High-voltage protection device or high-voltage relay with one-piece actuator housing part made of plastic

Abstract

A high-voltage protection device (10) or a high-voltage relay is known, comprising: an electromagnetic actuator (12) having a coil (14), a magnetic core (20) surrounding the coil (14), and an armature (22); a housing (58) having an inner contact chamber (42), said housing having an actuator housing part (60) with a radial delimiting wall (66) which completely surrounds a coil (14) of the electromagnetic actuator (12) in the radial direction; a first contact element (54), which protrudes into the contact chamber (42); a second contact element (56), which protrudes into the contact chamber (42); 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 into a second position, in which the first contact element (54) is electrically connected to the second contact element (56) via the contact bridge (44). The electrical contact between the first contact element (54) and the second contact element (56) is interrupted. In order to improve the sealing performance and reduce the installation space, it is proposed according to the invention that the actuator housing part (60) has an axial delimiting wall (69) which delimits the coil (14) and the magnetic core (20) in the axial direction with respect to the contact chamber (42), the radial delimiting wall (66) and the axial delimiting wall (69) being produced in one piece by overmolding the actuator (12) with plastic.

Description

Field of the Invention

[0001] The present invention relates to a high-voltage protection device (Hochvoltschütz) or a high-voltage relay, which has: an electromagnetic actuator; a housing having an internal contact chamber, the housing having an actuator housing part with a radial boundary wall that completely surrounds the coil of the electromagnetic actuator in the radial direction; a first contact element that extends into the contact chamber; a second contact element that extends into the contact chamber; and a contact bridge that can be moved by the actuator at least into a first position and into a second position in the contact chamber. In the first position, the first contact element and the second contact element are electrically connected via the contact bridge, and in the second position, the electrical contact between the first contact element and the second contact element is interrupted. Background Art

[0002] Such high-power switching devices are needed in order to establish and disconnect electrical connections in the unloaded and loaded states, where voltages above 1000 V and currents above 1000 A can exist in the loaded state, for example, between a battery and a drive motor in an electrically driven motor vehicle or between a charging station and a battery. Since arcs can be generated especially in the loaded state, during driving or charging or in the case of a short-circuit current, when the contact is disconnected due to the high voltage, the contact chamber should be as sealed as possible to the outside and have high strength, in order to avoid, on the one hand, the ejection of particles, gases or plasma and, on the other hand, to withstand the pressure generated by the arc for a sufficient length of time. In future hybrid, electric and fuel cell vehicles and in on-board charging systems, short-circuit currents of up to 30,000 A are even expected at the protection device of the traction battery or at the fast-charging protection device. The housing should correspondingly withstand the conditions formed inside for a few milliseconds without external effects such as material spillage or damage to the outer casing until additional short-circuit separation elements such as melting or pyrolysis protection devices disconnect the short-circuit current.

[0003] Such a high-voltage protection device is known, for example, from EP 3 846 193 Al. The high-voltage protection device consists of an actuator housing that surrounds the coil in the radial direction and on the side opposite the contact chamber. An external housing is fixed to the actuator housing, and the external housing bounds the contact chamber to the outside. A separate arc chamber housing is provided inside the external housing, and the arc chamber housing is connected to the magnetic yoke plate (Rückschlussplatte) of the actuator via a seal, such that the arc chamber housing, the seal, the magnetic yoke plate and the guide sleeve of the armature should bound the arc chamber.

[0004] In the protection device, a plurality of individual components are correspondingly required to delimit the arc chamber, and the individual components must additionally be connected to each other as tightly and durably as possible. In the case of the short-circuit currents and the resulting pressures expected in the future, sufficient tightness and durability cannot be ensured. Summary of the Invention

[0005] Therefore, the following object is proposed, namely to provide a high-voltage protection device or a high-voltage relay, by means of which sufficient strength and tightness can be achieved in the simplest possible way, wherein as few individual components as possible should be used in order to avoid leak-tightness caused by assembly errors and in order to save as much structural space and cost as possible in such a high-voltage protection device. The tightness can be ensured not only in the event of a shutdown or a short-circuit current flowing from the inside to the outside, but also in the opposite direction over a service life of more than ten years, in order to prevent materials from entering the high-voltage protection device, since gases penetrating from the outside can have a negative impact on the contact resistance and the breaking capacity.

