Research On Spring Adjustment Technology And System Developement Of Flexible Weighing For Subway Vehicles Carbody

Traction and braking performance and safety performance of metro vehicle closely contacts with the balance of wheel load and axle load, and the secondary suspension spring load influences wheel load and axle load badly. As long as the secondary suspension load is controls well, wheel load and axle load would also be balanced better, then metro vehicle would exert traction performance and braking performance, at the same time, improve production efficiency and economic benefits. The standard GB/T14894-2005 requires the difference between each motor axle load and the average axle load can’t surpass average axle load±2%; the difference between each wheel load and the average wheel load can’t surpass average axle load±4%.At present, the main method of adjusting the secondary suspension spring load is to weigh carbody firstly, then adjust it by adding washers, but carbody rigidity weighing test bench is made up of four absolutely rigid support pillars to support the carbody. When carbody fall on rigid weighing test bench, it would occur deformation because of the existence of torsion. The weighing data can’t correctly reflect the vehicle load distribution, namely, weighing data isn’t accurate enough, causing the corresponding washers is not accurate. At the same time, air spring vertical stiffness is small, so the carbody does not occur deformation when falls on it, but this state does not match the state on the rigid weighing test bench.This article puts forward the theory of carbody flexible weighing to avoid weigh deformation. Firstly, it analyzes the influence of the deviation of vehicle wheel (axis) on traction performance and braking performance, then analyzes influence of secondary suspension spring load on wheel load and the law of adding washer. It also analyzes the relationship between flexible weighing and rigidity weighing, then compares the testing data with theoretical analysis to verify correctness of the theoretical analysis and draw the theoretical foundation for carbody flexible weighing instead of the rigid weighing.This article improves the existing weighing testing bench and develops carbody flexible weighing testing bench. Carbody flexible weighing testing bench need select the appropriate springs and check their strength with ANSYS software and stability with Adams software. Stiffness error and height error existing in the springs will influence weighing result, article puts forward the error neutralization principle to eliminate the effect of manufacturing error.Finally, this article develops the "Metro Vehicle Carbody Flexible Weighing System" bases on Windows7, which uses C # as developing language and SQL2012 as database with three layers structure technology. The system could calculate adding washer with simple and efficient algorithm called one-dimensional adding washer algorithm. When the users login system, they could calculate adding washer and location intelligently and manage carbody information real-time, as well as test and manage carbody flexible weighing test bench.