JP2003151716A - Discharge lightning pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lightning pipe which can be mounted on a circuit board of surface mounting type, and a construction capable of mounting the pipe on a circuit board of the surface mounting type, without changing conventionally accumulated discharge characteristic and other electric characteristic. SOLUTION: Continuously protruding portions are provided on electrode planes. In this protruding portions, parallel pieces are formed on a plane parallel to a central axis of the pipe. These pieces are welded to the circuit board. Designs of respective conventional time-proven structures of an inside of the pipe and thereabout are not modified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as an element of a lightning arrester connected to a telephone line, an internet connection line, and other wired communication lines. The present invention is for substantially short-circuiting a pair of lines or for grounding the lines at the same time when a high voltage or current that exceeds the set value arrives at the communication line due to lightning strikes or contact with power lines. Used as an element of. The present invention relates to improvement of a mounting structure of a lightning arrester.

[0002]

2. Description of the Related Art Communication lines are equipped with induction
Unexpectedly high due to current flow, contact with power lines, etc.
Voltage may arrive. Such high voltage is directly
Enter the communication device and damage the device due to the generated current
To prevent this, a discharge arrester has been conventionally used.
Lightning arresters are widely used. Figure 4 shows a bipolar discharger
It is a circuit diagram of a lightning arrester using. A pair of track-side terminals
L₁ , L₂ And a pair of device-side terminals T₁ , T₂ Between
Fuse F in series with line current₁ , F₂ And
Anti-R₁ , R₂ Is connected to the device side terminal T₁ And T₂ With
A bipolar discharge arrester 12 is connected between them. Something different
A normal phenomenon occurs and the line side terminal L₁ And L₂High between
When the voltage arrives, the discharge arrester 12 starts to discharge and the
Qualitatively, the device side terminal T₁ And T₂ And short-circuited between
This allows the resistor R₁ And R₂ A large current flows through
The voltage across the resistor is high,
Side terminal T₁ And T₂ The voltage between is the line side terminal L₁ And
And L₂ It is correspondingly lower than the voltage between them. With a lightning strike
The abnormal high voltage disappears instantly, but there is no contact with the power line.
In some cases, the high voltage may last long,
Is a fuse F due to the current passing through the discharge arrester 12.₁ 
Or F₂ Is blown out and the device side terminal T₁ And T ₂ Between
The high voltage that occurs at is cut off.

FIG. 5 is similar to the one using the triode discharge arrester 13.
Lightning arrester. This circuit is basically its operating principle
Is equivalent to the one using the above bipolar discharge arrester,
The discharge arrester 13 has a three-pole structure, and
Connect one of the poles to ground potential. And these three
When the polar discharge arrester 13 is in a discharge state, the device side terminal T ₁ 
And T₂ Is substantially short-circuited and the device side
Terminal T₁ And T₂ Has a low impedance to ground potential E
It will be in the state of being connected via. Widely used equipment
In this installation, the three-pole discharge arrester 13 has three electrodes.
The structure is arranged in the atmosphere of the discharge gas communicating with
ing. Thereby, the pair of terminals L₁And L₂ Between
Even if the discharge start voltage is reached, the pair of terminals L₁ And L₂ 
The potential between any of the above and the ground potential E becomes the discharge start voltage.
However, the entire tube is ionized and the three electrodes are
It is effective as a lightning protection device because it sometimes short-circuits.
It For this reason, three electrodes are stacked via two insulating tubes.
In the case of the discharge arrester formed in the raised three-layer structure,
Is used as the ground electrode, and this ground electrode has an atmosphere on both sides.
Vents are formed so that the surrounding air communicates.

The lightning protection device is a device composed of several parts in this way. In recent years, not only the components illustrated here, but also a circuit in which a varistor, a capacitor, an induction winding, or the like is mounted is available. These components are attached to one board and soldered.

The structure for attaching the discharge arrester to the substrate will be described by taking a discharge arrester having a three-pole structure as an example. As shown in FIG. 6, electrodes 1 and 2 on both sides of the discharge arrester 13 and the ground. Short lead wires 4, 5 and 6 are soldered to the electrodes 3, respectively. When the triode discharge arrester 12 is mounted on a circuit, the lead wires 4, 5 and 6 penetrate through the holes provided in the insulating substrate 7,
Each is soldered on the back surface of the insulating substrate 7.

