CN2115578U

CN2115578U - Proximity type positive pressure switch

Info

Publication number: CN2115578U
Application number: CN 92213129
Authority: CN
Inventors: 吴尊龙; 沈锦仁
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-01-25
Filing date: 1992-01-25
Publication date: 1992-09-09

Abstract

The utility model relates to a proximity type positive pressure switch with micro air pressure, which belongs to a micro-pressure control device used for explosion preventing electric apparatus of positive pressure type in the petroleum and chemical industry. The utility model is composed of contactless proximity push buttons of instrinsical safety type and air cavities, and can control the opening or closed status of a gas precharge valve for maintaining the micro-pressure in the controlled cavity higher than that preset in the ambient environment. The proximity type positive pressure switch, which is suitable for work in the 1st and the 2nd districts of explosive preventing and dangerous places and in the condition that the cavities are controlled under a higher ambient environment pressure of 30-700 mmh 2, has the advantages of no contact, good interference immunity and long service life, and integration element is formed under the on-off action of the switch by means of a damping element.

Description

Proximity type positive pressure switch

The utility model is in oil, the chemical industry class positive pressure type explosion-proof electric equipment, a kind of in order to keep the specific little air pressure of projecting environment in the Be Controlled cavity in the required control device.

General little baroswitch is mechanical contact-making switch, easily produces spark during its action, and useful life is not long simultaneously.

The little baroswitch of proximity positive pressure type of the present utility model, purpose is to the decline improvement of air pressure contact-making switch of existing machinery, makes it to be operated near under the state promptly contactless work, just can not produce spark, so this switch working life prolongs greatly like this owing to the action of contact.Simultaneously, switch motion forms a delay component to the return-air process, so just helps eliminating the frequent movement curve of switch at preset air pressure small sway time institute product, has reduced generation of false action.

The purpose of this utility model is to realize like this, when the air pressure in the lower chamber reaches predetermined value, the diaphragm pressurized certain distance that moves up, when making circular standard iron plate not touch the contactless button of intrinsic safety type, this switch motion, and then control harbor qi of chong channel ascending adversely valve, make it to stop qi of chong channel ascending adversely in the Be Controlled cavity; When causing air pressure to drop to certain value when inevitable leakage of lower chamber gas, diaphragm is owing to deadweight moves down certain distance, this switch moves once more, and then the qi of chong channel ascending adversely valve of control harbor is opened, permission qi of chong channel ascending adversely in the Be Controlled cavity, simultaneously, can reach the purpose of keeping different air pressure by regulating the relative distance between contactless button of intrinsic safety type and the diaphragm.

Its specific implementation and operation principle can describe in detail with reference to accompanying drawing.

Among the figure, 1 is the switch lead-out wire, and 2 are the switch motion indicator light; 3 is that intrinsic safety type is contactless near button, and 4 is hex nut, and 5,10 is locking spring washer; 6 is upper cavity, and 7 is the metal coating sheet of the with holes and projection of circular central, and 8 is circular standard iron plate; 9 fillister head screws for fluting, 11 is lower chamber, 12 is gas joint pressure cap; 13 is the gas joint, and 14 is O-ring seals, and 15 for filtering felt; 16 is capillary, and 17 is circular film, and 18 is the upper cavity venthole.

Intrinsic safety type is contactless to have screw thread one end by hex nut 4 and locking spring washer 5 tightly fixedly on the upper wall of upper cavity 6 near button 3.Contactless at intrinsic safety type near button 3; the other end has an indication action indicator 2 and a switch lead-out wire 1 during as switch motion; utilize switch lead-out wire 1 to connect respectively at the qi of chong channel ascending adversely valve of harbor work with in the hazardous area 1; the little baroswitch of proximity positive pressure type of 2 districts work; intrinsic safety type is contactless to can be LJ series near button near button 3; on upper cavity 6 sidewalls, opened an aperture 18; air gas outlet as the pressurized of upper cavity 6; the metal coating sheet 7 of upper cavity 6 and projection with holes with circular central; the rubber I-2 film of circular high-quality oil resistant gas becomes 17; lower chamber 11 utilizes slotted cheese head screw 9 and locking spring washer 10 tightly to be fixed together together in order; circular standard iron plate 8 utilizes 502 glue tightly to be bonded at the center of circular film 17; afterbody is pressing the capillary 16 that filters felt 15 to head on by the top of the gas joint 13 that screws; and be fixed in the screw of gas joint 13 engagements on lower chamber 11 sidewalls; gas joint 13 meshes with lower chamber 11 by screw thread; and utilized " O " shape sealing ring 14; thereby play good sealing function; pressure cap 12 is tightened on the gas joint 13; play with the good anastomosis of Be Controlled cavity; material is the upper cavity 6 of ZL102; lower chamber 11; form an explosion-proof body of complete positive pressure type with intrinsic safety type is contactless together near button etc., thereby it can use fully in explosion-proof hazardous area 1; 2 districts.

