Heavy coupling online fatigue detection device

Abstract

The invention discloses a heavy coupling online fatigue detection device, and relates to the technical field of rotating shaft detection, the heavy coupling online fatigue detection device comprises a gearbox, one side of the gearbox is provided with a motor, the other side of the gearbox is provided with a rolling mill, a coupling is arranged between the rolling mill and the gearbox, the outer wall of the coupling is provided with an arc-shaped sleeve 1, and the arc-shaped sleeve 1 is provided with an arc-shaped sleeve 2. A second arc-shaped sleeve is arranged above the first arc-shaped sleeve, the first arc-shaped sleeve and the second arc-shaped sleeve are rotationally connected through a rotating shaft, a connecting column is arranged on the outer wall of the first arc-shaped sleeve, a connecting rod is arranged at the bottom of the connecting column, a workbench is arranged on the bottom face of the connecting rod, and a detection unit is arranged between the first arc-shaped sleeve and the coupler. And the detection unit is used for online positioning and marking crack positions on the surface of the coupler. According to the device, the surface stress condition of the coupler is detected in real time, compared with the prior art, online detection and marking of cracks of the coupler are achieved, and the working efficiency of continuous and automatic production of steel is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of shaft detection, and particularly to an on-line fatigue detection device for a heavy-duty coupling. Background Art

[0002] In the rolling mill processing industry, in the structure of the rolling mill, there is generally a heavy-duty coupling connecting the rolling roll and the motor. During the rolling process, due to the complex and changeable rolling working conditions and the huge torsional impact, the coupling is extremely prone to fatigue cracking accidents.

[0003] To avoid sudden fatigue cracking of the coupling, the factory is forced to stop production for inspection, and magnetic powder or ultrasonic testing is almost used every day to detect key parts. In the common magnetic powder testing method, the staff needs to manually spray the magnetic suspension liquid evenly on the outer wall surface of the coupling first, and then use a magnetic powder flaw detector to magnetize multiple areas on the outer wall surface of the shaft body, so that the suspension liquid is magnetized and instantly adsorbed to the damaged area to form cracks. This detection method is not only troublesome to operate, but also needs to stop the equipment for detection, greatly reducing the working efficiency of the continuous automated production of steel.

[0004] Therefore, the present invention proposes an on-line fatigue detection device for a heavy-duty coupling. Summary of the Invention

[0005] The purpose of the present invention is to provide an on-line fatigue detection device for a heavy-duty coupling to solve the problems raised in the above background art. To achieve the above purpose, the present invention provides the following technical solution: An on-line fatigue detection device for a heavy-duty coupling, including a gearbox, with a motor provided on one side of the gearbox, a rolling mill provided on the other side of the gearbox, a coupling provided between the rolling mill and the gearbox, an arc-shaped sleeve one provided on the outer wall of the coupling, an arc-shaped sleeve two provided above the arc-shaped sleeve one, the arc-shaped sleeve one and the arc-shaped sleeve two are rotationally connected by a rotating shaft, a connecting column provided on the outer wall of the arc-shaped sleeve one, a connecting rod provided at the bottom of the connecting column, a workbench provided on the bottom surface of the connecting rod, and a detection unit provided between the arc-shaped sleeve one and the coupling, and the detection unit is used for on-line positioning and marking the crack position on the surface of the coupling.

[0006] Preferably, the detection unit includes a connecting block located on the inner wall of the arc-shaped sleeve two, a shaft body one provided inside the connecting block, a signal connector provided on the outer wall of the shaft body one, magnetic strips provided at both ends of the signal connector, the outer walls of the magnetic strips are in contact with the outer wall of the coupling, a vibration detector provided above the signal connector, and the vibration detector is used for detecting the vibration frequencies of the two magnetic strips. A liquid storage bin one is provided inside the arc-shaped sleeve one, a liquid outlet pipe is provided in the wall body of the arc-shaped sleeve one, the liquid inside the liquid storage bin one has a marking function, and the liquid storage bin one is connected to an external liquid supply device through a pipe body.

[0007] Preferably, a liquid storage bin II is arranged inside the arc-shaped sleeve II. The liquid storage bin II is used for loading magnetic suspension liquid. A liquid bundling tank body is arranged below the liquid storage bin II. The signal connector has a power supply function, which can make the area between the two magnetic strips in a magnetic conduction state. The liquid storage bin II is connected to an external liquid supply device through a pipe body. The marking liquid inside the liquid storage bin I covers the magnetic suspension liquid and is in a display state.

