JP7244381B2 - Relative displacement measuring device - Google Patents

Description

The present invention relates to a relative displacement measuring device that measures the relative displacement of two objects with respect to each other.

In order to measure the horizontal displacement of the seismic isolation layer of a base-isolated building during an earthquake, measurement equipment using accelerometers, measurement equipment using laser displacement meters, measurement equipment using cameras, marking equipment, etc. Various devices are used. A measuring device using an accelerometer measures the absolute acceleration of two structures to be measured, estimates the absolute displacement of each structure by calculation, and calculates the difference in the estimated absolute displacement of each structure. is the relative displacement of A measuring device using a laser displacement gauge attaches two laser displacement gauges to one structure, and measures the relative displacement in the X direction and the Y direction with respect to the other structure by the two laser displacement gauges. A measurement device using a camera photographs a target attached to one structure with a camera attached to the other structure, and calculates the relative displacement between the structures by analyzing the photographed image.

However, when an accelerometer is used, filter processing is often performed for calculation stability in integration processing for estimating displacement from acceleration data, and the reliability of the applied filter greatly affects the estimation result. When a camera is used, the installation conditions of the device, the measurement range, the accuracy of the data to be acquired, the measurement sampling, etc. are restricted depending on the performance (angle of view, resolution, etc.) of the camera. Moreover, when the illuminance at the target installation location changes greatly, measurement is difficult, and it is necessary to ensure stable illuminance or change the target according to the illuminance. Furthermore, the price of the device is influenced by the performance of the camera, and the study and verification of the trade-off between performance and price is complicated. The marking device cannot leave measurement data, and the maximum value and the residual value can be easily grasped. Therefore, there are problems such as difficulty in confirming the history of displacement and inability to install in a narrow space due to restrictions on external dimensions. Also, as a system for dynamically measuring the relative displacement between two points in three-dimensional coordinates, there is a non-contact system using ultrasonic waves, light, laser light, or the like. However, while these measurement systems can provide high accuracy, they are generally expensive and often have large dimensions.

As a solution to these problems, there has been proposed a displacement measuring device that obtains the displacement direction and displacement amount of a measuring point using a wire and an arm that extend and contract by connecting a probe and a displacement gauge (Patent Document 1). . In addition, it has a first connecting part that rotatably connects the upper end of the first rod-shaped member to the lower surface of the upper structure of the two structures that are vertically opposed, and is attached to the upper surface of the lower structure. Displacement having a second connecting portion rotatably connecting the lower end of the first rod-shaped member to the upper end of the second rod-shaped member held by the holding member so as to be able to move in the out-of-plane direction (vertical direction) A measuring device has been proposed (Patent Document 2).

JP 2015-215333 JP 2018-136311

In the displacement measuring device described in Patent Document 1, tension is applied to the wire so that the length of the wire can be measured when the probe is displaced. Therefore, if the displacement measuring device described in Patent Document 1 is used for a long period of time, there is a risk that the wire will stretch and the tension will decrease, making it impossible to measure the displacement accurately.

Further, in the displacement measuring device described in Patent Document 2, when the upper structure is displaced in the horizontal direction with respect to the lower structure, the second rod-shaped member receives a horizontal force from the first rod-shaped member. moves in the vertical direction (direction perpendicular to the displacement direction) with respect to the holding member. Therefore, the bending rigidity of the second rod-shaped member must be increased so that the second rod-shaped member does not bend and lower the measurement accuracy, and the diameter of the second rod-shaped member becomes large and heavy. In addition, the holding member must be robust and heavy in order to hold the large-diameter rod-shaped member slidably without rattling. Therefore, it takes time and effort to transport and install the device.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a relative displacement measuring device capable of accurately measuring displacement even after long-term use, and facilitating transportation and installation of the device.

In order to solve such problems, an embodiment of the present invention is a relative displacement measuring device (10), comprising a first base member (11) fixed to a first object (2); A second base member (12) fixed to an object (3), one end connected to said first base member via a first universal joint (13), and a second universal joint (13) connected to said second base member. 14), and an extendable connecting member (15) having the other end connected via 14), and a rotation angle (θ _X , θ _Y ), and the connecting member is coaxially inserted into the first cylindrical member (21) and the first cylindrical member, and a second tubular member (22) axially slidably connected to the second tubular member (22).

