Maintenance of Cold Stamping Molds

Abstract: Cold stamping molds may experience various malfunctions and problems after a period of use, which can affect the normal production of stamping and even cause damage to the stamping die or safety accidents. In order to ensure the safe and reliable operation of the stamping die, it is necessary to pay attention to the maintenance of the mold.

Keywords: cold stamping die; Maintenance

Classification number: G718.5

1、 Preface

Cold stamping die is an important basic process equipment for modern industrial production, which is widely used in machinery, electronics, light industry, automobile, aerospace and other industries. It can be used to produce products with thin wall, light weight, complex shape, good surface quality and good rigidity, and the products have the characteristics of "identical". Therefore, the concepts of "mold is product quality" and "mold is economic benefit" have been increasingly recognized and accepted by more and more people. Cold stamping molds, as a special product, have a long manufacturing cycle, high cost, and complete sets in production. After a period of use, it may experience various malfunctions and problems, which can affect the normal production of stamping and even cause damage to cold stamping molds or safety accidents. Therefore, in order to ensure the normal operation of production, improve the quality of parts, and reduce the cost of parts Extending the service life of cold stamping molds, improving the technical status of cold stamping molds, and ensuring product quality (especially product consistency) from the source, "repairing (defective products) is better than repairing (including maintenance) molds" has become a consensus in the industry. Therefore, in order to ensure the safe and reliable operation of cold stamping molds, it is necessary to pay attention to the maintenance work of the molds, which should be integrated into all aspects of the use, repair, and storage of cold stamping molds.

2、 Cold stamping die usage and disassembly

Before using cold stamping molds, first check the process documents to ensure that the molds used are correct and that the specifications and models are consistent with the process documents. The operator should first understand the performance, methods, structural characteristics, and operating principles of the mold used. Then check if the equipment used is reasonable, such as whether the stroke and mold opening distance of the press are compatible with the mold used. Whether the molds used are intact and whether the stamping materials used meet the requirements of the parts. The mold installation should be correct, and there should be no looseness in the fastening parts. Before starting up, the debris on the workbench and mold should be cleaned to prevent damage to the mold or potential safety hazards after starting up.

After the mold is turned on, the first piece must be carefully inspected and qualified before production can begin. If it is not qualified, the machine should be stopped immediately to check the cause. During the operation, it is necessary to follow the regulations to prevent disorderly placement, collision, and violation of rules. If any abnormalities are found, the machine should be stopped immediately for rest. Simultaneously lubricate the sliding parts of the mold to prevent non-standard operations.

After using the mold, it should be removed from the machine tool according to the normal operating procedures. It is absolutely not allowed to dismantle or unload it randomly. During the lifting process, it should be handled steadily, slowly, and gently. The disassembled mold should be wiped clean and coated with oil for rust prevention. Inspect the last few parts of the mold processing to determine if they need maintenance, thus determining the technical status of the mold, ensuring its integrity, and promptly sending it to the designated location for storage.

After use, the punching die should be wiped clean in a timely manner and lubricating oil should be injected into the oil storage hole at the top of the guide column, and then covered with a piece of paper to prevent dust or debris from falling into the guide sleeve and affecting the guiding accuracy. To prevent rust on the cutting edges of the convex and concave molds, as well as on the guide posts, anti rust oil should be applied. In order to avoid the failure of the unloading device due to long-term pressure, limiting wooden blocks must be added during the storage and preservation of the mold. Stamps should be stored in a dry and ventilated mold warehouse, and small molds can be placed on shelves and arranged neatly in a certain order; Large molds are usually placed on the ground with wooden blocks on top to prevent rusting.

3、 Technical status assessment of cold stamping molds

During the use of cold stamping dies, natural wear of the die parts, unreasonable manufacturing processes of the die, improper installation or use of the die on the machine tool, and equipment failures can all cause the main components of the die to lose their original performance and accuracy. Resulting in the deterioration of stamping die technology, affecting the normal progress and efficiency of production as well as the quality of products. Therefore, in the management of stamping dies, it is necessary to actively grasp the changes in the technical status of the stamping dies and handle them carefully to ensure that the stamping dies can always work in good technical condition.

In addition, through the identification of the status of the stamping die technology, together with the defect content of the production quantity and quality of the product, the degree of wear of the stamping die, the reasons for the damage of the stamping die, etc., a stamping die repair plan and maintenance method can be formulated. This is necessary for extending the service life of the stamping die, reducing production costs, and improving the quality and technical manufacturing level of the stamping die.

The technical status assessment of stamping dies is generally carried out through two methods: the production of new molds and the repair of stamping dies. The technical status of stamping dies is assessed through mold testing. The identification of stamping die technology in use is mainly carried out by checking the quality condition of the parts and the working status of the stamping die. Here is an introduction to the technical identification methods during and after the use of stamping dies, for reference during identification.

1. Check the working performance of the punching die. During or after use, the performance and working status of the punching die should be evaluated Conduct a detailed inspection using the following main methods:

(1) Inspection of working parts for stamping dies

During or after the stamping process, the convex and concave dies should be inspected based on the quality of the parts, including whether there are cracks, damage, and severe wear on the convex and concave dies, whether the gap between the convex and concave dies is uniform and the size is appropriate, and whether the cutting edge is sharp (for punching dies). When burrs are found on the punched parts It is certain that the edges of the convex and concave molds will become dull and the gaps will be uneven. At this time, necessary adjustments and treatments must be made.

(2) Inspection of guidance device

Check whether the guide column, guide sleeve, and guide plate of the guiding device are severely worn, whether their fitting clearance is too large, and whether they are loose when installed on the template.

(3) Inspection of unloading device

Check whether the pushing and unloading devices of the die are sensitive and reliable, whether the top rod is bent or broken, the elasticity of the rubber and spring used for unloading, whether it works smoothly, and whether there is severe wear and deformation.

(4) Inspection of positioning device

Check whether the positioning device is reliable, whether the positioning pin and positioning plate are loose or severely worn. If the appearance and hole position of the product change and the quality does not meet the requirements during the inspection of the component, it is a problem with the positioning device and strict inspection should be carried out.

(5) Inspection of safety protection devices

In some stamping dies, safety protection devices such as protective plates are generally installed to ensure safety and reliability during operation. During inspection, emphasis should be placed on checking the reliability of its use, whether it operates sensitively and safely.

(6) Inspection of automatic systems

In some automatic punching dies, it is necessary to check whether the various parts of the automatic system are damaged, whether the actions are coordinated, and whether they can automatically perform normal feeding and discharging