9 Precision Stamping Progressive Mold Design Details

Precision Stamping progressive mold can be very good for establishing a low-cost and high-efficiency automatic stamping line. We must consider design issues as continuous die requires precision and complex parts. This article describes 9 major design details of continuous die for stamping, mainly for the following aspects.

progressive mold

(1) When punching more holes, the length of the small die should not be too large. For a multi-die mold, the die can be made into different heights according to the size of the mold, forming a ladder type, which can prevent the maximum value of pressure in each mold from being generated at the same time, effectively reducing the punching pressure of the mold and reducing the load of the punching machine. (However, it should note that for the stepped die, to ensure the die has enough rigidity, the smaller die size should be made shorter and the larger one longer, with a difference of one height for the thickness of the sheet). This way, the large hole is punched first, and then the small hole is punched. Otherwise, the material will be squeezed by the small die when the medium and large holes are punched and will break the small mold due to insufficient rigidity.

(1) When punching more holes, the length of the small die should not be too large. For a multi-die mold, the mold can be made into different heights according to the size of the die, forming a ladder type, which can prevent the maximum value of pressure in each die from being generated at the same time, effectively reducing the punching pressure of the die and reducing the load of the punching machine. (However, it should note that for the stepped die, to ensure the die has enough rigidity, the smaller die size should be made shorter and the larger one longer, with a difference of one height for the thickness of the sheet). This way, the large hole is punched first, and then the small hole is punched. Otherwise, the material will be squeezed by the small die when the medium and large holes are punched and will break the small mold due to insufficient rigidity.

(2) Progressive mold to try to add stopper, side blade, and other step positioning devices.
In progressive mold, the commonly used positioning devices are fixed stopper pin, guide pin, guide plate, side edge, and other forms. When stamping, the fixed stopper pin is used for initial positioning, and the guide pin installed in the die is used to ensure the correct positioning of the strips when the material is dropped. The side edge controls the distance of feeding the strip in each step. The length of the side edge should be equal to the step length plus 0.05-0.5mm, depending on the material thickness.

(3) The guide pin of the progressive mold should not be too long. The progressive mold must have a good positioning device to control the feeding step. The commonly used positioning devices are guide pin, initial stop pin, side edge, guide pin, etc. The guide pin is a precision positioning method widely used in continuous die. It can also be used with a misfeed detection sensor to alarm stop and protect the die, often used in continuous stamping die. In high precision continuous press dies, it is common to punch a pre-center hole and then use a guide pin to guide the coil in each step. In this case, the diameter of the guide pin is usually 1.2-6 mm and must take care that the length of the guide pin is not too large, nor is the length of the guide hole too large, otherwise it will cause poor feeding of the die and carry the material. For this reason, the length of the straight body of the guide pin of the continuous medium compression die should be the thickness of the fixed template of the guide pin + 1 material thickness.

(4)It should use a progressive mold, and another automatic punching dies to unload the rubber. Polyurethane rubber for progressive mold this high-efficiency production dies, its life is often more than 500-5 million strokes, punching speed in more than 40 times/min if the use of rubber and polyurethane such elastic components unloading, on the one hand, unloading force may be insufficient, unloading unreliable, on the other hand, their life is also limited, to To ensure that the continuous die works reliably and normally, and to reduce maintenance, the spring with healthy life should be used as the unloading element.

(5) It should not punch out complex or slender shapes in the progressive stamping mold a second time.

The complex and slender shapes in the continuous die should not be punched out at one time but should be divided into several middle heads and punched out step by step if the process allows. Improve production efficiency.

(6) The design of a reserved empty step is convenient for debugging and mold change.
The design of continuous deep drawing parts or forming size hazardous products can not ignore the design of an empty station. For this kind of mold, in the sample drawing design, the first human often pulls tea into will D after leaving an empty station. Leaving some room to make the mold after the trial can also be appropriate changes and adjustments. Cover parts in the third deep drawing and the second deep drawing between the empty station. In addition, when the stamping die or concave die opening distance is too close to protect the convex die. The concave, small die holder, carbide insert, and other structures must be left space on the sample drawing. The space is left between the shaping step and the final drop step to facilitate the installation of the concave die and unloading plate and improve the concave die’s strength.

(7) Anti-scrap design
The continuous die is a continuous stamping process, especially when there are many punching holes and cutting edges, to avoid crushing the products during the stamping process. To avoid crushing the product and the stability of the die, it is usually necessary to do an anti-scrap jumping structure. Mainly from the starting points: 1. punch made of shaped, can increase the adhesion of the scrap in the moon day; 2. punch with blow hole; 3. edge to do V or dovetail card form; 4 reasonable put punching gap, reduce jump 5. die suction scrap device

(8) The carrier of the continuous die cannot be deformed
The workpiece of each process in the continuous die is transferred by the lap side of the strip material, and the part is usually separated from the strip material in the last drop process. This lap is called the carrier of the continuous die. In the continuous die, the common carrier forms are edge, intermediate, double-sided, single-sided, etc. The edge carrier is used to punch a guide hole on the edge of the workpiece to position it for the forming process, such as deep drawing and bending. This type of carrier is simple, reliable, and material-saving in design, so it is widely used. The middle carrier is a carrier that cuts most of the material around the workpiece along the strip, leaving only a small amount of connecting material in the middle of the strip width. A double-sided carrier is to leave less pry material on both sides of the strip, which is rigid and not easy to deform and is often used for continuous stamping of thin material and large pitch workpieces. This carrier is less rigid and can only be used for continuous stamping of workpieces with larger material thickness and smaller feed distance. Since the continuous die requires high accuracy of step, the carrier cannot be deformed to ensure the dimensional accuracy of the step and improve the stability of the continuous die work, so the carrier’s design is an important aspect of the continuous die design. To ensure that the carrier has enough strength and rigidity, it is often used to increase the lap size appropriately; when the strength of a single-sided carrier is not enough, it can design a double-sided carrier and intermediate carrier; punch out the process cutout between the carrier and the workpiece, so that the carrier and the workpiece are separated, and the deformation of the workpiece will not affect the deformation of the carrier and other measures.

(9) Quick release and parts anti-stalling
In the continuous mold design, quick release and parts/standard parts anti-stalling are especially important. Because to achieve the purpose of fast mold repair, so continuous mold maintenance rarely removes the whole set of mold off the machine. Still, to stop the parts and templates that need to be repaired separately, it is necessary to design a quick disassembly structure. While removing the parts and template to replace them with new parts, it is often easy to misload the parts and get the wrong direction of the template, resulting in breaking the mold, so it needs to pay attention to the parts and template anti-dulling.