CN109357606B

CN109357606B - A clamping mechanism for a vibrating wire strain sensor calibration device

Info

Publication number: CN109357606B
Application number: CN201811453115.0A
Authority: CN
Inventors: 王一凡; 王晓伟; 贾晓杰; 邹晓华; 张红岩; 毛森; 牛国栋; 李博; 王伟鹏
Original assignee: Henan Institute Of Metrology And Testing Science
Current assignee: Henan Institute Of Metrology And Testing Science
Priority date: 2018-11-30
Filing date: 2018-11-30
Publication date: 2024-07-12
Anticipated expiration: 2038-11-30
Also published as: CN109357606A

Abstract

The invention discloses a clamping mechanism for a vibrating wire type strain sensor calibration device, which comprises a left clamp and a right clamp, wherein the left clamp comprises a left sliding block, a left smooth through hole for penetrating a guide sliding rod and a left threaded through hole for being in threaded connection with a power screw rod are formed in the left sliding block, and a left clamping head is fixed at the top of the left sliding block; the right clamp comprises a right sliding block, a right smooth perforation for penetrating through the guide sliding rod and a right smooth perforation for penetrating through the power screw rod are arranged on the right sliding block, and a right clamping head is fixed at the top of the right sliding block; the left displacement sensor and the right displacement sensor are used for detecting sliding amounts of the left end and the right end of the vibrating wire type strain sensor simultaneously, so that measurement accuracy is improved, and the stressed change condition can be detected in real time.

Description

Clamping mechanism for vibrating wire type strain sensor calibration device

Technical Field

The invention belongs to the technical field of metering calibration equipment, and particularly relates to a clamping mechanism for a vibrating wire type strain sensor calibration device.

Background

The vibrating wire type strain sensor is an advanced sensor in the current stress strain measurement, the sensor outputs frequency instead of voltage, and the sensor can not cause obvious attenuation of signals due to the change of wire resistance and temperature fluctuation, has the advantages of simple structure, high precision, strong anti-interference capability, long signal transmission distance, good long-term stability and the like, can be applied to severe environments such as low temperature, high temperature and high radiation, and is widely applied to safety pre-warning and safety detection in the fields such as dams, bridges, large buildings, subways, ship building, mines, coal mines, foundation pits, water conservancy and hydropower, petrochemical industry, nuclear power stations and the like.

Aiming at the vibrating wire type strain sensor, the national formulates general technical conditions of the vibrating wire type strain sensor of the geotechnical test instrument geotechnical engineering instrument of GB/T13606-2007 and the calibration standard of the JJF 1305-2011 linear displacement sensor, and provides the technical requirements and the calibration method of the basic error and the linearity of the vibrating wire type strain sensor, but does not specify which standard instrument is adopted to ensure the accurate and reliable magnitude, and does not specify a unified calibration method and device. In recent years, the domestic part of the mechanism designs a calibration device according to the specification, for example, a chinese patent CN101738157a discloses a vibrating wire type strain sensor calibration device, which is mainly of a purely mechanical structure, uses a dial indicator to perform measurement, and mainly has the problems of high calibration labor intensity, low calibration efficiency and difficulty in obtaining repeatability errors. Chinese patent CN107621222a discloses a vibrating wire strain gauge calibration device, which measures the tiny length variation during the calibration process, but has a significant influence on the calibration result due to the sliding problem of the clamping part of the sensor; when calibrating a wide-range vibrating wire sensor, the device can deform, and the rigidity of the device cannot meet the calibration requirement.

In the calibration process, the clamping stability requirement on the vibrating wire type strain sensor is high, however, no special vibrating wire type strain sensor clamping device is used for the vibrating wire type strain sensor calibration device at present.

Disclosure of Invention

The invention aims to provide a clamping mechanism for a vibrating wire type strain sensor calibration device; the technical scheme adopted for achieving the purpose is as follows:

The clamping mechanism for the vibrating wire type strain sensor calibration device comprises a left clamp and a right clamp, wherein the left clamp comprises a left sliding block, a left smooth through hole for penetrating a guide sliding rod and a left threaded through hole for being in threaded connection with a power screw rod are formed in the left sliding block, and a left clamping head is fixed at the top of the left sliding block; the right clamp comprises a right sliding block, a right smooth perforation for penetrating through the guide sliding rod and a right smooth perforation for penetrating through the power screw rod are arranged on the right sliding block, and a right clamping head is fixed at the top of the right sliding block.

