FR2950474A1 - Electrical interrupter device for e.g. tripolar circuit breaker, has chambers connected to channels that discharge onto upstream surface of case, where surface is positioned opposite to downstream surface placed in contact with trigger - Google Patents

Abstract

The device has a single-pole interrupter block (10) including stationary contacts (41, 51) engaging with a movable contact bridge (22). The contacts are connected to respective current distribution conductors (4, 5). Arc interrupter chambers (24) open onto an open space of the bridge, and are connected to an interrupter gas exhaust channel (38) and a lateral interrupter gas exhaust channel that discharge onto an upstream surface of a flat case. The surface is positioned opposite to a downstream surface placed in contact with a trigger. One of the channels has a wall covered with a metal sheet. An independent claim is also included for a circuit breaker comprising an interrupter device.

Description

TECHNICAL FIELD OF THE INVENTION The invention relates to a cut-off device having at least one unipolar cut-off block. Said block comprises a movable contact bridge, a pair of fixed contacts cooperating with said movable contact bridge and respectively connected to a current supply conductor. Said block comprises two arc cutting chambers respectively opening on an opening volume of the contact bridge. The invention also relates to a circuit breaker comprising a cut-off device. STATE OF THE ART The evacuation of the cut-off gases in an electrical cut-off device, in particular a circuit-breaker comprising at least one arc-breaking chamber, is generally carried out by directly placing an evacuation hole on a rear face of the chamber. arc cut. The gases generated at the time of the cut through the breaking chamber, pass and cool in contact with one or more deionization fins and are discharged at the bottom of the arc cutting chamber through an opening. A grid preferably associated with additional filtering means allows the evacuation of gases outside the cutoff apparatus while stopping a large number of molten metal particles. Despite these precautions of use, the gases remaining strongly ionized are very polluting. This pollution can particularly deteriorate the electronic means of triggering the switchgear when they are placed near the discharge grid of an arc extension chamber. In addition, when the gases are discharged in an area close to a current lead in the switchgear, electrical rebooting phenomena during the break can be observed. 2 To remedy these problems, some solutions described in particular in US5731561, or in a patent of Applicant EP1667179, eliminate any evacuation of cutoff gas to the outside of the circuit breaker. This is called a cut-off device without external manifestation. The arc extension chambers are connected to gas flow channels within the cut-off device. The more or less long path of the cutoff gases inside a closed volume theoretically authorizes their sufficient cooling. These solutions, however, have the disadvantage of generating very high pressures inside the casing of the cut-off device. In fact, the ~ o cleavage gases confined during their cooling generate significant overpressure inside the housing, overpressure can cause bursting of the casing of the cutoff device. The sizing of the walls of the housing as well as its overall design must then be made taking into account these new constraints. SUMMARY OF THE INVENTION The invention therefore aims to remedy the disadvantages of the state of the art, so as to provide a cut-off device comprising effective means for evacuating the cutoff gases. Each cut-off chamber of the breaking device according to the invention is connected to at least one exhaust channel of the cutoff gases, said exhaust channels being opening on an upstream face of the case of the cutoff block, said upstream face being positioned opposite another downstream face intended to be placed in contact with triggering means. According to a development mode, said exhaust gas escape channels meet in a common duct leading to the upstream face of the casing of the cutoff block. Advantageously, the exhaust channels of the cutoff gas respectively of a first and second cutoff chamber are of different lengths, the cutoff gases flowing in a first exhaust gas channel being 3o intended to suck the circulating gases by Venturi effect. in a second channel. Preferably, each arc-breaking chamber comprises a stack of at least two deionization fins separated from each other by a gas exchange space, at least one exchange space being connected to a channel. exhaust gas cutoff. According to a particular embodiment, said at least one gas escape channel of an arc cutting chamber passes through at least one decompression chamber comprising at least one wall covered with a metal sheet. Advantageously, the decompression chamber is positioned under a lower wall of the arc extension chamber, the wall covered by the metal sheet being in a plane forming an angle of between 45 ° and 180 ° with respect to the direction of the arc. flow of gases. Advantageously, the wall covered by the metal sheet is in a plane perpendicular to the direction of the gas flow. Advantageously, a gas exhaust channel comprises a rotary valve intended to be rotated by the passage of the cutoff gases, the rotation of the valve from a first position to a second position being intended to actuate triggering means to cause the opening of the contacts of the cut-off device. According to a particular embodiment, the movable contact bridge is rotatable and is positioned in a rotary bar having a transverse housing orifice of said contact bridge, which protrudes on either side of the bar, said rotary bar being inserted between two lateral faces of the casing of the cutoff block, two sealing flanges being placed respectively between the radial faces 25 of the rotary bar and the lateral faces to ensure a seal between the inside and the outside of the cutoff block. Preferably, the rotary bar comprises at least one channel in direct connection between the transverse housing orifice and a radial face so that the cutoff gases can flow directly via said channel to at least one sealing flange in order to push it against one of the side faces to ensure a seal. Advantageously, said channel is opening and passes on either side of the rotary bar from a first to a second radial face, said channel opening having a longitudinal axis parallel to a longitudinal axis of the rotary bar.

