薄壁铜管游动芯头拉拔机上料系统关键技术及拉拔成形过程影响研究

发布时间：2018-06-28 10:09

本文选题：薄壁铜管 + 上料系统　；参考：《江西理工大学》2017年硕士论文

【摘要】：现有的薄壁铜管游动芯头拉拔机都采用人工进行上料,但人工上料不仅劳动强度大,而且生产效率低,已经不能满足现代工程的需要,要实现薄壁铜管游动芯头拉拔机自动上料存在两大技术难点,一是游动芯头穿芯定位精度高,二是因铜管长且挠度大造成铜管单根分选困难。同时,铜管缺陷和拉拔工艺参数等对拉拔成形具有较大的影响。因此,本文的研究具有良好的研究价值与应用前景。论文采用理论分析、数值模拟与试验分析相结合的方法完成以下工作:针对游动芯头穿进铜管装配问题,通过游动芯头穿芯空间误差分析,建立装配尺寸链并求解,确定游动芯头穿芯技术方案;针对大挠度铜管单根分选问题,对铜管分选进行动力学仿真分析,确定分选方案;完成拉拔机自动上料系统机械结构与控制系统设计;结合实际生产,对游动芯头拉拔过程进行有限元模拟分析。论文的主要研究结果:(1)对管坯、芯杆、游动芯头组成的空间装配系统进行分析,定量描述游动芯头穿芯空间定位误差,以游动芯头与铜管间隙为封闭环,建立铜管穿芯装配空间尺寸链,采用大数互换法对装配尺寸链实例求解说明,确定游动芯头穿芯方法和穿芯技术方案,即采用V型块定位,结合双旋自定心夹紧机构方式可完成芯头定位穿芯。(2)在分析单根铜管分选特征基础上,基于ADAMS建立铜管分选模型,以分选Φ106mm薄壁管材为例,探讨工艺参数(分选速度、倾斜角度、铜管挠度)对单根铜管分选技术指标(上升高度、分选完成时间、接触力)的影响,再基于ADAMS建立多根铜管分选模型,探讨工艺参数(分选速度、倾斜角度)对铜管分选效果(分选率、分选时间、重叠率)的影响,得到分选速度在400mm/s~800mm/s、倾斜角度在35°~40°分选效果较好,并通过试验验证。(3)在常规拉拔机的基础上,结合游动芯头穿芯技术方案和铜管分选装置仿真分析结果,将自动上料系统分为分选、输送、定位穿芯、双移位和送进5个模块,对每个模块进行结构设计,并完成上料系统控制系统初步设计。(4)针对铜管壁厚不均匀等问题,以H62合金为例,通过H62铜合金单向拉伸试验,采用弹粘塑性模型,构建H62铜合金本构模型,基于MARC软件对薄壁铜管游动芯头拉拔过程数值模拟,定量分析铜管壁厚波动与摩擦系数对拉拔过程(拉拔力、等效应力应变、芯头轴向运动)的影响,并对比分析游动芯头拉拔和固定芯头拉拔,发现游动芯头拉拔有助于提高产品质量。
[Abstract]:The existing thin-walled copper pipe moving core drawing machines use manual feeding, but the manual feeding not only has a large labor intensity, but also has low production efficiency, so it can not meet the needs of modern engineering. In order to realize the automatic feeding of thin wall copper pipe moving core drawing machine, there are two major technical difficulties: one is the high positioning accuracy of the swimming core head through the core, the other is the difficulty of single copper pipe sorting due to the long copper pipe and large deflection. At the same time, copper tube defects and drawing process parameters have great influence on drawing forming. Therefore, the research of this paper has good research value and application prospect. In this paper, the method of theoretical analysis, numerical simulation and experimental analysis is used to accomplish the following work: to solve the assembly problem of the floating core head, the dimension chain is established and solved by analyzing the spatial error of the swimming core head through the copper pipe. To solve the problem of single separation of large deflection copper pipe, the dynamic simulation analysis of copper pipe sorting is carried out to determine the separation scheme, and the mechanical structure and control system design of automatic feeding system of drawing machine are completed. Combined with the actual production, the drawing process of the moving core head is simulated and analyzed by finite element method. The main results of this paper are as follows: (1) the spatial assembly system composed of tube billet, core rod and swimming core head is analyzed, and the space positioning error of walking core head is quantitatively described. The gap between the swimming core head and copper pipe is taken as the closed ring. The space dimension chain of copper pipe through core assembly is established, and the example of assembly dimension chain is solved by large number exchange method. The core piercing method and the core piercing technique scheme are determined, that is, V-shaped block positioning is adopted. Combined with the double rotation self-centring clamping mechanism, the core head can be positioned through the core. (2) on the basis of analyzing the separation characteristics of a single copper pipe, the separation model of copper pipe is established based on Adams. Taking 桅 106mm thin wall pipe as an example, the process parameters (separation speed) are discussed. The influence of inclined angle, deflection of copper pipe on the technical index of single copper pipe separation (rising height, finishing time, contact force) is discussed. Based on Adams, the separation model of multiple copper pipes is established, and the process parameters (separation speed, separation speed) are discussed. The effect of inclined angle on the separation efficiency (separation rate, separation time, overlap rate) of copper pipe shows that the separation speed is 400 mm / s / s, and the inclination angle is 35 掳/ 40 掳, which is proved by experiments. (3) on the basis of conventional drawing machine, the separation speed is 400 mm / s / s and the angle is 35 掳/ 40 掳. (3) on the basis of conventional drawing machines, Combined with the technical scheme of core piercing and the result of simulation analysis of copper pipe sorting device, the automatic feeding system is divided into five modules: sorting, conveying, locating, double shifting and feeding into the core, and the structure of each module is designed. The control system of feeding system is designed. (4) aiming at the problem of uneven wall thickness of copper pipe, taking H62 alloy as an example, the constitutive model of H62 copper alloy is constructed by using elastic-viscoplastic model through uniaxial tensile test of H62 copper alloy. Based on the numerical simulation of the drawing process of the floating core of thin wall copper pipe by Marc software, the effects of wall thickness fluctuation and friction coefficient on the drawing process (drawing force, equivalent stress and strain, axial movement of the core head) are quantitatively analyzed. By comparing and analyzing the moving core head drawing and the fixed core head drawing, it is found that the swimming core head drawing is helpful to improve the product quality.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG356

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