Spiral micrometer? Micrometer, also known as micrometer, micrometer and micrometer card, is a tool for measuring length more accurately than vernier caliper. It can accurately measure the length to 0.0 1 mm, and the measuring range is several centimeters.
Part of it is processed into a thread with a pitch of 0.5 mm. When it rotates in the screw sleeve of the fixed sleeve B, it will move forward or backward. The movable sleeve C is connected with the screw as a whole, and its periphery is divided into 50 squares. The complete number of turns of the screw is measured by the scribed lines on the fixed sleeve with an interval of 0.5 mm, and the part less than one turn is measured by the scribed lines around the movable sleeve, and the final measurement result is estimated to one decimal point.
The first micrometer was patented by French inventor Jean Laurent Palmer on 1848, and was improved by two American engineers, Joseph Brown and Lucian Sharp. After that, the product was mass-produced and successfully promoted in the market.
Species classification
Screw micrometer can be divided into mechanical micrometer and electronic micrometer. ① Mechanical micrometer. For example, the standard outside micrometer, referred to as micrometer for short, is a portable universal length measuring tool that uses the principle of precision thread pair to measure length. 1848, J.L. Palmer of France obtained the patent for the outside micrometer. 1869, J.R. Brown and L.Sharp of the United States made the outside micrometer into a commodity to measure the outside diameter of metal wire and the thickness of plate. There are many kinds of micrometer. Micrometers with different purposes can be made by changing the shape of measuring surface and ruler frame, such as micrometer for measuring inner diameter, pitch diameter of thread, common normal of gear or depth. ② Electronic micrometer such as digital display outside micrometer. Also known as digital micrometer, grating length measurement technology and integrated circuit are applied in the measurement system. Electronic micrometer appeared in the mid-1970s, and was used to measure the outside diameter.
Classification introduction
1. Vernier reading outside micrometer is used for ordinary outside diameter measurement.
2. Small-head micrometer is suitable for measuring precision parts of clocks and watches.
3. The structural feature of the pointed outside micrometer is that the two measuring surfaces are 45 conical tips. It is suitable for measuring the groove diameter of small grooves, such as drill bit, straight end milling cutter, flat groove tap and the diameter of the root circle of clock gear.
4. The invention is characterized in that the measuring surface is spherical, the measuring surface is flat and the ruler frame is irregular, which is suitable for measuring the wall thickness of pipelines.
5. The thickness micrometer refers to an outside micrometer with a spherical side measuring surface, a flat side and a special-shaped ruler frame, which is suitable for measuring the thickness of the plate.
6. The micrometer with micrometer head is structurally characterized in that the micrometer head is used to replace the fixed anvil of ordinary outside micrometer. It is very convenient to classify and check the workpieces with the same size, and the indication value is relatively stable. The measuring range is 0-25mm, 25-50mm, 50-75mm and 75-100mm. Mainly used for size comparison measurement.
7. The measuring surface diameter of the micrometer with large plane side is relatively large (12.5mm) and can be replaced, so the pressure between the measuring surface and the measured workpiece is relatively small. It is suitable for measuring the thickness of elastic materials or soft metal parts, such as metal foil, rubber and paper.
8. The feature of large micrometer is that it can change the anvil or adjust the measuring rod, which is beneficial to reduce the number of micrometers and expand the application range of micrometers.
9. The outside micrometer with word-to-word reading has a small window on the differential cylinder, and the display reading is 0.1mm..
10. Electronic digital display outside micrometer refers to an outside micrometer that reads the distance between two measuring surfaces on the ruler frame by using the principles of electronic measurement, digital display and screw pair.
1 1. Measure the groove diameter with a thin micrometer.
12. Measure the span of spur gear and helical gear with a disk micrometer.
13.v Odd Tapes of Felt Micrometer and Measurement of Tool Outer Diameter
14. Measurement of gear groove diameter of spline micrometer
15. measurement of the width of small diameter narrow groove of caliper micrometer
16. Measurement of effective diameter of thread micrometer