JP2002051432A - Bus bar with fuse function and bus bar circuit board - Google Patents

Abstract

(57) [Problem] To reduce the size of a bus bar circuit board incorporated in, for example, an in-vehicle electric connection box and improve the manufacturing efficiency. SOLUTION: As a bus bar 20 with a fuse function, a bus bar integrally having an input unit 24 connected to a power supply, a plurality of output units 26 branched from the input unit 24, and a fuse unit 26b provided at each output unit. Is formed from a single metal plate. This bus bar 20 is connected to the bus bar circuit board 1
4 is assembled in parallel with the substrate, and a bus bar circuit for power distribution is constructed as a whole. This busbar circuit board 1
4 is particularly suitable as a vehicle-mounted electrical junction box.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bus bar which is used in an electric connection box for a vehicle and has a fuse function of fusing when an overcurrent occurs and automatically cutting off a circuit, and a bus bar using the bus bar. It relates to a circuit board.

[0002]

2. Description of the Related Art FIG. 9 shows a conventional general electric connection box for a vehicle. The illustrated electric connection box includes a lower case 10 and an upper case 12, and a bus bar circuit board 14 is housed in both cases 10 and 12. The bus bar circuit board 14 constitutes a power distribution circuit for distributing electric power output from an unillustrated vehicle-mounted power supply to a plurality of electric loads, and includes a plurality of insulating plates 16 and a plurality of bus bar layers 18. ,
These insulating plates 16 and busbar layers 18 are alternately stacked.

The ends of the bus bars in each bus bar layer 18 are bent upward to form tabs 18a protruding above the substrate.
And a relay terminal 19 for connecting the fuse block to an appropriate tab 18a. The relay terminal 19 has female terminal portions formed at both upper and lower ends, and one of the female terminal portions is connected to the tab 1.
The fuse block is connected to the bus bar via the relay terminal 19 by fitting the terminal of the fuse block into the other female terminal portion while being fitted to the bus bar circuit, and is incorporated in the middle of the bus bar circuit. It has become.

The upper case 12 is provided with a relay mounting portion 12a for mounting a relay block (not shown) and a fuse mounting portion 12b for mounting a fuse block connected to the relay terminal 19. I have.

As the fuse block, FIG.
What is shown in (a) is generally known. The conductor portion of the fuse block 70 shown in FIG. 7 is formed by integrally forming a pair of left and right pin-shaped input terminals 71 and output terminals 72 and a curved fusing portion 74 having a small cross-sectional area connecting both terminals 71, 72. The fusing portion 74 and the upper halves of both terminals 71 and 72 are covered with an insulator 76. The lower ends of the terminals 71 and 72 are connected to the relay terminals 19 shown in FIG.
Each of the fuse blocks 70 is connected to the bus bar circuit via the relay terminal 19 by being inserted into the female terminal portion of the fuse. In such a connection state, when an overcurrent flows through the fusing portion 74 between the terminals 71 and 72, the fusing portion 74 is blown, thereby automatically shutting off the power supply circuit.

In recent years, as shown in FIG.
A plurality of output terminals 72 are branched from one input terminal 71, and a plurality of conductors are integrated with an insulator 76 to form a part of a complicated power distribution circuit with a small structure. Something has been done to make it possible.

[0007]

FIG. 10 (a)
The conventional plug-in type fuse block as shown in FIG. 1B and the electric junction box using the same have the following problems to be solved.

Since the fuse block has a structure in which the lower ends of the terminals are respectively inserted into the relay terminals 19 erected on the bus bar substrate, as shown in FIG. Connection becomes difficult. Accordingly, there is a limit to increasing the number of terminals (that is, increasing the number of fuse portions 74 included in one fuse block), as in the case of a power distribution circuit incorporated in a vehicle-mounted electric connection box as shown in FIG. In order to construct a circuit requiring a large number of fuses, it is necessary to form a corresponding number of fuse blocks and insert them one by one into a fuse mounting portion of an electrical junction box. For this reason, as the number of fuses increases, the manufacturing efficiency becomes very poor.

