A safety monitoring device for crane girder structures with self-powered power supply

Abstract

The present invention discloses a safety monitoring device for a crane girder structure with a self-powered power supply, which includes a crack sensor, a vibration-powered power supply, and an automatic alarm. The vibration-powered power supply is fixed to the lower flange of the crane girder, and its output terminal is connected to the crack sensor to provide monitoring current. The crack sensor is arranged on the surface of the structure, and its output terminal is electrically connected to a micro-current measuring instrument. The automatic alarm judges the crack state based on the current change threshold in the metal foil and the conductive film and issues an alarm signal. The present invention can monitor strain data and has a large coverage area, and simultaneously monitors the changes in the position, length, and width of the crack. By utilizing the vibration characteristics of the monitored object itself to provide current for the monitoring device, there is no need to connect to the plant power supply system, and the installation is convenient, enabling long-term and effective monitoring.

Description

Technical Field

[0001] The present invention relates to a safety monitoring device for a crane beam structure with a self - power supply. Background Art

[0002] The crane beam is an important structural member in an industrial building, and its safe use plays a crucial role in the normal production of the industrial building. The crane beam is subjected to the alternating load of the traveling crane for a long time, and fatigue cracks are likely to occur in the structure. To ensure the structural safety of the crane beam, it is necessary to timely detect the development of fatigue cracks in the crane beam to avoid fatigue fracture.

[0003] At present, the main way to check the safety of fatigue cracks in the crane beam structure is manual inspection. However, there are a large number of crane beams in industrial buildings. Regularly conducting safety inspections on crane beams involves a large amount of work and high cost. When cracks expand in the crane beam, not only are the initial cracks relatively fine, and the surface is often covered with dust, but also due to the narrow space, it is often difficult for workers to conduct a close - up inspection. Affected by many factors above, even if regular safety inspections are carried out on crane beams, some cracks are difficult to be detected in time. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a safety monitoring device for a crane beam structure with a self - power supply, which can conduct safety inspections on the crane beam at any time, with high accuracy, and can achieve long - term and effective monitoring, greatly reducing the monitoring cost and improving the efficiency; further, it can also monitor strain data and simultaneously monitor the changes in the position, length, and width of cracks; it has a large coverage area, and crack sensors with different crack monitoring accuracies and coverage areas can be used according to actual requirements.

[0005] Furthermore, the vibration characteristics of the monitored object itself are utilized to provide current for the monitoring device, and the self - supplied current is used to generate a closed magnetic circuit to fix the vibration power supply under the lower flange of the crane beam, without the need to connect to the plant power supply system, which is convenient for installation.

[0006] To solve the above - mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A safety monitoring device for a crane beam structure with a self - power supply, characterized by comprising:

[0008] At least one crack sensor 1, arranged on the surface of the crane beam structure to be monitored;

[0009] An automatic alarm 3, composed of a micro - current measuring instrument 301, a micro - processor 302, a buzzer 303 and / or an alarm signal lamp 304 connected in sequence, and the output of the crack sensor 1 is connected to the micro - current measuring instrument 301;

[0010] A vibration power supply 2, fixedly connected to the lower flange of the mid - span of the crane beam structure, with the output end connected to the automatic alarm 3 to provide monitoring current;

[0011] The described crack sensor 1 includes an insulating layer 104, a conductive thin film layer, a metal foil layer, and a shielding layer 101 that are stacked in sequence; the insulating layer 104 is electrically insulated from the crane girder structural material, and the conductive thin film layer is directly on the upper surface of the insulating layer 104 (of course, it can also be made on an additional layer that is closely attached to the insulating layer 104 and will not move relative to each other). A plurality of rectangular conductive thin film blocks 103 perpendicular to the crack propagation direction are parallelly distributed and connected in parallel by wires 105, where the resistivity of each conductive thin film block 103 is different; a plurality of strip-shaped metal foils 102 perpendicular to the crack propagation direction are parallelly distributed on the metal foil layer and connected in series by wires 105. The crack sensor 1 is electrically connected to the automatic alarm 3 through the wire 105.

