Electrical contactor including an arc-extinguishing device by extension

Abstract

Electrical contactor comprising an arc extinguishing device by elongation The invention relates to a contactor (1) comprising a contact chamber (23), a double electrical contact (3) in the contact chamber (23) movable between an open and closed position and an arc extinguishing device by elongation comprising: a stack of insulating walls (51a) spaced from each other forming a space (52a) between each neighboring insulating wall (51a), each insulating wall (51a) in which several insulating walls (51a) are made of polyamide-based thermoplastic.at least one magnetic field emitter positioned against one face of a peripheral wall (2b, 2d) generates a magnetic force of constant direction in the contact chamber (23) to move an electric arc towards the first extinction zone (5a), appearing at the transition of the double contact (3) from closed to open state during current flow in a first direction of current flow in the double contact. Figure to be published with the abbreviation: Figure 1.

Description

Title of the invention: Electrical contactor comprising an arc-extinguishing device by elongation. TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of high voltage direct current contactors in the aeronautical field and more particularly that of high voltage direct current contactors comprising an electric arc extinguishing device allowing the electric arc to be lengthened until the electric arc is extinguished.

[0002] The present invention relates to a high-voltage DC contactor with two electrical contacts comprising an arc-extinguishing device for extending the electric arc until it is extinguished. More particularly, the present invention relates to the arc-extinguishing device of such a contactor. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] High Voltage Direct Current (HVDC) is a voltage used with power electronics technology to reduce the current and therefore the losses for supplying a load at the same power compared to a low voltage direct current.

[0004] High-voltage direct current (HVDC) contactors are possibly double-contact type, comprising two electrical contacts for establishing, maintaining, and breaking an electrically conductive connection for continuous currents with a voltage typically in the range of 270 to 3000 volts in the aerospace or automotive industries. During contact separation, electrical arcs appear, accompanied by high thermal stresses and difficulties in extinguishing the electrical connection. These problems are even more critical when the electrical voltage is high. Furthermore, in the aerospace industry, at high altitudes, the contactor chamber is not hermetically sealed, so the arc length must be greater at a given voltage to achieve successful breaking; therefore, the distance between the moving and fixed contacts may be insufficient.It is therefore necessary to add arc flash extinguishing devices to extinguish them quickly.

[0005] Typically, in current contactors, the arc-extinguishing device comprises at least one extinguishing chamber in which each electric arc is displaced by a magnetic field towards arc-extinguishing fin blocks of the extinguishing device. This displacement of each electric arc is achieved by means of the Laplace electromagnetic force. Each arc-extinguishing block An arc extinguishing device (AUD) consists of multiple stacked fins spaced apart to break the electric arc into several arcs, each traveling through a different fin within the same AUD unit. Breaking the arc increases the arc voltage, thus extinguishing the arc. Each fin is electrically conductive and therefore needs to be insulated by being sufficiently far from the contactor contacts. The arc extinguishing chamber is typically located away from a contact chamber housing the double contacts. DC contactors are therefore equipped with an electrical plate, also called a switching plate, arc guide, or deflector, which begins near the first contact point and extends to the first or last fin of the AUD unit.This distance from the extinguishing chamber and the switching plates results in additional weight and an increase in the size of the contactor.

[0006] On low-current contactors of approximately 10 amperes (A), the maximum breaking current is typically greater than 100 A. It is also known that for these low-current contactors, ceramic plates are used in the extinguishing chamber instead of conductive fins to extend the electric arc from the switching plate rather than breaking it. However, these ceramic plates significantly increase the weight.

[0007] Current solutions are therefore unsatisfactory. There is thus a need for an arc-extinguishing device that is as light and compact as possible for a small-gauge HVDC contactor without increasing the mass and size of the contactor. Summary of the invention

[0008] The invention offers a solution to the problems mentioned above, by allowing the size of the electric arc in the cutting chamber to be increased using insulating walls and magnets.

[0009] Whereas prior solutions require a person skilled in the art to cut or extend the electric arc to direct it to an area far from the breaking chamber, necessitating the movement of the electric arc using a conductive plate also called a deflector or arc guide, the solution of the invention consists, on the contrary, of extending the electric arc in an area close to the breaking chamber. Thus, the contactor is compact.

