Method for determining the sharpness of cutting edges of chopper blades

Patent metadata

Field	Value
Publication number	US-9801342-B2
Application number	US-201213465377-A
Country	US
Kind code	B2
Filing date	May 7, 2012
Priority date	May 21, 2011
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A method for determining the sharpness of cutting edges ( 16 ) of chopper blades ( 1 ) at a rotationally driven chopper drum ( 14 ) of a forage harvester includes scanning a blade surface of at least one of the chopper blades located behind the cutting edge by at least one electrode operating as a contact sensor and determining a duration of contact of the at least one electrode with the blade surface.

First claim

What is claimed is:

1. A method for determining a sharpness of cutting edges ( 16 ) of chopper blades ( 1 ) at a rotationally driven chopper drum ( 14 ) of a forage harvester, comprising a shear bar ( 19 ) and a sharpening device ( 15 ) having a sharpening stone ( 2 ) for resharpening the chopper blades ( 1 ), comprising steps of:
scanning a blade surface ( 5 ) of at least one of the chopper blades ( 1 ) located behind a cutting edge ( 16 ) thereof by at least one electrode ( 3 ) disposed at the sharpening stone ( 2 ) of the sharpening device ( 15 ) and having direct contact with the blade surface ( 5 ), and
using a measurement system ( 24 ), determining a duration of contact of the at least one electrode ( 3 ) with the blade surface ( 5 ).

2. The method according to claim 1 , wherein the at least one electrode ( 3 ) is moved in and axial direction of the chopper drum ( 14 ).

3. The method according to claim 1 , further comprising closing an electric circuit, formed by connecting the at least one electrode ( 3 ) and the chopper blades ( 1 ) to an electric current source ( 7 ), for the duration of contact of the at least one electrode ( 3 ) with the blade surface.

4. The method according to claim 3 , further comprising determining, using the measurement system, a duration of electric current flow resulting from the closing of the electric circuit and feeding the duration to an evaluation unit ( 34 ) as an input signal.

5. The method according to claim 4 , wherein measurement values for the electric current flow and/or the duration of the electric current flow are fed, as input signals, to a μ-controller ( 26 ) as part of the evaluation unit ( 34 ), and corresponding output signals from the μ-controller ( 26 ) provide a driver of the forage harvester with information on a sharpness state of the cutting edge ( 16 ) of the chopper blades ( 1 ).

6. The method according to any one of the claim 4 , wherein measurement values of the electric current flow and the duration of the electric current flow are registered by the measurement system ( 24 ) and are fed to a μ-controller ( 26 ) as input signals, and corresponding output signals from the μ-controller ( 26 ) are used to control the sharpening device ( 15 ).

7. The method according to claim 1 , wherein the at least one electrode ( 3 ) is energized by a current flow, wherein a magnitude and a duration of the current flow has a correlation to the sharpness of the cutting edge ( 16 ), and wherein the correlation is provided to a driver as information.

8. A device for determining a sharpness of cutting edges ( 16 ) of chopper blades ( 1 ) at a rotationally driven chopper drum ( 14 ) of a forage harvester, comprising a shear bar ( 19 ) and a sharpening device ( 15 ) having at least one sharpening stone ( 2 ) for resharpening the chopper blades ( 1 ), comprising:
at least one electrode ( 3 ) configured as a contour sensor ( 27 ) for scanning a blade surface ( 5 ) of at least one of the chopper blades ( 1 ) located behind a cutting edge ( 16 ), the at least one electrode ( 3 ) disposed at the at least one sharpening stone ( 2 ) of the sharpening device ( 15 ) and having direct contact with the blade surface ( 5 ); and
a measurement system ( 24 ) for detecting a cutting edge sharpness of chopper blades ( 1 );
wherein the measurement system ( 24 ) determines a duration of contact between the chopper blade ( 1 ) and the at least one electrode ( 3 ).

9. The device according to claim 8 , wherein the at least one electrode ( 3 ) is adjustable in a radial direction.

10. The device according to claim 8 , wherein the measurement system ( 24 ) comprises an electric current source ( 7 ), the at least one electrode ( 3 ), the chopper blade ( 1 ) and a measurement device ( 8 ).

11. The device according to claim 10 , wherein the measurement system ( 24 ) determines the duration of contact as a function of a current flow in the electric current source ( 7 ).

12. The device according to claim 10 , wherein the measurement system ( 24 ) comprises an evaluation unit ( 34 ) having a μ-controller ( 26 ), wherein input signals from the measurement system are provided to the μ-controller ( 26 ) and are used to generate information for a driver regarding the cutting edge sharpness of the chopper blades ( 1 ).

13. The device according to claim 8 , wherein the contour sensor ( 27 ) further comprises at least one of a leading electrode ( 28 ) or a trailing electrode ( 29 ).

14. The device according to claim 8 , wherein the contour sensor ( 27 ) further comprises a leading electrode ( 28 ) and a trailing electrode ( 29 ).

Assignees

• Loebe Stefan
• Schulze Klaus
• Rauch Hans
• Claas Saulgau Gmbh

Inventors

• Loebe Stefan
• Schulze Klaus
• Rauch Hans

Classifications

• A01D43/085 Primary

  Control or measuring arrangements specially adapted therefor · CPC title

• B24B3/55

  of knife bars for harvesting machines · CPC title

• B24B3/368

  installed as an accessory on another machine (B26D7/12 takes precedence) · CPC title

• A01F29/22

  Arrangement of knife sharpening devices · CPC title

• B24B3/363

  of blades mounted on a turning drum · CPC title