[0012] The insulating layer has a high volume resistivity at room temperature, can withstand a breakdown strength greater than 10 KV / mm, and is resistant to aging and corrosion.

[0013] The conductive thin film is a doped conductive coating, and fine-particle conductive metal particle materials are mixed with an inorganic binder to form a conductive thin film with conductivity. The resistivity of the required conductive thin film can be adjusted by controlling the content of the metal material in the conductive thin film or by using different types of metal materials. The width of the conductive thin film can be set to different widths according to the required monitoring accuracy of the crack, and different numbers of conductive thin films can be set according to the required monitoring range of the crack.

[0014] The described vibration power supply 2 includes a power supply box 201, a tubular coil support 202, a copper coil 203, two upper and lower insulating bases 204, two upper and lower springs 205, and a permanent magnet 206; the copper coil 203 is wound around the outside of the coil support 202, the upper and lower insulating bases 204 respectively fix the upper and lower springs 205, and the permanent magnet 206 is connected between the upper and lower springs 205 so as to be movable up and down. The lower insulating base 204 and the bottom of the coil support 202 are fixed in the power supply box 201. The power supply box 201 is installed at a location with large vibrations in the lower flange of the crane girder span. Due to the up and down vibration of the structure, the springs 205 are elastically deformed, and the permanent magnet 206 makes a cutting magnetic induction line movement. The vibration power supply 2 is electrically connected to the automatic alarm 3 through the wire 105 and provides current.

[0015] Further, a rectifier 201A, a storage battery 201B, and a filter 201C are also provided inside the power supply box 201; the rectifier is electrically connected to the copper coil joint, converts the electromagnetic induction alternating current into direct current, and its output terminal is connected to the storage battery and the filter, and at the same time provides a charging voltage for the storage battery, which is equivalent to a charger; the storage battery can store electricity and provide current for the circuit; the filter eliminates the influence of various external interference waves on the micro-current output by the storage battery. It allows signals in a fixed frequency band of the signal to pass through, and can suppress the passing of interference and other frequency band signals, and can ensure that the storage battery continuously provides a stable micro-current signal for the monitoring device.

[0016] As a monitoring device, it cannot cause damage to the monitored structure during monitoring. The vibration-powered power supply 2 is fixed to the lower flange of the middle span of the crane beam structure by means of clamping and / or electromagnetic attraction.

[0017] Preferably, holes are opened on the bottom plate of the power supply box 201 of the vibration-powered power supply 2, and the electromagnetic attraction support 207 passes through the bottom plate opening and is connected to the surface of the lower flange of the crane beam: one end of the support 207 is a cylinder, and the other end is a screw 213. A cylindrical iron core 210 is provided inside the cylinder end. A copper coil 203 is wound outside the iron core 210 and sealed with resin 214. The copper coil 203 is electrically connected to the vibration-powered power supply 2 through the wiring hole 211 on the side. Two locking nuts 212 are provided on the screw 213 to lock the fixed position after the screw passes through the bottom plate opening. When the vibration-powered power supply 2 generates current through vibration, the copper coil 203 is energized, forms a closed magnetic circuit with the lower flange 4 of the crane beam, and generates a magnetic force to be fastened to the lower flange 4 of the crane beam.

[0018] Further, the length of the screw can be adjusted by the height adjustment screw 213 so that the reinforcement can adapt to the installation of crane beams with different flange plate thicknesses and fix the vibration-powered power supply 2.

[0019] The automatic alarm includes a micro-current measuring instrument, a microprocessor, a buzzer, an alarm signal lamp, and a wireless signal transmitter; the output terminal of the crack sensor is connected to the micro-current measuring instrument to collect current signals, outputs the current signals and is connected to the microprocessor. The input terminal of the microprocessor is connected to the micro-current measuring instrument, compares and analyzes the input current signal with the basic current value, and its output terminal is connected to the buzzer and the alarm signal lamp. When the change of the current signal reaches the set threshold, corresponding alarm signals are sent out. The buzzer continuously emits a beeping sound, the alarm signal lamp starts to flash at a high frequency, and at the same time the microprocessor sends the alarm information to the remote handheld device through the wireless signal transmitter.

