• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.4
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• pp.40-45
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• 2016

Interrupted cutting has different cutting characteristics compared with continuous cutting. In interrupted cutting, the workpiece has a groove that regularly impacts the cutting tool and workpiece. Therefore, tool damage occurs rapidly, and this increases the cutting force and surface roughness. In this study, we performed interrupted cutting of carbon steel for machine structure (SM45C) using a coated carbide tool (TT7100). To predict the cutting force, we analyzed the experimental results with a regression analysis. The results were as follows: We confirmed that the factors affecting the principal force and radial force were cutting speed, depth of cut, and feed rate. From the multi-regression analysis, we deduced regression equations, and their coefficients of determination were 89.6, 89.27, and 28.27 for the principal, radial, and feed forces, respectively. This means that the regression equations were significant for the principal and radial forces but not for the feed force.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.9
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• pp.86-93
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• 2010

Any relative deformation between the cutting tool and the workpiece at the machining point, results directly in form and dimensional errors. The source of relative deformations between the cutting tool and the workpiece at the contact point may be due to thermal, weight, and cutting forces. Thermal and weight deformations can be measured at various positions of the machine tool and stored in the compensation registers of the CNC unit and compensated the errors during machining. However, the cutting force induced errors are difficult to compensate because estimation of cutting forces are difficult. To minimize the error induced by cutting forces, it is important to improve the machining accuracy. This paper presents the pre-calculated method of form error induced by cutting forces. In order to estimate cutting forces, Isakov method is used and the method is verified by comparing with the experimental results. In order to this, a cylindrical-outer-diameter turning experiments are carried out according to cutting conditions.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.178-185
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• 1999

In tool condition monitoring systems, parameters should be set to a certain threshold. In many cases, however, the threshold is dependent on cutting conditions, especially the radial immersion ratio. In this presented is a method of on-line estimation of the radial immersion ratio in face milling. When a tooth finishes sweeping, a sudden drop of cutting force occurs. The force drop is equal to the cutting force that acting on a tooth at the swept angle of cut and can be acquired from cutting force signals in feed and cross-feed directions. Average cutting force per tooth period can also be calculated from cutting force signals in two directions. The ratio to cutting forces in two directions acting on a tooth at a certain swept angle of cut and the ratio of average cutting forces in two directions per tooth period are functions of the swept angle of cut and the ratio of radial to tangential cutting forces. Using these parameters, the radial immersion ratio is estimated. Various experiments are performed to verify the proposed method. The results show that the radial immersion ratio can be estimated by this method regardless of other cutting conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.176-180
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• 2002

All types of VLM-s process include the linear heat cutting of EPS foam to generate a layer with 3D shape. The dimensional accuracy and part quality of the cut part are dependent on the thermal characteristics in the EPS foam. The thermal characteristics are determined by operating parameters such as an effective heat input and cutting angle. The objective of this study is to investigate into the influence of cutting angle on the kerfwidth and the melted length of the cut part using the numerical analysis and the experiments in generally sloped cutting with two cutting angles. In order to estimate an accurate temperature field, the transient thermal analysis using moving coordinate system, the fully conformed mesh and the heat flux model with two cutting angles is carried out. From the results of the analysis and the experiments, it has been found that the influence of the rotational angle about x-axis in which the rotational axis is normal with hotwire cutting direction is appreciably negligible in comparison with that of the rotational angle about y-axis.

• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.101-105
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• 2011

In most shipbuilding company, cutting procedure is proceed by cutting machine which run by CNC(Computer Numerical Code) data. In our cutting process, all CNC data is created by our nesting post processor system automatically. Among them, in case that cutting piece in the remnant plate, our system creates only one piece CNC data. Because remnant plate is not typical shape, and ship designers don't know remnant plate shape and quantity. In can happen some merit and good point if we modify 1:1 piece NC data by shorten cutting path, reducing cutting time or re-arrangement piece. For modifying cutting data, outside workers have to call to ship designer or have to go to NC control room where control the CNC system and cutting machine. It makes stop work process, and it waste time. In this paper, we introduce a program that can modify and replace 1:1 NC data with continuous or common NC data automatically.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.2
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• pp.69-77
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• 1991