Since the fuse block is mounted upright on the bus bar circuit board 14, the height of the board and thus the height of the storage case (in the illustrated example, the height of the entire electrical connection box) are necessarily large. turn into.

In the electric connection box provided with the bus bar circuit board 14, the fuse mounting portion 12 for mounting the fuse block 70 on the upper case 12 is provided.
b must be formed, and each fuse block 70 is mounted so as to protrude from the fuse mounting portion 12b to the outside of the case, so that it is difficult to obtain a good appearance of the electric connection box.

An object of the present invention is to solve the above problems.

[0012]

As a means for solving the above-mentioned problems, the present invention provides a bus bar circuit board for distributing electric power output from a power supply to a plurality of electric loads. A bus bar with a fuse function arranged in parallel with the substrate, comprising a single metal plate, an input portion connected to the power supply, and a branch from the input portion in a direction parallel to the substrate, The bus bar circuit board integrally has a plurality of output portions that can be connected to other bus bars and a fuse portion provided at each output portion and having a smaller cross-sectional area than the other portion of the output portion.

If this bus bar with a fuse function is incorporated on a bus bar circuit board in a state parallel to the board, a required structure is required compared to a conventional structure in which a fuse block is connected to a bus bar circuit board in an upright state. A power distribution circuit having a large number of fuse portions can be constructed in a simple process while dramatically reducing the height dimension.

Here, the specific shapes of the input section and the output section are not particularly limited, but the input section extends in a direction parallel to the substrate and is connected to the power supply at one end in the longitudinal direction. Preferably, an input terminal portion is formed, and a plurality of output portions having a smaller width than the input portion are branched from both sides of the input portion in the width direction. According to this structure, the input section and the plurality of output sections are arranged in a reasonable layout, and it is possible to include many output sections and fuse sections in a compact structure.

Further, as a structure for joining the output portion to another bus bar, for example, a tab terminal formed on another bus bar can be formed by bending an end portion of each output portion at a substantially right angle. Output terminals that are joined in abutted state are formed, and output terminals that are erected in the thickness direction of other portions of the output portion at the ends of the output portions are formed. It is preferable that the output terminal portion is configured so as to be pressure-connected to the slot blade formed on another bus bar in the vertical direction. According to the former structure, the output portion and the other bus bar can be connected in a stable state by abutting the output terminal portion and the tab terminal, and according to the latter structure, the output terminal portion is moved in the upright direction. Simply by inserting the bus bar into the slot blade, the output portion and another bus bar can be easily pressed and connected.

The bus bar with a fuse function can function as a circuit component by itself. However, as a bus bar unit with a fuse function, an insulator is formed around the bus bar so as to cover at least the fuse portion. With this configuration, it is possible to prevent the blown fuse portion from being scattered around, and to more reliably prevent a short circuit between the output portions.

Further, by utilizing the molding of the insulator,
A bus bar with a fuse function, comprising a plurality of bus bars including the bus bar with a fuse function, wherein the bus bars are arranged on substantially the same plane and the insulator is molded outside the bus bar so as to be integrally formed. It is also possible to construct a unit, and according to this unit, it is possible to make the whole unit simple and easy to handle while configuring a complicated power distribution circuit with a plurality of bus bars.

The present invention also relates to a bus bar circuit board having a plurality of bus bars and an insulating plate arranged in parallel with the bus bars and holding the bus bars, wherein a part of the bus bars is provided with the fuse function. And a power distribution circuit for distributing a power supply connected to an input portion of the bus bar with a fuse function to a plurality of electric loads.

In this bus bar circuit board, since the bus bar with a fuse function is arranged in a plane on the board, a power distribution circuit in which a large number of fuse portions are integrated without increasing the height of the board almost. Can be built by busbar.

Specifically, the bus bar with a fuse function is arranged on the insulating plate in a state parallel thereto, and an output portion of the bus bar with a fuse function is connected to an end of another bus bar in a conductive manner. Configuration.

