circuit components

Abstract

This invention discloses a circuit configuration that can suppress thermal damage to voltage detection lines connected to busbars without increasing the cross-sectional area of ​​the busbars that constitute the current path. [Solution] The circuit configuration 10 includes a busbar 20 that constitutes an energizing path 18, a voltage detection line 26 consisting of an insulated wire 22 and terminals 24 provided at the ends of the insulated wire 22, a voltage detection unit 28 formed by a part of the busbar 20a and to which the terminals 24 of the voltage detection line 26 are connected, and a heat transfer member 32 whose one end is thermally connected to the voltage detection unit 28 and whose other end is thermally connected to the heat dissipation target 16, thereby constituting a heat dissipation path 30 from the voltage detection unit 28 to the heat dissipation target 16.

Description

Technical Field

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

Background Art

[0002] Conventionally, in a circuit component including heat-generating components such as a relay or a fuse that generates heat when energized, a structure for dissipating heat through a bus bar connected to a connection portion of the heat-generating component may be provided. For example, Patent Document 1 discloses a heat dissipation structure in which a part of a bus bar connected to a connection portion of a relay housed in a case is thermally contacted with a heat dissipation target such as a metal housing, and the heat of the relay is transferred to the heat dissipation target through the bus bar.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a circuit component having such a conventional structure, in many cases, a terminal provided at the end of a voltage detection line is fastened to a bus bar constituting an energization path by bolt fastening or the like. Therefore, when a large current flows through the circuit component, the temperature of the bus bar often exceeds 100°C due to energization, exceeding the allowable temperature of the insulation coating covering the core wire extending from the terminal of the voltage detection line, and there is a risk that the voltage detection line may be damaged. On the other hand, it is conceivable to protect the voltage detection line from thermal damage by increasing the cross-sectional area of the bus bar constituting the energization path to suppress heat generation of the bus bar itself, but the circuit component itself inevitably becomes larger, and the development of an effective countermeasure has been desired.

[0005] Therefore, a circuit component is disclosed that can suppress thermal damage to a voltage detection line connected to a bus bar without increasing the cross-sectional area of the bus bar constituting the energization path. [Means for solving the problem]

[0006] The circuit configuration of this disclosure includes a busbar that constitutes an energizing path, a voltage detection line consisting of an insulated wire and terminals provided at the end of the insulated wire, a voltage detection unit that is made up of a part of the busbar and to which the terminals of the voltage detection line are connected, and a heat transfer member that has one end thermally connected to the voltage detection unit and the other end thermally connected to a heat dissipation object, thereby constituting a heat dissipation path from the voltage detection unit to the heat dissipation object. [Effects of the Invention]

[0007] According to the circuit configuration of this disclosure, thermal damage to the voltage detection line connected to the busbar can be suppressed without increasing the cross-sectional area of ​​the busbar that constitutes the current path. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing the main parts of the circuit configuration according to Embodiment 1 with the upper case removed. [Figure 2] Figure 2 is a plan view showing the main components of the circuit configuration shown in Figure 1 with the upper case removed. [Figure 3] Figure 3 is a longitudinal cross-sectional view showing an enlarged view of the main part of the III-III section in Figure 2. [Figure 4] Figure 4 is a perspective view showing the cooling busbars that make up the circuit configuration shown in Figure 1. [Figure 5] Figure 5 is a perspective view showing an example of the specific structure of a part of the circuit configuration according to Embodiment 1, excluding the main part, with the upper case removed. [Figure 6] Figure 6 is a perspective view of the same area as shown in Figure 5, but from a different angle. [Figure 7] Figure 7 is a plan view of the portion shown in Figure 5. [Figure 8]Figure 8 is a vertical cross-sectional view showing an enlarged view of the main part of the circuit configuration according to Embodiment 2, and corresponds to Figure 3. [Figure 9] Figure 9 is a vertical cross-sectional view showing an enlarged view of the main part of the circuit configuration according to Embodiment 3, and corresponds to Figure 3. [Modes for carrying out the invention]

[0009] <Description of Embodiments in this Disclosure> First, embodiments of this disclosure will be listed and described. The circuit configuration disclosed herein is (1) The device includes a busbar that constitutes an energizing path, a voltage detection line consisting of an insulated wire and a terminal provided at the end of the insulated wire, a voltage detection unit that is made up of a part of the busbar and to which the terminal of the voltage detection line is connected, and a heat transfer member that has one end thermally connected to the voltage detection unit and the other end thermally connected to a heat dissipation object, and which constitutes a heat dissipation path from the voltage detection unit to the heat dissipation object.

[0010] According to the circuit configuration of this disclosure, in a busbar constituting the current path, one end of a heat transfer member is thermally connected to the voltage detection section of the busbar to which the terminals of the voltage detection line are connected, and the other end of the heat transfer member is thermally connected to the heat dissipation target, so that a heat dissipation path from the voltage detection section to the heat dissipation target is formed by the heat transfer member. This quickly promotes heat dissipation from the voltage detection section of the busbar to which the terminals of the voltage detection line are connected, making it possible to avoid or suppress the temperature of the voltage detection section of the busbar from exceeding, for example, 100°C. Therefore, it is possible to provide a circuit configuration that can suppress thermal damage to the voltage detection line caused by the high temperature of the busbar without increasing the cross-sectional area of ​​the busbar constituting the current path.

[0011] Furthermore, any material and shape of heat transfer material can be used, as long as it has excellent thermal conductivity. In addition, the objects to which heat is dissipated may include external components such as the casing of a battery pack located near the circuit component, and the case that houses the circuit component superimposed on the casing.

[0012] (2) In the above (1), it is preferable that the voltage detection unit of the busbar has a first surface and a second surface facing each other in the thickness direction, the terminal of the voltage detection line is connected to the first surface, and one end of the heat transfer member is thermally connected to the second surface. Since the first surface to which the terminal of the voltage detection line is connected and the second surface to which one end of the heat transfer member is thermally connected face each other in the thickness direction of the busbar, thermal damage to the voltage detection line can be suppressed even more reliably.

