JPH0216550Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a gas-filled discharge tube type lightning arrester for communications to protect communication equipment from lightning surges, etc. The present invention relates to a trigger means.

(Prior Art) Conventionally, gas-filled discharge tube type lightning arresters (hereinafter referred to as lightning arresters) for communication use have been constructed in such a way that an insulating envelope is sealed with a pair of electrodes, and a discharge is generated in a discharge gap between the electrodes. has been done.

Such lightning arresters may not be able to respond quickly to interference waves with short rising waveforms such as lightning surges, so they generate a concentrated electric field at the electrode during discharge to promote ionization of electrons and reduce the discharge delay. A trigger means is provided to eliminate the problem. As a trigger means, JP-A-52-93946 and JP-A-54-
As in Japanese Patent Publication No. 8967, a micro cap is formed between the insulating tube and the metal electrode, or the shape of the electrode is changed, or as in Japanese Patent Publication No. 51-46893, a thin conductive layer is formed on the inner wall of the insulating tube. There are some known devices that have a .

However, the first two types have complicated structures such as minute gaps and electrode shapes, which not only result in high costs, but also have specialized structures that cannot be applied to various existing types. On the other hand, although the latter elongated conductive layer does not have the above-mentioned drawbacks, it can be formed by metallizing, applying a liquid carrier, or scribing a conductive material on an insulating surface. They are different.

That is, when metallizing to form an elongated conductive layer, the cost is inevitably high as in the above case, and
In the sealing manufacturing process, there was a problem that the metallized layer portion was deformed during firing. In addition, when applying a liquid carrier, not only does the carrier portion mix into the internal gas during sealing production and change the gas characteristics, but also the carrier portion changes during firing, causing variations in trigger characteristics. Furthermore, a method in which conductive material is scribed on an insulating surface can be formed extremely easily and inexpensively using, for example, a pencil containing carbon or graphite, and has the advantage that it can be applied to existing structures. Ta.

(Problem to be solved by the invention) By the way, when marking the inner wall of the insulating envelope with a conductive material, since the insulating envelope constituting the discharge tube is small and cylindrical, A pencil or the like must be inserted obliquely from the opening toward the inner wall, and a line must be drawn on the elongated conductive layer in this oblique state. Therefore, it is difficult to make accurate markings, and variations in trigger characteristics are unavoidable.

A jig may be used to overcome the above drawbacks, but it requires inserting a scribing jig inside the cylinder, scribing along this jig, and then removing the jig. It had the disadvantage of being time consuming. In view of this situation, a marking device as shown in Japanese Patent Publication No. 54-22570 has been developed, but it is not easy to use and requires a large-scale device.

Therefore, the present invention has been devised in view of the above-mentioned circumstances, and can not only guarantee consistent trigger characteristics but also provide a lightning arrester with excellent workability in which a trigger means can be easily provided. Its purpose is to do so.

(Means for Solving the Problems) In order to solve the above object, the gas-filled discharge tube type lightning arrester for communications having an insulating envelope according to the present invention has a structure in which the insulating envelope is sealed with an electrode, and the gap between the electrodes is In a gas-filled discharge tube type lightning arrester for communications, which is configured to obtain discharge through a discharge gap, a cylindrical insulating inner envelope is installed in the internal space of the insulating envelope while being spaced apart from the insulating envelope. The present invention is also characterized in that a conductive ruled line is provided on the outer wall of the insulating envelope as a trigger means.

(Function) After marking the outer wall of the insulating envelope with conductive ruled lines, it is manufactured by assembling it inside the insulating envelope.

When a lightning surge is applied, a trigger discharge occurs using the conductive ruled line of the insulating envelope as a trigger, and a main discharge starts. Sputtering accompanying the discharge is blocked and absorbed by the internal space of the insulating envelope.

(Embodiment of the invention) The drawing is a cross-sectional perspective view showing an embodiment of a communication gas-filled discharge tube type lightning arrester having an insulating envelope according to the invention.

