High-voltage contactor

Abstract

The invention relates to a high-voltage contactor (10) having: an electromagnetic actuator (12) that has a coil (14) and a ferromagnetic armature (22) movable by the coil (12); a housing (58) that has a contact chamber (42); an electrically conductive contact bridge (44) that is movable in the contact chamber (42) by means of the actuator (12) into a contact position, in which a first contact element (54) that is fixed to the housing is electrically connected via the contact bridge (44) to a second contact element (56) that is fixed to the housing, and into an opening position, in which electrical contact between the first contact element (54) and the second contact element (56) is interrupted; and a single-piece actuating rod (38) that is supported directly on the armature (22), holds the contact bridge (44) and has an integrally connected stop (48) for a restoring spring (36) which is supported on the housing and which preloads the actuating rod (38) into its opening position.

Description

[0001] High-voltage contactor

[0002] Description

[0003] The invention relates to a high-voltage contactor or high-voltage relay with an electromagnetic actuator with a coil, a movable armature, a housing with a contact chamber, and a contact bridge which can be moved by means of the actuator in the contact chamber into a first position, the contact position, in which a first contact element fixed to the housing is electrically connected to a second contact element fixed to the housing via the contact bridge, and into a second position, the open position, in which an electrical contact between the first contact element and the second contact element is interrupted.

[0004] Such high-voltage contactors are required to be able to establish and disconnect electrical connections in the no-load case or in the load case, where voltages of more than 1000 V and currents of more than 1000 A can occur in the load case, which can occur, for example, in an electric motor-driven vehicle between the traction battery and the drive motor or between a charging station and the traction battery.

[0005] DE 44 39 177 B4 and GB 2 277 834 B disclose typical high-voltage contactors which each have two axially aligned actuating rod elements, namely an actuator-side actuating rod element and a contact bridge-side actuating rod element which is pushed into its contact position by the actuator-side actuating rod element when the actuator is activated.

[0006] The present invention is based on the object of creating a simple and reliable high-voltage contactor.

[0007] This object is achieved with a high-voltage contactor according to the invention having the features of claim 1. For the sake of simplicity, the term "high-voltage contactor" will be used below, although this also includes a high-voltage relay. Furthermore, the terms "radial," "axial," and "diametrical" refer to the center axis of the high-voltage contactor, along which the actuator's armature can move linearly.

[0008] The high-voltage contactor according to the invention has a linear electromagnetic actuator. In this context, an electromagnetic actuator is understood to be any actuator that generates a linear movement due to a force caused by electromagnetism. The electromagnetic actuator comprises a coil, which preferably consists of a coil carrier and a winding wound thereon, as well as a ferromagnetic armature that is movable due to the electromagnetic force of the activated actuator and is arranged, for example, within the coil.

[0009] The high-voltage contactor further comprises a preferably multi-part housing, made, for example, of plastic, with an inner contact chamber arranged axially adjacent to the actuator. The housing is preferably designed such that the contact chamber is almost completely sealed from the environment, so that only a minimal air exchange and thus a minimal pressure equalization with the environment takes place. Generally, when an arc is formed, a relatively high gas pressure is suddenly generated in the contact chamber compared to the environment. This pressure cannot be immediately compensated or reduced due to the slow air exchange and pressure equalization between the contact chamber and the environment. The high gas pressure promotes the extinguishing of the arcs.

[0010] The high-voltage contactor has a first and second contact element fixedly mounted on the housing. Both of these contact elements extend into the contact chamber and can each be permanently connected to a busbar outside the high-voltage contactor. In a motor vehicle, one of these contact elements can lead to a traction battery, while the other, for example, can lead to power electronics for an electric vehicle drive motor or can be connected to an external charging station. An electrical connection between these two contact elements can be established, if required, via a contact bridge, which is moved along a linear motion axis in the contact chamber by the actuator.In this case, the contact bridge, at the ends of which two electrical contacts can be formed, is usually moved axially against the two contact elements fastened to the housing by energizing a coil winding of the electromagnetic actuator in order to establish, in a first position, the contact position, an almost resistance-free electrical connection between the first contact element and the second contact element via the contact bridge.

