Automatic-meshing nut protection device for reactor bolt stretcher

Abstract

The invention discloses an automatic meshing nut protection device for a reactor bolt stretcher, relates to the technical field of bolt stretching, and provides the technical scheme of the automatic meshing nut protection device for the reactor bolt stretcher. The nut protection device comprises a supporting seat, a shifting mechanism, a fixing seat, a hydraulic cylinder and a stretching head, the fixing seat is clamped with the supporting seat, the hydraulic cylinder is slidably connected with the fixing seat, the stretching head is in transmission connection with the hydraulic cylinder, the shifting mechanism is rotatably connected with the supporting seat, the nut is sleeved with the shifting mechanism, and the shifting mechanism can prevent the bolt and the nut from generating eccentricity. Therefore, the bolt and the nut are protected.

Description

Technical Field

[0001] The invention relates to the technical field of bolt tensioning, in particular to an automatically engaged nut protection device for a reactor bolt tensioning machine. Background Art

[0002] In the manufacturing of nuclear reactors, large pressure vessels, and heavy equipment, high-strength bolt connections are crucial for ensuring structural sealing and load-bearing safety. Bolt tensioners, crucial for achieving precise bolt pre-tightening, have a direct impact on the reliability and lifespan of the connection. Traditional bolt tensioners apply axial tension to the bolts via a hydraulically driven tensioning head. After reaching a predetermined elongation, the nut is tightened, generating a uniform pre-tightening force.

[0003] During the stretching process, if the axis of the bolt and nut deviates from the direction of force applied by the stretcher, a lateral force component will be generated, leading to localized stress concentration on the threads. This can accelerate wear at best, or even cause bolt breakage at worst. Traditional devices lack real-time detection and dynamic adjustment capabilities, relying solely on manual adjustment. This makes it difficult to avoid eccentricity caused by uneven workpiece surfaces or installation errors.

[0004] Furthermore, the flange or base surface of the workpiece is often uneven, and the support base of a traditional tensile machine is in rigid contact with the workpiece, unable to adaptively compensate for local depressions or protrusions. This can cause the tensile machine to tilt as a whole, causing the force axis to deviate from the bolt axis, further exacerbating the eccentricity problem, affecting the uniformity of the preload force, and even threatening the sealing of the equipment.

[0005] To address the above issues, the industry urgently needs a nut protection device with automatic detection, dynamic adjustment and high wear resistance to improve the accuracy, safety and efficiency of bolt tensioning operations. Summary of the Invention

[0006] The object of the present invention is to provide a nut protection device which can automatically engage for a reactor bolt tensioning machine, so as to solve the problems raised in the prior art.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: The present invention provides a technical solution of an automatically engageable nut protection device for a reactor bolt tensioner, the nut protection device being used to protect bolts and nuts, the nut protection device comprising a support seat, a toggle mechanism, a fixed seat, a hydraulic cylinder and a stretching head, the fixed seat being clamped with the support seat, the hydraulic cylinder being slidingly connected to the fixed seat, the stretching head being transmission-connected to the hydraulic cylinder, the toggle mechanism being rotationally connected to the support seat, the toggle mechanism being sleeved on the nut, the toggle mechanism being able to prevent the bolt and nut from becoming eccentric, thereby protecting the bolt and nut.

[0008] The support seat is placed on the surface of the workpiece, the toggle mechanism is sleeved on the nut, the fixed seat is clamped on the support seat to provide an installation basis for the hydraulic cylinder, and the stretching head is installed on the hydraulic cylinder; when stretching the bolt, first tighten the stretching head onto the bolt, then start the hydraulic cylinder, and the hydraulic cylinder moves upward along the fixed seat, thereby driving the stretching head upward, applying axial tension to the bolt, and the bolt is stretched to a predetermined length. When the bolt is stretched, turn the toggle mechanism to rotate the nut to fit the surface of the workpiece to ensure that the bolt cannot rebound. Finally, the hydraulic cylinder releases the hydraulic pressure, the bolt contracts to generate a pre-tightening force, and the stretching machine is removed to complete the tightening.

[0009] Furthermore, the stretching head is provided with an internal thread and an adjustment hole, the internal thread is engaged with the bolt, and the adjustment hole is used to rotate the stretching head, thereby achieving automatic engagement of the stretching head and the bolt.

