• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.2
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• pp.28-33
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• 2017

Recently, the operation of precision pocket machining has been studied for the high speed and accuracy in industry to increase production and quality. Moreover, the demand for products with complex 3D free-curved surface shapes has increasing rapidly in the development of computer systems, CNC machining, and CAM software in various manufacturing fields, especially in automotive engineering. The type of aluminum (Al6061) that is widely used in aerospace fields was used in this study, and end-mill down cutting was conducted in fillet cutting at a corner with end-mill tools for various process conditions. The experimental results may demonstrate that the end mill cutter with four blades is more advantageous than that of the two blades on shape forming in the same condition precise machining conditions. It was also found that cutting forces and tool deformation increased as the cutting speed increased. When the tool was located at $45^{\circ}$ (four locations), the corner was found to conduct the maximum cutting force rather than the start point of the workpiece. The experimental research is expected to increase efficiency when the economical precision machining methods are required for various cutting conditions in industry.

• Journal of Computational Design and Engineering
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• v.2 no.4
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• pp.218-232
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• 2015

Piecewise linear (G01-based) tool paths generated by CAM systems lack $G_1$ and $G_2$ continuity. The discontinuity causes vibration and unnecessary hesitation during machining. To ensure efficient high-speed machining, a method to improve the continuity of the tool paths is required, such as B-spline fitting that approximates G01 paths with B-spline curves. Conventional B-spline fitting approaches cannot be directly used for tool path B-spline fitting, because they have shortages such as numerical instability, lack of chord error constraint, and lack of assurance of a usable result. Progressive and Iterative Approximation for Least Squares (LSPIA) is an efficient method for data fitting that solves the numerical instability problem. However, it does not consider chord errors and needs more work to ensure ironclad results for commercial applications. In this paper, we use LSPIA method incorporating Energy term (ELSPIA) to avoid the numerical instability, and lower chord errors by using stretching energy term. We implement several algorithm improvements, including (1) an improved technique for initial control point determination over Dominant Point Method, (2) an algorithm that updates foot point parameters as needed, (3) analysis of the degrees of freedom of control points to insert new control points only when needed, (4) chord error refinement using a similar ELSPIA method with the above enhancements. The proposed approach can generate a shape-preserving B-spline curve. Experiments with data analysis and machining tests are presented for verification of quality and efficiency. Comparisons with other known solutions are included to evaluate the worthiness of the proposed solution.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.8
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• pp.759-763
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• 2015

The laser machining process has been proposed as an advanced process for the selective fabrication of electrodes without a mask. In this study, we adapt laser machining to metals that have different thermal properties. Based on the results, the metals exhibit a different surface morphology, heat-affected zone (HAZ), and a recast layer around the machined surface according to their thermal conductivity, boiling point, and thermal diffusivity. Then, we apply ultrasonic-assisted laser machining to remove the recast layer. The ultrasonic-assisted laser machining exhibits a better surface quality in metals with higher diffusivity than those having lower diffusivity.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.3
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• pp.104-114
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• 2022

The purpose of using coolant in machining is both to increase a tool life and also to prevent product deformation and thus, stabilize the surface quality by lubricating and cooling the tool and the machining surface. However, a very small amount of cutting mist should be used because chlorine-based extreme pressure additives are used to generate environmental pollutants in the production process and cause occupational diseases of workers. In this study, medical titanium alloy (Ti-6Al-7Nb) was subjected to a processing experiment by selecting factors and levels affecting cutting power in the processing of the Aerosol Dry Lubrication (ADL) method using vegetable oil. The machining shape was a slot to sufficiently reflect the effect of the cutting depth. As for the measurement of cutting force, the trend of cutting characteristics was identified through complete factor analysis. The factors affecting the cutting force of ADL slot processing were identified using the reaction surface analysis method, and the characteristics of the cutting force according to the change in factor level were analyzed. As the cutting speed increased, the cutting force decreased and then increased again. The cutting force continued to increase as the feed speed increased. The increase in the cutting depth increased the cutting force more significantly than the increase in the cutting speed and the feed speed. Through the reaction surface analysis method, the regression equation for predicting cutting force was identified, and the optimal processing conditions were proposed. The cutting force was predicted from the secondary regression equation and compared with the experimental value.

• International Journal of Quality Innovation
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• v.5 no.1
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• pp.10-22
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• 2004

The paper outlines a comprehensive three-step approach to the development of advanced strategies for quality control of a complex machining process. The research framework is a developed concept for Integrated Supervisory Process Control. The promising results obtained demonstrate a non-traditional approach to the deployment of quality and productivity requirements set by the system users, whereby the efficiency and systematization of the development of quality control strategies can be significantly improved.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.1-8
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• 2002

At present, company has to produce a product that consumer like with a competitive price, a good quality, and a fitting time to supply. Process control and qualify control are very important to supply with a product uniformly and inexpensively In this paper, the characteristic of product quality is monitored by control chart during the machining process and construction of quality control cycle is considered to divide into two types in this case that different assignable causes lead to shifts having different magnitudes. Then we are intended to find a process shift magnitude which has economical quality cost policy and are considered to quality cost functions to find a process shift magnitude. Those costs are categorized into the well-known categories of prevention, appraisal, and internal failure and external failure. This paper ends with numerical examples that demonstrate the usefulness of the model.

• Journal of Korean Society for Quality Management
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• v.20 no.1
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• pp.136-146
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• 1992

Most of scheduling papers on FMS have been considered that the fabrication process, the machining process and the assembly process etc. are independent and the releasing, routing, dependent, batching, loading problem are treated separetely. In this paper, we discuss that the integrated scheduling problem which can be solved for efficient use. We combine two systems that each process system which in order to produce a product is treated dependently, the releasing and the routing problem are combined one system and we present the efficient flexible manufacturing system as including the alternate process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.14-18
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• 2001

Rise in cutting force causes tool damage and worsens product quality resulting in machining accuracy deterioration. Especially, fragile material cutting brings about breakage of material and worsens product surface quality. In this study, we trace the locus of cutting force and examine the machined surface corresponding to the cutting force loci. and build up a monitoring system for deciding normal operation or not of cutting process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.507-512
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• 2000

Due to increasing demand toward improving product quality, various methodologies have been introduced. A brush type grinding tool is one of the most frequently used one to facilitate required process. In order to produce consistent burr shape, various machining conditions have been combined applied to disk grinding process. It has been observed that the burr dimension(shape and width) depends on the inclination angle between grinding disk and workpiece. Drastic increase of tool Wear has been also observed along the inclination angle variation. Various burr shapes have been captured and analyzed using image processing technique.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.10-15
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• 2004

A machining processes for flange panel has been introduced. Contrary to the conventional methods like forming and welding, roll-seaming method has been utilized for better quality and less cost. Several measurement methods including digital image processing have been used to confirm the product quality assurance.