Deformation detection device

Abstract

To provide a deformation detection device capable of inexpensively and reliably detecting deformation generated in a joint part for connecting one bridge girder and the other bridge girder adjacent thereto, and transmitting the detected deformation to the outside.SOLUTION: A deformation detection device 10 comprises a disconnection sensor that is installed on one bridge girder connected by a joint part and is switched off when there is no disconnection and is switched on when there is disconnection, a communication module that is installed on one bridge girder and is connected to the disconnection sensor, and a wire fixing jig that is installed on the other bridge girder connected by the joint part, and a wire having one end fixed to the wire fixing jig and the other end separably connected to the disconnection sensor through prescribed connection means. When prescribed vibration acts on the bridge and the other end of the wire is separated from the disconnection sensor by the vibration, the disconnection sensor is switched ON, and an ON signal of the disconnection sensor is transmitted to the communication module, and the communication module receiving the ON signal transmits the ON signal to the outside via a network.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a deformation detection device that detects deformation occurring in a joint that connects one bridge girder to another adjacent bridge girder. [Background technology]

[0002] A bridge structure monitoring system has been disclosed that is made up of a monitoring device that collects image data from a monitoring camera that monitors the condition of a bridge structure, and a system management center that processes the image data collected by the monitoring device and stores it as structure condition information, in which the monitoring camera is mounted on a carriage that can move along a pair of wire ropes installed between a pair of piers that support the bridge body, and the monitoring camera is moved together with the carriage to photograph various parts of the bridge and obtain the image data (see Patent Document 1).

[0003] Also disclosed is a road monitoring system that includes an inclinometer attached to a bridge to measure the inclination angle of the bridge, a measurement control means for managing the execution of measurement work using the inclinometer, an inclinometer information generation means for generating inclination information consisting of the bridge step amount and bridge collapse information using the inclinometer measurement values, and a display means for generating a monitoring screen that displays a mark that visualizes the inclination information on a map (see Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-158112 [Patent Document 2] Japanese Patent Publication No. 2020-016115 Summary of the Invention [Problem to be solved by the invention]

[0005] The bridge structure monitoring system disclosed in Patent Document 1 requires that monitoring cameras be operated continuously to photograph each part of the bridge in order to monitor changes in each part of the bridge, which results in problems such as high system power consumption and high bridge monitoring costs.Furthermore, the road monitoring system disclosed in Patent Document 2 uses an inclinometer to measure the inclination angle of the bridge, but when monitoring for bridge abnormalities, so-called traffic vibrations caused by vehicles traveling on the bridge affect the system, and it may not be possible to accurately measure the amount of change in the bridge inclination angle.

[0006] The object of the present invention is to provide a deformation detection device that can reliably detect deformation that occurs at a joint connecting one bridge girder to another adjacent bridge girder at low cost and that can transmit the detected deformation to the outside. [Means for solving the problem]

[0007] The premise of the present invention to solve the above problem is a deformation detection device that detects deformation that occurs in a joint connecting one bridge girder to another adjacent bridge girder when a predetermined vibration acts on the bridge.

[0008] The feature of the present invention based on the above premise is that the deformation detection device is formed from a wire break sensor installed on one of the bridge girders connected by a joint and which switches OFF when there is no wire break and switches ON when there is a wire break, a communication module installed on one of the bridge girders and connected to the wire break sensor via a signal line, a wire fixing jig installed on the other bridge girder connected by the joint, and a wire which has one end fixed to the wire fixing jig and the other end separably connected to the wire break sensor via a specified connecting means, and in the deformation detection device, when a specified vibration acts on the bridge and the other end of the wire separates from the wire break sensor due to the vibration, the switch of the wire break sensor turns ON, and the ON signal of the wire break sensor is sent to the communication module via the signal line, and the communication module, having received the ON signal, transmits the ON signal to the outside via a specified network.

[0009] In one example of the present invention, a predetermined connecting means is formed from either a male member or a female member installed on the wire breakage sensor and the other of the male member and female member to which the other end of the wire is connected, and in the deformation detection device, the connected state between the wire breakage sensor and the wire is maintained with the male member and the female member engaged with each other, and a predetermined separation force acts on the male member and the female member due to vibrations acting on the bridge, and when a separation force greater than the engagement force between the male member and the female member acts on the male member and the female member, the male member and the female member separate, and the other end of the wire separates from the wire breakage sensor.

[0010] In another example of the present invention, the male member is formed from a connecting stick that connects the other end of the wire, a magnet case that is connected to the front end of the connecting stick and holds the magnet, and a pair of elastically deformable hooks that extend radially outward from the magnet case across a unidirectional center line that bisects the connecting stick in a direction that intersects with the one direction, and the female member is formed from a pair of guide rails that abut on both sides of the hooks and elastically deform the hooks when a predetermined pulling force is applied to the hooks.

[0011] In another example of the present invention, one of the pair of hooks has a first straight portion extending straight outward in the radial direction from the magnet case, and a first inclined portion extending forward from a tip of the first straight portion and inclined downward with respect to the one-directional center line so that the distance from the one-directional center line gradually increases as it moves forward, and the other of the pair of hooks has a second straight portion extending straight outward in the radial direction from the magnet case in parallel to the first straight portion, and a second inclined portion extending forward from a tip of the second straight portion and inclined upward with respect to the one-directional center line so that the distance from the one-directional center line gradually increases as it moves forward, and one of the pair of guide rails is located outside the first straight portion of one of the hooks and has a first parallel portion extending parallel to the first straight portion, and a second parallel portion located at the tip of the first parallel portion and inclined upward with respect to the one-directional center line the other of the pair of guide rails has a second parallel portion located outside the second straight portion of the other hook, extending parallel to the first parallel portion and the second straight portion, and a second inclined sliding portion located at the tip of the second parallel portion, inclined downwardly with respect to the one-directional center line so that the distance from the one-directional center line gradually decreases as it extends forward, and an outer first inclined surface of the first inclined sliding portion of one hook slidably abuts on an inner first inclined surface of the first inclined sliding portion of one guide rail, and a outer second inclined surface of the second inclined portion of the other hook slidably abuts on an inner second inclined surface of the second inclined sliding portion of the other guide rail.

[0012] As another example of the present invention, in a deformation detection device, when a predetermined pulling force is applied to a pair of hooks, the outer first inclined surface of the first inclined portion of one hook slides over the inner first inclined surface of the first inclined sliding portion of one guide rail, and the outer second inclined surface of the second inclined portion of the other hook slides over the inner second inclined surface of the second inclined sliding portion of the other guide rail, elastically deforming the first and second inclined portions so that they gradually approach each other, and when the outer end of the first inclined portion passes over the inner end of the first inclined sliding portion and the outer end of the second inclined portion passes over the inner end of the second inclined sliding portion, the hooks come off the guide rails, and the male member connected to the other end of the wire is separated from the wire break sensor.

[0013] As another example of the present invention, in a deformation detection device, the magnetic force of the permanent magnet held in the magnet case of the male member opens the contacts of the switch of the wire breakage sensor, turning the switch OFF, and when the hooks of the male member connected to the other end of the wire come off the guide rails, the magnetic force of the permanent magnet is released, closing the contacts of the switch of the wire breakage sensor and turning the switch ON.

