Electrical connection box

Abstract

An electrical connection box (1) comprises a pair of relays (20A, 20B) that are separated by a gap (S), a case (10), and a heat transfer member (70). Each of the pair of relays (20A, 20B) has a plurality of terminals (51–54) and a protruding part (23) that protrudes toward the gap (S) near at least one (51, 52) of the plurality of terminals. The heat transfer member (70) absorbs heat emitted from the terminals and transfers the heat away from the terminals.

Description

Electrical junction box

[0001] The present invention relates to an electric junction box in which a relay is housed in a case.

[0002] Conventionally, electrical connection boxes used in automobiles and the like are configured to mount electronic components such as relays and fuses in a case of a predetermined shape made of resin or the like, and to electrically connect the input / output terminals of these electronic components to bus bars held in the case or terminals connected to an external load (see, for example, Patent Document 1).

[0003] Japanese Patent Application Publication No. 2005-158479

[0004] In the above-described electrical junction boxes, when an electronic component (especially a relay or fuse) is activated, Joule heat is generated at current-carrying points, such as the input / output terminals of the electronic component. In particular, Joule heat can be generated at contact points between the input / output terminals of the electronic component and bus bars or the like connected to the input / output terminals due to the large contact resistance. Since the heat generated at such contact points is also transmitted to the internal mechanisms of the electronic component via the input / output terminals, it is desirable to efficiently dissipate the heat generated at the contact points to the outside of the electronic component in order to ensure proper operation of the electronic component over a long period of time.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide an electrical junction box that is excellent in heat dissipation from a relay housed in a case of the electrical junction box.

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

[0007] An electrical connection box comprising: a pair of relays arranged with a gap therebetween; a case that houses the pair of relays; and a heat transfer member that is arranged within the case, wherein each of the pair of relays has a plurality of terminals that are connected to an internal circuit of the relay, and a protrusion that has a shape that protrudes toward the gap near at least one of the plurality of terminals, and the heat transfer member is configured to absorb heat released from the at least one terminal and transfer the heat in a direction away from the at least one terminal.

[0008] Fig. 1 is a perspective view of an electrical junction box according to an embodiment of the present invention. Fig. 2 is a top view of the electrical junction box shown in Fig. 1. Fig. 3 is an enlarged view of part B in Fig. 2. Fig. 4 is a bottom view of the electrical junction box shown in Fig. 1 (only bus bars and electronic components (relays and fuses) are shown). Fig. 5 is an enlarged bottom view of the relay shown in Fig. 4. Fig. 6 is a diagram for explaining the internal circuitry of a pair of relays shown in Fig. 4.

[0009] An electrical junction box 1 according to an embodiment of the present invention will be described below with reference to the drawings. The electrical junction box 1 is typically a relay box mounted on a vehicle such as an automobile and housing electronic components such as relays and fuses. As shown in FIGS. 1 to 6 , the electrical junction box 1 includes a case 10, a plurality of electronic components housed in the case 10 (specifically, relays 20 and fuses 30 (see FIG. 4 )), and a plurality of bus bars 40 (see FIG. 4 ) held in the case 10.

[0010] For the sake of convenience, the following definitions are used for "front," "rear," "left," "right," "upper," and "lower" as shown in FIG. 1 and elsewhere. The front-to-rear direction, left-to-right direction, and upper-to-lower direction are perpendicular to one another. The "upper" and "lower" sides correspond to the "upper" and "lower" sides of the vehicle when the electrical junction box 1 is mounted on the vehicle. Note that these directions are defined merely for the sake of convenience, and do not necessarily correspond to the front-to-rear direction, left-to-right direction, and upper-to-lower direction of the vehicle when the electrical junction box 1 is mounted on the vehicle. Each component constituting the electrical junction box 1 will be described below in order.

[0011] 1 and 2, the case 10 is a resin housing having a generally rectangular parallelepiped shape extending in the front-rear, left-right, and up-down directions. The case 10 may be formed from a single resin molded body or a combination of multiple resin molded bodies. Furthermore, the case 10 may be formed such that the portions that require insulation, such as the portions that hold the electronic components and the bus bars 40, are made of resin, and the other portions (e.g., the exterior portion) are made of metal.

[0012] 1 and 2, a plurality of relays 20 are housed in the front region of the upper part of the case 10. Each of the plurality of relays 20 is housed from top to bottom in a corresponding housing portion (cavity) in the upper part of the case 10. A rear region A (see FIG. 2), adjacent to the rear side of the front region of the upper part of the case 10, is a region where electronic components such as fuses 30 (see FIG. 4) are housed. The fuses 30 and the like are also housed from top to bottom in corresponding housing portions (cavities) in the upper part of the case 10.

