Form milling cutter is built-for-purpose cutter which process the form surface, for example, usually process male and female circular arc face and form trench and so on. From the traditional concept, form milling cutt...Form milling cutter is built-for-purpose cutter which process the form surface, for example, usually process male and female circular arc face and form trench and so on. From the traditional concept, form milling cutter is divided into pointed tooth and relieving follow its structure. Relieving shaped cutter is more convenient than pointed tooth milling cutter, because only its rake face is needed to grind after it turn into blunting, so the current books which are used in college almost select relieving shaped cutter in order to introduce how to design the form milling cutter.The curve of the back of tooth of relieving cutter is the transversal which is formed by the rear face of tooth in the end cut plane of the milling cutter. In the past, because of the limit of the manufacturing technology, the curve of the back of tooth is often selected Archimedes’ curve, in order that the shovel-nose tool acquire the uniform motion when the cutter shovel the back, in other word, the rear face of the milling cutter rotate its axis by the new cutting lip, in the same time, it move uniformly to the axis in order to form the surface. Although this curve of the back of tooth meet the fixedness of the form of blade around grinding the cutter, the rear angle of the dot of the cutting lip don’t keep fixedness. With the development of the modern manufacturing technology, the unmanageable problem of many complex curves is already easily solved. So it is need to study the optimum profile of the curve of the back of tooth in theory, and study the design theory of the relieving shaped cutter under the condition of new manufacture, in order to ensure that the rear angle of the dot of the cutting lip keep fixedness after the relieving shaped cutter is grinded. The paper derive the curve profile of tooth of the form cutter and the modifier calculation formula of the profile of the cutter edge from the definition of the rear angle of the cutter, which establish the foundation for the precision design and manufacture of other form cutter.展开更多
Playing a critical role in transmitting movement and power, the meshing performance of spiral bevel gears has a significant effect on products' operational performance. To evaluate the meshing performance, the acc...Playing a critical role in transmitting movement and power, the meshing performance of spiral bevel gears has a significant effect on products' operational performance. To evaluate the meshing performance, the accurate three-dimensional(3D) spiral bevel gear models are established through the Pro/E and MATLAB softwares, and the finite element analysis(FEA) methods are applied to the theoretical investigation of the influence of cutter diameter on meshing performance in spiral bevel gears. The results obtained show that the cutter diameter has a significant influence on spiral bevel gears' meshing performance, such as the contact area, contact pressure, bending stress, torsional stiffness and transmission error.展开更多
How to generate rake faces of nonconventional milling cutters (NCMC) with constant spiral angled and normal rake angled edges on NC machine tools is presented by use of a blunt cup grinder or a cup milling cutter. Mot...How to generate rake faces of nonconventional milling cutters (NCMC) with constant spiral angled and normal rake angled edges on NC machine tools is presented by use of a blunt cup grinder or a cup milling cutter. Motion functions of the NC machining system are mathematically deduced and exam- ed by a experiment. The research will provide theoretical and practical guidance for machining noncon- ventional tools on NC machine tools.展开更多
为了提高机械除草的作业效率、降低地头频繁调头引起的伤苗率,该文研制了3GY-1920型宽幅水田中耕除草机。该机由12 k W水田拖拉机提供动力,工作幅宽为5.7 m,一次作业可覆盖6行插秧机3个行程的作业宽度,并配备了4个双作用液压缸,控制整...为了提高机械除草的作业效率、降低地头频繁调头引起的伤苗率,该文研制了3GY-1920型宽幅水田中耕除草机。该机由12 k W水田拖拉机提供动力,工作幅宽为5.7 m,一次作业可覆盖6行插秧机3个行程的作业宽度,并配备了4个双作用液压缸,控制整个机架的展开闭合与除草轮位置的横向调节。该文结合水田土壤特性和现有除草部件的特点,通过对除草轮的运动学与显式动力学仿真分析,设计并优化了螺旋刀齿式样除草轮,该除草轮通过与土壤及杂草的剪切、翻耕作用实现中耕除草作业。田间除草试验结果表明:在机具不同前进速度(0.3、0.6、0.9 m/s)和除草轮入土深度(3、6、9 cm)条件下,该机平均除草率为82%,伤苗率为4.8%;根据机具作业速度和幅宽可知该机作业效率为0.6~1.8 hm2/h;整机工作性能和作业效率满足水稻田机械中耕除草作业的技术要求。机械除草与化学除草产量对比试验结果表明:在试验区域内,机械除草产量高于化学除草,该研究可为中耕除草对水稻田产量的影响提供参考。展开更多
文摘Form milling cutter is built-for-purpose cutter which process the form surface, for example, usually process male and female circular arc face and form trench and so on. From the traditional concept, form milling cutter is divided into pointed tooth and relieving follow its structure. Relieving shaped cutter is more convenient than pointed tooth milling cutter, because only its rake face is needed to grind after it turn into blunting, so the current books which are used in college almost select relieving shaped cutter in order to introduce how to design the form milling cutter.The curve of the back of tooth of relieving cutter is the transversal which is formed by the rear face of tooth in the end cut plane of the milling cutter. In the past, because of the limit of the manufacturing technology, the curve of the back of tooth is often selected Archimedes’ curve, in order that the shovel-nose tool acquire the uniform motion when the cutter shovel the back, in other word, the rear face of the milling cutter rotate its axis by the new cutting lip, in the same time, it move uniformly to the axis in order to form the surface. Although this curve of the back of tooth meet the fixedness of the form of blade around grinding the cutter, the rear angle of the dot of the cutting lip don’t keep fixedness. With the development of the modern manufacturing technology, the unmanageable problem of many complex curves is already easily solved. So it is need to study the optimum profile of the curve of the back of tooth in theory, and study the design theory of the relieving shaped cutter under the condition of new manufacture, in order to ensure that the rear angle of the dot of the cutting lip keep fixedness after the relieving shaped cutter is grinded. The paper derive the curve profile of tooth of the form cutter and the modifier calculation formula of the profile of the cutter edge from the definition of the rear angle of the cutter, which establish the foundation for the precision design and manufacture of other form cutter.
基金Project(51575416) supported by the National Natural Science Foundation of ChinaProject(IRT13087) supported by Innovative Research Team Development Program of Ministry of Education of China+1 种基金Project(2014CFB876) supported by the Natural Science Foundation of Hubei Province,ChinaProject(2012-86) supported by High-end Talent Leading Program of Hubei Province,China
文摘Playing a critical role in transmitting movement and power, the meshing performance of spiral bevel gears has a significant effect on products' operational performance. To evaluate the meshing performance, the accurate three-dimensional(3D) spiral bevel gear models are established through the Pro/E and MATLAB softwares, and the finite element analysis(FEA) methods are applied to the theoretical investigation of the influence of cutter diameter on meshing performance in spiral bevel gears. The results obtained show that the cutter diameter has a significant influence on spiral bevel gears' meshing performance, such as the contact area, contact pressure, bending stress, torsional stiffness and transmission error.
文摘How to generate rake faces of nonconventional milling cutters (NCMC) with constant spiral angled and normal rake angled edges on NC machine tools is presented by use of a blunt cup grinder or a cup milling cutter. Motion functions of the NC machining system are mathematically deduced and exam- ed by a experiment. The research will provide theoretical and practical guidance for machining noncon- ventional tools on NC machine tools.
