CN111272062A

CN111272062A - Strain gauge

Info

Publication number: CN111272062A
Application number: CN202010223419.9A
Authority: CN
Inventors: 张洪伟; 王学营; 叶伟; 何东明
Original assignee: Mianyang Mingyu Electronics Co ltd; Inner Mongolia Autonomous Region Traffic Construction Engineering Quality Supervision Administration
Current assignee: Mianyang Mingyu Electronics Co ltd; Inner Mongolia Autonomous Region Traffic Construction Engineering Quality Supervision Administration
Priority date: 2020-03-26
Filing date: 2020-03-26
Publication date: 2020-06-12

Abstract

An embodiment of the present invention discloses a strain gauge, including: the device comprises an elastic cavity, filling liquid, a PVDF piezoelectric film and a moving part; the elastic cavity is filled with filling liquid, the PVDF piezoelectric film is arranged in the elastic cavity and suspended in the filling liquid, and the movable piece is arranged at two ends of the elastic cavity. The strain gauge can be suitable for both static measurement and dynamic measurement, has wider application range, and can be suitable for high-temperature and low-temperature environments.

Description

Strain gauge

Technical Field

The invention relates to the field of sensors, in particular to a strain gauge.

Background

The strain gauge is suitable for monitoring the stress strain in various hydraulic structures, concrete structures and steel structure surfaces for a long time, and can be divided into a vibrating wire type and a resistance type according to types. The vibrating wire strain gauge converts the surface or internal strain of the measured object into the working frequency of the steel wire for measurement, and the resistance strain gauge converts the surface or internal strain of the measured object into stress for measurement. The vibrating wire strain gauge uses an electromagnetic coil as a sensitive element, and the resistance strain gauge uses a resistance strain gauge as a sensitive element. The use temperature of the vibrating wire type strain gauge and the resistance type strain gauge cannot be too high, the highest use temperature can only be 80 ℃, the vibrating wire type strain gauge is mainly used for static measurement, the resistance type strain gauge is used for dynamic measurement, the creep precision of the resistance type strain gauge can be reduced after long-term use, and the vibrating wire type strain gauge and the resistance type strain gauge are not suitable for being used under asphalt and concrete pouring.

Therefore, it is necessary to develop a strain gauge which is suitable for both static measurement and dynamic measurement, has a wider application range, and can be applied to high and low temperature environments.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention aims to provide a strain gauge and a strain gauge, wherein the strain gauge is suitable for static measurement and dynamic measurement, has a wider application range, and can be suitable for high-temperature and low-temperature environments.

In order to achieve the above object, according to the present invention, there is provided a strain gauge including: the device comprises an elastic cavity, filling liquid, a PVDF piezoelectric film and a moving part;

the elastic cavity is filled with filling liquid, the PVDF piezoelectric film is arranged in the elastic cavity and suspended in the filling liquid, and the movable piece is arranged at two ends of the elastic cavity.

Preferably, the filling liquid is silicone oil.

Preferably, still include elasticity chamber protective sheath, elasticity chamber protective sheath establish the elasticity chamber outside.

Preferably, the movable piece detection device further comprises a fixing clamp, wherein the fixing clamp is arranged on the movable piece and is used for fixing the movable piece on the piece to be detected.

Preferably, the piezoelectric film further comprises an output lead, and one end of the output lead passes through the elastic cavity and is connected to the PVDF piezoelectric film.

Has the advantages that: the strain gauge takes the PVDF piezoelectric film as a sensitive element, converts the pressure change of a measured object into a strain quantity by measuring the pressure change of the measured object, and can be used for static measurement and dynamic measurement. The PVDF piezoelectric film has the characteristics of no creep after long-term use and can be used in high and low temperature environments.

Drawings

Fig. 1 is a schematic diagram of the structure of an embodiment of the strain gauge of the present invention.

