EP1851781B1 - Safety arrangement for a switchgear assembly, in particular for a medium voltage switchgear assembly - Google Patents

Description

The invention relates to a fuse arrangement for a switchgear, in particular for a medium-voltage switchgear, according to the preamble of claim 1.

Such a fuse arrangement is for example from the DE 41 16 058 known. This fuse arrangement comprises a cylindrical quiver made of insulating material, which is closed at one end and there has a contacting device for a security cartridge inserted into the quiver. At the other, open end a quiver lid is arranged, which bears against the free end of the quiver and is screwed there. An electrically conductive connection between the fuse and a terminal contact is generated by a tensioning device having an inner ring with outer cone and an outer ring with inner cone, which are formed in the form of spring-ring clamping elements. The movement of the release pin on the fuse is transmitted by means of a slider and a reversing lever on a striker, which is movably guided in the quiver lid and perpendicular to the central axis of the fuse.

From the FR 2 607 330 a fuse arrangement has become known in which a fuse is inserted into a cylindrical container closed at one end; at the closed end is located within the container, a contact cylinder, with the inner surface of the inner end of the fuse comes into contact. This contact container has a pin which is led out of the bottom side of the container, so that there an electrical line can be connected. The opposite, open end of the container has an inner cone shape which tapers towards the interior of the container into which a conical plug adapted to its outer surface cooperates, the outer surface of the plug being forced against the inner surface of the cone shape on the container is. In the region of the free end of the cylindrical container is located on the inside of a contact element, which is led out to the outside, so that from the outside, another electrical conductor can be connected. A similar electrode is also formed on the contact cylinder, so that a total of three connection options exist: a first at the open end, the second at the closed end, both perpendicular to the center axis of the fuse and running in the direction of the central axis of the fuse third at the bottom ,

A similar embodiment is also the EP 0 881 653 A1 refer to. The fuse box in which the fuse is inserted is closed at one end and has there a contact cylinder having a projection which protrudes in the direction of the securing longitudinal axis of the bottom of the container. The other end is the same as in the arrangement of the FR 2 607 330 closed by means of a cone plug made of elastic material, wherein it is not specified how the plug is fixed. In all known arrangements easy disassembly of the fuse is not possible.

From the EP 0 389 029 A1 a fuse arrangement has become known which has a container of insulating material closed on one side into which the fuse can be inserted; at the other end a handle device is provided with a disassembly is possible. This handle device has a shaft of insulating material which is inserted into the interior of the container. At the inner end, the shaft has an electrically conductive contact sleeve, which comes with the adjacent contact of the fuse in electrically conductive connection. At its other end, it has a gripping device formed by a plate on which are mounted two walls perpendicular thereto and fixed therebetween, between which there is a spindle acting as a shaft for handling the gripping device.

From the US Pat. No. 3,829,810 For example, a fuse assembly for an electrical device, such as a transformer, has been disclosed which includes a first end open cylindrical fuse receptacle of high dielectric strength material into which a fuse cartridge or fuse may be inserted having its first end connected to a first contact assembly at the first open end of the fuse holder and the second end with a second contact arrangement is in electrically conductive connection in the region of the second end of the fuse holder. In addition, in the region of the first end of the fuse holder, a sealing body is provided whose outer surface has a tapering in the direction of the fuse outer cone shape, which corresponds to a matched inner cone shape at the first end of the fuse holder.

The object of the invention is to further improve a fuse arrangement of the type mentioned, so that the disassembly and assembly of the fuse is simplified.

This object is achieved by the features of claim 1.

Thereafter, the invention is characterized in that between the sealing body and the sealing head a spring arrangement is provided, which exerts in the final assembly position on the sealing body a pressing this in the inner cone shape of the insulating container.

In a particularly advantageous manner, a spring arrangement is provided which has a non-linear spring core line. Such a non-linear spring core line preferably has a plate spring arrangement with at least one disc spring.

According to a particularly advantageous embodiment of the invention, at least one composed of two disc springs spring pair is provided, wherein the plate springs of each spring pair abut against each other at their inner edges and with their outer edges against the sealing body or the sealing head.

