Ultrasonic inspection device for main bolt of reactor pressure vessel

Abstract

The invention discloses a reactor pressure vessel kingbolt ultrasonic inspection device, which comprises a positioning mechanism, a detection mechanism, a circumferential movement mechanism and an axial movement mechanism, and is characterized in that the positioning mechanism is used for positioning and clamping a kingbolt, the detection mechanism is used for detecting the kingbolt, and the axial movement mechanism is connected to the detection mechanism; the circumferential movement mechanism is connected to the positioning mechanism and the axial movement mechanism at the same time, and the circumferential movement mechanism is used for driving the axial movement mechanism to rotate in the circumferential direction. And the detection mechanism can spirally move relative to the main bolt under the combined action of the circumferential movement mechanism and the axial movement mechanism. The ultrasonic inspection device for the kingbolt of the reactor pressure vessel can perform spiral scanning on the kingbolt, and can perform comprehensive scanning on a thread area and a polish rod area of the kingbolt, so that defects such as cracks, stress corrosion, collision traces and scratches on the surface of the kingbolt can be found and displayed in time, and the inspection efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to the field of ultrasonic inspection of nuclear power plants, and in particular to an ultrasonic inspection device for main bolts of a reactor pressure vessel. Background Art

[0002] The main bolts of nuclear power plant level I components are important components in the nuclear power plant reactor. They are fasteners for sealing the reactor pressure vessel and the reactor pressure vessel top cover. Such forgings need to work for a long time in harsh environments such as high strength, high impact, high stress, and high radiation. They are required to have high comprehensive mechanical properties and high-quality material organization. They are inspection parts required by the specifications and are also inspection parts required by the specifications and standards for the in-service / pre-service inspection of nuclear power plants.

[0003] In the prior art, the inspection of the main bolts of the reactor pressure vessel is mainly carried out when the bolts are removed, and the center hole inspection is mostly adopted. However, there are many problems such as bulky equipment and low inspection efficiency. Therefore, it is necessary to use a sophisticated, stable and reliable ultrasonic scanning device to regularly conduct a comprehensive scan of the main bolt thread area and the bare rod area, so as to timely discover defects such as cracks, stress corrosion, collision marks and scratches on the surface of the main bolts, improve the efficiency of ultrasonic inspection, and reduce the risk of personnel being exposed to radiation. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an ultrasonic inspection device for main bolts of a reactor pressure vessel.

[0005] The technical solution adopted by the present invention to solve the technical problem is: constructing an ultrasonic inspection device for main bolts of a reactor pressure vessel, which includes a positioning mechanism, a detection mechanism, a circumferential motion mechanism and an axial motion mechanism;

[0006] The positioning mechanism is used to position and clamp the main bolt;

[0007] The detection mechanism is used to detect the main bolt;

[0008] The axial motion mechanism is connected to the detection mechanism and is used to drive the detection mechanism to perform axial lifting movement;

[0009] The circumferential motion mechanism is connected to the positioning mechanism and the axial motion mechanism at the same time. The circumferential motion mechanism is used to drive the axial motion mechanism to perform circumferential rotational motion. The detection mechanism can perform spiral motion relative to the main bolt under the joint action of the circumferential motion mechanism and the axial motion mechanism.

[0010] In some embodiments, the positioning mechanism includes a positioning support frame, an upper fixed plate arranged on the positioning support frame, a locking clip arranged on the positioning support frame, a lower fixed plate connected to the positioning support frame and located below the upper fixed plate, and a limiting member arranged on the lower fixed plate.

[0011] In some embodiments, the positioning mechanism further comprises a fixed clamping ring disposed at the bottom of the positioning support frame and a movable clamping ring connected to the fixed clamping ring, an accommodation space for accommodating the main bolt is formed between the fixed clamping ring and the movable clamping ring, the fixed clamping ring and the movable clamping ring are rotatably connected via a rotating pin, and the fixed clamping ring and the movable clamping ring can be fixed together via a locking member;

[0012] The inner wall surface of the fixed clamping ring and the inner wall surface of the movable clamping ring are both provided with buffer pads.

[0013] In some embodiments, the circumferential motion mechanism includes a circumferential positioning seat, a plurality of positioning pins fixedly connected to the bottom of the circumferential positioning seat, and a locking hook connected to the side wall surface of the circumferential positioning seat;

[0014] The upper fixing plate is provided with a plurality of positioning holes;

[0015] The positioning pin is arranged corresponding to the positioning hole. When the positioning pin is positioned and connected to the positioning hole, the locking clip can be connected with the locking hook in a cooperative manner.

[0016] In some embodiments, the circumferential motion mechanism further includes a shaft sleeve, a roller support frame, a circumferential support plate, a circumferential drive motor, a circumferential driving gear, and a circumferential driven gear;

[0017] The shaft sleeve is fixedly connected to the circumferential positioning seat by a first fastener, and a matching portion is provided on the outer wall surface of the shaft sleeve;

[0018] The roller support frame is provided with a centering roller and an eccentric roller, and both the centering roller and the eccentric roller are connected with the matching part;

[0019] The circumferential support plate is fixedly connected to the roller support frame;

[0020] The circumferential drive motor is connected to the eccentric position of the circumferential support plate through a circumferential motor mounting frame, and the input end of the circumferential drive motor is drivingly connected to the circumferential driving gear;

[0021] The circumferential driving gear is meshedly connected with the circumferential driven gear;

[0022] The circumferential driven gear is fixedly connected to the shaft sleeve via a second fastener;

[0023] The shaft sleeve, the roller support frame, the circumferential driven gear, the circumferential support plate, and the circumferential positioning seat are coaxially arranged.