[0013] An electric wire insertion portion 11 is provided at the lower right end of the front surface of the case 10 (see FIGS. 1 and 2). From the electric wire insertion portion 11, electric wires 2 electrically connected to the bus bar 40 and electric wires 2 electrically connected to electronic components such as the relay 20 and the fuse 30 extend forward from the inside of the case 10 to the outside (see FIGS. 1 and 2).

[0014] 4 , each of the bus bars 40 held in the case 10 is an elongated metal plate having a predetermined shape when viewed from the top to bottom. Each of the bus bars 40 is attached to and held in a corresponding predetermined location on the lower part of the case 10 from bottom to top, with the plate thickness direction aligned with the direction perpendicular to the top to bottom direction (with the plate surface facing the direction perpendicular to the top to bottom direction). As a result, each of the bus bars 40 is electrically connected to the input terminal or output terminal of one or more corresponding electronic components (e.g., relays 20 or fuses 30), and the electronic components (e.g., relays 20 or fuses 30) are electrically connected to the electric wires 2 (see FIGS. 1 and 2 ) via the bus bars 40.

[0015] Hereinafter, we will focus on a pair of relays 20A, 20B (see FIGS. 1 to 5 ) among the multiple relays 20. In this example, the pair of relays 20A, 20B are relays for low-voltage circuits, but in some embodiments, they may be relays for high-voltage circuits. As shown in FIGS. 1 to 5 , the resin relay body of each of the pair of relays 20A, 20B has a generally rectangular parallelepiped shape extending in the front-rear, left-right, and up-down directions. The relay bodies of the pair of relays 20A, 20B are arranged side by side in the left-right direction, with a gap S (see FIGS. 2 to 4 ) between them. Therefore, when viewed from the direction in which the relay 20 is housed in the case 10 (the up-down direction), each relay body of the pair of relays 20A, 20B has a rectangular shape having one side 21 facing the gap S and an opposite side 22 opposite the one side 21. The one side 21 of each of the pair of relays 20A, 20B has a protrusion 23 protruding toward the gap S (see FIGS. 3 to 5 ). In this example, the protruding portions 23 of the pair of relays 20A and 20B are arranged so that the protruding ends face each other with a gap in the left-right direction.

[0016] Each of the pair of relays 20A, 20B has a plurality of terminals 51-54 (see FIGS. 4 to 6 ) connected to an internal circuit 60 (see FIG. 6 ) built into the relay body. Each of the plurality of terminals 51-54 is a metal flat (tab-shaped) terminal provided so as to protrude downward from the bottom end surface of each of the pair of relays 20A, 20B. In this example, as shown in FIGS. 4 and 5 , the two terminals 51, 52 are arranged opposite each other with a gap in the left-right direction in an area closer to the one side surface 21 on which the protrusion 23 is provided than the left-right center of the relay body. In other words, the protrusion 23 is arranged near two of the plurality of terminals 51-54, the terminals 51, 52. The two terminals 53, 54 are arranged opposite each other with a gap in the front-rear direction in an area closer to the opposite side surface 22 than the left-right center of the relay body.

[0017] Terminals 51 of relays 20A and 20B function as, for example, input-side contact terminals. Specifically, bus bar 40A is connected to terminal 51 of relay 20A via connection terminal 41, and bus bar 40B is connected to terminal 51 of relay 20B via connection terminal 41. Electric wires (not shown) connected to an external power supply (not shown) are connected to bus bars 40A and 40B. Meanwhile, terminals 52 of relays 20A and 20B function as, for example, output-side contact terminals. Specifically, electric wires (not shown) connected to an external load (not shown) are connected to terminals 52 of relay 20A and 20B. Each of bus bars 40A and 40B has a shape that extends generally in the front-to-rear direction when viewed in the up-down direction, although it includes a crank-shaped bent portion in part.

[0018] 6, the internal circuit 60 of each of the pair of relays 20A, 20B has a switch unit 61. The switch unit 61 has a fixed contact 62 and a movable contact 63, and is connected to the terminals 51, 52. The switch unit 61 is provided with a biasing member such as a spring (not shown), and this biasing member biases the movable contact 63 in a direction away from the fixed contact 62.

