• 한국정밀공학회지
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• 제21권9호
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• pp.32-40
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• 2004

This paper deals with an automated computer-aided process planning and die design system by which designer can determine operation sequences even if they have a little experience in process planning and die design for axisymmetric products. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM softwares, DEFORM and ANSYS, to form a useful package. The system is composed of four main modules. The process planning and the die design modules consider several factors, such as the complexities of preform geometry, punch and die profiles, specifications of available multi former, and the availability of standard parts. They can provide a flexible process based on either the reduction in the number of forming sequences by combining the possible two processes in sequence, or the reduction of deviation of the distribution on the level of the required forming loads by controlling the forming ratios. Especially in die design module an optimal design technique and horizontal split die were investigated for determining appropriate dimensions of components of multi-former die set. It is constructed that the proposed method can be beneficial for improving the tool life of die set at practice.

• Design & Manufacturing
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• 제11권3호
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• pp.29-34
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• 2017

Increased demand for parts with micro-pattern structure made of metals, ceramics, and composites in various fields such as medical ultrasonic sensors, CT collimators, and ultra-small actuator parts. Micro powder injection molding (PIM) is a technology for manufacturing micro size, high volume, complex, precision, net-shape components from either metal or ceramic powder. In the present study, a standard mold with a variable insert core capable of producing various micro patterns was investigated. An injection molding test was performed on a standard mold using a line type micro-pattern core having an aspect ratio of 2, a slenderness ratio of 70, a pattern size of $200{\mu}m$, and a pattern spacing of $150{\mu}m$. During the filling process, the deformation of the mold with large aspect ratio and slenderness ratio was analyzed by the experiment and the numerical simulation according to the position of the gate. We proposed a mold structure that minimizes mold deformation by gate modification and enables uniform pattern filling behavior.

• 의료법학
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• 제17권2호
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• pp.29-56
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• 2016

의료사고에 대하여 의사측에게 손해배상책임을 묻기 위해서는 가해행위, 위법성, 유책성의 요건이 충족되어야 한다. 본 논문은 유책성의 요건인 과실에 대한 판례를 검토한 것이다. 의료손해배상에 대한 판례가 오랫동안 유지하고 있는 판결요지는 수정이 필요하다. 판결요지에 따르면 유책성 요소로서 의료과실은 주의의무 위반을 기준으로 한다. 주의의무 위반은 의료수준을 기준으로 한다. 의료수준은 임상의학의 실천수준에 따라 판단된다. 판결요지에서는 이를 사실적 판단대상이 아닌 규범적 판단대상이라고 한다. 그러나 개개 사안에서 판례는 판결요지와는 다르게 의료수준을 사실적으로 판단하고 있다. 주의의무는 의료수준이 아니라 의료수준에 따라 최선의 진료를 하여야 할 의무이다. 그리하여 의료수준을 규범적으로 판단하고, 이를 기준으로 주의의무를 다시 규범적으로 판단하여야 한다는 판결요지는 동어반복에 지나지 않는다. 판례는 과실로서 주의의무 위반에 이르지 않았다고 하여 의료손해배상책임을 부정한다. 그러나 실제 사안을 보면, 위법성이 부정되거나, 과실이 없거나, 인과관계가 없는 등 손해배상책임의 성립이 부정되는 이유는 다양하다. 판례는 일반인의 상식에 따른 증명, 간접사실을 통한 과실의 추정, 개연성을 통한 제한으로 과실증명에 대한 법리를 전개해 왔다. 구체적 사안의 해결에서 개연성에 대한 증명은 의학적 판단의 문제로 전환되었다. 요컨대 과실에 대한 증명부담의 완화라는 판례의 태도는 개연성을 통해 한걸음 후퇴하고 있는 모습이다. 이러한 배경하에서 의료지침을 위반한 중대한 치료상 잘못을 과실로 보고, 인과관계를 추정하는 독일민법 제630조의 h 제5항을 눈여겨 볼 필요가 있다. 이 조항은 독일에서 사실상 증명책임의 전환이라고 평가된다. 마취사고, 감염사고와 같이 일정한 의료지침을 준수하기만 한다면 경험칙상 악결과를 상당부분 예방할 수 있는 사안에서는 이와 같은 규정이 기능할 수 있는 가능성이 있다.

• 한국CDE학회논문집
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• 제12권3호
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• pp.182-192
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• 2007

The reduction of product development time is exposed to the competitive pressure due to shortened product-and production technology lifecycles as well as increasingly dynamic markets. Specially in automobile companies, that is of major importance for designing die because it is a bottleneck process in the development of a new car. To improve this conventional design process, this paper describes how to design it fast and flexibly. This was done by a modular method using standard template and a feature and knowledge based design method along the design process.

