【作者】 黄城；

【导师】 李明哲；

【作者基本信息】 吉林大学 ， 材料加工工程， 2010， 硕士

【摘要】 柔性辊旋压成形为回转类板类件提供了新的加工方法,具有比传统旋压效率更高、精度更高、工作环境更好的优点,具有很好的研究价值。柔性辊旋压成形与板材之间的接触是线接触,成形区域为抛物线状,能够实现柔性化的连续局部成形,而且由于其柔性化不需要传统旋压中所必须的芯模,节省了大量的芯模制造成本。对于回转板类件的加工,柔性辊旋压成形是一种更符合现代工业生产要求的新型加工方式。本文对柔性辊旋压成形的原理和特点及研究现状进行了简单的介绍。介绍了柔性辊的调形方式,分别推导出上辊和下辊的辊单元的位移公式,根据得到的公式借助其他数据处理软件可以方便的得到每一个辊单元需要的位移数据。在ABAQUS中用动态显式算法对碟形件成形的过程进行了数值模拟。对旋转圈数作了模拟分析,探讨了旋压圈数对成形过程的影响。对不同曲率半径碟形件的成形过程做了模拟分析,对比了成形效果并作了具体分析。对不同下辊间距的旋压成形过程做了模拟,分析了不同下辊间距对成形的影响以及原因。模拟分析了两端柔性辊之间距离对成形的影响。模拟分析了两端柔性辊的下辊间距不相等时的成形过程,并与下辊间距相等时作了对比研究。模拟并对比分析了双组三辊、双组四辊、双组六辊旋压成形对起皱的抑制情况。更多还原

