JPH031909Y2 - - Google Patents

Description

[Detailed description of the invention] (1) Technical field of the invention This invention is a gas-filled discharge tube type for communications, which generates a discharge in a gas-sealed discharge gap to protect communication equipment from lightning surges, etc. This relates to the improvement of lightning arresters.

(2) Prior Art and its Problems Conventionally, this type of gas-filled discharge tube type lightning arrester (hereinafter referred to as lightning arrester) for communications has been provided as a so-called button-shaped structure as shown in FIG. In this button-shaped lightning arrester, an insulating spacer 1 is formed into a cylindrical tube shape, and the open end surface of the cylindrical insulating spacer 1 is sealed with end electrodes 2, 2, and an intermediate electrode 3 is sandwiched as necessary. A discharge gap is formed between the discharge surfaces 4 and 5 which are close to each other and has a predetermined gap _g1 . In the figure, 6 is a terminal for mounting on a printed circuit board (not shown), and 7 is a terminal connected to the end electrode 2 at one end and a trigger gap at the other end.
g ₂ is a conductive strip spaced from the intermediate electrode 3. The trigger gap _g2 is set narrower than the gap _g1 , and the above structure is known.

By the way, with the recent computerization of communication equipment, the above-mentioned button-shaped lightning arrester is mounted horizontally on a printed circuit board, but due to its large overall length and tube diameter, it occupies extra mounting space. There were flaws. It is conceivable to make the cylindrical shape smaller in diameter to achieve miniaturization, but in this case, the internal capacity is lacking, so it is inevitable that the repeatability will be poor. Further, since the component of the cylindrical insulating tube 1 is larger than the electrodes 2 and 3, discharge heat caused by continuous wave mixed current cannot be dissipated quickly, and there is a high risk of breakage due to opening from the sealed portion.

In view of the above circumstances, the applicant was faced with the need to improve the button-shaped lightning arrester so that it would be compatible with the electronicization of equipment. First, the lightning arrester must occupy as small a mounting space as possible.
In general, printed circuit boards have few restrictions in the height direction, so it is desirable to have a shape that can be extended in the height direction without changing the internal capacity. Second,
Miniaturization of the lightning arrester itself must be achieved. For this purpose, the pipe length of the cylindrical insulating spacer 1 may be made to be approximately the same size as the gap g ₁ or the trigger gap g ₂ to the maximum extent possible. However, since the distance between the inner walls becomes small, the insulation deteriorates early due to inner wall contamination, and the drawback of lacking repeated durability is unavoidable. Therefore, there was a limit to the reduction of the head office.

Thirdly, responsiveness must be improved to the extent that it can cope with computerization. One of the methods is to narrow the trigger gap g ₂ of the conductive strip 7, but if it is too narrow, the trigger gap will be more susceptible to overall tube wall contamination.
An early short circuit at g ₂ will occur. Therefore, it was necessary to improve the triggering means in a structure that does not induce premature short circuits.

(3) Purpose of the invention The present invention was developed in view of the above circumstances, and is designed to reduce the mounting space on the printed circuit board and improve the heat dissipation effect. , its main purpose.

(4) Features of the invention The characteristics of the gas-filled discharge tube type thin lightning arrester for communications according to the invention are that the insulating spacer is thinly formed in the direction of the discharge gap, and the inner wall of the insulating spacer is provided with an inclined wall that intersects with the direction of the discharge gap. A protruding strip having a shape is formed to protrude inwardly, and a trigger hole is passed through the inclined wall of the protruding strip. Hereinafter, the present invention will be explained based on the drawings from FIG. 2 onwards.

(5) An embodiment of the invention Figures 2 to 5 show an embodiment of the gas-filled discharge tube type thin lightning arrester for communications according to the invention, and Figure 2 is a perspective view of the entire device, and Figure 3 is a perspective view of the entire device. The drawings are a sectional view taken along the line -- in FIG. 2, FIG. 4 is an exploded perspective view of an intermediate electrode and an insulating spacer, and FIG. 5 is an enlarged sectional view of a main part of FIG. 3. The drawing shows a three-pole implementation.