[0010] One aspect of the invention relates to a DC contactor comprising: • a case containing: • at least one peripheral wall of a contact chamber of the housing, • an upper wall and a lower wall opposite each other, joining at least one peripheral wall covering the contact chamber of the housing, • a double electrical contact in the contact chamber comprising, a first fixed contact, a second fixed contact and a movable electrical bridge that can be positioned between a closed position and an open position, • characterized in that it further comprises an arc-extinguishing device by arc-extension located in the contact chamber comprising: • a first extinction zone located between the upper wall and the lower wall, comprising a stack of electrically spaced insulating walls forming a gap between each adjacent insulating wall, in which several insulating walls are made of polyamide-based thermoplastic, • at least one magnetic field emitter positioned against a peripheral wall generating a magnetic force of constant direction in the contact chamber to move an electric arc towards the first extinction zone, appearing when the moving bridge moves from the closed position to the open position during current flow in the first direction of current flow in the double contact

[0011] Thanks to the stack of electrically insulating walls extending into the contact chamber and the magnet directing the electric arc towards these insulating walls, the electric arc includes sections extending between each gap formed between two electrically insulating walls, thus lengthening the electric arc until it is extinguished. An additional effect is achieved through the material of the insulating walls, which contributes to cooling the arc. Indeed, the polyamide-based thermoplastic, upon contact with an electric arc, produces outgassing of the plastic material, which cools the arc, and an increase in pressure in the interruption zone. These two phenomena are favorable to the interruption of the electric arc.

[0012] Thus, by increasing the electric arc through the insulating plates in an extinction zone opposite the double contact, the contactor according to the invention advantageously makes it possible to neutralize the electric arc, without having to manifestly increase the volume or mass of said contactor.

[0013] According to one embodiment, the arc flash extinguishing device comprises a second extinguishing zone located in the contact chamber opposite the first extinguishing zone, the double electrical contact being located between the first extinguishing zone and the second extinguishing zone, the second extinguishing zone comprising a stack of insulating walls spaced apart between the upper and lower walls, forming a gap between each adjacent insulating wall, and in which several insulating walls in this second zone are made of polyamide-based thermoplastic. This allows the electric arc to be interrupted on each side of the moving bridge.

[0014] According to one embodiment, the insulating walls include a free edge opposite the double contact. The fact that each insulating wall includes a free edge opposite the double electrical contact allows for a contactor without a conductive plate of the deflector type that directs the electric arc to the extinction zone.

[0015] According to one embodiment, each insulating wall comprises a free edge, of which: • at least one insulating wall includes its free edge opposite the two fixed contacts, • at least one insulating wall includes its free edge opposite the movable bridge in the closed position and • at least one insulating wall includes its free edge opposite the movable bridge in the open position.

[0016] The fact that insulating walls include a free edge opposite the double electrical contact, some of which are opposite the two fixed contacts, allows, on the one hand, for a contactor without a conductive plate of the deflector type bringing the electric arc to the extinction zone and, on the other hand, for a single block of wall to operate in the event of an electric arc forming between the moving bridge and either the first or the second fixed contact.

[0017] According to one embodiment, the insulating walls are appendages, each extending from at least one internal surface of a peripheral wall of the housing, and are made of the same material as the insulating walls. This allows the insulating walls and a peripheral wall to be made in a single block, thus simplifying and reducing the cost of the contactor.

[0018] According to an example of this embodiment, the housing comprises: • an external block comprising the upper wall and • an internal block mounted within the external block comprising the lower wall, at least one peripheral wall, and the insulating walls.

[0019] This makes it possible to produce the insulating walls and part of the housing in a single block, thus simplifying and making the contactor less expensive.

[0020] According to one embodiment, each insulating plate comprises a free edge located: • opposite the entire length of one edge of the movable bridge and • opposite the first electrical contact and the second electrical contact, • The first magnetic field emitter is located against a wall peripheral located opposite the first electrical contact and a second The magnetic field emitter is located against a peripheral wall situated opposite the second electrical contact.