According to this configuration, the two objects that are relatively displaced are connected by the connecting member configured by the first cylindrical member and the second cylindrical member and capable of expanding and contracting in the axial direction. Relative displacements of two objects can be measured based on rotation angles about two axes. The first tubular member and the second tubular member do not need to be subjected to an external force such as tension in order to obtain the displacement direction and displacement amount of the measurement point, and there is no fear of deformation due to the external force. Therefore, even if it is used for a long period of time, it is possible to accurately measure the amount of displacement. In addition, since the length of the connecting member is adjusted by sliding the first tubular member and the second tubular member against each other, the weight of the connecting member can be reduced while ensuring the bending rigidity. Furthermore, since both ends of the connecting member are connected to both base members via universal joints, it is not necessary to make both base members robust. Therefore, it becomes possible to make the device simple in structure and light in weight, and to facilitate transportation and installation of the device.

In the above configuration, the sliding amount (r) in the axial direction of the first tubular member and the second tubular member is accommodated in at least one of the first tubular member and the second tubular member. It is preferable to further have a stroke sensor (40) for measuring the .

According to this configuration, when the two objects are displaced relative to each other, it is possible to measure the amount of sliding in the axial direction of the first tubular member and the second tubular member that slide against each other. As a result, when converting the detection value obtained by the angle sensor into the relative displacement of the two objects, the amount of sliding in the axial direction of the first tubular member and the second tubular member is incorporated into the conversion formula, so that the displacement of the object can be more accurately calculated. can measure the relative displacement of Also, a stroke sensor is housed inside the tubular member. As a result, the stroke sensor is protected, and the relative displacement can be measured in a smaller space than a relative displacement measuring device having a configuration in which the stroke sensor is attached to the outside of the device.

In the above configuration, the stroke sensor comprises a TOF sensor (40) attached to one of the first tubular member and the second tubular member and measuring a distance to a target (41) provided on the other. A distance sensor is preferable.

According to this configuration, since the stroke sensor is a non-contact TOF sensor, the amount of axial sliding between the first tubular member and the second tubular member is accurately measured based on the distance from the sensor to the target. can do.

In the above configuration, at least one of the first universal joint and the second universal joint includes a ball (36) having a hollow portion provided integrally with the connecting member, and a spherical bearing (35) holding the ball. wherein the angle sensor is a joystick (51) tiltable about the two axes and a sensor for detecting tilting angles (θ _X , θ _Y ) of the joystick about the two axes A joystick module (38) having a main body (50), and preferably provided in the hollow portion so that the tilting center of the joystick coincides with the center of the ball.

According to this configuration, it is possible to measure the relative displacement of two objects around two orthogonal axes using an inexpensive and small joystick module. Moreover, since the joystick module is arranged in the hollow part of the ball joint, it is not necessary to separately provide a protective member for the sensor, and the device can be miniaturized.

The above configuration may further include a protective member (16) that covers the one end and the other end of the connecting member.

According to this configuration, the universal joint provided at one end and the other end of the connecting member is covered with the protective member, so that the universal joint can be protected from water, dust, and the like.

In the above configuration, the first tubular member includes a first pipe (23) having an inner diameter larger than the outer diameter of the second tubular member, and is housed in the first pipe spaced apart in the axial direction, and two bushings (24) slidably retaining said second tubular member.

According to this configuration, the second tubular member is connected to the first tubular member in a manner held by two axially spaced bushes. As a result, rattling of the first tubular member and the second tubular member is suppressed, and the rotation angle of the connecting member can be detected with high accuracy. In other words, the contact area and sliding resistance of both tubular members can be reduced, and assembly is easy, compared to the case where both tubular members are connected without rattling without using bushes. .

Thus, according to the present invention, the displacement can be accurately measured even after long-term use. In addition, transportation and installation of the device can be facilitated.

