Magnetic holder and magnetic sensor assembly

Abstract

A magnetic holder (100) for holding a magnet (202) of a magnetic sensor arrangement (200), wherein the magnetic holder (100) comprises a fastening part (20) for attaching the magnetic holder (100) to a first component (2) and a contact part (40) for providing contact with a second component (4) comprising a magnetic field-sensitive element (204) of the magnetic sensor arrangement (200), wherein the contact part (40) is configured to touch and guide the second component (4) during a relative movement of the second component (4) with respect to the first component (2), characterized in that the magnetic holder (100) comprises a flexible strut arrangement (30) connecting the fastening part (20) and the contact part (40), wherein the flexible strut arrangement (30) is configured to prevent compression of the magnetic holder (100) in a confined state (C) of the magnetic holder (100).to cushion the impact in which the magnetic holder (100) is wedged between the first component (2) and the second component (4).

Description

Technical field

[0001] The present invention relates to a magnetic holder for holding a magnet of a magnetic sensor assembly. The present invention further relates to a magnetic sensor assembly and a vehicle comprising the magnetic sensor assembly. State of the art

[0002] Magnetic sensors known from the prior art comprise a magnet and a magnetic field-sensitive component. Such magnetic sensors can be configured to detect a changing position of the magnet relative to the magnetic field-sensitive component. Metallic particles or metallic components that may be part of a magnetic sensor or that may be located near the magnetic sensor can cause electromagnetic interference affecting the magnetic sensor, which can impair its detection behavior.

[0003] A magnetic sensor arrangement with a magnetic field-sensitive element and a magnet is known from DE 101 12 146 A1. The magnet is movably guided on a component to compensate for relative movement between components on which the magnetic field-sensitive element and the magnet are arranged. Another sensor arrangement is known from DE 10 2005 004 489 A1, which includes spring-loaded means for coupling a sensor slide to a movable component. An actuator with a rotary angle sensor is known from DE 10 2016 215 620 A1, which includes a magnet holder that is movable by means of a spring element. Furthermore, a device for detecting a displacement for a linear drive is known from DE 10 2005 007 561 A1. The device includes a movable magnet and a stationary Hall sensor. Summary of the invention

[0004] One aspect of the present invention relates to a magnet holder for holding a magnet of a magnetic sensor assembly. The magnet holder can be configured to accommodate the magnet. The magnetic sensor assembly can include the magnet. The magnetic sensor assembly can be configured as a magnetic pulse sensor assembly or as a magnetic proximity sensor assembly. The magnetic sensor assembly can be configured to detect a relative rotational movement of a component. Alternatively or additionally, the magnetic sensor assembly can be configured to detect a relative translational movement of the component.

[0005] The magnetic holder includes a mounting element for attaching the magnetic holder to a first component. The mounting element can be configured to connect the magnet to the first component. Alternatively, the mounting element can be configured to rigidly attach the magnetic holder to the first component. Movement of the first component can result in a combined movement of the magnet and the first component.

[0006] The magnet holder further comprises a contact element for establishing contact with a second component. The contact element can be configured to movably mount the magnet holder to the second component. The contact element can also be configured to assemble with the second component. The second component comprises a magnetic field-sensitive element of the magnetic sensor assembly. The magnetic sensor assembly can be configured to detect relative movement of the magnet with respect to the magnetic field-sensitive element. The magnetic field-sensitive element can include an electromagnetic coil for detecting changes in the magnetic field generated by the magnet.

[0007] The magnetic holder further comprises a flexible strut assembly that connects the mounting part and the contact part. The flexible strut assembly can be designed and manufactured from a material that allows it to bend when a compressive stress is applied to the magnetic holder. The flexible strut assembly can directly connect the mounting part and the contact part, either directly to the mounting part or directly to the contact part.

[0008] The flexible strut assembly is configured to absorb compression of the magnet holder in a constrained state, where the magnet holder is wedged between the first and second components. This compression absorption can involve converting compressive stress into bending stress, which may be present in the constrained state of the magnet holder within the flexible strut assembly.

