• 제목/요약/키워드: Manufacturing pressure

검색결과 1,604건 처리시간 0.037초

자유분류와 충돌분류의 소음특성에 관한 실험적 비교 (Experimental comparison on the noise characteristics of free and impinging jets)

  • 이동훈
    • 한국생산제조학회지
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    • 제5권2호
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    • pp.83-89
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    • 1996
  • The objective of this study is to find experimentally the characteristics of the noise generated by the impinging jet on the normal plate, and also to compare the noise characteristics of the impinging jet with those of the free jet. The experiment is performed for the measurement of the noise specturm, the noise power, and the directivity for the free and impinging jets. From the experiment. it is found that the power of noises generated by the free jet as well as the impinging jet is proportional to the eighth power of the jet velocity through the circular converging nozzle, and that the noise power of the impinging jet is 15dB as high as one of the free jet when the plate distance is about within one to three times the nozzle diameter at the pressure ratio 1.39. The sound pressure level of the impinging jet depends upon the jet pressure and the plate distance. The plate distance with the maximum overall sound pressure level is increased with the jet pressure. The directivities with 1/3 octave band frequency for both the free jet and the impinging jet are greatly influenced by the convection effect.

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사출성형기용 실린더의 응력안전성에 관한 수치적 연구 (Numerical Study on the Stress Safety of a Cylinder for an Injection Molding Machine)

  • 김청균;김경섭
    • 한국생산제조학회지
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    • 제20권4호
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    • pp.401-406
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    • 2011
  • This study presents the stress safety analysis of a cylinder, which is manufactured by a tempered ASTM D2, tempered SM45C and normalized SM45C materials, respectively. The inner diameter of three cylinder models are 85mm, 95mm, and 11 Omm and the total length of a cylinder is 2,365mm for a high pressure injection molding machine. The FEM computed results show that the inner diameter of 85mm with a thick thickness of 62.5mm may produce the injection pressure of 325MPa and the inner diameter of 110mm with 50mm thickness reduces up to the injection pressure of 220MPa because of a reduced thickness of a cylinder. These injection pressures are enough for a high pressure injection molding machine assembled by ASTM D2 cylinder. And also, an injection cylinder manufactured by a tempered SM45C material in which is low priee may produce 225MPa injection molding pressure and this may sufficiently endure stress safety compared to that of ASTM D2 cylinder material. Thus, this study recommends that tempered SM45C cylinder is appropriated for a mild injection molding machine as an alternative cylinder material when the safety strength and low prices are considered. But the normalized SM45C cylinder material does not meet a stress safety of yield strength in general.

토글 조인트장치를 이용한 가변예압장치 개발을 위한 기초 연구 (A Fundamental Study on the Development of a Variable Preload Device Using Toggle Joint Mechanism)

  • 최치혁;차나현;이춘만
    • 한국정밀공학회지
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    • 제30권3호
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    • pp.260-265
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    • 2013
  • To increase the machine accuracy by improving the stiffness of spindle bearings, preload was applied to the spindle bearings. The methods of fixed position preload, convertible preload, constant pressure preload, and variable preload are used to apply the preload to the spindle bearing. The previous studies performed by the author of this study were variable preload methods using rubber pressure and centrifugal force based on mechanical systems. This study proposed a toggle joint mechanism that could be applied to variable preload method using centrifugal force and rubber pressure to increase the preload. Also, a finite element analysis was conducted to predict the deformation of the rubber and change of the preload. And the analysis results showed that the preload by the device using rubber pressure only was increased by the toggle joint mechanism using rubber pressure.

미세입자 분사가공시 직교배열표의 통계적 분석에 의한 표면형상의 최적 분사 조건 (Optimal Blasting Conditions for Surface Profile when Micro Particle Blasting by Statistical Analysis of Orthogonal Arrays)

  • 권대규;왕덕현
    • 한국기계가공학회지
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    • 제15권4호
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    • pp.148-154
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    • 2016
  • A study on the micro particle blasting was conducted to find the optimum conditions of the blasted surface of aluminum 6061. The particle type such as $Al_2O_3$ and SiC, nozzle diameter, pressure, standoff distance and injection time were used as blasting conditions. Statistical method of orthogonal arrays(ANOVA) was used to find optimum conditions of maximum depth and maximum diameter of blasted surface. Particle type, nozzle diameter, and pressure were found to be the main factors of maximum blasted depth and diameter. Maximum blasted diameter was affected by increasing pressure and nozzle diameter but saturated maximum diameter. Maximum blasted depth was affected by pressure and nozzle diameter when aluminum 6061 was blasted with $Al_2O_3$ particle. The value of surface roughness was increased as pressure and nozzle diameter increased when aluminum 6061 was blasted with SiC.

배열회수보일러 기수분리기의 응력해석 및 평가 (Stress Analysis and Evaluation of Steam Separator of Heat Recovery Steam Generator (HRSG))

  • 이부윤
    • 한국기계가공학회지
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    • 제17권4호
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    • pp.23-31
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    • 2018
  • Stress of a steam separator, equipment of the high-pressure (HP) evaporator for a HRSG, was analyzed and evaluated according to ASME Boiler & Pressure Vessel Code Section VIII Division 2. First, from the analysis results of the piping system model of the HP evaporator, reaction forces of the riser tubes connected to the steam separator, i.e., nozzle loads, were derived. Next, a finite element model of the steam separator was constructed and analyzed for the design pressure and the nozzle loads. The results show that the maximum stress occurred at the bore of the riser nozzle. The primary membrane stresses at the shell and nozzle were found to be less than the allowable stress. Next, the steam separator was analyzed for the steady-state operating conditions of operating pressure, operating temperature, and nozzle loads. The maximum stress occurred at the bore of the riser nozzle. The primary plus secondary membrane plus bending stress at the shell and nozzle was found to be less than the allowable stress.

