• 제목/요약/키워드: Blocker process

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이산 웨이블릿 변환을 이용한 형단조 공정의 예비성형용 금형 설계에 관한 연구 (A Study on the Blocker Design of Closed Die Forging with Discrete Wavelet Transform)

  • 한상훈;임성한;오수익
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 춘계학술대회논문집
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    • pp.27-33
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    • 2003
  • In closed-die forging process, blocker has been used to fill and distribute metal well in finisher die. Generally, the blocker shape was determined by an expert with many experiences. However, the manual blocker design process takes much time and efforts, so various automatic methods for the blocker design process have been suggested for the last three decades. The method with filtering in FFT (Fast Fourier Transform) for the blocker design provides general solution than other methods. But, due to the properties of FFT in time-frequency domain, this method has some drawbacks such as long calculation time, difficulty of local control and additional boundary process after filtering. In this study, DWT (Discrete Wavelet Transform), which is more flexible and is more wildly used than FFT, is applied to the blocker design. The method with filtering in DWT is very proper to design blocker in both 2-D and 3-D shapes. To verify the efficiency of this method, blockers of some models are designed and the results show that blocker design with DWT is effective fer the blocker designs

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이산 웨이블릿 변환을 이용한 형단조 공정의 예비성형용 금형 설계 (Blocker Design of Closed Die Forging with Wavelet Transform)

  • 한상훈;임성한;오수익
    • 소성∙가공
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    • 제12권4호
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    • pp.277-283
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    • 2003
  • In a closed-die forging process, blocker has been used to fill and distribute metal well in finisher die. Generally, the blocker shape was determined by an expert with many experiences. However, the manual blocker design process takes much time and efforts, so various automatic methods for the blocker design process have been suggested for the last three decades. The method with filtering in FFT (Fast Fourier Transform) for the blocker design provides general solution than other methods. But. due to the properties of FFT in time-frequency domain, this method has some drawbacks such as long calculation time, difficulty of local control and additional boundary process after filtering. In this study. DWT (Discrete Wavelet Transform), which is more flexible and is more wildly used than FFT, is applied to the blocker design. The method with filtering in DWT is very proper to design blocker in both 2-D and 3-D shapes. To verify the efficiency of this method, blockers of some models are designed and the results show that blocker design with DWT is effective for the blocker designs.

비대칭 형상제품의 단조공정에 관한 연구 (An Investigation on the Forging Process of an Irregular Shape Product)

  • 정경빈;김현수;최영순;김용조
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.1101-1104
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    • 2004
  • A brake spider in an irregular shape, which is used as a part in the braking system of a vehicle like a big truck and a trailer, is subjected to a large torque and hence requires both strength and endurance over the brake heat. Manufacture of this product in practice is generally composed of hot forging processes and machining. At the present study, two or more processes were considered for the hot forging. With an initial circular billet, blocker and finisher processes were analyzed using the rigid-plastic finite element method and also in addition to the preforming process. Proper forging processes to manufacture an irregular product without forging defects, which are preforming, blocker and finisher, were discussed and commented upon.

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등속조인트 외륜 열간단조의 금형수명 향상을 위한 단조공정 유한요소해석 (FE Analysis of Forging Process for Improving Tool Life in Hot Forging of CV Joint Outer Race)

  • 김용조
    • 한국기계가공학회지
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    • 제13권3호
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    • pp.56-62
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    • 2014
  • During the hot forging process, the most common cause of tool failure is wear. Tool wear results in the gradual loss of part tolerances, after which eventually the tool must be replaced or repaired. In order to maximize the lifetimes of forging tools, it is important to investigate the wear mechanisms of these tools. In this study, the hot forging of the outer race of an automotive constant-velocity joint was analyzed by a finite element method to investigate the wear distribution, especially the amount and location of the maximum expected wear damage, using Archard's wear model, which was modified considering the forging temperature. Forging analyses were carried out after modifying blocker forging tools based on established versions. The modified blocker tools resulted in an increase in the tool life up to 31% with a finisher punch.

