Detection arrangement for detecting a state of wear of a chopping assembly

Patent metadata

Field	Value
Publication number	US-10568271-B2
Application number	US-201815896485-A
Country	US
Kind code	B2
Filing date	Feb 14, 2018
Priority date	Feb 21, 2017
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

A detection arrangement for detecting a state of wear of a chopping assembly comprises at least one magnet arrangement which includes a magnetic excitation arrangement and a flux-conducting device magnetically coupled thereto. The magnet arrangement provides a pole arrangement which forms at least one magnetic pole for outwardly conducting magnetic flux. At least one portion of the chopping blades moves past the pole arrangement during a rotation of the cutting cylinder, and forms an air gap arrangement including at least one air gap with respect to the pole arrangement and, as a result, at least one magnetic circuit excited by the excitation arrangement is closed via the chopping blade. At least one portion of the magnetic flux generated by the magnetic excitation arrangement is longitudinally guided in the chopping blade at least across one longitudinal portion of the chopping blade.

First claim

What is claimed is:

1. A detection arrangement for detecting a state of wear of a chopping assembly of a forage harvester intended for processing a crop stream, wherein the chopping assembly comprises a cutting cylinder including elongate chopping blades situated thereon, and at least one shear bar which interacts with the chopping blades, the detection arrangement comprising:
at least one magnet arrangement which includes a magnetic excitation arrangement and a flux-conducting device magnetically coupled thereto, said magnet arrangement providing a pole arrangement which forms at least one magnetic pole including a pole surface for outwardly conducting magnetic flux, wherein the magnet arrangement is configured so that at least one portion of the chopping blades moves past the pole arrangement during a rotation of the cutting cylinder, a particular one of the chopping blades moving past the pole arrangement forms an air gap arrangement including at least one air gap with respect to the pole arrangement and, as a result, at least one magnetic circuit excited by the excitation arrangement is closed via the particular chopping blade,
a measuring arrangement configured to detect, with respect to at least one magnetic measured variable, the magnetic flux in the at least one magnetic circuit excited by the excitation arrangement, and
an evaluation unit configured to determine the state of wear of the particular chopping blade on the basis of the at least one detected magnetic measured variable,
wherein at least one portion of the magnetic flux generated by the magnetic excitation arrangement is longitudinally guided in the particular chopping blade at least across one longitudinal portion of the particular chopping blade moving past the pole arrangement.

2. The detection arrangement as claimed in claim 1 , wherein the pole arrangement forms at least two magnetic poles which are mutually spaced along the particular chopping blade moving past the pole arrangement, each magnetic pole forming one of the air gaps of the air gap arrangement together with the particular chopping blade and the magnetic flux generated by the magnetic excitation arrangement being longitudinally guided in the particular chopping blade between the magnetic poles, wherein the evaluation unit is configured to determine the state of wear of the chopping in the longitudinal portion between the two poles.

3. The detection arrangement as claimed in claim 1 , wherein the evaluation unit is configured to determine the state of wear in different longitudinal portions of the particular chopping blade, wherein the different longitudinal portions are each situated between different poles of the pole arrangement.

4. The detection arrangement as claimed in claim 1 , wherein the pole arrangement forms at least three magnetic poles which are mutually spaced along the particular chopping blade moving past the pole arrangement, each magnetic pole forming one of the air gaps of the air gap arrangement together with the particular chopping blade moving past the pole arrangement, wherein the at least one magnetic circuit excited by the magnetic excitation arrangement comprises two magnetic circuits, and wherein at least one of the poles is a component of the two magnetic circuits excited by the magnetic excitation arrangement.

5. The detection arrangement as claimed in claim 1 , wherein the pole arrangement forms at least five magnetic poles which are mutually spaced along the particular chopping blade moving past the pole arrangement, each one of the magnetic poles forming one of the air gaps of the air gap arrangement together with the particular chopping blade moving past the pole arrangement, wherein the at least one magnetic circuit excited by the magnetic excitation arrangement comprises two magnetic circuits, and wherein at least one of the poles is a component of the at least two magnetic circuits excited by the magnetic excitation arrangement.

6. The detection arrangement as claimed in claim 1 , wherein at least one of the poles of the pole arrangement is situated along the cutting edge of the particular chopping blade moving past the pole arrangement or along the shear bar, or at least one portion of the poles of the pole arrangement is passed simultaneously by the chopping blades.

7. The detection arrangement as claimed in claim 1 , wherein the flux-conducting device comprises a central portion, from which the poles of the pole arrangement branch off, wherein the central portion of the flux-conducting device is designed to be straight or extends along the cutting edge of the particular chopping blade moving past the pole arrangement, or extends along the shear bar.

8. The detection arrangement as claimed in claim 1 , wherein the magnet arrangement together with the measuring arrangement is designed as an assembly which is separate from the shear bar.

9. The detection arrangement as claimed in claim 1 , wherein the magnet arrangement together with the measuring arrangement is mechanically coupled and mechanically connected to the shear bar and wherein the magnet arrangement together with the measuring arrangement is situated above the shear bar or under the shear bar.

10. The detection arrangement as claimed in claim 1 , wherein the at least one magnetic circuit excited by the magnetic excitation arrangement comprises at least two magnetic circuits, and wherein the measuring arrangement comprises at least one measuring unit for detecting the at least one magnetic flux-based measured variable, such that one measuring unit of the at least one measuring unit is assigned to each of the at least two magnetic circuits excited by the magnetic excitation arrangement.

11. The detection arrangement as claimed in claim 10 , wherein the at least one measuring unit comprises a coil arrangement, through which the magnetic flux in the flux-conducting device flows, and wherein the at least one measuring unit detects, as the measured variable, voltage induced in the coil arrangement.

12. The detection arrangement as claimed in claim 10 , wherein the at least one measuring unit is designed as a magnetic field sensor and wherein the at least one measuring unit detects, as the measured variable, a value for the magnetic flux density in one of the magnetic circuits excited by the magnetic excitation arrangement.

13. The detection arrangement as claimed in claim 1 , wherein the evaluation unit is configured to determine the state of wear of the particular chopping blade on the basis of a peak value of the at least one measured variable or on the basis of a progression of the at least one measured variable, during a rotation of the cutting cylinder.

14. A chopping assembly of a forage harvester intended for processing a crop stream, comprising:
a cutting cylinder including elongate chopping blades situated thereon,
at least one shear bar which interacts with the chopping blades, and
a detection arrangement according to claim 1 for detecting a state of wear of the chopping assembly.

15. A forage harvester for processing a crop stream, comprising:
a compression unit which includes at least two compression rollers forming a bale chamber, and
a chopping assembly as claimed in claim 14 .

Assignees

• Claas Selbsfahrende Erntemaschinen Gmbh
• Claas Selbstfahrende Erntemaschinen Gmbh

Inventors

• Neitemeier Dennis
• Huster Jochen
• Kettelhoit Boris
• Fischer Frederic
• Grove Carsten

Classifications

• A01F15/08

  Details · CPC title

• A01F29/095 Primary

  Mounting or adjusting of knives · CPC title

• A01F29/22 Primary

  Arrangement of knife sharpening devices · CPC title

• G01B7/293

  for measuring radius of curvature · CPC title

• G01B7/14

  for measuring distance or clearance between spaced objects or spaced apertures (G01B7/30 takes precedence) · CPC title