DE102008031113B4 - Spark gap arrangement with at least two electrodes - Google Patents

Abstract

The invention relates to a spark gap arrangement having at least two electrodes, which are arranged in the interior of the pressure-resistant, encapsulated housing, wherein in case of a charge by means of igniting and burning an arc between the electrodes a pressure increase results in the interior, and at least one channel having a small cross-section is provided for the slow depressurization of the overpressure, or the compensation of the interior pressure to the atmospheric pressure, said channel being located within the range of at least one of the electrodes or of an electrode connection part, and said electrode or the electrode connection part comprising a tapped bore. According to the invention, a straight groove extending inside the tapped bore in a tap longitudinal direction is provided, the first groove end of which is directed toward the interior, and the second groove end of which reaches up to a connection flange, wherein the connection flange has a surface that is oriented perpendicular to the tap longitudinal direction, which has a spiral or radial groove, wherein the second straight groove end and the end of the spiral or radial groove directed toward the tapped bore extend at an offset to each other.

Description

The invention relates to a spark gap arrangement with at least two electrodes, which are arranged in the interior of a pressure-resistant, encapsulated housing, wherein in the load case by igniting and burning an arc between the electrodes results in an increase in pressure in the interior and for slowly reducing the overpressure or equalizing the internal pressure to the at least one channel of small cross-section is provided at atmospheric pressure, which is located in the region of at least one of the electrodes or an electrode connection part and this electrode or the electrode connection part comprises a threaded bore, according to the preamble of patent claim 1.

In DE 20 2004 020 260 U1 and DE 103 38 835 A1 spark gaps are disclosed with flameproof enclosure in which a pressure equalization via channels in a screw thread. Of the DE 20 2004 020 260 U1 It can also be seen to use individual, spaced partial threads to create intermediate chambers for the effluent gas.

In the WO 95/05322 A1 are described closures of pressurized containers for liquids. Here, it is provided to provide thread pulls of the closures with openings in order to produce a defined pressure equalization when opening the container.

Also from the DE 196 55 119 C2 is a spark gap arrangement with two electrodes previously known, which are arranged in the interior of a pressure-resistant housing.

The volume of the interior is dimensioned and matched to the height of an expected follow-on flow, that is given by the arc of the line follower current a short-term pressure increase by a multiple of the atmospheric pressure.

To slowly reduce the overpressure or to equalize the internal pressure to the atmospheric pressure, according to DE 196 55 119 C2 Channels of small cross-section formed. As a result, a constant response voltage is ensured even with multiple temporally spaced extinguishing operations with otherwise increasing pressure increases.

To match the steady state internal pressure in the housing assembly DE 196 55 119 C2 To allow for the ambient conditions, the necessary ventilation channels must have very small, well-defined passage cross-sections, which are radially oriented in at least one of the electrodes or an electrode foot. The previously known channels pass into threaded bores of connecting parts and, as it were, continue in the screw thread pairing provided there. Accordingly, the thread pairing of the threaded bore and the connection part forms a pressure equalization channel without the need for additional openings or bores in the housing.

In this case, the degree of thread pairing, d. H. the thread play or the thread pitch the way of taking place pressure equalization. An adaptation to changed parameters can only be done by changing the thread pairing, which, however, runs counter to the usual desired purpose of using standard threads.

From the foregoing, it is therefore an object of the invention to provide a further developed spark gap arrangement with at least two electrodes which are arranged in the interior of a pressure-resistant, encapsulated housing, where it is necessary to create opportunities, such as a pressure equalization channel of small cross-section to the respective performance parameters of the spark gap arrangement can be adapted without additional parts are required or elaborate custom made necessary.

The object of the invention is achieved by a spark gap arrangement according to the feature combination according to claim 1, wherein the dependent claims disclose at least expedient refinements and developments.

It is therefore assumed that a spark gap arrangement with at least two electrodes, which are arranged in the interior of a pressure-resistant, encapsulated housing. In the case of loading, the ignition and burning of an arc between the electrodes results in an increase in pressure in the interior. For slowly reducing the overpressure or adjusting the internal pressure to the atmospheric ambient or external pressure, at least one channel of small cross-section is provided, which is located in the region of at least one of the electrodes or an electrode connection part and this electrode or the electrode connection part comprises a threaded bore.