[0006] The object is achieved by a high-voltage protection device or a high-voltage relay having the features of independent claim 1.

[0007] The high-voltage protection device or high-voltage relay according to the invention has an electromagnetic actuator via which the protection device is switchable. An electromagnetic actuator is understood to mean all actuators that produce movement due to forces caused by an electromagnetic field. Thus, the electromagnetic actuator is in particular either composed of a coil, a magnetic core (Eisenkreis) surrounding the coil, and an armature movable due to the electromagnetic force, or has an electric motor, the coil being composed of a bobbin and a winding wound around the bobbin, the armature being arranged inside the coil and the magnetic core, and the electric motor having a rotor and a wound stator. Furthermore, the high-voltage protection device has a multi-piece housing that delimits an internal contact chamber. The housing has an actuator housing part with a radial delimiting wall that completely surrounds the coil of the electromagnetic actuator in the radial direction, such that the coil is completely enclosed in the radial direction. The terms "radial" and "axial" relate to the central axis of the actuator.

[0008] Furthermore, the high-voltage protection device has a first contact element and a second contact element fixedly arranged at the housing. The first contact element and the second contact element extend into the contact chamber and are connected to two busbars outside the high-voltage protection device. One of the busbars is led to the battery and the other busbar is led to, for example, the drive motor or another busbar is connected to the vehicle's charging station and the battery. The electrical connection between the two contact elements can be established via a contact bridge, which moves in the contact chamber by means of an actuator. Here, usually by energizing the winding, the contact bridge moves or rotates axially relative to the two contact elements fixed to the housing so as to establish an electrical connection between the first contact element and the second contact element via the contact bridge at a first position. Two electrical contact parts can be formed at the ends of the contact bridge. For this purpose, the contact bridge is, for example, operatively connected to the armature via a lever or operatively connected to the rotor of the electric motor via a shaft, and correspondingly, due to the movement of the armature or the rotor by the electromagnetic force, it is pressed against the contact element. To disconnect the electrical connection, the contact bridge is loaded in the opposite direction, which is usually achieved by means of a spring force that acts on the armature, the rotor or the contact bridge in the opposite direction to the electromagnetic force, so that the contact bridge moves or rotates into a second position, in which the electrical contact between the first contact element and the second contact element is interrupted.

[0009] According to the invention, the actuator housing part has, in addition to the radial bounding wall, also an axial bounding wall, which bounds the actuator axially relative to the contact chamber, i.e., is arranged between the contact chamber and the actuator. The radial bounding wall and the axial bounding wall are integrally manufactured by injection molding the actuator with plastic. By this embodiment, the actuator is completely shielded from the contact chamber except for a small opening through which the operating rod extends. By closing the housing relative to the contact chamber, high strength is achieved even in the case of a relatively thin wall thickness in the region where the maximum force occurs and the necessary sealing surfaces are completely avoided. Additionally, the strength is also enhanced by the injection molding and the resulting sealed abutment of the surrounding plastic against the coil or the magnetic core and the gaps between the components in which pressure can be built up are avoided. The manufacturing is significantly simplified by the injection molding because fewer individual components have to be required and installed. Compared with the known embodiments, the position requirements for reducing the otherwise necessary gaps between the housing parts are eliminated and the manufacturing costs are also reduced. Furthermore, a stable system is provided in which the actuator cannot move in the housing. Additionally, lower acoustic emissions are generated by avoiding the resonance space between the actuator and the housing.

[0010] The electromagnetic actuator advantageously has a coil, a magnetic core surrounding the coil and an armature. Thus, an actuator that acts purely translationally is manufactured, in which the conversion of motion can be omitted. Such an actuator can be manufactured particularly small and cost-effectively.

