| Because of the obvious regional differences of potato harvest in our country, according to the characteristics that block size, soil conditions in different regions, design and research of the corresponding harvest machines. But potato harvesters were common exist heap soil and weeds winding problems almost in every region during the process of potato harvesting. Especially in the northern heavy clay soil conditions, heap soil problem was more apparently, the negative effects to the potato harvest were brought huge increase about the machine tractive resistance, increased the energy consumption, damaged to machine parts and affected harvesting efficiency and quality of harvest. Realized from the field trials and the feedback information of machine using, heap soil problem under the condition of heavy clay soil was more outstanding in the north, but the weeds winding problems were quite obvious in the north area with one season and mid-plain area with two-time crops. Weeds winding problems on both sides in the front of rack were easily affecting the normal work of the machine. Heap soil problems were easily occurred in the digging shovel underside, too much of the weeds winding could also lead to heap soil problems. Rocks and big clods where between digging shovel and elevator chain were easily cause stuck problems, thus, how to solve the congestion of potato harvest and its weeds winding problem s become the key which to improve the quality and efficiency of potato harvest.This article in view of the heap soil and weeds winding problems in the front of rack when the conveyor chain of potato digger operation. Studied and designed corresponding anti-blocking system, each device structure design in the system and the work performance of the anti-blocking system were analyzed and studied. The main contents of the research are as follows:(1). According to the first study on the characteristics of heap soil problems and weeds winding problems of the potato digger, designing corresponding prevent heap soil and winding devices based on the characteristics of block, decorated prevent devices reasonable in the anti-blocking system, the purpose is to make the design of devices more targeted and rationality, can better solve the heap soil and weeds winding problems.(2). Combined with the overall structure of the machine and the characteristics of the block, carrying structural design of the block device of the anti-blocking system. The device can not only meet the requirements of the overall structure but also meet the requirements of preventi ng heap soil and weeds winding.(3). Analysis of the winding resistance of the winding mechanism and the winding roller itself whether have the function of toss back, gain absolute displacement function image of edge points of roller, simulation research on the performance of the prevention of winding, set the simulation parameters of roller with actual working parameter, purpose of the simulation is to get the image of speed, acceleration and trajectory of the wheel edge points, combination of theory and simulation to prove the practicability and reliability of the prevention about winding device.(4). According to the national industry standard for the research of field experiment. Determination potato digger with anti-blocking system performance and technical and economic index parameters, analysis the effect of the anti-blocking system on the performance of potato harvest, through the contrast test of different models under different soil conditions, analysis the differences of the potato harvest performance under the different models of potato diggers, so as to prove anti-blocking system is beneficial to improve the efficiency and the quality of ha rvest.The research results show as follows.(1) Each unit in the structural design is reasonable, through the calculate and determine the digging shovel length is 330 mm, the disc cutter radius is 300 mm, the winding roller radius is 200 mm, four pieces of digging shovel were assembled on machine, each row corresponding to 2 slices, configuration for four disc cutters to cut soil and weeds, configuration the prevent winding device on both sides of the frame, it can play a role corresponding heap soil prevention and prevent winding.(2) The prevention winding roller edge points to obtain the absolute motion curve is trochoid in the process of potato digger operation. The prevention winding roller where contact with conveyor chain in 1.16π+2kπ~1.84π+2kπ(k=1、2、3…) has the absolutely backward speed, suggesting that the prevention winding roller has the effect of toss back to the weeds, the clamping force and friction between the winding roller and the conveyor chain have pull back force to winding weeds, can have very effective prevention.(3) Installation of floating disc knife which cut the soil of feeding potato digger and both sides of potato digger, reduce the digging resistance, less energy consumption, the stone gate and the devices of preventing winding reduce the possible of block, may improve the machine reliability and working efficiency. Obvious rate of potato digger with anti-blocking system is 3.95% higher than unassembled one under the condition of the black clay, loss rate were reduced by 0.54%, the injury rate of potato were reduced by 3.01%, pure working hour productivity rate is 0.08hm2/h higher, fuel consumption was reduced by 1.16 kg/hm2, reliability is increased by 2.4%. Every indicators of this potato digger are better than the standard level under the condition of black clay, it shows that the machine is suitable for conditions of the black clay; Operation resistance is small under the condition of the sandy loam than black clay, adhesion and cohesion of sandy loam is relatively small than black clay, moisture content is low, make the separation of the soil and potato become more easily. Obvious rate of potato digger with anti-blocking system under the condition of the sandy loam is 1.2% higher than under the condition of the black clay, loss rate was reduced by 0.58%, the injury rate of potato was reduced by 0.1%, pure working hour productivity rate is more 0.09 hm2/h higher, fuel consumption reduce by 0.89kg/hm2, reliability is increased by 4.3%. Field experiments showed that the operation performance of potato digger with anti-blocking system is better than the one without anti-blocking system, and under the condition of sandy loam machine operation performance is better than under the condition of the black clay.This article provides a new thought and new method for the design and study of the anti-blocking devices of potato digger, a reference for the potato digger to collect research, promote further development of the potato digger. |
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