Schematic diagram of a base-isolated building to which the relative displacement measuring device according to the embodiment is attached Perspective view of relative displacement measuring device An exploded perspective view showing a relative displacement measuring device partially transparently Cross-sectional view of the relative displacement measuring device Enlarged sectional view of V part in FIG. (A) Cross-sectional view of the main part of the relative displacement measuring device before the relative displacement of the upper structure and the lower structure, and (B) of the relative displacement measuring device after the relative displacement of the upper structure and the lower structure Cross-sectional view of main part (A) the relative displacement measuring device before the relative displacement of the upper structure and the lower structure, (B) the relative displacement measuring device after the relative displacement of the upper structure and the lower structure in the horizontal direction, and (C) Relative displacement measuring device after relative displacement of upper structure and lower structure in horizontal and vertical directions

A relative displacement measuring device 10 according to the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, the relative displacement measuring device 10 of the present embodiment includes an upper structure 2 as a first object and a lower structure 3 as a second object in a base isolation layer of a base isolated building 1. is installed between In this embodiment, one relative displacement measuring device 10 is installed substantially in the center of the plane of the base isolation layer. In another embodiment, a plurality of relative displacement measurement devices 10 may be installed at different positions on the plane.

The upper structure 2 is seismically isolated and supported on the lower structure 3 via a plurality of seismic isolation devices 4 . As a result, the upper structure 2 and the lower structure 3 are horizontally displaced relative to each other when subjected to an external force such as an earthquake or strong wind. When the seismic isolation device 4 uses laminated rubber, elastic deformation of the rubber causes the upper structure 2 and the lower structure 3 to tilt relative to each other or change the distance in the vertical direction. relative displacement. In this case, the portions of the upper structure 2 and the lower structure 3 where the relative displacement measuring device 10 is installed are slightly displaced in the vertical direction. In FIG. 1, the base-isolated building 1 is in an initial state without inter-story displacement. In the present embodiment, the relative displacement measuring device 10 is installed so as to face a substantially vertical direction when the base-isolated building 1 is in the initial state.

As shown in FIG. 2, the relative displacement measuring device 10 includes a first base member 11 fixed to the upper structure 2, a second base member 12 fixed to the lower structure 3, and an upper end (one end). ) is connected to the first base member 11 via a first ball joint 13 (see FIG. 4) which is a first universal joint, and the lower end (the other end) is a second ball joint which is a second universal joint and a telescopic connecting member 15 connected to the second base member 12 via 14 (FIG. 4). Both ends of the connecting member 15 are liquid-tightly covered with bellows-like boots 16 made of rubber. A boot 16 is a protective member that protects the joint portion from water, dust, and the like.

The first base member 11 is configured by a plate-shaped member having a substantially rectangular surface that contacts the upper structure 2 . Fastening holes 17 for fastening to the upper structure 2 are provided near the four corners of the first base member 11, respectively. In this embodiment, the fastening holes 17 are formed by notches. The second base member 12 is a plate having substantially the same shape as the surface of the first base member 11 in contact with the upper structure 2 . As with the first base member 11 , the second base member 12 is provided with one fastening hole 18 for fastening to the lower structure 3 near each of its four corners. The fastening holes 18 are formed by notches. The fastening hole 18 is provided at substantially the same position as the fastening hole 17 on the surface of the first base member 11 in contact with the upper structure 2 .

A plurality of anchors 19 ( FIG. 4 ) are driven into the lower surface of the upper structure 2 at positions corresponding to the fastening holes 17 of the first base member 11 . A plurality of anchors 19 ( FIG. 4 ) are driven into the upper surface of the lower structure 3 at positions corresponding to the fastening holes 18 of the second base member 12 . The first base member 11 is arranged such that the fastening holes 18 receive the bolt portions of the corresponding anchors 19, and is fixed to the upper structure 2 by a plurality of nuts 20 screwed onto the bolt portions. Similarly, the second base member 12 is also fixed to the lower structure 3 by a plurality of nuts 20 screwed onto the bolt portions of the anchors 19 .

As shown in FIGS. 2 and 3 , the connecting member 15 includes a first tubular member 21 and a second tubular member 22 . The first tubular member 21 is accommodated in a first pipe 23 having an inner diameter larger than the outer diameter of the second tubular member 22, and is spaced apart in the axial direction from the first pipe 23 to accommodate the second tubular member 22. and two bushings 24 that slidably retain it. In this embodiment, the first pipe 23 is composed of two vertically divided pipe members, an upper outer pipe 25 disposed above and an outer pipe 25 disposed below the upper and outer pipes with a space therebetween. and a lower pipe 26 . The outer upper pipe 25 and the outer lower pipe 26 are connected to each other through an inner pipe 27 having an outer diameter substantially the same as their inner diameters. The inner pipe 27 is divided vertically into three pipe members, that is, an inner upper pipe 28, an inner middle pipe 29, and an inner lower pipe 30; and two bushes 24 arranged between the inner and lower pipes 30 .

