Arc chamber for a contactor and contactor to extinguish electric arcs

Abstract

The present invention relates to an arc chamber to extinguish electric arcs for a contactor with an extinguishing system, a blowing device which blows electric arcs into the extinguishing system, and a plurality of lamellar electric arc extinguishing elements between which flow channels are formed, wherein the flow channels each have a scattering section and wherein the scattering sections of adjacent flow channels are formed with different inclinations so that the blown air is deflected into different directions by the flow channels. The invention further relates to a contactor with such an arc chamber.

Claims

1. Arc chamber to extinguish electric arcs for a contactor (1) with an extinguishing system (74), a blowing device (63, 64, 67, 68) which blows electric arcs (65, 66) into the extinguishing system (74), and a plurality of lamellar electric arc extinguishing elements (41) between which flow channels (82) are formed, wherein the flow channels (82) respectively include a scattering section (80), characterized in that the scattering sections (80) of adjacent flow channels (82) are formed with different inclinations so that the blown air is deflected in different directions by the flow channels (82).

2. Arc chamber according to claim 1, characterized in that the flow channels (82) extend into opposite directions.

3. Arc chamber according to claim 1, characterized in that the extinguishing system (74) includes several electric arc extinguishing elements (41) that are arranged next to each other so that at least one flow channel (82) is formed between two adjacent electric arc extinguishing elements (41).

4. Arc chamber according to claim 1, characterized in that the electric arc extinguishing elements (41) are formed identically, wherein two consecutive electric arc extinguishing elements (41) are respectively arranged in a way so that they are turned to each other by 180 degrees wherein the electric arc extinguishing elements (41) each include at least one first air-deflecting recess at a first side area and at least one second air-deflecting recess at a second side area that is located opposite to the first side area, wherein the first recess and the second recess are inclined relative to the blowing direction and aligned relative to each other so that the first recesses form a scattering section (80) with the adjacent second recesses in a way that the scattering sections (80) respectively deflect the air differently.

5. Arc chamber according to one of the claim 1, characterized in that the flow channels (82) each have a change in cross-section that separates an extinguishing section (81) from the scattering section (80).

6. Arc chamber according to claim 1, characterized in that the arc chamber (7) comprises at least one contact area (52, 53) with a fixed contact (54, 55), wherein the blowing device (63, 64, 67, 68) serves to create a magnetic blowout filed which blows electric arcs (65, 66) into the extinguishing system (74), wherein the blowing system (63, 64, 67, 68) includes at least one permanent magnet (63, 64), which is arranged adjacent to the contact area (52, 53), to create a permanent magnetic blowout filed and/or at least one coil (67, 68), which is arranged adjacent to the contact area (52, 53), to create an electromagnetic blowout filed so that an electric arc (65, 66), that emerges on opening of the contact area (52, 53) is blown into the at least one extinguishing system (74), wherein at least two magnetically conductive pole plates (11, 13) are arranged in parallel to each other with intermediate arrangement of the permanent magnet (63, 64) and/or the coil (67, 68) so that the blowing effect is amplified by magnetic fields to guide the electric arcs (65, 66), wherein at least one of the pole plates (11, 13) is formed as a swivelable locking system by means of which the arc chamber (7) is removable from a base part (3) of a contactor (1) in an unlocked state and connectable to the base part (3) of the contactor (1) in a form-locking way in a locked state.

7. Arc chamber according to claim 6, characterized in that a locking lever (17) is eccentrically and pivotally connected to the swivelable pole plate (11) in an and supported by a holder (19) in a way that a swivel movement of the pole plate (11) leads to a translational movement of the locking lever (17).

8. Arc chamber according to claim 7, characterized in that the locking lever (17) is pivotally connected to the pole plate (11) at an end and supported on the opposite, free end by the holder (19) which comprises a movable safety locking device (49) that in the locked state of the pole plate (11) is pressed into a locked position over the free end by a spring element so that the translational movement of the locking lever (17) is prevented by the safety locking device (49).

9. Arc chamber according to claim 8, characterized in that a display element arranged on the locking lever (17) is visible in the unlocked state and not visible in the locked state.

10. Arc chamber according to claim 6, characterized in that the swivel movement of the swivelable pole plate (11) is limited in both directions by a respective stop surface (33 with 35, 31).

11. Arc chamber according to claim 10, characterized in that the blowing device (63, 64, 67, 68) comprises at least one coil (67, 68) with a swivelable first pole plate (11) as well as at least one permanent magnet (63, 64) with a non-rotatable second pole plate (13), wherein the first and the second pole plate (11, 13) are separated from each other by an intermediate gap.

