High-strength bolt and threaded hole machining process thereof

Abstract

The invention relates to the technical field of fasteners, in particular to a high-strength bolt and a threaded hole machining process thereof, and the high-strength bolt comprises a screw rod, a first nut, an axial restraining piece and a plurality of screws. Specifically, the first nut is in threaded connection with the screw, and a plurality of threaded holes penetrating through the upper face and the lower face of the first nut are formed in the first nut. The axial restraining piece is connected with the screw and used for being matched with the first nut to clamp an object. The screws are in threaded connection with the threaded holes in a one-to-one correspondence mode, and the ends of the screws can protrude out of the face, close to the axial restraining piece, of the first nut. The bolt connection structure has the effects of improving the bolt connection strength and reliability and widening the application range of the bolt.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of fasteners, in particular to a high-strength bolt and a thread hole machining process thereof. BACKGROUND

[0002] The bolt connection between the parts of a large machine requires reliable connection and strong pre-tightening force of the bolt. Usually, a large hammer, heating, hydraulic stretching, hydraulic wrench and other methods are required to make the pre-tightening force of the bolt connection meet the requirements and realize reliable connection of the bolt. If the space of the connection part is cramped, the large hammer, hydraulic tool and other appliances cannot be used, and the bolt connection cannot be realized. SUMMARY

[0003] In order to improve the strength and reliability of the bolt connection and improve the application range of the bolt, the application provides a high-strength bolt and a thread hole machining process thereof.

[0004] The high-strength bolt and the thread hole machining process thereof provided by the application adopt the following technical scheme: A high-strength bolt comprises: a screw rod; a first nut in threaded connection with the screw rod, a plurality of thread holes penetrating through the upper and lower surfaces of the first nut are formed in the first nut; an axial constraint member connected with the screw rod and used for clamping an object together with the first nut; a plurality of screws in threaded connection with the plurality of thread holes one by one, and the end of each screw can protrude from the surface of the first nut close to the axial constraint member.

[0005] By adopting the above technical scheme, the operation problem in a narrow space is solved, and the connection strength, anti-loosening reliability and application range are improved. Specifically, after the conventional first nut and the axial constraint member clamp an object, the screw is screwed into the thread hole and protrudes from the end of the screw and is in abutment against the connected object (or an intermediate part therebetween), so that a strong axial reaction force is generated between the first nut and the connected object. The reaction force greatly increases the friction between the first nut and the screw thread pair, and provides excellent anti-loosening performance. On the other hand, the force is equivalent to an additional stretching pre-tightening force applied to the screw rod, thereby improving the strength and reliability of the bolt connection. Moreover, since the volume of the screw is much smaller than that of the first nut, the operator only needs to use a small wrench to screw the screw in a narrow space, thereby perfectly solving the problem that large tools cannot be used, and greatly improving the application range of the bolt.

[0006] Optionally, the device further comprises a first gasket and a piston, the first gasket is sleeved on the screw rod and located between the first nut and the axial constraint; the first gasket is provided with an adsorption cavity, a piston cavity and a communication hole, the adsorption cavity is provided on the side of the first gasket facing the axial constraint, the piston cavity is provided on the side of the first gasket away from the axial constraint; the communication hole connects the adsorption cavity and the piston cavity, and the end hole of the communication hole connected with the piston cavity is located on the bottom surface of the piston cavity; the piston is slidably arranged in the piston cavity, and the side wall of the piston is in sealing sliding abutment with the inner side wall of the piston cavity; when the screw moves towards the axial constraint, the screw can drive the piston to move towards the bottom surface of the piston cavity.

[0007] By adopting the above technical scheme, when the screw is rotated to move towards the axial constraint, the screw can drive the piston to move towards the bottom surface of the piston cavity. Since the piston and the piston cavity are in sealing sliding abutment, this action can compress the gas in the piston cavity; the compressed gas is forced to be discharged into the adsorption cavity through the communication hole, and is sprayed out of the adsorption cavity facing the connected object. The high-pressure gas flow can effectively blow off the dust or impurities on the contact surface of the first gasket and the connected object. By ensuring the cleanliness of the contact surface, the stability of the friction coefficient is ensured, the loss of pre-tightening force or stress unevenness caused by impurities is avoided, and the reliability of the bolt connection is further improved.

