loop construct

Abstract

By shortening the heat dissipation distance, high heat dissipation performance is achieved. [Solution] The circuit configuration 10 comprises a heat-generating component having a terminal 31 that generates heat when energized, a columnar conductor 20 which is made of a solid columnar shape and has a terminal 31 connected to a first end 21, and a bus bar 40 on which the columnar conductor 20 is arranged on a first surface 41 and an external cooling member 70 is arranged on a second surface 42 opposite to the first surface 41. The bus bar 40 has a connection hole 43 that penetrates between the first surface 41 and the second surface 42 in the thickness direction, and the columnar conductor 20 has a connection projection 23 at the second end 22 opposite to the first end 21 that protrudes in the direction from the first surface 41 to the second surface 42 and is inserted into the connection hole 43. The protruding end face 24 of the connection projection 23 is housed inside the connection hole 43 in such a manner that it does not protrude outside the connection hole 43 from the second surface 42, and the outer edge of the protruding end face 24 is joined to the inner wall of the connection hole 43.

Description

Technical Field

[0001] The present disclosure relates to a circuit assembly.

Background Art

[0002] Conventionally, as a technique for electrically connecting a terminal to a bus bar without using bolts and nuts, an electrical connection box described in Japanese Patent Laid-Open No. 2001-238329 (Patent Document 1 below) is known. This electrical connection box includes an electrical connection box main body and a cover openably and closably supported on the electrical connection box main body via a hinge. A bus bar is installed in the electrical connection box main body, and a terminal is placed on the bus bar in an overlapping manner. A pressing portion is integrally formed on the cover, and when the cover is closed, the pressing portion presses the terminal downward, whereby the terminal and the bus bar are electrically connected to each other.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the electrical connection box described above, a metallic heat radiating member with excellent heat radiation characteristics is provided, but it is a sheet metal heat radiating member with a small heat capacity, so there is a risk that the heat drawing performance is not sufficient when using a heat generating component that generates heat due to energization. Also, a method of using a plate-shaped bus bar as a heat radiation path instead of a sheet metal heat radiating member is also conceivable. However, in the connection method of fastening the bus bar with bolts and nuts, in order to provide a fastening surface, multiple bending of the bus bar occurs, which results in poor space efficiency, and additionally, the distance from the heat source to the heat radiation surface (heat drawing distance) becomes long.

[0005] The present disclosure has been completed based on the above circumstances, and an object thereof is to achieve high heat radiation performance by shortening the heat drawing distance. [Means for solving the problem]

[0006] The circuit configuration of the present disclosure comprises a heat-generating component having terminals and generating heat when energized, a columnar conductor having a columnar solid structure with the terminals connected to its first end, and a busbar having the columnar conductor on its first surface and an external cooling member on its second surface opposite to the first surface, wherein the busbar has a connection hole penetrating between the first surface and the second surface in the thickness direction, the columnar conductor has a connection projection at its second end opposite to the first end that protrudes from the first surface toward the second surface and is inserted into the connection hole, the protruding end face of the connection projection is housed inside the connection hole in such a manner that it does not protrude from the second surface toward the outside of the connection hole, and the outer edge of the protruding end face is joined to the inner wall of the connection hole. [Effects of the Invention]

[0007] According to this disclosure, high heat dissipation can be achieved by shortening the heat dissipation distance. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a cross-sectional view of the circuit configuration and the external cooling member in the embodiment. [Figure 2] Figure 2 is a cross-sectional view showing how a columnar conductor is joined to a busbar and how terminals are bolted to the columnar conductor. [Modes for carrying out the invention]

[0009] [Description of Embodiments in this Disclosure] First, embodiments of this disclosure will be listed and described.

[0010] [1] The circuit configuration of the present disclosure comprises a heat-generating component having terminals and generating heat when energized; a columnar solid conductor having a first end to which the terminals are connected; and a busbar having the columnar conductor on a first surface and an external cooling member on a second surface opposite to the first surface, wherein the busbar has a connection hole penetrating between the first surface and the second surface in the thickness direction, the columnar conductor has a connection projection at the second end opposite to the first end that protrudes from the first surface toward the second surface and is inserted into the connection hole, the protruding end face of the connection projection is housed inside the connection hole in such a manner that it does not protrude from the second surface toward the outside of the connection hole, and the outer edge of the protruding end face is joined to the inner wall of the connection hole.

[0011] The heat generated by the heat-generating components when power is applied is transferred to the external cooling element via the terminals, columnar conductors, and busbars. The columnar conductors are constructed as solid columns and have a large heat capacity, enabling higher heat dissipation compared to sheet metal heat dissipation elements. Furthermore, using columnar conductors allows for heat to be drawn from the terminals to the busbars over the shortest possible distance.

