Bolt stretching device

Abstract

A bolt stretching device relates to the technical field of stretching tools and comprises a supporting sleeve, a stretching connecting assembly and a stretching force application assembly. The stretching connecting assembly is installed on the supporting sleeve and is coaxial with the supporting sleeve, the lower end of the stretching connecting assembly extends into the supporting sleeve and is used for being detachably connected with the stretching bolt, and the upper end of the stretching connecting assembly is located on the outer side of the supporting sleeve; the stretching force application assembly is arranged between the supporting sleeve and the stretching connecting assembly, the stress end of the stretching force application assembly is located on the outer side of the stretching connecting assembly in the axial direction of the supporting sleeve, and the force application end of the stretching force application assembly abuts against the supporting sleeve in the axial direction of the supporting sleeve. The stretching force application assembly is used for driving the stretching connection assembly to reciprocate in the axial direction. A mechanical structure is adopted to replace a traditional hydraulic bolt stretching mode, the clamping force can be accurately controlled, the discreteness of the clamping force is reduced, the cost is reduced, and the reliability is improved.

Description

Technical Field

[0001] This utility model relates to the field of tensioning tool technology, and in particular to a bolt tensioning device. Background Technology

[0002] In current medium-speed diesel engines, especially those with a cylinder diameter greater than 230mm, large bolts and nuts are often used for connection. During the assembly and disassembly process, due to the small installation space, it is often difficult to tighten and disassemble.

[0003] Initially, ordinary wrenches were used to tighten bolts and nuts. Bolts and nuts tightened using ordinary tightening torque methods could only achieve 50% accuracy in clamping force control. However, bolts and nuts tightened using a combination of tightening torque and rotation could achieve 30% accuracy in clamping force control. Later, in order to precisely control the clamping force, cylinder head bolts and main bearing bolts generally used hydraulic stretching tools. Compared with ordinary tools, hydraulic stretching tools can precisely control the clamping force, and the clamping dispersion can be within 20%.

[0004] Hydraulic stretching tools are tools that use liquid pressure to load, unload, and tighten bolts of various specifications. They employ hydraulic cylinders and achieve bolt stretching by injecting pressurized liquid. Because they are not affected by the friction force when tightening bolts, the clamping force after hydraulic stretching can be kept within 20%.

[0005] However, hydraulic bolt tensioners are expensive, accounting for about 1.3% of the total cost of a diesel engine. As a tool that is rarely used after a diesel engine leaves the factory, this proportion of cost is too high. Moreover, after being in the vehicle for a long time, its hydraulic system is prone to aging and oil leakage, resulting in low reliability. Utility Model Content

[0006] In view of this, the technical problem to be solved by this utility model is to provide a bolt tensioning device that uses a mechanical structure to replace the traditional hydraulic bolt tensioning method, which can accurately control the clamping force, reduce the dispersion of the clamping force, reduce costs, and improve reliability.

[0007] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0008] A bolt tensioning device includes a support sleeve, a tensioning connection assembly, and a tensioning force application assembly;

[0009] The tension connection assembly is installed on the support sleeve and is coaxial with it. The lower end of the tension connection assembly extends into the interior of the support sleeve for detachable connection with the tension bolt, and the upper end of the tension connection assembly is located on the outside of the support sleeve.

[0010] The tensioning force application component is disposed between the support sleeve and the tensioning connection component. The force-receiving end of the tensioning force application component is located outside the tensioning connection component along the axial direction of the support sleeve, and the force-applying end of the tensioning force application component abuts against the support sleeve along the axial direction of the support sleeve. The tensioning force application component is used to drive the tensioning connection component to reciprocate along its axial direction.

[0011] Preferably, the tension connection assembly includes a tensioning disc located outside the support sleeve, and the force-receiving end of the tensioning force application assembly is located outside the tensioning disc.

[0012] Preferably, the tensioning force application component includes a pressure-bearing pad, a height-fixing lever, and several tensioning screws;

[0013] The pressure-bearing pad has a ring structure and is coaxially disposed between the height-fixing lever and the support sleeve.

[0014] The height-fixing lever has a ring structure and is coaxially arranged with the pressure-bearing pad. The height-fixing lever is disposed between the pressure-bearing pad and the tensioning plate. The height-fixing lever has several accommodating through holes, and the pressure-bearing pad has several pressure-bearing protrusions.