[0009] Compressive stress can be caused by a confinement between the first and second components, where either the first or the second component exerts a compressive stress on the magnet holder. The magnet holder can be clamped between the first and second components, and such a clamped arrangement of the magnet holder between the first and second components can lead to compression of the magnet holder, which can be absorbed by the flexible strut assembly by converting the compressive stress into a bending stress in the flexible strut assembly.

[0010] The magnet holder can thus provide advantageous, permanent contact between the magnet and the magnetic field-sensitive element, regardless of differing compression states between the first and second components. The magnet holder therefore includes the flexible strut arrangement for converting a compressive stress into a bending stress, which can generate a reaction force in the magnet holder to achieve the permanent contact. Due to the permanent contact between the magnet and the magnetic field-sensitive element, electromagnetic interference on the magnetic sensor assembly can be reduced, as a constant distance between the magnet and the magnetic field-sensitive element of the magnetic sensor assembly can be maintained.Furthermore, the captive contact can provide an advantageous counter-contact between the magnet and the magnetic field-sensitive element, which can prevent metallic particles remaining in a contact area between the magnet and the magnetic field-sensitive element from accumulating.

[0011] According to one embodiment of the magnetic holder, the mounting part, the contact part, and the flexible strut assembly can be manufactured in one piece from a single plastic material. The mounting part, the contact part, and the flexible strut assembly can thus be integrally formed from the plastic material. The flexible strut assembly can also be made from the plastic material, and it can be metal-free. The magnetic holder can therefore advantageously reduce electromagnetic interference on the magnetic sensor assembly, based on the material properties of the magnetic holder according to this embodiment.

[0012] According to a further embodiment of the magnet holder, the magnet holder can also include the magnet, which may be a permanent magnet. According to this embodiment, the magnet can be arranged on the contact part. The contact part can therefore be configured to provide contact with the second component without an air gap between the magnet and the second component. The magnet can be overmolded with a plastic material. The magnet can be arranged on the opposite side of the contact part from the side configured to contact the second component. Overmolding the magnet on the opposite side of the contact part can provide gap-free contact between the magnet and the second component.Metallic residual particles that can be attracted by the magnet can thus be advantageously collected on parts of the magnet that do not interfere with the magnetically inducing effect of the magnet's magnetic field on the magnetic field-sensitive element, since the metallic residual particles cannot accumulate between the magnet and the magnetic field-sensitive element.

[0013] According to another embodiment of the magnetic holder, the holder can be manufactured in a single production step using a plastic molding process. This process can include molding the mounting part, the contact part, and the flexible strut assembly. It can also include overmolding the magnet. Alternatively, or additionally, the overmolding can be performed in a separate production step using a plastic molding process. This allows for efficient and robust manufacturing of the magnetic holder. Furthermore, the holder can be produced without an additional metal support part to hold the magnet to the contact part.

[0014] According to another embodiment of the magnetic holder, the plastic material can be a glass fiber reinforced plastic. The inventors found that the glass fiber reinforced plastic material can have advantageous material properties, such that the magnetic holder has a tensile strength that allows it to be resilient and not be damaged when clamped.

[0015] According to a further embodiment of the magnet holder, the mounting part, the contact part, and the flexible strut arrangement can together enclose a receiving space for the magnet. The mounting part, the contact part, and the flexible strut arrangement can provide an enclosed environment for the magnet. This enclosed environment can include a circumferential surface that surrounds the magnet. The magnet can thus be advantageously protected and shielded within the receiving space.

[0016] According to a further embodiment of the magnet holder, the flexible strut assembly can comprise two flexible struts, each connecting the mounting part and the contact part. The two flexible struts can surround the receiving space, with the magnet being held between them. The two flexible struts can be spaced apart. The flexible strut assembly can thus have a symmetrical design with respect to the direction of stress acting on the magnet holder in its clamped state. Torsional stresses in the clamped state can therefore be avoided to provide a defined and secure contact between the magnet and the magnetically sensitive element.