[0012] By inserting the connecting projection of a columnar conductor into the connecting hole of a busbar, with the protruding end face of the connecting projection housed inside the connecting hole, and joining the outer edge of the protruding end face to the inner wall of the connecting hole, the columnar conductor and the busbar can be electrically and thermally connected. For example, when joining with laser light, the laser output required for joining can be kept low by precisely laser processing the corner between the outer edge of the protruding end face and the inner wall of the connecting hole. As a result, the heat-generating components are electrically and thermally connected to the busbar via terminals and columnar conductors.

[0013] In the circuit configuration described in [2][1], it is preferable that the connecting protrusion is lightly press-fitted into the connecting hole. By lightly press-fitting the connecting projection into the connecting hole, it becomes unnecessary to manually hold the outer edge of the protruding end face and the inner wall of the connecting hole together to prevent them from shifting, thus facilitating the joining process.

[0014] In the circuit configuration described in [3][1] or [2], it is preferable that the columnar conductor has a protruding surface extending from the base end of the connecting projection to the outer surface of the columnar conductor. When inserting the connecting projection into the connecting hole, the position of the connecting projection in the insertion direction is determined by the contact of the projection surface with the first surface of the busbar, thus facilitating the insertion process.

[0015] In the circuit configuration described in [4][3], the busbar includes a first busbar having the first surface and a second busbar having the second surface, and the connection hole has a large-diameter hole formed in the first busbar and a small-diameter hole formed in the second busbar that is smaller in diameter than the large-diameter hole, and it is preferable that the connection projection protruding from the large-diameter hole toward the second busbar is inserted into the small-diameter hole and the outer edge of the protruding end face of the connection projection is joined to the inner wall of the small-diameter hole.

[0016] Multiple busbars, including a first busbar and a second busbar, can be simultaneously connected to a columnar conductor. Since the edge of the large-diameter hole in the first busbar is sandwiched between the abutment surface and the second busbar, the first busbar and the second busbar can be electrically and thermally connected to the columnar conductor.

[0017] In the circuit configuration described in any of [5], [1] to [4], it is preferable that the terminal is bolted from above to the first end of the columnar conductor. Because there is more space above the terminal compared to below the busbar, it is easier to bolt the first end of the columnar conductor to it.

[0018] [Details of the embodiments of this disclosure] Embodiments of the present disclosure will be described below. The present disclosure is not limited to these examples, and is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. In each drawing, for convenience of explanation, a part of the configuration may be exaggerated or simplified. Further, the dimensional ratio of each part may differ among the drawings. The term "orthogonal" as used herein is not limited to strictly orthogonal cases, and also includes approximately orthogonal cases within the range where the functions and effects of the present embodiment are achieved.

[0019] Further, the term "opposing" as used herein means that surfaces or members are positioned facing each other, and includes not only the case where they are completely facing each other but also the case where they are partially facing each other. Further, the term "opposing" as used herein includes both the case where a member other than the two parts is interposed between the two parts and the case where nothing is interposed between the two parts. In the following description, the direction indicated by arrow Z is referred to as upper, the direction indicated by arrow X is referred to as front, and the direction indicated by arrow Y is referred to as right. Note that for a plurality of identical members, reference numerals are only given to some members, and reference numerals for other members may be omitted.

[0020] <Embodiment> >(Overall configuration of circuit assembly 10) As shown in FIG. 1, the circuit assembly 10 includes a columnar conductor 20, a fuse 30 that has a terminal 31 and generates heat when energized, and a bus bar 40. The bus bar 40 is disposed on an external cooling member 70. The fuse 30 is an example of a heat-generating component in the present disclosure, and the heat-generating component is not limited to the fuse 30, and may be an electric circuit component such as a relay. Heat generated inside the fuse 30 is transferred from the terminal 31 to the columnar conductor 20.

[0021] The external cooling member 70 includes a metal case 71, a metal plate 72, and a sealing member 73. The metal case 71 has a flow path recess 71A. The metal plate 72 is fixed to the metal case 71 via the sealing member 73 so as to close the flow path recess 71A. Cooling water 75 is filled in the flow path 74 defined by the flow path recess 71A and the metal plate 72. That is, the external cooling member 70 of the present embodiment is a water-cooled type in which the cooling water 75 is circulated.