[0006]

In recent years, in connection with the integration and miniaturization of circuits, a circuit structure for surface-mounting electronic parts has also been required for a lightning arrester. That is, in this circuit structure, all electronic components and their connecting circuits are mounted on one side of the substrate without providing through holes for mounting the components on the substrate, and the one side of the substrate also mechanically supports the electronic components. In order to surface-mount the discharge arrester (the one shown in FIG. 6) described as the above-mentioned conventional structure, one electrode end flat portion is placed on the substrate surface, and a cylindrical discharge arrester is used. A structure that stands upright on the substrate surface is conceivable. However, this structure increases the height of the components mounted on the surface, and loses the advantage of the surface mount structure. If this structure is adopted, even if the height of the two-pole discharge arrester is acceptable, the height of the three-pole discharge arrester is not acceptable.

In order to reduce the height, that is, the axial length of the discharge arrester, it is possible to newly design a discharge arrester with a small electrode interval. Since the electrical characteristics such as the starting voltage and the large current characteristic are changed, the know-how accumulated so far cannot be used for the internal gas pressure and the temperature characteristic during discharge. Furthermore, a fundamental design change is not desirable, because designing a new discharge arrester that changes its basic shape requires an extremely long time to test its aging characteristics. .

The present invention has been made in view of such a background, and an object thereof is to provide a structure of a discharge arrester capable of surface mounting without changing its electrical characteristics and fundamental shape. And An object of the present invention is to provide a discharge arrester capable of surface mounting without basically changing the design that has been accumulated in the past.

[0009]

SUMMARY OF THE INVENTION According to the present invention, only the external shape of each electrode is changed without changing the structure relating to the discharge characteristics inside the discharge tube, that is, the shape or material of the inside of the discharge tube. The greatest feature is the improvement of the structure that allows the discharge arrester to be mounted on a surface-mounted board.

That is, the present invention is directed to a bipolar discharge arrester (1
Regarding 2), a pair of electrodes (1, 2) and a tube (8) made of an insulating material sandwiched between the pair of electrodes.
And a discharge arrester in which a discharge gas is enclosed in the tube (8), the pair of electrodes (1, 2) are
At least a part thereof is provided with a protruding portion larger than the radius of the pipe in a plane direction perpendicular to the axial center of the pipe, and the protruding portion has one virtual plane parallel to the axial center of the pipe. A side parallel to (1 '
2 ') is formed.

With this structure, a cut edge parallel to one plane parallel to the axial center of the tube can be obtained without changing the shape of the tube in which the discharge phenomenon occurs and the electrode structure inside the tube. By using (1'2 '), this discharge arrester can be attached to a single-sided mounting type circuit board. Since there is no change in the shape of the tube in which the discharge phenomenon occurs and the electrode structure inside thereof, there is no change in its discharge characteristics and other electrical characteristics, and the know-how accumulated from the past can be used as it is.

It is desirable that this electrode has a structure in which the surface of the portion where the cut edge is formed is plated with a metal material (for example, nickel) that is compatible with solder. That is, this structure allows the electrodes to be directly soldered to the substrate.

The numbers in the above parentheses are reference numbers in the embodiment drawings described later. This is given for easy understanding of the structure of the present invention, and is not for limiting the understanding of the structure of the present invention to the embodiments. The same applies to the following description.

