A device for monitoring the preload of turbine cover bolts based on ultrasonic detection

Abstract

The present invention discloses a turbine top cover bolt preload monitoring device based on ultrasonic detection. The device comprises a plurality of bolts fixed to the turbine volute and top cover. The top of each bolt is covered with a detection unit. A fixing sleeve is provided around the outer periphery of the bolt head. An inner mating sleeve is provided on the top of the fixing sleeve. An outer mating sleeve is provided within the detection unit. The outer mating sleeve is sleeved around the outer periphery of the corresponding inner mating sleeve. An ultrasonic probe is coaxially inserted into the outer and inner mating sleeves. The present invention uses ultrasonic signals to detect changes in the length of the bolts to assess changes in the preload provided by the bolts. The number of revolutions of the bolts is calculated based on changes in the force applied to the spring wire, thereby comprehensively determining the current state of the bolts. Based on the state change data over a period of time, future state change data is comprehensively predicted. This provides timely warnings to relevant maintenance personnel when bolt maintenance is required, ensuring the safe operation of the turbine.

Description

Technical Field

[0001] The present invention relates to the technical field of water turbine design, and more particularly to a water turbine top cover bolt pre-tightening force monitoring device based on ultrasonic detection. Background Art

[0002] The turbine top cover is used to seal the upper end of the volute and to install mechanisms such as guide vanes. The turbine top cover is mainly fixed to the top of the volute with bolts. However, due to the vibration generated by the turbine during operation, the bolts used to fix the top cover may become loose. When the bolts become loose or even fall off, serious accidents may easily occur. Therefore, it is necessary to periodically inspect the bolts used to fix the turbine top cover.

[0003] Traditionally, inspection of turbine cover bolts primarily involves manually measuring the bolt preload and assessing the degree of loosening. This approach also involves predicting the future loosening state of the bolts, allowing for timely maintenance. However, due to the lengthy inspection cycle, difficulty, and labor consumption associated with manual inspection, a more convenient and rapid monitoring method is urgently needed. Prior art, such as patent publication number CN219777568U, discloses a turbine bolt preload monitoring device. While this device features an automatic wire reel and an ultrasonic probe that prevents the bolts from falling off, it only monitors the bolt preload in real time, making it difficult to comprehensively predict future state changes and provide timely warnings. Summary of the Invention

[0004] The present invention provides a turbine top cover bolt preload monitoring device based on ultrasonic detection, which can automatically perform periodic preload monitoring and loosening status assessment on the turbine top cover fixing bolts, thereby providing timely warning to relevant maintenance personnel when bolt maintenance is required, thereby ensuring the safe operation of the turbine.

[0005] To achieve these objects and other advantages according to the present invention, a device for monitoring the preload force of a turbine top cover bolt based on ultrasonic detection is provided, comprising a plurality of bolts fixed to a turbine volute and a top cover, wherein a detection unit is provided on the top of each bolt;

[0006] In which, the bottom of each detection unit is fixedly connected to the top cover, a fixing sleeve is provided on the outer periphery of the head of the bolt, a cylindrical inner matching sleeve is fixedly connected to the top of the fixing sleeve, and a cylindrical outer matching sleeve is vertically fixed to the inner top wall of the detection unit. The outer matching sleeve is movably sleeved on the outer periphery of the corresponding inner matching sleeve, and a spiral groove is opened around the inner side wall of the outer matching sleeve, and a spring wire is matched and accommodated in the spiral groove. A pressure detection sensor is provided on the inner wall of the spiral groove near the top of the spring wire, and the bottom side wall of the spring wire is connected to the inner matching sleeve. An ultrasonic probe is fixedly inserted into the outer matching sleeve and the inner matching sleeve, and the detection end of the ultrasonic probe passes through the fixing sleeve and faces the top of the bolt.

[0007] Preferably, each detection unit is coaxially arranged with the fixing sleeve, inner matching sleeve, outer matching sleeve and ultrasonic probe inside the detection unit.

