• Journal of the Korean Society for Precision Engineering
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• v.13 no.9
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• pp.149-155
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• 1996

Recent researches in the trouble monitoring system of grinding process have emphasized the use of deep knowledge. Such works include the monitoring and diagnostic systems for cylindrical grinding using sensors on chatter vibration and grinding burn during the process. But, since grinding operations are especially related with a lalrge amount of ambique parameters, it is effectively difficult to detect the grinding troubles occuring during the grinding process. In this paper, monitoring system for grinding utilizes the neural networks based on grinding power signatures. The monitoring system of grinding operations, which makes use of PDP neural networks, is presented. Then, the implementation results by computer simulations and experimental data with respect to chatter vibration and grinding burn are compared.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.3
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• pp.174-183
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• 2000

Non-Parallelism the axial direction occurs during grinding process of long slender shafts. The reason for the axial error is due to elastic deformation of the components, accumulation phenomenon of the grinding and wheel wear during the grinding process. The accumulation phenomenon, the size generation mechanism and the wheel wear process during traverse grinding result in complicated process at each step on the wheel surface. The grinding system stiffness obtained from the stiffness of the center on the tailstock and the workpiece varing according to the relative position of the wheel and the workpiece. Further more, the value of wheel wear increases as the grinding process advances. The above mentioned issues make the shape generation process during traverse grinding quite complicated. This research analyzes the shape generation process in the direction of the work spindle. First, the formulation of the grinding system stiffness was conducted and the simulation analysis method of the traverse grinding was established. Also, a measuring system for assessing the dimensinal accuracy of the workpiece has been developed.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.45-52
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• 2000

To reduce two preprocess operations to one in the surface grinding operation the laminated grinding wheel was introduced and its availability has already been investigated in the cylindrical grinding process. Thus in this study the experiment was carried out to attempt to prove that the laminated grinding wheel can be used in the surface grinding process with respect to the roughness and grinding force.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.555-559
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• 1996

Based on the general drill grinding mechanism, termed the helical grinding system, the conceptual design of 5 axes CNC drill grinding machine is proposed. Unique determination of the grinding parameters for precise production of the desired flank geometry is discussed by utilizing a mathematical model. Also, different combinations of grinding parameters are mentioned in order to produce various drill geometries (conical, cylindrical, and planar drill) on the single proposed CNC machine. A manual helical grinding machine has been fabricated and consequently helical drills have been ground in order to check the feasibility of the proposed grinding mechanism and its functionality.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.10
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• pp.118-125
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• 1999

In the grinding process, generally, the exciting forces with high frequency can be generated due to the wheel wear and the grinding process. As the grinding speed increases, the precise investigation about the wheel dynamic characteristics is required. Conventionally the wheel-spindle has been considered with lumped model in dynamic modeling. With this lumped model, the significant mode resulted from the shell mode of wheel can be readily ignored. This paper suggests the new analysis model which includes the shell mode of wheel in modeling the wheel-spindle assembly. Furthermore, based on the suggested model, the effects of the bolt tightening force and the taper tightening force on the dynamic properties are investigated by the finite element modal analysis and the experimental method. As a result of investigation, the shell mode vibration of wheel affects the dynamic characteristics of the spindle assembly. Also, the vibration modes of the spindle assembly are significantly affected by the joint tightening forces.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.2
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• pp.138-143
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• 2000

The establishment of a practical ultra-precision grinding technique using Diamond and CBN wheels is one of the major key technolo-gies to improve production techniques for machine-to-difficult materials without finishing process such as lapping and polishing. But the special efficient dressing technique for ultra-fine grit type grinding wheels to stabilize the grinding ability was not developed. Recently electrolytic in-process dressing technique is proposed to ultra-fine grit type metal bonded diamond wheels to protrude abra-sives continuously from the tool surface. This technology can be widely used to surface grinding and cylindrical grinding but cannot be used efficiently to internal grinding because of the electrode attachment trouble. This paper describes the effect of interval type electrolytic dressing as proposed newly to cast iron bonded diamond wheel for efficient internal grinding with mirror type high quality ground surface.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.1018-1021
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• 1997

This paper presents a result of simulation and improvement of grinding process for linear motion guide blocks. A simulation software, which is based on cylindrical grinding process. is used to predict the grinding wheel wear during the grinding process. To validate the simulation, the simulation result is compared with the experimental one. Simulation study is extended to obtain an optimal grinding condition for minimizing the grinding wheel wear. The optimal condition is validated through an experiment.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.3
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• pp.35-39
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• 2001

The precision grinding process is carried out with fine-cutting operation after coarse-cutting operation. So, the laminated grinding wheel has been developed to reduce the ineffectiveness induced by changing the operations. In this study, to investigate the possibility of the practical use of the laminated grinding wheel, the surface residual stress of the workpiece ground by the laminated grinding wheels was compared with that ground by the general grinding wheel, and the influence of the difference in grain sizes, between the coarse grit and fine grit of the laminated grinding wheel, on the surface roughness of the workpiece was investigated.

• Journal of Mechanical Science and Technology
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• v.14 no.7
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• pp.773-781
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• 2000

The focus of this study is the development of a credible fault detection system of the cylindrical plunge grinding process. The acoustic emission (AE) signals generated during machining were analyzed to determine the relationship between grinding-related faults and characteristics of changes in signals. Furthermore, a neural network, which has excellent ability in pattern classification, was applied to the diagnosis system. The neural network was optimized with a momentum coefficient, a learning rate, and a structure of the hidden layer in the iterative learning process. The success rates of fault detection were verified.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.176-181
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• 1994

As tools for machining precesion componants, end mills and ball end mill are widely used. For the end mill have longer cylindrical shape comparing diameter, they are liable to deflect when machining and induce geometrical error and deterioration of surface roughness. To improve the stiffness and the sharpness of the cutting edge of end mill, a software for manufaturing end mills are developed. The progeam predicts the result of helical flute grinding and the configuration of cutting edge which is located in cylindrical surface. Furthermore to facilitate the manufacturing end mill using CNC grinding machine, the setting conditions which satisfy the geometrical requirments like tool rake angle and stiffness are obtained.