scholarly journals Improvement of Shape Error for Slender Parts in Cylindrical Traverse Grinding by Part-Deformation Modelling and Compensation

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1990
Author(s):  
Ivan Mendez ◽  
Jorge Alvarez ◽  
David Barrenetxea ◽  
Leire Godino
Keyword(s):  
Prediction Model ◽  
Experimental Validation ◽  
Grinding Force ◽  
Error Prediction ◽  
Grinding Wheel ◽  
Shape Error ◽  
Distributed Load ◽  
Force Monitoring ◽  
Traverse Grinding ◽  
Ground Part

Achieving geometrical accuracy in cylindrical traverse grinding for high-aspect slender parts is still a challenge due to the flexibility of the workpiece and, therefore, the resulting shape error. This causes a bottleneck in production due to the number of spark-out strokes that must be programmed to achieve the expected dimensional and geometrical tolerances. This study presents an experimental validation of a shape-error prediction model in which a distributed load, corresponding to the grinding wheel width, is included, and allows inclusion of the effect of steady rests. Headstock and tailstock stiffness must be considered and a procedure to obtain their values is presented. Validation of the model was performed both theoretically (by comparing with FEM results) and experimentally (by comparing with the deformation profile of the real workpiece shape), obtaining differences below 5%. Having determined the shape error by monitoring the normal grinding force, a solution was presented to correct it, based on a cross-motion of the grinding wheel during traverse strokes, thus decreasing non-productive spark-out strokes. Due to its simplicity (based on the shape-error prediction model and normal grinding force monitoring), this was easily automatable. The corrective compensation cycle gave promising results with a decrease of 77% in the shape error of the ground part, and improvement in geometrically measured parameters, such as cylindricity and straightness.

scholarly journals Research On Roundness Error Consistency Model For Crank Journal Cylindrical grinding

2021 ◽  
Author(s):  
Xu Zeng ◽  
Xiong Wanli ◽  
Hongyan Ye ◽  
Zhiyong Tang
Keyword(s):  
Prediction Model ◽  
Field Experiments ◽  
Transition Process ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Shape Error ◽  
Simulation Algorithm ◽  
Cylindrical Grinding ◽  
Consistency Model ◽  
Grinding System

Abstract Cylindrical grinding is an important way to form the external shape error of the crank journal, and the accuracy consistency directly affects the interchangeability of products. To study the accuracy consistency of crank journal，a dynamic model of the grinding wheel-crankshaft grinding system based on Timoshenko beam is established, and the grinding transition process simulation algorithm with iterative convergence of grinding force-transient grinding amount cycle adapted to the model is proposed, which realizes the simulation of the roundness of the crank journal coupled with the process parameters of the grinding system. Aiming at the grinding position of each crank journal, the grinding roundness of five crank journals is simulated respectively. On this basis, the crank journal roundness consistency prediction model is established, and the effectiveness of the prediction model is verified by field experiments. Finally, the influence of grinding parameters on the consistency of the roundness of crank journal is studied. The research conclusion can provide a reference for the grinding accuracy consistency design of this type of crank journal.

Effect of Steady Rest in Cylindrical Traverse Grinding of Slender Workpiece

2020 ◽  
Author(s):  
Hidetaka Fujii ◽  
Takashi Onishi ◽  
Chinhu Lin ◽  
Moriaki Sakakura ◽  
Kazuhito Ohashi
Keyword(s):  
Elastic Deformation ◽  
Contact Point ◽  
Traverse Speed ◽  
Grinding Force ◽  
New Method ◽  
Beam Model ◽  
Shape Error ◽  
Form Error ◽  
Low Stiffness ◽  
Traverse Grinding

Abstract In the case of traverse grinding of a slender workpiece, the ground workpiece is easily deformed by the normal grinding force due to its low stiffness. To reduce the form error caused by the elastic deformation of the workpiece, a steady rest is widely used. Generally, a steady rest is set to push the ground area of the workpiece. However, the stepped shape error is generated at the contact point where a steady rest pushed the workpiece because the pushing force of a steady rest is decreased after the material of the contact point is removed. In this study, to reduce the stepped shape error of the ground workpiece, we proposed a new method to set a steady rest. In this method, the steady rest was set to push the area where was not ground. In addition, the traverse speed of the workpiece was adjusted to keep the elastic deformation of the workpiece constant. The suitable method to control the traverse speed was estimated by using a beam model that could simulate the elastic deformation of the workpiece during the grinding process. It was confirmed that the new method could improve the form accuracy of a slender workpiece through grinding experiments.

