WO2014180616A1

WO2014180616A1 - Housing for an electrical module and method for assembly

Info

Publication number: WO2014180616A1
Application number: PCT/EP2014/057108
Authority: WO
Inventors: Sebastian Schäfer; Frank Brokmann
Original assignee: Phoenix Contact Gmbh & Co. Kg
Priority date: 2013-05-08
Filing date: 2014-04-09
Publication date: 2014-11-13
Also published as: DE202013012371U1; CN205694025U; DE102013007909A1

Abstract

The invention relates to a housing (1) for a micro-inverter (50), having a wall (2) that separates an inside (3) from an outside (4). A cable feedthrough (5) is provided in the wall (2), by means of which a cable (6) is fed through the wall (2) from the outside (4) to the inside (3). The cable feedthrough (5) has a bushing (7) on the inside (3), through which the cable (6) is fed. A prestressed and/or elastic sealing element (8) is provided, which fits in a leaktight manner around a longitudinal section (9) of the bushing (6) and an adjoining longitudinal section (10) of the cable (6) arranged on the inside (3).

Description

Housing for an electrical unit

and method of assembly

The present invention relates to a housing for an elec- fresh assembly and in particular for a micro-inverter. Housing for electrical components must be carried out in particular during outdoor use regularly against water tight. If a cable to be connected is passed through a wall of the housing, the connection point must be

be sealed in order to maintain the required water resistance. Furthermore, a sufficient strain relief is regularly required so that the cable is secured from the housing before moving out. Core requirements for the cable bushing through housings with electrical components such as micro-inverters are therefore always the tightness against water and the

Resistance to the extension of the cable from the housing or the micro-inverter. There are various approaches to achieve the required tightness. For example, a plastic ^¬ element is molded onto the leading out of the housing cable, which protrudes through the housing wall to the outside to prevent the ingress of moisture between the cable and the overmolded plastic part. A shrink tube can be previously over the outer cable end and the

overmolded plastic part are pushed, which contracts by heat and causes a seal between the cable and plastic part. Basically, such a system initially ensures reliable protection against ingress of water. In addition, the shrink tube acts as an elastic strain relief. However, it has been found that such a solution does not always permanently meet the requirements.

If the housing is outdoors and exposed to environmental conditions, even natural UV radiation can cause the shrink tubing to age, causing its elastic properties to diminish over time. This leads to embrittlement. In addition, mechanical stresses occur, for example by bending the

Cable, this leads to an increased load, which can be exacerbated by frost and water.

This can cause cracks or other leaks that allow water to enter the housing.

To reduce problems due to aging and mechanical stress, other components can be used, such. As a crimp sleeve or other devices that surround the shrink tube or other sealing elements and thus protect against environmental influences. The disadvantage of this is

However, the increased through the components effort and also the significantly increased effort during installation.

It is therefore an object of the present invention, a housing for an electrical unit and in particular for a micro-inverter and a method for mounting to

To provide, which with less effort, even when used outdoors a high tightness against ingress of water can be guaranteed.

This object is achieved by a housing for a

electrical unit with the features of claim 1 and by an electrical device with the features of claim 13 and by a method with the features of claim 14. Preferred embodiments of the invention are the subject the dependent claims. Further advantages and features of

Present invention will become apparent from the description of the embodiments. An inventive housing for an electrical unit and in particular for a micro-inverter has at least one wall which separates an inner side from an outer side. It is at least one cable entry at the

Wall provided, wherein at the cable entry a cable from the outside through the wall to the inside ge ^¬ leads. The cable bushing has on the inside a sleeve through which the cable is performed.

At least one prestressed and / or elastic ^sealing element spans at least one longitudinal section of the sleeve and in particular directly adjoining it

Longitudinal section of the inside of the wall

arranged tight cable.

The housing according to the invention has many advantages. A considerable advan- tage of the housing according to the invention for an electrical assembly is that the cable ^¬ guide a having on the inside of the housing in particular of the grommet directly inwardly projecting sleeve through which the cable is carried out and on which a sealing element, the cable and the sleeve tightly wrapped.

This construction will make that or at least one

Sealing element laid from outside the housing into the interior, so that the prestressed and / or elastic

Sealing element is not arranged outside of the housing in the environment or outdoors, but within the housing on the inside of the wall. This will cause the sleeve and / or the sealing element reliably against harmful

Protected against environmental influences. UV radiation, for example, can not impinge on the sealing element and to a

Cause embrittlement or aging of the sealing element.

Characterized in that the housing is sealed, a skull ston ^¬ Licher influence by water and in particular water freezing is prevented by the sealing member. Overall, a housing for an electrical unit is available

provided, which has a durable and reliable seal the cable entry against ingress of water.

