Wiegand sensor arrangement

Abstract

The invention relates to a Wiegand sensor arrangement (100) comprising: a shaft (11), a permanent magnet excitation unit (12) arranged to rotate with the shaft (11), and a Wiegand sensor (10-1; 10-2) with: a Wiegand wire (2), a sensor coil (3) surrounding the Wiegand wire (2), and two field guide elements (4, 5) arranged at opposite ends (2.1, 2.2) of the Wiegand wire (2), wherein the two field guide elements (4, 5) each have a detection section (4.3, 5.3) arranged between the Wiegand wire (2) and the permanent magnet excitation unit (12), and directed towards a median plane (M) extending transversely to the Wiegand wire (2) through the center of the Wiegand wire (2), wherein the detection sections (4.3, 5.3) of the two field guide elements (4, 5) are each designed to point away from the Wiegand wire (2).

Description

[0001] The present invention relates to a Wiegand sensor arrangement comprising: a shaft, a permanent magnetic excitation unit arranged to rotate with the shaft, and a Wiegand sensor with: a Wiegand wire, a sensor coil surrounding the Wiegand wire, and two field guide elements arranged at opposite ends of the Wiegand wire, wherein the two field guide elements each have a detection section arranged between the Wiegand wire and the permanent magnetic excitation unit and configured to point towards a central plane extending transversely to the Wiegand wire through the center of the Wiegand wire.

[0002] Such a Wiegand sensor arrangement is known, for example, from WO 2022 / 230651 A1.

[0003] The present invention is based on the objective of creating a reliable Wiegand sensor arrangement.

[0004] This problem is solved according to the invention by a Wiegand sensor arrangement with the features of main claim 1.

[0005] The Wiegand sensor arrangement according to the invention comprises a shaft and a permanent magnet excitation unit, which is arranged to rotate with the shaft. Preferably, the permanent magnet excitation unit is attached to the shaft so that it always rotates at the same speed as the shaft. However, it is also conceivable that the permanent magnet excitation unit is coupled to the shaft via a gearbox or the like, whereby, depending on the gearbox design, the permanent magnet excitation unit rotates at the same speed as the shaft or at a different speed. In any case, the shaft and the permanent magnet excitation unit are coupled such that a rotational movement of the shaft causes a rotational movement of the permanent magnet excitation unit.The permanent magnet excitation unit can be a single component, consisting of a single permanent magnet, or it can be a multi-component unit comprising one or more permanent magnets mounted on a support. The permanent magnet excitation unit is designed such that, at a defined sensor position, the at least one permanent magnet generates an alternating magnetic field when the unit rotates, i.e., when the shaft rotates.

[0006] The Wiegand sensor arrangement according to the invention further comprises a Wiegand sensor positioned at the sensor location, such that an alternating excitation magnetic field is generated at the location of the Wiegand sensor during a rotational movement of the permanent magnet excitation unit. The Wiegand sensor comprises a Wiegand wire and a sensor coil radially surrounding the Wiegand wire. Such Wiegand sensors are also known as pulse wire sensors and are generally known. Wiegand wires generally have a hard magnetic sheath and a soft magnetic core, or vice versa. Under the influence of an external magnetic field, here the excitation magnetic field generated by the permanent magnet excitation unit, one magnetization direction of the Wiegand wire is abruptly inverted, thereby generating a short Wiegand voltage pulse in the sensor coil radially surrounding the Wiegand wire, which can be tapped at the two sensor coil ends.This effect is known as the Wiegand effect, or also as the macroscopic or large Barkhausen effect, and is generally known.

[0007] The Wiegand sensor of the Wiegand sensor arrangement according to the invention further comprises two one-piece field guide elements, wherein a first field guide element is arranged at a first end of the Wiegand wire and a second field guide element is arranged at a second end of the Wiegand wire opposite the first end. The field guide elements consist of a soft magnetic material, preferably ferrite, and are used to guide an external excitation magnetic field selectively to the two ends of the Wiegand wire and thereby generate an excitation magnetic field that is as axial as possible in the Wiegand wire.