[0014] In another example of the present invention, the pulling force required to remove the hook from the guide rail is 20 kg or more.

[0015] In another example of the present invention, a wire break sensor and a communication module are installed in the central reservation of one bridge girder, and a wire fixing jig is installed in the central reservation of the other bridge girder adjacent to the one bridge girder.

[0016] In another example of the present invention, a wire break sensor and a communication module are installed on the railing of one bridge girder, and a wire fixing jig is installed on the railing of the other bridge girder adjacent to the one bridge girder.

[0017] In another example of the present invention, a wire connected to the wire fixing jig and the wire breakage sensor is stretched between the wire fixing jig and the wire breakage sensor with a predetermined slack. [Effects of the Invention]

[0018] According to the deformation detection device of the present invention, when a predetermined vibration acts on a bridge, the vibration deforms the joint connecting one bridge girder to the other. When the deformation causes the other end of the wire to separate from the wire break sensor, the wire break sensor switch turns ON, and the wire break sensor's ON signal is sent to the communication module via the signal line. This reduces the power consumption of the device and enables deformation of the joint to be detected at low power and cost compared to using a surveillance camera to continuously photograph each part of the bridge. When the joint deforms, the other end of the wire separates from the wire break sensor in response to the deformation, so the deformation detection device can reliably detect deformation occurring in the joint. When the communication module receives the ON signal, it transmits a deformation signal of the joint to the outside via a predetermined network. This allows appropriate measures to be taken promptly in response to deformation occurring in the joint, preventing accidents on the bridge.

[0019] The specified connecting means is formed from either the male or female member installed on the wire breakage sensor and the other of the male or female member to which the other end of the wire is connected, the connected state between the wire breakage sensor and the wire is maintained with the male and female members engaged with each other, a specified separating force acts on the male and female members due to vibrations acting on the bridge, the male and female members separate when a separating force greater than the engaging force between the male and female members acts on the male and female members, and the other end of the wire separates from the wire breakage sensor.In this deformation detection device, when the male and female members are separated due to deformation of the joint, the other end of the wire separates from the wire breakage sensor, the switch of the wire breakage sensor is turned ON and the ON signal of the wire breakage sensor is sent to the communication module via the signal line, so compared to when a surveillance camera is operated continuously to photograph each part of the bridge, the power consumed by the device is less and deformation of the joint can be detected with less power and at low cost. When the joint is deformed, the male and female members separate in response to the deformation, and the other end of the wire separates from the wire break sensor, so by using the male and female members, deformation occurring in the joint can be reliably detected. The deformation detection device transmits a deformation signal of the joint to the outside via a specified network when the communication module receives an ON signal, so appropriate measures can be taken quickly in response to deformation occurring in the joint, preventing accidents on the bridge.

[0020] The deformation detection device is formed from a connecting stick to which the male member connects the other end of the wire, a magnet case connected to the front end of the connecting stick and holding the magnet, and a pair of elastically deformable hooks extending radially outward from the magnet case, with female members abutting both sides of the hook and formed from a pair of guide rails that elastically deform the hook when a predetermined pull-out force is applied to the hook.When a predetermined pull-out force is applied to the hook due to vibrations acting on the bridge, and a pull-out force that exceeds the engagement force between the hook and the guide rail is applied to the hook, the hook is elastically deformed by the guide rail and separates from the guide rail, the other end of the wire separates from the wire break sensor, turning the switch of the wire break sensor ON, and the ON signal of the wire break sensor is sent to the communication module via the signal line.Therefore, compared to a case in which a surveillance camera is continuously operated to photograph each part of the bridge, the power consumed by the device is smaller, and deformation of the joint part can be detected with less power and at low cost. When the joint is deformed, the hook elastically deforms in response to the deformation, causing the hook to separate from the guide rail and the other end of the wire to separate from the wire breakage sensor, so by using the hook and guide rail, deformation occurring in the joint can be reliably detected. The deformation detection device transmits a deformation signal of the joint to the outside via a specified network after the communication module receives an ON signal, so appropriate measures can be taken quickly in response to deformation occurring in the joint, preventing accidents on the bridge.

[0021] One of the pair of hooks has a first straight portion extending straight outward in the radial direction from the magnet case, and a first inclined portion extending forward from the tip of the first straight portion and inclined downward with respect to the one-way center line so that the distance from the one-way center line gradually increases as it moves forward, and the other of the pair of hooks has a second straight portion extending straight outward in the radial direction from the magnet case in parallel with the first straight portion, and a first inclined portion extending forward from the tip of the second straight portion and inclined upward with respect to the one-way center line so that the distance from the one-way center line gradually increases as it moves forward. one of the pair of guide rails is located outside the first straight portion of one hook and has a first parallel portion extending parallel to the first straight portion, and a first inclined sliding portion located at the tip of the first parallel portion and inclined at an upward gradient with respect to the one-directional center line so that the distance from the one-directional center line gradually decreases as it moves forward; the other of the pair of guide rails is located outside the second straight portion of the other hook and has a second parallel portion extending parallel to the first parallel portion and the second straight portion, and a tip of the second parallel portion and a second inclined sliding portion that is inclined downward relative to the one-way center line so that the distance from the one-way center line gradually decreases as it moves forward, and an outer first inclined surface of the first inclined portion of one hook slidably abuts against an inner first inclined surface of the first inclined sliding portion of one guide rail, and an outer second inclined surface of the second inclined portion of the other hook slidably abuts against an inner second inclined surface of the second inclined sliding portion of the other guide rail. In this deformation detection device, a predetermined pulling force is applied to the hook due to vibration acting on the bridge, and the hook and the guide rail When a pulling force greater than the engagement force acts on the hook, the hook, whose outer inclined surface of the inclined portion slidably abuts against the inner inclined surface of the inclined sliding portion of the guide rail, elastically deforms and separates from the guide rail, the other end of the wire separates from the wire break sensor, turning the wire break sensor switch ON, and the ON signal of the wire break sensor is sent to the communication module via the signal line.Therefore, compared to when a surveillance camera is operated continuously to photograph each part of the bridge, the power consumed by the device is smaller, and deformation of the joint can be detected with less power and at low cost.When the joint is deformed, the outer inclined surface of the inclined portion of the deformation detection device elastically deforms the hook, which slidably abuts against the inner inclined surface of the inclined sliding portion of the guide rail, in response to the deformation, and the hook separates from the guide rail, causing the other end of the wire to separate from the wire breakage sensor.By using the hook and guide rail, deformation occurring in the joint can be reliably detected.When the deformation detection device receives an ON signal, the communication module transmits a deformation signal of the joint to the outside via a specified network, so appropriate measures can be taken quickly in response to deformation occurring in the joint, preventing accidents on the bridge.