According to the invention, a straight groove running in the longitudinal direction of the thread is provided inside the threaded hole.

The first groove end of the straight groove is directed to the interior and the second groove end of the Straight groove points to a substantially flat connection flange.

The connecting flange has a thread longitudinally oriented perpendicular surface, which has a spiral or radial groove.

The second straight groove end and the threaded bore end of the spiral or radial groove are spaced, d. H. run staggered and do not go directly into each other.

In a first embodiment of the invention, the straight groove can extend over the entire length of the threaded bore.

In a second embodiment of the invention, the straight groove extends only over a partial section in the longitudinal direction of the threaded bore. As a result, a measure for controlling the time course of the pressure reduction can be specified.

The cross section of the straight groove preferably has a semicircular shape and can be easily introduced by milling in the threaded hole.

The spiral or radial groove is formed in a preferred embodiment as a notched groove or notched with a cutting steel in the Anschlußflanschfläche.

The spiral groove tangentially engages the threaded bore and then passes as a spiral or spiral portion over the substantially planar portion of the Anschlußflanschfläche away.

In an expedient embodiment of the invention, the cross-section of the spiral or radial groove increases, starting from the threaded-bore end over the course to the outside.

At least the connection flange with electrode or electrode connection part is rotationally symmetrical and can consist of a rotating part.

With the help of the threaded hole and using the surface of the connection flange via a screw or a threaded pin, the necessary electrical Außenkontaktierung and establishing the flameproof enclosure state of the housing.

About the threads of the threaded hole an indirect pressure-equalizing connection between the straight groove and the spiral or radial groove is created.

The threaded hole is formed in one embodiment of the invention as a through hole, which extends to the interior.

Ausgestaltend, the connection of the through hole to the interior via an inside channel, which runs in the electrode can be realized.

About the distance between the mutually facing ends between the straight groove and spiral or radial groove in accordance with the invention, the pressure compensation curve, in particular in terms of time, can be specified.

About the geometric course of the spiral groove and its length in the connection flange, the cooling of the emerging from the interior for pressure equalization gases is influenced to a large extent.

The invention will be explained below with reference to exemplary embodiments and with the aid of figures.

Hereby show:

1 a perspective top view of an electrode with electrode terminal part, designed as a rotationally symmetrical component with recognizable straight groove and extending over the flange spiral groove with a small distance of the two mutually facing groove ends;

2 a representation similar to that after 1 wherein the connecting flange has two key surfaces;

3 a representation similar to that after 1 with a straight groove which extends over only a portion of the threaded bore and wherein the distance between the opposite ends of the grooves is selected to be maximum and

4 a sectional view of a spark gap with pressure compensation and

5 a detail with groove.

The embodiments of the 1 to 3 is an electrode 1 together. This electrode is connected to another electrode 8th in the interior of a pressure-resistant housing 10 located, as in the 4 shown.

The electrode 1 goes in the embodiments shown in a connection flange 2 over which a threaded through hole 3 having.

The threaded through hole 3 serves to accommodate a fixing pin or a fixing screw 11 for producing the external contact via another terminal part 12 , which is in contact with the vertical in thread longitudinal direction surface 4 of the connection flange 2 arrives.

For reasons of mounting and / or centering can in the region of the connection flange 2 an arrangement of key areas 5 be introduced (see 2 ).

Inside the threaded hole 3 is a straight groove running in the thread longitudinal direction 6 , quasi forming a channel introduced.

This straight groove runs in the embodiment according to 1 on the 1 entire thread area; however, in the representation according to 3 only over a portion of the thread of the threaded hole 3 , In other words ends here the straight groove and the channel formed thereby 6 before the end of the cut thread. The channel or the straight groove 6 So here have no direct access to the interior of the housing of the spark gap arrangement. The connection is given here over the course of the remaining threads and the resulting gap dimensions, which are retained when screwing a screw or a threaded pin.

In the vertical area 4 of the connection flange 2 is a spiral or radial groove 7 brought in. The second end of the straight groove, which faces towards the surface 4 runs, and the tapped hole 3 directed end of the spiral or radial groove 7 are offset from each other, wherein over the distance of the respective ends of the grooves (close distance according to the examples 1 or greater distance after 2 and 3 ) the pressure equalization process is temporally vorgeb- and controllable.