[0008] Preferably, the bottom side wall of the spring wire and the inner matching sleeve are connected by an auxiliary pushing device, and the auxiliary pushing device is provided with an L-shaped pushing arm, one end of the pushing arm is fixedly connected to the side wall of the spring wire, and the other end is vertically connected with a rotating shaft on both sides, and two parallel hinged ears are fixedly installed on the top of the inner matching sleeve, and waist-shaped holes are provided on the two hinged ears, and the two ends of the rotating shaft are movably inserted into the two waist-shaped holes.

[0009] Preferably, the head of the bolt and the fixing sleeve are fixedly connected by a clamping device, the clamping device includes a screw rod, an end head is provided at the end of the screw rod, the end head is a T-shaped structure formed by vertically connecting a cross bar and a vertical rod, the cross bar is fixedly connected to the screw rod, the vertical rod is away from the screw rod, both ends of the cross bar are hinged with a first clamping arm, the side wall of the first clamping arm is provided with a ridge, and the ridges on the two first clamping arms are respectively connected to the two sides of the vertical rod through a first return spring;

[0010] Among them, the side wall of the head of each bolt is provided with a plurality of threaded holes extending radially, the outer side wall of each fixing sleeve is provided with a plurality of C-shaped clamping seats extending vertically outward, and the side wall of the fixing sleeve is provided with a plurality of through holes. Any fixing sleeve is arranged on the outer periphery of the head of any bolt, and the plurality of threaded holes correspond one-to-one with the plurality of through holes. The screw of any clamping device is rotatably inserted into the corresponding through hole and threaded hole, and the two first clamping arms are limited and clamped on the corresponding two clamping seats.

[0011] Preferably, a plurality of mounting openings are provided on the side wall of each detection unit, and a detachable closing plate is installed at each mounting opening.

[0012] Preferably, a U-shaped mounting port base extending outwardly perpendicular to the side wall of the detection unit is provided on the periphery of each mounting port, and the mounting port base is provided with two arms opposite to each other away from the side wall of the detection unit, and a second clamping arm is symmetrically hingedly installed on both sides of each arm, and the two clamping arms are respectively connected to the two sides of the arm via a second return spring;

[0013] Limiting holes are opened at opposite ends of each closing plate. Any closing plate is sealed and covers the outside of any mounting base, and the corresponding support arm and the second clamping arm pass through the two limiting holes. Under the elastic force of the second return spring, the two second clamping arms are clamped at both ends of the corresponding limiting holes.

[0014] Preferably, an annular bracket is also provided on the top cover, and a plurality of support rods are vertically connected between the bracket and the top cover. An ultrasonic detector and a controller are fixedly mounted on the bracket, and the controller is electrically connected to the ultrasonic detector and a plurality of pressure detection sensors. Each ultrasonic probe is connected to an ultrasonic probe line, and the ultrasonic probe line passes through the top of the corresponding detection unit and is connected to the ultrasonic detector.

[0015] Preferably, a line collecting groove for accommodating a plurality of ultrasound probe lines is provided at the bottom of the bracket.

[0016] Preferably, the controller is a PLC controller having a built-in 5G communication module, and is connected to an external control center by signals via the 5G communication module.

[0017] The present invention includes at least the following beneficial effects: the present invention uses ultrasonic signals to detect the change in the length of the bolt to evaluate the change in the preload force provided by the bolt, and then combines the change in the force on the spring wire to calculate the number of turns the bolt has rotated, thereby comprehensively judging the current state of the bolt, and comprehensively predicting future state change data based on the state change data over a period of time, thereby providing timely warnings to relevant maintenance personnel when bolt maintenance is required, ensuring the safe operation of the turbine, and having high practical value.

