• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.46-48
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• 2002

It needs to study on proper brake performance used in servo system of industrial application. In this study, braking torque of eddy current brake between electromagnet stator and rotating disk are analyzed. The torque-speed characteristics and proper disk construction are presented in this paper. From the computer simulation results, it was found that eddy current braking torque is linear or approximately constant over the desired speed range depending on the rotor material, disk construction, pole number and pole displacement of stator.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.11
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• pp.930-936
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• 2008

This paper studies the effect of pad at initial stage and wear during braking on the dynamic contact pressure distribution. Wear is influenced by variable factor (contact pressure, sliding speed, radius, temperature) during dynamic braking and variation in contact pressure distribution. Many researchers have conducted complex eigenvalue analysis considering wear characteristic with Lim and Ashby wear map. The conventional analysis method is assumed the pad has smooth and flat surfaces. The purpose of this paper is to validate that wear rate induced by braking is considered for the precise squeal prediction. After obtaining pad wear from experiment, it is incorporated with FE model of brake system. Finally, the comparisons in fugitive nature of squeal will be carried out between the complex eigenvalue analysis and noise dynamometer experiment.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.820-825
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• 2002

As the speed of rail transit is higher, it is very important to secure the safety and confidence of the braking device and in the point of view, by means of the rise of the temperature from the friction between the disk and pad which are the actual part of a braking system, the damage of brake disk is the main cause to lose the safety of braking device. Therefore, in this study, to predict the danger of a disk brake and to know its max. temperature in the train service the module of a temperature measurement by the non-contact method was developed.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.779-786
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• 2002

The Friction Brake Pad of High Speed Train is the most important parts in brake system, which is usually made of Cu-based Sintered friction material. This study has been carried out about the formulation effects of sintered friction material and made lots of sample brake pads. Then, we have done the performance test of the developed product by using full scale inertia Dynamo-meter. This performance test (braking speed 300km/h) was conducted as GEC Alsthom Standard test procedure and High Speed Brake Test (braking speed 350km/h) was done at "Poli" in Italy. The friction properties of this product was almost identical with the brake pad which is currently used to TGV. And the temperature of brake disk on braking speed 350Km/h was a little higher.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.473-478
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• 2003

The hydraulic buffer stop placed on the end of the railway brakes the train could not reduce the velocity sufficiently because of the braking system troubles or driver's mistakes. The hydraulic buffer stop is composed of 2 operating parts; hydraulic buffers and rail clamps. Hydraulic buffers brake trains non-destructively in low speed, otherwise rail clamps begin to work in higher speed. In this paper, The braking process of the hydraulic buffer stop is investigated by numerical methods. The hydraulic buffer is numerically analyzed and designed to absorb the kinematic energy of the train below 3.2km/h speed. The hydraulic buffer stop crushed by the train with 5km/h speed is analyzed by FEM package-PAM CRASH in order to obtain the stress profile in rail clamps and buffer stop frame.

• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.607-612
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• 2007

In this paper, operation mode of train was divided into powering, coasting, and braking and rail wear phenomenon has been done comparative analysis by each section. Data of train velocity is transferred to acceleration and deceleration from ATO Logging data. Amount of rail wear has been done comparative analysis by traction force of acceleration and braking force of deceleration and a plan for management of track irregularity is come up with by the result of the analysis.

• 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.

• Journal of the Korean Society of Safety
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• v.28 no.2
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• pp.6-13
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• 2013

This study focuses on finding ECO driving patterns which consider driving safety of the ATO system train and reliability and which optimize efficiency of the driving energy consumption. Research results derived by performing simulation of those 5 models show that the emergency braking which affects safety of passenger and the machinery is minimized, and safe driving speed is maintained by the prohibition of drastic acceleration/deceleration, coasting and constant-speed driving. Therefore if this result is applied to the urban railway train by amending or making ATO program to save energy usage that improve environmental quality, its effects as ECO driving pattern is huge.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.1
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• pp.46-53
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• 2002

The brake system of a high speed train has a crucial role for the safety of the train. To develop a safe brake system of the high speed train, it is necessary to understand the braking principle and phenomena of the total brake system and its subsystems. In this paper, we have suggested a mathematical model which includes car dynamics, interactions between cars, adhesive forces, brake blending algorithm, and the dynamics of each brake devices. Also, we have proposed a ready-time compensation algorithm of eddy-current brake system and a brake control logic on electric-pneumatic blending. A simulation study has shown the proposed models and algorithms are effective on the braking of the train.

• Journal of Mechanical Science and Technology
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• v.15 no.1
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• pp.66-80
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• 2001

In brake systems, a proportioning valve(P. V), which reduces the brake line pressure on each wheel cylinder for the anti-locking of rear wheels, is closely related to the safety of vehicles. However, it is impossible for current P. V. s to completely control brake line pressure because, mechanically, it is an open loop control system. In this paper we describe an electronic brake force distribution system using a direct adaptive fuzzy controller in order to completely control brake line pressure using a closed loop control system. The objective of the electronic brake force distribution system is to change the cut-in-pressure and the valve slop of the P. V in order to obtain better performance of the brake system than with mechanical systems.