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 EP2023072247_13022025_PF_FP_ABST
Abstract
Description
[0001] DESCRIPTION
[0002] High-voltage protection 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 displaced 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 displaced into a second position in which electrical contact between the first contact element and the second contact element is interrupted, at least two permanent magnets arranged diametrically opposite one another in the contact chamber, at least one arc shielding wall which is arranged radially between the permanent magnets and the contact bridge, and a contact chamber boundary wall.
[0004] Such high-performance switchgear is required to establish and break electrical connections both under load and under no-load conditions, 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, particularly during load conditions while driving or charging, or in the event of a short-circuit, such switchgear is equipped with an arc-quenching device that uses so-called blowout magnets to extinguish any arcs that occur after a relatively short time, thereby preventing thermally induced damage to the surrounding components.
[0005] Such a high-voltage contactor is known from EP 3 989 258 A1. The high-voltage contactor disclosed therein has two permanent magnets at opposite radial ends of the contact chamber, namely one permanent magnet for each contact point. These permanent magnets are arranged such that the Lorentz force exerted by the magnetic fields of the permanent magnets manipulates the arcs, causing them to be deformed into an arc. The elongation of the arcs causes a surface enlargement, which allows the arcs to cool more quickly and ultimately extinguish them. The permanent magnets are protected from the arcs by an arc shielding wall, thus preventing the arcs from directly jumping to the magnets.
[0006] In this design, the permanent magnets are completely separated and insulated from the current-carrying part of the contact chamber by means of the arc shielding wall, which is relatively complex and therefore cost-intensive from a manufacturing point of view, particularly with regard to sealing the current-carrying space in the contact chamber from the permanent magnets.
[0007] The present invention is therefore based on the object of creating a high-voltage contactor that is characterized by simple and cost-effective manufacture and yet reliably shields the permanent magnets from the arcs occurring in the contact chamber. This prevents the arc from penetrating the blowout magnetic field and thus causing a short circuit, which could reignite the arc, causing thermal damage to the contactor. This object is achieved by a high-voltage contactor or high-voltage relay according to the invention having the features of main claim 1.
[0008] 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.
[0009] For the sake of simplicity, only the term high-voltage contactor is used below, although this also includes the term high-voltage relay.
[0010] 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.
[0011] The high-voltage contactor further comprises a multi-part housing, preferably made of plastic, with an inner contact chamber arranged axially adjacent to the actuator. The housing is designed such that the contact chamber is almost completely sealed from the environment, allowing only a slow exchange of air and a slight pressure equalization with the environment.
[0012] 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 moved 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 the electrical connection between the first contact element and the second contact element is interrupted.
[0013] The high-voltage contactor further comprises at least two permanent magnets arranged diametrically opposite one another in the contact chamber, each of which is preferably 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 permanent magnets are aligned in such a way that the Lorentz force deforms the arcs radially outwards. This effect is more pronounced the closer the permanent magnet is brought to the respective contact point and thus to the arcs.
[0014] Furthermore, the high-voltage contactor has at least one arc shielding wall arranged radially between the permanent magnets and the contact bridge. The arc shielding wall is preferably made of a magnetically non-conductive material so that the magnetic field of the permanent magnets, which acts on the arcs through the arc shielding wall, is not impaired. Plastic is particularly suitable as a material here because it is lightweight, inexpensive, and easy to process. The arc shielding wall can either be a single, continuous arc shielding wall that completely encloses the contact chamber radially or, alternatively, be formed from several arc shielding walls, each assigned to one of the permanent magnets.
[0015] Furthermore, the high-voltage contactor has a contact chamber boundary wall which preferably limits the contact chamber in the axial and / or radial direction.
