High-voltage contactor or high-voltage relay with a single-piece actuator casing part made of plastic

Abstract

The invention relates to high-voltage contactors (10) or high-voltage relays comprising an electromagnetic actuator (12) with a coil (14), an iron core (20) which surrounds the coil (14), and an armature (22); a casing (58) that has an inner contact chamber (42) and includes an actuator casing part (60) with a radial delimiting wall (66) which completely radially surrounds the coil (14) of the electromagnetic actuator (12); a first contact element (54) which protrudes into the contact chamber (42); a second contact element (56) which protrudes into the contact chamber (42); and a contact bridge (44) which can be moved, in the contact chamber (42) by means of the actuator (12), 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 a second position, in which the electric contact between the first contact element (54) and the second contact element (56) is interrupted. In order to improve the tightness and reduce the installation space, the invention proposes that the actuator casing part (60) has an axial delimiting wall (69) which axially delimits the coil (14) and the iron core (20) from the contact chamber (42), and the radial delimiting wall (66) and the axial delimiting wall (69) are produced as a single piece by encapsulating the actuator (12) with plastic.

Description

[0001] HIGH-VOLTAGE CONTACTOR OR HIGH-VOLTAGE RELAY WITH A ONE-PIECE PLASTIC ACTUATOR HOUSING PART

[0002] The invention relates to a high-voltage contactor or high-voltage relay with an electromagnetic actuator, a housing with an inner contact chamber, which has an actuator housing part with a radial boundary wall which radially completely surrounds the coil of the electromagnetic actuator, 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 an electrical contact between the first contact element and the second contact element is interrupted.

[0003] 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.

[0004] 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.

[0005] 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.

[0006] The challenge, therefore, is to create a high-voltage contactor or high-voltage relay that achieves sufficient strength and tightness in the simplest possible way, using as few individual parts as possible to avoid leaks due to assembly errors and to save as much space and cost as possible for such a high-voltage contactor. This tightness must be ensured both from the inside out in the event of a shutdown or short-circuit current, and maintained in the opposite direction over a service life of more than ten years to prevent the ingress of material into the high-voltage contactor, as gases penetrating from the outside can have a negative impact on the contact resistance and breaking capacity.

[0007] This task is solved by a high-voltage contactor or high-voltage relay having the features of the 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. The term "electromagnetic actuator" refers to all actuators that generate movement due to a force caused by electromagnetism. The electromagnetic actuator thus consists in particular either of a coil consisting of a coil carrier and a winding wound thereon, as well as an iron circuit surrounding the coil and an armature movable due to the electromagnetic force, which is arranged within the coil and the iron circuit, or of an electric motor with a rotor and a wound stator. The high-voltage contactor further comprises a multi-part housing that defines an inner contact chamber.This housing comprises an actuator housing part with a radial boundary wall that completely surrounds the coil of the electromagnetic actuator, thus completely enclosing the coil. The terms "radial" and "axial" refer to the actuator's central axis.

[0009] 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 or rotated 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, or to the rotor of the electric motor via a shaft, 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 shifted or rotated into a second position in which electrical contact between the first contact element and the second contact element is interrupted.

[0010] According to the invention, the actuator housing part has, in addition to the radial boundary wall, an axial boundary wall that axially delimits the actuator relative to the contact chamber, i.e., is located between the contact chamber and the actuator. The radial boundary wall and the axial boundary wall are manufactured as a single piece 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 protrudes into the contact chamber. Because the housing is closed to the contact chamber, high strength is achieved in the area where the highest forces occur, even with relatively thin walls, and the necessary sealing surfaces are completely eliminated.This strength is also increased by overmolding and the resulting tight contact of the surrounding plastic with the coil or iron circuit, and gaps between the parts in which pressure can build up are 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 components, as well as reducing manufacturing costs compared to conventional designs. In addition, a stable system is created in which the actuator cannot move within the housing. Furthermore, acoustic emissions are reduced by avoiding resonance cavities between the actuator and the housing.

[0011] 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 inexpensively and without any additional components.

[0012] Preferably, the iron circuit of the electromagnetic actuator is also completely overmolded radially inside and out during the overmolding, while the iron circuit is axially limited in the direction of the contact chamber by the axial boundary wall of the actuator housing part. This means that the actuator is radially outwardly limited to the contact chamber on the one hand, and the iron circuit is radially limited opposite the coil by the plastic. The plastic fills the gap between the coil winding and the iron circuit, so that relative movement to each other is also excluded here. Contact between the iron circuit and the winding is prevented because the plastic of the actuator housing is arranged radially between the iron circuit and the coil, and the coil carrier is arranged axially between the winding and the iron circuit. This creates an almost gap-free actuator housing with high strength and low wall thickness. Leaks are thus reliably prevented.

