• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.7 no.4
• /
• pp.56-63
• /
• 1998

The purpose of this is to analyze experimentally how the change of cutting speed have effects on hole over size of cutting hole, surface roughness of workpiece and roundness during the deep hole machining of SM55C with solid BTA drill using BTA drilling system. Conclusion reached is as follows. (1) The diameter was expanded for 25$\mu$m at the first section and then was reduced 0$\mu$m and 15$\mu$m respectively at the 10m and 20m section comparing to the diameter of tool with respect to the variation of cutting length at 70m/min of cutting speed. 0.15mm/rev of feed. (2) It was proved that roughness was below 8.67$\mu$m for the whole section of cutting length. (3) The roundness has been below 12$\mu$m. Regarding the polygon phenomenon, it has been proved that not only uneven best at 70m/min of cutting speed. 0.15mm/rev of feed.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.25 no.6
• /
• pp.401-409
• /
• 2016

The formation of micro-burrs in micro-milling processes causes several problems related to productivity and surface integrity. It should be minimized and suppressed by effective monitoring of the cutting conditions. This paper presents the correlation between the micro-burr length and cutting signals in the micro-milling process of an Al alloy (Al6061-T6). The acoustic emission (AE) signals and cutting force signals are acquired during the experiments. The characteristics of the cutting signals are obtained by analyzing the AE root mean square value and resultant cutting force. In addition, the micro-burr length is measured according to the cutting conditions by analyzing a scanning electron microscopy image of the machined surface. The results of this study can be used to enhance the surface quality of micro parts.

• Journal of the Korean Society for Precision Engineering
• /
• v.10 no.4
• /
• pp.206-215
• /
• 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.

• Journal of Bio-Environment Control
• /
• v.19 no.3
• /
• pp.153-158
• /
• 2010

To obtain the basic information for late-cultivation of sweet potato [Ipomoea hatalas (L.) Lam. cv. 'Jinhongmi'], vine growth and storage root yield were investigated in variously cutting sizes (10, 20, and 30 cm) and planting depths (1~4 nodes in 30 cm vine) using black-film vinyl mulching cultivation ($75{\times}25\;cm$ planting density, June 20). At 30 days after planting, main vine length, number of node, and vine fresh weight were significantly affected by the cutting length, and these were significantly different 10 and 30 cm at 120 days. The vine elongation affected by planting depths showed the best growth in 2-nodes planting depth and the lowest growth in 4-nodes planting depth at 30 days, but the vine growth was not significantly different among planting depths at 120 days. Number of storage root per plant, weight of storage root per plant, mean weight of storage root and yield of storage root were increased in longer cutting length, and those in 10 cm cutting length were significantly reduced compared to the 20 and 30 cm cutting length. Number of storage root per plant in the deeper planting was much increased, but mean weight of storage root was much decreased. Yield of storage root per 10a was highest in 3-nodes planting depth. Therefore, planting methods by cutting length over 20 cm and planting depth of 2~3 nodes in late-cultivation of sweet potato will be more efficient to improve the vine growth and storage root yield.

• 유공압시스템학회:학술대회논문집
• /
• 2010.06a
• /
• pp.66-69
• /
• 2010

A punched pipe in a muffler for an automobile has many important variables, like location of holes in the pipe and length of the pipe related to noise reduction of a diffuser. This pipe is cut depending on length of product and this process, generally workers cut pipes by hands. In this process, there are many errors and it relies on the skill of workers, so it can happen that cycle time for complete product gets long and productivity gets low. Therefore, we need a vision system to distinguish holes in the punched pipe and a transfer system to set the cutting position automatically by moving the pipe depending on forward and backward part of the holes. This paper explains the development of an automatic transfer device which will cause the beating pipe to be cut correctly, exactly the same length as the product.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.12 no.2
• /
• pp.252-261
• /
• 1988

Through the careful interpretation of the results of the cutting tests carried out in this study, it is found that under the cutting conditions when the internal shear of the chips take place the cutting can be treated essentially as a steady state problem. A new shear angle equation has been developed employing the conditions of force and moment equilibrium about the tool edge and the stress distribution model suggested by Zorev.The equation contains the chip-tool contact length C and stress distribution index n as important parameters.

• Journal of the Korean Society for Precision Engineering
• /
• v.33 no.6
• /
• pp.447-452
• /
• 2016

The simulation of Carbon fiber reinforced polymer (CFRP) machining facilitates the selection of optimal cutting parameter for high machining efficiency and better surface quality. In this study, This paper proposes a dual-dexel model to represent the fiber laminate with computational geometry method to calculate the fiber length removed per revolution and fiber cutting angles. A flat end milling simulation software is developed in C# to simulate and display the CFRP milling process. During simulation, fiber lengths, fiber cutting angle and engaged cutting angle can be displayed in real-time. A CFRP plate with different angles in different layer is used to compare the simulation results.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.5 no.5
• /
• pp.22-29
• /
• 2002

This study was conducted to suggest develop revegetation methods and to classification of cutting-rock slopes revegetation type. The data was collected from pre-experienced data, reports and journal. Also research result was reflected from field research for the conditions of construction, vegetation types and field conditions. As the result of analyze, the factors affecting the plant coverage rates of cutting-rock slopes were period of construction, revegetation methods, slope gradient and slope length. Classification of cutting-rock slopes revegetation type was fourth from material of revegetation measures and spray type. It is recommended to adjust the proposed factor as environment, field condition and characteristic related with revegetation measures on slopes for the presentation of revegetation standard.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.6
• /
• pp.837-844
• /
• 2001

Jet cutting technology currently makes use of a generic supersonic gas jet to improve the cutting speed and performance. In order to get a better understanding of the flow characteristics involved in the supersonic jet cutting technology, the axisymmetric Navier-Stokes equations have been solved using a fully implicit finite volume method. Computations have been conducted to investigate some major characteristics of supersonic coaxial turbulent jets. An assistant gas jet has been imposed on the primary gas jet to simulate realistic jet cutting circumstance. The pressure and the temperature ratios of the primary and assistant gas jets are altered to investigate the major characteristics of the coaxial jets. The total pressure and Mach number distributions, shock wave systems, and the jet core length which characterize the coaxial jet flows are strongly affected by the pressure ratio, but not significantly dependent on the total temperature ratio. The assistant gas jet greatly affects the basic flow characteristics of the shock system and the core length of under and over-expanded jets.

• Journal of the Korean institute of surface engineering
• /
• v.34 no.4
• /
• pp.337-341
• /
• 2001

TiN coating of high speed end mill is recently generalized. The study of coating layer using ion plating is mainly about the coating method and the why of the longer life of coated tools. In CNC machning process, metal cutting isn't carry out until the tools including the end-mill and so on are fractured. Namely, it is difficult precision processing when the cutting force of the cutting tool is near the limit the fracture cutting force. So, the estimate of the life by wear and fracture is important. Therefore, this study is about the method to estimate the capacity of the coating layer in relation to the tendency of cutting force and the influence of the cutting capacity of coated end-mill by the condition N2, Ar, temperature. The cutting length is in inverse proportion to the cutting force ratio. So, the life of the TiN coated end mill can be predicated by the ratio of the increase of the cutting force.