High-voltage contactor or high-voltage relay
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- PIERBURG GMBH
- Filing Date
- 2023-08-10
- Publication Date
- 2026-06-17
Smart Images
Figure EP2023072248_13022025_PF_FP_ABST
Abstract
Description
[0001] DESCRIPTION
[0002] High-voltage contactor or high-voltage relay
[0003] The invention relates to a high-voltage contactor or high-voltage relay with an electromagnetic actuator, a housing with an inner contact chamber, a first contact element which projects into the contact chamber, a second contact element which projects into the contact chamber, a contact bridge which can be moved by means of the actuator in the contact chamber at least into a first position in which the first contact element is electrically connected to the second contact element via the contact bridge, and can be moved into a second position in which an electrical contact between the first contact element and the second contact element is interrupted, a magnetic field conducting body which magnetically connects at least two permanent magnets arranged diametrically opposite one another in the contact chamber.
[0004] Such high-performance switching devices are required to be able to establish and break electrical connections both under load and without load, where voltages of over 1000 V and currents of over 1000 A can occur, for example between the battery and the drive motor in electrically powered vehicles or between a charging station and the battery. Since arcs can occur when the contacts are separated due to the high voltages, especially during load when driving or charging or in the event of a short-circuit current, the contact chamber should be as sealed to the outside as possible and be very strong. This is to prevent particle, gas or plasma emissions and also to withstand the pressure caused by the arc for a sufficiently long time.In future hybrid, electric, and fuel cell vehicles, as well as in on-board charging systems, short-circuit currents of up to 30,000 A are to be expected at the traction battery contactor or the rapid charging contactor. The housings should therefore be able to withstand the internal conditions for several milliseconds without any external influences, such as material leakage or damage to the outer shell, until an additional short-circuit isolating element, such as a fuse or pyroelectric fuse, interrupts the short-circuit current.
[0005] Such a high-voltage contactor is known, for example, from EP 3 846 193 A1. It consists of an actuator housing that surrounds the coil radially and on the side opposite the contact chamber. An outer housing is attached to this actuator housing, which defines the contact chamber to the outside. A separate arc chamber housing is arranged inside this outer housing, which is connected to the actuator's return plate via a seal, so that the arc chamber housing, the seal, the return plate, and a guide sleeve of the armature are intended to define the arc chamber.
[0006] This contactor requires a large number of individual components to limit the arc chamber, which must also be connected to each other as tightly and durably as possible. Given the short-circuit currents and resulting pressures expected in the future, sufficient tightness and durability cannot be guaranteed.
[0007] Furthermore, such a high-voltage contactor typically includes an arc-quenching device consisting of several permanent magnets arranged in the area of the contact elements in such a way that an arc occurring when the contacts are separated is manipulated in an arc-like manner by the magnetic field of the permanent magnets, thereby elongating the arc and ultimately extinguishing it. These permanent magnets are therefore also referred to as blowout magnets in technical terms.
[0008] Such a high-voltage contactor is known, for example, from US 2015 / 0054605 A1. This contactor has a permanent magnet radially adjacent to each contact element, which is located where the contact element is contacted by the respective contact of the contact bridge. Each permanent magnet is arranged on a magnetic field conductor, with each magnetic field conductor being in magnetically conductive contact with the return plate located between the contact chamber and the actuator.
[0009] The radial contact chamber wall, which radially encloses the contact chamber, is made of plastic and is also relatively thin, so that the contact chamber wall can burst and thus become leaky, particularly in the event of a sudden occurrence of high pressures in the contact chamber.
[0010] The invention is therefore based on the object of creating a high-voltage contactor or high-voltage relay with which sufficient strength and tightness of the contact chamber is achieved in the simplest possible way, using as few individual parts as possible in order to avoid leaks due to errors in assembly, but nevertheless creating a robust housing in the area of the contact chamber that can withstand the relatively high pressure in the contact chamber.
[0011] This object is achieved with a high-voltage contactor or high-voltage relay according to the invention having the features of claim 1.
