EP3065228A1 - Explosion-proof cable connection - Google Patents

Abstract

It is proposed a detachable plug connection (1) for connecting an electrical line (2) to a resource (3) having a first connecting element (6), a second connecting element (7) and a sleeve-shaped body (5). Both connecting elements (6, 7) are arranged in the sleeve-shaped body (5) and form a detachable plug connection (1). According to the invention, the connecting elements (6, 7) are arranged in the sleeve-shaped body between the operating means (3) and a sealing element (10). The sealing element (10) seals the plug connection (1) in such a gap-free manner relative to the sleeve-shaped body (5) that the detachable plug connection (1) is arranged in a flameproof enclosure.

Description

The invention relates to a releasable plug-in connection, which is arranged in a flameproof enclosure.

It is generally known that explosion-protected electrical equipment is used in particular in potentially explosive areas, for example in underground coal mining or in the chemical industry. Such equipment is a source of ignition and is designed so that a potentially explosive atmosphere can not be ignited. The person skilled in various designs for preventing ignitions known as so-called ignition protection.

The requirements for the explosion protection are e.g. specified by DIN EN 60079-1 (for example DIN EN 60079-1 (VDE 0170-5): 2008-04)). The DIN EN 60079-1 and its contents are expressly used for the disclosure in relation to the present invention.

The person skilled in the art is aware that different types of protection exist in explosion protection. In particular, in the context of protection types for sensors, actuators or electric motors is a protection that is important, the so-called intrinsic safety. Here, the electrical equipment of the level of performance is so low settled, the it can not generate critical heating on the device surface even in faulty operation. An associated intrinsically safe power supply also ensures that even a direct separation of the electrical supply line or a short circuit can not ignite the surrounding potentially explosive atmosphere.

Another known type of protection is the so-called Vergusskapselung, in which all electrical components and the electrical power supply within an electrical equipment are surrounded by a potting material of certain thickness. Voids are filled by the casting agent so that no flammable atmosphere can get into the equipment, for example in the form of volatile gases. Furthermore, the potting compound of a Vergusskapselung prevent electrical sparks from the equipment can escape to the outside. Thus, it can also be ensured that an explosive mixture according to the outside can not be ignited by an electric spark. In this regard, it is known that an electrical supply line, generally referred to as a cable for the equipment is usually firmly connected to the electrical equipment and in the equipment by a specially approved for explosion protection line feedthrough, a so-called cable gland, is performed. These permanently installed cable solutions have disadvantages especially for end users. For example, individual wishes regarding the cable used or the electrical line used can not be taken into account. Furthermore, large amounts of cable waste accumulate during production. Finally, it is a disadvantage that cable guides with already connected equipment are cumbersome to handle.

Furthermore, the expert in the context of explosion protection at the outset already mentioned term "flameproof enclosure" is familiar. Here are all electrical components in a pressure-tight encapsulated Housing, whereby a flammable atmosphere may penetrate according to the regulations in a resource. A spark occurring within the equipment may occur and may also ignite the internal atmosphere. However, a spark must not leave the area of the flameproof enclosure, as this could ignite a potentially explosive atmosphere that is outside the equipment.

Electrical leads are often firmly connected with this type of protection with the associated electrical equipment. They enter the equipment through a more robust and elaborately designed cable bushing specially approved for explosion protection. There continue to be the disadvantages already mentioned, especially for end consumers. For example, individual wishes regarding the cable used or the electrical line used can not be taken into account. Furthermore, large amounts of cable waste accumulate during production. Finally, it is a disadvantage that cable guides with already connected equipment are cumbersome to handle. One way of installing the flameproof enclosure is to open the equipment and make the electrical connection. However, this is only allowed under certain conditions and usually entails expensive and expensive safety precautions.

The person skilled in the art is known in connection with the degree of protection "flameproof enclosure" that so-called "gaps" are of great importance in this case since, for example, the escape of a flame can be prevented. In connection with "gaps" in explosion protection, in particular in connection with the degree of protection "flameproof enclosure", reference is expressly made to the content of the already mentioned DIN EN 60079-1.

For example, with protection type "Ex d" (so-called flameproof enclosure), the ignitable atmosphere is ignited within the protection type construction, as long as it is ensured that a spark generated therein can not escape to the outside. The so-called "flameproof enclosure" is a type of protection in which parts which can ignite an explosive atmosphere are arranged in a housing which withstands the pressure of the explosion of an explosive mixture in the interior. A transfer of the explosion to the surrounding the housing explosive atmosphere is prevented. This is essentially due to the fact that the explosion pressure in the housing depends on its free internal volume and on the shape of the housing. The requirements for this type of protection are listed in DIN EN 60079-1. In order to meet the requirements of DIN EN 60079-1 and to prevent the transmission of the explosion to the outside, usually gaps between housing parts are provided, which must be designed accordingly so that escaping gases outside the housing have no ignitability. This means that the gaps in their length and width must not fall below certain values.

