JPH09306331A - Fuse device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent infiltration of moisture or the like into its cover in a fuse device having a cover. SOLUTION: A waterproof rubber 31 is fitted around a lower part of an insulating carrier member 15 where a fuse element 11 is arranged. A lip part 34 is formed on an outer peripheral surface of its waterproof rubber 31. In the insulating carrier member 15, a cover 21 to cover the fuse element 11 is installed on the outside of the waterproof rubber 31 in a condition where the lip part 34 is compressed. Therefore, since the inside of the cover 21 is sealed in a watertight condition, infiltration of moisture or the like into the cover 21 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuse device having a waterproof structure.

[0002]

2. Description of the Related Art Generally, a fuse element is rarely used alone and is fixed to an insulating holding member of some kind, and a cover for protecting the fuse element is attached to the holding member. Many. Then, they are used as fuse devices by being fitted into a socket housing provided in, for example, a vehicle junction box.

The junction box shown in FIG.
A circuit board 3 having a bus bar 2 arranged therein is housed in a lower case 1, and an upper case 5 integrally formed with a socket housing 4 is fitted above the circuit board 3. Also, the circuit board 3
The bus bar 2 arranged above is inserted into the female terminal fitting 8 assembled in the socket housing 4. The fuse device 6 is attached to the socket housing 4 from above.
The connection piece 7 protruding from the fuse device 6 is inserted into the female terminal fitting 8. As a result, the fuse element can be incorporated in the power supply path to each device via the junction box.

[0004]

However, in the conventional fuse device, the cover is mainly intended to protect the fuse element from damage, and no particular consideration has been given to watertightness. Of course, rainwater and the like do not directly enter the cover, but there is a possibility that capillary action or moisture may enter the cover from the very small gap between the cover and the holding member for the following reasons. As a result, the fuse element may be rusted or corroded.

In a vehicle junction box, rainwater may drop onto the upper case 5. When such rainwater enters the lower case 1 through the gap between the upper case 5 and the side wall of the lower case 1 and accumulates in the lower case, the humidity in the lower case 1 increases. Then, the moisture penetrates into the cover 9 through the insertion hole of the bus bar 2 in the socket housing 4 and the insertion hole of the connection piece 7 through a very small gap between the cover 9 and the holding member 10 (Fig. (See arrow a in 10.). In addition, rainwater may directly enter the socket housing 4 through the gap between the fuse device 6 mounted on the socket housing 4 and the socket housing 4. Then, a very small amount between the cover 9 and the holding member 10 may occur. Rainwater will enter the cover 9 through such a gap due to the capillary phenomenon (in FIG. 10,
(See arrow b). The present invention has been made in view of the above circumstances, and an object thereof is to provide a fuse device including a cover, which can prevent intrusion of moisture and the like into the cover.

[0006]

To achieve the above object, in a fuse device according to a first aspect of the present invention, a fuse element is disposed on an insulator, and the insulator is covered so as to cover the fusing part of the fuse element. In a fuse device having a body attached, a waterproof member is arranged between an insulator and a cover body to make the cover body watertight.

A fuse device according to a second aspect is the fuse device according to the first aspect, characterized in that the waterproof member has thermal conductivity and is formed so as to be capable of contacting the fuse element and the cover body. .

[0008]

According to the invention of claim 1, which has the above-described structure, the inside of the cover mounted on the insulator is made watertight by the waterproof member. Therefore, it is possible to prevent moisture and the like from entering the cover body, and prevent the fuse element from rusting or corroding.

According to the second aspect of the present invention, since the waterproof member has thermal conductivity and is in contact with the fuse element and the cover body, the amount of heat in the fuse element is conducted to the cover body through the waterproof member. . Therefore, since the heat radiation effect for the fuse element is enhanced, it is possible to reduce the adverse effects due to the thermal influence of the fuse element.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the fuse device of the present invention will be described below with reference to FIGS. As shown in the upper side of FIG. 5, the fuse device 29 of the present embodiment includes a fuse element 11, an insulating carrying member 15 for assembling the fuse element 11, and a cover 21 that covers them.

