Variable range displacement sensor for seismic isolation support displacement measurement

Abstract

The utility model belongs to the field of seismic isolation support displacement monitoring, and particularly relates to a variable range displacement sensor for seismic isolation support displacement measurement, which comprises a variable range displacement measurement device and a displacement conversion device, the variable range displacement measurement device comprises a circular truncated cone gear and a measurement pull rope, the circular truncated cone gear is fixedly connected with the displacement conversion device, and the measurement pull rope is connected with the measurement pull rope. The circular truncated cone gear comprises a circular truncated cone upper bottom face, a circular truncated cone inclined conical face and a circular truncated cone lower bottom face which are sequentially connected, a first sliding groove and a third sliding groove are formed in the circular truncated cone upper bottom face and the circular truncated cone upper bottom face respectively, and the winding diameter of the third sliding groove is smaller than that of the first sliding groove. One end of the measuring pull rope is fixed on the lower bottom surface of the circular truncated cone and then is wound from the first sliding chute on the lower bottom surface, and finally the measuring end is led out from the third sliding chute on the upper bottom surface of the circular truncated cone after passing through the second sliding chute and is connected with the seismic isolation support. The wide-range ultimate stretching monitoring requirement of the seismic isolation support can be met, and the tiny displacement change of the seismic isolation support can be monitored.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of shock insulation support displacement monitoring, concretely relates to a variable range displacement sensor for shock insulation support displacement measurement. BACKGROUND

[0002] In recent years, earthquake disasters are frequent, and the damage to buildings cannot be ignored. In order to reduce the damage caused by earthquakes to buildings, flexible connection is realized by installing shock insulation supports in the shock insulation layer, which can effectively isolate seismic energy and significantly reduce the damage of earthquakes to buildings. As a key component in the shock insulation structure system, the performance and health status of the shock insulation support are crucial to the seismic capacity and safety performance of the building. However, with the long-term use of the shock insulation support, a certain degree of damage deformation will occur. Therefore, real-time monitoring of the deformation displacement of the shock insulation support is beneficial to exploring the dynamic information of the structure, understanding the remaining life of the structure, and mastering the seismic capacity of the structure.

[0003] At present, the deformation displacement detection of the shock insulation support mainly uses displacement sensors for measurement. However, in the existing displacement sensors for shock insulation support health monitoring, small-range sensors cannot meet the limit stretching demand of the range and are directly damaged when an earthquake occurs, and large-range sensors have too low precision to monitor the small displacement change when measuring small displacement.

[0004] Therefore, how to provide a variable range displacement sensor that can meet the large range limit stretching monitoring demand of the shock insulation support and also monitor the small displacement change has become a problem that needs to be solved by the technical personnel in the field. UTILITY MODEL CONTENTS

[0005] In view of the problems existing in the prior art, the utility model discloses a variable range displacement sensor for shock insulation support displacement measurement. The utility model can meet the limit stretching demand of large displacement monitoring of the shock insulation support by adopting the variable range measurement structure of the circular truncated cone gear and the measurement rope, and can also consider the high precision demand of small displacement, thereby ensuring the real-time monitoring of the shock insulation support under two different conditions of normal and earthquake.

[0006] To achieve the above purpose, the utility model discloses the following scheme:

[0007] A variable range displacement sensor for displacement measurement of an isolation bearing, comprising a variable range displacement measurement device and a displacement conversion device, the displacement conversion device is fixed on the lower base plate of the isolation bearing, the variable range displacement measurement device includes a circular truncated cone gear and a measurement pull rope, the circular truncated cone gear is fixedly connected with the displacement conversion device, the circular truncated cone gear comprises a circular truncated cone upper bottom surface, a circular truncated cone inclined conical surface and a circular truncated cone lower bottom surface which are connected in sequence, the circular truncated cone lower bottom surface and the circular truncated cone upper bottom surface are respectively provided with a first sliding groove and a third sliding groove in the inner part, the winding diameter of the third sliding groove is smaller than that of the first sliding groove, the circular truncated cone inclined conical surface is provided with a second sliding groove, the second sliding groove is connected with the first sliding groove and the third sliding groove respectively, and is used for smooth switching of the first sliding groove and the third sliding groove, one end of the measurement pull rope is fixed to the circular truncated cone lower bottom surface and is wound from the first sliding groove of the lower bottom surface, and the measurement end of the measurement pull rope is led out from the third sliding groove of the circular truncated cone upper bottom surface through the second sliding groove and is connected with the upper top plate of the isolation bearing.