It is also known that the aforementioned resources, such as electric motors or solenoid valves or the like are marketed as electrical components with fixed electrical line. The electrical line is in this case mounted inside the equipment and brought to the outside via an explosion-proof cable bushing. Usually fixed cable lengths, for example of three or ten meters, are used for installation in systems. In the case of lower mounting distances thus incurred large amounts of cable waste. Electrical equipment or equipment that needs to be repaired, serviced or replaced must be opened to disconnect the electrical wiring. As a rule, this requires trained or certified specialist personnel. Moreover, repair, replacement or maintenance work means an increased amount of time and thus an associated cost.

From the prior art of DE 10 2013 113 013 A1 a detachable plug connection is shown which meets the requirements of DIN EN 60079-1 and is available at the column. A disadvantage of this prior art is that on the one hand an increased design effort is necessary and on the other hand, the flameproof enclosure is canceled by damage to columns. This is associated with increased maintenance and thus cost.

The present invention is therefore based on the object to provide a connector for resources for hazardous areas, which is inexpensive to manufacture and reduces maintenance, replacement or repair costs.

This object is solved by the features of patent claim 1. Further advantageous embodiments emerge in particular from the dependent claims.

Accordingly, a detachable plug-in connection for connecting at least one electrical line to an operating means, for example a solenoid valve or an electric motor, comprising a first connecting element, for example a connecting bush and a second connecting element, for example a connecting plug and a sleeve-shaped body, is proposed. In this case, both connecting elements are releasably connectable to each other and the first connecting element is connected to the operating means and the second connecting element is connected to the at least one electrical line. The connecting elements are arranged in the sleeve-shaped body between the operating means and at least one sealing element, wherein the at least one sealing element is arranged plug-in connection of the connecting elements in the assembled state relative to the sleeve-shaped body so gap-free sealing that the plug-in connection is arranged in a flameproof enclosure.

By gap-free sealing without complex geometry of the connector is thus realized by means of a cost-producible connection possibility of a resource to an electrical line that maintenance, replacement or repair work on this or on the electrical line are greatly simplified.

The releasable plug connection according to the invention is characterized in particular by the fact that an electrical connection with a resource can be provided without dissolving the flameproof enclosure or having to open the resource.

In a preferred embodiment it is provided that the sealing element can be made of elastic material and preferably of rubber.

In areas where there is a risk of explosion, the sealing element used to seal the plug-in connection without a gap is very important. Sealing materials made of elastic material allow a particularly good seal. Rubber is particularly suitable here.

A particularly advantageous embodiment of the invention provides that the sleeve-shaped body is detachably connected to a housing portion of the operating means or at least partially formed by a recess in this threaded portion.

It is thereby possible, for example, that the sleeve-shaped body from the housing portion of the equipment for cleaning or repair purposes is easily disassembled or assembled. It is also possible that the plug connection can be arranged in the interior of the housing section, wherein a separate sleeve is not necessary. As a result, the manufacturing cost can be reduced because it can be dispensed with an additional component. Finally, a more compact design is possible, the can be used, for example, in confined space conditions.

A further particularly advantageous embodiment of the invention provides that the sleeve-shaped body may preferably be permanently connected to the first connecting element.

As a result, the first connection element and in the assembled state, the entire plug-in connection in the sleeve-shaped body at the occurrence of an increased pressure within the equipment is not changed position and ensures the maintenance of explosion protection.

In a further embodiment, the sleeve-shaped body and the first connecting element can be designed as a one-piece component.

The use of a one-piece component means a reduced installation effort and a further consolidation of the connector in the presence of an increased pressure within the resource or sleeve-shaped body.

In an advantageous embodiment of the sleeve-shaped body can be made of metal. It is also particularly advantageous that the first connecting element is made of plastic.

Existing cable glands are usually made of metal and can therefore be used, whereby no separate production costs incurred. The production of the first connecting element as a plastic injection-molded part is also inexpensive and additionally provides the required insulator properties.

A further embodiment provides that both connecting elements can be arranged in the assembled state within the opening of the housing section.

