DE102008027589A1 - Spark gap arrangement with a short-circuiting device - Google Patents

Abstract

The invention relates to a spark gap arrangement with a short-circuiting device, comprising two opposite, main electrodes that are arranged in a pressure-resistant housing, said main electrodes being electrically connected to an external connection. According to the invention, a cavity which houses a movable, conductive short-circuit element, is provided in at least one of the main electrodes. Said short-circuit element is geometric such that the distance between the main electrodes can be bridged. Said short-circuit element is subjected to a pretensioning force that is released during thermal or overcurrent load.

Description

The Invention relates to a spark gap arrangement with a short-circuiting device, comprising two opposite, in a pressure-resistant housing arranged main electrodes, each with an external connection be in electrical connection, according to the preamble of claim 1

From the EP 1 407 460 A2 a surge arrester with a center electrode and at least one outer electrode is previously known, in which an electrically conductive spring clip is attached to the center console and exerts a spring force on the outer electrode. Between the spring clip and the outer electrode, an electrical component is arranged, which is not conductive at the ignition voltage of the surge arrester and which generates heat when current flows. The spring clip abuts against an electrically conductive contact element, which is attached by means of a fusible mass to a spacer element and spaced from the outer electrode. With molten mass, the contact element can be pressed by the spring clip on the outer electrode, so that a trigger mechanism is formed. In this surge arrester of the prior art, the insulation required in the normal operation of the arrester between the spring clip and the outer electrode is effected by spacing the contact element from the outer electrode by means of the spacer element. The fusible mass is only required to attach the contact element to the spacer element, and therefore may be provided in a small amount, which ensures that the contact element can be held by the spacer element.

The current carrying capacity of the short circuiter according to EP 1 407 460 A2 is limited due to the design and materials used there. In addition, the reaction of the short-circuiter is greatly delayed by the necessary heating of the entire arrester. Due to the external attachment of the short-circuiter creates an increased space requirement and in addition, a possible sparking in the outdoor area when responding to the short circuiter be critical. In addition, the prior art arrangement is a parallel connection of two spark gaps, namely gas discharge in combination with a separation distance of the short circuiter. To avoid a rollover of the separation distance in the outer region and thus an extreme sparking, the Ansprechspannungen the two parallel spark gaps over a very wide Frequency range be matched to each other and also the aging of the gas discharge are considered over a longer period of time and under different loads.

The EP 0 603 428 A1 discloses a gas discharge tube having a short-circuiting heater responsive to heating outside the discharge area. This short circuiter and the gas discharge arrester are in contrast to the EP 1 407 460 A2 in an additional housing. Due to this higher complexity, the danger to the environment can be minimized in the event of a malfunction of the arrangement, but a corresponding space requirement is necessary. In addition, due to the additional mass, the reaction time increases until the response of the short-circuiter. An effective coordination of the safety function on the performance of the spark gap used is so difficult.

The spark gap after DE 100 25 239 A1 has a short-circuiter integrated within the flameproof spark gap housing. This short circuiter becomes active at high pressure development within the spark gap. A reliable protection against a thermal overload of the spark gap with internal or even external causes is not possible with this solution.

For special applications of spark gaps it is necessary that the devices used in a defined state Short circuit or open circuit. One typical example of such a fail-safe behavior is the possibility of thermal cutting, as they are for overvoltage protection devices with varistors used many times. In case of imminent overload separates the thermally sensitive separation device the device in question from the network and thus prevents a momentous destruction.

In A similar direction is aimed at back-up backups, such as they are used with arresters with spark gaps. For the case that the arrester in question is not able to work automatically to interrupt the streaming stream, this takes over associated back-up fuse and disconnects the arrester from Network.

at Special cases of use is this fail-safe behavior by switching off not readily feasible. This can be z. B. caused by supply networks in which the operating current is almost the same size as the short-circuit current. Such Behavior is in emergency generators or in photovoltaic systems in front.

