EP2648199A2 - Arc quenching device and installation switch device with same - Google Patents

Abstract

The device has a funnel-shaped intake region (6) narrowing asymmetrically in an arc running direction with respect to a longitudinal center axis. Arc extinguishing plates (1, 1') are alternately arranged one above the other at a longitudinal center axis for formation of an arc-extinguishing plate stack (2). The arc extinguishing plates are reflected one above other at the longitudinal center axis, so that each arc extinguishing plate is partially covered with the adjacent arc extinguishing plate at intake legs (8, 8 ') in a stacking direction. An independent claim is also included for an installation switching device.

Description

The invention relates to an arc quenching device for an electrical service switching device, wherein the service switching device comprises a contact point formed from a fixed and a movable contact on which an arc is generated in an elimination, and wherein the arc quenching device comprises a plurality of arc extinguishing panels exhibiting arc splitter stack in which the arc enters and is extinguished therein, the arc quenching plates being arranged in a stack parallel to each other and held spaced apart by a holding device, each arc quenching plate having two longitudinal side edges extending symmetrically to a longitudinal center axis and having an inlet region in which, starting from an inlet narrow side edge, an in Arcing direction extending and the arc entry point open inlet opening between two inlet legs is formed, according to the Ob Concept of Claim 1.

The invention further relates to an installation switching device, in particular a circuit breaker or a circuit breaker, with a fixed and a movable contact piece, which together form a contact point, and with an arc extinguishing device for extinguishing an arc occurring at the contact point, according to the preamble of claim 10.

Fire extinguishers are used in circuit breakers to extinguish electric arcs. These can be used in single-chamber systems and two-chamber systems. In general, the quenching plates have a V-shaped cutout and are in the same direction arranged. An arc is decomposed in the quenching chamber into many partial arcs and finally extinguished.

A generic arc quenching device is housed in a circuit breaker, a circuit breaker, but also for example in a motor protection switch. The arc splitter stack is composed of several arc quenching plates, which are identical in the known state of the art with respect to the outer shape and dimensions. The sheets have a symmetrical, V - shaped inlet contour, which is open towards the arc - generating point.

DE 10 2008 021 138 A1 shows a generic arc quenching device for an electrical switch, with mutually parallel quenching plates, which are held by means of a holding device formed by a cuboid box of insulating material at a distance from each other.

Now, if an arc between a movable contact piece and a fixed contact piece of a contact point, for example in a short circuit current, it is guided over arc guide rails, which limit the splitter stack on both sides in the stacking direction in the arc splitter stack and divided there into partial arcs, whereby the Arc voltage increased and the short-circuit current thereby limited.

In order to ensure a rapid quenching of the arc, it is necessary for the arc to run quickly into the splitter stack. In order to be able to switch off a high short-circuit current, it is necessary that a high arc voltage be formed between the individual arc-quenching plates and that this remains as stable as possible.

The maximum number of splitter plates is determined by the installation height, whereby the splitter plate thickness and the distance between the plates has an influence. Since the installation height and the maximum number of splitter plate is responsible for the size of the resulting arc voltage and thus for the possible limitation of the short-circuit current at the inlet of the arc in the quenching chamber, it is endeavored to accommodate as many arc quenching in an arc extinguishing chamber, which in practice a minimum Sheet thickness due to the thermal Strength and a minimum distance of the plates with each other can not be fallen below and falls below the minimum possible sheet thickness or the minimum possible distance values does not lead to increase the arc voltage. Thus, the maximum achievable arc voltage and thus the maximum possible short-circuit current limit are determined geometrically for physical reasons for a certain installation height.

It is the object of the present invention to develop a generic arc quenching device so that given geometric dimensions, a faster increase in the arc voltage and overall higher arc voltage can be achieved.

It is a further object of the present invention to provide a service switching device in which under given geometric constraints fast and safe extinguishing of the arc at high short-circuit current, both DC and AC application is guaranteed.

The object is achieved by an arc quenching device with the features of claim 1, as well as by a service switching device with the features of claim 10 ..

According to the invention, the inlet cut-out narrows in a funnel shape and asymmetrically in the arc running direction with respect to the longitudinal center axis, and the arc quenching plates are alternately mirrored one above the other at their longitudinal central axis, so that each arc quenching plate with one of its inlet legs respectively views the inlet section of the adjacent arc quenching plates in the stacking direction partially covered ..

