scholarly journals Surface microgeometry treated with a precast textured grinding wheel

2020 ◽  
Vol 329 ◽  
pp. 03019
Author(s):  
Vladimir Gusev
Keyword(s):  
Surface Layer ◽  
Thermal Damage ◽  
Transverse Plane ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Geometric Errors ◽  
Time Process ◽  
Cutting Surface ◽  
Surface Microgeometry ◽  
Textured Grinding Wheel

The article considers the formation of the geometry of internal cylindrical surfaces when grinding with a precast textured wheel, which is under the influence of the unbalances main vector and a variable cutting force caused by the discreteness of the cutting surface (texture). Under the influence of these factors, each point of the axis of the textured tool makes vibrations in the transverse plane in the form of a wavelike sinusoid consisting of two sinusoids. The Space-time process of forming the processed surface is mathematically described. It is in applying wavelike sinusoids to the workpiece, taking into account their phase shift at each revolution of the workpiece. To ensure minimal geometric errors at the maximum possible productivity of the grinding process, phase shifts φf = (0.07–0.12)π and φf = (0.88–0.93)π are recommended. The results of the study are recommended for use in the production of high-precision details, primarily from materials that are prone to thermal damage to the surface layer under the influence of high temperature in the grinding zone.

Adaptive Grinding Process—Prevention of Thermal Damage Using OPC-UA Technique and In Situ Metrology

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Matthias Steffan ◽  
Franz Haas ◽  
Alexander Pierer ◽  
Gentzen Jens
Keyword(s):  
Thermal Damage ◽  
Control Variable ◽  
Safety Margin ◽  
Value Added ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Production Chain ◽  
Process Step ◽  
Edge Zone ◽  
Control Concept

The production process grinding deals with finishing of hardened workpieces and is one of the last stages of the value-added production chain. Up to this process step, considerable costs and energy have been spent on the workpieces. In order to avoid production rejects, significant safety reserves are calculated according to the present state of the art. The authors introduce two approaches to minimize the safety margin, thus optimizing the process’ economic efficiency. Both control concepts use the feed rate override of the machining operation as regulating variable to eliminate thermal damage of the edge zone. The first control concept is developed to avoid thermal damage in cylindrical plunge grinding by controlling the cutting forces. Therefore, the industrial standard Open Platform Communications Unified Architecture (OPC-UA) is used for the communication between a proportional–integral–derivative (PID) controller and the SINUMERIK grinding machine tool control system. For noncircular workpieces, grinding conditions change over the circumference. Therefore, thermal damage cannot be ruled out at any time during the grinding process. The authors introduce a second novel control approach, which uses a micromagnetic measure that correlates with thermal damage as the main control variable. Hence, the cutting ability of the grinding wheel and thermal damage to the workpiece edge zone is quantified in the process. The result is a control concept for grinding of noncircular workpieces, which opens up fields for major efficiency enhancement. With these two approaches, grinding processes are raised on higher economic level, independently of circular and noncircular workpiece geometries.

scholarly journals INFLUENCE OF THE GEOMETRIC CHARACTERISTICS OF THE DISCONTINUOUS PROFILE WORKING SURFACES OF ABRASIVE WHEELS FOR PRECISION AND TEMPERATURE WHEN GRINDING

2021 ◽  
pp. 115-125
Author(s):  
Oleksiy Yakimov ◽  
Liubov Bovnegra ◽  
Vladimir Tonkonogyi ◽  
Vladyslav Vaysman ◽  
Victor Strelbitskyi ◽  
...  
Keyword(s):  
Surface Layer ◽  
Heat Stress ◽  
Elastic System ◽  
Dynamic Interaction ◽  
Grinding Wheel ◽  
Stable Operation ◽  
Grinding Process ◽  
Abrasive Wheel ◽  
Working Surface

