| Fine blanking is an effective and economical metal cutting process which produces very highly precise work pieces with completely smooth, tear-free sheared surfaces. Compared to a conventional blanking, fine blanking processes have some special features:provides a clean-cut surface without the need for secondary machining such as shaving or milling, ensures stable production with high quality and precision, permits three-dimensional composite processing including coining, bending, and forging. Because of high efficiency, low expenditure, fine quality and some other characteristics, fine-blanking has been widely used in industrial production.Large-scale Fine blanking presses is the fundamental equipment for the automobiles, aviation, weapons and the high-tech and it is the significant guarantee for the economy and national security. However, there are few developments in the area of over large tonnage of 10000KN fine blanking equipment in China, which can't be used to make large-scale fine-blanking Parts and to satisfy the domestic need and manufacture demand for it.It was submitted that the design requirements of large size Fine blanking presses which can produce the shearing force with utmost 10000KN, the V-ring force with utmost 5000KN and the stripper force with utmost 2500KN. Through the virtual prototype technology, we successfully accomplish a complete top-down design process. After Calculating the fine blanking process parameters and structure parameters of key components, CAD models were created by using the 3D software CATIA. The CAD models were made up of eight main components, such as the press frame, the main cylinder, the V-ring cylinder, the counter cylinder, the quick stroke piston, the ram guide, the ram, the stroke limitation nut. These components were assembled into the CAD models of the machine according to inter-part orientation.The 10000KN fine blanking press is a large-scale Forging equipment, which support immense pressure and stamping frequency in the process. The deformation and vibration of the fine blanking press frame have direct relationship with the tool life and the component precision. Therefore, the high structural stiffness and the good dynamic performance are predominant requirements for the reliability of the machine tool. To ensure the virtual prototype of the 10000KN fine blanking press frame meets the requirements in the best way, the paper starts from the concept design of the machine frame by the desired workspace dimensions. Then a single aim optimization method is used to find optimization parameters and the multi-objective optimization method is applied to get the global optimum which can satisfies both the stiffness and the natural frequencies of the press frame. At last, remodel the structure of the fine blanking press frame according to the result of topology optimization and ensure the feasibility of the manufacture, shape optimization is used to find the best structural parameters for the light weight design. The optimized prototype of fine blanking press frame can be applied to provide references for the machine manufacture.After topology optimization, we obtained the best materials distribution of the frame and removed 40% volume of the frame, first natural frequency is 41.8Hz. Making a shape optimization on the frame of the machine tool, the deflection of the frame reached 0.325mm, decreased 18%., the ratio of the deflection to the length achieved 1/7300. With the sensitivity analysis with respect to the thicknesses of 10 plates, we find the more sensitive design variables, which will be of guiding significance on subsequent changes and more large-tonnage fine-blanking press design.The virtual prototyping was established by using the multi—body system dynamic simulation software of ADAMS. After setting feeding parameters according to fine blanking process, kinematical simulation was done, the working process of machine was observed, and the curves of kinematic characteristics were gained during the working cycle process.
|
PDF Full Text Request