• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
• /
• pp.363-368
• /
• 2001

Studies on brake system recently are focused on braking performance, especially the consideration on safety of braking system in an extreme situation and reduction of vibration and noise during braking operation. The thermal crack and Judder from the friction between brake disc and pad can bring the threaten of passengers' safety in the end. Braking force comes from the change of kinetic energy to friction energy. Since heat energy is developed from here, the analysis on thermal stress and thermal strain can be the good data when selecting the material of brake pad and designing heat radiation holes on the disc and it will also be the data when designing the thickness of the disc. This paper is intended to show a creative design method by suggesting the thermal analysis data through FEM study and using shape design parameters.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 춘계학술대회 논문집
• /
• pp.315-321
• /
• 2004

Dawin Friction Corp. has been advanced sintered brake pad for Korean concept high speed train (so called G7 train) with KRRI, You Jin and Rotem without the assistance of foreign company. In the course of development, the evaluation of our and foreign disk pads was performed by lab scale dynamometer and full scale dynamometer. As the result of dynamo test, it is shown that our developed brake disk is equal or superior to those of foreign companies in many respects, for example, wear resistance, noise, etc. The new brake pad which is developed through 'post G7-project' is equipped with G7 train and is under many tests without any problems at the present moment.

• 한국자동차공학회논문집
• /
• 제2권5호
• /
• pp.93-100
• /
• 1994

Friction-induced vibration characteristics of automotive brake lining pad are investigated on the basis of experimental observations from a pin-on-disk type friction-induced vibration experimental apparatus. The measured responses of the experimental apparatus show limit cycles of quasi-harmonics type and beat phenomena due to the velocity dependence of friction force. To deduce the friction coefficient vs. relative velocity Lienard method is adopted with least square fit. It shows Scurve which characterizes a quasi-harmonic vibration. The calculation of amplitudes and friquencies of the limit cycles is done using slowly changing phase and amplitude method. The theoretical and numerical results show fairly good agreements with those of experiments.

• 한국철도학회논문집
• /
• 제10권3호
• /
• pp.251-256
• /
• 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.

• 한국전자통신학회논문지
• /
• 제9권12호
• /
• pp.1397-1404
• /
• 2014

그랩 크레인은 부두 항만으로 모래 및 토사가 퇴적이 되거나, 해저 공사를 하기 위해 다목적으로 사용된다. 그립 크레인의 구성 요소 중 와이어 드럼과 디스크 브레이크 패드는 핵심적인 소모품으로 많은 열이 발생되며 교체 시 가격이 매우 비싸다는 단점이 있다. 본 논문에서는 그랩 크레인의 와이어 드럼에 작용되는 디스크 브레이크 패드에 대한 열화상 진단 시스템을 제안한다. 제안된 시스템은 브레이크 고장 및 디스크 패드 손상 전에 디스크 및 패드 표면의 온도가 비정상적으로 분포하는 특징을 이용하여 열화상을 통해 패드 열 진단 분석을 수행한다. 따라서 기계 부품의 이상을 고장 전에 미리 발견하여 고장으로 인한 피해를 방지할 수 있으며, 과부하 유무를 상시체크하면서 크레인을 작동시켜 패드의 수명 연장과 비용을 절감할 수 있다.

• 대한기계학회논문집A
• /
• 제38권12호
• /
• pp.1351-1358
• /
• 2014

본 논문은 차량 제동 시 발생하는 소음의 원인을 해석적으로 예측하고, 본 실험실에서 제작한 브레이크 다이나모 메터를 이용하여 실험적으로 검증하였다. 압력 변화에 따른 브레이크 시스템에 대한 주파수 응답 시험 및 유한 요소 해석(FEM)을 실시하여 캘리퍼 및 디스크의 수직 모드(Out-of-plane)의 시스템 주파수를 추적하였다. 이를 제동 시 발생한 스퀼 소음의 주파수와 비교해본 결과 스퀼 주파수는 캘리퍼 및 패드의 변위를 갖는 시스템 모드임을 확인하였다. 또한 유한 요소 해석을 이용한 복소수 고유치 해석 결과 패드의 회전변위를 발생시키는 캘리퍼 모드가 음의 마찰곡선 기울기와 연동하여 불안정하게 됨을 확인하였다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 추계학술대회 논문집
• /
• pp.1761-1765
• /
• 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.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 추계학술대회 논문집
• /
• pp.1407-1412
• /
• 2008

Squeal of disk brake is a noise and self excited vibration with frequency range of $1{\sim}10Khz$ cause by the friction force between the disk and the pad of the automobile. Passengers in a cehicle feel uncomfortable. In this paper modal analysis of wheel brake system was performed in order to prediction of squeal phenomenon. It was shown that the prediction of system instability is possible by FEM. finite element model of that brake system was made. Some parts of a real brake was selected and modeled. The normal mode analysis method performs analyses of each brake system component. Experiment of modal analysis was performed for each brake components and experimental results were compared with analytical result from FEM.

• 한국결정성장학회지
• /
• 제29권6호
• /
• pp.329-337
• /
• 2019

스플린터(splinter) 및 판상(plate shape) 형상을 가지는 티탄산칼륨염(K₂O·nTiO₂, PT)을 합성하고 브레이크 마찰재의 보강재로 이용하여 마찰 특성을 평가하였다. 스플린터형 티탄산칼륨염을 합성하기 위하여 먼저 판상 형상을 가지는 사티탄산칼륨염(K₂O·4TiO₂, PT4)을 합성하고 칼륨 이온(K⁺)을 일부 산침출(acid leaching)하여 육티탄산칼륨염(K₂O·6TiO₂, PT6)으로 변환시킨 후, 800℃에서 열처리하여 스플린터 형상의 입자를 얻었다. 판상형 티탄산칼륨염을 합성하기 위해서 염화칼륨을 융제로 사용하고 마그네슘(Mg)을 일부 첨가하여 판상의 형상을 가지는 마그네슘티탄산칼륨염(K_0.8Mg_0.4Ti_1.6O₄, PMT)을 합성하였다. 얻어진 육티탄산칼륨염 및 마그네슘티탄산칼륨염 입자를 보강재로 이용하여 브레이크 패드 마찰재를 제작하고 1/ 5-스케일 다이나모미터(scale dynamometer)를 이용하여 마찰 마모 특성을 평가하였다. 평가 결과, 두 종류의 보강재가 유사한 마찰계수 및 Fade & recovery 특성을 보였으며 판상형 마그네슘티탄산칼륨염의 경우, 스플린터형 육티탄산칼륨염보다 우수한 내마모성을 보이는 것을 알 수 있었다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2004년도 춘계학술대회논문집
• /
• pp.597-600
• /
• 2004

A two-degree-of-freedom out-of-plane model with contact stiffness is presented to describe dynamical interaction between the pad and disc of a disc brake system. It is assumed that the out-of-plane motion of the system depends on the friction force acting along the in-plane direction. Dynamic friction coefficient is modelled as a function of both in-plane relative velocity and out-of-plane normal force. When the friction coefficient depends only on the relative velocity, the contact stiffness has the role of negative stiffness. The results of stability analysis show that the stiffness of both pad and disc are equally important. Complex eigenvalue analysis is conducted for the case that the friction coefficient is also dependent on the normal force. The results further verify the importance of the stiffness. It has also been found that increasing the gradient of friction coefficient with respect to the normal force makes the system more unstable. Nonlinear analysis is also performed to demonstrate various responses. Comparing the responses with experimental data has shown that the proposed model may qualitatively well represent a certain type of brake noise.