JP2015104185A - Electric connection box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric connection box with a novel structure, which can prevent a vehicle fire after immersed in water without depending on a waterproof structure of the electric connection box.SOLUTION: In an electric connection box 10 in which a power supply side bus bar 46b connected to a power supply line, and a plurality of bus bars 46a1, a2, b, c containing downstream side bas bars 46a1, a2 connected to an electrical load or a ground line, form an internal circuit, the power supply side bus bar 46b and downstream side bus bars 46a1, a2 are arranged adjacent to each other, and a plurality of insulation barriers 60, 60 stand mutually at a gap between the power supply side bus bar 46b and downstream side bus bars 46a1, a2.

Description

  The present invention relates to an electrical junction box mounted on a vehicle such as an automobile, and more particularly to an electrical junction box including an internal circuit configured to include a bus bar.

  Conventionally, an electric junction box is provided at an appropriate place in an electrical system such as an automobile, and power distribution from a battery to various loads is performed efficiently. Specifically, a plurality of bus bars including a power source side bus bar connected to the power source line and a downstream side bus bar connected to the electrical load or the ground line are accommodated and arranged inside the electrical junction box. Power distribution is performed via an internal circuit configured to include

  By the way, if water enters the inside of such an electrical junction box, there is a risk of short circuiting between adjacent bus bars. Waterproofing measures are taken. For example, as described in Japanese Patent No. 4585980 (Patent Document 1), the gap between the cases of the electrical junction box is sealed with a sealing material or the like, or the water that has entered the interior by providing a drain slope at an appropriate place in the case It is known to encourage the drainage of water.

  However, since the conventional waterproof structure of the electrical junction box is assumed to be used when the vehicle is used, sufficient waterproof effect is exhibited in unexpected cases such as flooding due to tsunami or flood at the time of disaster such as the Great East Japan Earthquake. Of course it can't be done. Many cases have been reported in which an electrical junction box near the battery of a vehicle ignites and a vehicle fire occurs after unexpected flooding.

  It is urgent to devise any measures to prevent the electrical junction box from igniting after such unexpected flooding, but applying a waterproof structure to the electrical junction box that assumes flooding due to tsunami, flooding, etc. Not only does this increase the size and cost of the electrical junction box, but it may also hinder the function of the electrical junction box during normal vehicle use, which is not a realistic measure. Therefore, there has been a demand for an effective measure that can prevent ignition of the electrical junction box after flooding.

Japanese Patent No. 4585980

  The present invention has been made in the background of the above-mentioned circumstances, and its solution is a novel structure capable of preventing the occurrence of a vehicle fire after flooding without depending on the waterproof structure of the electrical junction box. Is to provide an electrical junction box.

As a result of inventor's earnest research on the cause of ignition after vehicle inundation, especially in the electrical connection box directly connected to the battery, the copper power supply side bus bar connected to the power supply line and the electrical load or the copper connection connected to the ground line It has been found that ignition occurs at a portion where the downstream bus bar is adjacently disposed. That is, when the vehicle is immersed in water containing an electrolyte such as salt water, electrolysis occurs between the power source side bus bar and the downstream side bus bar having a relatively large potential difference, and the cuprous oxide which is a copper oxide at the anode. (Cu ₂ 0) precipitates. When water is drawn, the deposited cuprous oxide is deposited between the power supply side bus bar and the downstream side bus bar, thereby forming a short-circuit path between the two due to the cuprous oxide deposit. Even after flooding, the battery continues to be energized, and when the temperature rises to some extent, the cuprous oxide lowers its resistance, causing a short circuit. It was newly found out that a fire occurs when the neighboring synthetic resin member burns due to the heat generated at that time. The present invention has been completed based on such a new viewpoint.

  A first aspect of the present invention is an electrical junction box in which an internal circuit is configured by a plurality of bus bars including a power source side bus bar connected to a power source line and an electrical load or a downstream side bus bar connected to a ground line. The power supply side bus bar and the downstream side bus bar are disposed adjacent to each other, and a plurality of insulating partition walls are provided between the power supply side bus bar and the downstream side bus bar with a gap therebetween. It is characterized by.