[0011] For this purpose, the contact bridge is operatively connected to the armature via a one-piece actuating rod and is pressed against the contact elements in the closing direction by the pushing movement of the activated armature. The one-piece actuating rod is supported directly on the armature. The one-piece actuating rod also holds the contact bridge and has a stop for a return spring formed integrally with the actuating rod. The return spring is supported at its other end on the housing side and preloads the actuating rod into its open position.

[0012] To open the electrical connection, the electromagnetic actuator is electrically deactivated, causing the return spring to push the one-piece actuating rod into its open position, which also pushes the armature and contact bridge into their open positions. By pushing the contact bridge into its open position, the electrical connection between the first contact element and the second contact element is interrupted.

[0013] The multifunctional, one-piece actuating rod is a cost-effective component that combines a variety of functions, simplifying assembly and improving functional reliability. The one-piece actuating rod can be designed as a substantially cylindrical and relatively narrow shaft, so that the overall mass of the actuating rod is low. The outer diameter of the cylindrical shaft body can be reduced to 3.0 mm. The spring stop is preferably provided on the contact bridge-side axial end of the one-piece actuating rod. This enables, in particular, simple assembly.

[0014] Preferably, the anchor-side axial end of the one-piece actuating rod rests directly on the proximal end face of the anchor, but is not necessarily firmly connected to it. This facilitates assembly.

[0015] The one-piece actuating rod is preferably formed by a metallic cold-extruded rod body. This allows the actuating rod to be manufactured very inexpensively. Particularly preferably, the armature-side axial end of the one-piece actuating rod is additionally swaged. Since the axial length of the rod body or the actuating rod cannot be precisely ensured during the production of the rod body by cold extrusion, the exact overall length is adjusted to the exact target overall length after cold extrusion by calibrating swaging, if necessary by several individual fine swaging steps. This is of great importance because it determines the axial contact forces between the contact elements fixed to the housing and the contact bridge in their contact position.

[0016] Preferably, the one-piece actuating rod is formed by a metallic rod body whose specific magnetic saturation is less than 1.8 Tesla. This ensures that the specific magnetic saturation of the ferromagnetic armature is considerably greater, so that at most a small magnetic disturbance of the main magnetic circuit is caused via the rod body.

[0017] The high-voltage contactor can preferably have a magnetic field conductor that magnetically connects at least two permanent magnets arranged diametrically opposite one another in the contact chamber. For this purpose, the magnetic field conductor is in direct contact with the at least two permanent magnets, which are preferably each arranged radially adjacent to the contact point between the first contact element and the first contact plate of the contact bridge or to the contact point between the second contact element and the second contact plate of the contact bridge. Separating the contact bridge from the contact elements can lead to arcing, which can damage the high-voltage contactor and, in particular, the contact chamber and its adjacent components.

[0018] By means of the magnetic fields of the permanent magnets, also known as blowout magnets, or by means of the Lorentz force exerted by the magnetic fields, the arc created when the contact plates and contact elements are separated can be deformed into an arc, thereby elongating it and thus extinguishing it. The permanent magnets are aligned in such a way that the Lorentz force deforms the arcs into an arc. The magnetic field conductor represents a magnetic short circuit between the permanent magnets, which, on the one hand, leads to relatively good magnetic field concentration and, on the other hand, is particularly beneficial for both the local field strength and the field homogeneity of the magnetic fields generated by the permanent magnets, which ultimately has a beneficial effect on the extinguishing of the arcs.

[0019] The magnetic field guide preferably rests axially against the return plate and is therefore in direct magnetically conductive contact with the return plate and thus also with the actuator's iron circuit. The magnetic field guide can furthermore have a plurality of lugs. These are projections that extend axially from an end wall of the magnetic field guide toward the return plate and that extend circumferentially along the side wall of the magnetic field guide. The lugs are thus part of the side wall of the magnetic field guide and are preferably rectangular, forming two lug side surfaces arranged parallel to one another and aligned parallel to the movement axis.

