Development Of The General-purpose CAD System For Sand Casting Based On SINOVATION

Since 2000,China has been the country with the highest casting output in the world for 17 years.China's foundry industry has entered the stage of industrial upgrading and steady development,which is focusing on quality and efficiency instead of scale and speed.To complete the transformation of our country from a big foundry country to a powerful foundry country,the improvement of casting quality is of utmost importance.Computer-aided design(CAD)technology can replace the traditional manual design method well and change the status quo that designers can only rely on the experience and repeated tests,which greatly shorten the design cycle,improve casting quality as well as save costs and achieve green manufacturing.Therefore,the use of computer-aided design will become a key measure for the progress of the enterprise and the foundry industry.At present,the domestic research on casting CAD is mainly secondary development based on foreign drawing software.The article is based on new 8.0 version of domestic three-dimensional CAD/CAM integrated application software system SINOVATION with independent intellectual property rights.By using Visual Studio 2013 as the development platform and using the latest V8 as the development tools,it completed the development of a general-purpose CAD system for sand casting.The article summarized the existing casting process design experience and data,improved the algorithm for hot spot,chill and other casting process elements,and added a variety of chill,core-head and other structural shape types.Besides,we designed user-friendly multiple command modules according to the use habits of technicians.These command modules are defined by XML(Extensible Markup Language),and functions such as drawing and calculation are implemented by C++language.These modules include hot spot analysis,core-head design,core-head pressure calculation,chill design and riser arrangement.The hot spot analysis module adopts a new point modulus algorithm,based on the two-step heat dissipation model of the solidification process.It's added three coefficients,taking into account the effect of the temperature,density and specific heat capacity of each material as well as the shape of the mold on heat dissipation.The core-head design module provides designers with a wide selection of core-head types and shapes to create a variety of core-heads quickly.Core-head pressure calculation can complete the pressure check after core-head design.For the chill module,the article improved the old algorithm that could only apply to the cast steel.In order to calculate the surface area expansion factor of the chill,a one-dimensional steady-state heat conduction model was established for the multilayer flat wall including the casting,the intermediate layer and the chill.According to the theory of riser filling,based on the relationship between the feeding distance of the riser and the ratio of the width and thickness,riser arrangement module was developed with the function of fast riser arrangement.It can also be used with chills.The article has designed a general-purpose CAD system for the sand casting.It includes the process design of multiple elements such as the core,the chill and the riser.The entire system is simple and easy to use.It improves design efficiency of casting process remarkably.