[0010] The size of the stretching head matches the bolt. After the stretching head is inserted into the hydraulic cylinder, the stretching head can be rotated by inserting the lever into the adjustment hole. With the cooperation of the internal thread and the bolt, the stretching head will be gradually tightened onto the bolt.

[0011] Furthermore, the toggle mechanism includes an adjusting ring and a movable ring. The adjusting ring is rotatably connected to the inner wall of the support seat, and the movable ring is clamped with the nut. The movable ring and the adjusting ring can be deflected relative to each other. By detecting the deflection angle of the movable ring, it can be determined whether the nut is deflected.

[0012] The inner hole of the movable ring is hexagonal and can be snapped onto the nut. The adjusting ring can rotate freely in the support seat, so that when the bolt is stretched, the movable ring is driven to rotate, thereby tightening the nut to the workpiece; however, the surface of the workpiece will be uneven, and the support seat is close to the surface of the workpiece, which will cause the bolt stretching machine to deflect to a certain extent. If stretched directly, the axial tension direction generated by the bolt stretching machine will not be on the same axis as the axis of the bolt and nut, causing the bolt and nut to be subject to a certain deflection force, which can easily damage the bolt and nut. By detecting the deflection angle of the movable ring, it can be determined whether the axis of the nut and the axis of the bolt stretching machine are on the same axis, and then the angle of the bolt stretching machine can be adjusted through the corresponding mechanism to avoid damage during the stretching process.

[0013] Furthermore, the support seat is placed on the locking member, and an opening is provided on one side of the support seat, and the opening is used to provide a movable space for the toggle mechanism.

[0014] The opening on the support seat is used to extend the shifting rod into, thereby driving the shifting mechanism to rotate, and then driving the nut to be tightened onto the locking member.

[0015] Furthermore, an oil inlet and a pressure relief port are provided on the fixing seat, and the oil inlet and the pressure relief port are respectively connected to the hydraulic station through high-pressure oil pipes. A pressure chamber is formed between the fixing seat and the hydraulic cylinder, and the pressure chamber is connected to the oil inlet and the pressure relief port.

[0016] During stretching, the hydraulic station introduces hydraulic oil into the pressure chamber through the oil inlet, so that the hydraulic cylinder moves up along the fixed seat. After the stretching is completed, the pressure relief port opens to discharge the high-pressure oil and the hydraulic cylinder returns to its original position.

[0017] Furthermore, a sealing ring is provided between the contact surface of the fixing seat and the hydraulic cylinder.

[0018] In order to prevent leakage of hydraulic oil, a sealing ring is used to ensure the sealing between the fixed seat and the hydraulic cylinder.

[0019] Furthermore, the adjusting ring is provided with a toggle hole, an arc groove and an arc surface, the movable ring is provided with a receiving groove, and a ball is provided in the receiving groove, and the ball is respectively connected to the receiving groove and the arc surface in a rolling manner.

[0020] The toggle hole is used to insert the corresponding toggle rod, thereby driving the adjusting ring to rotate, and then driving the nut clamped by the movable ring to tighten; if there is an uneven area on the surface of the workpiece, the support seat located on the concave side of the workpiece will deflect to this side, causing the axis of the bolt tensioner and the axis of the bolt and nut to deflect. Under the action of the deflection force, the movable ring and the adjusting ring can be relatively deflected through the cooperation of the ball, the receiving groove and the arc surface, and the movable ring will deflect to one side. By detecting the deflection of the movable ring, the deflection of the bolt tensioner can be judged. The more the support seat is offset downward on the side of the concave surface of the workpiece, the greater the downward deflection angle of the adjusting ring on the corresponding side will be.

[0021] Furthermore, the toggle mechanism also includes an arc block, a connecting rod, a support spring and a tension sensor. The arc block is slidingly connected to the arc groove, one end of the connecting rod is tightly connected to the arc block, and the other end of the connecting rod is tightly connected to the movable ring. The balls are located on both sides of the connecting rod, one end of the support spring is tightly connected to the arc block, and the other end of the support spring is tightly connected to the detection end of the tension sensor, and the tension sensor is tightly connected to the inner wall of the arc groove.

[0022] As the downward deflection angle of one side of the adjusting ring increases, the distance that the arc block deflects upward in the arc groove becomes longer under the drive of the connecting rod, the support spring is stretched, and the greater the tension detected by the tension sensor; that is, the greater the tension detected by the tension sensor, the greater the distance that the support seat on this side deflects downward.

