Research And Development Of The Computer Aided Injection Mold Design System For Plastic Gear

Gear is widely used in different kinds of fields as the main part of mechanicaltransmission. plastic gear has already taken the place of metal gear in many fields becauseof its lighter weight, lower cost, and better inertia. Injection mold is the key factor thataffects the quality of plastic gear. How to improve the quality and efficiency of the molddesign is the common problem that the gear industry faces. At the same time, due to thecontraction of the plastic material during the injection forming process, we need to modifythe mold cavity to meet the precision of the product, which is the difficulty in the molddesign. For these reasons, the paper has done some research and development of thecomputer aided injection mold design system for plastic gear.Firstly, the author analyzed the forming principle and relevant features of the involutetooth profile. According to the general contraction rules of plastic injection molding, theauthor studied the modification of mold cavity, and put forward a rapid and effectivemodification of injection mold cavity for plastic gear.Than the author made some research on parametric modeling technology, and createddifferent kinds of plastic gear templates using UG expressions, including involute spurgear and involute helical gear. The author also realized the parametric modeling of plasticgear by human-computer interaction. When users enter the key parameters of plastic gear,the corresponding gear model can be automatically created.On the basis above, the author developed a computer aided injection mold designsystem for plastic gear on UG NX platform. The system includes the cavity design,moldbase and standard part design, filling system, cooling system and so on. Whenapplying this system, the users not only can finish the injection mold design for plasticgear rapidly and orderly, but also can get the modified mold cavity automatically, whichgreatly improve the quality and efficiency of the mold design, short the design cycle.