[0008] Further, the displacement conversion device comprises a cantilever beam support block, a cantilever beam, a traction rope, a rotating shaft, a bearing, a fiber grating and a sensor shell, the cantilever beam support block, the cantilever beam, the traction rope, the rotating shaft, the bearing and the fiber grating are arranged in the sensor shell, the bearing is fixed on the sensor shell, the rotating shaft is arranged in the bearing, the end of the rotating shaft is arranged out of the sensor shell and is fixedly connected with the circular truncated cone gear, the cantilever beam support block is fixed on the top wall of the sensor shell away from the circular truncated cone gear, the cantilever beam is arranged on the cantilever beam support block, the fiber grating is arranged on the cantilever beam, one end of the traction rope is fixedly connected with the cantilever beam, and the other end of the traction rope is wound on the rotating shaft.

[0009] Further, the fiber grating is pasted and arranged at the center of the cantilever beam.

[0010] Compared with the prior art, the displacement sensor has the advantages that:

[0011] The displacement sensor utilizes the principle that the upper bottom surface and the lower bottom surface of the circular truncated cone gear have different winding diameters, and the measurement pull rope is wound on the circular truncated cone lower bottom surface, the circular truncated cone inclined conical surface and the circular truncated cone upper bottom surface in sequence, so that the rotation of the circular truncated cone upper bottom surface is driven by the measurement pull rope, the high-precision requirement in the micro displacement monitoring is realized, the rotation of the circular truncated cone lower bottom surface is driven by the measurement pull rope, the limit stretching monitoring of the large displacement is satisfied, and the measurement requirements of the isolation bearing in the normal state and the earthquake state are realized, and the real-time monitoring of the isolation bearing is satisfied. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is an external structure schematic view of the displacement sensor of the utility model;

[0013] Figure 2 It is an internal structure schematic view of the displacement sensor of the utility model;

[0014] Figure 3 Variable range structure schematic diagram of the utility model;

[0015] Figure 4 Variable range structure schematic diagram of the utility model;

[0016] Figure 5 Cantilever beam structure schematic diagram of the utility model;

[0017] Figure 6 Cantilever beam structure schematic diagram of the utility model;

[0018] In the figure, 1, round table gear;1-1, round table lower bottom;1-2, round table gear inclined conical surface;1-3, round table upper bottom;2, cantilever beam support block;3, cantilever beam;4, traction rope;5, bearing;6, measuring pull rope;7, fiber grating;8, top plate of shock isolation support;9, lower bottom plate of shock isolation support;10, variable range displacement sensor;11, sensor shell. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0020] Embodiment 1

[0021] As Figures 1-4 shown, the embodiment discloses a variable range displacement sensor for shock isolation support displacement measurement, containing variable range displacement measurement device and displacement conversion device, displacement conversion device is fixed on shock isolation support lower bottom plate 9, variable range displacement measurement device includes round table gear 1 and measuring pull rope 6, round table gear 1 is fixedly connected with displacement conversion device, round table gear 1 includes round table upper bottom 1-3, round table inclined conical surface 1-2 and round table lower bottom 1-1 connected in sequence, and the inside of round table lower bottom 1-1, round table upper bottom 1-3 is respectively provided with first sliding groove and third sliding groove, and the winding diameter of third sliding groove is less than the winding diameter of first sliding groove, and round table inclined conical surface 1-2 is provided with second sliding groove, and second sliding groove is connected with first sliding groove and third sliding groove respectively, for the smooth switching of first sliding groove and third sliding groove, one end of measuring pull rope is fixed to round table lower bottom 1-1 and then winds from the first sliding groove of lower bottom, and the measuring end of measuring pull rope is led out from the third sliding groove of round table upper bottom 1-3 after second sliding groove, and is connected with shock isolation support upper top plate 8.

[0022] As the preferred embodiment of the utility model, displacement conversion device includes cantilever beam support block 2, cantilever beam 3, tow rope 4, pivot, bearing 5, fiber grating 7 and sensor shell 11, cantilever beam support block 2, cantilever beam 3, tow rope 4, pivot, bearing 5, fiber grating 7 are all arranged in sensor shell 11, bearing 5 is fixed on sensor shell 11, pivot is arranged in bearing 5, the end of pivot is fixedly connected with circular gear 1 after going out sensor shell 11, cantilever beam support block 2 is fixed on the top wall of the side of sensor shell 11 away from circular gear 1, cantilever beam 3 is arranged on cantilever beam support block 2, fiber grating 7 is pasted and installed at the center of cantilever beam 3, one end of tow rope 4 is fixedly connected with cantilever beam 3, the other end of tow rope 4 is wound on pivot.