[0024] In some embodiments, the axial motion mechanism includes an axial drive motor, an axial driving gear, a first shaft, a first shaft driving wheel, a first shaft helical gear, a second shaft, a second shaft helical gear, a second shaft driving wheel, a third shaft, a third shaft driven wheel, a third shaft driving wheel, a fourth shaft, a fourth shaft gear, a rack rod, and a transmission shaft positioning support frame;

[0025] The axial drive motor is connected to the circumferential support plate through an axial motor mounting frame, and the axial driving gear is fixedly connected to the output end of the axial drive motor;

[0026] A first shaft driving wheel and a first shaft bevel gear are installed on the first shaft, and the first shaft driving wheel is meshed and connected with the axial driving gear;

[0027] The second shaft bevel gear and the second shaft driving wheel are installed on the second shaft, and the second shaft bevel gear is meshed and connected with the first shaft bevel gear;

[0028] The third shaft driven wheel and the third shaft driving wheel are installed on the third shaft, and the third shaft driven wheel is meshed and connected with the second shaft driving wheel;

[0029] The fourth shaft gear is installed on the fourth shaft, and the fourth shaft gear is meshed and connected with the third shaft driving wheel and the rack rod at the same time;

[0030] The first shaft, the second shaft and the third shaft are all connected to the transmission shaft positioning support frame.

[0031] In some embodiments, the circumferential support plate is provided with a first connecting hole, the circumferential driven gear is provided with a second connecting hole, the sleeve is provided with a third connecting hole, and the circumferential positioning seat is provided with a fourth connecting hole;

[0032] The first connecting hole, the second connecting hole, the third connecting hole and the fourth connecting hole are coaxially arranged and sequentially connected along the height direction of the circumferential positioning seat. The first connecting hole, the second connecting hole, the third connecting hole and the fourth connecting hole are commonly used for the rack rod to pass through.

[0033] In some embodiments, the detection mechanism includes an upper centering shaft, a first steel ball bushing, a connecting sleeve, a probe support shaft, a probe wedge, and a probe;

[0034] The upper centering shaft is connected to the bottom of the rack rod;

[0035] The first steel ball bushing is sleeved on the outer side of the upper centering shaft;

[0036] The probe support shaft is fixed to the bottom of the upper centering shaft through the connecting sleeve;

[0037] The probe wedge is mounted on the probe support shaft;

[0038] The probe is mounted on the probe wedge.

[0039] In some embodiments, the detection mechanism further includes a cable compression block, a lower centering shaft, and a second steel ball bushing;

[0040] The cable clamping block is mounted on the probe wedge and is used to fix the cable of the probe;

[0041] The lower centering shaft is connected to the bottom of the probe support shaft;

[0042] The second steel ball bushing is sleeved on the outer side of the lower centering shaft.

[0043] In some embodiments, the reactor pressure vessel main bolt ultrasonic inspection device further includes a limiting mechanism, wherein the limiting mechanism includes a steel ball bushing fixing shaft, a third steel ball bushing, a fourth steel ball bushing, an upper stopper, and a lower stopper;

[0044] The steel ball bushing fixed shaft is provided with a central through hole for the rack rod to pass through;

[0045] The third steel ball bushing is arranged above the central through hole, and the third steel ball bushing is connected to the steel ball bushing fixed shaft through the upper stopper, and the lower end surface of the upper stopper is connected to the upper end surface of the steel ball bushing fixed shaft;

[0046] The fourth steel ball bushing is arranged below the central through hole, and the fourth steel ball bushing is connected to the steel ball bushing fixed shaft through the lower stop block, the upper end surface of the lower stop block is connected to the lower end surface of the steel ball bushing fixed shaft, and the lower end surface of the lower stop block is connected to the circumferential support plate.

[0047] In some embodiments, the limiting mechanism further includes a housing and a limiting support plate, and the upper end surface of the upper stopper is connected to the limiting support plate;

[0048] The position-limiting support plate is connected to the upper end surface of the shell, and the lower end surface of the shell is connected to the circumferential support disk.

[0049] In some embodiments, the limiting mechanism further includes a pressing roller support, a pressing roller, and a pressing roller shaft;

[0050] The pressing roller support is installed on the steel ball bushing fixed shaft, and the pressing roller is fixed on the pressing roller support through the pressing roller shaft.

[0051] In some embodiments, the limit mechanism further includes a magnetic proximity switch;

[0052] The rack rod is provided with a magnet, the magnetic proximity switch is installed on the steel ball bushing fixed shaft, and the magnetic proximity switch is used to sense the position of the magnet.

[0053] In some embodiments, the reactor pressure vessel main bolt ultrasonic inspection device further includes an electric control mechanism, the electric control mechanism including an electric control slip ring fixing shaft, an electric control slip ring, an electric control joint, an electric control slip ring cover and a slip ring fixing plate;

[0054] The mover end of the electric control slip ring is connected to the limit support plate through the electric control slip ring fixed shaft;

[0055] The electric control slip ring cover is connected to the stator end of the electric control slip ring;

[0056] The electric control connector is connected to the electric control slip ring cover;

[0057] Two ends of the slip ring fixing plate are respectively connected to the electric control slip ring cover and the circumferential positioning seat.

[0058] In some embodiments, the electric control slip ring cover is provided with a connecting hole for the rack rod to pass through, and the electric control mechanism further includes a steel ball bushing fixing sleeve installed in the connecting hole and a fifth steel ball bushing installed in the steel ball bushing fixing sleeve.

