Electric connection box

Abstract

To provide an electric connection box excellent in heat radiation.SOLUTION: An electric connection box 1 includes: an electronic component 10; a circuit board 20 on which the electronic component 10 is mounted; a case 30 having a box shape in which the electronic component 10 and the circuit board 20 are stored, the case having a cylindrical first protrusion 34 which protrudes from an inner wall surface of the case 30 so as to surround a terminal 11 of the electronic component 10 and a second protrusion 35 protruding from an outer wall surface of the case 30; and a heat transfer member 40 disposed in a cylinder of the first protrusion 34 and coming into contact with both of a cylinder inner surface of the first protrusion 34 and the terminal 11. The first protrusion 34 is provided on an inner wall surface of one box wall 33 of the case 30, and the second protrusion 35 is provided on the outer wall surface of the box wall 33. The heat transfer member 40 is a soft body filled in the cylinder of the first protrusion 34.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electrical junction box in which a circuit board on which electronic components are mounted is housed in a case. [Background technology]

[0002] Conventionally, there have been proposed electrical junction boxes to be mounted on vehicles, etc. For example, one conventional electrical junction box has an overall box-like shape and includes electronic components such as relays and fuses, a circuit board on which the electronic components are mounted, and a case for storing the electronic components and the circuit board (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-005719 A [Patent Document 2] JP 2003-218563 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned type of electrical connection box, Joule heat is generally generated in the internal circuit of the electronic component or in contacts between the terminals of the electronic component and the circuit pattern of the circuit board when the electronic component is in operation, due to the passage of electricity. In particular, a large amount of Joule heat is generated in an electrical connection box using a high-voltage relay. On the other hand, such a heat generating portion is usually stored in a case and isolated from the outside for waterproofing or the like. Furthermore, the air in such an isolated space also acts as a heat insulator. For these reasons, depending on the magnitude of the Joule heat generated in the heat generating portion, it may be difficult to sufficiently dissipate the Joule heat to the outside by natural heat dissipation alone. From the viewpoint of proper operation of the electrical connection box for a long period of time, it is desirable to efficiently dissipate the heat generated in the heat generating portion when electricity is applied to the outside.

[0005] An object of the present invention is to provide an electrical junction box having excellent heat dissipation properties. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the electrical junction box according to the present invention has the following features.

[0007] Electronic components, a circuit board on which the electronic components are mounted; a box-shaped case for storing the electronic components and the circuit board, the case having a first cylindrical protrusion protruding from an inner wall surface of the case so as to surround a terminal of the electronic components, and a second protrusion protruding from an outer wall surface of the case; a heat transfer member disposed inside the cylinder of the first protrusion and in contact with both an inner cylinder surface of the first protrusion and the terminal; It is an electrical junction box. Effect of the Invention

[0008] According to the electrical connection box of the present invention, a heat transfer member is disposed inside the cylinder of the cylindrical first protrusion provided on the inner wall surface of the case, and the heat transfer member is in contact with both the terminal of the electronic component and the cylindrical inner surface of the first protrusion. As a result, Joule heat generated at the internal circuit of the electronic component or at the contact between the terminal of the electronic component and the circuit pattern of the circuit board during energization is transferred in this order to the terminal of the electronic component, the heat transfer member, and the first protrusion, and is dissipated to the outside from the box wall of the case on which the first protrusion is provided or the second protrusion provided on the outer wall surface of the case. In other words, heat generated during energization is transferred from the heat generating location to the outside of the electrical connection box (particularly, between the terminal of the electronic component and the cylindrical inner surface of the first protrusion) without passing through an air layer with low thermal conductivity. Therefore, compared to the case in which the electronic component and the circuit board are simply stored in the case, the Joule heat generated during energization can be dissipated to the outside more efficiently. Therefore, the electrical connection box of this configuration has excellent heat dissipation properties.