[0008] The two field-guiding elements each have a detection section arranged between the Wiegand wire and the permanent magnet excitation unit. This detection section extends from a base body section, which typically extends transversely to the Wiegand wire and typically surrounds it radially, towards a median plane running transversely to the Wiegand wire through its center point. Consequently, the detection sections of the two field-guiding elements are located at their ends furthest from the respective base body section at a smaller distance from the median plane than the base body section of the respective field-guiding element. Preferably, the two field-guiding elements have an end surface at their ends furthest from the respective base body section that extends parallel to the median plane, i.e., transversely to the Wiegand wire.

[0009] According to the invention, the detection sections of the two field-guiding elements are each designed to point away from the Wiegand wire, meaning that at their end furthest from the respective base body section they have a greater distance to the Wiegand wire and consequently a smaller distance to the permanent magnet excitation unit than at their end facing the base body section. This enables a particularly effective introduction of the excitation magnetic field generated by the permanent magnet excitation unit into the Wiegand wire and thus the realization of a reliable Wiegand sensor arrangement.

[0010] Preferably, the detection sections of the two field-guiding elements are each configured at an angle between 65° and 85°, preferably at an angle between 70° and 80°, to the central plane. This enables effective introduction of the excitation magnetic field generated by the permanent magnet excitation unit and simultaneously allows for the realization of a relatively compact Wiegand sensor.

[0011] In a preferred embodiment of the Wiegand sensor arrangement according to the invention, the Wiegand sensor is arranged radially adjacent to the permanent magnet excitation unit, wherein the Wiegand sensor is typically arranged on a radial outer surface of the permanent magnet excitation unit and the detection sections of the two field guide elements are consequently directed radially inwards. Radially adjacent here means that orthogonal projections of the Wiegand sensor and the permanent magnet excitation unit overlap onto a projection plane perpendicular to the radial direction in which the Wiegand sensor and the permanent magnet excitation unit are adjacent. The Wiegand sensor and the permanent magnet excitation unit are thus arranged at least partially at the same axial "height". The permanent magnet excitation unit is preferably arranged concentrically to the shaft at an axial end of the shaft.This creates a Wiegand sensor assembly that is relatively easy to assemble.

[0012] Preferably, a winding area of ​​the sensor coil in the region of the central plane has an outer diameter that is larger than an outer diameter in the region of an axial end of the winding area of ​​the sensor coil in order to generate particularly pronounced Wiegand voltage pulses in the sensor coil and thus create a particularly reliable Wiegand sensor arrangement.

[0013] Preferably, the distance between the detection sections of the two field guide elements is a maximum of 50%, preferably a maximum of 25%, of the distance between the base body sections of the two field guide elements that enclose the Wiegand wire. This creates a particularly reliable Wiegand sensor arrangement.

[0014] In a preferred embodiment of the Wiegand sensor arrangement according to the invention, the Wiegand sensor comprises a sensor housing to which the Wiegand wire, the sensor coil, and the two field guide elements are directly or indirectly attached, wherein the sensing sections of the two field guide elements project from the sensor housing on one side facing the permanent magnet excitation unit. The sensor housing provides reliable protection for the components of the Wiegand sensor, thereby creating a reliable Wiegand sensor arrangement. The sensor housing is preferably made of a plastic.

[0015] Preferably, the sensor housing is designed as an injection-molded part, with the two field guide elements each being overmolded by the sensor housing and thus reliably attached to it without the need for special fasteners or assembly steps. This results in a Wiegand sensor assembly that is easy to manufacture and cost-effective.

