Optimization Of The Crushing Device Of The Stalk Crusher And The Design Of The Hydraulic System

Tobacco stalk is a special by-product of tobacco leaves after being harvested.At present,the technology level of mechanized recovery in tobacco planting industry in China is relatively backward,as most of tobacco stalk pulling are carried out by manpower,which consumes too much time and labor.As the existing stalk pulling equipment cannot integrate pulling with shredding stalks at a time,which makes the low production efficiency.Movable tobacco stalk pulling and shredding machine developed in this subject integrates functions of stalk pulling,cleaning,stalk conveying,and shredding,all of them can be finished at one time,Thus,it can improve the production efficiency of tobacco stalks from three processes respectively,stalk pulling,recovery and shredding.The main contents of this paper are as follows: designing a feeding device for the movable tobacco stalk pulling and shredding machine,optimizing the shredder's cutting blade,improving the performance of the shredder's chamber,as well as the design of the hydraulic system and the trials of the prototype in the field.In case of appearing that the stalks being sucked into the shredder's chamber too quickly which results in poor shredding quality because of too much negative pressure in the crushing chamber.A feeding device of the shredder is designed to control the feeding speed of the tobacco stalks;To ensure the shredding quality,a feeding test device is designed,virtual assembly and the movement simulation is also carried out.After that,the feeding device for trial is produced and it is used to study on the relationship between the shredding quality and feeding speed by trails.To reduce the cutting power consumption and solve the problems of vibration,unbalanced force during cutting,according to the Gaolveqijin Theorem,an optimized design method of equal sliding-cutting angle blade which is based on energy consumption model is proposed.Firstly,the equal sliding-cutting curve of the cutting blade of the shredder is designed using the logarithmic spiral equation.Then,in order to obtain the blade curve with a low energy consumption,a power consumption model of cutting tobacco stalks based on the kinematics analysis of the straw stalk mass point is established and then the theoretical optimal sliding-cutting blade angle is obtained.Finally,a comparative cutting test is performed on the cutting edges with different sliding-cutting angles to verify the practical working effect of the designed equal sliding-cutting angle cutting edge with ?=48°.In order to distribute the flow to the actuators of the stalk pulling and shredding machine reasonably,a flow distribution method of installing the electro-hydraulic proportional speed regulating valve on the branch of the single-pump and multi-motor hydraulic system is proposed.The flow distribution simulation model of the hydraulic system is established using AMESim software,and the simulation analysis of the flow distribution and anti-saturation capability of the hydraulic system is conducted with the software.Based on the proposed flow distribution method,a hydraulic system for movable tobacco stalk pulling and shredding machine is designed and produced.Finally,for verifying the feasibility and performance of the design for the movable stalk pulling and shredding machine,the field trials are conducted.Through trials,the shredding quality at different conveying motor speeds is studied and the optimal rotation speed is also determined,the rotation speeds of the pulling motor and the conveying motor also get matched.The design scheme of the hydraulic system and the performance of the whole machine are verified in the end.