Preferably, a left positioning groove is formed in the bottom of the left clamping head, a left mounting perforation is formed beside the left positioning groove, a left positioning bulge corresponding to the left positioning groove is formed on the left sliding block, and a left fixing threaded hole corresponding to the left mounting perforation is formed beside the left positioning bulge; the bottom of the right clamping head is provided with a right positioning groove, a right mounting perforation is arranged beside the right positioning groove, a right positioning bulge corresponding to the right positioning groove is arranged on the right sliding block, and a right fixing threaded hole corresponding to the right mounting perforation is arranged beside the right positioning bulge.

Preferably, a left displacement sensor is fixed on the left sliding block, and the left displacement sensor is positioned at the left side of the left clamping head; a right displacement sensor is fixed on the right sliding block and is positioned on the right side of the right clamping head; the left displacement sensor and the right displacement sensor are matched to detect the left and right sliding quantity of the vibrating wire type strain sensor.

Preferably, a fixed table is fixed on the left sliding block, a sliding table is connected on the fixed table in a sliding way along the left-right direction, a fastening bolt for fixing the sliding table is arranged on the sliding table, and a left clamping seat for fixing a left displacement sensor is fixed on the top of the sliding table; a right clamping seat for fixing the right displacement sensor is fixed on the right sliding block.

Preferably, a main scale mark is arranged on the fixed table, a vernier scale mark is arranged on the sliding table, and the fixed table and the sliding table form a vernier caliper structure.

Preferably, the top of the sliding table is provided with mounting holes distributed in a matrix, and the left clamping seat is fixed at different positions on the top of the sliding table through different mounting holes.

The invention has the beneficial effects that: (1) The sliding quantity of the left end and the right end of the vibrating wire type strain sensor is detected through the left displacement sensor and the right displacement sensor, so that the measurement accuracy is improved, and the change condition of the stressed value can be detected in real time; (2) The left displacement sensor realizes the functions of coarse adjustment and fine adjustment through the cooperation of the fixed table and the sliding table; (3) The measuring displacement amounts of the left displacement sensor, the right displacement sensor and the grating ruler displacement sensor are in the same direction, so that Abbe errors caused by mechanism deformation are reduced; (4) The invention realizes the full-automatic calibration of the vibrating wire strain sensor, the vibrating wire displacement meter and the vibrating wire seam meter, and accords with the national standard of computing method of main static performance index of GB/T18459-2001 sensor, general technical condition of the vibrating wire sensor of geotechnical test instrument of GB/T13606-2007 and calibration specification of the JJF 1305-2011 linear displacement sensor.

Drawings

FIG. 1 is a schematic view of an assembled perspective structure of the present invention;

FIG. 2 is an enlarged perspective view of the left clamp of FIG. 1;

fig. 3 is an enlarged perspective view of the right clamp of fig. 1.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

As shown in fig. 1 to 3, firstly, the invention is assembled on a special vibrating wire type strain sensor calibration device, wherein the vibrating wire type strain sensor calibration device comprises a base 8, a left fixing seat 9 is fixed at the left end of the base 8, a right fixing seat 6 is fixed at the right end of the base 8, a guide sliding rod 4 is fixed between the left fixing seat 9 and the right fixing seat 6, a power screw 3 is rotatably connected, a clamping mechanism of the invention is assembled between the left fixing seat 9 and the right fixing seat 6, specifically, the clamping mechanism of the invention comprises a left clamp 1 and a right clamp 5, the left clamp 1 comprises a left sliding block 104, the left sliding block 104 is sleeved on the left half part of the guide sliding rod 4 and the power screw 3, the left sliding block 104 is in sliding connection with the guide sliding rod 4 and in threaded transmission connection with the power screw 3, and a left clamping head 103 is fixed on the left sliding block 104; the right clamp 5 comprises a right slider 505, the right slider 505 is sleeved on the right half part of the guide slide rod 4 and the power screw 3, the right slider 505 is in sliding connection with the guide slide rod 4 and the power screw 3, two ends of the S-shaped tension pressure sensor 504 are respectively fixed on the right slider 505 and the right fixing seat 6, a right clamping head 501 is fixed on the right slider 502, and the left clamping head 103 and the right clamping head 501 are matched to fix the vibrating wire type strain sensor.