[0008] Preferably, a plate body is arranged at the end of the connecting rod. An electric push rod is arranged on one side of the plate body. The bottom of the electric push rod is fixedly connected to the workbench. The electric push rod is started and closed through an external controller, and it pushes the connecting rod to perform a lateral displacement on the workbench.

[0009] Preferably, a fixed sleeve is arranged outside the coupling. A slide bar is arranged inside the fixed sleeve. A rotating ring is arranged at the end of the slide bar. Multiple electric telescopic rods are arranged inside the rotating ring. A connecting piece is arranged at the ejecting end of the electric telescopic rod. A stress piece for detecting the stress parameters on the surface of the coupling is arranged on the side of the connecting piece. In the state where multiple electric push rods simultaneously push the connecting piece to be attached to the surface of the coupling, multiple stress pieces are in contact with the detection shaft wall area of the coupling. A detection box is arranged above the workbench. A receiving lamp is arranged above the detection box. The receiving lamp is used for receiving the transmission electric signals of the stress pieces.

[0010] Preferably, a display screen and an alarm lamp are arranged on the outer wall surface of the arc-shaped sleeve II. The display screen, the alarm lamp and the vibration detector are all electrically connected.

[0011] Preferably, a rotating block is arranged on the outer wall of the shaft body I. A fixed block is arranged on the outer wall of the arc-shaped sleeve II. A limiting block is arranged inside the fixed block. A spring is arranged at the end of the limiting block. Multiple limiting grooves for inserting the limiting block are arranged inside the rotating block. The multiple limiting grooves are all symmetrically and equidistantly distributed around the center.

[0012] The present invention has at least the following beneficial effects: 1. In the present invention, the slider drives the connecting rod, the connecting column, the first arc-shaped sleeve, and the second arc-shaped sleeve to reciprocate left and right in the horizontal direction of the coupling. During this process, the contact area between the magnetic strip and the coupling will increase significantly, enabling the magnetic strip to more comprehensively detect crack phenomena on the surface of the coupling. When the vibration amplitude of the magnetic strip becomes too large due to the resistance of the crack, the vibration detector will send an electrical signal to the alarm lamp to turn it on. At this time, the staff can promptly stop the steel rolling work and repair or replace the coupling. Meanwhile, the electronic valve acting on the first liquid storage bin will also be automatically opened by the signal of the vibration detector, causing the marking liquid inside the first liquid storage bin to spray out from the liquid outlet pipe, achieving the marking of severely cracked areas. Compared with the prior art, the online detection and marking of cracks in the coupling are realized, greatly improving the working efficiency of continuous automated production of steel.

[0013] 2. In the present invention, when it is necessary to detect couplings with different diameters, the limit block can be pulled out from the limit slot and then the rotating block can be rotated, causing the first shaft body to rotate at an appropriate angle along with the rotating block until the magnetic strip contacts the surface of the coupling to be tested. Then, the limit block is inserted into the interior of other limit slots again to ensure the stability of the test of this device, enabling this device to be applicable to the detection of couplings with different diameters and further improving the applicability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is a schematic diagram of the structure of the detection unit and a cross-sectional view of the fixed block structure of the present invention; Figure 3 For the present invention Figure 2 enlarged view of the structure of area A; Figure 4 is a cross-sectional view of the first arc-shaped sleeve and the second arc-shaped sleeve structure of the present invention; Figure 5 For the present invention Figure 4 enlarged view of the structure of area B; Figure 6 is a side view of the structures of each component in Embodiment 3 of the present invention; Figure 7 is a cross-section of the fixed sleeve and the rotating ring structures in Embodiment 3 of the present invention.

[0015] In the figure: 1 - gearbox; 2 - motor; 3 - rolling mill; 4 - coupling; 5 - first arc-shaped sleeve; 6 - second arc-shaped sleeve; 7 - connecting column; 8 - connecting rod; 9 - workbench; 10 - detection unit; 11 - connecting block; 12 - first shaft body; 13 - signal connector; 14 - magnetic strip; 15 - vibration detector; 16 - first liquid storage bin; 17 - liquid outlet pipe; 18 - second liquid storage bin; 19 - liquid bundling trough body; 20 - plate body; 21 - electric push rod; 22 - fixed sleeve; 23 - sliding bar; 24 - rotating ring; 25 - electric telescopic rod; 26 - connecting piece; 27 - detection box; 28 - receiving lamp; 29 - alarm lamp; 30 - display screen; 31 - rotating block; 32 - fixed block; 33 - limiting block; 34 - spring; 35 - limiting groove; 36 - stress piece. Detailed implementation manners

