에어모터 하우징 양산용 다이캐스팅 금형의 불량과 대책에 관한 연구

김세환,최계광,Kim, Sei-hwan,Choi, Kye-kwang 한국금형공학회 2012 한국금형공학회지 Vol.6 No.1

HI-WORTH T-32, a non-powered plasma cutter, is a portable cutter that utilizes compressor-plasma inverter. With a special air-pressure piston, the cutter is semiautomatic. When they were produced by die casting dies, the bodies or housings of the cutter have defects about 100 percent of defect rate due to blisters and thermal deformation. Therefore, they are produced by mechanical machining, which leads to a hike in material and machining costs and to the loss of productivity. And companies are left with insignificant profit margins. Besides mechanical machining, this study proposes to modify defective mold and cut down defective rate and boost productivity.

드로잉 공정에서 소재 유입에 영향을 미치는 인자에 관한 연구

이성민,신진희,김경아,이춘규,Lee, Sung-Min,Shin, Jin-Hee,Kim, Kyung-A,Lee, Chun-Kyn 한국금형공학회 2022 한국금형공학회지 Vol.16 No.2

Sheet Metal Forming by Press Forming Process takes a lot of time and cost from mold design to manufacturing. Therefore, all of die-makers are continuously conducting research to reduce the number of mold processes or the size of blanks to reduce costs. In the case of Forming complex shapes such as automobile component, wrinkles and cracks occur, so draw beads are used. Draw beads play an important role in suppressing the inflow of materials and minimizing the size of blanks. Factors that affect material flow include draw bead, blank holding pressure, lubricant, and surface roughness of punch and die. Most of the factors affect friction. In this study, after classifying circular beads and rectangular beads in cylindrical drawing molds using the AutoForm analysis program, the factors affecting the material inflow were considered.

공공장소에서의 전기 자동차 충전기 디자인 콘셉트 제안

진아영,Jin, A-Young 한국금형공학회 2022 한국금형공학회지 Vol.16 No.2

Recently, electric vehicles are gaining popularity among many domestic and foreign users due to their eco-friendly advantages of reducing fine dust and environmental greenhouse gases. As the demand and supply of electric vehicles increase, the demand for electric vehicle charging infrastructure is also growing together. Many users are experiencing inconvenience due to poor charging infrastructure, which makes them hesitant to buy electric vehicles. Research on the user experience of chargers in apartment complexes, a common residential type in Korea, is being conducted somewhat, but research on the design of electric vehicle charging devices in public places is insufficient. The purpose of this research is to identify user requirements and complaints based on the product design of the electric vehicle charger in public places and propose a new electric vehicle product design concept that meets the requirements. The research method understood the charging base and status of electric vehicles in public places through literature research and examined and analyzed the characteristics and problems of product design cases that improved the charging problem of electric vehicles recently released in the market. It is intended to identify and analyze the problems of the charging device product design through user interviews, a qualitative research method, and based on this, it is intended to propose a user-centered product design concept that improves major complaints.

비화재보를 위한 X-ray tube 내 열 유동해석에 관한 연구

윤동민,전용한,Yun, Dong-Min,Jeon, Yong-Han 한국금형공학회 2022 한국금형공학회지 Vol.16 No.2

Currently, Korea is an aging society, and it is expected to enter a super-aging society in about 4 years. Accordingly, many X-ray technologies are being developed. In X-rays, 99% of X-rays are converted into heat energy and 1% into light energy (X-rays). 99% of the thermal energy raises the temperature of the anode and its surroundings, and the cooling system is an important factor as overheating can affect the deterioration of X-ray quality and shortened lifespan. There is a method of forced air cooling using natural convection. Therefore, in this study, when X-rays were taken 5 times, Flow analysis was performed on heat removal according to temperature rise and cooling time for the heat generated at the anode of the X-ray tube (input power 60kW, 75kW, 90kW). Based on one-shot, the most rapid temperature rise section increased by more than 57% to 0.03 seconds, A constant temperature rises from 0.03 seconds to 0.1 seconds, It is judged that the temperature rises by about 8.2% or more at one time. After one-shot cooling, the cooling drops sharply from about 60% to 0.03 seconds, It is judged that the temperature has cooled by more than 86% compared to the temperature before shooting. One-shot is cooled by more than 86% with cooling time after 0.1 seconds, As the input power of the anode increases, the cooling temperature gradually increases. Since the tungsten of the anode target inside the X-ray tube may be damaged by thermal shock caused by a rapid temperature rise, an improvement method for removing thermal energy is required when using a high-input power supply.

사출성형공정에서 다수 품질 예측에 적용가능한 다중 작업 학습 구조 인공신경망의 정확성에 대한 연구

이준한,김종선 한국금형공학회 2022 한국금형공학회지 Vol.16 No.3

In this study, an artificial neural network(ANN) was constructed to establish the relationship between process condition prameters and the qualities of the injection-molded product in the injection molding process. Six process parmeters were set as input parameter for ANN: melt temperature, mold temperature, injection speed, packing pressure, packing time, and cooling time. As output parameters, the mass, nominal diameter, and height of the injection-molded product were set. Two learning structures were applied to the ANN. The single-task learning, in which all output parameters are learned in correlation with each other, and the multi-task learning structure in which each output parameters is individually learned according to the characteristics, were constructed. As a result of constructing an artificial neural network with two learning structures and evaluating the prediction performance, it was confirmed that the predicted value of the ANN to which the multi-task learning structure was applied had a low RMSE compared with the single-task learning structure. In addition, when comparing the quality specifications of injection molded products with the prediction values of the ANN, it was confirmed that the ANN of the multi-task learning structure satisfies the quality specifications for all of the mass, diameter, and height.