Another advantage of the housing according to the invention is that the cable bushing with the sealing element continues to provide a reliable pull-out protection. ^¬ aging phenomena due to changing bending movements of the cable are largely prevented since the sealing element

Inside of the housing is added where movements of the

Cable are suppressed as much as possible, even if on the outside of the housing, the cable connected there is moved back and forth.

The invention thus makes it possible to provide an electrical device, such as a micro-inverter with a housing and an interior, which is separated from one or the environment by at least one wall.

At least one cable gland is on the wall

intended. At the cable gland, a cable is led from the environment through the wall into the interior or the interior of the housing. The cable bushing has a protruding into the interior of the housing from the wall or the cable bushing sleeve through which the cable

is performed. At least one in particular toughened and / or elastic sealing element surrounds at least a longitudinal portion of the sleeve and the cable arranged in the interior of the housing tightly. In all embodiments, it is preferred that the

Sealing element or at least one sealing element is configured hose-shaped. In particularly preferred embodiments, the sealing element has an adhesive coating at least on the inside of the sealing element. By a

Such adhesive coating is ensured during assembly reliable and secure adhesion of the sealing element to the cable and / or on the sleeve.

In all embodiments, it is preferred that the sleeve is in particular formed integrally with the cable feedthrough. In preferred embodiments, the sealing element comprises at least one shrink tube. The sealing element and / or at least one shrink tube is in particular

at least partially made of at least one polymeric

Material. In preferred embodiments, this is

Sealing element and / or the shrink tube at least

partly from at least one cross-linked polyethylene. In particular, the sealing element may consist of at least one material taken from a group of materials comprising polyolefins, polyvinylidene fluoride, fluoroelastomers, fluororubber, polyvinyl chloride and polytetrafluoroethene. Polyvinyl chloride can be abbreviated as PVDF and polyvinyl chloride as PVC and polytetrafluoroethene as PTFE. PTFE is also known under the trade name Teflon.

A shrink tube, which consists of one or more of the materials mentioned, has positive properties. The shrink tube consists in particular of plastic and contracts under the influence of heat. This ensures a reliable sealing of the cable with respect to the sleeve and thus with respect to the housing. The

Shrinkage can be different and depends on the specific conditions. The adhesive coating on the inside of the sealing element can in particular as

Hot glue should be designed so that when heating the

Shrink tubing of the hot melt adhesive is activated as an adhesive coating and allows a firm and / or tight bonding with the cable.

By such an adhesive coating a significant independence of the sealing system is achieved by the material of the jacket of the cable. In particular, in the case of radiant crosslinked material of the shrink tube, it may be difficult to achieve adhesion to the overmolded body, so that an adhesive coating promotes tightness significantly.

The sealing element is also used in particular as a pressure-loaded strain relief for the cable. Is pulled from the outside of the cable, the cable fixed inside the housing is subjected to a force to the outside, whereby the sealing element surrounding the cable end is subjected to pressure.

In preferred developments, the sleeve is provided integrally with the housing. The cable feedthrough then comprises the sleeve provided on the housing and at least one separate sealing element.

If the sleeve is manufactured in one piece with the housing, a particularly dense and simple design is made possible, in which leaks are reliably prevented. For example, the sleeve may be integrally injection molded together with the housing or otherwise

getting produced. It is possible that the sleeve consists of the same material as the housing. The sleeve can also consist of a different material, if z. B. a suitable injection molding method is used, in which also different materials can be processed during a casting process. In other embodiments, however, it is also preferred that the cable feedthrough is a separate component from the wall. This also allows pre-assembly of the cable to the cable gland. The cable feedthrough can have at least one groove on which the cable feedthrough can be received or received on the wall. As a result, a positive reception of the cable bushing on the wall of the housing is made possible. For sealing, an adhesive material or other sealing material can be used.

Preferably, the grommet is formed as a body molded onto the cable. Then the cable is overmolded during production, so that the cable gland is firmly connected to the cable. For further sealing is the sealing element, which is in particular designed as a shrink ^¬ hose and the sleeve of the cable gland seals permanently sealed against the cable. Preferably, the cable feedthrough is at least

partially and in particular at least substantially

completely made of a thermoplastic material. In particular, the body of the cable gland

completely made of a thermoplastic material.

Between the cable and the sleeve, a sealing material may be provided. For example, a silicone-containing material may be provided between the cable and the sleeve to prevent the entry of moisture from the outside of the

Housing in a possibly occurring between the cable and the cable gland gap as much as possible

prevent.

The electrical device according to the invention is designed in particular as a micro-inverter or the like and has a housing, as described above.

The inventive method for sealingly attaching a cable to a wall of a housing for an electrical unit is performed so that on the wall of the housing, a cable bushing with a sleeve and a cable passing through the sleeve is arranged such that the sleeve on the inside of the wall protrudes. The sleeve and the cable are on the inside of the wall at least partially surrounded by a prestressed and / or elastic sealing element.

