Connecting device for connecting electrical conductors

Abstract

The invention relates to a connecting device (1) for connecting electrical conductors (47, 49). The connecting device (1) comprises a housing (3), a first electrical connecting conductor (5) which has an end (23) that can be connected to a first conductor (47), and a plug element (7) which is inserted through a second housing opening (19) into a housing interior of the housing (3) such that the plug element (7) closes the housing interior air-tight toward the second housing opening (19). The plug element (7) has a second electrical connecting conductor (9), which can be connected to a second conductor (49), and an insulating sheath (27), which sheaths the second connecting conductor (9). The housing interior has a connection volume (25) which is connected to the second housing opening (19). The first connecting conductor (5) and the second connecting conductor (9) are detachably connected to each other in the housing interior. The connecting device (1) has a venting channel (31) through which air from the connection volume (25) can escape from the connecting device (1).

Description

[0001] Description

[0002] Connecting device for connecting electrical conductors

[0003] The invention relates to a connecting device for connecting electrical conductors.

[0004] Particularly in high-voltage applications, when connecting electrical conductors, it is important to ensure that the area surrounding the conductor connection is adequately protected from voltage surges. Therefore, the connection area of ​​electrical conductors is often encapsulated in an airtight manner. This poses the problem that air must be removed from the connection area during the encapsulation process.

[0005] EP 3 331 112 B1 discloses a venting tool for facilitating the discharge of air remaining in a connection portion when an outer wall surface of a protruding connection portion of a second electrical device is connected in a tightly fitted state to an inner wall surface of a recessed connection portion of a first electrical device when connecting the first electrical device and the second electrical device for a switchgear. The venting tool comprises a tubular body which is flexible and in which a vent hole is formed. The venting tool is attached to a connected surface of the connection portion of the first electrical device. The connection portions of the two electrical devices are brought close to each other to discharge gas from the connected surface to the outside via the venting tool.Finally, the venting tool is removed from the joined surface.

[0006] The invention is based on the object of providing an improved connecting device for connecting electrical conductors. This object is achieved according to the invention by a connecting device having the features of claim 1 and a surge arrester having the features of

[0007] Claim 15 resolved.

[0008] Advantageous embodiments of the invention are the subject of the dependent claims.

[0009] A connecting device according to the invention for connecting a first electrical conductor and a second electrical conductor comprises

[0010] - a housing with a first housing opening and a second housing opening,

[0011] - a first electrical connecting conductor arranged at least partially in the interior of the housing, which has an end protruding from the first housing opening or connectable to the first conductor through the first housing opening,

[0012] - a plug element which is inserted through the second housing opening into a housing interior of the housing so that the plug element hermetically seals the housing interior towards the second housing opening, and has a second electrical connecting conductor which can be connected to the second conductor and an insulating sheath which encloses the second connecting conductor and is made of an electrically insulating material, wherein

[0013] - the housing interior has a connecting volume which is connected to the second housing opening,

[0014] - the first connecting conductor and the second connecting conductor are detachably connected to one another in the housing interior and

[0015] - the connecting device has a venting channel through which air from the connecting volume can escape from the connecting device.

[0016] Under the inside of a housing a

[0017] Volume that is surrounded by the housing and not

[0018] Is part of the housing itself. The interior of the housing is generally not a hollow space, but can be connected to openings in the housing.

[0019] A connecting device according to the invention thus enables the connection of two electrical conductors by means of two connecting conductors, which can each be connected to one another with one of these conductors and in a housing. The wording that two electrical conductors can be connected to one another by means of the connecting device does not mean that only two electrical conductors can be connected to one another by means of the connecting device. Rather, more than two conductors can also be connected to one another by means of the connecting device. The wording therefore means that at least two electrical conductors can be connected to one another by means of the connecting device. Accordingly, the connecting device has at least two connecting conductors. The housing enables encapsulation of the connection region in which the connecting conductors are connected to one another in order to prevent voltage flashovers from the connection region into the area surrounding the housing.At least one of the connecting conductors is arranged in a plug element having an insulating sheath surrounding the connecting conductor. The plug element can be inserted into a housing opening in the housing, so that the housing interior is hermetically sealed by the plug element toward the second housing opening. This allows the plug element to be replaced and removed for testing purposes.