[0013] (3) In (2) above, it is preferable that the heat transfer member includes a cooling busbar in which both ends of a long metal plate are bent in a direction perpendicular to the middle part to form a first flat plate portion and a second flat plate portion, the first flat plate portion of the cooling busbar overlapping the second surface of the voltage detection unit, and the second flat plate portion of the cooling busbar overlapping the heat dissipation object. As a heat transfer member, a cooling busbar having a first flat plate portion and a second flat plate portion can be easily constructed by bending both ends of a busbar in a direction perpendicular to the middle part. Moreover, both ends of the cooling busbar (first and second flat plate portions) can be brought into contact with the voltage detection unit and the heat dissipation object with a wide contact area, which can advantageously promote heat dissipation of the voltage detection unit.

[0014] (4) In (3) above, it is preferable that the terminals of the voltage detection wire connected to the first surface of the voltage detection unit and the first flat plate portion of the cooling busbar superimposed on the second surface of the voltage detection unit are fastened to each other with the same bolt. Since the terminals of the voltage detection wire superimposed on both sides of the voltage detection unit of the busbar and the first flat plate portion of the cooling busbar can be fastened to each other with the same bolt, miniaturization and improved workability can be achieved.

[0015] (5) In the above (1) or (2), the terminal of the voltage detection line connected to the voltage detection unit is fastened to the bus bar by a bolt, and the bolt has an extension portion that penetrates the voltage detection unit and extends to the heat dissipation target and is thermally connected to the heat dissipation target, and the heat transfer member is constituted by the bolt. This is preferable. By simply providing an extension portion on the bolt, a heat transfer member can be constituted by using the bolt that fastens the terminal of the voltage detection line to the voltage detection unit, and miniaturization and improvement of workability can be achieved.

[0016] (6) In the above (1) or (2), the terminal of the voltage detection line connected to the voltage detection unit is fastened to the bus bar by a bolt, and one end portion of the heat transfer member abuts against the tip portion of the bolt that protrudes through the voltage detection unit and is thermally connected to the voltage detection unit via the bolt, and the heat transfer member is sandwiched between the tip portion of the bolt and the heat dissipation target. This is preferable. One end portion of the heat transfer member can be thermally connected to the voltage detection unit by using the bolt that fastens the terminal of the voltage detection line to the voltage detection unit, and further, the heat transfer member can be sandwiched and held between the bolt and the heat dissipation target by using the bolt. Thereby, with a small number of parts, the heat transfer member can be stably held to improve heat dissipation performance, and miniaturization and workability efficiency can also be achieved.

[0017] <Details of Embodiments of the Present Disclosure> A specific example of the circuit configuration body of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, and is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0018] <Embodiment 1> Hereinafter, the circuit configuration 10 of Embodiment 1 of this disclosure will be described with reference to Figures 1 to 7. This circuit configuration 10 is applicable, for example, to electric vehicles and hybrid vehicles, and is housed in a case 12 to constitute an electrical junction box 14. This electrical junction box 14 is located, for example, inside the housing 16 of a battery pack in a vehicle. The circuit configuration 10 and the electrical junction box 14 that houses the circuit configuration 10 can be positioned in any orientation, but in the following description, "upper" refers to the upper part in Figure 3, "lower" refers to the lower part in Figure 3, "left" refers to the left part in Figure 2, "right" refers to the right part in Figure 2, "front" refers to the lower part in Figure 2, and "rear" refers to the upper part in Figure 2. In addition, for multiple identical components, reference numerals may be assigned to only some of the components, while the reference numerals for other components may be omitted.

[0019] <Circuit construct 10> The circuit configuration 10 includes a busbar 20 that constitutes the current path 18, a voltage detection line 26 consisting of an insulated wire 22 and terminals 24 provided at the ends of the insulated wire 22, and a voltage detection unit 28 which is made up of a part of the busbar 20 (busbar 20a described later) and to which the terminals 24 of the voltage detection line 26 are connected. The circuit configuration 10 also includes a heat transfer member to which one end (upper end) is thermally connected to the voltage detection unit 28 and the other end (lower end) is thermally connected to the aforementioned housing 16 which is the target of heat dissipation, thereby constituting a heat dissipation path 30 from the voltage detection unit 28 to the target of heat dissipation (housing 16). In Embodiment 1, the heat transfer member is configured to include a cooling busbar 32.

[0020] <Case 12> In Embodiment 1, the case 12 housing the circuit component 10 is substantially rectangular in shape, extending horizontally in a plan view. The case 12 is composed of an upper case 34 and a lower case 36 that can be assembled and disassembled vertically. The upper case 34 has a substantially box shape with an opening downwards, and the lower case 36 has a substantially box shape with an opening upwards. The method of fixing the upper case 34 and the lower case 36 is not limited, and known fixing methods such as lock fitting or locking by protrusions and recesses may be used.

[0021] Specifically, the upper case 34 comprises a roughly rectangular, flat upper bottom wall portion 38 extending in the left-right direction, and an upper circumferential wall portion 40 projecting downward from the outer peripheral edge of the upper bottom wall portion 38 and extending in the circumferential direction. The lower case 36 comprises a roughly rectangular, flat bottom wall portion 42 extending in the left-right direction, and a lower circumferential wall portion 44 projecting upward from the outer peripheral edge of the bottom wall portion 42 and extending in the circumferential direction. The circuit component 10 of Embodiment 1 is housed inside the lower case 36. The upper case 34 is then placed on top of the lower case 36 containing the circuit component 10, and the lower case 36 and the upper case 34 are fixed together to form the electrical connection box 14. Furthermore, in the upper case 34, an upper through-window 46 is formed at the connection point with the outside of the busbar 20 that constitutes the power supply path 18, and when assembling the electrical junction box 14, the connection point with the outside of the busbar 20 is exposed to the outside space through this upper through-window 46.

[0022] Furthermore, as shown in Figure 3, a lower through-window 48 is formed in the bottom wall portion 42 of the lower case 36, which exposes the second flat plate portion 92 of the cooling bus bar 32 (described later) to the outside when the cooling bus bar 32 is assembled to the lower case 36. The lower through-window 48 is substantially rectangular in plan view and is formed to penetrate the bottom wall portion 42 in the plate thickness direction (vertical direction). In Embodiment 1, the lower through-window 48 is formed to be larger than the cooling bus bar 32 in plan view, and as will be described later, the cooling bus bar 32 can be inserted into the interior of the lower case 36 through the lower through-window 48.