[0020] Specifically, the micro-current measuring instrument includes a signal amplifier and a DC current collector; the signal amplifier realizes high-gain amplification of the current, and the DC current collector measures and records the micro-current data. The output terminal of the DC current collector is connected to the microprocessor.

[0021] The described microprocessor 302 is also connected to a wireless signal transmitter 305 to send signals to a remote handheld device.

[0022] The described microprocessor 302 includes: a data extraction module 302A, a crack diagnosis module 302B, a risk assessment module 302C, and an automatic alarm module 302D.

[0023] Preferably, the automatic alarm can add multi-channel management to realize the control of multiple crack sensors.

[0024] Specifically, the microprocessor includes a data extraction module, a crack diagnosis module, a risk assessment module, and an automatic alarm module; the microprocessor extracts the micro-current signal of the circuit through the data extraction module; through the crack diagnosis module, first, the micro-current data of the conductive thin film is compared and analyzed with the basic current value to determine the on-off state of each conductive thin film circuit, diagnose the crack propagation position and length, and secondly, the current value of the metal foil layer is compared and analyzed to determine the crack width; the current safety level of the crane beam structure is determined through the risk level divided by the risk assessment module; through the automatic alarm module, corresponding level alarm signals are sent to the on-site alarm device and the remote handheld device in a timely manner according to the risk assessment result.

[0025] Preferably, a communication connection is established with the intelligent gateway through the wireless signal transmitter; the intelligent gateway serves as a signal transfer station, and its output end is connected to the remote handheld device; the remote handheld device includes an image display, a wireless communicator, and a safety level signal lamp; the signal analysis result is synchronized through the image display to realize the visualization of terminal data, and the safety level signal lamp of the corresponding color flashes frequently based on the safety level; the wireless communicator can enable all remote handheld devices to establish a communication connection, form a wireless sensor network, and realize the function of mutual instant communication.

[0026] Preferably, the remote handheld device is equipped with all on-site staff in the factory area. The wireless signal transmitter can wirelessly transmit information such as the monitored current signal data, diagnostic analysis, safety assessment and processing methods, and alarm signals to the remote handheld device; the remote handheld device can be replaced by a mobile phone APP.

[0027] Preferably, the risk assessment module is divided into three stages according to different crack propagation lengths within the critical crack length. When the structural fatigue crack reaches 10% of the allowable maximum crack length, it is the upper limit of the low-risk stage. When it reaches 30% of the allowable maximum crack length, it is the demarcation value between the medium-risk stage and the high-risk stage. When the crack propagation length is lower than this demarcation value, it is the medium-risk stage, and when it is higher than this demarcation value, it is the high-risk stage. Thus, a risk level classification standard is established. The risk level is divided into three corresponding risk levels, namely, the low-risk level, the medium-risk level, and the high-risk level.

[0028] The low-risk level indicates that an initial crack has been detected, and the crack length is within the range of 10% of the allowable maximum crack length. The treatment method is to maintain the monitoring status and schedule regular unified repairs; the medium-risk level indicates that the crack is within the range of 10% - 30% of the allowable maximum crack length, which has a certain impact on the structure. The treatment method is to arrange for repair as soon as possible; the high-risk level indicates that the crack has exceeded 30% of the allowable maximum crack length, which may threaten the safe use of the structure. The treatment method is to urgently carry out repairs or even replace the crane beam; the remote output alarm information of the automatic alarm module includes the determined structural risk level and the corresponding treatment method established above.

[0029] A safety monitoring device for the structure of a crane beam with a self-powered power supply provided by the present invention arranges the safety monitoring device of the present invention in the key development area of fatigue cracks of the crane beam. When monitoring the development status of fatigue cracks of the crane beam, since the crack sensor is closely attached to the structure surface, when a crack appears in the covered area, it will cause the conductive film at the corresponding position covering the crane beam to break, resulting in the disconnection of the circuit of this branch, and the change of the loop circuit will further cause the current to change. When the crack lengths are different, the current values change correspondingly due to different changes in resistance values. By analyzing and calculating the change value of the current, the crack propagation position and length can be judged; when there is no crack in the structure, the metal foil can monitor the strain of the covered area and provide stress monitoring. After a crack appears, it provides crack width monitoring, realizing real-time monitoring of the crack condition of the crane beam; the monitoring device collects the dynamic data of the micro-current of the circuit through a micro-current measuring instrument, equivalently realizing the real-time dynamic monitoring of fatigue cracks. Through remote transmission, it has visual monitoring data and real-time alarm push, upgrading the safety inspection of the crane beam from regular inspection to real-time monitoring.

