A STUDY OF CRANK HOE TILLAGE FOR DEEP TILLING

本文介绍了一种新型耕作机械曲柄锄头的四杆联动系统的综合设计，为曲柄锄头提供了一种理想的功能。对四杆机构的运动进行了数学模拟，并对四连杆机构的四种连杆长度组合进行了现场试验。由摆锄切断的土片的形状取决于构成驱动机构的环节长度的相互比例。在高振动频率下可以得到小的土片。在低频和B型或C型叶片曲线下可获得大土片和深穿透。特别是附在刀刃上的刀尖，在稻田中具有有效的抛撒大片土的转向性能。土壤含水量影响锄的埋深性能，4种锄在旱地条件下无显著差异。利用功率谱分析技术分析了曲柄锄头在振动耕作过程中的时变特性。由四杆连杆机构产生的振动发生在高频率，在该频率下，执行器的分布部分被激发。由叶片和土壤之间的相互作用引起的振动在拖拉机-机具系统作为质量-弹簧系统振动的低频范围内上升。

The authors described the synthesis of four-bar linkage system to generate a desired function for new tillage machine, CRANK HOE that is a kind of pendulous hoe. Mathematical simulation of motion of four-bar linkage and field test were carried out with four combinations of coupler-lever lengths respectively.The shape of the soil slices cut off by the pendulous hoe, depends on the mutual ratio of the length of the links constituting the driving mechanism. Small soil slices can be obtained at high frequency of oscillations. Big soil slices and deep penetration can be obtained at low frequency and B or C type of blade curve. Especially, blade tips attached to the edge has effective turning property of throwing big soil slices in the paddy field. The soil moisture content affects the burying property of hoe and four kinds of hoe tested have no significant differences in dry condition field.Power spectral analysis technique is used to analyze the time varying nature of a vibrating tillage implement, CRANK HOE during tillage operations. The vibrations generated by the four-bar-linkage occurs at high frequency in which the distributed parts of the implement are excited. The vibrations caused by the interactions between the blades and soils rises in the low frequency ranges that the tractor-implement system oscillates as a mass-spring system.