[0020] In order to remove air that is displaced by the plug-in element when it is inserted into the housing interior, the connecting device has a vent channel through which this air can escape from the connecting device. Compared to the prior art known from EP 3 331 112 B1, no additional tool is required to remove the air. This simplifies the assembly of the plug-in element compared to the prior art known from EP 3 331 112 B1 and prevents assembly defects caused by incorrect operation of the tool, for example damage to the joint between the plug-in element and an inner surface of the housing by the tool.

[0021] In one embodiment of a connecting device according to the invention, the venting channel has a first channel section running along an outer surface of the first connecting conductor. For example, the outer surface of the first connecting conductor has a depression running parallel to a longitudinal axis of the first connecting conductor, for example in the form of a notch, to form the first channel section. As a result, the first connecting conductor is used to form at least part of the venting channel, so that at least for this part of the venting channel, no separate recess needs to be provided in the housing.

[0022] In a further embodiment of a connecting device according to the invention, at least a section of the outer surface of the first connecting conductor is guided in a guide sleeve in the interior of the housing, and the first channel section runs predominantly between an inner surface of the guide sleeve facing the first connecting conductor and the outer surface of the connecting conductor. The guide sleeve is made, for example, from a metal. For example, the first connecting conductor is essentially cylindrical, and the first channel section runs parallel to a cylinder axis of the first connecting conductor. The essentially cylindrical design of the first connecting conductor enables the first connecting conductor to be inserted into the housing by means of a correspondingly hollow-cylindrical design of the guide sleeve, the guide sleeve serving to guide the first connecting conductor.At the same time, the guide sleeve serves to form the first channel section of the venting channel. In a further embodiment of a connecting device according to the invention, the venting channel has a second channel section which runs within the first connecting conductor and leads out of the end of the connecting conductor. For example, the second channel section branches off from the first channel section. As a result, the second channel section of the venting channel is also formed by the first connecting conductor, so that no separate recess needs to be provided in the housing for this part of the venting channel either.

[0023] In a further embodiment of a connecting device according to the invention, a lubricating paste, for example a grease, is introduced between an outer surface of the insulating sheath of the plug element and an adjacent inner surface of the housing. The lubricating paste reduces the friction between the outer surface of the insulating sheath of the plug element and an adjacent inner surface of the housing, thereby enabling the plug element to be inserted into the housing.

[0024] In a further embodiment of a connecting device according to the invention, the housing interior widens conically from the connecting volume toward the second housing opening, and the plug-in element has a region that is inserted into the housing interior through the second housing opening and is correspondingly conical. This simplifies insertion of the plug-in element into the housing interior.

[0025] In a further embodiment of a connecting device according to the invention, the housing is made at least predominantly from an electrically insulating silicone. As a result, the housing is at least predominantly electrically insulating, so that it poses no risk of voltage flashovers. Furthermore, the silicone design of the housing in the area into which the plug-in element is inserted allows this area to expand slightly during insertion of the plug-in element and, after assembly of the plug-in element, to rest hermetically against the outer surface of the plug-in element. This is made possible by the elasticity of the silicone.

[0026] In a further embodiment of a connecting device according to the invention, the insulating jacket of the plug-in element is made of a cast resin, silicone, or ethylene-propylene-diene rubber (EPDM for ethylene-propylene-diene, M group). This enables a robust and age-resistant design of the insulating jacket.

[0027] In a further embodiment of a connecting device according to the invention, the connecting device has a third connecting conductor connectable to a third conductor, and the housing has a third housing opening. The third connecting conductor contacts the first connecting conductor and the second connecting conductor in the housing interior and is guided to the third housing opening in the housing interior. The connecting device thus enables the connection of (at least) three electrical conductors.

[0028] In a further embodiment of a connecting device according to the invention, the first connecting conductor and the second connecting conductor are connected to one another by a connecting bolt, and the third connecting conductor has an annular end region through which the connecting bolt is guided and which bears against the first connecting conductor and the second connecting conductor. For example, the connecting bolt is designed as a threaded bolt which has a first end region with a first external thread which is screwed to an internal thread of the first connecting conductor, and a second end region with a second external thread which is screwed to an internal thread of the second connecting conductor. This enables a detachable electrical and mechanical connection of all three connecting conductors in the interior of the housing by means of a single connecting bolt.

[0029] A surge arrester according to the invention comprises a connecting device designed according to the invention with a third connecting conductor and a varistor stack of varistors, wherein the third connecting conductor is connected to an electrical terminal of the varistor stack. A surge arrester according to the invention thus enables the protection of an electrical device connected to the first or second connecting conductor from electrical overvoltages.

