How to Improve the Machining Accuracy of the Mold

The precision of the mold is a very important criterion for evaluating the quality of a mold. The quality of the precision is directly related to the quality and usability of the products produced. Sometimes a small error will cause the entire product to be unusable. How to ensure the processing Precision is a problem that every mold processing engineer must consider. So what aspects can we start with? Wo Neng Precision's mold engineers will sort out related methods for everyone.





1. Start with the original error


This is mainly considered from the processing tools, such as machine tools, cutting tools, fixtures, etc. During the processing process, controlling the force of the process system, thermal deformation, tool wear, deformation caused by internal stress, and measurement errors are all directly reduced. raw error. For the processing of precision parts, the geometric accuracy, rigidity and control of processing thermal deformation of the precision machine tools used should be improved as much as possible;
For the processing of parts with formed surfaces, it is mainly how to reduce the shape error of the forming tool and the installation error of the tool.



2. Compensate the original error


The error compensation method is to artificially create a new error to offset the original error in the original process system. When the original error is negative, the man-made error will take a positive value, otherwise, take a negative value, and try to make the two equal in size; or use one original error to offset another original error, and try to make the two equal in size , in the opposite direction, so as to achieve the purpose of reducing machining errors and improving machining accuracy.





3. Transfer the original error


The error transfer method is essentially to transfer the geometric error, force deformation and thermal deformation of the process system. There are many examples of error transfer methods. For example, when the accuracy of the machine tool does not meet the processing requirements of the parts, it is often not to blindly improve the accuracy of the machine tool, but to find a way from the process or the fixture to create conditions so that the geometric error of the machine tool can be transferred to the aspect that does not affect the machining accuracy.


4. Average raw error


In mold processing, due to the existence of blanks or errors in the previous process, processing errors in this process are often caused, or due to changes in the properties of the workpiece material, or changes in the process of the previous process (such as after the blank is refined, the original cutting process Cancel
), causing a large change in the original error. To solve this problem, the method of grouping to adjust the average error is adopted. The essence of this method is to divide the original error into n groups according to its size, and the blank error range of each group is reduced to the original 1/n, and then adjust the processing according to each group.


5. Average raw error


Grinding process is often used for shafts and holes that require high matching accuracy. The grinding tool itself does not require high precision, but it can perform micro-cutting on the workpiece during relative movement with the workpiece, and the high point will be gradually worn off (of course, part of the mold is also worn off by the workpiece), so that the workpiece can reach a high level. accuracy. This process of friction and wear between surfaces is a process of continuous error reduction, which is the error averaging method.


6. In situ processing method


In mold processing and assembly, some precision problems involve the relationship between parts or components, which is quite complicated. If you blindly improve the precision of parts and components, sometimes it is not only difficult, but even impossible. If you use the in-situ processing method (also known as Self-processing and repairing method), it may be very convenient to solve the precision problem that seems very difficult. The in-situ processing method is often used in the processing of mechanical parts as an effective measure to ensure the processing accuracy of parts.