Grinding is the most common finishing method for hardened steel parts. Grinding is accompanied by a large heat release in the cutting area, under the influence of which structural changes appear in the thin surface of the processed parts, tensile stress and even microcracks, which significantly reduce the operational reliability of machines that include these parts. The use of abrasive wheels with an intermittent working surface makes it possible to reduce the temperature in the area of contact of abrasive grains with the material of the workpiece and, as a consequence, stabilize the quality of the surface layer of the workpieces. High-frequency vibrations in the elastic system of the machine, accompanying the work of an intermittent wheel, are a positive factor that reduces the energy consumption of the grinding process. However, under certain conditions of dynamic interaction of the tool with the workpiece, parametric resonance may occur, which worsens the geometric and physical-mechanical parameters of the quality of the surface layer of the processed part. The aim of the work is to realize the possibility of predicting the quality parameters of the surface layer of parts during intermittent grinding by studying the influence of the design features of the macrotopography of the working surface of abrasive wheels and processing modes on the nature of the dynamic interaction of the tool with the workpiece and the heat stress in the cutting area. It was found that the parametric vibrations of the elastic system of the machine tool can be shifted to a more stable area, due to an increase in the number of interruptions of the working surface of the abrasive wheel with a constant ratio of the length of the protrusions and depressions. The increase in the number of breaks on the wheel also contributes to a decrease in temperature in the cutting area. It was found that to maintain the stable operation of the elastic system of the machine, it is necessary to reduce the number of cavities on the grinding wheel with an increase in the cutting speed. However, both of these actions are accompanied by an increase in the heat stress of the grinding process. It has been experimentally established that for ordinary (pendulum) grinding, it is possible to achieve an increase in processing productivity by increasing the speed of the longitudinal movement of the table.

Virtual Truing and Dressing of Grinding Wheel

2008 ◽  
Vol 389-390 ◽  
pp. 362-367 ◽  
Author(s):  
Zbigniew M. Bzymek ◽  
Glenn M. Duzy ◽  
Richard B. Mindek
Keyword(s):  
Grinding Wheel ◽  
Grinding Process ◽  
Rotational Axis ◽  
Wheel Surface ◽  
Cutting Surface ◽  
Surface Replica ◽  
Process Prediction ◽  
Final Profile

Truing and dressing are essential processes of grinding wheel preparation. They make the wheel geometry true with respect to its rotational axis and its cutting surface sharp. These factors significantly influence the quality of the final profile and surface produced from the grinding process. Prediction of the optimum wheel surface for grinding, defined as one which produces an accurate profile and cuts most efficiently can greatly minimize the time to optimize grinding wheel performance. This paper describes virtual dressing and truing operations, takes under account vibration of the dressing apparatus and shows how to generate wheel surface replica under different conditions.

scholarly journals Automatic detection of thermal damage in grinding process by artificial neural network

2003 ◽  
Vol 56 (4) ◽  
pp. 295-300 ◽  
Author(s):  
Fábio Romano Lofrano Dotto ◽  
Paulo Roberto de Aguiar ◽  
Eduardo Carlos Bianchi ◽  
Rogério Andrade Flauzino ◽  
Gustavo de Oliveira Castelhano ◽  
...  
Keyword(s):  
Neural Network ◽  
Thermal Damage ◽  
Intelligent System ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Output Variable ◽  
The Neural Network ◽  
Wheel Drive ◽  
Drive Motor ◽  
Grinding Conditions

This work aims to develop an intelligent system for detecting the workpiece burn in the surface grinding process by utilizing a multi-perceptron neural network trained to generalize the process and, in turn, obtnaing the burning threshold. In general, the burning occurrence in grinding process can be detected by the DPO and FKS parameters. However, these ones were not efficient at the grinding conditions used in this work. Acoustic emission and electric power of the grinding wheel drive motor are the input variable and the output variable is the burning occurrence to the neural network. In the experimental work was employed one type of steel (ABNT-1045 annealed) and one type of grinding wheel referred to as TARGA model ART 3TG80.3 NVHB.

scholarly journals Temperature simulation of blank ground with face solid and segment disks in CAE-Solid Works complex