  According to this aspect, the plurality of insulating partition walls are erected between the adjacently disposed power supply side bus bar and the downstream side bus bar with a gap therebetween. As a result, even if the vehicle is inundated by a tsunami, flood, etc. and electrolysis occurs between the adjacent power supply side bus bar and the downstream side bus bar with a large potential difference, cuprous oxide is generated between them. It is possible to prevent the conductive path formed by the deposited oxide from being formed between the bus bars by the insulating partition walls provided in the gap and the gaps therebetween. In particular, since the plurality of insulating partition walls are erected with a gap between each other, it is possible to earn a separation distance between the power supply side bus bar and the downstream side bus bar constituted by the surfaces of the insulating partition walls. Therefore, even if the deposited oxide extends along the wall surface of the insulating partition, it can be advantageously prevented from reaching the length connecting the power supply side bus bar and the downstream side bus bar.

  The power source side bus bar includes not only those directly connected to the plus terminal of the battery as the power line but also those indirectly connected through other members. Further, the downstream bus bar includes not only those directly connected to the negative terminal of the battery, which is a ground line, but also those indirectly connected to the ground line via other members or electrical loads. In short, the power supply side bus bar and the downstream side bus bar are constituted by two bus bars arranged adjacent to each other having a potential difference.

  According to a second aspect of the present invention, in the first aspect, the internal circuit is accommodated and disposed in a synthetic resin main body, and a plurality of electrical components are mounted on the surface of the main body. A first receiving groove for receiving the power supply side bus bar and a second receiving groove for receiving the downstream side bus bar are provided on the back surface of the main body portion, extending in parallel with each other and receiving the power source side bus bar. The first receiving groove and the second receiving groove are formed by opening a space extending in parallel between the first receiving groove and the second receiving groove. Each of the inner wall portions of the housing groove constitutes the plurality of insulating partition walls that are erected with a gap from each other by the space.

  According to this aspect, the first and second receiving grooves that respectively accommodate the power source side bus bar and the downstream side bus bar are provided with a space extending in parallel along the first and second receiving grooves. It is possible to form a plurality of insulating partition walls that are erected with a gap therebetween. And, by using the inner wall portion of each housing groove as an insulating partition, it is possible to form a structure that prevents ignition after flooding without enlarging the electrical junction box and increasing the number of parts. is there.

  A third aspect of the present invention is the one described in the second aspect, wherein the space has a groove depth dimension larger than a groove width dimension.

  According to this aspect, the distance between the power supply side bus bar and the downstream side bus bar formed by the surface of the insulating partition wall can be increased by increasing the groove depth dimension of the void. Therefore, even if it is impossible to change the separation distance in the width direction, such as a relay input / output bus bar, the distance is advantageously increased by increasing the depth dimension, and the short-circuit path due to the deposited oxide. Can be prevented.

  According to a fourth aspect of the present invention, in the second or third aspect, each of the first receiving groove and the second receiving groove has a groove depth dimension larger than a groove width dimension. On the other hand, the power source side bus bar and the downstream side bus bar are formed in the first receiving groove and the second receiving groove so that the plate thickness direction of the power source side bus bar and the downstream side bus bar is the groove width direction. Contained and arranged.

  According to this aspect, the power supply side bus bar and the downstream side bus bar can be accommodated in the first and second accommodation grooves in a so-called vertical arrangement. Therefore, as compared with a so-called flat arrangement, substantially the entire bus bar can be accommodated in the first and second accommodation grooves to reduce the exposed surface. Therefore, even if it is immersed in water, the exposed surface of the bus bar can be reduced to limit the amount of oxide deposited.

  According to the present invention, the plurality of insulating partition walls are erected between the power supply side bus bar and the downstream side bus bar arranged adjacent to each other with a gap therebetween. Therefore, even if submerged oxide forms cuprous oxide between the adjacent power supply side bus bar and downstream side bus bar, a conductive path due to the deposited oxide is formed between the bus bars by the insulating partition walls and the gaps between them. Can be prevented. In particular, since the plurality of insulating partition walls are spaced from each other, the distance between the power supply side bus bar and the downstream side bus bar constituted by the surface of the insulating partition wall can be increased, so the power supply side bus bar and the downstream side Reaching the length connecting the bus bars can be advantageously prevented.