The quenching plates according to the invention therefore arranged alternately mirrored. This leads to an additional extension of the partial arcs in the division case and results in a generally faster rising and higher arc voltage. As a result, rapid and safe extinguishing of the arc can be ensured, especially in DC applications. A rapidly increasing and overall high arc voltage protects the circuit breaker especially in a DC application from overload and damage.

According to an advantageous embodiment of the invention, each arc quenching plate has a rectangular basic configuration, wherein a first inlet leg with a first, the inlet cutout on one side limiting inlet edge and a second inlet leg with a second, the inlet cutout on one side limiting inlet edge are formed and wherein the inlet cutout located at its in arc inlet direction End merges into a basic region connecting the two inlet limbs, so that the width of the first inlet limb at the base region is greater than the width of the second inlet limb at the base region, and wherein in the stacking direction on each side of the stack center plane defined by the longitudinal central axes of the stacked release plates an alternating sequence of first and second inlet legs arise.

One can think of the quenching plate stack according to the invention to a certain extent constructed from an alternating sequence of first and second quenching plates. The first quenching plates are those quenching plates which are arranged so that their first inlet legs lie one above the other in the stacking direction and on a first side of the stacking center plane defined by the longitudinal central axes of the stacked quenching plates. The second quenching plates are those quenching plates which are arranged so that their first inlet legs lie one above the other in the stacking direction and on a second side of the stack central plane defined by the longitudinal central axes of the stacked quenching plates, the second side lying opposite the first side. The structure of the quenching plate stack according to the invention can furthermore be imagined such that the first quenching plates form a first part quenching plate stack and the second quenching plates form a second part quenching plate stack, and that the first and second quenching plate stacks have been joined together. The first and second quenching plates are constructed identically, they differ only in that a second quenching plate emerges from a first quenching plate by mirroring on its longitudinal central axis.

The mode of operation of this inventive arc splitter arrangement can be explained as follows. When it enters the inlet opening, the arc first strikes the first inlet edges and enters the area between the first inlet legs. The distance between the first inlet legs is greater than the distance between the quenching plates in the rear view in the arc running direction Area of the quenching plates, therefore, the shrinkage of the arc takes place in the area between the first inlet legs faster than would be done if the inlet legs all the same, smaller distance would have, as is common in the prior art. Due to the greater distance between the first inlet legs in the region of the first inlet edges and the flow resistance before the arc is lower thereby increasing the inlet velocity. Thus, a good current limit is already achieved in the region of the first leading edges by the driving voltage opposing, rapidly increasing arc voltage. The arc is cooled and the short-circuit current drops. Upon impact of the arc on the second inlet legs in the region of the second inlet edges in the rear of the arc splitter stack a second subdivision of the partial arcs in almost twice, whereby the arc voltage increases to a value well above the driving mains voltage and the arc is quickly brought to extinction , As a result, the thermal load of the quenching plates is kept sufficiently low.

According to a further advantageous embodiment of the invention, the inlet cut-out has an asymmetrical V-shape with straight inlet edges relative to the longitudinal central axis.

According to a further advantageous embodiment of the invention, the arc quenching plates on their longitudinal sides projecting pins, with which they pass through holding holes in the holding device.

According to a further advantageous embodiment of the invention, the quenching plates are made of a ferromagnetic material and are covered with a copper layer. As the base material for the quenching plates while ferromagnetic materials are used, since the magnetic field which accompanies the arc, in the vicinity of a ferromagnetic material tends to pass through the magnetic better conducting quenching plates. This creates a suction effect in the direction of the quenching plates. This suction results in addition to a generated by the arc itself magnetic blowing field that the arc is moved to the arrangement of the quenching plates and divided between these into several partial arcs, which take on the quenching footholds

According to a further advantageous embodiment of the invention, the holding device comprises an insulating strip, the side walls having holding holes for the pins, wherein the side walls delimiting the splitter stack on the longitudinal side edges of the quenching plates, and wherein the insulating strip has a rear wall, the splitter stack in the arc in the direction of Limited narrow-side edges opposite rear edges of the quenching plates limited. The lateral boundary of the splitter stack through the side walls of the holding device causes a maintenance of the pressure within the quenching chamber, which promotes the arc quenching.

According to a further advantageous embodiment of the invention, the rear wall has opening slots through which the pressure generated by the arc can be reduced. This serves to tune the pressure conditions within the quenching chamber and helps to improve arc run-in and improved arc division.

According to a further advantageous embodiment of the invention, the rear wall has on its narrow sides projecting retaining lugs to align the arc quenching device in the housing of a service switching device.