[0020] The return plate can have recesses corresponding to the lugs, into which the lugs engage. The recesses are, for example, openings in the return plate that extend axially either partially into the return plate or completely through the return plate. The recesses are preferably rectangular with respect to a cross-sectional plane oriented orthogonal to the axis of movement of the actuator, but can also have any other suitable shape, for example a circle or an oval. The inner distance between the two walls of the respective recesses facing each other in the circumferential direction is only slightly greater than the width of the lug in the circumferential direction, so that each lug rests with at least one of its nose side surfaces against the corresponding inner wall of its assigned recess."Slightly larger" here means that the recess is preferably a few tenths of a millimeter larger, so that the magnetic field guide can be inserted relatively easily into the recess with its lugs, but the magnetic field guide can only be moved to a relatively small extent. This creates a positive connection between the magnetic field guide and the return plate, which prevents both translational movement of the magnetic field guide transverse to the movement axis and rotational movement around the movement axis.

[0021] In addition, the one-sided axial support of the magnetic field guide prevents translational movement in either axial direction, so that when assembled, only a single degree of freedom exists in the axial direction opposite to the return plate. This plug-in connection ensures that the magnetic field guide can be pre-assembled during the manufacturing process without the use of additional guide or fastening devices, and during subsequent manufacturing steps, it is securely held in its final position on the return plate by gravity, which acts against the last remaining degree of freedom. If necessary, an additional securing device can be provided, for example in the form of a hold-down device, a latching hook connection, or a lifting device, which also blocks the last degree of freedom and completely fixes the magnetic field guide in its final position.In this way, a particularly simple and cost-effective plug connection is created, which considerably simplifies the further manufacturing process compared to the switching device according to the prior art, which still requires additional devices for positioning and fixing the magnetic field guide body.

[0022] In a particularly preferred embodiment of the invention, the magnetic field conductor completely surrounds the contact chamber, i.e. the magnetic field conductor completely encloses the contact chamber radially. For this purpose, the magnetic field conductor can, for example, have a tubular shape with a rectangular or circular cross-section. The magnetic field conductor is preferably made of a ferromagnetic metal and is therefore relatively strong compared to the housing, which is usually made of plastic. The occurrence of arcs in the contact chamber is accompanied by a sudden, relatively high pressure increase in the contact chamber, which particularly stresses the housing sections radially surrounding the contact chamber and, in the worst case, can cause the housing to burst.The magnetic field conductor surrounding the contact chamber creates a metallic reinforcement for the housing section radially surrounding the contact chamber, which withstands the high pressures in the contact chamber caused by arcs and thus protects the housing from damage. Nevertheless, the contact chamber walls can be designed relatively thin, which is particularly advantageous for the compactness of the high-voltage contactor.

[0023] In a further particularly preferred embodiment of the invention, the magnetic field guide body has a particularly substantially flat contact surface with which the magnetic field guide body rests axially against the return plate, wherein the lugs extend from the contact surface in the axial direction into the recesses. The contact surface, which is flat with the exception of the lugs, is preferably an end face of the magnetic field guide body facing in an axial direction, the normal of which is aligned parallel to the axis of movement. The contact surface enables a relatively large-area contact between the magnetic field guide body and the return plate, which, for example, makes it more difficult for the magnetic field guide body to tilt during the manufacturing process. In a further particularly preferred embodiment of the invention, the magnetic field guide body has a total of two lugs which are arranged diametrically opposite one another.The diametrically opposed arrangement of the lugs makes it possible to achieve the necessary positive locking, which is required to block the translational movement transverse to the axis of movement and the rotational movement around the axis of movement, with just two lugs. This results in a relatively good cost-benefit ratio in terms of the structural design and production of the high-voltage contactor.

[0024] In a further advantageous embodiment of the invention, the return plate is arranged axially between the contact chamber and the actuator. The return plate thus forms a metallic partition or a metallic reinforcement of a partition between the actuator chamber and the contact chamber, making the contact chamber relatively robust against mechanical stresses that can occur, for example, due to an increase in pressure in the contact chamber, which can result from the formation of arcs when the contact bridge is separated from the two contact elements.