[0022] The circuit assembly 10 is, for example, a circuit component that constitutes an electrical connection box such as a junction box (JB) mounted on an automobile. The circuit assembly 10 includes a plurality of electrical circuit components such as a plurality of relays and fuses, but in the present embodiment, only the portion where one fuse 30 is disposed will be described. The circuit assembly 10 may also include other circuit components connected to the terminal 31 on the right side in the drawing.

[0023] (Configuration of Columnar Conductor 20) The columnar conductor 20 is, for example, a member obtained by cutting a conductive metal material. The columnar conductor 20 is formed into a columnar solid shape, and includes a first end 21 and a second end 22 opposite to the first end 21. A terminal 31 is connected to the first end 21. A bus bar 40 is connected to the second end 22.

[0024] As the columnar conductor 20, a high-strength metal material (for example, high-strength aluminum such as 6000-series aluminum alloy, copper, etc.) may be used, or pure aluminum (1000-series aluminum) may be used from the viewpoints of conductivity and weight reduction.

[0025] (Configuration of Bus Bar 40) The bus bar 40 is, for example, a member obtained by punching and bending a conductive metal plate. The bus bar 40 has a second surface 42 close to the external cooling member 70, a first surface 41 opposite to the second surface 42, and a connection hole 43 penetrating between the first surface 41 and the second surface 42 in the plate thickness direction.

[0026] The busbar 40 includes a first busbar 40A having a first surface 41 and a second busbar 40B having a second surface 42. In this embodiment, the busbar 40 is composed of two busbars (the first busbar 40A and the second busbar 40B), but it may also be composed of three or more busbars.

[0027] For the first busbar 40A and the second busbar 40B, high-strength busbars (for example, high-strength aluminum such as 6000 series aluminum alloy, copper, etc.) may be used, or pure aluminum (1000 series aluminum) may be used from the viewpoint of conductivity and weight reduction.

[0028] (Connection structure between fuse 30 and columnar conductor 20) The terminal 31 of the fuse 30 has a through hole 31A. On the other hand, a threaded hole 25 is formed in the first end 21 of the columnar conductor 20. The fuse 30 is fixed to the columnar conductor 20 and electrically and thermally connected to the columnar conductor 20 when the bolt B passes through the through hole 31A and fastens to the threaded hole 25 of the columnar conductor 20.

[0029] (Connection structure between busbar 40 and columnar conductor 20) The busbar 40 has a connection hole 43, which is a large-diameter hole 43A formed in the first busbar 40A and a small-diameter hole 43B formed in the second busbar 40B. The small-diameter hole 43B is formed to be smaller in diameter than the large-diameter hole 43A. The columnar conductor 20 has a connection projection 23 at the second end 22 that protrudes from the first surface 41 toward the second surface 42 and is inserted into the connection hole 43.

[0030] The connecting projection 23 is a cylindrical shaft, and the connecting hole 43 is a circular space. The diameter of the connecting projection 23 is smaller than the diameter of the large diameter hole 43A that makes up the connecting hole 43, and is the same as or slightly smaller than the diameter of the small diameter hole 43B that makes up the connecting hole 43. Therefore, when the connecting projection 23 is inserted into the connecting hole 43 from above, it passes through the large diameter hole 43A and is then lightly press-fitted into the small diameter hole 43B.

[0031] Since the connecting projection 23 is lightly press-fitted into the small-diameter hole 43B, the outer edge of the protruding end face 24 of the connecting projection 23 and the inner wall of the small-diameter hole 43B are positioned perpendicular to each other without any gaps. By performing laser processing on the corner between the outer edge of the protruding end face 24 and the inner wall of the small-diameter hole 43B, a joint 24A is formed. As a result, the hole edge of the large-diameter hole 43A in the first busbar 40A is sandwiched between the columnar conductor 20 and the second busbar 40B, and the columnar conductor 20 and the busbar 40 are electrically and thermally connected. In this way, only the joint 24A can be laser-processed with pinpoint precision, so the laser output required for joining can be kept low.

[0032] (Operation of circuit component 10) Next, the operation of the circuit configuration 10, which is configured as described above, will be explained. The method for connecting the columnar conductors 20 is carried out in the procedure shown in Figures 2(A) to (C). As shown in Figure 2(A), the first busbar 40A and the second busbar 40B are stacked and arranged, and the connecting protrusions 23 of the columnar conductors 20 are inserted into the connecting holes 43 from above. The connecting protrusions 23 that protrude downward from the large-diameter hole 43A are lightly press-fitted into the small-diameter hole 43B.