2017 ◽  
Vol 2 (11) ◽  
pp. 23-29 ◽  
Author(s):  
Алексей Морозов ◽  
Aleksey Morozov ◽  
Владимир Гусев ◽  
Vladimir Gusev
Keyword(s):  
Surface Layer ◽  
Solid State ◽  
Thermal Damage ◽  
Initial Conditions ◽  
Ground Surface ◽  
State Model ◽  
Cutting Surface ◽  
Grinding Tool ◽  
Solid Works ◽  
Face Grinding

Flat face grinding is characterized with large areas of a cutting surface contact with a blank under machining which re-sults in intensive heat generations in a cutting area which is able to cause a thermal damage of the surface layer. Thereupon there is developed a designed heat model of a blank, the initial conditions are defined, and there is created a solid-state model of an abrasive segment with a trapezoidal face cutting surface and a temperature simulation of the blank ground with a solid and discrete face tool is carried out in a modern CAE- Solid Works complex. The result of modeling have shown that the application of the discrete face grinding tool equipped with abrasive segments allows decreasing a temperature of the surface machined by 26-30% as compared to a face grinding tool with a solid cutting surface, which decreases considerably the likelihood of defects appearance in a ground surface layer of a part.

The effect of the grinding wheel modification on the state of the workpiece surface layer after internal cylindrical grinding of steel C45

2016 ◽  
Vol 231 (6) ◽  
pp. 1162-1173 ◽  
Author(s):  
Ryszard Wójcik ◽  
Krzysztof Nadolny
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Thermal Conditions ◽  
Active Surface ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Workpiece Surface ◽  
Cylindrical Grinding ◽  
Grinding Fluid ◽  
Internal Cylindrical Grinding

Internal cylindrical grinding is one of the most difficult grinding processes due to the very long zone of contact between the grinding wheel and the workpiece surface. Such conditions limit delivery of the grinding fluid into the grinding zone, as well as impeding the removal of chips from it. As a result, during the internal cylindrical grinding process, difficult thermal conditions occur in the machining zone which finally could lead to grinding defects. One of the most efficient and cost-effective ways of improving the grinding stability and repeatability is modifying the grinding wheel structure. As such, modifications usually do not require interfering with the construction of the grinding machine or its equipment, they are universal and, possibly, widely applicable. This article presents a modified grinding wheel with helical grooves shaped on its active surface. Such modification was developed to reduce the thermal load of the workpiece surface and the occurrence of thermal defects. The effectiveness of the proposed grinding wheel modification was examined experimentally in the reciprocal circumferential internal cylindrical grinding process of 45C steel. The goal of the described tests was to determine the influence of the suggested grinding wheel modification on the condition of the workpiece surface layer (the surface roughness and residual stresses). The test results obtained indicated that application of the modified grinding wheel has a positive influence on the residual stresses in the workpiece surface layer, resulting in better delivery of the grinding fluid into the area of contact between the wheel and the machined material. Moreover, a decrease of the Ra parameter value by approximately 7–19%, as compared to the results of the process carried out with the (unmodified) reference grinding wheel was indicated.

Investigation of the Surface Layer Structure of High-Chromium and High-Strength Steels at the Variation of the Heating Temperature

2016 ◽  
Vol 870 ◽  
pp. 431-436 ◽  
Author(s):  
V.B. Dementyev ◽  
T.N. Ivanova
Keyword(s):  
Surface Layer ◽  
High Speed ◽  
Layer Structure ◽  
Heating Temperature ◽  
High Strength Steels ◽  
High Strength ◽  
Grinding Wheel ◽  
High Chromium ◽  
Cutting Surface ◽  
Grinding Tool