The method according to the invention also has many advantages, since it allows a simple and permanently tight assembly.

Preferably, the sealing element is shrunk. The

Cable gland can be molded onto the cable. The invention is particularly suitable for use in the solar sector, as it provides a reliable function cost-effective. Further advantages and features of the present invention will become apparent from the description of the embodiments, which are explained below with reference to the accompanying figures. In the figures show:

Fig. 1 is a highly schematic cross section of a

housing according to the invention;

Fig. 2 is a perspective schematic view of a

Part of a housing according to the invention with a cable bushing received thereon;

Fig. 3 is a highly schematic cross section of

Representation of Fig. 2;

4 shows the individual parts of the housing according to FIG. 2; and

Fig. 5 is a highly schematic cross section of a

Variant of a housing according to the invention.

With reference to FIGS. 1 to 4, a first exemplary embodiment of a housing 1 according to the invention for an electrical unit 20 and in particular for a micro-inverter 50 will be explained below. In the case 1 of Fig. 1, a side wall is removed or for the drawing

cut away, so that the interior 13 of the housing. 1 is recognizable. In the assembled state, the housing 1 is waterproof and can also be made gas-tight.

The housing 1 and the micro-inverter 50 are suitable

especially good for use in the field of photovoltaics. The housing is permanently sealed and performs the outdoor use suitable. The ingress of moisture can last for long

Periods are prevented. There are only a few and

Simple components needed and the assembly is simple and inexpensive.

Inside the housing 1, an electrical unit 20 is provided, which via individual wires with a cable. 6

connected is. The cable can have several individually insulated wires. On a wall 2 of the housing 1, a cable ^¬ execution 5 is arranged, through which the cable 6 is led out of the interior 13 in the environment 14. On the inner side 3 of the wall 2, the cable bushing 5 comprises a sleeve 7 extending from the inner side 3 into the inner space 13, through which the cable 6 is passed.

An end portion of the cable 6 and an end portion of the sleeve 7 are surrounded by a sealing element 8. The sealing element 8 reliably prevents the ingress of water and moisture from the environment 14 into the interior 13.

The cable bushing 5 with the sealing element 8 also serves as a strain relief 15 for the cable 6. If pulled from the outside of the cable 6, the sealing element is pressurized

loaded, which can even enhance the sealing effect. Fig. 2 shows a perspective view of a part of the housing 1, in which a wall 2 is shown with the cable gland. Since a plurality of walls 2 have been completely or partially cut away in the representation according to FIG. 2, the interior 13 of the housing 1 can be seen. The grommet 5 has grooves 16, projecting into the parts of the wall 2, so that the grommet 5 is positively received on the wall 2. In the interior 13 of the housing 1, the sleeve 7 extends from the inside 3 of the wall 2 from inside. The cable 6 is passed through the interior of the grommet 5. At a longitudinal portion 9 of the sleeve and a directly adjoining longitudinal portion 10 of the cable, the sleeve 7 and the cable 6 are surrounded by a sealing element 8, which is designed here as a shrink tube 18 or includes such. The cable feedthrough 5 is formed here as an overmolded body 17, which was produced by overmolding the cable 6. The shrink tube 18 ensures a dense

Connection between the outer surface of the cable 6 and the sleeve 7 and thus the cable duct 5, whereby the inner space 13 of the housing 1 is reliably and permanently protected from the entry of moisture.

Fig. 4 shows in a kind of an exploded view of the individual components.

It is possible that the grommet 5 is made by overmolding of the cable 6. It is also possible that the grommet 5 and the body 17 as a separate Component is first produced. Subsequently, the cable 6 can be pushed through the cable bushing 5, so that the cable 6 exits on the inside 3 from the opening provided there ^¬ seen. A shrink tube 18 can be pushed over the end of the cable 6 and the sleeve 7. In particular, by heat, the shrink tube is shrunk, so that a firm and tight connection between the cable 6 and the sleeve 7 is provided.

FIG. 5 shows a modified variant of a housing 1, in which case the shrinking tube 18 has an adhesive coating 11 on the inside as a sealing element 8. As a result, a particularly tight connection between the cable 6 and the sealing element 8 can be achieved.

Furthermore, in the exemplary embodiment according to FIG. 5, a sealing material 19 can be seen between the cable 6 and the cable feedthrough 5, which comprises, for example, silicone. As a result, a largely tight connection between the cable 6 and the interior of the cable feedthrough 5 can be achieved. The inward final and tight barrier is ensured by the sealing element 8.

