EP2593989B1 - Cable connection, in particular for photovoltaic systems - Google Patents

Description

The invention relates to a cable connection, in particular for use in photovoltaic systems. The cable connection according to the invention is used in particular for the electrical connection of individual solar modules and is suitable for safely and permanently transmitting the corresponding current strengths and voltages.

Photovoltaic systems are designed for years of service life of 20 years and more and are often mounted on roofs of houses and industrial plants. They contribute significantly to electricity production. The amount of electricity produced is regularly fed into the public grid and is thus generally available. Even smaller plants covering a few tens of square meters can produce 10,000 kWh and more of electricity per year.

The solar modules mounted on the roofs are installed during assembly e.g. electrically connected to one another via plug connections.

For such applications plug connections and cable connections for connecting solar modules have become known. The known cable connections work reliably and permanently. As photovoltaic installations on roofs and the like become more widespread, the assemblies do not always do business specialized in electrical wiring but increasingly companies that have focused on mounting photovoltaic modules on roofs.

On roofs, installation is often subject to difficult conditions, as many roofs are inclined.

The failure of a single cable connection can lead to a considerable maintenance effort, since all cable connections may have to be examined to find the defective cable connection. Increased maintenance required by the cable connections can be detrimental to the business. That is why it is important to be able to guarantee a long and reliable service life.

Special tools for a wide variety of connections are often not available on site. Therefore, it is advantageous if the installation work to be carried out with relatively little special electrical tool can get along, even if the connection cable of individual solar modules must be flexibly extended or freely assembled to adapt to the structural conditions.

The solar modules and the associated cable connections are exposed on the roofs to the prevailing ambient conditions. This means that in summer the cable connections can be exposed to high temperatures of over 40 degrees C and in winter temperatures far below zero degrees C, while at the same time moisture in the form of moisture and / or snow affect the cable connections.

Under these highly fluctuating conditions, the cable connections must make long-term and reliable contact over the long planned operating lives.

A cable connection according to the preamble of the main claim is from the document DE 10 2006 029 075 A1 known.

It is therefore the object of the present invention to provide an electrical cable connection, in particular for use in photovoltaic systems, which permanently produces reliable electrical contact and is relatively easy to assemble.

This object is achieved by the cable connection with the features of claim 1. Preferred developments of the invention are the subject of the dependent claims. Further advantages and features emerge from the exemplary embodiment.

An inventive electrical cable connection, in particular for solar cables to photovoltaic systems, comprises at least one contact housing and at least one connection housing. The connection housing can be connected to the contact housing and the connection housing is provided for receiving at least one cable with a conductor that can be assembled freely. The connection housing serves to accommodate the cable to be connected with the conductor. At the contact housing, a contact needle for contacting the conductor of the cable to be connected is arranged. A spring device is provided to surround the conductor and the contact needle radially at least partially and compress resiliently.

The cable connection according to the invention has many advantages. A considerable advantage of the cable connection according to the invention is that the spring device radially surrounds the conductor and the contact needle and compresses them in a spring-elastic manner. As a result, even after long and long periods of operation a reliable electrical contact between the contact pin and the connected conductor allows.

A further advantage is that a cable which can be freely assembled can be accommodated on the connection housing, whereby flexible mounting and flexible extension of connection cables for solar modules is possible. In addition, the cable connection can be made physically small.

The spring device is designed in particular as a separate part and surrounds the conductor and the contact needle radially in the connected state. The spring device need not completely surround the contact needle and the conductor radially, but it is also sufficient if the spring device pushes the contact needle and the conductor of two or more sides against each other to produce a reliable and permanent contact.

In a preferred embodiment, the spring device surrounds the insulating layer of the cable and presses over the insulating layer on the conductor contained therein and the contact needle inserted therein to exert permanent pressure on the conductor and the contact needle. In this case, the insulating layer can serve in particular as a spring-elastic memory.

Such a design uses the elastic properties of the insulating layer to permanently exert pressure on the electrical connection of the conductor with the contact needle. Settlement phenomena and the like are compensated by the elastic action of the spring device and the insulating layer, so that a permanently reliable contact is made possible.

In a further preferred embodiment, the spring device surrounds the stripped conductor, in particular directly. A small radial gap may be provided in the unconnected state between the stripped conductor and the spring means. Such a radial gap between the conductor and spring device in the unconnected state ensures that the insertion of the stripped conductor into the spring device is easily possible.

