JPH0511634Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of Use The present invention relates to a cylindrical fuse, which is an electrical transmission component for preventing damage to equipment caused by melting due to excessive current caused by short circuits or overloads.

BACKGROUND ART FIGS. 6 to 9 show examples of commonly used cylindrical fuses. A fusible material 2 such as tungsten is sealed inside a cylinder 1 made of a transparent glass tube along its axis, and both ends of the cylinder 1 are sealed with caps 3, which are cylindrical terminals. In the case of a cylindrical fuse as shown in this figure, it is used in a low-voltage, small-capacity circuit. As is clear from the partially assembled cross-sectional view of FIG. 7, the shape of the cap 3 is such that one side of the cylindrical shape is closed with a welding recess 3a conically recessed inward by press molding. A through hole 3b through which the fusible wire material 2 is inserted is bored at the conical top of the welding recess 3a. A fusible body 2 is inserted into the through hole 3b to protrude outside the welding recess 3a, and the protruding end of the fusible body 2 is welded to the welding recess 3a with solder 4.

That is, at both ends of the cylinder 1, there are caps 3 on the outer periphery.
is covered with a suitable adhesive 6. First, on one side of the cylinder 1, approximately 2/2 of the total circumference of the circumferential end surface is
The adhesive 5 is applied to a region 6A having a length of
is applied. Length of remaining 1/3 of end face entire circumference 6B
The adhesive 5 is not applied to the area, and this non-applied area 6B is set as an air vent passage.

The fusible body 2 passed inside the cylinder 1 along the axis is
It protrudes to the outside of the welding recess 3a of the cap 3 through the through hole 3b, and the protruding end of the fusible body 2 is welded to the welding recess 3a with solder 4.

In this way, after the cap 3 has been adhered to one end of the cylinder 1 and the fusible body 2 has been soldered in the welding recess 3a, another cap 3 is attached to the other end of the cylinder 1 in the same manner. They are combined to produce a cylindrical fuse as shown in FIG.

In addition, there are other similar cylindrical fuses in which the cylinder 1 is made of fiber, porcelain, plastic, etc. In this case, the fusible material 2 is made of zinc, lead, silver, etc. Two types are known: a large-capacity type in which an arc-quenching agent (filling) such as quartz grains or lime particles is placed around the fusible body 2 in the cylinder 1, and a small-capacity type in which no arc-quenching agent is placed.

Problems to be Solved by the Invention In the case of the conventional cylindrical fuse as described above, there is a gap between the end surface of the cylinder 1 and the inner circumferential surface of the cap 3 in a length section that is not bonded and is approximately 1/3 of the entire circumference of the end surface of the cylinder 1. The resulting gap is formed as an air vent passage 6B. This air bleed passage 6B utilizes a very small clearance around 1/3 of the contact area between the circular end surface of the cylinder 1 and the circular circumferential surface of the conical recess 3a of the cap 3. Therefore, the air inside the cylinder 1 cannot be sufficiently vented.

As a result, when the cap 3 is adhered and sealed on one side of the cylinder 1, another cap 3 is attached to the other side, and the fusible body 2 is welded, the solder 4 drips, which hinders the work. There is a problem that causes That is, as one side of the cylinder 1 is sealed, the solder 4 that has been raised in the welding recess 3a to weld the end of the fusible body 2 drips due to the difference in temperature and pressure between the inside and outside of the cylinder 1 due to heat. . At this time, some of the dripped solder 4 may be transmitted to the fusible body 2 in the form of fine particles, pass through the through hole 3b on the side of the welding recess 3a, and enter the cylinder 1.

In addition, in the case of this conventional cylindrical fuse, the cylinder 1 and the cap 3 are in contact with each other at their almost perfect circular inner and outer circumferences, so the end of the cylinder 1 is likely to be damaged due to fitting force, etc. .