From the foregoing, it is therefore an object of the invention to provide a further developed spark gap arrangement with a short-circuiting device, which on the one hand is durable current carrying and on the other hand without additional space the desired short-circuiting function ensures. The short-circuiting device should be thermally, namely triggered by internal or external heating. The design to be stated should allow an easy adjustment of the triggering temperature and the tripping time to different problems depending on the application of the spark gap arrangement.

The Solution of the object of the invention is carried out with a combination of features according to claim 1, wherein the dependent claims at least expedient Represent refinements and developments.

Of the Short circuiter according to the invention, comprising a conductive short-circuiting element, responds at least one or two or more response temperatures and may also be selective to overcurrents in one embodiment be set. The overcurrents can z. Within a trigger unit, a parallel control unit or a parallel overvoltage protection flow. In addition, the overcurrent function can be quasi also for a, externally triggered short circuit the spark gap can be used. This is z. B. for a additional protection independent of the overvoltage protection function the unit makes sense. So an electrical system in case of failure, z. B. when a fire, from arcs and so on targeted in a defined state, even in combination with an overcurrent protection device, such as a switch or a fuse.

According to the invention A cavity is provided in at least one of the main electrodes. This cavity occupies a movable, conductive short-circuiting element on, wherein the short-circuiting element has a geometric shape such that the distance between the main electrodes safely bridged is. The short-circuiting element is provided with a biasing force applied, which at thermal or overcurrent load is released.

These Solution has the advantage that the volume of the spark gap does not have to be enlarged. It is next to the Connections of the spark gap no additional Connections necessary. The performance of the Short circuiter is only through the connection cross section the spark gap limited. The short circuiter is located in the proposed solution within the flameproof encapsulation of the spark gap and thus provides no external Security risk.

The Responsiveness of the short circuiter can easily for different spark gaps and overloads be tuned, for which the response temperature and the response delay with respect to release of the biasing force is variable.

at A first embodiment is the short-circuiting element stored in the cavity in fit and it is the biasing force through generates a spring element.

The Biasing force of the spring element is adjustable. Therefor may be in the main electrode receiving the short-circuit member a through hole may be provided.

The Short-circuit element is in or on the cavity by means of a temperature-sensitive substance or such an element. exceeds the temperature in the vicinity of the short-circuiting element the melting point of the temperature-sensitive substance, then becomes allows the movement of the short-closing element, under the effect of the now released preload with the consequence of contact bridging between the two main electrodes of the spark gap arrangement.

The temperature-sensitive substance may be in the fitting space and is preferably in close thermal contact with the corresponding main electrode.

The Through hole may have an adjusting screw, which on the spring element acts, wherein the spring element between the short-circuiting element and the set screw, and although for the purpose of the biasing force of the spring depending on the application case also to be able to vary externally.

At the to the arc combustion chamber oriented portion of the cavity, the opening Surrounding laterally, is at least one wall-like projection or ring provided, which protects the cavity from contamination and the movement of the short-closing element in the sense of a Leadership promotes.

at a further embodiment of the invention, the Short-circuiting element oriented at its counter-main electrode End having at least one mandrel, which one on the counter-main electrode penetrate insulation layer or insulation film penetrate can.

at a further embodiment of the invention, the Preload force on releasing or separating a Fuse fusible conductor are released.

One end of the fuse fuse is in communication with an isolated relative to the respective main electrode auxiliary terminal in connection, the other end on the Kurzschließele ment with the main electrode is contacted to guide a tripping current.

Of the Fuse fuse is with a temperature-sensitive solder attached to the short-circuiting element and / or the auxiliary connection.

at a variant of the fuse fuse is located inside a preloaded or preloaded helical compression spring.

Of the Safety fuse is also in a through hole the main electrode can be arranged, wherein the through hole connects to the cavity or part of the cavity in the corresponding main electrode.