This is accompanied by the fact that the sleeve-shaped body has a shorter length, whereby the material and thus the cost of the sleeve-shaped body is reduced. In addition, possible risks of damage to the sleeve-shaped body, such as shear fracture, are reduced, which is of great importance in explosion-proof areas.

In an advantageous development of the invention, it is provided that the sleeve-shaped body can have at its end facing the operating means a constant or conical diameter, in particular with a threaded section, provided for fastening in the housing section.

As a result, existing components can be used and expensive processing steps are eliminated. In addition, a more compact design can be realized.

A further advantageous embodiment of the invention provides that in the sleeve-shaped body inner peripheral side, a bearing surface may be provided for supporting the sealing element. In a preferred embodiment, the support surface is arranged circumferentially within the sleeve-shaped body.

When pressing the sealing element is made possible by the support surface that the radial pressure of the sealing element is made possible by the fastening means from the axial pressure, since the support surface is a kind of resistance for the sealing element during the pressing.

In a preferred embodiment, a fastening means can be detachably mounted on the sleeve-shaped body, as a result of which the sealing element can be compressed directly or indirectly.

Sealing elements in the form of a pinch seal or stuffing box are established and are especially suitable for sealing rotationally symmetrical spaces. This is done by an axial pressure and a radial pressure.

In one embodiment it is provided that the fastening means may have an external or internal thread. This external or internal thread can cooperate in a further embodiment with a corresponding internal or external thread on the sleeve-shaped body.

It is possible in this way to be able to use existing components and thus reduce the production costs. In addition, the standard requirements with regard to explosion protection are met.

A further preferred embodiment provides that in the sleeve-shaped body, a clamping ring between the sealing element and the fastening means may be provided. In a preferred embodiment, the clamping ring may be made of metal. In a further embodiment, the clamping ring may be made of plastic.

In this way, the clamping ring and, as a consequence, the sealing element is uniformly compressed by the fastening element and the sealing effect is ensured by the sealing element. Depending on the mechanical stress of the clamping ring can thus be made of different materials.

In a further embodiment, the invention provides that the connecting elements, the sealing element and the clamping ring can be arranged in the opening of the housing section and / or that the fastening means in the assembled state can be connected to the sleeve-shaped body and flange-like against the housing section in that the detachable plug connection can be arranged in a flameproof enclosure.

This compact design allows additional Material savings can be achieved and in addition an assembly even under very limited space conditions are made possible.

A further embodiment of the invention also provides that the second connection element can be permanently connected to the electrical line.

This also makes it possible to use prefabricated electrical lines that can be used during maintenance, replacement or repair work.

Preferably, the electrical line is encapsulated in such a way that the second connecting element is permanently connected to the electrical line.

In an advantageous development of the invention, the sleeve-shaped body may have a tool engagement surface.

The tool-engaging surface reinforces the sleeve-shaped body.

A further embodiment of the invention provides that the tool engagement surface can be arranged in a flange manner on the side facing away from the housing section of the equipment.

It can thus be made possible to mount the sleeve-shaped body in the housing section up to a definable length.

A further embodiment of the invention provides that the fastening means can be configured as a means for strain relief.

This results in the advantage that the connection between the electrical line and the fastener is protected against mechanical stress.

For the purposes of the invention, the term "housing section" can be understood to mean the housing directly surrounding the equipment. It may also be understood to mean the equipment surrounding covers of the resource housing, such as lids. The housing section ensures explosion protection against the equipment in any case.
For the purposes of the invention, the term "sleeve-shaped" is essentially an elongated hollow body, in particular a hollow-cylindrical body is to be understood, wherein the inner and outer diameter of the hollow cylinder may be designed differently and need not be continuous. Furthermore, the term "sleeve-shaped" any geometric body can be understood, which may be formed on the outside or inside peripheral n-sided.

The present invention is related to the explosion protection in particular the degree of protection "flameproof enclosure". The term "protection class 3" is familiar to the person skilled in the art. The explosion-proof cable bushing for pressure-resistant encapsulation in the classic sense has the task of enabling electrical connection without having to compromise on IP protection (International Protection).

Figur 1

eine Längsschnittansicht der erfindungsgemäßen lösbaren Steckverbindung im montierten Zustand.

Figur 2

eine Längsschnittansicht einer weiteren Ausführungsform der lösbaren Steckverbindung im montierten Zustand.

Hereinafter, the present invention will be described with reference to the accompanying drawings. Show it:

FIG. 1

a longitudinal sectional view of the releasable connector according to the invention in the assembled state.

FIG. 2

a longitudinal sectional view of another embodiment of the releasable connector in the assembled state.