[0022] When a predetermined pulling force is applied to the pair of hooks, the outer first inclined surface of the first inclined portion of one hook slides on the inner first inclined surface of the first inclined sliding portion of one guide rail, and the outer second inclined surface of the second inclined portion of the other hook slides on the inner second inclined surface of the second inclined sliding portion of the other guide rail, elastically deforming the first and second inclined portions so that they gradually approach each other, and when the outer end of the first inclined portion moves over the inner end of the first inclined sliding portion and the outer end of the second inclined portion moves over the inner end of the second inclined sliding portion, the hooks come off the guide rails, and the male member connected to the other end of the wire separates from the wire breakage sensor. This deformation detection device acts on a bridge. When a predetermined pulling force is applied to the hook by the vibration generated by the wire, and the pulling force exceeds the engagement force between the hook and the guide rail, the inclined portions of the hook elastically deform so as to gradually approach each other, the outer end of the inclined portion overcomes the inner end of the inclined sliding portion, the hook separates from the guide rail, the male member connected to the other end of the wire separates from the wire break sensor, the wire break sensor switch turns on, and the wire break sensor's ON signal is sent to the communication module via the signal line. Therefore, compared to a case in which a surveillance camera is continuously operated to photograph each part of the bridge, the power consumed by the device is smaller, and deformation of the joint can be detected with less power consumption and at lower cost. When the joint deforms, the deformation detection device elastically deforms so as to gradually approach each other in accordance with the deformation, the hook separates from the guide rail, and the male member connected to the other end of the wire separates from the wire break sensor, so deformation occurring in the joint can be reliably detected by using the hook and the guide rail. When the deformation detection device receives an ON signal, the communication module transmits a deformation signal of the joint section to the outside via a specified network, allowing appropriate measures to be taken quickly in response to deformation that occurs in the joint section, thereby preventing accidents on the bridge.

[0023] The magnetic force of the permanent magnet held in the magnet case of the male member opens the contacts of the switch of the wire breakage sensor, turning the switch OFF, and the hooks of the male member connected to the other end of the wire come off the guide rails, releasing the magnetic force of the permanent magnet, causing the contacts of the switch of the wire breakage sensor to close and the switch to turn ON.In this deformation detection device, when the joint is deformed, the hooks separate from the guide rail in response to the deformation, the male member connected to the other end of the wire separates from the wire breakage sensor, releasing the magnetic force of the permanent magnet, closing the contacts of the switch and turning the switch ON, so deformation that occurs in the joint can be reliably detected, and the communication module that receives the ON signal transmits a deformation signal of the joint to the outside via a specified network, so that appropriate measures can be taken quickly in response to deformation that occurs in the joint, preventing accidents on the bridge.

[0024] A deformation detection device with a pulling force of 20 kg or more when the hook comes off the guide rail will prevent malfunctions caused by traffic vibrations from vehicles traveling on the bridge or wind vibrations from strong winds, as the hook will come off the guide rail when large vibrations act on the bridge and a pulling force of 20 kg or more is applied to the hook, and can accurately and reliably detect deformation that occurs in the joint.

[0025] A deformation detection device in which a wire break sensor and a communication module are installed in the central reservation of one bridge girder and a wire fixing jig is installed in the central reservation of the other bridge girder adjacent to the first bridge girder, by installing the wire break sensor, communication module, and wire fixing jig in the central reservation of the bridge girder, it is possible to install the wire break sensor, communication module, and wire fixing jig in the central reservation where they do not interfere with traffic, and yet reliably detect deformation that occurs at the joint using the wire break sensor, communication module, and wire fixing jig installed in the central reservation of the bridge girder.

[0026] A deformation detection device in which a wire break sensor and a communication module are installed on the railing of one bridge girder and a wire fixing jig is installed on the railing of the other bridge girder adjacent to the first bridge girder, by installing the wire break sensor, communication module and wire fixing jig on the railing of the bridge girder, it is possible to reliably detect deformation that occurs at the joint using the wire break sensor, communication module and wire fixing jig installed on the railing of the bridge girder, while still installing the wire break sensor, communication module and wire fixing jig on the railing where they do not interfere with traffic.

[0027] In a deformation detection device in which the wire connected to the wire fixing jig and the wire break sensor is stretched between the wire fixing jig and the wire break sensor with a predetermined slack, if the wire is stretched between the wire fixing jig and the wire break sensor in a taut state with no slack, slight deformation of the joint due to traffic vibrations from vehicles traveling on the bridge or wind vibrations from strong winds will cause a malfunction in which the hook comes off the guide rail. However, by stretching the wire between the wire fixing jig and the wire break sensor with a predetermined slack, it is possible to prevent malfunction of the deformation detection device due to traffic vibrations from vehicles traveling on the bridge or wind vibrations from strong winds, and to accurately and reliably detect large deformations and plastic deformations occurring in the joint due to large vibrations. The deformation detection device can adjust its operation in accordance with the deformation of the joint by adjusting the slack of the wire according to the degree of deformation occurring in the joint. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a perspective view of an example of a deformation detection device. [Figure 2] FIG. 2 is an exploded perspective view showing an example of a wire break sensor and a connecting means that form a deformation detection device. [Figure 3] FIG. 4 is a perspective view of the disconnection sensor and the connecting means with the cover member removed. [Figure 4] A perspective view of a deformation detection device installed in the central median strip of a bridge girder. [Figure 5] A perspective view of a deformation detection device installed on the railing of a bridge girder. [Figure 6]This is a diagram showing the state in which the male components (connecting stick, magnet case, hook) are separated from the wire break sensor, the contacts of the ON / OFF switch of the wire break sensor are closed, and the ON / OFF switch is turned ON. DETAILED DESCRIPTION OF THE INVENTION

[0029] The deformation detection device according to the present invention will be described in detail below with reference to the accompanying drawings. Fig. 1 is a perspective view of an example deformation detection device 10, and Fig. 2 is an exploded perspective view showing an example of a wire break sensor 14 and connecting means 18 that form the deformation detection device 10. Fig. 3 is a perspective view of the wire break sensor 14 and connecting means 18 with the cover member 28 removed. In Figs. 1 and 2, the front-to-rear direction (one direction) is indicated by arrow X, the up-down direction is indicated by arrow Y, and the width direction is indicated by arrow Z.

[0030] The deformation detection device 10 detects deformation occurring in a joint 13 connecting one bridge girder 12a to the adjacent other bridge girder 12b when a predetermined vibration acts on the bridge 11, and transmits the detected deformation as an ON signal to a management server (external) (not shown). The deformation detection device 10 is composed of a wire break sensor 14, a communication module 15, a wire fixing jig 16, a wire 17, and a predetermined connecting means 18.

[0031] The wire break sensor 14 is made of synthetic resin and is molded into a generally oval shape that is long in one direction. The wire break sensor 14 has a body portion 19 that is long in one direction, and a pair of fixing portions 20 that extend in the front-to-rear direction (one direction) from both sides of the body portion 19. The body portion 19 of the wire break sensor 14 has a built-in ON / OFF switch (not shown) that turns ON / OFF using the magnetic force of a permanent magnet.

[0032] One end of a signal line 21 (electrical wire) that is connected to an ON / OFF switch (switch) is connected to the lower (lower surface) of the body portion 19 of the wire break sensor 14. The signal line 21 is electrically connected to the ON / OFF switch of the wire break sensor 14, and extends from the body portion 19 of the wire break sensor 14 toward the communication module 15. The fixing portions 20 of the wire break sensor 14 are formed with threaded holes through which fixing screws 22 are inserted. The wire break sensor 14 is installed on one bridge girder 12a. The fixing screws 22 are inserted into the threaded holes of the fixing portions 20, and the fixing screws 22 are screwed into one bridge girder 12a, thereby installing and fixing the wire break sensor 14 to one bridge girder 12a.

