Electrical connection box

Abstract

An electrical connection box (1) is provided with a pair of relays (20A, 20B), bus bars (40A, 40B), and a case (10). Each of the pair of relays, when viewed from a direction in which the relay is accommodated in the case, has a quadrangular shape having one side surface (21) facing a gap (S) and an opposite side surface (22) on the opposite side to the one side surface. The bus bars (40A, 40B) have a shape such that, when viewed from the accommodating direction, the entire bus bars are positioned within an area (H1) sandwiched between a straight line (L1) in which the opposite side surface (22) of one relay (20A) is virtually extended and a straight line (L2) in which the opposite side surface (22) of the other relay (20B) is virtually extended.

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 electrical junction box of the above type, bus bars for supplying power to electronic components such as relays and fuses are generally provided so as to extend over the entire case. However, from the viewpoint of miniaturizing the electrical junction box, there is thought to be room for improvement in the arrangement and structure of the bus bars and electronic components.

[0005] An object of the present invention is to provide an electrical junction box that can be made compact.

[0006] In one aspect of the present invention, an electrical connection box comprises: a pair of relays arranged with a gap between them; a bus bar connected to each of the pair of relays; and a case that houses the pair of relays and the bus bar, wherein each of the pair of relays has a rectangular shape, when viewed from the direction in which the relays are housed in the case, having one side facing the gap and an opposite side opposite the one side, and the bus bar has a shape such that, when viewed from the housing direction, the entire bus bar is located within a range sandwiched between a straight line that is an imaginary extension of the opposite side of one of the relays and a straight line that is an imaginary extension of the opposite side of the other of the relays.

[0007] 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 a relay 20A shown in Fig. 4. Fig. 6 is a diagram for explaining the internal circuitry of a pair of relays 20A, 20B shown in Fig. 4.

[0008] 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.

[0009] For the sake of convenience, the following definitions are used for the terms "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, respectively. The upper-to-lower direction corresponds to the "storage direction" of the present invention. 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.

[0010] 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.

[0011] 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.

[0012] 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).

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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).

[0019] 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.

[0020] 4 , when viewed from the direction in which the relay 20 is housed in the case 10 (the up-down direction), the bus bar 40A connected to the terminal 51 of the relay 20A and the bus bar 40B connected to the terminal 51 of the relay 20B each have a shape such that the entire bus bar 40A, 40B is 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 the relay 20A and a line L2 extending in the front-rear direction as an imaginary extension of the reverse side surface 22 of the relay 20B. In other words, the bus bars 40A, 40B are arranged so as to fit within the minimum left-right width (i.e., inside the range H1) required for the case 10 to house the pair of relays 20A, 20B.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] Furthermore, when viewed from the direction in which the relay 20 is housed (the up-down direction), 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 straight line L1 extending in the front-rear direction as a virtual extension of the opposite side surface 22 of the relay 20A and a straight line L3 extending in the front-rear direction as a virtual 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. Similarly, when viewed from the direction in which the relay 20 is housed (the up-down direction), the bus bar 40B has a shape such that the entire bus bar 40B is located within a range H3 sandwiched between a straight line L2 extending in the front-rear direction as a virtual extension of the opposite side surface 22 of the relay 20B and a straight line L4 extending in the front-rear direction as a virtual extension of one side surface 21 of the relay 20A. In other words, the bus bar 40B is arranged so as to fit within the range H3 which is narrower than the range H1 described above. This further specifies the arrangement of the bus bars 40A and 40B, and it is believed that the electrical junction box 1 can be further miniaturized.

[0027] From a perspective separate from the above-described miniaturization, 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. The presence of the gap S between the pair of relays 20A, 20B prevents Joule heat generated at each of the terminals 51, 52 of the relays 20A, 20B from concentrating 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[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) is an electrical connection box (1) comprising: a pair of relays (20A, 20B) arranged with a gap (S) therebetween; bus bars (40A, 40B) connected to each of the pair of relays (20A, 20B); and a case (10) that houses the pair of relays (20A, 20B) and the bus bars (40A, 40B), wherein each of the pair of relays (20A, 20B) has a rectangular shape having one side surface (21) facing the gap (S) and an opposite side surface (22) that is opposite to the one side surface (21) when viewed from the direction in which the relays (20A, 20B) are housed in the case (10), and the bus bars (40A, 40B) are When viewed from the storage direction, the busbars (40A, 40B) have a shape in which the entire busbar (40A, 40B) is located within a range (H1) sandwiched between a straight line (L1) that is a virtual extension of the opposite side surface (22) of one of the relays (20A) and a straight line (L2) that is a virtual extension of the opposite side surface (22) of the other relay (20B).