A preferred embodiment may be that the sealing body at least partially made of a soft elastic material, for. B. silicone rubber. In this case, the sealing body can either consist entirely of a soft-elastic material or be provided on its outer cone shape with a soft elastic layer. Of course, there is also the possibility that a soft elastic layer is provided for sealing on the inner cone shape as well as on the outer cone shape.

In a preferred manner, when the sealing body is made of flexible material, on the end face facing the sealing head, a plate will be attached, which transfers the force of the spring arrangement to the sealing body.

According to an advantageous embodiment of the sealing head is coupled to a lever arrangement with which the sealing head from a position in which the spring assembly tensioned is, in a position Can be brought, in which the spring assembly is relaxed, and back.

According to a particularly advantageous embodiment of the invention may be attached to the fuse-side end of the sealing body is a tulip-shaped, located on a circular circumference finger assembly holding arrangement, with which the first end of the fuse is mechanically fixed. To the finger assembly also includes a clamping element with which the finger assembly is pressed against the fuse and pressed.

Further advantageous embodiments of the invention can be found in the further subclaims.

Reference to the drawing, in which an embodiment of the invention is shown, the invention, further advantageous refinements and improvements and other advantages to be explained and described in detail.

Fig. 1

eine Frontansicht einer Schaltanlage mit Sicherungsanordnung,

Fig. 2

eine schematische Schnittansicht durch das zweite Ende eines Sicherungsbehälters mit eingesetzter Sicherung,

Fig. 3

eine perspektivische Schnittansicht des anderen Endes des Isolierbehälters, ohne Sicherung,

Fig. 4

eine Schnittansicht eines Dichtkörpers mit Dichtkopf,

Fig. 5

eine perspektivische Ansicht einer Hebelanordnung, mit der der Dichtkopf und Dichtkörper demontiert oder montiert werden können, und

Fig. 6

eine Kraft-weg-Kennlinie einer Federanordnung zwischen Dichtkopf und Dichtkörper.

Show it:

Fig. 1

a front view of a switchgear with fuse arrangement,

Fig. 2

a schematic sectional view through the second end of a fuse box with inserted fuse,

Fig. 3

a perspective sectional view of the other end of the insulating, without fuse,

Fig. 4

a sectional view of a sealing body with sealing head,

Fig. 5

a perspective view of a lever assembly with which the sealing head and sealing body can be dismantled or mounted, and

Fig. 6

a force-displacement characteristic of a spring arrangement between the sealing head and the sealing body.

A switchgear, as for example from the parallel registered EP1851839 is known, has a switch panel 10, in the upper region of busbars 11 are mounted, where switch disconnectors 12 are connected. The lower end of the switch-disconnector, that is, each individual switch-disconnector pole 12, is electrically connected to conductors 13, 14 and 15, each having a fuse arrangement 16, 17 and 18. The fuse assemblies 16 to 18 are located below the switch-disconnector poles, and below the fuse assemblies 16 to 18 cable terminals 19, 20 and 21 are provided, which are electrically connected via further conductors 22, 23, 24 with the fuse assemblies 16 to 18.

In this case, the conductors 13, 14 and 15 connect to the second end of the insulating container, whereas the leading to the cable connection points 19, 20 and 21 conductors 22, 23 and 24 approximately in the central region, measured in the longitudinal direction of the fuse assemblies 16 to 18, connect to this ,

It is now referred to the Fig. 2 ,

A fuse arrangement according to the invention comprises a cylindrical insulating body 30 whose end on the left in the drawing, that is to say the second end 31, is closed by an electrically conductive cap 32, the cap 32 having a cylindrical wall 33 comprising the outer surface of the insulating body 30. In this case, the insulating body 30 has on its outer surface a groove 30a, in which an annular fixing element 30b is used, on which the cylindrical wall 33 of the cap 32 is attached. On the inner surface 32a of the cap 32 in the region of the wall 33, a circumferential groove 32b is introduced, which directly opposite a groove 30c in the region of the end edge of the insulating body 30; in the thus formed, circumferential torus shape is a seal 32c, preferably an O-ring seal inserted. On the inner surface 32a, a contact assembly 34 is further attached, which have a tulip contact shape.

