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cnc machining inspection process
Nov 16, 2018

The first-class machining factory must have the first-class inspection process and the inspection equipment.The following is a brief introduction of our inspection standards.

  Scope of application of inspection standards for machined parts

  This standard is applicable to the inspection of various inspection characteristics of machining, including turning, milling, grinding, boring, shaping, hole machining, broaching and bench work.At the same time, the basic principles of dimensional inspection, environmental requirements, appearance inspection, linear tolerance, and so on have certain provisions.

  Reference documents of inspection standards for machined parts

  GB/T 1958-1980 profile and position tolerance test requirements

  GB/T 1957-1981 smooth limit gauge

  Work instructions for Q/HXB 3000.1 sampling inspection

  Monitoring and measurement control procedures for Q/HXB 2005.1

  Q/HXB 2005.15 nonconforming product control procedure

  Iii. Dimension inspection standards

  1. Basic principle: this acceptance method only accepts the size acceptance work in the specified place. For the workpiece that meets the requirements, the size inspection shall conform to the Taylor principle.

  2. Principle of minimum deformation: in order to ensure the reliability and accuracy of the measurement results, various factors should be avoided to minimize the deformation programming.

  3. Principle of the shortest size chain: in order to ensure a certain measurement accuracy, the measuring chain should be as short as possible.

  4. Sealing principle: if the sealing condition can be satisfied during the measurement, the sum of the spacing deviation is zero, which is the so-called sealing principle.

  5. Basic consent principle: the vehicle benchmark should be consistent with the design benchmark and process benchmark.

  Iv. Standards for environmental inspection

  1. Temperature: the way to reduce and eliminate the error caused by the temperature is tested below 20 degrees Celsius of the standard temperature, so that the measuring tool and the workpiece material are consistent and the temperature is balanced.At the same time, ensure that the inspection site to avoid direct sunlight, heating and other heat sources and Windows out of the cold air caused by temperature changes.

  2. Humidity: excessive humidity has a huge impact on products.It is easy to cause rusting products, equipment moldy.When humidity is high, use a dehumidifier to remove water or use desiccant properly.At the same time, ensure that the inspectors are dry.

  3. Cleanliness: the content of cleanliness includes dustproof, corrosion-proof and so on.Inspection site should be away from dust sources such as grinding machine.Also corrosive gases in the way, away from laboratory, pickling and other work sites.

  4. Vibration: the table should be stable and away from vibration sources such as large machining equipment.

  V. appearance inspection

  1. Inspection method: inspect with visual inspection.This has certain requirements on the eyesight of the examiners, which requires the examiners to correct their vision to more than 1.0.

  2. Inspection eye distance: the distance from the workpiece to the eye is about 1000px.

  3. Inspection time: generally, an appearance is tested between 4 and 5 minutes.

  4. Surface defects: there shall be no obvious marks such as scratches, clamps and bruises on the finished surface of the workpiece.Also cannot appear obvious knife grain, vibration grain and so on.


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