• Proceedings of the KSR Conference
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• 2005.11a
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• pp.264-268
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• 2005

Most of the train brakes depends on friction between wheels and tracks. This requires braking force reduced in order not to cause wheel slides since the friction decreases as the train speed increases and consequently results in extension of braking distance. The braking system called 'Linear eddy current brake' or simply' Eddy current brake' is a braking system for making a brake independent from friction, which consists in creating electromagnet by coiling around shoes attached. to bogies; having the shoes above the tracks approached to the tracks upon acknowledgement of a braking command; and authorizing braking force that is irrelevant to friction through magnetic repulsion between electromagnet attached to the tracks and train set by the use of the electromagnet's magnet field characteristics. An electromagnetic attraction braking system that consists in pressing pole shoes attached to bogies against the tracks by using electromagnet's attraction force is called 'Electromagnetic track brake' or simply 'Track brake'. This paper has been prepared in purpose of studying technological tendencies of the eddy current brake and the track brake so that it can be utilized as fundamental data for commissioning Korean high-speed trains with the eddy current brake hereafter.

• Proceedings of the KSR Conference
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• 2008.06a
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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.

• 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 Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.9-13
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• 2003

The objective of this study is structural analysis of rope brake for elevator. The finite element model was developed to compute the stress, strain and friction force for rope brake. The ANSYS code was used for this analysis. In order to structural analysis of rope brake, many variables such as internal pressure, boundary condition, load condition and constraints were considered.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.1
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• pp.89-94
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• 2005

The objective of this study is structural analysis of rope brake by spring type. The finite element model was developed to compute the stress, strain and friction force for rope brake by spring type. The ANSYS code was used for this analysis. In order to structural analysis of rope brake, many variables such as internal pressure, boundary condition load condition and constraints were considered.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.150-155
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• 2004

The objective of this study is structural analysis of rope brake by spring type. The finite element model was developed to compute the stress, strain and friction force for rope brake by spring type. The ANSYS code was used for this analysis. In order to structural analysis of rope brake, many variables such as internal pressure, boundary condition, load condition and constraints were considered.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.294-299
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• 2006

Korean high speed train(HSR-350x) has adopted a combined electrical and mechanical(friction) braking system. Brake blending control unit(BBCU) controls each brake system to fulfill the required brake performances such as braking distance, deceleration and jerk. When the disc brake is applied in the high speed region, the wear of pad is increased rapidly. In this paper, we discuss the optimized patterns of the disc brake force from the view point of braking energy.

• 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.

• Journal of Auto-vehicle Safety Association
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• v.10 no.4
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• pp.13-24
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• 2018

According to DEKRA (a Germany Certification and Inspection Agency)'s accident rate analysis by vehicle defect factor, as a result of analysis of the causes of accidents by flaws, it was found that braking devices accounted for 41%. Defects in the braking system are closely related to the accident, so it is very important to find faulty brking systems to ensure safety. The EU and USA uses ISO brake tester and the Korea is brake teater is first introduse in Japan for vehicle inspection and maintanance. KOTSA introduce the ISO brake tester in order to promote the advanced standardization of the inspection equipment and inspection tecnology, and examined the detection characteristics and applied it to the improvement direction of the brake tester to secure the driving safety.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.11
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• pp.890-896
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• 2002

This paper deals with the dynamic stability of a brake shoe under pulsating frictional forces. A lining part of brake systems is assumed as a distributed spring, and the supported elements of a shoe are assumed as translational springs for a constant distributed frictional force and a pulsating frictional force. Governing equations are derived by the use of the extended Hamilton's principle, and numerical results are calculated by finite element method. The critical distributed frictional force and instability regions were investigated for the change of distributed spring constants and translational spring constants.