The bus bar circuit board may be composed of a single-layer bus bar and an insulator, or may include a plurality of bus bar layers and a plurality of insulating plates. And are alternately stacked,
A more complicated distribution circuit can be constructed. In the latter case, at least one bus bar layer and the bus bar with a fuse function may be connected to be conductive.

This bus bar circuit board is particularly suitable as a vehicle-mounted electric connection box. That is, in a vehicle-mounted electric connection box including the bus bar circuit board and a case for housing the bus bar circuit board, the height dimension of the electric connection box itself can be reduced, and a fuse is provided from outside the case as in the related art. Since there is no need to insert a block, a good appearance can be obtained.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the drawings.

The electric junction box shown in FIG. 1 includes a lower case 10 and an upper case 12, and a bus bar circuit board 14 is housed in both cases 10 and 12. On the lower surface of the lower case 10, a connector mounting portion (not shown) for mounting a connector for connecting the bus bar circuit board 14 to an external circuit is formed.

The bus bar circuit board 14 forms a power distribution circuit for distributing electric power output from an unillustrated in-vehicle power supply (for example, an alternator or a battery) to a plurality of electric loads. Multiple busbar layers 1
The insulating plates 16 and the bus bar layers 18 are alternately laminated. However, the bus bar circuit board according to the present invention may be composed of a single bus bar layer 18.

As a feature of the bus bar circuit board 14,
The area from the power input section to the fuse section is constituted by the bus bar 20 with a fuse function according to the present invention.

The bus bar 20 with a fuse function is shown in FIG.
As shown in FIG. 5, a wide input portion 24 which is formed of a single metal plate and extends in a direction parallel to the bus bar circuit board 14 (horizontal direction in the drawing), and branches from the input portion 24 to both sides in the width direction. A plurality (20 in the illustrated example) of output units 26 are integrally provided.

One end of the input section 24 in the longitudinal direction is bent upward to form a tab (input terminal section) 24a for power supply connection. Similarly, the end of each output section 26 is also bent upward to form a tab (output terminal section) 26a. Further, in the middle of each output unit 26,
A fuse portion 26b having a smaller cross-sectional area than the other portions (in the illustrated example, having a smaller thickness) is integrally formed. Therefore, as shown in FIG. 4, the bus bar 20 with the fuse function allows the electric power input to the tab 24a, which is the input terminal, to be transmitted to the tab 2a, which is the output terminal, via each fuse 26b.
6a is constructed.

The fuse section 26b has only to have a sectional area and a length set so as to obtain desired fuse characteristics (blown characteristics). For example, instead of making the fuse section 26b thin, May also be small. Also, the formation position of the fuse part 26b is determined by the output part 26.
Can be set as appropriate in accordance with the layout or the like.

Further, an insulator 22 made of a synthetic resin or the like is molded around the bus bar 20, thereby forming a bus bar unit with a fuse function as a whole. In the illustrated example, the insulator 22 is formed in a rectangular parallelepiped shape that covers most of the bus bar 20 (including the fuse portion 26b) except for the tabs 24a and the tabs 26a.

On the other hand, a tab 18a as shown in FIG. 3 is formed at an end of a suitable bus bar layer 18 in the bus bar circuit board 14 by bending the end upward as described above. When the tabs 18a and the tabs 26a of the bus bars 20 with the fuse function are brought into contact with each other and the tabs 18a, 26a are electrically connected to each other, the bus bars 20 with the fuse function are electrically incorporated into the bus bar circuit board 14, A circuit for distributing the electric power output from each output section 26 of the bus bar 20 to each electric load is formed.

Here, regardless of the specific means of the joining, the tabs 18a and 26a may be fixed to each other by welding or the like. The butting state may be maintained by fitting a rectangular tubular relay terminal 30 as shown in FIG.

Further, as shown in FIG. 5, by bending the end of each output portion 26 downward with a line parallel to the branch direction as a valley line, a pressure contact piece (e.g. While forming the output terminal portion 26c, FIG.
As shown in the figure, a slot blade 18c is formed at the end 18a of the appropriate bus bar layer 18, and the press contact piece 26c is press-connected to each of the slot blades 18c.
Electrical connection between the bus bar 20 with a fuse function and the other bus bar layer 18 is possible.