According to a further advantageous embodiment of the invention, the side walls leave the splitter stack in the area of the inlet legs of the quenching plates. In the inlet region In the inlet region of the arc, the quenching chamber is so to speak laterally opened to pass a portion of the resulting gas pressure past the quenching chamber.

An installation switching device according to the invention is in particular a circuit breaker or a circuit breaker, with a fixed and a movable contact piece, which together form a contact point, and with an arc extinguishing device for extinguishing an arc occurring at the contact point, wherein the arc quenching device is designed with a plurality of arc extinguishing plates having arc splitter stack in which the arc enters and is extinguished therein, the arc quenching plates being arranged in a stack parallel to each other and held spaced apart by a holding device, each arc quenching plate having two longitudinal side edges extending symmetrically to a longitudinal center axis and an inlet region, in which, starting from an inlet narrow side edge, extending in an arc direction and the arc entry point open inlet opening between two inlet legs is formed, and wherein the inlet neck funnel-shaped and with respect to the longitudinal center axis asymmetrically narrows in the arc direction, and wherein the formation of the arc splitter stack Arc quenching plates are alternately arranged mirrored one above the other at its longitudinal central axis, so that each arc quenching plate with one of its inlet legs each partially covers the inlet cutout of the arc quenching plates adjacent thereto in the stacking direction.

According to an advantageous embodiment of the invention, the service switching device has a double contact point with two arc quenching devices, each sub-contact point is associated with an arc quenching device, which is designed as described above.

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

Figur 1

eine Aufsicht auf ein erfindungsgemäß gestaltetes Lichtbogenlöschblech,

Figur 2

eine isometrische Ansicht auf ein erfindungsgemäßes Lichtbogenlöschblechpaket von der Lichtbogenentstehungsseite her,

Figur 3

eine Ansicht auf ein erfindungsgemäßes Lichtbogenlöschblechpaket von schräg oben und von der Lichtbogenentstehungsseite her,

Figur 4

eine isometrische Ansicht auf ein erfindungsgemäßes Lichtbogenlöschblechpaket von der Rückseite her.

Show it:

FIG. 1

a plan view of an inventively designed arc splitter plate,

FIG. 2

an isometric view of an inventive arc splitter stack from the arc formation side,

FIG. 3

a view of an inventive arc splitter stack from obliquely above and from the arc formation side,

FIG. 4

an isometric view of an inventive arc splitter stack from the back.

The same or equivalent components or elements are provided in the figures with the same reference numerals.

FIG. 1 shows a plan view of the broad side of a quenching plate 1, 1 'according to the invention. It has a rectangular basic configuration with two longitudinal side edges 5, 5 'extending symmetrically to a longitudinal central axis 4, an inlet narrow side edge 7 and a rear edge 14. It has an inlet region 6, in which, starting from the inlet narrow side edge 7, extending in the arc running direction and the arc entry point towards open inlet cutout between two inlet legs 8, 8 'is formed. The inlet cut narrows in a funnel shape and based on the longitudinal center axis 4 asymmetrically in the arc running direction. As a result, a first inlet leg 8 is formed with a first, the inlet cutout on one side limiting inlet edge 9 and a second inlet leg 8 'with a second, the inlet cutout on one side limiting inlet edge 9'. The inlet cutout merges at its end located in the arc inlet direction into a base region 10 connecting the two inlet legs 9, 9 '. The width of the first inlet limb 8 at the base region 10 is greater than the width of the second inlet limb 8 'at the base region 10.

The inlet cutout thus has an asymmetrical V-shape with straight inlet edges 9, 9 'relative to the longitudinal central axis 4. The first inlet edge 9 of the first inlet leg 8 forms a first angle 17 with the longitudinal central axis 4. The second inlet edge 9 'of the second inlet leg 8' forms a second angle 17 'with the longitudinal central axis 4. The first angle 17 is in a preferred embodiment here in a range between 20 - 25 °. Here, in a preferred embodiment, the second angle 17 'lies in a range between 10 and 15. The depth of the V-shaped cutout, that is the distance between the inlet narrow side edge 7 and the base region 10, lies here in one preferred embodiment Range between 6.5 - 7.0 mm.

The arc quenching plate (1, 1 ') has on its longitudinal sides 5, 5' in each case two projecting pins 11, with which it in retaining holes in the holding device 3, see below and the Figures 2 - 4, can take.

The quenching plate (1, 1 ') consists of a ferromagnetic material and is covered with a copper layer.

