Wiegand wire device

Abstract

The present invention relates to a Wiegand wire device (100) comprising: a Wiegand wire (1a), a sensor coil (2) and a trigger coil (4a), each surrounding the Wiegand wire (1a), and two field guide elements (3a, 3b) arranged at opposite ends (1.1, 1.2) of the Wiegand wire (1a) and surrounding the respective end (1.1, 1.2) of the Wiegand wire (1a), wherein the trigger coil (4a) is arranged within one of the two field guide elements (3a, 3b) and surrounds the respective end (1.1) of the Wiegand wire (1a).

Description

[0001] The present invention relates to a Wiegand wire device comprising: a Wiegand wire, a sensor coil and a trigger coil, each surrounding the Wiegand wire, and two field guide elements arranged at opposite ends of the Wiegand wire and surrounding the respective end of the Wiegand wire.

[0002] Wiegand wires as defined in this application are also referred to as impulse wires and generally have a hard magnetic sheath and a soft magnetic core, or vice versa. Under the influence of an external magnetic field, the magnetization direction of a Wiegand wire abruptly reverses as soon as a specific trigger field strength is exceeded at any point along the wire. This reversal of the magnetization direction of a Wiegand wire is hereinafter referred to as "triggering" the Wiegand wire. Triggering the Wiegand wire generates a short voltage pulse, also called a Wiegand pulse, in the sensor coil. This effect is known as the Wiegand effect and is well known in the prior art.

[0003] A Wiegand wire device of the type mentioned above is known from WO 2023 / 131396 A1, wherein an additional Wiegand release unit with its own Wiegand wire and a surrounding sensor coil is provided, which is connected to the release coil in such a way that a Wiegand pulse generated in the sensor coil of the Wiegand release unit energizes the release coil of the Wiegand wire device and thereby generates a release magnetic field acting on the Wiegand wire of the Wiegand wire device. However, a relatively strong release magnetic field, and thus the energizing of the release coil with a relatively high electric current, is required for the defined release of the Wiegand wire, which cannot be reliably provided by the Wiegand release unit.

[0004] Against this background, the present invention is based on the objective of reliably enabling a defined triggering of the Wiegand wire in a Wiegand wire device of the type mentioned above.

[0005] This problem is solved according to the invention by a Wiegand wire device with the features of claim 1.

[0006] The Wiegand wire device according to the invention comprises a Wiegand wire and a sensor coil surrounding the Wiegand wire, which are designed and arranged in a manner well known from the prior art such that a Wiegand pulse is generated in the sensor coil when the Wiegand wire is triggered.

[0007] The Wiegand wire device according to the invention further comprises a release coil which also surrounds the Wiegand wire, so that a release magnetic field acting on the Wiegand wire can be generated by energizing the release coil.

[0008] The Wiegand wire device according to the invention further comprises two field-guiding elements arranged at opposite ends of the Wiegand wire. Specifically, a first field-guiding element is arranged at a first end of the Wiegand wire, and a second field-guiding element is arranged at a second end of the Wiegand wire opposite the first end. The field-guiding elements consist of a soft magnetic material, preferably ferrite, and are also referred to as ferrite elements or ferrites. The two field-guiding elements surround the respective end of the Wiegand wire and thereby shield it from an external magnetic field acting on the Wiegand wire, thus reducing the strength of the external magnetic field in the region of both ends of the Wiegand wire.This is necessary because, due to its elongated shape, the Wiegand wire has a relatively low triggering field strength in the area of ​​its ends, so that without field-guiding elements even relatively weak interfering magnetic fields could cause an unintentional triggering of the Wiegand wire.

[0009] According to the invention, the relatively low trigger field strength in the region of the ends of the Wiegand wire is specifically utilized to reliably achieve a defined triggering of the Wiegand wire. For this purpose, the trigger coil is arranged within one of the two field-guiding elements, so that the trigger coil surrounds the respective end of the Wiegand wire. Thus, according to the invention, the trigger coil is arranged in a region of the Wiegand wire where it exhibits a relatively low trigger field strength. Therefore, to trigger the Wiegand wire in a defined manner, only a relatively weak trigger magnetic field needs to be generated by the trigger coil arranged according to the invention, and consequently, only a relatively small electric current needs to be impressed into the trigger coil.

[0010] The release coil arranged within the field guide element according to the invention therefore makes it possible to reliably achieve a defined release of the Wiegand wire even with the relatively low electrical energy that can be generated by a Wiegand release unit known from the prior art.

[0011] In principle, the release coil can be arranged in any way within the respective field guide element, for example, inserted into a suitably designed receptacle or opening of the field guide element. Preferably, however, the release coil is firmly embedded in the respective field guide element, so that the release coil is inseparably connected to the field guide element and consequently does not need to be mounted separately. Preferably, the release coil is completely enclosed by the field guide element.

[0012] Preferably, the field guide element in which the trigger coil is embedded is designed as an injection-molded part, i.e., manufactured by injection molding. Manufacturing the field guide element by injection molding allows the trigger coil to be integrated into the field guide element easily and reliably by inserting it into the injection mold.

