CN201004434Y

CN201004434Y - Gas density switch using gas compensation

Info

Publication number: CN201004434Y
Application number: CNU2007200665867U
Authority: CN
Inventors: 苏丽芳; 袁煜; 孙宝军
Original assignee: Shanghai Roye Electric Science and Technology Co Ltd
Current assignee: Shanghai Roye Electric Science and Technology Co Ltd
Priority date: 2007-01-23
Filing date: 2007-01-23
Publication date: 2008-01-09
Anticipated expiration: 2017-01-23

Abstract

The utility model discloses a gas density switch which utilizes the gas to compensate, which is characterized in that the utility model comprises a bourdon tube, a dolly bar, a sensitive switch, a first sealing element, a cover plate and a second sealing element, wherein, a casing is filled with a SF6 gas, one end of the bourdon tube is welded on a base and communicated with the base; an end seat is welded on the other end of the bourdon tube, the dolly bar is movably arranged on the end seat; the sensitive switch is fixed on a dead plate which is fixed on the base; and the sensitive switch is correspondingly arranged above or below the dolly bar; the junction leading-out wire of the sensitive switch is sealed; all conducting elements are hermetically fixed on an insulator through the first sealing element, the insulator is hermetically fixed on a flange through the second sealing element, the flange is hermetically fixed on the cover plate, and the cover plate is hermetically fixed on the casing. The gas density switch adopting the technique proposal has the advantages of more reliable sealing, exacter temperature compensation performance, higher precision and lower manufacturing cost.

Description

Gas density switch using gas compensation

Technical Field

The utility model relates to a SF6 gas density switch (density relay), in particular to an application in SF₆Use of SF in electrical equipment₆Gas compensated SF6 gas density switch.

Background

SF₆Electrical productThe method is widely applied to the power sector and industrial and mining enterprises, and promotes the rapid development of the power industry. Ensuring SF₆Reliable and safe operation of electrical products has become one of the important tasks of the power sector. SF₆The arc-extinguishing medium and the insulating medium of the electrical product are SF₆Gas cannot leak, and if gas leaks, SF cannot be guaranteed₆The electric product can operate reliably and safely. So that SF is monitored₆SF of electrical products₆Density values are very necessary. Is now used to monitor SF₆The density is generally measured by a mechanical pointer type density meter (comprising a relay) with SF as₆The density value can be displayed on site when the electrical product leaks, and the density meter or the relay basically measures the relative pressure of SF6 gas, and has the functions of alarming and locking. For some occasions (such as a low-pressure meter or a high-altitude area), the shell of the density switch (containing the density relay) is required to be sealed, so that the performance of the density switch is not influenced by the altitude and the climate, and the density switch can be applied to various places. Although the totally-sealed density switch for measuring the absolute pressure of SF6 gas exists in the market at present, a sensor for measuring the pressure adopts a corrugated pipe, a contact adopts a magnetic-assisted electric contact mode, and the sealing effect of a shell is not very reliable; the displacement of the corrugated pipe is small, so that the precision is difficult to be made; since the bellows is used as the pressure sensing element, the manufacturing cost is also high. In view of the foregoing, it is desirable to invent an SF₆Gas density switch (SF 6 containing gas density relay): the sealing is reliable, the temperature compensation performance is accurate, the precision is high, the contact is reliable, the vibration resistance is good, the sealing device is particularly suitable for an SF6 density switch with low pressure, the sealing performance of the shell is greatly improved, the air leakage phenomenon can not occur, the product quality is greatly improved, and the manufacturing cost is very necessary to be reduced.

Disclosure of Invention

The purpose of the utility model is to solve the above problems existing in the prior art and provide an SF utilization device₆Gas compensated SF6 gas density switch for control and monitoring in sealed containersSF₆Density of gas against SF₆The gas leakage condition in the electrical equipment can send out alarm signals and lock signals in time, and the gas leakage condition plays a role in guaranteeing the electric power safety.

The purpose of the utility model is realized like this: a gas density switch using gas compensation comprises a shell, a joint, a fixing plate, an insulating part, conductive parts, a flange, a base and an end seat, and also comprises a Bourdon tube, an adjusting rod, a microswitch, a first sealing part, a cover plate and a second sealing part, wherein the shell is filled with SF6 gas, one end of the Bourdon tube is welded on the base and communicated with the base, the end seat is welded on the other end of the Bourdon tube, the adjusting rod is movably arranged on the end seat, the microswitch is fixed on the fixing plate, the fixing plate is fixed on the base, the microswitch is correspondingly arranged below or above the adjusting rod, a contact leading-out wire of the microswitch is sealed, all the conductive parts are sealed and fixed on the insulating part through the first sealing part, the insulating part is sealed and fixed on the flange through the second sealing part, and the flange is sealed and fixed on the cover plate, the cover plate is hermetically fixed on the shell.

