Coil system for an inductive proximity switch for flush or non-flush installation in a housing

Abstract

A coil system for an inductive proximity switch for flush or non-flush installation in a housing includes a coil board. At least one first receiver coil and one transmitter coil are arranged on the coil board, wherein the first receiver coil includes a coil designed in a polygonal form. A method for producing a coil system for an inductive proximity switch includes forming at least one first receiver coil on a coil board in a layered arrangement and forming a transmitter coil on the first receiver coil in a layered arrangement. The first receiver coil includes a coil with a polygonal form.

Claims

1. An inductive proximity switch comprising: a housing; and a coil system, wherein the coil system includes a coil board on which at least one first receiver coil and one transmitter coil are arranged; wherein the first receiver coil includes a coil with a polygonal form; wherein the coil system is arranged in the housing in a flush or non-flush manner; wherein the housing has a square housing cross-sectional area suitable for receiving the coil system; and wherein the first receiver coil is arranged such that it is rotated through 45 with respect to the square housing cross-sectional area.

2. The inductive proximity switch according to claim 1, wherein the polygonal form of the first receiver coil is designed such that its corner points are arranged at least partially in an edge region of the coil board.

3. The inductive proximity switch according to claim 1, wherein the first receiver coil has a convex polygonal form.

4. The inductive proximity switch according to claim 1, wherein the first receiver coil has a rhomboidal form.

5. The inductive proximity switch according to claim 1, wherein the first receiver coil has a square form.

6. The inductive proximity switch according to claim 1, wherein the first receiver coil has a regular convex polygonal form.

7. The inductive proximity switch according to claim 6, wherein the regular convex polygonal form has four side lengths and four internal angles, which are distributed symmetrically and uniformly with respect to one another.

8. The inductive proximity switch according to claim 1, wherein the transmitter coil has a circular form.

9. The inductive proximity switch according to claim 8, wherein the transmitter coil has a maximum diameter that can be formed on the coil board.

10. The inductive proximity switch according to claim 1, further comprising: at least one second receiver coil; wherein the first receiver coil and the second receiver coil are arranged one above another on the coil board, in a layered manner; wherein the first and the second receiver coil in the layered arrangement are each formed with three layers; wherein the transmitter coil is arranged between the first and the second receiver coil; and wherein the transmitter coil includes multiple layers.

11. The inductive proximity switch according to claim 10, wherein a number of the multiple layers is in a range of two to five.

12. The inductive proximity switch according to claim 10, wherein the first receiver coil and the second receiver coil have opposite winding directions.

13. The inductive proximity switch according to claim 1, wherein a coil stack of the coil board has eight to sixteen layers, optionally eight to fourteen layers, further optionally fourteen layers.

14. The inductive proximity switch according to claim 1, wherein the housing is made at least partially from metal.

15. The inductive proximity switch according to claim 14, wherein, in an installed state, the coil system is at least partially surrounded by metal in a circumferential direction.

16. A method for producing a coil system for an inductive proximity switch, comprising: producing a coil system by: forming at least one first receiver coil on a coil board in a layered arrangement; and forming a transmitter coil on the first receiver coil in a layered arrangement; wherein the first receiver coil includes a coil with a polygonal form; and arranging the coil system in a housing in a flush or non-flush manner; wherein the housing has a square housing cross-sectional area suitable for receiving the coil system; and wherein the first receiver coil is arranged such that it is rotated through 45 with respect to the square housing cross-sectional area.

17. The method according to claim 16, wherein the transmitter coil comprises a coil having a circular form.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further details and advantages of the disclosure shall now be explained in more detail with reference to the exemplary embodiments illustrated in the drawings, in which:

(2) FIG. 1A to 1D show schematic illustrations of individual layers of a coil system according to the disclosure in an inductive proximity switch;

(3) FIG. 2 shows a schematic illustration of a layer in a further inductive proximity switch; and

(4) FIG. 3 shows a flow chart of a method according to the disclosure.

DESCRIPTION

(5) The drawings and the following explanation or description thereof is not intended to limit the disclosure.

(6) The accompanying drawings are intended to provide a greater understanding of the development of the disclosure. They show developments and, in conjunction with the description, serve to explain principles and concepts of the disclosure. Other developments and many of the said advantages are revealed with respect to the drawings. The elements of the drawing are not necessarily drawn to scale with one another.

(7) In the FIGS., similar, functionally similar and similarly acting elements, features and components are each denoted by the same reference symbols-unless stated otherwise.

(8) A first example of the inductive proximity switch 1 is explained with reference to FIG. 1A to 1D. Individual layers of a coil stack are shown merely by way of example and schematically.

(9) The inductive proximity switch 1 is provided for flush or non-flush installation in a housing 6. The housing 6 here may be metallic or it may comprise a metallic material.

(10) In the case of a flush or non-flush installation of the inductive proximity switch (sensor), the maximum sensing distances achieved may differ. In the example, the maximum sensing distance of a non-flush inductive proximity switch corresponds approximately to the coil diameter or housing diameter. The maximum sensing distance of a flush inductive proximity switch corresponds approximately to half the coil/housing diameter.

(11) On the one hand, a special characteristic of the coil design of the proximity switch 1 is that it can be adjusted to match the greater sensing distance for the inductive proximity switch installed in a non-flush manner, with the feature that the sensor assembly may be used in or on a metal surrounding area where otherwise only flush proximity switches may be used and the proximity switch continues to function with its guaranteed properties.

(12) If the proximity switch 1 is inserted into a metallic sensor housing, for example for flush cylindrical sensor variants, then this sensor assembly can be adjusted to the required sensing distance without additional work or measures.

(13) The inductive proximity switch 1, which is shown schematically in a plan view of a cross section of the housing 6, comprises a coil board 2.

