圆锯片的辊压适张机理及其工艺研究

发布时间：2018-01-14 16:18

本文关键词：圆锯片的辊压适张机理及其工艺研究　出处：《北京科技大学》2017年博士论文　论文类型：学位论文

【摘要】：圆锯片是工业行业中的一种广泛使用的加工工具,它被应用于加工木材、石材、钢材及混凝土等等多个领域。圆锯片是一种比较典型的薄片刀具,它的最主要的结构和工作特征是:厚度一般比直径小得多并且需要承受高速切削的极端工作条件。这些因素会严重影响到锯片的稳定性,导致锯片在加工过程当中发生强烈振动,影响锯片工作的加工精度和使用寿命。为了提高锯片的切削稳定性,可以通过应用适张原理的一些典型方法对锯片进行处理,比如锤击法、辊压法、喷丸法、加热法及胀孔法等,在这些处理方法当中,辊压法具有高效率、操作简单等一系列优点。本论文集中于研究辊压适张原理及其工艺,采用有限元方法建立了辊压模型,通过有限元数值模拟对辊压压力、辊压位置、压辊半径等工艺参数对其残余应力分布和刚度的影响进行了研究;通过理论计算、数值模拟及现场实验综合运用的手段对不同工艺参数下锯片的应力分布及其刚度特性进行了研究。本论文为圆锯片的辊压制造提供了相关理论依据及高效的加工处理方法,有助于提高圆锯片的刚度、稳定性和促进锯片生产的工艺水平。本文主要创新性成果体现在以下几个方面:(1)从理论上和仿真上解释了锯片应力工程测试方法的机理。利用有限元分析获得了检测参数及锯片内应力状态对检测特征曲线的影响。(2)采用理论公式计算了圆锯片周向应力和径向应力随不同辊压位置、辊压压力、压辊半径的变化规律。不同辊压位置:辊压位置越靠近内孔,辊压区内的周向压应力就越大,外沿部分的周向拉应力越小;辊压位置越靠近内孔处辊压,辊压区内部的径向压应力就越大,外沿部分的径向压应力越小。不同半径压辊辊压:相同辊压压力下,压辊半径越小,锯片的残余应力就越大,即用较小辊压半径的压辊辊压锯片可以获得更大的残余应力分布。(3)建立了圆锯片的辊压适张仿真模拟模型,并对锯片在辊压后的残余应力分布情况及其检测特征曲线进行了分析。分析结果表明辊压适张过程导致锯片的横向刚度减少,即辊压压力越大锯片的横向刚度越小,且辊压压力越大锯片的横向刚度变化范围越大(31172～18660)N/m;在相同辊压压力下,压辊的半径越大辊压后锯片的刚度就越大,在压辊半径为62mm时达到14955.8N/m。(4)通过现场辊压实验研究了锯片辊压时应力圆变化的规律,分别考虑了辊压压力、辊压道次、辊压位置以及局部辊压过程的影响因素,总结了辊压道次和局部辊压对应力圆的影响特征。
[Abstract]:Circular saw blade is a widely used processing tool in industrial industry. It is used in many fields such as wood, stone, steel and concrete. Circular saw blade is a typical thin blade tool. Its main structure and working characteristics are that the thickness is generally much smaller than the diameter and it needs to bear the extreme working conditions of high speed cutting. These factors will seriously affect the stability of the saw blade. In order to improve the cutting stability of the saw blade, the cutting accuracy and service life of the saw blade are affected by the strong vibration of the saw blade during the machining process. The saw blade can be treated by some typical methods of tensioning principle, such as hammering, roll pressing, shot peening, heating and expanding hole, etc. Among these methods, roll pressing has high efficiency. A series of advantages such as simple operation and so on. In this paper, the principle and process of roll compression are studied, and the roll compression model is established by using finite element method. The roll pressure and position are simulated by finite element method. The influence of process parameters such as roll radius on residual stress distribution and stiffness was studied. Through theoretical calculations. The stress distribution and stiffness characteristics of saw blade under different technological parameters are studied by means of numerical simulation and field experiment. This paper provides relevant theoretical basis and efficient processing for roller pressing manufacture of circular saw blade. Handling methods. It helps to improve the rigidity of circular saw blade. Stability and the technological level of promoting the production of saw Blade. The main innovative achievements of this paper are as follows: 1). The mechanism of stress engineering testing method of saw blade is explained in theory and simulation. The influence of testing parameters and stress state of saw blade on the characteristic curve of saw blade is obtained by using finite element analysis. The circular and radial stresses of circular saw blades are calculated with different roll pressure positions by theoretical formula. Different roll pressure positions: the closer the roll pressure position is to the inner hole, the greater the circumferential compressive stress in the roll pressing zone is, and the smaller the circumferential tensile stress is in the outer part; The closer the position of roll pressure is to the inner hole, the greater the radial pressure stress is, and the smaller the radial pressure stress is in the outer part. The larger the residual stress of the saw blade is, the greater the residual stress distribution can be obtained by using the smaller roll pressing radius of the saw blade.) the simulation model of roll compression tension of circular saw blade is established. The distribution of residual stress and the characteristic curve of the saw blade after roll pressing are analyzed. The results show that the transverse stiffness of the saw blade decreases during the process of roll compression. That is, the bigger the roll pressure is, the smaller the lateral stiffness of the saw blade is, and the larger the lateral stiffness of the saw blade is, the larger the variation range of the lateral stiffness of the saw blade is. Under the same pressure, the larger the radius of the roller, the greater the stiffness of the saw blade. At 62mm radius of pressing roller, 14955.8N / m 路m ~ (4)) the variation of stress circle of saw blade roll was studied by in-situ roll pressing experiment, and the roll pressure and pass times were considered respectively. The influence factors of roll pressure position and local roll pressing process are summarized, and the influence characteristics of roll pass and local roll pressure on stress circle are summarized.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TG717;TG306

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