[0015] Several tensioning screws are equidistantly arranged around the axis of the pressure bearing plate. The tensioning screws pass through the tensioning plate and their bottom ends pass through the receiving through hole and abut against the pressure bearing boss. The top ends of the tensioning screws are located on the outside of the tensioning plate.

[0016] Preferably, the number and position of the tensioning screw, the receiving through hole, and the pressure-bearing boss are in one-to-one correspondence;

[0017] The pressure-bearing boss is located inside the receiving through hole; or, the pressure-bearing boss is separated from the receiving through hole, and the height-fixing lever is located on the pressure-bearing boss.

[0018] Preferably, the tensioning disc has a plurality of scale lines, and the height-fixing lever has a plurality of indicator notches that are adapted to the scale lines. The number and position of the indicator notches, the scale lines, and the pressure-bearing protrusions are all in one-to-one correspondence.

[0019] The scale line group includes an initial scale line, and when the indicator notch is aligned with the initial scale line, the pressure-bearing boss is located in the hole of the receiving through hole.

[0020] Preferably, the scale line group includes a limit scale line, the indicator notch is located between the initial scale line and the limit scale line, or, when the indicator notch is aligned with the limit scale line, the height-fixing lever is located on the pressure-bearing protrusion.

[0021] Preferably, the pressure-bearing boss has a screw pressure-bearing groove recessed on its surface, and the tensioning screw abuts against the bottom of the screw pressure-bearing groove.

[0022] Preferably, the pressure-bearing boss is provided with a guide slope, and the guide slope is located on the side away from the screw pressure groove along the circumference of the pressure-bearing pad;

[0023] The guide ramp is inclined from the surface of the pressure pad to the side near the screw pressure groove.

[0024] Preferably, the tension connection assembly further includes a tension arm and an adjusting nut;

[0025] The lower end of the tension arm extends into the interior of the support sleeve for detachable connection with the tension bolt, and the upper end of the tension arm extends out of the tensioning disc and is located outside it.

[0026] The adjusting nut is located outside the tensioning disc and is threadedly connected to the tension arm.

[0027] Preferably, it also includes a lever, and the support sleeve has a relief hole arranged radially thereon, the lever being used to move the tension nut by passing through the relief hole.

[0028] After adopting the above technical solution, the beneficial effects of this utility model are:

[0029] The bolt tensioning device of this application includes a support sleeve, a tensioning connection assembly, and a tensioning force application assembly; wherein, the support sleeve is used to be sleeved on the outside of the tensioning bolt, and when the tensioning bolt is tensioned in this application, the bottom end of the support sleeve is supported on the support surface.

[0030] The tension connection assembly is installed on and coaxially with the support sleeve. The lower end of the tension connection assembly extends into the support sleeve for detachable connection with the tension bolt, while the upper end is located on the outside of the support sleeve. A tensioning force-applying assembly is positioned between the support sleeve and the tension connection assembly. The force-receiving end of the tensioning force-applying assembly is located on the outside of the tension connection assembly, while the force-applying end abuts against the support sleeve. The tensioning force-applying assembly drives the tension connection assembly to reciprocate along its axial direction. When tensioning the bolt, the lower end of the tension connection assembly is first connected to the bolt. Then, the tensioning force-applying assembly drives the tension connection assembly to move upwards along its axial direction, causing the top of the bolt to move upwards as well, thus stretching it. Once stretched, the tension nut installed on it separates from the support surface, making it easy to unscrew and remove the bolt or to re-attach it to the support surface, fulfilling the requirements for installing or removing the tension nut. Compared to the traditional method of hydraulically tensioning bolts, this method can precisely control the clamping force, reducing the dispersion of clamping force. At the same time, the mechanical structure has low cost, no aging or oil leakage, and improved reliability. Attached Figure Description

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] Figure 1 This is a schematic diagram of the bolt tensioning device according to an embodiment of the present invention;

[0033] Figure 2 This is an exploded view of the bolt tensioning device according to an embodiment of this utility model;

[0034] Figure 3 yes Figure 2 Schematic diagram of the structure of the intermediate pressure bearing pad and the height fixing lever;

[0035] Figure 4 This is a schematic diagram of the structure of the bolt tensioning device of this utility model when applied to cylinder head nuts;

[0036] Figure 5 This is a schematic diagram showing the state of the bolt when the tension screw is tightened to stretch it.