[0033] The columnar conductor 20 has a contact surface 26 extending from the base end of the connecting projection 23 to the outer surface of the columnar conductor 20, and the position of the connecting projection 23 in the insertion direction is determined to be the correct position when this contact surface 26 contacts the first surface 41. The protruding end face 24 of the connecting projection 23 remains inside the small diameter hole 43B and is housed inside the small diameter hole 43B in such a manner that it does not protrude from the second surface 42 to the outside of the small diameter hole 43B.

[0034] When the connecting projection 23 is inserted into the connecting hole 43 in the correct position, the outer edge of the protruding end face 24 is positioned without any gaps against the inner wall of the small-diameter hole 43B. Next, a laser beam is shone from the laser processing machine L towards the corner between the outer edge of the protruding end face 24 and the inner wall of the small-diameter hole 43B. By scanning the galvanometer mirror, the corner is shone all around, and the corner between the outer edge of the protruding end face 24 and the inner wall of the small-diameter hole 43B is joined by the laser beam. As a result, the columnar conductor 20 and the busbar 40 are electrically and thermally connected.

[0035] Next, as shown in Figure 2(C), after placing the terminal 31 on the first end 21 of the columnar conductor 20, the bolt B is inserted into the through hole 31A from above and fastened to the threaded hole 25 of the columnar conductor 20, thereby fixing the terminal 31 to the first end 21 of the columnar conductor 20. This connects the fuse 30 and the columnar conductor 20 electrically and thermally.

[0036] The busbar 40 of the circuit component 10 is placed on the external cooling member 70. The heat generated by the fuse 30 is transferred to the metal plate 72 via the terminal 31, the columnar conductor 20, and the busbar 40. Since the metal plate 72 is constantly cooled by the cooling water 75, the heat from the fuse 30 is dissipated by the external cooling member 70. Because the terminal 31 and the busbar 40 are connected by the columnar conductor 20 over the shortest distance, high heat dissipation can be achieved.

[0037] (Effects of the embodiment) (1) The circuit configuration 10 comprises a fuse 30 having a terminal 31 that generates heat when energized, a columnar conductor 20 which is made of a solid columnar shape and has a terminal 31 connected to a first end 21, and a bus bar 40 on which the columnar conductor 20 is arranged on a first surface 41 and an external cooling member 70 is arranged on a second surface 42 opposite to the first surface 41, wherein the bus bar 40 has a connection hole 43 that penetrates between the first surface 41 and the second surface 42 in the thickness direction, the columnar conductor 20 has a connection projection 23 at the second end 22 opposite to the first end 21 that protrudes in the direction from the first surface 41 to the second surface 42 and is inserted into the connection hole 43, the protruding end face 24 of the connection projection 23 is housed inside the connection hole 43 in such a manner that it does not protrude outside the connection hole 43 from the second surface 42, and the outer edge of the protruding end face 24 is joined to the inner wall of the connection hole 43.

[0038] The heat generated in the fuse 30 when power is applied is transferred to the external cooling member 70 via the terminal 31, the columnar conductor 20, and the busbar 40. The columnar conductor 20 is made of a solid columnar structure and has a large heat capacity, so it can achieve higher heat dissipation compared to sheet metal heat dissipation members. In addition, by using the columnar conductor 20, heat can be drawn from the terminal 31 to the busbar over the shortest distance.

[0039] By inserting the connecting projection 23 of the columnar conductor 20 into the connecting hole 43 of the busbar 40, with the protruding end face 24 of the connecting projection 23 housed inside the connecting hole 43, and joining the outer edge of the protruding end face 24 to the inner wall of the connecting hole 43 with a laser beam, the columnar conductor 20 and the busbar 40 can be electrically and thermally connected. At that time, by precisely laser processing the corner between the outer edge of the protruding end face 24 and the inner wall of the connecting hole 43, the output of the laser beam required for joining can be kept to a minimum. As a result, the fuse 30 is electrically and thermally connected to the busbar 40 via the terminal 31 and the columnar conductor 20.

[0040] (2) The connecting projection 23 is lightly press-fitted into the connecting hole 43. By lightly press-fitting the connecting projection 23 into the connecting hole 43, it is not necessary to hold the outer edge of the protruding end face 24 and the inner wall of the connecting hole 43 in place to prevent them from shifting when joining them, thus facilitating the joining process.

[0041] (3) The columnar conductor 20 has a protruding surface 26 that extends from the base end of the connecting projection 23 to the outer surface of the columnar conductor 20. When inserting the connecting projection 23 into the connecting hole 43, the position of the connecting projection 23 in the insertion direction is determined by the contact of the projection surface 26 with the first surface 41 of the bus bar 40, thus facilitating the insertion work.

