Root Rolling Centering Technology Research Of Lotus Seed

At present,lotus seed goes to the core mainly by using a rotating drill bit to drill the lotus seed core into a gray along the axis of the lotus seed core.Since lotus seed is a naturally-produced plant,its outline is irregular.When it is positioned,it tends to cause the drill bit to be biased,so that there is a lotus seed core residue inside the lotus root and an increase in the processing loss of the centering process.In order to explore the factors affecting the precision of lotus seed root centering,this thesis studies the mechanism of lotus center rolling centering,and proposes the evaluation method of lotus seed centering precision according to the principle of lotus seed root self-adaptive centering,which measures and analyzes the influence of lotus root centering.The geometric parameters of precision lotus seed root are analyzed by dynamics analysis of the lotus seed centering process,and the relevant parameters affecting the precision of the lotus seed center are found.Through the dynamic simulation test of the rolling centering process,the rolling centering is obtained.The influence of the relevant parameters of the mechanism on the accuracy of the lotus seed center rolling centering accuracy,and the optimal process parameters for ensuring the centering accuracy of the lotus seed root is obtained through the removing lotus seed core test.The obtained research results can provide evidence to optimize for the lotus seed center rolling centering mechanism.The specific research contents are as follows:1.Measurement and analysis of geometric parameters affecting the quality of lotus roots.The three-coordinate measuring method is used to measure the roundness error of the outer dimensions,sphericity and outer contour of lotus kernel.The distribution law of related geometric parameters is obtained.It has found that the roundness error of lotus kernel changed along the direction of its long axis to approximate parabolic law.The closer to the maximum cross-sectional position,the smaller the roundness error.The effect of lotus sphericity and cross-sectional roundness error on the precision of lotus root centrifugation is studied by group test method.It is found that the greater the sphericity of lotus kernel,the lower the centering precision of lotus kernel;the greater t degree of error about the cross section of lotus kernel,the lower centering accuracy of lotus seed.2.Analysis of the dynamics of lotus seed rolling process.The main factors affecting the friction of lotus root are analyzed: the rotation speed of the centering roller,the material and surface roughness of the centering roller and the weight of the pressure roller;based on the principle of rigid body dynamics,the expression of ZYX Euler angle is used.The orientation change of lotus seed during the movement process was established.The Euler’s kinematicdifferential equation of lotus seed in the process of movement and the Euler equation of lotus seed movement were established,and the dynamic equation of lotus seed was derived.3.Simulation analysis of the lotus center rolling centering process.The simulation model of lotus seed and centering mechanism is established.The simulation experiment is carried out by using Recurdyn software.And when the range of the friction coefficient of the centering roller from 100r/min to 200r/min,under the condition of 0.4 to 0.8 and the self-weight of the pressure roller between 8N and 14 N,the center of mass beat is small and the square effect is ideal.4.Lotus kernel test and parameter optimization.Based on the influence of various factors on the rolling centering process of lotus seed,the optimal de-centering process parameters of lotus seed are obtained by orthogonal test: centering roller speed: 135r/min,the coefficient of friction between lotus seed and centering roller: 0.46,the weight of the press roller: 14 N,the verification test is carried out.The error of the concentricity of the lotus root to the heart axis and its geometrical axis is 0.35 mm,and the average diameter of the lotus root was 2.17 mm,which is better than the original one,lotus root’s centering accuracy has been greatly improved.