• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.613-618
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• 2007

The performance of the railway bogie is classified into the stability and the steering performance. Testing for the bogie stability is conducted on the roller rig, but testing for the bogie steering performance on test facility is very difficult, so the testing for the vehicle curving performance is conducted on the real curve track. Testing the railway bogie on the full scale test rig is desirable, but it caused many problems relating to test costs and test time. As a possible alternative to overcome these problems, a small scaled test rig is actively used in the field of bogie stability. Thus, in this paper, we have studied a scaled track to test the bogie steering performance. For this purpose, we designed the 1/5 scaled test track equivalent to radius 200 curve and confirmed the validity of the testing for the bogie steering performance on the sealed curve track through the testing using 1/5 scaled bogie.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1550-1556
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• 2009

The sophisticated technologies, ensuring both stability and curving performance, are required for the medium high speed train running on conventional railway line where tangent and curved section mixed together. We can hardly meet the both requirements conflicting each other with the conventional type of bogie. Effective solution is to apply stabilizing mechanism for the bogie design, which increase hunting stability or dynamically critical speed while maintaining curving performance. In this research the numerical analysis by means of multi-body dynamic simulation S/W, experiments by using roller test rig and main line running test have been comprehensively performed for the 200km/h Korean Tilting Train with newly developed stabilizer. The paper proposes the effectiveness of stabilizer and its usefulness based on the results of analyses.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.715-721
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• 2007

On a conventional rail vehicle, passive primary suspensions stabilize wheelsets in the longitudinal and yaw direction. However, these suspensions reduce the natural curving ability due to the profile of the wheels. Stabilizing and steering of the wheelsets generate the conflict problems in design process. Therefore, most systems are designed to guarantee the stability in spite of decreased curving performance. As a result, severe wear of the wheels and rails occur on tight curves and squeal noise on curving is high. Active steering has been proposed to satisfy stabilizing and steering performance simultaneously. This paper describes the possibility investigation about the application of the active steering bogie for a urban railway vehicle. Vehicles run on an amount of tight curves at mid or low speed in urban railways. Thus, it is important to reduce the wear and squeal noise between wheels and rails. Simulations show that active steering can be reduce the wear and squeal noise significantly compared to conventional systems.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.301-305
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• 2007

The performance of the railway bogie is classified into the stability and the steering performance. Testing for the bogie stability is conducted on the roller rig. But testing for the bogie steering performance on test facility is very difficult, so the testing for the vehicle curving performance is conducted on the real curve track. And it is desirable to test on the full scale test rig, but it caused many problems relating to test costs, test time. To overcome these problems, the small scale test rig is actively used in the field of bogie stability. Thus, in this paper, we have studied the scale track to test the bogie steering performance. For this, we designed the 1/5 scale test track equivalent to radius 200 curve and confirmed the validity of the testing for the bogie steering performance on the scale curve track through the testing using 1/5 scale bogie.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.6
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• pp.526-535
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• 1984

An analysis has been developed to evaluate the lateral stability and curving performance of rigid bogies having side bearer friction. A bogie model having 2 degree of freedom in lateral and yaw direction is utilized, and it's validity is examined. The effect of various design parameters are investigated. It is shown that there is no change in curving performance as lateral load is varied, and that varing side bearer friction has no significant effect on both critical speed and curving.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.125-134
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• 2000

This paper presents the results of vehicle dynamics simulation for development of single axle bogie for freight vehicle. Those results consists of hunting stability, ride comfort and curving performance such as derailment ratio, unloading ratio. Dynamic behaviors of vehicle having single axle bogie is carried out using the multi-body dynamics simulation program(VAMPIRE). The results of analysis meet the criteria proposed by Korean National Railroad(KNR) and Korea Railroad Research Institute(KRRI).

• Journal of the Korean Society for Precision Engineering
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• v.28 no.5
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• pp.559-564
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• 2011

For the safety of railway, it should be evaluated for the running safety by measuring the derailment coefficient. Although railway has run the fixed and maintained rail, some of railway is derailed. This report shows the results that performed the static load test, main line running test on the basis of the derailment theory and experience. It is executed main line test into more than 90km/h for estimating the curving performance and running safety of depressed center flat car of 3-axle bogie. As the test results, could confirm the curving performance and running safety of depressed center fiat car of 3-axle bogie from the results of the wheel unloading, lateral force, derailment coefficient etc. Derailment coefficient was less than 0.6, and lateral force allowance limit and wheel load reduction ratio were enough safe.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.3
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• pp.205-210
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• 2017

Critical speed analysis was conducted for a active steering bogie prototype, developed to improve the curving performance of railway vehicles. The critical speed for the design concept was about 169.2k m/h. To validate the analysis result, we performed a critical speed test for the prototype bogie using a roller-rig tester. The test results showed that the critical speed for the prototype bogie was about 165 km/h. From the analysis and test results, The critical speed for the prototype bogie was determined to be 165 km/h. Considering the maximum operating speed of the test vehicle is 100 km/h, the prototype bogie is considered stable.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.361-364
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• 2005

Some bogie frames manufactured in 1999, 2000 year have the fatal problem. Three or four years later, the cracked end beam among them have discovered in 2002, 2003 year. The crack situation of the end beam have a bad effect on brake system. In that case, the cars would be in danger of derailment. To improve the end beam, a research of covering the whole field of welded type bogie frame was started. Main line real tests were performed at Young-Dong line. The stress of main positions for bogie frame was measured. Also up-down direction and left-right direction vibration acceleration of the bogie frame were measured. At this time the tests were performed for the three types bogie. The test result concludes that the crack cause of the end beam is not brake load but vibration at running mainly. It is estimated that the life of the improved car which end beam reinforced is safe within the car permitted life(25 years). The improvement methods of the end beam are presented by construction modification, parts modification. The integrity evaluation is inspected by analysis the real line test results, the improvement methods of the end beam.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.854-859
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• 2008

In a railway vehicle, contact between wheel and rail is a peculiar characteristic and variations of wheel and rail profile influence on the dynamic characteristics of railway vehicle. Thus the variations of the wheel and rail profile are very important in railway dynamics. Recently a research relating to active steering to improve the curving performance of vehicle is progressing actively at home and abroad. In this field, a pre-study for the wheel/rail contact geometry is needed and especially the variation of the wheel/rail contact geometry with wheel wear is the key design parameter to develop the controller of the active steering bogie. In this paper, we have experimentally studied to analyze the variation of the wheel/rail contact geometry with wheel wear as a pre-study to develop the active steering bogie for electric multiple unit (EMU). For this, we have made an experiment with EMU operating in curving area. We have measured the wear profiles of the wheel of the test vehicle and analyzed the wheel/rail contact geometry with a mileage of the test vehicle. In experiment with test vehicle, we have got the useful data to design the steering controller of the wheelset.