According to vibrating wire strain sensors with different specifications and models, a plurality of sets of clamping heads can be correspondingly manufactured, each set of clamping head comprises a left clamping head 103 and a right clamping head 501, anti-skidding patterns are arranged in clamping holes of the left clamping head 103 and the right clamping head 501, a left positioning groove is formed in the bottom of the left clamping head 103 for facilitating quick replacement and accurate positioning, left mounting through holes are formed beside the left positioning groove, left positioning protrusions corresponding to the left positioning grooves are formed on the left sliding block 104, and left fixing threaded holes corresponding to the left mounting through holes are formed beside the left positioning protrusions; a right positioning groove is arranged at the bottom of the right clamping head 501, a right mounting perforation is arranged beside the right positioning groove, a right positioning bulge corresponding to the right positioning groove is arranged on the right sliding block 505, and a right fixing threaded hole corresponding to the right mounting perforation is arranged beside the right positioning bulge.

As shown in fig. 2 and 3, a fixed table 108 is fixed to the left slider 104, a slide table 109 is slidably connected to the fixed table 108 in the left-right direction, a fastening bolt (not shown in the back view) for fixing the slide table 109 is provided to the slide table 109, a left clamp seat 102 for fixing the left displacement sensor 101 is fixed to the top of the slide table 109, and the left displacement sensor 101 is positioned on the left side of the left clamp head 103; a right clamping seat 502 for fixing a right displacement sensor 503 is fixed on the right slider 505, the right displacement sensor 503 is located on the right side of the right clamping head 501, and the left displacement sensor 101 and the right displacement sensor 503 are matched to detect the left-right sliding amount of the vibrating wire strain sensor.

Meanwhile, a main scale mark 106 is arranged on the fixed table 108, a vernier scale mark 105 is arranged on the sliding table 109, and the fixed table 108 and the sliding table 109 form a vernier caliper structure. The top of the sliding table 109 is provided with mounting holes 1010 distributed in a matrix, and the left clamping seat 102 is fixed at different positions at the top of the sliding table 109 through different mounting holes 1010, so that the left displacement sensor 101 can perform coarse adjustment and fine adjustment with high accuracy at a large distance for vibrating wire type strain sensors with different specifications.

On the other hand, the left clamping seat 102 is provided with a plurality of left clamping holes for fixing the left displacement sensor 101, and the right clamping seat 502 is provided with a plurality of right clamping holes for fixing the right displacement sensor 503.

In order to ensure stability in the moving process, the left slider 104 and the right left slider 505 are suspended on the guide slide rod 4 and the power screw rod 3, two of the guide slide rods 4 are respectively positioned at two sides of the power screw rod 3, and the third guide slide rod 4 is positioned below the guide slide rod 4.

When the vibrating wire type strain sensor is used, firstly, a proper left clamping head 103 and right clamping head 501 are selected according to the specification and model of the vibrating wire type strain sensor to be calibrated, and are respectively fixed on a left sliding block 104 and a right sliding block 505, and then two ends of the vibrating wire type strain sensor are respectively fixed on the left clamping head 103 and the right clamping head 501; adjusting the right displacement sensor 503 to detect the right end face displacement of the vibrating wire type strain sensor, and zeroing the reading; the left displacement sensor 101 is adjusted by adjusting the mounting position of the left clamping seat 102 on the sliding table 109 and the micro-movement of the sliding table 109 so as to detect the left end face displacement of the vibrating wire strain sensor, and the reading is zeroed; then, the servo motor 12 is started to drive the power screw 3 to slowly rotate, so that the left slider 104 is driven to move rightwards, the grating ruler displacement sensor detects the displacement in the moving process, the S-shaped tension pressure sensor 504 detects the stress, and according to the displacement data, the required calibration parameters can be evaluated by combining the related measurement data of the vibrating wire type strain sensor.

