7s words believes that the definition of precision machining is to complete the final processing of main surfaces according to steps and procedures, including workpiece parallelism, surface finish, surface perpendicularity, surface hardness, etc., so that the processing accuracy and surface quality of parts can meet the requirements of the drawing.
1. Parallelism requirements
The so-called parallelism requirement is to require the tolerance around the workpiece. For example, for a rectangular workpiece, the thickness of the four corners of the workpiece is required to reach a certain tolerance range. If the thickness of the four sides cannot meet the tolerance requirements, the parallelism requirements cannot be met. This requires readjusting the workpiece. The problem may occur in the suction cup of the grinder. The suction cup is worn due to excessive use, resulting in parallelism errors; It may also be that the grinding wheel is not repaired well, or the grinding wheel has cracks and gaps. At this time, it is necessary to regrind the grinding wheel; It may also be that the suction cup is not cleaned, so it is necessary to clean the suction cup again and carefully; It may also be that the workpiece is not trimmed well and burrs appear.
2. Verticality requirements
The so-called perpendicularity requirement is to require the side and ground of the workpiece to meet the tolerance requirements. The best understanding is the proper body. From the number axis, it is divided into XYZ three sides. Generally, XZ and YZ are required to meet the tolerance requirements. The error is also roughly consistent with the requirements of parallelism. Generally, it can be handled according to the requirements of parallelism.
3. Other requirements
For example, finish. It is required to achieve, such as mirror effect, etc.