• 한국정밀공학회지
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• 제14권3호
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• pp.57-65
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• 1997

In this study, a cutting force in the Ball-end milling process is calculated using Z-map. Z-map can describe any type of cutting area resulting from the previous cutting geometry and cutting condition. Cutting edge of a ball-end mill is divided into infinitesimal cutting edge elements and the position of the ele- ment is projected to the cutter plane normal to the Z axis. Also the cutting area in the cutter plane is obtained by using the Z-map. Comparing this projected position with cutting area, it can be determined whether it engages in the cutting. The cutting force can be calculated by numerical integration of cutting force acting on the engaged cutting edge elements. A series of experiments such as contouring and upward/downward ramp cutting was performed to verify the calculated cutting force.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.779-782
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• 2000

This paper aimes to clarify the effects of tool geometry on the tool life in machining of STS 304. The main conclusions obtained were as follows. The lift of TiN coated cermet tool was the longest, exhibiting shorter life in the order of P2O, cermet, TiCN coated carbide and TiAIN coated carbide tools. S-type tool showed the best performance of all tools used in this tests due to preventing the boundary wear of the side cutting edge.

• 한국공작기계학회논문집
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• 제13권6호
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• pp.1-9
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• 2004

For improvement of productivity and cutting tool lift, cutting force in end milling needs to be predicted accurately. In order to analyze cutting force, the cutting dynamics was modelled mathematically by using chip load, cutting geometry, and the relationship between cutting forces and the chip load. Specific cutting force coefficients of the cutting dynamics model were obtained by average cutting forces, tool diameter, cutting speed, fled, axial depth and radial depth of cut. The effects of the cutting conditions on the specific cutting force constants in milling were studied. The model is verified through comparisons of model predicted cutting forces with measured cutting forces obtained from machining experiments.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.93-98
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• 2004

A reasonable analysis of cutting force in end milling may give much advantage to improvement of productivity and cutting tool life. In order to analyze cutting force, the cutting dynamics was modelled mathematically by using chip load, cutting geometry, and the relationship between cutting forces and the chip load. Specific cutting constants of the cutting dynamics model were obtained by average cutting forces, tool diameter, cutting speed, feed, axial depth, and radial depth of cut. The effects of the cutting conditions on the specific cutting force constants in milling were studied. The model is verified through comparisons of model predicted cutting forces with measured culling forces obtained from machining experiments

• 한국공작기계학회논문집
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• 제11권3호
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• pp.72-79
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• 2002

Though the laser cutting process is increasingly used in industry, a process automation and systematic database is still yet to be developed. In this study, as the fundamental step toward the construction of a reliable process expert system, a laser cutting quality monitoring/analysis system is developed based on simulations and experimental results. The relations between laser process parameters and laser cutting surface quality parameters such as kerf geometry, striation, surface roughness and dross formation are characterized and analyzed. A graphical user interface is used to visualize the results.

• 한국공작기계학회논문집
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• 제13권4호
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• pp.9-15
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• 2004

A reasonable analysis of cutting force in end milling may give much advantage to improvement of productivity and cutting tool life. In order to analyze cutting force, the cutting dynamics was modelled mathematically by using chip load, cutting geometry, and the relationship between cutting forces and the chip load. The specific cutting constants of the cutting dynamics model were obtained by average cutting forces, tool diameter, cutting speed, feed, axial depth, and radial depth of cut. The model is verified through comparisons of model predicted cutting forces with measured cutting forces obtained from machining experiments. The results showed good agreement and from that we could predict reasonably the cutting forces in end milling.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.52-57
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• 2000

STD11 is one of difficult-to-cut materials and its cutting characteristic data is not built enough. A bad cutting condition of it leads to low productivity of die and mould, so it is necessary to evaluate the machining characteristics of STD11. In this paper, the relations of the geometry of ball-end mill and mechanics of machining with it are studied. The helix angle of ball-end mill varies according to a location of elemental cutting edge in the cutting process are difficult to calculate accurately. To calculate instantaneous cutting forces, it is supposed that the tangential, radial and axial cutting force coefficients are functions of elemental cutting edge location. Elemental cutting forces in the x,y and z direction are calculated by coordinate transformation. The total cutting forces are calculated by integrating the elemental cutting forces of engaged cutting edge elements. This model is verified by slot and side cutting experiments of STD11 workpiece which was heat-treated to HRC45.

• 한국정밀공학회지
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• 제10권4호
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• pp.206-215
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• 1993

The finite element method is applied to analyze the mechanism of metal cutting, especially micro metal cutting. This paper introduces some effects, such as constitutive deformation laws of workpiece material, friction of tool-chip contact interfaces, tool rake angle and also simulate the cutting process, chip formation and geometry, tool-chip contact, reaction force of tool. Under the usual plane strain assumption, quasi-static analysis were performed with variation of tool-chip interface friction coefficients and tool rake angles. In this analysis, cutting speed, cutting depth set to 8m/sec, 0.02mm, respectively. Some cutting parameters are affected to cutting force, plastic deformation of chip, shear plane angle, chip thickness and tool-chip contact length and reaction forces on tool. Several aspects of the metal cutting process predicted by the finite element analysis provide information about tool shape design and optimal cutting conditions.

• 한국정밀공학회지
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• 제23권3호
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• pp.39-46
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• 2006

In this work a dynamic cutting force model in ball end milling of inclined surface is introduced. To represent the complex cutting geometry in ball end milling of inclined surface, workpiece is modeled with Z-map method and cutting edges are divided into finite cutting edge elements. As tool rotates and vibrates, a finite cutting edge element makes two triangular sub-patches. Using the number of nodes in workpiece which are in the interior of sub-patches, instant average uncut chip thickness is derived. Instant dynamic cutting forces are computed with the chip thickness and cutting coefficients. The deformation of cutting tool induced by cutting farces is also computed. With iterative computation of these procedures, a dynamic cutting force model is generated. The model is verified with several experiments.

• Journal of Mechanical Science and Technology
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• 제14권6호
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• pp.622-632
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• 2000

In a high precision vertical machining center, the estimation of cutting forces is important for many reasons such as prediction of chatter vibration, surface roughness and so on. The cutting forces are difficult to predict because they are very complex and time variant. In order to predict the cutting forces of end-milling processes for various cutting conditions, their mathematical model is important and the model is based on chip load, cutting geometry, and the relationship between cutting forces and chip loads. Specific cutting force coefficients of the model have been obtained as interpolation function types by averaging forces of cutting tests. In this paper the coefficients are obtained by neural network and the results of the conventional method and those of the proposed method are compared. The results show that the neural network method gives more correct values than the function type and that in the learning stage as the omitted number of experimental data increase the average errors increase as well.