Armature arrangement for an electromagnetic drive and electromagnetic drive

Abstract

The invention relates to an armature arrangement (1) for an electromagnetic drive comprising an armature body (2) extending about a central axis (100), which is designed to interact with a coil (11) of the drive (10) in order to displace the armature arrangement (1) along the central axis (100), a permanent magnet (3) which is arranged axially adjacent to the armature body (2) with respect to the central axis (100), and a retaining part (4) for attaching the armature body (2) and the permanent magnet (3) to one another, wherein the retaining part (4) has a first axial section (5) and a second axial section (6), and wherein the armature body (2) is mounted on the first axial section (5) and the permanent magnet (3) is mounted on the second axial section (6).

Description

[0001] The invention relates to an armature arrangement for an electromagnetic drive. The electromagnetic drive is, in particular, part of an electromagnetic hydraulic valve.

[0002] Electromagnetic drives for a wide variety of applications are known from the prior art. For example, DE 10 2013 102 276 B4 discloses a bistable electromagnet in which permanent magnets are positioned between two coils. The permanent magnets are encased in an additional component, the casing being geometrically very large and increasing the radial working distance due to its wall thickness.

[0003] US Patent 2009 / 0322453A1 discloses an electromagnetic device. This electromagnetic device has a drive shaft comprising an axis center mounted to reciprocate in an axial direction around a center hole of a coil wound with a coil, and a movable iron core fixed at the lower end of the drive shaft at the axis center. The drive shaft is reciprocated by the movable iron core, which reciprocates based on the excitation and demagnetization of the coil. A permanent magnet is integrally arranged on the movable iron core at the same axis center.

[0004] DE 38 36 513 A1 discloses an electromagnetic control device. This device comprises an armature surrounded by a winding, both enclosed by a yoke. A pole is formed in the upper part of the yoke. In the middle region of the armature, there is a stepped opening into which a stepped pin is pressed. The pin extends through the pole and the opposite part of the yoke. The armature is made of a magnetically hard material; the winding is connected to an electrical pulse source. The electromagnetic control device achieves low electrical energy consumption, low consumption of active material, and reduced external dimensions.

[0005] DE 102017 114 246 A1 discloses an actuating device with a housing and at least two electromagnetic linear actuators, each of which - a housing-mounted coil arrangement extending around a coil axis, - an armature arrangement, at least partially enclosed in a cavity arranged within the coil assembly, movable along the coil axis relative to the coil assembly, and comprising an axially magnetized permanent magnet and - encompass a plunger actuated by the armature arrangement and guided slidably in the housing along a plunger axis, wherein at least one of the linear actuators has an offset between the coil axis and the plunger axis.

[0006] DE 10 2008 000 534 A1 discloses an electromagnetic actuating device with a longitudinally movable actuating element that can be locked in three detent positions and two coils by which the actuating element can be switched into a first or a second detent position, the end positions.

[0007] The object of the invention is to provide an armature arrangement for an electromagnetic drive that is easy and inexpensive to manufacture and allows a reliable connection of a permanent magnet.

[0008] This problem is solved by the features of the independent claim. The dependent claims contain preferred embodiments of the invention.

[0009] The solution is thus achieved by an armature arrangement for an electromagnetic drive, wherein the armature arrangement comprises an armature body, a permanent magnet, and a retaining element. The armature body extends around a central axis of the armature arrangement. The central axis is also preferably an axis of movement of the armature arrangement. The armature body is designed to interact with a coil of the drive to displace the armature arrangement along the central axis. The direction along the central axis is hereinafter also referred to as the axial direction. For example, the armature body is designed to be magnetically attracted to or repelled by the coil. The armature body is, for example, made of a ferromagnetic material.

[0010] The permanent magnet is arranged axially adjacent to the armature body with respect to the central axis. In particular, the permanent magnet enables reliable position detection of the armature assembly. For example, the permanent magnet generates a magnetic field that can be detected by a Hall sensor to perform position detection. The permanent magnet can be non-magnetic during assembly and only magnetized after the armature assembly is mounted. The retaining element is designed to fasten the armature body and the permanent magnet together. Thus, the position of the permanent magnet allows the position of the armature body, and consequently the position of the entire armature assembly, to be determined. Specifically, the individual components of the armature assembly are not movable relative to each other. The permanent magnet is preferably permanently fixed by the retaining element.