On the outer surface of the wall 32, a connection 35 is provided, on which, for example, the conductor 13 should be connected radially.

Within the cylindrical container or the insulating container 30 is a fuse 36, from whose one end face a contact pin 37 protrudes, which has entered into contact with the contact assembly 34 in electrically conductive connection. The other end of the fuse 36 is contacted with a contact device, see below, which is electrically connected via inside the insulating body 30 extending lines 38 with a perpendicular to the longitudinal axis of the fuse 36 extending terminal 39, which is approximately in the middle between the located at both ends of the insulating body 30 and to each of which a conductor 22, 23, 24 are connected.

It is now referred to the Figures 3 and 4 ,

The insulating container 30 has at its first end 31 a, which is opposite to the second end with the metal cap 32, see Fig. 3 , on its inner surface a conical surface 40, which tapers into the interior of the insulating container or widens outwards. In this conical surface 40, a sealing body 41 is inserted, which consists of elastic material, for example made of silicone, whose outer surface 42 has a cone shape, which tapers into the interior of the container 30 and the inner cone surface 40 is adjusted. Coupled to the sealing body 41 is a sealing head 43, wherein the sealing head 43 is movable relative to the sealing body 41 to a small extent. Within the sealing body 41, an insulating tube 44 is guided, which faces the fuse in the drawing Fig. 4 left end, an external thread 45, with which the tube 44 is screwed into a connecting ring 46 with internal thread has. At the tapered end of the sealing body 41 has a cup-like recess 47 against the inner surface 48, a support ring 49 is applied made of electrically conductive material, which is adapted to the contour of the inner surface 48 and is in high-voltage potential when befindlicher fuse. The support ring 49 also abuts against the inner surface 48. The support ring 49 has a bell shape, wherein the open side of the bell shape is opened in the direction of the interior of the insulating container. The sealing body 41 comprises the outer surface 48 of the bell shape; this bell shape is chosen so that the sealing body 41, when pressed together, is supported on its entire outer surface 42 in the direction of the outer surface 42. Between the L-shaped ring 46 and the support member 49 inwardly angled webs 50, 51 are held by fixing elements 52, 53, the long legs 52a, 53a are perpendicular to the longitudinal extension of the fuse. In the Fig. 4 are only two fixing elements 52, 53 visible; However, there are several arranged, which together form a kind of tulip, which is surrounded from the outside by means of a clamping device 54, so that the inner diameter of the fixing elements 52, 53 is variable. The first end of the fuse 36, which is partially shown here by dashed lines, is inserted with an extension 36a between the fixing elements 52, 53 and held between the fixing elements 52, 53, in which the fixing elements 52, 53 outside comprehensive clamping device 54, the one Pipe clamp may be, this fixing elements 52, 54 presses against the outer surface of the extension 36 a, so that the fuse 36 is fixedly connected to the sealing head 41.

On the fixing elements 52, 53, which also serve as contact fingers, contact springs 131 are mounted, which are pressed by a resilient clamping ring 132 radially outward, so that when the sealing body 41 is inserted together with the fuse 36 in the container 30, these contact elements 131 are pressed against contact elements 133 which correspond to the line 38. Thus, the current flows through the fuse 36 to the fixing elements 52 and 53 and thus to the contact elements 131 and via the inner line 133, 38 to the junction 39. The inner line 38 may be formed of a plurality of elongated conductor portions, which on the inner surface of the insulating 30 are attached.

To the fuse (not shown) includes a transmission element 55, to which a trigger bar 56 is connected, which is movably guided through the interior of the tube 44 and in the in Fig. 4 shown position does not protrude beyond the sealing head 43. In the case of a response of the fuse, the trip bar 36 is moved in the direction of arrow P by means of a spring, whereby a trigger for a higher-level circuit breaker is made.

On the inside of the tube 44 in the region of the thread, a guide element 57 is formed for the trip bar 56, which is annular and connected via a peripheral conical web 58 on the inner wall of the tube 44. The conical web 58 opens towards the thread 45. On the thread 45 remote side of the guide member 57, a circumferential groove 59 is provided, into which a seal 60 is inserted. The guide member 57 has a through hole 134 through which the trip bar 26 is guided.