[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0017] Please refer to Figures 1-7 , the present invention provides a technical solution: an on-line fatigue detection device for a heavy-duty coupling, including: Embodiment 1 A gearbox 1 is provided on one side of the gearbox 1, a motor 2 is provided on the other side of the gearbox 1, a rolling mill 3 is provided on the other side of the gearbox 1, and a coupling 4 is provided between the rolling mill 3 and the gearbox 1. The motor 2 provides power to drive the coupling 4 to rotate through the gearbox 1, and finally the pressure roller on the other side of the rolling mill 3 presses the steel sheet. The above belongs to the prior art, so it will not be described in detail.

[0018] In this solution, a first arc-shaped sleeve 5 is provided on the outer wall of the coupling 4, a second arc-shaped sleeve 6 is provided above the first arc-shaped sleeve 5, and the first arc-shaped sleeve 5 and the second arc-shaped sleeve 6 are rotatably connected by a rotating shaft. When the first arc-shaped sleeve 5 and the second arc-shaped sleeve 6 are in a closed state, they are in contact with each other and form a closed circular ring, and the coupling 4 is located in the central area of the ring. The first arc-shaped sleeve 5 and the second arc-shaped sleeve 6 are closed by the buckles on the outer wall, and this buckle can also be relatively disassembled. The staff can stop the motor 2 at any time, then rotate and open the second arc-shaped sleeve 6 to observe the crack phenomenon of the coupling 4, making the inspection work of the crack more convenient.

[0019] The outer wall of the first arc-shaped sleeve 5 is provided with a connecting column 7 and is fixedly connected thereto. The bottom of the connecting column 7 is provided with a connecting rod 8 and is fixedly connected thereto. The bottom surface of the connecting rod 8 is provided with a workbench 9. The connecting rod 8 can slide freely on the surface of the workbench 9. A detection unit 10 is provided between the first arc-shaped sleeve 5 and the coupling 4. The detection unit 10 is used for on-line positioning and marking the crack position on the surface of the coupling 4. For the existing technology, the detection unit 10 can be used to detect the cracks of the coupling 4 on-line without stopping the equipment, which greatly improves the working efficiency of the continuous automatic production of steel.

[0020] The detection unit 10 includes a connecting block 11 located on the inner wall of the second arc-shaped sleeve 6. One side of the connecting block 11 is fixedly connected to the inner wall of the second arc-shaped sleeve 6. A first shaft body 12 is provided inside the connecting block 11 and is rotatably connected thereto. A signal connector 13 is provided on the outer wall of the first shaft body 12 and is fixedly connected thereto. Two magnetic strips 14 are provided at both ends of the signal connector 13. Both magnetic strips 14 are electrically connected to the signal connector 13. The outer wall of the magnetic strip 14 is in contact with the outer wall of the coupling 4. A vibration detector 15 is provided above the signal connector 13 and is electrically connected thereto. The vibration detector 15 is used to detect the vibration frequencies of the two magnetic strips 14. A display screen 30 and an alarm lamp 29 are provided on the outer wall surface of the second arc-shaped sleeve 6 and are both fixedly connected thereto. The display screen 30, the alarm lamp 29 and the vibration detector 15 are all electrically connected. The signal connector 13 has a power supply function, which can make the area between the two magnetic strips 14 in a magnetically conductive state. At the same time, the vibration information of the magnetic strip 14 sent by the vibration detector 15 will also be displayed on the display screen 30, so as to facilitate the staff to check the vibration situation of the magnetic strip 14 in real time and ensure that the coupling 4 works in a safe state.

