Intelligent monitoring method for working state of high-strength bolt

Abstract

The invention provides an intelligent monitoring method for the working state of a high-strength bolt. The intelligent monitoring method comprises the following steps that the head of the high-strength bolt is machined; processing the rod part of the high-strength bolt; the intelligent laser transceiving and monitoring all-in-one device and the high-strength bolt are connected and combined into an assembly body; the intelligent laser transceiving and monitoring all-in-one device is connected with the central controller; the central controller controls the intelligent laser transceiving and monitoring all-in-one device to emit laser and receives a feedback signal; and the central controller judges the working state of the high-strength bolt according to the feedback signal. The device has the beneficial effects that normal work, loosening and breakage of the high-strength bolt are rapidly and accurately monitored, reliable guarantee is provided for safe operation of an engineering structure, a feedback signal is formed through the change of the pre-tightening force, danger is warned in advance, the situation that due to the fact that the pre-tightening force of the bolt is reduced and the bolt is broken, connection failure is caused, and consequently heavy economic losses are caused is prevented, and the working efficiency is improved. And life safety is threatened.

Description

Technical Field

[0001] This invention belongs to the field of mechanical connection technology, and in particular relates to an intelligent monitoring method for the working status of high-strength bolts. Background Technology

[0002] High-strength bolts are widely used in numerous engineering fields such as automobile manufacturing, large steel structure buildings, bridges, and wind turbine generators. Their function is to tightly connect the components by applying preload, ensuring the integrity and stability of the structure. Effective monitoring of the preload is crucial for ensuring the reliability and safety of the connection and the long-term performance of the structure. During operation, insufficient preload may lead to loosening and slippage of the connection, reducing the load-bearing capacity of the structure; if the bolt breaks, it can easily cause a safety accident and result in significant economic losses.

[0003] Currently, the following methods exist for monitoring the working condition of bolts: vibration analysis, which relies on fixed threshold alarms and cannot distinguish between loosening and normal vibration noise; and acoustic emission technology, which is highly sensitive to temperature (error > 5% / ℃). Given the aforementioned problems with existing high-strength bolt preload monitoring methods, there is an urgent need for a more accurate, convenient, and reliable monitoring method to meet actual engineering needs. Summary of the Invention

[0004] In view of this, the present invention aims to propose an intelligent monitoring method for the working status of high-strength bolts, in order to solve the problems of existing high-strength bolt preload monitoring technology, such as difficulty in distinguishing between loosening and normal vibration noise, and high sensitivity to temperature.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A method for intelligent monitoring of the working status of high-strength bolts includes the following steps: S1. Process the head of the high-strength bolt; S2. Process the high-strength bolt shank; S3, the intelligent laser transceiver monitoring unit is combined with high-strength bolts to form an assembly; S4, the intelligent laser transceiver monitoring unit is connected to the central controller; S5. The central controller controls the intelligent laser transceiver monitoring device to emit lasers and receive feedback signals. S6. The central controller determines the working status of the high-strength bolts based on the feedback signal.

[0006] Furthermore, in step S1, the head of the high-strength bolt undergoes processing, including: S11, High-strength bolt head is machined with threaded holes; S12, Flattening of the bottom of the threaded hole; S13. The bottom surface of the hole is smoothed.

[0007] Furthermore, in step S2, the high-strength bolt shank is processed, including: The high-strength bolt shank is reinforced by thickening.

[0008] Furthermore, in step S3, the intelligent laser transceiver monitoring unit is combined with high-strength bolts to form an assembly, including: S31, Intelligent laser transceiver monitoring unit connected with high-strength bolts; S32, the intelligent laser transceiver monitoring unit and high-strength bolts form a cavity structure; S33. The laser transmitting and receiving surface of the intelligent laser transceiver monitoring device is directly facing the bottom plane of the threaded hole of the high-strength bolt, and the distance between the two is a set value.