[0025] In a further preferred embodiment of the invention, the recesses are arranged at the edge of the return plate and are open radially outward. The recesses are therefore preferably designed as rectangular pockets that form part of the outer contour of the return plate. This allows the return plate to be designed and manufactured relatively simply, since the recesses, as part of the outer contour, can be produced in a single step during the manufacturing process. Furthermore, the return plate can be designed to be relatively compact in the radial direction, which ultimately also leads to a compact design of the high-voltage contactor.

[0026] In a further embodiment of the invention, each recess is formed by two projections of the return plate, which are arranged adjacent to each other in the circumferential direction and spaced apart from each other and extend radially outward. The projections preferably extend parallel to each other from the radial surface of the return plate outward, whereby only the two inner walls of the projections facing each other in the circumferential direction, against which the lugs rest, need to be arranged parallel to each other. By designing the return plate with the projections, the return plate can be designed to be particularly compact, resulting in a relatively compact high-voltage contactor from a structural perspective.

[0027] In another particularly preferred embodiment of the invention, the return plate and the magnetic field conductor are overmolded with plastic when plugged together. The housing of the high-voltage contactor, or at least parts thereof, are manufactured using an injection molding process. In order to create a particularly sealed contact chamber, it can be advantageous to overmold the return plate and the magnetic field conductor with plastic in a single injection molding process, thus creating a smooth and seamless border around the contact chamber. The plug connection, created by the lugs engaging in the recesses, serves to position the magnetic field conductor on the return plate and to hold it in position during the injection molding process.If the injection point through which the injection mold is filled is placed on the axial side of the magnetic field conductor, towards which the magnetic field conductor can be moved, the injection pressure can press the magnetic field conductor against the return plate and thus securely hold it in position. Alternatively, a hold-down device can be provided in the injection mold to do this. The overmolding creates a metal-reinforced wall around the contact chamber, with the magnetic field conductor reinforcing the contact chamber wall that radially encloses the contact chamber, whereas the return plate reinforces the contact chamber wall that axially limits the contact chamber in the direction of the actuator. The plug-in connection can significantly simplify the injection molding process, as no additional holding devices are required for the magnetic field conductor.This allows the production cycle rate to be increased compared to a high-voltage contactor with a non-pluggable magnetic field conductor, thereby reducing manufacturing costs. In another particularly advantageous embodiment of the invention, the magnetic field conductor is made of sheet metal. The magnetic field conductor is thus relatively thin-walled, with a sheet thickness of less than 3 mm. This allows the magnetic field conductor to be manufactured relatively easily in large quantities, for example, by bending or deep-drawing, and is therefore particularly well-suited for a series-produced high-voltage contactor.

[0028] In a further embodiment of the invention, the magnetic field guide body is designed in the shape of a rectangular tube and has two long side walls and two short side walls. Accordingly, the contact chamber also has a rectangular shape. This shape is particularly suitable because the contact bridge also has an elongated, usually rectangular shape, so that the shape of the contact chamber is adapted to the shape of the contact bridge and the distance between the contact bridge and the radial side walls of the contact chamber is approximately the same on all sides. Thus, the contact chamber does not require more space than necessary, which overall leads to a relatively compact design of the high-voltage contactor.

[0029] In a further embodiment of the invention, the magnetic field guide is manufactured by bending a flat sheet metal strip. The flat sheet metal strip is bent by 90° at at least three points forming the corners, creating a rectangular tube, with the two ends of the sheet metal strip meeting in the fourth corner when bent. However, the sheet metal strip particularly preferably has four bending points with 90° bends, so that the two ends of the sheet metal strip meet in the area of ​​a side wall between the two corners, enabling a clean connection of the joints. Manufacturing by bending is particularly cost-effective and therefore particularly suitable for series production. In addition, a bent magnetic field guide has a constant sheet thickness, which would not be possible with a deep-drawn magnetic field guide due to manufacturing difficulties.