[0019] The internal circuit 60 has a coil portion 64 that functions as an electromagnet and is composed of a coil and an iron core (not shown). The coil portion 64 is connected to the terminals 53 and 54. The terminals 53 and 54 function as coil terminals. When a control current is supplied to the coil portion 64 via the terminals 53 and 54, the coil portion 64 generates a magnetic force, which attracts the movable contact 63 against the biasing force of the biasing member. As a result, when the coil portion 64 is energized, the movable contact 63 of the switch portion 61 contacts the fixed contact 62, and the switch portion 61 is in a closed state (ON). Conversely, when the coil portion 64 is not energized, the movable contact 63 of the switch portion 61 is separated from the fixed contact 62, and the switch portion 61 is in an open state (OFF).

[0020] The operation of the pair of relays 20A, 20B is controlled, for example, by an ECU (Electronic Control Unit) (not shown). When a control current is supplied from the ECU to the coil portion 64 of relay 20A via terminals 53, 54 and the switch portion 61 of relay 20A is closed, power from an external power source is supplied to an external load via relay 20A. When a control current is supplied to the coil portion 64 of relay 20B via terminals 53, 54 and the switch portion 61 of relay 20B is closed, power from the external power source is supplied to an external load via relay 20B.

[0021] In the electrical junction box 1 described above, each of the pair of relays 20A, 20B housed in the case 10 has a protrusion 23 that protrudes toward the gap S between the relays 20A, 20B. These protrusions 23 prevent the pair of relays 20A, 20B from being disposed excessively close to each other, and an appropriate gap S exists between the pair of relays 20A, 20B. Furthermore, the protrusions 23 are disposed near the two terminals 51, 52 of each of the pair of relays 20A, 20B. Because of the gap S between the pair of relays 20A, 20B, Joule heat generated at each of the terminals 51, 52 of the relays 20A, 20B is not concentrated in an excessively small area, and air flow through the gap S promotes heat dissipation. Therefore, the electrical junction box 1 has excellent heat dissipation properties from the relays 20A, 20B housed in the case 10. In addition, compared to dissipating the heat generated from each of the terminals 51 and 52 to different locations, dissipating the heat generated from each of the terminals 51 and 52 together in the gap S described above also contributes to making the electrical connection box 1 smaller.

[0022] Furthermore, the pair of relays 20A and 20B are arranged so that the protruding portion 23 of the relay 20A and the protruding portion 23 of the relay 20B do not come into contact with each other, thereby making it possible to widen the gap between the pair of relays 20A and 20B compared to when the protruding portions 23 come into contact with each other.

[0023] Furthermore, the protrusion 23 of the relay 20A does not contact the relay 20B, and the protrusion 23 of the relay 20B does not contact the relay 20A. This makes it possible to widen the gap S between the pair of relays 20A and 20B compared to when each protrusion 23 contacts the other relay 20.

[0024] Furthermore, the protrusion 23 is disposed near two terminals 51 and 52 of the plurality of terminals 51 to 54. This allows the Joule heat generated at the two terminals 51 and 52 of each of the relays 20A and 20B to be properly dissipated.

[0025] Furthermore, the protruding end (right end) of the protruding portion 23 of the relay 20A is closer to the relay 20B than the terminal 51 of the relay 20A, and the protruding end (left end) of the protruding portion 23 of the relay 20B is closer to the relay 20A than the terminal 51 of the relay 20B. This allows the terminal 51 of the relay 20A to be reliably disposed at a position away from the relay 20B, and the terminal 51 of the relay 20B to be reliably disposed at a position away from the relay 20A. This allows the Joule heat generated at the terminal 51 to be properly dissipated.

[0026] Furthermore, a protrusion 23 is provided on one side surface 21 of the relay body of each of relays 20A and 20B facing the gap S. This allows the shape of the protrusion 23 to be simpler than when the protrusion 23 protrudes from another side surface of the relay body toward the gap S. This allows the manufacturing cost of the relay 20 to be reduced.

[0027] Furthermore, as shown by the dashed line in Fig. 4, a heat transfer member 70 may be provided in the electrical junction box 1 to absorb heat emitted from at least one terminal (terminals 51 and 52 in Fig. 4) of the terminals 51 to 54 of each of the pair of relays 20A and 20B and transfer the heat in a direction away from the terminal. The heat transfer member 70 is made of, for example, a metal plate and is configured to extend from the vicinity of the terminals 51 and 52 toward the outside of the case 10. The heat transfer member 70 is also referred to as a heat-dissipating component. This can further improve the heat dissipation from the relays 20A and 20B housed in the case 10.

