Pulse wire module and method for producing a pulse wire module

Description

[0001] The present invention relates to a pulse wire module comprising a module housing defining a housing chamber, a wire winding formed by a winding wire and arranged at least partially within the housing chamber, a pulse wire extending at least partially within the wire winding, and a contacting device for external electrical contacting of the pulse wire module, which contacting device is fastened to the module housing and is electrically connected to the wire winding.

[0002] Such pulse wire modules - also known as Wiegand modules - are used, for example, in magnet-based angle measuring devices to detect an excitation magnetic field generated by an excitation magnet.

[0003] Such a pulse wire module is known from DE 10 2020 100 732 A1, wherein the contacting device comprises a connecting element around which the winding wire is wound to electrically connect the contacting device to the wire winding. The disclosed pulse wire module has a multi-part construction, enabling automated winding of the connecting element with the winding wire. However, due to the complex multi-part construction, the manufacturing costs of the disclosed pulse wire module are relatively high.

[0004] Another pulse wire module of the type mentioned above is known from CN 201 331 360 Y.

[0005] From GB 2 100937 A, a pulse wire module of the type mentioned above is known, in which the winding wire is soldered to the contacting device.

[0006] From US 4 743 780 A, a pulse wire module of the type mentioned above is known, in which the winding wire is welded to the contacting device.

[0007] From US 2019 / 316934 A1, a pulse wire module is known in which the ends of the winding wire are led out of the module housing.

[0008] Against this background, the task is to enable cost-effective production of a pulse wire module.

[0009] This object is achieved by a pulse wire module having the features of claim 1.

[0010] The pulse wire module according to the invention comprises a module housing that defines a housing chamber. Typically, the module housing is made of plastic and is an injection-molded part. The module housing is typically substantially trough-shaped and thus defines a housing chamber that is open on one side (typically on an underside of the module housing). Typically, the housing chamber comprises a cylindrical segment-shaped section for accommodating the wire winding. The module housing can have special structures for aligning and positioning the module housing during assembly.

[0011] The pulse wire module according to the invention further comprises a wire winding and a pulse wire. The wire winding is formed by a winding wire and arranged at least partially within the housing chamber. The wire winding is preferably designed as a so-called air-core coil without a winding core. The pulse wire extends at least partially within the wire winding, i.e., the wire winding radially encloses the pulse wire at least partially. Preferably, an inner diameter of the coil is slightly larger than an outer diameter of the pulse wire, so that the pulse wire is positioned and supported in the radial direction by the wire winding. Typically, a ferritic element is arranged on both axial sides of the wire winding, by which one end of each pulse wire is held.The ferritic elements are attached to the module housing, preferably overmolded by the module housing. The pulse wire is preferably bonded to the two ferritic elements using a relatively soft adhesive, such as silicone, that cures under UV light. The pulse wire is magnetically bistable and is also referred to as a Wiegand wire. Under the influence of an external magnetic field, the magnetization direction of the pulse wire suddenly inverts, generating a short voltage pulse in the wire winding. The pulse wire module according to the invention further comprises at least one contacting device for externally electrically contacting the pulse wire module. The contacting device is attached to the module housing, preferably overmolded by the module housing.The contacting device is electrically connected to the wire winding, allowing the voltage pulses generated in the wire winding to be tapped externally via the contacting device. Typically, the contacting device comprises several contact elements, also known as contact pins, which are arranged at a defined distance from one another to enable mounting of the pulse wire module on a standardized circuit board.

[0012] Preferably, the contacting elements are arranged on the underside of the module housing and designed for mounting on the surface of a printed circuit board, so that the pulse wire module is designed as a so-called "surface-mounted device" (SMD).

[0013] According to the invention, the winding wire is connected to the contacting device via a material-to-material connection. The material-to-material connection can, in particular, be a welded connection or a soldered connection. In principle, however, the material-to-material connection can be any type of material-to-material connection that creates an electrical connection between the winding wire and the contacting device. The material-to-material connection can, in principle, be arranged in any desired region of the contacting device. However, the contacting device preferably has a specially configured connection region for forming the material-to-material connection with the winding wire.Preferably, the winding wire is connected to the contacting device exclusively via the integral connection. It is also conceivable that the integral connection could be surrounded by a protective layer, such as a varnish or a potting compound, to protect it from environmental influences. However, the protective layer does not significantly contribute to the connection between the winding wire and the contacting device, but merely serves to protect the integral connection. The integral connection creates a reliable connection between the winding wire and the contacting device, which can be produced relatively easily and automatically using appropriate machines. This enables particularly cost-effective production of the pulse wire module according to the invention.

[0014] According to the invention, the contacting device comprises a base body that is embedded in the module housing, and a connecting element that protrudes from the module housing and on which the material connection to the winding wire is arranged. According to the invention, the connecting element is formed integrally with the base body. The base body embedded in the module housing ensures reliable fastening of the contacting device to the housing. According to the invention, the base body is completely or at least partially overmolded by the module housing. Typically, several contacting elements are also molded onto the base body, which also protrude from the module housing and serve to make external electrical contact with the pulse wire module. The connecting element is preferably arranged on a side of the base body facing the wire winding.The connecting element protruding from the module housing is easily accessible and enables easy creation of the material connection with the winding wire.

