高秆作物双限位滑轨抑振机构式链轨割台设计与试验

Design and Experiment of Chain-track Header with Dual-limiting Slide-rail Vibration Suppression Mechanism for Tall-stalk Crops

摘要:

针对现有往复式和圆盘锯式割台在收获作物时存在振动剧烈、功耗高及适应性差等问题,设计了一种带有双限位滑轨抑振机构的链轨式割台。通过运动学分析,确立了实现先割后输且无漏割的理论切割速比范围为3.75 < λ≤5。针对链传动引起的非线性振动,研究所引入的双限位滑轨机构使动刀在竖直方向的振幅显著下降44%,并基本消除了水平横向的周期性波动。基于刚柔耦合模型进行响应面优化分析,结果表明,各因素对切割性能影响的显著性主次顺序为:切割速度、前进速度、切割倾角。仿真寻优得出的最佳作业参数为:前进速度3.0 m/s、切割速度13.5 m/s、切割倾角8°。在此条件下,甜高粱单位直径最大切割力为9.5 N/mm,单位面积切割功耗为0.09 J/mm2。台架试验进一步验证了实际最优参数为:前进速度3.3 m/s、切割速度12.5 m/s、切割倾角7.5°,此工况下单位直径最大切割力实测值为(8.8 ± 0.3) N/mm,与仿真值的相对误差稳定在6.3% ~ 13.2%之间。该结果充分证实了设计的割台结构对作物具有优异的低阻、高效切割性能与广泛的适用性。

Abstract:

Aiming to address the severe vibration, high power consumption, and poor adaptability of existing reciprocating and disc-saw headers during crop harvesting, a chain-track header equipped with a dual-limit slide-rail vibration damping mechanism was designed. Kinematic analysis established the theoretical cutting speed ratio range of 3.75 < λ≤5 to achieve a zero-miss “cut-and-convey” sequence. To mitigate nonlinear chain drive vibrations, the introduced slide-rail mechanism significantly reduced the vertical amplitude of the moving blade by 44% and essentially eliminated periodic horizontal fluctuations. Response surface optimization based on a rigid-flexible coupled model revealed that the factors influencing cutting performance ranked in significance as follows: cutting speed, forward speed, and cutting tilt angle. Simulation optimization identified the optimal operating parameters as forward speed of 3.0 m/s, cutting speed of 13.5 m/s, and cutting tilt angle of 8°. Under these conditions, the maximum cutting force per unit diameter for sweet sorghum was 9.5 N/mm, with a cutting energy consumption per unit area was 0.09 J/mm2. Bench tests further verified the actual optimal parameters as forward speed of 3.3 m/s, cutting speed of 12.5 m/s, and cutting tilt angle of 7.5°. Under this state, the measured maximum cutting force was (8.8 ± 0.3) N/mm per unit diameter, with a relative error of 6.3% ~ 13.2% compared with the simulated values. These results fully demonstrated that the designed header possessed excellent low-resistance, high-efficiency cutting performance and broad crop applicability.