JPH071555U - Tube type fuse and tube type fuse with lead wire - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a tubular fuse in which the insulating tube is not damaged when blown. [Structure] In a tubular fuse having a structure in which conductive caps are attached to both ends of the insulating tube and a fusible body is electrically connected between the conductive caps, the inner diameter and the wall thickness of the insulating tube are selected to be approximately the same size. At the same time, form grooves cut in the outer circumference of both ends of the insulating tube in the circumferential direction, insert the end of the insulating tube into the melted solder in the conductive cap, and solder the meltable body inserted into the hollow part of the insulating tube. A tubular fuse that is electrically connected to a conductive cap and has a structure in which solder engages with a groove formed in an insulating tube to prevent it from coming off.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tube fuse and a tube fuse with a lead used in various electric devices.

[0002]

[Prior art]

 4 and 5 show the structure of a conventional tubular fuse. In the tubular fuse shown in FIG. 4, a hole is formed in the center of the conductive cap 1, the fusible body 2 is inserted into the hole, and the fusible body 2 is electrically and mechanically attached to the outside of the conductive cap 1 by the solder 3. Is connected to the conductive cap 1 and the fusible body 2 is supported at the axial center position of the insulating tube 4.

In the tubular fuse shown in FIG. 5, a fusible body 2 is hooked on an end of an insulating tube 4, a conductive cap 1 is put on the fusible body 2, and a solder piece is put in the conductive cap 1. The fusible body 2 and the conductive cap 1 are soldered by melting the solder pieces. In any structure, the fusible body 2 is supported so as not to contact the inner wall surface of the insulating tube 4. That is, when the fusible body 2 is in contact with the inner wall of the insulating tube 4, if the fusible body 2 generates heat due to overcurrent, the heat escapes to the insulating tube 4 and does not melt within the specified time. .

For this reason, conventionally, the wall thickness is reduced in order to increase the inner diameter of the insulating tube 4, and the fusible body 2 does not come into contact with the inner wall of the insulating tube 4 as much as possible. By the way, in the case of a fuse of length L = 20 mm, wall thickness t = 0.5-0.7 mm, inner diameter D = 3.3-3.7 mmφ, in case of L = 30 mm fuse, wall thickness t = 0.7- In the case of a fuse of 0.9 mm, inner diameter D = 4.1 to 4.5 mmφ, L = 38 mm, an insulating tube with wall thickness t = 0.9 to 1.2 mm and inner diameter D = 6.6 to 7.2 mmφ is used. To be

[0005]

[Problems to be Solved by the Invention] However, when the wall thickness of the insulating pipe is thin, the strength thereof becomes weak, and in particular, the meltable body is damaged by an impact generated when it is melted, and an accident such as a fragment scattering occurs. There is inconvenience. Therefore, in the past, the thickness was selected so that the insulating tube would not be damaged by the shock during fusing, and the fusible body was soldered to the conductive cap with the tension applied as much as possible. The solution is stretched so that it is supported inside the insulating tube. For this reason, the soldering of the fusible material requires manual work, which is a troublesome manufacturing process.

Further, the conductive cap 1 is adhered to the insulating tube 4 with an adhesive. When the conductive cap 1 is adhered to the insulating pipe 4, if the adhesive goes around the entire circumference of the insulating pipe 4, there is no escape path for the air from the insulating pipe 4, so that the impact when the fusible body 2 melts is isolated. The pipe 4 is directly hit, and the insulating pipe 4 is easily damaged at this point as well. Therefore, when applying adhesive to the inside of the conductive cap 1 or to the end of the insulating tube 4, care must be taken because if the adhesive is accidentally applied too much, the component will be defective. It is a point.

[0007]

[Means for Solving the Problems]

 In this invention, the thickness and the inner diameter of the insulating tube are set to be approximately the same, the strength thereof is increased, and the fusible body always contacts the inner wall of the insulating tube, so that the fusible body having a small fusing current is selected in advance. Along with this, a groove cut in the circumferential direction is formed at the inner end of the insulating tube, the end of the insulating tube is inserted into the melted solder in the conductive cap, the solder is immersed in the groove, and the solder that has entered the groove is cured. In this structure, the conductive cap is fixed to the insulating tube.

According to the structure of the present invention, since the wall thickness of the insulating tube becomes large, the strength thereof becomes large, and the insulating tube can sufficiently withstand the impact generated by the fusing of the fusible body. Since a fusible material having a diameter smaller than the diameter to be originally selected is selected as the fusible material, even if the fusible material comes into contact with the inner wall of the insulating tube, the fusible material can be blown out in the vicinity of the specified current value. Further, the conductive cap and the insulating tube are fixed by soldering, which facilitates manufacturing. In particular, the solder can be melted in the conductive cap, and the end of the insulating tube can be inserted into the melted solder, which has the advantage of facilitating automation.

[0009]

【Example】

 FIG. 1 shows an embodiment of this invention. In the figure, 1 is a conductive cap, 2 is a fusible body, 3 is a solder, and 4 is an insulating tube, which is the same as the description of the conventional technique. The characteristic structure of this invention is the shape of the insulating tube 4. That is, in this invention, the inner diameter D and the wall thickness t of the insulating tube 4 are selected to be almost equal. By the way, as the insulating tube used for the tubular fuse with the length L = 20 mm, the wall thickness t = 1.5 mm and the inner diameter D = 1.7 mmφ were selected. As the insulating tube used for the tubular fuse with the length L = 30 mm, the wall thickness t = 1.9 mm and the inner diameter D = 2.0 mmφ were selected. As the insulating tube used for the tubular fuse with the length L = 38 mm, the wall thickness t = 3.4 mm and the inner diameter D = 2.4 mmφ were selected.