[0023] Furthermore, a pair of support arms 50, 50 are provided on both the left and right sides of the lower through-window 48 in the bottom wall portion 42 of the lower case 36 to support the cooling bus bar 32 assembled to the lower case 36. Each support arm 50 protrudes upward from both the left and right sides of the lower through-window 48 and is elastically deformable in the left and right directions. The upper end portion of each support arm 50 is provided with a support claw portion 52 that protrudes inward in the left and right directions. The lower surface of each support claw portion 52 is an inclined surface 54 that slopes inward in the left and right directions as it goes upward, and the upper surface of each support claw portion 52 is a horizontal plane 56 that extends horizontally (in a direction perpendicular to the vertical direction). In Embodiment 1, a substantially plate-shaped reinforcing plate portion 58 connected to the bottom wall portion 42 is provided at the lower end of each support arm 50, reinforcing the lower end of each support arm 50.

[0024] <Electrical junction box 14> As shown in Figure 3, the electrical connection box 14 is superimposed on the housing 16 of the battery pack and bolted to the housing 16 by bolts 60 provided around the case 12 (lower case 36 in Embodiment 1), for example. That is, the lower surface of the bottom wall portion 42 of the lower case 36 is superimposed on the upper surface of the housing 16. As described above, a lower through-window 48 is formed in the bottom wall portion 42, and the second flat plate portion 92 of the cooling bus bar 32 is exposed to the outside through the lower through-window 48. An insulating sheet 62 and a gap filler 64 are fixed to the lower surface of the bottom wall portion 42 so as to cover this lower through-window 48. These insulating sheet 62 and gap filler 64 have good thermal conductivity, and known materials can be used. Therefore, the second flat plate portion 92 of the cooling bus bar 32 is thermally connected to the housing 16, which is the heat dissipation target, via these insulating sheet 62 and gap filler 64.

[0025] Note that in Figure 3, the thickness dimensions of the insulating sheet 62 and gap filler 64 are exaggerated for clarity, and the bottom wall portion 42 and the housing 16 are separated by a predetermined distance. However, it is preferable that these insulating sheet 62 and gap filler 64 are compressible in the vertical direction, and the bottom wall portion 42 and the housing 16 may overlap almost without any gap. Also, in Figures 1 to 3, only the portion of the electrical junction box 14 related to this disclosure is shown, and the structure of the electrical junction box 14 other than the portion related to this disclosure is not limited, but an example of such a specific structure is shown in Figures 5 to 7, which will be described later.

[0026] Furthermore, the shape of the housing 16 on which the electrical connection box 14 is superimposed is not limited, but the housing 16 is, for example, a roughly box-shaped structure with an opening at the top, and the electrical connection box 14 is superimposed and fixed to its bottom wall. A fluid channel 66 may be formed inside the bottom wall of the housing 16, as shown in Figure 3, and cooling water 68 may flow inside the fluid channel 66. This improves the heat dissipation performance through the heat dissipation path 30.

[0027] <Power supply path 18> The current path 18 in Embodiment 1 is composed of a plurality of busbars 20, and these busbars 20 are electrically connected to each other. In addition, several electronic components may be arranged on the current path 18, and a relay 70, which is a heat-generating component, is provided on the current path 18 in Embodiment 1. Some of the aforementioned busbars 20 are electrically and thermally connected to the terminals of this relay 70, so the current path 18 transmits not only electricity but also heat. Furthermore, insulated wires 22 may be connected to several electronic components arranged on the current path 18, and in Embodiment 1, a plurality of insulated wires 22 are bundled together to form a wire harness 72.

[0028] One of the insulated wires 22 branching from this wire harness 72 is the aforementioned voltage detection wire 26, and a terminal 24 is provided at the end of the insulated wire 22 that constitutes the voltage detection wire 26. This terminal 24 is connected to one of the busbars 20a of the multiple busbars 20 that constitute the current path 18, and a bolt insertion hole 74 is formed at the connection position of the terminal 24 (voltage detection unit 28) on this busbar 20a, through which a bolt 76, described later, is inserted. In addition, in the wire harness 72 that includes the voltage detection wire 26, the end opposite to the side connected to each electronic component and busbar 20a is connected to, for example, a circuit board (not shown), and a microcomputer or the like mounted on this circuit board can perform voltage detection in the voltage detection unit 28 and output the detected voltage to the outside.

[0029] <Terminal 24> In Embodiment 1, the terminal 24 is a ring terminal and has an annular tongue portion 80 having a bolt insertion hole 78 through which a bolt 76 is inserted in the central part, and a wire connection portion 82 extending from the tongue portion 80. In particular, in Embodiment 1, the insulated wire 22 is connected to the wire connection portion 82 by crimping, and the insulation coating is stripped at the end of the insulated wire 22 to expose the core wire, and the wire connection portion 82 is crimped to this exposed core wire, thereby connecting the terminal 24 to the end of the insulated wire 22 and forming the voltage detection wire 26.

[0030] Then, the bolt insertion holes 74 in the busbar 20a and the bolt insertion holes 78 in the terminal 24 are aligned with each other, and bolts 76 are inserted through these bolt insertion holes 74 and 78 and fastened with nuts (clinching nuts 100) described later, so that the terminal 24 of the voltage detection wire 26 is superimposed on and fixed to the busbar 20a.Therefore, in Embodiment 1, the voltage detection unit 28 to which the terminal 24 of the voltage detection wire 26 is connected is formed by the portion around the bolt insertion holes 74 in the busbar 20a.In short, the voltage detection unit 28 in the busbar 20a has an upper surface 84 as a first surface and a lower surface 86 as a second surface that face each other in the plate thickness direction, and the terminal 24 is superimposed on and connected to the upper surface 84, which is the first surface.

