Design And Experimental Study Of Striping Boom Sprayer For Soybean-maize Strip Intercropping

Soybean-maize strip intercropping is an important technical way for the compatible development of the soybean and maize,which can solve the problem of food security in China.In 2022,the Ministry of Agriculture and Rural Affairs will promote this plant model in 16 provinces across China to more than 15 million acres,focusing on increasing the planting area and yield of the soybean.Mechanization of field weeding is one of the key links in the mechanization of the whole process of this planting mode.At present,conventional plant protection machinery is difficult to meet the requirements of the synchronous application of the soybean and maize agronomics,which restricts the promotion and application of this kind of planting technology.To address the above issues,this paper designed a soybean-maize striping boom sprayer,through the design of a double spray system and anti-drift device,the synchronous application process of the soybean and maize,and the reduction of drug harm was realized and carried out a prototype field application effect test research.The research results provide theoretical and technical support for the development and application of plant protection machinery for sub-strip synchronous application.The main research contents are as follows:(1)The structure design of the soybean-maize striping boom sprayer.Combined with the agronomic requirements,the performance parameter design index of the spray rod sprayer supporting the(4-6)rows of soybean and 2 rows of maize strip intercropping mode was determined.It mainly designs a double spray system,anti-drift device between the soybean and maize rows,wheel gauge adjustment device and chassis frame,etc.Through the calculation and the selection,the key component parameters such as the liquid pump,the medicine tank,the type of nozzle,and the number of nozzles were determined.Using FLUENT software to simulate the drift of droplets under different driving speed conditions of the machine,the length of the anti-drift device which was 1.5 m between the soybean and maize rows was determined.(2)The optimization test of a multi-nozzle combination method.According to the requirements of agronomic and spray performance,the combination method with an 80°anti-drift fan nozzle and an 110°anti-drift fan nozzle was selected,and the response surface methodology was used to study the combination of the sprays of the soybeanmaize strip and the soybean strip.The results show that when the spray height,the spacing of the soybean row edge sprinklers,and the spacing of the spray heads between the two crops are 54 cm,54cm,and 34 cm respectively,the uniform variation coefficient of droplet distribution is 10.74%,which meets the operational requirements.(3)Chassis static dynamic simulation analysis.Taking the chassis frame of the designed striping boom sprayer as the research subject,using ANSYS Workbench software to establish a finite element model of the chassis frame to analyze the static characteristics of the chassis frame for horizontal bending and ultimate torsion conditions.The analysis results show that: The maximum stress of the frame in the extreme torsion state is 239.09 MPa,the maximum deformation size is 12.18 mm,and the strength and stiffness of the chassis frame meet the yield limit requirements of the material.Using finite element software to carry out modal analysis of the self-propelled chassis frame,the first six-order natural frequency of the self-propelled chassis frame is between 34 Hz and 65 Hz and the mode shape is relatively smooth,the common excitation frequency range of the chassis frame is 3Hz~25Hz,ensuring that the loworder mode of the first few stages of the self-propelled chassis frame is within the common excitation frequency range,avoiding resonance.(4)The Field performance test study of striping boom sprayer.It mainly includes the droplet drift test,the pass test,and the nozzle flow uniformity test of the double spray system.The results show that the amount of droplets drifting across the belt in the double spray system increases with the increase of the vehicle speed.When the vehicle speed is 4km/h,the average coverage density of the soybean liquid droplets drifting across the soybean row to the maize row is 1.57 drops/cm2,The average coverage density of liquid droplets drifting across the soybean row is 0.84 drops/cm2;when the vehicle speed is 5km/h,the average coverage densities of droplets are 2.68 drops/cm2 and 2.11 drops/cm2 respectively;when the vehicle speed is 6km/h,the average coverage density of droplets are 9.60 drops /cm2 and 5.54 drops/cm2 respectively.With the significantly increasing of drifting droplets,which may causes phytotoxicity.Therefore,the vehicle speed of the Soybean-maize striping boom sprayer should not be higher than 5km/h.The passability of the sprayer and the uniformity of the flow distribution of the nozzles meet the national standards.