[0008] Optionally, the side of the piston close to the first nut is provided with an annular clamping groove, the annular clamping groove extends in the circumferential direction of the rotation axis of the first nut and is connected end to end; the end of the screw close to the axial constraint is connected with a sliding block, the sliding block is slidably clamped in the annular clamping groove; when the screw moves away from the axial constraint, the screw can drive the piston to move away from the bottom surface of the piston cavity.

[0009] By adopting the above technical scheme, when the screw is rotated to move away from the axial constraint, the screw can drive the piston to move away from the bottom surface of the piston cavity. Due to the sealing property of the piston cavity, this action can increase the volume of the piston cavity, so that negative pressure is generated in the piston cavity and the adsorption cavity, so that the first gasket is firmly “adsorbed” on the surface of the connected object. When the material of the fixed object is soft and easy to deform, the vacuum adsorption effect can be used to resist the loosening of the first nut, so that the effect of anti-loosening and tightening is achieved without applying (or applying small) tightening force, the connection reliability is ensured while the vulnerable parts are protected, and the application range of the scheme is further improved. In addition, when the screw rod is accidentally broken, due to the vacuum adsorption effect of the first gasket and the connected object, the first nut, the screw and the part of the screw rod connected with the first nut can be adsorbed on the connected object, so as to prevent them from falling or flying out to hurt people and cause safety accidents.

[0010] Optionally, the piston is provided with an access groove, one end of the access groove penetrates the side wall of the annular clamping groove and communicates with the annular clamping groove, and the other end penetrates the side wall of the piston, and the sliding block can enter or exit the annular clamping groove through the access groove.

[0011] By adopting the above technical scheme, when the connecting screw and the piston are connected, the sliding block with the screw end is easily pushed into the access groove from the side wall of the first gasket, and the sliding block enters the annular clamping groove. This design avoids complex axial nesting installation in a limited space, so that the connection and separation of the screw and the piston become simple and fast, and the production and assembly efficiency and the subsequent maintenance convenience are significantly improved.

[0012] Optionally, the outer side edge and the inner side edge of the one side of the first gasket away from the first nut are each provided with a sealing ring.

[0013] By adopting the above technical scheme, when the first gasket contacts the object, the sealing ring is compressed, and two reliable sealing lines are formed. This can effectively prevent external air from leaking into the adsorption cavity from the edge, ensure that a stable negative pressure can be formed and maintained in the adsorption cavity for a long time, and make the anti-loose function of the first gasket and the connected object more reliable and durable.

[0014] Optionally, the plurality of threaded holes are arranged in a circumferential array with the rotation axis of the first nut as the central axis.

[0015] By adopting the above technical scheme, the plurality of threaded holes arranged in a circumferential array ensure that the tightening force generated by all the screws is evenly distributed on the circumference of the first nut, so that the first nut is uniformly stressed and stable in posture, thereby ensuring that the provided anti-loose and pre-tightening effects are more stable and reliable.

[0016] Optionally, the screw is an internal hexagonal flat end screw, one end of the screw away from the axial constraint member is completely accommodated in the threaded hole, and a plugging cover is threadedly connected to one end of the threaded hole away from the axial constraint member.

[0017] By adopting the above technical scheme, the internal hexagonal structure makes the contact surface between the wrench and the screw large and not easy to slip, and facilitates the application of a larger torque to generate the required reaction force for fastening; the flat end structure enables the screw to be completely hidden in the threaded hole after bolt connection, thereby improving the appearance. Furthermore, sealing the threaded hole with the plugging cover can effectively prevent external dust, moisture, oil stains or corrosive media from invading the threaded hole, thereby protecting the screw and its threaded pair. This ensures that the screw as the core anti-loose component will not rust and jam, guarantees the long-term reliability and reusability of the anti-loose function, and is particularly suitable for use in harsh industrial environments.

[0018] Optionally, the screw rod is a double-end screw rod; the axial constraint member comprises a second nut and a second washer, the second nut is threadedly connected with the screw rod, and the second washer is sleeved on the screw rod and located between the first nut and the second nut.