[0009] The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by reading the following description of the embodiment of the present invention (hereinafter, referred to as "embodiment") with reference to the accompanying drawings. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a main cross-sectional view of an electrical junction box according to an embodiment of the present invention. [Diagram 2] 2 is a perspective view showing a first protrusion provided on a bottom wall of the lower case shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Embodiment> An electric junction box 1 according to an embodiment of the present invention will be described below with reference to the drawings. The electric junction box 1 shown in Fig. 1 is typically mounted on a vehicle or the like for use. As shown in Fig. 1, the electric junction box 1 includes a plurality of electronic components 10, a circuit board 20 on which the plurality of electronic components 10 are mounted, a box-shaped case 30 in which the plurality of electronic components 10 and the circuit board 20 are stored, and a heat transfer member 40 disposed inside the case 30. Note that wires, bus bars, and the like that connect the electric junction box 1 to an external power source or an external load are omitted from the illustration.

[0012] For ease of explanation, the "front-rear direction", "up-down direction", and "left-right direction" are defined below as shown in Figs. 1 and 2. The "front-rear direction", "up-down direction", and "left-right direction" are mutually perpendicular. The up-down direction coincides with the up-down direction (vertical direction) of the vehicle when the electrical junction box 1 is mounted on the vehicle. On the other hand, the front-rear direction and left-right direction do not necessarily have to coincide with the front-rear direction and left-right direction of the vehicle when the electrical junction box 1 is mounted on the vehicle. The configuration of the electrical junction box 1 will be described below.

[0013] As shown in FIG. 1, the case 30 has a lower case 31 having a box shape that opens upward and an upper case 32 having a box shape that opens downward. The upper case 32 is assembled to the lower case 31 so as to close the upper opening of the lower case 31, thereby forming the case 30. The case 30 typically has a substantially rectangular box shape that extends in the front-rear, up-down, and left-right directions. The material of the case 30 is not particularly limited, but in this example, the box wall that constitutes the case 30 (lower case 31 + upper case 32) is made of metal in consideration of the thermal conductivity (heat dissipation) of the case 30 itself. In addition, in consideration of the waterproofing of the electronic components 10 and the like stored inside the case 30, the inside and outside of the case 30 obtained by assembling the upper case 32 to the lower case 31 are substantially separated by the box wall that constitutes the case 30.

[0014] A resin circuit board 20 is stored inside the case 30. The circuit board 20 is fixed to the lower case 31 or the upper case 32 by a predetermined locking structure (not shown). The circuit board 20 typically has a rectangular flat plate shape extending in the front-rear and left-right directions. A conductive circuit pattern (not shown) having a predetermined shape is provided on the upper surface (or upper and lower surfaces) of the circuit board 20.

[0015] A plurality of electronic components 10 are mounted on the upper surface of the circuit board 20 so as to be spaced apart from one another. The electronic components 10 are typically relays or fuses. Terminals 11 of each of the plurality of electronic components 10 are arranged to pass vertically through corresponding through holes (not shown) provided in the circuit board 20, and are electrically connected to the circuit pattern of the circuit board 20. A tip side (lower end side) of each terminal 11 protrudes toward the lower surface side of the circuit board 20 so as to face the bottom wall 33 of the lower case 31 with a gap therebetween in the vertical direction.

[0016] On the inner wall surface (upper surface) of a bottom wall 33 (typically a rectangular flat box wall extending in the front-rear and left-right directions) of a lower case 31 constituting the case 30, a cylindrical first protrusion 34 protruding upward is provided at each of a plurality of locations corresponding to lower positions of the terminals 11 of the plurality of electronic components 10 so as to surround the corresponding terminal 11. As shown in FIG. 2, the first protrusion 34 typically has a cylindrical shape that opens upward.

[0017] A heat transfer member 40 having excellent heat transfer properties is disposed inside each of the cylinders of the multiple first protrusions 34. The heat transfer member 40 is preferably a soft material (e.g., a gel-like heat transfer material or a paste-like heat transfer material) that fills the inside of the cylinder of the first protrusions 34. Specifically, the heat transfer member 40 may be a mixture of a soft base material (e.g., grease or silicone) and a heat transfer material (e.g., alumina particles). The heat transfer member 40 disposed inside the cylinder of the first protrusions 34 is in contact with both the inner surface of the cylinder of the first protrusions 34 and the terminal 11 disposed inside the cylinder.

