Search

DE-102025003333-A1 - SCALE ELEMENT FOR AN INDUCTIVE ANGLE MEASURING DEVICE

DE102025003333A1DE 102025003333 A1DE102025003333 A1DE 102025003333A1DE-102025003333-A1

Abstract

The invention relates to a scale element (2) comprising a substrate (2.1) on which a division track (2.2) is arranged. The division track (2.2) is formed along a circumferential direction (x) from a periodic sequence of alternatingly arranged electrically conductive division areas (2.21) and non-conductive division areas (2.22), wherein the electrically conductive division areas (2.21) are each formed from a layer of electrically conductive material. At least one bore (2.11) is arranged in the substrate (2.1). The electrically conductive division areas (2.21) each have an opening (2.211), wherein the electrically conductive material surrounds the opening (2.211). The bore (2.11) extends through the opening (2.211) in at least one of the electrically conductive division areas (2.21) in the substrate (2.1). Furthermore, two electrically conductive partition areas (2.21) adjacent in the circumferential direction (x) are designed such that the angular distances (α, β, γ) between their conductive layers are of different sizes along the radial direction.

Inventors

  • Martin Heumann
  • Christoph Heinemann

Assignees

  • DR. JOHANNES HEIDENHAIN GMBH

Dates

Publication Date
20260513
Application Date
20250926
Priority Date
20241111

Claims (11)

  1. Scale element (2) for an inductive angle measuring device, comprising a substrate (2.1) on which a graduation track (2.2) is arranged, wherein the graduation track (2.2) is formed along the circumferential direction (x) from a periodic sequence of alternately arranged electrically conductive graduation areas (2.21) and non-conductive graduation areas (2.22), wherein the electrically conductive graduation areas (2.21) are each formed from a layer of electrically conductive material extending along the circumferential direction (x) and the radial direction, wherein at least one bore (2.11) is arranged in the substrate (2.1) for fastening the scale element (2) to a machine part, wherein at least one electrically conductive graduation area (2.21) has an opening (2.211), wherein the electrically conductive material surrounds the opening (2.211), wherein in the at least one electrically conductive graduation area (2.21) through the opening (2.211) the at least one bore (2.11) is arranged in the substrate (2.1), characterized in that two electrically conductive partition areas (2.21) adjacent in the circumferential direction (x) are designed such that angular distances (α, β, γ) between their conductive layers are of different sizes along the radial direction.
  2. scale element (2) according to the Claim 1 , wherein a further bore (2.11) is arranged in the substrate (2.1) in a non-conductive division area (2.22).
  3. Scale element (2) according to one of the preceding claims, wherein the division track (2.2) has n electrically conductive division areas (2.21) and m bores (2.11) are arranged in the substrate (2.1), wherein: n ≠ m.
  4. Scale element (2) according to one of the preceding claims, wherein n < m.
  5. Scale element (2) according to one of the preceding claims, wherein n is an odd number and m is an even number.
  6. Scale element (2) according to one of the preceding claims, wherein a first distance (α) and a second distance (β) are larger than a third distance (γ) lying radially between the first and the second distance (α, β).
  7. Scale element (2) according to one of the preceding claims, wherein at least one electrically conductive division area (2.21) is bounded in the circumferential direction (x) with a convex contour.
  8. Scale element (2) according to one of the preceding claims, wherein at least one electrically conductive division area (2.21) is bounded in the circumferential direction (x) with a round contour.
  9. Scale element (2) according to one of the preceding claims, wherein the graduation track (2.2) has n electrically conductive graduation areas (2.21) and the scale element (2) comprises p fastening elements (2.4) arranged in the bores (2.11), wherein n ≠ p.
  10. scale element (2) according to the Claim 9 , where n < p.
  11. scale element (2) according to the Claims 9 or 10 , where n is an odd number and p is an even number.

Description

AREA OF TECHNOLOGY The invention relates to a scale element for an inductive angle measuring device according to claim 1 for determining an angular position of the scale element relative to a scanning element. Inductive angle measuring devices are used, for example, to determine the angular position of machine parts that can rotate relative to each other. In inductive angle measuring devices, excitation tracks and receiver tracks, often in the form of conductive traces, are typically mounted on a common, usually multilayer, printed circuit board (PCB) that is rigidly connected to, for example, a stator of the angle measuring device. Opposite this PCB is a scale element with graduations, which is rigidly connected to a moving part of the angle measuring device. When a time-varying electrical excitation current is applied to the excitation tracks, position-dependent signals are generated in the receiver tracks during the relative movement between the scale element and the sensing element. These signals are then processed by evaluation electronics. STATE OF THE ART From the EP 4 421 454 A1 The applicant is aware of a scale element for an inductive angle measuring device. The scale element described therein comprises two graduation tracks, each consisting of a periodic sequence of alternating electrically conductive and non-conductive graduation areas. The scale element is fastened by means of screws in mounting holes, all of which are arranged within electrically conductive graduation structures. SUMMARY OF THE INVENTION The invention is based on the objective of creating a compact and cost-effectively manufactured scale element that offers flexible mounting options and is nevertheless usable for a comparatively accurate inductive angle measuring device. This problem is solved according to the invention by the features of claim 1. The scale element, which is suitable and intended for an inductive angle measuring device, comprises a substrate on which a graduation track is arranged. The graduation track is formed along a measuring direction by a periodic sequence of alternating electrically conductive graduation areas and comparatively non-conductive graduation areas, wherein the electrically conductive graduation areas are each formed from a layer of electrically conductive material. The layer or surface of electrically conductive material extends both circumferentially and radially. Furthermore, at least one bore is provided in the substrate, suitable for attaching the scale element to a machine part. At least one electrically conductive graduation area has an opening, the opening being enclosed by the electrically conductive material. In addition, at least one bore in the substrate extends through the opening in at least one of the electrically conductive graduation areas. Two circumferentially adjacent electrically conductive partition areas are designed such that, along the radial direction, the angular distances in the circumferential direction between the conductive layers of the electrically conductive partition areas are of different sizes. Accordingly, adjacent electrically conductive divisions at different distances from the axis exhibit different angular distances (in the circumferential direction). In other words, if one measures a first distance radially inward between two circumferentially opposite points on the respective contour of an electrically conductive division, a second distance at a radially offset point will be different from the first. Opposite points lie, in particular, on the same virtual circle whose center lies on the axis. The contours of the respective electrically conductive divisions or electrically conductive layers therefore do not run straight in the radial direction over their entire radial extent. Angular distances between two circumferentially adjacent electrically conductive divisions refer to a respective central angle around the axis and are given here in degrees. In particular, a first distance exists between two circumferentially adjacent electrically conductive division areas, and a second distance exists radially offset from this. The first and second distances can be larger than a third distance located radially between the first and second distances. The electrically conductive partition areas are therefore formed from a layer of electrically conductive material. The comparatively non-conductive partition areas can be made of plastic (e.g., from printed circuit board material). The scale element can preferably have a printed circuit board material made of plastic as a substrate. Alternatively, the substrate can be formed from a layered body comprising a relatively thick steel layer and a non-conductive layer (e.g., a plastic layer), with the steel layer being arranged on the side of the scale element facing away from the division areas. The aforementioned term "comparatively non-conductive" thus refers to the ratio of the electrical conductivities of the materia