• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.05a
• /
• pp.535-538
• /
• 2008

Insert-injection molding can inject two different materials or two colors in the same mold and process. If this injection process use, product has ability because the base part maintain strength and specified part can inject soft-material. It makes the cost down by single operation automatically for saving wages. In this paper, we designed double-injection mold for automobile remote control to inject secondary using this part as insert after inject external appearance of product. CAE analysis was progressed gate location and runner size as variable and analysis result is reflected in mold design process. As a result, it could solved badness that is generated at the conventional mold. Additionally, cost is downed by reducing loss of runner as well as could omit painting process because surface of finished product is improved through new mold.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.6
• /
• pp.29-35
• /
• 2020

Transition Nozzles are used in industrial air-cooled heat exchangers and widely used in industrial sites as an important component in the heat energy transfer between a heat source and an actuating fluid. There is a worldwide demand for transition nozzles with various materials and shapes, depending on the use environment. This paper aims to improve the transition nozzle forging process suitable for the production of many varieties using Steps 1 to 6 of the TRIZ Methodology for Problem Solving. By utilizing the TRIZ Methodology, this study derives a method to design a variable mold, which is more efficient and can reduce costs compared with having to use several molds. To verify the suitability of the methods derived using the TRIZ technique, a forging analysis is performed on a transition nozzle using DEFORMⓇ, a commercial program for plasticity analysis, and the nozzle material is evaluated for damage as a result of deformation of the transition nozzle thickness. The derived methods can be applied to transition nozzle formation equipment to improve the efficiency of the formation process.

• Design & Manufacturing
• /
• v.2 no.6
• /
• pp.49-55
• /
• 2008

Double-injection molding can inject two different materials or two colors in the same mold and process. If this injection process use, product has ability because the base part maintain strength and specified part can inject soft-material. It makes the cost down by single operation automatically for saving wages. In this paper, we designed double-injection mold for automobile remote control to inject secondary using this part as insert after inject external appearance of product. CAE analysis was progressed gate location and runner size as variable and analysis result is reflected in mold design process. As a result, it could solved badness that is generated at the conventional mold. Additionally, cost is downed by reducing loss of runner as well as could omit painting process because surface of finished product is improved through new mold.

• Design & Manufacturing
• /
• v.6 no.2
• /
• pp.84-89
• /
• 2012

In recent years, technology of press plastic working having made remarkable progress. We can say this because it facilitates mass production and have superior performances in machining speed and equivalency of quality than other processing methods. In characteristics of press plastic working, mold manufacturing according to characteristics of each product should be preceded before processing and it has a great influence on machining speed and quality of products and etc according to manufacturing method. Therefore, mold design technology is a critical technology in press plastic working. There are lots of variables in press plastic working according to worked material, mold materials, conditions of heat treatment, clearance and so on. Abrasion of mold depends on these kind of conditions and sheared surface which is crucial for quality of product also depends on them. In this study, we conduct research on abrasion loss of mold according to 8, 10 and 12% of clearance for thickness of 1.0mm of worked material out of mold design variables of the products whose worked materials are high carbon steel and carbon tool steel by a practical experiment.

• Journal of Korea Foundry Society
• /
• v.40 no.2
• /
• pp.25-33
• /
• 2020

The effects of mold variable and main alloying element on the mechanical properties of ductile cast iron poured into shell stack mold were investigated. The strength and hardness of with the smaller cross-section of the diameter of 6.25mm were higher than those of 12.50mm. On the other hand, the elongation of the former was lower than that of the latter. The strength and hardness of the specimens obtained from the center layer in the 5-story stack mold were the lowest and those for other specimens were increased with increased distance from the center. The elongation of those were the highest of all. The strength and hardness of the specimens obtained from the center layer were decreased the elongation was increased with the increased number of layers. The strength and hardness were increased and the elongation was decreased roughly with the increased amounts of reaidual magnesium and carbon content added, respectively. The strength and hardness were increased and the elongation was decreased roughly with the increased amounts of silicon content added to 2.45wt% and rather decreased with that to 2.85wt%. The effect of silicon content showed the opposite tendency to those of residual magnesium and carbon content.

