• 제목/요약/키워드: Injection Speed

검색결과 813건 처리시간 0.122초

사출성형에서 Gate Mark의 형성에 관한 연구 (A Study on the Formation of Gate Mark in Injection Molding)

  • 김준민;김동우;황수진;류민영
    • 소성가공
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    • v.15 no.8
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    • pp.628-632
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    • 2006
  • The gate mark in injection molded part is a kind of surface defects. The formation of gate mark has been investigated in this study. SEM photographs and surface roughness have been examined to study gate mark. The specimens were molded for various injection conditions, such as injection temperature, mold temperature, and injection speed. Gate diameter and mold surface condition were also molding variables. Gate marks were reduced as injection speed and mold temperature increased. Gate diameter and injection temperature did not affect the gate marks. No etching of mold surface showed no gate marks for any molding conditions.

Study molded part quality of plastic injection process by melt viscosity evaluation

  • Lin, Chung-Chih;Wu, Chieh-Liang
    • Advances in materials Research
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    • v.3 no.2
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    • pp.91-103
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    • 2014
  • A study that demonstrates how to investigate the molded part quality and the consistency of injection process based on the rheological concept is proposed. It is important for plastic material whose melt viscosity is variable with respect to the processing condition. The formulations to couple the melt viscosity with injection pressure and fill time are derived first. Taking calculations of the measured pressure and the time by using these formulations, the melt viscosity in injection process can be determined on machine. As the relation between the injection speed and the melt viscosity is constructed, the influences of the setting parameter of injection machine on the molded part quality can be investigated through evaluating the state of the melt viscosity. In addition, a pressure sensor bushing (PSB) designed with a quick installation feature is also provided and validated. The results show that a higher injection speed improves the tensile strength of the molded part but also the consistency of the molded part quality. This work provides an alternative to evaluate the molding quality scientifically.

중형 디젤 엔진의 연료분사노즐 형상에 따른 성능 해석 연구 (Performance Simulation for the Variation of Fuel Injection Nozzle Configurations in Medium Speed Diesel Engine)

  • 김기두;윤욱현;김병석;하지수;안광헌;김주태
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.6
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    • pp.662-668
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    • 2006
  • The effects of fuel injection nozzle hole on the NOx emission and fuel oil consumption of medium speed diesel engine HYUNDAI HiMSEN 6H21/32 engine are investigated by engine performance simulation. The results of performance simulation are verified by experimental results of NOx omission fuel oil consumption, cylinder pressure, and heat release rate according to the variation of the number of fuel injection nozzle hole and engine load. The performance simulations are also carried out to optimize the fuel injection nozzle of 6H21/32 engine in respect to the NOx emission and fuel oil consumption. The engine performance measurements are performed to verify the results of performance simulation and to investigate the effects of fuel injection nozzle on engine performance. The results of measurement indicate that significant NOx reduction can be achieved with minimum deterioration in fuel oil consumption by optimizing the geometry of fuel injection nozzle on 6H21/32 engine.

A Simple Strategy for Sensorless Speed Control for an IPMSM During Startup and Over Wide Speed Range

  • Sim, Hyun-Woo;Lee, June-Seok;Lee, Kyo-Beum
    • Journal of Electrical Engineering and Technology
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    • v.9 no.5
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    • pp.1582-1591
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    • 2014
  • This paper presents a hybrid sensorless control for an interior permanent magnet synchronous motor (IPMSM) for zero-, low-, and high-speed regions. Many sensorless control methods such as an observer-based estimator have been introduced. However, most of the observer-based estimators have a disadvantage at start-up and in the low-speed region. To solve this problem, a simple strategy of using a hybrid system is proposed by integrating a high-frequency (HF) signal injection method and a full-order flux observer. In addition, an HF signal injection method with only a low pass filter (LPF) is proposed to simplify the hybrid system. The hybrid system achieves high-performance drive throughout the entire speed range. The effectiveness of the proposed hybrid technique is verified by experiments using an 11-kW IPMSM drive system.

박용 대형 저속 디젤기관 연료분사계통의 시뮬레이션에 관한 연구 (A Study on the Simulation of the Fuel Injection System in a Large Low-speed marine Diesel Engine)

  • 이창식
    • 한국마린엔지니어링학회:학술대회논문집
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    • pp.36-44
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    • 2000
  • In his study the simulation was carried out by simplifing and modeling dividing into fuel injectioin pump high pressure pipe and fuel injection valve in the fuel injection system of a low speed marine diesel engine. A computer simulation model was developed using the method of characteristics to analyze the unsteady flow in the fuel injection system considering cavitation and variation of fuel density and bulk modulus. Comparison was commenced between the calculated data and experimental data of pressure and injection quantity at the high pressure distributor in fuel injection system for the training ship "M/V hanara" the effects of the high pressure pipe length diameter plunger diameter nozzle openning pressure were also investigated by simulating results.g results.

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아음속 수직분사제트에서의 가진 분무의 분무 특성연구 (Penetration and Breakup Characteristics of Pulsed Liquid Jets in Subsonic Crossflowse)

  • 김진기;송진관;김민기;황용석;윤영빈
    • 한국추진공학회:학술대회논문집
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    • pp.83-88
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    • 2007
  • 횡단류 아음속 유동장에서 연료의 가진 수직 분사 시 나타나는 액적영역의 분무특성에 대하여 고속 카메라 촬영기법을 통하여 분석하였다. 본 연구의 목적은 정상 분무와 가진 분무의 분열길이 및 궤적을 관찰하고 가진 분무의 주파수 크기가 커지는 영향이 분무특성에 미치는 영향을 확인하는 것이다. 실험을 통하여 정상 분무와 가진 분무의 궤적과 분열길이가 차이를 연구하였다.