First, the fuse element 11 will be described. FIG. 6 is for stamping and forming the fuse element 11 in the present embodiment, which is a metal plate material 12 (for example, zinc material) having conductivity and is a hoop material. Further, the metal plate member 12 is a profile member in which both side portions are formed thick along the longitudinal direction and the central portion is formed thin. Then, the thick-walled portion 12a formed as the thick-walled portion is used as the connecting piece portion 16 described later, and the thin-walled portion 12b formed as the thin-walled portion is used as the fusing portion 20 to punch the fuse element 11.

In FIG. 1, the upper side shows the fuse element 11 stamped and formed from the metal plate material 12,
Bands 13 are arranged on both sides (upper left side and lower right side) in the drawing, and a plurality of fuse elements 11 are arranged in the longitudinal direction between them. Each fuse element 11 is connected to the strip 13 through a thin connecting portion 14 whose both ends are easily cut. In addition, each fuse element 11 is formed to have a wide width from both end portions to a predetermined inside portion, and a central portion is formed narrower than both sides thereof. The widened portion is the connecting piece portion 16, and is the metal plate member 12 described above.
This is a portion punched from the thick wall portion 12a. The widened portion is the fusing part 20, which is the thin-walled part 12b of the metal plate material 12 or the punched part.

The connecting piece portion 16 has a tapered end portion, and is set so as to be inserted into a female terminal metal fitting 18 of a socket 17 to be described later and electrically connected thereto. In addition, a pair of positioning recesses 16a is provided in a portion from the center of each connecting piece portion 16 (on the side connecting to the narrow portion) so as to face both side edge portions thereof at a predetermined interval in the longitudinal direction. There is. Each positioning recess 16a is formed by cutting out a side edge of the connecting piece 16 in a semicircular shape, and a caulking projection 19 described later is fitted therein.

In the case of forming the fuse element 11 by stamping from a profiled material, it is usually difficult to make the punching width narrower than the sheet thickness. Therefore, a normal sheet material having the sheet thickness necessary for the connecting piece portion 16 is formed. This is because the punching width of the fusing part 20 cannot be made narrower than the plate thickness required for the connecting piece part 16 and the current capacity of the fuse element 11 cannot be reduced. That is, by using the deformed material for the metal plate material 12, the punching width of the fusing part 20 can be considerably reduced, and the fuse element 11 having a small current capacity can be obtained.

Next, the insulating carrying member 15 for assembling the fuse element 11 will be described. As shown in the lower side of FIG. 1, the insulating carrying member 15 is a resin-made rectangular plate material, and the length dimension thereof is four fuse elements 11 connected to the strip 13. It is a length that can be provided, and its width dimension is set shorter than the length dimension of the fuse element 11. Four square openings 22 are arranged side by side in the longitudinal direction at a predetermined interval in the central portion of the insulating carrying member 15, and both left and right sides (the upper left side in the figure) sandwiching each opening 22 therebetween. Two pairs of caulking projections 19 facing each other at a predetermined interval are formed in the section and the lower right side section.

The protruding position of each caulking protrusion 19 corresponds to the positioning recess 16a of the fuse element 11, the fusing portion 20 of the fuse element 11 is bridged over the opening 22, and the connecting piece portion 16 of the fuse element 11 is provided. The positioning recesses 16a and the caulking projections 19 can be fitted to each other in a state in which they are projected to the left and right sides.
Further, the height dimension of the positioning protrusion 19 is determined by the connection piece 1
6 is set higher than the plate thickness of 6 and the positioning recess 16a
The upper end of the positioning projection 19 is set to slightly project from the upper surface of the connecting piece 16 in a state where the positioning projection 19 and the positioning projection 19 are fitted together. Then, the fuse element 11 can be fixed onto the insulating carrying member 15 by heat-caulking (including ultrasonic welding) the protruding portion.
In addition, each opening 22 is provided at the center of the upper surface of the insulating carrier member 15.
A self-hinge portion 23, which is a groove having an inverted triangular cross section and extending across the length direction, is formed as a notch, and the insulating carrier member 15 is bent around this self-hinge portion 23 to be superposed in a palm-like state. You can do it.