열경화성 수지 재료를 이용한 광학 렌즈 제조공정에서 렌즈 변형에 대한 수축률이 영향에 관한 연구

박시환 한국금형공학회 2022 한국금형공학회지 Vol.16 No.3

In order to reduce the manufacturing costs of the glass lens, it is necessary to manufacture a lens using a UV curable resin or a thermosetting resin, which is a curable material, in order to replace a glass lens. In the case of forming a lens using a thermosetting material, it is necessary to form several lenses at once using the wafer-level lens manufacturing technologies due to the long curing time of the material. When a lens is manufactured using a curable material, an error in the shape of the lens due to the shrinkage of the material during the curing process is an important cause of defects. The major factors for these shape errors and deformations are the shrinkage and the change of mechanical properties in the process of changing from a liquid material during curing to a solid state after complete curing. Therefore, it is necessary to understand the curing process of the material and to examine the shrinkage rate and change of physical properties according to the degree cure. In addition, it is necessary to proceed with CAE for lens molding using these and to review problems in lens manufacturing in advance. In this study, the viscoelastic properties of the material were measured during the curing process using a rheometer. Using the results, Rheological investigation of cure kinetics was performed. At the same time, The shrinkage of the material was measured and simple mathematical models were created. And using the results, the molding process of a single lens was analyzed using Comsol, a commercial S/W. In addition, the experiment was conducted to compare and verify the CAE results. As a result, it was confirmed that the shrinkage rate of the material had a great influence on the shape precision of the final product.

판재 점진 성형 공정의 정밀도 향상을 위한 다이 구조 개선에 대한 연구

이원준,김민석,선민호,유제형,이창환,LEE, Won-Joon,KIM, Min-Seok,Seon, Min-Ho,YU, ․Jae-Hyeong,Lee, Chang-Whan 한국금형공학회 2022 한국금형공학회지 Vol.16 No.2

Unlike other press forming processes, ISF (Incremental sheet forming) doesn't require a punch and die set. However, during the ISF processes unwanted bending deformation occurred around the target geometry. This paper is aimed to analyze the effect of the die structure, which is supported by bolts, on the geometric accuracy of the ISF processes. In this research, the ISF processes with Al5052 sheet of 0.5 mm, the tool diameter of 6 mm and the stepdown of 0.4 mm was employed. L-shaped, step-shaped, relief-shaped geometry were employed in experiments. Sectional view and the plastic strain were compared. From this research we find out that the bolt supported ISF processes increases the geometric accuracy of products very effectively.

자동차 허브의 내경 및 평행도 자동검사 시스템에 대한 연구

강병수,유형민 한국금형공학회 2022 한국금형공학회지 Vol.16 No.3

In order to reduce the weight of parts and materials for the development of high-efficiency engines in accordance with the strengthening of automobile fuel efficiency regulations, the existing casting material is changed to a iron plate material, and plastic processing and turning operations are performed to lighten the weight and reduce the manufacturing cost. Among the pulley components applied to the damper pulley, the HUB product was manufactured by plastic machining instead of the existing casting process, and the inspection standardized for automating the inner diameter and parallelism measurement of the turning result of the new hub part with improved quality, and the inspection system for this Development of design and operation software to automate the inspection of the inner diameter and parallelism of the hub was described. The representative specifications of the development equipment are a hub inner diameter 22mm inspection system, a three-point inspection system with a parallelism of 0.15mm on the top.

피어싱 공정에서의 펀치 마모가 전단면에 미치는 영향 분석

전용준,김동언 한국금형공학회 2022 한국금형공학회지 Vol.16 No.3

The recent increasing application rate of advanced high-strength steel(AHSS) for automotive parts makes it difficult to ensure the durability of forming tools. Significant load and friction generated during the piercing process of AHSS increase the wear rate and the damage degree to dies. These harsh process conditions also yield product failures, such as dimensional inconsistency of pierced holes and insufficient quality of hole's sheared edge. This study analyzed the effect of punch wear on the sheared surface of pierced parts and the forming load during the piercing process. Wear-shaped punches showed approximately 20% higher piercing load than normal-shaped punches, and the rollover ratio of the sheared surface also increased. It is considered that the dull edge of wear-shaped punches does not penetrate directly into the material but shears after tensioning it in a piercing direction. In addition, wear-shaped punches experienced compressive load even after completing the piercing process during the down-stroke and tensile load during the up-stroke. This load variation is related to the smaller diameter piercing holes produced by wear-shaped punches compared to normal-shaped punches. Thus, we demonstrated the predictability of the wear level of dies through a comparative analysis of the piercing load pattern.

제약 반복적인 정규표현식 패턴 매칭의 효율적인 방법에 관한 연구

서병석 한국금형공학회 2022 한국금형공학회지 Vol.16 No.3

Regular expression pattern matching is widely used in applications such as computer virus vaccine, NIDS and DNA sequencing analysis. Hardware-based pattern matching is used when high-performance processing is required due to time constraints. ReCPU, SMPU, and REMP, which are processor-based regular expression matching processors, have been proposed to solve the problem of the hardware-based method that requires resynthesis whenever a pattern is updated. However, these processor-based regular expression matching processors inefficiently handle repetitive operations of regular expressions. In this paper, we propose a new instruction set to improve the inefficient repetitive operations of ReCPU and SMPU. We propose REMPi, a regular expression matching processor that enables efficient iterative operations based on the REMP instruction set. REMPi improves the inefficient method of processing a particularly short sub-pattern as a repeat operation OR, and enables processing with a single instruction. In addition, by using a down counter and a counter stack, nested iterative operations are also efficiently processed. REMPi was described with Verilog and synthesized on Intel Stratix IV FPGA.