Further, according to the present invention, a three-pole discharge arrester is formed by three electrodes (1, 2, 3) arranged in parallel and an insulating material sandwiched between the three electrodes. 2 tubes (8, 9) are provided, and a vent hole for communicating the internal atmosphere of the two tubes is formed in the electrode located in the center among the three electrodes, and inside the tubes. In a three-pole discharge arrester in which a discharge gas is filled, at least a part of each of the three electrodes (1, 2, 3) is provided with the tube in a direction perpendicular to the axial center of the tube. Is provided with a protruding portion larger than the radius of, and a cut edge (1'2'3 ') parallel to one virtual plane parallel to the axial center of the tube is formed in this protruding portion. Characterize. It is desirable that this electrode has a structure in which the surface of the portion where the cut edge is formed is plated with a metal material that is compatible with solder.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment apparatus will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a device of an embodiment in which the present invention is applied to a discharge arrester having a triode structure. FIG. 2 is a vertical sectional view thereof. Tubes 8 and 9 made of ceramics, which are an insulating material, are arranged between three metal electrodes 1, 2 and 3, and between the electrodes 1, 2, 3 and the tubes 8 and 9, respectively. Adhered airtightly by brazing. When this structure is compared with the structure of the conventional example (FIG. 6), the structures of the tubes 8 and 9 and the inside thereof are the same as the structure of the conventional example, but the electrode 1,
Outside the position where the two or three pipes are bonded, a protruding portion larger than the radius of the pipe is provided in a plane direction perpendicular to the axial center of the pipes 8 and 9, and the protruding portion is provided with the protruding portion of the pipe. Cut edges 1'2 'are formed parallel to one virtual plane parallel to the axis center. This section 1'2'3 '
Are soldered to the surface of the substrate 7 at the positions indicated by arrows in the figure. The substrate 7 is a surface mount type substrate.
In order to facilitate this soldering, nickel is plated on the surfaces of the electrodes 1 and 2, particularly on the sections 1'2'3 '.

As described above, the shape of the discharge arrester of this embodiment is as follows.
Conventionally, a structure equivalent to the structure designed according to its use is followed. That is, on the outer electrodes 1 and 2, a convex portion is formed toward the inside of the tube, and the discharge starting voltage is controlled to be low. Regarding the ground electrode 3, a vent hole 10 is formed so as to communicate the internal atmospheres of the two tubes 8 and 9. The discharge gas containing argon as a main component and sealed in this tube is also filled with the same component as the conventionally used gas.

FIG. 3 is a perspective view of a bipolar discharge arc arrester according to an embodiment of the present invention. This figure is drawn upside down with the section 1'2 'facing upwards. Also for this structure, the structure of the tube 8 and its internal structure is designed to be equivalent to the conventional structure so that the electrical characteristics such as discharge characteristics can utilize the know-how accumulated from the past. To be done. Similarly, a piece 1'2 'is formed, and the part of this piece 1'2' is soldered to the surface of the circuit board.

Reference will be made to a method of manufacturing such a structure.
Hereinafter, a method of manufacturing a discharge arrester having a three-pole structure will be described, but the same applies to a discharge arrester having a two-pole structure. With respect to the electrodes 1, 2, and 3, metal pieces (nickel alloy in this example) are cut out by pressing, and at the same time, a convex portion and / or a vent hole 10 in the central portion are formed. On the other hand, for the tubes 7 and 8, a ceramic tube is cut out and pretreatment for brazing is performed by a well-known method. And on a shelf in the vacuum furnace,
Electrode 1, tube 8, electrode 3, tube 9, and electrode 2 are stacked in this order. The atmosphere in the furnace is once set to a predetermined vacuum state, and then discharge gas is injected into the furnace. This discharge gas penetrates inside the tubes 7 and 8. And each electrode 1,
A brazing process is performed between the tubes 2 and 3 and the tubes 8 and 9. Then, after cooling the atmosphere in the furnace, the finished product is taken out. The brazing process is executed by a well-known technique.

In this process, in the conventional structure, the tube has a cylindrical shape and the electrode has a disk shape, but in the apparatus of the present invention, the electrode has a disk shape even if the tube has a cylindrical shape. is not. Therefore, in the stacked state as described above, the position of the center of gravity of the electrodes does not match the position of the central axis of the tube. Therefore, in the process of manufacturing the discharge tube of the present invention, when the temperature in the furnace is raised or lowered, the force distribution between the end of the tube and the electrode plane may change due to slight distortion. This causes defects in the brazing process. From the results of repeated tests by the inventor of the present application, it was found that this is not a problem when the shape of the electrode is designed to be small outside the circumference of the tube. Also, when a shape in which this protruding portion is relatively large is required, by using a small balance weight jig so that the center of gravity of each electrode matches the position of the central axis of the tube, The defective product generation rate can be reduced by mounting the electrode on each electrode and performing the brazing process.