FIG. 3 shows a state in which the fuse element 11 is fixed on the insulating carrying member 15, and then the fuse element 11 is bent and superposed in a palmed state. A waterproof rubber 31 is fitted in the lower portion of the bent insulating supporting member 15. As shown in FIG. 8, the waterproof rubber 31 is formed in a rectangular shape extending in the lateral direction, and a holding member fitting chamber 32 having an open upper surface is formed therein. A recess 32a is formed on the inner peripheral surface of the carrying member fitting chamber 32 so as to correspond to the connecting piece 16 of the fuse element 11 fixed to the insulating carrying member 15. The size of the carrying member fitting chamber 32 is slightly smaller than the outer circumference of the bent insulating carrying member 15, and the lower end of the insulating carrying member 15 pushes the carrying member fitting chamber 32 apart. It is designed to be closely inserted.

As shown in FIG. 4, at the bottom of the carrying member fitting chamber 32, a connecting piece corresponding to the connecting piece 16 of each fuse element 11 and having a diameter slightly smaller than the cross section of the connecting piece 16 is inserted. Hole 3
3 are formed. Then, when the lower end of the insulating carrying member 15 is closely inserted into the carrying member fitting chamber 32, each connecting piece 1
6 is closely inserted in the connection piece insertion hole 33 and projects downward. The depth of the recess 32a formed on the inner peripheral surface of the carrying member fitting chamber 32 is such that the lower end of the insulating carrying member 15 is closely inserted in the carrying member fitting chamber 32. Member fitting chamber 3
The inner peripheral surface of No. 2 is set to have a size that contacts the connecting piece portion 16 of the fuse element 11.

Further, a lip portion 34 is formed on the outer peripheral surface of the waterproof rubber 31 at the upper end portion and the lower end portion so as to project over the entire circumference. Engagement holes 35 extending in the lateral direction are formed between the upper and lower lip portions 34 on the left and right side surfaces. The position of the engagement hole 35 is the same as the position of the positioning protrusion 19 arranged on the lower side in FIG. 3 in a state where the lower portion of the insulating carrying member 15 is fitted in the carrying member fitting chamber 32. There is. That is, the waterproof rubber 31 is prevented from coming off by engaging the upper ends of the positioning protrusions 19 with the engaging holes 35.

By the way, in the molding material of the waterproof rubber 31, a silicone rubber is used as a base material, and a highly heat conductive filler such as alumina or magnesium oxide is filled therein. That is, the thermal conductivity of the waterproof rubber 31 is increased by mixing the base material with a material having high thermal conductivity. In this case, in order to disperse the filler well and adapt it to the base material, the particle size of the filler should be 5 to 1
The thickness is preferably 0 μm, and good results can be obtained by adding a silane coupling agent as a compound. As for the number of parts to be mixed, it is desirable that the filler is 100 to 300 parts and the silane coupling agent is 1 to 5 parts with respect to 100 parts of the base material. The thermal conductivity can be dramatically improved.
Note that the range of the thermal conductivity of the rubber material used for the waterproof rubber 31 is 2 × 10 ⁻³ to 10 × 10 ⁻³ cal / cm · sec in consideration of the heat radiation property to the fuse element 11 described later.
・ It is desirable to set the temperature to ° C.

As shown in the upper side of FIGS. 4 and 5, the cover 21 is constructed so that it can be put on the insulating supporting member 15 in the bent state from above. That is, the cover 21 is formed of a transparent resin material and is formed in a box shape having an open lower surface. The inner peripheral dimension of the cover 21 is substantially equal to the outer periphery of the waterproof rubber 31, and the cover 21 is fitted in a state in which the lip portion 34 of the waterproof rubber 31 is compressed.

The lower side of FIG. 5 shows a socket 17 for mounting the fuse device 29. This socket 17
Comprises a socket housing 24 which is integrally formed on the upper case of the junction box and is formed in a substantially rectangular parallelepiped shape. Inside the socket housing 24, a total of eight terminal accommodating chambers 25 are arranged side by side in two rows along the length direction. The terminal accommodating chambers 2 facing each other
The distance between 5 is equal to the distance between both ends of the fuse element 11 in the bent state, and the distance between the terminal accommodating chambers 25 that are adjacent to each other in the length direction is arranged in parallel with the insulating carrying member 15. It is equal to the distance between the fuse elements 11. Further, a female terminal fitting 18 formed in a rectangular tube shape is vertically installed in the terminal accommodating chamber 25, and a fuse is inserted through a terminal insertion opening 25a formed on the upper surface side of the terminal accommodating chamber 25. The connecting piece 16 of the element 11 is adapted to be inserted. Further, an opening is also formed on the bottom surface side of the terminal accommodating chamber 25, and the bus bar 26 arranged on the circuit board 30 accommodated in the junction box is inserted into the female terminal fitting 18 through this opening. It is like this.

