• 한국소음진동공학회논문집
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• 제20권6호
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• pp.577-582
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• 2010

The squeak propensity in the gear box of an automotive seat system is investigated analytically. The mating parts in the gear box are the lead screw and the nut, where the friction stresses are exerted on the thread of the screw. The lead screw is modeled as a circular beam allowing the bending and torsional vibrations. In the system, the lead screw converts rotating to translating motion so that it moves the automotive seat slightly tilted on the floor. The tilting angle is considered one major parameter in this study. Therefore, the equations of motion associated with the non-conservative friction force are derived with the inclusion of the tilting angle. It is found that the squeak noise corresponds to the several bending modes of the lead screw and its propensity is increased by the tilting angle of the seat.

• 대한기계학회논문집A
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• 제37권5호
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• pp.679-683
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• 2013

BSR 소음은 특히 자동차에서 도로 표면과 엔진 및 차량내부 스피커등의 진동에 의해 발생한다. 이러한 현상은 진동하는 시스템의 약화된 체결부나 접촉부에서 공진모드와 가진력의 중첩으로 인해서 발생하는 불규칙한 타격이나 스틱슬립(stick-slip)으로 발생한다. 이와 같인 국부적인 현상을 관찰하기 위해서 모든 BSR 발생 부위를 상세 유한요소 모델로 만드는 과정은 현실적으로 불가능 하므로 부분구조 모델 (Sub-structure) 해석 기술이 필요하다. 이번 연구에서는 부분구조 모델 (sub-structure) 해석 기술을 적용하여 실제 가진력이 구조물을 통해 전달되어 발생하는 래틀(rattle)과 스퀵(Squeak)을 검출하고 분석하는 해석적인 방법을 정리하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.617-621
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• 2007

Recent advances in automotive noise control engineering have reduced major sound sources in the vehicle, customers perceive Buzz, Squeak and Rattle (BSR) as one of important indicators of vehicle quality and durability. As the long-term goal, we expect to establish the integrated design cycle for the reduction of BSR noise in the early stage of development, which consist of design, prediction, and evaluation procedures. This is possible only with great bulk of experimental data for BSR noise. In this paper, BSR noise is experimentally identified for vehicle doors, which have been traditionally considered as one of main sources of BSR noise. Based on this result, we proposed method for the prevention of BSR noise in the vehicle doors.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.675-679
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• 2006

Today, the interior noise perceived by the occupants is an important factor in the design of automotive interior assemblies. Buzz, Squeak and Rattle Noises in a Seats are one of the major concerns mentioned above. In this study, the terms 'Buzz, squeak and rattle' were defined as the noise originating from structural vibrations in an assembly. And, the BSR noise of vehicle seat was investigated and the improvement of BSR noise level was confirmed though the structural treatment based on the structural analysis results from the modal and sound intensity of seat.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 춘계학술대회 논문집
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• pp.662-663
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• 2014

In most vehicle manufactures have traditionally relied on find-fix method of human auditor, mainly due to variation excitation source. To solve the BSR noise, the requirements for BSR test are presented in terms of detection of noise source, analysis of time-frequency and sound pressure, sound quality for noise. A number of new technology direction, particularly in the field of noise source identification application and psycho-acoustics from the Zwicker's sound quality parameter, the computed objective sound metrics and subjective jury test result.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 춘계학술대회 논문집
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• pp.330-331
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• 2010

In this paper, BSR noise from an instrument panel of a vehicle are investigated with integrated experimental methods. First, potential source regions of the instrument panel for BSR are localized by using the module-excitor and near-acoustic field visualization system. Then, subjective evaluation of BSR nosie from the detected potential noise source regions is made with the Zwicker's loudness and time-varying loudness methods.

• 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.

• 한국소음진동공학회논문집
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• 제22권6호
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• pp.550-555
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• 2012

Among the various elements affecting a customer's evaluation of automobile quality, buzz, squeak and rattle(BSR) have been considered to be major factors. In most vehicle manufacturers, the BSR problems are solved by find-fix method with the vehicle road test, mainly due to various excitation sources, complex generation mechanism and subjective response. To systematically tackle the BSR problems in early stage of the vehicle development cycle, these difficulties should be resolved. The aim of the present paper is to characterize the sound quality property of BSR noise that can be used to assess the subjective responses to BSR. The four sound metrics from Zwicker's sound quality parameter are computed for the signals recorded for eight BSR noise source regions localized by using the acoustic-field visualized results. Then, the jury test of BSR noise are performed. On the basis of the computed sound metrics and jury test result is evaluated to represent the harshness of BSR noise. It is expected that the developed BSR measuring system and sound quality properties can be used to reduce the automotive interior BSR noise in terms of subjective levels as well as objective levels.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.447-452
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• 2012

Among the various elements affecting a customer's evaluation of automobile quality, buzz, squeak and rattle (BSR) are considered to be major factors. In most vehicle manufacturers, the BSR problems are solved by find-fix method with the vehicle road test, mainly due to various excitation sources, complex generation mechanism and subjective response. The aim of this paper is to develop the integrated experimental method to systematically tackle the BSR problems in early stage of the vehicle development cycle by resolving these difficulties. To achieve this aim, the developed experimental method ought to include the following requirements: to find and fix the BSR problem for modules instead of a full vehicle in order to tackle the problem in the early stage of the vehicle development cycle; to develop the exciter system including the zig and road-input-signal reproducing algorithm; to automatically localize the source region of BSR; to develop sound quality index that can be used to assess the subjective responses to BSR. Also, the BSR sound quality indexes based on the Zwicker's sound quality parameters using a multiple regression analysis. The four sound metrics from Zwicker's sound quality parameter are computed for the signals recorded for eight BSR noise source regions localized by using the acoustic-field visualized results. Then, the jury test of BSR noise are performed for participants. On a basis of the computed sound metrics and jury test result, sound quality index is developed to represent the harsh of BSR noise. It is expected that the developed BSR detection system and sound quality indexes can be used to reduce the automotive interior BSR noise in terms of subjective levels as well as objective levels.

• 한국자동차공학회논문집
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• 제25권2호
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• pp.257-265
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• 2017

In this work, the effect of field-degradation of automotive polymeric interior parts on the squeak characteristics was studied for a number of used vehicles with various mileages and years of service. The purpose of this study was to characterize the squeak noise related with long-term degradation in service life. The characteristics of field-degraded polymeric samples are analyzed using Fourier transform infrared(FT-IR) spectroscopy and scanning electron microscopy(SEM). Complicated carbonyl spectra from FT-IR were deconvoluted into various carbonyls to trace field-degradation phenomenon. In addition, various mechanical tests, i.e. tensile test, hardness test as well as coefficient of friction test, were performed to analyze the variation in mechanical properties due to field-degradation. Squeak noise was measured and analyzed by frequency analysis. It was shown that the changes in the chemical structures of polymer due to field-degradation influenced the variation in mechanical properties, and squeak noise may worsen by increasing the squeak noise level in the wide frequency range. The results indicated that customer complaints regarding the squeak noise coming from used vehicles might be one of the important reliability issues because the increase in sound pressure level especially in the high frequency range could annoy drivers and passengers.