[0023] Furthermore, several adjustment mechanisms are provided in the support seat, and the positions of several adjustment mechanisms correspond to the tension sensors. Several adjustment mechanisms include a hydraulic rod and an adjustment pad. The hydraulic rod is fastened to the support seat, and the output end of the hydraulic rod is transmission-connected to the adjustment pad. The greater the tension detected by the tension sensor, the longer the hydraulic rod at the corresponding position extends.

[0024] Since the greater the tension detected by the tension sensor, the longer the distance the support seat on this side is offset downward, the hydraulic rod at the corresponding position is activated to drive the adjustment pad to extend a certain distance, thereby lifting the support seat on the concave side of the workpiece surface, so that the axis of the support seat coincides with the axis of the bolt and nut, thereby preventing the nut from being affected by lateral force during the stretching process, thereby ensuring the stretching quality.

[0025] Furthermore, the surface of the internal thread is provided with a hard alloy wear-resistant layer generated by laser cladding, and the hard alloy wear-resistant layer is made of titanium alloy.

[0026] The high strength of the carbide wear layer made of titanium alloy prevents damage to the threads on the bolt during the stretching process.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The nut deflection angle is detected in real time through the toggle mechanism (adjustment ring, movable ring). Combined with the linkage of the tension sensor and the adjustment mechanism (hydraulic rod, adjustment pad), the support seat height is automatically adjusted to ensure that the axis of the stretcher always coincides with the axis of the bolt and nut, avoiding thread wear or breakage caused by lateral force during the stretching process; the inner hole of the movable ring adopts a hexagonal design, which is precisely engaged with the nut to further reduce the risk of eccentricity.

[0029] 2. The rolling fit design of the ball and arc groove in the toggle mechanism allows the movable ring and the adjustment ring to deflect relative to each other. Combined with the tension sensor to provide real-time feedback on the support seat offset, the height of the gasket is dynamically adjusted through the hydraulic rod to compensate for depressions or protrusions on the workpiece surface, ensuring that the axis of the bolt tensioner remains aligned with the axis of the bolt and nut; significantly improving the safety, precision and efficiency of the bolt tensioning operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 It is a cross-sectional view of the support seat and the fixing seat;

[0032] Figure 3 It is a partial cross-sectional view of the present invention;

[0033] Figure 4 for Figure 3 A local enlarged view of point A;

[0034] Figure 5 It is a partial cross-sectional view of the toggle mechanism;

[0035] Figure 6 for Figure 5 A partial enlarged view of point B;

[0036] Figure 7It is a partial cross-sectional view of the support seat;

[0037] Figure 8 Schematic diagram of the operation of the adjustment mechanism.

[0038] In the figure: 1. Bolt; 2. Nut; 3. Support seat; 31. Opening; 4. Toggle mechanism; 41. Adjusting ring; 413. Arc surface; 411. Toggle hole; 412. Arc groove; 42. Movable ring; 421. Accommodating groove; 43. Ball; 44. Arc block; 45. Connecting rod; 46. Support spring; 47. Tension sensor; 5. Fixed seat; 51. Oil inlet; 52. Pressure relief port; 6. Hydraulic cylinder; 61. Pressure chamber; 7. Tensile head; 71. Internal thread; 72. Adjusting hole; 8. Sealing ring; 9. Adjusting mechanism; 91. Hydraulic rod; 92. Adjusting pad. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] Example: Figures 1-8 As shown, the present invention provides a technical solution of an automatically engaging nut protection device for a reactor bolt tensioner, wherein the nut protection device is used to protect the bolt 1 and the nut 2. The nut protection device includes a support base 3, a toggle mechanism 4, a fixed base 5, a hydraulic cylinder 6 and a stretching head 7. The fixed base 5 is clamped with the support base 3, the hydraulic cylinder 6 is slidingly connected to the fixed base 5, the stretching head 7 is transmission-connected to the hydraulic cylinder 6, the toggle mechanism 4 is rotationally connected to the support base 3, and the toggle mechanism 4 is sleeved on the nut 2. The toggle mechanism 4 can prevent the bolt 1 and the nut 2 from being eccentric, thereby protecting the bolt 1 and the nut 2.