[0030] A safety monitoring device for the structure of a crane beam with a self-powered power supply provided by the present invention has high precision compared with directly arranging maintenance personnel to conduct regular inspections on the fatigue cracks of the crane beam. It can achieve long-term effective monitoring, greatly reduce the monitoring cost and improve the efficiency. Compared with using only strain sensors to monitor strain data, the present invention can monitor strain data and simultaneously monitor the changes in the crack position, length and width; it has a large covered area, and crack sensors with different crack monitoring precisions and covered areas can be used according to actual requirements; it uses the vibration characteristics of the monitored object itself to provide current for the monitoring device, and uses the self-supplied current to generate a closed magnetic circuit to fix the vibration power supply under the lower flange of the crane beam, without the need to connect to the plant power supply system, and is convenient to install. Brief Description of the Drawings

[0031] Figure 1a It is one of the three-dimensional schematic diagrams of the crack sensor structure of the safety monitoring device provided by the embodiment of the present invention;

[0032] Figure 1b It is the second three-dimensional schematic diagram of the crack sensor structure of the safety monitoring device provided by the embodiment of the present invention;

[0033] Figure 1c The third three - dimensional schematic diagram of the crack sensor structure of the safety monitoring device provided by the embodiment of the present invention;

[0034] Figure 2 The schematic diagram of the conductive thin - film layer structure of the safety monitoring device provided by the embodiment of the present invention;

[0035] Figure 3 The schematic diagram of the metal strain layer structure of the safety monitoring device provided by the embodiment of the present invention;

[0036] Figure 4a The first decomposition schematic diagram of the vibration - powered power supply of the safety monitoring device provided by the embodiment of the present invention;

[0037] Figure 4b The second decomposition schematic diagram of the vibration - powered power supply of the safety monitoring device provided by the embodiment of the present invention;

[0038] Figure 4c The third decomposition schematic diagram of the vibration - powered power supply of the safety monitoring device provided by the embodiment of the present invention;

[0039] Figure 5 The schematic diagram of the vibration - powered power supply structure of the safety monitoring device provided by the embodiment of the present invention;

[0040] Figure 6 The sectional schematic diagram of the vibration - powered power supply support of the safety monitoring device provided by the embodiment of the present invention;

[0041] Figure 7 The schematic diagram of the vibration - powered power supply support structure of the safety monitoring device provided by the embodiment of the present invention;

[0042] Figure 8 The schematic diagram of the vibration - powered power supply reinforcement structure of the safety monitoring device provided by the embodiment of the present invention;

[0043] Figure 9 The schematic diagram of the vibration - powered power supply installation structure of the safety monitoring device provided by the embodiment of the present invention;

[0044] Figure 10 The schematic diagram of the on - site alarm process of the safety monitoring device provided by the embodiment of the present invention;

[0045] Figure 11 The schematic diagram of the automatic alarm structure of the safety monitoring device provided by the embodiment of the present invention;

[0046] Figure 12 The schematic diagram of the micro - processor structure of the safety monitoring device provided by the embodiment of the present invention. Detailed implementation manners

[0047] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0048] A safety monitoring device for a crane girder structure with a self-powered power supply, characterized in that it includes a crack sensor 1, a vibration-powered power supply 2, and an automatic alarm 3. The automatic alarm 3 is composed of a micro-current measuring instrument 301, a microprocessor 302, a buzzer 303, and an alarm signal lamp 304 connected in sequence.

[0049] The crack sensor 1 is arranged on the surface of the structure to be monitored through a special structural adhesive, and its output end is electrically connected to the micro-current measuring instrument 301; the vibration-powered power supply 2 provides current based on the vibration of the structure using electromagnetic induction, is fixed to the lower flange of the middle span of the crane girder, and its output end is connected to the automatic alarm 3 to provide monitoring current.