[0012] The high-voltage contactor or high-voltage relay according to the invention has an electromagnetic actuator via which the contactor can be switched. An electromagnetic actuator is understood to mean all actuators that generate movement due to a force caused by electromagnetism. The electromagnetic actuator thus consists in particular of either a coil consisting of a coil carrier and a winding wound thereon, as well as an iron circuit surrounding the coil and an armature that can be moved due to the electromagnetic force and is arranged within the coil and the iron circuit.
[0013] For the sake of simplicity, only the term high-voltage contactor is used below, although this also includes the term high-voltage relay.
[0014] Furthermore, the terms radial, axial and diametrical refer to the central axis of the high-voltage contactor along which the armature of the actuator can be moved.
[0015] The housing is designed in such a way that the contact chamber is almost completely sealed from the environment, allowing only a slow exchange of air and thus a slight pressure equalization with the environment. When an arc is generated, a relatively high pressure is suddenly generated in the contact chamber compared to the environment. This pressure cannot be immediately reduced due to the slow air exchange between the contact chamber and the environment. While this high pressure promotes arc extinction, it also places increased strength requirements on the housing.
[0016] The high-voltage contactor further comprises a first and second contact element fixedly arranged on the housing, which protrude into the contact chamber and are connected outside the high-voltage contactor to two busbars, one of which leads to the battery and the other, for example, to the drive motor or which are connected to a charging station and the vehicle's battery. An electrical connection between these two contact elements can be established via a contact bridge, which is moved in the contact chamber by means of the actuator. In this case, the contact bridge, at the ends of which two electrical contacts can be formed, is usually displaced axially against the two contact elements fastened to the housing by energizing the winding in order to establish an electrical connection between the first contact element and the second contact element via the contact bridge in a first position.For this purpose, the contact bridge is operatively connected to the armature, for example, via an actuating rod, and is pressed against the contact elements by the movement of the armature or rotor due to the electromagnetic force. To open this electrical connection, the contact bridge is loaded in the opposite direction, which is usually achieved by a spring force acting on the armature, rotor, or contact bridge in a manner opposite to the electromagnetic force, so that the contact bridge is moved to a second position in which electrical contact between the first contact element and the second contact element is interrupted.
[0017] The high-voltage contactor further comprises 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. By means of the magnetic fields of the permanent magnets or by means of the Lorentz force exerted by the magnetic fields, the arc created when the contact plates and the contact elements are separated can be deformed into an arc, thereby elongating it and thus extinguishing it.The magnetic field guide body represents a magnetic short circuit between the permanent magnets, which on the one hand leads to a relatively good magnetic field bundling and on the other hand is particularly advantageous both for the local field strength and for the field homogeneity of the magnetic fields generated by the permanent magnets, which ultimately has a beneficial effect on the extinguishing of the arcs.
[0018] According to the invention, the magnetic field conductor completely surrounds the contact chamber, i.e., the magnetic field conductor completely radially encloses the contact chamber. 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.
[0019] In a particularly preferred embodiment of the invention, the housing has a radial contact chamber wall that radially delimits the contact chamber completely around its circumference. The radial contact chamber wall is formed by an inner contact chamber wall and an outer contact chamber wall. The inner and outer contact chamber walls are radially spaced apart and arranged parallel to one another. The radial contact chamber wall is thus double-walled, with a gap formed between the inner and outer contact chamber walls that radially surrounds the contact chamber completely around its circumference. This gap can, for example, also be annular in the case of a contact chamber with a cylindrical cross-section and a corresponding annular contact chamber wall. Alternatively, in the case of a rectangular cross-section contact chamber, the contact chamber wall can have four double-walled sides, each side having an inner and an outer wall section.
[0020] In another particularly preferred embodiment of the invention, the magnetic field conductor is arranged radially between the contact chamber inner wall and the contact chamber outer wall. The magnetic field conductor is thus located in the gap between the contact chamber inner wall and the contact chamber outer wall, which completely surrounds the contact chamber. Furthermore, the magnetic field conductor is precisely fitted into the gap, ensuring a play-free fit. This strengthens, in particular, the contact chamber inner wall and also the contact chamber outer wall, so that they can withstand the relatively high pressure, particularly when arcs occur in the contact chamber. The magnetic field conductor runs entirely within the radial contact chamber wall and is therefore not directly exposed to the arcs.The inner wall of the contact chamber forms an insulating layer between the magnetic field conductor, which is usually made of metal and thus electrically conductive, and the arcs, thus preventing the arc from jumping to the magnetic field conductor. Furthermore, the magnetic field conductor is shielded from the environment by the outer wall of the contact chamber and is therefore not exposed to environmental influences.
