• Tribology and Lubricants
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• v.22 no.2
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• pp.87-92
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• 2006

In tread brake of freight cars, brake force is produced by the friction between the wheel and the brake shoe. Friction coefficients associated with the brake power, weight variation and brake shoe types should be sensitively treated as the design parameters. The conditions of the car, empty and loaded, should also be taken into consideration in brake force design and the control of brake force has some limitations in terms of the brake system design so that the brake friction materials selection should be considered as important measures to solve that difficulties. Friction characteristics of brake friction materials should remain within the range of maximum and minimum value and the friction performance should remain stable regardless of brake time and temperature. This study presented an experimental evaluation method to secure optimum brake performance by keeping safe brake effect and brake distance by the friction coefficient of the brake shoe of the freight cars.

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.391-402
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• 2005

Despite its superior braking performance to conventional vehicles on test tracks, the performance of the ABS-equipped car seems disappointing on real highway. The poor braking performance results from questionable design of the human-machine interface(HMI) of the brake system. Force-displacement relation at the brake pedal has a strong effect on the braking performance. Recently developed brake-by-wire (BBW) system may allow us to tailor the force feel at the brake pedal. This study aims at exploring analytical ways of designing human-machine interface of BBW system. In this paper, mathematical models of brake pedal feel for electro-hydraulic BBW (EH-BBW) system are developed, and the braking motion and the characteristics of the driver's leg action are modeled. Based on the dynamic characteristics of the brake pedal and the driver, two new HMI designs for EH-BBW system are proposed. In the designs, BBW system is modeled as a type of master-slave teleoperator. The effectiveness of the proposed designs is investigated using driving simulation.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.87-92
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• 2000

In this paper, we investigated the braking performance of a composite brake shoe for power car. Laboratory bench test and field tests were carried out to characterize the braking performance by the parameters such as friction coefficient, wear rate, braking temperature and stopping distance. Density distribution was found to have a significant influence on the wear rate. The composite brake shoe with even density distribution showed better braking performance. The braking performance of a composite brake shoe was also compared with that of a cast iron brake shoe which is currently being used. The result indicated the performance of the composite brake shoe is better than the cast iron brake shoe.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.3
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• pp.108-120
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• 2001

In this paper, the braking performance considering the dynamic weight is analyzed about the tractor-semitrailer vehicle. The basic brake performance, the parking brake performance, the emergency brake performance and the locking point deceleration etc. are to be calculated for the brake system design of the tractor-semitrailer vehicle. This braking performance is related to traffic regulations and braking characteristics according to the vehicle deceleration, the tire-road friction coefficient and specifications of the air brake system. The design program for the braking performance based on various design variables of the vehicle and the air brake system is developed integrating the analysis functions. This design program is developed by an object oriented programming method that is windows based. GUI (Graphic User Interface) function and the convenience of operating are greatly considered.

• International Journal of Railway
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• v.8 no.1
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• pp.30-34
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• 2015

The Maglev(UTM-02) project is leading by Korea Institute of Machinery & Materials and financially supported from the ministry of Commerce, Industry and Energy. The early development stagy of Maglev(UTM-02) was adopted the general urban railway pneumatic brake system due to the Korea domestic industrial environment. Currently there is two commercial operation Light Railway Train(LRT) system in Korea. One is U-Line in Uijungbu, and the other is Everline in Yongin. Both LRT systems are adopting high performance light weight hydraulic brake system. But those design and manufacturing core technology of the brake system is came from a major brake system companies located from aboard. Currently various studies have been continued to increase practical application and to improve competitiveness on performance for each sub-system of Maglev. Also in case of brake system, developing competitive hydraulic brake system is required. In this study, we have introduced the development process and performance evaluation of the new hydraulic brake system of Maglev.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.338-348
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• 1998

The study was carried out about the design and the performance study of brake system for Korean High Speed Train of maximum operating speed of 350km/h. The brake system was studied to two parts the function of brake system and the performance of brake system base on Korean-TGV. According to the simulation of brake system, the train should be provided the eddy current brake system for maximum operating speed of 350km/h. The eddy current brake system take charge of about 31% on normal condition and about 22% on emergency by condition. The performance study of brake system would be continued for definition of adhesion factor un friction factor assumed to analysis and simulation.

• Journal of Power System Engineering
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• v.7 no.4
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• pp.19-24
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• 2003

Exhaust brake system for Diesel engines is composed of gate valve, pneumatic cylinder and exhaust brake valve with on-off solenoid. Exhaust brake valve which is core component of exhaust brake system should have characteristics such as high reliability and long life. In this paper. exhaust brake valve with on-off solenoid which is used for vehicle brake system was studied. For the performance evaluation of on-off solenoid, electromagnetic characteristics and dynamic characteristics are analyzed. As a basic study for the performance improvement of exhaust brake system, pneumatic circuit and pneumatic valve with on-off solenoid were suggested and the performance of the pneumatic valve was evaluated through tests.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.377-382
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• 2003

In tread braking of freight cars, braking force is produced by the friction between the wheel and the braking shoe. Friction coefficients such as the brake power, weight variation and brake shoe types should be sensitively treated as the design parameters. The conditions of the car, empty and weighted, should also be taken into consideration in brake force design and the control of brake force has some limitations in terms of the brake system design so that the brake materials selection should be considered as important measures to solve that difficulties. Friction characteristics of brake materials should remain within the range of maximum and minimum value and the friction performance should remain stable regardless of braking time and temperature. This study presented an experimental evaluation method to secure optimum braking performance by keeping safe braking effect and braking distance by the friction coefficient of the brake shoe of the freight cars.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.580-585
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• 2003

Korean high speed train (KHST) has adopted a combined electric/ mechanic (friction) braking system. Electric brakes are consist of rheostatic brake, regenerative brake and eddy current brake and mechanical brakes are composed of disc brake, wheel disc brake and tread brake. In this paper, we introduce the braking performance test and the measuring method of mechanical brake. And disc brake performance has been reviewed by the experimental method. The on-line test of KHST has been carried out up to 260 km/h and proved that the disc braking capacity of KHST is sufficient.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.798-803
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• 2007

The brake system of railway plays an important role to enhance the speed of train, and the brake disc is one of major components relating to frictional braking. The performance enhancement of brake disc directly affects the braking performance of train. It is required to understand and investigate the factors need to be considered for the development of new brake disc with improved materials and performance. In this study, through the literature reviews of previous study, several factors including thermal crack phenomena, friction coefficient, materials and durability of disc, temperature characteristics, etc., were introduced for the design of improved brake disc. Moreover, based on the review results, the design direction of new brake disc was suggested. Eventually, a new brake disc with improved performance would be developed based on this investigation.