JPH0716319Y2 - Gas sealed multipole arrester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a gas-sealed multi-pole arrester for protecting communication devices and human body from abnormal surge. The present invention relates to a device provided with a fail-safe function to prevent the destruction of the lightning arrester.

[Prior Art] A gas-sealed arrester of this type is known to have a fail-safe function because it breaks open from a brazed portion due to heat generation due to continuous discharge and is in a dangerous state. As a fail-safe function of this kind, the applicant of the present invention has disclosed the utility models of Sho 57-130540, 163655, 58-135889 and 59-95.
592, 60-26191, 61-107182, 63-162483, etc.
No. 162484 is provided.

[Problems to be Solved by the Invention] In the above-mentioned gas-sealed lightning arrester, it is desirable that the fail-safe function be activated immediately before the open destruction due to heat generation. However, variations in operating time may cause a danger to equipment and human body. It was In this case, in addition to the baking error at the time of heat sealing the ceramic and the metal electrode, the assembly error of the ceramic and the metal electrode was a major cause. In particular, when the discharge gap is formed in a ring shape, deviation on the circumference cannot be avoided. When the gas-sealed arrester has multiple poles, it is more difficult to avoid the above-mentioned variation between the gaps.

In addition to the fail-safe nature of the gas-sealed arrester,
It is necessary to devise from the viewpoint of pipe wall contamination. From the viewpoint of pipe wall contamination, it is desirable to have a pollution prevention structure as much as possible. It must have a pollution control structure across multiple poles.

Therefore, the present invention was developed in view of the above-mentioned various circumstances, and an object thereof is to provide a multipolar gas-sealed arrester that ensures accurate fail-safety and has a long life. It is a thing.

[Means for Solving the Problems]

To achieve the above object, the gas-sealed multipole arrester according to the present invention is characterized in that the heated insertion electrode expands and comes into close contact with the annular electrode so that it is coaxially arranged and cooled. In the configuration in which the linear expansion coefficient of the insertion electrode is set to be larger than that of the annular electrode so that a ring-shaped discharge gap is formed between the outer peripheral surface of the insertion electrode and the inner peripheral surface of the annular electrode. is there.

[Operation] When the insertion electrode expands during heating, the insertion electrode is positioned so as to be in close contact with the annular electrode, and the insertion electrode contracts due to cooling and solidification during sealing to form a uniform ring-shaped gap.

The heat generated by the continuous discharge expands the interpolating electrode having a large coefficient of linear expansion, resulting in short-circuiting between the discharge caps.

Further, since the sputtering due to the discharge is blocked by the annular electrode which is separated from the inner wall and surrounds the insertion electrode, contamination between the electrodes is prevented.

[Embodiment] FIG. 1 is an overall sectional view showing an embodiment of a gas-sealed multi-pole lightning arrester according to the present invention, FIG. 2 is the same longitudinal sectional view in an assembled state, and FIG. 3 shows the same in a heated state. FIG. A triode is shown as an arrester.

Gas-sealed arrester 1 is an insulating envelope 2 made of ceramics,
3 and the intercalation electrodes 4 and 5 as metal electrodes between these and the annular electrode 6 are gas-sealed inside, and between the outer peripheries of the interpolating electrodes 4 and 5 and the inner perimeter of the annular electrode 6. The discharge cap 7 has a ring shape. The discharge gap 7 is preferably, for example, 45 to 30 which enables air discharge even if airtight leakage occurs.
A minute gap of about several tens of microns is formed.

Therefore, the insertion electrodes 4 and 5 are the bridging parts which are brazed to the tube end surfaces of the discharge parts 8 and 8 and the insulating envelopes 2 and 3 which project in the opposite direction.
It is possible to form recesses 10 and 10 provided with a coating material and the like on the opposite end faces of the discharge portions 8 and 8. Interpolation electrode
Cu having a large linear expansion coefficient is suitable as 4,5. Cu has a length change of 1.24% from room temperature to 800 ° C.

The annular electrode 6 is composed of a collar portion 11, cylindrical discharge surfaces 12 and 13 extending in the vertical direction inside, and a communication hole 14 inside the cylindrical discharge surfaces 12 and 13. The cylindrical discharge surfaces 12 and 13 are configured to have a vertical length sufficient to surround and bend the discharge portions 8 and 8 of the insertion electrodes 4 and 5 and serve as a sputtering barrier. As the annular electrode 6, it is possible to use Kovar (trade name), which is an alloy of Co, Ni, and Fe, in combination with the insertion electrodes 4 and 5. The change in length of Kovar from room temperature to 800 ° C during heat sealing is 0.62
%.