The other end of the tube 44 protrudes from the sealing body 41 and ends in a stepwise adjoining extension 61, whose outer diameter is greater than the outer diameter of the tube 44. Against the step 62 formed by the extension 61 is a peripheral edge 63 of a cup body 64th whose bottom 65 has a guide passage 66 for the trip bar 56. On the outside of the bottom 66 is a groove 67, in which a seal 68 is introduced.

Between the support member 57 and the bottom 65 there are two approximately tubular spacer elements 69 and 70, which are guided at opposite ends with flange edges 71 and 72 within the tube 44 and lie with their adjacent ends against each other. The outer diameter of the flange edges 71, 72 corresponds to the inner diameter of the tube 44. These spacers 69 and 70 serve with their flange edges 71 and 72 to intercept any pressure forces that also act inwardly upon compression of the sealing body. The space 135, which is located between the flange edges 71 and 72 within the tube 44 is filled with insulating oil, which via radial openings 136 which are located at least in the spacer element 69, and in the space between the spacer elements 69, 70 and Trigger bar 56 can flow into it.

The cup body 64 has in the region of its free end, d. H. in the region of the peripheral edge 63, a radially outwardly projecting bead 137, and on the inner surface of the extension 63, a circumferential, inwardly projecting nose 138 is formed; when the cup body 64 is pressed into the interior of the tube 44, the bead 137 snaps behind the circumferential nose 138, so that the cup body 64 is fixed there. In addition, located in the bottom of the cup body on the outer surface, d. H. on its wall facing the space 135 a circumferential groove 139 in which a seal 140 is located. The seals 60, 68 and 140 serve to seal the inner space 135, so that the insulating oil located there is prevented from flowing out of the space 135, and thus serve to prevent leakage.

The sealing head 43, in which the extension 61 is located, has a passage opening 73, which has a gradation 74 in the direction of the sealing body 41, with the gradation 62 of the tube cooperates, wherein between the two in the dargstellten position a distance is provided.

The tube 44, which consists of insulating material, has on its outer surface a cone shape, which tapers towards securing.

At the fusing-side end of the sealing body 41 is a support plate 80 and between the support plate 80 and the opposite surface 81 there are two disc springs 82 and 83, which in the in Fig. 4 shown position under mechanical tension, ie are tense and push the sealing body 41 against the arrow P in the inner cone 40 of the insulating container 30.

Instead of such disc springs can of course also be provided a coil spring assembly. Of particular importance is that the spring arrangement has a non-linear characteristic, as shown in the Fig. 6 is shown. On the horizontal axis is the path around which the spring is compressed and on the vertical axis the force that compresses the spring is recorded. The characteristic K of the spring arrangement, as desired, has an increase which decreases as the path increases. As a result, with a path difference μs in the region in which the rise of the characteristic curve K becomes smaller, a force difference μp corresponding to the path difference μs is relatively small. In this way it is achieved that compensated tolerances have a relatively small influence on the force that is required to push the sealing body into the sealing cone, so that cavities in which discharges can form are avoided.

In studies, it has been found that for the purpose here a pair of disc springs from two disc springs whose inner edges are placed against each other, has an optimal effect.

The Fig. 3 shows the sealing body 41, inserted into the insulating container 30. The sealing head 43 has an elongated shape which is perpendicular to the longitudinal extent of the fuse, so that the sealing head 43 forms a T-shape with the sealing body 41 in the assembled state.

At the opposite ends of the sealing head 43 pins 84, 85 are formed, via which the distance between the sealing head 43 and the sealing body 41 can be changed. Thus, the spring arrangement of the two plate springs is relaxed and a tension between the sealing body and the insulating container is terminated, so that the sealing head and the sealing body together with the fuse located inside, which is firmly connected to the sealing body, can be removed.

It is now referred to the Fig. 5 ,

On the front side of the switchgear 10, a plate 100 is fixed, which has three openings 101 to 103, whose inner diameter corresponds to the outer diameter of the sealing head 41.