[0021] Advantageously, the radial contact chamber wall is manufactured by overmolding the magnetic field conductor. By overmolding the magnetic field conductor with a plastic material, the magnetic field conductor is embedded in the contact chamber wall with a form-fitting, precise fit. Overmolding on the radial inside of the magnetic field conductor creates the contact chamber inner wall, and overmolding on the radial outside of the magnetic field conductor creates the contact chamber outer wall. This creates a metal-reinforced, radial contact chamber wall in a so-called sandwich construction, which, despite the lightweight and insulating plastic material, is characterized by its compactness and particularly high strength.
[0022] In another particularly advantageous embodiment of the invention, the permanent magnets are arranged radially between the contact chamber inner wall and the contact chamber outer wall. The permanent magnets are therefore arranged inside the radial contact chamber wall, similar to the magnetic field conductor, and are thus protected from the arcs in the contact chamber. This is particularly important for permanent magnets, since the arcs are preferably deformed in the direction of the permanent magnets, so that if these were arranged directly in the contact chamber, the arc could jump to the permanent magnets. Thus, the contact chamber inner wall also forms an insulating barrier here, protecting the usually electrically conductive permanent magnets from the arcs.
[0023] Furthermore, the permanent magnets preferably contact the radial inner side of the magnetic field conductor, whereby the permanent magnets are in direct contact with the magnetic field conductor. This creates both an electrically and magnetically conductive contact between the permanent magnets and the magnetic field conductor, which further enhances the aforementioned advantages regarding field homogeneity and local field strength. Accordingly, the magnetic field conductor is not overmolded with plastic on the radial inner side where the permanent magnets are arranged. The internal arrangement with respect to the magnetic field conductor also ensures that the permanent magnets can be brought particularly close to the contact points, thus ensuring a particularly high arc extinction effect.
[0024] In a further advantageous embodiment of the invention, the magnetic field guide body is formed by a ferromagnetic magnetic field guide plate. The magnetic field guide plate preferably has a relatively small sheet thickness of less than 2 mm, whereby the magnetic field guide plate is designed with relatively thin walls in relation to its axial extent. Furthermore, the magnetic field guide plate is arranged with respect to the contact chamber such that the sheet thickness is oriented in the radial direction, resulting in a relatively compact design of the radial contact chamber wall, so that the high-voltage contactor is equally compact in its external dimensions. The magnetic field guide plate can, for example, be formed into a corresponding shape from a simple sheet metal strip by forming it.For example, the sheet metal strip can be bent into a substantially rectangular and tubular magnetic field guide plate, which is arranged in such a way that a cuboid-shaped contact chamber is formed, which is radially circumferentially enclosed by the magnetic field guide plate. This results in particular in advantages with regard to the manufacturing costs of the magnetic field guide body and thus of the entire high-voltage contactor.
[0025] Advantageously, the magnetic field guide plate in the non-overmolded state has a plurality of openings which are filled with the overmolded plastic after overmolding. The openings can be formed, for example, by bores that are introduced into the magnetic field guide plate during its manufacture. The openings are preferably distributed around the circumference of the magnetic field guide plate and extend in a radial direction with respect to the installation position. In the case of a rectangular tubular magnetic field guide plate, each of the four sides preferably has at least one such opening. During overmolding of the magnetic field guide plate, the plastic penetrates through the openings, whereby the inner wall of the contact chamber and the outer wall of the contact chamber are integrally connected to one another in the region of the opening. This creates a simple, positive connection that holds the magnetic field guide plate securely in its position.
[0026] In another particularly advantageous embodiment of the invention, in addition to the radial contact chamber wall, the housing also has an axial contact chamber wall, which defines the actuator axially relative to the contact chamber, i.e., is arranged axially between the contact chamber and the actuator. The axial contact chamber wall, which is preferably made of plastic, acts as an electrical insulator and protects the actuator from arcs occurring in the contact chamber, thereby preventing damage to the actuator and its sensitive components.
