Sensor arrangement for contactless linear position detection

Patent metadata

Field	Value
Publication number	US-10760927-B2
Application number	US-201815923714-A
Country	US
Kind code	B2
Filing date	Mar 16, 2018
Priority date	Mar 31, 2017
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

A sensor arrangement for contactless linear position detection includes a target having a measuring transducer running along a measuring path, and a magnetic field sensor arranged at a distance from the measuring transducer and in a relatively movable manner along the measuring path. The magnetic field sensor at least partially covers the measuring transducer. The measuring transducer is magnetically conductive. The magnetic field sensor includes a carrier having at least one measuring sensor with a two-dimensional or three-dimensional detection range, and at least one permanent magnet that generates a local magnetic field. The magnetic flux of the at least one permanent magnet is introduced into the measuring transducer, which includes an influencing device configured to influence the introduced magnetic flux based on a current position of the magnetic field sensor along the measuring path.

First claim

What is claimed is:

1. A sensor arrangement for contactless linear position detection, comprising:
a target including a measuring transducer running along a measuring path;
a magnetic field sensor arranged at a distance from the measuring transducer and arranged in a relatively movable manner along the measuring path, the magnetic field sensor configured to at least partially cover the measuring transducer,
wherein the measuring transducer is magnetically conductive,
wherein the magnetic field sensor includes a carrier having (i) at least one measuring sensor including a two-dimensional or three-dimensional detection range, and (ii) at least one permanent magnet configured to generate a local magnetic field,
wherein magnetic flux of the local magnetic field is introduced into the measuring transducer,
wherein the measuring transducer includes at least one air gap configured to influence the introduced magnetic flux based on a current position of the magnetic field sensor along the measuring path, and
wherein the at least one measuring sensor is configured to detect a current direction of the local magnetic field; and

an evaluation and control unit configured to evaluate the current direction of the local magnetic field in order to determine the current position of the magnetic field sensor based on the measuring path,
wherein the at least one air gap extends completely through the measuring transducer.

2. The sensor arrangement according to claim 1 , wherein the at least one measuring sensor includes a Hall sensor element, a GMR sensor element, or an AMR sensor element.

3. The sensor arrangement according to claim 1 , wherein the at least one permanent magnet is arranged below the at least one measuring sensor on a surface of the carrier facing away from the measuring transducer.

4. The sensor arrangement according to claim 1 , wherein the at least one permanent magnet includes two permanent magnets laterally integrated in the carrier beside the at least one measuring sensor and oriented in a direction of the measuring transducer.

5. The sensor arrangement according to claim 4 , further comprising:
a magnetic conductor arranged on a surface of the carrier facing away from the measuring transducer and configured to connect the two permanent magnets to one another and to cover the at least one air gap.

6. The sensor arrangement according to claim 1 , wherein the at least one permanent magnet is integrated in the carrier under the at least one measuring sensor.

7. The sensor arrangement according to claim 6 , wherein the at least one measuring sensor covers the at least one permanent magnet, and the sensor arrangement further comprises:
a magnetic conductor arranged on a surface of the carrier facing away from the measuring transducer and configured to cover the at least one measuring sensor and the at least one air gap.

8. The sensor arrangement according to claim 1 , wherein the at least one permanent magnet is integrated in the carrier upstream or downstream of the at least one measuring sensor in a direction of the measuring path and is configured to cover the at least one air gap.

9. The sensor arrangement according to claim 8 , further comprising:
a magnetic conductor arranged under the at least one permanent magnet on a surface of the carrier facing away from the measuring transducer and configured to cover the permanent magnet and the at least one air gap.

10. A sensor arrangement for contactless linear position detection, comprising:
a target including a measuring transducer running along a measuring path;
a magnetic field sensor arranged at a distance from the measuring transducer and arranged in a relatively movable manner along the measuring path, the magnetic field sensor configured to at least partially cover the measuring transducer,
wherein the measuring transducer is magnetically conductive,
wherein the magnetic field sensor includes a carrier having (i) at least one measuring sensor including a two-dimensional or three-dimensional detection range, and (ii) at least one permanent magnet configured to generate a local magnetic field,
wherein magnetic flux of the local magnetic field is introduced into the measuring transducer,
wherein the measuring transducer includes at least one air gap configured to influence the introduced magnetic flux based on a current position of the magnetic field sensor along the measuring path, and
wherein the at least one measuring sensor is configured to detect a current direction of the local magnetic field; and

an evaluation and control unit configured to evaluate the current direction of the local magnetic field in order to determine the current position of the magnetic field sensor based on the measuring path,
wherein the at least one air gap has a predefined width and length, and
wherein a longitudinal direction of the at least one air gap runs at a predefined angle with respect to the measuring path.

11. The sensor arrangement according to claim 10 , wherein the at least one measuring sensor below the at least one air gap is configured (i) to detect the current direction of the local magnetic field at a first edge of the at least one air gap in a starting position and at a second edge of the at least one air gap in an end position, (ii) for movement along the measuring path from the starting position to the end position over the predetermined width of the at least one air gap, and (iii) to detect the current direction of the local magnetic field over the predetermined width of the at least one air gap.

12. The sensor arrangement according to claim 10 , wherein the at least one measuring sensor includes a Hall sensor element, a GMR sensor element, or an AMR sensor element.

13. The sensor arrangement according to claim 10 , wherein the at least one permanent magnet includes two permanent magnets laterally integrated in the carrier beside the at least one measuring sensor and oriented in a direction of the measuring transducer.

14. The sensor arrangement according to claim 13 , further comprising:
a magnetic conductor arranged on a surface of the carrier facing away from the measuring transducer and configured to connect the two permanent magnets to one another and to cover the at least one air gap.

15. The sensor arrangement according to claim 10 , wherein the at least one permanent magnet is integrated in the carrier upstream or downstream of the at least one measuring sensor in a direction of the measuring path and is configured to cover the at least one air gap.

16. A sensor arrangement for contactless linear position detection, comprising:
a target including a measuring transducer running along a measuring path;
a magnetic field sensor arranged at a distance from the measuring transducer and arranged in a relatively movable manner along the measuring path, the magnetic field sensor configured to at least partially cover the measuring transducer,
wherein the measuring transducer is magnetically conductive,
wherein the magnetic field sensor includes a carrier having (i) at least one measuring sensor including a two-dimensional or three-dimensional detection range, and (ii) at least one permanent magnet configured to generate a local magnetic field,
wherein magnetic flux of the local magnetic field is introduced into the measuring transducer,
wherein the measuring transducer includes at least one air gap configured to influence the introduced magnetic flux based on a current position of the magnetic field sensor along the measuring path, and
wherein the at least one measuring sensor is configured to detect a current

Assignees

• Bosch Gmbh Robert

Inventors

• Buck Thomas
• Krause Anna
• Leidich Stefan

Classifications

• G01B7/02 Primary

  for measuring length, width or thickness (G01B7/004, G01B7/12 take precedence) · CPC title

• G01D5/147 Primary

  influenced by the movement of a third element, the position of Hall device and the source of magnetic field being fixed in respect to each other · CPC title

• G01R33/02

  Measuring direction or magnitude of magnetic fields or magnetic flux (G01R33/20 takes precedence) · CPC title

• G01D5/16

  by varying resistance · CPC title