Grinding Device Radial Adjustment for Uniform Chopping Knife Sharpening

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Solution Overview

Problem

Existing grinding devices for chopping knives in agricultural harvesting machines result in uneven material removal, leading to undesirable shapes and non-uniform cutting gaps between knives and counter-blades, affecting chopping quality and causing wear-related shape deviations.

Innovation Solution

A grinding device with a second actuator that allows variable radial adjustment of the grindstone along the entire axial extent of the chopping drum, coupled with a control device to maintain a constant preload force, ensuring uniform grinding and preventing shape deviations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional grinding device with fixed radial position is used, then the structure is simple, but uneven material removal occurs leading to undesirable shapes and non-uniform cutting gaps

Engineering Contradiction:
Improveuniformity of material removalVSAvoidgrinding device structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The grinding device employs a movable grinding carriage that can be radially adjusted along the chopping drum axis. The grinding wheel is mounted on a sliding carriage that moves parallel to the drum axis, allowing dynamic positioning of the grinding wheel at different radial distances from the drum surface. This dynamic adjustment enables uniform material removal across the entire axial length of the chopping knives, eliminating the formation of undesirable shapes and ensuring consistent cutting gaps.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The grinding device divides the grinding process into multiple radial positions along the axial direction. By segmenting the grinding contact points into different radial locations, the system can independently control material removal at each position, ensuring uniform grinding across the entire chopping knife length and preventing localized shape deviations.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the grinding wheel is positioned at a fixed radial distance, then the device operation is simple, but shape deviations occur due to wear and uneven grinding

Engineering Contradiction:
Improveconsistency of chopping qualityVSAvoidgrinding operation simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The grinding carriage is designed to move radially along the chopping drum axis, allowing the grinding wheel to be positioned at different radial distances. This dynamic positioning compensates for wear and maintains consistent contact pressure between the grinding wheel and chopping knives throughout the grinding process, ensuring reliable and uniform chopping quality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The device incorporates a control system that monitors the grinding process and adjusts the radial position of the grinding wheel accordingly. This feedback mechanism ensures that the grinding wheel maintains optimal contact with the chopping knives, compensating for wear and preventing shape deviations while maintaining consistent chopping quality.

Inventive Principle:
Principle #23Feedback

3Productivity

If material removal is not controlled uniformly, then the grinding process is faster, but undesirable shapes and contours are formed on the chopping blades

Engineering Contradiction:
Improvegrinding speedVSAvoidchopping blade geometry
Core Design Contradiction:
ProductivityVSShape

Solution Approach 1:

The movable grinding carriage allows the grinding wheel to be positioned at different radial distances along the axial direction. This dynamic positioning enables controlled and uniform material removal across the entire length of the chopping knives, maintaining the desired blade geometry while achieving efficient grinding through optimized contact pressure and wheel position.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The grinding device applies different grinding conditions at different radial positions along the chopping knife axis. By locally adjusting the grinding parameters (wheel position, contact pressure) at each radial location, the system achieves uniform material removal that preserves the desired chopping blade shape and contour.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution enables uniform cutting gaps and improved chopping quality by preventing uneven material removal and shape deviations, extending the service life of both knives and grinding stones.

Implementation Method 1

When sharpening the chopping blades of a chopping drum, material is removed not only from the blades themselves but also from the grinding wheel.

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP4427580A1Grinding device for cutter blades of a cutter, cutter and method for grinding the cutter blades of a cutter
Publication Date: 2024.09.11 CLAAS SAULGAU GMBH
  • EP4427580A1 patent drawingFigure 1~2
  • EP4427580A1 patent drawingFigure 3~4
  • EP4427580A1 patent drawing

AI summary

Grinding device (110) for chopping knives (13) of a chopping unit (12) of an agricultural harvesting machine, comprising a grinding slide (111) which, by means of a first actuator (112), is displaceable in the axial direction (A) of the chopping drum (11) carrying the chopping knives (13) along a housing-fixed guide (113) parallel to a rotational axis (19) of a chopping drum (11) of the chopping unit (12), which is rotatably mounted on a housing of the chopping unit (11), and comprising a grinding stone assembly (114) mounted on the grinding slide (111) comprising a grinding stone (115) and a grinding stone receptacle (116), wherein at least the grinding stone (115) is adjustable in the radial direction (R) of the chopping drum (11) against the chopping knives (13), wherein the grinding stone assembly (114) together with the same and together with the grinding slide (111) a second actuator (118) which can be displaced along the housing-fixed guide (113) is operatively connected,and wherein the relative position of at least the grinding stone (115) to the chopping knives (13) in the radial direction (R) of the chopping drum (11) is variably adjustable via the second actuator (118) at each axial position of the grinding stone assembly (114) along the chopping drum (11).