JP2002084631A - Fuse circuit construction of junction box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the thickness of a fuse module of a junction box. SOLUTION: An internal circuit to be accommodated in an upper case 12 and a lower case 11 of the junction box is divided, to individually provide a connector module 13, a fuse module 14 and a relay module 15. A horizontal part 41d of an L-shape terminal 41e projected from a fuse 40 is welded in direct to a bus bar 20 for fuse laminated on an insulation plate 21 of the fuse module 14 to form a fuse circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuse circuit structure of a junction box, and more particularly, to reducing the number of fuse module circuit layers in a modularized junction box.

[0002]

2. Description of the Related Art In recent years, with the rapid increase of electrical components mounted on automobiles and the like, the number of circuits accommodated in electrical junction boxes for automobiles, especially junction boxes, has increased. Since circuits and the like are also formed, the number of parts is extremely increased, and the number of assembly steps is also increasing.

In a junction box 1 shown in FIG. 5 among the electric connection boxes for automobiles, bus bars 5A to 5D are stacked and arranged between upper case 2 and lower case 3 with insulating plates 4A to 4E interposed therebetween. Upper case 2
Are provided with a connector housing 2a, a relay housing 2b, and a fuse housing 2c. A connector 6, a relay 7, and a fuse 8 are mounted in these housings, and these terminals and terminals and tabs protruding from the bus bars are provided. Are connected directly or via a relay terminal. The lower case 3 is also provided with a connector accommodating portion 3a, and the terminal 5a of the bus bar is protruded and connected to the connector.

[0004]

In the junction box 1, there is a problem that the area of the bus bar and the number of laminations increase as the number of circuits increases, and the junction box becomes large. When a connector housing, a relay housing, and a fuse housing are provided in both the upper case and the lower case, and the connector, relay, fuse and the internal circuit are connected to the upper and lower surfaces of the junction box, the upper case or It is possible to suppress an increase in the area of the junction box as compared with a case where the junction box is provided only on one side of the lower case.

However, if the connector housing portion and the relay housing portion or the fuse housing portion are provided at upper and lower opposing positions, tabs and terminals refracted by the bus bar overlap and cannot be deployed. Therefore, it is necessary to provide terminals on the bus bar of another layer. This causes an increase in the number of busbar layers. When the number of busbar layers increases in this way, the thickness of the junction box increases and the size of the junction box increases, and there is a certain limit to the car body space. Becomes difficult.

Further, since the connector, the fuse and the relay are connected to the bus bar in the junction box, the whole internal circuit is changed when a change in the connection condition between the fuse and the relay and the internal circuit occurs. And cannot easily cope with circuit changes.

[0007] In view of the above circumstances, if the bus bars to be respectively connected to the connector, the relay, and the fuse are separately arranged in a region, it is possible to cope with an increase in the number of stacked bus bars due to the overlap of tabs and the like erected from the bus bar. This can lead to a reduction in the thickness of the junction box.
Furthermore, if the above-mentioned regional separation is modularized for each of the connector connection circuit section, the relay connection circuit section, and the fuse connection circuit section, it can often be shared by different models and grades, and even for circuit changes, etc. Correspondence can be achieved for each module, and the circuit has flexibility in changing.

Each of the modules separated as described above may be, for example, a fuse module as shown in FIG. That is, the bus bar 9 for the fuse, which forms only the portion related to the fuse circuit in the internal circuit.
Are arranged on the insulating plate Z, and a tab 9a having a press-fitting blade 9b is erected from the bus bar 9 to form a terminal 8a of the fuse 8.
And press-fit connection.

However, due to the formation of the fuse circuit, the band-shaped bus bar portion 9 of the fuse bus bar 9 as shown in FIG.
In the case where it is desired to form c and form a tab 9a for a fuse upright, a bus bar 9 formed by punching a single conductive plate is used.
In this case, the strip-shaped circuit portion 9c and the tab 9a (indicated by a two-dot chain line in the drawing) before being developed by bending work interfere with each other, which is not practically feasible. Therefore, in order to avoid this, the bus bars must be stacked,
Even if the number of layers of internal circuits is reduced by modularizing the junction box, the situation is forced to increase the number of layers for each module like the above fuse module, achieving a thin junction box There is a problem that becomes difficult.

