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.

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.

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 Traverse grinding of low-stiffness shafts with the use of a grinding wheel’s path correction

Mechanik ◽  
2018 ◽  
Vol 91 (8-9) ◽  
pp. 741-743
Author(s):  
Jan Burek ◽  
Paweł Sułkowicz ◽  
Robert Babiarz
Keyword(s):  
Force Measurement ◽  
Dimensional Accuracy ◽  
Grinding Force ◽  
Grinding Process ◽  
Shape Errors ◽  
Low Stiffness ◽  
Traverse Grinding

This paper presents a method of increasing the shape and dimensional accuracy of low-stiffness shafts manufactured in traverse grinding process. In order to achieve that, grinding force measurement was used. It allowed to calculate such a correction of a grinding wheel’s path, that allowed to decrease dimensional and shape errors of grinded workpieces.

Improvement of the Form Accuracy Ground by a Slender Wheel in Internal Grinding

2020 ◽  
Author(s):  
Takashi Onishi ◽  
Yusuke Nakabayashi ◽  
Moriaki Sakakura ◽  
Go Ichiba ◽  
Kazuhito Ohashi
Keyword(s):  
Aspect Ratio ◽  
Elastic Deformation ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Deep Hole ◽  
Form Error ◽  
Form Accuracy ◽  
Internal Grinding ◽  
Inner Surface

Abstract In the case of internal grinding of a deep hole, the inner surface of the hole was ground by a slender grinding wheel that has a high aspect ratio. A slender grinding wheel is bent by the normal grinding force during the grinding process. Therefore, the form accuracy of the ground workpiece is decreased especially when the aspect ratio of a wheel is high. In our previous study, it was confirmed that the biggest factor that generated the form error of the workpiece was the elastic deformation owning to the normal grinding force. To reduce the form error of the ground workpiece, it is effective to expand the spark-out duration. However, the expansion of the spark-out duration leads to the low productivity. In this study, the form of the grinding wheel was modified by a diamond dresser to improve the form accuracy of the workpiece without expanding the spark-out duration. The modified form of a wheel was determined to compensate the form error of the workpiece generated by the elastic deformation of the grinding wheel. Thorough several grinding experiment, it was confirmed that the form accuracy of the ground workpiece was successfully improved by modifying the form of a slender grinding wheel without expanding the spark-out duration.

Parameter Optimization for Grinding Process of Micropores with High Aspect Ratio

2015 ◽  
Vol 1095 ◽  
pp. 795-799
Author(s):  
Feng Che Tsai ◽  
Yann Long Lee ◽  
Ju Chun Yeh
Keyword(s):  
Surface Roughness ◽  
Aspect Ratio ◽  
Parameter Optimization ◽  
High Aspect Ratio ◽  
Grinding Process ◽  
Average Roughness ◽  
Abrasive Particles ◽  
Abrasive Jet Machining ◽  
Mix Proportion ◽  
Labor Consuming

Parameter optimization for grinding process of micropores with high aspect ratio is discussed in this research. To ensure the surface accuracy on the inner side of deep micropore, the manual polishing or reaming process is a commonly adopted method. However, this process has disadvantages of limitation by operators’ experience and technique, labor consuming, and high cost. Skilled operators are also difficult to train nowadays. In order to address those flaws, this study applied the subtle abrasive jet machining technology and Taguchi Method for experimental design, so as to effectively obtain the appropriate surface roughness and processing uniformity. The Taguchi experimental results showed that when applying a Vacuum Pressure of 60 cmHg and a Air Pressure of 0.5 Mpa, the optimal polishing effect was attained using #2000SiC abrasive particles and an Mix Proportion (SiC: Additive) 2: 1. The average roughness of lifting pin hole was reduced from an original value of Ra 2.39 mm (Rmax: 10.74 mm) to a final value of Ra 0.07 mm (Rmax: 1.10 mm).

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 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.

The Study of the Simulation of Low Rigidity, Variable Cross-Section Shaft Electrolytic Grinding

2013 ◽  
Vol 668 ◽  
pp. 465-469
Author(s):  
Xue Juan Zhang ◽  
Liu Yong ◽  
Xu Feng
Keyword(s):  
Cross Section ◽  
Simulation Analysis ◽  
Processing Parameters ◽  
Variable Cross Section ◽  
Grinding Force ◽  
Grinding Process ◽  
Variable Cross ◽  
Shape Error ◽  
Element Simulation ◽  
Main Factors

The very trajectory of electrolytic method of grinding process is suitable for processing high-precision, ultra-low rigidity variable cross-section of the shaft grinding new electrolytic process. On the basis of methods to the original trajectory of electrolysis in a grinding process, in this paper establishes the mechanical model of electrolytic grinding to finite element simulation analysis of electrolytic grinding shape error, by analyzing the factors affection the quality and the main factors of the electrolytic grinding force to. This research gets the rule that is between the grinding force and the shape error, and it also provides constraints for the future optimization of processing parameters.

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