【作者】 刘建慧；

【导师】 邹慧君； 颜鸿森；

【作者基本信息】 上海交通大学 ， 机械设计及理论， 2006， 博士

【摘要】 本论文内容以图论和组合理论为基础,运用机构配置矩阵、树图以及功能分析等方法主要针对四轴、五轴加工中心研究其机构拓扑结构、换刀动作及其运动链结构。将拓扑结构特性、换刀动作特性以及运动链设计特点三部分基础内容相融合,提出以加工中心为典型机构的开链机构运动方案系统化设计方法。首先针对现有的加工中心做广泛的资料收集和分析整理,以机构配置矩阵和图论理论分析了加工中心的拓扑结构和换刀动作,提出拓扑结构特性和换刀动作特性。运用功能分析法揭示ATC换刀的基本规律,根据换刀动作和方向性提出换刀动作类型以及动作顺序,作为加工中心动作综合以及运动方案设计的基础。接着利用构型码和形状创成函数从机构运动链的角度研究加工中心运动链的设计需求和限制条件,将其同加工中心拓扑结构特性以及换刀动作特性相融合并转化为基于树图的特殊化规则以及设计限制条件,进而提出加工中心运动方案设计方法,并以实例详细说明设计方法和设计步骤,系统地得出加工中心的运动方案。在加工中心运动链分析过程中,详细分析了五轴加工中心的运动链构成类型及不同类型的优、缺点,并简单讨论了其工作空间问题。本文对加工中心自动换刀装置的各种换刀时间的计量和标示方法也做了详细讨论,并提出了合理、实用的换刀时间计量和标示方法。本设计方法的第一步是给出一个或多个合乎设计需求的现有加工中心机构,当作设计的原始机构。分析此类型现有机构,并归纳出其拓扑结构、动作特性和运动链设计条件;第二步是根据坐标系统和基于图论理论的机构树图定义,将加工中心机构以树图方法来表示;第三步是根据机构的一般化方法,将具有各种不同机件和运动副的机构树图转化成只具有连杆和一般化运动副的一般化树图;第四步是根据图论理论,找出具有所需连杆数和运动副数的所有树图,给出树图目录;第五步是根据机构的拓扑结构特征和运动链设计限制条件所制定出的特殊化规则,将所需要的连杆类型和运动副类型特殊化到每一个树图上去,并将不合乎设计要求的树图删除,从而得到所有的特殊化树图;第六步是根据运动以及动作特征所制定的动作设计程序,将所需的连杆间的相对运动形态分配到每一个可行特殊化树图上去,并将不符合设计需求的机构删除,最后得到可行的运动方案。根据本研究所提出的运动方案系统化设计方法,主要以四轴加工中心实例来说明设计方法的整个过程。得到无换刀臂四轴轮鼓式刀库加工中心,其七杆和八杆的机构运动方案数分别为20个和70个,其中的R副可特殊化为A轴或B轴;对更多还原

【Abstract】 The theoretical basis of this research is the topological, kinematical characteristics of mechanisms and the analysis of kinematical chain configuration. The main objects are four- five-axis machining centers with tool change arm and without tool change arm. We study their topological, motion characteristics and kinematical chain configurations, and then present a systematical creative scheme design method for open-chain mechanisms like as machining centers with or without automatic tool changers.First of all, starting by investigating and collecting the relevant literatures and existing implements of machining centers, we introduce mechanism allocation matrix and tree-graph theory to analyze and conclude the topology and motion characteristics. This work serves as the basis of mechanism motion synthesis and scheme design of machining centers. Then, analyzing the kinematical chain design requirements and restricts of machining centers from the view of mechanism kinematical chain, combining with the characteristics of topology and tool change motion of machining centers, we present a creative scheme design method for machining center. By this method, the atlas of creative mechanism for machining centers is given systematically. On the analysis process of kinematical chain of machining centers, we discussed their workspace briefly. In this paper, some evaluating methods for tool changing time of automatic tool change on machining centers are discussed in detail, and a more reasonable and practicable calculating and evaluating method for automatic tool changer is proposed.The first step of the design method starts by investigating existing mechanisms and concludes their topology and motion characteristics; the second step is to describe the topological structures of existing mechanisms based on the coordinate systems and tree-graph representations; the third step is to transform these mechanisms into their corresponding generalized tree graphs according to the process of generalization; the fourth step is to obtain all possible tree graphs with the given numbers of edges and vertices based on graph enumeration; the fifth step is to assign certain type of links and joints into available tree graphs subject to required topology constrains through the process of specialization; the last step of the design process is to obtain the atlas of mechanisms subject to specified motion constrains.According to the concept of coordinate systems, graph theory, generalization, specialization, and motion synthesis, we use the design methodology synthesize the configurations of machining center with automatic tool changers. As the result, for the machining centers with the drum type tool magazine, the number of configurations of four-axis machining centers with 7, and 8 links are更多还原