Advantageously, the opening channel comprises a longitudinal axis aligned with a longitudinal axis of the rotary bar so that the cutoff gases can exert a force to push substantially aligned with the longitudinal axis of the bar and evenly distributed over the sealing flanges. . Preferably, the sealing flanges comprise lateral cheeks at least partially covering the longitudinal surface of the rotary bar to partially close the transverse housing hole of the bar. Preferably, the movable contact bridge is rotatable between an open position and a closed position of the contacts in a clockwise direction. The invention relates to a circuit breaker comprising a breaking device as defined above. Said circuit breaker comprises a trigger connected to the downstream ranges of the breaking device. BRIEF DESCRIPTION OF THE FIGURES Other advantages and features will become more clearly apparent from the following description of a particular embodiment of the invention, given by way of non-limiting example, and represented in the appended drawings in which: FIG. 1 represents an overall perspective view of a circuit breaker comprising a cut-off device according to one embodiment of the invention; FIG. 2A represents an exploded perspective view of a circuit breaker comprising a cut-off device according to one embodiment of the invention; Figure 2B shows a perspective view of a cut-off device during assembly according to one embodiment of the invention; Figures 3 to 7 show perspective views of a unipolar cutoff block and part of its housing for a cutoff device according to a preferred embodiment of the invention; FIGS. 8A and 8B show sectional detail views of an exhaust gas channel of a cut-off unit according to the invention. DETAILED DESCRIPTION OF AN EMBODIMENT According to one embodiment of the invention, the switchgear 100, generally a circuit breaker comprises a trigger 7 associated with a cut-off device 600. The cut-off device 600 comprises at least one unipolar cut-off block 10. The unipolar cutoff block is connected on the one hand to the trigger 7 at the downstream range 5 and on the other hand to a current line to be protected at an upstream range 4. The block Unipolar cutoff 10 is also called light bulb. According to a preferred embodiment of the invention as shown in Figure 2A, the cutoff device 600 comprises three unipolar breaking blocks. The switching device 100 is then a three-pole circuit breaker. According to other embodiments not shown, the switchgear could be a uni circuit breaker, bi or four-pole. For the sake of simplification of the presentation of a preferred embodiment of the invention, the elements making up the switching apparatus 100, and in particular the unipolar breaking blocks 10 forming the breaking device 600, will be described in relation to the use position in which the circuit breaker 100 is placed in a table, with the nose 9 comprising a vertical handle and parallel to the mounting wall, the upstream connection pads 4 on the power line located at the top and forming the face upper 74 of the cut-off device 100 and the trigger 7 at the bottom. The use of relative positional terms, such as "lateral", "superior", "background", etc., should not be construed as a limiting factor. The handle is intended to control an actuating mechanism 8 of the electrical contacts.