[0019] By adopting the above technical scheme, when one side of the connected object is narrow in space, so that the conventional screw rod with a fixed head cannot be inserted from this side, the double-end screw rod adopted in the scheme allows the operator to insert the screw rod into the threaded hole from the relatively open side of the space, so that the screw rod passes through the connected object. Then, the operator can install the second nut and the second washer as the axial constraint on the other side of the narrow space. Finally, the first nut is installed and fastened by the screw. This flexible assembly method makes the bolt connection operation no longer limited by the insertion direction of the fixed head bolt, effectively solving the installation problem in narrow space.

[0020] Optionally, the screw rod, the first nut and the second nut are all made of UNS N07718 alloy.

[0021] By adopting the above technical scheme, the use of this material can ensure that the entire bolt can withstand and transmit a large pre-tightening force, and maintain long-term mechanical properties and connection reliability under extreme working conditions such as high temperature, high pressure and strong corrosion, greatly expanding the application scenarios of the bolt.

[0022] A threaded hole machining process of a high-strength bolt as described above, comprising the following steps: S1, boring the first nut blank to process the base hole of all threaded holes; S2, rough machining the threads of the first nut; S3, replacing the new machining tool to finish the thread fine machining of the first nut; S4, using the tool after the thread fine machining of the first nut to perform thread rough machining on the next first nut; S5, repeating steps S3-S4 until the machining of all threaded holes of the first nut is completed By adopting the above technical scheme, the first nut is thread fine machined by replacing the new machining tool, which ensures that the key process determining the accuracy of the final product is always completed by the tool in the best state, and ensures that all threaded holes have highly consistent precision tolerances and surface finishes. At the same time, the tool after the thread fine machining of the first nut is used to perform thread rough machining on the next first nut, which utilizes the slightly worn tool in echelon. This process maximizes the overall service life of the expensive tool while ensuring the highest accuracy, significantly reducing production costs.

[0023] In summary, the present application includes the following beneficial technical effects: 1. The operation problem in a small space is solved, the connection strength, anti-loosening reliability and application range are improved. Specifically, after the conventional first nut and axial constraint clamp the object, the screw is screwed into the threaded hole and protrudes from the end of the screw and rests on the connected object (or the intermediate part therebetween), which generates a strong axial reaction force between the first nut and the connected object. On the one hand, the reaction force greatly increases the friction between the first nut and the screw threaded pair, providing excellent anti-loosening performance; on the other hand, the force is equivalent to applying an additional tensile pre-tightening force to the screw, thereby improving the strength and reliability of the bolt connection. Moreover, since the volume of the screw is much smaller than that of the first nut, the operator only needs to use a small wrench to rotate the screw in a narrow space, perfectly solving the problem that large tools cannot be used, and greatly improving the application range of the bolt; 2. When the screw is rotated to move towards the axial constraint, the screw will drive the piston to move towards the bottom surface of the piston chamber. Since the piston and the piston chamber are in sealed sliding abutment, this action will compress the gas in the piston chamber; the compressed gas is forced to be discharged into the adsorption chamber through the communication hole, and is sprayed out of the adsorption chamber facing the connected object. This high-pressure gas flow can effectively blow off the dust or impurities on the contact surface between the first gasket and the connected object. By ensuring the cleanliness of the contact surface, the stability of the friction coefficient is ensured, and the loss of pre-tightening force or stress unevenness caused by impurities is avoided, thereby further improving the reliability of the bolt connection; 3. When the screw is rotated to move away from the axial constraint, it can drive the piston to move away from the bottom surface of the piston chamber. Due to the sealing of the piston chamber, this action will increase the volume of the piston chamber, causing negative pressure in the piston chamber and the adsorption chamber, so that the first gasket is firmly "adsorbed" on the surface of the connected object. When the material of the connected object is soft and easily deformed, the vacuum adsorption effect can be used to resist the loosening of the first nut, achieving the effect of anti-loosening and tightening without applying (or applying smaller) tightening force, protecting the vulnerable parts while ensuring the connection reliability, and further improving the application range of the scheme. In addition, when the screw rod breaks accidentally, due to the vacuum adsorption effect of the first gasket and the connected object, the first nut, the screw and the part of the screw rod connected to the first nut are all adsorbed on the connected object, preventing them from falling or flying out and causing safety accidents. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a front view of an embodiment of the present application.