The micro switches and the corresponding adjusting rods can be respectively provided with one, two, three, four or more. The base is fixed to the cover plate and the flange is sealingly fixed to the housing.

The utility model relates to an utilize SF₆The SF6 gas density switch with gas compensation has the advantages of more reliable sealing, more accurate temperature compensation performance, higher precision, more reliable contact, better vibration resistance and lower manufacturing cost, is particularly suitable for the SF6 density switch with low pressure, greatly improves the sealing performance of a shell, can not generate gas leakage phenomenon, and greatly improves the product quality.

Drawings

FIG. 1 is a schematic diagram of a gas density switch utilizing gas compensation according to the present invention;

FIG. 2 is a schematic diagram of the core structure of the gas density switch using gas compensation according to the present invention;

FIG. 3 is a side view of the gas density switch core structure with gas compensation according to the present invention;

fig. 4 is a schematic structural diagram of a gas density switch using gas compensation according to another embodiment of the present invention.

Detailed Description

Referring to fig. 1, 2 and 3, the present invention utilizes SF₆The gas-compensated SF6 gas density switch (i.e. density relay) comprises a shell 5, a joint 1 arranged in the shell 5, a Bourdon tube 2, a fixing plate 3, a first sealing element 4, an insulating element 6, a cover plate 7, a sealing element 8, a conductive element 9, a flange 10, a base 11, an end seat 12, a microswitch 13, an electric wire 14, an adjusting rod 15, a seal 16, a guide pipe 17, a cable head 18, a cable 19 and the like. Wherein the joint 1 is fixed on a base 11, the base 11 is fixed on the shell 5, one end of the bourdon tube 2 is welded on the base 11 and communicated with the base, and the other end is welded on the end seat 12. An adjusting rod 15 is fixed on the end seat 12. The micro switch 13 is fixed on the fixing plate 3, the fixing plate 3 is fixed on the base 11, and the micro switch 13 is correspondingly arranged below the adjusting rod 15. The contact of the micro switch is connected to one end of the conductive member 9 through the electric wire 141, and the electric wire 142 connects the other end of the conductive member 9 to the cable 19, wherein the conductive member 91 is hermetically fixed on the insulating member 6 through the first sealing member 41, the conductive member 92 is hermetically fixed on the insulating member 6 through the first sealing member 42, the insulating member 6 is hermetically fixed on the flange 10 through the sealing member 8, the flange 10 is hermetically fixed on the cover plate 7, and the cover plate 7 is hermetically fixed on the housing 5. The seal 16 is fixed on the cover plate 7 in a sealing way, and the conduit 17 is welded on the seal 16. The cable head 18 is fixed on the flange 10, and the cable 19 is fixed on the cable head 18, so that the internal line can be protected from mechanical damage and invasion of dirt and rainwater. The function of the conduit 17: when the density switch is manufactured and set, the guide pipe 17 is used for filling S with standard pressureF6 gas is introduced into the housing and the duct 17 is securely sealed immediately after filling, typically by welding.

The micro switches 13 and the corresponding adjusting rods 15 can be 1 pair, 2 pairs, 3 pairs or 4 pairs, and the micro switches are correspondingly arranged below or above the adjusting rods. The number of the present embodiment is 1 pair.

Referring to fig. 4, it can be seen that: the density switch of the utility model, its base 11 also can be fixed on the apron 7, and the flange 10 is sealed to be fixed on the casing 5.

The function principle of the utility model is based on the elastic element Bourdon tube 2, and the shell is filled with the standard SF₆Gas to varying pressure and temperature, reaction SF₆The change in gas density. That is, the temperature in the SF6 electrical equipment is increased or decreased under the same environmental temperature, and the standard pressure of the SF6 gas in the shell is also increased or decreased, so that the influence of the temperature is overcome. I.e. in the measured medium SF₆The density value and the pressure value of the gas change under the action of the pressure of the gas, so that the tail end of the Bourdon tube 2 generates corresponding elastic deformation-displacement, if the electrical equipment leaks gas, the density value of the gas outside the Bourdon tube 2 is reduced, the Bourdon tube 2 generates corresponding downward displacement, so that the end seat 12 also moves downward, the density value is reduced to a certain degree (reaching an alarm or locking value) lower than the standard SF6 gas density value in the shell, the adjusting rod 15 on the end seat 12 pushes the corresponding microswitch 13, the contact of the corresponding microswitch 13 is switched on, and a corresponding signal (alarm or locking) is sent out to monitor and control SF in the electrical equipment such as the electrical switch₆The gas density makes the electrical equipment work safely. If the density value rises, the pressure value also rises correspondingly to a certain degree, the Bourdon tube 2 also displaces upwards correspondingly, so that the end seat 12 displaces upwards, the adjusting rod 15 on the end seat 12 displaces upwards, the density value rises to a certain degree (reaching an alarm or locking value) higher than the standard SF6 gas density value in the shell, the corresponding micro switch 13 is far away, the contact point is disconnected, and the signal (alarm or locking) is released. Since the temperature is the same as the ambient temperatureIf SF₆If the gas density value is high, the pressure value is also large; if SF₆If the gas density value is low, the pressure value is also small. In this way the effect of temperature on the density measurement is overcome. When SF₆SF for electrical equipment₆If the gas density is higher than the standard SF6 gas density in the shell to a certain degree, then SF₆SF for electrical equipment₆The gas pressure value is larger than the standard SF6 gas pressure value in the shell, namely the contact is disconnected when the gas pressure value is larger than the set point, and the signal (alarm or lock) is released; when SF₆SF for electrical equipment₆If the gas density is lower than the standard SF6 gas density in the shell to a certain extent, the SF₆SF for electrical equipment₆The gas pressure is lower than the standard SF6 gas pressure in the shell, namely the contact is closed when the gas pressure is lower than the set point, and a corresponding signal (alarm or lock) is sent out.