[0041] The support seat 3 is placed on the surface of the workpiece, the toggle mechanism 4 is sleeved on the nut 2, the fixed seat 5 is clamped on the support seat 3 to provide an installation basis for the hydraulic cylinder 6, and the stretching head 7 is installed on the hydraulic cylinder 6; when stretching the bolt, first tighten the stretching head 7 to the bolt 1, then start the hydraulic cylinder 6, the hydraulic cylinder 6 moves upward along the fixed seat 5, thereby driving the stretching head 7 to move upward, applying axial tension to the bolt 1, and the bolt 1 is stretched to a predetermined length. When the bolt 1 is stretched, the toggle mechanism 4 is turned to rotate the nut to fit the surface of the workpiece to ensure that the bolt 1 cannot rebound. Finally, the hydraulic cylinder 6 releases the hydraulic pressure, the bolt 1 contracts to generate a pre-tightening force, and the stretching machine is removed to complete the tightening.

[0042] The stretching head 7 is provided with an internal thread 71 and an adjustment hole 72 . The internal thread 71 is engaged with the bolt 1 . The adjustment hole 72 is used to rotate the stretching head 7 , thereby achieving automatic engagement between the stretching head 7 and the bolt 1 .

[0043] The size of the stretching head 7 matches the bolt 1. When the stretching head 7 is inserted into the hydraulic cylinder 6, the stretching head 7 can be rotated by inserting the lever into the adjustment hole 72. With the cooperation of the internal thread 71 and the bolt 1, the stretching head 7 will be gradually tightened onto the bolt 1.

[0044] The toggle mechanism 4 includes an adjusting ring 41 and a movable ring 42. The adjusting ring 41 is rotatably connected to the inner wall of the support seat 3, and the movable ring 42 is clamped with the nut 2. The movable ring 42 and the adjusting ring 41 can deflect relative to each other. By detecting the deflection angle of the movable ring 42, it can be determined whether the nut 2 is deflected.

[0045] The inner hole of the movable ring 42 is hexagonal and can be snapped onto the nut 2. The adjusting ring 41 can rotate freely in the support seat 3, so that when the bolt 1 is stretched, the movable ring 42 is driven to rotate, thereby tightening the nut 2 to the workpiece; however, the surface of the workpiece will be uneven, and the support seat 3 is close to the surface of the workpiece, which will cause the bolt stretching machine to deflect to a certain extent. If stretched directly, the axial tension direction generated by the bolt stretching machine will not be on the same axis as the axis of the bolt 1 and nut 2, so that the bolt 1 and nut 2 are subjected to a certain deflection force, which can easily damage the bolt 1 and nut 2. By detecting the deflection angle of the movable ring 42, it can be determined whether the axis of the nut 2 and the axis of the bolt stretching machine are on the same axis, and then the angle of the bolt stretching machine can be adjusted through the corresponding mechanism to avoid damage during the stretching process.

[0046] The support base 3 is placed on the locking member. An opening 31 is provided on one side of the support base 3 . The opening 31 is used to provide a movable space for the toggle mechanism 4 .

[0047] The opening 31 on the support base 3 is used for inserting the shifting rod into, thereby driving the shifting mechanism 4 to rotate, and further driving the nut 2 to be screwed onto the locking member.

[0048] An oil inlet 51 and a pressure relief port 52 are provided on the fixing seat 5. The oil inlet 51 and the pressure relief port 52 are respectively connected to the hydraulic station through high-pressure oil pipes. A pressure chamber 61 is formed between the fixing seat 5 and the hydraulic cylinder 6. The pressure chamber 61 is connected to the oil inlet 51 and the pressure relief port 52.

[0049] During stretching, the hydraulic station introduces hydraulic oil into the pressure chamber 61 through the oil inlet 51, so that the hydraulic cylinder 6 moves up along the fixed seat 5. After the stretching is completed, the pressure relief port 52 opens to discharge the high-pressure oil, and the hydraulic cylinder 6 returns to its original position.

[0050] A sealing ring 8 is provided between the contact surface of the fixing seat 5 and the hydraulic cylinder 6 .

[0051] In order to prevent leakage of hydraulic oil, a sealing ring 8 is used to ensure the sealing between the fixing seat 5 and the hydraulic cylinder 6.

[0052] The adjusting ring 41 is provided with a toggle hole 411 , an arc groove 412 and an arc surface 413 . The movable ring 42 is provided with a receiving groove 421 . A ball 43 is arranged in the receiving groove 421 . The ball 43 is rollingly connected to the receiving groove 421 and the arc surface 413 .