Each unipolar break block 10 allows the breaking of a single pole. Said block is advantageously in the form of a flat housing 12 of molded plastic, with two large parallel faces 14 distant of a thickness e. In particular, in the illustrated embodiment, the thickness e is of the order of 23 mm for a 160 A caliber. The housing 12 is formed of two parts, preferably mirror-symmetrical, secured to one another. on their large face 14 by any suitable means. As illustrated in a preferred embodiment in FIG. 3, a mortise / tenon type complementary system allows the fitting of the housing portions 12 to one another, one of the two portions (not shown) comprising lugs adapted to penetrate recesses of the other. Arrangements 18 are also made in order to allow the juxtaposition of the housings 12 of unipolar block 10 and their connection to a multipolar circuit breaker 100. The unipolar break block comprises a cutoff mechanism 20 housed in the housing 12. According to a method of FIG. Particular embodiment illustrated in Figures 4 to 7, the cutoff mechanism 20 is preferably double rotary cut. In fact, the switching device 100 according to the invention is particularly intended for applications up to 630 A and in some applications up to 800 A, for which the simple cut may not be sufficient. The cutoff mechanism 20 comprises a movable contact bridge 22 having at each end a contact pad. The breaking block comprises a pair of fixed contacts 41, 51. Each fixed contact is intended to cooperate with a contact pad of the movable contact bridge 22. A first fixed contact 41 is intended to be connected to the current line by a pad. A second fixed contact 51 is intended to be connected to the trigger 7 by a downstream zone 5. Each housing part 12 comprises a corresponding passage recess. Said bridge is mounted between an open position in which the contact pads are spaced apart from the fixed contacts 41, 51 and a current flow position in which they are in contact with each of the fixed contacts. The unipolar break block 10 comprises two arc cutting chambers 24

for extinction of electric arcs. Each interrupting chamber 24 opens on an opening volume between a contact pad of the contact bridge 22 and a fixed contact. Each breaking chamber 24 is delimited by two side walls 24A, a rear wall 24B remote from the opening volume, a bottom wall 24C close to the fixed contact and an upper wall 24D. As shown in FIGS. 4 to 6, each interrupting chamber 24 comprises a stack of at least two deionization vanes 25 separated from each other by a gap of exchange of the cutoff gases. According to a preferred embodiment, the casing 12 of the cut-off block 10 further comprises arrangements allowing an optimization of the gas flow. Each interrupting chamber 24 comprises at least one output connected to at least one exhaust channel 38, 42 of the cutoff gases. Said exhaust channels 38, 42 are intended to evacuate the gases through at least one opening orifice 40 positioned on an upstream face of the housing 12 positioned opposite another downstream face. The downstream face of the housing 12 is intended to be placed in contact with the trigger 7. Each arc cutting chamber 24 preferably comprises at least one exchange space between two fins 25 connected to a gas exhaust channel 38 , 42. Preferably, all the exchange spaces are connected to the exhaust gas channels 38, 42 at a zone remote from the opening volume towards the rear wall and at the side walls of the chamber. 24. According to a particular embodiment, the movable contact bridge 22 is rotatable about one axis of rotation Y. The contact areas of said bridge are preferably placed symmetrically with respect to the Y axis of rotation. The movable contact bridge 22 is mounted floating in a rotary bar 26 having a transverse housing hole of said contact bridge. The movable contact bridge 22 passing through the transverse housing orifice protrudes on either side of the bar 26. Said rotary bar 26 is interposed between the two lateral faces 14 of the housing 12 cut-off block 10. In addition, according to this embodiment, the mounting of the contact bridge 22 and the rotary bar 26 in a unipolar breaking block 10 is "inverted": it is desired that the lever 9 of the mechanism 8 for actuating the contacts (see FIGS. 2A) is centered on the cut-off device 600 of the circuit breaker 100 in operation, the protection faceplate of the protection devices of the electrical line can then be symmetrical. To this end, a reversal of the direction of rotation of the bar 26 has been chosen, that is to say that the connection area 5 to the trigger 7 is located towards the rear of the circuit breaker 100 and the upstream connection range 4 is forward, above. Thus, as shown in FIG. 4, the movable contact bridge 22 is rotatable between an open position and a closed position of the contacts in a clockwise direction. Thus, in this preferred embodiment in which the direction of rotation of the rotating contact bridge is reversed, the escape of the gas from the contact connected to the downstream range 5 which would have traditionally been downwardly directed and rear of the device is brought up and the front of the cutoff unit 10. The area placed at the back and bottom of the device corresponds to an area in which are placed the trigger 7 and possible supports fixing such as in particular a DIN rail. In particular, the substantially parallelepipedal shape of the casing of the casing 12 of the cut-off block 10 is extended on the front side by a first gas exhaust channel 38. Said first channel makes it possible to direct the cutoff gases of the downstream range 5 coupled to the trigger 7 to the upper part of the switchgear 100.

