应用塑件的工艺限制收缩特性获得塑件高精密孔的工艺方法

High Accuracy Hole Craftwork Based on Secondary Technical Limited Contraction Characteristic When Plastic Injection Molding

塑件外形的尺寸和形位精度可以通过精密注射模的精确导向、定位及二次定位加以解决,而塑件内形的尺寸和形位精度,要获得标准公差数值为IT6～7级,圆柱度小于0.01mm精度的要求,看起来是乎是不现实的事情。通过应用塑料的成型二次工艺限制收缩特性解决了这一塑件成型的难题,并成功地使塑件的内孔获得IT6精度,孔的不圆柱度可小于0.002mm的水平,并且加工的方法极其简单。

The size and shape accuracy of injection mold can be obtained by using precision guidance, positioning and the second location in precision injection molds, for the size and shape accuracy in injection mold, the standard value of tolerance is IT6 - 7 level, noncylindricity is no more than 0.01mm, which appears to be unrealistic things. We resolved the issue by using secondary technical limited contraction characteristic on plastic molding, obtained IT6 hole accuracy successfully, noncylindricity of the hold is less than 0.002mm, and the processing method is extremely simple.