[0030] Instead of being used for a surge arrester, the connecting device designed according to the invention can also be used for a cable outlet, wherein the third connecting conductor of the connecting device is connected to a cable.

[0031] The above-described properties, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of exemplary embodiments, which are explained in more detail in conjunction with the drawings.

[0032] FIG 1 shows a sectional view of an embodiment of a connecting device according to the invention during assembly of a plug-in element of the connecting device,

[0033] FIG 2 is a sectional view of the connecting device shown in Figure 1 after assembly of the plug-in element,

[0034] FIG 3 shows an embodiment of a surge arrester according to the invention.

[0035] Corresponding parts are provided with the same reference numerals in the figures. Figure 1 (FIG. 1) and Figure 2 (FIG. 2) each show a sectional view of an embodiment of a connecting device 1 according to the invention. The connecting device 1 comprises an electrically insulating housing 3, a first electrical connecting conductor 5, a plug-in element 7 with a second connecting conductor 9, a third connecting conductor 11, a guide sleeve 13 and a connecting bolt 15. Figure 1 shows the connecting device 1 during assembly of the plug-in element 7, Figure 2 shows the connecting device 1 after assembly of the plug-in element 7. It is assumed that the first connecting conductor 5 has already been assembled.

[0036] The housing 3 has a first housing opening 17, a second housing opening 19 and a third housing opening 21.

[0037] The first connecting conductor 5 is substantially cylindrical, has an end 23 projecting from the first housing opening 17 and runs in a housing interior of the housing 3 between the first housing opening 17 and a connecting volume 25 of the housing interior, which is connected to the second housing opening 19.

[0038] The plug-in element 7 has the second connecting conductor 9 and an insulating sheath 27 that encloses the second connecting conductor 9. The insulating sheath 27 is made of an electrically insulating material, for example, a cast resin, silicone, or ethylene-propylene-diene rubber. During assembly, the plug-in element 7 is inserted into the interior of the housing 3 through the second housing opening 19.

[0039] The housing interior widens conically from the connecting volume 25 toward the second housing opening 19, and the plug-in element 7 has a region that can be inserted into the housing interior through the second housing opening 19, which region is also conical. During assembly of the plug-in element 7, the housing interior is hermetically sealed toward the second housing opening 19 by the plug-in element 7.

[0040] The connecting bolt 15 has a first end region 15.1 and a second end region 15.2, each end region 15.1, 15.2 having an external thread. The first connecting conductor 5 has a recess 5.1 with an internal thread, which is screwed to the external thread of the first end region 15.1 of the connecting bolt 15. The second connecting conductor 9 has a recess (not shown) with an internal thread, which is screwed to the external thread of the second end region 15.2 of the connecting bolt 15 during assembly of the plug element 7.

[0041] Longitudinal axes of the first connecting conductor 5, the second connecting conductor 9 and the connecting bolt 15 run along a straight line 29. A longitudinal axis of the third connecting conductor 11 runs perpendicular to the straight line 29.

[0042] The third connecting conductor 11 has a first end region 11.1, which extends annularly around a central region 15.3 of the connecting bolt 15 and bears against the first connecting conductor 5 and, after assembly of the plug-in element 7, against the second connecting conductor 9. In other words, after assembly of the plug-in element 7, the first end region 11.1 of the third connecting conductor 11 is arranged between mutually facing ends of the first connecting conductor 5 and the second connecting conductor 9 and bears against these ends, so that it is electrically connected to the first connecting conductor 5 and the second connecting conductor 9.

[0043] Furthermore, the third connecting conductor 11 has a second end region 11.2 facing away from the connecting bolt 15, which has a recess 11.3 with an internal thread. Figures 1 and 2 also show a conductor 51 having one end with an external thread that is screwed to the internal thread of the recess 11.3 of the third connecting conductor 11, so that the conductor 51 is electrically connected to the third connecting conductor 11.

[0044] A portion of the outer surface 5.2 of the first connecting conductor 5 is guided within the housing interior of the hollow-cylindrical guide sleeve 13. The guide sleeve 13 is made of a metal, for example, aluminum, and extends from the first housing opening 17 almost to the annular first end region 11.1 of the third connecting conductor 11. The guide sleeve 13 serves to guide the first connecting conductor 5 within the housing 3, particularly during insertion of the first connecting conductor 5 into the housing 3.

[0045] The housing 3 is made of silicone. A first region 3.1 of the housing 3 is made of an electrically insulating silicone, while a second region 3.2 and a third region 3.3 of the housing 3 are each made of an electrically conductive silicone.