[0015] Preferably, the contacting device is tinned, i.e., coated with tin, at least in the connection area where the integral connection between the winding wire and the contacting device is arranged. This enables a particularly simple and reliable production of the integral connection, for example, by means of thermocompression welding or soldering.

[0016] Advantageously, the integral connection between the winding wire and the contacting device is arranged within the housing chamber, and the housing chamber is filled with a potting compound such that the integral connection between the winding wire and the contacting device is enclosed by the potting compound. The potting compound reliably protects the integral connection from environmental influences, in particular from moisture and mechanical impact. Furthermore, the potting compound also reliably fixes the wire winding and the pulse wire within the housing chamber and likewise protects them from environmental influences. This creates a particularly durable pulse wire module. The potting compound is preferably UV-curing to enable relatively fast and reliable curing of the potting compound.

[0017] Particularly preferably, the connecting element is folded over in such a way that it rests against a surface of the module housing. By folding over the connecting element, a relatively large connection surface is easily provided for establishing the material-to-material connection. Furthermore, the connecting element - and thus also the material-to-material connection to the winding wire arranged thereon - is arranged relatively close to the module housing as a result of the folding over and is thus relatively well protected from external mechanical influences. Preferably, the surface of the module housing against which the connecting element rests is formed within the housing chamber in such a way that the connecting element and the material-to-material connection to the winding wire arranged thereon are arranged within the housing chamber.

[0018] Advantageously, the pulse wire module comprises a further contacting device that is electrically connected to the wire winding, wherein the winding wire is connected to the further contacting device via a further material connection. Typically, the two contacting devices are arranged on opposite lateral sides of the wire winding and are each connected to one end of the winding wire, so that the voltage pulses generated in the wire winding can be easily tapped externally via the two separate contacting devices. Preferably, the two contacting devices are identical, so that the same component can be used for both contacting devices.

[0019] A method for producing the pulse wire module according to the invention comprises the following process steps: Inserting the wire winding into the module housing, guiding the winding wire to the contacting device, and establishing the material connection between the winding wire and the contacting device.

[0020] The wire winding is manufactured in a suitable winding machine, with a sufficiently long connecting section at each end of the wire winding to connect the wire winding to the contacting device. The wire winding is inserted into the module housing as a finished component.

[0021] Subsequently, the connecting section of the winding wire is guided to the contacting device, in particular to the connecting area of the contacting device.

[0022] Using a suitable method, such as a welding or soldering process, the integral connection between the winding wire and the contacting device is then established to permanently electrically connect the winding wire to the contacting device. Typically, a portion of the winding wire protruding on a side of the connecting area of the contacting device facing away from the wire winding is then severed. Preferably, after the integral connection has been established, the winding wire is secured to the contacting device exclusively via the integral connection.

[0023] Advantageously, the integral connection between the winding wire and the contacting device is created automatically by a suitably configured machine. This enables particularly cost-effective production of the pulse wire module.

[0024] Preferably, the integral connection between the winding wire and the contacting device is established by thermal welding, particularly preferably by thermocompression welding. Thermal welding machines are relatively inexpensive and allow the creation of relatively small-area welded joints. This enables cost-effective and reliable production of the pulse wire module.

[0025] Advantageously, after establishing the integral connection between the winding wire and the contacting device, the housing chamber of the module housing is filled with a potting compound such that the integral connection between the winding wire and the contacting device is enclosed by the potting compound. This creates a particularly durable pulse wire module.

[0026] Preferably, after filling the housing chamber, the potting compound is cured relatively quickly and reliably by irradiation with UV light.

[0027] An embodiment of a pulse wire module according to the invention is described below with reference to the attached figures, wherein Figure 1 shows a plan view of a bottom side of a pulse wire module according to the invention, and Figure 2 a sectional view of the pulse wire module from Figure 1 along the drawn line II-II, and Figure 3 a contacting device of the pulse wire module Figure 1 shows.

[0028] The figures show a pulse wire module 10 with a module housing 12 that defines a housing chamber 14. In the present embodiment, the module housing 12 is a substantially trough-shaped injection-molded plastic part, so that the housing chamber 14 is open on the underside of the module housing 12.

[0029] The pulse wire module 10 further comprises a wire winding 16 and a pulse wire 18, which extends in the axial direction through the wire winding 16. The pulse wire 18 is thus radially enclosed by the wire winding 16 in a central region. The wire winding 16 is formed by a winding wire 20 and is partially arranged within the housing chamber 14. In the present exemplary embodiment, the wire winding 16 is designed as an air coil and has an inner diameter that is slightly larger than an outer diameter of the pulse wire 16, such that the pulse wire 16 is positioned and supported in the radial direction by the wire winding 14. A ferritic element 21 is arranged at each of the two axial ends of the wire winding 14, into which an axial end of the pulse wire 18 is inserted.In the present embodiment, the two ferritic elements 21 are overmolded by the module housing 12, and the two ends of the pulse wire 18 are each attached to the respective ferritic element 21 via an adhesive connection 23. In the present embodiment, the adhesive connections 23 are made of a UV-curing and relatively soft material, specifically silicone.