[0059] In some embodiments, the electric control mechanism further includes a signal slip ring, a signal slip ring cover, an ultrasonic joint mounting plate, and an ultrasonic joint;

[0060] The mover end of the signal slip ring is connected to the upper end of the rack rod;

[0061] The signal slip ring cover is connected to the stator end of the signal slip ring;

[0062] The ultrasonic joint mounting plate is mounted on the signal slip ring cover;

[0063] The ultrasonic joint is mounted on the ultrasonic joint mounting plate.

[0064] The implementation of the present invention has the following beneficial effects: the ultrasonic inspection device for the main bolts of the reactor pressure vessel uses a positioning mechanism to position and clamp the main bolts, and uses the circumferential motion mechanism and the axial motion mechanism to cooperate so that the detection mechanism can perform spiral motion relative to the main bolts, that is, the detection mechanism can perform spiral scanning on the main bolts, and can perform a comprehensive scan of the threaded area and the bare rod area of ​​the main bolts, so as to timely discover defects such as cracks, stress corrosion, collision marks and scratches on the surface of the main bolts. Compared with the grid scanning method, it can greatly save the time of scanning a single bolt, greatly improve the inspection efficiency, reduce the work intensity and the radiation dose received by personnel, and solve the problem of cable entanglement in the rotational motion. During installation, you only need to move the ultrasonic inspection device to the top of the main bolt and fix it. When inspecting a large number of main bolts, there is no need for the assistance of a crane. The ultrasonic inspection work of the main bolts when they are taken out and in place can be realized, which greatly reduces the on-site coordination work of the staff and reduces the work pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work. In the drawings:

[0066] Figure 1 is a schematic diagram of the overall structure of an ultrasonic inspection device for main bolts of a reactor pressure vessel in some embodiments of the present invention;

[0067] Figure 2 is a schematic diagram of the structure of the positioning mechanism in some embodiments of the present invention;

[0068] Figure 3 is a front cross-sectional view of a circumferential motion mechanism in some embodiments of the present invention;

[0069] Figure 4 is a left side cross-sectional view of a circumferential motion mechanism in some embodiments of the present invention;

[0070] Figure 5 is a top cross-sectional view of a circumferential motion mechanism in some embodiments of the present invention;

[0071] Figure 6 is a front view of an ultrasonic inspection device for main bolts of a reactor pressure vessel in some embodiments of the present invention;

[0072] Figure 7 is a rear view of an ultrasonic inspection device for main bolts of a reactor pressure vessel in some embodiments of the present invention;

[0073] Figure 8is a cross-sectional view of an electric control mechanism in some embodiments of the present invention;

[0074] Fig. 9 is a schematic diagram of the structure of the limiting mechanism in some embodiments of the present invention;

[0075] Fig.10 It is a schematic diagram of the structure of the detection mechanism in some embodiments of the present invention. DETAILED DESCRIPTION

[0076] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0077] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or one or more intermediate elements may be provided. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of the features. 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.

[0078] See also Figures 1 to 10, is a main bolt ultrasonic inspection device for a reactor pressure vessel in some embodiments of the present invention, which includes a positioning mechanism 1, a detection mechanism 2, a circumferential motion mechanism 3 and an axial motion mechanism 4. The positioning mechanism 1 is used to position and clamp the main bolt 5, the detection mechanism 2 is used to detect the main bolt 5, the axial motion mechanism 4 is connected to the detection mechanism 2, and is used to drive the detection mechanism 2 to perform axial lifting and lowering movement, the circumferential motion mechanism 3 is connected to the positioning mechanism 1 and the axial motion mechanism 4 at the same time, the circumferential motion mechanism 3 is used to drive the axial motion mechanism 4 to perform circumferential rotational movement, and the detection mechanism 2 can perform spiral movement relative to the main bolt 5 under the joint action of the circumferential motion mechanism 3 and the axial motion mechanism 4.

[0079] It can be understood that the ultrasonic inspection device for the main bolts of the reactor pressure vessel uses the positioning mechanism 1 to position and clamp the main bolts 5, and uses the circumferential motion mechanism 3 and the axial motion mechanism 4 to cooperate with each other so that the detection mechanism 2 can perform spiral motion relative to the main bolts 5, that is, the detection mechanism 2 can perform spiral scanning on the main bolts 5, and can perform a comprehensive scan on the threaded area and the bare rod area of ​​the main bolts 5, so as to timely discover the defects such as cracks, stress corrosion, collision marks and scratches on the surface of the main bolts 5. Compared with the grid scanning method, it can greatly save the time of scanning a single bolt, greatly improve the inspection efficiency, reduce the work intensity and the radiation dose received by personnel, and solve the problem of cable entanglement in the rotational motion. During installation, it is only necessary to move the ultrasonic inspection device to the top of the main bolt 5 and fix it. When inspecting a large number of main bolts 5, there is no need for the assistance of a crane. The ultrasonic inspection work of the main bolts 5 when they are taken out and in place can be realized, which greatly reduces the on-site coordination work of the staff and reduces the work pressure.

[0080] like Figure 2 As shown, the positioning mechanism 1 includes a positioning support frame 11, an upper fixing plate 12 disposed on the positioning support frame 11, a locking clip 13 disposed on the positioning support frame 11, a lower fixing plate 14 connected to the positioning support frame 11 and located below the upper fixing plate 12, and a stopper 15 disposed on the lower fixing plate 14. A rectangular parallelepiped frame structure is formed between the upper fixing plate 12, the positioning support frame 11, and the lower fixing plate 14.