On each side of each opening 101 to 103 is a post-like stand 104, 105; 106, 107 and 108 and 109 are placed vertically, which stands are each composed of two identical stator elements 104a and 104b, which take a distance between them. The stands 105 to 109 are formed in the same way as the stand 104 with the two stator elements 104a and 104b.

An arm 110 and 111 of a handle arrangement 112 engages between the upright elements of each upright, in which case only the handle arrangement 112 for the opening 101 is described; the handle assembly for the openings 102 and 103 are the same. The two arms 110 and 111 extend approximately parallel to one another and together with two obliquely arranged bends 113 and 114 form a U-shape; the bends 113 and 114 are (not visible) at their ends facing each other provided with further bends, which are parallel to the arms 110 and 111 and perpendicular to the line connecting the posts 104 and 105, these two bends as extensions of a handle 115 from Insulating material are included. The length of the handles is dimensioned to remain within the range bounded by side walls in any position in which the handles 115 are parallel to the plate, so that the movement of the handles is not hindered by wall sections.

The arms 110 and 111 are pivotally connected via pivots 116 and 117 to the posts 104 and 105, so that the handle assembly 112 can be pivoted from the position in which the arms are parallel to the plate 100, into a position in which the arms run perpendicular to the plate, as well as the handle 115. The handles can of course be spent in a position in which they compared to the in the Fig. 5 shown position are pivoted by 180 °, so that the handles 115 project in the opposite direction than the one in Fig. 5 is shown.

The arms 110 and 111 each have a recess 118 and 119; the ends of the posts 104, 105 are fork-shaped with a fork opening 120 and 121 slotted.

The pins 84 and 85 of the sealing head 43 engage in the recess 118 and reach through this and also engage in the fork opening 120, 121 a.

In the position according to Fig. 5 press the handles, the pins 84, 85 via the recesses 118, 119 into the interior of the insulating into it, whereby the disc springs 83, 82 are biased with a certain force, so that the sealing body 41 just-if with a certain force in the inner cone surface on the insulator is pressed in, whereby an electrical tightness between the two cone surfaces is generated.

When the handles 115 are moved from the one end position to their other end position, then the pins 84, 85 slide in the recesses 118, 119 because they are fixed in position by the fork opening 120 and 121 respectively and due to the curved shape of the recesses 118 and 119, the pins 84, 85 and thus the sealing head 43 in the direction of arrow P (see Fig. 4 ) is removed from the plate 100, whereby the spring assembly is relaxed, so that the pressure force is reduced or reduced to the sealing body, so that in a simple way, the fuse can be dismantled.

After inserting the fuse into the interior of the insulated container, the movements of the handles are reversed.

Above it is described that the sealing body 41 in its entirety consists of soft elastic material. Of course, it is also possible to produce the sealing body of rigid material and to coat only the outer cone surface with soft elastic material. In the same way, of course, it is also possible to produce the sealing body made of rigid material and to coat the inner cone surface of the insulating container with this material.

In both cases, of course, as in the execution according to Fig. 4 in that the contact surfaces of the inner and outer cones are sealed over the entire axial length and over the entire radial circumference, so that there are no spaces in which discharges can result which can damage or destroy the sealing body and thus the entire safety arrangement ,

Claims (16)

