FLAT COIL CARRIER

Abstract

A flat coil carrier may include a carrier body. The carrier body may include, on an axial front side, a groove spiral configured to receive a coil wire. The groove spiral may have an axially open groove opening and may include a plurality of radially consecutive groove sections. The plurality of radially consecutive groove sections may each have an axially open groove section opening of a plurality of groove section openings. The plurality of radially consecutive groove sections may each be separated from one another by a common separating wall section of a plurality of separating wall sections of the carrier body. At least one of the plurality of separating wall sections may protrude from the carrier body and may have at least one undercut section including a radially protruding protrusion such that an undercut for the coil wire is formed in the at least one undercut section.

Claims

1. A flat coil carrier for a flat coil, comprising: a carrier body for receiving a spirally wound coil wire; the carrier body including, on an axial front side, a groove spiral configured to receive the coil wire, the groove spiral having an axially open groove opening and extending spirally on the carrier body transversely to an axial direction such that the groove spiral includes a plurality of radially consecutive groove sections; the plurality of radially consecutive groove sections each having an axially open groove section opening, of a plurality of groove section openings; wherein the plurality of radially consecutive groove sections are each separated from one another by a common separating wall section of a plurality of separating wall sections of the carrier body; and wherein at least one of the plurality of separating wall sections protrudes from the carrier body and has at least one undercut section including a radially protruding protrusion that radially reduces a corresponding groove section opening of the plurality of groove section openings such that an undercut for the coil wire is formed in the at least one undercut section.

2. The flat coil carrier according to claim 1, wherein the at least one undercut section includes at least two undercut sections spaced apart from one another along the groove spiral via a plurality of separating sections of the groove spiral, which are free from undercuts.

3. The flat coil carrier according to claim 1, wherein: the groove spiral has a rectangular basic layout having a plurality of consecutive longitudinal sides, which extend at least essentially tangentially; and the plurality of consecutive longitudinal sides transition into one another via a plurality of curved corner sections of the groove spiral.

4. The flat coil carrier according to claim 3, wherein: the groove spiral has a plurality of radially extending undercut segments, in which the plurality of separating wall sections each have a respective protrusion projecting radially therefrom and forming a respective undercut; and the groove spiral has a plurality of radially extending separating segments, which are free from undercuts and which separate consecutive undercut segments of the plurality of undercut segments from one another.

5. The flat coil carrier according to claim 4, wherein an extension of the respective protrusion along the groove spiral increases with increasing radial distance of the respective protrusion from a radial center of the groove spiral around which the groove spiral extends spirally.

6. The flat coil carrier according to claim 5, wherein the plurality of separating segments each include a plurality of radially consecutive separating sections.

7. The flat coil carrier according to claim 6, wherein an extension along the groove spiral of each of the plurality of radially consecutive separating sections is identical.

8. The flat coil carrier according to claim 3, wherein at least one of the plurality of consecutive longitudinal sides has a curved curvature section with a radius of curvature, which is ten times to one hundred and fifty times a radius of curvature of an adjacent curved corner section of the plurality of curved corner sections.

9. The flat coil carrier according to claim 1, wherein the carrier body is an injection molded component.

10. The flat coil carrier according to claim 1, wherein the protrusion protrudes radially to an outside.

11. A method for producing a flat coil carrier according to claim 1, comprising: providing an injection molding tool including an upper tool part and a lower tool part, which define a hollow space in a closed state of the injection molding tool, the upper tool part and the lower tool part configured to cooperate with one another without being engaged behind such that the injection molding tool is openable via separating the upper tool part from one another with a movement of the upper tool part and the lower tool part relative to one another in an axial direction; closing the injection molding tool and injecting a plastic into the hollow space to produce the flat coil carrier; and opening the injection molding tool and removing the produced flat coil carrier.

12. The method according to claim 11, wherein: the upper tool part has a first shoulder, which, in the closed state, protrudes toward the lower tool part; the lower tool part has a second shoulder, which, in the closed state, protrudes toward the upper tool part; the first shoulder has a first flat side and the second shoulder has a second flat side, the first flat side and the second flat side radially facing and abutting one another in the closed state; and the first shoulder is axially spaced apart from the lower tool part in the closed state such that the hollow space extends axially between the first shoulder and the lower tool part and extends radially to the second flat side of the second shoulder for producing a corresponding protrusion.

13. An injection molding tool for producing a flat coil carrier according to the method of claim 12.

14. A flat coil, comprising a flat coil carrier and a coil wire, the coil carrier including: a carrier body including a groove spiral; the groove spiral disposed on an axial front side of the carrier body and having an axially open groove opening; the groove spiral extending spirally on the carrier body such that a spiral separating wall protruding axially from the carrier body extends parallel to the groove spiral and separates radially adjacent portions of the groove spiral; wherein the spiral separating wall includes at least one protrusion projecting radially therefrom into the groove spiral such that an undercut configured to receive the coil wire is defined; and wherein the coil wire is received in the groove spiral.