The cutoff gases are discharged outside the housing through a through opening 40. The positioning of the opening opening 40 in the upper part of the cutoff device and in particular above the upstream range 4 also reduces risks. rebooting the bow. Furthermore, advantageously, the escape of the gases from the contact 41 connected to the upstream range 4 are also directed upwards and forward of the breaking block 10 via at least a second exhaust channel 42. at least one exhaust channel 42 is positioned at least partly in the large parallel faces 14 of the housing 12 of the cut-off block 10. As shown in FIGS. 3 and 5, according to a development mode, two lateral exhaust channels 42 are arranged in part outside the housing 12 of the cutoff unit 10. These two channels are connected to the same cutoff chamber 24. Each lateral exhaust channel 42 is connected to 9 inside the housing 12 by two orifices 44A , 44B. The portion of the outer lateral flow channel 42 may preferably be hollowed out in the wall of the housing 12. As, according to a particular embodiment of the invention, such as in particular described in the French patent application filed today in the name of the Applicant and entitled: "Functional separating spacer of the bulbs in a multipole breaking device and circuit breaker", the unipolar blocks 10 are assembled via spacers 46 to form a double envelope 48. It is advantageous to take advantage of this architecture for integrating each lateral flow channel 42 in part with the spacer 46. In particular, as illustrated in FIGS. 2A and 2B, the spacers 46 are made of molded plastic and mainly comprise a central partition 52, intended to be parallel to the large faces 14 of the cutoff blocks 10. The juxtaposition of two spacers 46 and defines a cavity 56 in which comes to house a unipolar break block 10; advantageously, two opposing bottom flanges 54 of each spacer 46 close the cavity 56 on its rear in a substantially watertight manner when the spacers 46 are tightened one on the other. Each spacer 46 includes arrangements to define in part the second lateral channels 42 of gas evacuation. Advantageously, each lateral flow channel 42 is partially etched in the large outer face 14 of the housing 12 of the bulb 10, between the two through-holes 44A, 44B, and a corresponding element 68, etching and / or contour in FIG. projection, on the central partition 52. At the time of juxtaposition and clamping of the spacer 46 on the bulb 10, it is then possible to direct the gas from the discharge port 44A to the top orifice 44B the 25 along the partition 52. The unipolar break blocks 10 are intended to be driven simultaneously, and are coupled for this purpose by at least one rod 30, in particular at the bar 26, and for example by orifices 32 forming the stops. In a preferred embodiment, a single drive rod 30 is used and each housing portion 12 includes an arc-shaped hole 34 allowing at least the mobilization of the stem 30 the tr obverse between the current flow position and the open position. As, according to a particular embodiment of the invention, such as in particular described in the French patent application filed today in the name of the Applicant and entitled: "Cutoff device comprising effective means for evacuation of cut gas", said at least second gas exhaust channel 42 passes through at least one decompression chamber 43 having at least one wall covered by a metal sheet 85. Said decompression chamber is preferably positioned as close as possible to the outlet of the chamber of decompression. arc cut. According to a particular embodiment, the decompression chamber is placed under the lower wall of the arc extension chamber 24. The inner wall of the exhaust channel covered by the metal sheet 85 is in a plane forming an angle between 45 ° and 180 ° with respect to the direction of flow of the exhaust gas. The inner wall covered with the metal sheet 85 is preferably in a plane perpendicular to the exhaust gas channel 38 (a = 90 °). The metal sheet 85 at least partially covers the inner wall of the discharge channel. The metal sheet 85 extends along a longitudinal axis of the channel. The total length L of internal wall covered by the metal sheet 85 in the direction of flow is at least equal to the square root of the weakest flow section S of said channel measured upstream of said sheet. The greatest possible length is desirable to reduce the temperature of the gases. In addition, the metal sheet 85 extends over an internal perimeter P of the exhaust channel in a direction perpendicular to the direction of the gas flow.