[0037] Figure 6 yes Figure 5 A sectional view;

[0038] Figure 7 yes Figure 5 A schematic diagram showing the positions of the center height adjustment lever relative to the pressure-bearing boss and tensioning screw before it is moved.

[0039] Figure 8 yes Figure 7 A schematic diagram showing the positions of the center height adjustment lever, the pressure-bearing boss, and the tensioning screw after the lever is moved.

[0040] Figure 9 yes Figure 6 A schematic diagram showing the state of the tensioning screw when it is reverse-tightened to release the bolt.

[0041] Figure 10 yes Figure 9 A schematic diagram showing the state of the middle nut after it has been moved.

[0042] In the picture:

[0043] 1. Support sleeve; 11. Clearance hole;

[0044] 2. Tension connection assembly; 21. Tensioning disc; 22. Scale line group; 221. Initial scale line; 222. Limit scale line; 23. Tension arm; 24. Adjusting nut;

[0045] 3. Tensioning component; 31. Pressure bearing pad; 311. Pressure bearing boss; 312. Screw pressure bearing groove; 313. Guide slope; 32. Height setting lever; 321. Receiving through hole; 322. Indicating notch; 33. Tensioning screw;

[0046] 4. Lever;

[0047] 5. Tension bolts;

[0048] 6. Tension nut. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0050] like Figure 1 and Figure 2 As shown in the figure, the present invention includes a support sleeve 1, a tension connection assembly 2, and a tension force application assembly 3; wherein, the support sleeve 1 is used to be sleeved on the outside of the tension bolt 5, and when the tension bolt 5 is tensioned in this application, the bottom end of the support sleeve 1 is supported on the support surface.

[0051] The tension connection assembly 2 is installed on the support sleeve 1 and is coaxial with it. The lower end of the tension connection assembly 2 extends into the interior of the support sleeve 1 for detachable connection with the tension bolt 5. The upper end of the tension connection assembly 2 is located on the outside of the support sleeve 1. The tension force application assembly 3 is disposed between the support sleeve 1 and the tension connection assembly 2. The force-receiving end of the tension force application assembly 3 is located on the outside of the tension connection assembly 2 along the axial direction of the support sleeve 1. The force-applying end of the tension force application assembly 3 abuts against the support sleeve 1 along the axial direction of the support sleeve 1. The tension force application assembly 3 is used to drive the tension connection assembly 2 to reciprocate along its axial direction.

[0052] When tension bolt 5 needs to be stretched, the lower end of tension connecting assembly 2 must first be connected to tension bolt 5. Then, tension force application assembly 3 drives tension connecting assembly 2 to move upward along its axis, causing the top end of tension bolt 5 to move upward as well, thus stretching it. After stretching, tension nut 6 installed on it will separate from the support surface, making it easy to screw tension nut 6 to disassemble it or further abut against the support surface, meeting the needs of installing or disassembling tension nut. Compared with the traditional hydraulic tensioning method for tension bolt 5, it can precisely control the clamping force, reduce the dispersion of clamping force, and at the same time, the mechanical structure has low cost, no aging and oil leakage, and improves reliability.

[0053] In this application, the tension connection assembly 2 includes a tensioning disc 21, which is located outside the support sleeve 1, and the force-receiving end of the tensioning force application assembly 3 is located outside the tensioning disc 21.

[0054] like Figures 1 to 3 As shown, the tensioning component 3 includes a pressure-bearing pad 31, a height-fixing lever 32, and several tensioning screws 33. Among them,

[0055] The pressure pad 31 has a ring structure and is coaxially arranged between the height fixing plate 32 and the support sleeve 1. The height fixing plate 32 has a ring structure and is coaxially arranged with the pressure pad 31. The height fixing plate 32 is arranged between the pressure pad 31 and the tensioning plate 21. The height fixing plate 32 has several receiving through holes 321. The pressure pad 31 has several pressure-bearing bosses 311 protruding. Several tensioning screws 33 are equidistantly arranged around the axis of the pressure pad 31. The tensioning screws 33 pass through the tensioning plate 21 and their bottom ends pass through the receiving through holes 321 and abut against the pressure-bearing bosses 311. The top ends of the tensioning screws 33 are located on the outside of the tensioning plate 21.