[0030] In a further embodiment of the invention, the magnetic field guide body has a connecting structure by means of which the ends of the magnetic field guide body that abut in the bent state are connected to one another. The connecting structure is designed such that the two abutting ends cannot move away from one another in the circumferential direction, thereby preventing the rectangular tube forming the magnetic field guide body from expanding during the manufacturing process, for example, during an injection molding process. This is achieved by a connecting structure that creates a positive connection in the circumferential direction, whereas in the orthogonal direction, which is perpendicular to the sheet plane, the connection can be easily released.The two ends of the magnetic field conductor are designed like puzzle pieces that, when plugged together, are securely connected to prevent relative movement in the plane of the sheet metal. For this purpose, one end has a recess undercut in the circumferential direction and the other end has a correspondingly shaped extension that sits in the recess. In addition, after being inserted into the recesses, the extension can be widened within the plane of the sheet metal during the manufacturing process using a suitable tool so that the extension fits precisely and without play in the recess. This can be achieved, for example, by inserting a dome that is pressed into the center of the extension and thereby displaces the material outwards, whereby it is pressed against the inner walls of the recess and adheres positively to the inner walls.This ensures that the noses of the magnetic field guide sit securely in the recesses of the return plate and that the magnetic field guide is thus fixed in its position.

[0031] Advantageously, the connecting structure has at least one dovetail joint. The dovetail joint is one of the possible puzzle-like configurations of the connecting structure and is characterized by its excellent dimensional stability in all directions of the sheet plane. For further improvement, multiple dovetail joints can be arranged along the abutting ends, which additionally reinforce and stabilize the connecting structure.

[0032] The lugs are preferably formed on the short side walls, since the short side walls are more stable and less susceptible to deformation than the long side walls, so that an arrangement of the lugs on the short side can achieve a more secure connection between the magnetic field guide body and the return plate than an arrangement of the lugs on the long side.

[0033] In a further advantageous embodiment of the invention, the magnetic field conductor has a plurality of openings that radially penetrate the magnetic field conductor. The openings fill with plastic during the overmolding of the magnetic field conductor during an injection molding process for producing the contact chamber walls, thereby creating an additional positive connection between the magnetic field conductor and the contact chamber wall enclosing the magnetic field conductor, which securely holds the magnetic field conductor in its position.

[0034] In a further embodiment, the openings are arranged on the long side wall of the magnetic field guide body. This allows multiple openings to be provided in the side wall of the magnetic field guide body without significantly weakening the side wall.

[0035] In a further advantageous embodiment of the invention, the permanent magnets are located on the short side wall of the magnetic field conductor. This allows the permanent magnets to be positioned particularly close to the contact points, resulting in a particularly high quenching effect.

[0036] An embodiment of a high-voltage contactor or high-voltage relay according to the invention is shown in the figures and is described below.

[0037] Figure 1 shows a side view of a high-voltage contactor according to the invention in a sectional view.

[0038] Figure 2 shows a perspective view of the return plate and the magnetic field conductor of the high-voltage contactor of Figure 1 in the pre-assembled state. The high-voltage contactor 10 or high-voltage relay shown in Figure 1 is used, for example, in an electrically powered motor vehicle for the electrical isolation or connection of a traction battery from or to other electrical components as required. The high-voltage contactor 10 comprises an electromagnetic actuator 12 having a coil 14 consisting of a coil carrier 16 and a winding 18 wound thereon, a ferromagnetic iron circuit 20, and an armature 22. The ferromagnetic iron circuit 20 has a U-shaped yoke 24, the legs 26 of which rest on a return plate 28 or are fastened to the return plate 28, so that the closed iron circuit 20 is formed.

[0039] The yoke 24, which forms the electromagnetic return path, has a central opening 32 at its base part 30, the diameter of which essentially corresponds to the inner diameter of the coil carrier 16. A bushing 34 is fastened in this opening 32, in which the armature 22 is slidably arranged and guided. When current is applied to the coil 14, the armature 22 is pulled into its closed position in a known manner against the force of a return spring 36 in the contact chamber 42 toward the return plate 28. The distal end of the return spring 36 is axially supported and radially guided in a spring support chamber 110 of the housing.

[0040] On the contact chamber side of the armature 22, on its proximal flat end face 221, there is a one-piece actuating rod 38 which projects through a further central opening 40 in the return plate 28 into a contact chamber 42.