[0016] According to the invention, the arc shielding wall and the contact chamber boundary wall are designed such that a labyrinth-like gap is formed between the arc shielding wall and the contact chamber boundary wall. The arc shielding wall and the contact chamber boundary wall are designed to correspond to one another, but are arranged at a distance from one another, wherein the distance between the contact chamber boundary wall and the arc shielding wall is relatively small, so that the labyrinth-like gap is relatively narrow. The arc shielding wall and the contact chamber boundary wall are shaped and arranged in such a way that the labyrinth-like gap has several meandering changes in direction, preferably at 90° angles, so that no straight connection exists between the permanent magnet and the contact bridge.This can be achieved, for example, by having the contact chamber boundary wall with an uneven, partially crenellated shape featuring elevations and depressions, with the arc shielding wall preferably projecting into one of the depressions. This nested design of the contact chamber boundary wall and the arc shielding wall prevents the resulting arc from directly flashing onto the permanent magnet or onto other metallic components adjacent to the permanent magnets. Thus, the permanent magnet does not need to be completely separated or electrically insulated from the current-carrying space in the contact chamber. Therefore, in the area of the labyrinthine gap, the arc shielding wall and the contact chamber boundary wall do not need to be sealed off from one another and therefore require less precision machining, keeping overall manufacturing costs low.
[0017] In a particularly advantageous embodiment of the invention, the labyrinth-like gap is at least U-shaped. Accordingly, the labyrinth-like gap has at least three preferably rectilinear gap sections, each arranged at an angle of 90° to one another. The three gap sections can be of different widths, with the two legs of the U-shaped gap preferably being narrower than the gap section connecting the two legs. To further increase safety against arc flashover, it can be advantageous to provide additional gap sections following the three gap sections, creating, for example, a meandering, S-shaped gap. The higher the number of gap sections, the lower the probability of the arc flashing onto the permanent magnet or other metallic components arranged adjacent to the permanent magnet.Nevertheless, an increasing number of gap sections increases the design and manufacturing effort, so that a relatively balanced cost-benefit ratio is achieved with the i-shaped gap.
[0018] In a further advantageous embodiment of the invention, the contact chamber boundary wall has a recess into which the arc shielding wall projects without contact. The recess is preferably rectangular in cross-section and open on one side. The arc shielding wall projects centrally from the open side of the recess into the recess, wherein the arc shielding wall does not touch the side walls extending from the open side of the recess and is arranged parallel to these, so that a gap of constant width is formed between the arc shielding wall and the side walls of the recess on both sides of the arc shielding wall. Furthermore, the arc shielding wall only projects far enough into the recess to create a gap between the end face of the arc shielding wall and the base of the recess, so that the recess and the arc shielding wall ultimately form a U-shaped gap.In this way, the labyrinth-like gap can be realized relatively easily from a manufacturing perspective. Alternatively, instead of the recess, two parallel and spaced-apart wall segments can protrude from the contact chamber boundary wall into the contact chamber, with the arc shielding wall extending between them, thus forming a labyrinth-like gap based on the same principle.
[0019] 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 circumferentially to a contact chamber wall radially delimiting the contact chamber, in particular 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.
[0020] In a further embodiment, the contact chamber boundary wall is formed by the contact chamber cover, whereby the number of components of the high-voltage contactor and thus the assembly effort is relatively low.
[0021] In a further particularly advantageous embodiment of the invention, the contact chamber boundary wall is at least partially formed by the contact elements. A crenellated structure of the contact chamber boundary wall can be formed relatively easily by means of the contact elements, since the contact elements extend axially relatively far into the contact chamber. The arc shielding wall also extends axially parallel to and spaced from the side wall of the contact elements, thereby easily forming a first gap section between the contact element and the arc shielding wall. This first gap section can be continued relatively easily by cleverly designing the contact chamber boundary wall sections adjacent to the contact elements.
[0022] In a further particularly preferred embodiment of the invention, the contact chamber is radially delimited by a double-walled, radial contact chamber wall formed by the arc shielding wall and a contact chamber outer wall. The arc shielding wall and the contact chamber outer wall are radially spaced and arranged parallel to one another. The radial contact chamber wall is thus double-walled, at least in the region in which the permanent magnets are arranged, with a permanent magnet being located in each gap formed between the arc shielding wall and the contact chamber outer wall. The double-walled contact chamber wall is open on the side facing the contact chamber boundary wall, with the arc shielding wall protruding into a recess in the contact chamber boundary wall and thus forming a labyrinth-like gap between itself and the contact chamber boundary wall.This results in a relatively simple design of the high-voltage contactor.
[0023] In a further advantageous embodiment of the invention, the contact chamber boundary wall has a projection that protrudes between the arc shielding wall and the contact chamber outer wall. The projection is designed such that the axially extending side wall of the projection is spaced apart from and arranged parallel to the arc shielding wall or the contact chamber outer wall, so that a gap section of the labyrinth-like gap is formed, in particular, between the arc shielding wall and the projection.
