• 제목/요약/키워드: cold extrusion

검색결과 142건 처리시간 0.041초

중공축 내접 스플라인 성형을 위한 설계변수의 영향 (Effect of the Design Parameter for Internal Spline Forming Using the Tube)

  • 왕창범;임성주;박용복
    • 소성∙가공
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    • 제15권7호
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    • pp.512-517
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    • 2006
  • In this paper, the cold extrusion process for internal spline forming using a thin and long tube has been analyzed by using a rigid plastic finite element code. The internal spline consists of 10 tooths. The cold extrusion process has been focused on the comparisions of load-stroke relation and filling states of the teeth according to design parameters. The design parameters involve extrusion ratio, extrusion angle and friction factor. The internal spline forming can cause the buckling and folding during the cold extrusion process because of using a thin and long tube. The optimum design parameters have been obtained through rigid-plastic finite elements analysis. The extrusion ratio and extrusion angle have great effects on the deformation characteristics of the cold extrusion process.

저온 및 재래식 공정에 따른 쌀·야채류 압출성형물의 항산화 활성 비교 (Comparison of Antioxidant Activities of Extruded Rice with Vegetables by Cold and Conventional Extrusion)

  • 안상희;류기형
    • 한국식품영양과학회지
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    • 제44권8호
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    • pp.1212-1218
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    • 2015
  • 본 연구는 저온 및 재래식 압출성형 공정에 따른 쌀 야채류 압출성형의 항산화 활성에 대해 분석하였다. 압출성형 조건은 수분 함량 25%, 스크루 회전속도 150 rpm으로 고정하였다. 저온 압출성형 조건은 사출구 온도 $80^{\circ}C$, $CO_2$ 주입량 300 mL/min, 재래식 압출성형은 사출구 온도 $140^{\circ}C$, $CO_2$ 0 mL/min으로 조절하였다. 원료는 쌀 분말에 단호박, 토마토, 딸기 및 녹차 분말을 각각 10%씩 혼합하여 사용하였다. 단호박 및 토마토 첨가한 압출성형물의 DPPH 라디칼 소거능은 저온 압출성형 공정보다 재래식 압출성형 공정에서 더 높았다. 단호박, 토마토 및 딸기를 첨가한 압출성형물은 압출성형 후 총 페놀 함량이 증가하였으며, 저온 압출성형물보다 재래식 압출성형물에서 총 페놀 함량이 다소 높았다. 총 플라보노이드 함량은 녹차를 첨가한 재래식 압출성형물이 18.82 mg/g으로 가장 높았다. 압출성형 후 단호박을 첨가한 압출성형물의 총 카로티노이드 함량은 낮아졌으나 토마토 압출성형물은 증가하였다. 토마토 압출성형물의 라이코펜 함량은 압출성형 후 증가하였으며, 재래식 압출성형에서 더 높았다. 딸기 압출성형물의 안토시아닌 함량은 저온 압출성형보다 재래식 압출성형 공정에서 높았다. 압출성형 후 녹차 압출성형물의 총 클로로필 함량은 감소하였으며 클로로필 a, b 및 총 클로로필은 저온 및 재래식 공정에 따른 유의적인 차이는 없었다.

극세선 냉간 정수압 압출에서 금형과 윤활의 영향 (Effect of Die and Lubrication in Fine Wire Cold Hydrostatic Extrusion)

  • 나경환;박훈재;김승수;윤덕재;최태훈;김응주
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2002년도 금형가공 심포지엄
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    • pp.225-230
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    • 2002
  • As in most metal forming processes, die and lubrication are of vital importance in hydrostatic extrusion. An efficient die design and lubrication system selection reduce the pressure required for a given reduction ratio by lowering friction at the billet-die interface. In contrast to the conventional macroscopic extrusion, fine-wire fabrication requires higher extrusion pressure and effect of friction is much more significant. Forming fine Au, Ag, and Cu wire with hydrostatic extrusion process in cold condition, the effect of extrusion die angle, lubrication and billet's initial diameter was studied.

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냉간 압출시 Chevron Crack 방지에 대한 고찰 (A Study of Preventing Chevron Crack in Cold Extrusion)

  • 최영순;이정환
    • 소성∙가공
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    • 제6권3호
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    • pp.221-226
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    • 1997
  • Chevron crack in cold extrusion has been studied in view of deformation conditions and material characteristics. There is V formed chevron crack is occasionally occurred in core part of shaft by multistage free extrusion. Although many research results were reported and theoretical analyses were accompanied, in this study we discussed practical method to prevent chevron crack in the field of working conditions and material characteristics. We have found that chevron crack is eliminated under condition of high hydrostatic state in deformation and decreased segregation, refinement of micro structure of materials.

