• Tribology and Lubricants
• /
• 제35권3호
• /
• pp.183-189
• /
• 2019

The driver seat of an automobile is in direct contact with the driver and provides the driver with a safe and comfortable ride. The seat consists of a frame, a rail, and many recliners. In recent years, strength and operating force measurement testing of the recliner have become vital for designing car seats. However, performance evaluation requires expensive testing equipment, numerous seat products, and considerable time. Therefore, the trend is to reduce experimentation through interpretation. This study examines the lubrication of solid lubricant for automotive seat recliners and confirms the friction and wear performance. In this study, the lubrication behavior of solid lubricants for car seat recliners is investigated to ascertain the friction and wear performance and to provide accurate values for the strength analysis. The friction material consists of a pin and a plate made from steel, which is widely used in recliners. The friction and wear under lubrication conditions are measured by a reciprocating friction wear tester. The friction coefficient is obtained according to the load and speed. Based on the obtained results, it is possible to achieve a reduction in the error of the test value and the analysis by providing the friction coefficient and wear of the lubricant. The results can be applied to the analysis of automobile seat design.

• 한국분말재료학회지
• /
• 제25권6호
• /
• pp.501-506
• /
• 2018

With the recent remarkable improvements in the average speeds of contemporary trains, a necessity has arisen for the development of new friction modifiers to improve adhesion characteristics at the wheel-rail interface. The friction modifier must be designed to reduce slippage or sliding of the trains' wheels on the rails under conditions of rapid acceleration or braking without excessive rolling contact wear. In this study, a novel composite material consisting of metal, ceramic, and polymer is proposed as a friction modifier to improve adhesion between wheels and rails. A blend of Al-6Cu-0.5Mg metallic powder, $Al_2O_3$ ceramic powder, and Bakelite-based polymer in various weight-fractions is hot-pressed at $150^{\circ}C$ to form a bulk composite material. Variation in the adhesion coefficient is evaluated using a high-speed wheel-rail friction tester, with and without application of the composite friction modifier, under both dry and wet conditions. The effect of varying the weighting fractions of metal and ceramic friction powders is detailed in the paper.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 춘계학술대회 논문집
• /
• pp.1069-1073
• /
• 2011

When the train is running on the small curved line, there would be severe contact between the rail and wheels, which cause noise and vibration as well as abnormal wear on the rail and the wheels. In order to solve these problems, the steering bogie has been developed. To verify steering performance of the steering bogie, steering angles of two trains, one is the advanced EMU with the steering bogie, another is a conventional EMU with the conventional bogie, were measured while running on the small curve. this comparing test shows that the steering bogie has much higher steering performance than the conventional bogie on the same curved line. To verify more performance data of the steering bogie, further testing and monitoring will be done with the advanced EMU in the test track.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 추계학술대회 논문집
• /
• pp.515-520
• /
• 2002

Automatic Transfer Crane is needed for automation of container terminal. It requires the control capability of exact position for loading/unloading job in yard. But it has the limitation of improvement because it has the operational environmental and its structural problems. It has the positioning errors caused by the deformation of rail, yawing motion of crane, wear of wheel, sliding motion between wheel and rail and so on. This study shows the calibration method of crane position by using the primitivity sensor and calibrating plate fixed on the ground.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2005년도 추계학술발표대회 개요집
• /
• pp.177-179
• /
• 2005

As rail steel at a crossing area must undergo much higher loading than those at regular railway, Mn-containing casting steel is normally used for its high load-carrying capability and reduced wear rate. However, as these Mn-containing casting steel is tend to have casting defects, manufacturing cost to produce defect-free Mn-containing casting steel becomes quite expensive. Therefore, in order to investigate the possibilities of replacing expensive Mn-containing casting steel with a mild steel with a surface build-up using a Mn-alloyed steel electrode.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2006년도 추계학술대회 논문집
• /
• pp.66-71
• /
• 2006

A geometric contact conditions of wheel/rail affect the dynamic behavior of rolling stock. Mechanical force acted on the wheel/rail causes excessive wear and increase the maintenance cost. In this study, we have studied the dynamic behavior of the urban railway vehicle with new and worn wheel by VAMPIRE program. And we have tested the accelerations of wheelset on the conventional line. The results of simulation are compared with the measuring data of field test. It shows that the acceleration of worn wheel is greater than the acceleration of new wheel in the straight track line but on the contrary, the acceleration of new wheel is greater than the acceleration of worn wheel in curved track. That results explain that the new wheel is worn out greater than the worn wheel in curved track line and need to be maintained more seriously when running in curved track line.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
• /
• pp.1305-1306
• /
• 2006

A new material was developed to achieve improvement of heat durability, improvement of wear resistance, stability of friction coefficient and reduction in aggression to counterpart, because it is difficult to maintain braking properties by using currently available materials in the train wagons used for high-speed transportation. As a result, the new material showed a stable wear resistance even in the speed range of 350km/h, where improvement was also confirmed in reduction of aggression to counterpart material by more than approximately 10%. This development was adopted for the brake lining in the Taiwan High Speed Rail project.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2002년도 추계학술대회 논문집(II)
• /
• pp.863-869
• /
• 2002

Studied in this paper was the kinematic envelope of the railway vehicle to calculate the lateral displacement using the multi-body dynamic simulation program (VAMPIRE) and the BASS 501. The lateral displacement of railway vehicle is occurred by the clearance between wheel flange and rail, the track irregularity, the property of each suspension of vehicle and the cant of track etc. The results of analysis shown that Vehicle is not interfere with subway platform in any conditions namely the tare and full load condition, the wheel wear condition and the stationary and running of vehicle.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2002년도 춘계학술대회 논문집
• /
• pp.312-316
• /
• 2002

Tilting train is the best solution to provide faster passenger service on conventional railway lines without too costly modification of infrastructure. Kinematic envelope gauging is very important when applying tilting trains % conventional railways with limited clearance. Due to tilting motion, the kinematic envelope of tilting train is larger than that of non-tilting train. This study was done to estimate the maximum dimension of tilting train being suitable for Korean conventional lines. In this study the two worst cases of tilting train movement was assumed and related suspension displacements, geometrical overthrow of train on une, wear of wheel ＆ rail were combined to determine kinematic envelope.

• 한국정밀공학회지
• /
• 제31권9호
• /
• pp.783-790
• /
• 2014

Railway wheels and axles are the most critical parts of the railway rolling stock. The wheel carry axle loads and guide the vehicles on the track. Therefore, the contact surface of wheel are subjected to wear and fatigue process. The wheel damage can be divided into three types; wear, contact fatigue failure and thermal crack due to braking. Therefore, in the contact surface between the wheel and the rail, the materials are heat treated to have a specific hardness. The manufacturing quality of the wheel have a considerable influence on the formation of tread wear and damage. Also, the residual stress on wheel is formed during the manufacturing process is one of the main sources of the damage. In this paper, the mechanical characteristic and the residual stress according to wheel material have been evaluated by applying finite element analysis and conducting mechanical tests.