[0027] The radial contact chamber wall and the axial contact chamber wall are preferably formed as one piece and manufactured, for example, by jointly overmolding the actuator and the magnetic field conductor with plastic. Particularly preferably, the axial contact chamber wall is formed as one piece with the contact chamber inner wall. The radial contact chamber wall and the axial contact chamber wall are thus integrally connected, whereby the contact chamber is completely sealed from the environment, particularly at the transition between the axial contact chamber wall and the radial contact chamber wall. This eliminates the need for separate sealants, which would significantly complicate assembly and lead to increased production costs. Furthermore, leaks due to aging processes or damage to the sealants cannot occur. Furthermore, the contact chamber is electrically insulated towards the actuator, so that the actuator circuit remains galvanically isolated from the switching circuit.
[0028] In a further advantageous embodiment of the invention, the radial contact chamber wall has at least two diametrically opposed pockets that are open on the axial side opposite the actuator. One of the permanent magnets is arranged in each pocket and can be inserted into the pocket from the open side during assembly. The shape of each pocket corresponds to the shape of the respective permanent magnet, so that the permanent magnet fits precisely and without play in the pocket. Alternatively, each permanent magnet can be overmolded with plastic in the demagnetized state and magnetized after overmolding, whereby the pocket is formed around the permanent magnet.The pockets preferably protrude radially from the actual contact chamber inner wall into the contact chamber, whereby the permanent magnet can be brought relatively close to the contact point between the contact element and the contact bridge, but the contact chamber inner wall arranged radially on the inside of the permanent magnet protects the permanent magnet from direct contact with the arc.
[0029] In a further advantageous embodiment of the invention, each pocket has a stop structure against which the respective permanent magnet arranged in the pocket axially rests. The stop structure can be formed, for example, by at least one rib arranged in the pocket, which runs between two opposite walls of the pocket. Preferably, several ribs extend between the contact chamber inner wall and the contact chamber outer wall and form webs on which the permanent magnet rests. Alternatively or additionally, a wall projection can be formed, which projects from at least one of the walls of the pocket into the interior of the pocket and forms a stop for the permanent magnet.By means of the stop structure, the permanent magnet can be arranged at the level of the contact points in relation to the axial direction without having to accept manufacturing disadvantages such as material accumulation or uneven wall thicknesses, which would lead to quality losses with regard to the processing of the overall product, especially when using plastic materials.
[0030] The housing preferably has a contact chamber cover that closes the contact chamber on the axial side opposite the actuator. The contact chamber cover is attached to the radial contact chamber wall in a circumferentially integral manner, particularly by adhesive bonding, laser welding, ultrasonic welding, or rotational vibration welding. This attachment is highly durable and completely sealed without the need for additional seals. The contact chamber is thus completely airtight and electrically insulated from the environment.
[0031] In a further embodiment, the contact chamber cover axially closes the pockets in which the permanent magnets are arranged, thereby completely securing the permanent magnets in the pocket. The permanent magnets are therefore held in place solely by a positive connection on all sides without any additional fasteners, which significantly simplifies the installation of the high-voltage contactor.
[0032] The contact chamber cover preferably has a collar extending axially toward the actuator, which completely encloses the radial contact chamber wall. The collar preferably extends axially over at least 20% of the axial extent of the radial contact chamber wall and rests positively on the radial outside of the contact chamber wall. The contact chamber cover is preferably secured to the radial contact chamber wall by a material fit, in particular by gluing, laser welding, ultrasonic welding, or rotational vibration welding. In this way, a further radially delimiting outer wall is created at least in a partial section of the radial contact chamber wall, which further increases the strength.
[0033] In a further particularly preferred embodiment of the invention, the housing has an actuator housing part that is manufactured by overmolding the actuator with plastic. This design completely shields the actuator from the contact chamber, with the exception of the small opening through which the actuating rod projects into the contact chamber. Because the housing is closed to the outside, high strength is achieved even with relatively thin walls, and necessary sealing surfaces are completely avoided. Overmolding significantly simplifies production, as fewer individual parts are required and must be assembled. The space requirement is also reduced by eliminating the otherwise necessary clearance between the housing parts, as well as manufacturing costs, compared to known designs. In addition, a stable system is created in which the actuator cannot move within the housing.