[0031] <Heat transfer component (cooling busbar 32)> One end (upper end) of a cooling busbar 32, which serves as a heat transfer member constituting the heat dissipation path 30, is thermally connected to the second surface (lower surface 86) of the voltage detection unit 28. As shown in Figure 4, the cooling busbar 32 is made of a long, strip-shaped metal plate, with both ends bent perpendicular to the middle section 88 in the longitudinal direction, and these ends constitute a first flat plate section 90 and a second flat plate section 92, respectively. When the cooling busbar 32 is fixed to the lower case 36, the middle section 88 extends vertically, and the first flat plate section 90 and the second flat plate section 92 extend to the right from both the upper and lower ends of the middle section 88. The extended end (right end) of the first flat plate section 90 is further bent downward, and a downward extension section 94 is provided at the right end of the first flat plate section 90. In other words, in the cooling busbar 32, the first flat plate portion 90 and the second flat plate portion 92 are separated from each other and facing each other in the vertical direction, while the intermediate portion 88 and the downward extension portion 94 are separated from each other and facing each other in the left-right direction.

[0032] Furthermore, in the upper portion of the intermediate portion 88 and the downward extension portion 94, which are mutually opposed in the left-right direction, a substantially rectangular engagement hole 96 is formed in the intermediate portion in the width direction (front-to-back direction) and penetrates in the thickness direction (left-to-right direction). In addition, a through hole 98 is formed in the central portion of the first flat plate portion 90 and penetrates in the thickness direction (up-to-down direction), and a nut is fixed at the lower opening of this through hole 98. In Embodiment 1, a clinching nut 100 is fixed at the lower opening of the through hole 98. The method of fixing this clinching nut 100 is not limited and can be fixed by press-fitting or welding.

[0033] The cooling bus bar 32, shaped in this manner, is supported and assembled to the lower case 36 by its respective support arms 50. When assembling the cooling bus bar 32 to the lower case 36, it is inserted from below the bottom wall 42 of the lower case 36 through the lower through-window 48. As a result, the upper ends of the intermediate portion 88 and the downward extension portion 94, which are the left and right walls of the cooling bus bar 32, come into contact with the inclined surfaces 54 of the support claw portions 52 that protrude inward in the left-right direction from each support arm 50, causing each support arm 50 to elastically deform outward in the left-right direction along the inclination of each inclined surface 54. Then, each support claw portion 52 overcomes the lower wall portion of each engagement hole 96 in the intermediate portion 88 and the downward extension portion 94 and enters each engagement hole 96, causing each support arm 50 to elastically return to its original shape and come into contact with the horizontal surface 56 of each support claw portion 52 and the upper surface that constitutes the inner surface of each engagement hole 96. As a result, downward leakage through the lower through-window 48 in the cooling bus bar 32 is prevented.

[0034] Furthermore, when the cooling busbar 32 is assembled to the lower case 36, one end of the cooling busbar 32 (the upper end, which is the first flat plate portion 90) abuts against the voltage detection portion 28 of the busbar 20a from below, and is superimposed on the second surface (lower surface 86) of the voltage detection portion 28, thus being thermally connected. In this state, the bolt insertion hole 78 in the terminal 24, the bolt insertion hole 74 in the busbar 20a, and the through hole 98 in the first flat plate portion 90 are in communication in the vertical direction, and these are fixed by inserting bolts 76 through each of these bolt insertion holes 74, 78 and through hole 98 and fastening them to the clinching nut 100. In short, the terminal 24 of the voltage detection wire 26 connected to the first surface (upper surface 84) of the voltage detection unit 28 and the first flat plate portion 90 of the cooling bus bar 32 superimposed on the second surface (lower surface 86) of the voltage detection unit 28 are fastened to each other with the same bolt 76.

[0035] Furthermore, when the cooling busbar 32 is assembled to the lower case 36, the second flat portion 92 of the cooling busbar 32 is exposed to the outside through the lower through-window 48 in the bottom wall portion 42, and in Embodiment 1, the lower surface of the second flat portion 92 protrudes slightly below the lower surface of the bottom wall portion 42. This allows the second flat portion 92 to be stably superimposed on the housing 16 via the insulating sheet 62 and gap filler 64 when the electrical junction box 14 is fixed to the housing 16.

[0036] As mentioned above, the structure of the electrical junction box 14 is not limited to the part relating to this disclosure, but an example of its specific structure is shown in Figures 5 to 7. That is, as mentioned above, the voltage detection wire 26 was branched from the wire harness 72, but an earth wire 104, which has an earth terminal 102 at its end, may also be branched from the wire harness 72. The earth wire 104 is constructed in the same way as the voltage detection wire 26, by stripping the insulation coating from the end of the insulated wire 22 to expose the core wire, and fixing the earth terminal 102 to this exposed core wire. That is, a wire fixing part 105 is provided at the end of the earth terminal 102 (the right end in Embodiment 1), and the core wire exposed at the end of the insulated wire 22 can be fixed to this wire fixing part 105 by press-fitting, welding, or the like.

[0037] More specifically, as shown in Figures 5 to 7, a slit 106 is provided at a predetermined position on the lower case 36, extending from the upper end of the lower peripheral wall portion 44 over a predetermined vertical dimension and penetrating in the thickness direction. The ground terminal 102, provided at the end of the ground wire 104, protrudes to the outside of the case 12 through this slit 106. In addition, a bolt fixing portion 108 that extends horizontally is provided in the upper and lower intermediate portion of the outer peripheral surface of the lower case 36 (lower peripheral wall portion 44), adjacent to the slit 106. In Embodiment 1, the bolt fixing portion 108 is substantially rectangular in plan view, and a bolt insertion hole (not shown) that penetrates vertically is formed in the central portion. On the outer peripheral side of the bolt insertion hole in the central portion of the bolt fixing portion 108, a positioning projection 110 is provided that protrudes upward and positions the tongue portion 120 of the ground terminal 102, as will be described later. In Embodiment 1, four positioning protrusions 110 are provided, with each positioning protrusion 110 located on both the front-to-back and left-to-right sides of the bolt insertion hole in the central portion.

