RU2290710C1 - Explosion-proof push-button element - Google Patents

Abstract

FIELD: electrical engineering; push-button switches.

SUBSTANCE: switching chamber mounted in explosion-proof push-button element case is formed at point of intersection of blind opposing cylindrical holes; open parts of these cylindrical holes perform auxiliary function and are closed upon assembly by means of end caps or lids so that normally arcing parts (fixed contacts and contact bridge) are enclosed in explosion-tight shell made by using cylindrical explosion-tight joints.

EFFECT: enhanced degree of protection against mechanical damage, ability of taking explosion pressure and preventing its escape to environment.

1 cl, 2 dwg

Description

The technical field to which the invention relates.

The invention relates to electrical products, in particular to contact elements and blocks, and is an Ex-component, does not have independent use and can be used for incorporation into electric devices intended for remote control of electric drives of machines and mechanisms in stationary installations and on mobile ground vehicles and maritime transport, as well as for signaling associated with the aforementioned electric drives, or other electrical devices in alternating current circuits on maskers and 380 in DC voltage of 220 V. The rated current is 6.3 A.

State of the art

Known push-button switch of the KE series, consisting of a housing, a top cover with a pusher, a bottom cover, fixed contacts, a contact bridge and a return spring (see. Brief reference book “Industrial low-voltage equipment of mass series, Moscow, 1992).

The disadvantages of this switch are:

- low switching current U _nom. - 380 V, I _nom. - 5 A;

- general industrial design and the inability to use the switch in hazardous areas.

Known circuit breaker that performs protective functions, which relates to low-voltage electrical switching devices, in particular to circuit breakers. In the circuit breaker, the locking forces in the two latches are divided into “small” and “large” using trip units only to break the engagement with low force. Another engagement is carried out by a traverse with a spring-loaded protrusion, and its disruption is carried out by the energy of the contact pressing spring. The movable contact holder is provided with a beak and a through groove, located at the end of the contact pressing spring. The release lever is provided with a hook and two coaxial grooves, placed on the movable contact holder, and the traverse is made in the form of a flat fork trident, passed by the extreme teeth through the grooves of the release lever and the movable contact holder, the central tooth is pressed against the release lever so that one extreme tooth freely enters the spring contact pressing, and the other in engagement with a spring-loaded protrusion (see US Pat. RF No. 2074441, CL N 01 N 73/18, publ. 02.27.1997).

The disadvantage of this switch is the large mass and dimensions, low reliability.

The closest in technical essence and the achieved positive effect and adopted by the authors for the prototype is an explosion-proof microswitch type MPV-1, consisting of a housing with a switching chamber, covers with a pusher and a lower cover, plugs, fixed contacts, a contact bridge and a return spring, and fixed contacts and a contact bridge are installed in the switching chamber (see. Product catalog Explosion-proof low-voltage products, VELAN OJSC, p. 35-36, p. 62-65, 1995).

The disadvantages of this microswitch are the large dimensions of 52 × 21 × 43.5 mm and the fact that in order to ensure explosion protection along with standard flameproof connections, special types of explosion protection are used, such as, for example: pouring with compound, installation on glue, application labyrinth flameproof joints, which gives low reliability of explosion protection.

Disclosure of invention

The technical result that can be achieved using the present invention is reduced to a high degree of protection against the danger of mechanical damage, withstanding the pressure of the explosion and the exclusion of the transfer of the explosion into the environment due to the fact that the switching chamber in the housing of the explosion-proof button element is formed at the intersection of oncoming, deaf, cylindrical holes, while the open parts of the cylindrical holes play a technological role and at the end of the assembly are closed with plugs or caps, in As a result, normally sparkling parts are enclosed in a flameproof enclosure made using cylindrical flameproof joints in accordance with the requirements of GOST R 51330.1-99.

The technical result is achieved using an explosion-proof push-button element consisting of a housing with a switching chamber, top covers with a pusher and a lower cover, plugs, fixed contacts, a contact bridge and a return spring, and fixed contacts and a contact bridge are installed in the switching chamber, while the switching chamber the housing is formed by the intersection of oncoming, blind, cylindrical holes, the axes of which are located either in parallel planes or in one plane, and the open parts of the holes are made us the chance processability and closing plugs or caps, thus normally sparkling portion disposed in flameproof enclosure made flameproof cylindrical holes.