[0018] A plurality of second protrusions 35 protruding downward are provided on the outer wall surface (lower surface) of the bottom wall 33 of the lower case 31 constituting the case 30 so as to be spaced apart from each other. The second protrusions 35 typically have a flat plate shape extending in the front-rear direction. The flat plate-shaped second protrusions 35 are also referred to as heat dissipation fins. The configuration of the electrical junction box 1 has been described above.

[0019] <Actions and Effects> As described above, according to the electrical junction box 1 of the present embodiment, the heat transfer member 40 is disposed inside the cylindrical first protrusion 34 provided on the inner wall surface (upper surface) of the bottom wall 33 of the case 30, and the heat transfer member 40 contacts both the terminal 11 of the electronic component 10 and the cylindrical inner surface of the first protrusion 34. As a result, Joule heat generated in the internal circuit of the electronic component 10 or at the contact point between the terminal 11 of the electronic component 10 and the circuit pattern of the circuit board 20 when the electronic component 10 is energized is transferred from the terminal 11 of the electronic component 10 to the first protrusion 34 via the heat transfer member 40, and is dissipated to the outside from the bottom wall 33 of the case 30 where the first protrusion 34 is provided and the box wall other than the bottom wall 33, and the second protrusion 35 provided on the outer wall surface (lower surface) of the bottom wall 33 of the case 30. In other words, heat generated during energization is transferred from the heat generating location to the outside of the electrical junction box 1 (particularly between the terminals 11 of the electronic component 10 and the cylindrical inner surface of the first protrusion 34) without passing through an air layer with low thermal conductivity. Therefore, compared to when the electronic component 10 and the circuit board 20 are simply stored in a case (i.e., when the terminals 11 of the electronic component 10 protruding from the underside of the circuit board 20 are covered by an air layer with low thermal conductivity), Joule heat generated during energization can be dissipated to the outside more efficiently. Therefore, the electrical junction box 1 according to this embodiment has excellent heat dissipation properties.

[0020] Furthermore, according to the electrical junction box 1 of this embodiment, a first protrusion 34 is provided on the inner wall surface of the bottom wall 33 of the case 30, and a second protrusion 35 is provided on the outer wall surface of the same bottom wall 33. This allows Joule heat transferred from the terminals 11 of the electronic component 10 to the first protrusion 34 via the heat transfer member 40 to be quickly dissipated to the outside from the second protrusion 35. Therefore, the electrical junction box 1 of this embodiment has even better heat dissipation properties.

[0021] Furthermore, in the electric junction box 1 according to this embodiment, the heat transfer member 40 is a soft body. As a result, when the electric junction box 1 is mounted on an automobile or the like, even if an external force such as vibration acts on the electric junction box 1, the heat transfer member 40 can be properly maintained in contact with both the terminal 11 of the electronic component 10 and the cylindrical inner surface of the first protrusion 34. Therefore, the electric junction box 1 according to this embodiment can properly maintain a state with excellent heat dissipation properties during actual use.

[0022] <Other forms> The present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the above-described embodiments, and appropriate modifications, improvements, etc. are possible. In addition, the material, shape, size, number, arrangement location, etc. of each component in the above-described embodiments are arbitrary as long as the present invention can be achieved, and are not limited.

[0023] For example, in the above embodiment, the first protrusion 34 is provided on the inner wall surface of the bottom wall 33 of the case 30, and the second protrusion 35 is provided on the outer wall surface of the same bottom wall 33. In contrast to this, the second protrusion 35 may be provided on the outer wall surface of the box wall of the case 30 other than the bottom wall 33 of the case 30 on which the first protrusion 34 is provided.

[0024] Here, the features of the embodiment of the electrical junction box 1 according to the present invention described above will be briefly summarized and listed in the following [1] to [3].

