• Transactions of Materials Processing
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• v.17 no.6
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• pp.443-448
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• 2008

Fiber reinforced injection molded parts are widely used in recent years because of their improved properties of materials such as specific stiffness, specific strength, and specific toughness. The demand for products with high precision is increasing and it is important to minimize the warpage of the products. The warpage of short-fiber reinforced product is caused by anisotropy induced by fiber orientation as well as the residual stresses induced during the molding process. In order to reduce the warpage of the part, it is important to achieve successful mold design, processing control, and part design. In the present study, the design of gating system, molding condition, and part structure were carried out and verified with numerical analysis using a commercial CAE code Moldflow. The numbers and locations of gates were iteratively determined, and the molding conditions which can decrease the warpage of the part were investigated. Finally, slight structural modification of the part was conducted to reduce the locally concentrated warpage.

• International Journal of Automotive Technology
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• v.1 no.1
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• pp.1-8
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• 2000

This paper reviews the main drivers forcing change and progress in powertrains for passenger cars in the coming years. The environmental drivers of omissions and CO2 will force better technical performance, but customer demand for increased choice will force change in the basic engine design and provide opportunities for alternate configurations of powertrain. Gasoline engines will embody refinements of valve train actuations as well as developments in combustion, especially direct injection and possibly a lean booated form of direct injection. Nevertheless, the conventional, port injected engine will continue to be the dominant engine for some years to come. The high speed direct injection diesel will very soon supplant its indirect injection predecessor completely. It will take an increasing share of the total powertrain market as improved specific power and refinement make it even more attractive to the customer. Car manufacturers will provide diesel models to satisfy this customer demand as well as using the efficiency of the diesel to enable them to meet their fleet CO2 commitments. Both gasoline and diesel engines will see an increasing degree of electrification and partial hybridisation as efficient flywheel mounted electrical devices become available.

• Journal of KSNVE
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• v.7 no.6
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• pp.909-918
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• 1997

Combustion oriented noise is a part of engine noise, which is mainly determined by the in-cylinder pressure profile and the structure attenuation of an engine. A numerical model for predicting the in-cylinder pressure profile and the resultant combustion noise developed by the use of a commercial code. The model is experimentally validated and updated based on the performance as well as the noise by considering the fuel injection timing, the fuel injection rate, Cetane number, intake temperature, and compression ratio. For providing a design guide of a fuel injector for a low combustion noise engine model, the optimal parameters of injection pressure profile, injection rate profile, and injection timing are determined, which gives the 5 dBA noise reduction.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.882-885
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• 2002

Magnesium alloys are very attractive materials for appling to the development of autemobile parts or electric goods where light weight and higher stiffness. Due to higher ratio of strength vs. weight and stillness vs. weight, various magnesium alloys are well applied in much weight saving design applications though extrusion or die-casting process. However for the requisites of higher strength and weight savings, some new fabrication processes has been and it can be realized though the aid of injection modeling technology. To obtain the parametric data base for the injection molding process, various experiments were executed for AZ91D magnesium alloy. This paper propose the optimum condition of injection temperature, first and second pressure. the process was lined-up successfully often changing the injection unit. fluid pressure system from the conventional plastic injection molding process.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.4
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• pp.388-395
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• 2015

The waste gate valve (WGV) for gasoline vehicles operate in a harsh high-temperature environment. Hence, WGVs are typically made of Inconel 713C, which is a type of Ni-based superalloy. Recently, the metal injection molding (MIM) process has attracted considerable attention for parts used under high-temperature conditions. In this study, an MIM analysis for the head and other parts of the WGV is conducted using a commercial CAE program Moldflow. Further, optimal manufacturing conditions are determined by analyzing flow characteristics at various injection times and locations. Moreover, to improve the accuracy of the analysis results, we compare the actual temperature of the mold during injection processing with that observed through the analysis. As the results, metal injection patterns of analysis are well in accord with these of short shot test. And the temperature variations of analysis is also very similar with those of feedstock when metal injection molding.

• Transactions of Materials Processing
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• v.18 no.2
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• pp.160-165
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• 2009

A Study on Effects of the Runner and the Gate of double shot injection molded Parts using CAE Double shot injection molding can inject two different materials or two different colors in the same mold in a injection molding process. Double shot injection molded parts can be characterized that the base part maintains strength and specified part can inject soft-material. It can reduce the production cost by single automatic operations. In this paper, we designed double shot injection mold for automobile emote control To inject secondary part, this part is used as an insert after external appearance of product is injected. CAE analysis was progressed gate location and runner size as variables. The analysis result is reflected in mold design process. As a result, it could solve problems which are generated in the conventional mold. Additionally, cost can be downed by reducing runner weight. As well as it could omit painting process because the surface of finished product is improved through new mold.

• Transactions of Materials Processing
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• v.11 no.5
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• pp.414-422
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• 2002

Most of numerical analyses for injection molding have been based on the Hele Shaw's approximation: two-dimensional flow analysis. In some cases, that approximation causes significant errors due to loss of geometrical information as well as simplification of the flow characteristics along the thickness direction. The present work covers numerical analyses of injection molding using three-dimensional solid elements. The accuracy of the analysis results has been verified through some numerical examples in comparison with the classical shell-based approach. The Proposed approach is then applied to predict product defects and to improve flow characteristics for a precision electronics part. In addition, design of experiment has been utilized in order to find the optimal process conditions for better product quality.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.02a
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• pp.68-75
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• 2002

Most of numerical analyses for injection molding have been based on the Hele Shaw's approximation: two-dimensional flow analysis. In some cases, that approximation causes significant errors due to loss of geometrical information as well as simplification of the flow characteristics along the thickness direction. The present work covers numerical analyses of injection molding using three-dimensional solid elements. The accuracy of the analysis results has been verified through some numerical examples in comparison with the classical shell-based approach. The proposed approach are then applied to predict product defects and to improve flow characteristics for a precision electronics part. In addition, design of experiment has been utilized in order to find the optimal process conditions for better product quality.

• Design & Manufacturing
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• v.13 no.2
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• pp.12-16
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• 2019

For optimal injection molding, various molding conditions should be combined well. Therefore, engineers should be thoroughly familiar with mold design, fabrication, and injection molding. The choice of resin among the various molding conditions is closely related to the productivity of the molded part and the deformation after molding, so the engineer must select the appropriate resin. Engineers work on the basis of data provided by resin manufacturers during molding. However, in actual molding work, it is necessary to apply values slightly different from those provided to obtain molded articles of desired performance. In this study, various deformations of molded products were compared with respect to crystalline resin and amorphous resin when molded according to the data provided by the resin maker and molded at the changed values at the work site.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.119-123
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• 2005

Mold design is a knowledge-intensive decision making process where product designer, injection molding engineer as well as mold designer affect each other. Representation and management of design knowledge is a prerequisite for an intelligent design system, which aims to guide and support designer to carry out design activity in more efficient way by avoiding or minimizing unnecessary trial and errors. This paper discusses the issues in knowledge-based mold design, and describes the structure of a knowledge-based mold design system fur parts with micro features under development.