Machined parts need to be inspected after production, which can not only detect the defective products in processing and production, but also provide beneficial help for the use of products in subsequent work. Machining inspection report is one of the important documents delivered to customers. Then, what is the factory inspection report of mechanical parts processing?
1、 General
1. Inspectors need to have professional knowledge and practical work experience, and also need to meet the requirements of leading products for inspection work.
2. The measuring instruments used by the inspectors need to be verified by the measurement department and within the specified verification cycle.
3. Before accepting products, inspectors need to be familiar with relevant drawings and technical documents, and understand the key dimensions of parts and the key points of assembly.
4. The inspectors need to judge the parts in strict accordance with the requirements of the drawings and technical documents.
5. The inspectors shall mark the products in process in the workshop as required.
2、 Inspection system
1. First inspection system: for the first part processed by each operator, it is necessary to conduct a comprehensive inspection and keep it.
2. Patrol inspection system: ensure that key parts can be controlled throughout the process.
3. Transfer inspection system: parts that are about to be transferred to the next process should be inspected to prevent unqualified products from flowing into the next process.
4. Completion inspection system: for products that are about to be warehoused after production, completion inspection shall be carried out, including size and shape, whether there are missing processing procedures, etc.
3、 Inspection method
1. Basic dimension and shape inspection
(1) Measurement of outer diameter
When measuring the outer diameter, it is necessary to measure and record in two parts in the circumferential direction. When the length of the part with the same diameter is greater than 50mm, the straightness should be checked, the working surface of the knife edge ruler should be in contact with the outer diameter bus, the width of the building should be observed, and then it should be judged by comparing with the standard optical gap.
(2) Measurement of inner diameter
When measuring the inner diameter of parts, only measure in three parts in the circumferential direction, and make records at the same time. When the length of the same diameter is greater than 40mm, the cylindricity should be checked, and the measurement should be made at two positions with a large interval within the length direction of the same diameter. Calculate the cylindricity error.
(3) Length measurement
External thread measurement: the pitch diameter of external thread is measured with thread ring gauge or three pins, and the minor diameter is detected with thread ring gauge (go gauge).
Internal thread measurement: the external diameter of internal thread is inspected with thread plug gauge (go gauge), and the medium diameter is inspected with thread plug gauge.
The large, medium and small diameter of threads shall be accepted according to the accuracy level required by the drawing.
The effective length tolerance of thread: according to the requirements of hy/qt001 fastener inspection specification.
2. Detection of surface plane
(1) Surface roughness detection: sample block comparison method is used for comparison and judgment.
(2) Inspection of Flatness: use the marking method to detect. Place three adjustable supports on the flat plate, place the measuring surface of the part upward on the support point, adjust the support point, and make the three points equal in height. The peak and valley values measured by marking the table are the flatness error of the plane.