The structure for connecting the input unit 24 to the power supply is not particularly limited. For example, as shown in FIG.
2, a connector housing portion 12c is formed at an appropriate position, and the tab 24a is protruded inside the connector housing portion 12c.
The input section 24 may be connected to the power supply side wiring by fitting with the 4a, or the input section 24 may also be connected to an appropriate bus bar layer 18 on the bus bar circuit board 14 and through the bus bar circuit board 14. The input unit 24 may be connected to a power supply.

According to the bus bar 20 with the fuse function and the bus bar circuit board 14 described above, the following effects can be obtained.

Since the fuse portion 26 b is formed integrally in the middle of the bus bar 20 forming the power distribution circuit, it is not necessary to insert the fuse blocks into the relay terminals 19 on the board one by one as in the related art. After the insulator 22 is formed by punching from a metal plate, the power distribution circuit in which each fuse portion 26b is incorporated is formed simply by abutting and joining the tab 26a of each output portion 26 to the tab 18a of the appropriate bus bar layer 18. can do. Therefore, the manufacturing efficiency of the bus bar circuit board is high, and this effect becomes more remarkable as the required number of fuses increases.

Further, even if the number of fuses increases, it is only necessary to change the punching shape of the bus bar in accordance with the increase, and it is not necessary to increase the number of fuse blocks to be formed as in the prior art. Is also advantageous in terms of cost.

The bus bar 20 with a fuse function is such that each fuse portion 26 b is formed integrally with the bus bar.
Further, since the fuse block is incorporated on the bus bar circuit board 14 in a state parallel to the board, the circuit board and the electric board are more electrically connected than a conventional structure in which a fuse block is inserted into a relay terminal erected on the bus bar circuit board. The height dimension of the entire junction box can be drastically reduced.

The bus bar 20 with the fuse function
Has a configuration in which the fuse portions 26b are arranged in a direction parallel to the substrate. However, the substrate area hardly increases as compared with the conventional case where the fuse block is erected on the substrate, and conversely, It is also possible to reduce the area.
That is, in a conventional type in which a large number of fuse blocks are inserted on a substrate, a certain gap must be secured between the fuse blocks in order to make the insertion work possible, and furthermore, the fuse blocks themselves must be secured. Due to the thickness (the thickness of the insulator 76 in FIG. 10), the arrangement pitch of the fuse blocks must be increased to some extent. On the other hand, the bus bar 20 according to the present invention does not require the block insertion work. Further, since it is not necessary to cover each fuse portion 26b individually with an insulator, each fuse portion 26b
The pitch between them can be set very small, and as a result, the occupied area of the entire bus bar and thus the area of the entire bus bar circuit board can be set to be equal to or less than the conventional one.

Since each of the fuse portions 26 b is planarly assembled on the bus bar circuit board 14, it is not necessary to form the fuse mounting portion 12 b on the upper case 12 of the electric connection box as in the related art. There is no possibility that the fuse block projects outside. Therefore, the appearance is dramatically improved as compared with the conventional on-vehicle electric connection box shown in FIG.

In the present invention, regardless of the specific shape of the input section and the output section, the branch direction of each output section is not limited. For example, the output unit may be branched only in one direction from the input unit. However, the input unit 2 extending in one direction as described above
If the output portion is branched on both sides in the width direction of 4, a large number of output portions 26 and fuse portions 26b can be arranged in a reasonable and reasonable layout.

Each of the output sections 26 does not necessarily have to be linear. For example, as shown in FIGS. 7 (a) and 7 (b), the output section 26 is bent in the middle thereof so that the output terminal section (tab 26a
It is also possible to arrange the pressing pieces 26c) on both sides in the longitudinal direction of the input section 24.

