Saw Tooth Regrinding Using Wheel-Wear Compensated Profile Scanning

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Solution Overview

Problem

Existing methods for grinding saw blades with sawtooth profiles often result in uneven regrinding due to variations in grinding wheel wear and unknown or changed sawtooth profiles, leading to premature blade breakage and inefficiencies.

Innovation Solution

A method involving scanning the sawtooth profile with a grinding wheel of any wear, using the wheel as a measuring device to record and save a scanning profile, and then grinding along an offset profile to compensate for wheel wear and ensure even regrinding, regardless of the sawtooth profile's known status or wheel age.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If profile grinding is performed using conventional methods with worn grinding wheels, then the grinding process can continue without wheel replacement, but the grinding results become uneven and inaccurate

Engineering Contradiction:
Improveservice life of grinding wheelVSAvoidgrinding accuracy
Core Design Contradiction:
Duration of action of moving objectVSManufacturing precision

Solution Approach 1:

The method performs a preliminary scanning measurement of the sawtooth profile before grinding. This preliminary action captures the actual profile geometry and wheel wear characteristics, which are then used to generate corrected grinding paths that compensate for wheel wear, maintaining precision throughout the wheel's service life

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The scanning measurement provides feedback about the actual sawtooth profile and wheel condition. This feedback is used to adjust and optimize the grinding process parameters and paths, creating a closed-loop system that maintains grinding accuracy despite wheel wear

Inventive Principle:
Principle #23Feedback

2Loss of information

If the sawtooth profile is measured and electronically imported for regrinding, then the original profile can be replicated, but the results often fall short of requirements due to profile changes and wheel wear

Engineering Contradiction:
Improveprofile data accuracyVSAvoidregrinding quality
Core Design Contradiction:
Loss of informationVSManufacturing precision

Solution Approach 1:

Instead of relying on stored historical profile data, the method performs a preliminary scanning measurement of the actual current profile. This captures any changes that have occurred due to wear or previous grinding, ensuring the grinding process is based on accurate, up-to-date profile information

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The method replaces reliance on electronic profile databases with direct physical scanning measurement using the grinding wheel itself. This substitution ensures that the profile data reflects the actual physical state of the saw blade and wheel, rather than idealized or outdated digital representations

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

3Ease of manufacture

If excessive chip removal is performed during grinding, then the saw blade can be resharpened, but the tooth base becomes hardened and problematic grooves and notches develop

Engineering Contradiction:
Improveresharpening capabilityVSAvoidtooth base hardening and groove formation
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The preliminary scanning measurement determines the exact amount of material that needs to be removed to restore the profile. This allows for precise control of chip removal, removing only what is necessary to regenerate the profile without excessive removal that would cause hardening and groove formation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The method dynamically adjusts grinding parameters including depth of cut, wheel speed, and feed rate based on the scanned profile data. These parameter changes optimize the grinding process to achieve profile restoration while minimizing harmful effects like tooth base hardening and groove formation

Inventive Principle:
Principle #35Parameter changes

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 ensures reliable and even regrinding, reducing errors from wheel wear and simplifying the process, applicable to all saw profiles and wheel conditions, thereby extending blade life and maintaining performance.

Implementation Method 1

a grinding wheel with a wheel axis, a wheel plane perpendicular to the wheel axis and a grinding contour which forms the radially outermost edge of the grinding wheel

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP4059660B1Method for grinding saw teeth of a saw blade
Publication Date: 2024.04.17 ISELI & CO AG MASCHFAB
  • EP4059660B1 patent drawingFigure 1~2c
  • EP4059660B1 patent drawingFigure 3a~4

AI summary

The invention relates to a method for grinding a saw blade (1) with a sawtooth profile (2) having an undercut (4) with a rake angle (γ) and a tooth pitch (3), using a grinding wheel (10) with a grinding contour (11) which forms the radially outermost edge of the grinding wheel (20), wherein the following steps are carried out: scanning or tracing the sawtooth profile (2) including the undercut (4) in the area of ​​at least one tooth pitch (3) with a grinding wheel (10) of any wear; recording and storing a scanning profile (20) which includes all positions of a virtual, stationary point (14) on the grinding wheel (1), for example a wheel edge point, when touched at the contact points (5) relative to the sawtooth profile (2), and together with the current grinding contour (11) has a uniquely defined correlation to the sawtooth profile (2);Grinding the saw blade (1) with the same grinding wheel (10) in the rotating state in all tooth pitches (3) by guiding it along a grinding profile (22) which is offset by a predetermined grinding depth (21) from the scanning profile (20) in the direction of the rake angle (γ).