JPH06132064A - Arrester with fail safe function - Google Patents

Abstract

PURPOSE:To electrically short-circuit a line electrode and an earth electrode so as to stop a discharge in the case of continuing the discharge by an arrester, by surely holding a spring retainer piece prevented from normally coming into contact with an external surface of the electrode. CONSTITUTION:An insulating film 22, melted at a melting temperature or less of a conductive low melting point metal 24 to provide electric insulation, is arranged in external surfaces of an insulating cylinder 14, line electrode 12 and an earth electrode 10, and a spring retainer piece 20, pressed into contact in a direction of approaching the external surface of the line electrode 12 from the outside of the insulating film 22 relating to the line electrode 12, is provided by partly fixing the piece 20 to the earth electrode 10 by spot welding or the like. The conductive low melting point metal 24 is provided to be press interposed between these insulating film 22 and spring retainer piece 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arrester with a fail-safe function.

[0002]

2. Description of the Related Art A gas-filled arrester discharges a surge between electrodes when a high-voltage surge enters from the outside, and is used as a protective device to protect electronic equipment from external surge such as lightning. ing. When this arrester is discharged, the discharge may continue due to some reason.In such a case, the arrester becomes hot and there is a danger of fire, etc. A fail-safe mechanism may be provided.

There are various types of fail-safe mechanisms provided in the arrester, but a spring pressing piece made of a conductive metal is attached to the outer surface of the arrester so that one pressing piece does not contact the outer surface of the electrode, and the arrester discharges. There is a method of electrically short-circuiting the electrodes by bringing the spring pressing piece into contact with the outer surface of the electrode when the temperature becomes high. In this case, as a method for attaching the spring retainer piece, a heat-soluble insulator is elastically sandwiched between the outer surface of the insulating cylinder of the arrester and the spring retainer piece so that the insulator becomes A method of electrically short-circuiting the spring retainer piece and the electrode by melting, or a thin heat-soluble insulating film is sandwiched between the spring retainer piece and the electrode, and the insulating film is melted by heat There are some that are short-circuited.

[0004]

By the way, since the spring pressing piece used in the fail-safe mechanism using the heat-soluble insulator is a small part, the operation of inserting the insulator between the electrodes is performed. There is a problem that is complicated. Further, when the insulator is thin, there is a problem that the spring pressing piece and the outer surface of the electrode cannot be sufficiently spaced with the insulating material sandwiched therebetween, and the electrode and the spring pressing piece come into contact with each other. In the arrester, electrodes are brazed and joined to the end surface of the insulating cylinder made of ceramic, so the insulating cylinder and the electrodes may be slightly displaced and joined. In this way, the spring pressing piece may come into contact with the electrode. Also, if a thin insulating film is sandwiched between the spring retainer and the electrode, the insulating film may be broken and the spring retainer and the electrode may come into contact with each other when assembling the arrester or when handling the product. It was Therefore, the present invention has been made to solve the above problems, and an object thereof is to provide an arrester with a fail-safe function that can reliably avoid continuous discharge of the arrester and is easy to manufacture. is there.

[0005]

The present invention has the following constitution in order to achieve the above object. That is, in a fail-safe arrester in which a line electrode and a ground electrode are arranged so as to face each other with an insulating cylinder interposed therebetween, the insulating cylinder, the line electrode, and the ground electrode are provided on the outer surface of the conductive low melting point metal at a temperature not higher than the melting temperature. An insulating film having a melting property and an electrical insulating property is arranged, and by partially fixing it to one of the line electrode or the ground electrode by spot welding or the like, it is applied between the line electrode and the ground electrode. For the other electrode provided with a spring pressing piece that presses in a direction approaching the outer surface of the electrode from the outside of the insulating film, a conductive low melting point metal between the insulating film and the spring pressing piece. It is characterized in that it is provided by clamping. An insulating film having heat resistance and electrical insulation is arranged on the outer surface of the insulating cylinder, the line electrode, and the ground electrode, and is partially fixed to one of the line electrode or the ground electrode by spot welding or the like. By arranging the spring electrode between the line electrode and the ground electrode, a spring pressing piece is provided that presses against the other electrode in a direction approaching the outer surface of the electrode from the outside of the insulating film. And a conductive low melting point metal is sandwiched between the insulating cylinder and the insulating cylinder. Further, the insulating film is provided with a conductive low-melting metal piece housing hole that is opened on the outer surface of the insulating cylinder, and a conductive low-melting metal piece is inserted into the conductive low-melting metal piece housing hole,
The conductive low melting point metal piece is elastically sandwiched and supported between the spring pressing piece and the outer surface of the insulating cylinder. Further, the insulating film is provided with a communication groove communicating from an end portion where the conductive low melting point metal piece is arranged to an outer surface of the other electrode. Further, the insulating film is provided with a conductive low melting point metal piece accommodating hole that is opened on the outer surface of the insulating cylinder, and is connected to the conductive low melting point metal piece accommodating hole to reach the outer surface of the other electrode. With a groove,
The conductive low melting point metal piece is inserted into the conductive low melting point metal piece accommodating hole, and the conductive low melting point metal piece is elastically sandwiched and supported between the spring pressing piece and the outer surface of the insulating cylinder. It is characterized by