[0024] 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 pushed 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 sits precisely and without play in the pocket. The pockets preferably protrude radially from the contact chamber outer 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. In a further embodiment of the invention, the arc shielding wall forms the radial inner wall of the pocket, which is arranged between the permanent magnet and the contact bridge.This preferably extends axially and, as already described several times, protrudes at the open end of the pocket into a recess in the contact chamber boundary wall, forming the labyrinthine gap. The inner wall of the pocket is preferably relatively thin and thus allows the permanent magnet to be brought relatively close to the contact point. Nevertheless, the inner wall of the pocket protects the permanent magnet and other electrically conductive components adjacent to the permanent magnet from direct contact with the arc.
[0025] 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, for example, be formed by at least one rib arranged in the pocket, which runs between two opposite walls of the pocket. Preferably, several ribs extend between the arc shielding 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.The stop structure allows the permanent magnet to be positioned at the level of the contact points in the axial direction without having to accept manufacturing disadvantages such as material accumulation or uneven wall thicknesses, which would lead to quality losses in the overall product, especially when using plastic materials. The contact chamber cover is preferably arranged axially opposite the open side of the pockets, so that the labyrinthine gap can be formed in sections by the contact chamber cover and the pocket wall. This results in a relatively simple design of the high-voltage contactor.
[0026] 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 radially on the outside of the contact chamber wall. The contact chamber cover is preferably secured to the radial contact chamber wall by a material bond, 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.
[0027] In a further particularly advantageous embodiment of the invention, a magnetic field conductor magnetically connects the 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. The magnetic field conductor represents a magnetic short circuit between the permanent magnets, which on the one hand leads to relatively good magnetic field bundling and on the other hand is particularly advantageous 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.
[0028] The magnetic field conductor preferably 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 magnetic field conductor enclosing the contact chamber creates a metallic reinforcement for the housing section radially surrounding the contact chamber, which can withstand the high pressures in the contact chamber caused by the arcs and thus protects the housing from damage. Nevertheless, the contact chamber walls can be designed to be relatively thin, which is particularly advantageous with regard to the compactness of the high-voltage contactor.
[0029] In a further particularly preferred embodiment of the invention, the magnetic field conductor is arranged radially between the arc shielding wall and the contact chamber outer wall. The magnetic field conductor is thus located in the gap of the double-walled contact chamber wall, which completely surrounds the contact chamber, between the arc shielding wall and the contact chamber outer wall. Furthermore, the magnetic field conductor is precisely fitted into the gap away from the pocket, ensuring a play-free fit. This strengthens the arc shielding wall in particular, but 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 arc shielding wall thus forms a kind of insulating layer in the area of the magnetic field conductor, away from the permanent magnets, between the usually metallic and thus electrically conductive magnetic field conductor and the arcs, thus preventing the arc from jumping to the magnetic field conductor. In addition, the magnetic field conductor is shielded from the environment by the contact chamber's outer wall and is thus not exposed to environmental influences.
[0030] 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. The arc shielding wall is created by overmolding the radial inner side of the magnetic field conductor, and the contact chamber outer wall is created by overmolding the magnetic field conductor on the radial outer side. This creates a meta II 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.
[0031] 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.
[0032] Furthermore, the magnetic field guide body can be 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.
[0033] In a further particularly advantageous embodiment of the invention, in addition to the radial contact chamber wall, the housing also has an axial contact chamber wall which delimits the actuator axially 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, has an electrically insulating effect and protects the actuator from the arcs occurring in the contact chamber, thereby preventing damage to the actuator and its sensitive components. The radial contact chamber wall and the axial contact chamber wall are preferably formed as one piece and are produced, for example, by jointly overmolding the actuator and the magnetic field guide body with plastic. Particularly preferably, the axial contact chamber wall is formed as one piece with the arc shielding wall.The radial contact chamber wall and the axial contact chamber wall are thus integrally connected, which completely seals the contact chamber 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 from the actuator, so that the actuator circuit remains galvanically separated from the switching circuit.
[0034] 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.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. As a result, the entire housing, apart from the axial end faces, which are preferably provided with covers, forms a completely enclosed unit that seals the interior of the high-voltage contactor from the environment.
[0035] 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.
[0036] 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.