[0011] Preferably, in the injection molding encapsulation, the magnetic core of the electromagnetic actuator is also completely injection molded and encapsulated both radially inside and outside, and the magnetic core is axially bounded by the axial bounding wall of the actuator housing part towards the contact chamber. Thus, on the one hand, the actuator is bounded radially outwards with respect to the contact chamber and the magnetic core is bounded radially by the plastic with respect to the coil. The plastic fills the gap between the windings of the coil and the magnetic core here, so that the relative movement with respect to each other is also eliminated here. The abutment of the magnetic core with respect to the windings is eliminated because the plastic of the actuator housing is arranged radially between the magnetic core and the coil, and the bobbin is arranged axially between the windings and the magnetic core respectively. Thus, in the case of a small wall thickness, an actuator housing with high strength and almost no gaps is produced. Thus, leak tightness is reliably avoided.

[0012] Furthermore, it is advantageous that the actuator housing part produced by injection molding encapsulation of the actuator extends at least in the radially outer region of the actuator at its axially outer side facing away from the contact chamber and has an opening in the radially inner region, which opening is completely closed by a plastic cover. Correspondingly, after injection molding encapsulation from the outside, a sleeve can also be inserted into the bobbin in the axial direction and the armature together with the operating rod can be inserted into the sleeve. Nevertheless, high strength and complete enclosure outwards of the housing are achieved, so that contamination from the outside or outgassing outwards is avoided.

[0013] In an improved embodiment thereof, the plastic cover is fastened around the actuator housing part in a material-locking manner, in particular by bonding, laser welding, ultrasonic welding or rotary vibration welding. The fastening has high durability and is completely sealed without having to introduce additional seals.

[0014] Additionally, the actuator housing part produced by injection molding encapsulation preferably has a surrounding housing wall extending axially from the actuator, which housing wall bounds the contact chamber radially. Thus, joints and butting edges that may cause leak tightness in the region of the housing wall bounding the contact chamber are completely dispensed with. No additional components are required either.

[0015] The contact chamber is advantageously bounded axially by a switch housing part, which is fastened around the surrounding housing wall of the actuator housing part extending axially from the actuator. The switch housing part correspondingly forms a kind of cover. Thus, the entire housing can consist of only three parts, and all three parts can be mounted axially. There are no joints in the main radial propagation direction of the arc, so that high leak tightness and strength are achieved.

[0016] In an improved embodiment thereof, the switch housing part has a circumferential outer wall extending axially, by means of which the switch housing part abuts and is fastened in a material-locking manner, in particular by bonding, laser welding, ultrasonic welding or spin vibration welding, to the circumferential housing wall of the actuator housing part that extends axially from the actuator. Thus, an outer wall providing double radial bounding is provided, thereby additionally increasing the strength. Furthermore, a completely sealed connection is also achieved here by laser welding, ultrasonic welding or spin vibration welding.

[0017] In a further improved configuration therefor, a circumferential axial groove is formed inside the switch housing part in the radial direction relative to the outer wall, the housing wall of the actuator housing part engages into the axial groove, and the axial groove is bounded towards the radial outside by the outer wall of the switch housing part. In this way, on the one hand, the position of the actuator housing part relative to the switch housing part is determined for establishing a material-locking connection, but also for determining the correct orientation of the contact element relative to the contact bridge, and on the other hand, relative movement of the end section of the housing wall of the actuator housing part relative to the outer wall is avoided by form-fitting, thereby improving durability.

[0018] Preferably, the switch housing part has two axially extending openings in which the two contact elements are fastened such that their assembly can be carried out at the switch housing part in advance.

[0019] When assembling the housing of the high-voltage protection device, the additional introduction of the contact elements can correspondingly be dispensed with.

[0020] Furthermore, it is advantageous that the magnetic core is formed by a yoke plate and a U-shaped yoke, the free legs of which are placed on the yoke plate. The yoke can correspondingly be manufactured by simple bending, while the straight yoke plate serves as a support surface for forming an axial bounding wall during injection molding encapsulation.