[0050] When crack propagation occurs in the monitored structural area, it will cause a change in the current in the metal foil 102 and the conductive thin film 103. The automatic alarm 3 judges the crack state through the current change threshold and sends an alarm signal to the on-site alarm device and the remote handheld device.

[0051] As shown in Figure 1, the crack sensor 1 includes an insulating layer 104, a conductive thin film layer, a metal foil layer, and a shielding layer 101 stacked from bottom to top in sequence; the insulating layer 104 is electrically insulated from the base material. As shown in Figure 1 and Figure 3 shown, the conductive thin film layer is directly on the upper surface of the insulating layer 104 (of course, it can also be made on an additional layer that is closely attached to the insulating layer 104 and does not move relative to it). A plurality of rectangular conductive thin film blocks 103 perpendicular to the crack propagation direction are parallelly distributed and connected in parallel with wires 105 to determine the location and length of the crack. Among them, the resistivity of each conductive thin film block 103 is different; as shown in Figure 1 and Figure 2 shown, a plurality of strip-shaped metal foils 102 perpendicular to the crack propagation direction are parallelly distributed on the metal foil layer and connected in series with wires 105 to determine the crack width; the shielding layer 101 is arranged on the uppermost layer of the crack sensor 1 to shield external signal interference and protect the crack sensor 1. The crack sensor 1 is electrically connected to the automatic alarm 3 through the wire 105.

[0052] As shown in Figure 1 and Figure 3 shown, the resistivity of the conductive thin film 103 is different. When a crack appears and propagates in the area covered by a certain conductive thin film 103, causing the conductive thin film 103 in this interval to be open-circuited, the current in the circuit changes. The output end is connected to the automatic alarm 3. By comparing and analyzing the change in the current value, the interval of the open-circuited conductive thin film 103 is determined, and the crack position and propagation length are obtained.

[0053] Specifically, the resistances of the conductive thin films 103 are R1, R2, R3, R4, R5,..., R from top to bottom Figure 3 , , ,

[0052] , 12 ,

[0053] , the basic resistance in the circuit The basic current I = U / R. When cracks appear and expand in the structure covered by the conductive film R1, causing the conductive film R1 to break, the conductive film R1 is open-circuited, and the resistance in the circuit The current I' = U / R'. Since the current values when different conductive films 103 are open-circuited have been imported into the crack diagnosis module in advance, by comparing and analyzing the value of the current I', the crack position and the expansion length can be obtained.

[0054] Furthermore, the conductive film 103 is a blended conductive coating. Fine-grained conductive metal particle materials are mixed with an inorganic binder to form a conductive film 103 with conductive ability, and the resistivity of the required conductive film 103 can be adjusted by controlling the content of the metal material in the conductive film 103 or using different types of metal materials. The width of the conductive film 103 can be set to different widths according to the accuracy requirements for monitoring cracks, and the number of different conductive films 103 can be set according to the range of cracks to be monitored.

[0055] Such as Figure 2 As shown, when there are no cracks in the structure, the metal foil 102 of the metal foil layer monitors the microstrain as the structural elastic strain to achieve stress monitoring; when cracks occur in the structure, at this time, the microstrain monitored by the metal foil 102 is the sum of the crack width and the elastic strain. The output end is connected to the automatic alarm 3, and by analyzing and processing the current value in the circuit, the crack width can be obtained.

[0056] Specifically, the basic length of the metal foil is L. When there are no cracks in the structure, the microstrain ε = ΔL / L in the area covered by the metal foil 102, and the working length of the metal foil 102 is L + ΔL, where ΔL is the elastic deformation when the structure is stressed. At this time, the basic resistance of the circuit is R, and the basic current is I; when cracks occur in the structure, the working length of the metal foil 102 is L + ΔL + ΔL', where ΔL' is the crack width. Since the metal foil 102 is always in the elastic working stage, by analyzing and processing the current value in the circuit, the cumulative microstrain ε' = (ΔL + ΔL') / L in the area covered by the metal foil 102 when there are cracks is obtained. The change value of the length of the metal foil 102, ΔL + ΔL', minus the elastic deformation ΔL when the structure is stressed, can obtain the crack width ΔL'.