[0025] Figure 2 is Figure 1 a partial enlarged view of part A in

[0026] Explanation of reference signs: 1, screw rod; 2, first nut; 21, threaded hole; 3, axial constraint; 31, second nut; 32, second washer; 4, screw; 41, sliding block; 5, first washer; 51, adsorption cavity; 52, piston cavity; 53, communication hole; 6, piston; 61, annular clamping groove; 62, inlet and outlet groove; 7, sealing ring; 8, plugging cover. DETAILED DESCRIPTION

[0027] The following Figures 1-2 The present application is further described in detail.

[0028] The present application discloses a high-strength bolt and a threaded hole processing technology thereof.

[0029] Reference Figure 1 and Figure 2 In the present embodiment, the high-strength bolt comprises a screw rod 1, a first nut 2, an axial constraint 3, a plurality of screws 4, a first washer 5, and a piston 6. The first nut 2 is threadedly connected with the screw rod 1, and a plurality of threaded holes 21 penetrating through the upper and lower surfaces of the first nut 2 are formed on the first nut 2. The axial constraint 3 is connected with the screw rod 1 and is used to clamp an object together with the first nut 2. The plurality of screws 4 are threadedly connected with the plurality of threaded holes 21 one by one, and the end of the screw 4 can protrude from the surface of the first nut 2 close to the axial constraint 3.

[0030] In this way, the operation problem in a narrow space is solved, and the connection strength, anti-loosening reliability, and application range are improved. Specifically, after the conventional first nut 2 and the axial constraint 3 clamp an object, the screw 4 is screwed into the threaded hole 21, and when the end of the screw 4 protrudes and abuts against the connected object (or an intermediate part therebetween), a strong axial reaction force is generated between the first nut 2 and the connected object. The reaction force greatly increases the friction between the first nut 2 and the screw rod 1, providing excellent anti-loosening performance. On the other hand, the force is equivalent to an additional tensile pre-tightening force applied to the screw rod 1, thereby improving the strength and reliability of the bolt connection. Moreover, since the volume of the screw 4 is much smaller than that of the first nut 2, the operator only needs to use a small wrench to screw the screw 4 in a narrow space, perfectly solving the problem that large tools cannot be used, and greatly improving the application range of the bolt.

[0031] Specifically, the screw rod 1 is the main part of the bolt and is used to pass through the hole of the connected object. The screw rod 1 is usually cylindrical and has threads on the surface, and the material thereof can be various metal materials. In the present scheme, UNS N07718 alloy is used. This alloy material can ensure that the entire bolt can withstand and transmit a large pre-tightening force and maintain long-term mechanical properties and connection reliability under extreme working conditions such as high temperature, high pressure, and strong corrosion.

[0032] The first nut 2 is generally hexagonal nut-shaped, facilitating screwing operation with wrenches or other tools. The material is also UNS N07718 alloy, which ensures the strength and durability of the nut. A plurality of threaded holes 21 are arranged in a circumferential array with the rotation axis of the first nut 2 as the central axis. This ensures that the tightening force generated by all the screws 4 is evenly distributed on the circumference of the first nut 2, so that the first nut 2 is uniformly stressed and stable in posture, thereby ensuring that the effects of providing anti-loosening and increasing pre-tightening force are more stable and reliable.

[0033] In the present embodiment, the first washer 5 is generally circular ring-shaped, and the material can be high-strength steel to ensure a certain strength and durability. The first washer 5 is sleeved on the screw rod 1 and located between the first nut 2 and the axial restraint 3; the first washer 5 is provided with an adsorption cavity 51, a piston cavity 52, and a communication hole 53. The adsorption cavity 51 is provided on the side of the first washer 5 facing the axial restraint 3, and the adsorption cavity 51 is generally annular coaxial with the first washer 5; the piston cavity 52 is provided on the side of the first washer 5 away from the axial restraint 3, and the piston cavity 52 is also generally annular coaxial with the first washer 5. The communication hole 53 communicates the adsorption cavity 51 and the piston cavity 52, and the end hole of the communication hole 53 communicating the piston cavity 52 is located on the bottom surface of the piston cavity 52.