[0034] In a further embodiment, the radial contact chamber wall is formed integrally with the actuator housing part. This can be achieved, for example, by manufacturing the contact chamber wall and the actuator housing part in one and the same injection molding process. This completely eliminates connections and abutting edges that could lead to leaks in the area of the contact chamber wall bordering the contact chamber, whereby the entire housing, apart from the axial end faces, which are preferably provided with covers, forms a completely closed unit that seals the interior of the high-voltage contactor from the environment. Advantageously, the radial contact chamber wall extends axially from the actuator in the direction of the contact elements, so that the contact chamber wall is arranged axially adjacent to the actuator, thereby achieving a particularly compact design of the high-voltage contactor.
[0035] The electromagnetic actuator advantageously comprises a coil, an iron circuit surrounding the coil, and an armature. This creates a purely translational actuator that eliminates the need for motion conversion. Such an actuator can be manufactured particularly compactly and cost-effectively.
[0036] Furthermore, it is advantageous if the iron circuit is formed from a return plate and a U-shaped yoke, the free legs of which rest on the return plate. The yoke can be manufactured by simple bending, while the straight return plate serves as a support surface during overmolding to form the axial contact chamber wall.
[0037] Accordingly, the return plate is arranged axially between the coil or coil carrier and the axial contact chamber wall and rests against the axial contact chamber wall, so that the axial contact chamber wall is additionally reinforced by the return plate. Thus, not only is the radial contact chamber wall metal-reinforced by the magnetic field conductor, but the axial contact chamber wall is also metal-reinforced by the return plate, creating an almost entirely metal-reinforced contact chamber that can withstand extremely high pressures particularly well.
[0038] Advantageously, the magnetic field conductor is in direct magnetically conductive connection with the iron circuit. Particularly preferably, the magnetic field conductor is in direct magnetically conductive connection with the return plate. Because the return plate is preferably arranged at the actuator-side axial end of the magnetic field conductor, a direct magnetic connection can be easily established between the return plate and the magnetic field conductor, thereby closing the magnetic circuit also in the actuator-side axial region of the contact chamber.
[0039] In a further advantageous embodiment of the invention, the iron circuit of the electromagnetic actuator is completely surrounded radially inside and out by the actuator housing part produced by overmolding, and axially by the contact chamber wall in the direction of the contact chamber. The actuator, or rather the current-carrying part of the actuator, is thus completely galvanically isolated from the contact chamber, which also completely separates the actuator circuit from the circuit to be switched.
[0040] Furthermore, the contact chamber cover and the contact chamber outer wall are preferably bonded together. Such bonded connections are created, for example, by ultrasonic welding, laser welding, or other welding processes suitable for plastics. This completely seals the contact chamber from the outside, allowing the pressure within the contact chamber to be significantly increased relative to the ambient temperature, which is a significant advantage with regard to arc extinguishing.
[0041] Such a high-voltage contactor or high-voltage relay exhibits high sealing from the outside to the inside and vice versa over a long service life and is capable of withstanding the high pressures, particularly during the occurrence of an arc. An exemplary embodiment of a high-voltage contactor or high-voltage relay according to the invention is illustrated in the figures and described below.
[0042] Figure 1 shows a side view of a high-voltage contactor according to the invention in a sectional view.
[0043] Figure 2 shows a plan view of the high-voltage contactor according to the invention of Figure 1 in a sectional view, the section being shown in Figure 1.
[0044] The high-voltage contactor 10 shown in Figure 1 consists of 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 attached to the return plate 28, thus forming the closed iron circuit 20.
[0045] The yoke 24 has a central opening 32 at its base 30, the diameter of which essentially corresponds to the inner diameter of the coil carrier 16. A bushing 34 is secured in this opening, or rather, inside the coil carrier 16, in which the armature 22 is slidably arranged and guided. When current is applied to the coil 14, the armature 22 is drawn in a known manner against the force of a spring 36 in the contact chamber 42 toward the return plate 28.
