TO Sum up The Experience of Stamping Dies Helps You Reduce The Number of Trial Molds

Want to know the skills and precautions of stamping dies for punch presses? These will help you reduce the number of trial molds, and improve the accuracy of the mold, so that you are more skilled in stamping mold technology, we provide information about the design of the stamping die, mold design and materials, welcome to click More information.

Strip Design
Before designing "strip," be sure to understand the tolerance requirements of the parts, material performance, punch tonnage, punch table, SPM (punch per minute), feeding direction, feeding height, mold thickness requirements, material utilization rate, mold life. When designing a strip, CAE analysis should be performed at the same time, mainly considering the thinning rate of the material, which is generally below 25%. Special deep-drawing stainless steel material can be annealed after pre-stretching. Using a high-frequency annealing machine, the thinning rate can be accepted to 40%. When designing the strip, you must communicate with the customer. It is best to ask the customer to provide the previous. To refer to the mold photos or structural drawings, to stretch is also very important. If the length of the mold allows, it is beneficial to change the length of the mold after mold testing. The strip design is an analysis of the molding process of the product, which determines whether the mold is successful. In the design of progressive die, the lifting design is essential. If the lifting rod cannot lift the entire material belt, automatic continuous production cannot be carried out.

Mold Design
In the mold design, mold material selection and heat treatment and surface treatment (such as TD, TICN, TD time takes 3-4 days), especially for tensile parts, if there is no TD, the mold surface will easily pull and burn. For surfaces with small hole positions or tolerances, make adjustable inserts as much as possible to facilitate adjustment during trial and production, to easily achieve the size requirements of parts. Adjustable spare plate should be made at the same time.

Hydrogen Spring
When designing a hydrogen spring, design it according to the pressure analyzed by CAE. Do not design an oversized hydrogen spring to prevent the product from rupturing. The usual situation is low pressure, product wrinkling, high pressure, product rupture. To solve the wrinkle of the product, the method of locally increasing the draw bead can be used. The draw bead is first used to fix the sheet and then stretched to reduce wrinkles.

Suggestions for the first trial
During the first mold test, the top plate must be closed slowly. For the stretching process, the thickness of the material level must be tested with a fuse. When the gap between the material levels reaches the thickness of the material, try the mold again. The knife-edge must be aligned first. Please use movable inserts for the draw beads to adjust the height of the draw beads. When testing the mold, the reference hole and reference surface must be equipped with the mold before placing the product on the inspection tool for measurement.

Customer sample requirements
At the laser grade, the red lead powder (the name of the powder used to repair the mold) should be matched, and the feeding materials should be adjusted to solve the problems of cracking, wrinkling, and dimensional tolerances. Correct the main problem when opening the shear, and then make local mold improvements. For 3D complex products, you can use the 3D laser method. Before the 3D laser, you must make 3D graphics, use the CNC to set the reference point, and then send the 3D laser. The 3D laser also needs to be positioned. For the high-strength steel plate, the hard material of the blade should be A88 or V4. In the trial mold, to test the tensile effect, you can put sandpaper on different positions on the material to test the effect.

Precautions

• For parts with many bends, adjust the bending step by step according to the process when adjusting the mold. When adjusting the forming angle, you can reduce the R angle during bending or move the folding line reference to achieve the purpose of forming angle. When adjusting the mold, most of the gaskets are used to adjust the height of the molding male, or the molding male is moved left and right, and the gasket is generally made of stainless steel hard film. It is necessary to determine when the official materials of the guests will arrive. In the trial mold, the materials will be used sparingly to avoid insufficient materials.
• There are two types of progressive die sensors, one is the step sensor and the other is the blanking sensor. The slope of the waste funnel is not less than 30 degrees. For low-angle scope boxes, you can use the installation of pneumatic vibration to solve.
• For product rupture, you can use a variety of methods such as adding packages, extruding materials, increasing the forming area of the bar, and opening holes during the early stretching. CAE analysis should be performed before the mold is changed.
• The product materials are divided into two types: coil and sheet. Some coils need to be slit to the width of the strip again when they arrive at the factory. Usually, the slit size is negative tolerance (negative 0.5mm), and the inner diameter of the coli should meet the size of the feeding rack. Avoid being too big or too small and too heavy.
• The concept of "fine blanking" is to leave no blanking gap (or only 0.5%). Generally, the blanking gap is 10% of the thickness of the material. The thicker the material, the larger the gap ratio.

The above is a summary of some experience in the actual stamping work, I hope to help those who read this article, improve the quasi-term pass rate of the mold, and reduce the number of mold testing.

knowledge base

​How to repair the mold with red lead powder?
Mix red lead powder to a thin paste with motor oil. When using, apply red lead powder to the surface where the male mold and the female mold are in contact with your fingers or a brush. Then close the male mold and the female mold, take it out and look at the point where the two touched. Repair the degree and scrape the contact points until the contact surface becomes larger and larger, it is best to ask enough to make the entire surface contactable.

Reference: caemolding.org