The lightning arrester is constructed by gas-sealing an insulating envelope 1 with electrodes 2 and 2', and forming a discharge gap 4 with discharge surfaces 3 and 3' protruding inward in a truncated conical shape to obtain a discharge. This configuration is known.

The insulating envelope 1 is formed into a cylindrical shape using an insulating material such as glass or ceramic, and a cylindrical insulating envelope 5 constituting a trigger means is disposed in the inner space of the insulating envelope 1 from an inner wall 1a of the envelope. They are placed at a distance. The insulating envelope 5 is preferably made of ceramic and molded into a cylindrical shape, and is arranged to surround the discharge gap 4, and has conductive ruled lines 7, which serve as trigger means, on the outer peripheral surface 6 as an outer wall thereof. ing. The conductive ruled line 7 can be scored along the axial direction of the outer circumferential surface 6, as shown in the figure.

The insulating envelope 5 is spaced apart from the inner wall 1a of the envelope via a spacer 9, and is arranged to surround the discharge gap 4. As shown in the figure, it is also possible to extend the insulating envelope 5 in the axial direction to form minute gaps 11, 11 between the end surfaces 10, 10, which are the outer walls thereof, and the electrodes 2, 2'.
In this case, the minute gap 11 can be configured as a trigger gap.

The lightning arrester having the above structure is prepared in advance by marking the outer circumferential surface 6 of the insulating envelope 5 with conductive ruled lines 7, and is also assembled in advance into the inner wall 1a of the insulating envelope 1 so that the lightning arrester is double-layered. It can be kept as a structure. As a result, during manufacturing, the electrodes 2, 2'
may be assembled into both openings of the insulating envelope 1.

According to the above configuration, when a lightning surge is applied, a trigger discharge occurs via the conductive ruled lines 7 of the insulating envelope 5. In this case, it is also possible to cause a trigger discharge at the minute gap 11 simultaneously or separately. In any case, the discharge will start immediately in the discharge gap 9 due to the trigger discharge.

In the above embodiment, the case where the conductive ruled lines were provided on the outer peripheral surface 6 of the insulating inner container 5 was illustrated and described.
It cannot be prevented from being installed in other locations. For example, the end surfaces 10 and 1 as the outer wall of the insulating envelope 5
It is also possible to annularly write a conductive ruled line on the 0, and in this case, a quick triggering action can be obtained due to the synergistic effect with the minute gaps 11, 11. Although a two-pole arrester has been illustrated and described, the present invention can also be applied to a multi-pole arrester by incorporating an insulating envelope.

(Effects of the invention) As explained above, according to the invention, the troublesome work of providing conductive ruled lines on the narrow inner wall as in the past is eliminated, and the outer wall of the insulating inner envelope is exposed before assembly. It was possible to easily provide conductive ruled lines on the surface, greatly improving workability. Moreover, it was possible to accurately provide conductive ruled lines on the exposed outer wall, and by incorporating such an insulating envelope, it was possible to obtain consistent trigger characteristics.

In addition to the above, the insulating inner envelope was also able to function as a barrier against inner wall contamination as disclosed in Japanese Utility Model Application No. 186589/1989 submitted by the present applicant.

[Brief explanation of the drawing]

The drawing is a cross-sectional perspective view showing an embodiment of a communication gas-filled discharge tube type lightning arrester having an insulating inner envelope according to the present invention. 1... Insulating envelope, 2, 2'... Electrode, 3,
3'... Discharge surface, 4... Discharge gap, 5... Insulating envelope, 6... Outer wall of the inner envelope, 7, 11... Trigger means.

Claims (1)

[Scope of Claim for Utility Model Registration] In a gas-filled discharge tube type lightning arrester for telecommunications, in which an insulating envelope is sealed with electrodes and a discharge is generated in a discharge gap between the electrodes, in the internal space of the insulating envelope. An insulating inner envelope characterized in that a cylindrical insulating inner envelope is installed in a state separated from an inner wall of the envelope, and a conductive ruled line is provided on the outer wall of the insulating inner envelope as a trigger means. A gas-filled discharge tube type lightning arrester for communications.