The inner upper pipe 28 is housed in the outer upper pipe 25 and fastened to the outer upper pipe 25 with a plurality of screws. A first bush 24 is arranged below the inner upper pipe 28 so as to contact the lower end of the inner upper pipe 28 . An inner middle pipe 29 is arranged below the first bush 24 so as to abut on its lower end. The upper portion of the inner and middle pipe 29 is housed in the outer upper pipe 25 and fastened to the outer upper pipe 25 with a plurality of screws. A longitudinal intermediate portion of the inner and middle pipes 29 is not accommodated by the outer upper pipe 25 and the outer lower pipe 26 . The lower portion of the inner/middle pipe 29 is housed in the outer/lower pipe 26 and fastened to the outer/lower pipe 26 with a plurality of screws. A second bush 24 is arranged below the inner middle pipe 29 so as to abut against the lower end of the inner middle pipe 29 . An inner and lower pipe 30 is arranged below the second bush 24 so as to abut on its lower end. The inner and lower pipes 30 are housed in the outer and lower pipes 26 and fastened to the outer and lower pipes 26 with a plurality of screws. As a result, in the outer upper pipe 25 , the inner upper pipe 28 and the inner middle pipe 29 sandwich the bush 24 . In the outer and lower pipes 26 , the inner and inner pipes 29 and the inner and lower pipes 30 sandwich the bushing 24 .

As shown in FIGS. 3 and 4, the inner upper pipe 28, the inner middle pipe 29, the inner lower pipe 30, and the bush 24 have substantially the same outer diameter, but different inner diameters. The bushing 24 has a smaller inner diameter than the inner upper pipe 28 , the inner middle pipe 29 and the inner lower pipe 30 . The bushing 24 has an inner diameter substantially equal to the outer diameter of the second tubular member 22 . The second tubular member 22 is coaxially inserted into the first tubular member 21 and is axially slidably held by two bushes 24 that are spaced apart from each other in the axial direction.

In the present embodiment, the first pipe 23 and the inner pipe 27 of the first tubular member 21 are round pipes made of aluminum. Also, the second cylindrical member 22 is a round tube made of stainless steel. The bush 24 is made of polyacetal resin. In another embodiment, the first tubular member 21 may be a stainless steel round tube, and the second tubular member 22 may be an aluminum round tube. Both the first tubular member 21 and the second tubular member 22 may be stainless steel or aluminum round pipes. Also, the first tubular member 21 and the second tubular member 22 may be rectangular tubes. The bushing 24 may be made of copper alloy, bronze, duralumin, or tetrafluoroethylene resin.

As shown in FIG. 4, a second ball joint 14 is attached to the portion of the second base member 12 covered by the boot 16 . The second ball joint 14 has a ball stud 31 and a spherical bearing 32 that rotatably holds the ball stud 31 . The ball stud 31 is fixed to a cylindrical socket 33 attached to the lower end of the second tubular member 22 . The spherical bearing 32 is fixed to the second base member 12 . The boot 16 connects the outer peripheral surface of the second tubular member 22 and the upper surface of the second base member 12, and seals the inside liquid-tight while allowing the second tubular member 22 to tilt.

A first ball joint 13 is attached to the lower surface of the first base member 11 . The first ball joint 13 has a case 34 , a spherical bearing 35 housed in the case 34 , and a ball 36 rotatably held by the spherical bearing 35 . The ball 36 has a hollow portion penetrating vertically, and this hollow portion holds a cylindrical socket 37 attached to the upper end of the first tubular member 21 . A joystick module 38 is arranged inside the socket 37 . The boot 16 connects the outer peripheral surface of the first tubular member 21 and the side surface of the case 34, and seals the inside in a liquid-tight manner while allowing the first tubular member 21 to tilt.

A TOF sensor 40 as a distance sensor is housed inside the first cylindrical member 21 . The TOF sensor 40 is attached to a predetermined position of the first tubular member 21 and directed downward in the axial direction of the first tubular member 21 . A target 41 to be measured by the TOF sensor 40 is provided above the socket 33 inside the second tubular member 22 . The TOF sensor 40 emits pulsed light toward the target 41, receives reflected light reflected by the target 41, and measures the distance to the target 41 based on the time required from emission to reception. The amount of sliding of the first tubular member 21 and the second tubular member 22 is calculated from the change in the distance to the target 41 measured by the TOF sensor 40 . That is, the TOF sensor 40 is used as a stroke sensor that measures the amount of axial sliding between the first tubular member 21 and the second tubular member 22 .

