordingly, there is a problem that the vehicle body is enlarged so that the height position of the hood is raised, and the above-mentioned requirement is not met.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a technique capable of reducing the size of a vehicle body while cooling electronic components disposed in an engine room.

  In order to solve the above problems, an electronic component heat dissipation structure according to an aspect of the present invention includes an exterior member having a cover portion and an insertion portion, a heat transfer member having a heat receiving portion and a heat dissipation portion, a heat dissipation fin, And a protective member. The cover portion covers and contacts the electronic component disposed in the engine room, and the insertion portion is a space separate from the engine room through a mounting hole formed in a wall portion defining the engine room. It is inserted toward the space for heat radiation partitioned as The heat receiving portion is thermally connected to the cover portion, the heat radiating portion is thermally connected to the insertion portion, and the heat transfer member is for transferring heat received by the heat receiving portion to the heat radiating portion. The heat radiating fin is provided in the insertion portion, and is for accelerating the heat radiation from the heat radiating portion to the heat radiating space. The protective member is interposed between the attachment hole and the exterior member, and protects the exterior member from contact with the attachment hole.

  According to this aspect, the heat of the electronic component is transmitted from the covering portion of the exterior member to the heat receiving portion of the heat transfer member, the heat transfer member transmits the heat received by the heat receiving portion to the heat dissipation portion, and the heat dissipation portion transmits the heat transferred. Heat is radiated to the heat radiation space through the heat radiation fins. As a result, the electronic component can be cooled using heat conduction by the heat transfer member. Therefore, the electronic component can be cooled without providing a duct for taking cooling air from the outside into the engine room. For this reason, it is possible to reduce the size of the vehicle body while cooling the electronic components disposed in the engine room.

  ADVANTAGE OF THE INVENTION According to this invention, size reduction of a vehicle body can be achieved, cooling the electronic component arrange | positioned in an engine room.

It is a top view which shows roughly the structure of the front part of a vehicle body. It is the sectional view on the AA line of FIG. FIG. 3 is an enlarged view of a range B in FIG. 2. It is a perspective view which shows an electronic component unit. It is the C1-C1 sectional view taken on the line of FIG. It is the C2-C2 sectional view taken on the line of FIG. It is a figure which shows typically the positional relationship of a heat pipe when an exterior member is seen from the front. (A) is a front view which shows a protection member with an exterior member, (b) is a figure which shows the state which removed the exterior member from the protection member.

FIG. 1 is a plan view schematically showing a configuration of a front portion of a vehicle body 10 according to the first embodiment.
An engine room 12 is provided at the front of the vehicle body 10. An engine 14 is mounted in the center of the engine room 12 in the vehicle width direction Y. Behind the engine room 12, a dash panel 16 that partitions the engine room 12 and a vehicle compartment (not shown) is installed as a vehicle body panel. On both sides of the engine room 12 in the vehicle width direction Y, fender apron panels 18 that divide the inside and outside of the engine room 12 in the vehicle width direction Y are installed as vehicle body panels. The fender apron panel 18 serves as a wall that defines the engine room 12.

  The fender apron panel 18 has a vertical wall portion 18a extending in the vertical direction Z and a horizontal wall portion 18b extending inward in the vehicle width direction Y from the lower end edge of the vertical wall portion 18a. A front side member 20 as a vehicle body skeleton member extending in the vehicle front-rear direction X is connected to the inner side of the lateral wall portion 18b in the vehicle width direction Y. The fender apron panel 18 is provided with a wheel house 22 for the front wheels so as to protrude upward. A suspension tower 24 that protrudes upward is provided at an intermediate portion in the vehicle longitudinal direction X of the wheel house 22. The suspension tower 24 supports an upper support (not shown) that is a part of the suspension for the front wheels.

2 is a cross-sectional view taken along line AA in FIG. In the drawing, only the outer shape of the electronic component unit 30 described later is shown by a two-dot chain line.
A front wheel 25 is disposed in the wheel house 22, and a fender liner 26 that is opposed to the front wheel 25 in the radial direction is installed on the vehicle body. The fender liner 26 is for preventing adhesion of mud or the like splashed by the front wheel 25 to the fender apron panel 18 or the like. The vehicle body 10 is provided with a heat radiating space 28 between the fender liner 26 and the dash panel 16 below the lateral wall portion 18 b of the fender apron panel 18. The heat dissipation space 28 is provided below the engine room 12 and behind the front wheel 25. A front side member 20 (see FIG. 1) as a vehicle body skeleton member is installed inside the heat radiation space 28 in the vehicle width direction Y.