[0057] Specifically, the insulating layer 104 has a high volume resistivity at room temperature, can withstand a breakdown strength greater than 10 KV / mm, and is resistant to aging and corrosion.

[0058] Such as Figures 4a to 5As shown in the figure, the vibration-powered power supply 2 includes a power supply box 201, a tubular coil support 202, a copper coil 203, two upper and lower insulating bases 204, two upper and lower springs 205, and a permanent magnet 206; the copper coil 203 is wound around the outside of the coil support 202, the upper and lower insulating bases 204 respectively fix the upper and lower springs 205, the permanent magnet 206 is fixed between the upper and lower springs 205, the lower insulating base 204 and the bottom of the coil support 202 are fixed inside the power supply box 201, and the power supply box 201 is installed at a location with large vibrations such as the lower flange of the crane girder span. Due to the up and down vibration of the structure, the spring 205 elastically deforms, the permanent magnet 206 makes a movement of cutting magnetic induction lines, and the vibration-powered power supply 2 is electrically connected to the automatic alarm 3 through a wire 105 and provides current.

[0059] Furthermore, the power supply box 201 includes a rectifier 201A, a storage battery 201B, and a filter 201C; the rectifier 201A is electrically connected to the joint of the copper coil 203, converts the alternating current of electromagnetic induction into direct current, and the output end is connected to the storage battery 201B and the filter 201C, while providing a charging voltage to the storage battery 201B, equivalent to a charger; the storage battery 201B can store electricity and provide current for the circuit; the filter 201C can eliminate the influence of various external interference waves on the micro-current output by the storage battery 201B. It allows signals in a fixed frequency band in the signal to pass through, and can suppress the passing of interference and other frequency band signals, ensuring that the storage battery 201B continuously provides a stable micro-current signal for the monitoring device.

[0060] As Figure 6 — Figure 9 As shown in the figure, a hole is opened on the bottom plate of the power supply box 201 of the vibration-powered power supply 2. One side of the bottom plate of the power supply box 201 is fixed to the lower flange of the crane girder by bolts through a fixing member 209, and the bottom surface of the bottom plate of the power supply box 201 is parallel to the surface of the lower flange of the crane girder. The remaining part of the bottom plate of the power supply box 201 is supported on the surface of the lower flange of the crane girder through a support 207 passing through the hole in the bottom plate.

[0061] One end of the support 207 is a cylinder, and the other end is a screw 213. There are two locking nuts 212 on the screw 213 that can lock the fixed position after the screw passes through the hole in the bottom plate. A cylindrical iron core 210 is provided inside the cylinder end. The copper coil 203 is wound around the iron core 210 and sealed with resin 214. The copper coil 203 is electrically connected to the vibration-powered power supply 2 through a wiring hole 211 on the side. The vibration-powered power supply 2 generates current through vibration, energizes the copper coil 203, and generates a magnetic force to be fastened to the lower flange 4 of the crane girder. A height adjustment screw 213 is provided on the support 207. By rotating the height adjustment screw 213, the height of the support suitable for the installation of the fixing member 209 is adjusted, and the position is fixed using the two locking nuts 212 on both sides.

[0062] Further, the length of the screw can be adjusted by the height fine-tuning screw 213 so that the reinforcement can adapt to the installation of crane beams with different flange plate thicknesses and fix the vibration power supply 2.

[0063] As Figures 10 - 11 shown, the automatic alarm 3 includes a microcurrent measuring instrument 301, a microprocessor 302, a buzzer 303, an alarm signal lamp 304, a wireless signal transmitter 305, and a multi-channel management 306. The output end of the crack sensor 1 is connected to the microcurrent measuring instrument 301 to collect current signals, output current signals and connect to the microprocessor 302. The input end of the microprocessor 302 is connected to the microcurrent measuring instrument 301, which compares and analyzes the input current signal with the base current value, and the output end is connected to the buzzer 303 and the alarm signal lamp 304. When the change of the current signal reaches the set threshold, corresponding alarm signals are sent out. The buzzer continuously emits a buzzing sound, and the alarm signal lamp starts to flash at a high frequency. At the same time, the microprocessor 302 sends the alarm information to the remote handheld device through the wireless signal transmitter 305.

