Haochen 20 years of focus on multimode cavities and small spacing hot runner

Today we will talk about the maintenance of molds. Good molds require frequent maintenance, so today we will talk about the maintenance of convex and concave molds in hot runner molds; Maintenance of discharge plates; Inspection of guide parts; Pay attention to the maintenance details of adjusting the mold gap in these four aspects

1. Maintenance of convex and concave molds
When disassembling the convex and concave molds, attention should be paid to the original condition of the mold, so that it can be easily restored during subsequent mold installation. If there is any padding or displacement, the thickness of the padding should be engraved on the parts and recorded. When replacing the convex mold, it is necessary to try inserting and unloading blocks, check whether the concave mold is smooth, and whether the gap between the insertion and the concave mold is even, When replacing the concave mold, it is also necessary to test whether the gap between the insertion and the punch is even. In order to shorten the convex mold after grinding, it is necessary to add shims to reach the required length. The effective length of the convex mold should be checked to see if it is sufficient. When replacing a broken convex mold, the cause should be identified, and the corresponding concave mold should be checked to see if there are any broken edges and if grinding is necessary. When assembling the convex mold, it is necessary to check whether the gap between the convex mold and the fixed block or plate is sufficient, If there is a pressure block, check if there is any movement margin left. The assembly of the concave mold should be placed horizontally, and then a flat iron block should be placed on the concave mold surface. Use a copper rod to gently tap it in place, and do not force it diagonally. The bottom of the concave mold should be chamfered. After installation, check whether the concave mold surface is flush with the mold surface. After the assembly of the convex mold, the concave mold, and the mold core, necessary checks should be made on the care belt to ensure that all parts are installed incorrectly or reversed. Check whether the concave mold and the cushion blocks of the concave mold are installed backwards, and whether the feeding holes are blocked, Is it necessary to steal materials for the newly replaced parts, is there enough to steal materials, and whether the parts that need to be locked in the mold are locked tightly? Pay attention to confirming the locking of the stripper plate screws, and lock them from the inside out with balanced force and cross locking. Do not lock one screw first and then another screw to avoid causing the stripper plate to tilt, causing the punch to break or the mold accuracy to decrease
2. Maintenance of discharge plate
The disassembly of the discharge plate can first be balanced by prying it up with two elevators, and then using both hands to remove the force. When it is difficult to disassemble, the mold should be checked for cleanliness, all locking screws should be removed, and whether there should be any damage to the mold caused by material jamming. The cause should be identified and corresponding measures should be taken. Blindly handling is not allowed. When assembling the discharge plate, the convex mold and discharge plate should be cleaned first, and lubricating oil should be added to the guide pillar and the convex mold at the inlet, and it should be smoothly inserted. Then, both hands should be used to press it into place, And repeat several times. If it is too tight, the reason should be identified (whether the guide pillar and guide sleeve guide are normal, whether there are damages in each part, whether the new convex mold can smoothly pass through the discharge plate position is correct, etc.), and the reason should be identified before corresponding treatment. If there are pressure blocks on the fixed plate, check whether there is enough stealing on the discharge back plate. The material contact surface between the discharge plate and the concave mold should be checked, Long term stamping produces indentations (the material gap between the discharge plate and the concave mold is generally 0.03-0.05mm reduction in material thickness. When the indentations are severe, it can affect the pressing accuracy of the material, causing abnormal and unstable product dimensions. It is necessary to repair or regrind the discharge insert and discharge plate. The precision of the contour sleeve should be checked, as it will cause the discharge plate to tilt when it is not of the same height, and its precise guidance and stable spring pressing functions will be damaged, requiring maintenance
3. Inspection of guide parts
What is the clearance between the guide pillar and guide sleeve, whether there are burns or wear marks, and whether the oil supply status of the mold guide is normal? Inspection should be conducted. The wear and damage of the guide components can reduce the accuracy of the mold, and various parts of the mold may have problems. Therefore, appropriate maintenance and regular replacement must be carried out. Check the accuracy of the guide components. If the guide nails are worn, the expected accuracy and function of the material belt guide have been lost, It is necessary to replace the spring. Check the condition of the spring (discharge spring and top spring, etc.) to see if it is broken, or if it has been used for a long time but has not broken, but has lost its original strength due to fatigue. Regular maintenance and replacement must be carried out, otherwise it may cause damage to the mold or hinder production
4. Adjustment of mold clearance
The positioning hole of the mold core causes wear due to frequent and multiple combinations of the mold core, resulting in large gaps (resulting in looseness after assembly) or uneven gaps (resulting in positioning deviation) after assembly, which can cause the shape of the cross-section to deteriorate after punching, the convex mold is easy to break, and burrs are generated. By checking the condition of the cross-section after offset cutting, appropriate gap adjustments can be made. When the gap is small, the cross-section is small, and when the gap is large, the cross-section is large and the burrs are large. By shifting, a reasonable gap can be obtained, After adjustment, appropriate records should be made, and markings can also be made on the edge of the concave mold for subsequent maintenance operations. Daily production should pay attention to collecting and preserving the original material strips when the mold is in good condition. If the subsequent production is not smooth or the mold undergoes variation, it can be used as a reference for mold maintenance. In addition, auxiliary systems such as whether the top material pin is worn, whether it can top the material, whether the guide pins and bushings are worn, should be inspected and maintained