[0021] A first liquid storage chamber 16 is provided inside the first arc-shaped sleeve 5. The inside of the first liquid storage chamber 16 is used to load the marking liquid. A liquid outlet pipe 17 is provided in the wall body of the first arc-shaped sleeve 5 and is fixedly connected thereto. The end of the liquid outlet pipe 17 is connected to the first liquid storage chamber 16. The liquid inside the first liquid storage chamber 16 has a marking function. The first liquid storage chamber 16 is connected to an external liquid supply device through a pipe. The external device is equipped with an electronic valve, and the electronic valve is electrically connected to the vibration detector 15. When the vibration detector 15 detects that the vibration amplitude of the magnetic strip 14 is too large, the electronic valve will be self-activated, and the marking liquid inside the first liquid storage chamber 16 will be sprayed outwards from the liquid outlet pipe 17. A second liquid storage chamber 18 is provided inside the second arc-shaped sleeve 6. The second liquid storage chamber 18 is used to load the magnetic suspension liquid. A liquid bundling trough body 19 is provided below the second liquid storage chamber 18. The upper part of the liquid bundling trough body 19 is fixedly connected to the inner wall of the second arc-shaped sleeve 6. The liquid bundling trough body 19 can guide the flowing magnetic suspension liquid so that the floating liquid can be better smeared on the surface of the coupling 4. The second liquid storage chamber 18 is connected to an external liquid supply device through a pipe. The marking liquid inside the first liquid storage chamber 16 will cover the magnetic suspension liquid above and be in a display state.

[0022] In addition, a plate body 20 is provided at the end of the connecting rod 8 and fixedly connected thereto. An electric push rod 21 is provided on one side of the plate body 20 and fixedly connected thereto. The bottom of the electric push rod 21 is fixedly connected to the workbench 9. The electric push rod 21 is started and closed by an external controller to push the connecting rod 8 to perform a lateral displacement on the workbench 9.

[0023] When the coupling 4 is working, the magnetic suspension liquid will flow downward from the inside of the liquid storage bin two 18 to the surface of the coupling 4, and gradually cover the outer wall surface of the coupling 4 with the rotation effect of the coupling 4. Immediately afterwards, the signal connector 13 will magnetize between the two magnetic strips 14. As the coupling 4 rotates, the surface of the coupling 4 will be in a magnetized state, and then the magnetic suspension liquid on the outer wall of the coupling 4 will be affected by magnetism and instantaneously adsorbed between each crack on the surface of the coupling 4, so as to facilitate the subsequent inspection of the surface damage of the coupling 4 by the staff.

[0024] On the other hand, through the program control of the external controller, the electric push rod 21 can be set to a reciprocating push state from left to right, and then the electric push rod 21 is used to drive the connecting rod 8, the connecting column 7, the arc-shaped sleeve one 5 and the arc-shaped sleeve two 6 to perform a reciprocating left and right displacement in the horizontal direction of the coupling 4. Since the magnetic strip 14 always contacts the outer wall of the coupling 4 during the rotation of the coupling 4, with the reciprocating displacement of the arc-shaped sleeve one 5 and the arc-shaped sleeve two 6, the contact area between the magnetic strip 14 and the coupling 4 will be greatly increased, so that the magnetic strip 14 can more comprehensively detect the crack phenomenon on the surface of the coupling 4. When the vibration amplitude of the magnetic strip 14 is too large due to the resistance of the crack, the vibration detector 15 will send an electrical signal to the alarm lamp 29 to make it light up. At this time, the staff can stop the steel rolling work in time to repair or replace the coupling 4. At the same time, during this process, the electronic valve acting on the liquid storage bin one 16 will also be self-activated by the signal of the vibration detector 15, so that the marking liquid inside the liquid storage bin one 16 will be sprayed out from the liquid outlet pipe 17, realizing the marking of the severely cracked area. Compared with the prior art, the on-line detection and marking of the cracks of the coupling 4 are realized, and the working efficiency of the continuous automatic production of steel is greatly improved.

[0025] At the same time, the reciprocating movement of the arc-shaped sleeve two 6 will also make the magnetic suspension liquid spread more comprehensively on the surface of the coupling 4. In the state where the machine stops, it is more convenient for the staff to comprehensively check the crack situation.

[0026] According to the above embodiment, Embodiment Two Since the pushing distance of the electric push rod 21 can be adjusted by the controller according to the actual situation of the detection environment, when detecting the coupling 4 with a longer length, the extension length of the electric push rod 21 can be simply adjusted, so that the displacement distances of the first arc-shaped sleeve 5 and the second arc-shaped sleeve 6 will also become longer, enabling the two magnetic strips 14 to detect a larger surface area of the coupling 4, thus improving the applicability of this device for detection.

[0027] A rotating block 31 is provided on and fixedly connected to the outer wall of the first shaft body 12. A fixed block 32 is provided on and fixedly connected to the outer wall of the second arc-shaped sleeve 6. A limiting block 33 is provided inside and slidably connected to the fixed block 32. A spring 34 is provided at the end of the limiting block 33, and both ends of the spring 34 are fixedly connected to the limiting block 33 and the fixed block 32 respectively. A plurality of limiting grooves 35 for the limiting block 33 to insert into are provided inside the rotating block 31. The plurality of limiting grooves 35 are evenly distributed in a central symmetric pattern at equal intervals. When the limiting block 33 is inserted into the inside of the limiting groove 35, the first shaft body 12 will be in a stable state, and the two magnetic strips 14 will be in contact with the outer wall of the coupling 4.