The purpose of this invention is to improve the structure so that air can be easily vented when sealing with a cap on one side of the cylinder, thereby preventing solder from dripping when sealing the other side of the cylinder afterward. Another object of the present invention is to provide a cylindrical fuse that can extremely suppress the occurrence of damage to cylinders during glass manufacturing operations.

Means for Solving the Problems The cylindrical fuse according to the present invention includes a glass cylinder, a cylindrical terminal cap that is glued over the outer periphery of both ends of the cylinder, and a cylindrical terminal cap that is housed within the cylinder and is attached to both ends. It consists of a fusible body connected to a cap with solder, the cap has a welding recess recessed inward on one end side, and a through hole through which the fusible body is inserted at the top of the welding recess. forming welding recesses so that the respective circumferential end faces of both ends of the cylinder partially contact the welding recesses of the cap from the inside, and bonding the contact portions with an adhesive to join the caps to both ends of the cylinder, respectively; A gap in the non-contacting part was formed as an air release passage, and the fusible material was inserted into the through holes of both caps and housed in the cylinder, and the fusible material was welded with solder on the outside of each welding recess of the caps on both sides. It is a structure.

Here, the welding recess of the cap is formed in a pyramid shape, and each circumferential end surface on both sides of the cylinder contacts the welding recess from the inside at a plurality of parts, and at least one of the plurality of gaps formed between the contact parts One is used as an air vent passage.

Further, the welding recess of the cap can be formed, for example, in the shape of a square pyramid.

Alternatively, a structure may be adopted in which a plurality of concave portions or convex portions are formed on a predetermined circumference of the welding concave portion, and the circumferential end surface of the cylinder is brought into contact with the concave portions or convex portions.

Action: The end face of the cylinder abuts the welding recess of the cap from the inside. Since this welding recess is, for example, pyramid-shaped, the circumferential end surface of the perfect circular cylinder comes into contact with the plurality of corners of the welding recess from the inside in a substantially point-contact state. That is, a plurality of gaps (half-moon-shaped spaces) are formed between both members.

Adhesive is applied so as to fill some of these gaps, and caps are placed and bonded to the outer peripheries of both ends of the cylinder. No adhesive is applied to the remaining at least one gap, which is formed as an air vent passage.

In the case of a structure in which the welding recess is provided with a recess or a projection on a predetermined circumference, the recess becomes the gap between the non-contact parts. In the case of convex portions, the space between adjacent convex portions becomes a gap.

On the other hand, after a cap is adhered to one end of the cylinder, the fusible material passed into the cylinder from the other side is inserted into the through hole of the cap. This insertion causes the end of the fusible body to protrude outside the welding recess. Solder is piled up in the welding recess from the outside, and the protruding end of the fusible body is welded to the welding recess.

Next, when the sealing with the cap at one end of the cylinder is completed in this way, another cap is connected in the same manner at the other end of the cylinder to produce a cylindrical fuse. When the cap is closed at the other end, the air trapped inside the cylinder is released from air vent passages (gaps formed by half-moon spaces) formed at both ends of the cylinder. Therefore, when the other end is sealed, it is possible to prevent the solder from dripping due to the difference in air pressure between the inside and outside of the cylinder.

Embodiments Hereinafter, embodiments of the cylindrical fuse according to the present invention will be described with reference to FIGS. 1 to 3.

Cylinder 1 made of transparent glass tube shown in Figure 6
A linear fusible body 2 is sealed inside the wire, which melts due to its own generated heat when an overcurrent flows through the circuit. Both open ends of the cylinder 10 are closed by caps 20, 20 made of metal cylinders, and these caps 20, 20 on both sides are connected to both ends of the fusible body 2 by soldering.