[0046] The second region 3.2 of the housing 3 surrounds a region of the housing interior in which the connecting conductors 5, 9, 11 contact one another after the assembly of the plug element 7, including an end region of the guide sleeve 13 and the connecting volume 25 facing the annular first end region 11.1 of the third connecting conductor 11. The second region 3.2 serves as electrical shielding which homogenizes an electrical field which is generated by the connecting conductors 5, 9, 11 when a current flows through the connecting conductors 5, 9, 11.

[0047] The first region 3.1 forms the largest part of the housing 3 and surrounds the region of the guide sleeve 13 not surrounded by the second region 3.2, the second region 3.2 of the housing 3 and the region of the housing interior in which the housing interior widens conically towards the second housing opening 19.

[0048] The third region 3 . 3 of the housing 3 surrounds, in a ring-like manner, an area on an outer side of the housing 3 in which the housing 3 narrows in steps towards the first housing opening 17. The third region 3 . 3 serves to homogenize an electric field in the region of this step-like housing narrowing.

[0049] As already explained above, during assembly the plug-in element 7 is inserted into the housing 3 through the second housing opening 19, the internal thread of the second connecting conductor 9 being screwed to the external thread of the second end region 15.2 of the connecting bolt 15. More precisely, during assembly the plug-in element 7 is inserted into the housing 3 through the second housing opening 19 by pushing the second housing opening 19 onto the plug-in element 7. The further the plug-in element 7 is inserted into the interior of the housing, the closer an outer surface 27.1 of the insulating jacket 27 of the plug-in element 7 comes to an inner surface 3.4 of the housing 3 facing the outer surface 27.1, until the outer surface 27.1 is on the inner surface 3, as shown in Figure 1. 4 and closes the housing interior towards the second housing opening 19.If the plug-in element 7 is inserted further into the housing interior up to the end position of the plug-in element 7 shown in Figure 2, the area of ​​the housing 3 surrounding the plug-in element 7 widens. This housing widening is possible because the housing 3 is made from the first silicone in this area and is therefore elastic. At the same time, air is displaced from the connecting volume 25 by the plug-in element 7. This air can no longer escape through the second housing opening 19 because the plug-in element 7 seals the housing interior airtight towards the second housing opening 19. The invention therefore provides a venting channel 31 through which air from the connecting volume 25 can escape from the connecting device 1.

[0050] 1 and 2, the venting channel 31 has a first channel section 31.1 which initially runs from the connecting volume 25 between the second region 3.2 of the housing 3 and the end region of the first connecting conductor 5, which ends towards the third connecting conductor 11, and then between an inner surface 13.1 of the guide sleeve 13, which ends towards the first connecting conductor 5, and an outer surface 5.2 of the first connecting conductor 5. For example, the outer surface 5.2 of the first connecting conductor 5 has a depression, for example in the form of a notch, running parallel to a longitudinal axis of the first connecting conductor 5 to form the first channel section 31.1. Furthermore, the venting channel 31 has a second channel section 31.2 which runs inside the first connecting conductor 5, from the first channel section 31.1 branches off and is led out of the end 23 of the connecting conductor 5 .

[0051] Figure 3 (FIG. 3) schematically shows an exemplary embodiment of a surge arrester 40 according to the invention. Objects shown in dashed lines are not visible from the outside. The surge arrester 40 comprises a connecting device 1 according to the invention and a varistor stack 41 of varistors 43. Each varistor 43 is made, for example, from a metal oxide and has a disk-like configuration. The varistor stack 41 comprises a plurality of varistors 43 stacked one above the other. The varistor stack 41 is arranged in an electrically insulating arrester housing 45.

[0052] The connecting device 1 is designed as in Figures 1 and 2. The first connecting conductor 5 of the connecting device 1 is connected to a first electrical conductor 47. The second connecting conductor 9 of the connecting device 1 is connected to a second electrical conductor 49. The third connecting conductor 11 of the connecting device 1 is connected to a third electrical conductor 51. For example, the first conductor 47 is a cable and the second conductor 49 is a terminal of an electrical power transmission device such as a switchgear. The third conductor 51 is a terminal of the surge arrester 40, which is connected to an upper end of the varistor stack 41. A lower end of the varistor stack 41 is connected to an earth terminal 53 of the surge arrester 40.