According to a development mode of the invention shown in FIGS. 4 and 5, all the gas exhaust ducts 38, 42 meet in a common duct leading to the upstream face of the casing 12 of the cut-off block 10. The gases cutoff are then evacuated via a single orifice opening 40. As an embodiment, the path of the cutoff gases inside the exhaust channels is shown in FIG. 5. Thus, the gases generated at the time of the breaking in the two breaking chambers 24 are advantageously directed away from the trigger 7 and any mounting brackets such as including a DIN rail. According to a first variant embodiment, the gas exhaust ducts 38 and 42 respectively of a first and second breaking chamber 24 are of different lengths, the cutoff gases flowing in a first exhaust gas channel being intended for Venturi effect the gases flowing in a second channel. According to a second variant embodiment, a gas exhaust channel 38 comprises a rotary valve 45 designed to be rotated by the passage of the cutoff gases. The rotation of the valve from a first position to a 1 o second position is intended to actuate triggering means of the cutoff device to cause the opening of the contacts. Advantageously, each part of the housing 12 is molded with internal arrangements allowing a relatively stable positioning of the various elements making up the cut-off mechanism 20, in particular two symmetrical housings for each of the breaking chambers 24, and a circular central housing allowing the setting In place of the bar 26. According to one embodiment of the invention, two sealing flanges 27 are placed respectively between the radial faces of the rotary bar 26 and the lateral faces 14 in order to ensure a seal between the inside and the outside. As an example, considering the shape of the rotary bar, the sealing flanges 27 are cylindrical in shape and may take the form of a washer. As, according to a particular embodiment of the invention, such as in particular described in the French patent application filed today in the name of the Applicant and entitled: "unipolar cutoff block comprising a rotary contact bridge, cutoff device comprising such a block and circuit breaker comprising such a device ", the rotary bar 26 comprises at least one channel 29 in direct connection between the transverse housing orifice and a side face 14 so that the cutoff gases can flow directly via said channel to at least one sealing flange 27 to push it against one of the side faces 14 to provide a seal. As shown in FIG. 7, the channel 29 of the rotary bar 26 is preferably opening and passes on either side of the rotary bar 26 from a first to a second radial face. Said opening channel 29 comprises a longitudinal axis parallel to a longitudinal axis of the rotary bar 26. In addition, the opening channel 29 preferably comprises a longitudinal axis aligned with a longitudinal axis of the rotary bar 26 so that the cutoff gases can exerting a thrust force substantially aligned with the longitudinal axis of the bar and evenly distributed on the sealing flanges. According to a particular embodiment of the sealing flanges 27 shown in Figure 7, said flanges have side flanges at least partially covering the longitudinal surface of the rotary bar 26 to partially close the transverse housing housing of the bar 26. The circuit breaker 100 according to the invention thus obtained makes it possible to best meet the following antinomic industrial constraints - the same architecture can be used for the whole range up to 800 A thanks to the use of a double break with a movable contact bridge 22; the reliability of the cutoff mechanisms and their optimization is proven by the use of proven solutions; - The trigger 7 can be connected from below to the downstream range of the cut-off device 600, which gives the best accessibility to the connection screws by reversing the direction of rotation of the rotary cutoff bridge 22; - The interchangeability of the triggers 7 is complete and allows a very delayed differentiation of the cut-off devices 100 25 - the nose 9 of the cut-off device 600 is centered, in particular at 42.5 mm, thanks to the reversal of the direction of rotation in the cutoff blocks 10, which allows to use symmetrical plastrons in the cabinets; the cut-off gases are not evacuated next to the trip unit 7, which limits the pollution on this element which can be sensitive, especially in its electronic version, and frees up the volume; the exhaust gas cutoff is also not performed under the connections 4, 5 of the circuit breaker 100, which limits the risk of ignition in cutoff.