In FIG. 1 the detachable connector 1 according to the invention is shown. With the detachable connector 1 is a electrical line 2 connected to a non-illustrated operating means 3. The operating means 3, which has a housing section 4, is in the FIG. 1 arranged on the left of this housing section 4.

In the housing section 4, a sleeve-shaped body 5 is detachably arranged. The sleeve-shaped body 5 projects out of the housing section 4 on the region facing away from the operating means 3.

Within the sleeve-shaped body 5, a first connecting element 6 and a second connecting element 7 are arranged. Both connecting elements 6, 7 have contact pins 8 and female contacts 9, with which an electrical contact between the two connecting elements 6, 7 is made possible. The first connecting element 6 is connected in a manner not shown with a resource 3 and the second connecting element with the electrical line 2. Thus, the operating means 3 is connected to the electrical line 2 in the case of connected connecting plugs 6, 7.

In the sleeve-shaped body 5, a sealing element 10 is sealingly arranged gap-free. The sealing element 10 is held or compressed by a clamping ring 11 by means of a fastening means 12 in its position. By an axial pressure also takes place a radial pressure, whereby the gap-free sealing effect according to the invention is provided. The sleeve-shaped body 5 has on the inner circumference side a bearing surface 13 against which the sealing element 10 is pressed axially and as a result of which the radial expansion of the sealing element 10 is made possible in order to provide the sealing effect. Thus, the releasable connector within the sleeve-shaped body 5 after introduction of the sealing element 10 in a flameproof enclosure, arranged according to the degree of protection "Ex d".

In an embodiment not shown, not the sleeve-shaped body 5 a bearing surface, but the first connecting element. 6

It can be provided that the sealing element 10, 110 can enable IP protection (International Protection) of the operating means 3, 103.

Furthermore, the invention can provide that the sealing element 10, 110 is formed as an O-ring.

The invention can provide that the sealing element 10, 110 IP protection (International Protection) and explosion protection, in particular the degree of protection "flameproof enclosure" can allow.

The sleeve-shaped body 5 has inner diameter side on different diameters. In the region of the housing section 4, the diameter of the sleeve-shaped body 5 corresponds approximately to the diameter of the opening of the housing section 4 minus the wall thickness of the sleeve-shaped body 5. In the region in which the sealing element 10 is arranged, an enlarged inner diameter is present. This inner diameter substantially corresponds to the outer diameter of the sealing element 10.

The sleeve-shaped body 5 has on the outer circumference a flange 14 which bears against the housing section 4. In the embodiment shown, the flange 14 is designed as a tool engagement surface 15. The outer diameter of the sleeve-shaped body 5 are designed differently. In the region of the housing section 4, the outer diameter of the sleeve-shaped body 5 essentially corresponds to that of the housing section 4. At the region of the housing section 4 facing away from the operating means 3, the sleeve-shaped body 5 has an enlarged outer diameter. As already mentioned, this outer diameter is also configured as a flange. In the further course decreases the outer diameter of the sleeve-shaped body 5, however, has a relation to the outer diameter in the region of the housing portion 4 further enlarged outer diameter.

Another embodiment is in FIG. 2 shown. With the releasable connector 101, an electrical line 102 is connected to a non-illustrated operating means 103. The operating means 103, which has a housing portion 104 is in the FIG. 2 arranged to the left of this housing portion 104.

In this embodiment, the sleeve-shaped body can also be considered as a housing portion 104.

Within the housing portion 104, a first connecting member 106 and a second connecting member 107 are arranged. Both connecting elements 106, 107 have contact pins 108 and contact sockets 109, with which an electrical contact between the two connecting elements 106, 107 is made possible. The first connecting element 106 is connected in a manner not shown with a resource 103 and the second connecting element 107 with the electrical line 102. Thus, the operating means 103 is connected to the electrical line 102 when the connecting plugs 106, 107 are connected.

In the housing portion 104, a sealing element 110 is sealingly arranged gap-free. The sealing element 110 is held or compressed by a clamping ring 111 by means of a fastening means 112 in its position. By an axial pressure also takes place a radial pressure, whereby the gap-free sealing effect according to the invention is provided. The housing portion 104 has on the inner circumference side a support surface 113, against which the sealing element 110 is pressed axially and as a result of which the radial expansion of the sealing element 110 is made possible in order to provide the sealing effect. Thus, the releasable connector 101 within the housing portion 104 after introduction of the sealing element 10 in a flameproof enclosure, arranged according to the degree of protection "Ex d".

