切段式甘蔗收割机切段刀辊切割甘蔗过程中出现的碎屑和切口爆裂等问题,会造成甘蔗质量损失、蔗汁流失和产生较多的葡聚糖,增加甘蔗收获田间损失和制糖成本.为此,以切割甘蔗过程中切段刀辊配对刀片之间的位置关系对切割质量的影响为研究对象,利用仿真软件对配对刀片切入甘蔗的过程进行了仿真,用高速摄相机在1280×800分辨率下以2000fps速率记录了刀片切入甘蔗过程.对切入过程中甘蔗不同的状态进行了力学分析,研究了配对刀片的刃口间距对切割过程中碎屑的产生和切口端面轴向高度差的影响.结果表明:配对刀片切入甘蔗过程中,上刀片先切入甘蔗,下刀片随后切入,在切断甘蔗的过程中有碎屑产生;试验条件下,甘蔗直径对切口质量有影响,刃口间距为6mm时蔗段切口质量最佳,单位切口损失量为0.23g,切口端面轴向高度差为8.2mm.本研究成果对调整切段刀辊刀片具有一定指导意义.

[Objective]To provide a theoretical basis for designing a device cutting sugarcane tail stalk and establishing a mathematical model for dynamic simulation.[Method]The precision micro control electronic universal testing machine and static resistance strain gauge were used to perform tensile tests on sugarcane skin, core and joints of the fifth and sixth sections below the growing points of sugarcane tail stalk. The Poisson's ratio parameters of each component were obtained by electrometric method and mechanical analysis.[Result]The PRXY of sugarcane skin and core of the fifth section below the growing points of sugarcane tail stalk was less than 0.028 and 0.174, and the NUXY was 0.233 and 0.271, respectively. The PRXY of sugarcane skin and core of the sixth section below the growing points was less than 0.001 and 0.223, and the NUXY was 0.238 and 0.289 respectively. The PRXY of sugarcane joint was less than 0.305 and the NUXY was 0.344.[Conclusion]The PRXY has significant differences among different parts of the sugarcane tail stalk, while the NUXY has little difference. Sugarcane skin and core both have significant differences in PRXY between the fifth and sixth sections below the growing points of sugarcane tail stalk, which has no significant difference in NUXY.

甘蔗尾茎的物理力学特性对于解决甘蔗断尾位置难以控制、断尾误差大这一关键技术难点具有重要意义，促进了甘蔗收获机械化的发展。利用自制的夹具，采用悬臂梁弯曲方法研究甘蔗尾茎在弯曲载荷下的力学特性。试验结果表明，蔗尾节位对抗弯强度、弯曲弹性模量的影响极显著，抗弯强度、弯曲弹性模量均随节位数值的增大而增大，由中部向尾部顶端生长点方向减小，呈二次曲线高度正相关关系；蔗尾生长点以下1～5节与6～9节的抗弯强度差异极显著，在1～5节处施加弯曲载荷，蔗茎容易断裂，断面光滑整齐；蔗尾生长点以下第5节处的抗弯强度平均值为9．40 MPa，标准误差为0．46 MPa，弯曲弹性模量平均值为55．85 MPa，标准误差为4．86 MPa。

针对整秆式联合收获机机械收获后甘蔗夹杂物中青叶多、茎秆尾梢部分过长等问题，对国内外甘蔗尾梢部位确定及断尾机构现状进行深入分析，分析表明，断尾位置控制、紧密包裹尾部叶鞘的撕裂剥除是当前阻碍断尾除叶技术发展的2个关键技术难点，确定符合农艺要求又适合机械断尾的断尾位置，设计相应的断尾机构，对推动甘蔗收获机的发展有着积极和重要的意义。

In order to obtain the mechanical characteristic parameters of sugarcane tail stalk, tensile and compression tests were conducted in the accurate micro-controlled electronic universal testing machine.The results indicated that sug-arcane tail node had extremely significant effects on the tensile strength and the compressive strength which decreased from the middle to the tail apical growing points, the results also showed that the average values of tensile strength of 1~3 nodes below the tail apical growing points were 1.44,2.87,4.72MPa,respectively, and their average values of tensile modulus of elasticity were 22.02,27.60,37.09MPa, respectively;It was quadratic function negative correlation between the diameter and the tensile strength of each nodes in the tail, and the tensile strength decreases with the increase of di-ameter;their average values of compressive strength were 4.04,5.22,6.66MPa, respectively, average values of com-pression modulus of elasticity were 23.93,25.37,24.12MPa, respectively, it was power function positive correlation be-tween the diameter and the maximum compression load of each nodes in the tail,and with the increase of diameter, the maximum compression load increases.The conclusions provide the theoretical foundation to design tail -breaking mecha-nism of sugarcane harvester and establish mathematical model for dynamic simulation.

The computer graphics course,which is very practical,is a requirement for teachers of the theory and practice of combining teaching of professional basic courses,How to improve teaching quality is the current focus of higher education,and how to objectively and exactly evaluate the teaching quality have positive and important meanings for improving the teaching quality,Taking advantage of BP neural network theories,This paper establishes a reasonable and effective model for evaluating the teaching quality of computer graphics course which is based on working the index system out.After that,in order to find the existed problems in our teaching process,which provide a direction of teaching innovation,the teaching quality of computer graphics course in our university was evaluated by using this model.

The mechanical strength of rear end of sugarcane stalk is significant lower than the middle and basal part. A tail-breaking mechanism was designed. When the sugarcane stalk passing through this kind of mechanism, the tails and 5-6 pieces of young leaves could be broken. Its working principle was analyzed, and the orthogonal experiments were conducted to study the influence between the following four factors: rotate speed of feeding and output rollers, rotate speed of tail-breaking rollers, the center distance between the top and bottom tail-breaking rollers, and the relative installation position angle of the top and bottom tail-breaking roller's elastic components. The result shows that the optimal parameters were as following: rotate speed of feeding and output rollers of 250 r/min, rotate speed of tail-breaking rollers of 550 r/min, the center distance between the top and bottom tail-breaking rollers of 300 mm, and the relative installation position angle of the top and bottom tail-breaking roller's elastic components of -20°. The best tail-broken rate in 4-6 sections below the growth point of cane stalk reached to 63.3%. The average length of these tails was 212 mm and standard deviation was 57 mm which meet the agronomic requirements.