Shearbar Vibration Detection for Cutting Tool Alignment

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Solution Overview

Problem

Current methods for detecting the distance between the shearbar and cutting tool in agricultural harvesting machines are inaccurate due to subjective operator assessment and inability to detect non-parallel alignment, leading to inefficient and potentially damaging chopping processes.

Innovation Solution

The use of at least two spaced-apart sensors to detect vibrations caused by contact between the cutting tool and shearbar, with a signal analysis device determining the state of the cutting device by comparing signals and calculating sound propagation time differences to localize the point of contact and adjust the shearbar alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single knock sensor is used to detect contact between cutting tool and shearbar, then contact detection is achieved, but accurate localization of contact point and detection of non-parallel alignment is not possible

Engineering Contradiction:
Improvecontact detection accuracyVSAvoidcontact location information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The single sensor is divided into multiple sensors (at least two spaced-apart sensors) distributed along the shearbar. Each sensor independently detects vibrations, enabling the system to not only detect contact but also determine which specific area of the shearbar is experiencing contact, thus localizing the contact point and detecting non-parallel alignment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution transitions from a single-point detection (one sensor) to a distributed detection system (multiple sensors along the length of the shearbar). This spatial distribution adds a dimensional aspect to the detection, allowing the system to determine not just whether contact occurs, but where along the shearbar the contact is occurring, enabling alignment assessment.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If operator assessment of contact noises is used, then simple detection is achieved, but assessment is subjective and inaccurate

Engineering Contradiction:
Improvedetection simplicityVSAvoidalignment detection accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The manual, subjective assessment by the operator is replaced with automated electronic sensors and signal processing. The sensors objectively detect vibrations and the evaluation unit automatically analyzes the signals to determine contact conditions and alignment, eliminating human subjectivity while maintaining operational simplicity through automated control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If shearbar is moved close to rotating cutting tool until contact occurs, then distance setting is achieved, but inaccurate alignment detection leads to improper spacing

Engineering Contradiction:
Improvespacing position accuracyVSAvoidalignment information
Core Design Contradiction:
Manufacturing precisionVSLoss of information

Solution Approach 1:

The system uses multiple sensors to continuously monitor vibrations during the approach and positioning process. The evaluation unit analyzes these vibrations to provide feedback about contact location and alignment status, allowing the operator or automated system to adjust the shearbar position to achieve both correct spacing and proper parallel alignment, rather than relying solely on contact detection.

Inventive Principle:
Principle #23Feedback

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

This method enables faster and more accurate detection of the distance and alignment between the shearbar and cutting tool, improving the precision and energy efficiency of the chopping process while preventing material damage.

Implementation Method 1

the shearbar is assigned at least two spaced-apart sensors for detecting vibrations caused by the cutting tool when it comes into contact with the shearbar

Methodology Applied
Scientific EffectStructure-borne sound: Vibration

Data Source

PatentEP2559334B1Method and device for detecting the condition of a cutting device
Publication Date: 2016.08.31 CLAAS SELBSTFAHRENDE ERNTEMASCHINEN GMBH
  • EP2559334B1 patent drawingFigure 1
  • EP2559334B1 patent drawingFigure 2
  • EP2559334B1 patent drawingFigure 3

AI summary

The method involves assigning two interspaced sensors for detecting vibrations to a shear bar (4) caused by a cutting tool (3) upon contact with the shear bar, and transmitting signals generated by the sensors to a common signal analysis device. The common signal analysis device compares the signals and determines a state of a cutting device (2). The signal analysis device deduces information about an origin of the vibration on the shear bar on the basis of the presence of the signal from only one sensor or on the basis of the points in time of the arrival of signals from different sensors. An independent claim is included for a device for detecting state of a cutting device for agricultural crop.