杠杆式高速精密数控冲床机构的精度分析与设计

发布时间：2018-03-19 12:27

本文选题：高速冲床　切入点：精度　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着技术的革新,现代冲压向着高速化和精密化方向发展,本文从机构原理的创新设计入手,提出一种新型杠杆式高速冲床机构,重点研究该机构的精度问题,论文主要完成了以下几个方面的研究:基于目前曲柄滑块式高速压力机原理机构不足,提出一种杠杆式机构,该机构最大的特点在于能够避免主副滑块因高速运动时产生水平分力,而不是像平衡惯性力那样平衡水平分力,这样有效减少机身周期性的振动,也极大的减少了主副滑块与机身摩擦所产生的一大部分热量。此外,杠杆式机构简单,不需要进行运动学参数的优化,可极大简化设计过程。建立原理机构的运动学模型,得到机构运动学参数方程,依据同类型冲床设计各个杆件截面及长度的尺寸参数。运用达朗贝尔原理对机构自身的动平衡设计计算,得到杆件受力参数。随后对机床的动平衡进行分析设计,并建立实体样机模型。根据机床各个杆件的尺寸参数,按弹性体计算各杆件处于下死点受力状态时的弹性变形量,并由传动链得到下死点的偏移量。基于经典Hertz理论和Persson理论,分别建立求解运动副接触刚度的模型与方程。选取算例计算接触变形量,由此计算接触刚度,并分析不同转速下的运动副接触刚度的规律。同时根据各运动副配合实体模型,由ANSYS有限元分析计算出运动副的接触刚度,并与理论结果进行对比验证。运动副高速转动摩擦产生大量热,导致零件的变形,严重影响了机构的精度。根据传热学原理计算机床冷却系统与运动机构的冷却换热系数,并采用能量平衡法建立计算求解运动副温度场的有限差分方程,由温度场得到运动副间隙尺寸变化。同时研究了主传动机构、机身上梁温度对下死点精度的影响,以及立柱的温度对下死点的精度补偿。对机身的振动响应研究建立在已知实体样机模型以及机身所承受载荷基础之上。将样机模型导入ANSYS软件,傅里叶变换机身载荷曲线并加载。以机身轴承座孔处的节点振动响应情况来反映机身振动,并以此表示下死点的振动规律,另外分析了不同转速以及不同载荷下的下死点振动响应规律。
[Abstract]:With the innovation of technology and the development of modern stamping towards high speed and precision, this paper starts with the innovative design of mechanism principle, and puts forward a new type of lever type high speed punching mechanism, focusing on the precision of the mechanism. In this paper, the following aspects have been studied: based on the shortage of the principle of crank and slider high speed press, a kind of lever mechanism is put forward. The main characteristic of the mechanism is that it can avoid the horizontal component force produced by the main and auxiliary slider when moving at high speed, instead of balancing the horizontal component force as the balance inertial force, which effectively reduces the periodic vibration of the fuselage. In addition, the lever mechanism is simple and does not need to optimize the kinematics parameters, which greatly simplifies the design process, and establishes the kinematics model of the principle mechanism. The kinematics parameter equation of the mechanism is obtained, and the dimension parameters of each member section and length are designed according to the same type punching machine. The dynamic balance design of the mechanism itself is calculated by using the Darumbelian principle. Then the dynamic balance of the machine tool is analyzed and designed, and the model of the solid prototype is established. According to the dimension parameters of each member of the machine tool, the elastic deformation of each member is calculated according to the elastic body when the member is in the state of stress at the lower dead point. Based on the classical Hertz theory and the Persson theory, the models and equations for solving the contact stiffness of the kinematic pair are established, and the contact deformation is calculated by selecting an example to calculate the contact stiffness. At the same time, the contact stiffness of the pair is calculated by ANSYS finite element analysis according to the solid model of each pair. The results are compared with the theoretical results. A large amount of heat is produced by the high speed rotational friction of the moving pair, which results in the deformation of the parts, which seriously affects the accuracy of the mechanism. According to the principle of heat transfer, the cooling heat transfer coefficient between the cooling system of the computer bed and the moving mechanism is calculated. Using the energy balance method, the finite difference equation is established to solve the temperature field of the moving pair. The change of the clearance size of the pair is obtained from the temperature field. At the same time, the influence of the temperature of the main transmission mechanism and the upper beam of the fuselage on the precision of the lower dead point is studied. The vibration response of the fuselage is based on the known solid prototype model and the load borne by the fuselage. The prototype model is imported into ANSYS software. Fourier transform the fuselage load curve and load. The vibration response of the node at the hole of the fuselage bearing seat is used to reflect the fuselage vibration. In addition, the response law of the lower dead point vibration under different rotational speeds and different loads is analyzed.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG385.1

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