[0053] The toggle hole 411 is used to insert the corresponding toggle rod, thereby driving the adjusting ring 41 to rotate, and then driving the nut 2 clamped by the movable ring 42 to tighten; if there is an uneven area on the surface of the workpiece, the support seat 3 located on the concave side of the workpiece will deflect to this side, causing the axis of the bolt tensioner to deflect from the axis of the bolt 1 and the nut 2. Under the action of the deflection force, the movable ring 42 and the adjusting ring 41 can be deflected relative to each other through the cooperation of the ball 43 with the accommodating groove 421 and the arc surface 413. The movable ring 42 will deflect to one side. By detecting the deflection of the movable ring 42, the deflection of the bolt tensioner can be judged. The more the support seat 3 is offset downward on this side of the concave surface of the workpiece, the greater the downward deflection angle of the adjusting ring 41 on the corresponding side.

[0054] The toggle mechanism 4 also includes an arc block 44, a connecting rod 45, a support spring 46 and a tension sensor 47. The arc block 44 is slidingly connected to the arc groove 412, one end of the connecting rod 45 is fastened to the arc block 44, the other end of the connecting rod 45 is fastened to the movable ring 42, the ball 43 is located on both sides of the connecting rod 45, one end of the support spring 46 is fastened to the arc block 44, the other end of the support spring 46 is fastened to the detection end of the tension sensor 47, and the tension sensor 47 is fastened to the inner wall of the arc groove 412.

[0055] As the downward deflection angle of one side of the adjustment ring 41 increases, the distance that the arc block 44 deflects upward in the arc groove 412 becomes longer under the drive of the connecting rod 45, the support spring 46 is stretched, and the greater the tension detected by the tension sensor 47; that is, the greater the tension detected by the tension sensor 47, the longer the downward deflection distance of the support seat 3 on this side.

[0056] Several adjustment mechanisms 9 are provided in the support seat 3. The positions of the several adjustment mechanisms 9 correspond to the tension sensors 47. The several adjustment mechanisms 9 include a hydraulic rod 91 and an adjustment pad 92. The hydraulic rod 91 is fastened to the support seat 3. The output end of the hydraulic rod 91 is transmission-connected to the adjustment pad 92. The greater the tension detected by the tension sensor 47, the longer the hydraulic rod 91 at the corresponding position extends.

[0057] Since the greater the tension detected by the tension sensor 47, the longer the downward displacement of the support seat 3 on this side, by starting the hydraulic rod 91 at the corresponding position, the adjustment pad 92 is driven to extend a certain distance, thereby lifting the support seat 3 located on the concave side of the workpiece surface, so that the axis of the support seat 3 coincides with the axis of the bolt 1 and the nut 2, thereby preventing the nut from being affected by the lateral force during the stretching process, thereby ensuring the stretching quality.

[0058] The surface of the internal thread 71 is provided with a hard alloy wear-resistant layer generated by laser cladding, and the hard alloy wear-resistant layer is made of titanium alloy.

[0059] The hard alloy wear-resistant layer made of titanium alloy has high strength, thereby preventing the threads on the bolt 1 from being damaged during the stretching process.

[0060] The working principle of the present invention is as follows: when there is an uneven area on the surface of the workpiece, the support seat 3 located on the concave side of the workpiece will deflect to this side, causing the axis of the bolt tensioner to deflect from the axis of the bolt 1 and the nut 2. Under the action of the deflection force, the ball 43 cooperates with the receiving groove 421 and the arc surface 413, so that the movable ring 42 and the adjusting ring 41 can be relatively deflected. The movable ring 42 will deflect to one side. By detecting the deflection of the movable ring 42, the deflection of the bolt tensioner can be determined. The support seat 3 is located on this side of the concave surface of the workpiece. The more the downward offset is, the greater the downward deflection angle of the adjustment ring 41 on the corresponding side; the longer the distance that the arc block 44 deflects upward in the arc groove 412 is driven by the connecting rod 45, the support spring 46 is stretched, and the greater the tension detected by the tension sensor 47; then the hydraulic rod 91 at the corresponding position is started to drive the adjustment pad 92 to extend a certain distance, thereby lifting the support seat 3 located on the concave side of the workpiece surface, so that the axis of the support seat 3 coincides with the axis of the bolt 1 and the nut 2, thereby preventing the nut from being affected by lateral force during the stretching process.