바이오용 압전디스크방식 마이크로 펌프 설계 및 제작 (II) -임베드방식의 압전모듈의 최적설계 및 제작- (Design and Fabrication of PZT Disc Actuated Micro Pump for Bio-Applications (II): Optimal Design & Fabrication of Embedding-type PZT Module)

  • 김형진;장인배;서영호;김병희
    • 한국생산제조학회지
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    • 제21권3호
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    • pp.362-367
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    • 2012
  • Though a micro pump is a crucial element in miniaturized bio-fluidic systems or drug delivery systems, most of the conventional micro pumps still have some limitations to miniaturize their controller system and to obtain the sufficient back pressure which can rise over the inner pressure of human body or experimental animals. In this paper, to overcome these limitation, a new PZT disc and its controller were designed and fabricated to get the sufficient flowrate and the back pressure with guaranteeing embeddability of the controller into pumping body. The amplitudes of the disc deflections were as large as 40 ${\mu}m$ at 200 V - 100 Hz condition. As results of experiments, the flow rate and the back pressure increase when the frequency increases. The obtainable maximum flow rate and back pressure are 5.2 ml/min at 95 Hz and 13.14 kPa at 90 Hz respectively.

Influence of pressure-dependency of the yield criterion and temperature on residual stresses and strains in a thin disk

  • Alexandrov, S.;Jeng, Y.R.;Lyamina, E.
    • Structural Engineering and Mechanics
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    • 제44권3호
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    • pp.289-303
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    • 2012
  • Existing plane stress solutions for thin plates and disks have shown several qualitative features which are difficult to handle with the use of commercial numerical codes (non-existence of solutions, singular solutions, rapid growth of the plastic zone with a loading parameter). In order to understand the effect of temperature and pressure-dependency of the yield criterion on some of such features as well as on the distribution of residual stresses and strains, a semi-analytic solution for a thin hollow disk fixed to a rigid container and subject to thermal loading and subsequent unloading is derived. The material model is elastic-perfectly/plastic. The Drucker-Prager pressure-dependent yield criterion and the equation of incompressibity for plastic strains are adopted. The distribution of residual stresses and strains is illustrated for a wide range of the parameter which controls pressure-dependency of the yield criterion.

배압 성형기술을 이용한 Lock-up Hub의 정형제조 기술에 관한 연구 (A study on Net-shape technology of Automotive Lock-up Hub using Cold back pressure forming)

  • 권용철;이정환;이영선
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2007년도 추계학술대회 논문집
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    • pp.173-176
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    • 2007
  • The characteristics of the tool system give many effects into the costs and qualities for the finished components. This study proposes a new method for manufacturing of high manufacturing productivity, production process reduction and low cost through back pressure forming. The Lock-up hub is manufactured through many processes, such as upsetting($1^{st}$ Forming), piercing, direct extrusion($2^{nd}$ Forming), final sizing process($3^{rd}$ Forming). In this study, process design for closed-die forging of a Lock-up hub used for a component of automobile transmission was made using three-dimensional finite element simulations, and the strain distributions and velocity distributions are investigated through the post processor. The rigid-plastic finite-element method for back pressure forging has been used in order to reduce development time and die cost. Using the FEM simulation, we found the optimum value of back pressure. The prototypes of Lock-up hub parts were forged into the net-shape. In the experiment, lead precision of tooth are measured by the CCMM(Contact Coordinate Measuring Machine). The dimensional accuracy of forged part was improved up to the 40% when back press was applied.

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자동차 대시보드의 사출압력 최소화를 위한 게이트 위치와 공정조건의 강건설계 (Robust Design of Gate Locations and Process Parameters for Minimizing Injection Pressure of an Automotive Dashboard)

  • 김광호;박종천
    • 한국기계가공학회지
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    • 제13권6호
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    • pp.73-81
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    • 2014
  • In this paper, multiple gate locations and process conditions under concern are automatically optimized by considering robustness to minimize the injection pressure required to mold an automotive dashboard. Computer simulation-based experiments using orthogonal arrays(OA) and a design-range reduction algorithm are consolidated into an iterative search scheme, which is then used as a tool for the optimization process. The robustness of a design is evaluated using an OA-based simulation of process fluctuations due to noise as well as the signal-to-noise ratio. The optimal design solution for the automotive dashboard shows that the robustness of the injection pressure is significantly improved when compared to the initial design. As a result, both the die clamping force and the pressure distribution in the part cavity are also much improved in terms of their robustness.

전자기 펄스 용접시 누수압력을 예측하기 위한 실험모델의 개발 (A Development of Experimental Model Prediction of Leakage Pressure in MPW)

  • 심지연;김일수;김인주;강봉용
    • 한국생산제조학회지
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    • 제18권6호
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    • pp.652-657
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    • 2009
  • MPW(Magnetic Pulse Welding) is a technologies for welding of metals by means of repulsive force on account of the interaction between electro-magnetic field of coil and current induced in outer pipe. These MPW is one of the most useful welding process of welding ability of the dissimilar metal in which cylindrical materials, such as pipe, tube. As the quality of a weld joint is strongly influenced by process parameters during the welding process and the success of the welding to evaluated according to the leakage pressure. Generally, the process parameters is magnetic pressure, the gap between outer pipe and inner pipe, and the ratio of thickness to diameter of pipe(D/T) in MPW. Therefore, the goal of this study was to explain the effect of parameters on the weld joint leakage pressure. For these purposes, FFD(Fractional Factorial Design) were used for the experiment. The measured data were analyzed by regression analysis and verification experiments with random condition were conducted to confirm the suggested experimental model.

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