[0034] The piston 6 is also circular ring-shaped, and the size of the piston 6 matches the size of the piston cavity 52. The material of the piston 6 has good sealing and wear resistance, such as a structure of rubber wrapped around metal. The piston 6 is slidingly arranged in the piston cavity 52, and the side wall of the piston 6 is in sealing sliding abutment with the inner side wall of the piston cavity 52, so that the piston 6 can change the gas pressure in the piston cavity 52 when moving in the piston cavity 52.

[0035] When the screw 4 is screwed to move towards the axial restraint 3, the screw 4 will drive the piston 6 to move towards the bottom surface of the piston cavity 52. Since the piston 6 is in sealing sliding abutment with the piston cavity 52, this action will compress the gas in the piston cavity 52. The compressed gas is forced to be discharged into the adsorption cavity 51 through the communication hole 53 and sprayed out of the adsorption cavity 51 facing the connected object. This high-pressure gas flow can effectively blow off the dust or impurities on the contact surface between the first washer 5 and the connected object. By ensuring the cleanliness of the contact surface, the stability of the friction coefficient is ensured, and the loss of pre-tightening force or stress unevenness caused by impurities is avoided, thereby further improving the reliability of the bolt connection.

[0036] In the embodiment, the piston 6 is provided with an annular clamping groove 61 on the side close to the first nut 2, the annular clamping groove 61 has a reverse "T" shape in cross section, and extends around the circumferential direction of the rotation axis of the first nut 2 and is connected at the head and tail. The end of the screw 4 towards the axial constraint 3 is fixedly connected with a sliding block 41, and the sliding block 41 is of an integral structure with the screw 4; the sliding block 41 is matched with the annular clamping groove 61 in shape, and is slidingly clamped in the annular clamping groove 61.

[0037] When the screw 4 is screwed to move away from the axial constraint 3, the piston 6 is driven to move away from the bottom surface of the piston cavity 52. Due to the sealing property of the piston cavity 52, the volume of the piston cavity 52 is increased, and the negative pressure is generated in the piston cavity 52 and the adsorption cavity 51, so that the first gasket 5 is firmly "adsorbed" on the surface of the connected object. When the material of the fixed object is soft and easy to deform, the vacuum adsorption effect can be used to resist the loosening of the first nut 2, so that the loosening and fastening effects are achieved without applying (or applying a small) jacking force. The connecting reliability is ensured while the vulnerable parts are protected, and the application range of the scheme is further improved. In addition, when the screw rod 1 is accidentally broken, due to the vacuum adsorption effect of the first gasket 5 and the connected object, the first nut 2, the screw 4 and the section of the screw rod 1 connected with the first nut 2 are all adsorbed on the connected object, so that the connected object is prevented from falling or flying out to cause safety accidents.

[0038] The piston 6 is provided with an inlet and outlet groove 62, one end of the inlet and outlet groove 62 penetrates the side wall of the annular clamping groove 61 to communicate with the annular clamping groove 61, and the other end penetrates the side wall of the piston 6, and the sliding block 41 can enter or exit the annular clamping groove 61 through the inlet and outlet groove 62. In this way, when the screw 4 and the piston 6 are connected, the sliding block 41 at the end of the screw 4 is easily pushed into the piston 6 through the inlet and outlet groove 62, so that the sliding block 41 enters the annular clamping groove 61. This design avoids complex axial nesting installation in a limited space, so that the connection and separation of the screw 4 and the piston 6 become simple and fast, and the production and assembly efficiency and the subsequent maintenance convenience are improved.

[0039] The outer side edge and the inner side edge of the side of the first gasket 5 away from the first nut 2 are both provided with a sealing ring 7. When the first gasket 5 contacts the object, the sealing ring 7 is compressed, and two reliable sealing lines are formed. This can effectively prevent external air from leaking into the adsorption cavity 51 from the edge, so that stable negative pressure can be formed in the adsorption cavity 51 and maintained for a long time, so that the loosening function of the first gasket 5 and the connected object is more reliable and durable.