[0061] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A nut protection device capable of automatically engaging for use in a reactor bolt tensioning machine, the nut protection device being used to protect a bolt (1) and a nut (2), characterized in that: The nut protection device comprises a support seat (3), a toggle mechanism (4), a fixed seat (5), a hydraulic cylinder (6) and a stretching head (7); the fixed seat (5) is clamped with the support seat (3); the hydraulic cylinder (6) is slidably connected to the fixed seat (5); the stretching head (7) is transmission-connected to the hydraulic cylinder (6); the toggle mechanism (4) is rotationally connected to the support seat (3); the toggle mechanism (4) is sleeved on the nut (2); and the toggle mechanism (4) can prevent the bolt (1) and the nut (2) from being eccentric, thereby protecting the bolt (1) and the nut (2).

2. The automatically engaging nut protection device for a reactor bolt tensioner according to claim 1, characterized in that: The stretching head (7) is provided with an internal thread (71) and an adjustment hole (72), wherein the internal thread (71) is engaged with the bolt (1), and the adjustment hole (72) is used to rotate the stretching head (7), thereby achieving automatic engagement between the stretching head (7) and the bolt (1).

3. The automatically engaging nut protection device for a reactor bolt tensioner according to claim 1, characterized in that: The toggle mechanism (4) comprises an adjusting ring (41) and a movable ring (42); the adjusting ring (41) is rotatably connected to the inner wall of the support seat (3); the movable ring (42) is engaged with the nut (2); the movable ring (42) and the adjusting ring (41) can be relatively deflected, and whether the nut (2) is deflected can be determined by detecting the deflection angle of the movable ring (42).

4. The automatically engaging nut protection device for a reactor bolt tensioner according to claim 3, characterized in that: The support seat (3) is placed on the locking member, and an opening (31) is provided on one side of the support seat (3). The opening (31) is used to provide a movable space for the toggle mechanism (4).

5. The automatically engaging nut protection device for a reactor bolt tensioner according to claim 4, characterized in that: The fixing seat (5) is provided with an oil inlet (51) and a pressure relief port (52), and the oil inlet (51) and the pressure relief port (52) are respectively connected to an external hydraulic station through high-pressure oil pipes. A pressure chamber (61) is formed between the fixing seat (5) and the hydraulic cylinder (6), and the pressure chamber (61) is communicated with the oil inlet (51) and the pressure relief port (52).

6. The automatically engaging nut protection device for a reactor bolt tensioner according to claim 5, characterized in that: A sealing ring (8) is provided between the contact surface between the fixing seat (5) and the hydraulic cylinder (6).

7. The automatically engaging nut protection device for a reactor bolt tensioner according to claim 3, characterized in that: The adjusting ring (41) is provided with a toggle hole (411), an arcuate groove (412) and an arcuate surface (413); the movable ring (42) is provided with a receiving groove (421); a ball (43) is provided in the receiving groove (421); and the ball (43) is respectively connected to the receiving groove (421) and the arcuate surface (413) in a rolling manner.

8. The automatically engaging nut protection device for a reactor bolt tensioner according to claim 7, characterized in that: The toggle mechanism (4) further comprises an arc block (44), a connecting rod (45), a support spring (46) and a tension sensor (47); the arc block (44) is slidably connected to the arc groove (412); one end of the connecting rod (45) is tightly connected to the arc block (44); the other end of the connecting rod (45) is tightly connected to the movable ring (42); the balls (43) are located on both sides of the connecting rod (45); one end of the support spring (46) is tightly connected to the arc block (44); the other end of the support spring (46) is tightly connected to the detection end of the tension sensor (47); and the tension sensor (47) is tightly connected to the inner wall of the arc groove (412).

9. The automatically engaging nut protection device for a reactor bolt tensioner according to claim 8, characterized in that: A plurality of adjustment mechanisms (9) are provided in the support seat (3), and the positions of the plurality of adjustment mechanisms (9) correspond to the tension sensors (47). The plurality of adjustment mechanisms (9) include a hydraulic rod (91) and an adjustment pad (92). The hydraulic rod (91) is tightly connected to the support seat (3), and the output end of the hydraulic rod (91) is transmission-connected to the adjustment pad (92). The greater the tension detected by the tension sensor (47), the longer the hydraulic rod (91) at the corresponding position extends.

10. The automatically engaging nut protection device for a reactor bolt tensioner according to claim 2, characterized in that: The surface of the internal thread (71) is provided with a hard alloy wear-resistant layer generated by laser cladding, and the hard alloy wear-resistant layer is made of titanium alloy.

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