Zhejiang Ceeto Mold Co.,Ltd has rich experience in design and assembly of plastic injection molds in high level. Method for determining fit clearance and form and position tolerance of guide column and guide sleeve. In the specific design of the guide column guide sleeve, its ideas and methods are as follows:
1, according to the shape of the workpiece, the way of discharge and the situation of the press, first determine the layout of the guide column;
2, according to the change of the punching gap, the distribution of the tolerance of each part, the general convex and concave die manufacturing tolerance is half to one-third of the change, the guide column bending deflection is one-fourth to one-fifth of the change, the guide column guide sleeve with the gap to hedge the change of the gap is half to one-third of the change;
3. Determine the size of the guide column according to the allowable bending deflection of the guide column and the lateral force during punching (mainly when punching the unsealed parts);
4. Determine the maximum fit gap of the guide column and guide sleeve according to the change amount of the allocated fit gap and the arrangement form of the guide column and guide sleeve;
5, according to the maximum fit gap of the guide column guide sleeve and the processing tolerance of the guide column guide sleeve to determine the minimum fit gap of the guide column guide sleeve;
6, determine the shape and position tolerance of the guide column guide sleeve according to the minimum fit gap of the guide column guide sleeve.
Teach you how to choose the principle of selecting the accuracy of the mold guide column guide sleeve is that the clearance of the general mold guide column guide sleeve should be less than the clearance of the convex and concave die, and how to choose the coordination of the mold guide column guide sleeve under several circumstances. Although these statements are correct, they are not accurate enough and difficult to choose when it comes to practical application.
First of all, to ensure that the qualified parts are blanked and the die has a long life, the convex and concave die gaps in the blanking process should be within the maximum and minimum reasonable gaps; Secondly, in the punching process, in addition to the influence of the mold guide column guide sleeve with the gap hedging clearance, the side force during punching, mold processing, assembly accuracy and other factors also have an impact on the hedging clearance. The influence of these factors on the hedging clearance should be integrated to ensure that the mold clearance is within a reasonable punching clearance range.