In order to avoid damage to the instrument caused by rightward movement of the left slider 104 in the measuring process, the base 8 is provided with limit switches 2, one of the limit switches 2, for example, the left limit switch 2, can be fixed on the base 8, and the other limit switch 2 can be detachably fixed on the base 8, so that the position of the other limit switch 2 can be adaptively adjusted according to the measuring range of the vibrating wire type strain sensor to be calibrated. Further, the other limit switch 2 may be fixed to the base 8 by means of a magnetic attraction force by means of a magnetic seat.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may be modified or some technical features may be replaced with others, which may not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A clamping mechanism for a vibrating-wire strain sensor calibration device, characterized in that it comprises a left clamp and a right clamp, wherein the left clamp comprises a left slider, a left smooth through hole for passing a guide slider and a left threaded through hole for threadedly connecting a power lead screw are provided on the left slider, and a left clamping head is fixed on the top of the left slider; the right clamp comprises a right slider, a right smooth through hole for passing a guide slider and a right smooth through hole for passing a power lead screw are provided on the right slider, and a right clamping head is fixed on the top of the right slider; the two ends of the S-type tension and pressure sensor are respectively fixed on the right slider and the right fixing seat;

The vibrating wire strain sensor calibration device comprises a base, a left fixed seat is fixed at the left end of the base, a right fixed seat is fixed at the right end of the base, a guide slide bar is fixed between the left fixed seat and the right fixed seat, a power screw is rotatably connected, and a clamping mechanism is assembled between the left fixed seat and the right fixed seat;

A left positioning groove is provided at the bottom of the left clamping head, a left mounting through-hole is provided next to the left positioning groove, a left positioning protrusion corresponding to the left positioning groove is provided on the left slider, and a left fixing threaded hole corresponding to the left mounting through-hole is provided next to the left positioning protrusion; a right positioning groove is provided at the bottom of the right clamping head, a right mounting through-hole is provided next to the right positioning groove, a right positioning protrusion corresponding to the right positioning groove is provided on the right slider, and a right fixing threaded hole corresponding to the right mounting through-hole is provided next to the right positioning protrusion;

A left displacement sensor is fixed on the left slider, and the left displacement sensor is located on the left side of the left clamping head; a right displacement sensor is fixed on the right slider, and the right displacement sensor is located on the right side of the right clamping head; the left displacement sensor and the right displacement sensor cooperate to detect the left and right sliding amount of the vibrating wire strain sensor;

A fixed platform is fixed on the left slider, a slide is slidably connected to the fixed platform in the left-right direction, a fastening bolt for fixing the slide is provided on the slide, a left clamping seat for fixing the left displacement sensor is fixed on the top of the slide; a right clamping seat for fixing the right displacement sensor is fixed on the right slider;

Fix the two ends of the vibrating-wire strain sensor on the left clamping head and the right clamping head respectively, adjust the left displacement sensor and the right displacement sensor to detect the displacement of the left end face and the right end face of the vibrating-wire strain sensor, return the reading to zero, and then start the servo motor to rotate the power screw, thereby driving the left slider to move to the right. During the movement, the grating scale displacement sensor detects the displacement, and the S-type tension and pressure sensor detects the force. According to the displacement data, combined with the relevant measurement data of the vibrating-wire strain sensor, the required calibration parameters can be evaluated.

2. The clamping mechanism for the vibrating-wire strain sensor calibration device according to claim 1 is characterized in that a main scale mark is provided on the fixed platform, and a vernier scale mark is provided on the sliding platform, and the fixed platform and the sliding platform constitute a vernier caliper structure.

3. The clamping mechanism for the vibrating-wire strain sensor calibration device according to claim 1 or 2 is characterized in that mounting holes distributed in a matrix are provided on the top of the slide, and the left clamping seat is fixed at different positions on the top of the slide through different mounting holes.