It is possible and preferable that even in the execution example according to the Figures 1 to 4 an adhesive coating 11 on the inside of the sealing member 8 and the shrink ^¬ hose 18 and / or a sealing material are provided 19th

Overall, the housing 1 according to the invention and the electrical device 50 according to the invention allow a permanently sealed connection of a cable, so that a longer reliable operation of such an electrical device 50 is made possible. Even when used outdoors, a permanent Reliable function can be ensured because the sealing element 8 is provided inside the housing 1 and thus protected from the environmental conditions is added. Mechanical stress caused by, for example, bending of the connection cable has practically no effect on the

Inside arranged sealing element 8. Thereby can

Problems caused by embrittlement are avoided. The loss of sealing properties can be virtually eliminated.

The accommodated in the interior of the housing shrink tube 18 is against all occurring in daily operation

Loads well protected. The long-term properties of a housing 1 according to the invention become

significantly improved.

At the same time an economically advantageous embodiment is made possible by the invention. The provided inside the housing shrink tube 18 causes on the one hand an effective seal and on the other hand is a

advantageous strain relief provided without additional components such. B. a crimp sleeve or other elastomeric components must be mounted in advance and then encapsulated.

It is preferred to a body to the line 17 ^¬ squirt, whose outer contour forms the cable guide 5 and is adapted to the wall 2 of the housing. 1 At the appropriate mounting of a superiors in the interior of the housing 1 provided a tubular sealing element, and in particular cylindrical element is integrally formed on the cable guide ^¬ inside. Then the sealing element can be applied and a shrink tubing are shrunk in particular, so that the penetration of water is reliably prevented.

In particular, for the solar sector, in which electrical equipment and housing must be mounted with electrical components in the outdoor area, the invention offers great advantages. The housing according to the invention is easy to assemble and can be inexpensively manufactured and assembled.

Reference sign list

Housing 1

Wall 2 inside 3

Outside 4

Cable gland 5

Cable 6

Sleeve 7 sealing element 8

Longitudinal section of the sleeve 9

Longitudinal section of the cable 10th

Adhesive coating 11

Inner side of the sealing element 12 interior 13

Surroundings 14

Strain relief 15

Groove 16

Body 17 shrink tube 18

Sealing material 19

Assembly 20

Electrical device, micro-inverter 50

Claims

claims

1. housing (1) for an electrical assembly (20) and in particular for a micro-inverter (50) having a wall (2), which has an inner side (3) of a

Outside (4) separates, and with at least one

Cable bushing (5) on the wall (2), wherein at the cable bushing (5) a cable (6) from the outside (4) through the wall (2) to the inside (3) is guided,

characterized,

in that the cable feedthrough (5) has on the inside (3) a sleeve (7) through which the cable (6) is made, and in that at least one prestressed and / or elastic sealing element (8) at least one longitudinal section (9) of the sleeve (6) and an adjoining longitudinal section (10) of the on

Inside (3) arranged cable (6) tightly spanned.

2. Housing (1) according to claim 1, wherein the sealing element (8) is designed hose-shaped.

3. Housing (1) according to claim 2, wherein the sealing element (8) has an adhesive coating (11) on the inside (12).

4. Housing (1) according to one of the preceding claims, wherein the sealing element (8) at least one

Shrink tube (18) comprises, which consists in particular at least partially of at least one polymeric material.

5. housing (1) according to the preceding claim, wherein the shrink tube (18) at least partially networked! Polyethylene exists.

6. Housing (1) according to one of the preceding claims, wherein the sealing element (8) is a pressure-loaded strain relief (15) for the cable (6).

7. housing (1) according to any one of the preceding claims, wherein the sleeve (7) is integral with the housing (1) is provided.

8. Housing (1) according to one of the preceding claims 1 to 6, wherein the cable bushing (5) is one of the wall (2) separate component.

9. Housing (1) according to any one of the preceding claims, wherein the cable gland (5) has at least one groove (16) on which the cable gland (5) on the wall (2) can be accommodated.

10. Housing (1) according to any one of the preceding claims, wherein the cable bushing (5) is formed as a to the cable (6) molded body (17).

11. Housing (1) according to one of the preceding claims, wherein the cable bushing (5) consists at least partially of a thermoplastic material.

12. Housing (1) according to any one of the preceding claims, wherein between the cable (6) and the sleeve (7) a sealing material (19) is provided.

13. Electrical device (50), in particular micro-inverter, with a housing (1) according to one of the preceding claims.

14. Method for sealingly attaching a cable (6)

a wall (2) of a housing (1) for a

electrical assembly (20), wherein on the wall (2) a cable bushing (5) with a sleeve (7) and through the sleeve (7) leading cable (6) is arranged so that the sleeve (7) on the inside (3) protruding from the wall (2) and wherein the sleeve (7) and the cable (6) are at least partially surrounded by a prestressed and / or elastic sealing element (8).

15. The method according to the preceding claim, wherein the sealing element (8) is shrunk.

16. Method according to one of the two preceding

Claims, wherein the cable gland (5) is molded onto the cable (6).