[0021] This allows for a compact electric arc extinguishing device while having an electric arc that can enlarge by moving towards the opposite fixed contact.

[0022] By an element or edge opposite another element or edge, it is understood that there is only a space between the two elements or edges. In other words, an element or edge of an element of one that is opposite another element or edge can be seen from the other element or edge.

[0023] According to one embodiment, the height of the stack of insulating walls, measured along a first direction between one end of the stack at the level of the first insulating wall of the stack and an opposite end of the last insulating wall of the stack, corresponds, to within ±10%, to a height measured in the contact chamber along the first direction between one end of the moving electrical bridge and an opposite end of the first fixed contact or the second fixed contact. This optimizes the overall size while optimizing the enlargement of the electric arc by the insulating plates.

[0024] According to one embodiment, • The movable bridge includes a U-shaped section, • The upper wall includes a central zone comprising: • a protruding indentation in the contact chamber corresponding to the shape of the internal part of the U-shaped section of the moving bridge to guide it during its movement between the open and closed positions, • a central opening inside the imprint, • an actuator comprising • a second housing forming an actuator chamber mounted on the first box on the side of the top wall and • a control rod in the actuator chamber passing through the central opening, attached or integral with the moving bridge to move it from a closed position to an open position and vice versa.

[0025] This allows, on the one hand, to guide the mobile bridge and, on the other hand, to use the U-shaped profile to have a surface of the mobile bridge facing the extinction zone.

[0026] According to a particular feature of this embodiment, the first insulating wall of the battery has its free edge facing a surface of the moving bridge in the open position. This makes it possible to increase the distance of the electric arc while optimizing the sizing of the contactor.

[0027] According to one embodiment, the insulating walls are parallel to each other. This makes it easy to manufacture the insulating walls, for example by molding with at least one peripheral wall.

[0028] According to one embodiment, the periphery of the housing comprises a one-piece thermoplastic part based on polyamide comprising: • a first peripheral wall, • a second peripheral wall and a fourth peripheral wall opposite the second peripheral wall, each being contiguous to the first peripheral wall, and • the insulating walls of the first extinguishing zone having a rectangular plate shape parallel to each other including a free edge, each extending on one side from an internal surface of a first peripheral wall to their free edge and on the other side from the second peripheral wall to the fourth peripheral wall.

[0029] This shape reduces the overall size by following the shape of the movable bridge.

[0030] According to one embodiment, the housing is a rectangular parallelepiped in which the number of peripheral walls is four.

[0031] According to a variant of this embodiment, the housing is cylindrical and comprises a single peripheral wall.

[0032] The geometric specificities described above advantageously allow the electric arc to be enlarged compared to a contactor of the same dimensions under the same current, while minimizing the mass and volume of the contactor.

[0033] According to a particular feature of this invention, the contactor is devoid of an additional part attached to the housing serving as an arc deflector as in the prior art, which generally extend from the arc extinction zone towards the moving bridge.

[0034] In addition to the characteristics mentioned in the preceding paragraphs, the contactor according to one aspect of the invention may have one or more additional characteristics from among the following, considered individually or in all technically possible combinations: • In the closed position of the moving bridge, the first and second moving contacts are in contact with the first and second fixed contacts respectively, and in the open position of the moving bridge, the first and second moving contacts are at a distance from the first and second fixed contacts respectively; • Within the same arc extinction zone, the insulating walls are in the form of stacked fins, spaced apart and parallel; • Each arc flash zone comprises a first insulating wall opposite the moving electrical bridge in the open position and a final electrical wall opposite each fixed contact; • The maximum distance between two adjacent insulating walls is between 1 mm and 4 mm. • The maximum distance between the insulating wall closest to the moving bridge in the open position and the moving bridge is between 3 mm and 8 mm. • The maximum distance between the insulating wall closest to the first fixed contact and the moving bridge is between 3 mm and 8 mm. • The lower wall has a first and a second orifice, each traversed respectively by a first fixed stud and a second fixed stud, each comprising respectively the first fixed contact and the second fixed contact. • The lower wall has insulating separation walls between the first and second fixed pads and a central orifice through which the control rod passes to guide it.