[0028] When couplings 4 with different diameters need to be detected, the limiting block 33 can be pulled out from the limiting groove 35, and then the rotating block 31 is rotated to make the first shaft body 12 rotate by an appropriate angle along with the rotating block 31 until the magnetic strip 14 contacts the surface of the coupling 4 to be tested. Then, the limiting block 33 is inserted into the inside of other limiting grooves 35 again to ensure the stability of the test of this device, enabling this device to be applicable to the detection of couplings 4 with different diameters and further improving the applicability of the device.

[0029] Embodiment III Please refer to Figure 1 、 Figure 6 and Figure 7, a fixed sleeve 22 is provided outside the coupling 4 and fixedly connected thereto. The fixed sleeve 22 can rotate together with the coupling 4. A slide bar 23 is provided inside the fixed sleeve 22 and slidably connected thereto. A rotating ring 24 is provided at the end of the slide bar 23 and fixedly connected thereto. The staff can draw out the slide bar 23 from the inside of the fixed sleeve 22 to increase the distance between the fixed sleeve 22 and the rotating ring 24, so that the rotating ring 24 can perform detection work in multiple areas outside the coupling 4, improving the applicability of this equipment. A plurality of electric telescopic rods 25 are provided inside the rotating ring 24 and fixedly connected thereto. There are six electric telescopic rods 25 in total. A connecting piece 26 is provided at the ejecting end of the electric telescopic rod 25. A stress piece 36 for detecting the surface stress parameters of the coupling 4 is provided on the side of the connecting piece 26. The side of the connecting piece 26 is fixedly connected to the stress piece 36, and the junction of the two is made of a flexible material (during the process of the connecting piece 26 pressing against the surface of the coupling 4, the stress piece 36 will not exert pressure on the surface of the coupling 4). The outer wall of the connecting piece 26 is fixedly connected to the top end of the electric telescopic rod 25. When multiple electric push rods 21 simultaneously push the connecting piece 26 against the surface of the coupling 4, multiple stress pieces 36 are in contact with the detection shaft wall area of the coupling 4, enabling a comprehensive inspection of the surface stress of the detection area of the coupling 4.

[0030] Above the workbench 9, a detection box 27 is provided. Above the detection box 27, a receiving lamp 28 is provided and fixedly connected thereto. The receiving lamp 28 is used to receive the transmission electrical signal of the stress piece 36. When the electrical signal transmitted by the stress piece 36 is disordered, the receiving lamp 28 can automatically trigger the alarm function to facilitate the staff to perform maintenance work in a timely manner.

[0031] Working principle: Before the detection starts, the staff can drive a plurality of electric telescopic rods 25 to simultaneously eject the connecting piece 26 at their tops until the inner walls of each connecting piece 26 are in close contact with the outer wall of the coupling 4. In this state, multiple stress pieces 36 will also be in contact with the surface of the coupling 4. At this time, driving the coupling 4 to rotate, the coupling 4 will simultaneously drive the fixed sleeve 22 and the rotating ring 24 to rotate simultaneously. During this process, multiple stress pieces 36 will comprehensively inspect the detection area of the coupling 4, ensuring that the shaft wall stress coefficient of the detection area is captured more comprehensively and improving the comprehensiveness of the detection data.

[0032] In addition, the detection box 27 is equipped with a wireless transmission module, which can transmit all the data detected by all the stress gauges 36 to the detection box 27 through wireless transmission and clearly display it on its large screen, thus realizing real-time monitoring. Compared with the prior art, it is not necessary to stop the equipment for detection. Through the real-time data cooperation of the detection box 27 and multiple stress gauges 36, online detection data is obtained. The detection box 27 judges whether the transmission shaft is damaged according to the transmitted data, and obtains the fatigue damage value and the real-time remaining life, etc., greatly improving the working efficiency of the continuous automated production of steel.

