• Design & Manufacturing
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• v.1 no.1
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• pp.1-5
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• 2007

Double injection molding process is very efficient molding-method for molding the products which is consist of multi-materials. Fuel-tube holder which is necessary for automobil power train and circulation systems is composed of plastic and rubber materials to minimize the vibration and pulsation noises. In existing process, fuel-tube holder was made by the insert molding process or assembly process after molding. If fuel-tube holder is manufactured by double injection molding process, it may be realize to improve the product quality, efficiency of molding-process and retrenchment of manufacturing cost. In this study, for manufacturing fuel-tube holder by double injection molding process, the analysis of joining characteristics between PA6(polyamide 6) and TPE(thermoplastic elastomer) was executed and the double injectin mold for molding fuel-tube holder with core toggle mechanism was fabricated. Finally, fuel-tube holder was molding using fabricated double injection mold.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.5
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• pp.738-747
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• 1998

The purpose of this study was to compare the positional stability of removable dies using several dowel pin systems. The removable dies were made by using five dowel pin systems: single dowel pin(Group I), single dowel pin and prepared groove on the die base(Group II), two-single dowel pin(Group III), two separate parallel dowel pins with plastic sleeves(Group IV), double straight dowel pins with metal sleeve(Group V). Special aluminum mold was made for specimens, and the dies of specimens removed and replaced thirty times with universal testing machine. Horizontal and vertical shift of dies was measured by Olympus monocular scanning tunneling microscope(STM5). The results were as follows: 1. The vertical shift was larger than the horizontal shift in all the other groups except Group I. 2. Single dowel pin system(Group I) was the most unstable of five dowel pin systems. 3. Double dowel pin systems with steeve(group IV, V) were the most stable of five dowel pin systems. 4. This study indicates that excellent horizontal positional stability is attainable with use of additional groove on the die base or double dowel pin. and excellent vertical positional stability is attainable with use of sleeve.

• Transactions of Materials Processing
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• v.17 no.8
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• pp.600-606
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• 2008

In closed-die hot forging, a billet is formed in dies such that the flow of metal from the die cavity is restricted. Some parts can be forged in a single set of dies, whilst others, due to shape complexity and material flow limitations, must be shaped in multi sets of dies. The purpose of a performing operation is to distribute the volume of the parts such that material flow in the finisher dies will be sound. This study focused on the design of preforms, flash thickness and land width by theoretical calculation and finite element analysis, to manufacture the super hot forging product, 70MC type piston crown used in marine engine. The optimal design of preforms by the finite element analysis and the design experiment achieves adequate metal distribution without any defects and guarantees the minimum forming load and fully filling of the cavity of the die for producing the large piston crown. The maximum loads obtained by finite element analysis are compared with the results of experiments. The loads of the analysis have good agreements with those of the experiment. Results obtained using DEFORM-2D enable the designer and manufacturer of super hot forging dies to be more efficient in this field.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.3 s.96
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• pp.84-90
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• 1999

The finishing process for dies and molds is directly related to finished surface quality, but many parts of process depend on human labor which needs much time and value. So automatic finishing machine has been produced for dies and molds, and applied widely for finishing process. Conventionally finishing machine has applied resin bonded finishing pad as a tool, but the removal ability of pad decreases greatly as finishing process goes on. In the finishing mechanism for dies and molds, finishing process is affected severely by cutting process, so can be divided into removing cusp and smoothing surface process. So, this study investigated the application of cast iron bonded diamond pellet for press dies, which is considered to have better characteristics than the other metal bonded pellets. The finishing characteristics were compared the between finishing pellet and pad. And finishing performance was appraised as the several cutting surfaces.

• 한국기계연구소 소보
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• s.17
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• pp.75-82
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• 1987

Shrink-rings (Stress-rings) are used in the fabrication of powder compaction dies to increase the allowable compaction pressures for a given die material. Optimum Procedures are used to insure that the stress distributions in the die and stress-rings ultilize fully the strength available in each of the die elements. Two criteria for the optimum die design are used: Maximum shear stress limit for one-piece dies and zero tensile stress limit for combined dies. Examples for each case are presented in this paper.

• Transactions of Materials Processing
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• v.4 no.1
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• pp.69-78
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• 1995

The arbitrary Lagrangian-Eulerian(ALE) finite element analysis is applied to the axisymmetric hot extrusion through continuous dies. In order to simulate hot forming problems, an ALE scheme for temperature analysis is proposed. The computed results are compared with experimental results as with those by pure Lagrangian method. In the present study mesh control is accomplished by the use of isoparametric mapping of quadrilaterals.

• Transactions of Materials Processing
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• v.6 no.3
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• pp.192-202
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• 1997

This study presents an effect of number of passes in wire-cut electric discharge machining on fine blanking dies and products. Three part fine blanking dies were produced by the difference of numbers of passes discharge machining. Brake pad was produced, through the die produced like that, the objective of this study is the improvement in surface roughness of die block and punch, life extension of die block, the decrease of second fracture dimensions, the rise of productive.

• Design & Manufacturing
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• v.2 no.3
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• pp.51-57
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• 2008

It is important factor to design the strip layout drawing according to product properties in press die design. Press dies are important processes in production such as a car component, house electronics, computer parts etc. In this paper, the strip layout of parts was designed for transfer dies. Results of this study can be modify the punch, trim position and notching shapes of strip layout. Utilization ratio was 70.3% by conducting piercing and notching for scrap design and materials were arranged with wide width of blank layout.

• Transactions of Materials Processing
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• v.5 no.2
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• pp.156-164
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• 1996

To investigate the behavior of plastic deformation in axisymmetric extrusion through square dies, experimental works with the plasticine as a model material are carried out at the room temperature. Some mechanical properties of the model material are determined by compression and ring compression tests. Visioplasticity method using expermental grid distortion in extrusion is introduced to analyze the plastic flow strain rate and strain distribution. In spite of severe deformation during the extrusion through square die the visioplasticity method shows good results for the distribution of effective strain rate and effective strain.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.3 no.1
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• pp.44-50
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• 1995

Abutment dies which resemble the actual size and shape of crown abutment is essential in most of the research area of fixed prosthodontics like marginal accuracy, crown seating, behavior of luting agent and so on. Seeing the large portion of research is done with round shaped dies in different size and cone angles, the necessity of research on the crown abutment is self-evident. 500 molar abutments were collected randomly through the commercial dental laboratoy, regrdless of their position in the dental arch, sex, and age. The measurements of 22 points of a die were done, and the results were as fogbows : 1. The height of the molar dies was $3.9{\pm}1.2mm$ 2. The bucco-lingual width was $8.9{\pm}1.2mm$ at the base, and $7.4{\pm}1.2mm$ at the occlusal. 3. The desio-sistal width was $8.2{\pm}1.2mm$ at the base, and $7.0{\pm}1.3mm$ at the occlusal.