[0035] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0036] The figures are presented for illustrative purposes only and are in no way limiting of the invention.

[0037] [Fig.1] is a schematic cross-sectional view of part of a contactor according to a first embodiment of the invention.

[0038] [Fig.2A] is a schematic cross-sectional view along axis II of the [Fig.l] of the contactor according to the second embodiment.

[0039] [Fig.2B] is a schematic view according to a section II-II of the contactor of [Fig.l].

[0040] [Fig.3A] is a cross-sectional view along axis III-III of [Fig.2B] of a part of the contactor according to the first embodiment.

[0041] [Fig.3B] is a cross-sectional view along axis IV-IV of [Fig.2B] of a part of the contactor according to the first embodiment.

[0042] [Fig.4A] is a cross-sectional view along axis III-III of [Fig.2B] of a part of the contactor according to the second embodiment.

[0043] [Fig.4B] is a cross-sectional view along axis IV-IV of [Fig.2B] of a part of the contactor according to the first embodiment. DETAILED DESCRIPTION

[0044] The figures are presented for illustrative purposes only and are in no way limiting of the invention.

[0045] Figures 1 to 4B show different cross-sections of different parts of a contactor 1 according to one embodiment. The invention relates in particular to the part where a contact chamber 23 of the contactor 1 is located, as shown in each figure.

[0046] The double-break contactor 1 of the invention is preferably a high-voltage direct current (HVDC) contactor. However, the principle of the invention can be adapted to any type of contactor, including all switches and circuit breakers in which electric arcs are likely to be generated.

[0047] Conventionally, the contactor 1 of the invention comprises a housing 2 having at least one peripheral wall 2a, 2b, 2c, 2d delimiting the contact chamber 23. In this case, the housing 2 has a shape substantially of a rectangular parallelepiped and therefore comprises four peripheral walls designated: a first, a second, a third and a fourth peripheral walls 2a, 2b, 2c, 2d, extending to one another by a lateral edge forming between them one of the four internal corners of the contact chamber 23 of the housing 2. In other words, the first peripheral wall 2a is opposite the third peripheral wall 2c and is contiguous by a first and second lateral edges to respectively the second peripheral wall 2b and the fourth peripheral wall 2d referenced in Figures 2A to 4B. The [Fig.l] represents a cross-section of a portion of the contactor 1 located in the middle of the first and third peripheral walls 2a, 2c, oriented towards an internal surface of the second peripheral wall 2d. .

[0048] Of course, the shape of the housing 2 may have more or less than 4 peripheral walls, for example only one having a cylindrical shape.

[0049] The housing 2 further comprises an upper wall 2f and a lower wall 2e opposed to each other by joining the at least peripheral wall, in this case the four peripheral walls 2a, 2b, 2c, 2d, covering the contact chamber 23 of the housing 2.

[0050] Optionally, in this example, the housing 2 comprises an external block 20 including the upper wall 2f and four side walls 20a, 20c, of which only two are visible in [Fig. 1], an external lower wall 20e, and an upper actuator wall 20f. The external block 20 includes an actuator chamber 26 delimited on one side by the upper wall 2f and the upper actuator wall 20, and on the other side by the four side walls 20a, 20b, of which only two are referenced and visible in [Fig. 1]. The actuator is not shown but may be electromagnetic, hydraulic, or pneumatic. The housing 2 in this example includes an internal block mounted within the external block comprising the lower wall 2e and the four peripheral walls 2a, 2b, 2c, and 2d.In this example, the internal block, as shown in figures 2A to 4B, is formed by two half-shells joined to each other at a peripheral wall, in this case at the . middle of the first 2a and the third peripheral wall 2c. In this example, the external block is also formed in two half-shells, each mounted on a half-shell of the internal block, allowing the internal block to be covered.

