弧齿锥齿轮齿面精锻成形技术研究

发布时间：2018-01-22 07:08

本文关键词： 弧齿锥齿轮精锻成形齿面修形出模　出处：《河南科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：弧齿锥齿轮因齿面节线为曲线而得名,具有传动时局部瞬时点接触、啮合重合度大、传动平稳等优点。弧齿锥齿轮传统的加工方式为铣齿加工,加工效率低,材料利用率低,而精锻成形工艺对于发展高效、绿色、轻量化设计具有重要意义,解决了大批量生产过程中的质量及成本控制问题。针对弧齿锥齿轮大轮齿面的冷挤压净成形工艺,本文的主要研究内容如下:1根据局部共轭原理,齿面接触仿真与预控技术,保证齿轮副具有良好的齿面啮合性能,得到大小轮的齿面点数据,构造出齿面片。由基本的几何参数得到毛坯模型,通过建模里的求差命令得到大轮模型,以此建立凹模模型。预锻模具齿面的合理修形将直接影响冷挤压锻件的齿面精度,通过改变铣齿刀盘的直径,在保证几何参数不变的前提下,改变齿长曲率半径,对齿面进行修形,由此可得到一组预锻鼓形齿腔的凹模,为有限元模拟成形过程做准备。2本文拟采取的加工组合为:弧齿锥齿轮大轮的齿面由热锻近净成形-冷挤压净成形两次加工,小轮齿面采用常规展成法配对铣齿成形工艺。针对弧齿锥齿轮结构的特殊性,对可行性方案进行探讨,主要针对齿腔金属的填充性和成形后能否顺利出模展开研究。基于闭式模锻成形原理,对坯料的形状体积和模具的结构进行优化设计。3通过DEFORM-3D软件对弧齿锥齿轮大轮进行热锻近净成形-冷挤压净成形的过程模拟分析,设置模拟环境,材料属性及运动关系,在齿面存在回弹变形的条件下,分析出模的可行性及找到干涉点。在保证齿面金属充满模具型腔的基础上,通过对预锻齿面的修形,改变金属流线方向,降低冷挤压力,提高齿面的光洁度。4通过进行实际热锻近净成形-冷挤压净成形试验,对成形工艺及模具修形的方案进行验证,论述了通过对热锻模齿腔的修形,改变金属流向的方法,对于解决弧齿锥齿轮冷挤压净成形齿面精度的优越性。根据凹模的结构特点,提出了齿根圆角修形的工艺方案,解决了出模干涉的问题。由试验样件外观及精度检测结果可以看出,锻件齿形饱满,形状准确,表面光洁度好,无明显缺陷。本文围绕弧齿锥齿轮大轮的齿面冷挤压净成形工艺,开展了相关理论研究和试验研究,本文的研究为弧齿锥齿轮高效、绿色制造的理论和工艺实践奠定了基础。
[Abstract]:The arc bevel gear is named for the curve of the tooth surface, which has the advantages of local instantaneous point contact, large meshing overlap, stable transmission and so on. The traditional machining method of arc bevel gear is milling, and the machining efficiency is low. The material utilization ratio is low, and the precision forging process is of great significance for the development of high efficiency, green and lightweight design. The problem of quality and cost control in mass production is solved. In view of the cold extrusion net forming process of large tooth surface of arc bevel gear, the main research contents of this paper are as follows: 1 according to the local conjugate principle. The tooth surface contact simulation and pre-control technology ensure that the gear pair has good meshing performance of tooth surface, get the tooth surface point data of the big and small wheel, construct the tooth surface sheet, and get the blank model from the basic geometric parameters. The large wheel model is obtained by the difference command in the modeling, and the concave die model is established. The reasonable modification of the tooth surface of the pre-forging die will directly affect the precision of the tooth surface of the cold extrusion forgings, and the diameter of the cutter head of the milling tooth will be changed. On the premise of keeping the geometric parameters unchanged, the tooth surface can be modified by changing the radius of curvature of the tooth length, and a group of die for pre-forging drum tooth cavity can be obtained. In order to simulate the forming process of finite element, the machining combination proposed in this paper is as follows: the tooth surface of the arc bevel gear is machined twice by hot forging near net forming and cold extrusion net forming. The common generating method is used to form the gear surface of the small wheel. The feasibility scheme is discussed according to the particularity of the structure of the spiral bevel gear. Based on the theory of closed die forging, this paper mainly focuses on the filling property of metal in tooth cavity and whether the die can be produced smoothly after forming. The shape and volume of the blank and the structure of the die were optimized. 3. The simulation analysis of the process of hot forging near net forming and cold extrusion net forming of arc bevel gear was carried out by DEFORM-3D software. The simulation environment, material properties and motion relations are set up. The feasibility of the die is analyzed and the interference point is found under the condition that the tooth surface has springback deformation. On the basis of ensuring that the tooth surface metal is filled with the die cavity. By modifying the preforged tooth surface, changing the direction of the metal streamline, reducing the cold extrusion pressure and improving the finish of the tooth surface, through the actual hot forging near net formation-cold extrusion net forming test. The forming process and the plan of die modification are verified, and the method of changing metal flow direction by modifying the tooth cavity of hot forging die is discussed. According to the structure characteristics of the concave die, the technological scheme of tooth root fillet modification is put forward for solving the superiority of tooth surface precision of cold extrusion of arc bevel gear. From the test results of the appearance and precision of the sample, it can be seen that the forging tooth shape is full, the shape is accurate, and the surface finish is good. There is no obvious defect. This paper focuses on the tooth surface cold extrusion net forming technology of arc bevel gear, and carries out related theoretical and experimental research. The research in this paper is high efficiency of arc bevel gear. The theory and process practice of green manufacturing have laid the foundation.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG61

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