[0009] Furthermore, in step S4, the intelligent laser transceiver monitoring unit is connected to the central controller, including: The intelligent laser transceiver monitoring unit can be connected to the central controller via wired or wireless connection.

[0010] Furthermore, in step S6, the central controller determines the working status of the high-strength bolt based on the feedback signal, including: S61. The expression for calculating the signal feedback time is as follows: T=2L / C(1); In the formula, C is the speed of light, L is the distance between the laser emission and receiving surface of the intelligent laser transceiver monitoring device and the flat surface of the threaded hole of the high-strength bolt, and T is the signal feedback time. S62. If it is in normal working condition, the signal feedback time is the normal value and remains unchanged; S63. If the non-drilled part of the high-strength bolt is broken or loose, the preload disappears, the distance L becomes smaller, and the central controller calculates the signal feedback time T by formula (1) in step S61, which is shorter, and determines that the high-strength bolt is broken or loose. S64. If the drilled part of the high-strength bolt breaks, the preload disappears, and the central controller determines the working state of the high-strength bolt when the drilled part breaks by formula (1) in step S61. Furthermore, in step S64, the central controller determines the working state of the high-strength bolt when it breaks in the drilling part using formula (1) from step S61, including: S641. If the high-strength bolt breaks and is misaligned, the feedback signal cannot be received. The central controller calculates the signal feedback time T by formula (1) in step S61 and determines that the high-strength bolt drilling part is broken and the disconnected part is misaligned. S642. If the coaxiality of the fractured part of the high-strength bolt remains good, the distance L increases. The central controller calculates the signal feedback time T by formula (1) in step S61, and determines that the high-strength bolt is fractured in the drilling process and the coaxiality of the fractured part remains good.

[0011] Furthermore, in step S642, if the coaxiality of the fractured portion of the high-strength bolt remains good, the distance L increases, including: If the coaxiality of the fractured part of the high-strength bolt remains good, the stress of the connected parts is released, the compressed connected parts return to their original length, the distance of the fractured bolt increases, and the stress of the stretched bolt is released, the bolt becomes shorter in the relative working state. The coupling of these two factors makes the distance L increase.

[0012] Furthermore, steps S62 to S64 describe the feedback signal characteristics when the high-strength bolt is statically connected. If the high-strength bolt is under dynamic load and vibration, the feedback signal is a regular oscillating curve. After filtering, its feedback signal characteristics are attributed to the signal characteristics described in steps S62 to S64.

[0013] Compared with existing technologies, the intelligent monitoring method for the working status of high-strength bolts described in this invention has the following advantages: (1) The present invention can overcome the shortcomings of existing methods such as low accuracy, cumbersome operation and susceptibility to environmental influence, and realize rapid and accurate monitoring of high-strength bolts in normal operation, loosening and fracture, so as to provide reliable guarantee for the safe operation of engineering structures.

[0014] (2) The present invention generates a feedback signal by changing the preload, which can provide early warning of danger and prevent connection failure caused by reduced bolt preload or bolt breakage, thereby causing significant economic losses and threatening life safety. Attached Figure Description

[0015] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic cross-sectional view of the overall structure described in an embodiment of the present invention; Figure 2 This is a schematic diagram of the feedback signal under normal working conditions of the high-strength bolt as described in an embodiment of the present invention; Figure 3 This is a schematic diagram of the feedback signal under the condition of fracture and loosening of the non-drilled part of the high-strength bolt according to an embodiment of the present invention; Figure 4(a) is a schematic diagram of the feedback signal under the condition of fracture and misalignment of the high-strength bolt drilling part in the embodiment of the present invention; Figure 4(b) is a schematic diagram of the feedback signal under the condition that the high-strength bolt drilling part is fractured and the coaxiality of the fractured part is well maintained in the embodiment of the present invention.