The present invention has been made in view of the above-mentioned problems, and accommodates a circuit in a junction box in a junction box by modularizing a connector connection circuit, a relay connection circuit, and a fuse connection circuit. It is an object of the present invention to suppress an increase in the number of stacked bus bars, to reduce the thickness of the junction box, and to easily cope with circuit changes. Another object of the present invention is to reduce the thickness of each fuse module in the fuse module by avoiding the stacking of fuse circuits.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention divides a connector connection circuit section, a fuse connection circuit section, and a relay connection circuit section accommodated in an upper case and a lower case of a junction box. A connector module, a fuse module, and a relay module are separately provided, and the ends of the bus bars of the respective modules are protruded to form welding portions. The welding portions of the fuse modules and the relay modules are overlapped with the welding portions of the connector modules and welded. The fuse circuit structure of the junction box is characterized by joining the modules by joining the fuse terminals directly to the fuse bus bar of the fuse module by welding to form a fuse circuit. providing.

As described above, the internal circuit accommodated in the junction box is divided into a connector connection circuit section, a relay connection circuit section, and a fuse connection circuit section, and each is separately provided as a connector module, a fuse module, and a relay module. ing. That is, a bus bar for a circuit board for connector connection, a bus bar for a fuse circuit board, and a bus bar for a relay circuit board are provided separately.

Conventionally, one conductive plate is punched out to provide a connector connection circuit, a fuse connection circuit, and a relay connection circuit, and each of the circuits has a connector connection tab, a fuse connection tab, and a relay connection tab. Since the tabs are provided, the circuit layout is complicated, and as a result, the bus bar area is increased and the bus bars are multilayered.

On the other hand, according to the present invention, the bus bar for the connector, the bus bar for the fuse, and the bus bar for the relay are divided, punched out from separate conductive plates, and arranged at different positions. Can be suppressed, and the circuit layout of each bus bar can be simplified, so that the bus bar area can be reduced. Furthermore, by modularizing each electric component in this way, each module unit can be treated as one integrated component, so that it is possible to respond to a circuit change due to a specification change or the like in a module unit, The adaptability to a circuit change can be improved.

Further, in the modularized fuse module as described above, if the fuse is directly joined to the fuse bus bar by welding, there is no need to set up a connection tab from the bus bar, and the tab may be overlapped due to the expansion of the tab. No longer occurs. Therefore, the stacking of the bus bars due to these factors can be avoided, so that the stacking of the fuse circuits can be avoided and the fuse module can be reduced in thickness.

In the above fuse, at least two substantially L-shaped terminal portions and a fusing portion continuous between these terminal portions are formed from a single conductive plate, and the terminal portions are made to protrude from a resin. The horizontal portion of the terminal portion and the bus bar for the fuse are joined by any one of resistance welding, laser welding, and ultrasonic welding.

If the fuse is directly welded to the bus bar, the mini-fuse often used in a junction box is not suitable for joining with the bus bar because the fuse terminal extends in a straight line. . Therefore, when a fuse having a terminal portion having a substantially L-shaped terminal is used, the horizontal portion of the L-shape is placed on the bus bar, and this portion is joined by resistance welding or the like, so that the fuse is stably connected to the bus bar. Can be attached to Also,
A fusing portion is continuously formed from a single conductive plate between these terminal portions, and a resin fuse case is also molded with the conductive portion of the fuse to improve productivity and production costs. Reduction can be achieved.

The conductive plate of the fuse has a band in the center, and has a fusing portion on both sides in the width direction at intervals in the longitudinal direction of the band and the terminal portion continuous with the fusing portion. And each of the fusing portions is located in each of the fusing portion accommodating chambers juxtaposed to the fuse case, and a terminal portion is also provided at an end in a longitudinal direction of the band portion, and a terminal portion at an end of the band portion is provided. Are used for input, and the terminals via the fusing portions on both sides of the strip are used for output.