[0033] The communication module 15 is formed from a storage box 23 (housing) made from synthetic resin and molded into a box shape, a communication device (not shown) installed inside the storage box 23, and a battery (not shown) installed inside the storage box 23. The storage box 23 has an airtight structure to prevent the intrusion of rain and dust. Screw holes for inserting fixing screws 22 are formed in each corner of the storage box 23. The communication module 15 is installed on one bridge girder 12a. The communication module 15 is installed and fixed to one bridge girder 12a by inserting the fixing screws 22 into the screw holes in each corner of the storage box 23 and screwing the fixing screws 22 into one bridge girder 12a.

[0034] The communication device has a built-in microcomputer (controller) equipped with a central processing unit and memory and running on an independent operating system (OS), as well as a built-in antenna for transmitting electrical signals. The communication device transmits and receives data to and from a management server (external) using wireless communication technologies such as Flash-OFDM or iBurst wireless MAN, or LPWA 3G, 4G, 5G, cellular LPWA, and non-cellular LPWA wireless WAN. There are no particular limitations on the wireless communication technology, and any wireless communication technology developed in the future can be used.

[0035] The other end of a signal line 21 extending from the body portion 19 of the wire breakage sensor 14 is connected to the communication device (microcomputer). The signal line 21 is electrically connected to the communication device (microcomputer). The communication device receives an ON signal (a signal indicating deformation of the joint portion) from the wire breakage sensor 14 via the signal line 21, and transmits the ON signal received from the wire breakage sensor 14 to the management server via wireless communication. The battery is replaceably stored in a storage box 23. The battery supplies power to the communication device.

[0036] The management server is a physical server installed at a management company that manages and operates the deformation detection device 10, or a physical server installed at a data center contracted by the management company that manages and operates the deformation detection device 10. The management server is a physical computer equipped with a central processing unit (CPU or MPU) and memory (main memory and cache memory), and has a large-capacity storage area (or large-capacity hard disk) built in. Although not shown, input devices such as a keyboard and mouse, and output devices such as a display and printer are connected to the management server via interfaces.

[0037] The management server may be built in the cloud. A management server built in the cloud is a virtual server that has a virtual CPU or virtual MPU (central processing unit), a virtual main memory, and a virtual cache memory (memory) and runs on an independent operating system (virtual OS). Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS) can be used as the cloud.

[0038] The wire fixing jig 16 is made of synthetic resin and is molded into a generally oval shape that is long in the front-to-rear direction (one direction). The wire fixing jig 16 has a wire fixing portion 24 and a screw insertion portion 25 that extends in the front-to-rear direction (one direction) from the wire fixing portion 24. A wire insertion hole through which one end of the wire 17 is inserted is formed (drilled) in the wire fixing portion 24. With one end of the wire 17 inserted into the wire insertion hole of the wire fixing portion 24, the one end of the wire 17 is connected to the wire fixing portion 24 by a predetermined fixing means so that it is difficult to separate.

[0039] The screw insertion portion 25 of the wire fixing jig 16 has a threaded hole formed therein for inserting the fixing screw 22. The wire fixing jig 16 is installed on one bridge girder 12b adjacent to the other bridge girder 12a on which the wire breakage sensor 14 and the communication module 15 are installed. The wire fixing jig 16 is installed and fixed to the other bridge girder 12b by inserting the fixing screw 22 into the threaded hole of the screw insertion portion 25 and screwing the fixing screw 22 into the other bridge girder 12b.

[0040] The wire 17 is made by twisting six strands, each of which is made up of several to several tens of wires braided together in a single layer or multiple layers, around a core cord at a predetermined pitch. The wire 17 has high tensile strength, excellent impact resistance, and excellent flexibility. The wire 17 is durable enough not to break even when exposed to the external environment of the bridge girders 12a, 12b. As described above, the wire 17 is stretched across the wire fixing jig 16 installed on the other bridge girder 12b and the connecting stick 29 of the male member 26, which will be described later, installed on one bridge girder 12b.

[0041] The connecting means 18 is formed from a male member 26 attached to the wire breakage sensor 14 and a female member 27 detachably engaged with the male member 26. Alternatively, the connecting means 18 may be formed from a female member attached to the wire breakage sensor 14 and a male member detachably engaged with the female member. A cover member 28 is attached to the male member 26 and the female member 27. The male member 26 is made of synthetic resin. The male member 26 is formed from a connecting stick 29, a magnet case 30, and a pair of elastically deformable hooks 31a, 31b. The connecting stick 29, the magnet case 30, and the hooks 31a, 31b are integrally molded.

[0042] The connecting stick 29 is formed in the shape of a long plate extending in one direction, and has a wire insertion hole 32 formed (perforated) at its rear end, through which the other end of the wire 17 is inserted. With the other end of the wire 17 inserted through the wire insertion hole 32 of the connecting stick 29, the other end of the wire 17 is connected to the connecting stick 29 by a predetermined fixing means so that it is difficult to separate. The magnet case 30 is formed in the shape of a covered cylinder, and its peripheral surface is connected to the front end of the connecting stick 29, making it one piece with the connecting stick 29.

[0043] The magnet case 30 has a hollow cylindrical magnet storage space that protrudes upward from its bottom surface. A permanent magnet (not shown) is stored in the magnet storage space and is fixed so that it cannot fall out. The bottom surface of the permanent magnet is exposed from the bottom of the magnet case, and when the male member 26 and female member 27 are engaged, the magnetic force of the permanent magnet acts on the ON / OFF switch built into the body 19 of the wire breakage sensor 14. The magnetic force of the permanent magnet held in the magnet case 30 of the male member 26 opens the contacts of the ON / OFF switch of the wire breakage sensor 14, maintaining the OFF state of the ON / OFF switch.

[0044] The elastically deformable hooks 30 are connected to the peripheral surface of the magnet case 30 opposite to the peripheral surface connected to the front end of the connecting stick 29, and are integral with the magnet case 30. The hooks 30 extend forward in the front-to-rear direction (radially outward) from the magnet case 30, and are formed symmetrically on either side of a unidirectional center line L1 that bisects the connecting stick 29 in the width direction intersecting with the front-to-rear direction (one direction).

[0045] One of the hooks 30, 30a, has a first straight portion 33a extending linearly forward in the front-rear direction (radially outward) from the circumferential surface of the magnet case 30, and a first inclined portion 34a extending forward in the front-rear direction from the tip of the first straight portion 33a. The first inclined portion 34a is inclined downward with respect to the one-way center line L1 so that the distance from the one-way center line L1 gradually increases as the first inclined portion 34a extends forward in the front-rear direction from the magnet case 30. An outer first inclined surface 35a is formed on the first inclined portion 34a, inclined downward with respect to the one-way center line L1 so that the distance from the one-way center line L1 gradually increases as the first inclined portion 34a extends forward in the front-rear direction.

[0046] The other of the hooks, 31b, has a second straight portion 33b that extends linearly from the circumferential surface of the magnet case 30 forward in the front-rear direction (radially outward) in parallel with the first straight portion 33a of one hook 31a, and a second inclined portion 34b that extends forward in the front-rear direction from the tip of the second straight portion 33b. The second inclined portion 34b is inclined upward with respect to the unidirectional center line L1 so that the distance from the unidirectional center line L1 gradually increases as the second inclined portion 34b extends forward in the front-rear direction from the magnet case 30.

