Design And Test Of Additional Cutters Of The Ratoon Rice Harvester

Ratoon rice can be harvested twice in a short period with once planted.It is gradually favored by people in regions where there is more than one season but insufficient in two season,and double-season rice areas where only one season of rice is planted because of the advantages of high labor saving,high cropping index,high yield per unit area,and high efficiency.However,the large-area crushing of the rice stubbles by r crawler during the first-season rice harvesting operation is the main reason for reducing the yield of the regenerating season rice.This subject adds two sets of additional cutters on the basis of the wide cutting width of the ratoon rice combine harvester: the header cutter is used for harvesting the ears of rice,reducing the material entering the harvester Grass-to-valley ratio;the additional first cutter is used for the segmented cutting of the returned straw to facilitate the return of the returned straw;the additional second cutter is used for the stubble operation to meet the agronomic requirements of the first season rice harvesting-the specific implementation.The content are as follows :(1)Design of additional cutters: The design of two sets of additional cutters was completed according to the agronomic requirements of first-season rice harvesting,including the placement of additional first cutter and additional second cutter,the connection method with the harvester,and support arms dimensional design basis and results,transmission system design and transmission shaft size calculation.(2)Simulation: Carry out dynamic simulation and output three characteristic curve graphs of displacement,speed and acceleration.The simulation results show that the moving blade stroke of the additional cutters is 80 mm,the average cutting speed is 1.2 m/s;adjust the position of the fixed cutter to obtain the best cutting effect.(3)Prototype manufacturing and electro-hydraulic system design: completed the manufacturing of additional cutters.The additional cutter and the hydraulic cylinder of the cutting table are transformed as the hydraulic subsystem of the harvester.The hydraulic cylinders control the overflow valve corresponding to the electromagnetic directional valve through the three-position reset switch to complete the height adjustment.Build a real-time display and alarm system of the cutters' height on the STM 32 development board,obtain and display the cutter height through the displacement sensor;when the height difference between the cutting table and the additional first cutter is less than 120 mm,the height difference between the additional first and second cutter is less than 80 mm,the device starts to beep and the corresponding red LED flashes.(4)Field test: The comparative test and orthogonal test verified that the regenerated rice combine harvester reduced the rolling rate of the straight area from 50% to 30%,the turning area from 90% to 60%,it increased the yield of rice in the regeneration season by 130 kg/mu.The optimal working parameter combination of the orthogonal test is the harvester's speed of 0.97 m/s,the cutting height of 400 mm,the rotation speed of the drive shaft of the unit is 400 r/min;the speed of the harvest has the greatest impact on the stubble pass rate,the stubble height has the greatest impact on the return rate of stalks.The ratoon rice combine harvester designed in this project will reduce the rolling rate from 50% to 30% and increase the average yield of rice in the regenerating season by 130 kg/mu;the header cutter only applies to a few spikes It can reduce the ratio of the grass to the valley of the material entering the harvester,reduce the load of the threshing and cleaning system,provide the prerequisites for the weight reduction of the whole machine,and increase the feed rate of the whole machine without reducing the efficiency;the additional first cutter reduces the length of the returning stem It is easy to return to the field;the additional bottom cutter ensures that the height of the stubble meets the agronomic requirements of the regeneration season rice.It is an effective solution for regenerating rice harvester,and it is of significance to fill the research gap of additional cutters in China.