The insulator 22 can be omitted as appropriate. However, if the insulator 22 is formed around the bus bar 20 so as to cover at least the fuse portion 26b, the blown fuse portion 26b can be prevented from being scattered, and the short circuit between the output portions can be more reliably prevented. In addition, a plurality of bus bars including the bus bar 20 with a fuse function according to the present invention are arranged on the same plane, an insulator 22 is formed around the bus bars, and the bus bars are integrated to form a complicated circuit with a simple process. A busbar unit having the configuration can be constructed. In addition, since each bus bar is integrated, its handling (particularly, the work of assembling it to the bus bar circuit board) is easy.

FIGS. 8A and 8B show an example of a method for manufacturing such a composite bus bar unit.

In FIG. 8, first, one metal plate is used as shown in FIG.
A pair of busbar groups as shown in FIG. Each group integrally has a strip-shaped input unit 24 extending in one direction (the left-right direction in the figure) and a plurality of output units 26 branched from the input unit 24 in a direction orthogonal to the longitudinal direction. A fuse portion 26b having a smaller width than a tip portion 26a is formed at a root portion of the output portion 26. Further, one or a plurality of strip-shaped input units 25 are also branched together with the output unit 26.

In order to make the fuse portion 26b thinner than the other portions, a predetermined portion of the original plate (a portion where the fuse portion 26b is blown out; a portion shown by a dashed line in FIG. 8B) is previously formed. What is necessary is just to remove it.

These groups are arranged in such a manner that the input portions 24 are close to and parallel to each other, and an insulator 22 as shown in FIG. At the time of molding, each input portion 24 is provided on the insulator 22.
Connection window 22a for exposing the end 24a of the
And an end 25a of the input unit 25 and an end 2 of the output unit 26
A connecting window 22b for exposing 6a on both front and back sides is formed, and a cutting window 22c for exposing an intermediate portion of the input section 24 is formed.

Next, by cutting an appropriate portion (portion 24b shown by a mesh in FIG. 8B) of the input section 24 through the cutting window 22c by a press or the like, the groups are electrically independent from each other. Multiple busbars (input 2
4 or a bus bar which always includes one input unit 25). The ends 24a, 25a, 26a of the input units 24, 25 and the output unit 26 are connected to the connection windows 22a, 22b.
By connecting to an external circuit through the power supply circuit, a power distribution circuit having a plurality of input units can be formed.

As described above, if the method of forming the insulator 22 around the previously integrated bus bar and then cutting the appropriate bus bar portion is used, the bus bars divided into a plurality from the beginning can be arranged. It is possible to more easily manufacture a bus bar unit in which a plurality of bus bars are integrated as compared with a method of forming the insulator 22 by using the method.

[0050]

As described above, the present invention relates to a bus bar with a fuse function, which is made of a single metal plate and has an input part, an output part branched from the input part, and a fuse part. Since this bus bar is mounted on the bus bar circuit board in a state parallel to the board, the height of the board is smaller than the conventional structure in which a large number of fuse blocks are mounted on the board in an upright state. And the production efficiency of the bus bar circuit board can be increased. Further, in the electric connection box in which the bus bar circuit board is housed in the case, it is possible to contribute to the miniaturization of the entire electric connection box and the improvement of the appearance.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an electric junction box according to an embodiment of the present invention.

FIG. 2 is a perspective view of a bus bar unit assembled to a bus bar circuit board of the electric connection box.

FIG. 3 is a perspective view showing a connection structure between an output portion of the bus bar unit and a bus bar layer of a bus bar circuit board.

FIG. 4 is a diagram showing a circuit formed by the bus bar unit.

FIG. 5 is a perspective view showing a modified example of the bus bar unit.

6 is a perspective view showing a connection structure between an output portion of the bus bar unit according to FIG. 5 and a bus bar layer of a bus bar circuit board.

FIGS. 7A and 7B are perspective views showing a modified example of the bus bar unit.

FIG. 8A is a plan view showing an example of a bus bar unit in which a plurality of bus bars are integrated, and FIG. 8B is a plan view showing the bus bar portion.

FIG. 9 is a perspective view showing an example of a conventional electric connection box.

FIGS. 10A and 10B are perspective views showing examples of a conventional fuse block.

