JPH0584005U - Sealed fuse blowout display device - Google Patents

Abstract

(57) [Summary] [Structure] In a hermetically sealed fuse to be attached to a lead-in wire of a power distribution line, copper tube terminals 2 and 3 are connected to both ends of a fuse element 1, and the inner tube 6 is fixed by penetrating the copper tube terminals. To the tightening screws 11 and 12, the lead terminals 17 made of an alloy that melts at a temperature lower than the melting or ignition temperature of the fuse insulating member,
18 are also fastened together, and the end portions of the high resistance wire 19 connected in parallel with the fuse element 1 are connected to the alloy lead terminals 17 and 18. [Effect] At the same time when the fuse element is blown, when the current flowing through the high resistance wire 19 is sufficiently large, the high resistance wire instantly blows red heat and displays a trace on the thermal paper 20. Further, even if an electric current insufficient for blowing the high resistance wire 19 by red heat continues for a long time, the lead terminals 17, 18 made of alloy are melted and the circuit is cut off before the fuse insulating member is melted or ignited.
Further, the manufacturing and assembling work of the parts can be performed easily and easily.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hermetically sealed fuse which is attached to a lead wire of a distribution line to prevent an accident due to overcurrent.

[0002]

[Prior Art]

 Conventionally, as a sealed fuse attached to the lead-in wire, copper tube terminals are connected to both ends of the fuse element and covered with an insulating inner cylinder, and a high resistance wire is spirally wound around the outer circumference of the inner cylinder. There was a fusing display structure that was connected in parallel with the element, covered with thermal paper on the outer periphery of the high resistance wire, and was covered with a transparent outer cylinder. Also, a high-resistance wire in which a low-melting-point alloy is interposed in the central portion has been known.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned conventional sealed fuse, current flows through the high resistance wire wound around the inner cylinder at the same time as the fuse element is blown.However, if the cause of the blowout is a short circuit or an excessive load causes a large current to flow through the high resistance wire, However, it is common to instantly blow off the high resistance wire with red heat and also generate a trace on the thermal paper.By seeing this through the outer cylinder, it is possible to confirm the blowout of the fuse. However, if the current flowing through the high resistance wire is small for a long time, there is a risk of igniting the fuse insulation member such as the inner cylinder and the outer cylinder. In addition, although the low-melting-point alloy in the center of the above high-resistance wire can eliminate the risk of ignition, it has the drawback that manufacturing and assembling work of fuse parts takes a lot of time and cost. .. In view of this, the present invention completely eliminates the possibility of melting and igniting the insulating member that constitutes the fuse as in the prior art, and also facilitates the manufacturing and assembling work of the parts and further reduces the cost. It is a thing.

[0004]

[Means for Solving the Problems] In order to achieve the above object, in a blowout display device for a hermetically sealed fuse according to the present invention, a fuse element having copper tube terminals connected to both ends thereof is formed of a heat-resistant insulating inner cylinder. Cover, wrap a high resistance wire connected in parallel with the fuse element around the outer circumference of this inner cylinder, cover the outer circumference of this high resistance wire with heat-sensitive paper, and cover this heat-sensitive paper with a transparent outer cylinder. Type fuse, an alloy lead terminal that melts or melts at a temperature lower than the ignition temperature of the fuse insulating member is tightened together with the tightening screw that penetrates the copper tube terminal and fixes the inner cylinder. The end of the high resistance wire was connected to the terminal.

[0005]

[Action]

 In the present invention, an alloy lead terminal that melts or melts at a temperature lower than the ignition temperature of the fuse insulating member is tightened together with the tightening screw that fixes the inner cylinder by penetrating the copper tube terminal. Since the end of the high resistance wire is connected to the manufactured lead terminal, the current flows through the high resistance wire at the same time when the fuse element is blown. Thus, if the cause of the fuse blowout is a short circuit or an overload, and the current flowing through the high resistance wire is sufficiently large, the high resistance wire instantly blows red heat and displays a trace on the thermal paper. Also, even if the load remaining after the fuse is blown is small and the current that is insufficient to burn out the high resistance wire continues for a long time, the alloy lead terminals will blow before the fuse insulating member melts or ignites Display a trace on the paper.