In FIGS. 1 and 2, the shape of the cap 20 is press-formed so that one side of a cylindrical shape is closed inward as a welding recess 21 recessed in the shape of a pyramid. In this embodiment, the welding recess 21 is formed in the shape of a regular square pyramid, and has four bases 22a to 22d and corners 23a to 23d. Each side 22a to 22d does not have to be a strict straight line, but may be a slightly curved piece, and the whole has a regular square pyramid shape with corners 23a to 23d.
It is sufficient if it is provided. Further, a through hole 24 through which the fusible body 2 is inserted is formed at the top of the pyramid, and the end of the fusible body 2 passed through the cylinder 10 is inserted into the through hole 24.
The welding recess 21 can be inserted into the welding recess 21 and protruded outside the welding recess 21 . The protruding end of the fusible body 20 is welded to the welding recess 21 from the outside with solder 4 (see FIG. 7). That is, in the caps 20, 20 on both sides, solder is heaped up in the welding recesses 21, 21, passed through the cylinder 10, welded both ends of the fusible body 2, and the caps 20, 20 on both sides are electrically connected. The structure is connected to each other.

Next, an example of the manufacturing form of the cylindrical fuse of this embodiment will be explained.

FIG. 3 shows a side cross-section of the cylinder 10 and a cap 20 placed over the outer periphery of one end thereof. As is clear from this sectional view, the end surface 11 of the cylinder 10 abuts the welding recess 21 of the cap 20 from the inside. Since this welding recess 21 has the shape of a regular square pyramid, the end surface 11 of the perfectly circular cylinder 10 comes into contact with the four corners 23a to 23d of the welding recess 21 from the inside in a substantially point-to-point state. That is, four half-moon-shaped gaps are formed at the contact portion of both members,
Space portions 25a to 25d are formed by this gap.

Here, the half-moon-shaped space 25a~ generated at the contact part
For example, three spaces 25a to 25 among 25d
At c, the cap 20 is covered and bonded to the outer periphery of the cylinder 10 with adhesive 5. That is, in the same manner as shown in FIG. 8, the adhesive 5 is applied to about 3/411A of the entire circumference of the end face 11 of the cylinder 10 and to 3/412A of the outer peripheral surface 12 following this. The adhesive 5 is not applied to the half-moon-shaped space 25d surrounded by the remaining 1/411B of the end face, the remaining 1/412B of the outer peripheral surface, and the remaining bottom 22d of the welding recess 21 on the cap 20 side. This is formed as an air vent passage.

Therefore, at one end of the cylinder 10, the cap 20
After bonding, the fusible body 2 passed through the cylinder 10 from the other side is inserted into the through hole 24 of the cap 20. This insertion causes the end of the fusible body 20 to protrude outside the welding recess 21 . Weld the solder 4 into the recess 21
The protruding end of the fusible body 2 is welded to the welding recess 21.

Next, when the sealing with the cap 20 is completed on one end of the cylinder 10 in this way, another cap 20 is connected in the same manner on the other end of the cylinder 10, as shown in FIG. A cylindrical fuse is manufactured. When the cap 20 is rear-sealed at the other end, the air trapped inside the cylinder 10 is
The air is released from air vent passages (half-moon-shaped spaces 25d) formed at both ends of the cylinder 10. Therefore, when the other end is sealed, the solder 4 does not drip due to the air pressure difference between the inside and outside of the cylinder 10 and the welding heat.

In addition, the contact portions with the cap 20 at both ends of the cylinder 10 are almost point contacts at the four corners 23a to 23d in the case of the embodiment, and the contact length is extremely short compared to the conventional case, so it is possible to avoid contact with the cap 20 during the bonding work. There is almost no possibility that the end of the cylinder 10 made by the manufacturer will be damaged.

Note that in the above embodiments, the welding recess 21 of the cap 20 is approximately in the shape of a regular square pyramid;
As in the other embodiment shown in the figure, approximately hexagonal pyramidal shape 2
It is also possible to set it as 6a-26f. Also in this case, the inner peripheral surface of the cylinder 10 and the six bases 26a to 26
A semicircular space serving as an air vent passage is formed between at least one or about two of f.

