Fastening bolt loosening detection device and detection method

Abstract

The present application belongs to the field of bolt structure, and particularly relates to a bolt structure comprising a bolt, a connecting piece, a bolt sleeve and a detection box, the bolt sleeve is rotatably arranged in the detection box, the bolt sleeve is provided with a bolt groove for sleeving the bolt, and the outer contour of the bolt sleeve is a joint of a semicircle and a semi-ellipse; the detection box is provided with a pair of detection assemblies, each detection assembly comprises a force sensor and an elastic rope, one end of the two elastic ropes is connected to the inner wall of the detection box, the other end of the two elastic ropes is respectively connected to one force sensor, and when the bolt is fastened, the two elastic ropes are tangent to two connecting points of the semicircle and the semi-ellipse on the outer contour of the bolt sleeve. The detection device provided by the present application can detect the loosening degree of the bolt. When the bolt is loosened, the bolt drives the bolt sleeve to rotate, the elastic rope on the semicircle side is always tangent, the elastic rope on the semi-ellipse side is lifted and deformed, the force sensor of the deformed elastic rope changes in value, the deformation length of the elastic rope can be obtained according to the change value and the deformation curve, the rotation angle of the bolt sleeve can be calculated according to a geometric formula, and thus the loosening degree of the bolt can be obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of bolt detection, in particular to a fastening bolt loosening detection device and method. BACKGROUND

[0002] Bolt connection, as the most commonly used connection method, has been widely used in aerospace, mechanical engineering and civil engineering fields due to its high bearing capacity, strong reliability, convenient disassembly and other characteristics. In recent years, the infrastructure field in China has developed rapidly, and a large number of bolt structures have been used in many large engineering structures such as steel structure bridges and wind turbines. Such large engineering structures are complex, and most of them use factory programmed processing components in design and construction methods. After transportation, bolt connection parts are used to assemble and connect the installation on site, so stable and reliable bolt connection parts are extremely important in the construction of such structures. In actual engineering applications, bolt connection is prone to loosening due to long-term exposure to various high-strength loads and extreme external environments. After loosening, the bolt preload rapidly decreases, and the stability and reliability of the bolt connection structure are severely affected, which poses a great safety hazard to industrial production, is prone to structural damage, causes safety accidents, and in severe cases, even affects the safety of workers. Therefore, bolt detection technology is of great significance.

[0003] The detection methods in the prior art include acoustic elastomeric effect detection, piezoelectric active sensor detection, and strain resistance sheet detection. The acoustic elastomeric effect detection requires transmitting a longitudinal pulse wave from one end of the bolt and receiving the reflected wave signal, which is a complex detection process and cannot be applied to large-scale detection. The piezoelectric active sensor and strain resistance sheet detection obtain the bolt loosening condition by adding electronic elements to receive electrical signals to obtain pressure changes. The above methods require processing of the connecting parts or the bolt itself to fix the wires, pressure sensors and other elements therein, which also has certain application limitations. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to provide a fastening bolt loosening detection device to solve the problems in the prior art.

[0005] A fastening bolt loosening detection device, comprising a bolt, a connecting part, a bolt sleeve and a detection box, the bolt sleeve is rotatably arranged in the detection box, the bolt sleeve is provided with a bolt groove for sleeving on the bolt, and the outer contour of the bolt sleeve is a spliced half circle and half ellipse; the detection box is provided with a pair of detection assemblies, each detection assembly comprising a force sensor and an elastic rope, one end of the two elastic ropes is connected to the inner wall of the detection box, the other end is connected to one force sensor respectively, and when the bolt is fastened, the two elastic ropes are tangent to the two connection points of the half circle and the half ellipse of the outer contour of the bolt sleeve.

[0006] Further, a reset assembly is further included to reset the loosened bolt.

[0007] Further, the reset assembly includes a handle connected with the bolt sleeve and an arc-shaped slot arranged on the detection box, the handle passes through the arc-shaped slot, and rotating the handle drives the bolt sleeve to rotate, so as to change the tightness of the bolt.

[0008] Further, the edge of the arc-shaped slot is provided with a reference scale, and the handle is in the reference scale, which represents that the bolt is in a fastened state.

[0009] Further, a processor is further included to receive the force sensor data and calculate the loosening degree of the bolt.

[0010] Further, the detection box is fixed on the connecting piece.

[0011] The application further provides a detection method using the bolt loosening detection device, which includes the following steps.

[0012] S1, according to the angle of the bolt fastening, the bolt head is arranged in the bolt sleeve, the detection box is fixed on the connecting piece, and the two elastic ropes are respectively tangent to the two connecting points of the semicircle and the semi-ellipse of the outer contour of the bolt sleeve;

[0013] S2, when the bolt is loosened, the two force sensor values are obtained, the deformation length of the elastic rope is obtained according to the deformation degree of the elastic rope and the elastic force change curve, and the rotation angle value of the bolt sleeve is calculated according to the deformation length;

[0014] S3, whether the bolt reaches the loosening threshold is judged according to the calculated rotation angle value, and the loosening warning is performed when the threshold is reached.

[0015] The bolt loosening detection device provided by the application, by arranging the bolt head in the bolt sleeve, rotating the bolt sleeve in the detection box, arranging the outer contour of the bolt sleeve as a splicing of a semicircle and a semi-ellipse, arranging two elastic ropes tangent to the splicing points in the detection box, when the bolt is loosened, the bolt drives the bolt sleeve to rotate, the elastic rope on the semicircle side is always tangent, the elastic rope on the semi-ellipse side is lifted and deformed, the force sensor value of the deformed elastic rope changes, the deformation length of the elastic rope is obtained according to the change value and the deformation curve, and the rotation angle of the bolt sleeve is calculated according to the geometric formula, so as to obtain the loosening degree of the bolt.