[0036] In the electrical junction box having the above configuration, each of the pair of relays has a rectangular shape, when viewed from the direction in which the relays are housed in the case (e.g., vertically), with one side facing the gap between the relays and an opposite side opposite the one side. Furthermore, when viewed from the direction in which the relays are housed in the case, the bus bar is shaped so that the entire bus bar is located within a range between a line that is a virtual extension of the opposite side of one relay and a line that is a virtual extension of the opposite side of the other relay. This allows the bus bar to be positioned so that it fits within the minimum width (i.e., within the above-mentioned range) required for the case to house the pair of relays. The layout of other electronic components (e.g., fuses, etc.) is then designed based on this bus bar layout. As a result, the overall size of the electrical junction box is believed to be easier to achieve than when the bus bar layout is not restricted as in the present configuration and the bus bar is spread across the entire case. Therefore, the electrical junction box having the present configuration is capable of being miniaturized.

[0037] Furthermore, each of the pair of relays (20A, 20B) may have an input terminal (51) and an output terminal (52), and the bus bar (40A, 40B) may be connected to at least one (51) of the input terminal (51) and the output terminal (52).

[0038] In the electrical junction box having the above configuration, the bus bar is connected to at least one of the input terminal and the output terminal of the relay, which allows the electrical junction box to be miniaturized even when a large, thick bus bar is used to use the terminals for inputting and outputting power to and from the relay.

[0039] Furthermore, the bus bar (40A (40B)) connected to one of the relays (20A (20B)) may have a shape such that, when viewed from the storage direction, the entire bus bar (40A (40B)) is located within a range (H2 (H3)) sandwiched between a straight line (L1) that is a virtual extension of the opposite side (22) of one of the relays (20A (20B)) and a straight line (L3 (L4)) that is a virtual extension of one side (21) of the other relay (20B (20A)).

[0040] In the electrical junction box having the above configuration, the bus bar connected to one of the relays has a shape such that, when viewed from the direction in which the relays are accommodated, the bus bar is entirely located within a range sandwiched between a line that is an imaginary extension of the opposite side of one of the relays and a line that is an imaginary extension of one side of the other relay. This allows for more specific placement of the bus bar within the above range, thereby enabling further miniaturization of the electrical junction box.

[0041] Furthermore, the electrical junction box (1) may further include an electronic component (30) connected to the bus bar (40A) connected to one of the relays (20A). In addition, the electronic component may be a fuse (30) separate from the relays (20A, 20B).

[0042] According to the electrical junction box having the above-described configuration, an electronic component (for example, a fuse) connected to the bus bar is attached to the electrical junction box, thereby specifically realizing the present invention.

[0043] The electrical junction box of the present invention can be miniaturized. The present invention having this effect can be used, for example, as a relay box mounted on an automobile or the like.

[0044] 1 Electrical junction box 10 Case 20A Relay 20B Relay 21 One side 22 Opposite side 30 Fuse (electronic component) 40A Bus bar 40B Bus bar 51 Input terminal 52 Output terminal S Gap

Claims

1. An electrical junction box comprising: a pair of relays arranged with a gap between them; a bus bar connected to each of the pair of relays; and a case that houses the pair of relays and the bus bar, wherein each of the pair of relays has a rectangular shape having one side facing the gap and an opposite side opposite the one side when viewed from the direction in which the relays are housed in the case, and the bus bar has a shape such that, when viewed from the direction in which the bus bar is housed, the entire bus bar is located within a range between a straight line that is an imaginary extension of the opposite side of one of the relays and a straight line that is an imaginary extension of the opposite side of the other of the relays.

2. An electrical junction box according to claim 1, wherein each of the pair of relays has an input terminal and an output terminal, and the bus bar is connected to at least one of the input terminal and the output terminal.

3. An electrical junction box as claimed in claim 1 or 2, wherein the bus bar connected to one of the relays has a shape such that, when viewed from the housing direction, the entire bus bar is located within a range between a straight line which is an imaginary extension of the opposite side of one of the relays and a straight line which is an imaginary extension of the one side of the other of the relays.

4. An electrical connection box according to any one of claims 1 to 3, further comprising an electronic component connected to the bus bar which is connected to one of the relays.

5. The electrical junction box according to claim 4, wherein the electronic component is a fuse different from the relay.

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