[0051] The contactor 1 further includes a double electrical contact 3 located in the contact chamber 23. The double electrical contact 3 includes a first fixed contact 30a, a second fixed contact 30b and a movable electrical bridge 31 between a closed position and an open position. The actuator not shown includes a control rod 36 moving the electrical bridge between the open position and the closed position. The movable electrical bridge 31 includes a first movable contact 31a and a second movable contact 31b opposite each other in the open position and in contact in the closed position, respectively, with the first and second fixed contacts 30a, 30b. The movable electrical bridge 31a in this example has a first plate in the shape of a rectangular parallelepiped, and at least two walls extending each from a longitudinal edge of the first plate towards the upper wall 2f, as seen in [Fig.2B] representing a cross-section of the internal block of housing 2 according to cross-section ILII shown in [Fig. 1]. .

[0052] The double contact 3 comprises a first and second pad, each passing through the lower wall 3f, as can be seen in figures 3A to 4B, each comprising respectively the first and second fixed contacts 31a, 31b. For example, the first and second pads are mounted during the assembly of the two half-shells.

[0053] Depending on how the contactor 1 is electrically connected, one of the fixed terminals, in this case the first fixed terminal 3a, is a positive terminal while the other (here the second fixed terminal 3b) is a negative terminal as shown in [Fig. 2A] representing a cross-section of the internal block of the housing 2 according to section II shown in [Fig. 1]. In the figures, the first fixed terminal 24a is a positive terminal while the second fixed terminal 24b is a negative terminal.

[0054] When the moving bridge 31 is in the closed position, a current 1 flows from the first fixed contact 30a in contact with the first moving contact 31a to the second fixed contact 30b in contact with the second moving contact 31b through the moving bridge 30. Of course, the electrical flow of the current 1 can be reversed so that the current 1 flows from the second fixed contact 30b to the first fixed contact 30a through the moving bridge 31.

[0055] Figures 1 to 4B represent the movable bridge 31 in the open position. When the movable bridge 31 is opened, the moving contacts 31a, 31b gradually move away from the fixed contacts 30a, 30b, and a first electric arc 8a is likely to appear between the first moving contact 31a and the first fixed contact 30a, while a second electric arc 8b is likely to appear between the second moving contact 31b and the second fixed contact 30b. Figures 3A and 4A Figures 3B and 4B each represent a cross-section of the internal block of housing 2 according to section III-III shown in [Fig. 2B], where the first electric arc 8a is shown in black, which has just formed in [Fig. 3A] and will extinguish in [Fig. 4A]. Figures 3B and 4B each represent a cross-section of the internal block of housing 2 according to section IV-IV shown in [Fig. 2B], where the second electric arc 8b is shown in black, which has just formed in [Fig. 3B] and will extinguish in [Fig. 4B].

[0056] In order to quickly extinguish these electric arcs 8a, 8b in a conventional manner, the contactor 1 of the invention includes an electric arc extinguishing device 5, referenced in Figures 3B and 4B, intended to lengthen each electric arc 8a, 8b.

[0057] This arc blowing device 5 includes a first extinguishing zone 5a located between the upper wall 2f and the lower wall 2e, housed in the contact chamber 23 opposite the fixed contacts 30a, 30b and the movable electrical bridge 31.

[0058] The first extinguishing zone 5a comprises a stack of electrically insulating walls 51a spaced apart, forming a gap 52a between each adjacent insulating wall 51a. The insulating walls 51a, 51b of each zone are made of polyamide-based thermoplastic. This material contributes to arc cooling, thereby cooling the cutting gas flow. Indeed, this specific material, upon contact with the electric arc 8a, 8b, produces outgassing of the plastic, which cools the electric arc, and an increase in pressure in the contact chamber 23. These two phenomena are favorable to the interruption of the electric arc 8a, 8b.

[0059] Each insulating wall 51a includes a free edge 510a opposite the double electrical contact 3. The insulating walls 51a are in this example, located close to the double electrical contact 3, such that the distance between each free edge 510a and the first fixed contact 30a and the second fixed contact 30b are in this example each shorter than the smallest distance measured between the first fixed contact 30a and the second fixed contact 30b.