In the present invention, an electrical connection of a resource 3, 103 is realized within a flameproof enclosure. Such an electrical connection is realized within the sleeve-shaped body 5. The flameproof enclosure takes place inside the sleeve-shaped body 5.

In the illustrated embodiment, the fastener 112 has a flange 114 and a tool engagement surface 115.

The housing portion 104 has different diameters. The diameter decreases towards the resource. In the area of the bearing surface 113, the diameter of the housing section corresponds approximately to the outer diameter of the sealing element 110.

LIST OF REFERENCE NUMBERS

1, 101

detachable plug connection

2, 102

electrical line

3, 103

resources

4, 104

housing section

5

sleeve-shaped body

6, 105

first connecting element

7, 107

second connecting element

8, 108

contact pins

9, 109

Contact jacks

10, 110

sealing element

11, 111

clamping ring

12, 112

fastener

13, 113

bearing surface

14, 114

flange

15, 115

Tool engagement surface

Claims (14)

Detachable plug connection (1, 101) for connecting at least one electrical line (2, 102) to an operating means (3, 103), for example a solenoid valve or an electric motor, comprising a first connecting element (6, 106), for example a connecting bushing and a second one Connecting element (7, 107), for example, a connector and a sleeve-shaped body (5), - Wherein both connecting elements (6, 7, 106, 107) are detachably connectable to each other and wherein the first connecting element (106) is connected to the operating means (103) and the second connecting element (107) is connected to the at least one electrical line (102), characterized in that
the connecting elements (6, 7, 106, 107) are arranged in the sleeve-shaped body (5) between the operating means (103) and at least one sealing element (110), wherein the at least one sealing element (110) is the plug connection (101) of the connecting elements (110). 6, 7, 106, 107) in the mounted state relative to the sleeve-shaped body (5) is arranged in such a gap-free sealing, that the connector (101) is arranged in a flameproof enclosure. Detachable plug connection (101) according to claim 1, characterized in that the sealing element (110) made of elastic material and preferably made of rubber. Detachable plug connection (1, 101) according to claim 1 or 2, characterized in that the sleeve-shaped body (5) with a housing portion (4, 104) of the operating means (3, 103) releasably connected or at least partially by a recess in this housing portion ( 104) is formed. Detachable plug connection (1) according to one of the preceding Claims, characterized in that the sleeve-shaped body (5) is preferably non-detachably connected to the first connecting element (6, 106). Detachable plug connection (1, 101) according to one of the preceding claims, characterized in that both connecting elements (6, 7, 106, 107) are arranged in the assembled state within the opening of the housing section (4, 104). Detachable plug-in connection (1, 101) according to one of the preceding claims, characterized in that the sleeve-shaped body (5) at its to the operating means (3, 103) facing the end for attachment in the housing portion (4, 104) has constant diameter or conical diameter. Detachable plug connection (1, 101) according to one of the preceding claims, characterized in that in the sleeve-shaped body (5) on the inner peripheral side a bearing surface (13, 113) for supporting the sealing element (10, 110) is provided. Detachable plug connection (1, 101) according to one of the preceding claims, characterized in that on the sleeve-shaped body (5) a fastening means (12, 112) is detachably mounted, as a result of which the sealing element (10, 110) is compressed directly or indirectly , Detachable plug connection (1, 110) according to one of the preceding claims, characterized in that the fastening means (12, 112) has an internal or external thread. Detachable plug connection (1, 101) according to one of the preceding claims, characterized in that in the sleeve-shaped body (5) a clamping ring (11, 111) between the sealing element (10, 110) and the fastening means (12, 112) is provided. Detachable plug connection (1, 101) according to one of the preceding claims, characterized in that the connecting elements (6, 7, 106, 107), the sealing element (10, 110) and the clamping ring (11, 111) in the opening of the housing portion ( 4, 104) are arranged and / or that the fastening means (12, 112) connected in the assembled state with the sleeve-shaped body (5) and on the housing portion (4, 104) is flange-fitting, wherein the releasable connector (1, 101) is arranged in a flameproof enclosure. Detachable plug connection (1, 101) according to one of the preceding claims, characterized in that the second connecting element (7, 107) is inseparably connected to the electrical line (2, 102). Detachable plug connection (1, 101) according to one of the preceding claims, characterized in that the sleeve-shaped body (5) has a tool engagement surface (14, 114). Detachable plug connection (1, 101) according to one of the preceding claims, characterized in that the tool engagement surface (14, 114) is arranged in the manner of a flange on the side facing away from the housing section (4, 104) of the operating means (3, 103).

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