Owing to be linked together projecting ambient pressure 30-200mmH in the controlled cavity with controlled cavity by gas joint 13 near the baroswitch lower chamber 11 that declines ₂The gas of O post is after felt 15 filters after filtration from the gas joint 13 of this utility model, slowly enter in the lower chamber 11 through capillary 16, at this moment, upper cavity 6 is just different with the pressure in the lower chamber 11, cause circular film 17 pressurizeds and drive circular standard iron plate 8 moving up, gas is discharged by venthole 18 in the upper cavity 6, it is contactless near button 3 operating distances that circular standard iron plate 8 just enters intrinsic safety type, near the baroswitch action that declines, action indicator 2 is bright, and step switch control harbor qi of chong channel ascending adversely valve stops qi of chong channel ascending adversely.Gas is owing to reason such as leakage inevitably in the Be Controlled cavity, when causing air pressure to drop to preset air pressure, gas in the lower chamber 11 passes through capillary 16 slow release in the controlled cavity in the external world, at this moment, owing to the cause of circular standard iron plate 8 and diaphragm 17 own wts moves down some distances, it is contactless near button 3 operating distances promptly to leave intrinsic safety type, at this moment ambient atmos enters from the aperture 18 of upper cavity 6, the little baroswitch of proximity positive pressure type is decompression and moving once more, action indicator extinguishes, step switch and then control qi of chong channel ascending adversely valve qi of chong channel ascending adversely in the Be Controlled cavity so just can be kept certain little air pressure of the interior projecting environment of Be Controlled cavity.In order to satisfy the requirement of different specific little air pressure 30-200H20 posts, this utility model can be utilized by hex nut 4 adjusting intrinsic safety types are contactless and realize near the relative distance of button 3 with circular standard iron plate 8.The projection of the metal coating sheet 7 of the with holes and projection of circular central should be installed near the contactless direction near button 3 of intrinsic safety type, and it is to be used for protecting the rubber I-2 diaphragm of high-quality oil resistant gas owing to be subjected to above the pressure effect of the measuring range function that follows the string.Because the utility model utilized capillary 16 damping pieces, make the lower chamber air inlet, a process is arranged when giving vent to anger, switch motion forms a delay component, for positive-pressure explosion-proof type electric equipment has improved reliable parts.

Claims

1; the little baroswitch of a kind of proximity positive pressure type; comprise that intrinsic safety type is contactless near button 3; upper cavity 6; lower chamber 11; metal coating sheet 7 circular films 17 of the with holes and projection of circular central; circular standard iron plate 8; capillary 16 7 parts; it is characterized in that intrinsic safety type is contactless tightly is engaged in the last cinclides of upper cavity 6 near button 8 threaded ends by hex nut 4 and locking spring washer 5; upper cavity 6; the metal coating sheet 7 of the with holes and projection of circular central; circular film 17 links together with lower chamber 11 tightly by fillister head screw 9 and six locking spring washers 10 of six flutings in order; circular standard iron plate 8 usefulness 502 glue tightly are bonded on the center of circular film 17, and capillary 16 tail ends are being pressed and filtered felt 15 and the top by the gas joint 13 that screws and head on and be fixed on being used in lower chamber 11 sidewalls and install in the screw of gas joint.

2, switch according to claim 1 is characterized in that, intrinsic safety type is contactless can and to be fixed on the needed position by the threaded adjusting on hex nut (4) and upper cavity (6) upper wall near button (3).

3, switch according to claim 1 is characterized in that, the material of circular film 17 is the rubber I-2 of high-quality oil resistant gas.

4, switch according to claim 1 is characterized in that, the projection of the metal coating sheet 7 of the with holes and projection of circular central should be installed near button 3 directions near intrinsic safety type is contactless.