[0060] In this embodiment, the arc-blowing device 5 comprises a second extinguishing zone 5b located in the contact chamber 23 opposite the first extinguishing zone 5a. The second extinguishing zone 5b is similar to the first extinguishing zone 5a; here, it is symmetrical to the first extinguishing zone 5a with respect to a plane transverse to the moving bridge 23. The second extinguishing zone 5b therefore comprises a stack of insulating walls 51b located between the upper wall 2f and the lower wall 2e, housed in the contact chamber 23, with each insulating wall 51b facing the fixed contacts 30a, 30b and the moving electrical bridge 31.

[0061] The arc flash extinguishing device 5 includes at least one magnetic field emitting device 4a, 4b of constant direction, generating a magnetic force. This magnetic field emitting device 4a, 4b may, for example The device comprises one or more magnets and / or one or more coils; in this case, it is a magnet. The magnetic force generated by the magnetic field-emitting device 4a, 4b exerts a Laplace electromagnetic force on each electric arc 8a, 8b, displacing it in the direction and towards the corresponding electric arc extinction zone 5a, 5b. Optionally, as shown in [Fig. 1], the movable bridge 31 includes a U-shaped section whose first and second edges are opposite one of the insulating walls 51a, 51b, in this case, the first insulating walls 51a, 51b of the stack, respectively, to the first and second extinction zones 5a, 5b.

[0062] In this case, the contactor 1 includes a first magnetic field emitter 4a located in a first housing of the casing 2 formed by the fourth peripheral wall 2d located opposite the first fixed electrical contact 30a so as to move an electric arc in the direction and towards the first arc-quenching zone 5a. In this case, the contactor 1 includes a second magnetic field emitter 4b located opposite the first magnetic field emitter 4a in a second housing of the casing 2 formed by the second peripheral wall 2b located opposite the second fixed electrical contact 30b.

[0063] Thus, in this example, each half-shell comprises a housing for a magnet forming the magnetic field emitter 4a, 4b as seen in 2A and 2B. The internal block of the housing 2 further comprises a first side wall 21d and a second side wall 21b, each joining the opposite ends of two portions of the first and third peripheral walls 2a, 2c extending respectively on a first and second side, beyond the second and fourth peripheral walls 2b, 2d. The first housing is delimited on one side between the fourth peripheral wall 2d and the first side wall 21d and on the other side between the two portions on the first side of the first and third peripheral walls 2a, 2c. The second dwelling is delimited on one side between the second peripheral wall 2b and the second lateral wall 21b and on the other side between the two portions of the second side of the first and third peripheral walls 2a, 2c.

[0064] Each arc-extinguishing zone 5a, 5b comprises two extinguishing chambers, one opposite the first fixed contact 50a and the other opposite the second fixed contact 50b. The insulating walls 51a, 51b of each arc-extinguishing zone 5a, 5b are parallel and, depending on the direction of the current, are designed by each magnetic field-emitting device 4a, 4b to enlarge each electric arc 8a, 8b by forming waves as shown in Figures 4A, 4B. These waves thus lengthen each electric arc 8a, 8b until it is extinguished.

[0065] In this example, the insulating walls 51a, 51b are appendages, each extending from at least one internal surface of one of the peripheral walls of the housing. 2. In this example, the insulating walls 51a, 51b of the first and second extinction zones 5a, 5b each have a rectangular cross-section plate shape parallel to each other, each extending: • along a width of an internal surface of respectively the first and third peripheral walls 2a, 2c up to their free edge 510a and • along a length by connecting each a second peripheral wall 2b to a fourth peripheral wall 2d opposite each other.

[0066] In this example, the insulating walls 51a of the first arc-extinguishing zone 5a extend from the first peripheral wall 2a.

[0067] In this example, the insulating walls 51a are each formed in two parts according to the two half-shells forming the first peripheral wall 2a.

[0068] In this example, the insulating walls 51b of the second arc extinction zone 5b extend from the third peripheral wall 2c. In this case, they are like those of the first arc extinction zone 5a, formed in two parts by the two half-shells.

[0069] According to another example, each insulating wall 5la, 51b of the first or second arc-quenching zone 5a, 5b is monolithic (in one piece) and extends from a single monolithic peripheral wall. For example, some of the insulating walls 51a, 51b extend from part of the first or third peripheral wall 2a, 2c of one of the two half-shells, and others from the other part of the first peripheral wall 2a, 2c of the other half-shell. According to yet another example, some or all extend from the second peripheral wall 2b or the fourth peripheral wall 2d, preferably by coming into contact with the inner surface of the first peripheral wall 2a.

