Design And Experimental Study Of Key Components Of Eucommia Ulmoides Twig Stripping Machine

The bark of Eucommia ulmoides Olive（EUO）has a 2000-year history of medicinal use in China,and the short growth cycle and high survival rate of EUO in the leafy forest production mode have great economic value and promotion value.Traditionally,the bark is generally separated from EUO by roller peeling method,and the material requires a defoliation treatment before a mechanical operation,which leads to an inefficient and high impurity rate.Besides,the intermittent feeding and discharging method of the roller peeler greatly increases the labor cost.In this study,a dual-roller-type EUO leaf forest fine branch wood peeling machine was designed for the above mentioned problem of separating EUO fine branch wood bark.The details of the study are as follows.（1）The material properties of EUO fine branch bark were investigated,and the feasibility of dual-roller-type peeling was verified by using discrete element simulation.The model parameters of the bark were obtained by calibration test with EDEM software,and the optimal combination of parameters was determined by response surface analysis based on a single factor test,two-level analysis factor test,steepest climb test and measured shear force as the evaluation index.The results indicated the particle contact radius r of 0.854mm,the normal stiffness per unit area x₁ of 8.871×10⁶N/m³,tangential stiffness per unit area x₂ is 9.468×10⁶N/m³,and bond radius d of 0.825mm.The particle model was established based on the above optimal parameter combinations.Meanwhile,the feasibility of peeling by dual-roller-type was demonstrated with the interrelationship between the dual-roller-type screw pitch,dual-roller-type distance and speed ratio in the peeling operation by EDEM software analysis.（2）The structure design of the whole machine and key components was carried out by the peeling principle of dual-roller-type.The profile of the dual-roller-type was designed as a threaded structure with a diameter of 150.0mm and a length of1250.0mm.and the bark of the EUO fine branch bark was destroyed by pulling in the experimental process.In addition,according to the pre-test results the number of dual-roller was selected to be 2 pairs.The hammer blade mechanism was arranged symmetrically to reduce the vibration during the operation of the whole machine,and the spindle diameter of the defoliating hammer blade was 60.0mm and the length was1250.0mm.（3）The modal analysis of the peeling dual-roller-type was conducted,and the optimization results were evaluated by using dynamics simulation.Besides,the stability and feasibility of the peeling dual-roller-type were further verified by combining with the bench test results.The results of the modal analysis show that the vibration pattern of the peeling dual-roller-type is basically bending vibration deformation,and the maximum deformation reaches 6.50mm,Adams software was used to evaluate the stability of the optimized structure,and the results showed that the amplitude of the lower peeling dual-roller-type was 0.9mm,while that of the upper peeling dual-roller-type was only 0.15mm,the amplitude was less than 1.0mm,which indicated that the structure of the optimized model was reliable.Using the degree of bark damage as the evaluation index,the stability of the structure is further verified by bench tests.Meanwhile,the dual-roller-type screw pitch,dual-roller-type distance,and thread type of the counter rolls are screened to explore the optimal combination.（4）Prototype trial production and field test.To evaluate the peeling rate and production efficiency,an orthogonal test was conducted to explore the optimal combination of moisture content,feeding speed,and different materials in the peeling process.The optimal parameter combination for the Eucommia twig peeler was found to be the day’s harvest of Eucommia with leaves,a feed speed of 400r/min,and a peeling mechanism speed of 1200r/min.Results showed that only when the peeling and peeling rate reached 80.0%,the leaf peeling and peeling rate reached 41.0%,and the production efficiency reached 65.0%,did the fine branch wood peeling machine prove to be feasible and reliable.These findings provide a theoretical basis and technical support for the design of the fine branch wood peeling machine.