Improving the accuracy of mold processing has always been a headache for many enterprises. Today, the experienced engineer of Yangfan Mold will bring you a few methods to improve mold accuracy.
TV plastic mold
The methods to ensure and improve machining accuracy can be roughly summarized as follows:
1. Reduce the original error
Improving the geometric accuracy of the machine tool used for part processing, improving the accuracy of fixtures, measuring tools, and tools themselves, controlling the force and thermal deformation of the process system, tool wear, deformation caused by internal stress, measurement errors, etc., all belong to directly reducing the original error. In order to improve the machining accuracy, it is necessary to analyze the various original errors that cause machining errors, and take different measures to solve the main original errors that cause machining errors according to different situations. For the processing of precision parts, the geometric accuracy, stiffness, and control of machining thermal deformation of the precision machine tool used should be improved as much as possible; For machining parts with formed surfaces, the main focus is on reducing the shape error of the forming tool and the installation error of the tool.
This method is a widely used basic method in production. It is to identify the main factors that cause machining errors and then try to eliminate or reduce these factors.
2. Compensating for original errors
Error compensation method is the artificial creation of a new error to offset the original error in the original process system. When the original error is negative, the human error should be taken as positive. Conversely, negative values should be taken and the two should be made as equal as possible; Alternatively, one type of original error can be used to offset another type of original error, which is also to try to make the two equal in size and opposite in direction, in order to reduce machining errors and improve machining accuracy.
3. Transfer the original error
The error transfer method essentially involves transferring the geometric errors, stress deformation, and thermal deformation of the process system. There are many examples of error transfer method. When the precision of the machine tool cannot meet the requirements of part processing, it is often not simply to improve the precision of the machine tool, but to find ways from the process or fixture, create conditions, and transfer the geometric errors of the machine tool to aspects that do not affect processing accuracy.
4. Average the original error
In mold processing, the presence of errors in the blank or previous process often leads to machining errors in the cost process, or changes in the material properties of the workpiece, or changes in the process of the previous process (such as canceling the original cutting process after the blank is refined), resulting in significant changes in the original error. The solution to this problem is to use the method of adjusting the average division error by grouping. The essence of this method is to evenly divide the original error into n groups according to their size, and the error range of each group of blanks is reduced to 1/n of the original, and then adjust the processing according to each group.
5. Normalize the original error
Grinding technology is often used for shafts and holes that require high precision in fitting. The grinding tool itself does not require high precision, but it can perform micro cutting on the workpiece during relative motion, gradually grinding off the high points (of course, a part of the mold is also ground off by the workpiece), making the workpiece achieve high precision. The process of friction and wear between surfaces is a continuous reduction in error, which is known as the error equalization method.
6. On site processing method
In mold processing and assembly, some accuracy issues involve the interrelationships between parts or components, which are quite complex. If we blindly improve the accuracy of the parts or components themselves, sometimes it is not only difficult, but even impossible. If we use on-site processing method (also known as self processing and repair method), it may be very convenient to solve the seemingly difficult accuracy problem. The in-situ machining method is often used as an effective measure to ensure the machining accuracy of mechanical parts.
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