• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.698-701
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• 2005

Nowadays, because of the frequent market change and variable customer's requirements, product's life-circle is becoming shorter. So, automobile companies are forced to rapidly develop new products and efficiently reduce both manufacturing lead time and cost, with the world level quality. Among them, Press Die is not only just a bottle neck but also an important resource exerting certain effect in quality of car body appearance. Since 2000, due to efforts to reduce the time of design phase, many companies have used 3D design methods. Actually the method didn't reduce the period of design because the company didn't develop the best practice. This paper wish to solve this problem by modular based hybrid dies template.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.21-28
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• 2004

In modem manufacturing industries such as the airplane and automobile, aluminum alloys which are remarkable in durability have been utilized effectively. High-speed machining technology for surface roughness quality of workpiece has been applied in these fields. Higher cutting speed and feedrates lead to a reduction of machining time and increase of surface quality. Furthermore, the reduction of time required for polishing or lapping of machined surfaces improves the production rate. Traditional milling process for high speed cutting can be machined with end mill tool. However, such processes are generally cost-expensive and have low material removal rate. Thus, in this paper, face milling cutter which gives high MRR has developed face milling cutter body for the high speed machining of light alloy to overcome the problems. Also vibration experiment to detect natural frequency in free state and frequency characteristics during machining are performed to escape resonance.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.11-14
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• 2001

A systematic construction and re-use of technology related to the product development and production has been the most important for the semiconductor industry dependent on process and equipment. Therefore, numerous outputs in the form of paper has been produced in the process of information management ranging from the creation to recycling and disposal of technologies. In this research, the technology and documents necessary for the business management in the field of semiconductor manufacturing were classified in an effort to solve problems while the modeling of document management architecture at the enterprise level was performed by properly setting up the security system to prevent the unauthorized disclosure of the product development technology to the third parties. Especially, the product and process specification are designed in such a way as to ensure a real-time response in interface with the production system in order to shorten the development lead-time and improve the productivity. This paper is to discuss the modeling approach, the strategy to construct the system and its results.

• Proceedings of the Korean Reliability Society Conference
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• 2002.06a
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• pp.227-233
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• 2002

Suspension system is one of the most important components indespensible for stability and reliability of automobiles. The demands to more safe and durable suspension system have been increased as the automobiles get popular and improve in quality. The crack in the coil spring of the suspension system produced during manufacturing may grow under a fatigue load and cause a severe safety problems which lead to a catastrophic damage to the passengers. Many conventional NDT techniques including ET, RT, and UT are less sensitive or hard to apply to detect the surface breaking crack in the suspension coils partly because the techniques are point-to-point measurement methods, thus take too long time to inspect the coil spring longer than 1m. Contrary to this, Lamb wave technique is full-field measurement method that make it possible to examine the whole coil spring in real time. In this paper, the Lamb wave is applied to the coil spring to investigate the possibility to detect the cracks on the surface of the coil spring.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.3
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• pp.47-52
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• 2001

Rapid Prototyping(RP) has been widely applied in designing and developing process of new products. RP can reduce the lead time and expense required to bring a new product form initial concept to production. Among several RP process can dramatically reduce the total build time and be applied for fabrication of large-sized and free form object because it uses in LOM the paper thickness is 0.05∼0.38mm as deposition feature segment. In this study, mechanical properties of pattern with LOM system is studied for optimal design of sand mold casting. The main result is that tensile, compressive strength and pattern size are significantly affected by temperature of hot roll.

• Journal of Welding and Joining
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• v.22 no.2
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• pp.46-50
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• 2004

In today's highly competitive marketplace, it is of great significance for the manufacturing industry to reduce lead-time and costs fur the product development. Since first emerged in 1986, Rapid Prototyping (RP) technology has helped successfully to reduce time and costs. Recently, RP using functional materials such as metal has been researched. However RP using the molten metal has been struggling to resolve several drawbacks, such as dimensional inaccuracy, poor surface finish, post finishing, etc., that originate primarily from the overall deposition of molten metal for each layer. So, the purpose of this study is to develop a new RP technique using sheet metal and projection welding for reducing several drawbacks in occurring RP using molten metal. Also tensile and bending specimens were made by the developed RP process using projection welding and were verified.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.3
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• pp.313-324
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• 1996

A new policy to determine the waiting position of an idle Automated Guided Vehicle(AGV) is proposed and its performance is compared with the existing waiting position policies. Unlike the existing policies, the queue length in the input buffer is considered in the new policy. As a result, the waiting position based on the new policy depends on the status of the system. The simulation result indicates that the proposed policy reduces the waiting time in both the input and the output buffers significantly, regardless of the number of AGVs in the system. Therefore, the manufacturing lead time can be minimized.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.109-114
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• 2005

The large injection molded parts technology such as instrument panel, front and rear bumper are presented for a precision molding. Some lead time and cost are required to product these part from design to mass product. Recently, CAE is widely used in product design, mold design and analysis of molding conditions to reduce time and cost. The optimal molding conditions can be obtained by DOE(Design of Experiment). The optimal design applications with CAE and DOE have been used in small molded parts. However, application to the large molded body is not reported. In this paper, optimization of injection molding process is studied for quality control in mass production of automobile bumper. Mold temperature difference is chosen through robust design of injection molding process, the molding process being optimized in term of shrinkage and deflection. The optimal conditions through DOE are validated by using injection molding analysis.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.293-299
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• 1996

The breakdown of machines lead to the lateness of parts and the change of schedules. Its treatment is very important problem in the shop floor control system. In this study, we present an algorithm minimize the lateness, earliness and change of schedule by controlling machining speed of available machines. Production time and production cost required to manufacture a piece of product are usually expressed as a unimodal convex fuction with respect to machining speed, and each has its minimal point at the minimum time speed or the minimum cost speed, and a speed range between these two speeds is called 'efficiency speed range'. Therefore, the algorithm determines the machining speed in the efficiency speed range. An example is demonstrated to explain the algorithm.

• Korean Journal of Computational Design and Engineering
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• v.15 no.6
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• pp.425-439
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• 2010

The current challenge with which most shipyards are forced is to reduce the design time and the time-to-delivery because of explosive order of shipbuilding. Collaborative design and product data management have become important to reduce the lead time. Furthermore, enterprise information technologies such as ERP (Enterprise Resource Planning), SCM (Supply Chain management), and APS (Advanced Planning System) requires the collaborative environment. Also, manufacturing environment has been considered as a topic of strategic interest to get shorter product lifecycles in shipyards. Most shipyards have chosen an environment of ETO (Engineering To Order) strategy which designs and produces new products in response to various requirements of customer, rules and regulations. In the ATO (Assemble 10 Order) environment, most component parts have been designed to be procured or produced on the order requirement. The basic distinction between the ETO and ATO is the timing of the design. Thus in the ATO environment, it is more flexible in reducing the lead time to meet the specified requirements of customers. However, the ETO strategy requires new ship design process and ship product structures that are linked with the implementation of PLM. And, the function and architecture of current PLM solution has been designed based upon ATO environment properly. This paper presents the PLM architecture which effectively reflects the characteristics of shipbuilding. 4-layer architecture model is suggested to implement the PLM system. Also, implemented functions of ship PLM is explained in order to make a practical guidance for ship PLM implementation.