• 제목/요약/키워드: disc brake

검색결과 206건 처리시간 0.057초

제동시 피스톤 소재를 고려한 브레이크 오일 온도의 수치적 예측 (Numerical Prediction of Brake Fluid Temperature Considering Materials of Piston During Braking)

  • 김수태;김진한;김주신
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 추계학술대회 논문집
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    • pp.445-450
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    • 2004
  • Recently, many studies have been performed and good results have been reported in literature on the prediction of the brake disk temperature. However, study on the brake fluid temperature is rarely found despite of its importance. In this study, brake fluid temperature is predicted according to material property of brake piston. For the analysis, a typical disk-pad brake system is modeled including the brake disk, pad, caliper, piston and brake fluid. Vehicle deceleration, weight distribution by deceleration, disc-pad heat division and the cooling of brake components are considered in the analysis of heat transfer. Unsteady-state temperature distribution are analyzed by using the finite element method and numerical results are compared with the vehicle test data

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KTX 제동장치의 고유진동수와 스퀼소음 분석 (Analysis of Natural Frequencies and Squeal Noise of KTX Brake Unit)

  • 구병춘;나인균
    • 한국소음진동공학회논문집
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    • 제24권12호
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    • pp.954-961
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    • 2014
  • Brake squeal noise of KTX is very uncomfortable to passengers and workers in stations. A lot of study has been conducted to inquire into the mechanism of the squeal noise. But understanding of the brake squeal noise is still challenging. In this study, we developed a full-scale tester equipped with a KTX mechanical brake unit. And we measured the vibrational characteristics of each component of the brake unit and compared them with frequency response functions of brake squeal noise measured also in the tester. It was found that the brake squeal noise was more closely related to the vibrational characteristics of the brake pads and hangers in friction condition than those of free components.

고속 열차용 분할형 차륜디스크 개발 (Development of a Split Wheel-Mounted Brake Disc for a High Speed Train)

  • 조동현;강성웅;조연재
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.583-589
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    • 2010
  • This paper describes the design process and the test of split wheel-mounted brake discs for high speed train with maximum speed 180km/h. A disc set composed 2 disc rings and individual rings are partitioned into 3 pieces with the same circumferential angle. Because partitioned disc rigs are exposed to severe centrifugal force as the vehicle speed increase, finite element analyses used in the design process to ensure mechanical safety. A prototype was verified its mechanical safety through the spin test up to 250km/h. 2 prototypes for 1 wheelset are mounted to Korean Tilting Train(TTX) and have been running over 15,000km

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철도차량용 제동 디스크의 트라이볼로지 특성 연구 (Tribological Characteristics of Brake Disc for Train)

  • 김상호;이희성
    • Tribology and Lubricants
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    • 제23권1호
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    • pp.19-28
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    • 2007
  • Mechanical Brake system is inevitable equipment for stability of train and speed of the train. Especially brake disk and brake pads are core parts of mechanical brake system. It was investigated with tribological characteristics of brake discs for train by using lab-scale dynamometer. Gray cast iron disk was most attacked with sintered brake pad. Alloyed steel disk and NCM cast iron disk had suitable friction coefficient, high stability and low disk attack to the sintered brake pad. But at the view of economy, low alloyed cast iron will be most suitable choice.

디스크 정렬불량에 기인한 브레이크 스퀼소음 (Brake Squeal Noise Due to Disk Misalignment)

  • 박주표;최연선
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1690-1695
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    • 2003
  • In order to investigate the mechanism of brake squeal noise, the sound and vibration of an actua1 brake system were measured using a brake dynamometer. The experimental results show that disc run-out varies with brake line pressure and the factor of squeal generation is the run-out due to the misalignment of brake disk. A three degrees of freedom friction model is developed for the disk brake system where the run-out effect and nonlinear friction characteristic are considered. The results of numerical analysis of the model agree well with the experimental results. Also, the stability analysis of the model was performed to predict the generation of brake squeal due to the design parameter modification of brake systems. The results show that the squeal generation depends on the nm-out rather than the friction characteristic between the pad and the disk of brake.

