JP3149561U - Electric wire fuse - Google Patents

Abstract

Provided is an electric wire fuse that can reduce the number of manufacturing steps, reduce costs, can be made compact, and can easily adjust the fusing characteristics of a fusible element. An electric wire fuse having a fusible member 11 connected to a lead-in wire in a distribution line and fusing in an overload current region, and a cut-off member 12 connected in series to the fusible member 11 and fusing in a short-circuit current region. The cutoff body lead 32 integral with the cutoff body 12 is directly joined to the fusible body 11, and the cutoff body 12 and the fusible body 11 are connected in series. [Selection] Figure 2

Description

  The present invention relates to an electric wire fuse having a fusible body that is connected to a lead-in wire in a distribution line and is blown in an overload current region, and a cut-off member that is connected in series to the fusible member and is blown in a short-circuit current region.

  As a conventional electric wire fuse, for example, there is one disclosed in Patent Document 1. In the electric wire fuse disclosed in Patent Document 1, a fusible body that melts in an overload current region is cast and formed into a long length with solder, and at the time of casting, the both ends of the fusible body are wrapped with solder. A fusible lead composed of a pair of copper rivets is joined. Further, the cut body is formed by bending the center portion of a copper wire having a circular cross section into a flat plate shape having a small cross section, and both ends of the cut body are used as cut body leads.

  Then, one fusible body lead of the fusible body is inserted into a sleeve-like partition pin holding the partition plate forming the cut-off body housing chamber from one end portion thereof, and the one end portion is compressed to connect to the partition pin. At the same time, one cut-off body lead of the cut-off body is similarly inserted into the other end of the partition pin and the other end is compressed to connect to the partition pin, so that the fusible body and the cut-off body are connected in series. A fuse element formed by connecting to is formed. Thereafter, the other fusible body lead of the fusible body, which is one end of the fuse element, is joined to one connection terminal, and the other shattering body lead of the severing body, which is the other end of the fuse element, is joined to the other connecting terminal. I am doing so.

Utility Model Registration No. 3131231

  In the electric wire fuse disclosed in Patent Document 1, the heads of a pair of fusible leads each made of copper rivets are joined to the fusible body so as to be wrapped by the solder constituting the fusible body. There is an advantage that stress is less likely to concentrate and reliability can be improved.

  However, according to studies by the present inventors, it has been found that the above-described wire fuse has further points to be improved. That is, in the above-described electric wire fuse, the fusible body and the cut-off body are connected in series via the fusible-body lead, the partition pin, and the cut-off body lead. For this reason, when forming the fuse element, there is an operation of inserting a fusible body lead into one end of the partition pin and compressing and connecting, and an operation of inserting a cut-off body lead into the other end of the partition pin and compressing and connecting. There is a concern that the number of manufacturing steps will increase and the cost will increase.

  In addition, since the fusible body and the cut-off body are connected via the fusible-body lead, the partition pin, and the cut-off body lead, there is a concern that the entire fuse element becomes long and the electric wire fuse body is enlarged, Since the heat generated by the cut-off body in the overload current region is difficult to be transmitted to the soluble body, there is a concern that it is relatively difficult to adjust the melting characteristics of the soluble body.

  Accordingly, an object of the present invention made in view of such points is to provide an electric wire fuse that can reduce the number of manufacturing steps, reduce costs, can be made compact, and can easily adjust the fusing characteristics of a fusible body. It is in.

The device of the electric wire fuse according to claim 1 for achieving the above object is connected to a lead-in wire in a distribution line, melted in an overload current region, and connected in series to the fusible material and blown in a short-circuit current region. In an electric wire fuse having a cut-off body,
The cut body lead integrated with the cut body is directly joined to the fusible body, and the cut body and the fusible body are connected in series.

The device according to claim 2 is the electric wire fuse according to claim 1,
The fusible body and the cut-off body lead are joined by casting.

  According to the electric wire fuse according to the present invention, the cutting body lead integrated with the cutting body is directly joined to the fusible body, and the cutting body and the fusible body are connected in series. Compared to the case where the cut-off body and fusible body are connected via a lead, the number of man-hours for compression connection can be reduced, the cost can be reduced, the size can be reduced, and the fusing characteristics of the futurable body can be adjusted. It becomes easy.

It is the external view and sectional drawing which show the whole structure of the electric wire fuse which concerns on one embodiment of this invention. FIG. 2 is an external view and a cross-sectional view showing a configuration of a fuse element shown in FIG. 1.

