Simulation And System Parameter Optimization Of The Large-scale Wide Paver Spiral Distributor

For the high-grade highway in China,the problems of "segregation" has influenced the quality and life of the road.With the rapid development of road construction,technical requirements for the paver has become more and more high,and large-scale and wide paver has become the focus of paver industry research at home and abroad currently.Due to the weak technological base,Chinese large paver market is monopolized by imported products.As a main device of the paver,spiral distributor plays an important role in the dosing quality.Aimed at the unevenness of given material and unevenness of blend in required width of large-scale and wide paver,force and motion analysis of aggregate in spiral distributor are carried on.Simulation model of spiral distributor is established to investigate the influence of spiral distributor's structure and operating parameters on the motion of the granular.Meanwhile,variable diameter and variable pitch model is establishedand corresponding improvement scheme is put forward.The paper's specific work includes the following several parts:(1)The structure and working principle of the spiral distributor are introduced,and the force and motion of aggregate under the action of spiral distributor are analyzed.The influence of spiral distributor's structure and operating parameters on the motion of granular aggregate is investigated to find out the reason of the aggregate segregation.At the same time,screw paver speed,scraping plate velocity and the rotate speed model is established to realize effective speed matching of them.(2)Finite element simulation model of spiral distributor is established,and flow field simulation of aggregates in spiral distributor is carried on.The effects of spiral distributor's structure and working parameters on radial given aggregate's evenness and asphalt granular aggregate's blending effect are discussed.(3)The effect of the spiral discontinuity due to the existence of the boom on the aggregate distribution is analyzed,and the optimizations are carried on.(4)The parameter optimization of spiral distributor is carried on with variable diameter and variable pitch mathematical model to validate the feasibility of variable diameters and variable pitch technology.At the same time,the finite element analysis was used to verify the optimization results.Finally,the optimal variable diameter and variable pitch spiral distributor structure is determined.