At present, hard-to-machine materials such as structural alloy steels with various chemical element additives – tungsten, chromium, etc. - are most widely used in engineering. When conventional finish methods are used for the treatment of hard-to-machine materials, the most important problems are the difficulty of obtaining work surfaces of a required quality in terms of accuracy, roughness and the physicochemical composition, and the low output. In the present paper, a finish method for metal treatment– grinding – is discussed. Zones of the formation of the surface stress state due to heating have been revealed: the zone of an insignificant increase in temperature in the contour of the contact of a grinding wheel and a work surface; the zone of the temperature intensive growth; and the zone of the temperature abrupt drop. The investigation has been conducted of the surface layer structure of high-strength and high-chromium steels during high-speed heating – grinding. The peculiarities of the change of the surface layer state of the above steels have been revealed after grinding with the use of conventional grinding wheels with a continuous cutting surface and a discontinuous cutting surface. Some recommendations are given for grinding of the high-strength 12Cr18Ni9 and high-chromium Cr12, Cr12Mo and Cr12V steels, taking into account the specific features of different technological situation characteristic of a specific grinding tool, a grinding tool grade, and conditions of grinding and cutting.

Study on Edge Contact Area and Surface Integrity of Workpiece in Point Grinding Process

2009 ◽  
Vol 407-408 ◽  
pp. 577-581
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
Contact Area ◽  
High Speed ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Edge Contact ◽  
Cylindrical Grinding ◽  
Theoretic Foundations

During cylindrical grinding process, the geometric configuration and size of the edge contact area between the grinding wheel and workpiece have the heavy effects on the workpiece surface integrity. In consideration of the differences between the point grinding and the conventional high speed cylindrical grinding, the geometric and mathematic models of the edge contact area in point grinding were established. Based on the models, the numerical simulation for the edge contact area was performed. By means of the point grinding experiment, the effect mechanism of the edge contact area on the ground surface integrity was investigated. These will offer the applied theoretic foundations for optimizing the point grinding angles, depth of cut, wheel and workpiece speed, geometrical configuration and size of CBN wheel and some other grinding parameters in point grinding process.

scholarly journals Study on the Effect of Grinding Pressure on Material Removal Behavior Performed on a Self-Designed Passive Grinding Simulator

2021 ◽  
Vol 11 (9) ◽  
pp. 4128
Author(s):  
Peng-Zhan Liu ◽  
Wen-Jun Zou ◽  
Jin Peng ◽  
Xu-Dong Song ◽  
Fu-Ren Xiao
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Service Life ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Temperature ◽  
Grinding Efficiency

Passive grinding is a new rail grinding strategy. In this work, the influence of grinding pressure on the removal behaviors of rail material in passive grinding was investigated by using a self-designed passive grinding simulator. Meanwhile, the surface morphology of the rail and grinding wheel were observed, and the grinding force and temperature were measured during the experiment. Results show that the increase of grinding pressure leads to the rise of rail removal rate, i.e., grinding efficiency, surface roughness, residual stress, grinding force and grinding temperature. Inversely, the enhancement of grinding pressure and grinding force will reduce the grinding ratio, which indicates that service life of grinding wheel decreases. The debris presents dissimilar morphology under different grinding pressure, which reflects the distinction in grinding process. Therefore, for rail passive grinding, the appropriate grinding pressure should be selected to balance the grinding quality and the use of grinding wheel.

Calculation of Effective Ground Depth of Cut by Means of Grinding Process Model

2011 ◽  
Vol 496 ◽  
pp. 7-12 ◽  
Author(s):  
Takazo Yamada ◽  
Michael N. Morgan ◽  
Hwa Soo Lee ◽  
Kohichi Miura
Keyword(s):  
Process Model ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Wheel Wear ◽  
Elastic Deformations ◽  
Proposed Model ◽  
Effective Depth ◽  
Grinding Machine

In order to obtain the effective depth of cut on the ground surface, a new grinding process model taking into account thermal expansions of the grinding wheel and the workpiece, elastic deformations of the grinding machine, the grinding wheel and the workpiece and the wheel wear was proposed. Using proposed model, the effective depth of cut was calculated using measured results of the applied depth of cut and the normal grinding force.

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