카운터샤프트 기어의 스플라인 치형 정밀성형을 위한 열간단조 공정에 관한 연구 (A Study on Hot Precision Forging Processes for Spline Teethof a Counter Shaft Gear)

  • 김현필;김현수;김용조
    • Design & Manufacturing
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    • 제6권2호
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    • pp.6-11
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    • 2012
  • A counter shaft gear is an important part in the transmission system of vehicle. Its shape is relatively complicated and should meets high strength. Traditionally the counter shaft gear has been manufactured as follows; a spline body is firstly machined for teeth and then attached to the main gear body by frictional welding, and finally is finished by grinding. Therefore it is necessary to develop a new manufacturing technology eliminating both frictional welding and grinding processes. In this study, a new hot forging process was proposed and designed so that the spline body with teeth and main gear body are formed as one body. Finite element simulations and experimental works were peformed for design of forging processes to get the quality final precision-forged product. Consequently the most suitable blocker process could be obtained.

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자동변속기 이너레이스 스플라인 치형의 정밀열간단조 공정에 관한 연구 (A study on the precision hot forging process for spline teeth of inner-race in auto-transmission)

  • 김현수;이정환;김현필;김용조;강성훈
    • Design & Manufacturing
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    • 제6권2호
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    • pp.24-30
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    • 2012
  • In this study, the hot forging technology for precision forming of spline teeth of the inner race in the auto-transmission was developed in order to minimize its finishing allowance. Several blocker and finisher shapes for the precision hot forging process of the inner race were proposed and the forging processes were analyzed using the three-dimensional finite element method. The optimum hot forging process was obtained considering some parameters such as metal flow patterns, forging defects and forming load. Blocker and finisher dies for the hot forging process were designed by selecting the most suitable shapes obtained from the finite element analysis. Experimental works were also performed in order to verify the optimum design of hot forging process.

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알루미늄 부식에 대한 베타-차단제 억제제 효과 (Effect of β-Blocker Inhibitors on Aluminum Corrosion)

  • Fouda, A. S.;El-Ewady, G. Y.;Shalabi, K.
    • 대한화학회지
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    • 제55권2호
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    • pp.268-278
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    • 2011
  • 베타 차단제 억제제(atenolol, propranolol, timolol and nadolol)의 존재와 부존 하에서 0.1M HCl 용액에 담긴 알루미늄의 부식작용을 연구하였다. 이 연구에 무게감량, 변전위 편극, 전기화학 임피던스 분석법이 사용되었다. 억제 효과는 억제제의 농도 증가에 따라 증가하였으며, 온도가 증가함에 따라 감소하였다. 모든 억제제들은 Frumkin 등온을 따르는 알루미늄 표면에 흡착되었다. 부식반응은 전하이동과정에 의해 조절됨을 발견하였다. 억제 효과 측정을 위해 사용된 실험방법 들에 대해 조사한 결과 모두 억제효과가 우수하였다.

원 웨이 클러치 이너 레이스의 정밀 열간 단조 공정설계에 관한 연구 (Process Design Molding with Precision Hot Forging of One-Way Clutch Inner Race)

  • 김화정;진철규
    • 한국기계가공학회지
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    • 제17권4호
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    • pp.83-90
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    • 2018
  • In this research, we developed a process design hot-forging technology that precisely forms an inner race. The inner race transmits power to a one-way clutch of an automatic transmission and minimizes the CNC machining allowance. For a multi-stage hollow shape (inner race), we proposed several shapes of blocker and finisher for the precision hot-forging process and analyzed the forging process using DEFORM. The hot-forging process was optimized for several parameters, such as metal flow pattern, forging defect, and forming load. Blockers and finisher dies in the hot-forging process were designed to select optimal shapes from finite element analysis, and experiments were conducted to optimize the hot-forging process.

베어링 허브의 트랜스퍼 열간 단조 공정 설계에 관한 연구 (A Study on Transfer Process Design on Hot Forging of Bearing Hub)

  • 변현상;김병민;고대철
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 추계학술대회 논문집
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    • pp.993-996
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    • 2005
  • This paper is concerned with transfer process on hot forging of bearing hub. Workers on hot forging have difficulty in working by high temperature and weight workpiece. And In conventional got forging of bearing hub, the material wasted to the flash accounts approximately 10% of the original workpiece. It is need manufacture automation and reduce the cost of forged products. Surface treatment of die and lubricant are investigated from experiment and FE-simulation for analysis of forming simulation. In order to hot forging process design considered flash thickness and blocker geometry and initial temperature of die and billet. This transfer process gave comparatively good results compared with actual products.

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