[0028] 4 , when viewed from the direction in which relay 20 is housed in case 10 (the up-down direction), bus bar 40A connected to terminal 51 of relay 20A and bus bar 40B connected to terminal 51 of relay 20B are shaped so that the entire bus bars 40A, 40B are located within a left-right range H1 sandwiched between a line L1 extending in the front-rear direction as an imaginary extension of the reverse side surface 22 of relay 20A and a line L2 extending in the front-rear direction as an imaginary extension of the reverse side surface 22 of relay 20B. In other words, bus bars 40A, 40B are arranged so as to fit within the minimum left-right width (i.e., inside range H1) required for case 10 to house a pair of relays 20A, 20B.

[0029] Then, the layout of electronic components (e.g., fuses 30, etc.) different from relay 20 is designed based on the layout of bus bars 40A, 40B so that they fit within range H1. In the example shown in Fig. 4, the layout of two fuses 30 is designed so that two fuses 30 are connected to bus bar 40A based on the layout of bus bar 40A connected to terminal 51 of relay 20A. As a result, it is considered that the overall size of electrical junction box 1 can be more easily reduced than when bus bars 40A, 40B are spread over the entire case 10.

[0030] Furthermore, when viewed from the housing direction (vertical direction) of the relay 20, the bus bar 40A connected to the relay 20A has a shape such that the entire bus bar 40A is located within a range H2 sandwiched between a line L1 extending in the front-rear direction as an imaginary extension of the opposite side surface 22 of the relay 20A and a line L3 extending in the front-rear direction as an imaginary extension of one side surface 21 of the relay 20B. In other words, the bus bar 40A is arranged so as to fit within a range H2 narrower than the above-mentioned range H1.

[0031] Similarly, bus bar 40B connected to relay 20B has a shape such that, when viewed from the housing direction (vertical direction) of relay 20, bus bar 40B is entirely located within range H3 sandwiched between line L2 extending in the front-rear direction as an imaginary extension of reverse side surface 22 of relay 20B and line L4 extending in the front-rear direction as an imaginary extension of one side surface 21 of relay 20A. In other words, bus bar 40B is arranged so as to fit within range H3 which is narrower than range H1 described above.

[0032] In this way, it is believed that by further specifying the arrangement of the bus bars 40A, 40B so that they fall within the above-mentioned ranges H2 and H3, it is possible to further reduce the size of the electrical junction box 1.

[0033] Furthermore, bus bars 40A and 40B are connected to terminals 51 for inputting power to relays 20A and 20B, respectively. This allows the electrical junction box 1 to be made smaller even when large, thick bus bars 40A and 40B are used to input power to relays 20A and 20B using these terminals 51.

[0034] It should be noted that 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 modifications, improvements, etc. are possible as appropriate. Furthermore, the material, shape, dimensions, number, location, etc. of each component in the above-described embodiments are arbitrary as long as they can achieve the present invention, and are not limited thereto.

[0035] Here, in the above-described embodiment of the present invention, the electrical connection box (1) comprises: a pair of relays (20A, 20B) arranged with a gap (S) between them; a case (10) that houses the pair of relays (20A, 20B); and a heat transfer member (70) that is arranged in the case (10), wherein each of the pair of relays (20A, 20B) has a plurality of terminals (51 to 54) connected to an internal circuit (60) of the relay, and a protrusion (23) that has a shape that protrudes toward the gap (S) in the vicinity of at least one (51, 52) of the plurality of terminals (51 to 54), and the heat transfer member (70) is configured to absorb heat released from the at least one terminal (51, 52) and transfer the heat in a direction away from the at least one terminal (51, 52).

[0036] According to the electrical junction box having the above configuration, each of the pair of relays housed in the case has a protruding portion that protrudes toward the gap between the relays. These protruding portions prevent the pair of relays from being placed too close together, creating an appropriate gap between the pair of relays. Furthermore, the protruding portion is located near at least one terminal of the relay. The presence of a gap between the pair of relays prevents Joule heat generated at each relay terminal from concentrating in an excessively small area, and air flow through the gap promotes heat dissipation. Furthermore, the heat transfer member that absorbs heat emitted from at least one terminal and transfers it away from that terminal further improves heat dissipation from the relay housed in the case. Therefore, the electrical junction box having this configuration has excellent heat dissipation properties from the relay housed in the case. In addition, compared to dissipating heat from each terminal to different locations, dissipating heat from each terminal collectively through the above-mentioned gap contributes to the miniaturization of the electrical junction box.