[0038] Furthermore, inside the lower case 36, a retaining portion 112 is provided in the portion adjacent to the slit 106 to suppress displacement of the earth wire 104, particularly the insulated wire 22. The retaining portion 112 consists of an elastic piece 114 that protrudes upward from the bottom wall portion 42 of the lower case 36 and is elastically deformable in the front-rear direction, and an engaging claw portion 116 that protrudes forward from the upper end of the elastic piece 114. The upper end surface of the engaging claw portion 116 is an inclined surface 118 that gradually slopes downward as it protrudes forward.

[0039] In Embodiment 1, the ground terminal 102 is equipped with a substantially rectangular flat tongue portion 120, and a bolt insertion hole 124 through which a bolt 122 is inserted is formed in the central part of the tongue portion 120. The wire fixing portion 105 extends to the right from the right end of the tongue portion 120. Also, as shown in Figure 5, in the housing 16 (particularly the bottom wall portion of the box-shaped housing 16), a bolt fastening portion 126 is provided projecting upward at a position corresponding to the bolt fixing portion 108 provided on the outer circumferential surface of the case 12 (lower case 36), and a fastening hole (not shown) through which a bolt 122 is fastened is provided. When the electrical connection box 14 is placed on the bottom wall portion of the housing 16, the bolt fastening portion 126 and the bolt fixing portion 108 are superimposed in the vertical direction, and the fastening holes and bolt insertion holes provided in each are in mutual communication in the vertical direction. The ground terminal 102 of the ground wire 104 is superimposed on the bolt fixing portion 108 from above, and the tongue portion 120 of the ground terminal 102 is positioned by the positioning protrusions 110, so that the bolt insertion hole 124 and the fastening hole and bolt insertion hole are in communication, and the bolt 122 is inserted and fastened. As a result the ground terminal 102 is fixed to the bolt fastening portion 126 of the housing 16 together with the bolt fixing portion 108 of the case 12 (lower case 36).

[0040] Furthermore, a metal collar (not shown) is embedded and fixed in the central part of the bolt fixing portion 108, and the bolt insertion hole in the bolt fixing portion 108 is formed by the internal hole of the collar that extends in the vertical direction. Then, as described above, the earth terminal 102 is superimposed on the bolt fixing portion 108 and fixed to the bolt fastening portion 126 by bolt 122, so that the tongue portion 120 of the earth terminal 102 and the housing 16 are electrically connected via the collar, and the earth wire 104 is connected to the earth. In short, in Embodiment 1, when bolting the electrical connection box 14 to the housing 16, the earth connection of the earth wire 104 is achieved at the same time.

[0041] When manufacturing an electrical junction box 14 with such a configuration, when the wire harness 72 of the circuit assembly 10 is placed inside the lower case 36, the wire fixing portion 105 of the ground terminal 102 of the ground wire 104 branching from the wire harness 72 is inserted from above into a slit 106 provided in the lower peripheral wall portion 44. Then, the tongue portion 120 provided to the left of the wire fixing portion 105 is superimposed on the bolt fixing portion 108 and positioned and fixed in the area surrounded by the positioning protrusions 110, and the insulated wire 22 extending to the right from the wire fixing portion 105 is brought into contact with the retaining portion 112 from above. When the insulated wire 22 comes into contact with the inclined surface 118 of the engaging claw portion 116, the elastic piece 114 elastically deforms backward along the inclination of the inclined surface 118, allowing further insertion of the insulated wire 22, and when the engaging claw portion 116 overcomes the insulated wire 22, the elastic piece 114 elastically returns to its initial position. As a result, the upper part of the insulated wire 22 is covered by the engaging claw portion 116, preventing the insulated wire 22 from being pulled out upwards.

[0042] In particular, the clamping of the ground wire 104 by the clamping portion 112 is performed while the insulated wire 22 has a certain degree of tension, which effectively prevents the ground wire 104 from shifting position. In this state, the ground wire 104 is temporarily fixed to the case 12 (lower case 36). Then, as described above, the ground terminal 102 and the bolt fixing portion 108 are fixed to the bolt fastening portion 126 on the housing 16 by fastening the bolt 122, thereby permanently fixing the ground wire 104 to the case 12 and housing 16.

[0043] <Method for assembling the circuit component 10 and the electrical junction box 14> The following describes a specific example of how to assemble the circuit component 10 and the electrical junction box 14 that houses the circuit component 10. However, the assembly method of the circuit component 10 and the electrical junction box 14 is not limited to the description below.

[0044] First, the electronic components, including the relay 70, and the busbars 20, 20a are fixed to the lower case 36 with bolts or the like. Then, the cooling busbar 32 is inserted into the lower case 36 through the lower through-window 48. As a result, as described above, the support claws 52 engage with the engagement holes 96, and the cooling busbar 32 is assembled to the lower case 36. In this state, the cooling busbar 32 is temporarily fixed to the lower case 36. Also in this state, the first flat plate portion 90 of the cooling busbar 32 is superimposed on the second surface (lower surface 86) of the voltage detection unit 28, and the bolt insertion holes 74 and the through-holes 98 are in communication with each other in the vertical direction.

[0045] Subsequently, the terminals 24 of the voltage detection wire 26 are superimposed on the first surface (upper surface 84) of the voltage detection unit 28, and the bolt insertion holes 78 in the tongue portion 80 are connected vertically to the bolt insertion holes 74 and through holes 98. Then, bolts 76 are inserted through these bolt insertion holes 74, 78 and through holes 98 and fastened to the clinching nuts 100. As a result, the terminals 24 of the voltage detection wire 26 are connected to the voltage detection unit 28, and the cooling busbar 32 is permanently fixed to the lower case 36 via the busbar 20a. As a result, the circuit assembly 10 is completed. Next, the upper case 34 is superimposed on the lower case 36 containing the circuit assembly 10 from above, and the upper case 34 and the lower case 36 are fixed together. As a result, the electrical connection box 14 is completed. The insulating sheet 62 and gap filler 64 are fixed to the lower surface of the bottom wall portion 42 at any time.