Guide walls 27 are formed so as to project upward at the four corners of the upper surface of the socket housing 24, and the fuse device 29 is fitted in the portion surrounded by the guide walls 27. The female terminal fitting 18
Inside, a pair of elastic contact pieces (not shown) are formed by cutting and raising the upper and lower sides, and the connecting piece portion 16 of the fuse element 11 and the bus bar 26 are elastically brought into contact therewith.

A procedure for assembling the fuse device 29 will be described. First, the fuse element 11 is stamped out from the metal plate material 12 shown in FIG. In the punched fuse element 11, a plurality of fuse elements 11 are arranged side by side by a strip 13 in a chain, and the fuse elements 11 are assembled on an insulating carrier member 15 in an open state.
To assemble, the positioning recess 1 of each fuse element 11
6a and the caulking projection 19 on the insulating carrier member 15 are engaged with each other. As a result, the four fuse elements 11 are arranged at regular positions on the insulating carrier member 15. Further, thereafter, the portion of each caulking protrusion 19 projecting higher than the upper surface of each fuse element 11 is caulked by heat and crushed (see FIG. 7). Then, each fuse element 11 is fixed in a state of being positioned on the insulating carrying member 15 and in a state where the back surface thereof is in close contact with the upper surface of the insulating carrying member 15. Then, when the strip 13 and each fuse element 11 are cut from the connecting portion 14, the assembling of the fuse element 11 is completed (see FIG. 2).

After that, the left and right ends are bent downward with the self-hinge portion 23 of the insulating carrying member 15 as the center, and they are superposed in a palmed-up state. At this time, the fusing part 20 of each fuse element 11 gradually bends in an arched shape as the insulation carrying member 15 is bent, and the insulation carrying member 1
When 5 is completely superposed, it curves almost like a hairpin. Further, when the fusing part 20 is curved,
It will be installed in the air on the notch 28 formed by dividing the opening 22 of the insulating carrying member 15 (see FIG. 3).

A waterproof rubber 31 is fitted into the lower portion of the insulating supporting member 15 in the bent state. Waterproof rubber 31
In order to fit, the lower end portion of the insulating carrying member 15 is carried from above so that each connecting piece portion 16 projecting downward from the insulating carrying member 15 is inserted into the corresponding connecting piece insertion hole 33. It fits in the fitting chamber 32. Then, the connection piece portion 16 of each fuse element 11 projects downward through the connection piece insertion hole 33, and the upper end portion of the positioning protrusion 19 engages with the engagement hole 35 of the waterproof rubber 31 to allow the waterproof rubber to be engaged. 31 is retained. As a result, the inner peripheral surface of the carrying member fitting chamber 32 is brought into close contact with the insulating carrying member 15 and the connecting piece portion 16 of the fuse element 11 assembled therein, and the waterproof rubber 31.
There is no gap formed between the insulating supporting member 15 and the insulating supporting member 15.

Further, in a state in which the insulating carrying member 15 is bent, the cover 21 is covered with the insulating carrying member 1 from above.
Put on 5. Then, the cover 21 is fitted while compressing the lip portion 34 of the waterproof rubber 31. Therefore, the cover 21 and the waterproof rubber 31 are in close contact with each other, whereby the inside of the cover 21 is watertightly sealed (see FIGS. 4 and 5).
See above). This completes the assembly work of the fuse device 29.

Next, a mounting operation of the fuse device 29 will be described. To mount the fuse device 29 on the junction box, the fuse device 29 may be fitted into the socket 17. To do this, fuse device 2
9 above the socket 17 and fuse 2
Each of the connecting piece portions 16 projecting downward from 9 is inserted into the terminal insertion opening 25a of the socket housing 24, and the fuse device 29 is fitted into the portion surrounded by the guide wall 27 (see FIG. 9). As a result, each connecting piece 16 is connected to the bus bar 2 via the female terminal fitting 18.
6, and each fuse element 11 is incorporated into a power supply path to each device through a junction box.

