Design And Experiment Study Of Broccoli Two-stage Cutting Production Line

Broccoli is planted on a large scale in China.But currently most of them are manually cut,and the degree of mechanization of broccoli cutting is low.There is little research on the broccoli cutting production line in China,which mainly adopts pneumatic cutting-coring method to realize the integration of cutting-coring.But there are still many large-size flower block after cutting,which is not conducive to packaging,storage and transportation.There are many production lines for mechanized cutting of broccoli abroad,mainly using two methods: only cutting and only removing the core.The method of dicing only generally uses a cross-shaped specific cutter to divide the broccoli on the conveyor belt into equal pieces.But the broccoli is not cored,and there are more large-sized flower block after dicing.The core-only method generally uses curved or hemispherical cutters to dig out the root core of broccoli.This method has a good effect on small-sized broccoli,but may not cut thoroughly for large and medium-sized broccoli.There are more large flower block.Based on the above situation,the goal of this thesis is to realize the size of the flower block after two-stage cutting of broccoli is less than 70 mm.According to the physical characteristics of broccoli,a cutting mechanism was proposed to solve the problem of large flower block size caused by the existing single-process cutting.Based on the ideal cutting trajectory of broccoli,the kinematics model of the first cutting mechanism was established,and the cutting-coring mechanism was designed and optimized.According to the time of the first cutting,the transmission parameters of the first cutting production line are determined.According to the size and shape of the flower block obtained by the first cut,the mechanism schemes of flower block selection,large flower block posture adjustment,centered transportation and second cut were proposed,and the mechanism parameters were determined through kinematic analysis.Finally,the structure design,development and experimental research of the broccoli two-stage cutting production line are carried out.The main contents of this paper are as follows:1)According to the physical characteristics of broccoli,the proposal of the first dicing-coring production line and the dicing mechanism are proposed and the cutting tool structure is designed.The kinematics model of the first dicing-coring mechanism is established,and the dicing trajectory is optimized so as to obtain the optimal mechanism parameters.Establish the dynamic model of the dicing-coring mechanism,calculate the driving torque,and determine the power of the power source and other parameters.2)Determine the time of the first cutting,and according to the cutting time,determine the parameters of the non-circular gear mechanism in the non-uniform speed conveyor line to ensure the efficiency and continuity of the cutting.3)According to the size and shape of the broccoli block obtained after the first cutting,complete the differential round belt screening mechanism,the large flower block posture adjustment mechanism,the second cutting production line conveying structure,the flower block centering mechanism and the cutting tool.The design analysis of the differential speed and the kinematic analysis of the flower block posture adjustment mechanism are carried out to determine the speed range to avoid the flower block blockage.4)Complete the structural design,parts processing,assembly and commissioning of the broccoli two-stage cutting production line.Obtain the actual block trajectory through the high-speed camera to verify the rationality of the mechanism optimization.The best differential speed ratio of the differential round belt is determined through the flower block screening test with different speed ratios.Count the size of the flower block after two-level dicing to verify the feasibility and rationality of the production line.