[0011] The retaining element has a first axial section and a second axial section. The first and second axial sections are designed to accommodate the permanent magnet and the armature body, thus preferably creating a rigid connection between the components of the armature assembly. The first and second axial sections are particularly advantageous for a positive-locking and / or force-locking connection between the permanent magnet and the armature body. Preferably, the second axial section acts as a centering element.

[0012] The armature body is mounted on the first axial section, while the permanent magnet is mounted on the second. This allows for independent mounting of the armature body and permanent magnet. Advantageously, the first and second axial sections can be optimally adapted to the specific mounting requirements of the armature body or permanent magnet.

[0013] The retaining element is particularly easy and inexpensive to manufacture. It allows for a reliable and secure connection between the armature body and the permanent magnet. Furthermore, it preferably achieves centering between the armature body and the permanent magnet.

[0014] The second axial section of the retaining element preferably has at least one bead. The bead is particularly shaped outwards, i.e., away from the central axis. Preferably, the second axial section has one or more beads extending along the central axis. It is particularly advantageous if the second axial section is cloverleaf-shaped due to the beads. The bead or beads preferably form the second diameter. The use of the beads reduces the pressing force on the permanent magnet. This reduces the stress on the material of the permanent magnet, which is typically brittle, thus decreasing the risk of breakage or other damage. Furthermore, the assembly process of the armature assembly is optimized, as only low joining forces are required for the permanent magnet.

[0015] In a preferred embodiment, the retaining element has a planar section. The planar section is flange-shaped and located at one axial end of the retaining element. If the permanent magnet is mounted on the second axial section of the retaining element, the planar section rests against an end face of the permanent magnet. This means that the permanent magnet is positioned between the planar section and the armature body. The planar section serves, in particular, as a bearing for the permanent magnet, thus holding the permanent magnet in the axial direction. Furthermore, the planar section preferably serves as impact protection or a buffer, resting against a counter element when the armature assembly is moved into an end position. This prevents the permanent magnet itself from striking the counter element, thereby protecting the permanent magnet from impact by the counter element.

[0016] The armature body preferably has a first recess centered on the central axis. The first axial section of the retaining element rests within the first recess. The armature body is preferably hollow cylindrical or cup-shaped. The first recess is thus symmetrical about the central axis. The first axial section of the retaining element is, in particular, pressed into the first recess. Alternatively or additionally, the permanent magnet preferably has a second recess centered on the central axis. The permanent magnet is preferably hollow cylindrical or cup-shaped. The second recess is thus symmetrical about the central axis. The second axial section of the retaining element preferably rests within the second recess. It is particularly advantageous for the second axial section to be pressed into the second recess.By pressing the first axial section into the first recess and the second axial section into the second recess, the permanent magnet and armature body are centered. Manufacturing the armature assembly with this centering is therefore simple and cost-effective.

[0017] The second axial section of the retaining element has a second diameter, at least in some areas. The first axial section preferably has a first diameter, at least in some areas, but particularly throughout. It is preferably provided that the second diameter of the second axial section differs from the first diameter of the first axial section. The second diameter is preferably larger than the first diameter. This simplifies the assembly of the permanent magnet and armature body, and also ensures that the retaining element is optimally adapted to the armature body and the permanent magnet.The entire first axial section has a constant first diameter. The entire second axial section has a constant second diameter. A diameter transition zone is provided between the first and second axial sections, in which the diameter of the retaining element transitions between the first and second diameters. The transition between the first and second diameters is linear. The diameter transition zone thus has the first diameter at one end and the second diameter at the opposite end. The first axial section, the diameter transition zone, and the second axial section are preferably formed in one piece. The second diameter is preferably larger than the first diameter. The retaining element can be manufactured simply and cost-effectively in this way.At the same time, the holding part allows for reliable holding and / or centering of the armature body and permanent magnet.