[0040] The screw 4 is a hexagonal flat end screw 4, the end of the screw 4 away from the axial constraint 3 is completely accommodated in the threaded hole 21, and the threaded hole 21 is threadedly connected with a sealing cover 8 at the end away from the axial constraint 3. In this way, the hexagonal structure makes the wrench contact surface of the screw 4 large, facilitating the application of greater torque to generate the required reaction force for fastening. The flat end structure enables the screw 4 to be completely screwed into the threaded hole 21 to be hidden, thereby improving the aesthetics after bolting. Moreover, sealing the threaded hole 21 with the sealing cover 8 can effectively prevent the intrusion of external dust, moisture, oil stains or corrosive media into the threaded hole 21, protecting the screw 4 and its threaded pair. This ensures that the screw 4 as the core anti-loosening component will not rust and jam, ensuring the long-term reliability and reusability of the anti-loosening function, especially suitable for harsh industrial environments.

[0041] In the present embodiment, the screw rod 1 is a double-headed screw rod; the axial constraint 3 includes a second nut 31 and a second washer 32. The second nut 31 is threadedly connected with the screw rod 1, and the second washer 32 is sleeved on the screw rod 1 and located between the first nut 2 and the second nut 31. The second nut 31 and the first nut 2 are made of the same material, such as UNS N07718 alloy, to ensure their performance. The second washer 32 can be a common metal washer or a rubber washer, etc., which functions to increase the contact area, disperse the pressure, and protect the surface of the connected object.

[0042] When one side of the connected object is narrow in space, causing the conventional screw rod 1 with a fixed head to be unable to be inserted from that side, the double-headed screw rod 1 allows the operator to insert the screw rod 1 from the relatively open side of the space into the threaded hole, so that it passes through the connected object. Subsequently, the operator can install the second nut 31 and the second washer 32 as the axial constraint on the other side of the narrow space. Finally, the first nut 2 is installed from the relatively open side of the space and the screw 4 is used for anti-loosening and fastening. This flexible assembly method makes the bolting operation no longer limited by the insertion direction of the fixed head bolt, effectively solving the installation problem in narrow space.

[0043] The implementation principle of the embodiment of the application is that when the screw 4 is screwed into the threaded hole 21 to move towards the axial constraint 3, the screw 4 will drive the piston 6 to move towards the bottom surface of the piston cavity 52. This action will compress the gas in the piston cavity 52 and make the gas spray out of the adsorption cavity 51 towards the connected object, thereby blowing off the dust or impurities on the contact surface of the first gasket 5 and the connected object, avoiding the loss of pre-tightening force or uneven stress caused by impurities, and improving the reliability of the bolt connection. At the same time, this action will generate a strong axial reaction force between the first nut 2 and the connected object. The reaction force, on the one hand, increases the friction between the first nut 2 and the threaded pair of the screw rod 1, improving the anti-loosening performance; on the other hand, the force is equivalent to applying an additional tensile pre-tightening force to the screw rod 1, thereby improving the strength and reliability of the bolt connection. Moreover, since the volume of the screw 4 is much smaller than the volume of the first nut 2, the operator only needs to use a small wrench to rotate the screw 4 in a narrow space, perfectly solving the problem that large tools cannot be used, and greatly improving the application range of the bolt.

[0044] When the screw 4 is rotated to move away from the axial constraint 3, the piston 6 can be driven to move away from the bottom surface of the piston cavity 52. This action will generate negative pressure in the piston cavity 52 and the adsorption cavity 51, so that the first gasket 5 is firmly "adsorbed" on the surface of the connected object. When the fixed object is made of soft and deformable material, the vacuum adsorption effect can be used to resist the loosening of the first nut 2, so that the anti-loosening and tightening effects are achieved without applying or applying a small amount of tightening force. The application range of the scheme is further improved.

[0045] The embodiment of the application also discloses a threaded hole machining process of a high-strength bolt. S1, boring the first nut 2 blank to process the base hole of all threaded holes 21; S2, rough machining of threads of the first nut 2; S3, replacing the new machining tool to perform fine machining of threads of the first nut 2 after rough machining of threads; S4, using the tool for fine machining of threads of the first nut 2 to perform rough machining of threads of the next first nut 2; S5, repeating steps S3-S4 until the machining of all threaded holes 21 of the first nut 2 is completed.

[0046] The implementation principle of the embodiment of the application is that a first nut 2 is thread-processed by replacing a new machining tool, so that the key process determining the precision of the final product is always completed by the tool in the best state, and it is ensured that all the thread holes 21 have highly consistent precision tolerances and surface finishes. Meanwhile, the tool after thread-processing the first nut 2 is used to thread-roughen the next first nut 2, and the slightly worn tool is used in echelon. The process maximally prolongs the comprehensive service life of the expensive tool under the premise of ensuring the highest precision, and significantly reduces the production cost.