[0081] Furthermore, the positioning mechanism 1 further includes a fixed clamping ring 16 disposed at the bottom of the positioning support frame 11 and a movable clamping ring 17 connected to the fixed clamping ring 16. An accommodation space for accommodating the main bolt 5 is formed between the fixed clamping ring 16 and the movable clamping ring 17. The fixed clamping ring 16 and the movable clamping ring 17 are rotatably connected by a rotating pin 18, and the fixed clamping ring 16 and the movable clamping ring 17 can be fixed together by a locking member 19. The locking member 19 is preferably a locking bolt. The limiter 15 can be used to position the head of the main bolt 5. It can be understood that after the positioning mechanism 1 is positioned on the upper end surface of the main bolt 5 by relying on the lower end fixing plate 14, the fixed clamping ring 16 and the movable clamping ring 17 are clamped on the bare rod area on the main bolt 5. After the main bolt 5 is positioned, the locking member 19 is tightened to complete the positioning and locking of the main bolt 5, and then the main bolt 5 is detected by the detection mechanism 2.

[0082] In addition, the inner wall surface of the fixed clamping ring 16 and the inner wall surface of the movable clamping ring 17 are both provided with a buffer pad 161 to prevent damage to the main bolt 5. The buffer pad 161 is preferably a thin rubber pad.

[0083] like Figure 3 and Figure 4 As shown, the circumferential motion mechanism 3 includes a circumferential positioning seat 301, a plurality of positioning pins 302 fixedly connected to the bottom of the circumferential positioning seat 301, and a locking hook 303 connected to the side wall of the circumferential positioning seat 301. A plurality of positioning holes 121 are provided on the upper fixed plate 12. The positioning pins 302 are arranged corresponding to the positioning holes 121. When the positioning pins 302 are positioned and connected to the positioning holes 121, the locking clip 13 can be connected with the locking hook 303. In this embodiment, the number of the positioning pins 302 and the positioning holes 121 are both four, and the four positioning holes 121 are distributed at the four corners of the upper fixed plate 12. When the main bolt ultrasonic inspection device for the reactor pressure vessel needs to be installed, the four positioning pins 302 can be installed in the positioning holes 121, and the locking hook 303 and the locking clip 13 are locked to complete the positioning of the circumferential positioning seat 301 and the upper fixed plate 12. There are two locking clips 13 and two locking hooks 303 . The two locking clips 13 are installed on the left and right sides of the upper fixed plate 12 , and the two locking hooks 303 are installed on the left and right sides of the circumferential positioning seat 301 .

[0084] In addition, the circumferential motion mechanism 3 further includes a shaft sleeve 304, a roller support frame 305, a circumferential support plate 306, a circumferential drive motor 307, a circumferential driving gear 308 and a circumferential driven gear 309. The shaft sleeve 304 is fixedly connected to the circumferential positioning seat 301 by a first fastener 313, a matching portion 3041 is provided on the outer wall surface of the shaft sleeve 304, a centering roller 310 and an eccentric roller 311 are provided on the roller support frame 305, and the centering roller 310 and the eccentric roller 311 are both matched and connected with the matching portion 3041. More specifically, the matching portion 3041 is a V-shaped protrusion, and the centering roller 310 and the eccentric roller 311 are both provided with a V-shaped groove matching the shape of the V-shaped protrusion, and the roller support frame 305 is divided into an upper and lower layer, and the upper and lower layers of the roller support frame 305 are both installed with the centering roller 310 and the eccentric roller 311. During installation, first install two centering rollers 310 and clamp them on the matching part 3041 to ensure that the sleeve 304 is consistent with the central axis of the circumferential positioning seat 301, and then install two eccentric rollers 311 and press them on the matching part 3041, so that the roller support frame 305 can maintain a stable state and rotate along the central axis of the circumferential positioning seat 301.

[0085] The circumferential support disk 306 is fixedly connected to the roller support frame 305, the circumferential drive motor 307 is connected to the eccentric position of the circumferential support disk 306 through the circumferential motor mounting frame 312, the input end of the circumferential drive motor 307 is transmission-connected to the circumferential driving gear 308, the circumferential driving gear 308 is meshed and connected with the circumferential driven gear 309, and the circumferential driven gear 309 is fixedly connected to the sleeve 304 through the second fastener 314. The sleeve 304, the roller support frame 305, the circumferential driven gear 309, the circumferential support disk 306, and the circumferential positioning seat 301 are coaxially arranged. It can be understood that the sleeve 304 is connected to the circumferential positioning seat 301 through the first fastener 313, and the circumferential driven gear 309 is fixedly connected to the sleeve 304 through the second fastener 314, and the sleeve 304, the circumferential positioning seat 301, and the circumferential driven gear 309 are relatively fixed. At the same time, the roller support frame 305 utilizes a centering roller 310 and an eccentric roller 311, so that the roller support frame 305 can rotate along the central axis of the circumferential positioning seat 301. When the circumferential drive motor 307 is driven, the circumferential drive motor 307 drives the circumferential driving gear 308 to rotate along the circumferential side of the circumferential driven gear 309, so that the circumferential support plate 306 and the roller support frame 305 will also rotate along the central axis of the circumferential positioning seat 301.

[0086] like Figure 6 and Figure 7As shown, the axial motion mechanism 4 includes an axial drive motor 401, an axial driving gear 402, a first shaft 403, a first shaft driving wheel 404, a first shaft bevel gear 405, a second shaft 406, a second shaft bevel gear 407, a second shaft driving wheel 408, a third shaft 409, a third shaft driven wheel 410, a third shaft driving wheel 411, a fourth shaft 412, a fourth shaft gear 413, a rack rod 414 and a transmission shaft positioning support frame 415. The axial drive motor 401 is connected to the circumferential support disk 306 through the axial motor mounting bracket 416, and the axial driving gear 402 is fixedly connected to the output end of the axial drive motor 401. Since the axial drive motor 401 is fixed relative to the circumferential support disk 306, the axial motion mechanism 4 as a whole will also rotate along the central axis of the circumferential positioning seat 301 under the drive of the circumferential drive motor 307, and the detection mechanism 2 can also move up and down under the drive of the axial drive motor 401. When the circumferential drive motor 307 and the axial drive motor 401 are driven at the same time, the detection mechanism 2 can make a spiral motion relative to the main bolt 5.

