A STUDY OF CRANK HOE TILLAGE FOR DEEP TILLING

介绍了一种新型耕作机械--曲柄铲这一摆式耕作机械为实现预期功能而进行的四杆机构的综合。分别采用四种连杆长度组合进行了四杆机构运动的数学仿真和现场试验，结果表明，构成驱动机构的各连杆长度的相互比决定着被摆动铲截断的土片的形状。在高频振荡下，可以得到较小的土片。在低频和B、C型叶片曲线下，可获得较大的土片和较深的穿透深度。特别是安装在刀刃上的刀尖，具有在水田中抛撒大片土片的有效翻转性能。土壤含水率对耕作效果有一定的影响，在干旱条件下，4种耕作工具之间差异不显著，利用功率谱分析技术分析了振动耕作机具--曲柄耕作耕作过程中的时变特性。四杆机构产生的振动是在高频下发生的，激励了机具的分布部件。叶片与土壤相互作用引起的振动在拖拉机-机具系统作为质量-弹簧系统振荡的低频范围内上升。

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.