As shown in FIG. 5, a concave portion 45 is provided on the top surface of the first base member 11 . A shallow stepped portion 46 is formed along four sides of the bottom surface of the recessed portion 45 on the bottom surface of the recessed portion 45 . A substantially circular through hole 47 centered on the axis of the connecting member 15 is formed in the center of the bottom surface of the recess 45 . A support plate 48 for supporting the joystick module 38 is attached to the upper surface of the stepped portion 46 . A lateral hole is provided in the side surface of the recess 45, and a cable bush 49 is attached to the lateral hole.

The joystick module 38 has a sensor body 50 and a joystick 51 suspended from the sensor body 50 and held by the sensor body 50 so as to be tiltable in all directions. The sensor main body 50 is fixed to the lower surface of the support plate 48 via spacers 53 . The sensor main body 50 is an angle detection sensor capable of detecting the tilt angle of the joystick 51 about two orthogonal axes on the horizontal plane. Although these two axes are generally orthogonal, it is sufficient if they intersect. A free end 52 of joystick 51 is held in socket 37 . The sensor main body 50 is arranged at a position where the tilt center of the joystick 51 coincides with the center of the ball 36 by a spacer 53 . The joystick module 38 detects the tilting angle of the joystick 51 that tilts together with the connecting member 15 when the connecting member 15 tilts with respect to the first base member 11 . Detects the rotation angle around the axis.

A CPU board 55 of the joystick module 38 is attached to the upper surface of the support plate 48 . The joystick module 38 and TOF sensor 40 are connected to the CPU board 55 via predetermined wiring (not shown). Wiring extends from the CPU board 55 through the cable bush 49 to the outside of the first base member 11 and is connected to a power source and a computer (not shown). The concave portion 45 of the first base member 11 is closed from above by a lid plate 56 . The lid plate 56 is fastened to the upper surface of the first base member 11 with screws. An annular groove is formed in the upper surface of the first base member 11, and an O-ring 57 is mounted in the annular groove. The O-ring 57 elastically contacts the bottom surface of the annular groove and the bottom surface of the lid plate 56 to hermetically seal the recess 45 accommodating the CPU board 55 of the joystick module 38 .

Next, the behavior around the first base member 11 when the upper structure 2 and the lower structure 3 undergo relative displacement will be described with reference to FIGS. 6(A) and 6(B). When the upper structure 2 and the lower structure 3 are horizontally displaced relative to each other, the first base member 11 and the second base member 12 are horizontally displaced relative to each other. The upper end of the connecting member 15 is connected to the first ball joint 13 via the socket 37 . Also, the lower end of the connecting member 15 is connected to the second ball joint 14 via a socket 33 . As a result, the connecting member 15 tilts in the direction in which the lower structure 3 is relatively displaced with respect to the upper structure 2 . A free end 52 of a joystick 51 is held in the socket 37 . Therefore, the joystick 51 tilts in the direction in which the connecting member 15 tilts in conjunction with the tilting of the connecting member 15 . The sensor main body 50 detects the tilted angle of the joystick 51 . Thus, in the relative displacement measuring device 10, the joystick module 38 detects the direction in which the lower structure 3 is displaced relative to the upper structure 2 as the tilting angle about the two axes.

Next, with reference to FIGS. 7A, 7B, and 7C, a method of measuring the relative displacement of the upper structure 2 and the lower structure 3 with respect to each other by the relative displacement measuring device 10 will be described. As shown in FIGS. 7A and 7B, when the upper structure 2 and the lower structure 3 are horizontally displaced relative to each other, the gap between the first base member 11 and the second base member 12 is increased. distance increases from the initial state. The connecting member 15 expands and contracts according to the distance between the first base member 11 and the second base member 12 . Of the two rotation axes of the connecting member 15 with respect to the first base member 11 detected by the joystick module 38, one is the X axis and the other is the Y axis. The length of the connecting member 15 in the initial state (the distance between the rotation centers of the first ball joint 13 and the second ball joint 14) is L (FIG. 4), the rotation angle of the connecting member 15 around the X axis is θ _X , and the connection Let _θY be the rotation angle of the member 15 about the Y-axis. Using the length L of the connection member 15 in the initial state, the rotation angle θ _X of the connection member 15 about the X-axis, and the rotation angle θ _Y of the connection member 15 about the Y-axis, the lower structure 3 relative to the upper structure 2 The direction and amount of relative displacement of are measured.