[0017] According to a further embodiment of the magnet holder, the two flexible struts can each comprise a longitudinal strip-shaped element. The two flexible struts can be at least partially flattened. The flexible strut arrangement can further be configured as a fractured spring plate to cushion the compression of the magnet holder in the clamped state and to provide a reaction force, for example, a compressive force, which can ensure contact between the contact part and the second component. The captive contact between the contact part and the second component can thus be reliably guaranteed.

[0018] According to a further embodiment of the magnet holder, in an unconstrained state, the flexible strut arrangement can have a meandering shape with at least one bend. In this unconstrained state, the magnet holder is not confined between the first and second components. The meandering shape can have at least one bend, which may be a C-shaped bend or an S-shaped bend. A bend in the flexible strut arrangement in the confined state of the magnet holder can thus be pre-formed to define a specific meander pattern, for example, an outwardly directed bend.

[0019] According to a further embodiment of the magnet holder, in the constrained state of the magnet holder, the flexible strut assembly can be bent in a meandering shape, having at least one bend. The meandering shape can include a C-shaped bend or a double bend, which can be either a C-shaped bend or an S-shaped bend. The at least one bend can be bent outwards to provide receiving space for the magnet. The meandering shape of the flexible strut assembly in the constrained state can originate from or be caused by the meandering shape of the flexible strut assembly in the unconstrained state.

[0020] According to another embodiment of the magnetic holder, the mounting element can be configured for tool-free attachment of the magnetic holder to the first component. The mounting element can be configured for a positive-locking or force-locking connection of the mounting element to the first component. The mounting element can be configured for a clamp-on attachment to the first component. The mounting element can be configured for a cable tie attachment to the first component, wherein the mounting element can include a cable tie that can be an integral part of the mounting element. The magnetic holder can thus be attached directly to the first component without tools. The mounting element can also be configured for a metal-free attachment of the magnetic holder to the first component.Alternatively, the fastening part can be attached to the first component by plastic welding, plastic soldering or plastic gluing.

[0021] According to another embodiment of the magnetic holder, the mounting part can be configured to receive a fastener for attaching the magnetic holder to the first component. The mounting part can be configured for releasable retention of the fastener. The magnetic holder can include the fastener, which may be a separate part of the mounting part. The fastener can be manually attached to the mounting part. The fastener can be releasably attached to the mounting part. The fastener can be configured for tool-free attachment of the magnetic holder to the first component. The fastener can be configured for a positive-locking or force-locking connection of the mounting part to the first component.The fastening element can be configured for clamping to the first component. According to one embodiment, the fastening element can be a retaining ring for securing the magnet holder to a groove in the first component. The retaining ring can be a locking ring, a snap ring, or a clamping ring. According to another embodiment, the fastening element can be a cable tie for securing the magnet holder to the first component.

[0022] The contact element is configured to touch and guide the second component during a relative movement of the second component with respect to the first component. This relative movement can include a relative rotational movement of the second component with respect to the first component. Alternatively or additionally, the relative movement can include a relative translational movement of the second component with respect to the first component.

[0023] Another aspect of the invention relates to a magnetic sensor arrangement. The magnetic sensor arrangement comprises a magnet and a magnetic field-sensitive element. The magnet and the magnetic field-sensitive element can be configured as described in relation to the preceding aspect of the invention. The magnetic sensor arrangement can be configured to detect the relative movement of the second component with respect to the first component. According to the preceding aspect, the magnet of the magnetic sensor arrangement is held by the magnet holder. The magnetic sensor arrangement can include the magnet holder.

