Effects of blade sliding cutting angle and stem level on cutting energy of rice stems

Previous studies highlighted the significance of optimizing the cutting blade for crop harvesting and size reduction.This study investigated the effect of blade sliding cutting angle and stem level on cutting energy of single rice stem using a cutting apparatus that combined with texture analyzer.The cutting energy was determined for four blade angles.The results showed that the average cutting energy was the highest for cutting stem upper level and the lowest for cutting stem lower level.It was found that the peak cutting force per unit stem area decreased with blade sliding cutting angle increased.However,the least average cutting energy was 9.12 J/mm^(2) of 45°sliding angle when cutting without counter support blade and 32.3%less than that of 60°sliding angle.When cutting with counter support blade,the cutting energy per unit stem area varied from 6.57 to 12.54 J/mm 2 as the sliding angle varied from 0°to 60°,whereas the peak cutting force per unit stem area varied from 2.46 to 0.98 N/mm 2.It was concluded that the optimal sliding cutting angle was 45°without support blade and 30°with support blade,respectively.The experiments on rice stems in this study indicated that optimization of sliding cutting angle and stem level have a significant effect on cutting energy savings.Also this study emphasized the need to further investigate the effect of the case of more moisture content and cutting speed on the cutting energy to help in selection of optimum cutting speed and harvesting time.

Carbon Emission Modeling and Analysis in Manufacturing Process for Numerical Control Machine Tools

Reducing carbon emissions( CEs) is the urgent demand all over the world. In order to realize the low-carbon numerical control( NC) machining, the evaluation model of a part's manufacturing carbon emission with NC machine tools was built by considering the influences of the cutting tool geometrical parameters.The manufacturing CEs were produced by electric power,cutting tools,and cutting fluid consumed in manufacturing process. The parameters of cutting tools affected not only the CEs,but also the machining quality. Then the actual constraint models of the machine performance,machining quality were given in order to optimize the cutting parameters and achieve the low-CEs. Finally,a case was given to analyze the influences of the cutting tool angles on the manufacturing CEs. The results show that the CEs decrease as the rake angle and edge angle increase under the constraints of the machine specifications and machining quality.

Design of variable screw pitch rib snapping roller and residue cutter for corn harvesters

The blocking between two snapping rollers will seriously constrict the harvesting efficiency for corn harvester.A variable screw pitch rib snapping roller was developed to solve this problem.The comparative experiment between fixed screw pitch rib snapping rollers and variable screw pitch rib snapping rollers illustrated that variable screw pitch ribs can avoid corn-stalk blocking effectively,and it can improve working efficiency by 56.7%.Conservation tillage with standing corn residue was testified that it had a strong control of soil wind erosion.In order to implement this mode of conservation tillage at a production scale,a cutter was developed in this study.Subsequently,two experiments were conducted,one was to test the cutting ratio(defined as the totally cut off stalk population divided by total stalk population),and the other one was to test standing-residue height.The experiment results showed that the mean cutting ratio increased significantly(p<0.05)along with increasing height of cutter-head above the ground(cutting height);the cutting ratio’s mean value increased significantly(p<0.05)along with the decreasing angle between the cutter-head and the ground(cutting angle).The average standing-residue height increased along with the increase of cutting height from 300 mm to 500 mm.The average standing-residue height increased significantly(p<0.05)along with the decrease of cutting angle from 15°to 0°.Therefore,the newly designed snapping roller can improve the harvesting efficiency and prolong the working life of the cutting table;and the cutter can promote the popularization of the conservation tillage with standing corn residue in Northeast China.

Design and optimization on rootstock cutting mechanism of grafting robot for cucurbit

Cutting mechanisms in existing grafting machines are unable to completely cut through the rootstock growth point and can easily damage seedlings.During the mechanical operation of splice grafting,the cutting angle of the rootstock is an essential factor for ensuring the quality and survival rate of grafting seedlings and a stable process for grafting robots.Therefore,in this study,commonly used grafting rootstocks,e.g.,cucurbita moschata,and calabash gourd were used as research objects for studying and analyzing the cutting angle of a splice grafting method.The morphological and structural parameters of the rootstock and scion were measured,and a structural model of the internal cavity of the rootstock was constructed using an image analysis method.The critical cutting angles for the cucurbita moschata and calabash gourd seedlings were obtained.According to the analysis,the grafting cutting angles for cucumber seedlings matching with cucurbita moschata seedlings were 20°and 25°,respectively,and the fitting rate of the cutting surface of the rootstock and scion was 99.04%.A cutting mechanism for the rootstock growth point and geometric model of the cutting operation were established,and the structural parameters of the mechanism and cutting angle adjustment were optimized.A cutting performance test showed that the success rate of the pressing the cotyledons of cucurbita moschata seedlings was 96.67%,and the success rate of cutting was 98%.The cutting accuracy was 96.8%,and the cutting surface fitting rate of the rootstock and scion was 98.61%.The latter differed by 0.43%from the theoretical rate but met the requirements for the splice grafting method.Thus,this study can provide a reference for the design of a cutting mechanism for a grafting robot.