【作者】 侯文君；

【导师】 孙涛；

【作者基本信息】 哈尔滨工业大学 ， 机械制造及其自动化， 2011， 硕士

【摘要】 内斜齿轮是各类发动机的重要部件,在其众多加工方式中,采用螺旋拉刀加工可以获得极高精度,因而越来越多的受到重视。虽然螺旋拉刀较普通直拉刀来说具有强度高、切削平稳等特点,但由于其结构的复杂性和其对精度的较高要求,其研制难度大。目前我国的螺旋拉刀还主要依靠进口,价格十分昂贵。因此目前急需从现有的技术条件出发,设计制造出可以达到国际领先的加工精度的螺旋拉刀。本文即针对上述内容做一探索性研究。首先,在研究拉削原理的基础上,针对现有拉削方式的不足提出改进方案,设计出可以达到更高加工精度的拉削方式。并以此拉削方式为基础,设计相应的齿形,并针对设计的齿形计算在设计齿升量下的拉削力;设计拉刀的齿距、容削槽尺寸等其他结构,并针对目前处于设计前沿的装配式拉刀提供设计方案。其次,利用有限元仿真软件对拉削过程进行仿真分析,针对不同的前角、后角和侧刃后角分别分组模拟仿真,测量在不同的角度下的拉削力,刀尖表面最大应力以及拉削热,通过综合比较,确定最优的刀具角度,并将仿真计算的切削力与理论计算的切削力作比较,验证两者的符合性;针对受力较大的齿侧精拉削齿进行强度校核,检验其最大应力和变形量是否满足要求,这对拉刀设计与制造十分重要。最后,确定螺旋拉刀的整个加工工艺流程,对其中的重点工序进行详细的分析。结合目前直齿拉刀广为采用的成形法磨削方式,解决因磨削斜齿而造成的砂轮廓型改变的问题,计算针对磨削螺旋拉刀的砂轮齿廓方程并进行曲线拟合。设计出便于工人进行齿形误差计算的交互式系统,主要涵盖量柱距、公法线和弦齿厚等常用检测项。并利用现有的检测条件,对现有的检测方法进行改进,以优化检测方案,使其可以适用于螺旋拉刀的螺旋线误差测量。更多还原

【Abstract】 Among the methods processing the engine helical gear in the industry, the spiral broach has much high machining accuracy, and people pay more and more attention to processing ability of complex surface. Although spriral broach has the advantage of high strength and firmly cutting ability compared to the common broach, but because of its structural complexity and much higher requirements on the precision, the spiral broach mainly relies on import in our country and the price is very expensive. The processing machine and the process methods take responsibility of limiting the spriral broach development. That is why we should design and manufacture the spiral broach which can achieve the international leading machining accuracy in the existing technology conditions. In this paper some research is done on spriral broach that based on the above content.Firstly, some improvement is made on the disadvantage of the cutting method and a new cutting method that can achieve higher accuracy based on the broaching principle is designed. The corresponding tooth shape is designed based on the cutting method, and the cutting force of the designed tooth is calculated. The distance of the tooth、the size of the let cut groove and so on are designed. This paper also provides the design scheme about the fabricated broach which is popular nowadays.Secondly, by the use of the finite element simulation software, the cutting force、the maximum stress on the tool nose and the cutting heat about different rake angle、different tool orthogonal clearance and the different side clearance is measured. By comparision, the optimal cutting angle is selected. Compared by the theoretical calculation, the result of the simulation calculation is found ture. The intensity of the side cutting teeth which bear larger cutting force is checked and their maximum stress and deformation is made sure whether meet the requirements.Thirdly, the whole process procedure of the spiral broach is formulated and the key processes is analysised in detail. Combining with the forming method that grinds the straight teeth, the problems caused by the changes of the shape of the grinding wheel are solved when grinding the helical gear. a convenient system is designed to calculate the tooth profile error. This system includes the calculation of the inner gear length bar size, the common normal line, the chordal thickness and so on. And by using the existing detection conditions, the current test method is improved and the detection scheme is optimized in this paper, which can measure the spirals error.更多还原