FIG. 3 is an enlarged view of a range B in FIG.
A mounting hole portion 18c is formed in the lateral wall portion 18b of the fender apron panel 18 to communicate the engine room 12 and the heat radiation space 28. An insertion portion 34c of an electronic component unit 30 described later is inserted into the mounting hole 18c. The attachment hole 18 c is closed by the electronic component unit 30. Thus, the heat dissipation space 28 is partitioned as a separate space from the engine room 12 by a part of the vehicle body 10 such as the fender apron panel 18 and the front side member 20 and the electronic component unit 30. Such a heat radiation space 28 is a place where the ambient temperature is lower than that of the engine room 12 in which the engine 14 serving as a heat source is mounted.

  A fender panel (not shown) is installed outside the heat radiation space 28 in the vehicle width direction Y, and a part of the dash panel 16 (see FIG. 2) is installed on the lower side. Thus, the heat dissipation space 28 is formed by being surrounded by a part of the vehicle body 10.

4 is a perspective view showing the electronic component unit 30, and FIG. 5 is a cross-sectional view taken along line C1-C1 of FIG.
The electronic component unit 30 includes an ECU 32, an exterior member 34, a plurality of heat pipes 36, and a plurality of heat radiation fins 38. The electronic component heat dissipation structure 31 according to the present invention is configured as an electronic component unit 30 including these in the present embodiment.

  The ECU 32 is disposed between the suspension tower 24 and the dash panel 16 on the side in the vehicle width direction Y in the engine room 12 (see FIG. 1). The ECU 32 is an electronic component as an auxiliary machine for controlling the engine 14. As shown in FIG. 5, the ECU 32 includes a flat case 32a having a hollow structure as an outer shell, a circuit board 32b accommodated in the case 32a, a microcomputer element mounted on the circuit board 32b, an injector driver element, and the like. Circuit element 32c. The case 32a is arranged in a state where the lateral width direction is substantially parallel to the vehicle width direction Y, and a connector portion 32d for external connection is provided on the upper portion (see FIG. 4). On both side surfaces in the thickness direction of the case 32a, a plurality of inner fins 32e for promoting heat radiation from the ECU 32 are provided by integral molding. The plurality of inner fins 32e protrude in the vehicle front-rear direction X and are arranged side by side with an interval in the vehicle width direction Y.

  The exterior member 34 is formed flat so as to be elongated in the vehicle width direction Y. The exterior member 34 is configured by assembling a plurality of exterior panels 34a. Each exterior panel 34a is made of a heat conductive material that is excellent in heat conductivity and hard, such as a metal such as aluminum, in order to easily transfer heat between the ECU 32 and the heat pipe 36. The exterior member 34 is arranged in a state in which a part of the surface portions of each exterior panel 34a are abutted, and each surface portion is fixed by a first fixture 40 such as a bolt (see FIG. 4).

  As shown in FIGS. 2 and 4, the exterior member 34 is inserted into the heat radiating space 28 from the engine room 12 through a hollow cover portion 34 b that covers the ECU 32 and a mounting hole portion 18 c of the fender apron panel 18. It has the insertion part 34c. The width of the exterior member 34 is determined so that the insertion portion 34c is smaller than the cover portion 34b. The cover 34b of the exterior member 34 is fixed to the fender apron panel 18 using a fixing tool (not shown) such as a screw.

  The cover part 34b is formed in a rectangular cylindrical shape that opens to one side (upper side) in the vertical direction Z and is long in the vehicle width direction Y. The cover part 34b covers the ECU 32 inside thereof from both sides in the vehicle width direction Y and both sides in the vehicle front-rear direction X. The ECU 32 is fixed to the cover part 34b by a second fixing tool 42 such as a screw.

