The Simulation Of Working Process Of Spade Punch Planter Of Maize Base On The Discrete Element Method

The spade punch planter of maize(SPPM)is combined by the spade soil opener and the metering device,it is a new kind of seeder which can sow and dig a hole at the same time.The machine has advantages of simple structure,convenient operation and so on,but the performance in working process is the key to which can be used widely.The seeder works in the environment of uneven soil,so there makes sense to analyze the working process of the machine.Firstly,Simply introducing the basic theory of discrete element method(dem),including unit model,the calculation principle and contact model,and then elaborating the dem of soil.Systematically introduce the function of three dimensional discrete element software EDEM and to pave the way for the following.Secondly,the simple model of uneven soil,metering device and maize seeds are established,together constitute the simulation system of working process of metering device.Establishing the equation of seeds moving in metering device,introduce the calculation method of cleaning Angle of metering device,then using EDEM to simulate the process of metering device working in uneven soil.The simulation results show that: the factor of uneven soil can increase replay rate of metering device,and the greater the degree of uneven soil,the replay rate is higher.Adjust the machine speed to 1 m/s,replay rate minify.Again,establishing the simulation system of working process of cavitation device,including the model of cavitation device,soil particles and so on.Setup the relation between the size of hole of cavitation device digging and parameters of cavitation device,simulate working process of cavitation device.The simulation results show that the factor of uneven soil has little effect on the machine.Finally,the simulation system of working process of SPPM is established,including the model of metering device,cavitation device,maize seeds and particles of soil,etc.The adaptability of falling process of maize seeds and spade is analyzed,simulate working process of seeder working in uneven soil.Simulation resultsshowed that: the factor of uneven soil can make seed spacing uneven distribution,make the variation coefficient of seed spacing increased,the greater the degree of uneven soil,the coefficient of variation of seed spacing is higher,increasing the width of spade to 50 mm,the coefficient of variation of seed spacing is lower.