During the debugging stage of Kunshan stamping parts processing and trimming sequence molds, it is generally easy to encounter the phenomenon of upper mold clamping and material carrying. The main reasons are:
1. The core cannot be used for pressing and material return: the core is subjected to uneven force, there are gaps in the guide, and it is stuck without material return;
2. Insufficient core pressing force after trimming;
3. After trimming, the workpiece deformed and got stuck in the pressure core.
The improvement and preventive measures for trimming and material card parts are as follows:
1. Solve the problem
1) For the situation where the pressure core is stuck and cannot be returned normally due to uneven force and improper guidance, the gap between the guide plate and the sliding surface can be adjusted.
2) The arrangement of springs and the replacement of spring specifications ensure even force distribution.
3) Core guiding: Guiding the core to ensure a gap of 0.5mm between the core and the concave die edge.
4) Core pressing stroke: The core pressing stroke requires pre pressing the workpiece before cutting the blade edge; Cutting before pressing the workpiece can easily cause deformation, edge tearing, and jamming of the workpiece. Before the die comes into contact with the stamped part, the pre pressing stroke of the core should be ≥ 10mm.
2. Solve the problem
1) The return force varies depending on the thickness and shape of the plate, usually 4-20% of the punching force.
2) When there is vertical cutting in the edge trimming mold during stamping processing, it is necessary to increase the material return force.
3) Preferred spring for power source, with the power source arranged close to the working area; For those with low requirements for material return force, polyurethane or other materials can be used to provide material return force.
4) Calculation of force. Spring pressure F=kL, k is related to the cross-sectional shape, inner and outer diameter dimensions, and material properties of the spring steel, where L is the amount of deformation; The pressure of nitrogen gas springs varies almost linearly, with advantages such as no need for pre tightening, high initial pressure, small space occupation, long service life, and a response frequency of over 40 times per minute.
3. Regarding the issue
1) Improper mold fitting can cause deformation of the parts. Mold fitting can be performed to solve the problems of part deformation and jamming.
2) Add a spring pin inside the pressure core to determine the pressure core of the component.