[0087] In addition, the first shaft 403 is equipped with a first shaft driving wheel 404 and a first shaft bevel gear 405, the first shaft driving wheel 404 is meshed with the axial driving gear 402, the second shaft bevel gear 407 and the second shaft driving wheel 408 are installed on the second shaft 406, the second shaft bevel gear 407 is meshed with the first shaft bevel gear 405, the third shaft driven wheel 410 and the third shaft driving wheel 411 are installed on the third shaft 409, the third shaft driven wheel 410 is meshed with the second shaft driving wheel 408, the fourth shaft gear 413 is installed on the fourth shaft 412, the fourth shaft gear 413 is meshed with the third shaft driving wheel 411 and the rack rod 414 at the same time, and the first shaft 403, the second shaft 406, and the third shaft 409 are all connected to the transmission shaft positioning support frame 415. The torque output by the axial drive motor 401 is sequentially transmitted to the rack bar 414 through the axial driving gear 402, the first axis driving wheel 404, the first axis bevel gear 405, the second axis bevel gear 407, the second axis driving wheel 408, the third axis driven wheel 410, the third axis driving wheel 411, and the fourth axis gear 413 to drive the lifting movement of the rack bar 414. The axial drive motor 401 achieves a deceleration effect through the transmission of multiple gears.

[0088] like Figure 4As shown, the circumferential support plate 306 is provided with a first connecting hole 3061, the circumferential driven gear 309 is provided with a second connecting hole 3091, the sleeve 304 is provided with a third connecting hole 3042, and the circumferential positioning seat 301 is provided with a fourth connecting hole 3011. The first connecting hole 3061, the second connecting hole 3091, the third connecting hole 3042, and the fourth connecting hole 3011 are coaxially arranged and sequentially connected along the height direction of the circumferential positioning seat 301. The first connecting hole 3061, the second connecting hole 3091, the third connecting hole 3042, and the fourth connecting hole 3011 are used to allow the rack rod 414 to pass through. The rack rod 414 only passes through the above-mentioned connecting holes without contacting the connecting holes.

[0089] like Fig.10 As shown, the detection mechanism 2 includes an upper centering shaft 21, a first steel ball bushing 22, a connecting sleeve 23, a probe support shaft 24, a probe wedge 25, a probe 26, a cable clamping block 27, a lower centering shaft 28 and a second steel ball bushing 29. The upper centering shaft 21 is connected to the bottom of the rack rod 414, the first steel ball bushing 22 is sleeved on the outer side of the upper centering shaft 21, the probe support shaft 24 is fixed to the bottom of the upper centering shaft 21 through the connecting sleeve 23, the probe wedge 25 is installed on the probe support shaft 24, the probe 26 is installed on the probe wedge 25, the cable clamping block 27 is installed on the probe wedge 25 and is used to fix the cable of the probe 26, the lower centering shaft 28 is connected to the bottom of the probe support shaft 24, and the second steel ball bushing 29 is sleeved on the outer side of the lower centering shaft 28.

[0090] Specifically, the upper centering shaft 21 can be fixedly connected to the bottom of the rack rod 414, so that the rack rod 414 can drive the entire detection mechanism 2 to move together when it moves. The steel ball bushing is a bearing bushing made of a spherical structure, which adopts the radial contact between the steel ball and the shaft to bear the axial and radial loads. Its basic principle is to achieve friction and support through the rotation and rolling of the steel ball. The main characteristics are large bearing capacity, long service life, and not easy to deform. In this embodiment, the first steel ball bushing 22 is preferably 20mm in diameter and 40mm in length, and the second steel ball bushing 29 is preferably 20mm in diameter and 30mm in length. In addition, the probe 26 is used to scan and inspect the main bolt 5, the cable clamping block 27 is used to fix the cable of the probe 26, the probe 26 and the probe wedge block 25 are located at an eccentric position of the circumferential positioning seat 301, and under the joint drive of the circumferential drive motor 307 and the axial drive motor 401, the probe 26 can perform a spiral scan on the main bolt 5, and can perform a comprehensive scan of the threaded area and the bare rod area of ​​the main bolt 5.

[0091] like Fig. 9As shown, the reactor pressure vessel main bolt ultrasonic inspection device also includes a limiting mechanism 6, which includes a steel ball bushing fixed shaft 61, a third steel ball bushing 62, a fourth steel ball bushing 63, an upper stopper 64 and a lower stopper 65. The steel ball bushing fixed shaft 61 is provided with a central through hole for the rack rod 414 to pass through, the third steel ball bushing 62 is arranged above the central through hole, and the third steel ball bushing 62 is connected to the steel ball bushing fixed shaft 61 through the upper stopper 64, the lower end surface of the upper stopper 64 is connected to the upper end surface of the steel ball bushing fixed shaft 61, the fourth steel ball bushing 63 is arranged below the central through hole, and the fourth steel ball bushing 63 is connected to the steel ball bushing fixed shaft 61 through the lower stopper 65, the upper end surface of the lower stopper 65 is connected to the lower end surface of the steel ball bushing fixed shaft 61, and the lower end surface of the lower stopper 65 is connected to the circumferential support plate 306. In addition, the limiting mechanism 6 also includes a shell 66 and a limiting support plate 67 , the upper end surface of the upper stopper 64 is connected to the limiting support plate 67 , the limiting support plate 67 is connected to the upper end surface of the shell 66 , and the lower end surface of the shell 66 is connected to the circumferential support disk 306 .