[0018] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural diagram of a technical solution of the present invention;

[0020] Figure 2 A cross-sectional view of a technical solution of the present invention;

[0021] Figure 3 This is a schematic structural diagram of the bracket in one technical solution of the present invention;

[0022] Figure 4 A cross-sectional view of the detection unit in one technical solution of the present invention;

[0023] Figure 5 This is a cross-sectional view of the connection structure between the fixing sleeve and the bolt in one technical solution of the present invention;

[0024] Figure 6 for Figure 5 Schematic diagram of the structure of part A;

[0025] In the figure: 1. volute; 2. top cover; 3. detection unit; 4. bracket; 401. support rod; 5. ultrasonic detector; 6. controller; 7. auxiliary pushing device; 701. pushing arm; 702. rotating shaft; 703. waist-shaped hole; 704. hinge ear; 8. clamping device; 801. screw; 802. clamping seat; 803. first clamping arm; 804. first return spring; 805. cross bar; 806. vertical bar; 807. ridge; 901. closing plate; 902. second return spring; 903. second clamping arm; 904. mounting base; 905. support arm; 10. bolt; 11. wire collecting groove; 12. ultrasonic probe line; 13. outer matching sleeve; 14. spiral groove; 15. spring line; 16. ultrasonic probe; 17. fixing sleeve; 18. inner matching sleeve; 19. pressure detection sensor. DETAILED DESCRIPTION

[0026] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0027] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0028] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "set" should be understood in a broad sense, for example, they can be fixedly connected or set, or detachably connected or set, or integrally connected or set. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The orientations or positional relationships indicated by the terms "transverse", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0029] like Figure 1-6 As shown, the present invention provides a turbine top cover bolt preload monitoring device based on ultrasonic detection, comprising a plurality of bolts 10 fixed to a turbine volute 1 and a top cover 2, wherein a detection unit 3 is provided on the top of each bolt 10;

[0030] Among them, the bottom of each detection unit 3 is fixedly connected to the top cover 2, the outer periphery of the head of the bolt 10 is fixedly sleeved with a fixing sleeve 17, the top of the fixing sleeve 17 is fixedly connected with a cylindrical inner matching sleeve 18, the inner top wall of the detection unit 3 is vertically fixed with a cylindrical outer matching sleeve 13, the outer matching sleeve 13 is movably sleeved on the outer periphery of the corresponding inner matching sleeve 18, the inner side wall of the outer matching sleeve 13 is surrounded by a spiral groove 14, the spiral groove 14 is matched to accommodate a spring wire 15, the inner wall of the spiral groove 14 is provided with a pressure detection sensor 19 near the top of the spring wire 15, the bottom end side wall of the spring wire 15 is connected to the inner matching sleeve 18, and an ultrasonic probe 16 is fixedly inserted into the outer matching sleeve 13 and the inner matching sleeve 18, and the detection end of the ultrasonic probe 16 passes through the fixing sleeve 17 and faces the top of the bolt 10.

[0031] In the above technical solution, a plurality of bolts 10 are screwed onto the top cover 2, and a detection unit 3 is fixedly installed on the top of each bolt 10 of the top cover 2. The detection unit 3 is sealed with a sealed cover to prevent external dust and other pollutants from entering the monitoring unit and affecting the monitoring results. The detection unit 3 includes a fixed sleeve 17 fixed to the top of the bolt 10, and an inner matching sleeve 18 is provided on the top of the fixed sleeve 17, and an ultrasonic probe 16 for ultrasonic detection of the bolt 10 is fixedly installed inside the inner matching sleeve 18; the inner wall of the detection unit 3 is integrally formed with an outer matching sleeve 13 which is sleeved on the inner matching sleeve 18, and a spiral groove 14 is provided in the outer matching sleeve 13, and a spring wire 15 is provided in the spiral groove 14. The spring wire 15 can only be extended and retracted along the spiral groove 14 according to the stress state of its own end, and a pressure detection sensor 19 for detecting the stress of the spring wire 15 is provided at the top of the corresponding spring wire 15 in the spiral groove 14, and the bottom of the spring wire 15 is fixedly connected to the top of the inner matching sleeve 18. During use, the fixing sleeve 17 is mounted on the outer periphery of the head of the bolt 10. When the bolt 10 rotates to loosen and moves upward, it drives the fixing sleeve 17 and the inner mating sleeve 18 to rotate. Since the detection unit 3 and the outer mating sleeve 13 are fixed to the top cover 2, they do not rotate. At this time, the ultrasonic probe 16 detects that the distance between it and the bolt 10 has shortened. This change in distance is used to assess the change in the preload force provided by the bolt 10. Furthermore, because the inner mating sleeve 18 is connected to the spring wire 15, the rotation of the inner mating sleeve 18 generates pressure on the spring wire 15, which is monitored continuously by the pressure detection sensor 19 at the end of the spring wire 15. The change in the force on the spring wire 15 can be used to calculate the rotation angle and number of turns of the bolt 10. Combined with the change in preload force, the current state of the bolt 10 can be comprehensively determined. Based on the state change data over a period of time, future state change data can be comprehensively predicted, thereby providing timely warnings to relevant maintenance personnel when maintenance of the bolt 10 is required, ensuring the safe operation of the turbine.