[0046] Furthermore, when the configurations shown in Figures 5 to 7 above are adopted, after placing the circuit components 10 on the lower case 36, the ground wire 104 branching from the wire harness 72 is inserted into the slit 106 in the lower peripheral wall portion 44, the tongue portion 120 is overlapped within the area surrounded by the positioning protrusions 110, and the insulated wire 22 is held in place by the retaining portion 112. This temporarily fixes the ground wire 104 to the lower case 36. After that, the upper case 34 is fixed to the lower case 36 to complete the electrical junction box 14. Therefore, in the completed state of the electrical junction box 14, the ground terminal 102 of the ground wire 104 protrudes outward from the case 12 and is positioned by overlapping with the bolt fixing portion 108.

[0047] The electrical junction box 14 manufactured in this manner is placed on top of the housing 16 and fixed, for example, by bolts 60. In addition, when the configuration shown in Figures 5 to 7 is adopted, it is also fixed by bolts 122, and the grounding of the ground wire 104 is connected at the same time as the fixing to the housing 16. When the relay 70 in the electrical junction box 14 is energized, the relay 70 generates heat, and this heat is transmitted through each busbar 20 and electronic components to the busbar 20a to which the voltage detection line 26 is connected. Here, one end (first flat plate portion 90) of the cooling busbar 32 is thermally connected to the busbar 20a, and the other end (second flat plate portion 92) of the cooling busbar 32 is thermally connected to the housing 16, which is the target of heat dissipation, via an insulating sheet 62 and a gap filler 64. Therefore, the heat transmitted to the busbar 20a is dissipated through the housing 16. In other words, in Embodiment 1, the heat dissipation path 30 from the voltage detection unit 28 to the housing 16 is configured to include a cooling bus bar 32, which is a heat transfer member.

[0048] In the circuit configuration 10 of Embodiment 1, which has the structure described above, one end (first flat plate portion 90) of the cooling busbar 32, which is a heat transfer member, is thermally connected to the voltage detection unit 28 on the busbar 20a to which the voltage detection line 26 is connected, and the other end (second flat plate portion 92) of the cooling busbar 32 is thermally connected to the housing 16, which is the object of heat dissipation. As a result, heat transferred to the voltage detection unit 28 is transmitted to the insulated wire 22 via the terminal 24, preventing damage such as melting of the insulating coating constituting the insulated wire 22. In other words, the heat transferred to the busbar 20a is efficiently dissipated in the voltage detection unit 28, and the temperature rise in the voltage detection unit 28 is suppressed, thereby reliably avoiding damage to the voltage detection line 26. As a result, voltage detection through the voltage detection line 26 is achieved more reliably, and a circuit configuration 10 and electrical connection box 14 with improved voltage detection performance can be provided.

[0049] Furthermore, it is conceivable to improve heat dissipation performance by increasing the cross-sectional area of ​​the busbars constituting the circuit configuration, thereby suppressing temperature rise in the voltage detection unit and avoiding damage to the voltage detection line. However, in such cases, an increase in the overall size of the circuit configuration and electrical junction box would be unavoidable. In contrast, as in Embodiment 1, by providing a heat transfer member (cooling busbar 32) in the part of the circuit configuration 10 where heat dissipation is to be prioritized, the cross-sectional area of ​​the busbars 20 and 20a does not increase, and an increase in the size of the circuit configuration 10 and electrical junction box 14 can be avoided.

[0050] The voltage detection unit 28 has a first surface (upper surface 84) and a second surface (lower surface 86). The terminal 24 of the voltage detection wire 26 is connected to the upper surface 84, and one end (first flat plate portion 90) of the heat transfer member (cooling bus bar 32) is thermally connected to the lower surface 86. As a result, the heat transferred to the bus bar 20a is efficiently dissipated in the voltage detection unit 28, thereby more reliably preventing damage to the voltage detection wire 26.

[0051] The heat transfer member is configured to include a cooling busbar 32 having a first flat plate portion 90 and a second flat plate portion 92, with the first flat plate portion 90 superimposed on the second surface (bottom surface 86) of the voltage detection unit 28, and the second flat plate portion 92 superimposed on the heat dissipation target (housing 16). This ensures a stable contact area between the first flat plate portion 90 and the voltage detection unit 28, as well as a stable contact area between the second flat plate portion 92 and the housing 16, thereby improving heat dissipation efficiency.

[0052] The voltage detection unit 28, the terminals 24 of the voltage detection wires 26 superimposed on the upper and lower surfaces 84, 86 of the voltage detection unit 28, and the first flat plate portion 90 of the cooling busbar 32 are fastened together by the same bolt 76. This reduces the number of parts, costs, and assembly man-hours compared to, for example, fixing the voltage detection unit and terminals, and the voltage detection unit and the first flat plate portion, with separate bolts.

[0053] <Embodiment 2> Hereinafter, the circuit configuration 130 of Embodiment 2 of this disclosure will be described with reference to Figure 8. The circuit configuration 130 of Embodiment 2 also constitutes an electrical junction box 14 by being housed, for example, in a case 12. In Figure 5, the upper case 34 of the case 12 is not shown. The basic structure of the circuit configuration 130 of Embodiment 2 is the same as that of the circuit configuration 10 of Embodiment 1, except that the shape of the heat transfer member constituting the heat dissipation path 132 from the voltage detection unit 28 to the housing 16, which is the target of heat dissipation, is different from that of Embodiment 1. Therefore, in the following, the differences from Embodiment 1 will be explained, and detailed explanations will be omitted for components and parts that are substantially the same as those in Embodiment 1, by denoting them with the same reference numerals as in Embodiment 1 in the figures.

[0054] In Embodiment 2, the terminal 24 of the voltage detection line 26 and the voltage detection unit 28 (busbar 20a) are fixed by a bolt 134, and this bolt 134 extends to the housing 16, forming a heat dissipation path 132. In other words, in Embodiment 2, the heat transfer member is made up of the bolt 134.

[0055] Specifically, in Embodiment 2, a clinching nut 100 is provided in the lower opening of a bolt insertion hole 74 provided in the voltage detection unit 28. The bolt insertion hole 78 provided in the terminal 24 of the voltage detection wire 26 and the bolt insertion hole 74 provided in the voltage detection unit 28 are mutually connected in the vertical direction, and the bolts 134 inserted through each bolt insertion hole 74, 78 are fastened to the clinching nut 100. This bolt 134 is made of, for example, a metal with good thermal conductivity, and has an extension portion 136 that extends longer than the bolt 76 in Embodiment 1. This bolt 134 penetrates the tongue portion 80 of the terminal 24, the voltage detection unit 28, and the clinching nut 100, and the lower end of the extension portion 136 penetrates a lower through-window 138 provided in the bottom wall portion 42, and is thermally connected to the housing 16 via an insulating sheet 62 and a gap filler 64.