[0046] An actuating rod 38 rests axially on the armature 22 on the contact chamber side and projects through a further central opening 40 in the return plate 28 into a contact chamber 42. A contact bridge 44 is arranged at the end of the actuating rod 38 opposite the armature 22. This contact bridge 44 is preferably pressed by a spring element 46 against a stop 48 at the end of the actuating rod 38, which is supported on a shoulder 49 on the actuating rod 38 and is accordingly arranged on the actuating rod 38 so as to be slightly axially and tiltably movable. A contact plate 52, 53 made of a particularly highly conductive material is fastened to each end of the contact bridge 44. The first contact plate 52 is arranged axially opposite a first contact element 54, which can be connected in particular to a 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, via a busbar to a drive motor of a motor vehicle.
[0047] The entire high-voltage contactor 10 is arranged in a housing 58, which is composed of a total of three parts. 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 axially by this plastic in the direction of the contact chamber 42, thereby forming an axial contact chamber wall 45. The opening 40 of the return plate 28 is also covered radially inward by the plastic, leaving only a central guide opening 70 free, in which the actuating rod 38 is guided.
[0048] 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.
[0049] 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.
[0050] Furthermore, the actuator housing part 60 produced by overmolding the actuator 12 forms a molding 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.
[0051] 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.
[0052] The radial contact chamber wall 47 is designed in a so-called sandwich construction, as also shown in Figure 2. 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 magnetic field guide plate 51.
[0053] 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 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, thus extinguishing the arcs. The magnetic field guide plate 51 is not completely overmolded on the inside in the area of the pocket 471, 472. Instead, each permanent magnet 55, 57 contacts the magnetic field guide plate 51 on its respective inside, 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 inwards 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.
[0054] In addition, the magnetic field guide plate 51 extends axially in the actuator direction up to the return plate 28 and contacts it, 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.
[0055] The contact chamber 42 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 secured, for example, by ultrasonic welding or overmolding. Extending circumferentially in the axial direction from this contact chamber cover 88 is a collar 92 that radially encloses the circumferential contact chamber outer wall 476, so that these two walls 92, 476 can be joined together circumferentially 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 outwardly 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.
[0056] If the flow of current between the electric motor or the charging station and the battery is to be enabled, the coil 14 is energized, whereby the armature 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 a 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 loaded in the opposite direction by the spring 36 so that the contact bridge 44 is lifted off the contact elements 54, 56 and the circuit is interrupted. This creates an arc due to the high currents, which also results in an increase in pressure in the contact chamber 42.
[0057] 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, in particular by the molded-on axial contact chamber wall 45. The tight welding of only three housing parts also achieves 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 the assembly costs are very low.
[0058] It should be clear that various modifications are possible compared to the described embodiment. In particular, the design of the contact unit as well as the arrangement of the springs and the actuating rod guide and mounting may differ from the form shown.
Claims
P A T E N T A N S P R Ü C H E 1. A high-voltage contactor (10) or high-voltage relay comprising an electromagnetic actuator (12), a housing (58) with an inner contact chamber (42), a first contact element (54) which projects into the contact chamber (42), a second contact element (56) which projects into the contact chamber (42), a contact bridge (44) which can be displaced by means of the actuator (12) in the contact chamber (42) at least into a first position in which the first contact element (54) is electrically connected to the second contact element (56) via the contact bridge (44), and into a second position in which electrical contact between the first contact element (54) and the second contact element (56) is interrupted, a magnetic field conducting body (50) which magnetically connects at least two permanent magnets (55, 57) arranged diametrically opposite one another in the contact chamber (42), characterized in thatthat the magnetic field guide body (50) completely surrounds the contact chamber (42) radially., 2. High-voltage contactor (10) or high-voltage relay according to claim 1, characterized in that the housing (58) has a radial contact chamber wall (47) which radially delimits the contact chamber (42) completely, wherein the radial contact chamber wall (47) is defined by a contact chamber inner wall (474) and a contact chamber outer wall (476) which are radially spaced and arranged parallel to each other.