[0042] (4) The bus bar 40 includes a first bus bar 40A having a first surface 41 and a second bus bar 40B having a second surface 42. The connecting hole 43 has a large diameter hole 43A formed in the first bus bar 40A and a small diameter hole 43B formed in the second bus bar 40B which is smaller in diameter than the large diameter hole 43A. A connecting projection 23 protruding from the large diameter hole 43A towards the second bus bar 40B is inserted into the small diameter hole 43B, and the outer edge of the protruding end face 24 of the connecting projection 23 is joined to the inner wall of the small diameter hole 43B.

[0043] Multiple busbars, including the first busbar 40A and the second busbar 40B, can be connected to the columnar conductor 20 simultaneously. Since the edge of the large-diameter hole 43A in the first busbar 40A is sandwiched between the abutment surface 26 and the second busbar 40B, the first busbar 40A and the second busbar 40B can be electrically and thermally connected to the columnar conductor 20.

[0044] (5) The terminal 31 is bolted from above to the first end 21 of the columnar conductor 20. Since there is more space above the terminal 31 compared to below the busbar 40, it is easier to bolt the first end 21 of the columnar conductor 20 to it.

[0045] <Other Embodiments> The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0046] In the above embodiment, the outer edge of the protruding end face 24 is shown as being joined to the inner wall of the connecting hole 43 by laser light, but it may also be joined by ultrasonic welding or by crimping.

[0047] In the above embodiment, the connecting projection 23 is lightly press-fitted into the connecting hole 43, but this is not required. The connecting projection 23 may be fixed to the connecting hole 43 by normal press-fitting, or it may be fixed by laser processing without press-fitting.

[0048] In the above embodiment, the columnar conductor 20 was provided with abutment surface 26, but the busbar 40 may also be provided with abutment surface.

[0049] In the above embodiment, the bus bar 40 is composed of a first bus bar 40A and a second bus bar 40B, but it may also be composed of a single bus bar.

[0050] In the above embodiment, the terminal 31 is bolted to the first end 21 of the columnar conductor 20, but the terminal 31 may also be crimped and fixed to the first end 21 of the columnar conductor 20.

[0051] In the above embodiment, the busbar 40 is in direct contact with the external cooling member 70, but the busbar 40 may be in contact with the external cooling member 70 via a heat dissipation sheet such as silicone resin or grease. [Explanation of symbols]

[0052] 10:Circuit construct 20: Columnar conductor 21:First end 22:Second end 23: Connecting protrusion 24:Protruding end surface 24A: Joint 25: Screw hole 26: Immediately 30: Fuse (heat-generating component) 31: Terminals 31A: Through hole 40: Bus bar 40A: First bus bar 40B: Second bus bar 41: 1st page 42:Second side 43: Connection hole 43A: Large diameter hole 43B: Small diameter hole 70: External cooling components 71: Metal case 71A: Flow channel recess 72: Metal plate 73: Sealing material 74: Flow channel 75: Cooling water B: Bolt L: Laser processing machine

Claims

1. A heat-generating component having terminals and generating heat when power is applied, A columnar conductor is constructed as a solid columnar structure, with the terminal connected to its first end, A circuit configuration comprising a busbar on which the columnar conductor is arranged on the first surface and an external cooling member is arranged on the second surface opposite to the first surface, The busbar has a connecting hole that penetrates between the first surface and the second surface in the thickness direction, The columnar conductor has a connecting projection at the second end opposite to the first end that protrudes in the direction from the first surface toward the second surface and is inserted into the connecting hole. The protruding end face of the connecting projection is housed inside the connecting hole in such a manner that it does not protrude from the second surface to the outside of the connecting hole. The outer edge of the protruding end face is joined to the inner wall of the connection hole, forming a circuit component.

2. The circuit component according to claim 1, wherein the connecting projection is lightly press-fitted into the connecting hole.

3. The circuit configuration according to claim 1 or claim 2, wherein the columnar conductor has a protruding surface extending from the base end of the connecting projection to the outer surface of the columnar conductor.

4. The busbar includes a first busbar having the first surface and a second busbar having the second surface, and the connecting hole has a large-diameter hole formed in the first busbar and a small-diameter hole formed in the second busbar that is smaller in diameter than the large-diameter hole. The circuit configuration according to claim 3, wherein the connecting projection protruding from the large-diameter hole toward the second busbar is inserted into the small-diameter hole, and the outer edge of the protruding end face of the connecting projection is joined to the inner wall of the small-diameter hole.

5. The circuit configuration according to claim 1 or claim 2, wherein the terminal is bolted from above to the first end of the columnar conductor.

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