[0018] Advantageously, the second axial section features knurling and / or slots. The slots run particularly along the central axis. The knurling and / or slots act as press-fit elements that reduce the pressure on the permanent magnet. This also reduces the risk of damage to the permanent magnet. Furthermore, only minimal joining forces are required to attach the permanent magnet, simplifying the assembly process and reducing or eliminating the risk of damage to the permanent magnet from these forces.

[0019] The retaining element is advantageously designed in a sleeve-like or hollow cylindrical shape. This design makes the retaining element simple and cost-effective to manufacture. Furthermore, the retaining element is robust and allows for easy assembly of the anchor assembly as well as reliable retention of the anchor assembly components.

[0020] Preferably, the retaining element is made of austenitic metal and / or a non-magnetically conductive plastic and / or ceramic. These materials, in particular, reduce or prevent a magnetic field short circuit between the permanent magnet and the armature body. This makes it possible, in particular, to use the permanent magnet and the armature body for different tasks within the drive, minimizing or preventing mutual interference.

[0021] The retaining element is preferably formed in one piece. Particularly preferably, the retaining element is manufactured using a tool-free process. Specifically, the retaining element is manufactured by deep drawing or injection molding. Due to the tool-free manufacturing method, no post-processing is necessary. The retaining element is simple, cost-effective, and quick to manufacture. This makes the entire anchor assembly simple and cost-effective.

[0022] The invention also relates to an electromagnetic drive. The drive comprises a coil and an armature assembly as previously described. The armature assembly is movable by the coil, in particular by the interaction of a magnetic field of the coil with the armature body of the armature assembly. A Hall sensor is also preferably provided. The Hall sensor is designed to detect the permanent magnet of the armature assembly. This allows the position of the armature assembly to be monitored, thus enabling reliable position detection.

[0023] Further details, advantages and features of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawing. It shows: Fig. 1 a schematic view of an electromagnetic drive according to an embodiment of the invention, Fig. 2 a schematic detail view of an electromagnetic drive with an armature arrangement according to a first embodiment of the invention, Fig. 3 a further schematic detail view of an electromagnetic drive with the armature arrangement according to the first embodiment of the invention, Fig. 4 a schematic view of a holding part of the anchor arrangement according to the first embodiment of the invention, Fig. 5 a schematic detail view of an electromagnetic drive with an armature arrangement according to a second embodiment of the invention, and Fig. 6 a schematic view of a holding part of the anchor arrangement according to the second embodiment of the invention,

[0024] Fig. Figure 1 schematically shows an electromagnetic drive 10 according to an embodiment of the invention. The electromagnetic drive 10 has a coil 11 by which an armature assembly 1 is movable. The coil 11 and the armature assembly 1 have a common central axis 100, wherein the armature assembly 1 is displaceable by the coil 11 along the central axis 100. The direction along the central axis 100 is also referred to as the axial direction.

[0025] The armature assembly 1 has an armature body 2. The armature body 2 is, for example, made of ferromagnetic material and is designed to interact with the coil 11. If the coil 11 generates a magnetic field, the armature body 2 is attracted to it, causing the armature assembly 1 to move in the axial direction. This achieves the function of a linear actuator.

[0026] The electromagnetic drive 10 also includes a Hall sensor 12. The Hall sensor 12 serves to detect the position of the armature assembly 1. The armature assembly 1 has a permanent magnet 3 connected to the armature body 2. The permanent magnet 3 is detectable by the Hall sensor 12, thus allowing the position of the armature assembly 1 to be determined.

[0027] Fig. Figure 2 schematically shows a detailed view of the electromagnetic drive 10, wherein the armature arrangement 1 corresponds to a first embodiment of the invention. The permanent magnet 3 and the armature body 2 are arranged axially adjacent to each other with respect to the central axis 100 and are preferably connected to and centered relative to each other by a retaining element 4. Both the permanent magnet 3 and the armature body 2 are designed in a hollow cylindrical shape, with the retaining element 4 being pressed into the armature body 2 and into the permanent magnet 3.

[0028] Fig. Figure 3 shows a further detailed view of the anchor arrangement 1 according to the first embodiment, Fig. Figure 4 schematically shows the retaining part 4 of the anchor arrangement 1 according to the first embodiment.