[0025] [1] An electronic component (10); a circuit board (20) on which the electronic component (10) is mounted; a box-shaped case (30) for storing the electronic component (10) and the circuit board (20), the case (30) having a cylindrical first protrusion (34) protruding from an inner wall surface of the case (30) so as to surround a terminal (11) of the electronic component (10), and a second protrusion (35) protruding from an outer wall surface of the case (30); a heat transfer member (40) disposed inside the cylinder of the first protrusion (34) and in contact with both an inner cylinder surface of the first protrusion (34) and the terminal (11); Electrical junction box(1).

[0026] According to the electrical connection box having the configuration of [1] above, a heat transfer member is disposed inside the cylinder of the cylindrical first protrusion provided on the inner wall surface of the case, and this heat transfer member contacts both the terminal of the electronic component and the cylindrical inner surface of the first protrusion. As a result, Joule heat generated at the internal circuit of the electronic component or at the contact between the terminal of the electronic component and the circuit pattern of the circuit board during energization is transferred in this order to the terminal of the electronic component, the heat transfer member, and the first protrusion, and is dissipated to the outside from the box wall of the case on which the first protrusion is provided or the second protrusion provided on the outer wall surface of the case. In other words, heat generated during energization is transferred from the heat generating location to the outside of the electrical connection box (particularly, between the terminal of the electronic component and the cylindrical inner surface of the first protrusion) without passing through an air layer with low thermal conductivity. Therefore, compared to the case in which the electronic component and the circuit board are simply stored in the case, Joule heat generated during energization can be dissipated to the outside more efficiently. Therefore, the electrical connection box having this configuration has excellent heat dissipation properties.

[0027] [2] In the electrical connection box (1) described in [1] above, the first protrusion (34) is provided on the inner wall surface of a predetermined one of the box walls (33) of the case (30), and the second protrusion (35) is provided on the outer wall surface of the box wall (33); Electrical junction box(1).

[0028] According to the electrical junction box having the configuration [2] above, a first protrusion is provided on the inner wall surface of one box wall of the case, and a second protrusion is provided on the outer wall surface of the box wall. That is, the first protrusion and the second protrusion are provided on the inside and outside of a specific box wall, respectively. This allows Joule heat transferred from the terminal of the electronic component to the first protrusion via the heat transfer member to be quickly dissipated to the outside from the second protrusion. Therefore, the electrical junction box having this configuration has even better heat dissipation properties.

[0029] [3] In the electrical connection box (1) according to the above [1] or [2], The heat transfer member (40) is A soft body is filled in the cylinder of the first protrusion (34). Electrical junction box(1).

[0030] According to the electrical junction box having the configuration [3] above, the heat transfer member is a soft material (for example, a gel-like heat transfer member or a paste-like heat transfer member). As a result, when the electrical junction box is mounted on an automobile or the like, even if an external force such as vibration acts on the electrical junction box, the heat transfer member is properly maintained in contact with both the terminals of the electronic component and the cylindrical inner surface of the first protrusion. Therefore, the electrical junction box of this configuration can properly maintain a state with excellent heat dissipation properties during actual use. [Explanation of symbols]

[0031] 1 Electrical junction box 10. Electronic Components 11 Terminal 20 Circuit Board 30 cases 33 Bottom wall (first box wall) 34 1st protrusion 35 Second protrusion 40 Heat transfer material

Claims

1. Electronic components, a circuit board on which the electronic components are mounted; a box-shaped case for storing the electronic components and the circuit board, the case having a first cylindrical protrusion protruding from an inner wall surface of the case so as to surround a terminal of the electronic component, and a second protrusion protruding from an outer wall surface of the case; a heat transfer member disposed within the cylinder of the first protrusion and in contact with both an inner cylinder surface of the first protrusion and the terminal; Electrical junction box.

2. 2. The electrical junction box according to claim 1, The first protrusion is provided on the inner wall surface of a predetermined one of the box walls of the case, and the second protrusion is provided on the outer wall surface of the box wall. Electrical junction box.

3. The electrical junction box according to claim 1 or 2, The heat transfer member is A soft body is filled in the cylinder of the first protrusion. Electrical junction box.

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