[0056] The tensioning screw 33 and the tensioning disc 21 are connected by a thread. When the tensioning screw 33 is tightened, the tensioning disc 21 can be separated from the height-fixing lever 32. At this time, the height-fixing lever 32 can be moved to rotate around its axis. However, it should be noted that the tensioning screw 33 is always in contact with the bearing boss 311. That is to say, although the height-fixing lever 32 can be moved, its rotation distance is limited by the tensioning screw 33. After the height-fixing lever 32 is moved, it is located on the platform of the bearing boss 311, defining the platform of the bearing boss 311 as the main support surface. At this time, the height-fixing lever 32 is located between the bearing boss 311 and the tensioning disc 21, filling the gap between the two.

[0057] Preferably, the number and position of the tensioning screw 33, the receiving through hole 321, and the pressure bearing boss 311 are in a one-to-one correspondence; for this application, the number of tensioning screws 33, receiving through holes 321, and pressure bearing boss 311 are all six.

[0058] The pressure-bearing boss 311 is located inside the receiving through hole 321; or, the pressure-bearing boss 311 is separated from the receiving through hole 321, and the height-fixing plate 32 is located on the pressure-bearing boss 311. The thickness of the height-fixing plate 32 is not greater than the height of the pressure-bearing boss 311, so that the pressure-bearing boss 311 can be received inside the receiving through hole 321.

[0059] Whether the pressure-bearing boss 311 is located within the receiving through hole 321 is determined by moving the height-fixing lever 32.

[0060] To improve the installation and actuation accuracy of the height-fixing lever 32, the tensioning disc 21 is provided with several scale line groups 22, and the height-fixing lever 32 is provided with several indicator notches 322 that are adapted to the scale line groups 22. The number and position of the indicator notches 322, the scale line groups 22 and the pressure-bearing bosses 311 are all in one-to-one correspondence. The scale line group 22 includes an initial scale line 221. When the indicator notches 322 are aligned with the initial scale line 221, the pressure-bearing bosses 311 are located in the hole that accommodates the through hole 321.

[0061] The scale line group 22 includes a limit scale line 222. The indicator notch 322 is located between the initial scale line 221 and the limit scale line 222. Alternatively, when the indicator notch 322 is aligned with the limit scale line 222, the height setting lever 32 is located on the pressure-bearing boss 311.

[0062] When the indicator notch 322 is aligned with the limit scale line 222, it indicates that the height setting lever 32 has been moved to the limit position. The limit position here is a position that is close to but does not abut against the tensioning screw 33, so as to prevent the stability and support strength of the tensioning screw 33 from being affected after the height setting lever 32 is moved.

[0063] The pressure-bearing boss 311 has a recessed screw bearing groove 312 on its surface, and the tensioning screw 33 abuts against the bottom of the screw bearing groove 312. That is, the screw bearing surface of the tensioning screw 33 with respect to the pressure-bearing boss 311 and the main bearing surface of the height-fixing lever 32 with respect to the pressure-bearing boss 311 are not in the same plane, which prevents damage to the screw bearing surface after repeated use and extends the service life.

[0064] To facilitate the movement of the height-fixing lever 32 from the pressure-bearing pad 31 to the pressure-bearing boss 311, a guide slope 313 is provided on the pressure-bearing boss 311. The guide slope 313 is located circumferentially around the pressure-bearing pad 31 on the side away from the screw pressure groove 312. The guide slope 313 is inclined from the surface of the pressure-bearing pad 31 to the side closer to the screw pressure groove 312. In other words, the guide slope 313 and the screw pressure groove 312 are located on opposite sides of the pressure-bearing boss 311, increasing the support area of ​​the main pressure-bearing surface and enhancing the support stability.

[0065] The tension connection assembly 2 also includes a tension arm 23 and an adjusting nut 24. The lower end of the tension arm 23 extends into the support sleeve 1 for detachable connection with the tension bolt 5, and the upper end of the tension arm 23 extends outward from the tensioning disc 21. The adjusting nut 24 is located outside the tensioning disc 21 and is threadedly connected to the tension arm 23. The bottom end of the tension arm 23 has a threaded bolt hole for connecting the tension bolt. Multiple tension arms 23 can be prepared, each with a different sized bolt hole. By replacing the tension arm 23, tension bolts of different sizes can be tensioned.