[0006]

[Function] The insulating film and the conductive low-melting metal piece are interposed between the outer surface of the arrester and the spring holding piece, so that the spring holding piece always keeps the electrodes from electrically connecting and the discharge continues. When the arrester overheats,
The conductive low-melting metal piece melts, and the spring retainer that elastically clamps and supports the conductive low-melting metal piece comes into contact with the outer surface of the electrode, electrically short-circuits the ground electrode and the line electrode, and discharges the arrester. To stop. When a heat-resistant insulating film is used, when the conductive low-melting metal melts, the melted conductive low-melting metal flows into the communication groove, and the spring retainer piece and the electrode are electrically connected through the conductive low-melting metal. Short circuit to stop the arrester discharge.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows a perspective view of an embodiment of an arrester with a fail-safe function according to the present invention. The arrester of this embodiment is a three-pole arrester, in which the central electrode is the ground electrode 10 and the electrodes at both ends are the line electrodes 12. The ground electrode 10 and the line electrode 12 are electrically insulated by a ceramic insulating cylinder 14. The earth electrode 10 and the line electrode 12 are airtightly brazed and joined to the end surface of the insulating cylindrical body 14, and gas is sealed at a predetermined pressure in the arrester. The ground terminal 16 and the line terminal 18 are attached to the outer surfaces of the ground electrode 10 and the line electrode 12 by spot welding.

In FIG. 1, reference numeral 20 is a spring pressing piece attached to the outer surface of the arrester body along the longitudinal direction between the line electrodes 12, 12. The spring pressing piece 20 is attached to the ground electrode 10 by spot welding. 22 is a spring pressing piece 2
It is an insulating film arranged so as to be sandwiched between 0 and the outer surface of the arrester body. The insulating film 22 is the spring retainer piece 2.
This is for electrically insulating 0 and the line electrode 12. The spring pressing piece 20 extends in the width direction at a position where it presses the ground electrode 10 and the line electrode 12, and is curved so as to follow the outer peripheral curved surface of the electrode.

FIG. 2 shows the structure of the assembled parts of the arrester. The insulating film 22 is arranged so as to be sandwiched between the spring pressing piece 20 and the outer surface of the arrester body, and the solder piece 24 is arranged so as to be sandwiched and supported between the spring pressing piece 20 and the outer surface of the insulating cylindrical body 14. The solder piece 24 is housed in the solder piece housing hole 26 formed in the insulating film 22, and is pressed and supported by the inner surface of the spring pressing piece 20. FIG. 3 shows a plan view of the insulating film 22. Reference numeral 28 is a welding hole for spot welding the spring pressing piece 20 to the ground electrode 10, and 26 is the above-mentioned solder piece accommodating hole. The solder piece accommodating hole 26 is formed to have a size into which the solder piece 24 fits. The insulating film 22 has a size such that the spring pressing piece 20 does not protrude.

The spring pressing piece 20 and the insulating film 2
2. When assembling the arrester with the fail-safe function using the solder pieces 24, the side of the arrester body to which the spring holding piece 20 is attached faces downward, the insulating film 22 is placed on the inner surface of the spring holding piece 20, and the insulating film 22 After inserting the solder piece 24 into the solder piece receiving hole 26, spot welding is performed from the lower side so that the spring pressing piece 20 is pressed against the outer surface of the arrester. By thus attaching the spring pressing piece 20 from the lower side of the arrester body, the insulating film 22 and the solder piece 24 can be set inside the spring pressing piece 20 and easily attached.

FIG. 4 is an explanatory view showing a state in which the spring pressing piece 20 is attached to the arrester body. The spring pressing piece 20 elastically presses the solder piece 24 against the outer surface of the arrester body, and the tip of the spring pressing piece 20 is supported so as not to contact the outer surface of the electrode. Since the spring pressing piece 20 does not directly press the insulating film 22, the insulating film 22 is prevented from breaking. In this embodiment, the solder pieces 24 are arranged on the outer surface of the insulating cylindrical body 14 in order to maintain the electrical insulation. The solder piece 24 is used as a metal that melts when the arrester is overheated, and a conductive low melting point metal such as tin-bismuth alloy may be used. In the embodiment, as the insulating film 22, a heat-soluble synthetic resin material such as polyethylene that melts at a melting temperature of the solder or lower is used. By using the insulating film 22 together with the solder piece 24, it is possible to reliably prevent the spring pressing piece 20 from coming into contact with the outer surface of the line electrode 12.

