The Study Of Hydraulic Part And Assembly Parametric Drawing System

In this paper, the phylogeny of modem CAD is reviewed, and the characteristics of various primary methods of parametric design and the development tendency of CAD technology are discussed. On the basis of analyzing the data model of system and entity expressing, we adopt the method of object oriented, and develop the parametric system of hydraulic pressure part and assembly (HSCAD200 1). According to the idea of software engineering, this paper gives a rational design of HSCAD200 1. On the basis of synthetically considering the parametric characteristics of part and assemble drawing, we build a parametric mathematics model united part drawing and assembly drawing which based on compound nesting list table. Then the incorporate design of 2D part and assembly drawing is come true to a certain extent. In parametric design of part drawing based on characters, we analyze the characteristics of hydraulic pressure part and assembly graphics and decompose it as basic character graphs. At the same time, Boolean operation is introduced into the system, and use Boolean operation commands of AutoCAD offered and the 揃OUNDARY?commands which compounding basic character graphs to complicated drawing. Then just modifying the parameters of character graph, a new graphic is produced. So the design efficiency is improved. In this paper, the method searching contour and the technology collecting data of entity in block are mended, then the rapid hiding method applied in assembling complex 2D drawing from simple ones is put forward, and the operating speed is improved. According to these, the method applied of hiding technology in series product assembly drawing is developed, and realized in hydraulic pressure bracket assembly drawing. According to the characteristics of AutoCAD drawing and functions of operating the drawing in AutoCAD, it is proposed that the closed window boundary should be defined as region and be concerned with the calculation of window clipping, and the method automatically generating region is given. In addition, the clipped entities are classified into open loop entities and closed loop entities. For open loop entities, calculating the points of intersection and sorting these points are completed at one time using the intersection function provided by ObjectARX; For closed loop entities, the window clipping is completed by combining the Boolean operation of region. The parametric system (HSCAD2001) offers standard parts gallery and common parts gallery which automatically create parametric assemble drawing to hydraulic pressure bracket, and automatically build relationship in part and assembly drawing. Consequently the rapid design and drawing of whole set blueprint in hydraulic pressure bracket series products are realized.