| As the core of the development trend of modern agricultural technology to implement conservation tillage technology with straw mulching and no-tillage and less tillage,which is an important measure to strengthen the protection of black soil in Northeast China and promote the green development of agriculture.However,excessive straw residues on the field seriously affect the field preparation and sowing operations,which is not conducive to crop growth,resulting in low efficiency of related equipment and difficult to ensure the quality of cultivation.Strip tillage is a new conservation tillage technology that effectively solves the problem of straw mulching.It creates a clean seedbed on the straw mulching surface for crop growth and moves straw residue between two seedling belts to protect the soil.Strip tillage has the advantages of rapid increase of soil temperature of traditional tillage,and soil protection of no-tillage mode.So strip tillage has the advantages of security and green sustainability.Strip tillage is the basic link of strip tillage mode,and needs equipment to be replaced by the traditional tillage equipment.However,there are few studies on strip tillage technology in China,and lack of suitable strip tillage equipment.Based on the strip tillage technology,combined with the practical production conditions in the black soil area of northeast China,and using mechanical structure design and electronic control technology and other technical means,this paper carried out the research on the key technology of inter-row straw cleaning tillage and the adaptive strip tillage machine to solve the problem of lack of equipments and for strip tillage technology in China.Through theoretical analysis,the mechanical mechanism design,electronic control technology,computer simulation analysis and experimental research methods and means,such as the key part process quality influence rule,to carry out the disk coulter configuration optimization,clean straw device innovation design and tillage depth stability control system design of the key technology research,finally to row clean straw plowing adaptive strip tillage machine key technology integration and development,this article for further popularization and application of conservation tillage technology provides effective technical support,has important practical significance.The research content of this paper mainly includes the following aspects:(1)Disc plough motion analysis and operation qualityIn this paper,the roller cutting mechanism of disc plough is investigated,the dynamic and kinematics models of the roller cutting process are established,and the influencing factors on the operating resistance of disc plough as well as the influencing laws on the cutting performance under the condition of sliding rolling are analyzed.In order to optimize the configuration of disc plough,a dynamic testing system for the performance of field plough was designed and built.The full-factor test was carried out with the type of disc plough,straw coverage and working speed as test factors,and the groove contour,straw disturbance rate,working resistance and sliding rate of plough were determined.The results showed that the type of plough and the speed of advance had significant influence on all the indexes,and straw residue had significant influence on the working resistance and slip rate.Planar plough with minimum groove profile,residual disturbance rate,cutting resistance and maximum slip rate;In the measured corrugated plough,the cutting resistance,furrow width and groove area decrease with the increase of the number of ripples,and the slip rate and residual disturbance rate increase gradually.The experimental results were summarized and statistically analyzed,and the configuration optimization of the disc plough of the strip tillage machine was completed by comprehensively considering the operating conditions and technical requirements of the passive strip tillage machine.The 18 corrugated plough was selected to cut off the straw residues in the operating line,and the 13 corrugated disc plough was selected to loose and break the soil.(2)Research on the design of self-adaptive star-toothed concave disk cleaners and quality of cleanersA wide adaptive strip clearing device is designed by combining with mechanical structure design and electronic control technology.To design thetar-toothed concave disk cleaners device,the movement process of straw in clean straw plate surface and the working width structure theory analysis,to explore the affecting the quality of pure clear straw stalks device structure and working parameters and its scope,and using discrete element software EDEM clear straw,virtual test performance,makes a research on the various factors of black straw quality influence law,and obtain the optimal parameter combination plan.Virtual simulation experimental results show that the optimal structure parameters: clear straw plate,the radius of curvature radius of gyration is 152.5 mm to 160 mm,the disc surface projection length is 50.9 mm,the optimal working parameters: clear straw plate spacing for 90 mm,installation Angle of 30 °,installation Angle of 15 °.An adaptive width monitoring system was designed based on the star tooth concave strip and straw removal device,and the s-type tension pressure sensor and electric linear push rod were used to coordinate each other.The results of field experiment showed that the rate of strip and straw removal with the adaptive strip and straw removal device was 92.3%,the straws throwing distance was 40.2cm,the width of the adaptive monitoring system increased the width stability of the seedlings by 9.8%,and the cleaned strip met the agronomic and technical requirements of corn planting.(3)Design of tillage depth stability control system and establishment of single mechanical modelCombining with theoretical analysis and the mechanical structure design,determine the strip tillage machine contour scheme for the parallel four-bar hinge structure and single structure of synergy stripe contour plowing monomer layout,design the structure of parallel four-bar monomer profiling mechanism,the single hinge structure profiling scarification device and the hinge structure copying device v-shaped ground soil,and determined the profiling institutions mainly structural parameter values;Using electronic control technology and air spring as the downforce loading part of parallel four-link copying mechanism,a pneumatic monitoring system for deep ploughing stability was designed.By maintaining the air pressure in the air spring in real time,a constant downforce was provided for the whole row of strip tillage unit to improve the deep ploughing stability of the machine.The mechanical model of strip tillage monomer under the downforce applied by air spring is established,and the analysis shows that the pneumatic monitoring system can transfer the weight of frame and tractor to the strip tillage monomer,which is beneficial to realize the lightweight configuration of the machine.(4)Integration of key technologies and design and test of self-adaptive strip tillage machineA strip tillage machine suitable for the main corn growing areas in northeast China was developed by integrating the research results of key technologies of inter-row straw cleaning and tillage in the early stage,and the trial production of the prototype was completed.Field application performance and applicability test results show that the developed adaptive strip tillage machine cut through crop-cleaning-digging-breaking soil progressive working form,complete in a stripe in the land of straw mulching straw and plowing,pneumatic plow deep breadth of control systems and self-adaptive monitoring system can improve the working stability of the machine,formed high-quality planting strip,satisfied the maize planting agronomic requirements.The working speed range of this machine is 6~12km/h,the tilling depth range is 6~12cm,the working width range is 18~24cm,the research results may provide data reference for the follow-up optimization and improvement of the machine. |
PDF Full Text Request