The Solder attachment points of fuse fuse can a different temperature sensitivity, d. H. a different melting point have.

in the Exit region of the short-circuiting element can at a Another embodiment of the invention, a contact paragraph or a Contact ring in or on the cavity, preferably at the arc to the arc pointing end, be provided.

Prefers At least the main electrodes are rotationally symmetrical.

there again preferably one of the main electrodes can have a pot shape, wherein the opposite main electrode extends into the interior of the pot.

additional there is a possibility that one in the arc furnace Introduced trigger electrode is provided.

The Invention will be described below with reference to embodiments and explained in more detail with the aid of figures become.

in this connection demonstrate:

1 a longitudinal sectional view through a first embodiment of a spark gap arrangement with short-circuiting device, wherein the short-closing element is acted upon with an adjustable spring biasing force;

2 an embodiment of a spark gap arrangement with short-circuiting device in longitudinal section, wherein the movable short-circuiting member is located in a cavity of a quasi-inner main electrode;

3 an embodiment of a spark gap arrangement with a short-circuiting device in longitudinal section, wherein the short-circuiting element is held by a fuse fuse and an auxiliary terminal is present;

4 a representation similar to that after 3 , but with the possibility of adjusting the spring bias of a helical compression spring located in a through hole;

5 to 7 Block diagrams as applications for a spark gap with a short-circuiting device according to the exemplary embodiments according to 3 and 4 ;

8a a representation with the possibility of separating the mechanical connection and the electrical current flow;

8b a representation of an alternative way to realize the decoupling and

9 an arrangement for avoiding the arc attachment to the short-circuiting bolt.

The shown embodiments is common that within at least one main electrode, a displaceable part of the electrode or introduced another electrically conductive part which is when warming the outer Surrounding the spark gap, when heating the main electrodes or also with intensive arcing effect in the arc space of the spark gap by his movement to the counter electrode the entire spark gap short circuits inside the flameproof enclosure.

This briefly outlined solution has the following advantages. The volume of the spark gap does not have to be increased. There are no additional connections necessary in addition to the connections of the spark gap. The performance of the short-circuiting device is limited only by the connection cross section of the spark gap. In addition, there is the short circuiter inside the flameproof enclosure and thus does not pose a security risk. The variants according to the 3 and 4 solve the task of creating a short circuiter, which monitored in addition to the purely thermal tripping function by overcurrents in an auxiliary or parallel path of the arrester or can be specifically triggered in an external fault.

The longitudinal section after 1 shows an exemplary embodiment of a triggerable lightning current carrying spark gap, which can be used as N / PE or spark gap.

However, the invention is not limited to spark gaps, but may also in Spark gaps are used for network applications. The invention is not limited to spark gaps with additional trigger electrodes, but can also be used easily for simple, non-triggerable spark gaps.

The spark gaps shown have two external connections 1 , a pressure-resistant, preferably metallic sheath 2 , at least one insulating bushing 3 and two opposing main electrodes 4a . 4b ,

If necessary, the spark gap can be made using a third electrode 5 , z. B. over the coat 2 be triggered. The contacting of the auxiliary electrode 5 However, it can also be done by one opposite the coat 2 isolated implementation carried out.

In the presentation after the 1 . 3 and 4 there is a conductive short-circuiting element 6 within the main electrode 4b ,

The electrically conductive short-circuiting element 6 bridges after tripping the distance between the two main electrodes 4a . 4b in electrically conductive function.

The short-closing element 6 is retired with the help of a temperature sensitive substance 7 on or in the electrode 4b fixed.

As a temperature-sensitive substance 7 For example, solders, waxes, polymers, adhesives and the like with the highest possible melting point or melting range can be used.

About that In addition, bimetals or shape memory alloys to block the spring biasing force until reaching a certain Temperature be used.

The preload force is provided by a spring 8th in the simplest way when attaching the spark gap with the help of a screw 9 generates or varies.

For better guidance of the spring 8th when screwing can a pin 10 at the inside end of the preload adjusting screw 9 to be available.

