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  • Title/Summary/Keyword: Disk-Pad Brake

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A Study on Wear Life Prediction of Disk Brake Pads (디스크 브레이크 패드 수명 예측에 관한 연구)

  • 여태인
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.4
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    • pp.199-205
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    • 2002
  • This paper presents a numerical technique to analyze wear life of automotive disk brake pad, where FFT-FEM method is adopted to determine the transient temperature distribution of the disk surface. A specimen ova frictional material is tested on a small scale brake dynamometer to find the dependency of the wear rate on temperature change, from which and the temperature analysis results, given the wear test mode, wear behavior of the pad material fur the vehicle can be predicted. Numerical examples show the predicted wear life of the vehicle coincides with the manufacture's recommended time interval for replacing the pads.

Robust Wheel Slip Control for Brake-by-Wire System (Brake-by-Wire 시스템을 위한 강인한 휠 슬립 제어)

  • Hong Daegun;Huh Kunsoo;Kang Hyung-Jin;Yoon Paljoo;Hwang Inyong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.3
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    • pp.102-109
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    • 2005
  • Wheel-slip control systems are able to control the braking force more accurately and can be adapted to different vehicles more easily than conventional ABS systems. But, in order to achieve the superior braking performance through the wheel-slip control, real-time information such as the tire braking force is required. For example, in the case of EHB (Electro-Hydraulic Brake) systems, the tire braking force cannot be measured directly, but can be approximated based on the characteristics of the brake disk-pad friction. The friction characteristics can change significantly depending on aging of the brake, moisture on the contact area, heat etc. In this paper, a wheel slip The proposed wheel slip control system is composed of two subsystems: braking force monitor and robust slip controller In the brake force monitor subsystem, the tire braking forces as well as the brake disk-pad friction coefficient are estimated considering the friction variation between the brake pad and disk. The robust wheel slip control subsystem is designed based on sliding mode control methods and follows the target wheel-slip using the estimated tire braking forces. The proposed sliding mode controller is robust to the uncertainties in estimating the braking force and brake disk-pad friction. The performance of the proposed wheel-slip control system is evaluated in various simulations.

Structural and Thermal Analysis of Disk Brake (디스크 브레이크의 구조 및 열 해석)

  • Cho, Jae-Uug;Han, Moon-Sik
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.2
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    • pp.211-215
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    • 2010
  • Continuous contraction and expansion of disk brake can be due to friction and temperature difference at repeated sudden braking. As serious vibration at disk is produced, the braking force will be changed ununiformly and braking system can not be stabilized. Temperature and heat flux at disk brake are investigated by structural and thermal analysis in this study. The maximum equivalent stress and displacement are shown respectively at the ventilated hole and the lower part of disk plate. At thermal analysis of initial state, temperature on disk plate is distributed from 95.9C to 100C. The maximum heat flux of 0.0168W/mm2 is shown at the inner friction part between disk plate and pad. At thermal analysis of transient state, temperature on disk plate is distributed from 95C to 96.5C after 100 second. The maximum heat flux of 0.0024W/mm2 is also shown at the inner friction part between disk plate and pad. By comparing with initial state, the temperature on disk plate is more uniformly distributed and heat flux is more decreased by 7 times at transient state.

A Study on Wear loss of Motorcycle Brake Disk by Response Surface Method (반응 표면법을 이용한 이륜자동차 브레이크 디스크 마멸량에 관한 연구)

  • Jeon, H.Y.
    • Journal of Power System Engineering
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    • v.12 no.3
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    • pp.44-49
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    • 2008
  • In this research, I would like to choose sliding distance and ventilated hole number which affect to the amount of wear of disk and pad as experiment conditions of 'the amount of wear' through wear test of motorcycle brake disk. Also, I analyze the amount of wear according to the variation of coefficient of friction by using design of experiment that is being widely used in diverse areas. With the tests of least, I present the correlation of each experiment condition. Therefore, I analyzed the variation of the amount of wear of disk and pad according to test factors such as ventilated hole number, applied load, sliding speed, and sliding distance in wear test of motorcycle brake disk by applying the design of experiment. Also, I analyzed quantitatively the influence of test factors through Taguchi Robust experimental design, response surface and examined the most suitable level and estimation of the amount of wear of disk. From these, I reached the following conclusions. response surface design, mathematical model was constructed about amount of wear of disk and pad. The amount of wear that decrease according to increase of ventilated hole number, and it's increase according to Increase of applied load, sliding speed, and sliding distance.

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A test for friction and wear characteristic of brake disk materials (제동디스크 소재의 마찰-마모특성 시험)

  • Lim, Choong-Hwan;Goo, Byeong-Choon
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1761-1765
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    • 2008
  • In the braking of a railroad car, mechanical brake systems using wheel tread and brake disk are applied as well as electrical brake systems by regenerator and rheostat. It is very important to consider the frictional characteristic because kinetic energy of the vehicle is dissipated as converted thermal energy through friction between disk and brake pad during disk braking. A friction coefficient and wear characteristic are decided from the interrelationship of disk and friction material in the disk brake system. Lab-scale dynamometer test on developed brake disk materials for increasing heat resistance was performed in this study. Each candidate material was tested at various braking speeds and pressures and we obtained the friction coefficient and wear characteristic. And we executed comparative evaluation of the result from the test.