[0037] 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 therefore be manufactured by simple bending, while the straight return plate serves as a support surface during overmolding to form the axial contact chamber wall. 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 also the axial contact chamber wall 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, using 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] An embodiment of a high-voltage contactor or high-voltage relay according to the invention is shown in the figures and is 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 an enlarged section of the high-voltage contactor according to the invention of Figure 1 in a sectional view, the position of 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, 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.
[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 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.
[0051] In addition, a circumferential radial contact chamber wall 47 extends from the return plate 28 as an extension of the plastic surrounding the actuator 12. This circumferential radial contact chamber wall 47 radially delimits the contact chamber 42 and is also manufactured in one piece during the overmolding of the actuator 12, thus forming four side walls of the contact chamber 42 in the present exemplary embodiment. The radial contact chamber wall 47 is designed in a so-called sandwich construction. The radial contact chamber wall 47 is formed by an arc shielding wall 41 and a contact chamber outer wall 476, which are arranged at a distance from and parallel to one another. Between the arc shielding wall 41 and the contact chamber outer wall 476, a magnetic field guide body 50 is formed by a ferromagnetic magnetic field guide plate 51, which completely surrounds the contact chamber 42 radially, wherein the radial contact chamber wall 47 or the arc shielding wall 41 as well as the contact chamber outer wall 476 are connected by internal or external magnetic fields.The magnetic field guide plate 51 is manufactured by overmolding the outside with plastic. 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 arc shielding wall 41 is formed integrally with the axial contact chamber wall 45. Nevertheless, the arc shielding wall 41 and the contact chamber outer wall 476 can be integrally connected to one another at several points, for example, through openings in the magnetic field guide plate 51.
[0052] 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 shape and thus extinguishes the arcs.
[0053] Between each permanent magnet 55, 57 and the contact bridge 44, the arc shielding wall 41 is arranged, which forms the radial inner wall 473 of the pocket 471, 472 in the region of the pocket. The arc shielding wall 41 extends axially from the axial contact chamber wall 45 toward a contact chamber boundary wall 86, which bounds the contact chamber 42 in the axial direction. The contact chamber boundary wall 86 is formed by a contact chamber cover 88, which is arranged axially opposite the open side of the pockets 471, 472.
[0054] Two axial openings 90 are formed in the contact chamber cover 88, in which the two contact elements 54, 56 are received and secured, for example, by ultrasonic welding or overmolding, whereby the contact chamber boundary wall 86 is additionally formed in sections by the contact elements 54, 56 and therefore has a crenellated shape. In the region of the transition between the contact element 54, 56 and the contact chamber cover 88, a recess 861 is formed into which the arc shielding wall 41 projects without contact. The arc shielding wall 41 is arranged at a distance from the respective contact element 54, 56 and at a distance from the contact chamber cover 88, so that a labyrinthine, U-shaped gap 96 is formed between the contact chamber boundary wall 86 and the pocket wall 473 forming the arc shielding wall 41, as shown in Figure 2.A projection 87 also extends from the contact chamber boundary wall 86 and projects between the arc shielding wall 41 and the contact chamber outer wall 476, whereby the labyrinth-like gap 96 receives its U-shape.
[0055] Away from the pockets 471, 472, the arc shielding wall 41 shields the magnetic field guide plate 51 from the arcs occurring in the contact chamber 42.
[0056] 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 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 protrudes radially inward from the inside of the magnetic field guide plate 51. The ribs 477 each extend radially from the arc shielding wall 41 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.
[0057] 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 an improved homogeneity of the magnetic field, thereby achieving a relatively strong deformation of the arcs and thus a relatively rapid extinguishing of the arcs. Extending circumferentially in the axial direction from the contact chamber cover 88 is a collar 92 which radially encloses the circumferential contact chamber outer wall 476 so that these two walls 92, 476 can be connected to one another in a circumferentially 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.
[0058] 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 is extinguished by the arc extinguishing device formed by the permanent magnets 55, 57 and the magnetic field guide plate 51. The arc is deformed and thus elongated by the Lorentz force of the magnetic fields of the permanent magnets 55, 57, so that the arc is extinguished more quickly due to its increased surface area. The arc shielding wall 41 prevents the deformed arc from flashing over to the permanent magnets 55, 57 and / or the magnetic field guide plate 50.By using the labyrinth-like gap 96, the arc shielding wall 41, 43 does not have to be sealed against the contact chamber cover 88, so that no complete electrically insulating separation has to be created between the current-carrying contact chamber 42 and the pockets 471, 472, whereby the manufacture and assembly of the high-voltage contactor 10 is considerably simplified compared to a high-voltage contactor according to the prior art.