Study on the Shape Error in the Cylindrical Traverse Grinding of a Workpiece with High Aspect Ratio

2014 ◽  
Vol 1017 ◽  
pp. 78-81
Author(s):  
Takashi Onishi ◽  
Takuya Kodani ◽  
Kazuhito Ohashi ◽  
Moriaki Sakakura ◽  
Shinya Tsukamoto
Keyword(s):  
Aspect Ratio ◽  
Elastic Deformation ◽  
High Aspect Ratio ◽  
Grinding Force ◽  
Grinding Process ◽  
Shape Error ◽  
Shape Accuracy ◽  
Low Stiffness ◽  
Traverse Grinding ◽  
Main Factor

In cylindrical traverse grinding of a long workpiece with high aspect ratio, the shape accuracy of a workpiece worsens due to its low stiffness. In this study, the grinding force was measured during grinding process to calculate the elastic deformation of a workpiece caused by the normal grinding force. By comparing calculated elastic deformation with the measured shape error of ground workpiece, the cause for the shape error in case of grinding a long workpiece was investigated experimentally. From experimental results, it is confirmed that the main factor of the shape error of the long workpiece is its elastic deformation during grinding process.

scholarly journals Cylindricity error measurement and compensation in traverse grinding of low-stiffness shafts

Mechanik ◽  
2018 ◽  
Vol 91 (11) ◽  
pp. 970-972
Author(s):  
Jan Burek ◽  
Paweł Sułkowicz ◽  
Robert Babiarz
Keyword(s):  
Elastic Deformation ◽  
Force Measurement ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Error Measurement ◽  
Low Stiffness ◽  
Grinding Machine ◽  
Cylindricity Error ◽  
Traverse Grinding

This paper presents a system of measurement and compensation of cylindricity error in low-stiffness shafts grinding. A programme, that generates the path of a grinding wheel taking into account the elastic deformation of the shaft and grinding machine on the basis of the grinding force measurement was developed

scholarly journals Improvement of the Form Accuracy of a Slender Workpiece in Cylindrical Traverse Grinding

2019 ◽  
Vol 13 (6) ◽  
pp. 728-735
Author(s):  
Takashi Onishi ◽  
Teppei Takashima ◽  
Moriaki Sakakura ◽  
Koichi Sakamoto ◽  
Kazuhito Ohashi ◽  
...  
Keyword(s):  
Elastic Deformation ◽  
Cycle Time ◽  
Traverse Speed ◽  
Grinding Force ◽  
Wheel Speed ◽  
Grinding Wheel ◽  
Form Error ◽  
Form Accuracy ◽  
Peripheral Speed ◽  
Traverse Grinding

During the cylindrical traverse grinding of a slender workpiece, the ground workpiece is easily bent by the normal grinding force owing to its low stiffness. Therefore, it is difficult to finish the slender workpiece with high accuracy. To prevent the elastic deformation of a workpiece during the grinding process, a steady rest is generally used. However, considerable skill of the worker is required to use a steady rest. Therefore, we developed a new traverse grinding method without any steady rest. In this method, the elastic deformation of a workpiece was kept constant by controlling the traverse speed of the workpiece. At the middle of the ground workpiece, where the elastic deformation increased easily, the traverse speed was slowed down. However, this method had a longer grinding cycle time because the average traverse speed decreased compared to that of the conventional method. To shorten the cycle time, the peripheral speed of the grinding wheel was increased to decrease the normal grinding force. Basic grinding experiments were carried out under several grinding conditions by changing the peripheral speed of the wheel. From these grinding experiments, it was confirmed that the normal grinding force and the form error of the ground workpiece decreased as the peripheral wheel speed increased. By using results obtained from basic experiments, grinding experiments involving changes in the traverse speed were carried out at two peripheral wheel speeds. The grinding cycle time was reduced successfully by increasing the peripheral wheel speed without an increment in the form error of the ground workpiece. Furthermore, a form error was observed at the end of the workpiece where the grinding wheel traveled away from the workpiece. The form error occurred because the normal grinding force decreased rapidly when the contact length between the workpiece and the wheel was decreased at the end of the workpiece. To prevent rapid changes in the normal grinding force, the traverse speed of the workpiece was increased at the end of the workpiece. By using this method, a ground workpiece with high form accuracy was obtained.