[0047] The second inclined portion 34b is formed with an outer second inclined surface 35b that slopes upward with respect to the one-way center line L1 so that the distance from the one-way center line L1 gradually increases as it moves forward. The first inclined portion 34a (outer first inclined surface 35a) and the second inclined portion 34b (outer second inclined surface 35b) of the hooks 31a, 31b are inclined in a diverging manner so that the distance from each other gradually increases as it moves forward.

[0048] The female member 27 is formed from a pair of guide rails 36a, 36b. The guide rails 36a, 36b are made of synthetic resin and located on the upper surface of the body portion 19 of the wire breakage sensor 14. The guide rail 36a is located widthwise outside the first straight portion 33a of the hook 31a and elastically deforms the hook 31a when a predetermined pulling force is applied to the hook 31a. The guide rail 36a has a first parallel portion 37a extending parallel to the first straight portion 33a of the hook 31a and a first inclined sliding portion 38a located at the tip of the first parallel portion 37a and inclined upward with respect to the center line L1 so that the distance from the center line L1 gradually decreases as the guide rail 36a extends forward.

[0049] Two engaging claws 39 are formed on the first parallel portion 37a of one guide rail 36a, protruding outward in the width direction from the first parallel portion 37a and aligned in the front-to-rear direction (one direction). The first inclined sliding portion 38a of one guide rail 36a is formed with an inner first inclined surface 40a that slopes upward with respect to the one-way center line L1 so that the distance from the one-way center line L1 gradually decreases toward the front. The inner first inclined surface 40a of the first inclined sliding portion 38a of one guide rail 36a slidably abuts against the outer first inclined surface 35a of the first inclined portion 34a of one hook 31a.

[0050] The other of the guide rails 36a, 36b, the guide rail 36b, is located widthwise outside the second straight portion 33b of the other hook 31b and elastically deforms the other hook 31b when a predetermined pulling force is applied to the other hook 31b. The other guide rail 36b has a second parallel portion 37b extending parallel to the second straight portion 33b of the other hook 31b and a second inclined sliding portion 38b located at the tip of the second parallel portion 37b and inclined downward with respect to the one-way centerline L1 so that the distance from the one-way centerline L1 gradually decreases toward the front. The second parallel portion 37b of the other guide rail 36b is formed with two engaging claws 39 that protrude widthwise outward from the second parallel portion and are aligned in the front-to-rear direction (one direction).

[0051] The second inclined sliding portion 38b of the other guide rail 36b is formed with an inner second inclined surface 40b that slopes downward with respect to the one-way centerline L1 so that the distance from the one-way centerline L1 gradually decreases as the sliding portion extends forward. The inner second inclined surface 40b of the second inclined sliding portion 38b of the other guide rail 36b slidably abuts against the outer second inclined surface 35b of the second inclined portion 34b of the other hook 31b. The first inclined sliding portion 38a (inner first inclined surface 40a) and the second inclined sliding portion 38b (inner second inclined surface 40b) of the guide rails 36a, 36b are inclined so that the distance between them gradually decreases as the sliding portion extends forward.

[0052] The cover member 28, which is placed on the male member 26 (connecting stick 29, magnet case 30, hooks 31a, 31b) and the female member 27 (guide rails 36a, 36b), is made of synthetic resin and has a covering portion 41 that covers the male member 26 and the female member 27, and a pair of fitting portions 42a, 42b that fit into the guide rails 36a, 36b. The covering portion 41 is molded in a flat plate shape and, when the cover member 28 is placed on the male member 26 and the female member 27, prevents the male member 26 (connecting stick 29, magnet case 30, hooks 31a, 31b) placed on the body portion 19 of the wire breakage sensor 14 from slipping out above the body portion 19. The fitting portions 42a, 42b extend downward from both sides of the covering portion 41 in the front-to-rear direction.

[0053] One of the fitting portions 42a, 42b, that is, the fitting portion 42a, is formed with two first fitting holes 43a that penetrate the fitting portion 42a in the width direction and are aligned in the front-to-rear direction (one direction). The other fitting portion 42b, of the fitting portions 42a, 42b, is formed with two second fitting claws 43b that penetrate the fitting portion 42b inward in the width direction and are aligned in the front-to-rear direction (one direction). With the cover member 28, one engaging portion 42a is positioned widthwise outside one guide rail 36a, and the other engaging portion 42b is positioned widthwise outside the other guide rail 36b, the engaging claws 39 formed on the first parallel portion 37a of one guide rail 36a are engaged with the first engaging holes 43a of one engaging portion 42a, and the engaging claws 39 formed on the second parallel portion 37b of the other guide rail 36b are engaged with the second engaging holes 43b of the other engaging portion 42b.

[0054] The mating claws 39 of the first and second parallel portions 37a, 37b of the first and second guide rails 36a, 36b are fitted into the first and second mating holes 43a, 43b of the first and second mating portions 42a, 42b of the cover member 28, whereby the cover member 28 is installed and fixed to the body portion 19 of the wire breakage sensor 14. The covering portion 41 of the cover member 28 presses down the male member 26 (connecting stick 29, magnet case 30, hooks 31a, 31b), making it impossible for the male member 26 (connecting stick 29, magnet case 30, hooks 31a, 31b) to be removed upward from the body portion 19 of the wire breakage sensor 14.

[0055] To install the male member 26 (connecting stick 29, magnet case 30, hooks 31a, 31b) on the female member 27 (guide rails 36a, 36b), the male member 26 is placed on the body portion 19 of the wire breakage sensor 14 so that the first straight portion 33a of the connecting stick 29 of the male member 26 is located widthwise inside the first parallel portion 37a of one guide rail 36a of the female member 27, and the second straight portion 33b of the connecting stick 29 of the male member 26 is located widthwise inside the second parallel portion 37b of the other guide rail 36b of the female member 27. When the male member 26 is placed on the body portion 19, the inner first inclined surface 40a of the first inclined sliding portion 38a of one guide rail 36a slidably abuts the outer first inclined surface 35a of the first inclined portion 34a of one hook 31a, and the inner second inclined surface 40b of the second inclined sliding portion 38b of the other guide rail 36b slidably abuts the outer second inclined surface 35b of the second inclined portion 34b of the other hook 31b.

[0056] Next, the cover member 28 is placed on the male member 26 and the female member 27, and the cover member 28 is pressed downward with one of the engaging portions 42a of the cover member 28 positioned widthwise outside the first parallel portion 37a of one guide rail 36a and the other engaging portion 42b of the cover member 28 positioned widthwise outside the second parallel portion 37b of the other guide rail 36b. When the cover member 28 is pressed downward, one of the engaging portions 42a of the cover member 28 climbs over the first parallel portion 37a of one of the guide rails 36a in the width direction, and the engaging claws 39 formed in the first parallel portion 37a of the guide rail 36a engage with the engaging holes 43a of the engaging portion 42a, and the other engaging portion 42b of the cover member 28 climbs over the second parallel portion 37b of the other guide rail 36b in the width direction, and the engaging claws 39 formed in the second parallel portion 37b of the guide rail 36b engage with the engaging holes 43b of the engaging portion 42b.