1. Fuse arrangement for a switchgear assembly, in particular for a medium-voltage switchgear assembly, having a cylindrical insulating container (30), which is open at a first end and consists of insulating material and into which a fuse cartridge or fuse (36) can be inserted, whose first end is electrically conductively connected to a first contact arrangement (131, 133) at the first open end (31a) of the insulating container (30) and whose second end is electrically conductively connected to a second contact arrangement (34) in the region of the second end of the insulating container (30), and the fuse cartridge (36) is fixedly connected at its first end to a closure apparatus for the insulating container (30), which closure apparatus is arranged on the front side, preferably on the frame or on the front wall of the switchgear assembly and has a sealing body (41), whose outer face (42) has an outer cone form tapering in the direction of the fuse and corresponding to a matched inner cone form (40) at the first end of the insulating container (30), and a sealing head (43) connected to the sealing body (41), the sealing head being arranged outside of the insulating body, characterized in that a spring arrangement (82, 83) is provided between the sealing body (41) and the sealing head (43), said spring arrangement exerting a force on the sealing body (41) which presses it into the inner cone form of the insulating container (30) in the fitted position.
2. Fuse arrangement Claim 1, characterized in that the spring arrangement (82, 83) has a nonlinear spring characteristic.
3. Fuse arrangement according to Claim 1 or 2, characterized in that the spring arrangement is a disk spring arrangement and has at least one disk spring (82, 83).
4. Fuse arrangement according to one of the preceding Claims 1 to 3, characterized in that at least one pair of springs comprising two disk springs (82, 83) is provided, the disk springs of each pair of springs bearing against one another at their inner edges and bearing against the sealing body (41) or the sealing head (43) with their outer edges.
5. Fuse arrangement according to one of the preceding claims, characterized in that the sealing body (41) consists at least partially of a soft-elastic material, for example silicone rubber.
6. Fuse arrangement according to one of the preceding claims, characterized in that a soft-elastic layer for sealing purposes is provided on the inner cone form and/or on the outer cone form.
7. Fuse arrangement according to one of the preceding claims, characterized in that the sealing head (43) and the sealing body (41) are capable of moving slightly in relation to one another for the purpose of tensioning and detensioning the spring arrangement, the movement being delimited by a step-shaped integral formation on the sealing head (43) or on a holding element connected to the sealing body (41).
8. Fuse arrangement according to one of Claims 1 to 4, characterized in that, at least in the case of a sealing body (41) consisting of a soft-elastic material, a plate is attached to the end face facing the sealing head (43), which plate transfers the force of the spring arrangement onto the spring body (41).
9. Fuse arrangement according to one of the preceding claims, characterized in that the sealing head (43) is coupled to a lever arrangement, and the sealing head (43) can be brought from a position in which the spring arrangement is tensioned into a position in which the spring arrangement is relieved of tension, and back again.
10. Fuse arrangement according to one of Claims 1 to 8, characterized in that a holding arrangement, which has a tulip-shaped finger arrangement located on a circular circumference, is fitted to the fuse-side end of the sealing body (41), with which holding arrangement the first end of the fuse (36) is mechanically and fixedly connected.
11. Fuse arrangement according to Claim 10, characterized in that the inner diameter of the finger arrangement can be reduced by means of a tensioning element, with the result that the fuse (36) is held fixedly at its first end in the finger arrangement.
12. Fuse arrangement according to Claim 9, characterized in that the sealing head (43) has two bolt pins (84, 85) which protrude in the opposite direction and interact with the lever arrangement.
13. Fuse arrangement according to one of the preceding claims, characterized in that a tube arrangement (44) is integrally formed within the sealing body (41), which tube arrangement engages in the sealing head (43) and has an extension there, which engages in a corresponding extension on the sealing head (43), with the result that, when the sealing head is removed from the sealing body (41), the sealing head, via this step-like extension, takes the tube (44) and therefore the sealing body (41) with it.
14. Apparatus according to Claim 12, characterized in that the lever arrangement has a U shape with two parallel running arms for each fuse pole, the web sections of said arms being connected to one another and being provided with a handle, in that the arms of the lever arrangement are mounted rotatably between two connectors, which are positioned perpendicularly on both sides of a through-opening in the plate for the fuse (36), and in that the arms have a cutout, which forms a cam and into which the journals engage on the sealing head (43) and are guided therein.
15. Apparatus according to Claim 12, characterized in that the lever arrangement has a U shape with two parallel running arms and a web running transversely with respect thereto for each fuse pole, in that the arms of the lever arrangement are mounted rotatably between two connectors, which are positioned perpendicularly on both sides of a through-opening in the plate for the fuse, and in that the arms have a cutout, which forms a cam and into which the journals on the sealing head (43) engage and are guided therein, and in that the web acts as a handle.
16. Apparatus according to either of Claims 14 and 15, characterized in that the length of the arms is dimensioned such that the lever arrangement can be pivoted through 180° without its movement being impeded by parts of the switchgear assembly.

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