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

  1A and 1B are an external view and a cross-sectional view showing an overall configuration of a wire fuse according to an embodiment of the present invention. The wire fuse shown in FIG. 1 is connected to the lead-in wire in the distribution line, and the connection terminals 1L and 1R connected in series to the lead-in wire, the fuse element 2 connected between the connection terminals 1L and 1R, and the fuse element 2 The insulating inner cylinder 3 with one end containing the bottom, the insulating transparent outer cylinder 4 covering the inner cylinder 3, and the connection terminals 1L and 1R penetrate the both ends of the inner cylinder 3 and the outer cylinder 4. Insulating caps 5L and 5R.

  The connection terminal 1 </ b> L is disposed through the bottomed end of the inner cylinder 3. Inside the cap 5L having the connection terminal 1L, a waterproof cap 6L that penetrates the connection terminal 1L and prevents water from entering the inner cylinder 3 is provided at the ends of the inner cylinder 3 and the outer cylinder 4. The cap 5L is provided with a terminal cover 7L so as to cover the connection terminal 1L.

  The connection terminal 1 </ b> R is disposed through the embolus 8 that closes the open end of the inner cylinder 3. Inside the cap 5R having the connection terminal 1R, the end portions of the inner cylinder 3 and the outer cylinder 4 pass through the connection terminal 1R at the end portions of the inner cylinder 3 and the outer cylinder 4, and prevent water from entering the inner cylinder 3. A cap 6R is provided. The cap 5R is provided with a terminal cover 7R so as to cover the connection terminal 1R, similarly to the cap 5L.

  The fuse element 2 corresponds to a desired fusing characteristic (for example, 250 V, 50 A), and a fusible body 11 that blows in an overload current region and a cut-off member that is connected in series to the fusible member 11 and blows in a short-circuit current region. Twelve. A conductive partition pin 13 is provided between the fusible body 11 and the cut-off body 12, and an insulating partition plate 14 that partitions the inner cylinder 3 is fitted to the partition pin 13. Thereby, the inner cylinder 3 is separated into a storage chamber for the fusible body 11 and a storage chamber for the cutoff body 12. The accommodating chamber of the cut-off body 12 is filled with an arc extinguishing agent 15 such as silica sand. The detailed configuration of the fuse element 2 will be described later with reference to FIG.

  At both ends of the inner cylinder 3, connection pins 21L and 21R are provided through the connection terminals 1L and 1R, and connected to these connection pins 21L and 21R, and a high resistance wire such as a nichrome wire is provided on the outer periphery of the inner cylinder 3. 22 is spirally wound. As a result, the fuse element 2 and the high resistance wire 22 are connected in parallel between the connection terminals 1L and 1R. Although not shown, a low-melting alloy thermal fuse is connected in the middle of the high resistance wire 22. Further, a thermal paper 23 that is discolored by heating the high resistance wire 22 by fusing the fuse element 2 is wound around the outer periphery of the inner cylinder 3 around which the high resistance wire 22 is wound. Thereby, the presence or absence of fusing of the fuse element 2 can be confirmed from the presence or absence of discoloration of the thermal paper 23 observed through the outer cylinder 4.

  2 shows the configuration of the fuse element 2 shown in FIG. 1, FIG. 2 (a) is an external view, and FIG. 2 (b) is a cross-sectional view taken along line AA of FIG. 2 (a). The fusible member 11 is formed of solder, and a fusible lead 31 made of a copper rivet (thin flat rivet or cold-formed rivet pan) having a dish-like head is joined to one end thereof. The fusible body lead 31 joins the head of the copper rivet to the fusible body 11, and the shaft end is inserted into a connecting hole formed in the connecting end of the connecting terminal 1L, and the connecting end is formed in a hexagonal shape, for example. It connects to the connection terminal 1L by compressing.

  Further, the cut body lead 32 is directly joined to the other end portion of the fusible body 11. The cut body lead 32 uses a copper rivet (thin rivet or cold-formed rivet plate) having a head shape like the fusible lead 31, but has a longer shaft than the fusible lead 31. Is used. This cutting body lead 32 directly joins the head of the copper rivet to the fusible body 11, passes the partition pin 13 through the shaft portion, and compresses one end portion of the partition pin 13 into a hexagonal shape, for example, at a predetermined position. The partition pin 13 is fixed to Further, a cut body having a small cross-sectional area is formed on the shaft portion of the cut body lead 32 by pressing and drilling into a flat plate shape so as to be melted in the short-circuit current region between the partition pin 13 and the front end portion of the shaft portion. 12, the tip end of the shaft portion is inserted into a connection hole formed in the connection end portion of the connection terminal 1R, and the connection end portion is compressed into, for example, a hexagonal shape to be connected to the connection terminal 1R. The cut-off body 12 is arranged in a curved manner so that it can absorb the thermal stress generated by the difference in linear expansion coefficient between the exterior member and the fuse element 2 due to the temperature change caused by the outside air temperature or energization.

