无轴折弯机构的探索与研究

发布时间：2018-07-29 14:33

【摘要】：在基础工业生产中,板料折弯机的运用十分广泛。折弯机构作为板料折弯机中最为关键的机构,其设计与研究对满足制造业的多样化需求有着重大的意义。本文针对传统折弯机,工作形式单一、自动化程度不高、易对板料造成伤害等缺点,提出一种新型的无轴折弯机构。在铰链六杆机构的基础上建立了新型折弯机构的简图,并运用三维建模软件建立折弯机的简单模型,对该机构的工作形式以及应用情况进行了说明。在理论分析上,本文采用复数矢量法建立运动学模型,并推导出折弯机构在工作过程中,各位置点的运动轨迹、速度、加速度等运动学性能;再依据达朗贝尔原理,对机构进行动态静力分析,得到了铰点、重心坐标与力之间的关系式。为使加工件能得到较好的折弯效果,本文以折弯旋转点的轨迹为目标函数,并将机构的相关铰点坐标与杆长定为设计变量,结合折弯设备的实际性要求确立了约束条件。运用虚拟样机技术建立折弯机构参数化模型,对机构杆组进行了优化。优化结果显示在折弯角度为90度的情况下,折弯板旋转点x轴坐标的偏移量在0.4mm以内,对折弯效果的影响可忽略不计,折弯板旋转点y轴坐标偏移较大,但该坐标的变化对折弯效果影响较小,可通过外部方式得到补偿。根据优化设计结果,对折弯机构进行运动学仿真分析,确定机构在全工况下各构件的位移、转角、转速、转角加速度,并对所得数据进行了分析;通过动力学仿真确定各铰点在x轴和y轴的受力情况,对各构件的受力情况进行了分析。本文基于上述研究,通过理论分析和机构仿真,所提出的新型折弯机构方案具有一定的可行性,在折弯形式扩展方面具有显著优势。
[Abstract]:In the basic industrial production, sheet metal bending machine is widely used. As the most important mechanism in sheet metal bending machine, the design and research of bending mechanism is of great significance to meet the diversified needs of manufacturing industry. Aiming at the shortcomings of traditional bending machine, such as single working form, low degree of automation and easily causing damage to sheet metal, a new type of shaftless bending mechanism is proposed in this paper. On the basis of the hinged six-bar mechanism, the simplified diagram of the new bending mechanism is established, and the simple model of the bending machine is established by using the three-dimensional modeling software. The working form and application of the mechanism are explained. In the theoretical analysis, the kinematics model is established by using complex vector method, and the kinematics performance of the bending mechanism at each position, such as trajectory, velocity, acceleration and so on, is deduced, and then according to the principle of Darembert, the kinematics performance of the bending mechanism is deduced. The dynamic static analysis of the mechanism is carried out, and the relationship among hinge point, barycenter coordinate and force is obtained. In order to obtain better bending effect, the trajectory of bending rotation point is taken as the objective function, and the coordinate of the relevant hinge point and the length of the rod are taken as the design variables, and the constraint conditions are established according to the practical requirements of the bending equipment. The parametric model of bending mechanism is established by using virtual prototyping technology, and the bar group of the mechanism is optimized. The optimized results show that the deviation of the x axis coordinate of the bending plate rotation point is within 0.4mm, and the influence on the bending effect can be ignored, and the y axis coordinate deviation of the bending plate rotation point is larger, the optimization result shows that the bending angle is 90 degrees, and the deviation of the x axis coordinate of the bending plate rotation point is within 0.4mm, and the influence on the bending effect can be ignored. However, the change of coordinate has little effect on bending effect and can be compensated by external method. According to the results of optimal design, the kinematics simulation analysis of the bending mechanism is carried out to determine the displacement, rotation angle, rotational speed and angular acceleration of each component of the mechanism under all working conditions, and the obtained data are analyzed. The dynamic simulation is used to determine the stress on the x axis and y axis, and the stress of each member is analyzed. Based on the above research, through theoretical analysis and mechanism simulation, the proposed new bending mechanism scheme is feasible and has significant advantages in bending expansion.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG305

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