[0066] This application also includes a lever 4. The support sleeve 1 has a radially arranged clearance hole 11. The lever 4 is used to pass through the clearance hole 11 to move the tension nut 6. The tension nut 6 is a round nut with a hole in its side wall, and the lever 4 can directly enter the hole in its side wall to move it.

[0067] Based on the above-mentioned technical features, the working principle of this application is described below.

[0068] like Figures 4 to 10 As shown in the diagram, this application is an improvement for the installation, removal, and tightening of cylinder head bolts and main bearing bolts. The bolt tensioning device of this application includes three steps in use: tensioning, height setting, and turning.

[0069] Tensioning refers to the process whereby, after placing the bolt tensioning device of this application on the support surface, the bottom end of the tension arm 23 needs to be connected to the tension bolt. After the connection is completed, its position is fixed by adjusting the nut 24. The adjusting nut 24 is required to abut against the tensioning plate 21, and the tensioning plate 21 presses the height setting plate 32 and the pressure bearing plate 31. At this time, the pressure bearing boss 311 is located in the receiving through hole, and the tensioning screw 33 abuts against the bottom of the screw pressure bearing groove 312.

[0070] Then, using external tools such as wrenches, the tensioning screws 33 are tightened clockwise or counterclockwise. This can be done by tightening adjacent tensioning screws 33 sequentially or symmetrically. In this application, clockwise tightening is used sequentially. Tightening the tensioning screws 33 moves the tensioning disc 21 upwards. During this upward movement, the adjusting nut 24 lifts the tension arm 23, causing the top of the tension bolt to move upwards and stretch its body. At this time, the tension nut 6 moves upwards along with it, creating a distance h1 between it and the support surface. Due to the influence of the hardness or material of the tension bolt, the distance between the tensioning disc 21 and the bearing boss 311 is approximately h1, which is greater than the thickness of the height-fixing lever 32.

[0071] "Height setting" means that after the tension bolt is stretched, the height setting lever 32 is moved to separate the pressure-bearing boss 311 from the receiving through hole 321, so that the height setting lever 32 is located between the pressure-bearing boss 311 and the tensioning plate 21.

[0072] Then, the tensioning screw 33 is turned in the opposite direction, causing the tensioning disc 21 to move downwards until it abuts against the height-fixing plate 32. At this time, the height-fixing plate 32 is clamped between the tensioning disc 21 and the bearing boss 311. At this time, the thickness of the height-fixing plate 32 is equal to the distance h2 between the tension nut 6 and the support surface. The thickness of the height-fixing plate 32 determines the distance h2 between the tension nut 6 and the support surface. By replacing the height-fixing plate 32 with one of different thicknesses, the distance h2 between the tension nut 6 and the support surface can be changed.

[0073] "Turning" refers to moving the tension nut 6. After the set height is achieved, there is a gap h2 between the tension nut 6 and the support surface. At this time, it does not contact the support surface, making it easy to install, remove, or tighten. Insert the lever 4 into the side opening of the tension nut 6 and move the lever 4 to rotate the tension nut 6.

[0074] Finally, completely loosen the tension screw 33, and the tension arm 23 is in a relaxed state, allowing the bolt tensioning device of this application to be freely removed.

[0075] Compared with conventional hydraulic bolt tensioners, the bolt tensioning device of this application has at least the following advantages:

[0076] 1. Precise control: The bolt clamping force is converted into bolt elongation, and the clamping force dispersion can be controlled within 12%. Furthermore, with the improvement of machining accuracy, there is still room for improvement in dispersion.

[0077] 2. Low cost: Compared to hydraulic bolt tensioners, it does not require a hydraulic pump, thus reducing costs.

[0078] 3. High reliability: This application adopts a purely mechanical structure, which is not affected by hydraulic system leakage, aging of seals, etc., compared with the requirement of hydraulic system. It is easy to store and has higher reliability.

[0079] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A bolt tensioning device, characterized in that The device comprises a supporting sleeve (1), a stretching connecting assembly (2) and a stretching force applying assembly (3); The stretching connecting assembly (2) is mounted on the supporting sleeve (1) and arranged coaxially with the supporting sleeve (1), the lower end of the stretching connecting assembly (2) extends into the inside of the supporting sleeve (1) for detachable connection with a stretching bolt (5), and the upper end of the stretching connecting assembly (2) is located outside the supporting sleeve (1); The stretching force applying assembly (3) is arranged between the supporting sleeve (1) and the stretching connecting assembly (2), the force receiving end of the stretching force applying assembly (3) is located outside the stretching connecting assembly (2) along the axial direction of the supporting sleeve (1), and the force applying end of the stretching force applying assembly (3) abuts against the supporting sleeve (1) along the axial direction of the supporting sleeve (1), and the stretching force applying assembly (3) is used for driving the stretching connecting assembly (2) to reciprocate along the axial direction thereof.