【Abstract】 The flexible-roller spinning technology to form axisymmetric three-dimensional surface is based on the idea of multi-point forming technology .The main idea of multi-point forming technology is to discrete the overall die into many respectively independent small units. In the flexible-roller spinning technology, this idea is reflected as to switch the spinning roll in the traditional spinning into flexible roll of the flexible-roller spinning, using many points set on the flexible roll to control the flexible roll to form all kinds of curves which are needed in the forming process of all kinds of axisymmetric three-dimensional surfaces. The flexible-roller spinning technology to form axisymmetric three-dimensional surface is developed by the traditional spinning, merges the advantages of multi-point forming technology and the traditional spinning , enables continuous line forming, greatly enhances processing efficiency, greatly improved the inefficient and only small-batch production shortcomings of traditional Spinning. The contact type of flexible-roller spinning with the plate is linear contact, forming a parabolic-shaped region; this is favorable to achieve a continuous flexible partial forming. And because of its flexibility, the core module of conventional spinning is not needed, saved a lot of core module manufacturing costs. The flexible-roller spinning technology provides a new method for sheet metal forming process of axisymmetric three-dimensional surface,it is more efficient,has higher accuracy and better working environment than conventional spinning,so that it also has very good value of research and economic value. The flexible-roller spinning technology to form axisymmetric three-dimensional surface is a kind of new process that meets the requirements of modern industrial production.It used ABAQUS/Explicit numerical simulation to analyze the process of disc part formed by dual three-roller flexible-roller spinning equipment in this paper. It analyzed how the flexible roll go to contact with the goal parts of the surface of disc, and established the mathematical model of spatial displacement of unit roller, and thus respectively deduces the spatial displacement formula of each unit roller of upper roller and Lower roller. It also analyzed the mechanism of how different flexible-rollers layout to affect the forming of dish pieces.The main contents and results are as follows:1)Established the finite element model of the process of dual three-roller flexible-roller spinning system forming dish parts. It used 1010 steel as the material of the plate, introduced the material properties of 1010 steel; Showed the concrete steps of process of dual three-roller flexible-roller spinning system forming dish parts, and thus decide the simulation steps. The entire process is divided into three steps: The first step, is the step to adjust the form of flexible-roller. The second is the step that flexible-rollers drive plate to rotate. The last step is the uninstall process of the system; It established the local coordinate system of unit roller according to the need of numerical simulation; It chose reasonable contacts according to the real situation and the need of numerical simulation; It identified a reasonable pseudo-velocity as 1.35rad/ms.It properly meshed plate, unit roller, and centering institution, the plate was meshed into 9447 units, the unit roller was meshed into 26 units, and centering institution was meshed into 231 units; It identified the motion load in different analysis step according to the need of Mora of flexible-roller and the rotation of plate. As there are too many unit roller, number of the load motion and rotation motion that needed be imported into the model is very large, it innovatively merged data processing software and command statement of ABAQUS, that dramatically lowed the work to import the load motion and rotation motion into the model, and improved the accuracy of input.2) Established mathematical model of flexible roll go to contact with the goal parts of the surface of disc. Introduced the principles and methods of flexible roll go to contact with the goal parts of the surface of disc, deduced the displacement process and the way of unit rollers which are discreted by flexible roll, and thus established the Mathematical model of displacement of each unit roller of upper roller and Lower roller, and further deduced the spatial displacement formula of each unit roller of upper roller and Lower roller. Thus find the law of displacement of each unit roller; this is a key to these displacement data processing in data processing software.3)Analyzed the results of forming simulation with different number of spinning turns in the spinning process to a disc,and the conclusion is: when different space between down rollers is certain,to form a disc with certain radius of curvature,more the number of turns is,more perfect the effect of spinning is. But when the turns is more than two, the extent of Tran shape is very small, the number of spinning turns is set as two in the numerical simulation in this paper so as to save computing resources.4)Analyzed the results of simulation of forming process with certain space between down rollers which is to form discs with different radius of curvature, and the conclusion is: when the space between down rollers is certain, there is a interval for the radius of curvature of discs ,and if the radius of curvature of disc was in this interval ,the effect of the forming is perfect. If the radius is too large, the plate would not be formed well because the lack of forming force. If the radius is too small, the disc which is formed would show a lot of wrinkles because of plastic instability which is caused by that the force of constraint of flexible-rollers to the plate would be too small. And if the radius goes further larger, the process would not going on because of the contact between plate and flexible-rollers is not enough to get the plate turn round.5)Analyzed the results of simulation of forming process with certain radius of curvature which is to form discs with different space between down rollers, and the conclusion is: when the radius of curvature is certain, there is a interval for the space between down rollers of discs ,and if space between down rollers of disc was in this interval ,the effect of the forming was perfect. If the space is too small, the forming force in the effective forming zone would be too small, and the great mass of forming force is centralized in blend zone, and that resulting in the plate would not be formed well. If the space is too big, the force of constraint of flexible-rollers to the plate would become too small, because the disc which is formed would show a lot of wrinkles because of plastic instability. And the space go further bigger, ,the process would not going on because of the contact between plate and flexible-rollers is not enough to get the plate turn round.6) Analyzed the results of simulation of forming process which is to form discs with certain radius of curvature under the situation of the dual three-roller flexible-roller spinning system has unequal space between down rollers in each side, and compared with the situation that space between down rollers in each side is equal, and studied the mechanism. The conclusion is: if the space is properly chose, the dual three-roller flexible-roller spinning system will effectively improved the defects that the system with certain equal space between down rollers in each side can not form the disc in good shape or the disc formed has a lot of wrinkles.7)Simulated the forming process to form discs respectively with dual three-roller flexible-roller spinning system, dual four-roller flexible-roller spinning system, dual six-roller flexible-roller spinning system ,and compared the production and remove of wrinkles in these system, and analyzed these phenomenon . Here is the conclusion: if the space between down rollers is too big, wrinkles would show in the discs that formed by dual three-roller flexible-roller spinning system, the dual four-roller flexible-roller spinning system has more control to the production of wrinkles than the dual three-roller flexible-roller spinning system, the dual six-roller flexible-roller spinning system has more control to the production of wrinkles than the dual four-roller flexible-roller spinning system, it can deduce that more flexible-rollers is helpful to the remove of wrinkles in spinning system.更多还原