Cylindrical discharge surfaces 12 and 13 on the inner peripheral surface of the annular electrode 6 and the insertion electrode
The discharge gap 7 is formed in the same ring-shaped width between the outer peripheral surfaces 4,5 and the discharge portions 8, 8.

When manufacturing and assembling the gas-sealed multipolar lightning arrester 1, as shown in FIG. 2, the tube end surface of the lower insulating envelope 3 is positioned on the collar portion 9 of the lower insertion electrode 5, and the upper end Ring electrode 6
Put the collar part 11 of. In this state, the discharge part 8 is inserted into the communication hole 14 of the lower cylindrical discharge surface 13. Next, after placing the upper insulating envelope 2, the discharge portion 8 of the upper insertion electrode 4 is inserted into the communication hole 14 of the upper cylindrical discharge surface 12, and the collar portion 9 is inserted.
Are placed in the insulating envelope 2 and assembled. In such an assembled state, as shown in the figure, the concentric state 1 between the cylindrical discharge surfaces 12 and 13 and the discharge portions 8 and 8 may not be ensured.

Next, when heated to, for example, about 800 ° C. in a bell jar (not shown), the discharge parts 8 of the insertion electrodes 4 and 5 expand. With this expansion, the discharge parts 8 and 8 come into close contact with the cylindrical discharge surfaces 12 and 13, so that the positions of the discharge parts 8 and 8 are corrected around the cylindrical discharge surfaces 12 and 13. .

Each of the metal electrodes 4 to 6 is brazed and fixed in position with the subsequent sealing, and the discharge parts 8 and 8 contract in this state to form the ring-shaped discharge gap 7. Become.

One side comes into contact during assembly and the clearance on the other side is 0.1 mm
, The inner diameter of the cylindrical discharge surfaces 12, 13 is φ4.2 mm, and the discharge part 8,
The case where the outer diameter of 8 is φ4.11 mm and it is heated to 800 ° C is illustrated.

Cylindrical discharge surfaces 12 and 13 are as follows, φ4.2 × 1.0062 = 4.226mm Discharge parts 8 and 8 are as below, φ4.11 × 1.0124 = 4.1651mm .

4.226-4.1651 ÷ 2 = 0.030mm That is, at the time of heat sealing, the discharge part on the cylindrical discharge surfaces 12 and 13
Since 8 and 8 are in close contact with each other with a clearance of about 30μ, the position is corrected and they become concentric. After that, the minute discharge gap 7 of 0.45 mm is formed.

As described above, according to the above-mentioned embodiment, the discharge surfaces 8 and 8 of the cylindrical discharge surfaces 12 and 13 are corrected in position so as to be concentric.
Since the discharge gaps 7 having the same width are formed in a ring shape, a fail-safe function without variation can be exhibited.
In particular, even when the actual discharge parts are different, since the discharge parts have the same gap, it is possible to accurately short-circuit due to overheating melting and ensure safety.

In the above-described embodiment, the specific numerical values shown are merely examples, and do not impede the implementation of different standards and different dimensions. Also, the interpolating electrodes 4,5 and the annular electrode 6
The design of the metal material can be changed.

As described above, according to the present invention, the expansion and contraction of the insertion electrode can correct the discharge gap having the same ring-shaped width with the annular electrode across multiple poles, and ensure accurate discharge characteristics. Therefore, the accuracy of the fail-safe operation can be secured in multiple poles.

[Brief description of drawings]

Drawing FIG. 1 is an overall cross-sectional view showing an embodiment of a gas-sealed multi-pole lightning arrester according to the present invention, FIG. 2 is the same vertical sectional view in an assembled state, and FIG. 3 is the same vertical sectional view in a heated state. is there. 1 …… Gas sealed multi-pole lightning arrester, 2,3 …… Insulation envelope, 4,5
...... Interpolation electrode, 6 ...... Ring electrode, 7 ...... Discharge gap, 8
…… Discharge part, 12, 13 …… Cylindrical discharge surface.

Claims (1)

[Scope of utility model registration request] 1. A metal electrode composed of an insertion electrode projecting in the opposite direction and an annular electrode surrounding and bending the outer circumference of the insertion electrode is heated and cooled during manufacturing to be sealed to an insulating envelope. In a gas-sealed multipole surge arrester that is gas-sealed inside, the heated insertion electrode expands and comes into close contact with the annular electrode, so that it is coaxially arranged and cooled. A gas seal characterized in that the linear expansion coefficient of the insertion electrode is set larger than that of the annular electrode so that a ring-shaped discharge gap is formed between the outer peripheral surface and the inner peripheral surface of the annular electrode. Static multi-pole lightning arrester.