[0057] Fig. 4 is a perspective view of the deformation detection device 10 installed on the median strip 44 of bridge girders 12a and 12b, and Fig. 5 is a perspective view of the deformation detection device 10 installed on the parapet 45 of bridge girders 12a and 12b. Fig. 6 is a diagram showing a state in which the male member 26 (connecting stick 29, magnet case 30, hooks 31a and 31b) has separated from the wire break sensor 14, closing the contacts of the ON / OFF switch of the wire break sensor 14 and turning the ON / OFF switch ON. Figs. 4 and 5 show one deformation detection device 10 installed on the median strip 44 and parapet 45, but in reality, a deformation detection device 10 is installed on each of the median strip 44 and parapet 45 between one bridge girder 12a and the adjacent other bridge girder 12b, and multiple deformation detection devices 10 are installed on the bridge 11.

[0058] As shown in Fig. 4, the deformation detection device 10 installed in the median strip 44 of the bridge girders 12a, 12b has a wire breakage sensor 14 and a communication module 15 installed in the median strip 44 of one bridge girder 12a, and a wire fixing jig 16 installed in the median strip 44 of the other bridge girder 12b adjacent to the one bridge girder 12a. The other end of the wire 17 is fixed to the connecting stick 29 of the wire breakage sensor 14 installed in the median strip 44 of the one bridge girder 12a, and one end of the wire 17 is fixed to the wire fixing jig 16 installed in the median strip 44 of the other bridge girder 12b.

[0059] As shown in Fig. 5, the deformation detection device 10 installed on the parapet 45 of the bridge girders 12a, 12b has the wire breakage sensor 14 and communication module 15 installed on the parapet 45 of one bridge girder 12a, and the wire fixing jig 16 installed on the parapet 45 of the other bridge girder 12b adjacent to the one bridge girder 12a. The other end of the wire 17 is fixed to the connecting stick 29 of the wire breakage sensor 14 installed on the parapet 45 of one bridge girder 12a, and one end of the wire 17 is fixed to the wire fixing jig 16 installed on the parapet 45 of the other bridge girder 12b.

[0060] The wire 17 extending between the wire fixing jig 16 and the connecting stick 29 of the wire breakage sensor 14 is stretched between the wire fixing jig 16 and the connecting stick 29 with a predetermined slack. If the wire 17 is stretched between the wire fixing jig 16 and the connecting stick 29 in a taut state with no slack, slight deformation of the joint part 13 due to traffic vibrations caused by vehicles traveling on the bridge 11 or wind vibrations caused by strong winds blowing against the bridge 11 will cause the hooks 31a, 31b to come off the guide rails 36a, 36b, and the deformation detection device 10 will send an ON signal indicating this deformation to the management server.

[0061] However, by bridging the wire 17 between the wire fixing jig 16 and the connecting stick 29 of the wire breakage sensor 14 with a predetermined slack, the deformation detection device 10 can prevent malfunction of the deformation detection device 10, which transmits an ON signal due to traffic vibrations from vehicles traveling on the bridge 11 or wind vibrations from strong winds blowing against the bridge 11, and can accurately and reliably detect deformation occurring in the joint part 13 due to vibrations (such as large earthquakes) that are strong enough to damage the bridge 11, other than traffic vibrations and wind vibrations. By adjusting the degree of slack in the wire 17 according to the degree of deformation occurring in the joint part 13, the deformation detection device 10 can adjust its operation (transmission of an ON signal) according to the deformation of the joint part 13 (the size of the deformation).

[0062] The deformation detection devices 10 installed on the central median strip 44 or parapet 45 of the bridge girders 12 of the bridge 11 are set with a device identification number (device identifier) ​​that identifies the deformation detection device 10. The individual identification number of the deformation detection device 10 can be used as the device identification number (device identifier), or the management server can independently generate a unique identifier that identifies each deformation detection device 10, and use the generated identifier as the device identification number (device identifier).

[0063] The large-capacity storage area (or large-capacity hard disk) of the management server stores (contains) the device identification number (device identifier) ​​of each deformation detection device 10, as well as the abbreviated number of the deformation detection device corresponding to the device identification number of each deformation detection device 10, the name of the bridge on which each deformation detection device 10 is installed, the location (address) of the bridge 11 on which each deformation detection device 10 is installed, the installation location of each deformation detection device 10 on the bridge 11, and the installation date and time of each deformation detection device 10 on the bridge 11, all of which are stored (contained) in association with the device identification number (device identifier) ​​of the deformation detection device 10.

[0064] An example of the ON / OFF operation of the deformation detection device 10 will be described below. If an earthquake occurs in an area including the bridge 11 on which the deformation detection device 10 is installed and the resulting vibrations act on the bridge 11, and the vibrations are so great that deformation occurs at the joint 13 between one bridge girder 12a and the other bridge girder 12b, causing a step between the one bridge girder 12a and the other bridge girder 12b, the wire 17 stretched between the wire fixing jig 16 and the connecting stick 29 becomes tensed, and a pulling force (predetermined separation force) acts on the hooks 31a, 31b (male members 26) in the pulling direction (rearward in the fore-and-aft direction) so as to pull the hooks 31a, 31b (male members 26) out of the guide rails 36a, 36b (female members 27).

[0065] When a pulling force acts on 31a, 31b (male member 26), the outer first inclined surface 35a of the first inclined portion 34a of one hook 31a slides against the inner first inclined surface 40a of the first inclined sliding portion 38a of one guide rail 36a, and the outer second inclined surface 35b of the second inclined portion 34b of the other hook 31b slides against the inner second inclined surface 40b of the second inclined sliding portion 38b of the other guide rail 36b, and the one hook 31a As the hooks 31a, 31b elastically deform so that the first inclined portion 34a of one hook and the second inclined portion 34b of the other hook 31b gradually approach each other, one hook 31b (first straight portion 33a, first inclined portion 34a) gradually retreats rearward in the front-to-rear direction relative to one guide rail 36a, and the other hook 31b (second straight portion 33b, second inclined portion 34b) gradually retreats rearward in the front-to-rear direction relative to the other guide rail 36b.

[0066] As the hooks 31a, 31b retreat rearward from the guide rails 36a, 36b, the outer end of the first inclined portion 34a of one hook 31a climbs over the inner end of the first inclined sliding portion 38a of one guide rail 36a, and the outer end of the second inclined portion 34b of the other hook 31b climbs over the inner end of the second inclined sliding portion 38b of the other guide rail 36b. The pulling force required to release the hooks 31a, 31b from the guide rails 36a, 36b (the force required to pull the outer ends of the first and second inclined portions 34a, 34b over the inner ends of the first and second inclined sliding portions 38a, 38b) is 20 kg or greater.

[0067] Traffic vibrations from vehicles traveling on the bridge 11 and wind vibrations from strong winds blowing against the bridge 11 act on the bridge 11, and even if these vibrations cause a pulling force (predetermined separation force) in the pulling direction (rearward in the fore-and-aft direction) to act on the hooks 31a, 31b (male members 26), the pulling force acting on the hooks 31a, 31b will not exceed 20 kg. This prevents the deformation detection device 10, which sends an ON signal due to traffic vibrations from vehicles traveling on the bridge 11 and wind vibrations from strong winds, from malfunctioning, and makes it possible to accurately and reliably detect deformations occurring in the joint part 13 due to vibrations (such as large earthquakes) that are strong enough to damage the bridge 11, other than traffic vibrations and wind vibrations.

