Research On The Electromagnetic-field-aided Whole Die Of Rapid Prototyping Technique For Automatic Flow Control Valves

The thesis focuses on the application of the electromagnetic-field-aided whole die of rapid prototyping technique for sheet-metal parts, which our laboratory put forward, in forming of automatic flow control valves.In this context, our laboratory put forward the electromagnetic-field-aided whole die of rapid prototyping technique for sheet-metal parts. It is a new manufacturing technology for sheet metal, by using a series of regularly arranged pins whose relative heights are adjustable to form the working surface, and in virtue of the aided modifying technology of ferromagnetic material powder, the pins and ferromagnetic material powder are integrate into a whole body, becoming a whole die; At last, the tool is drived by the hydraulic power system deform the sheet metal to the 3D curved face. The basic principle of the electromagnetic-field-aided whole die of rapid prototyping technique is break up the whole into the discrete, then integrate the discrete into the whole again. Not only does this technique have the virtues of the muti-point forming technique, but also it has the virtues of the traditional whole die which are the better forming precision and smooth surface, so it can satisfy the manufacturing need of sheet metal parts.The main work I have done in this thesis is as follows:(1) In this paper, reverse engineering and surface reconstruction is used in the electromagnetic-field-aided whole die of rapid prototyping technique for automatic flow control valves, the gathering and pretreatment of the three dimensional data of the valve core were researched, and using B-Spline to restructure the valve core surface.(2) According to the restructured valved core surface, the length of pins was calculated, this paper fitted the valve core's surface in a parametic bicubic spline surface. However, the valve core's surface with flatter shape (differentiated by a given tolerance) was fitted in hyperbobic paraboloid so that the length of pins can be calculated.(3) Single control unit has been designed and fabricated. It consists of communication interface circuit, clock circuit, watch dog circuit, light-electricity coupling circuit, drive circuit, and feedback circuit. It fulfils the function of communication, collecting data, dealing with data, and controlling the height of sigle pin. The master computer software and slave computer software are designed.(4) In this paper, magnetic field shielding is researched. The shield that was suitable for the electromagnetic-field-aided whole die of rapid prototyping technique was designed.(5) According to several kind of valve cores of automatic flow control valves, the process of the electromagnetic-field-aided whole die of rapid prototyping for automatic flow control valves was designed, including the pins were selected, the work piece was located and the process of forming.