• Tribology and Lubricants
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• v.25 no.6
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• pp.381-386
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• 2009

In general, a brake system of axle for heavy duty machine as a wheel excavator makes use of wettype multiple disk brakes. These disk bakes are very important parts of heavy duty machine because they are dvanced in durability and braking power, and can be designed compactly. Thus, we adesigned and made wettype multiple disk brakes of axle for the wheel excavator to be localization of these imported all. In this study, wet multiple disk brakes were made a comparative test with the 3 types materials of friction disk by the SAE No.2 dynamometer. The friction characteristics were measured and analyzed to decide a suitable material as wear depth of friction disk and dynamic and static friction coefficient on temperature of oil and applied pressure.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.792-797
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• 2007

This study investigates the change of the temperature and fatigue property of the braking disk (GC25-30 material) for the railway vehicle. The average temperature is measured about $100^{\circ}C$ and the maximum temperature is measured over $200^{\circ}C$ by non-contact sensor from Seoul to Chun-an. In the $20^{\circ}C-300^{\circ}C$. The Fatigue tests did for new and used disk specimens. The fatigue test results of new disk specimens were similar due to the temperature change. But the compare of specimens between new disk and old disk, The fatigue life of old disk specimens was smaller than new disk specimens about 10%.

• Journal of Auto-vehicle Safety Association
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• v.7 no.2
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• pp.19-24
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• 2015

Ferritic Nitro Carburizing (FNC) cast iron brake discs is known to improve corrosion resistance and brake creep groan noise as well as prevent corrosion-induced pulsation. But, it is necessary to treat honing machining on braking surface to avoid grinding noise during braking.

• 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.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.4
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• pp.39-45
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• 2022

In this study, it was verified that carbon-ceramic brake discs can replace existing cast-iron brake discs of the same size. In addition, a method of pretreating carbon fiber to secure heat dissipation characteristics while using a small amount of carbon fiber was established. The thermal conductivity and bending strength characteristics were analyzed according to the carbon content, and brake braking tests were conducted. Through pretreatment, the maximum temperature was lowered by 16 ℃ compared to the case using only carbon fiber, and the cooling rate was improved by approximately 10% compared to metal brake discs. However, the total heat capacity increased as the mass increased owing to the reaction. Thus, the measured temperature was higher than that of the metal brake disc; therefore, additional research is required.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.432-439
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• 2020

Brake judder has been identified in some operating military units of Korean Light Tactical Vehicles(KLTV) with In-board brake systems to improve braking performance. Severe vibration generated while driving the vehicle may reduce the KLTV's driving stability and further lead to accidents. For the prevention of this, this study analyzes the root cause through the failure analysis on the vehicles with the brake judder identified. Furthermore, the improvement factor was derived by identifying a vibration transmission path by analyzing the vibration transmission mechanism. The study analysis confirmed that the vibration of the frame during braking in the tactical vehicle is a cold judder phenomenon, which is caused by an increase in disk thickness variation due to rust and foreign substances under excessive brake disc's run-out. In addition, it was confirmed that such vibration can be reduced by improving the mounting structure. So, an improvement method for each factor was suggested and its effectiveness was verified by comparison test. Finally, it is expected that the improvement plans derived through this study can be used in the development of a next military vehicle.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.971-974
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• 2011

Aluminum matrix composites reinforced with SiC particles(AMC) are one of the candidate materials for the weight reduction of rolling stock brake discs. It is known that weight reduction of about 40% is possible when they replace conventional cast iron brake discs. But casting is not easy because of bad wettability of SiC with Al alloy. We developed two AMC brake discs with SiC volume fraction of 20% by a new casting method. It was found the developed method produced brake discs of good quality.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.29-30
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• 2006

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.761-766
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• 2007

A brake disc is one of the key elements of friction brake system. Thermal cracks of discs may shorten the lifetime of a disc and increase maintenance cost. Therefore, prevention of thermal cracks is very important to ensure the safety of the vehicle operation and reduction of maintenance cost. In this study, the influence of parameters on the friction heat of brake disc is examined.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1000-1004
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• 2007

Thermal cracks are among the key factors that control the quality of a brake disk. Thermal cracks may shorten the lifetime of the disc and increase brake noise. Therefore, high heat-resistant brake disk materials are needed. In this study, three kinds of disk material were tested. They are composed of C, Si, Mn, P, S, Cu, Cr, Mo, and Ni. For the three materials, tensile tests, hardness measurement, metallurgical structure analysis, image analyzer analysis, etc were carried out. And friction tests were performed by a small scale dynamometer.