[0013] Furthermore, it is advantageous if the actuator housing part produced by overmolding the actuator extends at least over a radially outer region of the actuator on its axial outer side opposite the contact chamber and has an opening in the radially inner region that is completely closed by a plastic cover. Accordingly, after overmolding, a bushing can be inserted into the coil carrier from this outer side in the axial direction, and the armature with the actuating rod can be inserted into the bushing. Nevertheless, a high level of strength and complete sealing of the housing to the outside are achieved, thus preventing external contamination or outgassing.

[0014] In a further embodiment, the plastic cover is attached to the actuator housing part with a material bond all the way around, particularly by adhesive bonding, laser welding, ultrasonic welding, or rotational vibration welding. This attachment is highly durable and completely leak-proof, without the need for additional seals.

[0015] In addition, the actuator housing part manufactured by overmolding preferably has a circumferential housing wall extending axially from the actuator, which radially defines the contact chamber. This completely eliminates the need for joints and abutting edges that could lead to leaks in the area of ​​the housing wall defining the contact chamber. Furthermore, no additional components are required.

[0016] The contact chamber is advantageously axially delimited by a switch housing part, which is attached circumferentially to the circumferential housing wall of the actuator housing part, which extends axially from the actuator. This switch housing part accordingly forms a kind of cover. This allows the entire housing to be assembled from just three parts, all of which can be mounted axially. There are no connecting seams in the main radial propagation direction of the arc, thus achieving a high level of tightness and strength.

[0017] In a further embodiment, the switch housing part has an axially extending, circumferential outer wall, with which the switch housing part rests against the circumferential housing wall of the actuator housing part, which extends axially from the actuator, and is firmly attached, in particular by adhesive bonding, laser welding, ultrasonic welding, or rotational vibration welding. This creates a double radially delimiting outer wall, which further increases strength. Furthermore, laser welding, ultrasonic welding, or rotational vibration welding also creates a completely sealed connection.

[0018] In a further development of this, a circumferential axial groove is formed on the switch housing part radially inward relative to the outer wall, into which the housing wall of the actuator housing part engages and which is delimited radially outward by the outer wall of the switch housing part. This not only fixes the position of the actuator housing part relative to the switch housing part to establish the integral connection but also to correctly align the contact elements to the contact bridge. Furthermore, a positive fit prevents relative movement of the end section of the housing wall of the actuator housing part relative to the outer wall, thereby improving durability.

[0019] Preferably, the switch housing part has two axially extending openings in which the two contact elements are mounted, so that their assembly can be carried out in advance on the switch housing part. Accordingly, additional insertion of the contact elements is not necessary when assembling the housing of the high-voltage contactor.

[0020] 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 boundary wall.

[0021] Accordingly, the return plate is arranged axially between the coil or the coil carrier and the axial boundary wall and rests against the axial boundary wall, so that additional parts can be dispensed with.

[0022] The actuator housing part preferably extends radially between the coil and the U-shaped yoke and surrounds the U-shaped yoke radially, so that it is completely enclosed by the plastic. Movements of the individual actuator parts or the electromagnetic circuit are thus reliably prevented, as a complete gap-free arrangement is achieved.

[0023] Furthermore, connecting lines are led from the coil winding through the actuator housing part to the outside, whereby the actuator housing part has formations for direct connection to a voltage source. These formations can, for example, form a connector housing for supplying current to the coil and are accordingly molded integrally with the actuator housing part. Accordingly, only the necessary contact lines protrude from the actuator housing part. These, however, are tightly molded over with the other parts. This eliminates the need for additional components and sealing surfaces, which also simplifies assembly. In an alternative embodiment, the electromagnetic actuator has an electric motor with a rotor and a stator with a winding, the rotary movement of which can either be used directly to establish the contact connection or can be converted into a translatory movement by means of a gear.

[0024] Such a high-voltage contactor or high-voltage relay has a high degree of sealing from the outside to the inside and vice versa over a long service life and is able to withstand the high pressures when the arc occurs.

[0025] An embodiment of a high-voltage contactor or high-voltage relay according to the invention is shown in the figures and is described below.

[0026] Figure 1 shows a side view of a high-voltage contactor according to the invention in a sectional view.

[0027] Figure 2 shows a perspective external view of the high-voltage contactor according to the invention as shown in Figure 1.

[0028] 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.

[0029] 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 toward the return plate 28 in a known manner against the force of a spring 36.

[0030] Connected to the armature 22 is an actuating rod 38 which 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. 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 50 on the actuating rod 38 and is arranged on the actuating rod 38 so as to be slightly axially and tiltably movable. A contact plate 52, 53 made of a particularly 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.

[0031] 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 2. 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 surrounded radially by this plastic and is thus shielded from the environment. Furthermore, the return plate 28, which bears 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 and forms an axial boundary wall 69.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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] In addition, a circumferential housing wall 86 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.