The FIGS. 2 to 4 show one of sixteen arc quenching plates 1, 1 ', each of which we in Fig. 1 is constructed, formed arc splitter stack 2, in which an arc run into and can be deleted, the arc quenching plates 1, 1 'arranged in a stack parallel to each other and held by a holding device 3 from each other. The number of However, used quenching plates and their thickness can vary application specific, according to the invention constructed splitter stack with a different number of quenching plates are also possible.

In order to form the arc splitter stack 2, the arc quenching plates 1, 1 'are arranged alternately mirrored one above the other at their longitudinal central axis 4, so that each arc quenching plate 1.1' with one of its inlet legs 8, 8 'in each case the inlet section of the adjacent thereto arc extinguishing plates 1', 1 in the stacking direction partially covered. Thus, in the stacking direction, an alternating sequence of first and second inlet legs 8, 8 'is formed on each side of the stack center plane defined by the longitudinal central axes 4 of the stacked quenching plates 1, 1'.

The quenching plate stack according to the invention can be thought of as being built up from an alternating sequence of first and second quenching plates 1, 1 '. The first quenching plates 1 are those quenching plates which are arranged so that their first inlet legs 8 lie one above the other in the stacking direction and on a first side of the stacking middle plane defined by the longitudinal central axes 4 of the stacked quenching plates. In FIG. 3 These are the quenching plates, the first inlet leg 8 are left of the longitudinal center axes 4 of the quenching plates. The second quenching plates 1 'are those quenching plates which are arranged so that their first inlet legs 8 lie one above the other in the stacking direction and on a second side of the stacked central plane defined by the longitudinal central axes 4 of the stacked quenching plates, the second side lying opposite the first side. In FIG. 3 These are the quenching plates, the first inlet leg 8 are right of the longitudinal center axes 4 of the quenching plates.

It is also possible to imagine the structure of the quenching plate stack according to the invention such that the first quenching plates 1 form a first part quenching plate stack and the second quenching plates 1 'form a second part quenching plate stack, and that the first and the second quenching plate stacks have been joined together. The first and second quenching plates 1, 1 'are constructed identically, they only differ in that a second quenching plate 1' emerges from a first quenching plate 1 by mirroring on its longitudinal central axis 4.

The holding device 3 comprises an insulating strip which has side walls 12, 12 'with holding holes for the pins 11, the side walls 12, 12' delimiting the splitter stack at the longitudinal side edges 5, 5 'of the quenching plates 1, 1'. There are four mounting holes are provided for each quench 1, 1 ', which are arranged in pairs symmetrically to the longitudinal central axis 4.

The insulating strip has a rear wall 13 which delimits the splitter stack 2 at the rear side edges 14 of the quenching plates 1, 1 'lying opposite the inlet narrow side edges 7 in the arc inlet direction.

The rear wall 13 has opening slots 15 through which the pressure generated by the arc can be dissipated.

The rear wall 13 has on its narrow sides projecting retaining lugs 16 to align the arc quenching device in the housing of a service switching device. Here are two asymmetrically arranged lugs 16 are provided, these are used to align the extinguishing chamber in the device.

The side walls 12, 12 'leave the splitter stack 2 in the region of the inlet legs 8, 8' of the quenching plates 1, 1 'free.

The opening slots 15 in the rear wall 13 serve to tune the pressure conditions within the quenching chamber and ensure optimum arc inlet and optimum arc division. The release of the splitter stack 2 laterally in the region of the inlet legs 8, 8 'ensures that a portion of the resulting gas pressure is passed to the quenching chamber. In the remaining lateral area, outside of the inlet legs 8, 8 ', the splitter stack 2 is closed by the side walls 12, 12', this serves to maintain the pressure within the quenching chamber.

The quenching plates are summarized, held by a splitter holder and aligned against each other in parallel. The quenching plates are arranged alternately mirrored. This leads to a division of the arc additional extension of the partial arcs and results in an overall faster rising and higher arc voltage. As a result, rapid and safe extinguishing of the arc can be ensured, especially in DC applications. A fast rising and overall high arc voltage protects the service switching device especially in DC application from overload and damage.

The illustrated arc quenching device according to the invention with the quenching chamber according to the invention can be used in DC and AC circuit breakers or switch disconnectors. The arc quenching device with the quenching chamber according to the invention can advantageously be used in single-chamber systems as well as in a two-chamber system for the rapid extinction of electric arcs.