(14) The coil board 2 is designed to receive at least one first receiver coil 3.

(15) The first receiver coil 3 in the example has a square form, wherein it is arranged such that it is rotated through 45 with respect to the likewise square housing cross section. It has a maximum coil diameter at the four corner points, which means that the corner points extend up to the edge of a printable region of the coil board 2. It furthermore forms a greater distance from the surrounding housing 6 at the four side lengths of the square, so that an influence on the detected measurement signal by the surrounding housing 6 (in the case of flush installation) is minimized.

(16) The receiver coil 3 may be printed onto the coil board 2.

(17) The first receiver coil 3 may have a square form or the form of a rhomboid or it may, optionally, have a convex polygonal form. The first receiver coil 3 comprises a coil designed in a polygonal form, optionally with four side lengths and internal angles, which are distributed optionally symmetrically and uniformly with respect to one another.

(18) A polygonal form here may also be understood in general to mean that the form has corners at which the coil is arranged near to the surrounding housing 6, and edges at which a greater distance from the housing 6 is obtained so that the housing 6 has less influence on the measurement signal there.

(19) In the example, a second receiver coil 4 is furthermore provided, which is formed substantially analogously to the first receiver coil 3.

(20) Furthermore, the coil system of the inductive proximity switch 1 comprises a transmitter coil 5 which, in the example, is arranged between the first 3 and second receiver coil 4.

(21) The transmitter coil 5 comprises a coil having, optionally, a circular form.

(22) Moreover, the transmitter coil 5 has the maximum diameter that can be formed on the coil board 2, which means that it has the greatest diameter possible within the printable region of the coil board 2.

(23) In the example, provision is furthermore made for a coil layer 7 to be provided with a grid 7, which shields the coil stack against electromagnetic interference in one direction or which shields the field generated by the transmitter coil in one direction.

(24) The coil forms and examples shown in FIG. 1A to 1D are merely examples, and do not represent a restrictive configuration of the coil system of the inductive proximity switch 1.

(25) Optionally, provision is made for the grid 7, the first receiver coil 3, the transmitter coil 5 and the second receiver coil 4 to be arranged on the coil board 2 in a stacked manner.

(26) In the example, the first receiver coil 3 and the second receiver coil 4 are arranged in a layered arrangement.

(27) The receiver coils 3, 4 may each be formed with 3 layers, for example.

(28) The first receiver coil 3 and/or the second receiver coil 4 may have a square form or the form of a rhomboid; however, other forms of at least one of the receiver coils 3, 4 may also be provided.

(29) The transmitter coil 5 may be arranged between the first receiver coil 3 and the second receiver coil 4.

(30) The transmitter coil 5 may be formed with a range of 3 to 5 layers.

(31) In the example, the coil board 2 in the embodiment of the inductive proximity switch 1 with a first and a second receiver coil 3, 4 may have 14 layers.

(32) The first receiver coil 3 and the second receiver coil 4 have, optionally, opposite winding directions.

(33) In the example, the inductive proximity switch 1 has a housing 6.

(34) In the example shown in FIG. 1A to 1D, the housing 6 has a square housing cross-sectional area. In the square housing cross-sectional area, the first and the second receiver coil 3, 4 may be provided in a square form, circular form or rhomboidal form.

(35) In an alternative configuration of the inductive proximity switch 1, shown in FIG. 2, the housing 6 has a circular cross section. The coil board 2 also has a circular design here. By way of example, only one layer of a first receiver coil 3, which is designed in a square form, is shown here.

(36) The corners lie at the edge of a printable region of the coil board 2, while the sides of the square are at a greater distance from the housing 6.

(37) In this example, a first receiver coil 3 and second receiver coil 4 are formed analogously to the case shown in FIG. 2. A transmitter coil 5 is arranged between the first receiver coil 3 and second receiver coil 4.

(38) In this example, the proximity switch 1 is otherwise formed analogously to the example explained above.

(39) In further examples, the housing 6 may have an elongated, oval or rectangular design. Optionally, in such alternative configurations, a rhomboidal form of the first receiver coil 3 and second receiver coil 4 is advantageous.

(40) FIG. 3 shows a flow chart of a method according to the disclosure. The above-described exemplary embodiments of the coil system or the inductive proximity sensor are taken as the starting point.

(41) In FIG. 3, the reference symbol V denotes an embodiment of the method.

(42) The method V for producing a coil system for an inductive proximity switch 1 has a plurality of method steps.

(43) In a first method step S1, at least one first receiver coil 3 is formed on a coil board 2 of the inductive proximity switch 1 in a layered arrangement, optionally by printing the traces of the coils.

(44) In a further method step S2, a transmitter coil 5 is formed on the first receiver coil 3 in a layered design. The transmitter coil 5 comprises a coil which has, optionally, a circular form.

(45) The first receiver coil 3 comprises a coil designed in a polygonal form, optionally with four side lengths and internal angles, which are distributed optionally symmetrically and uniformly with respect to one another.

(46) Furthermore, a further method step S3 is provided, in which a second receiver coil 4, which is designed analogously to the first receiver coil 3, is formed on the transmitter coil 5 in a layered design.

(47) In the example, the first receiver coil 3, the second receiver coil 4 and the transmitter coil 5 are stacked one above another.

(48) Moreover, further layers for a shield grid, connecting traces and a layer with connection pads for an electronic board are provided.

(49) With the arrangement of the coils, both non-flush and flush proximity switches with the necessary and customary standard sensing distances may be realized.

REFERENCE SYMBOLS

(50) 1 Inductive proximity switch 2 Coil board 3 First receiver coil 4 Second receiver coil 5 Transmitter coil 6 Housing 7 Grid V Method S1, S2, S3 Method steps