Three cone bit is the important tool in oil drilling, whether its performance is good or bad will directly affect the quality of drilling, drilling efficiency and drilling cost. Three cone bit's design in the traditional is based on practical experience and combined with the method of trial and error, repeated design and calculation, so the accuracy of design is low, the cycle is long and it is difficult to improve the quality of design. And the design of each calculation can only be a bit and with low efficiency. Therefore, to develop a set of three teeth wheel drill bit CAD system and realize parametric drawing of three cone bit are very necessary.
Total design of the system. The parametric drawing system of three teeth wheel drill adopts the modular programming method; the whole system is divided into four functional modules: user interface management module, the bit of tooth surface structure design module, database management module and parametric drawing module. The performance of roller cone bit design of user interface use VBA, which is embedded in AutoCAD, to realize second tools development. The user through the user interface module input relevant parameters of three cone bit design to realize the man-machine communication. The main function of the bit teeth structure design module is designed according to the theory of three cone bit three bit data for the design of complex calculations. Database management module is composed of Access 2003 as a data from the establishment of the database.