拼焊板帽形件弯曲焊缝移动及回弹控制
发布时间：2019-07-06 17:53
【摘要】：面对环境污染、能源短缺等一系列问题,实现汽车轻量化成为汽车行业发展的必然趋势。由于采用拼焊板冲压成形的零件装配汽车,能在很大程度上减轻车重,降低生产成本,因此拼焊板冲压成形技术在汽车行业中的应用越来越广泛。拼焊板在弯曲成形过程中由于板厚的差异、材料的差异、焊缝及其热影响区等因素的影响会产生焊缝移动、回弹等缺陷,这些缺陷严重影响弯曲件的尺寸精度,降低产品质量,因此对拼焊板弯曲成形过程中的焊缝移动和回弹进行研究具有重要的意义。在拼焊板弯曲件中,以帽形件最为典型,为有效控制拼焊板帽形件在弯曲成形过程中的焊缝移动和回弹问题,本文以横向拼焊板帽形件和纵向拼焊板帽形件为研究对象,首先建立了各自的有限元模型,并利用有限元软件DYNAFORM对其弯曲成形过程以及卸载后的回弹过程进行数值模拟,主要分析了压边力、摩擦系数、凸模圆角半径、凹模圆角半径、料厚比对焊缝移动和回弹的影响。此外对焊缝不在中间位置的横、纵向拼焊板帽形件(焊缝偏向薄侧或偏向厚侧)进行了研究,得到了压边力、料厚比和焊缝位置对其弯曲成形的影响。本文对压边力进行了详细的研究,研究了薄厚侧不同组合的恒压边力对焊缝移动和回弹的影响,在此基础上研究了变压边力中初始压边力、压边力随凸模行程变化点以及高压边力对焊缝移动和回弹的影响。基于以上研究,针对横、纵向拼焊板帽形件和横、纵向非对称拼焊板帽形件的弯曲成形,提出了可以有效减小焊缝移动和回弹的方法:成形初期施加较小且合理的薄厚侧压边力组合,保证焊缝移动较小,当凸模行程接近总的弯曲行程时,同时增大薄厚侧压边力,使回弹减小。
文内图片：
图片说明：轿车车体结构中拼焊板的使用情况
[Abstract]:In the face of a series of problems, such as environmental pollution, energy shortage and so on, the realization of automobile lightweight has become an inevitable trend in the development of automobile industry. Because the assembly of parts with welded plate can reduce the weight of the car and reduce the production cost to a great extent, the stamping technology of welded plate is more and more widely used in the automobile industry. Due to the difference of plate thickness, material, weld and its heat affected zone, the defects such as weld movement and springback will occur in the bending process of welded plate. These defects seriously affect the dimensional accuracy of bending parts and reduce the product quality. Therefore, it is of great significance to study the weld movement and springback in the bending forming process of welded plate. In order to effectively control the weld movement and springback of welded plate cap parts in bending forming process, the finite element models of transverse welded plate cap parts and longitudinal welded plate cap parts are established, and the bending forming process and springback process after unloading are simulated by using the finite element software DYNAFORM, and the blank holder force is mainly analyzed in this paper. Effects of friction coefficient, punch fillet radius, concave die fillet radius and material thickness ratio on weld movement and springback. In addition, the effects of blank holder force, material thickness ratio and weld position on the bending forming of transverse and longitudinal welded plate cap parts (weld inclined to thin side or inclined to thick side) where the weld is not in the middle position are studied. In this paper, the blank holder force is studied in detail, and the effects of different combinations of constant blank holder force on weld movement and springback are studied. on this basis, the effects of the initial blank holder force, the change point of blank holder force with punch stroke and the high pressure edge force on weld movement and springback in variable blank holder force are studied. Based on the above research, aiming at the bending forming of transverse, longitudinal welded plate cap parts and transverse, longitudinal asymmetric welded plate cap parts, a method is proposed, which can effectively reduce the weld movement and springback: in the initial stage of forming, a small and reasonable combination of thin and thick side blank holder force is applied to ensure the small weld movement. When the punch stroke is close to the total bending stroke, the thin and thick side blank holder force is increased at the same time, and the springback is reduced.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG386
本文编号：2511225
文内图片：
图片说明：轿车车体结构中拼焊板的使用情况
[Abstract]:In the face of a series of problems, such as environmental pollution, energy shortage and so on, the realization of automobile lightweight has become an inevitable trend in the development of automobile industry. Because the assembly of parts with welded plate can reduce the weight of the car and reduce the production cost to a great extent, the stamping technology of welded plate is more and more widely used in the automobile industry. Due to the difference of plate thickness, material, weld and its heat affected zone, the defects such as weld movement and springback will occur in the bending process of welded plate. These defects seriously affect the dimensional accuracy of bending parts and reduce the product quality. Therefore, it is of great significance to study the weld movement and springback in the bending forming process of welded plate. In order to effectively control the weld movement and springback of welded plate cap parts in bending forming process, the finite element models of transverse welded plate cap parts and longitudinal welded plate cap parts are established, and the bending forming process and springback process after unloading are simulated by using the finite element software DYNAFORM, and the blank holder force is mainly analyzed in this paper. Effects of friction coefficient, punch fillet radius, concave die fillet radius and material thickness ratio on weld movement and springback. In addition, the effects of blank holder force, material thickness ratio and weld position on the bending forming of transverse and longitudinal welded plate cap parts (weld inclined to thin side or inclined to thick side) where the weld is not in the middle position are studied. In this paper, the blank holder force is studied in detail, and the effects of different combinations of constant blank holder force on weld movement and springback are studied. on this basis, the effects of the initial blank holder force, the change point of blank holder force with punch stroke and the high pressure edge force on weld movement and springback in variable blank holder force are studied. Based on the above research, aiming at the bending forming of transverse, longitudinal welded plate cap parts and transverse, longitudinal asymmetric welded plate cap parts, a method is proposed, which can effectively reduce the weld movement and springback: in the initial stage of forming, a small and reasonable combination of thin and thick side blank holder force is applied to ensure the small weld movement. When the punch stroke is close to the total bending stroke, the thin and thick side blank holder force is increased at the same time, and the springback is reduced.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG386
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