[0041] The actuating rod 38 is formed from a weldable stainless steel rod body 38', which is formed by a metallic cold extrusion process. After the cold extrusion process step, the armature-side axial end 381 of the actuating rod was additionally compressed in several compression steps in order to set the exact axial target length of the actuating rod 38. The metallic rod body 38' has a specific magnetic saturation of less than 1.8 Tesla. A contact bridge 44 is arranged at the end 382 of the actuating rod 38 opposite the armature 22. The contact bridge 44 is pressed against a stop 48 at the contact bridge-side end 382 of the actuating rod 38 by a spring element 46 designed as a helical spring, wherein the spring element 46 is supported axially with its other spring end on a shoulder 49 on the actuating rod 38.The shoulder 49 is formed by an annular disc welded to the actuating rod 38 by a weld 49'. The contact bridge 44 is thus tiltable against the spring force of the spring element 46 and held axially movably on the actuating rod 38. The stop 48 also serves, on its distal side, to center the proximal end of the return spring 36. Alternatively, the spring element can also be designed as a leaf spring, which is centrally supported on the shoulder 49, and whose two leaf spring ends introduce the spring force at the two contact bridge ends.

[0042] Attached to each end of the contact bridge 44 is a contact plate 52, 53 made of a material with particularly good electrical conductivity. The first contact plate 52 is arranged axially opposite a first contact element 54, which can be connected, in particular, to a traction high-voltage battery via a busbar (not shown). The second contact plate 53 is arranged opposite a second contact element 56, which can be connected, for example, to an electric drive motor of a motor vehicle via a busbar.

[0043] The entire high-voltage contactor 10 is arranged in a housing 58, which is composed of a total of three parts, as can be seen particularly in Figure 1. For this purpose, the actuator 12 is overmolded with a plastic to form an actuator housing part 60. This plastic completely surrounds the coil 14 radially to form a radial boundary wall 66 and also fills a gap 68 radially between the coil 14 and the yoke 24. In addition, the yoke 24 itself is completely radially surrounded by this plastic and is thus shielded from the environment. Furthermore, the return plate 28, which rests against the coil carrier 16 on its side facing the coil carrier, is covered by this plastic axially in the direction of the contact chamber 42, whereby an axial contact chamber wall 45 is formed.The opening 40 of the return plate 28 is also covered radially inwards by the plastic and leaves only a central guide opening 70 free, in which the actuating rod 38 is guided.

[0044] On the axial outer side 72 of the actuator housing part 60 opposite the contact chamber 42, the plastic extends further radially inward along a radially outer region 74 of the base part 30 of the yoke 24 or of the actuator 12 and leaves an opening 78 free only in the central, radially inner region 76, which opening is designed symmetrically to the opening 32 but has a slightly larger diameter so that there is sufficient space for pressing in the bushing 34.

[0045] This opening 78 is closed by a plastic cover 80, which is firmly attached to the actuator housing part 60 in the opening 78, in particular by laser welding, ultrasonic welding or rotational vibration welding.

[0046] Furthermore, the actuator housing part 60 produced by overmolding the actuator 12 forms a formation 82 in the form of a plug housing 82, through which the connecting lines 84 to the winding 18 of the coil 14 are led outwards, so that the electrical connection of the coil 14 to a voltage source can be established via a plug counterpart.

[0047] In addition, a circumferential radial contact chamber wall 47 extends from the return plate 28 in extension of the plastic surrounding the actuator 12, which radially delimits the contact chamber 42 and is also manufactured in one piece during the overmolding of the actuator 12 and thus forms four side walls of the contact chamber 42 in the present exemplary embodiment.

[0048] The radial contact chamber wall 47 is designed in a so-called sandwich construction. The radial contact chamber wall 47 is formed by a contact chamber inner wall 474 and a contact chamber outer wall 476, which are spaced apart and arranged parallel to one another. Between the contact chamber inner wall 474 and the contact chamber outer wall 476, a magnetic field guide body 50 formed by a ferromagnetic magnetic field guide plate 51 is arranged, which completely radially surrounds the contact chamber 42. The radial contact chamber wall 47, the contact chamber inner wall 474, and the contact chamber outer wall 476 are manufactured by overmolding the magnetic field guide plate 51 with plastic on the inside and outside, respectively.The overmolding takes place in the same work step in which the actuator 12 is overmolding, whereby the contact chamber outer wall 476 is formed integrally with the actuator housing part 60 and the contact chamber inner wall 474 is formed integrally with the axial contact chamber wall 45. Nevertheless, the contact chamber inner wall 474 and the contact chamber outer wall 476 are integrally connected to one another at several points, for example, by openings 512 in the long side walls 506 of the magnetic field guide plate 51.

