Design And Development Of Self-propelled Mulberry Branch Cutting And Laying Machine And Experimental Study On Cutting And Laying

Mulberry branch cutting is a very important operation in the production of mulberry silkworm.It is not only related to the growth of high-quality mulberry leaves,but also related to the comprehensive utilization of mulberry branches,The most difficult problem of mulberry cutting is to ensure that the stubble section is flat and smooth when cutting.Mulberry cutting by hand has always been used,low efficiency,labor intensity,far from meeting the needs of the development of silkworm production process mechanization.In view of this situation,this paper developed a more practical self-propelled mulberry branch cutting and laying machine.Small loader is selected as the loading power,and vertical harvesting method is adopted to develop a mulberry cutting and laying machine that integrates auxiliary lifting device,feeding device,cutting device and horizontal branch arrangement and laying device.Different from the traditional mulberry cutting machine,this machine can conveniently adjust the stubble height,ensure the quality of the stubble cutting of mulberry plants,and can discharge the cut mulberry branches horizontally and spread them on the side of the machine.Combined with the agronomic requirements of mulberry cutting strips and the planting and growth characteristics of mulberry trees,the overall design objectives and research and development ideas of the whole machine were determined.The main technical difficulties were pointed out,and the cutting and laying method of mulberry branches were given.By means of high-speed unsupported cutting with circular saw,mulberry branches are arranged and laid by transverse conveyor chain with poking tooth.Pro/Engineer software is used for three-dimensional assembly modeling.The hydraulic lifting device of the loading vehicle is transformed into the lifting device of the cutting and laying platform,so that the cutting and laying platform can rise and fall vertically within the range of 50 mm～1132 mm in the vertical plane.This paper analyzes the composition of the cutting and laying system and the function,working principle and working flow of each device,discusses the relationship between each device,and provides a reference for the development of the whole cutting and laying machine,and determines the main technical indicators and routes.Based on the design method of ANSYS/LS-DYNA numerical simulation orthogonal test,the changes of circular saw stress and cutting force in the mulberry branch cutting process under the level of sawtooth number,cutting speed,feeding speed and mulberry branch diameter were researched.The cutting force measurement test was carried out on a test platform,and it was found that the simulation results were in good agreement with the test results.On the premise of ensuring cutting quality and working efficiency,the operation parameter matching with 72 T sawtooth number,3000 r/min cutting speed and 3 km/h feed speed was finally determined.Under this condition,the cutting force and stress of the circular saw blade are greatly reduced.Using the designed cutting device,the cutting test was carried out under the selected optimal operating parameters,and a relatively flat and smooth cutting surface of mulberry branch was obtained.Researched the mulberry branch orderly smooth conveying and laying condition relation,find out the guarantee the condition of laying Angle to 90°.The horizontal branch arrangement test platform was built,and high-speed camera technology was used to observe and record the conveying posture of mulberry branches.The main factors affecting the performance of conveying laying were found out by setting up a horizontal test platform for laying branches:poking tooth spacing,poking tooth length,poking tooth angle and conveyor chain speed.Through orthogonal test and result analysis,the influence rule of each factor level on the success rate of mulberry branch transportation was studied,and the reason was analyzed.Finally,the optimal parameter ratio was determined:poking tooth spacing is 127 mm,poking tooth length is 10 mm,poking tooth angle is 0° and conveyor chain speed is 1.5 m/s.The physical prototype of self-propelled mulberry branch cutting and laying machine was manufactured and adjusted.The outdoor test platform was built to verify the cutting and branch laying performance of the prototype.Finally,a better working feed speed of the whole machine was obtained,which was 3.36 km/h.Under this working feeding speed,the cutting damage rate is between 5%to 8%,the average complete cutting rate is as high as 99.6%,the branch transportation and laying rate is more than 90%,and the production efficiency basically meets the requirements.