Sensor for testing deformation degree of mining coal seam floor

Abstract

The invention discloses a sensor for testing the deformation degree of a mining coal seam floor. The sensor comprises a steel pipe skeleton, strain rosettes and an epoxy resin layer. Four strain rosettes are arranged and are pasted on the upper part and the lower part of the outer wall of the steel pipe skeleton respectively at an included angle of 90 degrees; each strain rosette is formed by twostrain gauges perpendicular to each other; each strain gauge includes a substrate formed by bonding of an upper thin piece and a lower thin piece and a sensitive grid is arranged between the upper thin piece and the lower thin piece; two wiring terminals are arranged at one end of each substrate and are connected with the sensitive grid by tin-plated copper wires; and an adhesive is arranged on the outer surface of the substrate, one side of the adhesive is adhered to the outer surface of the substrate and a piece of oily gummed paper is pasted on the other side. The outer wall of the steel pipe skeleton is coated with an epoxy resin by means of pouring. According to the invention, with the strain gauges, a phenomenon that the strain gauges fail to work because of lead dragging during theconnection process is prevented; the strain gauges can work normally and effectively in various severe environments. The data processing is simple; and the tested data reproducibility and comparativeproperty are good.

Description

technical field [0001] The invention relates to the technical field of anti-gas outburst safety management in coal mines, in particular to a sensor for testing the deformation degree of a mining coal seam floor. Background technique [0002] The strain sensor currently used is a hollow inclusion ground stress sensor developed by the Institute of Geomechanics, Chinese Academy of Geological Sciences. Each sensor is pasted with 3 sets of strain rosettes, each set of strain rosettes differs by 120°, and each set of strain rosettes has a difference of 45°. Composed of 4 strain gauges. [0003] When we tested the depth and degree of deformation and damage of mining floor, we found that this "sensor" has the following deficiencies: [0004] 1. Too many channels lead to troublesome data processing. This type of sensor has a total of 14 channels, including 12 working channels, 1 ground channel and 1 compensation channel. After the test, it is more troublesome to process the data bec...

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Problems solved by technology

[0004] 1. Too many channels lead to troublesome data processing. This type of sensor has a total of 14 channels, including 12 working channels, 1 ground channel and 1 compensation channel. After the test, it is more troublesome to process the data because the channels need to be converted The test results are better interpreted for axial and radial

[0005] 2. The data reproduction contrast is not high. Because the angles differ by 120°, the strain rosettes are all in the middle. The reproducibility of the strain value displayed by the vertical and horizontal force of the sensor under the action of mine pressure at a certain depth of the bottom plate is not good. Strong, not targeted

[0009] (2) The lead wire of the strain gauge is easily pulled during the connection process with the wire, resulting in the failure of the strain gauge;

[0010] (3) The outer protective layer has weak anti-scouring ability, and the sensitive grid of the strain gauge is broken due to force, etc.

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