With the continuous improvement of wages for workers in the stamping industry, reducing the manual manufacturing cost of stamping has become a top priority for hardware manufacturers. One commonly used method is the use of continuous molds, which can be used to build a low-cost and high-efficiency automated stamping production line. Because continuous molds require precision and complex components. Compared with general stamping molds, the issues that need to be paid attention to in design are more complex, mainly manifested in the following aspects:

(1) When there are many punching holes, the length of the small convex die should not be too large

For multi punch stamping molds, different heights of punch can be made according to the size of the punch, forming a stepped pattern, which can avoid the simultaneous generation of large punch pressure in each punch, effectively reducing the punch pressure of the mold and relieving the load on the punch press. However, it should be noted that for stepped convex molds, in order to ensure sufficient rigidity, small-sized convex molds should be made shorter, while large-sized convex molds should be made longer. The difference between the two is the height of the sheet metal thickness. When drilling in this way, first drill large holes, then drill small holes. Otherwise, when punching large holes, small convex molds will form, which will break due to insufficient rigidity.

(2) Attempt to add step positioning devices such as stoppers and side blades on the continuous mold

When using a continuous die to punch workpieces, it is necessary to solve the problem of precise positioning of the strip and ensure that the steps of the continuous die are consistent, so as to be able to punch qualified workpieces. In continuous molds, commonly used positioning devices include fixed blocking pins, guide pins, guide plates, side blades, and other forms. During stamping, use a fixed stop pin for initial positioning, and during cutting, use a guide pin installed in the mold to ensure the correct positioning of the strip. The side blade is used to control the feed distance of each step of the material. The length of the side blade should be equal to the step length plus 0.05-0.5 millimeters, depending on the material thickness.

(3) The guide pin (guide needle) of the continuous mold should not be too long

In order to control the feeding steps, the continuous mold must have better positioning devices. The commonly used positioning devices include guide pins, initial stop pins, side blades, guide pins, etc. Among them, guide pins are a precision positioning method widely used in continuous molds. When used in conjunction with misdelivery detection sensors, they can also alarm and stop, protecting the mold. Therefore, they are often used in continuous stamping molds. In high-precision continuous stamping molds, punching and pre punching are usually used, and then the method of aligning the coil material with guide pins is adopted in each working step. At this time, the diameter of the guide pin used is usually between Φ 1.2~6mm. It must be noted that the length of the guide pin and the length of the guide hole should not be too large, otherwise it may cause problems such as poor feeding and material carrying in the mold. Therefore, the straight length of the continuous stamping die guide pin should be: the thickness of the guide pin fixed template is equal to the thickness of the material.

(4) Continuous stamping molds and other automatic stamping molds should not use Yuli rubber or polyurethane rubber as demolding components

For high-efficiency continuous molds, their service life is often over 500000 to 5 million times, and the stamping speed is over 40 times per minute. If elastic components such as Yuli glue and polyurethane are used for unloading, on the one hand, the unloading force may be insufficient and unreliable; On the other hand, their lifespan is also limited. In order to ensure the reliable and normal operation of the continuous mold and reduce maintenance, springs with a longer service life should generally be used as unloading components.

(5) Complex or elongated shapes in continuous stamping molds should not be stamped out at once

Complex and slender shapes in continuous molds should not be stamped out at once. If the process allows, it should be split into several punches and stamped simultaneously, which can make the mold hole easier to process, extend its service life, facilitate mold maintenance, and improve production efficiency.

(6) Reserve empty steps in the design for easy debugging and mold modification

When designing continuous deep drawn parts or products with unstable forming dimensions, the design of empty workstations should not be ignored. For this type of mold, when designing the layout diagram, there are often one or two empty workstations left after the first deep drawing forming, leaving some space for appropriate changes and adjustments after the trial mold. For the pressing parts, there is an empty workstation between the first and second deep drawing. In addition, when the hole spacing of the punch or die is too close, it is necessary to leave space on the layout diagram to protect structures such as convex molds, concave mold inserts, small mold frames, and hard alloy inserts. There is a vacant workstation between the forming step and the final feeding step, which facilitates the installation of the die and discharge plate, and improves the strength of the die.

(7) Anti jumping chip design

Continuous die is the process of continuously stamping products, especially when there are multiple punching and edge cutting. In order to avoid product breakage and mold stability, it is usually necessary to make anti bounce waste structures. Mainly starting from the following points: 1 The punch is made into a special shape, which can increase the adhesion of waste on the cutting edge; 2. Add a blow hole on the punch; 3. The cutting edge is in the form of a V-shaped or dovetail clip; 4. Reasonably set the cutting gap to reduce material jumping; 5. In mold waste suction device.

(8) The carrier of the continuous mold cannot deform

The workpiece in each process of the continuous mold is transferred from the strip edge material, and in the material dropping process, the workpiece is usually separated from the strip. This circle is called the carrier of continuous modules. In continuous molds, common carrier forms include: edge carrier, intermediate carrier, double-sided carrier, single-sided carrier, etc. The edge material carrier is used to punch guide holes on the leftover material of the workpiece, and then use this positioning for forming processes such as deep drawing and bending. This carrier design is simple, reliable, material saving, and widely used. The intermediate carrier runs along the strip, with most of the material cut around the workpiece and only a small amount of connecting material left in the middle of the strip width direction. This type of carrier has poor rigidity and poor continuous stamping stability. A double-sided vehicle is designed to leave less prying material on both sides of a long strip. The carrier has good rigidity and is not easily deformed, commonly used for continuous stamping of thin and long-distance workpieces. Single sided carriers only leave a small amount of material on one side of the strip, with poor rigidity, and can only be used for continuous stamping of workpieces with large material thickness and small feed distance. Due to the high requirement for step pitch accuracy in continuous molds, in order to ensure the dimensional accuracy of the steps and improve the working stability of the continuous mold, the carrier cannot deform. Therefore, the design of the carrier is an important aspect of continuous mold design. In order to ensure that the carrier has sufficient strength and stiffness, it is usually necessary to increase the overlap size appropriately; When the strength of the single-sided carrier is insufficient, double-sided carriers and intermediate carriers can be designed. Make a process incision between the carrier and the workpiece to separate them, ensuring that the deformation of the workpiece does not affect the deformation of the carrier.

(9) Quick disassembly, parts are foolproof

In continuous mold design, rapid disassembly of parts and error prevention of parts/standard components are particularly important. In order to achieve the goal of rapid mold repair, the entire mold is rarely removed from the machine during continuous mold repair. Instead, the parts and templates that need to be repaired are separated and removed when the machine is stopped. Therefore, a quick disassembly structure needs to be designed. When disassembling parts and templates and replacing them with new ones, it is often easy to install the parts incorrectly and make mistakes in the direction of the template, resulting in mold breakage. Therefore, it is necessary to pay attention to the prevention of parts and templates from being damaged.