JP2001057283A - Surge absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the stable surge absorbability of a long service life by using a comparatively inexpensive material with a simple manufacturing process by accommodating a pair of electrodes in an air-tightly sealed insulating housing, mounting a bulk glass body (core) between the electrodes, and having a pair of lead terminals taken out of the electrodes to the external of the insulating housing. SOLUTION: A bulk glass body is preferably manufactured by cutting a glass plate by a cutter and grinding both end surfaces thereof. When the excess voltage surge reached between lead terminals 13A, B, the discharging is generated along a side surface of a core 15 between electrodes 12A, B, and absorbs the surge. After the discharging, a side surface of the core 15 recovers an original normal condition, and keeps high insulating characteristic to the normal voltage. the discharging voltage is determined on the basis of a dimension of a gap between the electrodes or the like, and the stable discharging voltage can be obtained by improving the accuracy in size of the core 15. As the original condition is recovered after the discharging, long life of the surge absorber can be kept.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surge absorber for protecting electronic parts, electronic equipment, and the like from an overvoltage surge that has entered wiring.

[0002]

2. Description of the Related Art In order to protect various electronic components and electronic devices from overvoltage surges, various surge absorbers have been developed which absorb overvoltage surges by discharging them. 2. Description of the Related Art As a conventional surge absorber, for example, a surge absorber disclosed in Japanese Patent Laid-Open No. 7-6833 is known. In this method, two opposing electrodes are provided inside an insulating cylinder, a minute conductive silicon chip is inserted into a gap between the electrodes, and sealed with an inert gas. On the surface of the conductive silicon chip, fine gap grooves are provided, and a large number of rectangular projections are formed. Then, by forming an oxide film on the surface, the oxide film functions as an insulator at a normal voltage, but by conducting with an overvoltage, good discharge characteristics can be obtained.

[0003] Similarly, a surge absorber disclosed in Japanese Patent Application Laid-Open No. Hei 7-169553 is a surge absorber in which a pair of electrodes are similarly arranged facing each other in an insulating cylinder, and a silicon core is covered with an insulating film therebetween. It has been inserted. The insulating films on both end surfaces of the silicon core act as a high-resistance insulating film with respect to a normal voltage, thereby maintaining electrical insulation between the sealing electrodes. When an instantaneous abnormal voltage as a surge is applied between both electrodes, a discharge phenomenon occurs between the electrodes and the conductive silicon core with the insulating film interposed therebetween, and the abnormal voltage is instantaneously absorbed. When the application of the abnormal voltage stops, the discharge stops, and the electrical insulation between the two electrodes is restored. Thus, good discharge characteristics and a long life can be obtained.

[0004] The surge absorber disclosed in Japanese Patent Application Laid-Open No. 8-306467 has substantially the same configuration as the above-described surge absorber, but uses a tube material inserted between a pair of opposing electrodes and a nonconductive material. It is configured in a step-like or tower-like form by arbitrarily combining conductive materials. The air chamber between the electrodes in the insulating cylinder is filled with an inert gas, whereby a surge absorber having a wide operating voltage range and a high operating speed can be obtained.

[0005]

However, these conventional surge absorbers all require a complicated shape or structure as a core involved in the discharge inserted between the electrodes, and are relatively expensive. It requires a semiconductor material such as silicon. In some cases, there is a problem in the stability of the surge voltage absorption characteristics, and the production thereof is not always easy, and the production cost is sometimes increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a surge absorber that uses a relatively inexpensive material and has a simple and long manufacturing process to provide a highly stable and long-life surge absorption characteristic. The purpose is to:

[0007]

SUMMARY OF THE INVENTION A surge absorber according to the present invention comprises an insulating housing hermetically sealed, a pair of electrodes housed in the housing, and a bulk glass body disposed between the electrodes. And a pair of lead terminals extracted from the electrode to the outside of the insulating housing.

According to the above-described present invention, since the glass bulk material is used as the core inserted between the opposing electrodes,
Highly stable discharge characteristics against overvoltage surge are obtained, and a long life surge absorber can be obtained. In addition, since the core material itself is very common, the processing is easy, and the manufacturing cost can be reduced.

Preferably, the bulk glass body is formed by cutting a glass plate with a cutter and polishing both end surfaces. Thereby, the adhesiveness with the electrode end surface can be improved, and the stability of the characteristics can be improved.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of a surge absorber according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II, and FIG. 3 is a perspective view of a core.

A pair of opposed electrodes 12A and 12B are sealed in an insulating tube 11 such as a glass tube. Electrode 12
A and 12B are formed of, for example, a gimette wire, and lead terminals 13A and 13B are formed integrally with the electrodes. A core 15 made of a bulk glass body is inserted between the opposed electrodes 12A and 12B, and an inert gas such as Ar, N ₂ , SF ₆ or the like is sealed in a space between the electrodes.

The core 15 made of a bulk glass body is
This is a glass piece having a rectangular parallelepiped shape as shown in FIG. 3, and is polished so that both end faces 15a and 15b are in close contact with the electrodes. As the glass material, for example, commercially available plate glass can be used. The method of manufacturing the core 15 is as follows.
For example, a commercially available plate glass having a thickness of about 1 mm is purchased. Then, both end faces are polished to be mirror-finished, and a thickness t between the required gaps is obtained. This is cut into dies with a cutter or the like while water is applied. And wash and dry,
It is inserted and fixed between the electrodes 12A and 12B in the insulating tube 11.

According to the surge absorber having such a configuration, when an overvoltage surge arrives between the lead terminals 13A and 13B, a discharge occurs between the electrodes 12A and 12B along the side surface of the core 15 to absorb the surge. After the discharge, the side surface of the core 15 returns to the original normal state, and has a high insulating property with respect to a normal voltage. The discharge voltage is determined by the size of the gap between the electrodes and the like. By increasing the dimensional accuracy of the core 15, a stable discharge voltage can be obtained. Then, after the discharge, it returns to the original state, so that a long-life surge absorber can be obtained.

In the above description, an example in which a bulk glass body is polished using a commercially available plate glass has been described. However, it is a matter of course that quartz glass or the like having dimensional accuracy that has been obtained in advance may be used. However, ceramics or the like can be used as long as they are insulators. Further, the shape may be a columnar shape, a cylindrical shape, a polygonal shape having a triangle shape or more, a polygonal shape having a triangle shape or more, or a bead shape.

[0015]

As described above, according to the present invention, by using a bulk glass body as a core inserted between electrodes, highly stable discharge characteristics can be obtained and a long life surge absorber can be obtained. be able to. Furthermore, this surge absorber uses extremely common materials for the core,
Since it has a simple structure and can be manufactured by simple processing,
It is possible to provide a surge absorber with low manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of a surge absorber according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is a perspective view of a bulk glass body (core).

[Explanation of symbols]

 11 Insulation cylinder 12A, 12B Electrode 13A, 13B Lead terminal 15 Core (bulk glass body)

Claims (2)

[Claims] 1. An insulating housing hermetically sealed inside,
A surge comprising a pair of electrodes housed in the housing, a bulk glass body disposed between the electrodes, and a pair of lead terminals taken out of the insulating housing from the electrodes. Absorber. 2. The surge absorber according to claim 1, wherein the bulk glass body is formed by cutting a glass plate with a cutter and polishing both end surfaces.