CN88103210A - The vacuum switch tube that has encapsulating shell - Google Patents

Abstract

1. the vacuum switch tube that has encapsulating shell.

2.1 the shell of vacuum switch tube under because of the short circuit current overload situations, should have higher durability.

2.2 wire rod or band and heat insulation layer formation that the encapsulating shell of vacuum switch tube is crossed with resin impregnation.Heat insulation layer is between the coiling body and switching tube tube wall of wire rod or band formation.Heat insulation layer can be the molding made from pottery-felt or Aramid fiber, for example, and half hull shape molding.

2.3 improved vacuum switch tube is applicable in the environment of mine gas or explosion hazard.

Description

The present invention relates to a kind of vacuum switch tube that has encapsulating shell, its encapsulating shell has a coiling body made from impregnated wire rod of synthetic resin or band.Such vacuum switch tube for example has been disclosed among No. the 8508473rd, the Germany utility model specification.This switching tube is particularly useful for having in the environment of mine gas or explosion hazard.The task of encapsulating shell is, in the vacuum switch tube overload or sew and lost efficacy, and therefore discharges under the situation of a large amount of heats, prevents to light explosive gas mixture.Vacuum switch tube overload or the heat that produces when sewing are more much bigger than the heat that produces in the normal switch process.Because fault current can cause the fusing and the evaporation of metal parts in the switching tube, so encapsulating shell inside will be subjected to the effect of very big compression.

Scheme of the present invention can improve the durability of encapsulating shell under failure condition of the above-mentioned type.Its measure is to add one deck thermal insulation layer between coiling body and switching tube tube wall.This insulating barrier can apparatus has desired properties, and known inorganic material or organic material are made.The thermal insulation layer that suggestion is adopted is the molded part made from insulating material.Can be easy to like this guarantee that the heat insulation layer around the vacuum switch tube all has identical thickness.According to of the present invention, preferably above-mentioned molded part is made half hull shape that is consistent with the profile of vacuum switch tube, the manufacturing of vacuum switch tube is oversimplified.

As mentioned above, can use various inorganic material or organic material as insulating barrier.Facts have proved that the insulating barrier that adopts pottery-felt to become has good electric insulating quality and thermal insulation.Some staple fibre also can be used to make insulating barrier.For example a kind of relatively more successful insulating barrier with the Aramid(trade name Kevlar) fiber makes.

The coiling body that wire rod of crossing with resin impregnation or band are made has a kind of instinct, and when promptly just contacting with water or water vapour, the moisture that has denier enters coiling body inside, and is penetrated into the surface of vacuum switch tube.So, the dielectric strength of vacuum switch tube is poorer than the dielectric strength of the switching tube that does not have encapsulating shell.According to a kind of improvement of the present invention, can avoid occurring above-mentioned phenomenon.Promptly adopt a kind of hydrophobicity impregnating agent in the contacted one side of the insulated part of thermal insulation layer and vacuum switch tube.The moisture that so just can prevent to infiltrate coiling body inside enters thermal insulation layer and assembles at this place.And the contained technical moisture that can't eliminate in the coiling body on thermal insulation layer can not produce adverse effect to the insulation property of packaged vacuum switch tube.

As the replacement of the local water-proofing treatment of heat insulation layer or replenish, heat insulation layer can also be made the composite product that the synthetic resin by particle with thermal endurance and low heat conductivity and sclerosis constitutes.This heat insulation layer has enough thermal insulation properties, and is stable under the humidity load.

A metal cap also is housed on aforementioned known encapsulating shell, and its effect is a metal garden post shell of strengthening switching tube.It also is very favourable in the present invention that this metal cap uses.A kind of organization plan of the best is to allow heat insulation layer surround this additional metal parts.Advise that this metal parts not only will cover the stage casing, switch gear room of vacuum switch tube, also will cover simultaneously the end of metal rim, the problem of heat load because raising also may appear in the end.

The present invention is further illustrated for contrast example shown in the drawings below.Shown in Figure 1 is the longitudinal sectional drawing of a vacuum switch tube, Fig. 2 and shown in Figure 3 be the thermal insulation layer that is half hull shape.

In Fig. 1, vacuum switch tube 1 therein Duan Youyi with metal switch gear room 2, this chamber constitutes radome simultaneously.As shown in Figure 1, two switch contacts 3 and 4 that are connection status are arranged in switch gear room 2, wherein switch contact 3 is contained in one one end and is exposed on the cramp bar 5 outside the switching tube end, and cramp bar 5 can move back and forth by direction shown in the four-headed arrow 6, with the purpose that reaches path or open circuit.The effect of bellows 7 is in known manner, guarantees that cramp bar can move on the one hand, guarantees that on the other hand switching tube inside is in vacuum state all the time.Lower switches contact 4 connects together with another cramp bar 10, and maintains static.At two of middle part metallic room 2 earthenware 11 and 12 are housed, these two earthenwares have constituted the insulation between the switching tube tie point.

In order in the environment that mine gas or explosion hazard are arranged, to use switching tube safely, also be provided with an encapsulating shell 13, its each several part face as follows is described.