[0064] Specifically, the microcurrent measuring instrument 302 includes a signal amplifier and a DC current collector; the signal amplifier realizes high-gain amplification of the current, and the DC current collector measures and records the microcurrent data. The output end of the DC current collector is connected to the microprocessor.

[0065] Preferably, the automatic alarm can add a multi-channel management 306 to simultaneously control eight crack sensors 1.

[0066] As Figure 12 shown, the microprocessor 302 includes a data extraction module 302A, a crack diagnosis module 302B, a risk assessment module 302C, and an automatic alarm module 302D; the microprocessor 302 extracts the circuit microcurrent signal through the data extraction module 302A; through the crack diagnosis module 302B, first, the microcurrent data of the conductive film 103 is compared and analyzed with the base current value to determine the on-off state of each conductive film 103 circuit, diagnose the crack propagation position and length, and second, the current value of the metal foil 102 layer is compared and analyzed to determine the crack width; the current safety level of the crane beam structure is determined through the risk level divided by the risk assessment module 302C; through the automatic alarm module 302D, corresponding level alarm signals are sent to the on-site alarm device and the remote handheld device in a timely manner according to the risk assessment result.

[0067] Preferably, a communication connection is established with the intelligent gateway through the wireless signal transmitter 305; the intelligent gateway serves as a signal transfer station, and its output end is connected to the remote handheld device; the remote handheld device includes an image display, a wireless communicator, and a safety level signal lamp; the signal analysis result realizes the visualization of terminal data through the image display, and the safety level signal lamp corresponding to the color flashes frequently based on the safety level; the wireless communicator enables all remote handheld devices to establish a communication connection, forming a wireless sensor network to realize the function of mutual instant communication.

[0068] Preferably, the remote handheld device is equipped with all on-site staff in the factory area. The wireless signal transmitter 305 can wirelessly transmit information such as the monitored current signal data, diagnostic analysis, safety assessment and processing methods, and alarm signals to the remote handheld device; the remote handheld device can be replaced by a mobile phone APP.

[0069] Preferably, the risk assessment module is divided into three stages according to different crack propagation lengths within the critical crack length. When the structural fatigue crack reaches 10% of the allowable maximum crack length, it is the upper limit of the low-risk stage. When it reaches 30% of the allowable maximum crack length, it is the demarcation value between the medium-risk stage and the high-risk stage. When the crack propagation length is lower than this demarcation value, it is the medium-risk stage, and when it is higher than this demarcation value, it is the high-risk stage. Thus, a risk level classification standard is established. The risk level is divided into three corresponding safety levels, namely the low-risk level, the medium-risk level, and the high-risk level. The low-risk level represents that an initial crack has been detected, and the crack length is within the range of 2 conductive films 103. The treatment method is to maintain the monitoring state and schedule regular unified repairs; the medium-risk level represents that the crack is within the range of 2-6 conductive films 103, which has a certain impact on the structure. The treatment method is to arrange for repair as soon as possible; the high-risk level represents that the crack has exceeded the crack length within the range of 6 conductive films 103, which may threaten the safe use of the structure. The treatment method is to urgently carry out repairs or even replace the crane beam; the remote output alarm information of the automatic alarm includes the established structural risk level and the corresponding treatment method.

[0070] The above are only the preferred embodiments of the invention and are not intended to limit the invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the invention shall be included within the scope of protection of the invention.