[Explanation of symbols]

 Reference Signs List 10 lower case 12 upper case 14 bus bar circuit board 16 insulating plate 18 bus bar layer 18a tab of bus bar layer 20 bus bar with fuse function 22 insulator 24, 25 input section 24a tab (input terminal section) 26 output section 26a tab (output terminal section) ) 26b Fuse part 26c Pressure contact piece (output terminal part)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01R 4/24 H01R 4/24 (72) Inventor Shigeki Yamane 1-7-10 Kikuzumi, Minami-ku, Nagoya City, Aichi Prefecture No. Within Harness Research Institute, Inc. (72) Inventor Takahiro Onizuka 1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi Prefecture Inside Harness Research Institute, Inc. (72) Isao Isshiki 1, Kikuzumi, Minami-ku, Nagoya-shi, Aichi 7-7-10 Harness Research Institute, Inc. (72) Inventor Hiroe Ikeda 1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi F-term in Harness Research Institute, Inc. 5E012 AA02 5G361 BA04 BA07 BB01 BB02 BC01 5G502 AA01 AA20 BA01 BB07 GG09

Claims (10)

[Claims] 1. A bus bar with a fuse function, which is disposed on a bus bar circuit board for distributing electric power output from a power supply to a plurality of electric loads, as a part of the bus bar, and is arranged in parallel with the board. An input unit formed of one metal plate and connected to the power supply; and a plurality of output units branched from the input unit in a direction parallel to the board and connectable to another bus bar in the bus bar circuit board. A bus bar with a fuse function, wherein the bus bar has a fuse function, wherein the bus bar has a fuse section provided in the output section and having a smaller cross-sectional area than other portions of the output section. 2. The bus bar with a fuse function according to claim 1, wherein the input portion extends in a direction parallel to the substrate.
An input terminal portion connected to the power supply is formed at one end in the longitudinal direction, and a plurality of output portions smaller in width than the input portion are branched from both sides of the input portion in the width direction. Bus bar with fuse function characterized by the following. 3. The bus bar with a fuse function according to claim 1, wherein an end portion of each output portion is bent at a substantially right angle so as to be joined with a tab terminal formed on another bus bar. A bus bar with a fuse function, wherein an output terminal portion is formed. 4. The bus bar with a fuse function according to claim 1, wherein an output terminal portion is formed at an end of each output portion so as to be erected in the thickness direction of another portion of the output portion. A bus bar with a fuse function, wherein a terminal portion is configured so as to be press-connected to the slot blade formed in another bus bar in the vertical direction. 5. A bus bar unit with a fuse function, wherein an insulator is formed around the bus bar with a fuse function according to any one of claims 1 to 4 so as to cover at least the fuse portion. 6. The bus bar unit with a fuse function according to claim 5, further comprising a plurality of bus bars including the bus bar with a fuse function, wherein the bus bars are arranged on substantially the same plane and the insulator is provided outside the bus bar. A busbar unit with a fuse function, wherein the busbar unit is integrally formed by being molded. 7. A bus bar circuit board comprising a plurality of bus bars and an insulating plate arranged in parallel with the bus bars and holding the bus bars, wherein a part of the bus bars is any one of claims 1 to 4. A bus bar circuit board, comprising: a power distribution circuit configured by the bus bar with a fuse function described in 1) and configured to distribute a power supply connected to an input unit of the bus bar with a fuse function to a plurality of electric loads. 8. The bus bar circuit board according to claim 7, wherein the bus bar with a fuse function is arranged on the insulating plate in a state parallel thereto, and an output portion of the bus bar with a fuse function and an end of another bus bar. A bus bar circuit board, wherein the bus bar circuit board is electrically connected to the bus bar circuit board. 9. The bus bar circuit board according to claim 7, further comprising a plurality of bus bar layers and a plurality of insulating plates, wherein the bus bar layers and the insulating plates are alternately stacked, and at least one of the bus bar layers and the insulating plates is laminated. A bus bar circuit board, wherein a bus bar layer and the bus bar with a fuse function are connected to be conductive. 10. The bus bar circuit board according to claim 9,
A case for accommodating the bus bar circuit board.