When the upper structure 2 and the lower structure 3 are displaced relative to each other only in the horizontal direction, the vertical distance between the first base member 11 and the second base member 12 is constant, and the relative displacement measuring device 10 is substantially the same as the length L in the initial state of . The length L of the connecting member 15 in the initial state can be measured with a measure or the like after the relative displacement measuring device 10 is installed at a predetermined installation location. Let Δ _X1 be the horizontal displacement of the lower structure 3 relative to the upper structure 2 in the X-axis direction, and Δ _Y1 be the horizontal displacement in the Y-axis direction. The horizontal displacement _ΔX1 and the horizontal displacement _ΔY1 can be calculated by a predetermined conversion formula using the length L in the initial state of the relative displacement measuring device 10 and the detected values θ _X and θ _Y obtained by the joystick module 38 .

Furthermore, a case in which vertical relative displacements of the upper structure 2 and the lower structure 3 are taken into consideration will be described. As shown in FIGS. 7B and 7C, the tilting angle of the connecting member 15 is affected by the vertical displacement of the upper structure 2 and the lower structure 3 with respect to each other. For example, when the upper structure 2 is relatively displaced upward with respect to the lower structure 3, the tilting angle of the connecting member 15 is greater than when the upper structure 2 is not relatively displaced upward, even if the horizontal displacement is the same. , the tilting angle of the connecting member 15 becomes smaller. By measuring the amount of expansion and contraction of the connecting member 15 with the TOF sensor 40, it is possible to measure the relative displacement of the upper structure 2 and the lower structure 3 with respect to each other, including the displacement in the vertical direction. Let the amount of expansion and contraction of the connecting member 15 measured by the TOF sensor 40, that is, the amount of sliding between the first tubular member 21 and the second tubular member 22, be r. The length of the connecting member 15 when the upper structure 2 and the lower structure 3 are displaced relative to each other is the length L in the initial state, the first tubular member 21 and the second tubular member 22. and the sliding amount r. ΔX2 is the horizontal displacement in the X-axis direction, _ΔY2 is the horizontal displacement in the _Y -axis direction, and _ΔZ is the vertical displacement of the lower structure 3 with respect to the upper structure 2 when affected by the vertical displacement. do. The horizontal displacement Δ _X2 , the horizontal displacement Δ _Y2 and the vertical displacement Δ _Z are the length L in the initial state of the relative displacement measuring device 10 and the detection values θ _X and θ _Y obtained by the joystick module 38 , as well as the TOF sensor It can be calculated by a predetermined conversion formula using the detected value r obtained by 40.

θ _X and θ _Y are measured by joystick module 38 . r is measured by the TOF sensor 40 . The computer also records these measurements. From these measured values, horizontal displacements Δ _X1 , Δ _{X2 in the X-axis direction and horizontal displacements Δ Y1} , Δ _Y2 in the Y-axis direction of the lower structure 3 relative to the upper structure ₂ can be calculated. Furthermore, since the conversion formula is based on geometrical calculations, errors do not occur during the calculation process. Thereby, the horizontal relative displacement of the lower structure 3 with respect to the upper structure 2 can be grasped.

Next, the effects of the relative displacement measuring device 10 according to this embodiment will be described. As shown in FIGS. 2, 3 and 4, one end is connected to the first base member 11 via the first ball joint 13, and the second base member 12 is connected via the second ball joint 14. An extendable connecting member 15 having the other end is configured to include a first tubular member 21 and a second tubular member 22 coaxially inserted into the first tubular member 21 . The relative displacement measuring device 10 measures the relative displacement of the upper structure 2 and the lower structure 3 with respect to each other by detecting the rotation angles θ _X and θ _Y of the connecting member 15 about two axes by the joystick module 38 . can be done.

