• Design & Manufacturing
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• 제8권1호
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• pp.14-18
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• 2014

Even though 3D press die design gains more attention everyday in Korea, there are shortages of infrastructure and proper environments for it. What is most needed is human resources development and 3D die design standardization, on which the pace of 3D die design adoption depends. This study focuses on 3D press die design process by looking into an instance in which 3D die design system had been used to sell dies to a company "S" in Japan.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.316-321
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• 2000

Die Casting is one of the forming methods to manufacture large number of products with short period time and clean surface by high forming pressure and temperature of cast alloy. Die design is composed of selection of cast alloy, design of die casting product, runner and gate design etc. In reality, however, die design of die casting has been performed by trial and error method, which cause economic and time loss. This paper describes a research work of developing computer-aided design of die casting product and die design. Approach to the CAD system has been written in AutoLISP on the AutoCAD with personal computer. In this study, die design system for gate of die casting process has been developed to present algorithm for automation of die design, especially runner-gate system. As forming process and die design system using 3-D geometry handling are integrated with technology of process planning, die design is possible to set. In addition, specific rules and equations for the runner-gate system have been presented to avoid too many trails and errors with expensive equipment. It is possible for engineers to make automatic and efficient die design of die casting and it will result in reduction of expense and time to be required. An example is applied to cap-shaped casting using proposed algorithm.

• 한국기계가공학회지
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• 제12권3호
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• pp.7-12
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• 2013

In Die casting process, the problem of die degradation is often issued. In oder to increase of die life the material degradation of die steel was investigated using test core pins. Three test core pins were positioned in front of the gate entry and observed washout and soldering resistance during Mg die casting process. The test parameters are set as different commercial die materials, coatings condition and hardness of die surface. Usign 220t magnesium die casting machine was employed to cast AZ91 magnesium alloys. After 150 shots, macroscopic observation of die surface was carried out. Additional 50 cycles later, test pins were chemically cleaned with 5% HCl aqueous solution to find out the existence of washout and soldering layers. Microstructural characterization of die surface and the die roughness measurement were performed together. Computational simulation using AnyCasting program was also beneficial to correlate the extent of die damage with the position of test pin inside die cavity. As results, the optimal combination of die steel with productive coating as well as its hardness was drawn out. it will be helpful to decide the material and condition considering increasing of tool life.

• ETRI Journal
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• 제36권4호
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• pp.635-642
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• 2014

Three-dimensional integrated circuits (3D ICs) implement heterogeneous systems in the same platform by stacking several planar chips vertically with through-silicon via (TSV) technology. 3D ICs have some advantages, including shorter interconnect lengths, higher integration density, and improved performance. Thermal-aware design would enhance the reliability and performance of the interconnects and devices. In this paper, we propose thermal-aware floorplanning with min-cut die partitioning for 3D ICs. The proposed min-cut die partition methodology minimizes the number of connections between partitions based on the min-cut theorem and minimizes the number of TSVs by considering a complementary set from the set of connections between two partitions when assigning the partitions to dies. Also, thermal-aware floorplanning methodology ensures a more even power distribution in the dies and reduces the peak temperature of the chip. The simulation results show that the proposed methodologies reduced the number of TSVs and the peak temperature effectively while also reducing the run-time.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.143-147
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• 2003

Despite of outstanding optical performance of glass lens, glass lens have not been widely used because of poor productivity and high cost due to manufacturing process i.e. grinding, polishing. However, press-forming method of glass lens overcomes this disadvantage because of mass production. When glass lens is produced by press-forming method using closed die, it is needed that the volume of glass lens preform precisely measured in order to prevent incomplete products and to increase in life of die. The present paper shows the shortcoming of forming process with closed die, and performs FEM simulation of forming process with open die in order to overcome this shortcoming. The design parameter of open die is selected in standard of assembly with optical module and maintenance of optical performance. FEM simulation is carried out with selected parameter of open die and two basic preform. According to distribution of effective strain in glass lens, optical property of glass lens formed at each set of die and preform is compared.

• 소성∙가공
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• 제12권4호
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• pp.296-301
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• 2003

Though a glass tens has outstanding optical performance, it has not been widely used because manufacturing process shows poor productivity and high cost. However, press-forming method of glass lens overcomes these disadvantages with mass production. When glass lens is produced by press-forming method using closed die, it is needed that the volume of glass lens preform is precisely measured in order to prevent incomplete products and to increase in life of die. The present. paper shows the shortcoming of forming process with closed die, and performs FEM simulation of forming process with open die in order to overcome this shortcoming. The design parameters of open die are selected on the basis of assembly with optical module and maintenance of optical performance. FEM simulation is carried out with selected parameter of open die and two basic preform. According to distribution of effective strain in glass lens, optical property of glass lens formed at each set of die and preform is compared.

• 한국기계기술학회지
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• 제20권6호
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• pp.924-928
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• 2018

The objective of this study is to solve a problem that is occurred during the spline machining of tubular shaft yoke in both side IMS module. In order to simulate the problem, the movement direction of upper die was set as standard case and error case. The material of tubular shaft yoke was set to S20C as refer to the analysis library. The movement directions of upper die were separated with standard case and error case. The error case was set to simulate the problem in the spline machining of tubular shaft yoke. In order to solve the problem, the outer radius of upper die were modelled from 9.40mm to 9.44mm. The simulation results were analyzed and compared in terms of effective stress, metal flow line and folding phenomena characteristics. In case of the outer radius of upper die was 9.42mm, it was observed a relatively uniform effective stress distribution and had a straight metal flow line.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 The 8th Asian Symposium on Precision Forging ASPF
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• pp.152-157
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• 2003

A typical die-set for enclosed-die forging of half axle gears in double action hydraulic press is presented, the important factors those influence on precision forming of half axle gears are analyzed, warm forming process of half axle gears is simulated by FEM software $DEFORM\_3D$. The results show, that proper die structure and dimension, suitable web thickness and position can improve material filling, ensure full filling of tooth cavity.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.86-89
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• 1999

Structural analysis of die set in cold forging is conducted by the finite element method and the results are introduced in this paper. The problem formulation is introduced in detail. In the approach, amount of shrink fit is controlled by thermal load, i.e., temperature difference between die insert and shrink fits. The loading conditions are extracted automatically from a forging simulator. An application example is given.

• Design & Manufacturing
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• 제2권4호
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• pp.16-23
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• 2008

This paper describes $R_p,\;R_d,\;R_c,\;R_{cp},\;R_{cd}$ for design and manufacture of die by comparing the results. Results of this study could be reduced from three processes to two processes and drawing can be conducted using one die set by modifying structure of the punch head and die plate. Oil canning phenomenon can be prevented when circle blanking or ellipse blanking in blanking drawing. $R_c$, the important factor of drawing process was able to evaluate properly in designing of product.