[0016] Explanation of reference numerals in the attached figures: 1. High-strength bolts; 2. Intelligent laser transceiver monitoring device. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] like Figure 1 As shown in Figure 4, a method for intelligent monitoring of the working status of high-strength bolts includes the following steps: S1. Process the head of the high-strength bolt; S2. Process the high-strength bolt shank; S3, the intelligent laser transceiver monitoring unit is combined with high-strength bolts to form an assembly; S4, the intelligent laser transceiver monitoring unit is connected to the central controller; S5. The central controller controls the intelligent laser transceiver monitoring device to emit lasers and receive feedback signals. S6. The central controller determines the working status of the high-strength bolts based on the feedback signal.

[0022] The specific implementation method is as follows: The monitoring device of this invention mainly consists of a high-strength bolt and an intelligent laser transceiver monitoring unit. Its key feature is that the high-strength bolt has a threaded hole machined at the head, a flat-headed bottom, and a smooth bottom surface. The shank of the high-strength bolt with the threaded hole is thickened and strengthened to ensure its load-bearing capacity. The intelligent laser transceiver monitoring unit is threadedly connected to the high-strength bolt, forming a cavity structure with the bolt. The intelligent laser transceiver monitoring unit has a built-in laser transmitter and receiver and is connected to a central controller (wired or wireless).

[0023] The central controller controls the intelligent laser transceiver monitoring unit to emit lasers and receive feedback signals. Based on the feedback signals, it determines the working status of the bolts, such as normal, loose, or broken.

[0024] Feedback signal generation principle: After applying preload, the high-strength bolt is in working condition. The intelligent laser transceiver monitoring device is tightened into the flat-head threaded hole. The distance between the laser emitting and receiving surface of the intelligent laser transceiver monitoring device and the flat-head surface of the threaded hole of the high-strength bolt is L0. The signal feedback time is T0 = 2L0 / C, where C is the speed of light. Under normal operating conditions, time T0 remains constant. Figure 2 As shown. When the non-drilled portion of the bolt is broken or loose, the preload disappears, the distance L0 decreases to L1, and the signal feedback time shortens to T1 = 2L1 / C. Figure 3 As shown in Figure 4(a), when the bolt breaks during drilling, the preload disappears, and the bolt fails and no longer participates in the work, the feedback signal characteristics are as follows: a) The broken part of the bolt is misaligned and cannot receive the feedback signal, and the signal transmission and reception time tends to infinity, as shown in Figure 4(a); b) The coaxiality of the broken part of the bolt remains good, and it can still receive the signal. Due to the release of stress in the connected parts, the compressed connected parts return to their original length, the distance of the moving broken bolt increases, and the tensioned bolt releases stress, and the bolt's relative working state becomes shorter. The coupling of these two factors causes the distance L0 to increase to L2, and the signal feedback time to increase to T2=2L2 / C, as shown in Figure 4(b). Figure 2 , Figure 3 Figure 4 shows a typical static load connection signal. For dynamic load and vibration conditions, the feedback signal should be a regular fluctuating curve. After filtering, its signal characteristics are reduced to... Figure 2 , Figure 3 The features shown in Figure 4.

[0025] Feedback signals are transmitted to the central controller to provide technical personnel with decision-making support and prevent casualties and economic losses.

[0026] The advantages and beneficial effects of this invention are as follows: (1) The present invention can overcome the shortcomings of existing methods such as low accuracy, cumbersome operation and susceptibility to environmental influence, and realize rapid and accurate monitoring of high-strength bolts in normal operation, loosening and fracture, so as to provide reliable guarantee for the safe operation of engineering structures.

[0027] (2) The present invention generates a feedback signal by changing the preload, which can provide early warning of danger and prevent connection failure caused by reduced bolt preload or bolt breakage, thereby causing significant economic losses and threatening life safety.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for intelligent monitoring of the working status of high-strength bolts, characterized in that: Includes the following steps: S1. Process the head of the high-strength bolt; S2. Process the high-strength bolt shank; S3, the intelligent laser transceiver monitoring unit is combined with high-strength bolts to form an assembly; S4, the intelligent laser transceiver monitoring unit is connected to the central controller; S5. The central controller controls the intelligent laser transceiver monitoring device to emit lasers and receive feedback signals. S6. The central controller determines the working status of the high-strength bolts based on the feedback signal.