The ultimate target of machining process is to get both precision and productivity simultaneously. To obtain these effects, many kinds of machining methods have been considered and various research effort has been made for a long time. Ultrasonic vibration cutting method is one of these methods. When the ultrasonic vibration is applied on the workpiece or the tool, the cutting tool makes periodical contact with workpiece due to vibration. The cutting is performed by vibrating impact force while the cutting tool contacts the workpiece, and it makes the displacement of both the tool and workpiece minimum in three force component (principal, axial, radial force) direction during the cutting process. So the cutting precision is better than conventional cutting method. The main results that obtained by the expriments of ultrasonic vibration cutting are as follows; 1. The value of roundness is about 1.4 ~ 2.5 [${\mu}m$] and this value is three or four times less than that of conventional cutting. 2. The value of surface roughness is about 1.2~2.2 [${\mu}m$] and this value is the two or three times less than that of conventional cutting.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.3 s.96
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• pp.72-77
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• 1999

This paper presents 2-dimensional vibration cutting increases dynamic stiffness of tool support and improves the quality of machined surface in micro-machining. 2-dimensional vibration cutting is generated by two piezo actuators arranged orthogonally. A sine-type voltage is input to one actuator and a phase-shifted sine-type voltage is input the other. Then the vibration device actuates the tool in a 2-D elliptical motion with pulsed cutting force. It is a characteristic of 2-D vibration cutting that some negative thrust force occurs as the direction of friction on a tool rake surface is reversed. It helps not only chip flow smoothly and continuously but also cutting force be reduced. The quality of machined surface by 2-D vibration cutting depends on such parameters as vibration amplitude, frequency, cutting speed, depth of cut, etc. Compared to conventional cutting through tool path simulation and experiments under several conditions, the 2-D vibration cutting is verified to bring forth a great decrease of cutting forces, much better surface roughness and moreover much less burr.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.4
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• pp.373-378
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• 2002

This paper presents a method to predict tool deflection induced by the thermal distribution and the cutting force using FEM in milling operation. The thermal distribution of cutting tool was predicted using FEM after measuring the temperature of the end of tool and of the tool holder. The thermal deflection of cutting tool was predicted using FEM as well. The tool deflection induced by the cutting force was analyzed with the solid model of cutting tool. An end mill tool caused most of tool deflection comparing to tool holder. Most of thermal deflection came from Z-direction and most of tool deflection induced by the cutting force came from X and Y direction. Precision cutting will be accomplished when tool locations are generated considering the thermal deflection of cutting tool and the tool deflection induced by the cutting force in CAD/CAM.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.1
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• pp.126-133
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• 1993

Conventional cutting(CC) and Ultrasonic Vibration Cutting(UVC) of 20[KHz] are practised with standard lathe for fine ceramics(A1$_{2}$O$_{3}$. UVC is suggested to good cutting method for difficult-to-machine-materials and it is known to excellent cutting method to super precision cutting and elevation of productibility for general, nonferrous matals. In this research, main results to be obtained are as follows: 1. From the CC and UVC results by general lathe with sintering diamond tool, the surface roughness and roundness are improved in UVC. Also tool life is longer in UVC than CC. From the observation of machined surface, it is found that brittle fracutural material remove occured in fine ceramics cutting. 2. It is verified that the thrust force is the biggest in fine ceramics cutting, principal force is the next, and feed rate force the third and it is appear a little, on the other hand the principal force is the biggest in metal cutting, feed rate frece is the second, and thrust force is the next.

• Journal of Digital Contents Society
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• v.18 no.7
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• pp.1387-1391
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• 2017

Cutting power estimation can be used to select appropriate actuators in the design process of machine tools. Therefore, accurate estimation of cutting power is an important part of the design process. In this study, pipe cutting power is first calculated theoretically using the slotting cutting power equation and then verified experimentally. In this case, a pipe cutting machine is used to cut two pipes made of different materials. Power consumptions in the motor during pipe cutting are measured by using the embedded software, Labview, and NI hardware. The slotting cutting power equation can thus be confirmed easily comparing theoretically calculated cutting powers with experimentally measured cutting powers. The pipe materials used in this study are SUS304 and AL6N01. The specific cutting power of AL6N01 material is proposed through our cutting experiment. As a result, this cutting power can be used to design machining tools for AL6N01 material.