薄板深孔内螺纹成形仿真分析

发布时间：2019-04-02 18:33

【摘要】：随着这些年机械行业突飞猛进的发展,新兴的绿色加工方式将会成为机械行业的发展方向。现阶段,螺纹孔的成形方式大多采用切削的方式通过去除多余的材料而成形内螺纹,本文是在利用摩擦热挤压出孔深大于板厚的光孔上加工孔内螺纹。根据光孔壁厚度的差异,分别利用热挤压和内高压这两种方法成形孔内螺纹。这两种加工方式都是利用了金属的塑性变形,在成形过程中不会产生废屑,并且得到的成形件有合理的流线分布,机械性能更好。本文通过分析热挤压成形和内高压成形内螺纹的基本原理及成形特点,预见了在成形过程中可能出现的质量缺陷,为下面模拟工作中解决成形时出现的质量缺陷提供了理论依据。对热挤压成形内螺纹进行有限元模拟,分析了成形过程中的应力、应变的分布情况,扭矩载荷的变化规律,金属的流动方向,温度的变化规律。采用单因素循环法研究主要参数对热挤压成形过程的影响,最终确定合理的参数并进行了试验验证。对内高压成形内螺纹的过程进行有限元模拟,分析了成形过程中壁厚的变化、应变的分布、成形过程中能量的变化规律。研究了主要参数对螺纹质量的影响。在不影响成形件的尺寸和性能的前提下,应该尽量选择过渡区圆角半径大的模具。在加工过程中尽量减少摩擦力的影响。为满足成形要求,左右冲头选择双线性的进给方式,第一阶段充分进给,第二阶段选择少量进给。为了提高成形质量,内压力的加载分为两个阶段,第一阶段负责成形,第二阶段负责整形。本文不但对成形过程进行了系统分析,还对影响成形质量的因素进行了深入的研究,为实际生产中提高成型件质量提供了保障。
[Abstract]:With the rapid development of the machinery industry in recent years, the new green processing will become the development direction of the machinery industry. At present, the screw thread is formed by cutting the screw hole by removing the excess material. In this paper, the inner thread is machined on the smooth hole with the hole depth greater than the plate thickness by using friction heat extruding out the hole depth is greater than the thickness of the plate. According to the difference of the thickness of the hole wall, hot extrusion and internal high pressure are used to form the inner thread of the hole respectively. These two kinds of machining methods make use of the plastic deformation of metal, do not produce waste chips in the forming process, and get the forming parts have reasonable streamline distribution, and the mechanical properties are better. Based on the analysis of the basic principles and forming characteristics of hot extrusion forming and internal high pressure forming of internal threads, the possible quality defects in the forming process are predicted. It provides a theoretical basis for solving the quality defects in forming in the following simulation work. The distribution of stress and strain, the variation of torque load, the direction of metal flow and the change of temperature in hot extrusion forming process are analyzed by finite element simulation. The influence of main parameters on hot extrusion forming process was studied by single factor cycle method. Finally, reasonable parameters were determined and verified by experiments. The process of internal high pressure forming is simulated by finite element method. The variation of wall thickness, the distribution of strain and the variation of energy in forming process are analyzed. The effect of main parameters on thread quality is studied. On the premise that the size and performance of forming parts are not affected, the die with large fillet radius in transition zone should be selected as far as possible. Minimize the impact of friction during machining. In order to meet the forming requirements, the left and right punches choose bilinear feed mode, the first stage full feed, the second stage select a small amount of feed. In order to improve the forming quality, the loading of internal pressure is divided into two stages, the first stage is responsible for forming, the second stage is responsible for shaping. In this paper, not only the forming process is analyzed systematically, but also the factors affecting the forming quality are deeply studied, which provides the guarantee for improving the quality of the forming parts in practical production.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG62

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