[0092] Specifically, the rack rod 414 can pass through the third steel ball bushing 62 and the fourth steel ball bushing 63, and the limiting mechanism 6 is connected to the limiting support plate 67 through the upper end face of the upper stop block 64, and the lower end face of the lower stop block 65 is connected to the circumferential support disk 306, thereby realizing the positioning of the limiting mechanism 6 relative to the axial motion mechanism 4. The limiting mechanism 6 as a whole can axially position the rack rod 414, so that the rack rod 414 can ensure rotational motion along the central axis of the circumferential positioning seat 301 during the movement, reduce the vibration of the rack rod 414 during the movement, reduce the impact on the ultrasonic data signal, improve the reliability of the data, and ensure the stability of the rack rod 414 during the movement.

[0093] like Fig. 9 As shown, the limiting mechanism 6 also includes a pressing roller support 68, a pressing roller 69 and a pressing roller shaft 601. The pressing roller support 68 is installed on the steel ball bushing fixed shaft 61, and the pressing roller 69 is fixed on the pressing roller support 68 through the pressing roller shaft 601. The pressing roller 69 can ensure that the rack rod 414 remains in a pressed state during movement.

[0094] The limiting mechanism 6 also includes a magnetic proximity switch 602. A magnet 416 is provided on the rack rod 414. The magnetic proximity switch 602 is installed on the steel ball bushing fixed shaft 61. The magnetic proximity switch 602 is used to sense the position of the magnet 416. When the magnet 416 moves to the position of the magnetic proximity switch 602, the magnetic proximity switch 602 can send a signal to the control system of the ultrasonic inspection device for the main bolts of the reactor pressure vessel to stop the movement of the rack rod 414 to play a protective role.

[0095] like Figure 7 and Figure 8 As shown, the reactor pressure vessel main bolt ultrasonic inspection device also includes an electric control mechanism 7, which includes an electric control slip ring fixing shaft 71, an electric control slip ring 72, an electric control joint 73, an electric control slip ring cover 74 and a slip ring fixing plate 75. The mover end of the electric control slip ring 72 is connected to the limit support plate 67 through the electric control slip ring fixing shaft 71, the electric control slip ring cover 74 is connected to the stator end of the electric control slip ring 72, the electric control joint 73 is connected to the electric control slip ring cover 74, and the two ends of the slip ring fixing plate 75 are respectively connected to the electric control slip ring cover 74 and the circumferential positioning seat 301.

[0096] It can be understood that the electric control connector 73 is used for the output of electrical signals such as motors and encoders. The electric control slip ring 72 is an electrical connector that can transmit power in a rotating state. The main components of the electric control slip ring 72 are the slip ring body and the brush. The relative rotation and sliding contact between the slip ring body and the brush is used to complete the transmission of power. By setting the slip ring fixing plate 75, the stator end of the electric control slip ring 72 can be relatively fixed to the circumferential positioning seat 301, ensuring the positioning of the stator end of the electric control slip ring 72. At the same time, because the movable end of the electric control slip ring 72 is connected to the limit support plate 67 through the electric control slip ring fixing shaft 71, the movable end of the electric control slip ring 72 can move with the movement of the limit support plate 67.

[0097] In addition, a connecting hole for the rack rod 414 to pass through is opened in the electric control slip ring cover 74, and the electric control mechanism 7 also includes a steel ball bushing fixing sleeve 701 installed in the connecting hole and a fifth steel ball bushing 702 installed in the steel ball bushing fixing sleeve 701, and the fifth steel ball bushing 702 plays a centering role.

[0098] Furthermore, the electric control mechanism 7 also includes a signal slip ring 76, a signal slip ring cover 77, an ultrasonic joint mounting plate 78 and an ultrasonic joint 79. The mover end of the signal slip ring 76 is connected to the upper end of the rack rod 414, the signal slip ring cover 77 is connected to the stator end of the signal slip ring 76, the ultrasonic joint mounting plate 78 is installed on the signal slip ring cover 77, and the ultrasonic joint 79 is installed on the ultrasonic joint mounting plate 78. The signal slip ring 76 can be used to transmit ultrasonic signals, and the ultrasonic joint 79 can be relatively fixed by connecting a steel wire rope with a traction effect, and the steel wire rope can be connected to an external mechanism. Since the mover end of the signal slip ring 76 is connected to the upper end of the rack rod 414, the mover end of the signal slip ring 76 can move with the movement of the rack rod 414.

[0099] The steps for using the ultrasonic inspection device for main bolts of a reactor pressure vessel are as follows:

[0100] 1. Before officially starting the scan, calibrate the probe 26 and add deionized water into the center hole of the main bolt 5;

[0101] 2. Install the positioning mechanism 1 into the top of the main bolt 5 through the stopper 15 on the lower fixed plate 14, rotate the movable clamping ring 17 to make it fit with the fixed clamping ring 16, and tighten the locking piece 19;

[0102] 3. Move the circumferential motion mechanism 3 to the upper side of the upper fixed plate 12, align the positioning pin 302 with the positioning hole 121, and align the locking clip 13 with the locking hook 303, and then lock the locking clip 13 with the locking hook 303;

[0103] 4. Align the probe wedge 25 with the circumferential starting position of the main bolt 5 and set it as the circumferential zero point;

[0104] 5. Move the rack rod 414 to the lower limit position, where the magnet 416 is aligned with the magnetic proximity switch 602 and is set as the axial limit position;

[0105] 6. According to the design dimensions, the rack rod 414 is moved axially downward to the axial starting position of the scan, and is set as the axial zero point;

[0106] 7. Set the spiral scanning parameters, i.e. the circumferential and axial movement speeds, axial movement stroke and other parameters, and start scanning;

[0107] 8. After the scanning is completed, the rack rod 414 is moved to the lower limit position;

[0108] 9. Release the locking clip 13 and the locking hook 303, and remove the circumferential motion mechanism 3 and other mechanisms.