[0023] Example 2

[0024] The embodiment discloses a use method of the variable-range displacement sensor 10, a mathematical model is established in the sensor, and the displacement measured by the displacement sensor can be calculated by converting the center wavelength drift of the fiber grating to the value actually measured by the variable-range displacement sensor 10 according to the mathematical model.

[0025] When the displacement of the shock insulation support changes, the measuring pull rope connected with the support is subjected to a stretching force, drives the circular gear to rotate, the pivot connected with the circular gear rotates with the circular gear at the same angular displacement (but the linear displacement is different, the linear displacement of the circular gear is large, and the linear displacement of the pivot tow rope is small), and the cantilever beam is connected with the pivot through the tow rope, when the pivot rotates, the cantilever beam is driven to generate a downward degree of change through the tow rope, and then the center wavelength of the fiber grating pasted at the center of the cantilever beam changes, and the displacement measured by the displacement sensor can be calculated by measuring the center wavelength change of the fiber grating.

[0026] When the temperature in the external environment or the cantilever beam deforms, the following expression can be obtained according to the sensing principle of the fiber Bragg grating:

[0027]

[0028] In the formula, ΔT is the temperature change of the environment of the fiber grating;

[0029] K T is the temperature sensitivity coefficient of the fiber grating;

[0030] ε is the axial strain of the fiber grating;

[0031] K ε is the strain sensitivity coefficient of the fiber grating;

[0032] λ B is the center wavelength of the fiber grating;

[0033] Δλ B is the center wavelength shift of the fiber grating.

[0034] wherein the strain sensitivity coefficient K ε can be expressed as:

[0035] K ε = 1-P e (1-2)

[0036] In the formula, P e is the elasto-optical coefficient of the fiber grating.

[0037] FBG1 and FBG2 are made of the same material and have the same temperature and strain sensitivity coefficients. The two fiber gratings are designed in a differential structure, have the same environmental temperature change, and are subjected to stress in opposite directions, i.e.

[0038] ΔT1 = ΔT2, ε = ε1-ε2.

[0039] The respective parameters of FBG1 and FBG2 are brought into (1-1) and subtracted to obtain:

[0040]

[0041] In the formula, Δλ B1 , Δλ B2 are the center wavelength shifts of FBG1 and FBG2 respectively;

[0042] λ B1 , λ B2 are the center wavelengths of FBG1 and FBG2 respectively.

[0043] It can be known from formula (1-3) that by subtracting the relationship between the wavelength change and the center wavelength of FBG1 and FBG2, the influence of the environmental temperature on the center wavelength shift of the two fiber gratings can be reduced, and the difference between the two is only related to the deformation of the cantilever beam and has a linear relationship.

[0044] When the cantilever beam is disturbed, the strain calculation formula at a certain position on the surface is:

[0045]

[0046] In the formula, ε is the strain at a distance x from the fixed end;

[0047] L is the length of the uniform strength cantilever beam;

[0048] x is the distance from the fixed end of the uniform strength cantilever beam;

[0049] E is the elastic modulus of the uniform strength cantilever beam;

[0050] A— is the cross-sectional area of the cantilever beam at a distance x from the fixed end;

[0051] h— is the thickness of the cantilever beam of equal strength.

[0052] From the attached Figure 5 It can be seen that the width of the cantilever beam at the fixed end is b0, and the width of the cantilever beam at a distance x from the fixed end is b x The cross-sectional area A x of the cantilever beam at a distance x from the fixed end is:

[0053]

[0054] Substituting equation (1-5) into equation (1-4) gives the strain ε of the cantilever beam:

[0055]

[0056] The perturbation of the free end of the cantilever beam of equal strength is:

[0057]

[0058] Substituting equation (1-7) into equation (1-6) gives the surface strain calculation formula of the cantilever beam:

[0059]

[0060] When measuring the displacement of the pull rope driving the circular truncated cone gear in the third sliding groove on the upper bottom surface, the central shaft will rotate with the same angular displacement. The relationship between the external measurement displacement X1 and the bending perturbation ω of the cantilever beam can be obtained from the diameter r of the central shaft and the diameter R1 of the upper bottom surface of the circular truncated cone gear:

