Positioning apparatus and its positioning method

Abstract

The invention relates to a positioning device applying to the thickness measurement of a large-size lamella, which comprises a fixed seat and a locking seat fixed under the fixed seat; wherein, the fixed seat is provided with a positioning hole running through the thickness of the fixed seat; the positioning hole is internally provided with a supporting mechanism; the supporting mechanism comprises three spherical supporting surfaces running out of the upper opening part of the positioning hole; the peaks of the three spherical supporting surfaces form a supporting plane; the locking seat is further provided with a central vacuum line for vacuumizing the positioning hole. By adopting surface contact to replace point contact between the lamella and the supporting mechanism, the lamella can be ensured to keep high parallelism opposite to a machine station after being placed on the positioning device at every time and the measuring accuracy of the lamella thickness can be ensured. By keeping the lamella to have high parallelism opposite to the machine station after being placed on the positioning device at every time, good repeated measuring accuracy can be ensured in every measurement.

Description

technical field [0001] The invention relates to a positioning device applied to a large-size sheet thickness measuring device and a positioning method of the positioning device. Background technique [0002] The positioning device is an essential device in the large-scale thin plate thickness measuring device. At present, the positioning part of the positioning device is generally a finished positioning reference plane, and the thin plate to be measured is placed on the positioning reference plane and clamped. Although the positioning datum plane is finely machined, it is inevitable that there will be uneven thickness due to surface tension problems, such as some local warping or depression. When the thin plate is placed on the positioning datum plane, some positions of the thin plate will be relatively The machine platform is tilted, which leads to the deviation of the thickness measurement of the thin plate; in addition, when the thin plate is placed on the positioning re...

AI Technical Summary

Problems solved by technology

Although the positioning datum plane is finely machined, it is inevitable that there will be uneven thickness due to surface tension problems, such as some local warping or depression. When the thin plate is placed on the positioning datum plane, some positions of the thin plate will be relatively The machine platform is tilted, which leads to the deviation of the thickness measurement of the thin plate; in addition, when the thin plate is placed on the positioning reference plane every time, the thin plate will rotate a certain angle relative to the positioning reference plane, and different positions of the thin plate will be tilted relative to the machine. This results in low repeatability for thin plates

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