[0021] Correspondingly, the yoke plate is axially arranged between the coil or the bobbin and the axial bounding wall and abuts against the axial bounding wall, such that additional components can be dispensed with.

[0022] The actuator housing part preferably extends radially between the coil and the U-shaped yoke and radially surrounds the U-shaped yoke such that the yoke is completely surrounded by plastic in the radial direction. In this way, movement of the individual actuator components or the electromagnetic circuit is reliably avoided because complete clearance-freedom is achieved.

[0023] Furthermore, the connecting line is guided outwards through the winding of the coil and through the actuator housing part, wherein the actuator housing part has a molding for direct connection to a voltage source. The molding can for example form a plug-in housing for energizing the coil and is correspondingly injection-molded integrally with the actuator housing part. Correspondingly, only the necessary contact lines project from the actuator housing part. However, the contact lines are injection-molded and encapsulated hermetically by means of the remaining parts. Thus, additional necessary components and sealing surfaces are avoided, which also simplifies the assembly.

[0024] In an alternative design, the electromagnetic actuator has an electric motor which has a rotor and a stator with a winding, and the rotational movement of the winding can either be used directly to establish a contact connection or can be converted into a translational movement by means of a transmission.

[0025] Such a high-voltage protection device or high-voltage relay has high tightness from the outside to the inside and in the opposite direction over a long service life and is able to withstand high voltages when an electric arc occurs. Description of the Drawings

[0026] Embodiments of the high-voltage protection device or high-voltage relay according to the invention are shown in the drawings and are described below.

[0027] Figure 1 A side view of the high-voltage protection device according to the invention is shown in a sectional view.

[0028] Figure 2 Shown according to Figure 1 a perspective external view of the high-voltage protection device according to the invention. Detailed Description

[0029] In Figure 1 the high-voltage protection device 10 shown in

[0030] is composed of an electromagnetic actuator 12 which has a coil 14 composed of a bobbin 16 and a winding 18 wound around the bobbin, a ferromagnetic core 20 and an armature 22. The ferromagnetic core 20 has a U-shaped bent yoke 24, the legs 26 of which are placed on or fastened to a yoke plate 28 such that a closed core 20 is produced.

[0031] The joystick 38 is connected to the armature 22. The joystick extends through another central opening 40 in the yoke plate 28 and into the contact chamber 42. A contact bridge 44 is provided at the end of the joystick 38 opposite to the armature. The contact bridge is preferably pressed against a stop 48 at the end of the joystick 38 via a spring element 46. The spring element is supported on a shoulder 50 of the joystick 38 and is correspondingly slightly axially and pivotably arranged on the joystick 38. Contact plates 52, 53 are respectively fastened at the ends of the contact bridge 44. The contact plates are made of a material with particularly good electrical conductivity. The first contact plate 52 is axially opposed to a first contact element 54. The first contact element can be connected to a high-voltage battery via a bus bar not shown. The second contact plate 53 is opposed to a second contact element 56. The second contact element can be connected to a drive motor of a motor vehicle via a bus bar, for example.

[0032] The entire high-voltage protection device 10 is arranged in a housing 58. The housing consists of a total of three components, as can be seen particularly in Figure 2 . For this purpose, the actuator 12 is injection-molded with plastic to form an actuator housing part 60. The plastic completely surrounds the coil 14 radially to form a radial limiting wall 66 and also fills the intermediate space 68 between the coil 14 and the yoke 24 radially. Additionally, the yoke 24 itself is completely surrounded by the plastic radially, so as to be shielded from the environment. Furthermore, the yoke plate 28 is axially covered by the plastic towards the contact chamber 42 to form an axial bounding wall 69. The yoke plate abuts against the bobbin 16 on its side facing the bobbin. The opening 40 of the yoke plate 28 is also covered radially inwards by the plastic and only a central guiding opening 70 is left. The joystick 38 is guided in the guiding opening.