When the contact needle is inserted into the conductor, the radial volume of the conductor increases with the inserted contact needle. As a result, the radial gap is overcome and the conductor with the inserted contact needle is pressed radially against the spring device, so that the spring device permanently exerts pressure on the conductor with the inserted contact needle.

Such a configuration, in which the spring device surrounds the stripped conductor, allows particularly long and reliable contact times, since the spring device is directly in contact with the conductor and possibly the contact needle and thus flow of the insulating layer from the spring device out is not possible. Depending on the insulating material used, the softer insulating layer can be forced out by the close connection between the spring device and conductor or contact needle, which can possibly reduce the contact pressure. With suitable materials and dimensions this can be avoided.

If the insulation is used as a spring-loaded storage, the insulation in addition to the elastic effect and a sealing function take over, as are reliably closed by the applied pressure small and smallest gaps, whereby a particularly high density against penetrating moisture can be achieved.

If the insulating layer of the cable is at least partially or completely removed before the connection and the spring device surrounds the conductor of the cable directly, an additional sealing compound or sealing device may be provided around the spring device in order to more reliably prevent the penetration of moisture.

In all embodiments, it is particularly preferred that the spring device can be installed in the connection housing. In particular, the spring device is installed in the connection housing and received there preferably captive. A captive recording of the spring device allows a particularly simple and reliable installation, since the fitter does not have to pay attention to whether the spring device is inserted into the terminal housing or not.

In preferred embodiments, the spring device comprises at least one spring sleeve. The spring sleeve preferably has a cylindrical receiving area for the conductor of the cable. Optionally, the spring sleeve may have a funnel-shaped insertion region, which prevents a nudging of the spring sleeve during insertion of the conductor.

The conductor, which consists in particular of a plurality of wires, can in a spring sleeve with a slightly larger inner diameter or a funnel-shaped Insertion reliably and reproducibly inserted into the spring sleeve, without the individual wires on edges or the like nudge and bend.

Preferably, the spring device is designed slotted. It is possible, for example, that parallel to the axis of the spring sleeve, the spring sleeve has a slot, whereby the spring sleeve has good elastic and resilient properties. It is possible for the slit ends to overlap so that the spring sleeve extends in a spiral around a received conductor. But it is also possible that the slot ends abut each other or have a certain distance from each other.

Particularly preferred is a helical slot which not only extends in the axial direction but spirally extends around the spring sleeve. This prevents even more reliable that individual wires of the conductor are forced out of the spring sleeve to the outside, whereby the pressing force of the spring sleeve would sink to the head and the contact needle received therein.

Particularly preferably, the spring device is at least partially made of a metal. In particular, the spring device may consist of a resilient metal and in particular of spring steel.

It is possible and preferred, however, that the spring device consists of a plastic. For example, a fiber composite material is possible.

It is also possible that the spring device consists of a viscoelastic plastic. In the case of a viscoelastic spring device, either an outer sleeve or, for example, the connection housing itself applies the required counterforce in order to apply the necessary spring force when the contact needle is inserted. A viscoelastic spring device concentrically surrounding the conductor with the contact needle received thereon, with a sleeve again concentrically disposed around it or the concentrically provided connector housing can absorb high forces, as the force is applied radially into the sleeve or into the connector housing and there the spring sleeve or the connector housing absorbs and dissipates this force along the circumference.

In all embodiments, a thread is arranged on the contact housing, which is intended to cooperate with a provided on the terminal housing thread to introduce the contact pin defined from the front into the conductor of the cable when screwing the contact housing with the terminal housing. In this case, the contact housing has an internal thread and the connection housing has an external thread. The screwing movement presses the contact needle into the conductor. Due to the thread pitch, a relatively small rotational force produces a high axial insertion force of the contact needle into the conductor of the connection cable. At the same time a defined immersion in the conductor is ensured by the contact needle, which ensures a high current transmitting contact surface, whereby permanently high currents at high applied voltages can be transmitted.

At the same time can be realized by the chosen construction, a small-sized cable connection whose outer diameter is smaller than three or four times the outer diameter of a solar cable to be connected. Thereby, the cable connection can also be laid in narrow channels, profiles and the like, whereby a particularly flexible application of the cable connection for the connection of solar modules of a photovoltaic system is made possible.

Further advantages and features of the present invention will become apparent from the embodiments, which will be explained with reference to the accompanying figures below.

