Design And Testing Of A Clamping And Picking Device For Fresh Maize

Fresh maize ears have a high water content and the ears are prone to breakage.If the kernels are broken they are not only difficult to store but also affect their taste.In order to ensure the quality of fresh maize,the ears are generally picked by hand.However,there is a mismatch between the increasing scale of fresh maize cultivation and the decreasing number of people willing to work in agriculture each year,resulting in increasingly high labour costs.It is imperative that mechanical harvesting replaces manual work to achieve a non-destructive harvest of fresh maize.Existing conventional maize harvesters are unable to meet the quality requirements of fresh maize harvesting due to structural or technological defects,and in order to promote the comprehensive use of maize straw,it is necessary to design a fresh maize harvesting device that is suitable for both cob and stalk harvesting of fresh maize.This study proposes to carry out the determination of physical and mechanical parameters of fresh maize plants during harvest,the design of a fresh maize clamping and picking device,the analysis of the fresh maize picking mechanism,finite element analysis,virtual simulation analysis and bench tests.The main research and results are as follows:(1)Taking the fresh corn plants at the end of milk ripening or early wax ripening planted in the Huanghuaihai area as the research object,the characteristics of fresh corn plants at the harvest period were studied,and the ear diameter and ear height of fresh corn at the harvest period were mainly measured et al.Calculate the stalk yield strength and ear compressive strength of fresh corn plants by using the measurement results of the universal testing machine,and measure the ear picking force by using the tensile machine;measure the moisture content of each part of the fresh corn plant by using a moisture meter;use physical measurement The static friction coefficient of the material was measured by the method;the high-definition microscope was used to observe and analyze the structure of the broken part of the ear picking,which provided a theoretical basis and data reference for the fresh corn clamping ear picking device.(2)According to the principle of reverse ear picking,a clamping ear picking device for fresh corn was designed.The device is composed of a directional clamping mechanism,an ear picking mechanism and a stalk pretreatment mechanism.Through motion analysis and operation efficiency analysis,it is determined that the overall inclination angle of the clamping and picking device is 15°,the effective working length of the directional clamping mechanism is 550 mm,and the operating speed is1.35-1.83 m/s;the effective rotation radius of the picking mechanism is 320 mm,The number of roots is 6;in order to realize corn stalk harvesting,a conveying-type stalk puller that satisfies the extrusion pretreatment of corn stalks and can effectively transport stalks is designed,and the diameter of the stalk puller is determined to be:86 mm,the length is 580 mm;the disc cutter is used to effectively cut the stalks after picking the ears to ensure the reliability of the stalk pretreatment during the operation process.static analysis.(3)The movement of the picking finger,the stress on the ear and the picking of the ear under different growth directions by the picking finger were analyzed.Through the ANSYS finite element method to apply the force direction during the picking process,it is concluded that the fracture position of the fruit stem is close to the joint between the fruit stem and the stalk.The fresh corn plant model was established by ADAMS software,and the virtual simulation analysis of the ear picking process and stem pretreatment process was carried out to provide parameter optimization data for the clamping and picking device mechanism of fresh corn.(4)Bench test was carried out.During the test,high-speed photography technology was used to analyze the ear-picking process,which verified the rationality of the structural design of the clamping and ear-picking device for fresh corn.In order to find the best operating parameters,a three-factor five-level orthogonal test was carried out.The test results showed that: at the clamping feeding speed of 1.67 m/s,the picking wheel speed of 80 r/min,and the machine’s forward speed of 1.07 m/s Under the optimal parameter combination conditions,the average ear damage rate was 0.57%,and the average harvest impurity content rate was 1.87%.The error between the verification results and the theoretical prediction value was small,which met the design requirements of the fresh corn harvesting device.