The discharge arrester according to the present invention manufactured as described above can be mounted on a single-sided mounting substrate as it is by soldering. Since the section has a width corresponding to the thickness of the electrode, the section can be soldered to be attached to the surface-mounted circuit board so as to hold the weight of the discharge arrester. And as the circuit of the lightning arrester, the circuit described in FIG. 4 or FIG.
Other circuit configurations conventionally used can be similarly implemented.

Incidentally, in considering the present invention, perspective views of the structure of the discharge arrester, which has been studied for the same purpose, are shown in FIG. 7 and FIG. 8 as reference diagrams, respectively.
The structure shown in FIG. 7 has a structure in which a lead wire is attached to an electrode having the same structure as the electrode of the conventional structure, and the lead wire is bent into a second-letter shape so that the lead wire can be connected to the planar mounting substrate. The structure shown in FIG. 8 has a structure in which a lead plate having an L-shaped cross section is attached to an electrode having a structure similar to that of the conventional structure.

[0022]

According to the present invention, a lightning arrester capable of surface mounting can be obtained without changing the electrical characteristics and the fundamental shape thereof. INDUSTRIAL APPLICABILITY The structure of the present invention is provided as a discharge arrester capable of surface mounting without basically changing the design that has been accumulated so far.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating the structure of a device according to an embodiment of the present invention for a three-pole discharge arrester.

FIG. 2 is a vertical cross-sectional view for explaining the structure of the device of the embodiment of the present invention for a three-pole discharge arrester.

FIG. 3 is a perspective view for explaining the structure of the device according to the embodiment of the present invention with respect to a bipolar discharge arrester.

FIG. 4 is a diagram for explaining a circuit example in the case of using the bipolar discharge arrester of the embodiment of the present invention or the conventional example.

FIG. 5 is a diagram illustrating a circuit example when the triode discharge arrester of the embodiment of the present invention or the conventional example is used.

FIG. 6 is a perspective view illustrating a triode discharge arrester having a conventional structure.

FIG. 7 is a perspective view (reference view) of a discharge arrester that has been studied for the same purpose as the present invention.

FIG. 8 is a perspective view (reference drawing) of a discharge arrester that has been studied for the same purpose as the present invention.

[Explanation of symbols]

1 and 2 electrodes 3 Grounding electrode 4,5 lead wire 6 (for grounding) lead wire 7 Insulation board 8 and 9 tubes (formed of insulating material) 10 vents 12 (two-pole) discharge arrester 13 (tripolar) discharge arrester

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tomoji Ogata             Saitama Prefecture Iruma City Oaza Sayamagahara 108 No. 3 shares             Ceremony company Nitatsu Electric Works (72) Inventor Tsunetaka Ema             2-3-1, Otemachi, Chiyoda-ku, Tokyo             Inside Telegraph and Telephone Corporation (72) Inventor Yuro Iwadate             2-3-1, Otemachi, Chiyoda-ku, Tokyo             Inside Telegraph and Telephone Corporation

Claims (4)

[Claims] 1. A discharge arrester having a pair of electrodes and a tube made of an insulating material sandwiched between the pair of electrodes, wherein discharge gas is enclosed in the tube. At least a part thereof is provided with a protruding portion larger than the radius of the pipe in a plane direction perpendicular to the axial center of the pipe, and the protruding portion has a protrusion parallel to the axial center of the pipe. A discharge arrester characterized in that a cut side parallel to two virtual planes is formed. 2. The discharge arrester according to claim 1, wherein the electrode is provided with a plating of a metal material compatible with solder on the surface of the portion where the cut edge is formed. 3. Three electrodes arranged in parallel and two tubes made of an insulating material sandwiched between the three electrodes, the central position of the three electrodes being provided. In the discharge arrester having a three-electrode structure, in which a ventilation hole that communicates the internal atmospheres of the two tubes is formed in the electrode, and a discharge gas is filled in the inside of the tube, the three electrodes are respectively At least a part thereof is provided with a protruding portion larger than the radius of the pipe in a direction perpendicular to the axial center of the pipe, and the protruding portion is provided with respect to one virtual plane parallel to the axial center of the pipe. Discharge arrester characterized in that parallel cut edges are formed. 4. The discharge arrester according to claim 3, wherein a surface of a portion of the electrode where the cut edge is formed is plated with a metal material compatible with solder.