The perspective view which shows the electrical-connection box as 1st embodiment of this invention. The top view of the electrical-connection box shown in FIG. The bottom view of the electrical junction box shown in FIG. The principal part enlarged view of the IV-IV cross section in FIG. The principal part expanded sectional view equivalent to FIG. 4 which shows the electrical-connection box as 2nd embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 4 show a relay block 10 as an electric junction box according to the first embodiment of the present invention. As shown in FIG. 1, the relay block 10 has a structure in which a fuse mounting portion 16 as a plurality of electrical component mounting portions and relay mounting portions 18 a to 18 c are provided on the surface 14 of the main body portion 12. Yes. In the following description, unless otherwise specified, “upper” means the upper side in FIG. 1, and “lower” means the lower side in FIG.

  As shown in FIG. 1 and FIG. 2, the main body 12 has a substantially rectangular block shape made of synthetic resin. The locking claw 20 and the guide rib 22 are integrally formed.

  A plurality of fuse mounting portions 16 protrude from the surface 14 and are integrally formed with the main body portion 12 at the central portion of the surface 14 of the main body portion 12. The fuse mounting portion 16 has a cavity shape that opens above the main body portion 12 into which a fuse as an electrical component can be inserted. That is, the fuse mounting portion 16 is configured to include fuse terminal insertion holes 24a and 24b into which fuse terminals are inserted, and one fuse terminal insertion hole 24a has bus bars 46a1, 46a2, 46b, and 46c described later. Is connected to the other fuse terminal insertion hole 24b, and is connected to a tubular fuse provided at the end of an electric wire constituting an external electric circuit (not shown). Terminals are provided. In the present embodiment, a plurality of fuse mounting portions 16 are arranged in a straight line, and three fuse mounting portion groups 28a to 28c surrounded by the peripheral wall 26 are formed, and these three fuse mounting portion groups 28a are formed. ˜c are juxtaposed in the central portion of the surface 14.

  In addition, relay attachment portions 18 a to 18 c are opened upward at both ends in the longitudinal direction of the surface 14 of the main body 12 and are integrally formed with the main body 12. In the present embodiment, one relay mounting portion 18a is formed at one end of the surface 14 in the longitudinal direction (left side in FIG. 2), while the other end (right side in FIG. 2) is formed at one end. A pair of relay mounting portions 18b and 18c are formed adjacent to each other. Relays 30a to 30c as electrical parts can be mounted on the relay mounting portions 18a to 18c.

  More specifically, a pair of locking protrusions 32 and 32 protrude outward from the surface 14 and are integrally formed with the main body 12 at positions facing each other on the outer peripheral portions of the relay mounting portions 18a to 18c. Then, by inserting the relays 30a to 30c from above along the inner walls of the guide walls 34 protruding from the four corners of the relay mounting portions 18a to 18c, the pair of locking protrusions 32 and 32 are connected to the relays 30a to 30a. The relays 30a to 30c are accommodated and held in the relay mounting portions 18a to 18c in a state where they are engaged and fixed with locking protrusions (not shown) provided on the side surfaces of the c.

  On the other hand, as shown in FIG. 3, the rear surface 38 of the main body 12 has bus bar receiving grooves 40a1, 40a2, 40b, 40c communicated with the fuse terminal insertion holes 24a on the front surface 14 and fuse terminal insertion holes 24b. A plurality of connection terminal insertion holes 42 communicated with each other are formed. The bus bar housing grooves 40a1, 40a2, 40b, and 40c are formed at positions corresponding to the three fuse mounting portion groups 28a to 28c on the surface 14, and the bus bars 46a1, 46a2, 46b, and 46c are housed and arranged, respectively. On the other hand, each connection terminal insertion hole 42 is inserted with a connection terminal provided at an end of an electric wire constituting an external electric circuit (not shown). Thus, in the present embodiment, the internal circuit is configured including the bus bars 46 a 1, 46 a 2, 46 b and 46 c, the relays 30 a to 30 c, and the fuse (not shown), and is accommodated in the main body 12.