• 한국정밀공학회지
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• 제14권5호
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• pp.22-33
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• 1997

This paper describes a research work of developing a computer-aided design of blanking and piercing for stator and rotor parts. Based on knowledge-based rules, the die design system, STRTDES2, is designed by considering several factors, such as complexities of blank geometry and punch profile, and availability of press equipment and standard parts. Therefore this system can carry out a die design for each process which is obtained from the result of an automated process planning system, STRTDES1 and generate part drawing and the assembly drawing of die set in graphic forms. Knowledges for die layout are extracted from plasticity theories, relevant references and empirical know-hows of experts in blanking industries.

• 소성∙가공
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• 제14권3호
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• pp.239-244
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• 2005

The die & mould-design system fur the productivity increase is developed by our company. This system is made by UG API and constructs the standard through DB of parts of die & mould. Besides, the result of engineering analytic method is reflected in the design process in this system and the product precision is secured by On Machine Measurement method. Therefore, the ground of quality improvement and process innovation is solidified by the developed system and the competitiveness of die & mould manufacturing is intensified.

• International Journal of Precision Engineering and Manufacturing
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• 제2권2호
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• pp.38-47
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• 2001

This paper decribes the development of computer-aided design of a very precise progressice die for lead frame of semiconductor chip. The approach to the system is based on knowledgr-based rules. Knowledge of fie이 experts. This system has been written in AutoLISP using AutoCAD ona personal computer and the I-DEAS drafting programming Language on the I-DEAS mater series drafting with on HP9000/715(64) workstation. Data exchange between AutoCAD and I-DEAS master series drafting is accomplished using DXF(drawing exchange format) and IGES(initial graphics exchange specification) files. This system is composed of six main modules, which are input and shape treatment, production feasibility check, strip layout, data conversion, die layout, and post processing modules. Based on Knowledge-based rules, the system considers several factors, such as V-notches, dimple, pad chamfer, spank, cavity punch, camber, coined area, cross bow, material and thickness of product, complexities of blank geometry and punch profiles, specifications of available presses, and the availability of standard parts. As forming processes and the die design system using 2D geometry recognition are integrated with the technology of process planning, die design, and CAE analysis, the standardization of die part for lead frames requiting a high precision process is possible. The die layout drawing generated by the die layout module s displayed in graphic form. The developed system makes it possible to design and manufacture lead frame of a semiconductor more efficiently.

• 대한치과보철학회지
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• 제37권5호
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• pp.640-650
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• 1999

As an optimal quality of the restorations, there should be a least amount of seating discrepancy between the casting and abutment teeth. However, high viscosity of the cementing medium and its resulting thickness may prevent complete seating of the restoration. The use of die spacing material provides adequate internal relief for the cementing medium. The purpose of this study is to compare the thickness of three commonly used die spacing materials. Materials and Methods: Stone plates were fabricated and divided into 12 sections to be painted with die spacers. Tru-Fit, Whip-Mix and Belle do St. Claire die spacer which are commonly used in dental practice were tested in this study. Each die spacers were painted layer by layer according to the manufacturer's recommendation. The average thickness of each die spacers were measured with light microscope(${\times}100$) and compared between them. Results and Conclusions. A silver-colored Tru-Fit die spacer has the lowest value of thickness without statistical significance comparing with a gold-colored Tru-Fit die spacer and a gray layer of Whip-Mix die spacer has the highest value of thickness without any statistical significance comparing with Belle de St. Claire die spacer. Three and four layers of Tru-Fit die spacer and two layers of Whip-Mix and Belle de St. Claire die spacers seem to be in the acceptable range of thickness of 25 to $45{\mu}m$ for optimal seating of the restorations. The standard experimental design and method should be fur thor evaluated for more consistent and objective results.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.444-447
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• 2005

Increasing competition is due to internationalization in market. This result requires various products in a rapid development of product. Die design is one of bottleneck areas in product development. It takes 40% of total time for whole car development. Therefore a new method should be developed as a fundament on which the design process of die can be carried out effectively. This can be realized by using modular design based on standard template. In this paper a modular design concept will be discussed.

• 대한기계학회논문집
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• 제18권1호
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• pp.223-231
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• 1994

When manufacturing mold dies, an operation sheet is required for each part of the mold dies. The consistent estimation of standard operation time in the operation sheet is difficult, because the estimation is mainly based on subjective judgement. In order to resolve it, concept of feature is introduced in this study. For CAD/CAPP integration, feature technology is being implemented to represent geometrical and technological information of part drawings. A feature database has already been designed, and then used to generate data for process and operation planning modules. Related to this former research, standard operation time is calculated using the feature information and tables used in a real factory.