• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.97-105
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• 2004

The vertical roller mill is the important machine grinding and mixing various crude materials in the manufacturing process of portland cement. Table liner is one of grinding elements of vertical roller mill and is subjected to the cyclic bending stress by rollers and the centrifugal force by rotation of table. It demands $4{\times}10^7$ expense of life but has $4{\times}10^6~-8{\times}10^6$ cycle. It fractures at the edge of grinding path of outside roller The repair expense fur it amounts to 30% of total maintenance of vertical roller mill. Therefore, this study shows the fracture mechanism of table liner of vertical roller mill using HDM and fatigue analysis

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.850-853
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• 2004

The development of 3D CAM system for the manufacturing of end mills becomes a key approach to save the time and reduce cost for end mills manufacturing. This paper presents the calculation and simulation of end mill tools CNC machining bases on 5-axes CNC grinding machine tool. In this study describes the process of generation and simulation of grinding point data between the tool and the grinding wheels through the machined time. Depend on input data of end mill geometry, wheels geometry, wheel setting, machine setting the end mill configuration and NC code for machining will be generated and visualized in 3 dimension before machining. The 3D visualizations of end mill manufacturing was generated by using OpenGL in C++. The development software was designed by using Microsoft Visual C++, which has many advantages for users, saving time and reducing manufacturing cost.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.157-160
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• 1995

Pencil cutting can eliminate overload in uncut area caused by large diameter ball-end mill before finish cutting. As ball-end mill for pencil cutting is long and type, it is easily deflected by cutting force. The tool deflection when pencil cutting with thin and long ball-end mill is one of the main reason of the machining errors on a free-form surface. The purpose of the research is to find the characteristics of deflected cutter trajectory by eddy-current sensor.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.565-583
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• 1993

In order to reduce the production cost and improve the quality of dairy feed, several dairy feed mill model suitable for Korean farm size are developed. Also, capital requirement and operating costs of the model mill are analyzed. And these analyzed data are compared with the commercial feed production cost, in order to test whether the model mills are suitable or not in Korean dairy farm. Also optimum model is recommended depending on size of dairy farm. As a result, developed model mill(TMR) is very useful in Korea dairy farm not only reduce production cost up to 78% but also improve the qualities.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.11
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• pp.47-56
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• 2013

Rolling speed, roll gap, and cooling pattern in hot strip finishing mill process should be determined before inserting strip into roll. Such parameters are initially calculated by a mathematical set-up model. The technique to find adequate roll speed via a mathematical model has inherently limit because required working conditions are various and rolling process is nonlinear. To improve the accuracy of initial rolling speed for a finishing mill, this paper suggests a correction technology for initial rolling speed. The proposed method was implemented in hot strip mill process. As the results, the magnitude of width error in strip head-end part caused by excessive strip tension was decreased remarkably.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.82-85
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• 2002

High-quality Sr-ferrite sintered magnets have been studied by using mill scale added SrCO$_3$ and oxidents before oxidation process. The pre-added SrCO$_3$ powders were improved the degree of oxidation and crush of mill scale and the magnetic properties of Sr-ferrite sintered magnets. The small added NaNO$_3$ oxidant was also highly improved the degree of oxidation and crush of mill scale and the magnetic properties of Sr-ferrite sintered magnets; 3805 G of remanent flux density, 3240 Oe of intrinsic coercivity, and 3.45 MGOe of maximum energy product.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.68.6-68
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• 2001

There is a looper for the safety threading between stands in finishing mill. In this looper system, it is 2 inputs 2 outputs MIMO )Multi Input Multi Output) system, which has two inputs that are the angle of looper and the tension of Strip and has two outputs that are the torque of looper motor and the speed of Mill Motor. In tension controller of looper, it calculates the range of tension variation into the compensation value of speed and outputs to the speed controller of Mill Motor, so that it controls the tension of strip between stands. In this study, using this tension controller of looper, we adjust the establishment value of ...

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.175.2-175
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• 2001

The strip profile and shape control is one of the most important technologies in Hot Rolling Mill System. Because the unbalance of strip´s shape and wave appearance between stands has a bad effect on Hot Rolling Mill System by making the inferior thickness, strip´s damage and so forth in factories. Many competition Plate Mill introduced shape control system, for example, pair cross-mill, work roll bender, which includes shape measuring instruments and shape control mathematical models. Shape meter, which is equipped for flatness, only does feedback control at the top of coil. And, for crown, we depend on initial setup value and there is no feedback control. Therefore we predict the shape of strip using rolling pressure, bender force and tension of inter-stand in ...

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.129.4-129
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• 2001

The looper control of hot strip finishing mill is one of the most important control item in hot strip rolling mill process. Loopers are placed between finishing mill stands and control the mass flow of the two stands. Another important action of the looper is to control the strip tension which influences on the width of the strip. So it is very important to control both the looper angle and the strip tension simultaneously but the looper angle and the strip tension are strongly interacted by each other. There are many control schemes such as conventional, non-interactive, LQ(Linear Quadratic), Hinf and ILQ(Inverse Linear Quadratic), Adaptive(gain scheduling) control in the looper control system. In this paper, we present the modeling for the looper of a hot strip finishing mill to control the tension of the strip and suggest another control method.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.67.1-67
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• 2002

We describe the looper controller design for a hot strip mill. The looper is to control the strip tension which influences on the width of the strip. It is very important to control the looper control of the hot strip mill, but difficult to control the looper, because there exists on mutual interaction among strip gauge, looper angle, and strip tension. In this paper, we present the modeling for the hot strip finishing mill to control the tension of the strip and suggest a cross control method of full-stand hot strip finishing mill. The cross control is a very simple method that allows non-interacting control.