JPS597176B2 - Shinkaiheiki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum switch, and more particularly to a vacuum switch provided with an elastic insulating coating layer on the outer peripheral surface of a vacuum container.

In a high-voltage, large-capacity vacuum switch, even if the gap between the electrodes is destroyed, it is necessary to turn on and off the gap between the electrodes in half a cycle or one cycle, which increases the speed and significantly increases the impact force.

Therefore, if the vacuum switch alone were to have a structure that could withstand this, it would be extremely expensive.

Furthermore, in order to withstand flashing when the external creeping surface is contaminated, it is necessary to increase the creepage distance.

Conventionally, in the type of vacuum suite where the vacuum vessel of the vacuum suite is directly coated with a resin molding in order to increase the external creepage distance, the casting temperature of the resin and the Tg (glass transition temperature) of the casting material are usually lower than the operating temperature of the equipment. Furthermore, since the operating temperature of the equipment is expected to fluctuate by several tens of degrees, the vacuum container may be damaged due to thermal stress due to the difference in thermal expansion coefficient between the casting material and the vacuum container, and also due to the generated clamping pressure.

Types in which the vacuum container is molded through flexible resin have the same problems as the above type, and even if they can withstand only the clamping pressure due to thermal stress, they can be destroyed by the impact force caused by the insertion and disconnection of electrodes. Strong sexuality.

Furthermore, in the type where the vacuum container is molded with a foam cushion in order to alleviate this thermal stress, the use of foam has a negative effect on the electrical insulation life due to the high voltage. It is necessary to provide a shield to alleviate the electric field.

Furthermore, especially in this type, the vacuum container of the vacuum switch is loosely wrapped with a thick cushion, so the tightening force is very small or almost non-existent.

If the tightening force is too large, the vacuum container will be destroyed as described above, but if the tightening force is too small, the flash line through the interface will be low.

A low end-of-flash value requires a longer interface distance, which results in a larger vacuum switch.

Furthermore, if the tightening pressure of the cushion is low, vibrations such as opening and closing of the electrodes will cause play between the cushion and the mold body.

Therefore, it is necessary to alleviate the thermal stress so that an appropriately large tightening pressure is applied.

In view of the above points, the present invention provides an insulating coating layer formed by casting a liquid mixture consisting of liquid polybutadiene and a hardening agent on the outer peripheral surface of the vacuum container, thereby increasing the flash fault voltage at the outer peripheral interface of the vacuum container. The purpose of the present invention is to provide a vacuum switch that can increase the pressure and reduce the variation thereof, as well as alleviate and absorb the clamping pressure on the vacuum container caused by thermal stress, and the impact force at the time of closing and closing. shall be.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a longitudinal sectional side view of a first embodiment of a vacuum switch according to the present invention.

The vacuum switch 1 is of 36 Kv, and its vacuum container is made of glass with a metal 6 sealed in the middle and at the ends, between an end plate 4 on the fixed electrode 2 side and an end plate 5 on the movable electrode 3 side. An insulating cylinder 7 is provided, and a fixed electrode 2,
A shield 8 is disposed near the contacts 2a, 3a of the movable electrode 3, and the shield 8 is supported and fixed to the intermediate portion of the insulating cylinder 7 by a support member 8a.

9 is a bellows.

A reinforcing plate 10 is provided on the end plate 4 of the vacuum switch 1.

The surface of the insulating cylinder 7 of the vacuum switch 1 has end plates 4 and 5.
In addition, the reinforcing plate 10 is provided with an elastic insulating coating layer 11 formed by casting a liquid mixture consisting of liquid polyptadiene and a curing agent, as described later. Insulator tube 12 made of resin molded material on top of
is provided.

The insulator tube 12 is fixed to the fixed substrate 13 by the embedded metal fittings 14 and bolts 15 at a certain temperature.

The vacuum switch 1 is formed by casting a liquid mixture of liquid polybutadiene and a curing agent (hereinafter referred to as "polybutadiene rubber").

) When providing the insulating coating layer 11 and the resin-molded insulator tube 12, first, the reinforcing plate 10 is provided on the end plate 4 and a vacuum tube is placed into the resin-molded insulator tube 12 fixed to the fixed substrate 13. The switches 1 are inserted and arranged concentrically.

At this time, the inner diameter of the resin molded insulator tube 12 is determined so that an appropriate distance is formed between the outer peripheral surface of the vacuum container of the vacuum switch 1 and the inner peripheral surface of the resin molded insulator tube 12.

For example, the resin molded insulator tube 12 has an average strength of 8 Kg/M.
”, modulus of longitudinal elasticity 10oOV4/wIt2, coefficient of expansion 4
X 1 0-5/°Cf)-1-hoquin resin or the like is used.

The outer peripheral surface of the resin molded insulator tube 12 is provided with pleats for stain resistance.