  As shown in FIG. 3, a heat conductive sheet 44 is attached to the inner side surfaces of the front wall surface portion 34e and the rear wall surface portion 34f facing the vehicle front-rear direction X of the cover portion 34b by adhesion or the like. The heat conductive sheet 44 is made of a heat conductive material having excellent heat conductivity and elasticity. The inner side surfaces of the front wall surface portion 34e and the rear wall surface portion 34f of the cover portion 34b are in contact with the front end portions of the inner fins 32e of the ECU 32 via the heat conductive sheet 44. The heat conductive sheet 44 is sandwiched between the exterior member 34 and the inner fin 32e of the ECU 32 in an elastically deformed state. As a result, the contact area with the other member that is the contact partner of the plurality of inner fins 32 e can be increased by contacting the heat conductive sheet 44 rather than contacting the exterior member 34. Therefore, heat is easily transferred from the plurality of inner fins 32 e to the exterior member 34 through the heat conductive sheet 44, and heat dissipation from the ECU 32 to the exterior member 34 is promoted, so that the cooling effect of the ECU 32 can be enhanced.

  A first mounted portion 34g for mounting a heat receiving portion 36a of a heat pipe 36 to be described later is provided on the outer surface of the front wall surface portion 34e and the rear wall surface portion 34f of the cover portion 34b. The first mounted portion 34g is a groove portion formed on the outer surface of the front wall surface portion 34e and the rear wall surface portion 34f.

6 is a cross-sectional view taken along line C2-C2 of FIG.
The insertion part 34c of the exterior member 34 includes a pair of plate-like heat absorbing parts 34h arranged with their inner surfaces facing each other, and a plurality of radiating fins 38 provided on the outer surface of each heat absorbing part 34h. Each of the pair of heat absorbing portions 34 h is configured by a separate exterior panel 34 a that configures the exterior member 34. A second mounted portion 34j for mounting a heat radiating portion 36b of a heat pipe 36 to be described later is provided on the inner side surfaces of the pair of heat absorbing portions 34h. The second mounted portion 34j is a groove formed on the inner side surface of each heat absorbing portion 34h.

  Returning to FIG. 4, the heat pipe 36 is a long body and is formed in a flat cylindrical cross-sectional shape. FIG. 7 is a diagram schematically showing the positional relationship of the heat pipes 36 when the exterior member 34 is viewed from the front. The heat pipe 36 includes a heat receiving portion 36a provided on one end side (upper side) in the axial direction and a heat radiating portion 36b provided on the other end side (lower side) in the axial direction. The heat receiving portion 36 a is disposed outside the cover portion 34 b of the exterior member 34, and the heat radiating portion 36 b is disposed inside the insertion portion 34 c of the exterior member 34. Although not shown, the heat receiving portion 36 a is disposed in the engine room 12, and the heat radiating portion 36 b is disposed in the heat radiating space 28. An intermediate portion between the heat receiving portion 36a and the heat radiating portion 36b is drawn inward from the outside of the cover portion 34b through a drawing port 34k formed in the exterior member 34. Although only two heat pipes 36 (the lower heat pipe 36 in FIG. 5) visible when the exterior member 34 is viewed from the front are shown in this figure, the two heat pipes 36 (in FIG. 5) viewed from the rear are shown. The same applies to the upper heat pipe 36).

  For example, an alcohol-based heat medium is sealed in the heat pipe 36 as a working fluid. In the heat pipe 36, the internal working fluid is vaporized by receiving heat at the heat receiving portion 36a, and the vaporized working fluid is liquefied by moving to the heat radiating portion 36b and being cooled, and the liquefied working fluid receives heat again. Move to section 36a. The heat pipe 36 transfers the heat received by the heat receiving part 36a to the heat radiating part 36b by the circulation of the hydraulic fluid. The heat pipe 36 is provided as a heat transfer member for transmitting the heat received by the heat receiving portion 36a to the heat radiating portion 36b.

  The heat receiving portions 36a of the plurality of heat pipes 36 are provided so as to extend in the vertical direction Z as shown in FIGS. Each heat receiving portion 36a is attached to the first attached portion 34g of the covering portion 34b of the exterior member 34 by soldering or the like. Thereby, the heat receiving part 36 a of the heat pipe 36 is thermally connected to the cover part 34 b of the exterior member 34. Here, the term “thermally connected” means that one of a plurality of members (the cover portion 34b of the exterior member 34) is in direct contact with the other (the heat receiving portion 36a of the heat pipe 36), or another member. It is indirect contact through

  The heat receiving part 36a is provided at a position away from the circuit element 32c in the thickness direction of the ECU 32. The heat receiving portion 36a is provided at a position away from these in the thickness direction, corresponding to the microcomputer element, the injector driver element, and the like that are the circuit elements 32c serving as a heat generation source in the ECU 32. Thereby, it becomes easy to receive heat by the heat receiving part 36a from the circuit element 32c used as a heat generating source.

