The Calculating And Study Of Plane Dimension Chain On The Secondary Development Of UG

In recent years, with the rapid development of CAD/CAM technology, the3D digitalmanufacturing technology has been developed and applied. The MBD technology, especially,which changes the traditional process design and the production mode, makes great change inthe manufacturing technology, and offer the technical condition for entering the era of3Ddigital manufacturing. It has been rapidly developed and widely used in the process ofmechanical manufacture. At present, calculating the problem of dimensions and tolerancesmanually has been wisely used in our country aircraft manufacturing industry. In this way,there are some problems, such as low efficiency, error prone, boring and so on. So, this waycan not meet the requirement of the development of China’s modern manufacture, restrictingthe further development of the manufacturing industry.In order to solve the complex problem of the dimension chain calculation and follow thedeveloping trend of the3D digital manufacturing technology, we have been developing thecomputer aided3D model dimension chain calculation system by using VB.NET to secondarydevelop the UG on the condition of MBD, which could help the designer to intuitively designand calculate the dimension and tolerance on the condition of3D model. What’s more, it willmake the designer free from the traditional boring solutions, save time to do other work, andimprove the working efficiency.The system of the plane dimension chain Calculation is secondary developed mainly inthe ways of projecting method, the differential, extremum method and probability method. Onthe basis of researching the solving process of the plane dimension chain in the projectingmethod, we put forward the reckoning method of the vector angle to calculate the functionequation of each loop, and use it to generate automatically the function equation thedimension chain and get the correct function between each loop which can ensure thecorrectness of the calculating result. In the process of the calculating, the system canautomatically judge the increase or decrease of the component loop, which makes the system higher operability and generality.