[0029] The retaining element 4 has a first axial section 5 with a constant first diameter d1 and a second axial section 6 with a constant second diameter d2. A diameter change region 9 is provided between the first axial section 5 and the second axial section 6, in which the diameter of the retaining element 4 changes linearly between the first diameter d1 and the second diameter d2. The diameter change region 9 can, in principle, be configured arbitrarily; it is only stipulated that the diameter changes in this region and that the diameter change region 9 preferably has a minimal axial extent. The second diameter d2 is larger than the first diameter d1.

[0030] The retaining part 4 is sleeve-shaped or hollow cylindrical and is formed in one piece. In particular, the retaining part 4 is manufactured using a tool-free manufacturing process. This makes the production of the retaining part 4 simple and cost-effective.

[0031] The armature body 2 is mounted on the first axial section 5, and the permanent magnet 3 is mounted on the second axial section 6. For this purpose, the armature body 2 has a first recess 2a centered on the central axis 100. The armature body 2 is, for example, hollow cylindrical. The first axial section 5 is pressed into the first recess 2a, thus securing the armature body 2 to the retaining part 4. The permanent magnet 3 has a second recess 3a centered on the central axis 100. The second axial section 5 is pressed into the second recess 3a. Thus, the permanent magnet 3 is secured to the retaining part 4. The retaining part 4 also serves to center the permanent magnet 3 and the armature body 2.

[0032] The permanent magnet 3 is, in particular, a dipole with different poles at its axial ends. The permanent magnet 3 can be detected by the Hall sensor 12, whereby the fixed connection to the armature body 2 and the centering by the retaining element 4 enable position detection of the entire armature assembly 1 via the permanent magnet 3.

[0033] The retaining part 4 also has a planar section 7, which is flange-shaped at one axial end of the retaining part 4. The planar section 7 rests against a side surface 3b of the permanent magnet 3, with the permanent magnet 3 being arranged between the planar section 7 and the armature body 2. When the armature assembly 1 is moved, contact between the permanent magnet 3 and the armature body 2 is prevented, as the planar section 7 acts as a stop. This shields the permanent magnet 3 from external influences and protects it from damage. Additionally, the planar section 7 serves as an end stop for mounting the permanent magnet 3 on the second axial section 6. The arrangement between the planar section 7 and the armature body 2 prevents the permanent magnet 3 from slipping.

[0034] The retaining element 4 is, for example, made of austenitic metal and / or a non-magnetic plastic and / or ceramic. This prevents or reduces a magnetic short circuit between the armature body 2 and the permanent magnet 3. Mutual interference between these elements is thus minimized.

[0035] The permanent magnet 3 is typically made of a brittle material. To reduce stress on the permanent magnet 3 from pressing forces and to facilitate joining the permanent magnet 3 with low pressing forces, the second axial section 6, for example, has knurling and / or slots running along the central axis 100.

[0036] By using the retaining element 4 according to the first embodiment, the anchor assembly 1 can be manufactured and assembled simply and cost-effectively. Furthermore, a reliable hold for the individual components of the anchor assembly 1 is achieved.

[0037] Fig. Figure 5 schematically shows a section of an electromagnetic drive 10 with an armature arrangement 1 according to a second embodiment of the invention. Fig. Figure 6 schematically shows a retaining part 4 of the anchor arrangement 1 according to the second embodiment of the invention.

[0038] The anchor arrangement 1 according to the second embodiment of the invention differs from the first embodiment only in the retaining part 4. In the second embodiment, the retaining part 4 again has a first axial section 5 with a constant first diameter d1 and a second axial section 6. The second axial section 6 has several beads 8 extending along the central axis 100. Due to the beads 8, the second axial section 6 has a second diameter d2 in certain areas, which is larger than the first diameter d1. The beads 8 are shaped outwards from the central axis 100, so that the second axial section 6 is cloverleaf-shaped. In the sections between the beads 8, the second axial section 6 preferably has the first diameter d1.