  Each of the bus bars 46a1, 46a2, 46b, 46c extends parallel to and adjacent to each other in the longitudinal direction of the main body 12 and has bus bar receiving grooves 40a1, 40a2, 40b, 40c is housed and arranged. Each of the bus bars 46a1, 46a2, 46b, and 46c is a belt-like member extending in a substantially rectangular cross-section formed by press punching a conductive metal plate. Such bus bars 46a1, 46a2, 46b, 46c have a so-called vertical arrangement in which the plate thickness direction is the groove width direction of the bus bar receiving grooves 40a1, 40a2, 40b, 40c, and the bus bar receiving grooves 40a1, 40a2, 40b, 40c. It is housed and arranged. Therefore, in order to facilitate the insertion work, the opening portions of the bus bar housing grooves 40a1, 40a2, 40b, and 40c have an inversely tapered shape that gradually becomes wider toward the opening.

  One end of the bus bar 46b accommodated in the bus bar accommodating groove 40b protrudes into the connector mounting portion 50 at one end in the longitudinal direction of the main body 12 (left side in FIG. 3), and the power supply side (not shown) When the power supply connector is attached to the connector attachment portion 50, a power supply voltage is applied to the bus bar 46b. The bus bars 46a1 and 46a2 accommodated in the bus bar accommodating grooves 40a1 and 40a2 are spaced apart from each other in the longitudinal direction of the main body 12, and the bus bars 46a1 and 46a2 are respectively connected to the bus bar 46b via relays 30a and 30b. It is connected to the.

  That is, by turning on the relays 30a and 30b, a power supply voltage is applied to the bus bars 46a1 and 46a2, and the power supply voltage is transmitted to an external electric circuit through fuses (not shown) attached to the plurality of fuse attachment portions 16. It is distributed and finally connected to a ground line (body earth) via a load such as an in-vehicle electrical component. In unexpected cases, such as the Great East Japan Earthquake, where the vehicle is inundated by a tsunami or flood, the vehicle is normally stopped, so the relays 30a and 30b are off, and the bus bar 46b 12V, 0V is applied to the bus bars 46a1 and 46a2. Therefore, in this embodiment, the bus bar 46b is a power supply side bus bar connected to the power supply line, while the bus bars 46a1 and 46a2 are downstream side bus bars connected to the ground line. In this embodiment, the bus bar housing groove 40b for housing the bus bar 46b (power supply side bus bar) constitutes the first housing groove, and the bus bar housing grooves 40a1, 40a2 for housing the bus bars 46a1, a2 (downstream bus bar) are the first. Two housing grooves are formed.

  As shown in FIG. 4, the cross-sectional shapes of the bus bar housing groove 40b as the first housing groove and the bus bar housing grooves 40a1 and 40a2 as the second housing groove are substantially the same, and the groove width dimension: W1 Also, the groove depth dimension: D1 is large. The bus bar 46b and the bus bars 46a1 and 46a2 are arranged so that the thickness direction of the bus bar 46b and the bus bars 46a1 and 46a2 is the groove width direction (left and right direction in FIG. 4). Contained.

  Further, as shown in FIG. 3, a space 52 extending in parallel along the bus bar accommodating groove 40b and the bus bar accommodating grooves 40a1 and 40a2 is formed as an opening. As shown in FIG. 4, the cavity 52 has a substantially rectangular cross-sectional shape, and includes a bottom surface 54 and a pair of side surfaces 56 and 56 as vertical surfaces extending from the bottom surface 54 in the vertical direction. It is configured. Thereby, each inner wall part of the bus-bar accommodation groove | channel 40b and the bus-bar accommodation groove | channel 40a1, 40a2 comprises the pair of insulating partition walls 60 and 60 standingly spaced apart from each other by the space 52. In short, the bus bar 46b and the bus bars 46a1 and 46a2 are disposed adjacent to each other, and the pair of insulating partition walls 60 and 60 are provided between the bus bar 46b and the bus bars 46a1 and 46a2 with a space 52 that forms a gap therebetween. It has been done. As shown in FIG. 4, the void 52 has a shape in which the groove depth dimension: D2 is larger than the groove width dimension: W2.