[0016] In a preferred embodiment of the Wiegand sensor arrangement according to the invention, an electrically conductive contacting means is arranged on each of the two field guide elements, which is electrically connected to the sensor coil. Specifically, the electrically conductive contacting means arranged on the first field guide element is electrically connected to a first sensor coil end of the sensor coil, and the electrically conductive contacting means arranged on the second field guide element is electrically connected to a second sensor coil end of the sensor coil, so that the Wiegand voltage pulses generated in the sensor coil can be easily tapped via the electrically conductive contacting means arranged on the two field guide elements.

[0017] Preferably, the two field conductors each have a contact section projecting from the sensor housing, with the contacting means being arranged outside the sensor housing on the contact section of the respective field conductor. Preferably, the contacting means are arranged on a contact surface of the respective contact section that runs parallel to the Wiegand wire, so that the Wiegand sensor can be easily mounted onto corresponding contact surfaces of a printed circuit board using the contact surfaces of the two field conductors. This enables particularly simple mounting of the Wiegand sensor on a printed circuit board and thus the realization of a relatively simple-to-manufacture Wiegand sensor assembly.

[0018] In a preferred embodiment, the two field conductors each have an electrically conductive coating that forms the electrically conductive contact element arranged on the respective field conductor. This allows for the relatively simple realization of contact elements that exhibit relatively good electrical conductivity and can be connected relatively well to corresponding contact surfaces of a printed circuit board. This results in a relatively simple and reliable Wiegand sensor arrangement.

[0019] Preferably, the first sensor coil end is electrically attached to the electrically conductive coating of the first field conductor, and the second sensor coil end is electrically attached to the electrically conductive coating of the second field conductor, for example by means of a soldered connection or another type of material-bonded, electrically conductive connection. This creates a relatively simple and cost-effective Wiegand sensor arrangement.

[0020] In an alternative preferred embodiment, the Wiegand sensor comprises two electrically conductive sheet metal bodies, each containing one of the two field-conducting elements, which forms the electrically conductive contact element attached to that element. Preferably, the two field-conducting elements are pressed, glued, or otherwise firmly connected to the respective sheet metal body. This allows for the relatively simple realization of contact elements that exhibit relatively good electrical conductivity and can be connected relatively well to corresponding contact surfaces of a printed circuit board. This results in a relatively simple and reliable Wiegand sensor assembly.

[0021] Preferably, the first sensor coil end is electrically connected to a first of the two sheet metal bodies, and the second sensor coil end is electrically connected to a second of the two sheet metal bodies, for example by means of a soldered connection or another type of metallurgical, electrically conductive connection. This creates a relatively simple and cost-effective Wiegand sensor arrangement.

[0022] Exemplary embodiments of the present invention are described below with reference to the accompanying figures. These show: Fig. 1 schematically a Wiegand sensor arrangement according to the invention, Fig. 2 schematically a top view of a side of a Wiegand sensor facing a circuit board of the Wiegand sensor arrangement Fig. 1, Fig. 3 schematically a top view of an end face of the Wiegand sensor Fig. 2, Fig. 4 schematically a cross-sectional view of the Wiegand sensor from Fig. 2 and Fig. 3, wherein the Wiegand sensor is located along the in Fig. The line IV-IV, as shown in the drawing, is intersected. Fig. 5 one of the representations from Fig. 4. Corresponding representation of an alternative Wiegand sensor for the Wiegand sensor arrangement according to the invention. Fig. 1.

[0023] Fig. Figure 1 shows a Wiegand sensor arrangement 100 according to the invention with a Wiegand sensor 10-1, a shaft 11 and a permanent magnetic excitation unit 12.

[0024] The permanent magnet excitation unit 12 is formed by a permanent magnet excitation magnet which is attached to an axial end of the shaft 11 so that it rotates with the shaft 11.

[0025] The Wiegand sensor 10-1 is arranged radially adjacent to the permanent magnetic excitation unit 12 on a circuit board 13, which is arranged axially adjacent to the permanent magnetic excitation unit 12.

[0026] Fig. 2 to Fig. Figure 4 shows different representations of the Wiegand sensor 10-1.