The spiral groove 7 touches the threaded hole 3 tangential and then as a spiral or spiral section over the connecting flange 2 or the area 4 guided, so that a connection is created to the outside with respect to the overall arrangement of the spark gap.

In one embodiment, the cross section of the spiral or radial groove increases 7 starting from the thread-side end to the outside.

Like from the 1 to 3 it can be seen, the connection flange with electrode or electrode connection part is preferably formed rotationally symmetrical as a rotating part.

About the threads of the threaded hole 3 is an indirect pressure compensating connection between the straight groove 6 and the spiral or radial groove 7 present.

The threaded hole 3 is formed as a through hole and extends to the housing interior of the spark gap assembly (see 4 ).

It is apparent from the foregoing explanations that without any changes in the threaded dimensions of the threaded bore solely by the choice of the length of the straight groove 6 and the distance to the spiral groove 7 to respond to various requirements regarding the performance parameters of a spark gap arrangement. In this case, first the electrode 1 or the corresponding electrode connection part are manufactured as a standard part, in which then depending on the required performance parameters, the straight groove 6 and the corresponding spiral groove 7 be introduced with the respective predetermined dimensions.

LIST OF REFERENCE NUMBERS

1

electrode

2

flange

3

Threaded through hole

4

area

5

key area

6

straight groove

7

Spiral or radial groove

8th

electrode

9

Insulation

10

pressure-resistant housing

11

screw

12

clamping part

Claims (12)

Spark gap arrangement with at least two electrodes ( 1 ; 8th ), which in the interior of a pressure-resistant, encapsulated housing ( 10 ), wherein in case of loading by igniting and firing an arc between the electrodes ( 1 ; 8th ) results in an increase in pressure in the interior and is provided for slowly reducing the overpressure or adjusting the internal pressure to the atmospheric pressure at least one channel of small cross-section, which in the region of at least one of the electrodes ( 1 ) or an electrode connection part and this electrode ( 1 ) or the electrode connection part has a threaded bore ( 3 ), characterized in that within the threaded bore ( 3 ) in a thread longitudinal direction extending straight groove ( 6 ) is provided, whose first groove end is directed to the interior and whose second groove end to a connection flange ( 2 ), whereby the connection flange ( 2 ) one to Thread longitudinal direction vertically oriented surface ( 4 ) which has a spiral or radial groove ( 7 ), wherein the second Geradnutende and the threaded hole ( 3 ) directed end of the spiral or radial groove ( 7 ) offset from each other. Spark gap arrangement according to claim 1, characterized in that the straight groove ( 6 ) over the entire length of the threaded hole ( 3 ) runs. Spark gap arrangement according to claim 1, characterized in that the straight groove ( 6 ) over a partial section in the longitudinal direction of the threaded bore ( 3 ). Spark gap arrangement according to one of the preceding claims, characterized in that the cross section of the straight groove ( 6 ) has a semicircular shape. Spark gap arrangement according to one of the preceding claims, characterized in that the spiral or radial groove ( 7 ) is designed as a notched groove. Spark gap arrangement according to one of the preceding claims, characterized in that the spiral groove ( 7 ) tangentially the threaded hole ( 3 ) and then as a spiral or spiral section over the connecting flange ( 2 ) runs. Spark gap arrangement according to one of the preceding claims, characterized in that the cross section of the spiral or radial groove ( 7 ) Increased from its threaded bore end side. Spark gap arrangement according to one of the preceding claims, characterized in that at least the connecting flange ( 2 ) with electrode ( 1 ) or electrode connecting part is rotationally symmetrical. Spark gap arrangement according to one of the preceding claims, characterized in that by means of the threaded bore ( 3 ) and the connection flange ( 2 ) via a screw or a threaded pin an electrical Außenkontaktierung takes place. Spark gap arrangement according to one of the preceding claims, characterized in that over the threads of the threaded bore ( 3 ) an indirect pressure compensating connection between the straight groove ( 6 ) and the spiral or radial groove ( 7 ) is created. Spark gap arrangement according to one of the preceding claims, characterized in that the threaded bore ( 3 ) is formed as a through hole, which extends to the interior. Spark gap arrangement according to claim 11, characterized in that the connection of the through hole to the interior takes place via an interior-side channel in the electrode.

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