The significance of study on flexible fixture CAD methods is summarized. Based on the AUTOCAD software, represented with slot Modular fixture dements, the flexible fixture CAD methods are discussed, such as part repre...The significance of study on flexible fixture CAD methods is summarized. Based on the AUTOCAD software, represented with slot Modular fixture dements, the flexible fixture CAD methods are discussed, such as part representative model,feature modeling,design method,structure of the graphic library, optimization of assembly drawing structure, optimal choice of interactive function, and CAD Information database management.展开更多
There are many welding fixture layout design problems of flexible parts inbody-in-white assembly process, which directly cause body assemble variation. The fixture layoutdesign quality is mainly influenced by the posi...There are many welding fixture layout design problems of flexible parts inbody-in-white assembly process, which directly cause body assemble variation. The fixture layoutdesign quality is mainly influenced by the position and quantity of fixture locators and clamps. Ageneral analysis model of flexible assembles deformation caused by fixture is set up based on'N-2-l' locating principle, in which the locator and damper are treated as the same fixture layoutelements. An analysis model for the flexible part deformation in fixturing is set up in order toobtain the optimization object function and constraints accordingly. The final fixture elementlayout could be obtained through global optimal research by using improved genetic algorithm, whicheffectively decreases fixture elements layout influence on flexible assembles deformation.展开更多
Multi-point forming (MPF) is an advanced manufacturing technology for three-dimensional sheet metal parts. In this paper, the MPF integrated system is described that can form a variety of part shapes without the need ...Multi-point forming (MPF) is an advanced manufacturing technology for three-dimensional sheet metal parts. In this paper, the MPF integrated system is described that can form a variety of part shapes without the need for solid dies, and given only geometry and material information about the desired part. The central component of this system is a pair of matrices of punches, and the desired discrete die surface is constructed by changing the positions of punches though the CAD and control system. The basic MPF process is introduced and the typical application examples show the applicability of the MPF technology. Wrinkle and dimple are the major forming defects in MPF process, numerical simulation is a feasible way to predict forming defects in MPF. In conventional stamping, the mode to form sheet metal with blankholder is an effective way to suppress wrinkling; the same is true in MPF. A MPF press with flexible blankholder was developed, and the forming results indicated the forming stability of this technique. Based on the flexibility of MPF, varying deformation path MPF and sectional MPF were explored that cannot be realized in conventional stamping. By controlling each punch in real-time, a sheet part can be manufactured along a specific forming path. When the path of deformation in MPF is designed properly, forming defects will be avoided completely and lager deformation is achieved. A work piece can be formed section by section though the sectional MPF, and this technique makes it possible to manufacture large size parts in a small MPF press. Some critical experiments were performed that confirmed the validity of two special MPF techniques.展开更多
针对当前柔性夹具设计过程中,用户需求掌握不明确,矛盾问题发现不精准,设计冲突的解决缺少创新等设计问题,结合质量功能展开理论(Quality Function Deployment,QFD)和发明问题解决理论(Teoriya Resheniya-Izobreatatelskikh Zadatch,TRI...针对当前柔性夹具设计过程中,用户需求掌握不明确,矛盾问题发现不精准,设计冲突的解决缺少创新等设计问题,结合质量功能展开理论(Quality Function Deployment,QFD)和发明问题解决理论(Teoriya Resheniya-Izobreatatelskikh Zadatch,TRIZ),将QFD和TRIZ理论融入柔性夹具概念性设计阶段,提出了基于QFD和TRIZ理论的柔性夹具创新设计模型,通过用户调研,整理得到柔性夹具的具体设计需求和针对需求实现的设计工程参数,建立了柔性夹具质量物矩阵,得到柔性夹具设计关键问题,并利用TRIZ冲突解决工具对问题进行了求解,最后以一种工程应用实例验证了模型的可行性。这对推动柔性夹具设计及上层柔性制造系统的发展起到了积极作用。展开更多
文摘The significance of study on flexible fixture CAD methods is summarized. Based on the AUTOCAD software, represented with slot Modular fixture dements, the flexible fixture CAD methods are discussed, such as part representative model,feature modeling,design method,structure of the graphic library, optimization of assembly drawing structure, optimal choice of interactive function, and CAD Information database management.
基金This project is supported by National 863 Plan (No.2001AA411140)National Natural Science Foundation of China (No.50175071).
文摘There are many welding fixture layout design problems of flexible parts inbody-in-white assembly process, which directly cause body assemble variation. The fixture layoutdesign quality is mainly influenced by the position and quantity of fixture locators and clamps. Ageneral analysis model of flexible assembles deformation caused by fixture is set up based on'N-2-l' locating principle, in which the locator and damper are treated as the same fixture layoutelements. An analysis model for the flexible part deformation in fixturing is set up in order toobtain the optimization object function and constraints accordingly. The final fixture elementlayout could be obtained through global optimal research by using improved genetic algorithm, whicheffectively decreases fixture elements layout influence on flexible assembles deformation.
文摘Multi-point forming (MPF) is an advanced manufacturing technology for three-dimensional sheet metal parts. In this paper, the MPF integrated system is described that can form a variety of part shapes without the need for solid dies, and given only geometry and material information about the desired part. The central component of this system is a pair of matrices of punches, and the desired discrete die surface is constructed by changing the positions of punches though the CAD and control system. The basic MPF process is introduced and the typical application examples show the applicability of the MPF technology. Wrinkle and dimple are the major forming defects in MPF process, numerical simulation is a feasible way to predict forming defects in MPF. In conventional stamping, the mode to form sheet metal with blankholder is an effective way to suppress wrinkling; the same is true in MPF. A MPF press with flexible blankholder was developed, and the forming results indicated the forming stability of this technique. Based on the flexibility of MPF, varying deformation path MPF and sectional MPF were explored that cannot be realized in conventional stamping. By controlling each punch in real-time, a sheet part can be manufactured along a specific forming path. When the path of deformation in MPF is designed properly, forming defects will be avoided completely and lager deformation is achieved. A work piece can be formed section by section though the sectional MPF, and this technique makes it possible to manufacture large size parts in a small MPF press. Some critical experiments were performed that confirmed the validity of two special MPF techniques.
文摘针对当前柔性夹具设计过程中,用户需求掌握不明确,矛盾问题发现不精准,设计冲突的解决缺少创新等设计问题,结合质量功能展开理论(Quality Function Deployment,QFD)和发明问题解决理论(Teoriya Resheniya-Izobreatatelskikh Zadatch,TRIZ),将QFD和TRIZ理论融入柔性夹具概念性设计阶段,提出了基于QFD和TRIZ理论的柔性夹具创新设计模型,通过用户调研,整理得到柔性夹具的具体设计需求和针对需求实现的设计工程参数,建立了柔性夹具质量物矩阵,得到柔性夹具设计关键问题,并利用TRIZ冲突解决工具对问题进行了求解,最后以一种工程应用实例验证了模型的可行性。这对推动柔性夹具设计及上层柔性制造系统的发展起到了积极作用。