After the vacuum switch 1 is placed in the insulator tube 12 of the resin molded body, the space formed between the outer circumferential surface of the vacuum container of the vacuum switch 1 and the inner circumferential surface of the insulator tube 12 of the resin molded body is filled with, for example, Liquid polyptadiene or its copolymer having a hydroxyl group at the end and a common incyanate as a curing agent are mixed in equivalent ratio, defoamed, and then injected.

In this case, the liquid mixture is injected through a ring-shaped gap 16 with a width of 1 to 2M formed around the end plate 5 of the vacuum switch 1 and left at room temperature.

The mixed liquid material is cured by a main chain extension reaction and a crosslinking reaction to become rubbery, and the insulating coating layer 11 is formed.

Examples of incyanates as curing agents include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, ingropylidene bis(4-7 chlorohexyl isocyanate), and hexamethylene diisocyanate. , methylcyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,3...phenylene diisocyanate, 1,4-phenylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, 4,4'-diphenyl Diisocyanate, 2,4,6-trimethyl, 1,3-phenylene diincyanate, 1,2-ethane diincyanate, 1,3...propane diisocyanate, 1,4-butane diisocyanate, 1,5-propane Diisocyanate, 1,6-hexane diisocyanate, 1,4-cyclohexane diisocyanate, 2,4...bis(4
(cyclohexylmetal-incyanate) One or a mixture of two or more of cyclohexyl isocyanate, polymethylene polyphenyl incyanate, etc. is used.

As a liquid polybutadiene having a hydroxyl group at the end, POYBAR-4 5M (trade name of Idemitsu Petrochemical),
POIy bd R-4 5 H T (same as above), PO
One type or a mixture of two or more of POIy bd CN-1 5 (acrylic nitrile copolymer, same as above) is used.

It also includes those in which the hydroxyl groups of polybutadiene are reacted with an excess equivalent of diisocyanate or polyisocyanate so that the reactive end groups of polybutadiene become incyanate groups (prebolymers).

Furthermore, a part of the liquid polyptadiene (including prepolymers) having hydroxyl groups at both ends can be mixed with a substance having divalent or polyvalent hydroxyl groups, such as 1,4-butashiol, trimesterolpropane, castor oil, glycerin, and ethylene glycol. It can be transformed with equals, etc.

In addition, in order to promote the reaction, a catalyst commonly used in urethanization reactions (stannas octoate, dibutyltin laurate), etc. may be added.

Further, as the liquid polybutadiene, it is also possible to use a liquid polybutadiene having a carboxylic acid group at the end.

ThiOKoA He 4 3 4 (ThioKo
l-Chemical CoPoration product name), Hycar CTB (B-F-Good Ri
One type or a mixture of two or more types, such as ch Chemical (trade name: amrany), can be used.

In this case, the insulating coating layer 11 is formed by using a mixture of epoxides instead of the incyanates and carrying out a main chain extension reaction and a crosslinking reaction.

Examples of epoxides used include bisphenol A type diglycidyl ether, 1,4-butanediol diglycidyl ether, epoxidized polybutadiene, vinylcyclohexene dioxide, ethylene glycol di(2-metal) glycidyl ether, glycerol triglycidyl ether, etc. It will be done.

In addition, a part of the liquid polybutadiene having a carboxylic acid group at the end can be converted into a substance having a divalent or polyvalent carboxylic acid group, such as succinic acid, glutaric acid, adipic acid, pimelic acid, and slip acid. Acid, azelic acid, sebac acid, oxalic acid, phthalic acid, maleic acid, aconitec acid, polymeric dimer fat acid, polymeric trimmer ・
It can be modified with one kind or a mixture of two or more kinds, such as -fatty acids.

It should be noted that the resin-molded insulator tube 12 may not be suitable for use outdoors or in a similar location, and in that case, a porcelain insulator tube is used and the structure is similar to that of the above embodiment.

FIG. 2 shows a longitudinal sectional side view of a second embodiment of the vacuum switch according to the present invention.

The vacuum switch 21 is of 72 Kv, and its structure is almost the same as that of the first embodiment.

An insulating coating layer 11 made of polyptadiene rubber is provided on the outer peripheral surface of the vacuum container of the vacuum switch 21.

The insulator tube 12 of the resin molded body in the first embodiment is not used.

To form the polybutadiene rubber insulating coating layer 11, the vacuum switch 21 is placed in a mold (not shown), and the vacuum switch 21 is placed in the space formed between the mold and the vacuum container of the vacuum switch 21. Liquid polybutadiene and incyanates having a hydroxyl group at the end as in the first example, or
A liquid polybutadiene having a carboxylic acid group at the end and an epoxide are mixed and defoamed, injected at °C, allowed to stand at room temperature, and subjected to main chain extension reaction and crosslinking reaction to harden into a rubbery state.