After the ignition of the arc 11 between the two main electrodes 4a and 4b they heat up. The short-closing element 6 or its attachment to the substance 7 can be exposed to the direct effect of the arc.

If the attachment heats up above the response temperature, the short-circuit element becomes 6 from the drawn rest position by the spring in the end position shown in dashed lines (see 1 ) emotional. In this way, the short-circuiting element 6 large area with the counter electrode 4a connected.

The electrical connection of the short-circuiting element 6 relative to the main electrode 4b can already before the release of the fastener or the substance 7 exist, but also only after the beginning of the movement z. B. be realized by positive locking and / or traction.

The contact surface between the short-circuiting element 6 and the main electrode 4b corresponds at least to the contact surface between the short-circuiting element 6 and the counter electrode 4a , Both contact surfaces are preferably larger than the connection cross section of the spark gap.

In terms of cost and manufacturing reasons, an embodiment with a solder joint as a substance 7 between the electrode 4b and the short circuiter 6 preferred, wherein the large-area contact between the two parts 4b and 6 in the shorting position is feasible over a tight fit between these parts.

The fit is preferably carried out in an axial region which is as far away as possible from the arc chamber, ie, away from the arc combustion chamber. In order to avoid impurities or to reduce the direct action of arcing in the active region of the short-circuiting device, it is possible to provide these coaxial protective barriers 14 be attached. These protective walls can also guide the short-circuiting element 6 assist in his movement.

The behavior of the short-circuit element 6 In addition to controlling the response over the melting or reaction temperature of the substance 7 be influenced and varied by further measures.

As already mentioned, the positioning of the temperature-sensitive Fixing as close as possible to the arc combustion chamber or in the direct area of action of the arc to a rapid Tripping of the short-circuiter both at impulse as well as with longer lasting fault currents be used.

By reducing the heat conduction behind the room behind the attachment or the substance 7 , z. B. in the form of a change of material within the electrode 4b or between the electrode 4b and the electrode terminal 1 , is targeted a heat accumulation in the area of the substance 7 producible, whereby a faster response is effected. Likewise, the heat capacity of the parts can be influenced by the geometry and the choice of materials be flown.

For example, if the temperature-sensitive attachment has a good thermal conductivity, the heat capacity of the actual short-circuiting element also becomes 6 taken into account, if the attachment is based solely on the heat in the main electrode 4b should be triggered. On the other hand, by the positioning of the short-closing element 6 in the arc furnace, the heating of the attachment over the substance 7 also on the heating of the short-circuiting element 6 be effected.

By choosing the mass, the materials and the geometries of the main electrode 4b , the short-circuiting element 6 , its fastening and the connection 1 stand next to the positioning of the substance 7 and the response temperature thus numerous options available to match the response of the short-circuiter on the application and possible hazards.

In addition to these possibilities, the different behavior of the arc within the spark gap can be used. If the short-circuiting element is not triggered by impulsive loads or only under extreme loads, but is released as quickly as possible in the case of small and long-lasting fault currents, then the migration behavior of the arc can be used for longer errors. During arcing, the arc predominates only in the region of its ignition, ie in the vicinity of the trigger electrode 5 stops the movement of the long fault current in the direction of the substance 7 be initiated. This is the behavior related to the release of the movement of the short-circuiting element 6 even with the same power sales differently formable. The arc may be at an electrically conductive part or electrically conductive substance 7 also directly on the short-circuit element 6 be steered to effect a faster response. In order to influence the behavior of the arc, it is usually possible to use the own current forces, the intrinsic and external magnetic fields or else also targeted gas flows and pressure differences occurring during operation.

The 2 shows an embodiment of a spark gap, which is similar to the basic structure of those already in the 1 was shown and described. In contrast to the variant as shown by 1 is the short-circuiting element 6 here within the main electrode 4a located.

The fixing substance 7 is heated almost directly here even with impulsive loads.