[0024] Another aspect of the invention relates to a vehicle comprising a first component and a second component. The first component and the second component can be configured as described in the preceding aspects. The vehicle includes the magnetic sensor arrangement according to the preceding aspect for detecting a relative movement of the second component with respect to the first component. The first component can be a vehicle component, and the second component can be another vehicle component. During operation of the vehicle, the second vehicle component can exhibit relative movement with respect to the first vehicle component. Brief description of the characters Fig. Figure 1 schematically shows a vehicle, a magnetic sensor arrangement and a magnetic holder according to embodiments of the invention. Fig. 2 shows the magnetic holder of Fig. 1 in an unconstrained state according to an embodiment of the invention. Fig. 3 shows the magnetic holder of Fig. 2 in a confined state according to an embodiment of the invention. Fig. 4 shows the magnetic holder of Fig. 1 in an unconstrained state according to a further embodiment of the invention. Detailed description of the embodiments

[0025] Fig. Figure 1 schematically shows a vehicle 300. The vehicle 300 comprises a first component 2 and a second component 4. During operation of the vehicle 300, the second component 4 moves relative to the first component 2. The second component 4 moves translationally relative to the first component 2. Alternatively or additionally, the second component 4 moves rotationally relative to the first component 2. Each movement of the second component 4 relative to the first component 2 is caused by at least one of the following: a translational movement of the first component 2 relative to the second component 4, a rotational movement of the first component 2 relative to the second component 4, a translational movement of the second component 4 relative to the first component 2, and a rotational movement of the second component 4 relative to the first component 2.

[0026] The vehicle 300 comprises a magnetic sensor assembly 200 for detecting the movement of the second component 4 relative to the first component 2. The magnetic sensor assembly 200 comprises a magnet 202 and a magnetic field-sensitive element 204. In some embodiments of the magnetic sensor assembly 200, the magnet 202 is a permanent magnet or an electromagnet. In other embodiments of the magnetic sensor assembly 200, the magnetic field-sensitive element 204 is an electrical coil or a magnetic sensor, for example, a Hall sensor. The magnetic field-sensitive element 204 is configured to detect a change in a magnetic field generated by the magnet 202. The magnetic field-sensitive element 204 is further configured to generate an electrical signal based on the detected change in the magnetic field.

[0027] Magnet 202 is attached to the first component 2, and the magnetic field-sensitive element 204 is attached to the second component 4. Magnet 202 is indirectly attached to the first component 2 via a magnetic holder 100, which is directly attached to the first component 2. The magnetic holder 100 movably contacts the second component 4. The magnetic holder 100 is in a constrained state C, in which it is wedged between the first component 2 and the second component 4. In this constrained state C, the magnetic holder 100 is clamped between the first component 2 and the second component 4, being compressed by a compressive stress acting upon it.The magnetic holder 100 is configured to absorb the compressive stress while it is still attached to the first component 2 and still in contact with the second component 4.

[0028] Fig. Figure 2 shows the magnetic holder 100 in a perspective view in an unconstrained state N of the magnetic holder 100. The magnetic holder 100 comprises a fastening part 20 configured for fastening the magnetic holder 100 to the first component 2. The magnetic holder 100 is attached to the first component 2, which, according to one embodiment, is a cylindrical component. The fastening part 20 comprises a tool-free fastening mechanism 22. The tool-free fastening mechanism 22 includes a snap mechanism that incorporates a locking element 24 for clamping the fastening part 20 to the first component 2. According to the embodiment of the first component 2, which is the cylindrical component, the locking element 24 comprises a flexible locking band 25 that includes a locking rod 26.The locking rod 26 can engage with a locking holder 27, which is arranged on the fastening part 20, in order to clamp the fastening part 20 to the first component 2.

[0029] The magnetic holder 100 further comprises a contact part 40 configured for contacting the second component 4. The magnetic holder 100 contacts the second component 4, which, according to one embodiment, is a cylindrical component. The magnetic holder 100 comprises a concave contact surface 42, which, according to the embodiment, is a cylindrically shaped surface. The magnet 202 is arranged on the contact part 40 on one side of the contact part 40 opposite the concave contact surface 42.

