scholarly journals Methods of grain separation from single-layer grinding wheel topography

Mechanik ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 926-928 ◽  
Author(s):  
Anna Bazan ◽  
Andrzej Kawalec

The paper presents results of research concerning methods used for determining grain separation from measured data representing single-layer grinding wheel topography. The methods apply information concerning determined threshold level (Threshold method) or concerning watershed segmentation (Watershed method). A method for determining the average level of bond was also proposed.

2019 ◽  
Vol 109 (07-08) ◽  
pp. 582-588
Author(s):  
E. Uhlmann ◽  
A. Muthulingam

Einen wesentlichen Bestandteil der Schleiftechnik ist der Konditionierprozess zur Herstellung der Schleifscheibenform und -schnittigkeit. Durch das Schärfen wird die Bindung zurückgesetzt und der notwendige Schleifkornüberstand und Spanraum geschaffen. Ein CNC-gesteuerter Schärfprozess kann zur prozesssicheren und ressourceneffizienten Einstellung der gewünschten Schleifbelagstopographie genutzt werden. Umfangreiche Schärfuntersuchungen sollen hierbei Aufschluss über die Wirkzusammenhänge zwischen Schärfeinstellgrößen und Schärfergebnis geben.   An essential part of grinding technology is the conditioning process for the generation of the grinding wheel shape and of a sharp topography. Through the sharpening process the required cutting grains are exposed from the bond and sufficient chip space is ensured by putting back the bonding. A CNC-controlled sharpening process can lead to an improvement in process reliability and the economic efficiency. Extensive experimental investigations were carried out to determine the relationship between the sharpening parameters and the sharpening result.


2016 ◽  
Vol 106 (01-02) ◽  
pp. 44-50
Author(s):  
T. Lierse ◽  
B. Karpuschewski ◽  
T. R. Kaul

Dieser Beitrag zeigt, dass die durch die Abrichtparameter erzeugte Schleifscheibentopographie nicht nur die Oberflächengüte des Werkstücks, sondern auch dessen Eigenspannungszustand in der Werkstückrandzone in weiten Grenzen verändert. Die Untersuchungen zum Abrichten von Korundschleifscheiben mit einer CVD-Diamantformrolle stellen den Zusammenhang zwischen dem Abrichten unterschiedlicher Schleifscheiben zur Bauteilqualität in Form der Oberflächenrautiefe und randzonennahen Eigenspannungen her.   The quality of the workpiece rim is changed by every grinding process. The grinding wheel topography created by the dressing process has not only influence on the workpiece roughness but also on the surface integrity. The pointed research using aluminum oxide abrasive wheels dressed by CVD diamond dressing discs shows a correlation between the dressing parameters, the workpiece roughness and the surface integrity.


2018 ◽  
Vol 108 (06) ◽  
pp. 441-447
Author(s):  
S. Barth ◽  
J. Röttger ◽  
D. Trauth ◽  
P. Mattfeld ◽  
T. Bergs ◽  
...  

In der Schleiftechnik besteht ein erhebliches Wissensdefizit über den Einfluss der Schleifscheibentopographie auf das Schleifprozessverhalten und die Ausbildung der Bauteilrandzoneneigenschaften. Ziel der Untersuchungen war daher die Identifikation und Analyse quantitativer Kenngrößen zur Beschreibung der geometrischen Schleifscheibentopographieeigenschaften. Diese Kenngrößen ermöglichten fortführend die Modellierung des thermo-mechanischen Belastungskollektivs im Schleifprozess in Abhängigkeit von der Schleifscheibentopographie.   In grinding technology, there is a considerable lack of knowledge about the influence of the grinding wheel topography on the process behaviour and the formation of the component surface zone properties. Therefore, the aim of the investigations was to investigate quantitative parameters for the description of the geometrical topography properties. These parameters enable to model the thermo-mechanical load collective in the grinding process as a function of the grinding wheel topography.