12. Arc chamber according to claim 10, characterized in that a stop surface (33 with 35) is formed by an enclosure.

13. Arc chamber according to claim 1, characterized in that the arc chamber includes at least one contact area (52, 53) with a fixed contact (54, 55), wherein a cooling element (37) of the arc chamber is connected to the fixed contact (54, 55) in a thermally conductive way.

14. Arc chamber according to the claim 13, characterized in that the arc chamber further includes an electrically insulating enclosure (15), wherein the fixed contact (54, 55) extends through the enclosure (15) and consequently forms an electric contact (9) at which the cooling element (37) is mounted.

15. Arc chamber according to claim 1, characterized in that the arc chamber comprises at least one contact area (52, 53) with a fixed contact, wherein the extinguishing system (74) includes an electric arc guiding plate (59, 60), wherein an air gap is provided in the proximity of the contact area (52, 53) between the electric arc guiding plate (59, 60) and the fixed contact (54, 55), and wherein the blowing device (63, 64, 67, 68) serves to create a magnetic blowout filed which blows electric arcs (65, 66) into the extinguishing system (74), wherein the blowing device (63, 64, 67, 68) comprises at least one permanent magnet, which is arranged adjacent to the contact area (52, 53), to create a permanent magnetic blowout filed, and/or at least one coil (67, 78), which is arranged adjacent to the contact area (52, 53), to create an electromagnetic blowout filed, so that an electric arc that emerges on opening of the contact area (52, 53) is blown into the at least one extinguishing system (74), wherein a protective cladding (75, 76) is arranged between the air gap and the permanent magnet (63, 64) and/or the coil (67, 68) and extends from the fixed contact (54, 55) towards the electric arc guiding plate (59, 60), and wherein the protective cladding (75, 76) is insertable in the direction of the extinguishing system (74) and hence replaceably arranged.

16. Arc chamber according to claim 15, characterized in that the protective cladding (75, 76) is fastened by means of a groove (79) or a protrusion which extends perpendicularly to the surfaces of the fixed contact (54, 55) and/or the surface of the electric arc guiding plate (59, 60).

17. Contactor for a direct current and/or alternating current operation with at least one movable contact (56, 57), characterized by an arc chamber (7) according to claim 1.

18. Contactor according to claim 17 with an arc chamber according to claim 6, characterized in that the contactor (1) includes a base part (3) with a locking mechanism that interacts with the swivelable pole plate (11) so that the arc chamber (7) is lockable and unlockable with the base part (3).

Description

(1) In the following, the invention will be explained in greater detail by means of the drawings. The drawings show:

(2) FIG. 1 front view of a contactor with an arc chamber and a base part in the locked state acc. to a first embodiment,

(3) FIG. 2 enlarged display of the locking mechanism,

(4) FIG. 3 perspective view of an arc chamber acc. to a second embodiment with two cooling elements,

(5) FIG. 4 perspective section view with two movable safety locking devices,

(6) FIG. 5 sectional view of a contactor acc. to the first embodiment,

(7) FIG. 6 enlarged display of the details VI from FIG. 5, and

(8) FIG. 7 enlarged perspective section view of an electric arc extinguishing element with a scattering section.

(9) FIG. 1 shows a front view of a contactor 1. The contactor 1 comprises a base part 3 with a drive 5 to drive movable contacts that are not shown in FIG. 1. An arc chamber 7 is arranged on and connected in a form-locking way to the base part 3. The arc chamber 7 is constructed in a substantially mirror-symmetric way around a central axis 8 with two electric contacts 9a, 9b. Further, the arc chamber is also constructed in a planar symmetric way so that the displayed front side is identical to the rear of the arc chamber 7 which is not shown. The arc chamber 7 further has four swivelable pole plates 11 and four fixed pole plates 13 that are arranged on an enclosure 15 of the arc chamber in pairs on the front and the rear. In this respect, only two swivelable and two fixed pole plates 11a, b, 13a, b are shown.