Further, in this invention, grooves 4A are formed in the outer circumference of both ends of the insulating tube 4 in the circumferential direction. Two grooves 4A are opposed to each other by 180 ° and three grooves are formed at an interval of 120 °. The fusible body 2 is inserted into the hollow hole of the insulating tube 4, and the fusible body 2 is bent and temporarily fixed to the insulating tube 4. A solder piece is inserted into the conductive cap 1 and heated to melt and melt the solder piece. One end side of the insulating tube 4 supporting the fusible body 2 is inserted into the melted solder 3. By this insertion, the solder enters the groove 4A formed in the insulating tube 4 and also contacts the fusible body. By hardening the solder 3 in this state, the conductive cap 1 and the insulating tube 4 are firmly bonded by the solder 3. That is, when the solder 3 that has entered the groove 4A is hardened, the conductive cap 1 and the insulating tube 4 are firmly coupled, and the insulating tube 4 does not come out. The conductive cap 1 is attached to the other end of the insulating tube 4 in the same manner to complete the tubular fuse.

FIG. 3 shows the structure of a tubular fuse with a lead wire. In this embodiment, the inner diameter of the conductive cap 1 is selected to be larger than the outer diameter of the insulating tube 4 by the diameter of the lead wire 5, and the lead wire 5 is sandwiched between the conductive cap 1 and the insulating tube 4. By melting the solder 3 in the conductive cap 1 in this state, the solder 3 is electrically and mechanically coupled between the fusible body 2 and the conductive cap 1 and between the fusible body 2 and the lead wire 5.

[0012]

[Effect of device]

 As described above, according to the present invention, the wall thickness t of the insulating tube 4 is selected to be approximately equal to the inner diameter D of the insulating tube 4, so that the wall thickness becomes larger than the conventional one. As a result, the insulating tube 4 will not be damaged by the impact when the fusible body 2 is fused. In the tubular fuse of the present invention, both ends of the insulating tube 4 are sealed by the solder 3, but since the thickness t of the tube is large, the strength is so strong that the fusible body 2 is not damaged. .

Further, in this invention, since the groove 4A is formed in the insulating tube 4, the conductive cap 1 does not come out of the insulating tube 4 by the engagement of the solder 3 and the groove 4A. Therefore, it is possible to provide a highly durable tubular fuse. Further, according to the present invention, the solder 3 is melted in the conductive cap 1 and the end of the insulating tube 4 is inserted into the melted solder, or the insulating tube 4 is inserted in the conductive cap 1. There is an advantage that automatic assembly is possible because either one of the solder pieces should be melted.

Furthermore, in this invention, since the inner diameter is made small in order to increase the wall thickness of the insulating tube 4, the fusible body 2 always contacts the inner wall of the insulating tube 4. Therefore, by selecting a fusible body having a diameter smaller than that of the fusible body 2 which should be originally selected, it is possible to obtain a fuse that blows within a prescribed time at a prescribed current.

[Submission date] October 6, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

[0005]

[Problems to be solved by the device]

However, if the wall thickness of the insulating tube is thin, its strength becomes weaker, and in particular, there is an inconvenience that accidents such as scattering of fragments and the like will occur due to the impact generated when the fusible body melts during the short-circuit breaking test . Therefore, in the past, the thickness was selected so that the insulating tube would not be damaged by the shock during fusing, and the fusible body was soldered to the conductive cap with the tension applied as much as possible. The solution is stretched so that it is supported inside the insulating tube. For this reason, the soldering of the fusible material requires manual work, which is a troublesome manufacturing process.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a completed state of the tubular fuse according to the present invention.

FIG. 3 is a sectional view for explaining a structure of a tubular fuse with a lead wire proposed in claim 2 of the present invention.

FIG. 4 is a sectional view for explaining a conventional technique.

FIG. 5 is a cross-sectional view for explaining a conventional technique.

[Explanation of symbols]

 1 Conductive Cap 2 Soluble Body 3 Solder 4 Insulation Tube 4A Groove 5 Lead Wire

Claims (2)

[Scope of utility model registration request] 1. A. An insulating tube having inner diameters and wall thicknesses of the same degree and having circumferentially cut grooves at the outer circumferences of both ends; A conductive fusible material inserted into the hollow hole of the insulating tube; Conductive caps electrically connected to both ends of the conductive fusible body attached to both ends of the insulating tube; A tube formed by solder that is melted in the conductive cap and electrically connected between the conductive cap and the conductive fusible body after curing and mechanically connected between the conductive cap and the insulating tube. Shape fuse. 2. The tubular fuse according to claim 1, wherein one end is sandwiched between the inner wall of the conductive cap and the outer peripheral surface of the insulating tube, and the conductive cap and each end of the conductive fusible body are sandwiched by the solder. A tubular fuse with a lead, characterized by a structure having a lead wire electrically and mechanically connected therebetween.