2. The bolt tensioning apparatus of claim 1, wherein, The stretching connecting assembly (2) comprises a tensioning disc (21), the tensioning disc (21) is located outside the supporting sleeve (1), and the force receiving end of the stretching force applying assembly (3) is located outside the tensioning disc (21).

3. The bolt tensioning apparatus of claim 2, wherein, The stretching force applying assembly (3) comprises a pressure receiving disc (31), a height fixing piece (32) and a plurality of tensioning screws (33); The pressure receiving disc (31) is annular in structure and arranged coaxially between the height fixing piece (32) and the supporting sleeve (1); The height fixing piece (32) is annular in structure and arranged coaxially with the pressure receiving disc (31), the height fixing piece (32) is arranged between the pressure receiving disc (31) and the tensioning disc (21), a plurality of accommodating through holes (321) are formed in the height fixing piece (32), and a plurality of pressure receiving bosses (311) are protruded on the pressure receiving disc (31); The plurality of tensioning screws (33) are equidistantly arranged around the axis of the pressure receiving disc (31), the tensioning screws (33) penetrate the tensioning disc (21) and the bottom ends thereof pass through the accommodating through holes (321) and abut against the pressure receiving bosses (311), and the top ends of the tensioning screws (33) are located outside the tensioning disc (21).

4. The bolt tensioning apparatus of claim 3, wherein, The number and position of the tensioning screws (33), the accommodating through holes (321) and the pressure receiving bosses (311) are one-to-one corresponding; The pressure receiving bosses (311) are located in the accommodating through holes (321), or the pressure receiving bosses (311) are separated from the accommodating through holes (321), and the height fixing piece (32) is located on the pressure receiving bosses (311).

5. The bolt tensioning apparatus of claim 4, wherein, A plurality of scale line groups (22) are formed in the tensioning disc (21), a plurality of indication notches (322) are formed in the height fixing piece (32) and matched with the scale line groups (22), and the number and position of the indication notches (322), the scale line groups (22) and the pressure receiving bosses (311) are one-to-one corresponding. The scale line group (22) comprises an initial scale line (221), and the pressure bearing boss (311) is located in the hole of the containing through hole (321) when the indicating gap (322) is aligned with the initial scale line (221).

6. The bolt tensioning apparatus of claim 5, wherein, The scale line group (22) comprises a limit scale line (222), and the indicating gap (322) is located between the initial scale line (221) and the limit scale line (222), or the fixed height paddle (32) is located on the pressure bearing boss (311) when the indicating gap (322) is aligned with the limit scale line (222).

7. The bolt tensioning apparatus of claim 3, wherein, The screw pressure bearing groove (312) is recessed on the surface of the pressure bearing boss (311), and the tension screw (33) abuts against the groove bottom of the screw pressure bearing groove (312).

8. The bolt tensioning apparatus of claim 7, wherein, The pressure bearing boss (311) is provided with a guide inclined surface (313), which is arranged on the side away from the screw pressure bearing groove (312) along the circumference of the pressure bearing disc (31). The guide inclined surface (313) is inclined from the disc surface of the pressure bearing disc (31) to the side close to the screw pressure bearing groove (312).

9. The bolt tensioning apparatus of claim 2, wherein, The tension connecting assembly (2) further comprises a tension arm (23) and an adjusting nut (24). The lower end of the tension arm (23) extends into the inside of the support sleeve (1) for detachable connection with the tension bolt (5), and the upper end of the tension arm (23) extends out of the tension disc (21) and is located on the outside thereof. The adjusting nut (24) is located on the outside of the tension disc (21) and is threadedly connected with the tension arm (23).

10. The bolt tensioning apparatus of claim 1, wherein, The tension connecting assembly (2) further comprises a tension arm (23) and an adjusting nut (24). The support sleeve (1) is provided with an avoiding dial hole (11) arranged along the radial direction thereof, and the dial rod (4) is used for dialing the tension nut (6) through the avoiding dial hole (11).

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