15. The flat coil according to claim 14, wherein at least one longitudinal end of the coil wire is fixed to the flat coil carrier.

16. The flat coil according to claim 14, wherein the at least one protrusion includes a plurality of protrusions arranged along the spiral separating wall longitudinally spaced apart from one another such that the spiral separating wall includes a plurality of longitudinal undercut sections and a plurality of longitudinal separating sections disposed in an alternating manner.

17. The flat coil according to claim 16, wherein: the carrier body includes a plurality of undercut segments and a plurality separating segments extending radially from a radial center of the groove spiral and disposed about the radial center in an alternating manner; the plurality of undercut segments are each defined by a subset of the plurality of undercut sections that are disposed in radial alignment with one another; and the plurality of separating segments are each defined by a subset of the plurality of separating sections that are disposed in radial alignment with one another.

18. The flat coil according to claim 16, wherein: the plurality of protrusions extend along the groove spiral a respective longitudinal distance and are disposed a respective radial distance from a radial center of the groove spiral; and the respective radial distance and the respective longitudinal distance are positively correlated.

19. The flat coil according to claim 16, the plurality of separating sections extend along the groove spiral an identical length.

20. The flat coil according to claim 16, wherein the groove spiral has a rounded rectangular basic layout having a plurality of sides connected to one another by a plurality of rounded corners.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In each case schematically,

[0044] FIG. 1 shows a top view onto a flat coil,

[0045] FIG. 2 shows a section through a first area of the flat coil,

[0046] FIG. 3 shows a section through a second area of the flat coil,

[0047] FIG. 4 shows a top view onto the flat coil in the case of another exemplary embodiment,

[0048] FIG. 5 shows a section through an injection molding tool for producing a flat coil carrier of the flat coil.

DETAILED DESCRIPTION

[0049] A flat coil 1, as it is shown, for example, in FIGS. 1 to 4, has a coil wire 2, which runs in a spiral and flat manner, which is received in a carrier 3, hereinafter also referred to as flat coil carrier 3, of the flat coil 1. The flat coil carrier 3 has a carrier body 4, which is formed in a plate-shaped manner. The carrier body 4 extends essentially perpendicular to an axial direction 5 in one plane. To receive the coil wire 2, the carrier body 4 has, on an axial front side 6, a groove spiral 7, which runs spirally in accordance with the course of the coil wire 2. The groove spiral 7 thus extends transversely to the axial direction 5 on the carrier body 4. The groove spiral 7 thereby has an axially open groove opening 8. Due to the spiral course of the groove spiral 7, the groove spiral 7 has radially consecutive groove sections 9, wherein the respective groove section 9 has for forms, respectively, a part of the groove opening 8, wherein this part will also be referred to below as groove section opening 10. The radially consecutive groove sections 9 are in each case separated from one another by means of a common separating wall section 11, which protrudes from the carrier body 4. In an undercut section 12, at least one of the separating wall sections 11 thereby has a radially protruding protrusion 13, which radially reduces the corresponding groove section opening 10, so that an undercut 14 (see FIG. 2) for the coil wire 2 is formed by means of the protrusion 13 in the undercut section 12.

[0050] In the shown exemplary embodiments, the carrier body 4 has several undercut sections 12 of this type, each comprising a corresponding protrusion 13, which are consecutive along the groove spiral 7, wherein consecutive undercut sections 12 are separated from one another by means of separating sections 15, which are free from protrusions 13 and/or undercuts 14.

[0051] In the shown examples, the groove spiral 7 has a rectangular basic layout comprising consecutive, at least essentially tangentially running longitudinal sides 16, wherein consecutive longitudinal sides 16 transition into one another via corner areas 17, which run in a curved manner.

[0052] In the shown examples, the flat coil carrier 3 has radially consecutive undercut sections 12, which each form an undercut segment 18. The undercut segments 18 are separated from one another by means of separating segments 19, wherein the respective separating segment 19 has radially consecutive separating sections 15. With regard to a center 20 of the groove spiral 7, the extension of the undercut sections 12 and thus of the protrusions 13 along the groove spiral 7 thereby increases with increasing radial distance. This means that radially consecutive undercut sections 12 and protrusions 13 have an increasing extension with increasing radial distance to the center 20 along the groove spiral 7. In the shown example, however, an extension of the separating sections 15 is identical. The undercut segments 18 thus in each case extend over an angular area 21, which is defined by the flanks 22 of the respective undercut segment 18, which run through the center 20 and which are illustrated by means of dashes in the figures.

[0053] In the shown examples, the undercut sections 12 and the undercut segments 18 are arranged equidistantly to one another. The undercut sections 12 and the undercut segments 18 are thereby also arranged in the corner areas 17 of the groove spiral.

[0054] A radial section through the flat coil 1 through one of the undercut segments 18 is shown in FIG. 2, and a radial section through one of the separating segments 19 is shown in FIG. 3.