[0070] Thus in this example, the internal block is also made of thermoplastic based on polyamide.

[0071] In this embodiment, each stack comprises four insulating walls 51a, 51b such that the first insulating wall 51a, 51b of the stack is opposite the moving bridge 31 in the closed position, and the last insulating wall 51a, 51b of the stack is opposite an edge of the first and second pads 3a, 3b in the contact chamber 23. Each longitudinal edge of each insulating wall 51a, 51b is opposite an edge of the moving bridge and of the first and second pads 3a, 3b. In this example, the maximum distance between the insulating wall closest to the moving bridge in the open position and the moving bridge is 5 mm. In this case, each free edge of each insulating wall is aligned in a plane parallel to the direction of movement of the moving bridge. The maximum distance between the insulating wall closest to the first fixed contact and the moving bridge is therefore also 5 mm. The same applies to the second fixed contact.In this case, each height value of space 52b, 52a between two walls. insulating walls 51a, 5b is identical. Thus the height of the stack of insulating walls 51a, 51b of each extinction zone 5a, 5b, measured along a first direction between one end of the stack at the level of the first insulating wall 5la, 51b of the stack and an opposite end of the last insulating wall 51a, 51b of the same stack, corresponds to + or - 10% a height measured in the contact chamber 23 along the first direction between one end of the moving electrical bridge 31 and an opposite end of the first fixed contact 30a or the second fixed contact 30b.

[0072] The value of the height between the upper wall 2f and the first insulating wall 51a, 51b is in this case the same + or - 10% as the value of the height of a space 52b, 52a between two insulating walls 51a, 5b. For example here the distance between two insulating walls 51a, 51b is 2mm.

[0073] The upper wall 2f comprises a central zone including: • a projecting recess 23f corresponding to the shape of the internal part of the U-shaped section of the movable bridge 31 to guide it during its movement between the open and closed positions, • a central opening inside the recess 23f through which the control rod 36 passes.

[0074] Thanks to the invention, the electric arc on each side of the moving bridge, if it forms, will, according to Laplace's law, move towards the first or second extinction zone without the addition of any magnetic field and, under the magnetic field of the emitter, be deformed by the insulating walls 51a, 51b as they enter each space 52a, 52b. Each electric arc 8a, 8b is naturally directed towards the other chamber of the extinction zone 5a, 5b, as shown in [Fig. 2B] by the arrows 81. This displacement also increases the electric arc 8a, 8b until it is extinguished. Thus it is important that each free edge 510a, 510b of the insulating walls 51a, 51b of each extinction zone 5a, 5b are opposite the double contact 3 that the distance between the two fixed contacts 30a, 30b.

[0075] Unless otherwise specified, the same element appearing on different figures has a unique reference.

Claims

1. Demands DC contactor (1) comprising: - a case (2) comprising: • at least one peripheral wall (2a, 2b, 2c, 2d) of a contact chamber (23) of the housing (2), • an upper wall (2f) and a lower wall (2e) opposite each other joining at least one peripheral wall (2a, 2b, 2c, 2d) covering the contact chamber (23) of the housing (2), - a double electrical contact (3) in the contact chamber (23) comprising, a first fixed contact (30a), a second fixed contact (30b) and a movable electrical bridge (31) that can be moved between a closed position and an open position, - characterized in that it further comprises an electric arc extinguishing device (5) by electric arc extension located in the contact chamber (23) comprising: • a first extinction zone (5a) located between the upper wall (2f) and the lower wall (2e), comprising a stack of electrically insulating walls (51a) spaced apart from each other to form a gap (52a) between each adjacent insulating wall (51a), in which several insulating walls (51a) are made of polyamide-based thermoplastic • at least one magnetic field emitter (4a, 4b) positioned against a peripheral wall (2b, 2d) generating a magnetic force of constant direction in the contact chamber (23) to move an electric arc (9, 10) towards the first extinction zone (5a), appearing at the movement of the moving bridge (31) from the closed position to the open position during a current flow in a first direction of current flow in the double contact (3).