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전동차 브레이크 스퀼소음 현상 및 개선에 대한 연구 (Study on the break squeal noise of rolling stock on tracks and improvements for reducing squeal noise)

  • 정수영;김성걸
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 추계학술대회 논문집
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    • pp.170-175
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    • 2005
  • In this study, experimental and theoretical methods were applied to understand brake squeal noise VVVF rolling stock on tracks. Trailer cars needed to payed a particular attention, because they were the major source of brake noise. VVVF rolling stocks for lines no 1 of the subway system in Seoul were used for experimental analyses. In order to study brake squeal noise, a dynamometer test at the S&T Brake, Co., which was a manufacturer of brake pads had performed. For measuring vibration and noise, vibration tests of brake parts (brake lining, brake lining head, back plates, etc.) at the SNUT were executed. Also, vibration tests of disc assembly and lining block at the heavy maintenance shop of the Gunja depot were performed. The modal analyses by using an ANSYS which was one of the CAE commercial program were simulated to know the relationship to the mechanism of brake noise. On the based of the tests and the simulations it was found that specific frequencies of the brake parts affected squeal noise, and improvements for reducing squeal noise were proposed.

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내열성 제동 디스크 소재 개발 (Development of a Heat-resistant Brake Disk Material)

  • 구병춘;임충환
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.1000-1004
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    • 2007
  • Thermal cracks are among the key factors that control the quality of a brake disk. Thermal cracks may shorten the lifetime of the disc and increase brake noise. Therefore, high heat-resistant brake disk materials are needed. In this study, three kinds of disk material were tested. They are composed of C, Si, Mn, P, S, Cu, Cr, Mo, and Ni. For the three materials, tensile tests, hardness measurement, metallurgical structure analysis, image analyzer analysis, etc were carried out. And friction tests were performed by a small scale dynamometer.

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디스크 브레이크 로터 마찰면 가공 형태에 따른 성능 변화 연구 (An Experimental Study for Machined Patterns of Friction Surface on Disc Brake Rotor in Performance Aspect)

  • 정택수;차바우;홍윤화;김청민;홍영훈;조종두
    • 한국자동차공학회논문집
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    • 제24권4호
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    • pp.471-479
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    • 2016
  • Cross-drilling and slotting on the frictional surface of a brake rotor are methods used for improving the performance of the brake system. These shapes have particular advantages, such as the shaving effect of a slotted shape, which maintains a clean pad-to-rotor contact surface, and the venting effect of a drilled shape, which provides passageways for the gas to escape. In order to understand the effect of the machined pattern on the brake performance aspect, an experimental method is adopted along with the dynamometer test. The cross-drilled rotor, slotted rotor, and mixed pattern rotor with cross-drilling and slotting machining are prepared and tested in terms of friction coefficient, temperature, braking torque, and noise.

실차 주행시험을 통한 디스크-패드 마찰계수 측정방법 (Measuring methods for friction coefficient of disc-pad through running test)

  • 목진용;김영국;김석원;박찬경;김기환
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.996-1001
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    • 2008
  • To stop the train safely within the limited traveling distance and reduce its speed to the desired speed, it is necessary to guarantee the correct braking force. Presently, most trains have electric propulsion system and have adopted combined electrical and mechanical(friction) braking system. The friction coefficient between brake disc and pad is an important parameter in determining the mechanical braking force. In general, friction coefficient data of braking material have been taken through the dynamo-test in a laboratory. This study have suggested two methodologies that can measure friction coefficient of braking material on the train's actual operating condition. The first is the direct method; measure the brake force and the clamping force applied on the mechanical brake by using strain gauges installed at the brake disk, and then calculate it. The second method is the indirect method; obtain the friction coefficient by using the train load and the equivalent brake force which is deducted the longitudinal force, such as resistance to motion, gradient resistance and curved resistance, from the inertia force applied to the train.

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광디스크 드라이브에서의 트랙 점프 안정도 향상 (Enhanced Track Jump Stability in Optical Disc Drives)

  • 유정래;도태용
    • 제어로봇시스템학회논문지
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    • 제15권7호
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    • pp.683-687
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    • 2009
  • Track jump control is a random access strategy for short distance movement. The most common track jump scheme is a bang-bang control of a kick and brake manner. In a conventional track jump scheme, a track-following compensator is turned off during kick and brake periods, and restarted at a target track for track pull-in. The inevitable controller switching with non-zero initial condition results in undesirable transient response, and excessive overshoot in the transient response causes track pull-in failure. In this paper, a new track jump scheme is proposed for enhancing track jump stability. Instead of control switching, internal states of a track-following controller are artificially manipulated for kick and brake actions in a digital control environment. Experimental results are provided in comparison with conventional track jumps.