  Here, the power supply side bus bar includes not only those directly connected to the plus terminal of the battery which is the power supply line, but also those connected indirectly through other members. Further, the downstream bus bar includes not only those directly connected to the negative terminal of the battery, which is a ground line, but also those connected indirectly through other members or electrical loads. In short, the power supply side bus bar and the downstream side bus bar are constituted by two bus bars arranged adjacent to each other having a potential difference. For example, in addition to 12V, the power supply side bus bar includes a bus bar to which a voltage such as 24V or 48V is applied and a bus bar to which a voltage of 12V or less is applied. In addition to the bus bar to which a voltage of 0 V is applied, the downstream bus bar includes a bus bar to which a voltage of 0 V or more lower than that of the power supply side bus bar is applied.

  According to the relay block 10 as the electrical junction box of the present embodiment having such a structure, the bus bar housing that accommodates the bus bar 46b that is the power supply side bus bar and the bus bars 46a1 and 46a2 that are the downstream side bus bars arranged adjacent to each other. Between the groove 40b and the bus bar housing grooves 40a1 and 40a2, a space 52 extending in parallel therewith is provided. By providing such a space 52, it is possible to configure the insulating partition walls 60 and 60 that are spaced apart from each other with the space 52 as a gap between the bus bar 46b and the bus bars 46a1 and 46a2. As a result, even if the vehicle is inundated by a tsunami, flood, etc., and electrolysis occurs when 12V is applied to the bus bar 46b (power supply side bus bar) and 0V is applied to the bus bars 46a1 and 46a2 (downstream bus bar), It is possible to prevent cuprous oxide, which is an oxide generated by electrolysis between the bus bars, from falling into the void 52 and forming a conductive path due to the deposited oxide between the bus bars 46a1 and 46a2 and the bus bar 46b. is there. That is, since a gap formed by the void 52 is provided between the bus bars 46a1 and 46a2 and the bus bar 46b, the pair of side surfaces 56 and 56 and the bottom surface 54 constituting the gap make the gap between the bus bars 46a1 and 46a2 and the bus bar 46b. The distance between the bus bars 46a1 and 46a2 and the bus bar 46b can be prevented from being conducted through the conduction path formed by the deposited oxide. Further, since the pair of side surfaces 56, 56 constituting the gap are vertical surfaces protruding from the bottom surface 54 in the vertical direction, the oxide is encouraged to fall downward, and the oxide is introduced by the deposited oxide. The passage can be advantageously prevented from depositing on the pair of side surfaces 56,56. As described above, a simple structure is provided in which a space 52 extending in parallel along the bus bar housing groove 40b (first housing groove) and the bus bar housing grooves 40a1 and 40a2 (second housing groove) is provided. Therefore, the present invention can be realized without side effects such as an increase in the size of the electrical connection box and an increase in the number of parts.

  In addition, since the void 52 has a shape in which the groove depth dimension: D2 is larger than the groove width dimension: W2, a pair of side surfaces 56, 56 which are vertical surfaces on which a conduction path made of deposited oxide is difficult to be formed. Thus, it is possible to prevent the formation of a conduction path by the deposited oxide more reliably. Moreover, for example, the distance between the bus bars 40a1 and 40a2 and the sbar 46b can be increased only by increasing the groove depth dimension D2 without changing the groove width dimension W2, and thus it is difficult to widen the gap in the width direction. The present invention can also be applied to an input / output bus bar of a relay.

  Further, in this embodiment, the bus bar 46b (power supply side bus bar) and the bus bars 46a1 and 46a2 (downstream side bus bar) constituting the electrodes that may cause electrolysis in the case of flooding are in a so-called vertical arrangement, and the thickness direction Since only one side surface 62 (see FIG. 4) is exposed mainly to water containing an electrolyte such as salt water to cause electrolysis, the effective area of the electrode that causes electrolysis can be reduced. Therefore, generation of oxide can be suppressed and formation of a conduction path by deposited oxide can be advantageously prevented.