Claims

1. A safety monitoring device for crane beam structure with self-powered power supply, characterized in that Comprising: At least one crack sensor (1), arranged on the surface to be monitored of the crane girder structure; an automatic alarm (3), composed of a micro-current measuring instrument (301), a microprocessor (302), a buzzer (303) and / or an alarm signal lamp (304) connected in sequence, the output of the crack sensor (1) is connected to the micro-current measuring instrument (301); a vibration power supply (2), connected to the lower flange at the mid-span of the crane girder structure, and the output end is connected to the automatic alarm (3) and provides monitoring current; the crack sensor (1) includes an insulating layer (104), a conductive thin film layer, a metal foil layer and a shielding layer (101) stacked in sequence; the insulating layer is electrically insulated from the crane girder structure material, and the conductive thin film layer is directly on the upper surface of the insulating layer or on the upper surface of an additional layer that is closely attached to the insulating layer and does not move relative to each other. A plurality of rectangular conductive thin film blocks (103) perpendicular to the crack propagation direction are parallelly distributed and connected in parallel by wires (105). The resistivity of each conductive thin film block (103) is different. The current values when different conductive thin films (103) are open-circuited are imported into the crack diagnosis module in advance. By comparing and analyzing the current values, the crack position and the propagation length can be obtained; a plurality of strip-shaped metal foils (102) perpendicular to the crack propagation direction are parallelly distributed on the metal foil layer and connected in series by wires. The crack sensor (1) is electrically connected to the automatic alarm (3) through wires; The vibration power supply (2) includes a power supply box (201), a tubular coil bracket (202), a copper coil (203), two upper and lower insulating bases (204), two upper and lower springs (205) and a permanent magnet (206); the copper coil is wound outside the coil bracket, the upper and lower insulating bases respectively fix the upper and lower springs correspondingly, the permanent magnet is movably connected up and down between the upper and lower springs, the lower insulating base and the bottom of the coil bracket are fixed in the power supply box, and the power supply box is installed at the vibration part of the lower flange at the mid-span of the crane girder; The microprocessor (302) includes: a data extraction module (302A), a crack diagnosis module (302B), a risk assessment module (302C) and an automatic alarm module (302D).

2. The safety monitoring device for crane beam structure with self-powered power supply according to claim 1, characterized in that: The insulating layer (104) is an insulating layer with a high volume resistivity at room temperature, capable of withstanding a breakdown strength greater than 10 KV / mm, and is resistant to aging and corrosion.

3. The safety monitoring device for crane beam structure with self-powered power supply according to claim 1, wherein: The conductive thin film is a blended conductive thin film formed by mixing fine-particle conductive metal particle materials and inorganic binders and having conductivity.

4. The safety monitoring device for crane beam structure with self-powered power supply according to claim 3, characterized in that: A rectifier (201A), a storage battery (201B) and a filter (201C) are also provided in the power supply box; the rectifier is electrically connected to the copper coil joint, and the output end is connected to the storage battery and the filter.

5. The safety monitoring device for crane beam structure with self-powered power supply according to claim 1, characterized in that: The vibration power supply (2) is fixed to the lower flange at the mid-span of the crane girder structure by clamping and / or electromagnetic suction.

6. The safety monitoring device for crane beam structure with self-powered supply according to claim 5, characterized in that: The electromagnetic suction method is fixed to the lower flange at the mid-span of the crane beam structure as follows: a hole is opened on the bottom plate of the power supply box (201) of the vibration power supply (2), and it is connected to the surface of the lower flange of the crane beam through the electromagnetic suction support (207) passing through the hole in the bottom plate; one end of the electromagnetic suction support (207) is a cylinder and the other end is a screw (213). A cylindrical iron core (210) is arranged inside the cylinder end. A copper coil (203) is wound outside the iron core (210) and sealed with resin (214). The copper coil is electrically connected to the vibration power supply (2) through the wiring hole (21) on the side. Two locking nuts (212) are arranged on the screw (213) to lock the fixed position after the screw passes through the hole in the bottom plate.

7. The safety monitoring device for crane girder structure with self-powered power supply according to claim 1, characterized in that: The described microprocessor (302) is also connected to a wireless signal transmitter (305) to send signals to a remote handheld device.

8. The safety monitoring device for crane girder structure with self-powered power supply according to claim 1, characterized in that: The microcurrent measuring instrument includes a signal amplifier and a DC current collector; the signal amplifier realizes high-gain amplification of the current, the DC current collector measures and records the microcurrent data, and the output end of the DC current collector is connected to the microprocessor.

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