Therefore, the first tubular member 21 and the second tubular member 22 do not need to be subjected to an external force such as tension in order to obtain the displacement direction and displacement amount of the measurement point. Therefore, even if the relative displacement measuring device 10 is used for a long period of time, the connecting member 15 will not be deformed by an external force for maintaining its shape, and it is possible to accurately measure the displacement amount even if it is used for a long period of time. .

In addition, since the length of the connecting member 15 is adjusted by sliding the first cylindrical member 21 and the second cylindrical member 22 against each other, the weight of the connecting member 15 can be reduced while ensuring bending rigidity. can. Furthermore, since both ends of the connecting member 15 are connected to the first and second base members 11 and 12 via universal joints, the first and second base members 11 and 12 can slidably support the connecting member 15. It doesn't have to be as ruggedly built. Therefore, the relative displacement measuring device 10 can be made simple and lightweight, and the relative displacement measuring device 10 can be easily transported and installed.

In this embodiment, a non-contact TOF sensor 40 is used as a stroke sensor for measuring the sliding amount r. As shown in FIG. 4 , the TOF sensor 40 is attached to the first cylindrical member 21 and the target 41 is provided on the second cylindrical member 22 . Accordingly, the axial sliding amount r of the first tubular member 21 and the second tubular member 22 can be accurately measured based on the distances to the TOF sensor 40 and the target 41 . Furthermore, the relative displacement of the structure can be measured more accurately by incorporating the sliding amount r into the conversion formula and taking into consideration the relative displacement of the lower structure 3 with respect to the upper structure 2 in the vertical direction.

In addition, since the TOF sensor 40 and the target 41 are both housed within the connecting member 15, they are protected from objects outside the connecting member 15, and there is space for attaching the TOF sensor 40 and the target 41 outside the connecting member 15. does not require Thereby, the relative displacement can be measured in a small space. Furthermore, the TOF sensor 40 can reliably measure the sliding amount r without being affected by the illuminance around the relative displacement measuring device 10 .

Furthermore, the TOF sensor 40, the joystick module 38, the first ball joint 13, and the second ball joint 14 can be commercially available products. Thereby, the manufacturing cost of the relative displacement measuring device 10 can be reduced.

As shown in FIGS. 4, 5, 6A and 6B, the ball 36 of the first ball joint 13 has a hollow portion. The joystick module 38 is thereby protected by the ball 36 from external objects. Therefore, there is no need to separately provide a protective member for the joystick module 38 . Therefore, the size of the device can be reduced.

As shown in FIG. 2, the upper and lower ends of the connecting member 15 are covered with a boot 16 to be liquid-tightly sealed. This protects the first ball joint 13 and the second ball joint 14 from water and dust. Therefore, the relative displacement measuring device 10 can be used for a long period of time. Moreover, the first ball joint 13 and the second ball joint 14 as well as the joystick module 38 and the target 41 arranged around them can be protected from the humidity around the relative displacement measuring device 10 .

As shown in FIG. 3, the second tubular member 22 is connected to the first tubular member 21 in a manner that it is retained on the first tubular member 21 by two axially spaced bushings 24 . This suppresses rattling of the first tubular member 21 and the second tubular member 22 . Therefore, the rotation angle of the connecting member 15 can be detected with high accuracy. Also, when the two tubular members are connected without rattling without using the bushing 24, the portion of the outer surface of the second tubular member 22 that is accommodated in the inner pipe 27 is the inner surface of the inner pipe 27 over its entire surface. abut. Therefore, the sliding resistance between the first tubular member 21 and the second tubular member 22 increases. On the other hand, by using two bushes 24, it is possible to reduce the contact area and sliding resistance between the first tubular member 21 and the second tubular member 22 while suppressing rattling. Therefore, assembly of these members can be facilitated.

Although the specific embodiments have been described above, the present invention is not limited to the above embodiments and can be widely modified. Although the first base member 11 and the second base member 12 are fixed by the anchors 19 in the above aspect, the present invention is not limited to this aspect. The first base member 11 and the second base member 12 may be suitably fixed relative to the first and second objects, for example clamped. Alternatively, the first base member 11 and the second base member 12 may be fixed by extending a reinforcing bar having an appropriate fixing length from the concrete surface and using the reinforcing bar.

Although the boot 16 is made of rubber in the above embodiment, it is not limited to this aspect. The boot 16 may be made of any material that can liquid-tightly seal both ends of the connecting member 15 . Also, the boot 16 has a bellows shape, but it may have any shape as long as it allows the tilting of the tubular member.