[0049] The contact chamber 42 is cuboid-shaped and therefore has a rectangular cross-section, which is radially delimited by four side walls, each formed by the radial contact chamber wall 47. On the two opposing short sides, the side walls of the contact chamber wall 47 each have a cuboid-shaped, inwardly projecting pocket 471, 472, which is open to the axial side opposite the actuator 12, with a permanent magnet 55, 57 arranged in each pocket 471, 472. Each pocket 471, 472 or each permanent magnet 55, 57 arranged in the pocket 471, 472 is arranged adjacent to one of the contact plates 52, 53 of the contact bridge 44.Each permanent magnet 55, 57 is aligned with respect to its magnetic poles in such a way that the Lorentz force exerted by the magnetic fields of the permanent magnets 55, 57 deforms the arc occurring between the contact plates 52, 53 and the contact elements 54, 56 into an arc and thus extinguishes the arcs due to the resulting elongation and faster cooling.

[0050] The magnetic field guide plate 51 is not completely overmolded on the inside in the area of ​​the pockets 471, 472. Instead, each permanent magnet 55, 57 contacts the magnetic field guide plate 51 on its respective short inner side, whereby the permanent magnets 55, 57 are magnetically connected to one another. Arranged within each pocket 471, 472 is a stop structure 475, each formed by two parallel and spaced-apart ribs 477 and a wall projection 478. The wall projection 478 projects radially inward from the inside of the magnetic field guide plate 51. The ribs 477 each extend radially from the contact chamber inner wall 474 to the wall projection 478. The permanent magnets 55, 57 rest axially against the respective stop structure 475, whereby each permanent magnet 55, 57 is arranged at the level of one of the contact points in the contact chamber 42 with respect to the axial direction.

[0051] In addition, the magnetic field guide plate 51 extends axially in the actuator direction up to the return plate 28 and rests axially against the return plate 28 with a flat contact surface 504, so that the magnetic field guide plate 51 is in direct, magnetically conductive contact with the return plate 28 and thus with the iron circuit 20. This leads to both an increased local field strength and improved homogeneity of the magnetic field, thereby achieving a relatively strong deformation of the arcs and thus a relatively rapid extinguishing of the arcs.

[0052] The magnetic field guide plate 51 is shaped like a rectangular tube and manufactured from a flat sheet metal strip by bending. The magnetic field guide plate 51 has four bending points 507 that form the corners of the magnetic field guide plate 51. At its two ends, which abut one another in the bent state, the magnetic field guide plate 51 has a puzzle-like connecting structure 510 formed by two axially adjacent and spaced-apart dovetail joints 511. These dovetail joints prevent the abutting ends of the magnetic field guide plate 51 from moving away from one another in the circumferential direction, thus preventing the magnetic field guide plate 51 from expanding radially.

[0053] On its two short side walls 508, the magnetic field guide plate 51 has two diametrically opposed lugs 502 that extend axially from the contact surface 504 in the direction of the return plate 28, as shown in Figure 2. At the edge of the return plate 28, two recesses 282 are arranged, into which the lugs 502 extend and into which the lugs 502 engage. Each recess 282 is formed by two projections 284 that are spaced apart from one another along the circumference of the return plate 28 and extend radially outwardly parallel to one another. The distance between the two facing inner walls of the adjacent projections 284 is 0.5 mm greater than the width of the lugs 502 in the circumferential direction, so that the lugs 502 are received in the recesses 282 with relatively little play. The recesses 282 are open radially outwards, whereby the return plate 28 is relatively compact.The lugs 502 prevent translational movement of the magnetic field guide plate 51 in all directions transverse to the movement axis of the actuator 12 and in the rotational direction around the movement axis of the actuator 12. Furthermore, the contact surface 504 axially abutting the return plate 28 prevents axial displacement of the magnetic field guide plate 51 in the direction of the actuator 12. This holds the magnetic field guide plate 51 and the actuator 52 in their position during joint overmolding without additional holding devices.