Brief Description of the Drawings

Figure 1 is a button element explosion-proof, General view.

Figure 2 is the same, the plane of the location of the axes of the holes.

The implementation of the invention

The explosion-proof button element consists of a housing 1 with a switching chamber (not indicated), a top cover 2 with a pusher 3, a bottom cover 4, plugs 5, fixed contacts 6, a contact bridge 7, a return spring 8, and the housing 1 and the covers 2 and 4 of the element are connected by screws or rivets, and the fixed contacts 6 and the contact bridge 7 are installed in the switching chamber in the housing 1, while the switching chamber in the housing 1 of the button element is formed when crossing counter, blind, cylindrical holes (not marked). The axes of the holes are located in parallel planes or in the same plane, while the open parts of the cylindrical holes play a technological role and, upon completion of assembly, are closed with plugs 5 or caps 2, 4, as a result of which normally sparking parts are enclosed in an explosion-proof shell made using cylindrical flameproof joints .

The explosion-proof button element is operated as follows.

Explosion-proof button element is made according to the circuit with double open circuit with two leads. When you press the pusher 3, mounted on the top cover 2, the contact bridge 7, moving rectilinearly, closes or opens the fixed contacts 6, and the bridge 7 and contacts 6 are installed in the switching chamber.

Upon termination of the impact on the pusher 3 under the influence of the spring 8, the contact bridge 7 takes its initial position.

Thus, the enclosure of normally sparking parts in a flameproof enclosure made using cylindrical flameproof joints has a high degree of protection against the danger of mechanical damage, withstands explosion pressure and prevents the explosion from being transferred to the environment.

Button elements can be used to control electromagnetic devices (relays, electromagnets, etc.) in low-power circuits of alternating current frequency of 50, 60 Hz and direct current with a rated voltage of at least 12 V and a rated current of at least 0.05 A. The elements have one make and one make contact with double open circuit. The overall dimensions of the contact element are length × width × height - 50 × 14 × 36 mm.

Explosion-proof push-button elements are labeled with ExedIU / ExedIICU explosion protection and are intended for operation in surface and underground rooms of coal mines in accordance with the current "Safety Rules in Coal Mines", as well as in hazardous areas according to the "Electrical Installation Rules" (PUE), chapter 7.3 "Electrical Installations in hazardous areas ”, GOST R 51330.9 and other regulatory documents that determine the applicability of electrical equipment in hazardous areas.

The invention in comparison with the prototype and other known technical solutions has the following advantages:

- types of explosion protection “d” - “flameproof enclosure” and protection of type “e”,

- type of protection "flameproof enclosure" (d) is provided by the following basic measures and means:

- the conclusion of normally sparkling parts in the flameproof enclosure of the contact elements, made in accordance with the requirements of GOST R 51330.1-99;

- the flameproof enclosure of the element has a high degree of protection against the danger of mechanical damage according to GOST R 51330.0-99, withstands the pressure of the explosion and eliminates the transfer of the explosion into the environment;

- the housing of the element is made of a tracking-resistant material, creepage distances and electrical clearances correspond to the values normalized by GOST R 51330.8-99 and GOST R 51330.20-99;

- contact electrical clamps are made in accordance with the requirements of GOST R 10434-82;

- limiting the heating of the outer parts of the shell: the temperature does not exceed 85 ° C;

- the presence of explosion protection markings.

Claims (1)

Explosion-proof push-button element, consisting of a housing with a switching chamber, top covers with a pusher and a lower cover, plugs, fixed contacts, a contact bridge and a return spring, and fixed contacts and a contact bridge installed in the switching chamber, characterized in that the switching chamber in the housing is formed by an intersection counter blind cylindrical holes, the axes of which are located in parallel planes or in the same plane, and the open parts of the holes at the end of the assembly are closed with plugs or lids using cylindrical flameproof joints.

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