scholarly journals Error Modeling and Experimental Validation of a Planar 3-PPR Parallel Manipulator With Joint Clearances

2012 ◽  
Vol 4 (4) ◽  
Author(s):  
Guanglei Wu ◽  
Shaoping Bai ◽  
Jørgen A. Kepler ◽  
Stéphane Caro
Keyword(s):  
Prediction Model ◽  
Parallel Manipulator ◽  
Experimental Validation ◽  
Upper Bounds ◽  
Error Modeling ◽  
Error Prediction ◽  
Experimental Measurements ◽  
Modeling And Analysis ◽  
Planar Parallel Manipulator ◽  
Joint Clearances

This paper deals with the error modeling and analysis of a 3-PPR planar parallel manipulator with joint clearances. The kinematics and the Cartesian workspace of the manipulator are analyzed. An error model is established with considerations of both configuration errors and joint clearances. Using this model, the upper bounds and distributions of the pose errors for this manipulator are established. The results are compared with experimental measurements and show the effectiveness of the error prediction model.

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.

Thermal Error Prediction of the Spindle Using Adaptive Neuro-Fuzzy Inference System

2015 ◽  
Vol 789-790 ◽  
pp. 263-267
Author(s):  
Yan Lei Li ◽  
Ming Yan Wang ◽  
You Min Hu ◽  
Bo Wu
Keyword(s):  
Prediction Model ◽  
Predictive Model ◽  
Fuzzy Inference System ◽  
Fuzzy Inference ◽  
Thermal Error ◽  
Temperature Data ◽  
Current Sensor ◽  
Error Prediction ◽  
Inference System ◽  
Neuro Fuzzy

This paper proposes a new method to predict the spindle deformation based on temperature data. The method introduces ANFIS (adaptive neuro-fuzzy inference system). For building the predictive model, we first extract temperature data from sensors in the spindle, and then they are used as the inputs to train ANFIS. To evaluate the performance of the prediction, an experiment is implemented. Three Pt-100 thermal resistances is used to monitor the spindle temperature, and an inductive current sensor is used to obtain the spindle deformation. The experimental results display that our prediction model can better predict the spindle deformation and improve the performance of the spindle.

scholarly journals Experimental Study on Grinding Force of Zirconia Ceramics in Dry/Wet Grinding Environment

2018 ◽  
Vol 198 ◽  
pp. 02004
Author(s):  
Junping Zhang ◽  
Weidong Wang ◽  
Songhua Li ◽  
Han Tao
Keyword(s):  
Grinding Force ◽  
Grinding Wheel ◽  
Feed Speed ◽  
Zirconia Ceramics ◽  
Grinding Forces ◽  
Measuring Device ◽  
Linear Speed ◽  
Wet Grinding ◽  
Dry Grinding ◽  
Force Ratio

The impacts of different linear speed of grinding wheel, grinding depth and workpiece feed speed with or without grinding fluid on grinding force were studied by plane grinding machining of zirconia ceramics. The impacts of different machining environment and grinding parameter on normal and tangential grinding forceswere studied by testing the grinding force during grinding with a force measuring device. The studies showed that the normal and tangential grinding forces decrease with the increase of the linear speed of grinding wheel and increase with the improvement of grinding depth and workpiece feed speed. The grinding depth has the greatest impacts on the normal and tangential grinding forces in dry grinding environment; while in wet grinding environment, the grinding depth exerts the greatest impacts on the normal grinding force and the linear speed of grinding wheel imposes the greatest impacts on the tangential grinding force. In addition, it was found that the normal grinding force in dry grinding is minor than that in wet grinding, that the tangential grinding force in dry grinding is greater than that in wet grinding, and that the grinding force ratio in dry grinding is lower than that in wet grinding.

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