• Design & Manufacturing
• /
• v.11 no.1
• /
• pp.26-29
• /
• 2017

Burrs generated during shear forming such as notching and piercing may cause lifting during product assembly, which may deteriorate the productivity and quality of products. In this study, various shear angles and variable clearances between the punch and the die were applied in experimental notching tests to investigate the shear fracture surface and the burr height due to various conditions. The experimental results show that the clearance has the greatest effect on shear and fracture surfaces. It is considered that the height of the shear section increases slightly as the shear angle increases.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.1
• /
• pp.34-39
• /
• 2011

Temperature control of a rubber injection mold is important for the dimensional accuracy of product. The main objective of this paper is to optimize the arrangement of heaters by FEM and optimal design method. Firstly, 3-dimensional transient heat transfer analysis was carried out for a square specimen mold. Results of FE analysis are a good agreement with the experimental results, showing about 1.22~7.22% error in temperature distribution. Secondly, we suggested the optimal method about an arrangement of heaters of rubber injection mold by using the optimal design technique. Distances between heater's center and the contact surface of mold, distances between heater's center and symmetric surface were considered as design variables. And the variances between the temperatures of cavity surfaces and their average temperature were used as the objective functions. Applying the optimal solution, the temperature variation was improved about 52.9~88.1 % compared to the existing mold. As a result of sensitivity analysis for design variables, design variables parallel to the direction of the split plane in mold affect the largest on the surface temperature variation in mold cavity.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.05a
• /
• pp.12-13
• /
• 2013

Free-form building is increasing because of request that an order to raise the value and request of the local residents and the government trying to own iconic and beautiful buildings. In addition, the installation and production of free-form concrete segment are now available because of development of construction technology, such as the development of materials and equipment. However, the production of free-form concrete segment requires a lot of time and manpower than shaping. In particular, resources of the mold for the production of free-from segment will be invested excessively because mold can not be recycled. Thus, the problems of increased costs, construction periods and loss of productivity occur. To solve these problems, this study proposes a technique of making the mold of for variable within a short time. Technique proposed in this study can be recycled die and will realize fast and accurate free-form concrete segment.

• Design & Manufacturing
• /
• v.10 no.1
• /
• pp.31-35
• /
• 2016

In sheet metal forming process, drawing is typical process. And the key factor of drawing is blank holding force (BHF) A low BHF can cause wrinkling, whereas a high BHF can cause fracture during a deep drawing process. Thus, formability can be influenced by application appropriate BHF. In this study, a variable blank holding force (VBHF) is applied to extend the forming limit by avoiding both wrinkling and fracture. To determine VBHF in drawing process, numerical simulations and statistical analysis are carried out using commercial FEM software.

• Journal of the Korean Ceramic Society
• /
• v.36 no.1
• /
• pp.89-96
• /
• 1999

Manufacturing conditions of the porous alumina mold were established to overcome various limits of the gypsum mold. For the preparations of the porous alumina mold, an activated charcoal was added to the Al2O3 with the wt% variation and then mixed. The binary slurry was study dispersed based on the examination of the ESA and rheological behaviro. The cylinder type alumina mold was cast in the gyspum mold and characterized by the shrinkage rate at the variable sintering temperature and the resistance against wear. It was proper to make a sintering of the Al2O3 by the surface diffusion which was non-shrinkage sintering mechansim, and intergranular neck growed stronger while sintering was being made. We studied a sintering by three categories; 1) thermodynamic method below 1,000$^{\circ}C$, 2) kinetic method above 1,000$^{\circ}C$ and 3) combined method. In the results of the respective works, combined method was superiro to the others. The prepared Al2O3 mold had relatively high strength, low drying rate, the resistance against the acid or base and good casting behavior.