With a small wall thickness of the electrode 4a and a break in heat dissipation towards the port 1 , z. B. by a screw connection or a change of material, the heat input of the arc root directly acts on the temperature-sensitive part 7 of the short-circuiting element 6 ,

In a DC circuit can also be the different heating of the anode or the cathode by the corresponding terminal of the electrode 4a be used. This thus allows an almost instantaneous reaching the response temperature of the substance or of the part 7 at a defined load of the spark gap.

The 2 also shows a design possibility of the short-circuiting element 6 in addition to this with a thorn 13 is provided. With the help of the releasable force of the spring 8th can in this embodiment, an isolation distance, for. B. a slide 12 be destroyed, the z. B. on the surface of the opposite main electrode 4b is located, so that then sets the desired short circuit.

Although the embodiments according to 1 and 2 exemplified by an axial direction of movement of the short-circuiter 6 Orientation, short-circuiting with a radial direction of movement within the meaning of the invention are possible.

In ungetriggered spark gaps in which the coat 2 the spark gap has the same potential as one of the electrodes, the short circuit can also directly to the jacket 2 the spark gap.

The solutions after the 1 and 2 show short-circuiters, which function forcibly heating in the area of the substance or the part 7 need to reach the response temperature. This heating is caused by the arc or leakage currents within the spark gap or by the heating of the spark gap from the outside, z. B. causes at elevated ambient temperature.

The embodiments of the 3 and 4 show short-circuiters, which can also react within a specific design to different temperatures and overcurrents.

That's how it shows 3 a longitudinal section through a spark gap arrangement, the basic structure similar to that according to 1 is. The short-closing element 6 However, here is not directly to the external connection 1 or the electrode 4b via a temperature-sensitive element 7 connected but movable afterwards 1 , within a featured there see through-hole, with the connection 1 stored in electrical contact with this.

The electrical contact is z. B. via protrusions 18 , Sliding or sliding contacts or realized via a corresponding fit.

The short-closing element 6 is also here about a spring 8th biased and is of a fuse fusion conductor 15 held.

The fuse fusion conductor 15 is electrically conductive and temperature sensitive, z. B. over a lot 7a , with the short-closing element 6 connected.

On the opposite side of the fuse fuse 15 with an auxiliary connection 16 electrically conductive and possibly also temperature sensitive at one point 7b fixed.

The feather 8th is here biased between the parts 1 and 16 located.

The auxiliary connection 16 has a clamp, which can be contacted outside the spark gap. The auxiliary connection 16 is opposite the main line 1 isolated and can be isolated 19 be attached.

The positioning of the short-closing element 6 inside the main terminal 1 can by paragraphs 20 fixed or adjustable by means of internal thread.

The type of contacting and positioning of the described items is shown only by way of example. It is crucial that one opposite the connection 1 isolated potential via the auxiliary connection 16 can be introduced into the spark gap.

The current through the auxiliary connection 16 flows over the fuse conductor 15 and the short-circuiting element 6 directly to the connection 1 the spark gap. The potential difference between the auxiliary terminal 16 and the main terminal 1 is thus extremely low in the unresolved state of the short circuiter and therefore only insignificant requirements related to the insulation and the flashover. This simplifies the structure inside the spark gap, but also in the outer connection area of the two potentials of the auxiliary terminal 16 and the connection 1 ,

Exceeds the current from the auxiliary terminal 16 to the main terminal 1 the time-current characteristic of fuse fuse 15 , becomes the short-circuiting element 6 triggered and the preloaded spring 8th moves the element 6 to the counter electrode 4a , This also takes place when the response temperature of the temperature-sensitive connections at the points is reached 7a and 7b ,

The operation with respect to the temperature is analogous to that in the 1 and 2 shown and explained.

The links at the points 7a and or 7b can have a different response temperature, allowing further coordination with regard to the tripping behavior and the requirements of the spark gap and the short circuiter.

The main connection 1 with internal short-circuiting device, in the versions with overcurrent release, preferably via an external thread.

