• Title/Summary/Keyword: Blocker process

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

  • 한상훈;임성한;오수익
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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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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Blocker Design of Closed Die Forging with Wavelet Transform (이산 웨이블릿 변환을 이용한 형단조 공정의 예비성형용 금형 설계)

  • 한상훈;임성한;오수익
    • Transactions of Materials Processing
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    • v.12 no.4
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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.

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

  • 정경빈;김현수;최영순;김용조
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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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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FE Analysis of Forging Process for Improving Tool Life in Hot Forging of CV Joint Outer Race (등속조인트 외륜 열간단조의 금형수명 향상을 위한 단조공정 유한요소해석)

  • Kim, Yohng-Jo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.13 no.3
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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.

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

  • Kim, H.P.;Kim, H.S.;Kim, Y.J.
    • Design & Manufacturing
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    • v.6 no.2
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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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A study on the precision hot forging process for spline teeth of inner-race in auto-transmission (자동변속기 이너레이스 스플라인 치형의 정밀열간단조 공정에 관한 연구)

  • Kim, Hyun-Soo;Lee, Jung-Hwan;Kim, Hyun-Pil;Kim, Yong-Jo;Kang, Seong-Hoon
    • Design & Manufacturing
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    • v.6 no.2
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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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Effect of β-Blocker Inhibitors on Aluminum Corrosion (알루미늄 부식에 대한 베타-차단제 억제제 효과)

  • Fouda, A. S.;El-Ewady, G. Y.;Shalabi, K.
    • Journal of the Korean Chemical Society
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    • v.55 no.2
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    • pp.268-278
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    • 2011
  • Corrosion of aluminum in 0.1 M HCl solution in the absence and presence of ${\beta}$-blocker inhibitors (atenolol, propranolol, timolol and nadolol) was investigated using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The inhibition efficiency increased with inhibitor concentration and decreased with rise of temperature. Potentiodynamic polarization curves revealed that they acted as cathodic inhibitors. Some thermodynamic parameters were calculated and discussed. All inhibitors were adsorbed on Al surface obeying Frumkin isotherm. All EIS tests exhibited one capacitive loop which indicates that the corrosion reaction is controlled by charge transfer process. The inhibition efficiencies of all test methods were in good agreement.

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

  • Kim, Hwa-Jeong;Jin, Chul-Kyu
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.4
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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.

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

  • Byun H.S.;Kim B.M.;Ko D.C.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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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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