Fig. 1

eine schematische Darstellung einer Fotovoltaikanlage, deren Module über einen erfindungsgemäßen Kabelanschluss verbunden sind;

Fig. 2

den Kabelanschluss nach Fig. 1 im verbundenen Zustand;

Fig. 3

den Kabelanschluss gemäß Fig. 2 beim Herstellen und beim Lösen der Verbindung;

Fig. 4

den Kabelanschluss gemäß Fig. 2 in einem teilweise dargestellten Querschnitt im unverbundenen Zustand;

Fig. 5

eine schematische Darstellung einer perspektivischen Ansicht beim Eindringen der Kontaktnadel in den Leiter;

Fig. 6

die Kontaktnadel und die Federhülse des Kabelanschlusses nach Fig. 5;

Fig. 7

einen schematisierten Querschnitt eines den Kabelanschlusses vor dem Eintauchen der Kontaktnadel;

Fig. 8

einen Kabelanschluss im verbundenen Zustand im Querschnitt; und

Fig. 9

eine weitere Ausführungsform eines den Kabelanschlusses in einem schematischen Querschnitt vor dem Eintauchen der Kontaktnadel.

In the figures show:

Fig. 1

a schematic representation of a photovoltaic system whose modules are connected via a cable connection according to the invention;

Fig. 2

the cable connection after Fig. 1 in the connected state;

Fig. 3

the cable connection according to Fig. 2 when making and breaking the connection;

Fig. 4

the cable connection according to Fig. 2 in a partially illustrated cross-section in the unconnected state;

Fig. 5

a schematic representation of a perspective view of the penetration of the contact needle in the head;

Fig. 6

the contact needle and the spring sleeve of the cable connection to Fig. 5 ;

Fig. 7

a schematic cross-section of the cable connection before immersing the contact needle;

Fig. 8

a cable connection in the connected state in cross section; and

Fig. 9

a further embodiment of the cable connection in a schematic cross section before immersing the contact needle.

In Fig. 1 is a highly schematic view of a photovoltaic system 100 shown here in the simple example, three solar modules 101, 102 and 103, which are equipped with photovoltaic cells not shown in detail to convert incident sunlight into electricity.

The individual solar modules 101 to 103 of the photovoltaic system 100 are connected to each other via cable 4 designed as a solar cable 5 in order to produce the necessary electrical connection.

The solar cable 5 carry the generated electrical power, but can also be additionally applied with control signals or sensor signals in order to control the photovoltaic system 100 suitable.

At light shafts, roofs, windows or other structural features and conditions, the normal distance of a solar module 102 to a solar module 103 changes.

A greater distance of the solar modules 102 and 103 must be bridged over an extension of the connecting cable 4. Since such photovoltaic installations are often done on sloping roof surfaces and there is not always every tool at hand when mounting there, a simple installation without special tools offers significant advantages.

Moreover, it is advantageous if the electrical cable connection 1 is designed to be physically small in order to be able to be performed by profiles, cable ducts or other small gaps.

In this case, it is possible for the cable connection 1 to be connected on one side to a freely configurable cable 4 or on both sides to freely connectable cables 4. In a two-sided connection option, in particular a symmetrical structure is advantageous.

Fig. 2 shows the cable connection 1 in a perspective view in the connection state 18, in which the contact housing 2 is connected to the terminal housing 3. Not shown here is the connection cable 4 shown as a solar cable 5, which emerges from the connection housing 3.

Fig. 3 shows the cable connection 1 in a perspective view, wherein the contact housing 2 and the terminal housing 3 are partially released from each other by twisting against each other or when establishing the connection.

Fig. 4 shows a partially sectioned schematic representation of the cable connection 1 prior to establishing the connection in the open state 20th

In the connection housing 3, a cable 4 which can be freely assembled has been inserted so far that the cable 4 or the conductor 6 abuts against the entrance surface 38. The connection housing 3 is designed as a hollow screw and has an external thread 17, which is intended to be screwed into an internal thread 16 of the contact housing 2.

Centrally in the hollow cylindrical receiving portion of the contact housing 2, a contact needle 7 is arranged, which defines defined in the manufacture of the compound in the conductor 6 of the recorded on the terminal housing 3 cable 4 axially from the front. By a number of revolutions, which may be, for example, between three and ten, depending on the application, the contact needle 7 is defined over virtually their full length or at least a substantial portion thereof inserted into the conductor 6 of the cable 4, so that the contact needle 7möglichst centric in the Conductor 6 is arranged and thus can produce a high contact area to the conductor 6.