[0033] At the axial outer side 72 of the actuator housing part 60 opposite to the contact chamber 42, the plastic continues to extend radially inwards along the radial outer region 74 of the yoke 24 or the base part 30 of the actuator 12 and only leaves an opening 78 in a central, radially inner region 76. The opening is formed symmetrically with respect to the opening 32, but has a slightly larger diameter so as to have sufficient space for pressing in the sleeve 34.

[0034] The opening 78 is closed by a plastic cover 80. The plastic cover is fastened in the opening 78 at the actuator housing part 60 in a material-fit manner, particularly by laser welding, ultrasonic welding or rotary vibration welding.

[0035] In addition, an actuator housing part 60 produced by injection molding encapsulation of the actuator 12 forms a molding part 82 in the form of a plug-in housing 82, through which the connecting line 84 is guided outwards to the winding 18 of the coil 14, so that an electrical connection between the coil 14 and a voltage source can be established via a plug-in mating part.

[0036] Additionally, a surrounding housing wall 86 extends from the yoke plate 28 as an extension of the plastic surrounding the actuator 12, the housing wall radially bounding the contact chamber 42 and also being produced in one piece during the injection molding encapsulation of the actuator 12, thus forming the four side walls of the contact chamber 42 in the present embodiment.

[0037] The contact chamber 42 is axially closed at the axial side facing away from the axial bounding wall 69 by a switch housing part 88. Two axial openings 90 are formed in the switch housing part 88, in which the two contact elements 54, 56 are received and fastened, for example, by ultrasonic welding or injection molding encapsulation. An outer wall 92 extends axially around from the cap-shaped switch housing part 88, the outer wall surrounding the surrounding housing wall 86 of the actuator housing part 60, so that the two walls 86, 92 can be connected to each other in a circumferential positive-locking manner, for example, by laser welding, ultrasonic welding or rotary vibration welding, thereby achieving a high-strength housing. A circumferential axial groove 94 is formed directly inside the outer wall 92, the axial groove being bounded outwards by the outer wall 92 of the switch housing part 88 and the end of the housing wall 86 of the actuator housing part 60 extending into the axial groove, whereby the actuator housing part is precisely fixed in its position relative to the switch housing part 88 before laser welding, ultrasonic welding or rotary vibration welding.

[0038] Additionally, two fastening holes 96 are formed in the switch housing part 88, through which a high-voltage protection device can be fastened, for example, in a vehicle.

[0039] If the current between the electric motor or the charging pile and the battery is now to be released, the coil 14 is energized, whereby the armature is attracted towards the yoke plate 28 due to the acting electromagnetic force. Thereby, the actuating lever 38 with the contact bridge 44 and the contact plates 52, 53 is pushed towards the contact elements 54, 56, so that the current can flow from the first contact element 54 to the second contact element 56 via the contact bridge 44, thus flowing from the battery to the electric motor or from the charging pile to the battery. If the coil 14 is not energized, the actuating lever 38 and the armature 22 are loaded by the spring 36 in the opposite direction, so that the contact bridge 44 is lifted from the contact elements 54, 56 and the circuit is interrupted. Here, an electric arc is formed due to the high current, and the electric arc also causes a pressure increase in the contact chamber 42.

[0040] Despite the thin boundary wall, the pressure increase can be well received by the housing, and the actuator is also reliably protected, in particular, by the axially molded boundary wall. The complete external tightness is also achieved by the sealed welding of only three housing parts, so that no gas can pass outwards from the contact chamber, the electric arc is reliably and quickly extinguished and no gas or liquid can penetrate from the outside. The required structural space and assembly costs are very low.

[0041] It should be clear that various modifications are possible compared to the described embodiments. In particular, the construction of the contact unit and the arrangement of the springs and the lever guides and fixing devices can be different from the form shown.

