• Title/Summary/Keyword: Core Injection

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A Study on the Measurement of Break-up Length for the Diesel Sprays (디젤분무의 분열길이 측정에 관한 연구)

  • Jang, S.H.;Ra, J.H.
    • Journal of Power System Engineering
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    • v.3 no.3
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    • pp.22-28
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    • 1999
  • The injected liquid does not break-up instantly after injection for diesel engine. There is some unbroken portion, which is the liquid core(The length of liquid core is called the break-up length) in the spray. If the liquid core is longer than the depth of the bowl in the small DI diesel engine, the liquid core impinges on the surface of the piston. Once the liquid core impinges on the surface, it cannot ignite or burn rapidly and thus prolongs burning time with a degradation in thermal efficiency. The break-up length of a diesel spray in a compressure vessel was measured by an electric resistance method, A voltage was applied between the nozzle and screen, bar, needle electrode inserted at various axial and radial positions into atomizing sprays. As a result, a current flows not only in the region of liquid core but also through the droplets of the spray. It is found that the break-up length measured with screen electrode is overestimated. The break-up length of the spray is found to be proportional to the square root of the density ratio of fuel and surrounding gas. The break-up length of the spray decreases as the injection pressure and the back pressure increase.

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Fabrication of large-capacity injection mold with the insert core for molding cap (인서트 코어 타입 Cap 성형용 대용량 금형 제작에 관한 연구)

  • Jung, Woo-Chul;Heo, Young-Moo;Shin, Gwang-Ho;Yoon, Gil-Sang;Lee, Jeong-Won
    • Design & Manufacturing
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    • v.2 no.3
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    • pp.16-21
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    • 2008
  • In recent, the demands of household cases and disposable products is increased significantly because a living standard of newly-emerging nations was risen. Therefore, multi-cavity mold and stack mold for the realization of high-productivity have been researched in forefront nations. In this paper, CAE analysis for minimizing the mold core deformation was performed. Finally, 64 cavities injection mold for molding cap which has the insert-type core was fabricated according to the result of CAE analysis.

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The Surface Roughness of Injection Product according to the change of Injection Conditions (성형조건에 따른 성형품의 표면 거칠기 변화)

  • Park, Joon-Hyoung;Kim, Kuy-Bok;Yoon, Se-Kwon;Lee, Hyeon-Woo;Kim, Sun-Kyung
    • Design & Manufacturing
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    • v.8 no.2
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    • pp.12-17
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    • 2014
  • Currently, injection molding process is a very useful technique that be applied to many field. And injection molding technology has been commercial based on many studies. However, there is no standard of surface roughness because there are few studies about surface technology of injection product. In addition, when designing the mold, changes of the core surface and the injection conditions are not considered. In this paper, change of surface according to the core and the injection conditions was compared with the surface of the injection product. Accumulation of these technologies will propose direction in mold design, manufacturing and injection molding technology.

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Development of Direct Metal Tooling (DMT) Process for Injection Mold Core with Curved Conformal Cooling Channel (곡선형 형상적응형 냉각채널을 갖는 금형 코어 제작을 위한 DMT 공정개발)

  • Han, Ji Su;Yu, Man Jun;Lee, Min Gyu;Lee, Yoon Sun;Kim, Woo-Sung;Lee, Ho Jin;Kim, Da Hye;Sung, Ji Hyun;Cha, Kyoung Je
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.11
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    • pp.103-108
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    • 2019
  • The cooling rate and the uniformity of mold temperature, in the injection molding process, possess great influences on the productivity and quality of replications. The conformal cooling channel, which is of a uniform spacing from the mold cavity by the metal additive manufacturing process, receives much attention recently. The purpose of this study is to develop a mold core with a curved conformal cooling channel for a pottery-shaped thick-wall cosmetic container through the hybrid method of direct metal tooling (DMT) process. In this study, we design a mold core that contains the curved cooling channel for the container. A method that divides the cavity is proposed and the DMT process is carried out to form the curved cooling channel. The test mold core, with the curved conformal cooling channel, has been fabricated by the proposed method to confirm the feasibility of the design concept. We show that no leakage is observed for the additive manufactured test mold core, and its physical properties demonstrate that it can be sufficiently used as the injection mold core.