The fuse fusion conductor 15 can have any characteristic curve and nominal current intensity according to the tripping function of the short-circuiter. The switching capacity of the fuse element 15 However, is of minor importance, since the destruction of the fusible conductor is virtually in the pressure-resistant housing of the spark gap and the short-term separation distance is hardly exposed to an arc load due to the short-circuit function.

The connection area of the spark gap is protected by the insulation and the heel against sparking. However, it is also possible to protect the active parts of the short-circuiter, in particular the moving parts, by a hose or sleeve with or without leadership before the usual extinguishing agents of the fuse production against the melt particles. At the chosen construction as shown 3 becomes the spring 8th already pre-tensioned before assembly, whereby this is fixed.

The representation according to 4 shows a variant in which the bias of the spring 8th takes place only during assembly of the entire spark gap arrangement and therefore is still adjustable even in the assembled state.

The representation after 4 Again, this is just an example and does not limit the core of the invention.

The short-closing element 6 will, as in the 3 shown with the help of a fusible conductor 15 through a temperature-sensitive material at the point 7a attached. The feather 8th is on the short closing element 6 guided and can on the opposite side at a fixed or also variable paragraph 20 in connection 1 be counterposed.

The fusible conductor 15 is on the side of auxiliary port 16 at the attachment point 7b fixed.

The auxiliary connection 16 will be in the sleeve 21 led and is opposite the terminal 1 kept isolated. Here, the sleeve 21 or the paragraph 20 in connection 1 consist of insulation material or it is again an insulation according to the part 19 according to 3 between the parts 16 and 21 available.

The insulation can also be carried out as an insulating coating. The sleeve 21 is opposite the paragraph 20 in connection 1 z. B. movable via a corresponding thread. By adjusting the position of the sleeve 21 in the paragraph 20 of the connection 1 can be the spring preload of the spring 8th be set. However, this is the distance and the stroke to the counter electrode 4a to be observed.

The 5 to 7 show applications for a spark gap with short-circuiting device according to the embodiments, as shown by the 3 and 4 were explained.

That's how it shows 5 a spark gap 22 with trigger circuit 23 , which has at least two connections with the spark gap 22 about the parts 5 and 16 are contacted.

The fuse fusion conductor 15 the short-circuiter is designed so that an overload of the trigger circuit can be avoided or a possible event of damage to the trigger circuit 23 is severely restricted.

The 6 shows a block diagram in which the current through a parallel to the spark gap 22 switched element 24 can be monitored. The element 24 can hereby z. B. another overvoltage protection element, an electronic device, an electronic short-circuiter or the like.

7 represents a block diagram in which the short circuit of the spark gap 22 over a circle of help 25 directly via a signal output from a controller 26 is controllable. The auxiliary circle 25 can in the simplest way a controllable element, for. B. a thyristor, a transistor, a gas discharge tube, a spark gap or the like.

The control 26 can be used on any detection signals, such. B. arcs, fire sensors, insulation monitors and the like. With the help of an overcurrent protection device 26 can be effected instead of a short circuit of the system and their shutdown.

The Short-circuiting of the presented spark gap arrangement is summarized without additional external Space requirement within a flameproof encapsulation of the spark gap locatable and responsive to external imprinted or internal temperature increases, the short circuit between the two main electrodes is realized.

It There is no restriction of the continuous current carrying capacity opposite the connection cross section of the spark gaps and it is preferred that the short-circuiting element or its Attachment directly exposed to the action of arcing.

The Response is due to the melting temperature of a temperature-sensitive Fixing or substance determined. The response delay is by the position, the geometry and the material properties of the short-closing element or its attachment determinable. Finally, the response delay can be due to the positioning of the short-circuiting element and by the different Running behavior of the arc within the spark gap determined or controlled.

The Response delay can be achieved despite the same power consumption chosen differently for pulse and continuous currents become. It is possible the response delay at lower power conversion with small continuous currents lower than in the case of pulse currents with high power conversion perform.

about the attachment of a fuse conductor at different points can independently adjustable temperature-sensitive Triggering possibilities are created.