On the connection housing 3, a non-return device 19 is provided, which secures a introduced into the hollow cylindrical connector housing cable 4 against being pushed back when the contact needle 7 enters the high penetration force axially from the front into the inlet surface 38 of the connection housing 3. Upon entry and in particular with increasing entry, the contact needle 7 spreads so that the axial force on the inserted cable 4 increases. At the same time, the radial pressure increases because the conductor 6 or its cores 15 spread radially and exert pressure to the outside.

Fig. 5 shows a schematic perspective view in which individual parts have been omitted to facilitate the overview. Clearly visible is the dipping into the conductor 6 contact needle 7. The conductor 6 is surrounded by a spring means 8 here. The insulating layer 13 of the connecting cable 4 has been removed via a stripped region 11, so that the spring sleeve 9 directly surrounds the stripped conductor 10.

The spring device 8 embodied here as a spring sleeve 9 has a helical slot 21 which ensures high elasticity of the spring sleeve 9 made here of an elastic metal. The annular shaped slot 21 reliably prevents individual wires 15 of the conductor 6 from passing through the slot to the outside.

It is also possible to provide an axially executed slot 21. Optionally, however, can then pass through the slot 21, a core 15 of the conductor 6 radially outward. This must be taken into account in the design, so that the remaining pressure is still sufficient to ensure the connection safely.

It is also possible that the spring device 9 is designed as a spiral spring whose individual turns are close to each other or spaced from each other. Such a spring device 9 also enables the application of the required force to a conductor arranged therein when a contact needle is inserted.

Fig. 6 shows the contact sleeve 9 of Fig. 5 with a schematically inserted contact needle 7, to a possible To show sizing. Here, a spiral annular slot 21 is provided in the contact sleeve 9.

Fig. 7 shows a schematic representation of a terminal housing 3 with a recorded therein cable 4, which has a stripped portion 11 via a stripped conductor 10. The individual wires 15 of the conductor 6 are here over the length of the stripped area 11 surrounded by a spring device 8 in the form of, for example, a spring sleeve 9. It is in the open state 20, as in Fig. 7 is shown, a small radial gap between the inner diameter of the spring sleeve 9 and the outer diameter of the conductor 6 with the bundle of wires 15 before. The radial distance may for example be between 5 and 25% of the diameter of the conductor. In any case, the radial distance is such that after immersing a contact needle 7 in the conductor 6, a radial pressure is applied from the contact needle 7 via the conductor 6 on the spring sleeve 9, so that, for example, provided with an axial slot or a ring slot 21 Spring sleeve 9 radially elastically expands and transmits a corresponding spring force on the conductor 6 and the contact needle 7.

Preferably, the spring device 8 or spring sleeve 9 in the exemplary embodiment Fig. 7 made of metal. But it is also possible that the spring device 8 consists of an example viscoelastic plastic. By inserting the contact needle 7 into the conductor 6, the radial volume is increased there, so that the pressure is transmitted to the outside on the viscoelastic spring device. The here viscoelastic spring device 8 is characterized by the spring device. 8 surrounding terminal housing 3 in its radial extension, so that a corresponding contact force on the conductor 6 and the contact needle 7 arranged therein is exercised.

The outer diameter 35 of the stripped conductor 10 is preferably between twenty and seventy-five percent of the outer diameter 33 of the cable 4. The outer diameter 33 of the cable 4 is preferably in a range between thirty-three and sixty-six percent or more of the outer diameter 32 of the cable terminal 1, so that a smaller Cable connection 1 is possible.

If the spring device 8 in the exemplary embodiment Fig. 7 formed by a metal part, a radially particularly small-sized cable connection 1 can be realized, as well as by a thin radial spring sleeve 9 high elastic forces on the conductor 6 and the contact needle 7 provided therein are transferable.

Fig. 8 shows a schematic sectional view of the cable connection 1 in the connection state 18, in which the connection housing 3 is screwed into the contact housing 2 and wherein the not visible here contact pin 7 is immersed in the conductor 6.

Fig. 8 shows two variants. On the one hand, it is possible that a spring device 8 of, for example, a viscoelastic material or a metal surrounds the insulating layer 13 of the connection cable 4 and exerts elastic pressure from the outside when the contact needle 7 penetrates into the conductor.