[0027] The Wiegand sensor 10-1 comprises a sensor housing 1 designed as an injection-molded part, in which a Wiegand wire 2, a sensor coil 3, a first field guide element 4 and a second field guide element 5 are arranged, wherein the Wiegand wire 2, the sensor coil 3, and the two field guide elements 4, 5 are attached directly or indirectly to the sensor housing 1.

[0028] The sensor coil 3 comprises a winding area 3.1 that radially surrounds the Wiegand wire 2, as well as a first sensor coil end 3.2 and a second sensor coil end 3.3.

[0029] The first field guide element 4 and the second field guide element 5 each consist of a soft magnetic material, specifically a soft magnetic ferrite, and are each overmolded by the sensor housing 1.

[0030] The first field-conducting element 4 and the second field-conducting element 5 are each completely coated on their outside with an electrically conductive coating 4.1, 5.1.

[0031] The first field guide element 4 and the second field guide element 5 each have a base body section 4.2, 5.2 which extends transversely to the Wiegand wire 2 and surrounds the Wiegand wire 2 radially, wherein the base body section 4.2 of the first field guide element 4 surrounds a first end 2.1 of the Wiegand wire 2 and the base body section 5.2 of the second field guide element 5 surrounds a second end 2.2 of the Wiegand wire 2.

[0032] The first field guide element 4 and the second field guide element 5 each have a detection section 4.3, 5.3, which is arranged between the Wiegand wire 2 and the permanent magnetic excitation unit 12, and which is directed from the respective base body section 4.2, 5.2 away from the Wiegand wire 2 in the direction of a median plane M running transversely to the Wiegand wire 2 through its center point, in particular running at an angle of 73° to the median plane M and protrudes from the sensor housing 1 on a side S1 of the sensor housing 1 facing the permanent magnetic excitation unit 12.

[0033] The detection section 4.3 of the first field guide element 4 and the detection section 5.3 of the second field guide element 5 each have at their end facing away from the base body section 4.2, 5.2 an end surface 4.3.1, 5.3.1 extending transversely to the Wiegand wire, wherein a distance A1 between the end surface 4.3.1 of the first field guide element 4 and the end surface 5.3.1 of the second field guide element 5 is less than 25% of a distance A2 between the base body section 4.2 of the first field guide element 4 and the base body section 5.2 of the second field guide element 5.

[0034] The first sensor coil end 3.2 is electrically conductively attached to the electrically conductive coating 4.1 of the detection section 4.3 of the first field guide element 4 in the area of ​​a first recess 1.1 of the sensor housing 1, and the second sensor coil end 3.3 is electrically conductively attached to the electrically conductive coating 5.1 of the detection section 5.3 of the second field guide element 5 in the area of ​​a second recess 1.2 of the sensor housing 1.

[0035] The first field guide element 4 and the second field guide element 5 each have a contacting section 4.4, 5.4 adjoining the base body section 4.2, 5.2 and running transversely to the Wiegand wire 2, which protrudes from the sensor housing 1 on a side S2 of the sensor housing 1 facing the circuit board 13.

[0036] The contacting section 4.4 of the first field conductor 4 and the contacting section 5.4 of the second field conductor 5 each have a contacting surface 4.4.1, 5.4.1 running parallel to the Wiegand wire at their end facing away from the base body section 4.2, 5.2 outside the sensor housing 1, wherein the contacting surface 4.4.1 of the first field conductor 4 is arranged parallel to the contacting surface 5.4.1 of the second field conductor 5.

[0037] At the contacting surface 4.4.1 of the first field conductor 4 and at the contacting surface 5.4.1 of the second field conductor 5, an electrically conductive contacting means 4.5, 5.5 is formed by the electrically conductive coating 4.1, 5.1 of the respective field conductor 4, 5, wherein the electrically conductive contacting means 4.5 formed by the electrically conductive coating 4.1 of the first field conductor 4 and arranged at the contacting surface 4.4.1 of the first field conductor 4 is electrically connected to the first sensor coil end 3.2, and wherein the electrically conductive contacting means 5.5 formed by the electrically conductive coating 5.1 of the second field conductor 5 and arranged at the contacting surface 5.4.1 of the second field conductor 5 is electrically connected to the second sensor coil end 3.3.