It should be pointed out that a direct transmission of the arc to the short-circuit element already in a solution according to illustration 1 is possible because the distance between the short-circuiter and counter-electrode is less than the distance between the electrodes. However, this is not a prerequisite for the transmission, since this is possible even at long distances between short circuiter and counter electrode by the choice of materials or the current forces or targeted gas flows.

The direct transmission of the arc requires a high quality material of the short circuiter. In addition, it is favorable, the power supply to the short circuit of the thermally sensitive attachment of the bolt 6 to separate. In this regard, reference is made to the illustrations according to 8a and 8b directed.

These figures show the direct footing of the arc 11 after his walk on the Earthing bolts 6 , which is designed erosion resistant at least on the surface. There is thus a direct heat transfer from the arc to the short circuiter. The melting temperature of the soldering point 7 can thus be reached very quickly. At high currents, it is advantageous to decouple the power supply from the temperature-sensitive junction. If the current is passed directly over the Lotstelle, the current forces can negatively affect the flow behavior of the solder and the movement of the bolt is inhibited. Under unfavorable conditions, welding of the parts may even occur.

The 8a shows a way to separate the mechanical connection and the electrical current flow. For this purpose has the bolt 6 a separate contact area 27 which is in good electrical contact with the electrode 1 in the area 28 stands. The transition area 27 . 28 is chosen by the materials and the tolerances so that there is a very good electrical connection, which does not weld even at high currents and has a low friction. Materials used for this purpose are known from switching devices or rotating electrical machines. In addition, the current flow in the area of the soldering point 7 be reduced or prevented by an appropriate choice of materials or electrical insulation (not shown).

As an alternative to the electrically conductive solder, temperature-sensitive materials can also be used 7 low electrical conductivity, but also insulating materials are used.

The 8b shows an alternative possibility for realizing the described decoupling.

Here is the bolt 6 with a flexible wire 29 or a flexible bellows 30 provided, which the movement of the bolt 6 does not restrict, but at the same time a permanent good electrical connection realized. The strand 29 or the bellows 30 can be connected to the connector 9 or also on the electrode 1 be attached or jammed.

If the short-circuiter is to be manufactured very inexpensively and if the arc transfer can not be safely avoided due to small sizes and distances to the short-circuiter, it is possible to provide a foreclosure. The heat transfer is reduced by the direct arc, but with the small dimensions, the heat conduction is sufficiently good, so that the tripping times hardly change. The movement of the short-circuiter is not hindered in this case by burn-off particles, which are hardly preventable with inexpensive materials. 9 shows an example of this representation. Accordingly, the leaves 9 an arrangement for avoiding the arc attachment to the short-circuiting bolt 6 detect. This is at very cheap materials for the bolt 6 and very tight spaces, where a transition of the arc in this area can not otherwise be ruled out, makes sense.

For this purpose, a, in this case insulating, protective part 14 to the counter electrode 4a extended.

1

external connections or main connections of the spark gap

2

flameproof, preferably metallic sheath

3

insulation

4a, 4a

main electrode

5

Auxiliary electrode / trigger electrode

6

portable conductive short-circuiting element

7, 7a, 7b

temperature-sensitive Attachment of the movable short-closing element

8th

feather

9

screw

10

pen

11

Electric arc

12

insulating foil

13

mandrel

14

rampart

15

fuse element

16

auxiliary port

17

An end / stop

18

head Start

19

insulation

20

paragraph

21

shell

22

radio link

23

trigger circuit

24

parallel element

25

auxiliary circuit

26

control

27

Overcurrent protection device

28

provided Area in the electrode 1

29

flexible braid

30

flexible bellows

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 1407460 A2 [0002, 0003, 0004]
• EP 0603428 A1 [0004]
• - DE 10025239 A1 [0005]