By the way, when a certain device is energized, as a current flows through the fuse element 11,
The temperature of the connecting piece portion 16 rises due to the heat generation of the fusing part 20. Then, the female terminal fitting 18 in contact with the connecting piece 16 is adversely affected. However, in the present embodiment, the waterproof rubber 31 is in contact with the connecting piece portion 16, and since the waterproof rubber 31 has a high thermal conductivity, the heat quantity of the connecting piece portion 16 causes the cover 21 via the waterproof rubber 31. Is dissipated into the atmosphere and released into the atmosphere. Therefore, the temperature rise of the connecting piece 16 is suppressed.

As described above, in the present embodiment, the inside of the cover 21 mounted on the insulating carrying member 15 is made watertight by the waterproof rubber 31, so that moisture or the like in the junction box penetrates into the cover 21 through the socket housing 24. It can be prevented from doing. Therefore, it is possible to prevent the fuse element 11, especially the fusing part 20, from being rusted or corroded.

Further, since the waterproof rubber 31 has a high thermal conductivity and the waterproof rubber 31 is in contact with the connecting piece portion 16 of the fuse element 11 and the cover 21, the waterproof rubber 31 is connected to the connecting piece portion 16 through the waterproof rubber 31. The heat dissipation is improved and the connecting piece 1
It is possible to reduce the adverse effects of 6 on the mating female terminal fitting 18 due to heat.

The present invention is not limited to the above-described embodiments, but can be modified and implemented as follows, for example, and these embodiments also belong to the technical scope of the present invention. (1) In the above-described embodiment, the fuse device 29 is constructed by assembling the fuse element 11 punched out from the profile material, but it is constructed by assembling the fuse element punched out from the flat metal plate material as a whole. Good. Further, instead of punching from a metal plate material, a wire material, a tape electric wire or the like may be assembled.

(2) In the above embodiment, the four fuse elements 11 are arranged on the insulating carrying member 15 in parallel, but the number is not limited to four, and any number may be arranged. .

(3) In the above embodiment, the insulating carrying member 15 is formed in a plate shape, and after the fuse element 11 is assembled to this, the fuse device 29 is formed by bending it integrally, but it is formed in a rectangular parallelepiped shape. It may be one in which a bent fuse element is later assembled to the insulated carrier member.

(4) In the above embodiment, the waterproof rubber 31
In the molding material, the thermal conductivity was enhanced by mixing, for example, alumina with silicone rubber, but the thermal conductivity may be low.

(5) In the above embodiment, the waterproof rubber 31
However, the waterproof member need not be a rubber material as long as it can seal the inside of the cover in a watertight manner. In addition, the present invention can be implemented with various modifications without departing from the scope.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a fuse element and an insulating carrying member of the present embodiment.

FIG. 2 is a perspective view showing a state in which a fuse element is assembled to an insulating carrier member.

FIG. 3 is a perspective view showing a state in which insulating supporting members are bent and overlapped.

FIG. 4 is a cross-sectional view of a fuse device.

FIG. 5 is an exploded perspective view showing a fuse device and a socket.

FIG. 6 is a perspective view showing a metal plate material.

FIG. 7 is a cross-sectional view showing a fuse element in a crimped state.

FIG. 8 is a perspective view showing a waterproof rubber.

FIG. 9 is a perspective view showing a state in which the fuse device is attached to the socket.

FIG. 10 is a cross-sectional view showing a junction box.

[Explanation of symbols]

 11 ... Fuse element 15 ... Insulating carrier member (insulator) 20 ... Fusing part 21 ... Cover (cover body) 29 ... Fuse device 31 ... Waterproof rubber (waterproof member)

Claims (2)

[Claims] 1. A fuse device having a structure in which a fuse element is disposed on an insulator, and a cover body is attached to the insulator so as to cover a fused portion of the fuse element. A fuse device, wherein a waterproof member is disposed between the cover body and the cover body to be watertight. 2. The fuse device according to claim 1, wherein the waterproof member has thermal conductivity and is formed so as to be able to contact the fuse element and the cover body.