  3 described above is also a cross-sectional view taken along the line DD of FIG. The heat radiating portions 36b of the plurality of heat pipes 36 are provided so as to extend in the vertical direction Z as shown in FIGS. The heat radiating portion 36b is attached to the second attached portion 34j of the insertion portion 34c of the exterior member 34 by soldering or the like. Thereby, the heat radiating part 36 b of the heat pipe 36 is thermally connected to the insertion part 34 c of the exterior member 34. Here, the term “thermally connected” means that one of a plurality of members (the insertion portion 34c of the exterior member 34) is in direct contact with the other (the heat radiating portion 36b of the heat pipe 36) or other members are connected. It is indirect contact through.

  The plurality of heat radiating fins 38 are provided integrally with the insertion portion 34 c of the exterior member 34. Each radiation fin 38 is formed in a plate shape extending in the vertical direction Z. The heat radiating fins 38 protrude in the vehicle front-rear direction X from the outer surface of the heat absorbing portions 34 h and are arranged in parallel in the vehicle width direction Y. Each heat radiation fin 38 is disposed in the heat radiation space 28. The heat radiating fins 38 are for receiving heat from the heat radiating portion 36 b of the heat pipe 36 and promoting heat radiating to the heat radiating space 28.

FIG. 8A is a front view showing a protective member 46 (described later) together with the exterior member 34, and FIG. 8B is a view showing a state in which the exterior member 34 is removed from the protective member 46.
The exterior member 34 includes a placement portion 34m that is placed on the peripheral surface of the mounting hole 18c from the engine room 12 side (see also FIGS. 3 and 4). A protective member 46 is interposed between the exterior member 34 and the mounting hole 18 c of the fender apron panel 18. The protection member 46 is made of a material such as a resin having a lower heat transfer coefficient than the exterior member 34 as a material. The protection member 46 is for protecting the exterior member 34 from direct contact with the mounting hole 18.

  Specifically, the protective member 46 includes a cylindrical portion 46a that is inserted into the mounting hole portion 18c of the fender apron panel 18 from the engine room 12 side, and a stepped portion that expands from the opening end of the cylindrical portion 46a on the engine room 12 side. 46b.

  A through hole 46c is formed inside the cylindrical part 46a, and the through hole 46c is shaped so that the insertion part 34c of the exterior member 34 can be inserted through the inside from the engine room 12 side toward the heat radiation space 28 side. Formed. The cylindrical portion 46a is interposed between the inner wall surface of the attachment hole portion 18c and the insertion portion 34c so as to surround the root portion of the insertion portion 34c of the exterior member 34.

  The step 46b is formed in an annular shape that extends along the peripheral surface of the mounting hole 18c on the engine room 12 side. The protection member 46 is positioned with respect to the attachment hole 18c by engaging with the peripheral surface of the attachment hole 18c. The stepped portion 46b is interposed between the peripheral surface of the mounting hole 18c and the placement portion 34m of the exterior member 34 so as to surround the base portion of the insertion portion 34c of the exterior member 34. The exterior member 34 is fixed in a state in which the placement portion 34m is in contact with the peripheral surface of the mounting hole portion 18c via the step portion 46b of the protection member 46.

The effect by the heat dissipation structure 31 of the above electronic components is demonstrated.
The ECU 32 has heat due to the heat generated by the circuit element 32c serving as a heat generation source, and the heat is transmitted from the case 32a to the inner fin 32e. The heat of the ECU 32 is transmitted from the inner fin 32e to the exterior member 34, and the heat receiving portion 36a of the heat pipe 36 receives the heat transmitted from the ECU 32 via the exterior member 34. The heat pipe 36 transmits the heat received by the heat receiving portion 36 a to the heat radiating portion 36 b, and the heat radiating portion 36 b radiates the transmitted heat to the heat radiating space 28 via the heat radiating fins 38. As a result, according to the heat dissipation structure 31 for electronic components, the ECU 32 can be cooled using heat conduction by the heat pipe 36 without using an electric device such as an electric fan. Therefore, the ECU 32 can be cooled continuously and stably with no power source.