(10) On the upper side that faces away from the base part 3, also a holder 19a is formed that extends through the enclosure 15 of the arc chamber 7, wherein two locking levers 17a, b are supported by the holder 19a between a semicircular support plate 21a and the enclosure 15 in a way that a translational movement of the locking levers 17a, b alongside their longitudinal axis is enabled. On the ends that face away from the holder 19a, the locking levers 17a, b are each swivelable supported around a swivel axis 18a, b on the respective swivelable pole plates 11a, 11b. The swivel axes 18a, b of the locking levers 17a, b are arranged in the proximity of the central axis 8 while the swivel axes 12a, b of the swivelalbe pole plates 11a, b are respectively arranged spaced apart from the central axis 8. Each swivelable pole plate 11a, b has a laterally extending operating lever 23 a, b which is provided above the respective electric contact 9a, b so that the swivelalbe pole plates 11a, b can be operated more easily by the operating levers 23a, b. Hence, swivel movements of the left swivelalbe pole plate 11a in clockwise direction or the right swivelable pole plate 11b in a counter-clockwise direction are limited. In the respective opposite direction, the swivel movement comes to a halt on the enclosure due to second stop surfaces 31a, b (see FIG. 1). On the sides that face away from the second stop surfaces 31, a respective hook 33a, b is formed at each swivelable pole plate 11a, b. In the locked state shown in FIG. 1, respectively one bolt 35a, b of the base part 3 engages with one of the hooks 33a, b so that the arc chamber 7 is not removable from the base part 3 and connected to the base part in a form-locking way.

(11) FIG. 2 shows an enlarged view of the locking mechanism, substantially consisting of the hooks 33a, b and the bolts 35a, b.

(12) FIG. 3 shows an arc chamber 7 according to a second embodiment, wherein the chamber 7 differs from an arc chamber according to the first embodiment as illustrated in FIGS. 1 and 2 essentially due to two cooling elements 37a, b provided at the electric contacts 9a, b. In FIG. 3, such parts, that have an identical or similar function as in the first embodiment, are identified with identical reference signs so that the above description relating to FIGS. 1 and 2 is also valid for the second embodiment.

(13) The cooling elements 37a, b have each a series of cooling ribs 39 that are arranged alongside the circumferential direction of the cooling elements 37a, b. A bolt formed as an electric contact is respectively received in a central borehole of the cooling elements 37a, b so that the plane of the contacts is elevated by the thickness of the cooling elements 37a, b. On the not depicted underside of the cooling elements 37a, b, the bolts formed as electric contacts 9a, b are respectively attached to a contact plate that is formed as a fixed contact and that extends through the enclosure 15. The electric contacts 9a, b as well as the fixed contacts are cooled efficiently by the cooling elements 37a, b.

(14) On the upper side of the enclosure 15 that faces away from the base part, an elongated, square-shaped free surface is provided so that the lamellar electric arc extinguishing elements 41 are exposed at the top. Several outlet apertures 43 of flow channels, which are formed respectively between two adjacent electric arc extinguishing elements 41, are displayed.

(15) The enclosure 15 consists of two enclosure halves 15a, b that are connected to each other through connector bolts 45 with respectively one internal borehole. On the top side of the enclosure 15, two holders 19a, b with respectively one support plate 21a, b, which are explained in greater detail with reference to FIG. 4, are provided.

(16) As shown in FIG. 4, each holder 19a, b initially comprises a semicircular support plate 21a, b that is fastened to the enclosure 15 by means of a screw and through intermediate arrangement of the free ends of the locking levers 17a, b. The support plate 21a, b is formed with two lateral lugs 47 in a way that the locking levers 17a, b are limited in movement in the circumferential direction and that they are substantially freely moveable along their longitudinal axis. In an unlocked state of the swivelable pole plate 11b, the free end of the corresponding locking lever 17b extends beyond the upper edge of the enclosure 15 so that the user can determine the state very easily due to the specific color marking of the locking levers 17a, b. In a locked state, the locking levers 17a, b extend only up to the upper edge of the support plate 21a, b. In this case, a movable safety locking device 49a, b is pushed into a locked position, i.e. from the position as shown in FIG. 4 in the direction towards the support plate 21a, b, by a spring element that is not shown, so that the movable safety locking device 49a, b covers the free ends of the locking levers 17a, b. Hence, an undesired translational movement of the locking lever 17a, b is prevented by the safety locking device 49a, b.

(17) FIG. 5 shows a sectional front view of the inside of a contactor 1 according to the first embodiment. However, the following explanations also apply for the second embodiment. The contactor 1 comprises two contact areas 52, 53 with a respective fixed contact 54, 55 and a respective movable contact 56, 57. The movable contacts 56, 57 of the two contact areas 52, 53 are arranged on a common contact bridge 58. The contact bridge 58 can be moved by a magnetic drive and transferred from a closing state of the contactor 1 in which the movable contacts 56, 57 touch the fixed contacts 54, 55 and hence in which the contact areas 52, 53 are closed into an open position. In the open position, the movable contacts 56, 57 are spaced apart from the fixed contacts 54, 55. Due to the high currents and high voltages that are switched with the contactor, electric arcs 65, 66 emerge between the respective fixed contacts 54, 55 and the associated movable contact 56, 57 on opening of the contact areas 52, 53.