Claims (18)

Spark gap arrangement with a short-circuiting device, comprising two opposite, in a pressure-resistant housing ( 2 ) arranged main electrodes ( 4a . 4b ), each with an external connection ( 1 ) are in electrical connection, characterized in that in at least one of the main electrodes ( 4a . 4b ) a cavity is provided, which comprises a movable, conductive short-circuiting element ( 6 ), wherein the short-circuiting element ( 6 ) has a geometric shape such that the distance between the main electrodes ( 4a . 4b ) is bridgeable and the short-circuiting element ( 6 ) is acted upon by a biasing force, which is released at thermal or overcurrent load. Arrangement according to claim 1, characterized in that the short-circuiting element ( 6 ) is mounted in the cavity on fit and the biasing force by a spring element ( 8th ) is produced. Arrangement according to claim 2, characterized in that the biasing force of the spring element ( 8th ) adjustable and in which the short-circuiting element ( 6 ) receiving main electrode ( 4b ) A through hole is provided. Arrangement according to one of the preceding claims, characterized in that the short-circuiting element ( 6 ) in or on the cavity by means of a temperature-sensitive substance ( 7 ) or such an element. Arrangement according to claim 2 and 4, characterized in that the temperature-sensitive substance ( 7 ) is in the fitting space and in close thermal contact with the corresponding main electrode ( 4a . 4b ) stands. Arrangement according to claim 3, characterized in that the through-bore a set screw ( 9 ), which on the spring element ( 8th ), wherein the spring element ( 8th ) between the short-circuiting element ( 6 ) and the adjusting screw ( 9 ) is located. Arrangement according to one of the preceding claims, characterized in that, at the side facing the opening, at the portion of the cavity oriented toward the arc-firing space, at least one wall-like projection ( 14 ) is provided, which protects the cavity from contamination and the movement of the short-closing element ( 6 ) promotes leadership. Arrangement according to one of the preceding claims, characterized in that the short-circuiting element ( 6 ) at its end facing the counter-main electrode at least one mandrel ( 13 ), which has an insulating layer or insulating film located on the counter-main electrode ( 12 ) can penetrate. Arrangement according to one of claims 1 to 4, characterized in that the biasing force on the loosening or separating a fuse fusion conductor ( 15 ) is releasable. Arrangement according to claim 9, characterized in that one end of the fuse melt conductor ( 15 ) with an isolated relative to the respective main electrode auxiliary terminal ( 16 ), wherein the further end via the short-circuiting element ( 6 ) with the main electrode ( 4b ) is contacted to guide a tripping current. Arrangement according to claim 9 or 10, characterized in that the safety fuse ( 15 ) with a temperature-sensitive solder on the short-circuiting element ( 6 ) and / or the auxiliary connection ( 16 ) is attached. Arrangement according to one of claims 9 to 11, characterized in that the safety fuse ( 15 ) inside a preloaded or prestressable helical compression spring ( 8th ) is located. Arrangement according to one of claims 9 to 12, characterized in that the securing fuse ( 15 ) in a through hole of the main electrode ( 4b ), wherein the through hole adjoins the cavity or is part of the cavity. Arrangement according to claim 11, characterized in that the soldering attachment points ( 7a . 7b ) of the fuse melting conductor ( 15 ) have a different temperature sensitivity. Arrangement according to one of the preceding claims, characterized in that in the exit region of the short-closing element ( 6 ) a contact paragraph or a contact ring ( 17 ) is provided in or on the cavity, preferably at the end facing the arc combustion chamber. Arrangement according to one of the preceding claims, characterized in that at least the main electrodes ( 4a . 4b ) are rotationally symmetrical. Arrangement according to claim 16, characterized in that one of the main electrodes ( 4b ) has a pot shape and the opposite main electrode ( 4a ) extends into the interior of the pot. Arrangement according to one of the preceding claims, characterized in that a guided into the arc combustion chamber trigger electrode ( 5 ) is provided.