[0013] In a preferred embodiment, the Wiegand wire device according to the invention comprises a further trigger coil, wherein one of the two trigger coils is arranged in each of the two field-guiding elements and surrounds the respective end of the Wiegand wire. This makes it possible to trigger the reversal of the magnetization direction of the Wiegand wire from either end of the Wiegand wire. By simultaneously energizing both trigger coils, a particularly rapid reversal of the magnetization direction of the Wiegand wire and thus a particularly pronounced Wiegand pulse can be achieved. Furthermore, it can also be advantageous, for example depending on the direction of an external magnetic field, to selectively energize either only the trigger coil or only the further trigger coil in order to selectively trigger the reversal of the magnetization direction of the Wiegand wire from the first end or from the second end of the Wiegand wire.

[0014] Preferably, the Wiegand wire device according to the invention comprises at least one further Wiegand wire surrounded by the sensor coil, thereby generating a particularly strong Wiegand pulse in the sensor coil. This enables, on the one hand, particularly reliable detection of the Wiegand pulse when the Wiegand wire device according to the invention is used in a sensor device, and on the other hand, the generation of particularly high electrical energy when the Wiegand wire device according to the invention is used as an energy generator. The strength of the Wiegand pulse generated when the Wiegand wires in the sensor coil are triggered is higher the more Wiegand wires are present in total. Preferably, all Wiegand wires are arranged substantially parallel to each other. Preferably, the two ends of the at least one further Wiegand wire are also each surrounded by one of the two field-conducting elements.

[0015] Preferably, the at least one additional Wiegand wire and the at least one trigger coil are arranged and configured such that at least one end of each Wiegand wire in the Wiegand wire device is surrounded by a trigger coil, so that the trigger magnetic field generated by energizing the trigger coil acts on the end region of each Wiegand wire, which has a relatively low trigger field strength. If the Wiegand wire device includes an additional trigger coil, preferably both ends of each Wiegand wire in the Wiegand wire device are surrounded by one of the two trigger coils. This allows for particularly synchronous triggering of all Wiegand wires and thus the generation of a particularly sharp Wiegand pulse in the sensor coil.

[0016] An embodiment of the present invention is described below with reference to the attached Fig. 1 described, which shows a schematic diagram of a Wiegand wire device according to the invention.

[0017] Fig. Figure 1 shows a Wiegand wire device 100 according to the invention, which in the present embodiment comprises four essentially identical Wiegand wires 1a - 1d arranged essentially parallel to each other.

[0018] The Wiegand wire device 100 further comprises a sensor coil 2 which surrounds the four Wiegand wires 1a - 1d.

[0019] The Wiegand wire device 100 further comprises two field-guiding elements 3a, 3b, both of which consist of a soft magnetic material, in particular a soft magnetic ferrite, and in the present embodiment both are designed as an injection-molded part.

[0020] The first field guide element 3a is arranged on a first axial side of the sensor coil at a first end 1.1 of the Wiegand wires 1a - 1d and surrounds the first end 1.1 of the Wiegand wires 1a - 1d.

[0021] The second field guide element 3b is arranged on the second axial side of the sensor coil opposite the first axial side and on the second end 1.2 of the Wiegand wires 1a - 1d opposite the first end 1.1 and surrounds the second end 1.2 of the Wiegand wires 1a - 1d.

[0022] The Wiegand wire device 100 further comprises two release coils 4a, 4b, wherein a release coil 4a is arranged within the first field guide element 3a and surrounds the first end 1.1 of the Wiegand wires 1a - 1d, and wherein a further release coil 4b is arranged within the second field guide element 3b and surrounds the second end 1.2 of the Wiegand wires 1a - 1d.

[0023] In the present embodiment, the two trigger coils 4a, 4b are embedded in the respective field guide element 3a, 3b and completely enclosed by the respective field guide element 3a, 3b. Reference symbol list 100 Wiegand wire devices 1a - 1d Wiegand wires 1.1 first end 1.2 second end 2 Sensor coil 3a first field guide element 3b second field guide element 4a Release coil 4b additional release coil 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 2023 / 131396 A1

[0003]

Claims

Wiegand wire device (100) comprising: a Wiegand wire (1a), a sensor coil (2) and a trigger coil (4a), each surrounding the Wiegand wire (1a), and two field guide elements (3a, 3b) arranged at opposite ends (1.1, 1.2) of the Wiegand wire (1a) and surrounding the respective end (1.1, 1.2) of the Wiegand wire (1a), characterized in that the trigger coil (4a) is arranged within one of the two field guide elements (3a, 3b) and surrounds the respective end (1.1) of the Wiegand wire (1a). Wiegand wire device (100) according to claim 1, wherein the release coil (4a) is embedded in the respective field guide element (3a). Wiegand wire device (100) according to claim 2, wherein the field guide element (3a) in which the release coil (4a) is embedded is an injection-molded part. Wiegand wire device (100) according to one of the preceding claims, comprising a further release coil (4b), wherein a release coil (4a, 4b) is arranged in each of the two field guide elements (3a, 3b) and surrounds the respective end (1.1) of the Wiegand wire (1a). Wiegand wire device (100) according to one of the preceding claims, comprising at least one further Wiegand wire (1b - 1d) surrounded by the sensor coil (2). Wiegand wire device (100) according to claim 5, wherein one end (1.1) of each Wiegand wire (1a - 1d) is surrounded by a release coil (4a, 4b).

Images