[0030] The magnetic holder 100 further comprises a flexible strut assembly 30, which has two flexible struts 32. Each flexible strut 32 comprises a longitudinal strip-shaped element 34 that is flattened in one bending direction of each flexible strut 32. The flexible strut assembly 30 and both flexible struts 32 each connect the mounting part 20 and the contact part 40 to each other. The flexible struts 32 are spaced apart from each other and connect the mounting part 20 and the contact part 40 to each other on opposite sides of the mounting part 20 and the contact part 40. The flexible struts 32 are arranged in a trapezoidal configuration, the trapezoidal configuration tapering towards the contact part 40. The flexible struts 32 comprise outer surfaces 11 of the magnetic holder 100.The fastening part 20, the bendable struts 32 and the contact part 40 surround the magnet 202, which is arranged in a receiving space 12, which is jointly surrounded by the fastening part 20, the bendable struts 32 and the contact part 40.

[0031] The mounting part 20, the contact part 40, and the flexible strut assembly 30 are manufactured in one piece from a plastic material 10, which, according to one embodiment, is a glass fiber reinforced plastic material. The mounting part 20, the contact part 40, and the flexible strut assembly 30 are manufactured without metal. The magnet 202 is overmolded by the plastic material 10. The overmolding 44, which covers the magnet 202, is arranged on the contact part 40. The overmolding 44 is arranged on the contact part 40 to ensure an air gap-free arrangement of the magnet 202 on the contact part 40. The magnet 202 is arranged at a constant distance with respect to the concave contact surface 42, without being in the confined state C, which is in the Fig. 1 and Fig. Figure 3 shows an open gap between the magnet 202 and the concave contact surface 42.

[0032] Fig. Figure 3 shows the magnet holder 100 in a perspective view in the constrained state C of the magnet holder 100. In the constrained state C, the flexible strut arrangement 30 absorbs the compressive stress by converting the compressive stress into a bending stress of the flexible struts 32. Both flexible struts 32 are bent outwards, each forming a bend 36 resulting from the bending stress. In the constrained state C, the magnet holder 100 is compressed, with the contact part 40 still in contact with the second component 4. The compressive stress and the bending stress flatten the receiving space 12 but do not affect the constant distance of the magnet 202 with respect to the concave contact surface 42.

[0033] Fig. Figure 4 shows the magnetic holder 100 in a further embodiment in a side view in an unconstrained state N of the magnetic holder 100. The magnetic holder 100 is referred to as the magnetic holder 100 according to the embodiment of Fig. 2 and Fig. 3 configured, wherein the magnetic holder 100 according to this embodiment differs from the magnetic holder 100 according to the embodiment of the Fig. 2 and Fig. 3 as described below. The magnetic holder 100 differs from the magnetic holder 100 according to the embodiment of the Fig. 2 and Fig. 3 by the fact that the fastening part 20, which is configured for fastening the magnetic holder 100 to the first component 2, is configured to receive a fastening element 50. The fastening part 20 comprises a receiving structure 28 in which the fastening element 50 is held in a form-fit releasable manner. According to the embodiment shown, the fastening element 50 is a retaining ring 52 for fastening the magnetic holder 100 to a groove of the first component 2, which is located in Fig. Figure 4 is not shown. In a state where the magnet holder 100 is attached to the first component 2, the retaining ring 52 engages the groove to prevent movement of the magnet holder 100 relative to the first component 2. If the first component 2 is cylindrical, the retaining ring 52 engages the groove, which is a circumferential groove of the cylindrical component, to prevent axial movement of the magnet holder 100 relative to the cylindrical axis of the first component 2. According to this embodiment, the tool-free fastening mechanism 22 includes the retaining ring 52, which snaps into the groove.