LIST OF REFERENCE NUMBERS

1

Arc splitter

1'

Arc splitter

2

Arc splitter stack

3

holder

4

Longitudinal central axis

5

Longitudinal side edge

5 '

Longitudinal side edge

6

intake area

7

Enema narrow side edge

8th

first inlet leg

8th'

second inlet leg

9

first leading edge

9 '

second inlet edge

10

basic area

11

spigot

12

Side wall

12 '

Side wall

13

rear wall

14

Rear edge

15

opening slot

16

retaining nose

17

first angle

17 '

second angle

Claims (11)

Arc quenching device for an electrical service switching device, wherein the service switching device comprises a contact point formed from a fixed and a movable contact on which an arc is generated at a power-off, and wherein the arc quenching device comprises a plurality of arc quenching plates (1, 1 ') exhibiting arc splitter stack (2), in which the arc enters and is extinguished therein, wherein the arc quenching plates (1, 1 ') arranged in a stack parallel to each other and by a holding device (3) spaced from each other, each arc quenching plate (1, 1') two symmetrically to a Longitudinal longitudinal axis (4) extending longitudinal side edges (5, 5 ') and an inlet region (6), in which, starting from an inlet narrow side edge (7) extending in the arc running direction and the arc entry point towards the inlet opening between two inlet legs (8, 8 '), characterized in that the inlet cut-out narrows asymmetrically in the arc running direction relative to the longitudinal central axis (4), and in that the arc-quenching plates (1, 1') are alternately formed on their longitudinal center axis (4) to form the arc splitter stack (2) ) are mirrored one above the other, so that each arc quenching plate (1,1 ') with one of its inlet legs (8, 8') each partially covers the inlet section of the adjacent thereto arc extinguishing plates (1 ', 1) seen in the stacking direction. Arc quenching device according to claim 1, characterized in that each arc quenching plate (1, 1 ') has a rectangular basic configuration, that a first inlet leg (8) with a first, the inlet cutout unilaterally limiting inlet edge (9) and a second inlet leg (8') with a second inlet edge (9 ') which delimits the inlet cutout on one side and that the inlet cutout merges into a base region (10) connecting the two inlet legs (9, 9') at its end located in the arc inlet direction such that the width of the first inlet leg (8 ) at the base region (10) is greater than the width of the second inlet limb (8 ') at the base region (10), and that in the stacking direction on each side of the longitudinal center axes (4) of the stacked Deflation plates (1, 1 ') defined stacking median plane an alternating sequence of first and second inlet legs (8, 8') is formed. Arc quenching device according to claim 2, characterized in that the inlet cutout has a relation to the longitudinal central axis (4) asymmetric V-shape with straight inlet edges (9, 9 '). Arc quenching device according to claim 1, characterized in that the arc quenching plates (1, 1 ') on their longitudinal sides (5, 5') projecting pins (11), with which they pass through holding holes in the holding device (3) Arc quenching device according to claim 1, characterized in that the quenching plates (1, 1 ') consist of a ferromagnetic material and are covered with a copper layer. Arc quenching device according to claim 4, characterized in that the holding device (3) comprises an insulating strip which has side walls (12, 12 ') with holding holes for the pins (11), wherein the side walls (12, 12') form the splitter stack (2). on the longitudinal side edges (5, 5 ') of the quenching plates (1, 1') limit, and which has a rear wall (13), the arc splitter stack (2) at the inlet narrow side edges (7) opposite in the arc inlet direction rear side edges (14 ) of the quenching plates (1, 1 ') limited. Arc quenching device according to claim 6, characterized in that the rear wall (13) has opening slots (15) through which the pressure generated by the arc can be dissipated. Arc quenching device according to claim 6, characterized in that the rear wall (13) has on its narrow sides projecting retaining lugs (16) to align the arc quenching device in the housing of a service switching device. Arc quenching device according to claim 5, characterized in that the side walls (12, 12 ') leave the splitter stack (2) in the region of the inlet legs (8, 8') of the quenching plates (1, 1 '). Installation switching device, in particular circuit breaker or circuit breaker, with a fixed and a movable contact piece, which together form a contact point, and with an extinguishing a occurring at the contact point Arc-serving arc quenching device, wherein the arc-quenching device is designed according to one of claims 1 to 7. Installation switching device according to claim 10, characterized in that the service switching device has a double contact point with two arc quenching devices, each sub-contact point is associated with an arc quenching device, and wherein each arc quenching device is designed according to one of claims 1 to 7.

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