[0033] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0034] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An on-line fatigue detection device for a heavy-duty coupling, comprising a gearbox (1), with an electric motor (2) provided on one side of the gearbox (1), and a rolling mill (3) provided on the other side of the gearbox (1). A coupling (4) is provided between the rolling mill (3) and the gearbox (1). It is characterized in that: An arc-shaped sleeve one (5) is provided on the outer wall of the coupling (4), and an arc-shaped sleeve two (6) is provided above the arc-shaped sleeve one (5). The arc-shaped sleeve one (5) and the arc-shaped sleeve two (6) are rotationally connected by a rotating shaft. A connecting column (7) is provided on the outer wall of the arc-shaped sleeve one (5), a connecting rod (8) is provided at the bottom of the connecting column (7), and a workbench (9) is provided on the bottom surface of the connecting rod (8). A detection unit (10) is provided between the arc-shaped sleeve one (5) and the coupling (4), and the detection unit (10) is used for on-line positioning and marking the crack position on the surface of the coupling (4).

2. The on-line fatigue detection device for heavy-duty couplings according to claim 1, characterized in that: The detection unit (10) includes a connecting block (11) located on the inner wall of the arc-shaped sleeve two (6). A shaft body one (12) is provided inside the connecting block (11), a signal connector (13) is provided on the outer wall of the shaft body one (12), magnetic strips (14) are provided at both ends of the signal connector (13), and the outer walls of the magnetic strips (14) are in contact with the outer wall of the coupling (4). A vibration detector (15) is provided above the signal connector (13), and the vibration detector (15) is used for detecting the vibration frequencies of the two magnetic strips (14). A liquid storage bin one (16) is provided inside the arc-shaped sleeve one (5), a liquid outlet pipe (17) is provided in the wall body of the arc-shaped sleeve one (5), and the liquid inside the liquid storage bin one (16) has a marking function. The liquid storage bin one (16) is connected to an external liquid supply device through a pipe body.

3. The on-line fatigue detection device for heavy couplings according to claim 2, characterized in that: A liquid storage bin two (18) is provided inside the arc-shaped sleeve two (6), and the liquid storage bin two (18) is used for loading a magnetic suspension liquid. A liquid bundling trough body (19) is provided below the liquid storage bin two (18). The signal connector (13) has a power supply function, enabling the area between the two magnetic strips (14) to be in a magnetically conductive state. The liquid storage bin two (18) is connected to an external liquid supply device through a pipe body, and the marking liquid inside the liquid storage bin one (16) will cover the magnetic suspension liquid and be in a display state.

4. The online fatigue detection device for heavy couplings according to claim 3, characterized in that: A plate body (20) is provided at the end of the connecting rod (8), an electric push rod (21) is provided on one side of the plate body (20), and the bottom of the electric push rod (21) is fixedly connected to the workbench (9). The electric push rod (21) is started and closed by an external controller, and pushes the connecting rod (8) to perform a lateral displacement on the workbench (9).

5. The on-line fatigue detection device for heavy-duty couplings according to claim 1, characterized in that: A fixed sleeve (22) is provided on the outside of the coupling (4). A slide bar (23) is provided inside the fixed sleeve (22). A rotating ring (24) is provided at the end of the slide bar (23). Multiple electric telescopic rods (25) are provided inside the rotating ring (24). A connecting piece (26) is provided at the ejecting end of the electric telescopic rod (25). A stress sheet (36) for detecting the surface stress parameters of the coupling (4) is provided on the side of the connecting piece (26). In a state where multiple electric push rods (21) simultaneously push the connecting piece (26) against the surface of the coupling (4), multiple stress sheets (36) are in contact with the detection shaft wall area of the coupling (4). Above the workbench (9), a detection box (27) is provided. Above the detection box (27), a receiving lamp (28) is provided. The receiving lamp (28) is used to receive the transmitted electrical signals of the stress sheet (36).

6. The on-line fatigue detection device for the heavy-duty coupling according to claim 3, characterized in that: A display screen (30) and an alarm lamp (29) are provided on the outer wall surface of the second arc-shaped sleeve (6). The display screen (30), the alarm lamp (29), and the vibration detector (15) are all electrically connected.

7. The on-line fatigue detection device for heavy-duty couplings according to claim 2, wherein: A rotating block (31) is provided on the outer wall of the first shaft body (12). A fixed block (32) is provided on the outer wall of the second arc-shaped sleeve (6). A limiting block (33) is provided inside the fixed block (32). A spring (34) is provided at the end of the limiting block (33). Multiple limiting grooves (35) for the limiting block (33) to insert into are provided inside the rotating block (31). The multiple limiting grooves (35) are all equidistantly distributed in a central symmetry manner.

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