• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2004년도 춘계학술대회 논문집
• /
• pp.317-322
• /
• 2004

This paper deals with a prediction method of tool life in view of the reliability assessment. In this study, the flank wear was studied among multi-factors deciding the tool wear state. Firstly, tool lift was predicted by correlation between flank wear and cutting time, based on the extended Taylor tool life equation of turning data, including parameters of cutting speed, feed rate, and cutting depth. Secondly, each of cutting conditions of endmilling was equivalently converted to apply ball endmill data to the extended Taylor equation. The web-based reliability prediction program for tool lift is being developed as one of reliability assessment programs to for the machine tools.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1994년도 추계학술대회 논문집
• /
• pp.9-14
• /
• 1994

The modern CNC machine require increasingly an exact monitoring and control of cutting process. They are to make final taret which construct full automation factories as unmanned system. In this study, we decided that we develop new techique to monitor and detect tool breakage on the machining operation using face milling machine with multi-point throwaway tips. The technology in which the tool is illuminated by an beam of Laser is used by image of tool fracture through CCD camera.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
• /
• pp.30-31
• /
• 2006

In a multi-action tooling system, which is usually used for the powder compaction process to fabricate the complex multilevel parts, crack formation is crucially detrimental and should be avoided. Among various process factors, tool shape is an important factor to prevent the crack formation during powder compaction process. In this work, the effects of different tool shapes were investigated through the experimental oberservation of pore distribution in real products and the finite element analysis of residual stresses. The results were interpreted based on non-uniform powder density in the compacted parts.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 춘계학술대회 논문집
• /
• pp.862-867
• /
• 1997

A 5-axis NC milling technology is presented on ruled surface. Problems in 5-axis NC machining are such as tool interference,tool collision and change of tool attitude,etc. The change of tool attitude causes rotation of cutter and variation of feedrate to overcut part surface. This poor control of tool attitude is the primary problem in multi-axis NC milling. This paper observes ruled surface for control of tool attitude. Ruled surface is composed of directrix and ruling, line of constant magnitude. Directrix corresponds to points on part surface and Ruling cutting tool. Trajectory of tool movement corresponds to ruled surface.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제48권4호
• /
• pp.419-442
• /
• 2009

This study was to find the difficulties students faced in their mathematical learning and to identify the instructional dimensions a teacher provided for the students from multi-cultural background. Since the study was focused on the process of students' learning, the qualitative method was chosen through clinical interviews with 2 students in a total of 11 units which played a role of compensating their learning of mathematics as an extra curriculum. The students solved the computational problems relying on formal procedure without understanding of concepts and principles and solved the word problems based on own interpretation of certain words without semantic comprehension out of math sentences. As the instructional dimensions of teaching mathematics, tasks, a tool and classroom norm were found in the activities they performed. For the tasks, situated tasks, challenging tasks, tasks with lack of conditions, and open-ended exploratory tasks were used. As the tool, pictorial representations were very useful to describe their ideas. Finally, as the classroom norm, consider equity for everyone, and cooperate and encourage each other were found.

• 한국정밀공학회지
• /
• 제33권3호
• /
• pp.235-242
• /
• 2016

The purpose of this study is an attempt to improve the functionality of a conventional Fused Deposition Modeling (FDM) process using the Automatic Tool Changer (ATC) to perform multimaterial production and post-processing. Hybrid-FDM means a fusion of an Additive Manufacturing process and grinding process using the ATC system. In order to enhance the potentiality of production capacity for multi-material fabrication and surface roughness improvement, two extrusion tools and one grinding tool system are suggested. A pneumatic chuck is attached on a moving platform in the XY axes plane and an extrusion head and grinding head are placed in a docking station, allowing for a quick changeover with each other. Therefore, the manufacturing lead time can be reduced efficiently for the fabrication of a product.

• 소성∙가공
• /
• 제30권3호
• /
• pp.125-133
• /
• 2021

In this study, response surface method (RSM), back propagation neural network (BPNN), and genetic algorithm (GA) were used for modeling and multi-objective optimization of the parameters of AA5052-H32 in incremental sheet forming (ISF). The goal of optimization is to determine the maximum forming angle and minimum surface roughness, while varying the production process parameters, such as tool diameter, tool spindle speed, step depth, and tool feed rate. A Box-Behnken experimental design (BBD) was used to develop an RSM model and BPNN model to model the variations in the forming angle and surface roughness based on variations in process parameters. Subsequently, the RSM model was used as the fitness function for multi-objective optimization of the ISF process the GA. The results showed that RSM and BPNN can be effectively used to control the forming angle and surface roughness. The optimized Pareto front produced by the GA can be utilized as a rational design guide for practical applications of AA5052 in the ISF process

• 한국기계가공학회지
• /
• 제21권3호
• /
• pp.22-28
• /
• 2022

In the semiconductor and display component industries, the use of ceramic materials, which are high-strength materials, is increasing for ensuring durability and wear resistance. Among them, alumina materials are used increasingly. Alumina materials are extremely difficult to process because of their high strength; as such, research and development in the area of mineral material processing is being promoted actively to improve their processing. In this study, the processability of an electrodeposition tool is investigated using the electrodeposition method to smoothly process alumina materials. Furthermore, processing is conducted under various processing conditions, such as spindle speed, feed speed, and depth of cut. In addition, the processing characteristics of the workpiece are analyzed based on the tooling.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 추계학술대회 논문집
• /
• pp.174-177
• /
• 2008

This paper replaces an conventional 300-austenitic stainless steel sheet to a 400-ferritic stainless steel for the cost reduction of a pulsator cover of a washing machine. However, ferritic stainless steel has poor formability in comparison with austenitic one. The low formability of ferritic steel results in problems during stamping such as fracture, wrinkling, shape inaccuracy and so on. Design modification of the stamping tool is carried out with the aid of the finite element analysis for multi-stage stamping process. The simulation results show that fracture occurs on top of the product while wrinkles are generated by the excess metal near the wing part. Modification of the initial stamping die is performed to improve metal flow and to eliminate problems during the stamping process. Simulation with the modified design fully demonstrates that safe forming is possible without inferiorities.

• 한국전자통신학회논문지
• /
• 제14권4호
• /
• pp.755-760
• /
• 2019

본 논문은 기존 열선조각기, 열선 커팅기, 스핀들을 통합한 멀티 툴 조각기 개발을 통해 복잡한 구조의 형상도 손쉽고 빠르게 제작할 수 있도록 하였다. 또한 G-Code가 단일 툴에만 적용되는 문제점을 해결하고 기존 3D 모델링 툴로써 관리할 수 없는 기계의 세부 동작들을 제어할 수 있도록 소프트웨어를 개발하였다.