Claims
P A T E N T A N S P R Ü C H E 1. High-voltage contactor (10) or high-voltage relay with 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 can be displaced into a second position in which electrical contact between the first contact element (54) and the second contact element (56) is interrupted, at least two permanent magnets (55, 57) arranged diametrically opposite one another in the contact chamber (42), at least one arc shielding wall (41, 43) which is arranged radially between the permanent magnets (55, 57) and the contact bridge (44),and a contact chamber boundary wall (86), characterized in that the arc shielding wall (41) and the contact chamber boundary wall (86) are designed such that a labyrinth-like gap (96) is formed between the arc shielding wall (41) and the contact chamber boundary wall (86).
2. High-voltage contactor (10) or high-voltage relay according to claim 1, characterized in that the labyrinth-like gap (96) is at least U-shaped.
3. High-voltage contactor (10) or high-voltage relay according to claim 1 or 2, characterized in that the contact chamber boundary wall (86) has a recess (861) into which the arc shielding wall (41) projects without contact.
4. 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).
5. High-voltage contactor (10) or high-voltage relay according to claim 4, characterized in that the contact chamber boundary wall (86) is formed by the contact chamber cover (88).
6. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that the contact chamber boundary wall (86) is at least partially formed by the contact elements (54, 56).
7. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that the contact chamber (42) is radially enclosed by a double-walled, radial Contact chamber wall (47) is limited by the Arc shielding wall (41) and a contact chamber outer wall (476) is formed.
8. High-voltage contactor (10) or high-voltage relay according to claim 7, characterized in that the contact chamber boundary wall (86) has a projection (87) which projects between the arc shielding wall (41) and the contact chamber outer wall (476).
9. High-voltage contactor (10) or high-voltage relay according to one of claims 2-8, 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).
10. High-voltage contactor (10) or high-voltage relay according to claim 9, characterized in that the arc shielding wall (41, 43) (471, 472) forms a radial inner wall (473) of the pocket (471, 472) which is arranged between the permanent magnet (55, 57) and the contact bridge (44).
11. High-voltage contactor (10) or high-voltage relay according to claim 10, characterized in that the radial inner wall (473) of the pocket (471, 472) is arranged between the contact element (54, 56) and the permanent magnet (55, 57).
12. High-voltage contactor (10) or high-voltage relay according to one of claims 9-11, characterized in that each pocket (471, 472) has a stop structure (475, 476) 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 claims 4-12, characterized in that the contact chamber cover (88) is arranged axially opposite the open side of the pockets (471, 472).
14. High-voltage contactor (10) or high-voltage relay according to one of claims 4-13, characterized in that the contact chamber cover (88) has a collar (92) extending axially in the direction of the actuator (12) and completely enclosing the radial contact chamber wall (47) radially.
15. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that a magnetic field conducting body (50) magnetically connects the at least two permanent magnets (55, 57) arranged diametrically opposite one another in the contact chamber (42).
16. 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).
17. High-voltage contactor (10) or high-voltage relay according to claim 17, characterized in that the axial contact chamber wall (45) and the radial contact chamber wall (47) are formed in one piece.
18. 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.
19. High-voltage contactor (10) or high-voltage relay according to claim 18, characterized in that the radial contact chamber wall (47) is formed integrally with the actuator housing part (60).
20. High-voltage contactor (10) or high-voltage relay according to one of claims 7-19, characterized in that the radial contact chamber wall (47) extends axially from the actuator (12) in the direction of the contact elements (52, 53).
21. 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), wherein the iron circuit (20) is formed from a return plate (28) and a U-shaped yoke (24), the free legs (26) of which rest on the return plate (28), and wherein the return plate (28) is arranged axially between the coil (14) and the axial contact chamber wall (69) and rests against the axial contact chamber wall (69).
22. High-voltage contactor (10) or high-voltage relay according to claim 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).
23. High-voltage contactor (10) or high-voltage relay according to one of claims 7-22, characterized in that the contact chamber cover (88) and the contact chamber outer wall (476) are integrally connected to one another.