[0038] The Wiegand sensor 10-1 is electrically attached to corresponding coil contact surfaces (not shown here) of the circuit board 13 via the electrically conductive contacting means 4.5, 5.5 arranged on the contact surfaces 4.4.1, 5.4.1.

[0039] Fig. Figure 5 shows an alternative Wiegand sensor 10-2, which replaces the Wiegand sensor 10-1 in the Fig. 1 shown in the invention, Wiegand sensor arrangement 100 can be used.

[0040] For the description of the Wiegand sensor 10-2, the corresponding reference numerals are used for features that are identical or similar to those known from the previously described Wiegand sensor 10-1. Fig. 1 to Fig. 4 used.

[0041] The Wiegand sensor 10-2 differs from the Wiegand sensor 10-1 in that the first field guide element 4 and the second field guide element 5 are not coated, but rather an electrically conductive first sheet metal body 6 is present in which the first field guide element 4 is arranged, and an electrically conductive second sheet metal body 7 is present in which the second field guide element 5 is arranged.

[0042] In the Wiegand sensor 10-2, the first sheet metal body 6 therefore forms the electrically conductive contacting means 4.5 arranged on the contacting surface 4.4.1 of the first field conductor 4, and the second sheet metal body 7 forms the electrically conductive contacting means 5.5 arranged on the contacting surface 5.4.1 of the second field conductor 5.

[0043] In the Wiegand sensor 10-2, the first sensor coil end 3.2 is electrically conductively attached to the first sheet metal body 6 and the second sensor coil end 3.3 is electrically conductively attached to the second sheet metal body 7.

[0044] The Wiegand sensor 10-2 differs from the Wiegand sensor 10-1 in that the winding area 3.1 in the area of ​​the central plane M has an outer diameter D1 that is larger than an outer diameter D2 in the area of ​​the axial ends of the winding area 3.1. Reference symbol list 100 Wiegand sensor arrangement 11th wave 12 permanent magnet excitation units 13 Circuit board 10-1; 10-2 Wiegand sensor 1 Sensor housing 1.1 first exclusion 1.2 second recess 2 Wiegand wire 2.1 first end 2.2 second end 3 Sensor coil 3.1 Winding area 3.2 First end of sensor coil 3.3 Second end of sensor coil 4 first field guide element 4.1 Electrically conductive coating 4.2 Basic body section 4.3 Data Collection Section 4.3.1 End surface 4.4 Contact section 4.4.1 Contact surface 4.5 Electrically conductive contacting medium 5 second field guide element 5.1 Electrically conductive coating 5.2 Basic body section 5.3 Data Collection Section 5.3.1 End surface 5.4 Contact section 5.4.1 Contact surface 5.5 Electrically conductive contacting medium 6 first sheet metal body 7 second sheet metal body A1 distance A2 distance D1 Outer diameter D2 outer diameter M Middle level S1 page S2 page QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2022 / 230651 A1

[0002]