[0056] Therefore, in Embodiment 2, the bolt 134 is fastened with the clinching nut 100 at one end (upper end), and the upper end of the bolt 134 is thermally connected to the clinching nut 100. In short, in Embodiment 2, as in Embodiment 1, the terminal 24 of the voltage detection line 26 is connected to the first surface (upper surface 84) of the voltage detection unit 28, and one end (upper end) of the heat transfer member (bolt 134) is thermally connected to the second surface (lower surface 86) of the voltage detection unit 28. Therefore, the same effects as in Embodiment 1 can be achieved in Embodiment 2, which has the structure described above. In particular, since Embodiment 2 does not employ a separate component such as a cooling busbar 32, a further reduction in the number of parts can be achieved.

[0057] <Embodiment 3> Hereinafter, the circuit configuration 140 of Embodiment 3 of this disclosure will be described with reference to Figure 9. In Embodiment 3, although the same bolt 76 as in Embodiment 1 is used to fix the terminal 24 of the voltage detection line 26 to the voltage detection unit 28, a heat transfer member 142 with a different shape from that in Embodiment 1 is used, and the heat dissipation path 144 is configured including this heat transfer member 142.

[0058] Specifically, similar to Embodiment 2, a clinching nut 100 is fixed to the lower opening of the bolt insertion hole 74 in the voltage detection unit 28, and the terminal 24 of the voltage detection wire 26 superimposed on the upper surface of the voltage detection unit 28 and the voltage detection unit 28 (bus bar 20a) are fastened together by a bolt 76.

[0059] Furthermore, the heat transfer member 142 in Embodiment 3 is shaped like a rectangular or cylindrical column and is made of a metal with good thermal conductivity. One end (upper end) of the heat transfer member 142 abuts against the tip 146 of a bolt 76 that protrudes through the voltage detection unit 28, and is thermally connected to the second surface (lower surface 86) of the voltage detection unit 28 via the bolt 76 and the clinching nut 100. This heat transfer member 142 is sandwiched between the tip 146 of the bolt 76 and the housing 16 which is the object of heat dissipation in the vertical direction, in other words, the other end (lower end) of the heat transfer member 142 is superimposed on the housing 16 and is thermally connected. In Embodiment 3 as well, the lower end of the heat transfer member 142 protrudes below the bottom wall 42 through a lower through-window 148 provided in the bottom wall 42, and the lower end of the heat transfer member 142 is superimposed on the housing 16 via an insulating sheet 62 and a gap filler 64.

[0060] Such a heat transfer member 142 can be fixed to a predetermined position in the lower case 36 by a fixing mechanism (not shown) provided in the lower case 36. The specific configuration of the fixing mechanism is not limited, but for example, support arms 50 similar to those in Embodiment 1 may be provided on both the left and right sides of the lower through-window 148 in the bottom wall portion 42 of the lower case 36, and engaging recesses may be provided on both the left and right sides of the heat transfer member 142 into which the support claws 52 of each support arm 50 can be fitted. The heat transfer member 142 can then be fixed to the lower case 36 by inserting it into the lower case 36 from below through the lower through-window 148 and fitting each support claw 52 into each engaging recess.

[0061] In short, in Embodiment 3, as in Embodiment 1, the terminal 24 of the voltage detection line 26 is connected to the first surface (upper surface 84) of the voltage detection unit 28, and one end (upper end) of the heat transfer member 142 is thermally connected to the second surface (lower surface 86) of the voltage detection unit 28 via a bolt 76 and a clinching nut 100. Therefore, the same effects as in Embodiment 1 can be achieved in Embodiment 3, which has the structure described above. In particular, in Embodiment 3, a simple rectangular or cylindrical heat transfer member 142 is used, so the shape of the heat transfer member 142 can be made simpler compared to Embodiment 1.

[0062] <Variation> While Embodiments 1 to 3 have been described in detail above as specific examples of the present disclosure, the present disclosure is not limited by these specific descriptions. Modifications, improvements, etc., to the extent that they can achieve the objectives of the present disclosure are included in the present disclosure. For example, the following modifications of embodiments are also included in the technical scope of the present disclosure.

[0063] (1) In Embodiment 1, a lower through-window 48 is provided in the bottom wall portion 42, and the other end of the heat transfer member (the second flat plate portion 92 of the cooling busbar 32) is superimposed on the housing 16 via an insulating sheet 62 and a gap filler 64 and thermally connected. However, the embodiment is not limited to this. For example, the bottom wall portion of the lower case does not need to have a lower through-window, and the other end of the heat transfer member may be superimposed on the bottom wall portion of the lower case, for example, via a gap filler, or directly. Furthermore, the bottom wall portion of the lower case may be superimposed on the housing via a gap filler and thermally connected, for example, and the heat dissipation target may include the housing and / or the bottom wall portion of the lower case. The same applies to Embodiments 2 and 3.

[0064] (2) In the embodiment 1 described above, the terminal 24 of the voltage detection wire 26, the voltage detection unit 28, and one end of the heat transfer member (the first flat plate portion 90 of the cooling busbar 32) were fixed by the same bolt 76, but the embodiment is not limited to this. For example, the bolt that fixes the terminal of the voltage detection wire to the voltage detection unit and the bolt that fixes the voltage detection unit to one end of the heat transfer member may be different. That is, the position in which one end of the heat transfer member is fixed in the busbar on which the voltage detection unit is provided may be, for example, near the voltage detection unit. Specifically, the position in which one end of the heat transfer member is fixed in the busbar on which the voltage detection unit is provided may be spaced away from the voltage detection unit, as long as the insulating coating constituting the insulated wire is not damaged by the temperature rise of the terminal superimposed on the voltage detection unit as a result of heat dissipation through the heat transfer member. Furthermore, when the heat transfer member is fixed at a position away from the voltage detection unit, the method of fixing the busbar on which the voltage detection unit is provided to the heat transfer member is not limited to bolt fixing. For example, the busbar and the heat transfer member may be fixed by welding, or the heat transfer member may be fixed to the lower case by welding or press-fitting, so that one end of the fixed heat transfer member is in close contact with the busbar.