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디젤기관의 연소에 미치는 분사계의 영향 (Effects of the fuel injection system on combustion in a diesel engine)

  • 권순익;김완
    • 오토저널
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    • v.15 no.1
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    • pp.37-44
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    • 1993
  • Fuel injection system is an important tool in the exhaust emission and performance of a diesel engine. Effects of the fuel injection system in diesel combustion was investigated experimentally by measuring the performance and analyzing the combustion phenomena in a D.I. diesel engine. The selected injection parameters were nozzle opening pressure, nozzle projection length, and nozzle spray angle. From the measured results, it is shown that the fuel injection pipe diameter is an effective means to improve engine performance in a middle and high speed range and the 2 stage spring nozzle holder has the advantage of increasing the engine performance due to the initial injection pressure in a low speed range. It has been also shown that increasing nozzle opening pressure resulted in decrease in smoke, but increase in NO$_{x}$ from the engine.e.

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스프레이 특성에 가솔린 - 바이오 디젤 혼합 연료의 효과 (The effects of Gasoline-Biodiesel Blended Fuels on Spray Characteristics)

  • 삭다 통사이;임옥택
    • 한국수소및신에너지학회논문집
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    • v.26 no.3
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    • pp.287-293
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    • 2015
  • The current study has investigated the effects of biodiesel blended with gasoline on the spray characteristics in a Constant Volume Combustion Chamber (CVCC). With the concentration of 5, 10, 15 and 20% by volume, biodiesel was blended with commercial gasoline and performed on the macroscopic visualization test. Pure gasoline and biodiesel were also tested as the reference. The shadowgraph technique was conducted in the constant volume chamber. The spray images were recorded by a high speed video camera with frame speed 10,000 frame per second. Fuel injection was set at 800, 1000 and 1,350 bar with the simulated speed 1,500 and 2,000 rpm. The back pressure was controlled at 20 bar. The spray angle and penetration tip were measured and analyzed by using the image processing. At the high injection pressure, the spray penetration length with the simulated speed 1,500 rpm showed that B100 was lower than GB00-20 whereas the spray penetration length with the simulated speed 2,000 rpm exhibited that GB blends and B100 were insignificantly different. Due to biodiesel concentration, its effects on spray angles were observed throughout injection periods (T1, T2 and T3). At the simulated speed 1,500 rpm, the spray angle of GB blends and B100 presented the same pattern following injection timing. In addition, when the simulated speed increased to 2,000 rpm the different spray angle of all blends disappeared at main injection (T3).

천연가스 개조 승용차에 대한 실험적 연구(2) - 분사 시스템 평가 (Experimental Study on Natural Gas Conversion Vehicle(2) - Evaluation of Injection System)

  • 김형구;권순태;엄인용
    • 한국자동차공학회논문집
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    • v.23 no.4
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    • pp.444-453
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    • 2015
  • In the previous study, several problems were observed in a NG conversion vehicle, which were fail of air-fuel ratio closed loop control, aggravated fuel economy, increased harmful emission and declined roadability. It was provisionally supposed that the mismatch of injection system with the engine caused these performance deterioration. In this context, the characteristics of fuel injection system of commercial conversion kit for NG were investigated experimentally varying the engine speed, fuel rail pressure and volume. The results are as follows; The injection quantity decreases as the engine speed increases due to the extremely small rail volume of the presenting system and flow rate of No. 2 injector are always lower than that of the other ones regardless of the speed under the dynamic operation condition. Furthermore the existing system does not meet the required fuel quantity for the normal engine operation over 3000 RPM. On the other hands, the large rail volume systems ease and/or eliminate the difference of injection quantity between the injectors according to the speed variation, however, these systems decrease injection flow rate and still cannot supply sufficient fuel. Finally, suitable combination of the higher rail pressure and the larger rail volume might be a solution about these problems.

연료레일 압력과 엔진 속도가 가스연료 시스템에 미치는 영향에 관한 연구 (A Study on the Effects of Fuel Rail Pressure and Engine Speed on Gas Fuel System)

  • 곽윤기
    • 한국정보전자통신기술학회논문지
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    • v.11 no.5
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    • pp.579-585
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    • 2018
  • 이번 연구는 가스 연료의 연료 공급 시스템에서 분사 압력과 엔진 속도에 따른 연료 분사 특성을 확인하였다. 이번 실험에서 연료 레일 압력은 1.5에서 6.0 bar까지 1.5 bar 단위로 증가시키고, 엔진 속도는 1,000 에서 6,000 RPM으로 1000 RPM 간격으로 설정하였다. 실제 엔진 작동을 고려하여 분사 펄스폭은 각각 2.5 ms, 5.0 ms 및 13.0 ms로 설정하였으며, 이는 각각 엔진 주행상태에서 저, 중 및 고 부하 운전조건에 해당한다. 결론적으로 100cc 연료레일의 경우, 분사 압력 4.5bar에서 가장 우수한 성능을 보였고, 1000 ~ 6000RPM의 엔진 속도에서 엔진 출력을 보장하는 최소 요구 분사량 53 cc을 얻을 수 있다.