  Next, the electric junction box 64 as the second embodiment of the present invention will be described in detail with reference to FIG. 5. The members and parts having the same structure as the above embodiment are described above in the drawing. By attaching the same reference numerals as those of the embodiment, detailed description thereof will be omitted. That is, the main body portion 66 is a bus bar circuit body, and is configured such that the bus bars 72a and 72b are superposed on the bus bar fitting grooves 70a and 70b provided on the surface of the insulating plate 68 having a substantially thin flat plate shape. In this regard, an embodiment different from the above embodiment is shown. Also in the present embodiment, a bus bar fitting groove 70a that is a first receiving groove and a bus bar fitting groove 70b that is a second receiving groove that respectively accommodate a bus bar 72a that is a power supply side bus bar and a bus bar 72b that is a downstream side bus bar that are adjacently disposed. A space 74 extending in parallel therewith can be provided, and the space 74 can form a pair of insulating partition walls 60 and 60 with a gap between the bus bar 72a and the bus bar 72b. As with the above embodiment, it is possible to prevent ignition after water immersion.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, in the present embodiment, the cavities 52 and 74 are holes provided with the bottom surface 54, but may be through holes. By forming the through hole, it is possible to more reliably prevent the formation of a conduction path due to the deposited oxide. Further, the shape, number and interval of the voids 52 and 74 can be arbitrarily set.

  Moreover, the rib which protrudes outward may be provided in the front end surface 76 (refer FIG.4 and FIG.5) of the insulating partition 60. FIG. As a result, a separation distance between the bus bars 46b and 72a and the bus bars 46a1, 46a2 and 72b can be obtained, so that a conductive path made of deposited oxide is formed between the bus bars 46b and 72a and the bus bars 46a1, 46a2 and 72b. You can stop even more reliably.

DESCRIPTION OF SYMBOLS 10: Relay block (electrical connection box) (1st embodiment), 12, 66: Main body part, 14: Surface, 16: Fuse mounting part (electric part mounting part), 18a-c: Relay mounting part (electric part) Mounting portion), 30a to c: relay (internal circuit), 38: back surface, 40a1, a2, b, c: bus bar receiving groove, 46a1, a2, b, c, 72ab: bus bar (internal circuit), 52, 74: Empty space, 60: Insulating partition, 64: Electrical junction box (second embodiment), 70ab: Bus bar fitting groove

Claims (4)

In an electrical junction box in which an internal circuit is constituted by a plurality of bus bars including a power source side bus bar connected to the power source line and an electrical load or a downstream side bus bar connected to the ground line,
The power supply side bus bar and the downstream side bus bar are disposed adjacent to each other, and a plurality of insulating partition walls are erected between the power supply side bus bar and the downstream side bus bar with a gap therebetween. And electrical junction box. The internal circuit is housed in a synthetic resin main body,
On the surface of the main body portion, a plurality of electrical component mounting portions are formed with openings,
On the back surface of the main body, a first accommodation groove that extends in parallel with each other and accommodates the power source side bus bar and a second accommodation groove that accommodates the downstream side bus bar are respectively formed to be open,
Between the first accommodation groove and the second accommodation groove, a space extending in parallel therewith is formed as an opening so that the respective inner wall portions of the first accommodation groove and the second accommodation groove are formed. The electrical junction box according to claim 1, wherein the plurality of insulating partition walls are erected with the gaps spaced apart from each other.   The electrical junction box according to claim 2, wherein the void has a groove depth dimension larger than a groove width dimension.   The first receiving groove and the second receiving groove are each shaped such that the groove depth dimension is larger than the groove width dimension, while the plate thickness direction of the power supply side bus bar and the downstream side bus bar is the groove width direction. 4. The electrical junction box according to claim 2, wherein the power supply side bus bar and the downstream side bus bar are accommodated and disposed in the first accommodation groove and the second accommodation groove.

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