Claims

[1] Wiegand sensor arrangement (100) comprising: a wave (11), a permanent magnetic excitation unit (12) which is arranged to rotate with the shaft (11), and a Wiegand sensor (10-1; 10-2) with: a Wiegand wire (2), a sensor coil (3) surrounding the Wiegand wire (2), and two field conducting elements (4, 5) arranged at opposite ends (2.1, 2.2) of the Wiegand wire (2), wherein the two field conducting elements (4, 5) each have a detection section (4.3, 5.3) arranged between the Wiegand wire (2) and the permanent magnetic excitation unit (12), and which is directed in the direction of a central plane (M) extending transversely to the Wiegand wire (2) through the center of the Wiegand wire (2), characterized by , that the detection sections (4.3, 5.3) of the two field conducting elements (4, 5) are each designed to point away from the Wiegand wire (2). [2] Wiegand sensor arrangement (100) according to claim 1, wherein the detection sections (4.3, 5.3) of the two field conducting elements (4, 5) are each formed to extend at an angle between 65° and 85°, preferably between 70° and 80°, to the center plane (M). [3] Wiegand sensor arrangement (100) according to one of the preceding claims, wherein the Wiegand sensor (10-1; 10-2) is arranged radially adjacent to the permanent magnetic excitation unit (12). [4] Wiegand sensor arrangement (100) according to one of the preceding claims, wherein a winding region (3.1) of the sensor coil (3) in the region of the center plane (M) has an outer diameter (D1) which is larger than an outer diameter (D2) in the region of an axial end of the winding region (3.1). [5] Wiegand sensor arrangement (100) according to one of the preceding claims, wherein a distance (A1) between the detection sections (4.3, 5.3) of the two field conducting elements (4, 5) is a maximum of 50%, preferably a maximum of 25%, of a distance (A2) between the base body sections (4.2, 5.2) of the two field conducting elements (4, 5) enclosing the Wiegand wire (2). [6] Wiegand sensor arrangement (100) according to one of the preceding claims, wherein the Wiegand sensor (2) comprises a sensor housing (1) to which the Wiegand wire (2), the sensor coil (3), and the two field conducting elements (4, 5) are directly or indirectly fastened, and wherein the detection sections (4.3, 5.3) of the two field conducting elements (4, 5) protrude from the sensor housing (1) on a side (S1) of the sensor housing (1) facing the permanent magnetic excitation unit (12). [7] Wiegand sensor arrangement (100) according to claim 6, wherein the two field conducting elements (4, 5) are each overmolded by the sensor housing (1). [8] Wiegand sensor arrangement (100) according to one of the preceding claims, wherein an electrically conductive contacting means (4.5, 5.5) is arranged on each of the two field conducting elements (4, 5), which is electrically connected to the sensor coil (3). [9] Wiegand sensor arrangement (100) according to one of claims 6 or 7 and claim 8, wherein the two field conducting elements (4, 5) each have a contacting section (4.4, 5.4) projecting from the sensor housing (1), and wherein the contacting means (4.5, 5.5) are each arranged outside the sensor housing (1) on the contacting section (4.4, 5.4) of the respective field conducting element (4, 5). [10] Wiegand sensor arrangement (100) according to one of claims 8 or 9, wherein the two field conducting elements (4, 5) each have an electrically conductive coating (4.1, 5.1) which forms the electrically conductive contacting means (4.5, 5.5) arranged on the respective field conducting element (4, 5). [11] Wiegand sensor arrangement (100) according to claim 10, wherein a first sensor coil end (3.2) of the sensor coil (3) is electrically conductively attached to the electrically conductive coating (4.1) of a first field conducting element (4) of the two field conducting elements (4, 5), and a second sensor coil end (3.3) of the sensor coil (3) is electrically conductively attached to the electrically conductive coating (5.1) of a second field conducting element (5) of the two field conducting elements (4, 5). [12] Wiegand sensor arrangement (100) according to one of claims 8 or 9, wherein the Wiegand sensor (10-1; 10-2) comprises two electrically conductive sheet metal bodies (6, 7), in each of which one of the two field conducting elements (4, 5) is arranged and which forms the electrically conductive contacting means (4.5, 5.5) arranged on the respective field conducting element (4, 5). [13] Wiegand sensor arrangement (100) according to claim 12, wherein a first sensor coil end (3.2) of the sensor coil (3) is electrically conductively attached to a first sheet metal body (6) of the two sheet metal bodies (6, 7), and a second sensor coil end (3.3) of the sensor coil (3) is electrically conductively attached to a second sheet metal body (7) of the two sheet metal bodies (6, 7).

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