Author(s):  
Abdalslam Darafon ◽  
Andrew Warkentin ◽  
Robert Bauer

This paper presents a new empirical model of the dressing process in grinding which is then incorporated into a 3D metal removal computer simulator to numerically predict the ground surface of a workpiece as well as the dressed surface of the grinding wheel. The proposed model superimposes a ductile cutting dressing model with a grain fracture model to numerically generate the resulting grinding wheel topography and workpiece surface. Grinding experiments were carried out using “fine”, “medium” and “coarse” dressing conditions to validate both the predicted wheel topography as well as the workpiece surface finish. For the grinding conditions used in this research, it was observed that the proposed dressing model is able to accurately predict the resulting workpiece surface finish for all dressing conditions tested. Furthermore, similar trends were observed between the predicted and experimentally-measured grinding wheel topographies when plotting the cutting edge density, average cutting edge width and average cutting edge spacing as a function of depth for all dressing conditions tested.


2017 ◽  
Vol 869 ◽  
pp. 128-138
Author(s):  
Kristin M. de Payrebrune ◽  
Matthias Kröger

The complex dynamics of grinding repeatedly cause critical or unstable process conditions. For a better understanding and prediction of such occurrences, the dominant excitation phenomena need to be identified and their interrelation with the system dynamics have to be analyzed.Based on measurements of the excited frequencies in several operation modes of the grinding machine, the grinding wheel rotation is identified as a major excitation source. Further analysis of the grinding wheel surface displays three main components that define the excitation frequencies of the system; these are the eccentricity, waviness and roughness (also named wheel topography). Moreover, the wheel topography and thus the excitation frequencies can change over time due to excessive wear.Following the experimental results, a grinding wheel topography and wear model are developed and included in an integrated simulation of tool grinding. The analysis of the calculated cutting forces in the frequency domain confirm the excitation due to the grinding wheel topography.Firstly, this work has extracted the grinding wheel as a prominent excitation mechanism and reproduced it with the developed grinding model. Secondly, we have evidence that a complete description of the complex grinding process is only possible when considering the interdependence between system dynamics, wheel kinematics and the grinding process.


Author(s):  
Sebastian Barth ◽  
Michael Rom ◽  
Christian Wrobel ◽  
Fritz Klocke

The prediction of the grinding process result, such as the workpiece surface quality or the state of the edge zone depending on the used grinding wheel is still a great challenge for today's manufacturers and users of grinding tools. This is mainly caused by an inadequate predictability of force and temperature affecting the process. The force and the temperature strongly depend on the topography of the grinding wheel, which comes into contact with the workpiece during the grinding process. The topography of a grinding wheel mainly depends on the structure of the grinding wheel, which is determined by the recipe-dependent volumetric composition of the tool. So, the structure of a grinding tool determines its application behavior strongly. As result, the knowledge-based prediction of the grinding wheel topography and its influence on the machining behavior will only be possible if the recipe-dependent grinding wheel structure is known. This paper presents an innovative approach for modeling the grinding wheel structure and the resultant grinding wheel topography. The overall objective of the underlying research work was to create a mathematical-generic grinding tool model in which the spatial arrangement of the components, grains, bond, and pores, is simulated in a realistic manner starting from the recipe-dependent volumetric composition of a grinding wheel. This model enables the user to determine the resulting grinding wheel structure and the grinding wheel topography of vitrified and synthetic resin-bonded cubic boron nitride (CBN) grinding wheels depending on their specification and thus to predict their application behavior. The originality of the present research results is a generic approach for the modeling of grinding tools, which takes into account the entire grinding wheel structure to build up the topography. Therefore, original mathematical methods are used. The components of grinding wheels are analyzed, and distribution functions of the component's positions in the tools are determined. Thus, the statistical character of the grinding wheel structure is taken into account in the developed model. In future, the presented model opens new perspectives in order to optimize and to increase the productivity of grinding processes.


Sign in / Sign up

Export Citation Format

Share Document