• 제목/요약/키워드: Hydraulic modulator

검색결과 21건 처리시간 0.026초

건설차량용 반자동 변속기 유압제어계의 성능 개선 (Performance Improvement of Clutch Actuating Hydraulic Control System at Semi-Automatic Transmission for Construction Vehicles)

  • 이일영;윤소남;양경욱;이덕규
    • 한국자동차공학회논문집
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    • 제4권3호
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    • pp.10-21
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    • 1996
  • In this study, as a strategy to improve shift characteristics, the authors developed a new style pressure modulator which can reduce shock torque during power shift by modulating the pattern of pressure increase in the cylinder for actuating the clutch. The remarkable merits of this new pressure modulator lie in its structural simplicity and durability, because the modulator is only composed of a poppet type valve and a few orifices. The usefulness of the new pressure modulator is confirmed by experiments and numerical analyses on a clutch control hydraulic system simplified for easy test. Also, the excellency of the transmission with the new pressure modulator is verified by experiments on a test bench for simulating the running power train of an excavator.

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ABS 유압 제어 밸브의 동 특성 해석에 관한 연구 (A Study on the Dynamic Characteristics of ABS Hydraulic Control Valve)

  • 김병우;송창섭
    • 한국자동차공학회논문집
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    • 제9권4호
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    • pp.121-130
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    • 2001
  • For the purpose of optimal control of anti-lock brake systems, precise dynamic characteristics analysis of hydraulic modulator, especially solenoid valve is necessary. However, most of researches so far have dealt with dynamic characteristic analysis of valve itself, and the results have been restrictively applied to the actual ABS modulator, where hydraulic pressure is acting. In this study, mathmatical modeling and experimental analysis were peformed in order to evaluate the valve dynamic characteristics when the hydraulic pressure is applied. High pressure on the master cylinder that affects on the valve dynamic characteristics have been analyzed quantitatively, and performance improvement methods have been suggested through parameter study. Consequently, results of solenoid valve dynamic characteristics analysis derived in the study can be utilized as criteria for the optimal control of anti-lock brake systems.

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차량 안정성 제어 시스템의 모듈레이터 성능개선 및 단순화에 관한 연구 (A Study on the Performance Improvement and Simplification of the Modulator for Vehicle Stability Control System)

  • 이종찬;송창섭
    • 한국정밀공학회지
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    • 제21권6호
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    • pp.84-93
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    • 2004
  • This study carries out the performance improvement and simplification of hydraulic modulator that plays an important role in vehicle stability control systems. The mathematical models for each component of a modulator, such as pump, wheel cylinder, check and solenoid valve, accumulator, damper are derived in detail. All the mathematical models are combined to form a modulator system and implemented through a computer program, which can be controlled by a user friendly GUI. To verity the simulation, comparison between simulation and experiments has been made. After the verification of the validity of the simulation, the effects of the design parameters of the modulator on the wheel cylinder pressure is investigated. The results show that the modulator without MPA has advantage in early time pressure rise rate, and it can be simplified.

차량 안정성 제어용 유압 모듈레이터의 특성 해석 (Analysis of the Characteristics of ASMS Hydraulic Modulator (Automotive Stability Management System))

  • 송창섭;김형태;신상원;정태천
    • 한국정밀공학회지
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    • 제18권10호
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    • pp.127-133
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    • 2001
  • In this study, the effect of the factors of a hydraulic modulator of ASMS was analysed. The modeling of ASMS was presented and the equation of ASMS was derived from the modeling. With this background, GUI analysis tool was developed. After the verification of the reasonability of simulation, the response of a hydraulic modulator is investigated through simulation of modeling. With this simulation, each behavior was predicted with changing the various parameters and determined the influenced factors to apply the designing process.

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미끄럼방지 제동장치용 솔레노이드 밸브의 맥동특성 해석 (Analysis on the Surge Characteristics of the Solenoid Valve for Anti-Lock Brake System)

  • 김병우;박호
    • 전기학회논문지
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    • 제59권11호
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    • pp.2083-2088
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    • 2010
  • It is necessary to carry out quantitative analysis for the ABS hydraulic modulator to upgrade the system performances. Mathematical modeling method for the ABS hydraulic modulator, is suggested in the view of electromagnetism and fluid mechanics. Also, an analytic method is proposed for the resultant forces of electromagnetism and hydraulic pressure generated in the real vehicle ABS. The relationships between the design factor of Inlet & outlet solenoid valve and the system performance of ABS, are investigated through the analytical precess.

