• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.831-832
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• 2011

• 한국자동차공학회논문집
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• 제20권5호
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• pp.65-70
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• 2012

Torque fluctuation of engine generate gear rattle noise of transmission and many researches have been studied to decrease rattle noise by adjusting clutch damper system. So design optimization of clutch system is very important to decrease rattle noise and need knowing clutch dynamic torque at real vehicle driving condition. This makes it possible to measure clutch dynamic torque by using a small-size magnetic sensor. We install a small-size magnetic sensor on the input shaft of the transmission and measure the relative angular displacement between clutch hub and disc plate. We can obtain the clutch torque correspond to the angular displacement in the clutch torsional characteristics test. The object of this research is to measure clutch dynamic torque on real vehicle condition. Therefore, Clutch dynamic torque is very useful for investigating operating range of clutch according to engine torque and predicting the damping performance of torsional vibration on the powertrain.

• 대한기계학회논문집A
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• 제22권4호
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• pp.762-767
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• 1998

The main torsional vibration source of the powertrain is the fluctuation of engine torque. The gear rattle is impact generating in the backlash of the free gear due to this torsional vibration. Optimization of the clutch torsional characteristic is one of the effective method to reduce the idle gear rattle. Many researches have been reported on this problem but only few of them give sufficient consideration to the detailed clutch modeling and the experiment. This paper pays attention to the optimization of clutch design parameters and the experiment to reduce the idle gear rattle vibration and noise.

• 한국자동차공학회논문집
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• 제6권3호
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• pp.88-96
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• 1998

The rattle noise is the most significant in many kinds of manual gearbox nioses, which is generated at the idle stage of the engine operation. The main torsional vibrat- ion source of the driveline is the fluctuation of the engine torque. The gear rattle is impacts generating in the backlash of the free gear due to this torsional vibration. Many researchers reported the clutch torsional characteristic optimization method to reduce the idle gear rattle but only few of them give sufficient consideration to the system parameters like gear backlash, drag torque, system inertia, inertia distribution, engine torque fluctuation, idle engine rotation speed, and accessory load. In this paper, influence rate of system parameters on the gear rattle is presented and counterplans like backlash reduction, drag torque increase, inertia addition, inertia distribution modification and engine torque characteristic control are suggested.

• 한국자동차공학회논문집
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• 제3권2호
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• pp.30-41
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• 1995

Gear rattle is a source of vibration and noise in automotive gearbox casing and generally occurs at or near system resonant frequencies. The neutral gear rattle of the gearbox. is affected by the stiffness and hysteresis torque in the clutch disk and drag torque determining balancing point of the clutch disk operating range. The experiment is carried out in the pre-damper type clutch and a manual transmission of a automobile equipped for inline four-sylinder four-cycle 1.5L MPI engine and the computer simulation is executed by 5th order Runge-Kutta method. The results of the simulation analysis and experimental studies show the dynamic behavior of clutch and a phenomenon of the neutral gear rattle with respect to drag torque and torsional characteristics of the clutch.

• 한국소음진동공학회논문집
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• 제21권8호
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• pp.774-780
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• 2011

Recently, customers have been concerned about vehicle NVH depending on vehicle designing and manufacturing technologies development. In choosing vehicle, vehicle NVH is becoming the most important factor to customers. Especially, a seat is the final stage of vibration transfer path to passengers from all sources of vibration like engine, transmission and etc. And seat is the nearest component from driver's ear. For this reason, seat is the most important component that directly related to ride comfort for passengers. And driver can be influenced sensitively by BSR caused by seat. Thus, evaluating the vibration characteristics of vehicle seat and BSR caused by vehicle seat is necessary to reduce the seat BSR. The rattle noise occurred from seat has evaluated through sound source visualization and multi-dimensional spectral analysis - coherence function technique in this paper. Vibration characteristics of the seat has verified through modal test.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.635-640
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• 2001

The small gear reductioner noise is caused by gear accuracy, assembling errors, and gear backlash. This main study is an investigation on noise quality of the small gear reductioner through the change of gear backlash. In this study included Gear design parameters related the small gear reductioner, the knowledge of rattle noise related gear backlash, and the experimentation results of the small reductioner noise through change of gear backlash. At last, this study propose the least method of the small gear reductioner noise that is caused by suitable existence of gear backlash.

• 한국소음진동공학회논문집
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• 제20권7호
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• pp.644-650
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• 2010

Among various elements to affect customer's evaluation of vehicle quality, BSR(Buzz, Squeak, Rattle) are considered to be a mostly contributing factor. In this paper, we provide the test method which can be used to reduce the BSR noise of instrument panel in a vehicle. First, potential source regions of the instrument panel for BSR are localized by using the vibration-excitor and near-acoustic field visualization system. Then, subjective evaluation of BSR noise from the detected potential noise source regions is made with the Zwicker's loudness and time-varying loudness methods. This illustrative analysis reveals that current experimental methods can be used as a test procedure to systematically tackle BSR issues in early stage of the vehicle development cycle, which can result in the reduction of the production cost.

• 한국음향학회지
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• 제43권1호
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• pp.49-59
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• 2024

최근 환경규제가 강화되고 고유가 문제로 인하여 전기차 시장이 점차 커지고 있으며 또한 내연기관 자동차에서도 엔진의 Noise, Vibration, Harshness(NVH) 관련 소음이 저감되고 외부에서 유입되는 소음의 차폐 기술이 발전됨에 따라 Buzz, Squeak, Rattle(BSR) 이음의 민감도가 증가하는 추세이다. 본 연구에서는 자동차의 Panoramic Curved Display(PCD)에서 발생하는 Stick-slip 이음과 고분자 플라스틱의 표면에너지 및 극성 성분과의 상관관계에 대하여 분석하였다. 극성 고분자 소재인 Acrylonitrile Butadiene Styrene(ABS)와 PolyCarbonate-Acrylonitrile Butadiene Styrene(PC-ABS)를 대상으로 컴파운드 소재를 제작하여 평가하였다. 결과적으로 고분자 플라스틱의 극성성분이 3.86 mN/m 이상일 때 Stick-slip 거동이 발생하였으며, 시간에 따른 마찰 거동에서 absolute transition slope가 증가할수록 Stick-slip의 이음 가능성이 증가하고 마찰계수의 값 차이가 클수록 Stick-slip 이음의 세기가 증가하였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 추계학술대회 논문집
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• pp.292-297
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• 1997

The rattle noise is the most significant in many kinds of manual gearbox noises, which is generated at the idle stage of the engine operation. The main torsional vibration source of the driveline is the fluctuation of the engine torque. The gear rattle is impacts generating in the backlash of the free gear due to this torsional vibration. Many researchers reported the clutch torsional characteristic optimization method to reduce the idle gear rattle but only few of them give sufficient consideration to the system parameters like gear backlash, drag torque, system inertia, inertia distribution, engine torque fluctuation, idle engine rotation speed, and accessory load. This paper pays attention to the gear impact mechanism and system design parameters to reduce the idle gear rattle with computer simulation.