In order to improve the quality of precision machining, it is the key to find out the main factors (original errors) that cause machining errors. However, how to take corresponding technological measures to control or reduce the influence of these factors? The following editor will understand with you Here are six ways to effectively improve the quality of precision machining:
1. Error grouping method
In this method, the working size reported by the previous process is divided into n groups according to the size of the error. The size error range of each group of workpieces is reduced to the original true /n; and then the relative tool is adjusted according to the error range of each group. Based on the position of the workpiece, the center of the size dispersion range of the named group of workpieces is basically the same. In order to greatly reduce the size dispersion range of the entire batch of workpieces. This method is often easier and more economical than improving the accuracy of guarding against gross damage. For example, when finishing the tooth profile, in order to ensure the coaxiality between the gear ring and the inner hole of the gear after processing, the clearance between the inner gear and the mandrel should be reduced. In production, the gears are often grouped according to the inner size of the gear, and then matched with the corresponding grouping mandrel, which evenly divides the original error caused by the gap, and improves the position accuracy of the gear ring.
2. Error compensation method
This method is to artificially create a new original error to offset the original error inherent in the original process system, so as to achieve the purpose of reducing processing errors and processing accuracy.
3. Error transfer method
This method essentially transfers the geometric errors, force deformation and thermal deformation of the process system to a direction that does not affect the machining accuracy. For example, for a multi-station process with indexing or indexing or a process using indexed tool holders, the indexing and conversion errors will directly affect the machining accuracy of the parts.
4. The error averaging method
This method makes use of closely related surfaces to correct each other, or use each other as a benchmark for processing. It can make those large local errors affect the entire processing surface more uniformly, and make the processing errors transmitted to the surface of the workpiece more uniform, so the processing accuracy of the workpiece is greatly improved accordingly.
5. In-situ processing method
Some precision in processing and equipment matching involves the interrelationship of parts and components, which is quite complicated. If you blindly improve the accuracy of the parts themselves, sometimes it is not only difficult or even impossible, but the use of in-situ processing can solve this problem. The main points of in-situ processing: to ensure what kind of positional relationship between parts, use a part to install a tool to process a part in this positional relationship. For example, in the manufacture of a hexagonal lathe, the axis of the six large holes on the turret for installing the tool holder must ensure that the machine tool and the spindle rotation line coincide, and the end face of each large hole must be perpendicular to the spindle rotation line.
6.Directly reduce the error method
This method is a basic method widely used in production. This method seeks to eliminate or reduce the main original error factors that affect the machining accuracy. For example, the turning of a slender shaft, due to the influence of force and heat, causes the work to bend and deform. The "big straight knife reverse cutting method" is now used, which basically eliminates the bending caused by the cutting force. Supplemented by the spring top can further eliminate the hazard of thermal elongation.