  In manufacturing the fuse element 2 shown in FIG. 2, for example, it is compressed and fixed at a predetermined position through a partition pin 13 that fits and holds the partition plate 14 to the shaft portion of the copper rivet constituting the breaker body lead 32. In this state, the cut body lead 32 is processed to form the cut body 12. Thereafter, the head of the copper rivet constituting the fusible body lead 31 and the head of the copper rivet constituting the cut-off body lead 32 are inserted into a fusible body mold, and the fusible body 11 is cast-molded by solder. Thus, the heads of the fusible body lead 31 and the cut body lead 32 each made of copper rivets are joined to both ends of the fusible body 11 so as to be wrapped by the solder constituting the fusible body 11. Thereafter, the shaft tip of the fusible body lead 31 is compression-connected to the connection end of the connection terminal 1L, and the shaft tip of the cut-off lead 32 is compression-connected to the connection end of the connection terminal 1R.

  Thus, after manufacturing the fuse element 2 and connecting the fuse element 2 between the connection terminals 1L and 1R, the fuse element 2 is inserted into the inner cylinder 3 from the open end side of the inner cylinder 3, and the connection terminal 1L is connected. The fuse element 2 is accommodated in the inner cylinder 3 through the bottomed portion of the inner cylinder 3. In this state, arc extinguishing agent 15 is filled into the portion where the cut-off body 12 partitioned by the partition plate 14 is located from the open end side of the inner cylinder 3, and the open end side of the inner cylinder 3 is closed with the plug 8. . Thereafter, connection pins 21L and 21R are provided through the connection terminals 1L and 1R, connected to these connection pins 21L and 21R, and the high resistance wire 22 is spirally wound around the outer periphery of the inner cylinder 3 via a thermal fuse. Then, heat sensitive paper 23 is wound around the paper. Then, after covering the outer cylinder 4 on the thermal paper 23, caps 5L and 5R are provided on both ends of the outer cylinder 4 via waterproof caps 6L and 6R, and terminals are provided on the caps 5L and 5R as necessary. Covers 7L and 7R are attached to manufacture a wire fuse.

  As described above, according to the electric wire fuse of the present embodiment, the cut body 12 that forms the cut body 12 is directly joined to the fusible body 11, and the cut body 12 and the fusible body 11 are connected in series. Therefore, compared to the case of connecting the cut body and fusible body via the conventional cut body lead, partition pin and fusible body lead, it is possible to reduce the manufacturing man-hours of compression connection and reduce the cost, Compactness is possible. Further, by adjusting the length of the cut body lead 32 or the cut body 12 or the fixing position of the partition pin 13, the fusing characteristics of the fusible body can be easily adjusted.

  Furthermore, copper rivets are used as the fusible body lead 31 and the cut-off body lead 32, respectively, and when the fusible body 11 is cast and formed, the head is encased in the fusible body 11 by solder constituting the fusible body 11. Since bonding is performed, as in the case of Patent Document 1, thermal stress is less likely to concentrate on the solder, and there is an advantage that reliability can be improved.

1L, 1R connection terminal 2 fuse element 3 inner cylinder 4 outer cylinder 5L, 5R cap 6L, 6R waterproof cap 7L, 7R terminal cover 8 plug 11 fusible body 12 cut off body 13 partition pin 14 partition plate 15 arc extinguishing agent 21L, 21R connection Pin 22 High resistance wire 23 Thermal paper 31 Fusible lead 32 Cutout lead

Claims (2)

In an electric wire fuse having a fusible body that is connected to a lead-in wire in a distribution line and is blown in an overload current area, and a cut-off body that is connected in series to the fusible body and is blown in a short-circuit current area,
The electric wire fuse characterized by connecting the said cut off body and the said meltable body in series by joining the cut body lead integral with the said cut off body directly to the said meltable body.   The wire fuse according to claim 1, wherein the fusible body and the cut-off body lead are joined by casting.

Images