As described above, in the fuse to be welded to the bus bar, a band having an input terminal is provided at the center and a number of output terminals are provided from the band via a fusing portion. The fuse can be a so-called multi-fuse, and a plurality of fuse circuit portions can be handled by one fuse. Therefore, it is possible to reduce the number of fuses to be welded, simplify the structure of the fuse module, and contribute to cost reduction.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an exploded state of a modularized junction box 10 according to an embodiment of the present invention. The junction box 10 includes an internal circuit accommodated in the upper case 12 and the lower case 11, and includes a connector connection circuit section, a fuse connection circuit section,
Divided as a relay connection circuit section, connector module 1
3. The module is designed as a fuse module 14 and a relay module 15.

The connector module 13 has a connector connection bus bar 16 vertically stacked via an insulating plate 17. The connector connection bus bar 16 of each layer is formed into a required circuit shape by punching a conductive plate. I have. The connector bus bar 16 is provided with welding portions 16 c and 16 d protruding from the insulating plate 17. The welding portion 16 c is for joining with the fuse bus bar 20 provided on the fuse module 14, and the welding portion 16 d and the relay module 15 for joining with the relay bus bar 30.

That is, the welding portion 16c is overlapped and welded to the welding portion 22 projecting from the side in an L-shape from the fuse bus bar 20, and the welding portion 16d is formed.
Are overlapped and welded to the welding portion 30a of the relay bus bar 30. In this way, the circuit for the connector and the circuit for the fuse and the circuit for the relay are electrically connected to each other, and the modules are arranged without interference from each other. Forming an internal circuit.

As shown in FIGS. 2A and 2B, the fuse module 14 has a fuse circuit formed by directly welding a fuse 40 to a fuse bus bar 20 arranged and fixed on an insulating plate 21. . This fuse busbar 2
In the case of No. 0, one conductive plate is formed by punching such as pressing so as to have a required circuit shape, but no tab for connection with a fuse is formed. However, the welding portion 22 for joining to the connector module 13 is formed so that the end of the bus bar 20 is bent and protrudes from the periphery 21 a of the insulating plate 21. The insulating plate 21 of the fuse module 14 is provided with a through hole 21b at a location where the fuse 40 is welded to the bus bar 20, so that a welding electrode can be inserted.

As shown in FIG. 3A, the fuse 40 welded to the bus bar 20 is made of a single conductive plate.
From a single strip 41a extending to the center, a large number of branches 4 are provided on both sides in the width direction at intervals in the length direction of the strip 41a.
1b is punched into a protruding shape, and these branch portions 4
1b are connected to the vertical portion 41c and the horizontal portion 41d.
The terminal portion 41e is formed by bending the terminal portion 41e into a substantially L-shape so as to have a shape. Further, a terminal portion 41e similar to the above-described shape is also formed at an end in the length direction of the band portion 41a.

Next, as shown in FIG.
1a so as to cover the vicinity of the protruding base of the branch 41b,
The fuse case 42 is molded with an insulating resin.
Are formed from the fuse case 42 and the respective terminal portions 41e are formed.
Are projected. At the time of the molding, the fuse case 42 is provided with a fusing portion accommodating chamber 42a that opens in a window-like shape at a location for forming a fusing portion that is blown when an overcurrent flows, The branch 41b made of a conductive plate is exposed.

Then, as shown in FIG. 3 (C), the conductive plate is punched with a punching die U through each of the fusing portion accommodating chambers 42a to form a fusing portion 41f having a smaller cross-sectional shape than the branch portion 41b. Thus, the fuse 40 is completed. In this embodiment, the terminal 41e provided at the end of the strip 41a is used for input, and the fusing portion 4 of the branch 41b is used.
The terminal 41e provided at the end via 1f is used for output. The required number of output terminal portions 41e is formed by providing the number of branch portions 41b for output in accordance with the required fuse portion in the fuse circuit.

The fuse 40 formed as described above
Is a fuse module 14 as shown in FIG.
The input terminal 41 e is connected to the bus bar 2 corresponding to the input circuit of the fuse bus bar 20.
0a, and the output terminal portion 41e is welded to the bus bar portion 20b corresponding to the output circuit.
As shown in FIG. 4, this welding is performed using spot welding, which is one type of resistance welding, in this embodiment.