[0047] The above are preferred embodiments of the application, and do not limit the protection scope of the application, so that: any equivalent changes made according to the structure, shape, principle of the application should be covered within the protection scope of the application.

Claims

1. A high-strength bolt, characterized in that, include: Screw (1); The first nut (2) is threadedly connected to the screw (1), and the first nut (2) has multiple threaded holes (21) that penetrate its upper and lower surfaces. An axial constraint member (3) is connected to the screw (1) and is used to clamp the object in conjunction with the first nut (2); Multiple screws (4) are threadedly connected to multiple threaded holes (21) one by one, and the ends of the screws (4) can protrude from the side of the first nut (2) near the axial constraint member (3).

2. The high-strength bolt according to claim 1, characterized in that: It also includes a first washer (5) and a piston (6). The first washer (5) is sleeved on the screw (1) and located between the first nut (2) and the axial constraint member (3). The first washer (5) has an adsorption cavity (51), a piston cavity (52), and a connecting hole (53). The adsorption cavity (51) is located on the side of the first washer (5) facing the axial constraint member (3), and the piston cavity (52) is located on the side of the first washer (5) away from the axial constraint member (3). The connecting hole (53) connects the adsorption chamber (51) and the piston chamber (52), and one end of the connecting hole (53) connecting the piston chamber (52) is located on the bottom surface of the piston chamber (52); the piston (6) is slidably disposed in the piston chamber (52), and the side wall of the piston (6) is in sealed sliding contact with the inner side wall of the piston chamber (52); when the screw (4) moves toward the axial constraint member (3), it can drive the piston (6) to move closer to the bottom surface of the piston chamber (52).

3. A high-strength bolt according to claim 2, characterized in that: The piston (6) has an annular groove (61) on the side near the first nut (2). The annular groove (61) extends circumferentially around the rotation axis of the first nut (2) and is connected end to end. The screw (4) has a slider (41) connected to one end facing the axial constraint member (3). The slider (41) is slidably engaged in the annular groove (61). When the screw (4) moves away from the axial constraint member (3), it can drive the piston (6) away from the bottom surface of the piston cavity (52).

4. A high-strength bolt according to claim 3, characterized in that: The piston (6) is provided with an inlet / outlet groove (62). One end of the inlet / outlet groove (62) passes through the side wall of the annular groove (61) and connects to the annular groove (61). The other end passes through the side wall of the piston (6). The slider (41) can enter or exit the annular groove (61) through the inlet / outlet groove (62).

5. A high-strength bolt according to claim 3, characterized in that: The first washer (5) has a sealing ring (7) on both the outer edge and the inner edge of the side facing away from the first nut (2).

6. A high-strength bolt according to claim 1, characterized in that: The multiple threaded holes (21) are arranged in a circular array with the rotation axis of the first nut (2) as the center.

7. A high-strength bolt according to claim 1, characterized in that: The screw (4) is an internal hexagonal flat-end screw (4). The end of the screw (4) away from the axial constraint member (3) is completely accommodated in the threaded hole (21). The end of the threaded hole (21) away from the axial constraint member (3) is threaded with a sealing cap (8).

8. A high-strength bolt according to claim 1, characterized in that: The screw (1) is a double-ended screw; the axial constraint member (3) includes a second nut (31) and a second washer (32), the second nut (31) is threadedly connected to the screw (1), and the second washer (32) is sleeved on the screw (1) and located between the first nut (2) and the second nut (31).

9. A high-strength bolt according to claim 8, characterized in that: The screw (1), the first nut (2) and the second nut (31) are all made of UNS N07718 alloy.

10. A thread hole machining process for a high-strength bolt as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. The blank of the first nut (2) is bored to machine the base holes of all the threaded holes (21); S2. Perform rough thread machining on the first nut (2); S3. Replace with a brand new machining tool and perform thread finishing on the first nut (2) after rough thread machining; S4. Using the tool used to finish the thread of the first nut (2), rough the thread of the next first nut (2); S5. Repeat steps S3-S4 until all the threaded holes (21) of the first nut (2) are machined.

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