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Tribological Characteristics of proposed brake disk for Tilting train (틸팅차량용 제동 디스크의 트라이볼로지 특성 연구)

  • Park Kyung-sik;Kang Sung-woong;Cho Jeong-whan;Lee Hisung
    • Proceedings of the KSR Conference
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    • 2005.05a
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    • pp.491-497
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    • 2005
  • Brake system is indispensible functional part to the transportation machines such as railroad cars, and all of industrial machines. It is mechanical element to stop the movement or slow the speed, transforming kinetic energy of motion object into thermal energy through solid friction. According that recently the railroad cars have become high-speed, the technique in braking domain to secure the overall braking effort is making rapid progress. In particular, material development and manufacturing process are so important to secure friction performance, which is the core in braking performance of mechanical brake units. Wear of brake disk could mainly result in the diminishment of its life span due to thermal cracking, so the endurance against high temperature is required. On the other hand, in this case, the problem is that the side wear of pad, relative material is slightly increased because of enlargement of plastic deformation. It is necessary, therefore, to develop a disk material that will be used in the Tilting System mechanical brake units. The purpose of this paper is to make a study prior to developing brake disk of Tilting Train travelling at 200km/h and to propose the component of brake disk. Accordingly, I will conduct sufficient researches on technical documents of brake disk, that are basic documentations, analyze an impact on components, and further, considering braking degree of train, study for the basic proposal on brake disk's component of the train travelling at 200km/h, which has relatively minor influence of heat stress and maintains the friction. In this respect, I would like to investigate friction characteristics between disk and relative friction material via Test on some possible test segments, analyze and propose friction performance, temperature impact and so forth coming from the contact with pad, relative material to demonstrate the friction characteristics.

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Compatibility Evaluation between NCM-CV Cast Iron Brake Disk and Various Pads (NCM-CV 주철 제동디스크와 다양한 패드의 적합성 평가)

  • Gil, Hyeong-Gyeun;Ko, Tae-Whan;Cho, Dong-Hyun;Han, Seong-Ho;Seo, Sung-Il
    • Journal of the Korean Society for Railway
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    • v.10 no.3 s.40
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    • pp.251-256
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    • 2007
  • The research analyzed dynamo test results to evaluate compatibility between brake disk made of NCM-CV cast iron and various pads. The dynamo test was executed with one kind of resin pad and three kinds of sintered pads suitable for 200 km/h trains according to a program which refers to UIC 541-3. The thermocouples were established in specific location in order to measure the temperature of disk and pads. In addition, the thermal imaging camera was used for capturing the instantaneous thermal characteristic of disk. The research results may be utilized to use as basis data of pad development for NCM-CV brake disk hereafter.

A Study on Thermal Behavior and Stress Characteristics of Discs under Braking Conditions for Automobiles (자동차 브레이크 제동시 디스크의 열적거동 및 응력 특성에 관한 연구)

  • Baek, Il-Hyun
    • Tribology and Lubricants
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    • v.28 no.5
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    • pp.246-251
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    • 2012
  • Disc brakes and brake linings are part of the braking system in automobiles; this system works due to the braking power between the disc and pad. Vehicle braking systems have complex environments due to the geometry of the disk and pad, the material properties, the braking conditions, etc. Braking energy is converted into thermal energy during the braking process, due to the frictional heat between the disc brake and pad. This heat is changed to a heat flux, which affects the thermal stress of the disc. The purpose of this study was to use the fluid dynamics software ANSYS CFX to investigate the inner flow characteristics of the air and the heat transfer of the disc, and to analyze the effects on the thermal stress of the disc brake.

A Study on the effect of Driving Speed and Breaking Power on Squeal Noise of Disk Break (주행속도와 제동력의 변화에 의한 디스크 브레이크의 스퀄 소음에 미치는 영향)

  • Kim J.H.;Kim K.H.;Choi M.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.269-270
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    • 2006
  • Brake noise is classified according to frequency territory: judder, groan and squeal. Squeal noise of disk brake is a noise and self excited vibration with frequency of 110Khz caused by the friction force between the disk and the pad of the automobile. Passengers in a vehicle feel uncomfortable. It causes unstable characteristic to the brake system when you try to stop the vehicle. Thus this study aims to find in which conditions the vehicles are stable during the braking hour and find ways to decrease a squeal noise and the vibration by measuring various factors including squeal noise and self excited vibration between the pad and disk brake system during the braking hour. From the result the countermeasure for a squeal noise and a vibration decrease is established. Also the analyzed data is found to be useful and can be applied to the actual brake model.

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

  • Park, Ju-Pyo;Choi, Yeon-Sun
    • Proceedings of the KSME Conference
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    • 2003.11a
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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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