Therefore, a gas-filled discharge tube type thin lightning arrester for communication (hereinafter referred to as a thin lightning arrester) has an insulating spacer 1
0, end electrodes 11, and intermediate electrodes 12, the overall appearance is approximately wafer-like, and the inside is sealed with gas. The insulating spacer 10 is made of an insulating material such as ceramic and is formed into a thin rectangular frame shape overall. Specifically, the insulating spacer 10 has a rectangular shape on the outside from the long side 10a and the short side 10b, and has a frame shape with a rectangular hollow chamber 13 opened in the center thereof. is the joint surface 1 which has been subjected to metallization treatment etc.
4 and 14 are formed. The thickness _g3 of the insulating spacer 10 is set to a dimension that approximately corresponds to the trigger gap distance. On the inner wall of the hollow chamber 13, a protrusion 15 is integrally formed in an annular shape so as to be inclined from the above-mentioned thickness _g3 . The protrusion body 15 has a cross-sectional shape of the tip 15.
It is made up of inclined walls 15b, 15b with a as a cutting edge, and is projected inward as much as possible to increase the creeping distance of the inclined walls 15b, 15b. The inclined walls 15b, 15b are symmetrically projected. A trigger hole 16 serving as a trigger means is provided in the protrusion 15 in the direction of the thickness of the insulating spacer 10. The trigger hole 16 is located on both inclined walls 15.
b, 15b, and the opening edge 16
a, 16a are configured to have an edge shape and an inclined shape. A trigger gap 1 is provided between the opening edges 16a, 16a and the electrodes 11, 12, which varies according to the inclination.
7 is composed. The trigger hole 16 is arranged on the short side 10b of the spacer that is away from the discharge surface.

Further, the end electrode 11 and the intermediate electrode 12 are
Each of them has a flat plate shape and is formed with rectangular dimensions corresponding to the outer shape of the insulating spacer 10, and a discharge surface coated with a coating agent or the like is formed in the center thereof. The intermediate electrode 12 is provided with an opening 18 at its center, and the opening 18 is preferably made smaller than the hollow chamber 13 of the insulating spacer 10, and the portion exposed to the hollow chamber 13 serves as a discharge surface. In addition, intermediate electrode 1
2, a guide hole 19 is penetrated at a position corresponding to the trigger hole 16. In addition, 20 in the figure is electrode 1
This is a terminal extending integrally from the short side edges of Nos. 1 and 12.

The above-mentioned thin lightning arrester has silver solder (not shown) interposed on the bonding surface 14 of the insulating spacer 10 with the thinness direction up and down, and the electrodes 1 in the order shown in the figure.
1 and 12 are stacked and sealed with gas.

To explain the operation based on the above configuration, when a lightning surge or the like is applied to one of the end electrodes 11, discharge immediately starts between the discharge surfaces having a thickness g ₃ that is approximately the same as the trigger gap. Moreover, a trigger discharge occurs alternatively or simultaneously at substantially the same timing as the above-mentioned discharge. That is, the opening edges 16a, 16a of the trigger hole 16 are connected to the inclined wall 1.
Since edge portions are formed corresponding to the inclinations of 5b and 15b, the degree of concentration of the electric field due to the edge portions is increased, and a trigger discharge is induced in the trigger gap 17. Trigger hole 16 is guide hole 19
through the other trigger hole 16 and its opening edge 16
Since the trigger gaps 17, .

According to the above embodiment, it is sufficient to have the mounting space for the printed circuit board equal to the length of the short side 10b of the insulating spacer 10 and the overall thickness.
This has the advantage of making it easier to miniaturize the device and integrate it into a unit with other wafer-shaped semiconductor devices. in this case,
Since the long side 10a can be extended and the short side 10b can be further shortened without changing the internal capacity, the mounting space can be kept small by the amount of the shortening. Moreover, the base side of the short side 10b and the printed circuit board can be brought into surface contact, and installation in a stable state is possible.