[0039] As in the first embodiment, the first axial section 5 is pressed into the first recess 2a of the armature body 2 and the second axial section 6 into the second recess 3a of the permanent magnet 3. The grooves 8 minimize the pressing force required to join the permanent magnet 3 as well as the pressing force exerted on the permanent magnet 3 by the retaining part 4. This reduces the stress on the permanent magnet 3 and minimizes the risk of damage to it.

[0040] The beads 8 are produced in particular by forming. The retaining part 4 is, as in the first embodiment, a single piece and is produced in particular using a tooling-based manufacturing process. Regarding the material of the retaining part 4 and the advantages thereof, reference is made to the description of the first embodiment.

[0041] The retaining part 4 of the anchor arrangement 1 according to the second embodiment has a planar section 7 analogous to the first embodiment.

[0042] In the second embodiment 3, the armature assembly 1 is also simple and inexpensive to manufacture. The connection of the individual components of the armature assembly 1 to one another is secure and reliable due to the retaining element 4. Furthermore, the retaining element 4 ensures centering of the armature body 2 and the permanent magnet 3.

[0043] In addition to the above written description of the invention, explicit reference is hereby made to the graphic representation of the invention in the figures for its supplementary disclosure. Reference symbol list 1 Anchor arrangement 2 anchor bodies 2a first exception 3 permanent magnets 3a second exemption 3b Side surface 4 Holding part 5 first axial section 6 second axial section 7 Planar section 8 groove 9 Diameter change range 10 electromagnetic drive 11 Coil 12 Hall sensor

Claims

[1] Armature arrangement (1) for an electromagnetic drive (10) comprising • an armature body (2) extending around a central axis (100) which is designed to cooperate with a coil (11) of the drive (10) in order to displace the armature arrangement (1) along the central axis (100), • a permanent magnet (3) which is arranged axially adjacent to the armature body (2) with respect to the central axis (100), and • a holding part (4) for fastening the armature body (2) and the permanent magnet (3) to each other, • wherein the holding part (4) has a first axial section (5) and a second axial section (6), and • wherein the armature body (2) is applied to the first axial section (5) and the permanent magnet (3) is applied to the second axial section (6), wherein the entire first axial section (5) has a constant first diameter (d1) and the entire second axial section (6) has a constant second diameter (d2), wherein a diameter change region (9) is provided between the first axial section (5) and the second axial section (6), in which the diameter of the holding part (4) transitions linearly between the first diameter (d1) and the second diameter (d2), wherein the second diameter (d2) is preferably larger than the first diameter (d1). [2] Anchor arrangement (1) according to claim 1, characterized bythat the holding part (4) has a planar section (7) which is flange-shaped at an axial end of the holding part (4), wherein the planar section (7) bears against a side surface (3b) of the permanent magnet (3) so that the permanent magnet (3) is arranged between the planar section (7) and the armature body (2). [3] Anchor arrangement (1) according to one of the preceding claims, characterized by that the armature body (2) has a first recess (2a) centrally to the central axis (100), within which the first axial section (5) rests, in particular is pressed in, and / or the permanent magnet (3) has a second recess (3a) centrally to the central axis (100), within which the second axial section (6) rests, in particular is pressed in. [4] [5] Anchor arrangement (1) according to one of the preceding claims, characterized bythat the second axial section (6) has at least one bead (8), in particular one or more beads (8) running along the central axis (100). [6] Anchor arrangement (1) according to one of the preceding claims, characterized by that the second axial section (5) has knurling and / or slots, in particular slots running along the central axis (100). [7] Anchor arrangement (1) according to one of the preceding claims, characterized by that the holding part (4) is sleeve-shaped or hollow-cylindrical. [8] Anchor arrangement (1) according to one of the preceding claims, characterized by that the holding part (4) is made of austenitic metal and / or of a plastic that does not conduct magnetic fields and / or of ceramic. [9] Anchor arrangement (1) according to one of the preceding claims, characterized bythat the holding part (4) is formed in one piece and is manufactured in particular in a tool-free manufacturing process. [10] Electromagnetic drive (10) comprising a coil (11) and an armature arrangement (1) according to one of the preceding claims, wherein the armature arrangement (1) is movable by the coil (11), and wherein preferably a Hall sensor (12) is provided which is designed to detect the permanent magnet (3) of the armature arrangement (1).

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