基于碰撞特性的鲜食玉米摘穗装置对比试验

Comparative experiment of fresh corn ear picking devices based on collision characteristics

【目的】探究缓冲弹簧和柔性触穗表面两种摘穗机构在摘取果穗中的低损作用及机制。【方法】以传统玉米收获用板式摘穗机构和具有缓冲弹簧加柔性触穗表面的柔性摘穗机构为2种摘穗结构,以刚性触穗表面、柔性橡胶触穗表面、柔性发泡材料触穗表面为3种触穗表面,得出6种摘穗机构,进行鲜食玉米果穗碰撞试验,采集和分析碰撞时间、碰撞加速度峰值,计算碰撞冲量,统计籽粒破碎率。【结果】柔性摘穗机构能够有效降低鲜食玉米果穗受到的碰撞时间,从而降低鲜食玉米果穗的籽粒破碎率。缓冲弹簧可缩短鲜食玉米果穗的碰撞时间,当柔性摘穗机构表面为柔性橡胶和柔性发泡材料时,碰撞时间分别比板式摘穗机构降低了66.2%、70.1%和70.1%。碰撞冲量分别降低了67.6%、77.9%和79.7%。籽粒破碎率降低了71.2%、51.3%和83.6%。对于柔性摘穗机构,鲜食玉米果穗与柔性橡胶、柔性发泡材料触穗表面的碰撞时间比刚性触穗表面分别延长了58.7%和63.2%。碰撞加速度峰值分别降低了62.5%和68.7%。碰撞冲量分别降低了42.4%和54.5%。籽粒破碎率分别降低了47.4%和68.4%。【结论】通过降低收获过程中鲜食玉米果穗受到的碰撞时间和碰撞加速度,从而有效降低了鲜食玉米果穗的籽粒破碎率,为鲜食玉米低损收获机的研制提供理论依据和设计参考。

【Objective】The study was conducted to explore the low loss effect and mechanism of two types of ear picking mechanisms,one with buffer spring and one with flexible contact surface,during the ear picking process.【Method】The traditional plate type ear picking mechanism for corn harvesting and the flexible ear picking mechanism with buffer spring and flexible contact surface were used as two basic ear picking structures to construct six ear picking mechanisms with rigid contact surface,flexible rubber contact surface,and flexible foam material contact surface as three contact surfaces.Collision tests were conducted on fresh corn ears during harvesting operations,the collision time and peak collision acceleration were collected and analyzed,and the collision impulse and grain breakage rate were calculated.【Result】The flexible ear picking mechanism can effectively reduce the collision time of fresh corn ears,thereby reducing the grain breakage rate of fresh corn ears.The buffer spring can shorten the collision time of fresh corn ears.When the surface of the flexible picking mechanism was made of flexible rubber and flexible foam material,the collision time was reduced by 66.2%,70.1%and 70.1%,respectively,compared with the plate picking mechanism.The collision impulse decreased by 67.6%,77.9%and 79.7%,respectively.The grain breakage rate decreased by 71.2%,51.3%and 83.6%,respectively.For the flexible ear picking mechanism,the collision time between fresh corn ears and the contact surface of flexible rubber and flexible foam material was 58.7%and 63.2%longer than that of the rigid contact surface,respectively.The peak collision acceleration decreased by 62.5%and 68.7%,respectively.The collision impulse decreased by 42.4%and 54.5%,respectively.The grain breakage rate decreased by 47.4%and 68.4%,respectively.【Conclusion】This study shows that reducing the collision time and collision acceleration of fresh corn ears during harvesting can effectively reduce the grain breakage rate of fresh corn ears,which provides a theoretical basis and design reference for the development of fresh corn low-loss harvester.