[0032] In another technical solution, each detection unit 3 is coaxially arranged with its internal fixing sleeve 17, inner mating sleeve 18, outer mating sleeve 13, and ultrasonic probe 16. In this technical solution, the fixing sleeve 17, inner mating sleeve 18, outer mating sleeve 13, and ultrasonic probe 16 are all coaxially arranged with the corresponding detection unit 3. This ensures that the fixing sleeve 17 and inner mating sleeve 18 can rotate synchronously and stably with the bolt 10, while generating synchronous and stable force on the spring wire 15, and ensures that the ultrasonic probe 16 can stably measure the height of the bolt 10.

[0033] like Figure 5-6As shown, in another technical solution, the bottom side wall of the spring wire 15 is connected to the inner matching sleeve 18 through an auxiliary pushing device 7, and the auxiliary pushing device 7 is provided with an L-shaped pushing arm 701, one end of the pushing arm 701 is fixedly connected to the side wall of the spring wire 15, and the other end is vertically connected to a rotating shaft 702 on both sides, and two parallel hinged ears 704 are fixedly installed on the top of the inner matching sleeve 18, and waist-shaped holes 703 are provided on the two hinged ears 704, and the two ends of the rotating shaft 702 are movably inserted into the two waist-shaped holes 703. In this technical solution, the auxiliary pushing device 7 includes a pushing arm 701 fixedly connected to the spring wire 15, and the end of the pushing arm 701 is fixedly installed with a rotating shaft 702, and the top of the inner matching sleeve 18 is fixedly installed with a hinged ear 704, and the hinged ear 704 is provided with a waist-shaped hole 703 that rotates with the rotating shaft 702. When the inner matching sleeve 18 rotates under the rotation of the bolt 10, the hinged ear 704 will drive the pushing arm 701 to rotate synchronously, and the pushing arm 701 will drive the spring wire 15 to be squeezed or stretched along the spiral groove 14, and the pressure or tension on the spring wire 15 will be detected by the pressure detection device. The sensor 19 detects and sends it to the controller 6 for analysis. The controller 6 determines how many turns the bolt 10 has rotated based on the changes in the corresponding pressure data transmitted by the pressure detection sensor 19, and thus determines the possible loosening changes of the bolt 10 in the future based on the detected preload data currently received by the bolt 10. Since the pitch of the thread on the bolt 10 and the pitch of the spiral groove 14 are not necessarily the same, the height difference generated when the bolt 10 rotates and the spring wire 15 rotates along the spiral groove 14 is compensated by the sliding fit between the waist-shaped hole 703 and the rotating shaft 702 to ensure the synchronous and stable rotation of the structure.

[0034] like Figure 4-5 As shown, in another technical solution, the head of the bolt 10 is fixedly connected to the fixing sleeve 17 by a clamping device 8, and the clamping device 8 includes a screw rod 801, and an end head is provided at the end of the screw rod 801. The end head is a T-shaped structure formed by vertically connecting a cross bar 805 and a vertical rod 806. The cross bar 805 is fixedly connected to the screw rod 801, and the vertical rod 806 is away from the screw rod 801. Both ends of the cross bar 805 are hinged with a first clamping arm 803, and the side wall of the first clamping arm 803 is provided with a ridge 807. The ridges 807 on the two first clamping arms 803 are respectively connected to the two sides of the vertical rod 806 through a first return spring 804;