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극세선 압출 기술 개발 (Fine Wire Extrusion Technology)

  • 김승수;박훈재;윤덕재;임성주;최태훈;나경환
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 추계학술대회 논문집
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    • pp.97-101
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    • 2001
  • Fine metal (Au, Ag, Cu) wire was extruded with hydrostatic extrusion process in cold condition. A vertical type 900kN hydrostatic extruder has been developed. The extruder was facilitated with high pressure container which are available for hot and cold forming. The container endured 1400MPa internal pressure and extrusion ratio To was achieved in cold forming for Au fine wire which had $600{\mu}m$ diameter. In contrast to the conventional macroscopic-sized-billet fine-wire requires higher extrusion pressure and effect of friction is much more significant.

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3차원 유한요소법을 적용한 냉간단조 기어 성형 해석 및 설계 (Forming Analysis and Design of Cold Gear Forging using 3D Finite Element Method)

  • 송종호;김수영;임용택
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2002년도 춘계학술대회 논문집
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    • pp.108-111
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    • 2002
  • It is important to predict forming procedure for minimizing trial-and-error in the application of cold forging of gears. In this study, 3-dimensional simulations of cold forging processes of spur and bevel gear were carried out using finite element method to investigate the characteristics of the processes. From the simulation result it was found that incomplete teeth forming of spur gear was occurred with increase of teeth number in forging by forward extrusion. It can be reduced through division of material flows at the initial forming state using forward/backward combined extrusion.

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Piston-Pin 제작공정의 비교해석 (A Comparisonal Analysis Among the Processes of Piston -Pin Production)

  • 김장군;장동환;황병복
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1996년도 춘계학술대회논문집
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    • pp.130-137
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    • 1996
  • Several cold extrusion processes to produce an axisymmetric steel piston-pin are investigated for comparing each other. Two methods among four conventinal ones are selected to be simulated using the rigid-plastic finite element method. One of the both methods using a mechanical press has one stage process and the other utilizing a cold header applies a multi-stage process to produce a final product. Because the main process is a backward extrusion, the design criteria such as the backward extrusion ration and punch diameter to depth rationare ocnsidered. FEM analysis is performed mainly for strain distributin and load-stroke relationshis. Based on the results of preliminary simulatin, both process sequences are proved to have proper charicteristics suitable for each production method in terms of maximum load. Those simulation results will be a good design criteria in the future work to advance the manufacturing process.

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이중 보강링으로 예압된 냉간압출 금형 설계 (Design of the Prestressed Cold Extrusion Die with Two Stress Rings)

  • 허관도;여홍태;예상돈
    • 한국정밀공학회지
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    • 제17권10호
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    • pp.77-82
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    • 2000
  • The design of the prestressed cold extrusion die with two stress rings has been performed in this study. The cold extrusion has been simulated by the rigid-plastic FEM. The stress analysis of die has been performed for both after shrink fitting and during extrusion by using the elastic FEM and the Lame's equation. According to the variation of interferences and diameter ratios, the maximum effective stress has been evaluated. As results, interferences and diameters were determined by the minimization of the maximum effective stress of die insert. The comparison of the maximum effective stress between the proposed design and the conventional design has been discussed. It was found that the maximum effective stress in the die insert is considerably affected by the stiffness of the first stress ring.

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다구치 방법을 이용한 튜브 냉간 압출 금형의 최적화 (Optimization of Die Design for Tube Cold Extrusion using Taguchi Method)

  • 임성식;임성주;최호준;조종두
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2006년도 춘계학술대회 논문집
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    • pp.153-158
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    • 2006
  • Nowadays, hollow upper-shaft of monobloc type has been considered for weight reduction and high quality in the automobile industry. To form the upper-shaft under tube cold extrusion, Taguchi method is applied to optimize the die design in this study. Taguchi method for optimum die design is to establish the optimal combination of design parameters and to reduce a number of experiments. Effect of parameters including the die relief, mandrel, die half angle is investigated and analyzed based on FEA analysis using a FEM commercial software MSC_Marc. Furthermore extrusion experiments have been performed to verify the results investigated in the FEM simulations.

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냉간압출을 이용한 롱넥 플랜지 성형에 대한 공정설계 (Process Sequence Design of Longneck Flange by Cold Extrusion Process)

  • 임중연;황병복;김철식
    • 소성∙가공
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    • 제8권2호
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    • pp.160-168
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    • 1999
  • This paper is concerned with the process sequence design of longneck flange forming by using cold extrusion with thick hollow pipe. The conventional hot forming process to produce a longneck flange is investigated by thermo-viscoplastic finite element method to observe the metal flow in detail and evaluate design requirements. Based on the results of simulation of the current hot forming process, design strategy for improving the process sequence are developed using the thick hollow pipe. The main goal is to obtain an appropriate improved process sequence which can produce the required product most economically without tensile cracking, workpiece buckling, and overloading of tools. Newly process condition such as semi-die angle, reductio ratio of cross-sectional area of axisymmetrical extrusion process. The final designed process can provide very useful guidelines to other flange forming industries.

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