  In addition, the ECU 32 can be cooled without providing the vehicle body 10 with a duct for taking cooling air from the outside into the engine room 12, and it is not necessary to secure an extra space for the duct in the vehicle body 10. Therefore, it is possible to reduce the size of the vehicle body 10 while cooling the ECU 32.

  Further, the heat radiation space 28 provided between the fender liner 26 and the dash panel 16 is normally a dead space in which no large parts are mounted. Since the heat radiating fins 38 of the electronic component unit 30 are provided in such a heat radiating space 28, the ECU 32 is cooled using heat conduction by the heat pipe 36 without hindering the mounting of other components in the engine room 12. it can.

  The protective member 46 is interposed between the insertion portion 34 c of the exterior member 34 and the inner wall surface of the attachment hole portion 18 c of the fender apron panel 18, and the placement portion 34 m and the attachment hole of the exterior member 34. It is interposed between the peripheral surface of the part 18c. As a result, the exterior member 34 is protected from direct contact with the mounting hole 18c, so that heat transfer from the fender apron panel 18 exposed to the high temperature engine room 12 to the heat pipe 36 and the heat radiating fin 38 through the exterior member 34 is performed. Can be prevented. Therefore, it is possible to prevent the heat transfer function from being lowered due to the heat of the fender apron panel 18 being transmitted to the heat pipe 36 and the heat radiation function from being lowered due to the heat being transferred to the heat radiating fins 38.

  Further, a case is considered in which the insertion portion 34c of the exterior member 34 is inserted in the direction P (see FIG. 8B) toward the heat radiation space 28 through the attachment hole 18c. In this case, the cylindrical portion 46a of the protection member 46 can suppress interference between the heat radiation fin 38 of the insertion portion 34c and the inner wall surface of the mounting hole portion 18c, and protect the fender apron panel 18 and the heat radiation fin 38 from the interference. it can.

  In the above, this invention was demonstrated based on the Example. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are within the scope of the present invention.

  The exterior member 34 may be in direct contact with an electronic component such as the ECU 32 without contacting through the heat conductive sheet 44. In this case, in order to increase the contact area between the exterior member 34 and the electronic component, the surface of the electronic component may be formed flat and both may be brought into surface contact. The surface of the electronic component here corresponds to the surface of the case 32a of the ECU 32 in the example of FIG.

  Further, the heat radiating space 28 in which the heat radiating portion 36 b of the heat pipe 36 is disposed has been described as being provided between the fender liner 26 and the dash panel 16. The position at which the heat dissipation space 28 is provided is not limited to this, and may be provided, for example, inside a fender panel serving as a wall section that defines the engine room 12. Since the inside of the fender panel also becomes a dead space in which large components are not normally mounted, the ECU 32 can be cooled using heat conduction by the heat pipe 36 without hindering mounting of other members in the engine room 12.

DESCRIPTION OF SYMBOLS 12 ... Engine room, 18 ... Fender apron panel (wall part) 28 ... Space for heat dissipation, 30 ... Electronic component unit, 31 ... Heat dissipation structure of electronic component, 32 ... ECU (electronic component), 34 ... Exterior member, 34b ... Cover 36, heat pipe (heat transfer member), 36a ... heat receiving part, 36b ... heat radiating part, 38 ... heat radiating fin, 46 ... protective member.

Claims (1)

The engine room is separated from the engine room through a cover part that covers and contacts the electronic part disposed in the engine room, and a mounting hole formed in a wall part that defines the engine room. An exterior member having an insertion portion that is inserted toward the heat dissipation space;
A heat receiving portion thermally connected to the cover portion, and a heat radiating portion thermally connected to the insertion portion, and transmitting heat received by the heat receiving portion to the heat radiating portion. A thermal member;
A heat dissipating fin for promoting heat dissipation to the heat dissipating space of the heat received from the heat dissipating part, provided in the insertion part;
A heat dissipation structure for an electronic component, comprising: a protective member interposed between the exterior member and the attachment hole portion, and protecting the exterior member from contact with the attachment hole portion.

Images