Main contents of machining quality and accuracy testing
The content of machining quality and accuracy testing is divided into many aspects. Inspectors can choose to test all or carry out targeted testing according to the characteristics of their own products.
1. The size and behavior tolerance of each part of the geometry and simple mechanical performance testing.
2. The appearance inspection can be directly judged by the naked eye, observe whether the surface has bumps, bruises, defects and other conditions, and check whether the surface roughness meets the requirements.
3. Observe whether the material of the product meets the requirements, whether the brand is complete and whether the specification is correct.
Basic steps of machining inspection
1. Professional inspectors need to undergo pre job training and obtain relevant qualifications before they can engage in full-time inspection work.
2. When inspecting the first toad slice, you should check whether the process paper is a valid version, whether the circulation card material has a material seal, and whether the filling of the third inspection card meets the requirements.
3. Inspectors need to know every step of the processing process very well.
4. Inspectors need to select special machine universal measuring tools and use them correctly according to the processing process requirements.
5. After the first inspection, it is necessary to fill in the identification for filing. During batch inspection, it is also necessary to group the original records for future content search.
Precautions for machining inspection
1. When inspecting the long shaft, special attention should be paid to the deformation of the workpiece. In many cases, it is more likely to cause excessive heat due to the improper processing method of the processor, eliminate the stress equipment, and deform the straight line during cooling, exceeding the free tolerance range, resulting in unqualified dimensions.
2. After the detection of slender workpieces, it is necessary to pay attention to the storage and transportation at the same time. Improper operation can easily cause deformation. For example, slender lead screws need to be transported and stored with hangers to prevent parts from deformation.
3. When machining slender holes, the workpiece will have certain requirements for the hole diameter. When the straightness and surface roughness are high, the following points should be paid attention to:
(1) Whether the aperture is polygonal can be processed by the central axis grinding method.
(2) The roundness and straightness of the section can be measured by measuring together.
(3) The surface roughness requirement is not high, which can be judged by visual inspection, or by comparison method, sample block method, etc.
4. When inspecting slender workpieces, such as Fitter's slender holes, the size may be qualified, but there may also be drift, dislocation, etc. Therefore, this requires the inspectors to have rich testing experience and pay attention to the vertical direction.