According to the arrester with a fail-safe function of the above-mentioned embodiment, when the arrester continues to be discharged for some reason and the temperature becomes high, the solder piece 24 and the insulating film 22 are melted, and the solder piece 24 and the insulating film 22 do not intervene. 20 contacts the outer surface of the line electrode 12 by its own elastic force, which electrically shorts the line electrode 12 and the ground electrode 10. As a result, the discharge is stopped and the fail-safe function of the arrester is exerted. The heated and melted solder adheres to the inner surfaces of the line electrode 12 and the spring pressing piece 20, and the electrical short circuit between the line electrode 12 and the spring pressing piece 20 is more reliably performed.

In the above embodiment, the insulating film 22 is made of an insulator that melts at a temperature not higher than the melting temperature of the solder, but it is also possible to use an insulator having heat resistance. Figure 5
Shows an example of the insulating film 30 when such an insulator having heat resistance is used. In this case as well, the solder piece 24 is elastically sandwiched between the outer surface of the arrester and the spring pressing piece 20, but the solder flows into the line electrode 12 side when the solder piece 24 melts. It is different in that it is configured to electrically short.

That is, the insulating film 30 is provided with a solder piece accommodating hole 26 for accommodating the solder piece 24, and
A communication groove 32 for guiding the melted solder from the front side of the solder piece accommodating hole 26 to the line electrode 12 side is provided, and after the solder piece 24 is melted, the solder flows into the communication groove 32 and the spring pressing piece 20 and the line electrode. 12 and 12 are electrically connected. The communication groove 32 is provided with a width narrower than that of the solder piece accommodating hole 26, and the tip of the communication groove 32 extends to a position where the tip contacts the outer surface of the line electrode 12. The solder piece accommodating hole 26 is formed in the insulating cylinder 14
It is the same as in the above embodiment that it is provided at the outer surface position.

6 to 8 show another embodiment in which the spring pressing piece 20 is attached to the arrester body. The embodiment shown in FIG. 6 is an example in which the solder pieces 24 are not provided in the insulating film 22a, and the solder pieces 24 are bonded to the insulating film 22a in advance. A heat-soluble film is used as the insulating film 22a. As illustrated, the solder piece 24 is interposed between the insulating film 22a and the spring pressing piece 20. When the arrester body is overheated, the insulating film 22a is melted, the solder piece 24 is melted, the spring pressing piece 20 contacts the outer surface of the line electrode 12, and the ground electrode 10 and the line electrode 12 are electrically short-circuited. The same applies when the solder piece 24 is arranged on the surface opposite to the insulating film 22a in FIG. 6, that is, on the arrester body side. The insulating film 22a melts together with the solder pieces 24, and the spring pressing pieces 20 come into contact with the line electrodes 12 to electrically short-circuit them.

The embodiment shown in FIG. 7 is an example in which a component in which a solder piece 24 is adhered to a heat-soluble insulating film 22b is used in the same manner as the above example, but the spring pressing piece 2 after melting the solder is used.
In order to ensure electrical continuity between 0 and the line electrode 12, a communication groove 32 is provided from the edge of the solder piece 24 to the line electrode 12. The communication groove 32 has the same structure as that of the example shown in FIG. 5, and the melted solder flows into the line electrode 12 at this communication groove 32 portion, and the spring pressing piece 20 and the line electrode 12 are surely electrically connected. Can be made.

The embodiment shown in FIG. 8 has an insulating film 30a.
Is an example of using a heat resistant insulator. Also in this example, the insulating film 30a is not provided with a solder piece accommodating hole, and the solder piece 24 is bonded and attached to the insulating film 30a in advance. When mounting an insulating film with solder pieces, the solder pieces 24 are placed on the side in contact with the insulating cylinder 14 as shown in the figure. The insulating film 30a is provided with a communication groove 32 similar to the above example in order to guide the melted solder to the line electrode 12 and surely cause an electrical short circuit. Note that the communication groove 32 may not be provided if electrical connection with the line electrode 12 can be achieved by melting the solder. Also, the communication groove 3
When two pieces are provided, the solder piece 24 can be arranged so as to be sandwiched between the insulating film 30a and the spring pressing piece 20.