[0035] Among them, the side wall of the head of each bolt 10 is provided with a plurality of threaded holes extending radially, the outer side wall of each fixing sleeve 17 is provided with a plurality of C-shaped clamping seats 802 extending vertically outward, and the side wall of the fixing sleeve 17 is provided with a plurality of through holes. Any fixing sleeve 17 is sleeved on the outer periphery of the head of any bolt 10, and the plurality of threaded holes correspond one-to-one with the plurality of through holes. The screw 801 of any clamping device 8 is rotatably inserted into the corresponding through hole and threaded hole, and the two first clamping arms 803 are limited and clamped on the corresponding two clamping seats 802. When the screw 801 is rotated, the first clamping arm 803 is clamped in the clamping seat 802 again. At this time, the first return spring 804 can be used to support and ensure that the first clamping arm 803 is in a clamping state with the clamping seat 802, thereby ensuring that the bolt 10 is fixed to the fixing sleeve 17 and convenient disassembly.

[0036] In another technical solution, the side wall of each detection unit 3 is provided with multiple installation openings, each of which is equipped with a removable closing plate 901. In this technical solution, the installation openings are provided to facilitate operation inside the detection unit 3, and the closing plate 901 is provided to close the installation openings.

[0037] like Figure 4 As shown, in another technical solution, a U-shaped mounting port base 904 extending outward perpendicularly to the side wall of the detection unit 3 is provided on the periphery of each mounting port. The mounting port base 904 is provided with two arms 905 opposite to the side wall of the detection unit 3. A second clamping arm 903 is symmetrically hingedly installed on both sides of each arm 905. The two clamping arms are respectively connected to the two sides of the arm 905 through a second return spring 902.

[0038] Each closing plate 901 has two opposing limiting holes formed therein. Any closing plate 901 seals against the outside of any mounting opening base 904, allowing the corresponding support arm 905 and second clamping arm 903 to pass through the two limiting holes. The two second clamping arms are clamped at both ends of the corresponding limiting holes by the elastic force of the second return spring 902. In this technical solution, the closing door is clamped to the outside of the mounting opening by the second clamping arms 903. When the closing plate 901 needs to be removed, the two opposing second clamping arms 903 only need to be pressed toward each other, thereby releasing the second clamping arms 903 from their clamping state against the outside of the closing plate 901. When the closing plate 901 needs to be fixed, the second clamping arms 903 are clamped into the limiting holes of the closing plate 901. At this point, the second return spring 902 can be used to ensure that the two opposing second clamping arms 903 remain clamped.

[0039] like Figure 3 As shown, in another technical solution, an annular bracket 4 is further provided on the top cover 2, and a plurality of support rods 401 are vertically connected between the bracket 4 and the top cover 2. An ultrasonic detector 5 and a controller 6 are fixedly mounted on the bracket 4. The controller 6 is electrically connected to the ultrasonic detector 5 and a plurality of pressure detection sensors 19. Each ultrasonic probe 16 is connected to an ultrasonic probe line 12, which passes through the top of the corresponding detection unit 3 and is connected to the ultrasonic detector 5. In this technical solution, the controller 6 is electrically connected to the ultrasonic detector 5 and the pressure detection sensor 19 respectively through cables, and the controller 6 is connected to the external control center signal through a built-in communication module for processing monitoring signals, thereby evaluating the loosening state of each bolt 10 and uploading the evaluation results to the external control center.

[0040] In another technical solution, a cable collection groove 11 for accommodating multiple ultrasonic probe wires 12 is provided at the bottom of the bracket 4. In this technical solution, the provision of the cable collection groove 11 can effectively prevent the ultrasonic probe wires 12 from being tangled and interfering with the normal operation of other equipment on the turbine.

[0041] In another technical solution, the controller 6 is a PLC controller with a built-in 5G communication module, and is connected to an external control center by signals through the 5G communication module.

