About some hardware machining
By shumijia | 05 November 2021 | 0 Comments

The principle of the definition and use of the percentage and micrometer

Nowadays, percentage and micrometer occupy an increasingly important position in mechanical engineering measurement tools, and I will explain the definition principle and usage of percentage and micrometer.
1: The definition principle of the percentage and micrometer
The micrometer and the percentage meter are made of precision rack and pinion mechanism, which is a universal length measuring tool. When the measuring rod moves 1 mm, this movement is amplified by the rack, the shaft gear 1, the gear and the shaft gear 2, and then passed to the pointer mounted on the shaft gear 2, which makes the pointer rotate once. If the circular dial is printed with 100 equal divisions along the circumference, each equal division is equivalent to the measuring rod moving 0.01 mm, this instrument measuring tool is often called a percentage meter, and if the amplification ratio of the gear amplification mechanism is increased so that the divisions on the circular dial are 0.001 mm or 0.002 mm (there are 200 or 100 equal divisions on the circular dial), then this type of measuring tool is called micrometer, and the principle of both is the same. The micrometer was made by B.C. Ames in the United States in 1890, and it is commonly used to measure shape and position errors and the length of small displacements. Micrometer indication range is generally 0 ~ 10 mm, the large can reach 100 mm, change the shape of the probe and with the corresponding bracket, can be made of micrometer deformation varieties, such as thickness micrometer, depth micrometer, internal diameter micrometer (see bore measurement), etc., if the lever instead of rack, you can make a lever percentage and lever micrometer, the indication range is small, but high sensitivity. In addition, their probes can be rotated within a certain angle, can adapt to the measurement of different directions, compact structure, suitable for measuring the shape and position errors of the outer circle, small holes and grooves, etc., which are difficult to measure by ordinary percentage table.
2: Use method
As the reading accuracy of the micrometer is higher than the percentage table, so the percentage table is suitable for the size accuracy of IT6 ~ IT8 parts of the correction and inspection, the micrometer is suitable for the size accuracy of IT5 ~ IT7 parts of the correction and inspection, the percentage table and the micrometer according to its manufacturing accuracy, can be divided into 0, 1, 2 three, 0 accuracy is higher, when using, should be in accordance with the shape and accuracy requirements of the parts, choose When using, according to the shape and accuracy requirements of the parts, the appropriate accuracy level and measurement range of the percentage or micrometer.
The above is an introduction to the commonly used gauges in the percentage table, micrometer tool, micrometer as a mechanical length measuring tool in a higher precision measuring instruments, has been widely used. We usually use the micrometer, must be in accordance with the correct use of the method to operate, so as to ensure the accuracy of the instrument measurement data and service life, etc.


Leave a Reply

Your email address will not be published.Required fields are marked. *
Verification code