Description of reference numerals:

1. an elastic cavity; 2. filling liquid; 3. PVDF piezoelectric film; 4. a movable member; 5. an elastic cavity protective sleeve; 6. fixing the clamp; 7. and (4) an output lead.

Detailed Description

The technical scheme of the invention is described in detail in the following with reference to the accompanying drawings.

According to an aspect of the present invention there is provided a strain gauge comprising: the device comprises an elastic cavity, filling liquid, a PVDF piezoelectric film and a moving part;

When the strain gauge provided by the invention is used, the movable parts arranged at two ends of the elastic cavity are fixed on the to-be-detected element, when the to-be-detected element deforms, the two movable parts are driven to stretch or compress to generate deformation, then the elastic cavity is squeezed or stretched to drive filling liquid in the elastic cavity to move, so that the PVDF piezoelectric film obtains pressure change, and further obtains the strain quantity to be detected.

Specifically, the PVDF piezoelectric film is used as a sensitive element of the strain gauge, and the strain gauge is converted into a strain quantity by measuring the pressure change of a measured object, so that the strain gauge can be used for static measurement and dynamic measurement. The PVDF piezoelectric film has the characteristics of no creep after long-term use and can be used in high and low temperature environments.

Further, the filling liquid is silicone oil.

Specifically, through the arrangement of the silicon oil, on one hand, when the diaphragm is pressed, the movement of the silicon oil can be sensed by the PVDF piezoelectric film as soon as possible, and the error in measurement is further reduced; on the other hand, the PVDF piezoelectric film is convenient to suspend in the filling liquid; on the other hand, the silicone oil can keep stable chemical properties under high temperature and low temperature conditions, so that the strain gauge is suitable for high and low temperature environments.

Further, still include elasticity chamber protective sheath, elasticity chamber protective sheath is established the elasticity chamber outside.

Specifically, the elastic cavity is protected by the elastic cavity protective sleeve, the elastic cavity is prevented from being damaged, and the service life of the strain gauge is prolonged.

Further, still include mounting fixture, mounting fixture sets up on the moving part for with the moving part is fixed on waiting to detect the piece.

Specifically, through the setting of mounting fixture, be convenient for fix the moving part on waiting to detect the piece, through firm fixed, can ensure measuring result's precision.

Further, the piezoelectric film also comprises an output lead, and one end of the output lead penetrates through the elastic cavity and is connected to the PVDF piezoelectric film.

Particularly, through the arrangement of the output lead, the PVDF piezoelectric film is convenient to output a measurement result.

Example 1

As shown in fig. 1, the strain gauge includes: the device comprises an elastic cavity 1, filling liquid 2, a PVDF piezoelectric film 3 and a movable piece 4;

the filling liquid 2 is filled in the elastic cavity 1, the PVDF piezoelectric film 3 is arranged in the elastic cavity 1 and suspended in the filling liquid 2, and the movable piece 4 is arranged at two ends of the elastic cavity 1.

Wherein the filling liquid 2 is silicone oil.

The device further comprises an elastic cavity protective sleeve 7, wherein the elastic cavity protective sleeve 7 is sleeved on the outer side of the elastic cavity 1.

The device further comprises a fixing clamp 6, wherein the fixing clamp 6 is arranged on the moving piece 4 and used for fixing the moving piece 4 on a piece to be detected.

The piezoelectric film also comprises an output lead 7, wherein one end of the output lead 7 penetrates through the elastic cavity 1 and is connected to the PVDF piezoelectric film 3.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A strain gauge, comprising: the device comprises an elastic cavity, filling liquid, a PVDF piezoelectric film and a moving part;

2. The strain gauge of claim 1, wherein the filler fluid is silicone oil.

3. The strain gage of claim 1 further comprising a spring cavity protective sleeve disposed outside the spring cavity.

4. The strain gauge of claim 1, further comprising a fixing clamp disposed on the movable member for fixing the movable member to the element to be sensed.

5. The strain gauge of claim 1, further comprising an output lead having one end connected to the PVDF piezoelectric film through the elastic cavity.