In the above aspect, the relative displacement measuring device 10 has the angle sensor in the first cylindrical member 21, but is not limited to this. The second tubular member 22 may have an angle sensor. The first tubular member 21 accommodates the TOF sensor 40, and the second tubular member 22 accommodates the target 41. The second tubular member 22 accommodates the TOF sensor 40, and the first tubular member 22 accommodates the TOF sensor 40. Member 21 may contain target 41 .

In the above aspect, the relative displacement measuring device 10 faces the vertical direction in the initial state, but is not limited to this aspect. The relative displacement measuring device 10 may be oriented horizontally in the initial state. Also, the relative displacement measuring device 10 may be oriented obliquely in the initial state.

In the above aspect, the relative displacement measuring device 10 is installed in the base isolation layer of the base isolation building 1, but it is not limited to this. The relative displacement measuring device 10 may be installed in a seismic isolation layer provided on an intermediate floor. The relative displacement measurement device 10 is also used not only for measuring the relative displacement of the upper structure 2 and the lower structure 3 of the seismic isolated building 1 with respect to each other, but also for temporary scaffolds and structures, suspended ceilings and upper story floor slabs. may be used to measure the displacement of the relative to each other.

2: Upper structure (first object)
3: Lower structure (second object)
10: Relative displacement measuring device 11: First base member 12: Second base member 13: First ball joint (first universal joint)
14: Second ball joint (second universal joint)
15: Connecting member 16: Boot (protective member)
21 : First tubular member 22 : Second tubular member 23 : First pipe 24 : Bush 35 : Spherical bearing 36 : Ball 38 : Joystick module (angle sensor)
40: TOF sensor (stroke sensor)
41: Target 50: Sensor body 51: Joystick r: Sliding amount _θX : Rotational angle θY around the X axis _Y : Rotational angle around the Y axis

Claims (6)

A relative displacement measuring device,
a first base member fixed to the first object;
a second base member fixed to the second object;
an extendable connecting member having one end connected to the first base member via a first universal joint and the other end connected to the second base member via a second universal joint;
an angle sensor for detecting rotation angles about two axes of the connecting member with respect to the first base member or the second base member;
The connecting member connects a first tubular member and a second tubular member coaxially inserted into the first tubular member and axially slidably coupled to the first tubular member. including
Further, a stroke sensor is accommodated inside at least one of the first tubular member and the second tubular member and measures the amount of sliding between the first tubular member and the second tubular member in the axial direction. wherein the stroke sensor is a distance sensor comprising a TOF sensor that is attached to one of the first cylindrical member and the second cylindrical member and that measures the distance to a target provided on the other. and relative displacement measuring device. A relative displacement measuring device,
a first base member fixed to the first object;
a second base member fixed to the second object;
an extendable connecting member having one end connected to the first base member via a first universal joint and the other end connected to the second base member via a second universal joint;
an angle sensor for detecting rotation angles about two axes of the connecting member with respect to the first base member or the second base member;
The connecting member connects a first tubular member and a second tubular member coaxially inserted into the first tubular member and axially slidably coupled to the first tubular member. including
A relative displacement measuring device, wherein the angle sensor is a joystick module having a joystick that can tilt about the two axes and a sensor body that detects a tilt angle of the joystick about the two axes. At least one of the first universal joint and the second universal joint is a ball joint having a ball having a hollow portion provided integrally with the connecting member and a spherical bearing that holds the ball ,
3. The relative displacement measuring device according to claim 2 , wherein the joystick is provided in the hollow portion so that the center of tilting of the joystick coincides with the center of the ball. Further, a stroke sensor is accommodated inside at least one of the first tubular member and the second tubular member and measures the amount of sliding between the first tubular member and the second tubular member in the axial direction. 4. The relative displacement measuring device according to claim 2 or 3, characterized by comprising: The relative displacement measuring device according to any one of claims 1 to 4, further comprising a protective member covering said one end and said other end of said connecting member. The first tubular member includes a first pipe having an inner diameter larger than the outer diameter of the second tubular member, and is accommodated in the first pipe while being spaced apart in the axial direction. 6. The relative displacement measuring device according to any one of claims 1 to 5, further comprising two bushes slidably held.

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