[0061]

[0062] Substituting equations (1-9) and (1-8) into equation (1-3) gives:

[0063]

[0064] When measuring the displacement of the pull rope driving the circular truncated cone gear in the first sliding groove on the lower bottom surface, the central shaft will rotate with the same angular displacement. The relationship between the external measurement displacement X2 and the perturbation ω can be obtained from the diameter r of the central shaft and the diameter R2 of the upper bottom surface of the circular truncated cone gear:

[0065]

[0066] Referring to the attached Figure 6 When the measurement pull rope drives the circular truncated cone gear to rotate in the second sliding groove on the conical surface, the corresponding relationship between the external measurement displacement X3 and the angular displacement θ can be represented as:

[0067]

[0068] In the formula, n is the number of grooves of the circular cone surface of the circular-trapezoidal gear.

[0069] Similarly, under the angular displacement θ, the linear displacement X of the central rotating shaft is θ :

[0070] X θ = r·θ (1-14)

[0071] By combining the formula (1-13) and (1-14), the relationship between X3 and X θ is obtained as follows:

[0072]

[0073] According to the displacement conversion principle, the linear displacement X of the central rotating shaft is θ the bending deflection ω of the equal-strength cantilever beam, and the corresponding relationship between the bending deflection ω of the equal-strength cantilever beam and the surface ε thereof is:

[0074]

[0075] By combining the formula (1-3), (1-15) and (1-16), it is obtained that

[0076]

[0077] The above is only the preferred embodiment of the present application, and does not limit the technical scope of the present application in any way. Therefore, any slight modification, equivalent change and modification made according to the technical essence of the present application to the above embodiment still belongs to the technical scope of the present application.

Claims

1. A variable range displacement sensor for seismic isolation bearing displacement measurement, characterized by, The variable range displacement measuring device and the displacement conversion device are fixed on the isolation bearing lower base plate (9), the variable range displacement measuring device includes the circular truncated gear (1) and the measuring pull rope (6), the circular truncated gear (1) is fixedly connected with the displacement conversion device, the circular truncated gear (1) includes the circular truncated upper bottom surface (1-3), the circular truncated inclined conical surface (1-2) and the circular truncated lower bottom surface (1-1) connected in sequence, the circular truncated lower bottom surface (1-1), the inner part of the circular truncated upper bottom surface (1-3) is respectively provided with a first sliding groove and a third sliding groove, the winding diameter of the third sliding groove is less than the winding diameter of the first sliding groove, the circular truncated inclined conical surface (1-2) is provided with a second sliding groove, the second sliding groove is connected with the first sliding groove and the third sliding groove respectively, and the first sliding groove and the third sliding groove are used for smooth switching, one end of the measuring pull rope is fixed to the circular truncated lower bottom surface (1-1) and is wound from the lower bottom surface first sliding groove, and the measuring end of the measuring pull rope (6) is led out from the third sliding groove of the circular truncated upper bottom surface (1-3) through the second sliding groove and is connected with the isolation bearing upper top plate (8).

2. The variable range displacement sensor for displacement measurement of seismic isolation bearings according to claim 1, wherein, The displacement conversion device includes a cantilever beam support block (2), a cantilever beam (3), a traction rope (4), a rotating shaft, a bearing (5), a fiber grating (7) and a sensor shell (11), the cantilever beam support block (2), the cantilever beam (3), the traction rope (4), the rotating shaft, the bearing (5) and the fiber grating (7) are arranged in the sensor shell (11), the bearing (5) is fixed on the sensor shell (11), the rotating shaft is arranged in the bearing (5), the end of the rotating shaft is arranged out of the sensor shell (11) and is fixedly connected with the circular truncated gear (1), the cantilever beam support block (2) is fixed on the top wall of the sensor shell (11) away from the circular truncated gear (1), the cantilever beam (3) is arranged on the cantilever beam support block (2), the fiber grating (7) is arranged on the cantilever beam (3), one end of the traction rope (4) is fixedly connected with the cantilever beam (3), and the other end of the traction rope (4) is wound on the rotating shaft.

3. The variable range displacement sensor for displacement measurement of seismic isolation bearings according to claim 2, wherein, The fiber grating (7) is pasted and mounted at the center of the cantilever beam (3).

Images