[0068] When the outer end of the first inclined portion 34a passes over the inner end of the first inclined sliding portion 38a and the outer end of the second inclined sliding portion 34b passes over the inner end of the second inclined sliding portion 38b, one hook 31a disengages from one guide rail 36a rearward in the front-to-rear direction, and the other hook 31b disengages from the other guide rail 36b rearward in the front-to-rear direction, and as shown in Figure 6, the engagement between the male member 26 (connecting stick 29, magnet case 30, hooks 31a, 31b) and the female member 27 (guide rails 36a, 36b) is released, and the male member 26 to which the other end of the wire 17 is connected is separated from the wire breakage sensor 14.

[0069] When the engagement between the male member 26 and the female member 27 is released and the male member 26 is separated from the wire break sensor 14, the permanent magnet contained and held in the magnet case 30 of the male member 26 comes off the wire break sensor 14, the magnetic force of the permanent magnet acting on the ON / OFF switch (switch) is released and the magnetic force no longer acts on the ON / OFF switch, the contacts of the ON / OFF switch of the wire break sensor 14 close and the ON / OFF switch turns ON.

[0070] When the ON / OFF switch is turned ON, an ON signal from the disconnection sensor 14 (ON / OFF switch) is transmitted to the communication module 15 via the signal line 21. Upon receiving the ON signal from the disconnection sensor 14, the communication device (microcomputer) of the communication module 15 transmits the ON signal (deformation signal of the joint portion), the device identification number (device identifier) ​​of the deformation detection device 10 that transmitted the ON signal, and the date and time of transmission of the ON signal to the management server.

[0071] The management server (computer) that receives the ON signal (deformation signal of the joint), the device identification number of the deformation detection device 10, and the date and time of transmission of the ON signal stores (stores) each piece of data of the deformation detection device 10 that transmitted the ON signal in a large-capacity storage area (or large-capacity hard disk). Furthermore, although not shown, it outputs (displays) on the display an ON signal reception message notifying that deformation of the joint 13 of the bridge 11 has been detected, and also outputs (displays) an open button on the display.

[0072] The data for each deformation detection device 10 that the management server that receives the ON signal stores in its large-capacity storage area (or large-capacity hard disk) includes the device identification number of each deformation detection device 10 that sent the ON signal, the abbreviated number of each deformation detection device 10 corresponding to the device identification number, the name of the bridge on which each deformation detection device 10 that sent the ON signal is installed, the location (address) of the bridge 11 on which each deformation detection device 10 that sent the ON signal is installed, the installation location of each deformation detection device 10 on that bridge 11, and the installation date (year, month, day) of each deformation detection device 10 on that bridge 11.

[0073] When the Open button displayed on the display is clicked, the management server outputs (displays) a deformation detection list screen on the display (not shown). The deformation detection list screen displays a deformation detection device list area that displays a list of each deformation detection device 10 that has sent an ON signal (deformation signal of the joint portion), a selection confirmation button, and an end button. When a desired deformation detection device 10 is selected from the deformation detection device list area (multiple selections are possible) and the selection confirmation button is clicked, the management server (computer) references the device identification number of the selected deformation detection device 10 and each piece of data stored in its large-capacity storage area (or large-capacity hard disk), and extracts the corresponding data that corresponds to the device identification number of the received deformation detection device 10.

[0074] The corresponding data extracted from the large-capacity storage area (or large-capacity hard disk) includes the abbreviated number of the deformation detection device 10 corresponding to the device identification number of the deformation detection device 10 that sent the ON signal, the name of the bridge on which the deformation detection device 10 that sent the ON signal is installed, the location (address) of the bridge 11 on which the deformation detection device 10 that sent the ON signal is installed, the installation location of the deformation detection device 10 on that bridge 11, the date and time (year, month, day, hour, minute, second) when the ON signal was sent by the deformation detection device 10, and the installation date (year, month, day) of the deformation detection device 10 on that bridge 11.

[0075] After extracting the corresponding data, the management server (computer) outputs (displays) on a display (not shown) a deformation detection device data display screen that displays the corresponding data of the selected deformation detection device 10. The deformation detection device data display screen displays an abbreviated number display area that displays the abbreviated number of the deformation detection device 10 that corresponds to the device identification number of the deformation detection device 10 that transmitted the ON signal, a bridge name display area that displays the bridge name of the bridge 11 on which the deformation detection device 10 that transmitted the ON signal is installed, a location (address) display area that displays the location (address) of the bridge 11 on which the deformation detection device 10 that transmitted the ON signal is installed, an installation location display area that displays the installation location of the deformation detection device 10 on that bridge 11, a transmission date and time display area that displays the date and time the ON signal was transmitted by the deformation detection device 10, an installation date display area that displays the installation date of the deformation detection device 10 on that bridge 11, and an exit button.

[0076] By looking at the deformation detection device data display screen output (displayed) on the display of the management server, it is possible to know the abbreviated number of the deformation detection device 10 that sent the ON signal (deformation signal of the joint), the name of the bridge 11 on which the deformation detection device 10 that sent the ON signal is installed, the location (address) of the bridge 11 on which the deformation detection device 10 that sent the ON signal is installed, the installation location of the deformation detection device 10 on that bridge 11, the date and time the ON signal was sent, and the installation date of the deformation detection device 10, and it is also possible to consider various measures such as repairing the bridge 11 (bridge girders 12a, 12b, piers, joints 13) and closing the bridge 11 to traffic at an early stage.

[0077] In the deformation detection device 10, when a predetermined vibration due to an earthquake or the like acts on the bridge 11, the vibration deforms the joint portion 13 connecting one bridge girder 12a and the other bridge girder 12b, and when a pulling force that exceeds the engagement force between the first and second hooks 31a, 31b and the first and second guide rails 36a, 36b acts on the hooks 31a, 31b due to the deformation of the joint portion 13, the hooks 31a, 31b are elastically deformed by the guide rails 36a, 36b and separated rearward in the front-rear direction from the guide rails 36a, 36b, and the male member 26 (connecting The connecting stick 29, magnet case 30, hooks 31a, 31b) and the female member 27 (guide rails 36a, 36b) are separated, the ON / OFF switch (switch) of the wire break sensor 14 is turned ON, and the ON signal of the wire break sensor 14 is sent to the communication module 15 via the signal line 21. Therefore, compared to the prior art where a surveillance camera is operated continuously to photograph each part of the bridge, less power is consumed in the deformation detection device 10, and deformation of the joint part 13 can be detected with less power consumption and at low cost.

[0078] When the joints 13 of the bridge girders 12a, 12b are deformed, the hooks 31a, 31b elastically deform in response to the deformation, causing the hooks 31a, 31b to separate from the guide rails 36a, 36b and the other end of the wire 17 to separate from the wire breakage sensor 14. Therefore, by utilizing the hooks 31a, 31b (male members 26) and the guide rails 36a, 36b (female members 27), the deformation detection device 10 can reliably detect deformation occurring in the joints 13. When the communication module 15 receives an ON signal, the deformation detection device 10 transmits the ON signal (deformation signal of the joints 13) to the management server (external) via a predetermined network. Therefore, appropriate measures can be taken quickly in response to the deformation occurring in the joints 13, and accidents on the bridge 11 can be prevented.

