Research On Un-wheeling Repair Mode Of Lanzhou Metro Vehicles

As the mechatronics equipment with high technical content,metro vehicles have high requirements for maintenance quality and traffic safety.Un-wheeling repair is a deep-level and advanced repair process that must be carried out in the life cycle of metro vehicles,with large repair scope,strict requirements and large investment.Choosing appropriate un-wheeling repair mode is beneficial to reduce maintenance cost,improve resource utilization rate and create good economic effect for enterprises.At present,the first phase of Lanzhou Metro Line 1 has been in operation for more than a year,the maximum mileage of vehicles has reached 150,000 kilometers.According to the current operating standards,the first vehicles are expected to meet the un-wheeling repair standards in 2023.In order to avoid the impact of vehicle disrepair on the normal operation of the metro,the first un-wheeling repair operation should start in 2023.According to the industry standard,the preparation period of un-wheeling repair usually takes 18 months.Therefore,it is extremely urgent to determine the un-wheeling repair mode of Lanzhou metro vehicles.This paper applies the theory of decision analysis to the selection of production and operation scheme of enterprises,and studies the selection of vehicle frame repair mode of Lanzhou metro from five steps: forming decision problem,drafting alternative scheme,evaluation and choice of scheme,guarantee measures of scheme implementation and evaluation of scheme implementation effect.The alternative scheme of un-wheeling repair mode for Lanzhou rail transit vehicles is determined by qualitative decision method.On this basis,the cost of each alternative mode is analyzed and calculated,the input cost of each alternative mode is determined,and the break-even point method in the quantitative decision-making method is used to find out the balance point of the cost input of the alternative scheme.Through quantitative calculation,the scheme with the lowest cost input is finally determined.At first,this paper puts forward the theory of rail transit vehicles maintenance management and decision analysis theory,mainly introduces the basic concept of un-wheeling repair and maintenance of the target,main influence factors affecting aircraft repair mode,and the basic steps and main methods of decision analysis,and combine the domestic current situation of the metro industry puts forward three kinds of un-wheeling repair mode,namely: independent repair mode,outsourcing repair mode and joint venture mode.Secondly,it systematically introduces the basic status of Lanzhou rail transit vehicles and vehicle maintenance mode from the aspects of vehicle allocation,maintenance mode,maintenance organization and maintenance management system.On this basis,the Lanzhou metro vehicle as the research object,based on three kinds of un-wheeling repair mode,combining Lanzhou metro vehicle basic situation,respectively from two aspects of the feasibility,reliability,make a comprehensive analysis and evaluation,feasibility and reliability in meeting,on the basis of the economic costs of every mode has carried on the quantitative calculation,comparison and analysis.Based on the above factors,un-wheeling repair mode of Lanzhou rail transit vehicles is determined to be independent maintenance mode.At last,the guarantee measures for the independent maintenance mode of un-wheeling repair are preliminarily drawn up,and the economic benefits of adopting the independent maintenance mode to complete the task of vehicle frame repair of existing lines are calculated.It is estimated that the maintenance cost can be reduced by 23% to 26%.