Vacuum retaining structure for high-resolution quartz flexible accelerometer

Abstract

The invention relates to a vacuum retaining structure for a high-resolution quartz flexible accelerometer. The vacuum retaining structure comprises upper and lower magnetic ring components, a pendulumcomponent and a connecting ring, wherein the pendulum component is composed of a quartz pendulum, a torquer coil and a coil skeleton; each of the upper and lower magnetic ring components is composedof a magnetic ring, a cylindrical permanent magnet, a magnetic cover and a magnetic base; the bottom of the magnetic ring is coaxially installed on the magnetic cover, a groove raised upward and opened downward is coaxially formed in the center of the magnetic cover, the cylindrical permanent magnet and the magnetic base are coaxially arranged inside the groove in sequence from top to bottom, andthe magnetic base is sealed with the magnetic cover together in a laser sealing manner to form a closed cavity; the magnetic ring components are used in pair, installed in a coaxial mirror image manner and welded together through the connecting ring in a laser sealing manner, and the pendulum component is fixedly installed therebetween. By improving the magnetic ring component structures based onthe existing quartz flexible accelerometer structure and increasing the laser welding seal design, the degree of vacuum inside the accelerometer is retained, and the resolution stability of the accelerometer over time is retained.

Description

technical field [0001] The invention belongs to the technical field of sensors, in particular to a vacuum holding structure for a high-resolution quartz flexible accelerometer, and is an accelerometer measuring element suitable for a high-resolution navigation system and a gravity gradiometer system. Background technique [0002] The quartz flexible accelerometer is a differential capacitive closed-loop high-precision sensor, which was first successfully developed by the US Sen Di Stein company in the 1970s. The specific structure is described in detail in the US patent (patent No. 4250757). The structure of the watch movement is as figure 1 , figure 2 As shown, it is the simplest high-precision accelerometer commonly used in domestic inertial navigation measurement and guidance systems. figure 1 is a three-dimensional exploded view of an ordinary quartz flexible accelerometer, figure 2 It is a two-dimensional axial cross-sectional view of an ordinary quartz flexible ac...

AI Technical Summary

Problems solved by technology

[0008] The material with the highest gas output rate inside the high-resolution quartz flexible accelerometer is the powder metallurgy permanent magnet, which has gaps and porosity, and contains gas, which cannot be removed during vacuum exhaust, and will be discharged to the accelerometer during a long period of work. Inside the accelerometer, the air pressure inside the accelerometer changes, causing a decrease in resolution and stability

[0009] At present, there are two main methods of vacuum maintenance: 1) using a suitable getter, but there is a certain number of times of use; 2) always connecting the inner cavity of the accelerometer to the vacuum pump, but in actual work, if the vacuum pump is connected to the accelerometer , it will cause mechanical vibration during operation and reduce the accuracy of the accelerometer

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