[0036] The contact chamber 42 is axially closed on the side opposite the axial boundary wall 69 by a switch housing part 88. Two axial openings 90 are formed on the switch housing part 88, in which the two contact elements 54, 56 are received and fastened, for example, by ultrasonic welding or overmolding. An outer wall 92 extends circumferentially in the axial direction from this cover-shaped switch housing part 88, which encloses the circumferential housing wall 86 of the actuator housing part 60, so that these two walls 86, 92 are connected circumferentially in a materially bonded manner, for example by

[0037] Laser welding, ultrasonic welding or rotational vibration welding can be joined together, thereby creating a high-strength housing. A circumferential axial groove 94 is formed directly within the outer wall 92, which is thus delimited outwardly by the outer wall 92 of the switch housing part 88 and into which the end of the housing wall 86 of the actuator housing part 60 projects, thereby protecting it from laser welding, ultrasonic welding or

[0038] Rotational vibration welding is used to precisely fix its position relative to the switch housing part 88.

[0039] In addition, two fastening eyes 96 are formed on the switch housing part 88, via which the high-voltage contactor can be fastened, for example, in the vehicle.

[0040] 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.

[0041] This pressure increase can be easily absorbed by the housing despite its thin boundary walls, and the actuator is also reliably protected, particularly by the molded-on axial boundary wall. The tightly welded, sealed design of the only three housing parts also ensures complete sealing to the outside, preventing gas from escaping from the contact chamber, reliably and quickly extinguishing the arc, and preventing gases or liquids from entering from the outside. The required installation space and assembly costs are very low.

[0042] 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. High-voltage contactor (10) or high-voltage relay with an electromagnetic actuator (12), a housing (58) with an inner contact chamber (42), which has an actuator housing part (60) with a radial boundary wall (66) which radially completely surrounds the coil (14) of the electromagnetic actuator (12), 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 an electrical contact between the first contact element (54) and the second contact element (56) is interrupted, characterized in that the actuator housing part (60) has a axial boundary wall (69),which delimits the actuator (12) axially to the contact chamber (42), wherein the radial boundary wall (66) and the axial boundary wall (69) are produced in one piece by overmolding the actuator (12) with plastic., 2. High-voltage contactor (10) or high-voltage relay according to claim 1, characterized in that the electromagnetic actuator (12) has a coil (14), an iron circuit (20) surrounding the coil (14) and an armature (22). High-voltage contactor (10) or high-voltage relay according to claim 2, characterized in that the iron circuit (20) of the electromagnetic actuator (12) is completely surrounded radially inward and outward and axially in the direction of the contact chamber (42) by the axial boundary wall (69) of the actuator housing part (60), which is produced by overmolding with plastic. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that the actuator housing part (60), produced by overmolding the actuator (12), extends on its axial outer side (72) opposite the contact chamber (42) at least over a radially outer region (74) of the actuator (12) and has an opening (78) in the radially inner region (76), which opening is completely closed by a plastic cover (80). High-voltage contactor (10) or high-voltage relay according to claim 4, characterized in that the plastic cover (80) is fastened circumferentially to the actuator housing part (60) in a materially bonded manner.High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that the actuator housing part (60) produced by overmolding has a circumferential housing wall (86) extending axially from the actuator (12) and radially delimiting the contact chamber (42). High-voltage contactor (10) or high-voltage relay according to one of the preceding claims. characterized in that the contact chamber (42) is axially delimited by a switch housing part (88) which is circumferentially fastened to the circumferential housing wall (86) of the actuator housing part (60) extending axially from the actuator (12).

8. High-voltage contactor (10) or high-voltage relay according to claim 7, characterized in that the switch housing part (88) has an axially extending, circumferential outer wall (92) with which the switch housing part (88) rests against the circumferential housing wall (86) of the actuator housing part (60) extending axially from the actuator (12) and is fastened in a materially bonded manner.

9. High-voltage contactor (10) or high-voltage relay according to claim 8, characterized in that a circumferential axial groove (94) is formed on the switch housing part (88) radially inwardly of the outer wall (92), into which groove the circumferential housing wall (86) of the actuator housing part (60) extending axially from the actuator engages and which is delimited radially outwardly by the outer wall (92) of the switch housing part (88).

10. High-voltage contactor (10) or high-voltage relay according to one of claims 7 to 9, characterized in that the switch housing part (88) has two axially extending openings (90) in which the two contact elements (54, 56) are fastened.

11. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, 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).

12. High-voltage contactor (10) or high-voltage relay according to claim 11, characterized in that the return plate (28) is arranged axially between the coil (14) and the axial boundary wall (69) and bears against the axial boundary wall (69).

13. High-voltage contactor (10) or high-voltage relay according to one of claims 11 or 12, characterized in that the actuator housing part (60) extends radially between the coil (14) and the U-shaped yoke (24) and radially surrounds the U-shaped yoke (24).

14. High-voltage contactor (10) or high-voltage relay according to one of the preceding claims, characterized in that Connecting lines (84) are led from the winding (18) of the coil (14) through the actuator housing part (60) to the outside, wherein the actuator housing part (60) has formations (82) for direct connection to a voltage source.

15. High-voltage contactor (10) or high-voltage relay according to claim 1, characterized in that the electromagnetic actuator (12) has an electric motor with a rotor and a stator with a winding.

Images