[0079] When a pulling force of 20 kg or more is applied to the hooks 31a, 31b (male members 26), the hooks 31a, 31b come off the guide rails 36a, 36b (female members 27). This prevents the deformation detection device 10 from malfunctioning, sending an ON signal due to traffic vibrations caused by vehicles traveling on the bridge 11 or wind vibrations caused by strong winds blowing against the bridge 11. This makes it possible to accurately and reliably detect deformations occurring in the joint portion 13 due to vibrations (such as large earthquakes) that are strong enough to damage the bridge 11, other than traffic vibrations and wind vibrations. [Explanation of symbols]

[0080] 10 Deformation detection device 11 Bridges 12a One side of the bridge girder 12b The other bridge girder 13 Joint 14 Wire break sensor 15 Communication Module 16 Wire fixing jig 17 wires 18 Connection means 19 Body 20 Fixed part 21 Signal line 22 Fixing screw 23 Storage Box 24 Wire fixing part 25 Screw insertion part 26 Male member 27 Female member 28 Cover member 29 Connecting Stick 30 Magnet Case 31a One Hook 31b Other hook 32 Wire insertion hole 33a 1st straight line section 33b 2nd straight line section 34a 1st slope section 34b 2nd slope section 35a Outside first slope 35b Second outer slope 36a One guide rail 36b The other guide rail 37a 1st parallel section 37b 2nd parallel section 38a First inclined sliding part 38b Second inclined sliding part 39 Interlocking claws 40a Inner first slope 40b Inner 2nd slope 41 Covering part 42 Fitting part 43a First fitting hole 43b 2nd fitting hole 44 Median Strip 45 Railing L1 One-way center line

Claims

1. A deformation detection device that detects deformation occurring at a joint connecting one bridge girder to another adjacent bridge girder when a predetermined vibration acts on the bridge, the deformation detection device is formed from a wire break sensor installed on one of the bridge girders connected by the joint portion, the switch of which is turned OFF when there is no wire break and turned ON when there is a wire break; a communication module installed on the one of the bridge girders and connected to the wire break sensor via a signal line; a wire fixing jig installed on the other bridge girder connected by the joint portion; and a wire whose one end is fixed to the wire fixing jig and whose other end is detachably connected to the wire break sensor via a predetermined connecting means; The deformation detection device is characterized in that when a predetermined vibration acts on the bridge and the vibration causes the other end of the wire to separate from the wire break sensor, the switch of the wire break sensor turns ON, an ON signal from the wire break sensor is sent to the communication module via the signal line, and the communication module, having received the ON signal, transmits the ON signal to the outside via a predetermined network.

2. 2. The deformation detection device of claim 1, wherein the predetermined connecting means is formed from one of the male and female members installed on the wire breakage sensor and the other of the male and female members to which the other end of the wire is connected, and in the deformation detection device, the connected state between the wire breakage sensor and the wire is maintained with the male and female members engaged with each other, and a predetermined separation force acts on the male and female members due to vibrations acting on the bridge, and when a separation force greater than the engagement force between the male and female members acts on the male and female members, the male and female members separate, and the other end of the wire separates from the wire breakage sensor.

3. 3. The deformation detection device of claim 2, wherein the male member is formed from a connecting stick that connects the other end of the wire, a magnet case connected to the front end of the connecting stick and holding a magnet, and a pair of elastically deformable hooks that extend radially outward from the magnet case across a unidirectional center line that bisects the connecting stick in a direction intersecting the one direction, and the female member is formed from a pair of guide rails that abut on both sides of the hooks and elastically deform the hooks when a predetermined pulling force is applied to the hooks.

4. One of the pair of hooks has a first straight portion extending straight outward in the radial direction from the magnet case, and a first inclined portion extending forward from a tip of the first straight portion and inclined downward with respect to the one-directional center line so that a distance from the one-directional center line gradually increases as it goes forward, and the other of the pair of hooks has a second straight portion extending straight outward in the radial direction from the magnet case in parallel to the first straight portion, and a second inclined portion extending forward from a tip of the second straight portion and inclined upward with respect to the one-directional center line so that a distance from the one-directional center line gradually increases as it goes forward, and one of the pair of guide rails is located outside the first straight portion of one of the hooks, and has a first parallel portion extending parallel to the first straight portion, and a first inclined portion located at a tip of the first parallel portion and inclined upward with respect to the one-directional center line as it goes forward.

4. The deformation detection device according to claim 3, wherein the other of the pair of guide rails has a first inclined sliding portion that is inclined upward with respect to the one-directional center line so that a distance from the one-directional center line gradually decreases, and the other of the pair of guide rails has a second parallel portion that is located outside the second straight portion of the other hook and extends parallel to the first parallel portion and the second straight portion, and a second inclined sliding portion that is located at a tip of the second parallel portion and inclined downward with respect to the one-directional center line so that a distance from the one-directional center line gradually decreases as it extends forward, and a first outer inclined surface of the first inclined sliding portion of the one hook slidably abuts against a first inner inclined surface of the first inclined sliding portion of the one guide rail, and a second outer inclined surface of the second inclined portion of the other hook slidably abuts against a second inner inclined surface of the second inclined sliding portion of the other guide rail.

5. 5. The deformation detection device according to claim 4, wherein, when a predetermined pulling force is applied to the pair of hooks, the outer first inclined surface of the first inclined portion of one of the hooks slides on the inner first inclined surface of the first inclined sliding portion of the one of the guide rails, and the outer second inclined surface of the second inclined portion of the other hook slides on the inner second inclined surface of the second inclined sliding portion of the other of the guide rails, elastically deforming the first and second inclined portions so that they gradually approach each other, and when the outer end of the first inclined portion moves over the inner end of the first inclined sliding portion and the outer end of the second inclined portion moves over the inner end of the second inclined sliding portion, the hooks come off the guide rails, and the male member connected to the other end of the wire is separated from the wire breakage sensor.

6. 6. The deformation detection device according to claim 5, wherein the magnetic force of the permanent magnet held in the magnet case of the male member opens the contacts of the switch of the wire breakage sensor, turning the switch OFF, and the hooks of the male member connected to the other end of the wire come off the guide rails, releasing the magnetic force of the permanent magnet, closing the contacts of the switch of the wire breakage sensor, turning the switch ON.

7. The deformation detection device according to claim 6, wherein the pulling force required to remove the hook from the guide rail is 20 kg or more.

8. The deformation detection device described in claim 7, wherein the wire break sensor and the communication module are installed in the central reservation of one of the bridge girders, and the wire fixing jig is installed in the central reservation of the other bridge girder adjacent to the one of the bridge girders.

9. A deformation detection device as described in claim 7, wherein the wire break sensor and the communication module are installed on the railing of one of the bridge girders, and the wire fixing jig is installed on the railing of the other bridge girder adjacent to the one bridge girder.

10. 10. A deformation detection device according to claim 9, wherein the wire connected to the wire fixing jig and the wire breakage sensor is stretched between the wire fixing jig and the wire breakage sensor with a predetermined slack.

Images