• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 제5회 압출 및 인발가공 심포지엄
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• pp.1-6
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• 2002

In the extrusion process, the working material is forced to flow through a die with the desired profile. In general the width of m extruded section is limited to about an inch less than the diameter of the round billet But through the lip die, material is spreaded to produce a wider extruded section than the diameter of round billet. In this study, the extrusion process of an aluminum plate using the lip die is investigated. The width of extruded plate is 450nm that is formed form the round billet with a diameter of 250mm. The flow characteristic through the lip die is considered to produce the wide-extruded plate with a small billet.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.311-318
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• 2001

A three-dimensional numerical analysis of the flow and heat transfer characteristic of wood-flour-filled polypropylene melt in an extrusion die was carried out Used for this analysis were Finite Concept Method based on FVM, unstructured grid and non-Newtonian fluid viscosity model. Temperature and flow fields are closely coupled through temperature dependent viscosity and viscous dissipation. With large Peclet, Nahme, Brinkman numbers, viscous heating caused high temperature belt near die housing, Changing taper plate thickness and examining some predefined parameters at die exit investigated the effect of taper plate on velocity and temperature uniformities. In the presence of taper plate, uniformity at die exit could be improved and there existed an optimum thickness to maximize it.

• 한국산학기술학회논문지
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• 제7권4호
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• pp.550-553
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• 2006

본 논문에서는 다이 플레이트(Die Plate)를 제작할 때 생산성 향상을 위해서 3D CAD/CAM 시스템을 적용하였다. 사용된 3D CAD/CAM 소프트웨어는 UG NX 3.0이며 생성된 NC 코드는 CNC밀링 및 와이어 컷 방전가공기에 전송되어 다이 플레이트를 자동 가공한다.

• 한국기계가공학회지
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• 제5권3호
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• pp.23-28
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• 2006

The focus of this study is placed on the enhancement of flatness for the shielded slot plate, one of main components of the MCFC stack. The shielded slot plate is to get curvature during manufacturing process since it is produced by forming operation from only one side of it. Therefore, a correction die is proposed to place just after the main die to apply unbending on the curved plate to get almost flat product. In the design for the correction die, four kinds of design factors are selected to study which factor is the most influencing one affecting the flatness of the plate. From the experimental results using Taguchi method, it has been revealed that the Young's modulus of urethane die is the most critical factor.

• 소성∙가공
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• 제19권8호
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• pp.447-451
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• 2010

In this paper, a useful die system for warm plate forging of a large axle housing of heavy-duty trucks is presented. A die system composed of material flow guide pin as well as upper die and lower die is proposed to reduce the inherent thickness reduction along the bent corner of the product which deteriorates structural strength and fatigue life in its service. The role of the pin assembled in the upper die is to prevent formation of sharp corner in early forming stage and to supply material in the lower die cavity sufficient enough to thicken the bent corner at the final stroke. The mechanism of the die system is given and its effect on corner thickness of the product is revealed by two-dimensional finite element analysis under plain strain assumption. Three-dimensional finite element solutions are also given to verify validity of the two dimensional approach and to show the mechanics of the die system in detail. The die system has been successfully applied to manufacturing the axle housing of heavy-duty trucks.

• 열처리공학회지
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• 제22권1호
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• pp.16-22
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• 2009

The rolling process is an efficient and economical approach for the manufacturing of plate metals. In the rolling process, the temperature variation is very critical for plate thickness accuracy. The main cause of thickness variation in hot plate mills is the non-uniform temperature distribution along the length of the slab. Also the exit plate thickness is mainly affected by the rolling conditions such as mill modulus, plate thickness and plate width. Hence the thickness variation in top-end is also dependent on these factors. Therefore this study has concentrated on determining the correct amounts of thickness variation due to top-end temperature drop and process parameters.

• 대한기계학회논문집B
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• 제27권2호
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• pp.147-154
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• 2003

A three-dimensional numerical analysis of the flow and heat transfer characteristic of wood-flour-filled polypropylene melt in an extrusion die was carried out. Used for this analysis were Finite Concept Method based on FVM, unstructured grid and non-Newtonian fluid viscosity model. Temperature and flow fields are closely coupled through temperature dependent viscosity and viscous dissipation. With large Peclet, Nahme, Brinkman numbers, viscous heating caused high temperature belt near die housing. Changing taper plate thickness and examining some predefined parameters at die exit investigated the effect of taper plate on velocity and temperature uniformities. In the presence of taper plate, uniformity at die exit could be improved and there existed an optimum thickness to maximize it.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.273-276
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• 2006

The focus of this study is on the enhancement of flatness for the shielded slot plate, one of main components of the MCFC stack. The shielded slot plate is to get curvature during manufacturing process since it is produced by forming operation from only one side of it. Therefore, a correction die is proposed to place just after the main die to apply unbending on the curved plate to get almost flat product. In the design for the correction die, four kinds of design factors are selected to study which factor is the most influencing one affecting the flatness of the plate. From the experimental results using Taguchi method, it has been revealed that the Young's modulus of urethane die is the most critical factor.

• 한국주조공학회지
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• 제32권2호
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• pp.65-74
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• 2012

In this paper, we present the results of our studies on optimal die design towards development of a vacuum die casting process to fabricate fuel cell bipolar plate with micro-channel array. Cavity and overflow shape is designed by computational filling analysis of MAGMA soft. Optimal die design consists of seven overflows at the end of cavity and three overflows at each side wall of cavity. The molten metal that passed the gate and reached the side wall flowed into the side overflow, no turbulent flow occurred, and the filling behavior and velocity distribution were uniform. In addition, partially solidified molten metal passing through the channel was perfectly eliminated by overflow without back-flow. When vacuum pressure, injection speed of low and high region was 300 mbar, 0.3 m/s and 2.5 m/s respectively with Silafont 36 die casting alloy, sound sample without casting defects was obtained. The experimental results are nearly consistent with simulation results.

• 소성∙가공
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• 제23권2호
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• pp.88-94
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• 2014

The under-drive brake piston is an essential part in the automatic transmissions of automobiles. This component is manufactured by forging after blanking from S55C plate with a thickness of 6mm. It is difficult to design the plate forging process using a thick plate approach since there will be limited material flow as well as large press loads. Furthermore, the under-drive brake piston has a complex shape with a right angle step, which often results in die unfill and abrupt increase in press load. To overcome these obstacles, a separate die for filling material sufficiently to the corner of the right angle step is proposed. However, this approach induces an uncontrolled workpiece surface between the dies, resulting in flash. This excess flash degrades the tool life in the final machining after cold forging as well as increases the cycle time to obtain the net-shape of the part. In the current study, we propose an optimum process design using a conventional die shaped with the benefit of finite element analysis. This approach enhanced the process efficiency without sacrificing the dimensional accuracy in the forged part. As the result, the optimum plate forging process was done with a two stage die, which reduces weight of by 6% compared with previous process for the under-drive brake piston.