After the insulating coating layer 11 of polybutadiene rubber is cured and formed, the mold is removed.

As in the first embodiment and the second embodiment, the vacuum switches 1 and 2
10 Insulating coating layer of butadiene rubber around the vacuum container 11
, the flash voltage at the interface between the vacuum container of the vacuum switch and the insulating coating layer 11 is increased, and its variation is reduced.

Each of the above-mentioned examples is compared with a vacuum switch alone, a vacuum switch having another rubber insulating coating layer, etc., and the results of a flashover value test are shown in a table below.

In the above table, Structure I is a single vacuum switch, Structure ■ is a single vacuum switch covered with a porcelain insulator through an air layer, Structure ■ is a vacuum switch with only an insulating coating layer, and Structure ■ is a vacuum switch with only an insulating coating layer. An insulating coating layer is provided and a resin porcelain tube is provided on the insulating coating layer.Structure V has a porcelain porcelain tube instead of the resin porcelain tube of structure (1).

! 8 to 10 and 16 to 20 are vacuum switches according to the present invention.

The material of the insulation coating layer is polybutadiene rubber■ PoI
ybdR-45HT and Nippon Polyurethane Industries' Millionate MR (polymethylene polyphenyl incyanate)
Polyptadiene rubber ■ is PoIy bd R-45 HT.
and PoIy bd Mp-9 (terminally incyanate-modified product, Idemitsu Petrochemical Co., Ltd.) were mixed in equivalent amounts, and the liquid mixture was left to stand at room temperature for one week.Polybutadiene rubber Idemitsu Petrochemical) and Isono
I C-1 0 0 (aromatic short chain diol, Up
John Co., Ltd.) was left at room temperature for one week.

Silicon type ■ is KE-106LTv (Shin-Etsu Chemical) left at room temperature for two weeks, silicon type ■ is KE-1 03R
TV (Shin-Etsu Chemical) left at room temperature for one week, epoxy system ■ is 100 parts of Epikote 871 (Shell Chemical) and 5 parts of polyamide (amine value 340).
The mixture with 0 parts was left at room temperature for one week.

As is clear from the above table, in the vacuum switch of the present invention, the flashover value is increased and its variation is reduced, making it possible to shorten the cylinder length of the vacuum switch.

Furthermore, polybutadiene rubber can be cured at room temperature compared to the curing conditions for other rubbers, so the curing process is extremely simple.

Moreover, since the material of the insulating coating layer 11 is polybutadiene rubber, the adhesion between the insulating coating layer 11 and the vacuum container is good, and a high final flash value is obtained as shown in the above test results.

In particular, in the case of the first embodiment, the resin molded body or porcelain insulator tube 12 serving as the fixed side is provided on the outer periphery of the insulating coating layer 11, so that the insulating ability as a high voltage vacuum switch is improved. It also has mechanical functions such as mechanical holding.

That is, in this case, the insulating coating layer 11 of polybutadiene rubber is interposed between the vacuum container and the insulating tube 12, and since they are well bonded, the interfacial flash final value can be dramatically increased, and It is capable of absorbing and relieving the clamping pressure caused by thermal stress on the vacuum container, and is also capable of sufficiently absorbing and relieving the impact force and vibrations at the time of turning on and turning off.

As described above, the present invention provides a vacuum switch in which an elastic insulating coating layer is provided on the outer peripheral surface of a vacuum container, in which the insulating coating layer is formed by casting a liquid mixture consisting of liquid polybutadiene and a curing agent. As a result, it is possible to increase the flash voltage at the interface of the vacuum vessel and reduce its variation, thereby making it possible to obtain a compact vacuum switch with a short cylinder length.

Further, the polybutadiene rubber forming the insulating coating layer cures at room temperature in a short time and is inexpensive, so that the manufacturing process can be shortened and a vacuum switch can be obtained at a low cost.

Furthermore, when an insulating layer is provided on the outer periphery of the insulation coating layer, it is possible to absorb and alleviate the clamping pressure caused by thermal stress, and it is also possible to sufficiently absorb and alleviate shock and vibration when turning on and off. It has the following effects.

[Brief explanation of the drawing]

1 and 2 are longitudinal sectional side views of a first embodiment and a second embodiment of a vacuum switch according to the present invention, respectively. 1, 2... Vacuum switch, 2... Fixed electrode, 3...
・Movable electrode, 4, 5... End plate, I... Insulating tube, 8.
...Shield, 9...Bellows, 11...Insulating coating layer, 12...Insulator tube, 13...Fixed substrate.

Claims (1)

[Claims] 1. A vacuum switch in which an elastic insulating coating layer is provided on the outer peripheral surface of a vacuum container and the insulating coating layer is formed by casting a liquid mixture consisting of liquid polybutadiene and a curing agent. switch.