[0042] Working principle: The present invention uses ultrasonic signals to detect the change in the length of the bolt, thereby evaluating the change in the preload force provided by the bolt 10, and then combines the change in the force on the spring wire 15 to calculate the number of revolutions of the bolt 10, thereby comprehensively judging the current state of the bolt 10, and comprehensively predicting the future state change data based on the state change data over a period of time, so as to provide timely warnings to relevant maintenance personnel when maintenance of the bolt 10 is required, ensuring the safe operation of the turbine. First of all, the spring wire 15 used in the present invention does not utilize the change in radial length of the spring when it is subjected to radial pressure, but utilizes the expansion and contraction change of its own length after the spring wire 15 is subjected to direct circumferential thrust. That is to say, the pitch and spiral radius of the spring wire 15 are limited by the spiral groove 14 and will not change. Only the length of the spring wire 15 itself changes after being subjected to direct thrust. Therefore, it is only necessary to know parameters such as the elastic modulus of the spring wire 15. The length change generated by the spring wire 15 can be calculated based on the pressure change detected by the pressure detection sensor 19 within a certain period of time. The length change combined with the pitch data of the spiral groove 14 can be used to calculate the arc length change of the spring wire 15 relative to the circular surface formed by the plane projection of the spiral groove 14, so that the arc change can be calculated based on the radius of the circular surface where the spiral groove 14 is located. Since the spring wire 15 rotates synchronously with the bolt 10, the arc is the arc of rotation of the bolt 10. When the bolt 10 is fixed to the volute 1 and the top cover 2, when the bolt 10 is under different pre-tightening forces, the bolt 10 itself will be stretched by the pre-tightening force, so that the overall length of the bolt 10 changes, that is, the top and bottom of the bolt 10 will be in different length states under different pre-tightening forces. Therefore, after the bolt 10 is subjected to force, the deformation variable generated by the bolt 10 in the height direction is linearly related to the pre-tightening force borne by the bolt 10. Therefore, it is only necessary to measure the deformation variable generated by the bolt 10, and the corresponding pre-tightening force data can be calculated according to the elastic modulus of the bolt 10 or the deformation and pre-tightening force comparison table detected by the corresponding bolt 10 through experiments. The deformation variable of the bolt 10 can be measured by ultrasonic Specifically, an ultrasonic probe 16 is used to detect the real-time length data of the bolt 10, and then the length of the bolt 10 when not under stress is subtracted, which is the deformation data of the bolt 10 at this time. Therefore, the deformation of the bolt 10 can be detected by ultrasonic wave and then the pre-tightening force data of the bolt 10 can be indirectly detected, thereby achieving the purpose of using ultrasonic wave to detect the pre-tightening force of the bolt 10. The pre-tightening force data of the bolt 10 is combined with the number of revolutions of the bolt 10 in the corresponding time period to predict the pre-tightening force change of the bolt 10 in the next time period, thereby providing timely warning for maintenance personnel's maintenance work, facilitating timely maintenance, and avoiding the occurrence of safety accidents.

[0043] The number of devices and processing scales described herein are intended to simplify the description of the present invention. Applications, modifications, and variations of the present invention will be readily apparent to those skilled in the art.

[0044] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A device for monitoring the preload force of turbine top cover bolts based on ultrasonic detection, characterized in that: It includes a plurality of bolts fixed to the turbine volute and the top cover, and the top of each bolt is covered with a detection unit; wherein the bottom of each detection unit is fixedly connected to the top cover, a fixing sleeve is fixedly provided on the outer periphery of the head of the bolt, a cylindrical inner matching sleeve is fixedly connected to the top of the fixing sleeve, a cylindrical outer matching sleeve is vertically fixedly connected to the inner top wall of the detection unit, the outer matching sleeve is movably sleeved on the outer periphery of the corresponding inner matching sleeve, a spiral groove is opened around the inner side wall of the outer matching sleeve, a spring wire is matched and accommodated in the spiral groove, a pressure detection sensor is provided on the inner wall of the spiral groove near the top end of the spring wire, the bottom end side wall of the spring wire is connected to the inner matching sleeve, an ultrasonic probe is fixedly inserted into the outer matching sleeve and the inner matching sleeve, and the detection end of the ultrasonic probe passes through the fixing sleeve and faces the top of the bolt; The bottom side wall of the spring wire is connected to the inner matching sleeve through an auxiliary pushing device, and the auxiliary pushing device is provided with an L-shaped pushing arm, one end of the pushing arm is fixedly connected to the side wall of the spring wire, and the other end is vertically connected to the rotating shaft on both sides, and two parallel hinged ears are fixedly installed on the top of the inner matching sleeve, and waist-shaped holes are provided on the two hinged ears, and the two ends of the rotating shaft are movably inserted into the two waist-shaped holes.