[0016] The bolt loosening detection device provided by the application does not need to process the bolt or the connecting piece, and can select the bolt sleeve with a corresponding shape according to the practical scene of the bolt, so that the application scene is wide and the use is simple. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural diagram of the application;

[0018] Figure 2 for the use state of the present application;

[0019] Figure 3 for the bolt loosening angle calculation method schematic diagram; DETAILED DESCRIPTION

[0020] Example 1:

[0021] As Figures 1-2 The present application provides a fastening bolt loosening detection device, including bolt, connecting piece, bolt sleeve 2 and detection box 3, the bolt sleeve 2 rotatably arranged in the detection box 3, the bolt sleeve 2 is provided with bolt groove for setting on the bolt, the bolt sleeve 2 outer contour is the splicing of semicircle and half ellipse; the detection box 3 is provided with a pair of detection components 4, each detection component 4 includes force sensor 41 and elastic rope 42, the two elastic ropes 42 are connected to the inner wall of the detection box 3 at one end, and the other end is connected with one force sensor 41 respectively, and when the bolt is fastened, the two elastic ropes are tangent to the two connecting points of the semicircle and half ellipse of the bolt sleeve 2.

[0022] When the bolt loosens, the bolt needs to be tightened, the present application provides a reset structure without disassembling the device to reset the bolt, wherein the reset structure is a reset component arranged in the detection box 3, including a handle connected with the bolt sleeve 2 and an arc-shaped groove arranged on the detection box 3, the end of the handle is fixed outside the bolt sleeve 2, the other end extends out through the arc-shaped groove, the edge of the arc-shaped groove can refer to the scale line, when the bolt is fastened, the position of the handle is located at the reference scale line, when the bolt loosens, the handle is away from the scale line, the operator holds the handle to rotate the bolt sleeve to the scale line, which can reset the bolt.

[0023] Example 2:

[0024] The present application provides a bolt loosening detection method based on the fastening bolt loosening detection device of example 1. The principle diagram is shown in Figure 3 The short semi-axis of the bolt sleeve half ellipse is the same as the radius of the semicircle, when the bolt loosens and the bolt sleeve rotates, the elastic rope on the semicircle side is always tangent to the contour of the bolt sleeve, the other elastic rope is lifted by the half ellipse and deformed, the initial length of the force sensor, the elastic rope and the contact point of the bolt sleeve is L, the length of the contact point and the force sensor after deformation is L', Figure 3 The vertical direction after deformation is S, the transverse displacement distance of the contact point is very small and can be ignored, so Set the rotation angle as θ, then Figure 3 There is the following relationship Wherein R0 is the length of the major axis of the semi-ellipse, R is the distance from the center point of the bolt sleeve to the connecting point, and R=S+r, wherein r is the length of the minor axis of the semi-ellipse, and the value of the rotation angle θ can be obtained. The deformation degree of the elastic rope and the force sensor value in the embodiment are known in advance by drawing a curve through prior measurement.

[0025] Those skilled in the art can understand that the above-mentioned advantageous modes can be freely combined and superimposed without conflict.

[0026] The above embodiments are illustrative of the present application, not limiting the present application, and any simple transformation of the present application also belongs to the protection scope of the present application.

Claims

1. A fastener loosening detection device, comprising a bolt, a connector, a bolt sleeve (2), and a detection box (3), wherein the bolt sleeve (2) is rotatably disposed within the detection box (3), characterized in that: The bolt sleeve (2) is provided with a bolt groove for sleeving on the bolt, and the outer contour of the bolt sleeve (2) is a joint of a semicircle and a semi-ellipse; the detection box (3) is provided with a pair of detection assemblies (4), each detection assembly (4) comprising a force sensor (41) and an elastic rope (42), the two elastic ropes (42) being connected at one end to the inner wall of the detection box (3) and at the other end to one force sensor (41) respectively, and when the bolt is fastened, the two elastic ropes are tangent to the two connecting points of the semicircle and the semi-ellipse of the outer contour of the bolt sleeve (2).

2. A fastener bolt loosening detection device according to claim 1, wherein: Further comprising a reset assembly for resetting the loose bolt.

3. A fastener bolt loosening detection device according to claim 2, wherein: The reset assembly comprises a handle connected with the bolt sleeve (2) and an arc-shaped groove provided on the detection box (3), the handle penetrating through the arc-shaped groove, and rotating the handle to drive the bolt sleeve (2) to rotate, so as to change the tightness of the bolt.

4. A fastener bolt loosening detection device according to claim 3, wherein: The edge of the arc-shaped groove is provided with a reference scale, and when the handle is at the reference scale, it represents that the bolt is in a fastened state.

5. The fastener bolt looseness detection apparatus of claim 1, wherein: Further comprising a processor for receiving the data of the force sensor (41) and calculating the looseness of the bolt.

6. A fastener bolt looseness detection device according to claim 1, wherein: The detection box (3) is fixed on the connecting piece.

7. A method of detecting using the fastener loosening detection device according to any one of claims 1 to 6, characterized by, The method comprises the following steps: S1, according to the angle of the bolt fastening, arranging the bolt head in the bolt sleeve (2), fixing the detection box on the connecting piece, and ensuring that the two elastic ropes are tangent to the two connecting points of the semicircle and the semi-ellipse of the outer contour of the bolt sleeve (2) respectively; S2, when the bolt is loose, obtaining the values of the two force sensors, obtaining the deformation length of the elastic rope according to the deformation degree of the elastic rope and the elastic force change curve, and calculating the rotation angle value of the bolt sleeve according to the deformation length; S3, judging whether the bolt reaches the looseness threshold value according to the calculated rotation angle value, and if the threshold value is reached, a looseness warning is given.

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