[0055] As shown by a comparison of FIGS. 2 and 3, a reduction of the groove section opening 10 in the area of the protrusion 13 and thus a reduction of the groove section opening 10 in the area of the undercut section 12, and a formation of the undercut 14 is realized by means of the respective protrusion 13, as described above. The coil wire 2 is fixed in a positive manner in the axial direction 5 in the respective undercut section 12 by means of the undercut 14, so that the coil wire 2 cannot be moved out of the coil carrier 4 in the axial direction 5, in particular cannot fall out of it. As can in particular be gathered from FIG. 2, the respective protrusion 13 is formed axially on the end side of the corresponding separating wall section 11. The protrusions 13 thereby extend radially in the same direction in such a way that the groove section opening 10 in the respective undercut section 12 is reduced by only one of the protrusions 13. As further shown by a comparison of FIGS. 2 and 3, a diameter 23 of the coil wire 2 is such that the coil wire 2 can axially also be inserted into the undercut sections 12, and such that the coil wire 2 is received in the respective undercut 14 in a positive manner as described.

[0056] In the case of the exemplary embodiment shown in FIG. 1, the longitudinal sides 16 of the groove spiral 7 run tangentially.

[0057] In the case of the exemplary embodiment shown in FIG. 4, the undercut sections 12, in particular the protrusions 13, as suggested for one of the undercut segments 18, have a curved course in the longitudinal sides 16 with a suggested radius of curvature 24, which corresponds to between ten times and one hundred and fifty times the radius of curvature of at least one of the next adjacent corner areas 17, preferably to one hundred times of both next adjacent corner areas 17. The longitudinal sides 16 thus run essentially tangentially. The radius of curvature 24 in particular increases from radially consecutive longitudinal sides 16.

[0058] In the case of the shown examples, the coil wire 2 is axially guided through the carrier body 4 on both longitudinal end sides 25. This means that the carrier body 4 has an axially running passage opening 26 for the respective longitudinal end side 25 of the coil wire 2. On the respective longitudinal end side 25, the carrier body 4 and the coil wire 2 thus form a non-positive connection 27 and/or a positive connection 28, which also fixes the coil wire 2 to the carrier boy 4 along the course of the coil wire 2.

[0059] As can be gathered from FIGS. 1 to 4, the protrusions 13 in each case protrude radially to the outside from the corresponding separating wall section 15. The protrusions 13 are thus directed away from the center 20 of the groove spiral 7, and in each case reduce the groove opening 8 on the side, which is radially close to the center 20. The respective undercut 14 is thus also arranged on the side of the corresponding undercut section 12, which is radially closer to the center 20. As can in particular be gathered from FIGS. 2 and 3, the flat coil carrier 2 is preferably of uniform material and monolithic.

[0060] The carrier body 4, in particular the flat coil carrier 3, is preferably an injection molded component 34, thus produced by means of an injection molding process, preferably of thermoplastic plastic 29.

[0061] As can in particular be gathered from FIG. 5, this takes place with the help of an injection molding tool 30, which has an upper tool part 31 and a lower tool part 32. FIG. 5 thereby shows a section through the injection molding tool 30 in an area, in which an undercut section 12 comprising a protrusion 13 or undercut 14, respectively, are formed in response to the production, wherein the carrier body 4 as well as the coil wire 2 are illustrated in FIG. 5 for a better understanding. FIG. 5 further shows a closed state 35 of the injection molding tool 30. In the closed state 35, the tool parts 31, 32 define a hollow space 36, into which the thermoplastic plastic 29 is injected to produce the flat coil carrier 3.

[0062] To produce the respective protrusion 13 comprising the corresponding separating wall section 11 and the corresponding undercut 14, the tool parts 31, 32 have corresponding shoulders 33, 37. The upper tool part 31 has a shoulder 33, which, in the closed state 35, protrudes axially in the direction of the lower tool part 32. The lower tool part 32 has a shoulder 37, which, in the closed state 35, protrudes axially in the direction of the upper tool part 31. The shoulders 33, 37 in each case have sides 38, which radially face one another in the closed state and which are formed to be flat and which will also be referred to as flat sides 38 hereinafter. In the closed state 35, the flat sides 38 abut against one another. To produce the separating wall section 11 comprising the protrusion 13, the shoulder 33 of the upper tool part 31 is axially spaced apart from the lower tool part 32. Due to the distance, the hollow space 36 extends axially between the shoulder 33 and the lower tool part 32, as well as radially to the flat side 38 of the shoulder 37 of the lower tool part 32, As illustrated in FIG. 5, the protrusion 13 is thus produced, without the tool parts 31, 32 engaging behind one another. The radial extension of the protrusion 13 is thereby defined in particular by the radial extension of the shoulder 33 of the upper tool part 31.

[0063] To form the groove spiral 7 in the area of the protrusion 13 comprising the undercut 14, the shoulders 33, 37 in each case have a cross section in the shape of a circular segment. In the case of the exemplary embodiment shown in FIG. 5, the cross section of the shoulder 33 of the upper tool part 31 is smaller than the cross section of the shoulder 37 of the lower tool part 32.