[0034] The magnetic holder 100 further comprises the contact part 40 and the magnet 202, both of which are described with reference to the embodiment of the magnetic holder 100 of the Fig. 2 and Fig. 3 are configured as described. The magnet holder 100 further comprises the flexible strut arrangement 30, which differs from the flexible strut arrangement 30 of the embodiment of the magnet holder 100 in that it is configured as described in Section 3. Fig. 2 and Fig. 3 distinguishes, as the flexible struts 32 each comprise a bend 36 which is already preformed in the unconstrained state N. The bends 36 each comprise an S-shaped bend 36. Reference sign 2 first component 4 second component 10 plastic material 12 Recording room 20 Fastening part 22 tool-free fastening mechanism 24 Locking 25 locking strap 26 Locking rod 27 locking holders 28 Recording structure 30 flexible strut arrangement 32 flexible struts 34 strip-shaped element 36 bend 40 Contact part 42 concave contact surfaces 44 Re-injection 50 fastening elements 52 retaining ring 100 magnetic holders 200 magnetic sensor arrangement 202 Magnet 204 magnetic field sensitive element 300 vehicles C confined state N unconstrained state

Claims

A magnetic holder (100) for holding a magnet (202) of a magnetic sensor arrangement (200), wherein the magnetic holder (100) comprises a fastening part (20) for attaching the magnetic holder (100) to a first component (2) and a contact part (40) for providing contact with a second component (4) comprising a magnetic field-sensitive element (204) of the magnetic sensor arrangement (200), wherein the contact part (40) is configured to touch and guide the second component (4) during a relative movement of the second component (4) with respect to the first component (2), characterized in that the magnetic holder (100) comprises a flexible strut arrangement (30) connecting the fastening part (20) and the contact part (40), wherein the flexible strut arrangement (30) is configured to prevent compression of the magnetic holder (100) in a confined state (C) of the magnetic holder (100).to cushion the impact in which the magnetic holder (100) is wedged between the first component (2) and the second component (4). Magnetic holder (100) according to claim 1, characterized in that the fastening part (20), the contact part (40) and the bendable strut arrangement (30) are made in one piece from a plastic material (10). Magnetic holder (100) according to claim 1 or 2, wherein the magnetic holder (100) further comprises the magnet (202), characterized in that the magnet (202) is arranged on the contact part (40), and wherein the magnet (202) is overmolded with a plastic material (10). Magnetic holder (100) according to claims 2 and 3, characterized in that the magnetic holder (100) is manufactured in one manufacturing stage using a plastic molding process comprising plastic molds of the fastening part (20), the contact part (40) and the bendable strut arrangement (30) and overmolding of the magnet (202). Magnetic holder (100) according to one of claims 2 to 4, characterized in that the plastic material (10) is a glass fiber reinforced plastic material. Magnet holder (100) according to one of the preceding claims, characterized in that the fastening part (20), the contact part (40) and the flexible strut arrangement (30) together surround a receiving space (12) for receiving the magnet (202). Magnetic holder (100) according to one of the preceding claims, characterized in that the flexible strut arrangement (30) comprises two flexible struts (32) which each connect the fastening part (20) and the contact part (40) to each other, wherein the two flexible struts (32) are arranged at a distance from each other. Magnetic holder (100) according to claim 7, characterized in that the two bendable struts (32) each comprise a longitudinal strip-shaped element (34). Magnetic holder (100) according to one of the preceding claims, characterized in that in an unconstrained state (N) of the magnetic holder (100) the bendable strut arrangement (30) has a meandering shape which has at least one bend (36). Magnetic holder (100) according to one of the preceding claims, characterized in that in the constrained state (C) of the magnetic holder (100) the bendable strut arrangement (30) is bent in a meandering shape which has at least one bend (36). Magnetic holder (100) according to one of the preceding claims, characterized in that the fastening part (20) is configured for tool-free fastening of the magnetic holder (100) to the first component (2). Magnetic holder (100) according to one of the preceding claims, characterized in that the fastening part (20) is configured to receive a fastening element (50) for fastening the magnetic holder (100) to the first component (2). Magnetic sensor arrangement (200) comprising a magnet (202) and a magnetic field sensitive element (204), characterized in that the magnet (202) is held by the magnet holder (100) according to one of the preceding claims. Vehicle (300) comprising a first component (2) and a second component (4), characterized in that the vehicle (300) comprises the magnetic sensor arrangement (200) according to claim 13 for detecting a relative movement of the second component (4) with respect to the first component (2).

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