It is also possible for a stripped region 11 of the conductor 6 to be surrounded by a spring device 24, which may consist of a viscoelastic material or of metal in order to transmit corresponding forces from the conductor 6 and the contact needle 7. The spring device 8, which is provided radially further outward, can then consist, for example, of a viscoelastic material or the like and serve as a sealing device 28 of the cable connection 1, in order to allow a permanently secure connection protected from moisture.

Furthermore, in Fig. 8 the non-return device 19 shown, which may include a spring means 22 with spring tongues 23, which prevent sliding back after the insertion of the cable 4, since the spring tongues obliquely angled against the insulating layer 13 of the conductor 6 and in the attempt of retraction further into the insulating layer 13 of the cable 4 dig, while the outer ends of the spring tongues abut a shoulder 26 in the terminal housing 3.

Fig. 9 shows in a schematic cross section another structure of a cable connection 1, in which the cable 4 does not have to be stripped. The inserted into the terminal housing 3 cable 4 is surrounded by the insulating layer 13 radially from the spring means 8, which in turn may be formed here as a spring sleeve 9. In this case, the spring sleeve 9 may have a slot 21 or the insulating layer 13 completely surrounded. After insertion of the contact needle 7 in the conductor 6, the conductor 6 is radially expanded due to the additional volume of the contact needle 7, whereby the insulating layer 13 as resilient memory 14 is used. Even with mechanical settlement phenomena or the like, the resilient force of the insulating layer, which is supported by the surrounding spring means 8, sufficient to allow a permanently sealed and reliable connection.

Overall, the invention provides a reliable cable connection 1, which permanently and safely enables electrical contact between a connecting cable 4 and a contact needle 7 and is designed, for example, as a plug connection. The connection can transmit high currents at high voltages and can be operated maintenance-free over long periods of time. LIST OF REFERENCE NUMBERS Electrical cable connection 1 Contact housing 2 connection housing 3 electric wire 4 solar cable 5 ladder 6 Contact Adel 7 spring means 8th spring sleeve 9 Stripped conductor 10 Stripped area 11 funnel-shaped insertion area 12 insulating 13 Spring elastic memory 14 Vein 15 inner thread 16 external thread 17 connection state 18 Rear sliding safety 19 opened state 20 slot 21 spring means 22 spring tongue 23 spring means 24 paragraph 26 seal means 28 conical stop surface 29 Outer diameter of the connector 32 Outer diameter of the cable 33 Outer diameter of the conductor 35 entry surface 38 Fotovoltaikanlage 100 solar module 101-103

Claims (11)

1. Cable connection (1) preferably for photovoltaic systems (100), comprising at least one contact housing (2) and at least one connection housing (3), wherein the connection housing (3) can be connected to the contact housing (2) and wherein at least one freely configurable cable (4) with a conductor (6) is accommodated in the connection housing, wherein a contact needle (7) is arranged on the contact housing (2) for contacting the conductor (6) of the cable (4), wherein a spring device (8) is provided in the connection housing (3), which device is provided to radially surround the conductor (6) and the contact needle (7) and to press together said conductor and said contact needle in a spring-elastic manner,
   characterized in that,
   the contact housing (2) has an internal thread (16) and the connection housing (3) has an external thread (17), wherein when the connection housing (3) and the contact housing (2) are screwed together, the contact needle (7) is pressed into the conductor (6).
2. Cable connection (1) according to Claim 1, wherein the spring device (8) surrounds the insulated conductor (10).
3. Cable connection (1) according to Claim 1, wherein the spring device (8) surrounds the insulating layer (13) of the cable (4).
4. Cable connection (1) according to the previous Claim, wherein the insulating layer (13) serves as a spring-elastic memory (14).
5. Cable connection (1) according to one of the previous claims, wherein the spring device (8) is mounted in the connection housing (3).
6. Cable connection (1) according to one of the previous claims, wherein the spring device (8) comprises an elastic sleeve (9).
7. Cable connection (1) according to the previous Claim, wherein the elastic sleeve (9) has a cylindrical receiving area (12) for the conductor (6) of the cable (4) and a funnel-shaped insertion area (12).
8. Cable connection (1) according to one of the previous claims, wherein the spring device (8) is slotted.
9. Cable connection (1) according to one of the previous claims, wherein the spring device (8) consists of metal.
10. Cable connection (1) according to one of the previous claims, wherein the spring device (8) consists of at least one visco-elastic plastic.
11. Cable connection (1) according to one of the previous claims, wherein the conductor (6) of the cable (4) consists of a plurality of flexible cores (15).

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