At first, switching tube 1 has metal cap 14 and 15 on the connector 8 and 9 of its end, and this metal cap for example can be made with copper coin or brass sheet.One is similarly covered or covers 16 outsides that wrap in the switch gear room, middle part 2 of switching tube 1. Metal parts 14,15 and 16 effect are by its additional thermal capacity, avoid occurring under failure condition rapid surface temperature rise.The reason that heat load produces is to cause owing to the effect of the electric arc that is not extinguished or its influence the molten metal that forms.The all topped insulating barrier 17 that becomes with pottery-felt on the surface of the remaining surface of switching tube and above-mentioned metal parts, this insulating barrier has constituted effective heat insulation layer of switching tube all surfaces.The shape at this heat insulation layer two ends of 2 in the switch gear room uses the lining 20 and 21 turning of being made by insulating material to process.Its concrete structure is seen aforesaid Germany utility model specification No. 8508473.The skin of encapsulating shell 13 is the coiling bodies that wire rod or band constituted 22 with resin impregnation.At end face the capping 23 and 24 made from solid insulating material is housed,, the insulating barrier and the external world is separated so that coiling body has smooth end face.

Pottery-carpet veneer as the vacuum switch tube heat insulation layer also can adopt similar mode to make other planforms different with the vacuum switch tube profile, particularly adopts through garden cylindrical shell.The planform of encapsulating shell for example can be put on display patent specification No. 3507949 referring to the Germany.Suggestion is used metal cap 14 and 15 at end face in this class formation.Also can be on this switching tube in a similar fashion with a metal cap with thermal conductive resin, for example the ring set made from copper or brass protects the metal rim at middle part.

Heat insulation layer can also use other suitable material except can using pottery-felt work.Employing Aramid(trade name Kevlar) best results of the heat insulation layer of fiber making.

Half shell that shown in Figure 2 is as a part of described heat insulation layer.Whole heat insulation layer is to be made of two half identical shells 25.As shown in the figure, half shell is to make according to the external shape of vacuum switch tube shown in Figure 1, and therefore two and half shells 25 can be close on the surface of vacuum switch tube.For simplicity, the tapered closing in two ends up and down of half shell 25 shown in the figure, different with the stepped closing in shown in Fig. 1.Half shell 25 is formed by pottery-felt compacting, and it has certain hole, therefore can absorb moisture.For fear of sucking moisture, the whole or local impregnating resin of double shell 25, to reduce or eliminate hole.Both can to as other part and each half shell of making flood respectively, also can the coiling body 22 in loading onto Fig. 1 before direct impregnation.Can also make the insulator of half shell and vacuum switch tube 1 connect together the dielectric property that this structure helps installing in this way.The position of dipping also should comprise and insulator 11,12 contacted garden cylindrical sections 26 and 27, because having relatively high expectations to dielectric property herein.Therefore insulating barrier and half shell 25 are made with heat-resisting and material granule and bonding agent poor thermal conductivity as composite product.

The shape of half shell 30 shown in Fig. 3 is the same with half shell 25 among Fig. 2 basically.Its difference is that this half shell does not have taper or step-like end.When the heat load intensity of the termination of vacuum switching tube 1 was low, this structure can meet the demands.A projection 32 is arranged at the top in the bigger stage casing 31 of diameter, and its effect is to hold the common bleeding point that has of vacuum switch tube.Two half identical shells 30 of shape are lumped together to constitute hold the required cavity of vacuum pumping opening.Wherein a kind of heat-insulating material can be used in the space of underfill, for example fills with the pottery of making half shell-felt.Different with half shell 25,30 on the half shell end of the position of garden cylindrical section 33 and garden, bottom cylindrical section 34 at an upper portion thereof carries out protection against the tide and handles.Can use local impregnation process for this reason, impregnating agent is seeped between the insulated particle.Prevent that these positions from absorbing moisture.In Fig. 1, needing the surface of dipping is to represent with the point 35 of representing impregnating agent.This just makes contact ceramics insulator 11 and 12(Fig. 1) heat insulation layer partly be protected.Because this is in maximum electric field strength is arranged in the work.

Suggestion was fixed on the vacuum switch tube 1 with a ring set 36 earlier before installing to half shell 25 and 30 on the coiling body 22.Its fixed position especially should be selected in the position of half shell near ceramics insulator 11 and 12.This structure helps the dielectric property of finished product encapsulating shell equally.

Claims (8)

1, vacuum switch tube has an encapsulating shell, and encapsulating shell has the coiling body made from the wire rod of resin impregnation or band, it is characterized in that, is provided with one deck heat insulation layer (17) between the tube wall of coiling body (22) and switching tube (1).

2, vacuum switch tube as claimed in claim 1 is characterized in that, heat insulation layer constitutes with insulating material molding (25,30).

3, vacuum switch tube as claimed in claim 2 is characterized in that, molding is made half shell (25,30) that the shape of shape and vacuum switch tube (1) matches.

4, vacuum switch tube as claimed in claim 1 is characterized in that, insulating barrier (17) becomes with pottery-felt.

5, vacuum switch tube as claimed in claim 1 is characterized in that, heat insulation layer (17) is with Aramid(trade name Kevlar) fiber makes.

6, vacuum switch tube as claimed in claim 1 is characterized in that, contains moistureproof impregnating agent with the position (33,34) of the contacted heat insulation layer of insulating part (11,12) (half shell 30) of vacuum switch tube.

7, vacuum switch tube as claimed in claim 1 is characterized in that, heat insulation layer (17,25,30) is by heat-resisting and have the particle of low heat conductivity and the resin of sclerosis is made.

8, as claim 1,2 or 3 described vacuum switch tubes, it is characterized in that, heat insulation layer (17) wraps in additional metal parts (14,15,16) outside, and the purpose that metal parts is set is the thermal capacity that is subjected to strong heat load position that increases vacuum switch tube (1) under the failure condition.

Images