Claims (15)

REVENDICATIONS1. Cutoff device (600) having at least one unipolar breaking block (10), said block comprising: - a movable contact bridge (22), - a pair of fixed contacts (41, 51) cooperating with said movable contact bridge and respectively connected to a current supply conductor (4,5), two arcing chambers (24) respectively opening to an opening volume of the contact bridge (22), characterized in that each interrupting chamber (24) is connected to at least one exhaust gas channel (38, 42), said exhaust ducts opening onto an upstream face of the casing (12) of the breaking block (10), said upstream face being positioned opposite another downstream face intended to be placed in contact with triggering means (7). 2. Cut-off device according to claim 1, characterized in that said exhaust channels cutoff gases (38, 42) meeting in a common conduit opening on the upstream face of the housing (12) of the cutoff block (10). ). 3. Cut-off device according to claim 2, characterized in that the exhaust gas channels (38, 42) respectively of a first and second breaking chamber (24) are of different length, the cutting gas flowing in a first gas exhaust channel for venting the gases flowing in a second channel. 4. Cut-off device according to one of claims 1 to 3, characterized in that each arc cutting chamber (24) comprises a stack of at least two deionization vanes (25) separated from each other by a gas exchange space, at least one exchange space being connected to an exhaust gas outlet channel (38, 42). 5. Cut-off device according to one of the preceding claims, characterized in that said at least one exhaust gas channel (42) of a chamber 1415 arc cutting (24) passes through at least one decompression chamber (43) having at least one wall covered with a metal sheet (85). 6. Cut-off device according to claim 5, characterized in that the decompression chamber (43) is positioned under a bottom wall of the arc extension chamber (24), said wall covered by the metal sheet (85). being in a plane forming an angle between 45 ° and 180 ° with respect to the direction of gas flow. 7. Cut-off device according to claim 6, characterized in that the wall covered by the metal foil (85) is in a plane perpendicular to the 1 o direction of the gas flow. 8. Cutoff device according to one of the preceding claims, characterized in that a gas exhaust channel (38) comprises a rotary valve (45) intended to be rotated by the passage of the cutoff gases, the rotation of the valve (45) from a first position to a second position being intended to actuate triggering means (7) to cause the opening of the contacts of the breaking device. 9. Cut-off device according to one of the preceding claims, characterized in that the movable contact bridge (22) is rotatable and is positioned in a rotary bar (26) having a transverse housing orifice 20 of said contact bridge, which protrudes from both sides of the bar (26), said rotary bar (26) being interposed between two lateral faces (14) of the housing (12) of the cutoff block (10), two sealing flanges (27) being respectively placed between the radial faces of the rotary bar (26) and the side faces (14) to ensure a seal between the inside and the outside of the cutoff block (10). 10. Cutoff device according to claim 9, characterized in that the rotary bar (26) comprises at least one channel (29) in direct connection between the transverse housing orifice and a radial face so that the gases of cutoff can flow directly via said channel to at least one sealing flange (27) to urge it against one of the side faces (14) to provide a seal. 16 11. Disconnection device according to claim 10, characterized in that said channel (29) is opening and passes on either side of the rotary bar (26) from a first to a second radial face, said channel opening comprising a longitudinal axis parallel to a longitudinal axis of the rotary bar. 12. Cutoff device according to claim 11, characterized in that the channel (29) opening comprises a longitudinal axis aligned with a longitudinal axis of the rotary bar (26) so that the cutoff gases can exert a force to push substantially aligned with the longitudinal axis of the bar and evenly distributed over the sealing flanges. 13. Cut-off device according to any one of the preceding claims 9 to 12, characterized in that the sealing flanges (27) comprise lateral cheeks at least partially covering the longitudinal surface of the rotary bar (26) to partially close the transverse housing housing of the bar (20). 14. Cut-off device according to one of the preceding claims 10 to 13, characterized in that the movable contact bridge (22) is rotatable between an open position and a closed position of the contacts in a clockwise direction. 15. Circuit breaker (100) having a cut-off device (600) according to the preceding claims, characterized in that it comprises a trigger (7) connected to the downstream ranges (5) of the cut-off device (600).