Method for microscope to measure single pitch diameter of screw thread

Abstract

The invention relates to a method for a microscope to measure a single pitch diameter of a screw thread, comprising steps of (1) putting a screw thread to be measured under a microscope, regulating the microscope until the image is clear, regulating the screw thread to be horizontal, collecting the image of the screw thread to be measured through the microscopic, importing the image into an automatic drawing software, wherein the image comprises at least two tooth side lines on one side of the screw thread to be measured and at least four tooth side lines on the other side of the screw thread to be measured, processing the image of the screw thread to be measure through the automatic drawing software and calculating the single pitch diameter of the screw thread to be detected according to a three-pin method. The image of the screw thread to be measured is collected through the microscope, the image of the screw thread to be measured is imported into the automatic drawing software, the drawing, size marking and result calculation are performed in the automatic drawing software through the principle of simulating the three-pin method to measure the single pitch diameter. The invention realizes the non-contact measurement of the single pitch diameter of the screw thread, and can accurately measure the single pitch diameters of unconventional screw threads like the small diameter increasing screw thread, the truncation screw thread, etc.

Description

technical field

[0001] The invention relates to a method for measuring the single pitch diameter of a thread with a microscope. Background technique

[0002] At present, the conventional method for measuring the single pitch diameter of the thread is the three-needle method, which is fast and accurate, and has high measurement accuracy. The three-needle method to measure the pitch diameter of the thread is to place three measuring needles with the same diameter in the tooth grooves on both sides of the thread to be tested, such as figure 1 shown. Use a measuring instrument to measure the span M between the busbars of the three measuring needles, and according to the pitch p and the half-angle of the teeth and the needle diameter d 0 Calculate the single pitch diameter of the thread for normal thread then there is d 2s =M-3d 0 +0.866p; for trapezoidal thread then there is d 2s =M-4.864d 0 +1.866p.

[0003] However, because the root of the small-diameter enlarge...

Images