3. High-voltage contactor (10) or high-voltage relay according to claim 2, characterized in that the magnetic field conducting body (50) is arranged radially between the contact chamber inner wall (474) and the contact chamber outer wall (476).
4. High-voltage contactor (10) or high-voltage relay according to claim 3, characterized in that the radial contact chamber wall (47) is produced by overmolding the magnetic field conducting body (50).
5. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that the permanent magnets (55, 57) are arranged radially between the contact chamber inner wall (474) and the contact chamber outer wall (476).
6. High-voltage contactor (10) or high-voltage relay according to claim 5, characterized in that the permanent magnets (55, 57) contact the radial inner side of the magnetic field guide body (50).
7. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that the magnetic field guide body (50) is formed by a ferromagnetic magnetic field guide plate (51).
8. High-voltage contactor (10) or high-voltage relay according to claim 7, characterized in that the magnetic field guide plate (51) in the non-overmolded state has a plurality of openings (512) which are filled with the overmolded plastic after overmolding.
9. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that the housing (58) has an axial contact chamber wall (45) which delimits the contact chamber (42) axially in the direction of the actuator (12).
10. High-voltage contactor (10) or high-voltage relay according to claim 9, characterized in that the axial contact chamber wall (45) and the radial contact chamber wall (47) are formed in one piece.
11. High-voltage contactor (10) or high-voltage relay according to one of claims 2-10, characterized in that the radial contact chamber wall (47) has at least two diametrically opposed pockets (471, 472) which are open to the axial side opposite the actuator (12), one of the permanent magnets (55, 57) being arranged in each pocket (471, 472).
12. High-voltage contactor (10) or high-voltage relay according to claim 11, characterized in that each pocket (471, 472) has a stop structure (475) against which the respective permanent magnet (55, 57) arranged in the pocket (471, 472) bears axially.
13. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that the housing (58) has a contact chamber cover (88) which closes the contact chamber (42) on the axial side opposite to the actuator (12).
14. High-voltage contactor (10) or high-voltage relay according to claims 11-13, characterized in that the contact chamber cover (88) axially closes the pockets (471, 472).
15. High-voltage contactor (10) or high-voltage relay according to one of claims 13 or 14, characterized in that the contact chamber cover (88) has a collar (92) extending axially in the direction of the actuator (12) and radially enclosing the radial contact chamber wall (47) completely.
16. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that the housing (58) has an actuator housing part (60) which is produced by overmolding the actuator (12) with plastic.
17. High-voltage contactor (10) or high-voltage relay according to claim 16, characterized in that the radial contact chamber wall (47) is formed integrally with the actuator housing part (60).
18. High-voltage contactor (10) or high-voltage relay according to one of claims 2-16, characterized in that the radial contact chamber wall (47) extends axially from the actuator (12) in the direction of the contact elements (52, 53).
19. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that the electromagnetic actuator (12) has a coil (14), an iron circuit (20) surrounding the coil (14) and an armature (22).
20. High-voltage contactor (10) or high-voltage relay according to claim 19, characterized in that the iron circuit (20) is formed from a return plate (28) and an I-shaped yoke (24), the free legs (26) of which rest on the return plate (28).
21. High-voltage contactor (10) or high-voltage relay according to claim 20, characterized in that the return plate (28) is arranged axially between the coil (14) and the axial contact chamber wall (69) and bears against the axial contact chamber wall (69).
22. High-voltage contactor (10) or high-voltage relay according to one of the claims 19-21, characterized in that the magnetic field conducting body (50) is in direct magnetically conductive connection with the iron circuit (20).
23. High-voltage contactor (10) or high-voltage relay according to one of the claims 20-22, characterized in that the magnetic field guide body (50) is in direct magnetically conductive connection with the return plate (28).
24. High-voltage contactor (10) or high-voltage relay according to one of claims 18-21, characterized in that the iron circuit (20) of the electromagnetic actuator (12) is completely surrounded radially inside and outside by the actuator housing part (60) produced by overmolding and is surrounded axially in the direction of the contact chamber (42) by the axial contact chamber wall (45).
25. High-voltage contactor (10) or high-voltage relay according to one of claims 12-23, characterized in that the contact chamber cover (88) and the contact chamber outer wall (476) are integrally connected to one another.