[0006]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, 1 is a fuse element in which copper tube terminals 2 and 3 are connected to both ends, 4 is a fusible body, and 5 is a copper element substrate. Reference numeral 6 denotes a heat-resistant and insulating inner cylinder made of polyester resin that covers both ends of the fuse element 1 and the copper tube terminals 2 and 3, and a partition wall 7 is provided at the center to divide the chamber into two chambers 8 and 9. Then, the fusible body 4 side is inserted into the one chamber 8 and the element substrate 5 side is inserted into the other chamber 9 through the partition wall 7, and the arc extinguishing agent 10 is filled into the element substrate 5 side.

As shown in FIGS. 1, 3 and 4, 11 and 12 are tightening screws that penetrate the screw holes 13 and 14 of the copper tube terminals 2 and 3 and fix both ends of the inner cylinder 6. The low-melting-point alloy lead terminals 17 and 18 are fastened to both screw heads 15 and 16, respectively. Reference numeral 19 denotes a high resistance wire, one end of which is connected to the alloy lead terminal 17 and the other end of which is connected to the lead terminal 18 while being spirally wound around the outer circumference of the inner cylinder 6 in parallel with the fuse element 1. It is connected. Reference numeral 20 denotes a thermal paper attached to the outer periphery of the high resistance wire 19.

The alloy lead terminals 17 and 18 are formed of a metal material that melts at a temperature lower than the melting or ignition temperature of the fuse insulating member such as the inner cylinder 6 and the outer cylinder 21. Therefore, it is necessary to use, as the lead terminals 17 and 18, those whose melting points are not too low in order to cause the thermal paper 20 to generate a trace by the heat generated by the high resistance wire 19. .. In this embodiment, the lead terminals 17 and 18 are made of low melting point alloy, but only one is made of low melting point alloy and the other is made of ordinary metal lead terminal. Produces the same effect. In the figure, 21 is a transparent outer cylinder made of polycarbonate resin fitted on the outside of the thermal paper, 22 and 23 are waterproof covers fitted from both ends of the outer cylinder 21 to the copper tube terminals 2 and 3, and 24 is a waterproof packing. 25 shows waterproof silicon, and 26 and 27 show terminal covers.

[0009]

【effect】

 According to the present invention, according to the configuration described in the claims, when the current flowing through the high resistance wire is sufficiently large after the fuse element is blown, the high resistance wire instantly blows red heat to display a trace on the thermal paper. In addition, even if the current is insufficient for burning out the high resistance wire after the fuse is blown for a long time, the alloy lead terminals will be blown before the fuse insulating member melts or ignites. You can secure the sex.

Further, in the present invention, it suffices to connect the end of the high resistance wire to the lead terminal provided on the head of the tightening screw, and attach the low melting point alloy to the center of the high resistance wire as in the conventional case. Since it is not necessary to manufacture the parts, the manufacturing and assembling operations of the parts are simple and easy, and automation is possible, which is very useful for cost reduction.

[0011]

[Brief description of drawings]

FIG. 1 is a sectional view of a sealed fuse according to the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is an enlarged cross-sectional view of a tightened portion of an alloy lead terminal.

FIG. 4 is a plan view showing a state in which high resistance wires are mounted on both lead terminals.

[Explanation of symbols]

 1 Fuse element 2 Copper tube terminal 3 Copper tube terminal 6 Inner cylinder 11 Tightening screw 12 Tightening screw 13 Screw hole 14 Screw hole 17 Low melting point alloy lead terminal 18 Low melting point alloy lead terminal 19 High resistance wire 20 Thermal paper 21 Outer cylinder

Claims (1)

[Scope of utility model registration request] 1. A fuse element, to which copper tube terminals are connected at both ends, is covered with a heat-resistant insulating inner cylinder, and a high resistance wire connected in parallel with the fuse element is wound around the outer circumference of the inner cylinder. In a sealed fuse in which a thermal paper is coated on the outer circumference of the wire and the thermal paper is covered with a transparent outer cylinder, an alloy lead terminal that melts at a temperature lower than the melting or ignition temperature of the fuse insulating member is used as the copper tube. A blowout display device for a hermetically sealed fuse, which is fastened together with a tightening screw for penetrating a terminal and fixing an inner cylinder, and connecting an end portion of the high resistance wire to the lead terminal.