[0037] Furthermore, the pair of relays (20A, 20B) may be arranged such that the protrusion (23) of one relay (20A) and the protrusion (23) of the other relay (20B) do not come into contact with each other.

[0038] In the electrical junction box having the above configuration, the pair of relays are arranged so that the protruding portion of one relay does not come into contact with the protruding portion of the other relay, thereby making it possible to widen the gap between the pair of relays compared to when the protruding portions come into contact with each other.

[0039] Furthermore, the protrusion (23) of one of the relays (20A) may not contact the other of the relays (20B), and the protrusion (23) of the other of the relays (20B) may not contact the one of the relays (20A).

[0040] With the electrical junction box having the above configuration, the protrusion of one relay does not contact the other relay, and the protrusion of the other relay does not contact the one relay, which allows the gap between the pair of relays to be wider than when each protrusion contacts the other relay.

[0041] Furthermore, the protrusion (23) may be disposed near two of the terminals (51, 52) of the plurality of terminals (51 to 54).

[0042] According to the electrical junction box having the above configuration, the protrusions are disposed near two of the plurality of terminals, thereby enabling Joule heat generated at the two terminals of the relay to be properly dissipated.

[0043] Furthermore, the protruding end of the protruding portion (23) of one of the relays (20A) may be closer to the other of the relays (20B) than the at least one terminal (51) of the one of the relays (20A), or the protruding end of the protruding portion (23) of the other of the relays (20B) may be closer to one of the relays (20A) than the at least one terminal (51) of the other of the relays (20B).

[0044] In the electrical junction box having the above configuration, the protruding end of the protruding portion of one relay is closer to the other relay than at least one terminal of the other relay. The same is true for the protruding portion of the other relay. This allows the terminals of one relay to be reliably positioned away from the other relay, and the terminals of the other relay to be reliably positioned away from the one relay. This allows Joule heat generated at each terminal to be properly dissipated.

[0045] Furthermore, the protrusion (23) may be provided on a side surface (21) of each of the pair of relays (20A, 20B) facing the gap (S), in the vicinity of the at least one terminal (51, 52).

[0046] According to the electrical junction box having the above configuration, a protrusion is provided on the side surface of each relay facing the gap between the pair of relays. This allows the shape of the protrusion to be simpler than when the protrusion protrudes toward the gap from another side surface, thereby reducing the manufacturing cost of the relays.

[0047] This application is based on a Japanese patent application (Patent Application No. 2023-097655) filed on June 14, 2023, the contents of which are incorporated herein by reference.

[0048] The electrical junction box of the present invention is excellent in heat dissipation from a relay housed in a case of the electrical junction box. The present invention having this effect can be used, for example, as a relay box mounted on an automobile or the like.

[0049] REFERENCE SIGNS LIST 1 Electrical junction box 10 Case 20A Relay 20B Relay 21 One side surface (side surface) 23 Protrusion 51 to 54 Terminal 60 Internal circuit 70 Heat transfer member S Gap

Claims

1. An electrical junction box comprising: a pair of relays arranged with a gap between them; a case that houses the pair of relays; and a heat transfer member arranged within the case, wherein each of the pair of relays has a plurality of terminals connected to an internal circuit of the relay and a protrusion having a shape that protrudes toward the gap near at least one of the plurality of terminals, and the heat transfer member is configured to absorb heat released from the at least one terminal and transfer the heat in a direction away from the at least one terminal.

2. An electrical junction box as claimed in claim 1, wherein the pair of relays are arranged such that the protrusion of one relay and the protrusion of the other relay do not come into contact with each other.

3. An electrical junction box as claimed in claim 1, wherein the protrusion of one of the relays does not come into contact with the other of the relays, and the protrusion of the other of the relays does not come into contact with the one of the relays.

4. An electrical connection box according to claim 1, wherein the protrusions are disposed in the vicinity of two of the plurality of terminals.

5. An electrical junction box as claimed in claim 1, wherein a protruding end of the protrusion of one of the relays is closer to the other of the relays than is at least one of the terminals of the one of the relays, and a protruding end of the protrusion of the other of the relays is closer to the one of the relays than is at least one of the terminals of the other of the relays.

6. An electrical junction box according to claim 1, wherein the protrusion is provided on a side surface of each of the pair of relays facing the gap, in the vicinity of the at least one terminal.

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