Research On Application And Maintenance Of Braking System Of SS4 Electric Locomotive

For a long time,railway freight transport has been growing and stable at a certain level,which has made a great contribution to China’s economic construction.Although the high-power AC drive locomotives have been put into operation since 2006,they have undertaken most of the railway transportation traction tasks,and the railway traction power is still in short supply.SS series electric locomotives and DF series diesel locomotives are still widely used.Due to the need of heavy haul development of Datong Qinhuangdao railway,some SS4 locomotives originally assigned to Hudong locomotive depot were replaced with CCB Ⅱ braking system.Later,due to the large number of harmonious high-power AC drive locomotives put into operation,some SS4 locomotives were assigned to Taiyuan locomotive depot.At present,the SS4 electric locomotive equipped with DK-1 and CCB II braking systems in Taiyuan locomotive depot continues to play a role in railway transportation traction,but the locomotive has been put into operation for a long time,its performance and quality are gradually declining,the locomotive failure rate is high,the maintenance quality is not high,and the emergency handling ability is low,which brings a lot of troubles to the locomotive operation and maintenance.Aiming at the operation and maintenance of SS4 electric locomotive,this paper briefly describes the development process of locomotive braking technology at home and abroad,as well as the composition and working principle of SS4 electric locomotive braking system.This paper focuses on the problems existing in the application and maintenance of the braking system of SS4 locomotive,and puts forward suggestions for improvement.It analyzes the common fault problems in the braking system of DK-1 and CCB II locomotive,and discusses the optimization of the braking system maintenance according to the requirements of the locomotive maintenance reform of China Railway Group.The main results are as follows(1)Statistics and analysis of common faults of locomotiveAccording to the statistics of the faults of SS4 electric locomotive in 2019,the failure rate of braking system is relatively high,but for the safe operation of locomotive,the importance is higher than other systems.(2)Research on main faults of DK-1 electro pneumatic braking systemTaking model 109 distribution valve as the research object,the performance and changes of model 109 distribution valve before and after loading were analyzed by the main method of experimental comparison.The research shows that the performance of109 type distributing valve has declined in a short period of time.Besides the influence of operation environment,the slide valve structure is also the main reason.The slide valve structure limits the short repair range of 109 type distributing valve and restricts the optimization of locomotive braking system repair.In view of the faults and repair problems exposed in the operation of 109 type distribution valve,through the performance test and structural analysis of the new distribution valve,the performance changes of the new and 109 type distribution valve after locomotive static test are studied.The research shows that the stability and reliability of the new distribution valve are better.If the new distribution valve can completely replace the 109 distribution valve,in addition to the performance guarantee,the maintenance work can be simplified,and the repair schedule of DK-1 locomotive electro pneumatic brake can be further optimized.Through the introduction of the structure of the electro pneumatic brake controller and the working principle of the neutral position after braking,this paper summarizes the common phenomenon of the neutral position not maintaining the pressure,studies and analyzes the causes of the fault phenomenon,and puts forward the corresponding preventive measures.(3)Fault analysis and research of DK-1 electro pneumatic braking systemBased on the statistics of the fault components of CCB Ⅱ braking system of SS4 locomotive in recent years,combined with the fault simulation test in the laboratory of Knorr company,the causes of IPM module and LCDM fault are studied and analyzed.This paper focuses on the field simulation test verification of IPM module fault,and puts forward corresponding improvement suggestions.Combined with the actual operation of locomotive,this paper summarizes the measures for crew to deal with CCB II brake system fault code.(4)Analysis and Research on repair schedule of braking system of SS4locomotiveThis paper summarizes the current situation and optimization measures of locomotive maintenance system,such as reasonable planning of maintenance cycle,optimization of maintenance scope,etc.,and analyzes the optimization effect from the aspects of locomotive fault change,maintenance cost,number of maintenance units,etc.The advantages and disadvantages of maintenance mode,maintenance cycle and scope optimization of key components of braking system are discussed.This paper studies the key valves of DK-1 electro pneumatic braking system,inertia fault of CCB II braking system and optimization of maintenance mode,which is of great significance to the operation and maintenance of locomotive.