橡胶辊不同转速对青核桃脱皮的影响分析

Influence of different rotation speed of rubber roller on peeling performance of green walnut

【目的】以小型通用型青核桃脱皮分离装置为研究对象,研究橡胶辊不同转速对青核桃脱皮的影响.【方法】首先分析单个青核桃下落接触螺旋橡胶辊边缘动态平衡时的受力情况,然后以甘肃庆阳地区的青核桃为研究对象,运用集成方法建立模型及网格划分,结合试验数据利用LS-DYNA得出最小破壳力203 N所对应的破壳应力临界值17.40 MPa,最后通过碰撞仿真,结合临界值分析橡胶辊不同转速对青核桃脱皮的影响.【结果】当螺旋橡胶辊的转速为90 r/min时,最大应力单元为青核桃与橡胶辊瞬间接触部位,应力值为0.518 MPa;而当转速提高到110 r/min时,青核桃两个部位出现应力峰值,其一是与橡胶辊接触点,峰值为0.34 MPa,之后稳定在0.21 MPa左右,其二是旋转时与筛网的接触点,最大值为0.55 MPa,而后稳定在0.259 MPa左右,同时得出不同转速对应青核桃单元的最大速度.【结论】说明两种转速最大应力小于破壳应力,橡胶辊转速较高时筛网对青核桃内部应力的影响较大.

【Objective】To study the effect of different rotating speeds of rubber roller on the performance of a small universal device designed for peeling and separating green walnut.【Method】Firstly,the force situation of a single green walnut falling in contact with the edge of the spiral rubber roller was analyzed.Then the green walnut from Qingyang of Gansu was used as the objects,the integrated method was used to establish the model and grid division,combined with the experimental data,the critical value of shell breaking stress corresponding to the minimum shell breaking force 203 N was 17.40 MPa by LS-DYNA.Finally,through collision simulation,the influence of different speed of rubber roller on the performance of green walnut was analyzed.【Result】When the rotational speed of the spiral rubber roller was 90 r/min,the maximum stress unit was the instantaneous contact part between the green walnut and the rubber roller,and the stress value was 0.518 MPa.When the rotation speed increased to 110 r/min,the stress peak appeared in two parts of green walnut.One was the contact point with the rubber roller,the peak value was 0.34 MPa,and then stabilized at about 0.21 MPa;the other was the contact point with the screen during rotation,the maximum value was 0.55 MPa,and then stabilized at about 0.259 MPa.At the same time,the maximum speed of green walnut unit corresponding to different rotational speeds was obtained.【Conclusion】The maximum stress of the two speeds is less than the shell breaking stress,and the sifter has a greater impact on the internal stress of green walnut when the rubber roller speed is higher.Combined with the speed curve,it provides a theoretical basis for the determination of the key parameters and optimization design of the subsequent elastic device.