Claims

1. A high-voltage protection device (10) or a high-voltage relay, the high-voltage protection device or the high-voltage relay having: An electromagnetic actuator (12), A housing (58) having an internal contact chamber (42), the housing having an actuator housing part (60) with a radial bounding wall (66), the radial bounding wall completely surrounding the coil (14) of the electromagnetic actuator (12) radially, A first contact element (54) extending into the contact chamber (42), A second contact element (56) extending into the contact chamber (42), A contact bridge (44) that can be moved by the actuator (12) at least into a first position and into a second position in the contact chamber (42), in the first position, the first contact element (54) is electrically connected to the second contact element (56) via the contact bridge (44), and in the second position, the 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 an axial bounding wall (69), the axial bounding wall bounding the actuator (12) axially relative to the contact chamber (42), wherein the radial bounding wall (66) and the axial bounding wall (69) are integrally manufactured by injection molding the actuator (12) with plastic.

2. The high-voltage protection device (10) or the high-voltage relay according to claim 1, Characterized in that, The electromagnetic actuator (12) has a coil (14), a magnetic core (20) surrounding the coil (14), and an armature (22).

3. The high-voltage protection device (10) or the high-voltage relay according to claim 2, Characterized in that, The magnetic core (20) of the electromagnetic actuator (12) is completely surrounded radially internally and externally and axially towards the contact chamber (42) by the axial bounding wall (69) of the actuator housing part (60), and the actuator housing part is manufactured by injection molding with plastic.

4. The high-voltage protection device (10) or the high-voltage relay according to any one of the above claims, Characterized in that, The actuator housing part (60) manufactured by injection molding the actuator (12) extends at least in the radial outer region (74) of the actuator (12) at its axial outer side (72) facing away from the contact chamber (42), and has an opening (78) in the radial inner region (76), and the opening is completely closed by a plastic cover (80).

5. The high-voltage protection device (10) or the high-voltage relay according to claim 4, Characterized in that, The plastic cover (80) is fastened around and materially to the actuator housing part (60).

6. The high-voltage protection device (10) or the high-voltage relay according to any one of the above claims, Characterized in that, The actuator housing part (60) manufactured by injection molding encapsulation has a surrounding housing wall (86) that axially extends from the actuator (12), and the housing wall radially bounds the contact chamber (42).

7. The high-voltage protection device (10) or high-voltage relay according to any one of the above claims, characterized in that, the contact chamber (42) is axially bounded by a switch housing part (88), and the switch housing part is circumferentially fastened to the surrounding housing wall (86) of the actuator housing part (60) that axially extends from the actuator (12).

8. The high-voltage protection device (10) or high-voltage relay according to claim 7, characterized in that, the switch housing part (88) has an axially extending surrounding outer wall (92), by means of which the switch housing part (88) abuts and is force-fitted to the surrounding housing wall (86) of the actuator housing part (60) that axially extends from the actuator (12).

9. The high-voltage protection device (10) or high-voltage relay according to claim 8, characterized in that, a surrounding axial groove (94) is formed inside the switch housing part (88) radially relative to the outer wall (92), the surrounding housing wall (86) of the actuator housing part (60) that axially extends from the actuator engages into the axial groove, and the axial groove is bounded towards the radial outside by the outer wall (92) of the switch housing part (88).

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

11. The high-voltage protection device (10) or high-voltage relay according to any one of the above claims, characterized in that, the magnetic core (20) is formed by a yoke plate (28) and a U-shaped yoke (24), and the free legs (26) of the yoke are placed on the yoke plate (28).

12. The high-voltage protection device (10) or high-voltage relay according to claim 11, characterized in that, the yoke plate (28) is axially arranged between the coil (14) and the axial boundary wall (69) and abuts against the axial boundary wall (69).

13. The high-voltage protection device (10) or high-voltage relay according to any 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. The high-voltage protection device (10) or high-voltage relay according to any one of the above claims, characterized in that, The connecting line (84) is led outwards from the winding (18) of the coil (14) through the actuator housing part (60), wherein the actuator housing part (60) has a molded part (82) for direct connection to a voltage source.

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

Images