| The development level of our country sweet potato production mechanization is low,especially in the part of killing sweet potato seedling which consumes manpower resource and in this part,the level of mechanization is not high which limits the enthusiasm of farmers production.Therefore,the implementation of mechanized seedling has become an inevitable trend.In this paper,according to the characteristics of sweet potato seedling growth and sweet potato maturity,a kind of chain-type sweet potato seedling crushing and recycling machine was explored in order to reduce stubble height and injury rate,improve the fluency and adaptability of the sweet potato machine,reduce the power consumption of potato seedling recycling and avoid the harm caused by pouring crushed potato seedling into the field,which provides a new idea of the structural design for seedling recovery.The main research contents include:(1)Machine structure design.The sweet potato seedling processing machinery can achieve cutting of the vine,cutting,delivery,crushing and recycling operations at one-time.Machine mainly includes the cutting device,clamping conveyor,crushing device,profiling seedling device and power transmission device.The working principle and working process of the recycling machine are determined(2)The growth characteristics of mature sweet potato were calculated and carried out the physiological characteristics of seedling test and analysis.The shear stress curve of the main stem(the position which opposed to machine cutter)was obtained.The results showed that the shear rate of the main stem of the cut potato was increased with the decrease of the moisture content of the seedling,and the lower the water content,the greater the shearing force is needed to cut the seedling.And provides a theoretical basis for the appropriate time of crushing and recovery operation for sweet potato seedling and the machine's design and manufacture.(3)The structural design and parameter analysis of the key components were carried out.The structural parameters and the motion parameters of the scissors,reciprocating cutter,clamping conveyor and shredder were determined.The parameters of the parts were: Inclination range of 7°-56°;cutting device selected standard?type reciprocating cutter,cutting speed 2m/s,cutting angle 15°;using the clamping conveyor chain as the machine clamping conveyor device,determining the chain angle 22°,the ratio between the chain speed and the machine speed is K=2-3.1.Choosing the hammer mill and detremining the two main factors that affect the balance of the hammer: the spindle rotation angle ?1 and the hammer around angular velocity of the relative rotation of the pin ?2.The working method that moving parameters of reciprocating cutter,clamping conveyor chain and pulverizer is determined according to the speed of machine operation is obtained.(4)Using the ADAMS software,the kinematics and dynamics analysis of the cutting device were carried out.Through the virtual test,the cutting force F received by the cutting blade was used as the evaluation index,the machine speed vg,the cutting speed vm and cutting angle? as the influencing factor.When the cutter is subjected to the minimum cutting force,the three parameter values are: 5km/h,2.14m/s,15.18°.(5)The performance test of the profiling seedling and cutting device provided the reference for the optimization and improvement of the part. |
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