As described above, in each of the embodiments shown in FIGS. 6 to 8, the parts are assembled using the insulating film or the spring retainer pieces to which the solder pieces are previously attached. Therefore, the parts can be easily handled and the assembling work can be performed efficiently. There is an advantage that it can be performed in a simple and reliable manner. In addition, in each of the above-described embodiments, a three-pole arrester has been described as an example.
The same applies to a two-pole arrester. That is, in the case of 2 poles, the spring pressing piece is spot welded to one electrode,
For the other electrode, a solder piece and an insulating film may be interposed between the outer surface of the insulating cylinder and the end of the spring pressing piece so as not to contact the outer surface of the electrode.

[0019]

As described above, according to the arrester with a fail-safe function according to the present invention, the end of the spring pressing piece not joined to the electrode by the solder piece and the insulating film is prevented from coming into contact with the outer surface of the electrode. It can be securely held, and can be held so that the spring pressing piece and the electrode are not electrically connected. Further, when the arrester is continuously discharged and the arrester is overheated, the line electrode and the ground electrode are surely electrically short-circuited and the discharge can be stopped.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of an arrester with a fail-safe function.

FIG. 2 is an assembly diagram of an arrester with a fail-safe function.

FIG. 3 is a plan view of an insulating film.

FIG. 4 is an explanatory diagram showing a state in which a spring pressing piece and the like are attached to the arrester body.

FIG. 5 is an explanatory diagram showing another configuration example of an insulating film.

FIG. 6 is an explanatory view showing another embodiment in a state where a spring pressing piece or the like is attached to the arrester body.

FIG. 7 is an explanatory view showing another embodiment in a state where a spring pressing piece and the like are attached to the arrester body.

FIG. 8 is an explanatory view showing another embodiment in a state where a spring pressing piece and the like are attached to the arrester body.

[Explanation of symbols]

 10 ground electrode 12 line electrode 14 insulating cylinder 16 ground terminal 18 line terminal 20 spring pressing piece 22, 22a, 22b insulating film 24 solder piece 26 solder piece accommodating hole 28 welding hole 30, 30a insulating film 32 communicating groove

Claims (5)

[Claims] 1. A fail-safe arrester in which a line electrode and a ground electrode are arranged so as to face each other with an insulating cylinder interposed therebetween, wherein an outer surface of the insulating cylinder, the line electrode, and the ground electrode comprises:
Arrange an insulating film that has an electrical insulation property while melting below the melting temperature of the conductive low-melting metal, and partially fixes the line electrode or one of the ground electrodes by spot welding or the like to the line. A spring retainer is disposed so as to extend between the electrode and the ground electrode and presses against the other electrode in a direction approaching the outer surface of the electrode from the outside of the insulating film, the insulating film and the spring retainer. An arrester with a fail-safe function, characterized in that a conductive low-melting metal is sandwiched between and. 2. An arrester with a fail-safe function, in which a line electrode and a ground electrode are arranged so as to face each other with an insulating cylinder interposed therebetween, wherein the insulating cylinder, the line electrode, and the outer surface of the ground electrode are provided with heat resistance and electrical insulation. An insulating film having the above is arranged, and the line electrode or the ground electrode is partially fixed to one of the electrodes by spot welding or the like so as to be placed between the line electrode and the ground electrode and arranged with respect to the other electrode. A spring pressing piece that is pressed against the outer surface of the insulating film in a direction approaching the outer surface of the electrode, and a conductive low melting point metal is sandwiched between the insulating film and the insulating cylinder. Characteristic arrester with fail-safe function. 3. An insulating film is provided with a conductive low melting point metal piece accommodating hole that opens at an outer surface of the insulating cylinder, and a conductive low melting point metal piece is inserted into the conductive low melting point metal piece accommodating hole, The arrester with a fail-safe function according to claim 1, wherein the conductive low-melting metal piece is elastically sandwiched and supported between a spring pressing piece and an outer surface of the insulating cylinder. 4. An arrester with a fail-safe function according to claim 1, wherein the insulating film is provided with a communication groove communicating from an end portion where the conductive low melting point metal piece is arranged to an outer surface of the other electrode. . 5. An insulating film is provided with a conductive low melting point metal piece accommodating hole that opens on the outer surface of the insulating cylindrical body, and communicates with the conductive low melting point metal piece accommodating hole to the outer surface of the other electrode. A communicating groove is provided, and the conductive low-melting metal piece is inserted into the conductive low-melting metal piece accommodating hole, and the conductive low-melting metal piece is elasticized between the spring retainer piece and the outer surface of the insulating cylinder. The arrester with a fail-safe function according to claim 2, characterized in that the arrester is supported by pinching.