[0053] The third conductor 51 has one end with an external thread, which is screwed to the internal thread of the recess 11.3 of the third connecting conductor 11 (see Figures 1 and 2). An upper end of the arrester housing 45 is connected to a lower end of the housing 3 of the connecting device 1.

[0054] Although the invention has been illustrated and described in detail by means of preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims

Patent claims 1. A connecting device (1) for connecting a first electrical conductor (47) and a second electrical conductor (49), the connecting device (1) comprising - a housing (3) with a first housing opening (17) and a second housing opening (19), - a first electrical connecting conductor (5) arranged at least partially in the interior of the housing (3), which has a first Housing opening (17) protruding or connectable to the first conductor (47) through the first housing opening (17), - a plug element (7) which is inserted through the second housing opening (19) into a housing interior of the housing (3), so that the plug element (7) hermetically seals the housing interior towards the second housing opening (19), and a second electrical connecting conductor (9) which can be connected to the second conductor (49) and an insulating sheath (27) which surrounds the second connecting conductor (9) is sheathed and made of an electrically insulating material, wherein - the housing interior has a connecting volume (25) which is connected to the second housing opening (19), - the first connecting conductor (5) and the second connecting conductor (9) are detachably connected to one another in the housing interior and - the connecting device (1) has a venting channel (31) through which air from the connecting volume (25) can escape from the connecting device (1).

2. Connecting device (1) according to claim 1, wherein the venting channel (31) has a first channel section (31.1) running on an outer surface (5.2) of the first connecting conductor (5).

3. Connecting device (1) according to claim 2, wherein at least a portion of the outer surface (5.2) of the first connecting conductor (5) is guided in the housing interior in a guide sleeve (13) and the first Channel section (31.1) runs predominantly between an inner surface (13.1) of the guide sleeve (13) facing the first connecting conductor (5) and the outer surface (5.2) of the first connecting conductor (5).

4. Connecting device (1) according to claim 2 or 3, wherein the guide sleeve (13) is made of a metal.

5. Connecting device (1) according to one of claims 2 to 4, wherein the first connecting conductor (5) is substantially cylindrical and the first channel section (31.1) runs parallel to a cylinder axis of the first connecting conductor (5).

6. Connecting device (1) according to one of the preceding claims, wherein the venting channel (31) has a second channel section (31.2) which runs within the first connecting conductor (5) and is led out of the end (23) of the first connecting conductor (5).

7. Connecting device (1) according to claim 6 and one of claims 2 to 5, wherein the second channel section (31.2) branches off from the first channel section (31.1).

8. Connecting device (1) according to one of the preceding claims, wherein a lubricating paste is introduced between an outer surface (27.1) of the insulating jacket (27) of the plug-in element (7) and an inner surface (3.4) of the housing (3) lying thereon.

9. Connecting device (1) according to one of the preceding claims, wherein the housing interior widens conically from the connecting volume (25) to the second housing opening (19) and the plug-in element (7) has a region which is introduced into the housing interior through the second housing opening (19) and which is of correspondingly conical design.

10. Connecting device (1) according to one of the preceding claims, wherein the housing (3) is made at least predominantly of an electrically insulating silicone.

11. Connecting device (1) according to one of the preceding claims, wherein the insulating jacket (27) of the plug element (7) is made of a casting resin or silicone or ethylene-propylene-diene rubber.

12. Connecting device (1) according to one of the preceding claims, with a third electrical Conductor (51) connectable third connecting conductor (11), wherein the housing (3) has a third housing opening (21) and the third connecting conductor (11) contacts the first connecting conductor (5) and the second connecting conductor (9) in the housing interior and is guided to the third housing opening (21) in the housing interior.

13. Connecting device (1) according to claim 12, wherein the first connecting conductor (5) and the second connecting conductor (9) are connected to one another by a connecting bolt (15) and the third connecting conductor (11) has an annular end region (11.1) through which the connecting bolt (15) is guided and which bears against the first connecting conductor (5) and the second connecting conductor (9).

14. Connecting device (1) according to claim 13, wherein the connecting bolt (15) is designed as a threaded bolt having a first end region (15.1) with a first external thread which is screwed to an internal thread of the first connecting conductor (5), and a second end region (15.2) with a second external thread which is screwed to an internal thread of the second connecting conductor (9).

15. Surge arrester (40) with a connecting device (1) designed according to one of claims 12 to 14 and a varistor stack (41) of varistors (43), wherein the third connecting conductor (11) is connected to an electrical conductor (51) which is an electrical terminal of the varistor stack (41).

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