Further, FIGS. 5a and 5b show other embodiments. In this case, the welding recess 21 is formed into a conical shape as before. On a predetermined circumference of this welding recess 21, that is, on the circumference where the circumferential end surface 11 of the cylinder 10 contacts from the inside, a plurality of (four in the illustrated example) protrusions 27 protrude to the outside of the welding recess 21. is provided. By forming this protrusion 27, a concave hole 27a is formed inside the welding concave portion 21. The circumferential end surface 11 of the cylinder 10 crosses these four concave holes 27a, and most of the other portions are in surface contact. That is, the structure is such that the four concave holes 27a are used as gaps between non-contact parts and air vent passages.

Effects of the Invention As explained above, in the cylindrical fuse according to the present invention, the welding recess of the cap is formed, for example, in the shape of a regular square pyramid, and the end face of the cylinder contacts the welding recess almost at a point, so that the inner periphery of the cap is Air vent passages can be easily provided on the surface and the outer peripheral surface of the cylinder. Therefore, it is possible to prevent solder from dripping during so-called post-sealing, in which a cap is bonded to one side of the cylinder and sealed, another cap is attached to the other side, and a fusible material is welded.

In addition, since the cap and the cylinder contact each other almost at a point, a mating force is applied over a long contact length, unlike the conventional structure where the cap and the cylinder are in contact for a long time on the inner and outer circumferential surfaces. This eliminates the problem of breakage at the end of the cylinder, making the manufacture of this type of cylindrical fuse more efficient.

[Brief explanation of the drawing]

Figures 1 to 3 show a first embodiment of the cylindrical fuse according to the present invention, Figures 1 and 2 are a perspective view of the cap and a side view seen from the inside, and Figure 3 shows the cylinder and the cap. It is an assembled side sectional view with. Fourth
The figure is a side view of a cap according to another embodiment of the present invention, and FIGS. 5a and 5b are side views and sectional views of essential parts of another embodiment of the present invention. FIG. 6 is an overall front view of a cylindrical fuse commonly obtained in the conventional example and the present invention, and FIGS. 7 to 9 are a partial sectional view, a perspective view of the cylinder, and an assembled sectional view of the cylindrical fuse of the conventional example. shows. 2... Fusible material, 4... Solder, 5... Adhesive,
10... Cylinder, 11... Cylinder end surface, 20... Cap, 21... Welding recess, 24... Through hole, 22
a to 22d... base of square pyramid, 23a to 23d...
...corner of a quadrangular pyramid, 27...protrusion (formed by a concave or convex portion).

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A cylinder made of glass, caps of cylindrical terminals that are glued over the outer peripheries of both ends of the cylinder, and caps of cylindrical terminals that are housed within the cylinder and are soldered to the caps at both ends. In a cylindrical fuse consisting of a fusible body connected to the cap, the cap has a welding recess concave inward on one end side, a through hole through which the fusible body is inserted at the top of the welding recess, and both ends of the cylinder A welding recess is formed so that each circumferential end surface of the cylinder partially contacts the welding recess of the cap from the inside, and the contacting parts are bonded with adhesive to join the cap to both ends of the cylinder, respectively, and the caps are not in contact with each other. The gap between the parts is formed as an air vent passage, the fusible material is inserted into the through holes of the caps on both sides and housed in the cylinder, and the fusible material is welded with solder on the outside of each welding recess of the caps on both sides. Features a cylindrical fuse. (2) The welding recess of the cap is formed in the shape of a pyramid, each circumferential end surface on both sides of the cylinder contacts the welding recess from the inside at a plurality of parts, and at least one of the plurality of gaps is formed between the contact parts. The cylindrical fuse according to claim (1), wherein the cylindrical fuse is an air vent passage. (3) A claim in which the welding recess of the cap is in the shape of a square pyramid.
The cylindrical fuse described in (1). (4) The cylindrical fuse according to claim (1), wherein a plurality of recesses or protrusions are formed on a predetermined circumference of the welding recess, and the circumferential end surface of the cylinder is brought into contact with the recesses or protrusions.