In particular, a major feature of the above embodiment is that a trigger gap with a novel structure different from the conventional one can be provided. That is, since the opening edge 16a of the trigger hole 16 forms the inclined edge portion, electric field concentration is increased in a state where an edge path is formed from the edge portion close to the electrode to the edge portion remote from the electrode. Achieve the most responsive trigger effect. Moreover, each trigger hole 16, 16 and each trigger gap 1 are connected to each other by the guide hole 19 of the intermediate electrode 12.
7 and 17 have a communicating structure, it is possible to simultaneously spread the trigger effect between each electrode,
Simultaneous triggering effect between each line could be achieved.
Although not shown, it is also possible to provide a conductive strip on one of the opening edges 16a to enhance the triggering effect.

(6) Another Embodiment of the Invention FIG. 6 is an enlarged perspective view of essential parts showing another embodiment of the trigger means. In the figure, Figures 2 to 5
Since the same reference numerals as those in the figures indicate equivalent parts, repeated explanation will be omitted.

30 is a trigger hole formed by cutting out the inclined wall 15b up to the tip 15a, and 31 is a trigger hole 3.
0 opening edge. Therefore, the opening edge 31 is
It is formed continuously at the tip 15a, slanting from the side of the bonding surface 14 that is close to the electrode 11 or 12.

According to this embodiment, the trigger effect can be directly propagated from the trigger hole 30 to the center of the hollow chamber, and a faster trigger effect can be obtained.

(7) Still another embodiment of the invention (a) Although a three-pole thin lightning arrester has been described, the present invention is not limited to this. Although not shown, depending on the number of intermediate electrodes 12 and insulating spacers 10, a multi-pole thin lightning arrester other than three poles can be implemented. Of course, it is also possible to implement two ultra-thin lightning arresters using one insulating spacer 10 and two end electrodes 11, 11.

(b) In the above embodiment, the case where one trigger hole 16, 30 is provided in the protruding strip body 15 on the short side 10b has been described, but it is not possible to provide one or more trigger holes at any arbitrary location on the protruding strip body 15. do not have.

(c) In the above embodiment, the insulating spacer 10 has a thin frame-like rectangular outer shape, but it can be implemented with other outer shapes as long as it is a thin frame.

(8) Effects of the invention As explained above, the invention provides the following effects.

(b) By protruding an inclined wall from the protrusion, the insulating spacer can be made thinner in the direction of the discharge gap, making the element thinner, improving responsiveness during discharge, and increasing the thickness of the tube wall. Contamination can also be prevented.

(b) An inclined edge can be formed by the opening edge of the trigger hole penetrating the inclined wall, and an electric field can be formed in such a state that an edge passage is formed from the edge near the electrode to the edge far away. It can strongly promote concentration and achieve the fastest response trigger effect.

[Brief explanation of the drawing]

Figures 1A and 1B are a cross-sectional view and a side view of a conventional button-shaped communication gas-filled discharge tube type lightning arrester;
The following figures show a gas-filled discharge tube type thin lightning arrester for communications according to the present invention, FIG. 2 is an overall perspective view showing one embodiment thereof, FIG. 3 is a sectional view taken along the line -- in FIG. 2,
FIG. 4 is an exploded perspective view of an intermediate electrode and an insulating spacer, FIG. 5 is an enlarged sectional view of the main part of FIG. 3, and FIG. 6 is an enlarged perspective view of the main part showing another embodiment of the trigger means. be. 10... Insulating spacer, 11... End electrode, 1
2... Intermediate electrode, 15, 40... Projection, 15
b, 40b, 40c... inclined wall, 16, 30...
Trigger hole.

Claims (1)

[Claims for Utility Model Registration] (1) In a gas-filled discharge tube type lightning arrester for communications, in which electrodes are separated via an insulating spacer to form a discharge gap, and gas is sealed inside the insulating spacer by the electrodes. , the insulating spacer is formed thinly in the direction of the discharge gap, and a protrusion body having an inclined wall intersecting the direction of the discharge gap is formed on the inner wall of the insulating spacer to protrude inwardly, and the inclined wall of the protrusion body has a trigger plate. A thin lightning arrester in the form of a gas-filled discharge tube for communications, characterized by having a hole penetrated through it. (2) A thin lightning arrester in the form of a gas-filled discharge tube for communications, as set forth in claim 1 of the utility model registration, characterized in that the insulating spacer is a rectangular frame.