Gas-driven miniature grating ruler

Abstract

A gas-driven miniature grating ruler comprises a shell, a mounting frame arranged in the shell, a probe assembly, a control structure used for controlling the probe assembly to stretch out and retract and a grating assembly. The mounting frame is fixedly arranged in the shell, and a sliding block capable of sliding in the axial direction of the shell is arranged in the mounting frame; the probe assembly, the mounting frame and the shell jointly form a gas chamber I; the probe assembly comprises a probe and a sliding optical axis connected with the probe, the end face, facing the sliding block, of the sliding optical axis is an air pressure stress end, and the sliding optical axis is connected with the sliding block through a connecting rod penetrating into the installation frame; and the control structure comprises a breather pipe arranged on the mounting frame and communicated with the first gas cavity, a permanent magnet arranged in the first gas cavity and used for attracting the sliding optical axis, and a coil, and the coil generates a magnetic field capable of being neutralized with a magnetic field of the permanent magnet in a power-on state. According to the invention, the grating ruler is wider in applicable detection object range and longer in service life.

Description

technical field [0001] The invention relates to the measurement field, in particular to an air-driven miniature grating ruler. Background technique [0002] The grating ruler displacement sensor is referred to as the grating ruler, which is a measurement feedback device that uses the optical principle of the grating. The essence of the grating measurement displacement is to measure the position weighing with the grating pitch as a standard ruler. At present, the grating scale displacement sensor system mostly adopts the electronic subdivision method. When the two gratings of the indicator grating and the scale grating overlap at a small inclination angle, Moiré fringes will be generated in the direction roughly perpendicular to the line of the indicator grating. As the scale grating moves, the moiré fringes also move up and down, so that the measurement of the grating pitch is converted into the measurement of the number of moiré fringes. [0003] In the traditional gratin...

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Problems solved by technology

[0005] 1: When the grating scale detects different workpieces, the requirements for the extension length of the probe and the extension length of the spring are different. In the prior art, the extension force of the probe depends not only on the air pressure, but also on the spring, and the extension force There is an attenuation phenomenon during the elongation of the spring, which will cause the probe to fail to meet the requirements for the extension length of the probe during actual detection. Therefore, the grating ruler in the prior art has a limited maximum extension of the probe and a limited detection capability. The scope of application of the tested workpiece is limited;

[0006] 2: The spring is a fragile part, and the service life of the grating ruler is likely to be shortened due to the fatigue of the spring

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