[0030] In the present embodiment, the pulse wire module 10 comprises two identical, one-piece contacting devices 22 for external electrical contacting of the pulse wire module 10. In the present embodiment, the two contacting devices 22 are fully tinned, i.e., completely coated with tin. The two contacting devices 22 are arranged on opposite sides of the wire winding 16 and each comprise a base body 24, a connecting element 26, and, in the present embodiment, four contacting elements 28.In the present exemplary embodiment, the two contacting devices 22 are overmolded by the module housing 12 in such a way that the base bodies 24 of the two contacting devices 22 are each embedded in a side wall of the module housing 12 and the connecting elements 26 and the contacting elements 28 of the two contacting devices 22 each protrude from the underside of the module housing 12.

[0031] In the present exemplary embodiment, the connecting elements 26 of the two contacting devices 22 are each folded over in such a way that they rest against a surface 30 of the module housing 12, which is formed within the housing chamber 14, and that they are each arranged completely within the housing chamber 14. The connecting elements 26 are each electrically connected to one end of the winding wire 20 via a material-to-material connection 32, so that the two contacting devices 22 are each electrically connected to one side of the wire winding 16. The winding wire 20 is fastened to the respective contacting device 22 exclusively via the material-to-material connection 32. The material-to-material connections 32 are each arranged on a connecting region 34 of the connecting elements 26, which is formed by the surface 32 of the connecting element 26 facing away from the surface 30 of the module housing 12.

[0032] In the present embodiment, the housing chamber 14 is completely filled, i.e., up to a lower housing edge 36, with a potting compound 38, so that the connecting elements 26 and the integral connections 32 arranged on the connecting regions 34 of the connecting elements 26 are each enclosed by the potting compound 38. In the present embodiment, the potting compound 38 cures under UV light.

[0033] During the manufacture of the pulse wire module 10, the wire winding 14 is inserted as a finished component into the housing chamber 14 of the module housing 12 and the two ends of the winding wire 20 forming the wire winding 16 are each guided to the connecting region 34 of the connecting element 26 of the respective contacting device 22.

[0034] The material connections 32 between the two ends of the winding wire 20 and the respective contacting device 22 are produced - in the present embodiment fully automatically by means of thermocompression welding - in order to electrically connect the wire winding 20 to the two contacting devices 22.

[0035] After inserting the wire winding 16 into the module housing 14, the pulse wire 18 is inserted into the wire winding 16 and glued to the two ferritic elements 21.

[0036] The housing chamber 14 is completely filled with liquid potting compound 38, so that the connecting elements 26 and the material-locking connections 32 arranged thereon are enclosed by the potting compound 38. The potting compound 38 is cured in a controlled manner by irradiation with UV light. List of reference symbols

[0037] 10 Pulse wire module 12 Module housing 14 Housing chamber 16 Wire winding 18 Pulse wire 20 Winding wire 21 Ferritic elements 22 Contacting devices 23 Adhesive connections 24 Base body 26 Connecting elements 28 Contacting elements 30 Surface 32 Material connection 34 Connection area 36 Housing bottom edge 38 Potting compound

Claims

1. Impulse wire module (10), comprising - a module housing (12) which defines a housing chamber (14), - a wire winding (16) which is formed by a winding wire (20) and which is arranged at least partially within the housing chamber (14), - an impulse wire (18) which extends at least in part within the wire winding (16), and - a contacting device (22) for external electrical contacting of the impulse wire module (10), which is fastened to the module housing (12) and is electrically connected to the wire winding (16), wherein the winding wire (20) is connected to the contacting device (22) via a material bond (32), characterized in that the contacting device (22) comprises a main body (24) which is at least partially overmolded by the module housing (12), and wherein the contacting device (22) comprises a connecting element (26) which is formed integrally with the main body (24), which projects out of the module housing (12) and on which the material bond (32) is arranged.

2. Impulse wire module (10) according to claim 1, wherein the contacting device (22) is tinned at least in a connection area (34) at which the material bond (32) is arranged.

3. Impulse wire module (10) according to claim 1 or 2, wherein the material bond (32) is arranged within the housing chamber (14) and the housing chamber (14) is filled with a potting compound (38) such that the material bond (32) is surrounded by the potting compound (38).

4. Impulse wire module (10) according to one of the preceding claims, wherein the connecting element (26) is bent down in such a way that it is in contact with a surface (30) of the module housing (12).

5. Impulse wire module (10) according to one of the preceding claims, additionally comprising a further contacting device (22) which is electrically connected to the wire winding (16), wherein the winding wire (20) is connected to the further contacting device (22) via a further material bond (32).