Because the utility model discloses a signal contact adopts the micro-gap switch form, and the control of micro-gap switch contact is whole to be controlled by adjusting the pole, and the control of adjusting the pole is carried out by end seat 12 and bourdon tube 2, and density value has descended, and bourdon tube 2 just moves down, until signal (warning or shutting) contact action, micro-gap switch contact switch-on promptly. The more the density value decreases, the more firmly the microswitch is switched on, the larger force is exerted on the microswitch by the Bourdon tube, and the microswitch is under good pressure and in good switching-on, and is not afraid of vibration. Meanwhile, the displacement of the Bourdon tube is larger than that of the corrugated tube, so that the accuracy is easy to be calibrated, the processing is easy, the debugging is easy, and the cost can be reduced. Meanwhile, the contact adopts a microswitch form, so that the contact capacity is large and the contact is reliable.

Because the utility model discloses a contact lead-out wire is sealed to have changed original method sealed with gluing, because of sealing with gluing, it is long-lived, temperature variation has, will produce the crack, will leak gas like this, makes whole density switch inefficacy. The contact lead-out wire is sealed: all conducting elements 9 are fixed in a sealing manner on the insulating element 6 by means of the first sealing element 4, the insulating element 6 is in turn fixed in a sealing manner on a flange 10 by means of a sealing element 8, the flange 10 is in turn fixed in a sealing manner on the cover plate 7, and the cover plate 7 is in turn fixed in a sealing manner on the housing 5. Therefore, the sealing is not sealed by glue but by the sealing element, and the sealing performance is reliable.

To sum up, the utility model discloses owing to adopted the bourdon tube as pressure sensor, and the contact adopts micro-gap switch, and reliable contact lead-out wire is sealed, adopts SF6 gas as temperature compensation in the totally enclosed casing. After the treatment, the performance is very good, and the following effects are achieved: A. the sealing is more reliable; B. the temperature compensation performance is more accurate; D. the precision is higher; E. the contact is more reliable; F. the vibration resistance is better; G. the manufacturing cost is lower. Therefore, the performance and the cost performance of the density switch (density relay) are greatly improved.

It will be appreciated by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be used as limitations of the present invention, and that changes and modifications to the above described embodiments will fall within the scope of the claims of the present invention as long as they are within the spirit and scope of the present invention.

Claims

1. A gas density switch using gas compensation comprises a shell, a joint, a fixing plate, an insulating part, a conductive part, a flange, a base and an end seat, and is characterized by also comprising a Bourdon tube, an adjusting rod, a microswitch, a first sealing part, a cover plate and a second sealing part,

wherein,

the shell is filled with SF6 gas;

one end of the Bourdon tube is welded on the base and is communicated with the base;

the end seat is welded on the other end of the Bourdon tube;

the adjusting rod is movably arranged on the end seat;

the micro switch is fixed on the fixing plate, the fixing plate is fixed on the base, and the micro switch is correspondingly arranged below or above the adjusting rod;

the contact leading-out wire of the microswitch is sealed, all the conductive pieces are sealed and fixed on the insulating piece through the first sealing piece, the insulating piece is sealed and fixed on the flange through the second sealing piece, the flange is sealed and fixed on the cover plate, and the cover plate is sealed and fixed on the shell.

2. The gas density switch using gas compensation of claim 1, wherein the micro switch and the corresponding adjustment lever are each provided one by one.

3. The gas density switch using gas compensation of claim 1, wherein the micro switch and the adjusting lever opposite thereto are two, three, four or more each.

4. The gas density switch using gas compensation of claim 1, wherein the base is fixed to the cover plate and the flange is sealingly fixed to the housing.