A Study on the Diesel Spray Evaporation and Combustion Characteristics in Constant Volume Chamber (정적연소실내의 디젤분무증발과 연소특성에 관한 연구)

  • Kim, S.H.;Kim, S.J.;Lee, M.B.;Kim, E.S.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.6
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    • pp.102-109
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    • 1994
  • As a fundamental study to apply high pressure injection system to direct injection diesel engine, fuel injection system and constant volume combustion chamber were made and the behaviors of evaporating spray with the variation of injection pressure and the ambient gas temperature were observed by using high speed camera, and the combusion characteristics with the variation of injection pressure and A/F ratio were analyzed. As injection pressure increases, spray tip penetration and spray angle increase and, as a results spray volume increases. This helps an uniform mixing of fuel and air. Spray liquid core length decreases as ambient gas temperature increases, while it decreases as injection pressure increases but the effect of ambient gas temperature is dorminant. As injection pressure increases, ignition delay is shortened and combustion rate being raised, maximum heat release rate increases. It become clear that High injection pressure has high level of potential to improve the performance of DI-diesel engine.

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THE ANALYTIC ANALYSIS OF THE CORE INJECTION COOLING FLOW RATE FOR EMERGENCY WATER SUPPLY SYSTEM IN HANARO (하나로 비상 보충수 공급계통의 노심 주입 냉각유량 해석)

  • Park Yong-Chul;Kim Bong-Soo;Kim Kyung-Ryun;Wu Jong-Sub
    • 한국전산유체공학회:학술대회논문집
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    • 2005.10a
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    • pp.39-44
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    • 2005
  • In HANARO, a multi-purpose research reactor of 30 MWth, the emergency water supply system consists essentially of an emergency water storage tank located in the level of about thirteen meter (13 m) above the reactor core, a three inch ('3\%') diameter water injection pipe line including injection valves from the tank to the reactor cooling inlet pipe and a test loop to do periodic system performance test. When the water level of the reactor pool comes down to the extremely low due to a loss of reactor pool water accident the emergency water stored in the tank should be fed to the core by the gravity force and at that time the design flow rate is eleven point four kilogram per second (11.4 kg/s). But it is impossible periodically to measure the injection flow rate under the emergency condition because the normal water level should be maintained during the reactor operation. This paper describes a flow network analysis to simulate the flow rate under the emergency condition. As results, it was confirmed through the analysis results that the calculated flow rate agrees with the design requirement under the emergency condition.

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Study of transcription ability of optic polymer and Micro-grooving machining of ultra-precision injection molding moulds (초정밀 사출성형 금형의 마이크로 홈가공과 전사성)

  • Kwak T.S.;Ohmori H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.623-624
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    • 2005
  • Micro injection molding is a branch of micro system technology and has been under development for the mass manufacture of micro parts. Enhanced technological products like micro optical devices are entering the market. This paper presents fundamental research on the injection molding technique in micro fabrication. In order to successful manufacturing of micro plastic parts, it is necessary to research for development of micro-injection machine, machining of micro mold, decision of optimum injection conditions and the research for polymer material. Therefore in this study, in order to machining of micro mold, a mold core with microscopic V-shaped groove was tooled by ultra-precise tooling machine. The transcription experiments with a polymer, PMMA resin on the surface of core with Ni plating were carried out and surface profile of injected parts was measured with AFM.

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A study on a structural analysis of the injection mold for the plastic subminiature barrel (모바일용 플라스틱 경통 금형의 구조해석에 관한 연구)

  • Chang, Sung-Ho;Heo, Young-Moo;Shin, Gwang-Ho
    • Design & Manufacturing
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    • v.2 no.3
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    • pp.10-15
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    • 2008
  • Recently, mobile-phone with camera module has an absolute majority in the released mobile-phones. For this trend, High precision of the plastic subminiature barrel which is the core part is needed significantly because the camera module of mobile-phone must have high performance. Therefore, Structural stability of the injection mold for plastic subminiature barrel has to be guaranteed. In this paper, structural analysis of injection mold for plastic subminiature barrel is performed. Finally, the deformation trend and stability of injection mold core are analyzed.

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