2. Contactor (1) according to claim 1, wherein the arc extinguishing device (5) comprises a second extinguishing zone (5c) located in the contact chamber (23) opposite the first extinguishing zone (5a), the double electrical contact (3) being located between the first extinguishing zone (5a) and the second extinguishing zone (5c), the second extinguishing zone (5c) comprising a stack of insulating walls (51c) spaced apart from each other between the upper wall (2f) and the lower wall (2e), forming a space (52b) between each adjacent insulating wall (51b), and wherein several insulating walls (51b) of this second zone are made of polyamide-based thermoplastic.

3. Contactor (1) according to claim 1 or 2, wherein each insulating wall (51a, 51b) comprises a free edge (510a, 510b), of which: • at least one insulating wall (5la, 51b) comprises its free edge (510a, 510b) opposite the two fixed contacts, • at least one insulating wall (5la, 51b) comprises its free edge (510a, 510b) opposite the moving bridge in the closed position and • at least one insulating wall (5la, 51b) comprises its free edge (510a, 510b) opposite the moving bridge in the open position.

4. Contactor (1) according to any one of the preceding claims, wherein the insulating walls (51a, 51b) are appendages extending each from at least one internal surface of a peripheral wall of the housing (2), and are of the same material as at least one peripheral wall (2a, 2b, 2c, 2d).

5. Contactor (1) according to the preceding claim, in which the housing (2) comprises: - an external block (20) comprising the upper wall (2f) and - an internal block mounted in the external block comprising the lower wall (2e), at least one peripheral wall, (2a, 2b, 2c, 2d) and the insulating walls (51a, 51b).

6. Contactor (1) according to any one of the preceding claims, characterized in that: - each insulating wall (51a) comprises a free edge (510a) located: • opposite the entire length of one edge of the movable bridge (31) and • opposite the first electrical contact (3a) and the second electrical contact (3b), - the first magnetic field emitter (4a) is located against a peripheral wall (2b) situated opposite the first electrical contact (3a) and a second magnetic field emitter (4b) is located against a peripheral wall (2d) situated opposite the second electrical contact (3a).

7. Contactor (1) according to any one of the preceding claims, wherein a height of the stack of insulating walls (51a, 51b) measured along a first direction between one end of the stack at the level of the first insulating wall (5la, 51b) of the stack and an opposite end of the last insulating wall (51a, 51b) of the stack, corresponds to within ±10% a height measured in the contact chamber along the first direction between one end of the moving electrical bridge (31) and an opposite end of the first fixed contact (30a) or the second fixed contact (30b).

8. Contactor (1) according to any one of the preceding claims, wherein: - the movable bridge (31) includes a U-shaped section, - the upper wall (2f) includes a central zone including: • a protruding indentation (23f) in the contact chamber (23) corresponding to the shape of the internal part of the U-shaped section of the movable bridge (31) to guide it during its movement between the open and closed positions, • a central opening inside the imprint, - an actuator comprising • a second casing forming a chamber actuator (26) mounted on the first housing on the upper wall side (2f) and • a control rod (36) in the actuator chamber (26) passing through the central opening, attached to or integral with the movable bridge (31) for to move it from a closed position to an open position and vice versa.

9. Contactor (1) according to any one of the preceding claims, characterized in that the insulating walls (51a, 51b) are parallel to each other.

10. Contactor (1) according to any one of the preceding claims, wherein the periphery of the housing (2) comprises a one-piece piece made of polyamide-based thermoplastic comprising: - a first peripheral wall (2a), - a second peripheral wall (2b) and a fourth peripheral wall (2d) opposite the second peripheral wall (2b), each being contiguous to the first peripheral wall (2a), and - the insulating walls (51a) of the first extinction zone (5a) having a rectangular cross-section plate shape parallel to each other comprising a free edge (510a), each extending on one side from an internal surface of a first peripheral wall (2a) to their free edge (510a) and on the other side from the second peripheral wall (2b) to the fourth peripheral wall (2d).