JPS59108290A - Arrester tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas-filled detonator for protecting communication devices and the like from abnormal voltages such as Hatake surge.

In general, a lightning arrester is used to protect communication equipment connected to a communication cable from lightning surges, for example, when lightning surges are induced in a communication cable. It works by transmitting a surge to the ground and protecting communication equipment.

Therefore, it is desirable that the lightning arrester operate, or discharge, at as low a voltage as possible within the range that does not interfere with communication services.

For this reason, in conventional detonation arresters, an elongated conductive part is provided on the inner wall surface of the airtight insulating envelope, and when an abnormal voltage is applied, the electric field is concentrated at the tip of the conductive part, and the detonator is A method is used in which the firing voltage against the surge voltage is lowered by promoting ionization of gas molecules sealed in that part.

Although this method is extremely effective, as many ICs and LSIs have come to be used in communication equipment in recent years, communication equipment has become extremely vulnerable to abnormal voltages such as surges. The problem with pipes is that they still lack sufficient functionality to protect communication devices.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned difficulties of conventional detonators and to provide a detonator having a low firing voltage with respect to surge voltage.

That is, the detonator of the present invention is characterized in that a conductive layer is provided on the outer wall surface of the airtight insulating envelope.
Thereby, when an abnormal voltage is applied, the electric field distribution at the tip of the elongated conductive portion on the inner wall surface of the envelope is controlled to facilitate creeping discharge, thereby achieving the above object.

EMBODIMENT OF THE INVENTION Hereinafter, an embodiment of a detonator according to the present invention will be described in detail based on the drawings.

FIG. 1 is a sectional view showing the structure of a detonator according to a first embodiment of the present invention.

In the lightning arrester shown in the figure, two opposing electrodes 1.2 are hermetically sealed by a cylindrical insulating envelope 3, for example, by a wax sealing method, and there is no space between these electrodes 1.2. A discharge gap 4 is formed in the detonator, and an inert gas 5 is filled inside the detonator. Reference numeral 6.7 denotes an elongated conductive portion provided on the inner wall surface of the envelope 3 to improve responsiveness to surges, and is, for example, a carbon wire drawn on the inner wall surface.

Further, 8 and 9 are conductive layers provided on the outer wall surface of the envelope 3. This conductive layer 8.9 is provided by pasting metal foil or applying conductive paint. In this embodiment, the conductive layer 8 is electrically connected to one electrode 2 of the detonator, and the conductive layer 9 is electrically connected to the other electrode 1.

FIG. 2 is an enlarged sectional view of the upper left part of FIG. 1 showing a first embodiment for explaining the present invention in detail. FIG. 3 is a diagram similar to FIG. 2, but is a partially enlarged sectional view of a conventional detonator without the conductive layer 8 for explaining its operation.

That is, as shown in FIG. 3, in the conventional detonator, when an abnormal voltage rises, electric lines of force 10/ are concentrated at the tip of the elongated conductive part 6, and the electric field concentration in this part causes the part to This promotes the ionization of gas molecules in the reactor, thereby lowering the discharge starting voltage relative to the surge voltage.

Note that the lines of electric force 10' when an abnormal voltage is applied to the conventional detonator shown in FIG.
In contrast, in the first embodiment of the present invention shown in FIG. 2, the conductive layer 8 provided on the outer wall surface of the envelope 3 is Due to its existence, the distribution state of the electric lines of force 100 changes as shown in the figure.

That is, in FIG. 2, the electric lines of force 10 intersect with the surface of the inner wall of the envelope 3. In FIG. The distribution state of the lines of electric force 100 shown in FIG. 2 is better than the state of distribution of the lines of electric force 10' shown in FIG. It is well known that creeping discharge is likely to occur along the surface of the inner wall of the device, as a so-called back electrode effect (for example, the IEEJ Discharge Handbook, Revised New Edition)
(See pages 226-227).

Thus, the electrode l promoted by the presence of the conductive layer 8
The creeping discharge between the electrodes 1 and 2 induces a discharge between the electrodes 1 and 2, so that the detonator according to the invention shown in FIG. 2 is better than the conventional detonator shown in FIG. 3. The discharge starting voltage is lower than the above. As shown in FIG. 1, in this first embodiment, the conductive layer 8 is connected to the electrode 2, and the conductive layer 9 is connected to the electrode 1, except for the polarity effect during discharge of the detonator. It's for a reason.

FIG. 4 is a sectional view showing a detonator according to a second embodiment of the present invention. In this embodiment, the conductive layer 89 is insulated from the electrode 1.2. However, the principle of operation and operation are the same as in the first embodiment shown in FIGS. 1 and 2, and the same effects as in the first embodiment are achieved.

FIGS. 5 and 6 are cross-sectional views showing detonator arresters according to third and fourth embodiments of the present invention, which are examples in which the present invention is applied to a three-pole detonator. As shown in FIGS. 5 and 6, in this three-pole detonator, electrodes 1.1' are connected to, for example, two communication lines, and electrode 2, which has a hole 11 in the center, is grounded. . In a third embodiment of the invention, shown in FIG.
Both electrodes are insulated from electrodes 1.1' and 2.

Note that the principles and operations in the third and fourth embodiments can be easily inferred from the first embodiment, so a description thereof will be omitted. It goes without saying that these embodiments also provide the same effects as the first embodiment.

According to the experimental results of the present inventors, the conductive layer (
8 and 9), the discharge starting voltage for the surge voltage was about 400V, but Fig. 1,
In the arrester according to the invention having the conductive layer 8.9 shown in FIG. 2, the voltage was reduced to about 300 V.

As explained above, the detonator according to the present invention has the effect of lowering the discharge starting voltage with respect to the surge voltage by providing the conductive layer on the outer wall surface of the envelope.

Therefore, it is clear that the present invention further improves the ability to protect communication devices and the like against abnormal voltages of detonators.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a detonator according to the first embodiment of the present invention;
The figure is a partially enlarged sectional view of FIG. 1, FIG. 3 is a partial sectional view of a conventional detonation arrester, and FIGS. FIG. 3 is a cross-sectional view of a lightning arrester according to an embodiment. 1.1', 2... Electrode (discharge electrode) 3.3' Envelope 4... Discharge gap 5 - Inert gas 6.6', 7.7' - Elongated conductive part 8゛89. 9'・Conductive layer 10.10'・-Electric line of force 1
1. Hole patent applicant Junnosuke Nakamura, patent attorney representing Nippon Telegraph and Telephone Public Corporation! 1 Figure ■ Figure 2 Figure 3

Claims (1)

[Claims] At least two discharge electrodes are arranged facing each other with a discharge gap formed between them, and are hermetically sealed by an insulating envelope, and an elongated conductive portion is provided on the inner wall surface of the envelope. 1. A gas-filled detonator, characterized in that a conductive layer is provided on the outer wall surface of the envelope.