[0065] The same applies to Embodiments 2 and 3. A bolt may be provided near the voltage detection unit that has an extension that penetrates the busbar and whose tip reaches the heat dissipation target (for example, the housing 16). Alternatively, a heat transfer member, such as a rectangular or cylindrical shape, may be provided near the voltage detection unit, with one end thermally connected to the voltage detection unit and the other end thermally connected to the voltage detection unit.

[0066] (3) In Embodiment 1, a relay 70 was described as a heat-generating component that generates heat when energized, but the invention is not limited to this embodiment, and other known heat-generating components such as fuses may be used. In addition, heat-generating components are not essential in the circuit configuration according to this disclosure, and heat-generating components may be provided outside the circuit configuration or electrical connection box. The same applies to Embodiments 2 and 3.

[0067] (4) In Embodiment 1, the terminal 24 of the voltage detection line 26 was a round terminal and the tongue portion 80 was an annular shape having a bolt insertion hole 78. However, the embodiment is not limited to this, and the shape of the tongue portion of the terminal may be, for example, a C-shape or U-shape in which a part of the annular shape is cut out. The same applies to Embodiments 2 and 3.

[0068] (5) In Embodiment 1, the cooling busbar 32 was formed separately from the lower case 36 and the cooling busbar 32 was later assembled to the lower case 36, but the embodiment is not limited to this. For example, the heat transfer member may be formed integrally with the case (e.g., lower case) by being set in a molding cavity when the case (e.g., lower case) is formed. The same applies to Embodiment 3, in which a case (e.g., lower case) integrally equipped with, for example, a prismatic or cylindrical heat transfer member may be formed.

[0069] (6) As stated above, the structure of the circuit components and electrical junction boxes is not limited to the parts relating to this disclosure, and the embodiments shown in Figures 5 to 7 do not have to be adopted. That is, the ground terminal of the ground wire may be bolted to the housing separately from the bolt fixing part of the case (ground connection). [Explanation of Symbols]

[0070] 10 Circuit configuration (Embodiment 1) 12 cases 14. Electrical junction box 16. (Battery pack) casing (heat dissipation target) 18 Power supply path 20 Bus Bar 20a (Busbar to which the voltage detection wire terminal is connected) 22 Insulated wires 24 terminals 26 Voltage detection line 28 Voltage detection unit 30 Heat dissipation paths 32 Cooling busbars (heat transfer components) 34 Upper Case 36 Lower Cases 38 Upper bottom wall 40 Upper peripheral wall 42 Bottom wall section 44 Lower peripheral wall 46 Upper through-window 48 Lower through-window 50 Support arm 52 Support claw part 54 Slope 56 Horizontal plane 58 Reinforcement plate section 60 volts 62 Insulating Sheet 64 Gap Filler 66. Fluid flow path 68 Cooling water 70 Relays (heat-generating components) 72 Wire Harness 74 Bolt insertion holes 76 volts 78 Bolt insertion holes 80 Tongue 82 Wire connection section 84 Top surface (first surface) 86 Bottom surface (second surface) 88 Middle section 90 1st flat plate part 92 2nd flat plate part 94 Downward extension part 96 Engagement holes 98 Through hole 100 Clinching nuts 102 Ground terminal 104 Ground wire 105 Wire fixing part 106 slits 108 Bolt fixing part 110 Positioning projection 112 Pressing part 114 Elastic piece 116 Engaging claw portion 118 Slope 120 Tongue 122 volts 124 bolt insertion holes 126 Bolt fastening section 130 Circuit configuration (Embodiment 2) 132 Heat dissipation path 134 bolts (heat transfer components) 136 Extension 138 Lower through-window 140 Circuit configuration (Embodiment 3) 142 Heat transfer components 144 Heat dissipation paths 146 Tip 148 Lower through-window

Claims

1. Busbars that constitute the power supply path, A voltage detection wire consisting of an insulated wire and a terminal provided at the end of the insulated wire, A voltage detection unit, which is formed by a part of the busbar and to which the terminals of the voltage detection line are connected, A heat transfer member having one end thermally connected to the voltage detection unit and the other end thermally connected to the heat dissipation target, thereby forming a heat dissipation path from the voltage detection unit to the heat dissipation target, A circuit component that includes this.

2. The circuit configuration according to claim 1, wherein the voltage detection unit of the busbar has a first surface and a second surface facing each other in the thickness direction, the terminal of the voltage detection line is connected to the first surface, and one end of the heat transfer member is thermally connected to the second surface.

3. The heat transfer member includes a cooling busbar formed by bending both ends of a long metal plate perpendicular to the middle section, forming a first flat plate section and a second flat plate section. The first flat plate portion of the cooling busbar is superimposed on the second surface of the voltage detection unit. The circuit configuration according to claim 2, wherein the second flat plate portion of the cooling busbar is superimposed on the heat dissipation target.

4. The circuit configuration according to claim 3, wherein the terminal of the voltage detection line connected to the first surface of the voltage detection unit and the first flat plate portion of the cooling busbar superimposed on the second surface of the voltage detection unit are fastened to each other with the same bolt.

5. The terminal of the voltage detection line connected to the voltage detection unit is fastened to the busbar by a bolt. The bolt has an extension that penetrates the voltage detection unit and extends to the heat dissipation target, and is thermally connected to the heat dissipation target. The circuit configuration according to claim 1 or claim 2, wherein the heat transfer member is formed by the bolt.

6. The terminal of the voltage detection line connected to the voltage detection unit is fastened to the busbar by a bolt. The one end of the heat transfer member abuts against the tip of the bolt that protrudes through the voltage detection unit, and is thermally connected to the voltage detection unit via the bolt. The circuit configuration according to claim 1 or claim 2, wherein the heat transfer member is sandwiched between the tip of the bolt and the heat dissipation target.

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