2. The intelligent monitoring method for the working status of high-strength bolts according to claim 1, characterized in that: In step S1, the head of the high-strength bolt is processed, including: S11, High-strength bolt head is machined with threaded holes; S12, Flattening of the bottom of the threaded hole; S13. The bottom surface of the hole is smoothed.

3. The intelligent monitoring method for the working status of high-strength bolts according to claim 1, characterized in that: In step S2, the high-strength bolt shank is processed, including: The high-strength bolt shank is reinforced by thickening.

4. The intelligent monitoring method for the working status of high-strength bolts according to claim 1, characterized in that: In step S3, the intelligent laser transceiver monitoring unit is combined with high-strength bolts to form an assembly, including: S31, Intelligent laser transceiver monitoring unit connected with high-strength bolts; S32, the intelligent laser transceiver monitoring unit and high-strength bolts form a cavity structure; S33. The laser transmitting and receiving surface of the intelligent laser transceiver monitoring device is directly facing the bottom plane of the threaded hole of the high-strength bolt, and the distance between the two is a set value.

5. The intelligent monitoring method for the working status of high-strength bolts according to claim 1, characterized in that: In step S4, the intelligent laser transceiver monitoring unit is connected to the central controller, including: The intelligent laser transceiver monitoring unit can be connected to the central controller via wired or wireless connection.

6. The intelligent monitoring method for the working status of high-strength bolts according to claim 1, characterized in that: In step S6, the central controller determines the working status of the high-strength bolt based on the feedback signal, including: S61. The expression for calculating the signal feedback time is as follows: T = 2L / C (1); In the formula, C is the speed of light, L is the distance between the laser emission and receiving surface of the intelligent laser transceiver monitoring device and the flat surface of the threaded hole of the high-strength bolt, and T is the signal feedback time. S62. If it is in normal working condition, the signal feedback time is the normal value and remains unchanged; S63. If the non-drilled part of the high-strength bolt is broken or loose, the preload disappears, the distance L becomes smaller, and the central controller calculates the signal feedback time T by formula (1) in step S61, which is shorter, and determines that the high-strength bolt is broken or loose. S64. If the drilled part of the high-strength bolt breaks, the preload disappears, and the central controller determines the working state of the high-strength bolt when the drilled part breaks through formula (1) in step S61.

7. The intelligent monitoring method for the working status of high-strength bolts according to claim 6, characterized in that: In step S64, the central controller determines the working state of the high-strength bolt when it breaks in the drilled part using formula (1) from step S61, including: S641. If the high-strength bolt breaks and is misaligned, the feedback signal cannot be received. The central controller calculates the signal feedback time T by formula (1) in step S61 and determines that the high-strength bolt drilling part is broken and the disconnected part is misaligned. S642. If the coaxiality of the fractured part of the high-strength bolt remains good, the distance L increases. The central controller calculates the signal feedback time T by formula (1) in step S61, and determines that the high-strength bolt is fractured in the drilling process and the coaxiality of the fractured part remains good.

8. The intelligent monitoring method for the working status of high-strength bolts according to claim 7, characterized in that: In step S642, if the coaxiality of the fractured portion of the high-strength bolt remains good, the distance L increases, including: If the coaxiality of the fractured part of the high-strength bolt remains good, the stress of the connected parts is released, the compressed connected parts return to their original length, the distance of the fractured bolt increases, and the stress of the stretched bolt is released, the bolt becomes shorter in the relative working state. The coupling of these two factors makes the distance L increase.

9. The intelligent monitoring method for the working status of high-strength bolts according to claim 6, characterized in that: Steps S62 to S64 describe the feedback signal characteristics when the high-strength bolt is statically connected. If the high-strength bolt is under dynamic load and vibration, the feedback signal is a regular oscillating curve. After filtering, its feedback signal characteristics are attributed to the signal characteristics described in steps S62 to S64.

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