[0054] The contact chamber 42 in Figure 1 is axially closed on the axial side opposite the axial contact chamber wall 45 by a contact chamber cover 88, which also axially closes the pockets 471, 472. Two axial openings 90 are formed on the contact chamber cover 88, in which the two contact elements 54, 56 are received and fastened, for example, by ultrasonic welding or overmolding. Extending continuously in the axial direction from this contact chamber cover 88 is a collar 92 which radially encloses the continuous contact chamber outer wall 476, so that these two walls 92, 476 can be continuously joined to one another in a materially bonded manner, for example by laser welding, ultrasonic welding, or rotational vibration welding, thereby creating a high-strength housing 58.Immediately within the collar 92, a circumferential axial groove 94 is formed, which is thus delimited to the outside by the collar 92 of the contact chamber cover 88 and into which the end of the housing wall 86 of the actuator housing part 60 projects, whereby the latter is precisely fixed in its position relative to the contact chamber cover 88 prior to laser welding, ultrasonic welding or rotational vibration welding.

[0055] If the flow of current between the traction electric motor or the charging station and the traction battery is to be enabled, the coil 14 is energized, whereby the ferromagnetic armature 22 is pulled towards the return plate 28 due to the acting electromagnetic forces. As a result, the actuating rod 38 with the contact bridge 44 and the contact plates 52, 53 is pushed against the contact elements 54, 56 so that an electric current can flow via the contact bridge 44 from the first contact element 54 to the second contact element 56 and thus from the battery to the electric motor or from the charging station to the battery. If the coil 14 is not energized, the actuating rod 38 and the armature 22 are moved by the spring force of the return spring 36 in the opposite direction to the previously acting closing force, so that the contact bridge 44 is lifted off the contact elements 54, 56 and the circuit is interrupted.At high currents, an arc is created, which also results in an increase in pressure in the contact chamber 42.

[0056] This pressure increase can be well absorbed by the housing 58 due to the metal-reinforced walls 45, 47 surrounding the contact chamber 42, and the actuator 12 is also reliably protected, particularly by the molded-on axial contact chamber wall 45. The tight welding of the only three housing parts also ensures complete sealing to the outside, so that no gas can escape from the contact chamber 42, the arc is extinguished reliably and quickly, and no gases or liquids can penetrate from the outside. The required installation space and assembly costs are very low.

Claims

Patent claims 1. A high-voltage contactor (10) comprising an electromagnetic actuator (12) with a coil (14) and a ferromagnetic armature (22) movable by the coil (12), a housing (58) with a contact chamber (42), an electrically conductive contact bridge (44) arranged in the contact chamber (42), which can be moved by means of the actuator (12) into a contact position in which a first contact element (54) fixed to the housing is electrically connected to a second contact element (56) fixed to the housing via the contact bridge (44), and into an open position in which electrical contact between the first contact element (54) and the second contact element (56) is interrupted, and a one-piece actuating rod (38) supported directly on the armature (22), which holds the contact bridge (44) and has an integrally connected stop (48) for a return spring (36),which is supported on the housing side and which preloads the actuating rod (38) into its opening position., 2. High-voltage contactor (10) according to claim 1, wherein the spring stop (48) is provided on the contact bridge-side axial end (382) of the one-piece actuating rod (38).

3. High-voltage contactor (10) according to one of the preceding claims, wherein the armature-side axial end (381) of the one-piece actuating rod (38) rests directly on the proximal end face (221) of the armature (22).

4. High-voltage contactor (10) according to one of the preceding claims, wherein the one-piece actuating rod (38) is formed by a metallic cold-formed rod body (38').

5. High-voltage contactor (10) according to claim 4, wherein the armature-side axial end (381) of the one-piece actuating rod (38) is additionally compressed.

6. High-voltage contactor (10) according to one of the preceding claims, wherein the one-piece actuating rod (38) is formed by a metallic rod body (38') whose specific magnetic saturation is less than 1.8 Tesla.

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