In the spot welding, an electrode D1 from above and
An electrode D2 from below through the through hole 21b of the insulating plate 21
Then, the horizontal portion 41d of the terminal portion 41e and the bus bar portions 20a and 20b of the bus bar 20 are sandwiched and pressurized, and power is supplied in this state to join the terminal portion 41e and the bus bar 20. As described above, all the terminal portions 41e are spot-welded to form a fuse circuit, and the fuse module 14 is completed. As described above, since the junction box 10 of the present embodiment does not connect an external mini-fuse as in the related art, the upper case 12 and the lower case 11 are not provided with a fuse accommodating portion.

The fuse module according to the present invention is not limited to the above-described embodiment. For example, instead of a fuse bus bar disposed on an insulating plate, a fuse bus bar molded with an insulating resin may be used. May be directly welded. Further, the fuse to be welded can be formed in various shapes in addition to the shape in which a large number of branch portions protrude from one band-shaped portion, in accordance with the number of terminals and the circuit shape required for input and output. The welding of the fuse to the bus bar may be performed by various welding such as laser welding or ultrasonic welding in addition to resistance welding such as spot welding.

[0030]

As is clear from the above description, when the fuse circuit structure of the present invention is used, first, since the connector module, the fuse module, and the relay module are provided separately, each module does not interfere with each other. Therefore, the number of stacked internal circuits can be suppressed, and the thickness of the junction box itself can be reduced. Also, by dividing each module, for example, if the specification change is only for the relay, only the relay module needs to be changed, and it does not affect other modules. Can respond.

Further, in the fuse module,
Since the fuses are welded directly to the bus bar, there is no need to set up tabs for connecting fuses, so there is no overlapping of tabs before deployment, preventing the stacking of fuse modules and making the junction box thinner. Can also contribute. Further, the fuse to be attached is not shaped like a conventional mini-fuse, but is shaped so as to be easily welded, so that it can be easily joined to a bus bar. further,
Since the fuse to be attached can be in the form of a multi-fuse, the circuit structure of the fuse module can be simplified.

[Brief description of the drawings]

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

FIGS. 2A and 2B are perspective views showing how a fuse is mounted in a fuse module.

FIGS. 3A, 3B, and 3C are schematic diagrams showing a procedure for forming a fuse. FIGS.

FIG. 4 is a schematic view showing a welding state of a fuse and a bus bar.

FIG. 5 is an exploded perspective view of a conventional junction box.

FIG. 6 is a schematic diagram showing a problem.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Junction box 13 Connector module 14 Fuse module 15 Relay module 20 Bus bar for fuses 20a, 20b Bus bar part 21 Insulating plate 22 Welding part 40 Fuse 41d Horizontal part 41e Terminal part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E085 BB06 BB27 CC01 DD03 DD04 HH11 HH12 HH13 JJ38 5G361 BA04 BB03 5G502 AA01 BA05 CC25 CC32 CC51 CC60

Claims (3)

[Claims] 1. A connector connection circuit section, a fuse connection circuit section, and a relay connection circuit section accommodated in an upper case and a lower case of a junction box are divided and provided separately as a connector module, a fuse module, and a relay module. The end of the bus bar of the module is projected to form a welded portion, and the welded portion of the fuse module and the relay module are overlapped and welded to the welded portion of the connector module, thereby joining each module, and A fuse circuit structure for a junction box, wherein a fuse circuit is formed by directly joining a terminal of a fuse to a bus bar for a fuse of a module by welding. 2. The method according to claim 1, wherein the fuse has at least two substantially Ls.
A terminal part having a U-shape and a fusing part continued between these terminal parts are formed from one conductive plate, and the terminal part is protruded and provided integrally with a resin fuse case. 2. The fuse circuit structure for a junction box according to claim 1, wherein the horizontal portion of the portion and the bus bar for the fuse are joined by any one of resistance welding, laser welding, and ultrasonic welding. 3. The conductive plate of the fuse has a band in the center, a fusing portion on both sides in the width direction, spaced apart in the length direction of the band, and the terminal portion connected to the fusing portion. And each of the fusing sections is located in each of the fusing section accommodating chambers juxtaposed to the fuse case, and a terminal section is also provided at an end in the longitudinal direction of the strip section. The fuse circuit of a junction box according to claim 2, wherein the terminal portion is used for input, and the terminal portion via the fusing portions on both sides of the band portion is used for output.