2. The device for monitoring the preload force of turbine top cover bolts based on ultrasonic detection according to claim 1, characterized in that: Each detection unit is coaxially arranged with the fixing sleeve, inner matching sleeve, outer matching sleeve and ultrasonic probe inside the detection unit.

3. The device for monitoring the preload force of turbine top cover bolts based on ultrasonic detection according to claim 1, characterized in that: The head of the bolt and the fixing sleeve are fixedly connected by a clamping device, the clamping device includes a screw rod, an end head is provided at the end of the screw rod, and the end head is a T-shaped structure formed by vertically connecting a cross bar and a vertical rod, the cross bar is fixedly connected to the screw rod, and the vertical rod is away from the screw rod, and both ends of the cross bar are hinged with a first clamping arm, and the side wall of the first clamping arm is provided with a ridge, and the ridges on the two first clamping arms are respectively connected to the two sides of the vertical rod through a first return spring; Among them, the side wall of the head of each bolt is provided with a plurality of threaded holes extending radially, the outer side wall of each fixing sleeve is provided with a plurality of C-shaped clamping seats extending vertically outward, and the side wall of the fixing sleeve is provided with a plurality of through holes. Any fixing sleeve is arranged on the outer periphery of the head of any bolt, and the plurality of threaded holes correspond one-to-one with the plurality of through holes. The screw of any clamping device is rotatably inserted into the corresponding through hole and threaded hole, and the two first clamping arms are limited and clamped on the corresponding two clamping seats.

4. The device for monitoring the preload force of turbine top cover bolts based on ultrasonic detection according to claim 1, characterized in that: The side wall of each detection unit is provided with a plurality of installation openings, and a detachable closing plate is installed at each installation opening.

5. The device for monitoring the preload force of turbine top cover bolts based on ultrasonic detection according to claim 4, characterized in that: A U-shaped mounting port base extending outward perpendicularly to the side wall of the detection unit is provided on the periphery of each mounting port. Two arms are provided on the mounting port base away from the side wall of the detection unit. A second clamping arm is symmetrically hingedly installed on both sides of each arm. The two clamping arms are respectively connected to the two sides of the arm through a second return spring. Limiting holes are opened at opposite ends of each closing plate. Any closing plate is sealed and covers the outside of any mounting base, and the corresponding support arm and the second clamping arm pass through the two limiting holes. Under the elastic force of the second return spring, the two second clamping arms are clamped at both ends of the corresponding limiting holes.

6. The device for monitoring the preload force of turbine top cover bolts based on ultrasonic detection according to claim 1, characterized in that: The top cover is also provided with an annular bracket, and a plurality of support rods are vertically connected between the bracket and the top cover. An ultrasonic detector and a controller are fixedly mounted on the bracket. The controller is electrically connected to the ultrasonic detector and a plurality of pressure detection sensors. Each ultrasonic probe is connected to an ultrasonic probe line, and the ultrasonic probe line passes through the top of the corresponding detection unit and is connected to the ultrasonic detector.

7. The device for monitoring the preload force of turbine top cover bolts based on ultrasonic detection according to claim 6, characterized in that: The bottom of the bracket is provided with a wire collecting groove for accommodating a plurality of ultrasonic probe wires.

8. The device for monitoring the preload force of turbine top cover bolts based on ultrasonic detection according to claim 6, characterized in that: The controller is a PLC controller with a built-in 5G communication module, and is connected to an external control center by signal through the 5G communication module.

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