[0109] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the scope covered by the claims of the present invention.

Claims

1. An ultrasonic inspection device for main bolts of a reactor pressure vessel, characterized in that: It comprises a positioning mechanism (1), a detection mechanism (2), a circumferential motion mechanism (3) and an axial motion mechanism (4); The positioning mechanism (1) is used to position and clamp the main bolt (5); The detection mechanism (2) is used to detect the main bolt (5); The axial movement mechanism (4) is connected to the detection mechanism (2) and is used to drive the detection mechanism (2) to perform axial lifting movement; The circumferential motion mechanism (3) is simultaneously connected to the positioning mechanism (1) and the axial motion mechanism (4); the circumferential motion mechanism (3) is used to drive the axial motion mechanism (4) to perform circumferential rotational motion; and the detection mechanism (2) can perform spiral motion relative to the main bolt (5) under the joint action of the circumferential motion mechanism (3) and the axial motion mechanism (4).

2. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 1, characterized in that: The positioning mechanism (1) comprises a positioning support frame (11), an upper fixing plate (12) arranged on the positioning support frame (11), a locking clip (13) arranged on the positioning support frame (11), a lower fixing plate (14) connected to the positioning support frame (11) and located below the upper fixing plate (12), and a limiting member (15) arranged on the lower fixing plate (14).

3. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 2, characterized in that: The positioning mechanism (1) further comprises a fixed clamping ring (16) arranged at the bottom of the positioning support frame (11) and a movable clamping ring (17) connected to the fixed clamping ring (16), a receiving space for receiving the main bolt (5) is formed between the fixed clamping ring (16) and the movable clamping ring (17), the fixed clamping ring (16) and the movable clamping ring (17) are rotatably connected via a rotating pin (18), and the fixed clamping ring (16) and the movable clamping ring (17) can be fixed together via a locking member (19); The inner wall surface of the fixed clamping ring (16) and the inner wall surface of the movable clamping ring (17) are both provided with a buffer pad (161).

4. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 2, characterized in that: The circumferential motion mechanism (3) comprises a circumferential positioning seat (301), a plurality of positioning pins (302) fixedly connected to the bottom of the circumferential positioning seat (301), and a locking hook (303) connected to the side wall surface of the circumferential positioning seat (301); The upper end fixing plate (12) is provided with a plurality of positioning holes (121); The positioning pin (302) is arranged corresponding to the positioning hole (121); when the positioning pin (302) is positioned and connected to the positioning hole (121), the locking clip (13) can be matched and connected with the locking hook (303).

5. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 4, characterized in that: The circumferential motion mechanism (3) further comprises a shaft sleeve (304), a roller support frame (305), a circumferential support plate (306), a circumferential drive motor (307), a circumferential driving gear (308) and a circumferential driven gear (309); The shaft sleeve (304) is fixedly connected to the circumferential positioning seat (301) via a first fastener (313), and a matching portion (3041) is provided on the outer wall surface of the shaft sleeve (304); The roller support frame (305) is provided with a centering roller (310) and an eccentric roller (311), and the centering roller (310) and the eccentric roller (311) are both connected to the matching portion (3041) in a matching manner; The circumferential support plate (306) is fixedly connected to the roller support frame (305); The circumferential drive motor (307) is connected to the eccentric position of the circumferential support plate (306) via a circumferential motor mounting frame (312), and the input end of the circumferential drive motor (307) is transmission-connected to the circumferential driving gear (308); The circumferential driving gear (308) is meshingly connected with the circumferential driven gear (309); The circumferential driven gear (309) is fixedly connected to the shaft sleeve (304) via a second fastener (314); The shaft sleeve (304), the roller support frame (305), the circumferential driven gear (309), the circumferential support plate (306), and the circumferential positioning seat (301) are coaxially arranged.

6. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 5, characterized in that: The axial motion mechanism (4) comprises an axial drive motor (401), an axial driving gear (402), a first shaft (403), a first shaft driving wheel (404), a first shaft bevel gear (405), a second shaft (406), a second shaft bevel gear (407), a second shaft driving wheel (408), a third shaft (409), a third shaft driven wheel (410), a third shaft driving wheel (411), a fourth shaft (412), a fourth shaft gear (413), a rack rod (414) and a transmission shaft positioning support frame (415); The axial drive motor (401) is connected to the circumferential support plate (306) via an axial motor mounting frame (416), and the axial driving gear (402) is fixedly connected to the output end of the axial drive motor (401); The first shaft (403) is provided with a first shaft driving wheel (404) and a first shaft bevel gear (405), and the first shaft driving wheel (404) is meshingly connected with the axial driving gear (402); The second shaft bevel gear (407) and the second shaft driving wheel (408) are installed on the second shaft (406), and the second shaft bevel gear (407) is meshingly connected with the first shaft bevel gear (405); The third shaft driven wheel (410) and the third shaft driving wheel (411) are installed on the third shaft (409), and the third shaft driven wheel (410) is meshingly connected with the second shaft driving wheel (408); The fourth shaft gear (413) is installed on the fourth shaft (412), and the fourth shaft gear (413) is meshedly connected with the third shaft driving wheel (411) and the rack rod (414); The first shaft (403), the second shaft (406), and the third shaft (409) are all connected to the transmission shaft positioning support frame (415).

7. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 6, characterized in that: The circumferential support plate (306) is provided with a first connecting hole (3061), the circumferential driven gear (309) is provided with a second connecting hole (3091), the shaft sleeve (304) is provided with a third connecting hole (3042), and the circumferential positioning seat (301) is provided with a fourth connecting hole (3011); The first connecting hole (3061), the second connecting hole (3091), the third connecting hole (3042), and the fourth connecting hole (3011) are coaxially arranged and are sequentially connected along the height direction of the circumferential positioning seat (301); the first connecting hole (3061), the second connecting hole (3091), the third connecting hole (3042), and the fourth connecting hole (3011) are commonly used for the rack rod (414) to pass through.

8. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 6, characterized in that: The detection mechanism (2) comprises an upper centering shaft (21), a first steel ball bushing (22), a connecting sleeve (23), a probe support shaft (24), a probe wedge (25) and a probe (26); The upper centering shaft (21) is connected to the bottom of the rack rod (414); The first steel ball bushing (22) is sleeved on the outer side of the upper centering shaft (21); The probe support shaft (24) is fixed to the bottom of the upper centering shaft (21) through the connecting sleeve (23); The probe wedge (25) is mounted on the probe support shaft (24); The probe (26) is mounted on the probe wedge (25).

9. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 8, characterized in that: The detection mechanism (2) also includes a cable pressing block (27), a lower centering shaft (28) and a second steel ball bushing (29); The cable clamping block (27) is mounted on the probe wedge block (25) and is used to fix the cable of the probe (26); The lower centering shaft (28) is connected to the bottom of the probe support shaft (24); The second steel ball bushing (29) is sleeved on the outside of the lower centering shaft (28).

10. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 6, characterized in that: The reactor pressure vessel main bolt ultrasonic inspection device further comprises a limiting mechanism (6), wherein the limiting mechanism (6) comprises a steel ball bushing fixing shaft (61), a third steel ball bushing (62), a fourth steel ball bushing (63), an upper stopper (64) and a lower stopper (65); The steel ball bushing fixing shaft (61) is provided with a central through hole for the rack rod (414) to pass through; The third steel ball bushing (62) is arranged above the central through hole, and the third steel ball bushing (62) is connected to the steel ball bushing fixed shaft (61) through the upper stopper (64), and the lower end surface of the upper stopper (64) is connected to the upper end surface of the steel ball bushing fixed shaft (61); The fourth steel ball bushing (63) is arranged below the central through hole, and the fourth steel ball bushing (63) is connected to the steel ball bushing fixed shaft (61) through the lower stop block (65), the upper end surface of the lower stop block (65) is connected to the lower end surface of the steel ball bushing fixed shaft (61), and the lower end surface of the lower stop block (65) is connected to the circumferential support plate (306).

11. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 10, characterized in that: The limiting mechanism (6) further comprises a housing (66) and a limiting support plate (67), and the upper end surface of the upper stopper (64) is connected to the limiting support plate (67); The position-limiting support plate (67) is connected to the upper end surface of the outer shell (66), and the lower end surface of the outer shell (66) is connected to the circumferential support disk (306).

12. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 11, characterized in that: The limiting mechanism (6) further comprises a pressing roller support (68), a pressing roller (69) and a pressing roller shaft (601); The pressing roller support (68) is mounted on the steel ball bushing fixed shaft (61), and the pressing roller (69) is fixed on the pressing roller support (68) via the pressing roller shaft (601).

13. The main bolt ultrasonic inspection device for a reactor pressure vessel according to claim 11, characterized in that: The limiting mechanism (6) further comprises a magnetic proximity switch (602); The rack rod (414) is provided with a magnet (416), the magnetic proximity switch (602) is installed on the steel ball bushing fixed shaft (61), and the magnetic proximity switch (602) is used to sense the position of the magnet (416).

14. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 11, characterized in that: The reactor pressure vessel main bolt ultrasonic inspection device further comprises an electric control mechanism (7), wherein the electric control mechanism (7) comprises an electric control slip ring fixing shaft (71), an electric control slip ring (72), an electric control joint (73), an electric control slip ring cover (74) and a slip ring fixing plate (75); The mover end of the electric control slip ring (72) is connected to the position limiting support plate (67) via the electric control slip ring fixing shaft (71); The electric control slip ring cover (74) is connected to the stator end of the electric control slip ring (72); The electric control connector (73) is connected to the electric control slip ring cover (74); Two ends of the slip ring fixing plate (75) are respectively connected to the electric control slip ring cover (74) and the circumferential positioning seat (301).

15. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 14, characterized in that: The electric control slip ring cover (74) is provided with a connecting hole for the rack rod (414) to pass through, and the electric control mechanism (7) also includes a steel ball bushing fixing sleeve (701) installed in the connecting hole and a fifth steel ball bushing (702) installed in the steel ball bushing fixing sleeve (701).

16. The reactor pressure vessel main bolt ultrasonic inspection device according to claim 14, characterized in that: The electric control mechanism (7) further comprises a signal slip ring (76), a signal slip ring cover (77), an ultrasonic joint mounting plate (78) and an ultrasonic joint (79); The movable end of the signal slip ring (76) is connected to the upper end of the rack rod (414); The signal slip ring cover (77) is connected to the stator end of the signal slip ring (76); The ultrasonic joint mounting plate (78) is mounted on the signal slip ring cover (77); The ultrasonic joint (79) is mounted on the ultrasonic joint mounting plate (78).

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