(18) An electric arc guiding plate 59, 60 is arranged adjacent to the fixed contacts 54, 55 at each contact area 52, 53, wherein the electric arc guiding plates 59, 60 are insulated from the respective fixed contact 54, 55 by a respective air gap 61, 62. The electric arc guiding plates 59, 60 are shaped in a way as to form an electric arc conductor pit 69 between the contact areas 52, 53 which is substantially perpendicular to the longitudinal extension of the contact bridge 58 and through which the electric arcs 65 or 66 (depending on the movement direction of the electric arc) are blown in the direction of an extinguishing unit 74 by means of the blowout fields of the permanent magnets 63, 64 and/or blowing coils 67, 68.

(19) The blowing coils 67, 68 are arranged substantially between the swivelable pole plates 11a, b, while the permanent magnets 63, 64 are arranged substantially between the fixed pole plates 13a, 13b. The pole plates 11a, b, 13a, b are not displayed in FIG. 5. Hence, respectively a homogeneous blowout filed is created which blows the electric arcs 65, 66 efficiently into the extinguishing system 74.

(20) On each of the two contact areas 52, 53, a protective cladding 75, 76 is arranged next to the air gap 61, 62. The protective claddings 75, 76 are arranged respectively between the air gap 61, 62, the permanent magnets 63, 64, the fixed contacts 54, 55 and the electric arc guiding plates 59, 60 and extend from the respective fixed contacts 54, 55 upwards to the respective electric arc guiding plates 59, 60. Therefore, a closed space is formed by the protective claddings 75, 76, the fixed contacts 54, 55 and the respective electric arc guiding plates 59, 60 so that the permanent magnets 63, 64 and the blowing coils 67, 68 are protected against electric arcs and the emerging plasma when electric arcs 65, 66 enter the closed space on activation of the blowing coils 67, 68. To fasten the protective claddings 75, 76, it is provided that each of the two cylindrical slots 77, 78 for the permanent magnets 63, 64 that extend through the enclosure are supposed to have a protrusion which extends in the direction of the magnetic blowout filed or the north-south direction of the permanent magnets 63, 64. The protective claddings 75, 76 each have a groove 79 through which the protective claddings 75, 76 are retained in the slots 77, 78. Hence, the protective claddings 75, 76 are also insertable in the direction of the extinguishing system and replacably arranged.

(21) The protective claddings 75, 76 are made of a material that is resistant to electric arcs. Preferably, a ceramic material, especially steatite or cordierite is used for this purpose. These materials have a certain porosity so that they are relatively stable even in case of temperature shocks. This is necessary especially because the electric arc temperature has values up to 20000 K.

(22) A plurality of electric arc extinguishing elements 41 is arranged in a lamellar shape in the extinguishing system 74 above the electric arc guiding plates 59, 60. Between the electric arc extinguishing elements 41, flow channels are formed which need to be further explained and which extend from the electric arc guiding plates 59, 60 in a substantially vertical upward direction. Hence, the air and possibly the plasma, which emerge between the contacts 54, 55, 56, 57 as well as between the electric arc guiding plates 59, 60, are blown into the flow channels and therefore are cooled by the electric arc extinguishing elements 41.

(23) FIG. 6 shows an enlarged display of the sectional view VI from FIG. 5. The electric arc extinguishing elements 41 and the flow channels 82 are each divided into a scattering section 80 and an extinguishing section 81 wherein the scattering section 80 is respectively separated from the extinguishing section 81 by two separating bars 83. In the extinguishing section, respectively a wedge 84 is provided which tapers from the separating bars 83 in the direction towards the electric arc guiding plates 60. An air-deflecting recess is formed at the side area of the electric arc extinguishing element 41 above the separating bars 83. A second air-deflecting recess is formed on the rear that is not shown, wherein the second recess extends in the opposite direction. The electric arc extinguishing elements 41 are stacked next to each other, wherein respectively two consecutive electric arc extinguishing elements 41 are mounted in a way that they are turned towards each other by 180. Hence, the electric arc extinguishing elements 41 can be formed identically so that they form two groups of scattering sections 80 with opposite directions. Deflector bars 85 with a curvature are respectively formed in the air-deflecting recesses 87 so that the air can be deflected more efficiently.

(24) FIG. 7 is an enlarged perspective section view of the scattering section 80. At the level of the separating bar 83, a change in cross-section is formed by a recess 86 which is formed between the two separating bars 83. The change in cross-section has the purpose of cooling and deflecting the air or the plasma more efficiently.