자동차 미끄럼방지 제동장치의 유압 제어 특성 (Hydraulic Control Characteristics of the ABS for an Automotive)

  • 김병우;박호
    • 한국산학기술학회논문지
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    • 제8권1호
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    • pp.10-17
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    • 2007
  • 자동차 미끄럼방지 장치의 최적 제어를 위해서는 유압 모듈레이터 특히, 솔레노이드 밸브에 대한 정확한 동특성 해석이 필요하다. 그러나, 현재까지 진행된 대부분의 연구들은 솔레노이드 밸브 자체만을 고려하였기 때문에 실제 자동차 미끄럼방지 장치에 제한적으로 적용되었다. 본 연구에서는 유압 모듈레이터에 작용하는 압력을 고려한 솔레노이드 밸브의 동특성 해석을 위하여 실험과 이론 해석을 실시하였다. 작동 압력이 솔레노이드 밸브의 동특성에 끼치는 영향을 정량적으로 해석하였고 설계인자를 변화시키면서 성능향상 방안을 제안하였다. 따라서, 본 연구에서 수행한 솔레노이드 밸브 동특성 해석결과는 자동차 미끄럼방지 장치의 최적 제어 기준으로 활용할 수 있을 것이다.

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미끄럼 방지 제동장치용 유압모듈레이터의 압력 특성 해석에 관한 연구 (A Study on the Analysis of Pressure Characteristics of Hydraulic Modulator for Anti-Lock Brake System)

  • 송창섭;양해정
    • 한국정밀공학회지
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    • 제13권8호
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    • pp.120-127
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    • 1996
  • Anti-lock Brake System has been developed to reduce tendency for wheel lock and improve vehicle control during sudden braking on slippery road surfaces. This is achieved by controlling the braking pressure, avoiding wheel lock, while retaining handling and brake performance. This paper is concerned about pressurecharacteristics of hydraulic modulator. Experimental sets which is consists of hydraulic modulator, duty controller, pressure regulator, pressure senset is consuructed. System modelling and computer simulation are performed for comparison with experimental results. Brake wheel pressure are measured under various driving pulse. The result of experiment show fairly agreement with the simulation. As a result, it is known that wheel pressure is affected by duty ratio, orifice diameter through computer simulation.

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ABS 유압 장치의 유충 현상에 관한 연구 (A Study on the Pressure Surge of ABS Hydraulic System)

  • 김병우;송창섭
    • 한국자동차공학회논문집
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    • 제9권5호
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    • pp.140-147
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    • 2001
  • The solenoid valve in ABS hydraulics, modulator is a two directional on-off valve and is controlled by around 100Hz high speed pulse width modulation. When the inlet valve is switched from open state to closed state, there are braking force degration, noise and vibration due to pressure surge phenomena in the hydraulic line and wheel cylinder. In this study, identifies pressure surge phenomenon in the braking process of a ABS, and investigates the way to reduce the phenomenon. For the purpose theoretical analysis on the pressure surge in the closed state hydraulic line, characteristic curve method based on wave equation was utilized. During this analysis, we could find pressure surge characteristics change due to hydraulic line change and PWM control conditions. In conclusion, by using the results of this study for the pressure surge prediction and reduction method, we could expect braking performance enhancement in Anti-Lock Braking System.

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트랙터용 파워시프트 전.후진 클러치의 압력 모듈레이션 제어 (Pressure Modulation Control of Powershift Shuttle Clutch of Tractor)

  • 조재문;허준영;정병학;김경욱
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1572-1577
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    • 2003
  • The powershift transmission have the advantage of easier operation and higher efficiency by using the hydraulic clutch and mechanical power transfer system. It is important to control the engaging pressure and time. The hydraulic control system is used for these controls of the modulator valve, the accumulator, the sump valve and etc. This study have made a simulator for verifying the pressure characteristic of the shuttle powershift transmission and developed the computer simulation model of the hydraulic components and system by using 'AMESim'. As a result, the design parameters which have an effect on the pressure modulation are verified to the spring stiffness of the modulator valve and the volume of the accumulator.

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솔레이노-유량제어 방식 ABS의 응답성 향상에 관한 연구 (A Study on the Impronement on the Response of Solenoid-Flow control type ABS Modulator)

  • 송창섭;김형태
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.569-572
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    • 1995
  • In this study, a hydraulic modulator of solenoid-flow type ABS, the master sylinder, and the wheel cylinder are modeled and simulated for increasing pressure characteristics of the brake. Response can be predicted by external force of the the master sylinder and pulses to the solenoid valve as input. For a demonstration of simulation result, experiment is done under the same condition as simulation condition after experimental apparatus of 1/4 car model is constructed. When factors of flow control valve are changed, the effect of each factor to response, how to improve response, and the most critical factors are considered from simulated result of time constant.

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