Butt-joint connection structure for reinforcing steel bars
By incorporating a sliding and rotating nut structure within the sleeve, the problem of difficult rebar splicing in traditional connection methods is solved, achieving the effects of simplified construction and improved assembly efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-10
- Publication Date
- 2026-04-07
AI Technical Summary
Traditional mechanical threaded sleeve connection methods make it difficult to flexibly adjust the reinforcing bars in precast components, and the grouting sleeve technology requires high positioning accuracy, which increases the difficulty and complexity of construction.
The sleeve features a sliding and rotating nut structure. With its side opening and different thread directions, the nut can be flexibly adjusted according to the position of the reinforcing bar, accommodating certain installation errors and simplifying the butt connection process.
It reduces the requirements for the positioning accuracy of steel bars, improves assembly efficiency and ease of operation on the construction site, and simplifies the construction process.
Smart Images
Figure CN224092846U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of building engineering technology, and in particular to a steel bar butt connection structure. Background Technology
[0002] Prefabricated industrial buildings are gradually becoming the mainstream as the future direction of the construction industry. However, in the process of promoting this model, the technical challenges of connecting steel bars in prefabricated components have become a major bottleneck restricting its further development. Especially in the application of prefabricated concrete structures, the connection of steel bars between prefabricated components faces many challenges.
[0003] Because the reinforcing bars are fixed in the concrete of the precast components, they are difficult to rotate and adjust, making traditional mechanical threaded sleeve connections impractical. This increases the complexity and difficulty of the assembly process. The industry has attempted to use grouting sleeve technology to achieve effective connections between reinforcing bars in precast components. However, this method places extremely high demands on the positioning accuracy of the precast components. It requires not only ensuring that the reinforcing bars are accurately inserted into the sleeve, but also ensuring that the distance between the two reinforcing bars precisely matches the requirements of the grouting sleeve. This high-precision operational requirement significantly increases the difficulty and complexity of construction.
[0004] Therefore, how to provide rebar butt connections for precast components with different gap spacing, while ensuring that the rebar butt connection structure is easy to operate, is an urgent problem to be solved. Utility Model Content
[0005] To address the aforementioned technical problems, this application provides the following technical solutions:
[0006] The first aspect of this application provides a steel bar butt connection structure, comprising: a sleeve with insertion ports at both ends communicating with a receiving cavity inside the sleeve and having an inner diameter smaller than the cavity diameter, and the side wall of the sleeve having a side opening extending axially; two nuts, slidably disposed in the receiving cavity and partially exposed in the side opening, the side opening being used to insert a tool to rotate the nuts in the receiving cavity, and the central axis of the inner hole of the two nuts being parallel to or coincident with the central axis of the receiving cavity.
[0007] In some embodiments, the inner walls at both ends of the receiving cavity are provided with pressure-bearing surfaces, which are concave spherical surfaces that are recessed away from the receiving cavity, and the opposite sides of the two nuts are convex spherical surfaces that are adapted to the concave spherical surfaces; the outer diameter of the nuts is different from the cavity diameter of the receiving cavity.
[0008] In some embodiments, the inner diameters of the two nuts are different to accommodate components of different diameters.
[0009] In some embodiments, the inner wall of the receiving cavity is provided with a left-hand threaded section and a right-hand threaded section, which are movably connected to the right-hand external thread and the left-hand external thread provided on the outer surface of the two nuts, respectively.
[0010] In some embodiments, the side opening extends axially through the sleeve and connects to the insertion port, so that the side opening forms a C-shaped opening.
[0011] In some embodiments, the area occupied by the C-shaped opening on the sleeve cross-section is less than one-quarter of the sleeve cross-sectional area.
[0012] In some embodiments, the sleeve includes a first cylindrical body and a second cylindrical body that are detachably connected.
[0013] In some embodiments, the steel bar butt connection structure further includes: a top pressure member, disposed in the receiving cavity and located between two nuts, the top pressure member being able to generate axial expansion at a preset temperature, so that its two ends abut against the two nuts respectively, and the opposite sides of the two nuts abut against the two bearing surfaces respectively, so as to lock the two parts to be connected.
[0014] In some embodiments, the outer periphery of the nut is circular and a plurality of first slots are provided on the outer peripheral wall at circumferential intervals.
[0015] In some embodiments, the axial length of the receiving cavity is at least 5 times the thickness of the nut.
[0016] Compared to existing technologies, the rebar butt connection structure provided in this application features a sleeve with a nut that can slide axially and rotate around its own central axis, allowing the nut to be flexibly adjusted according to the actual position of the parts to be connected (such as rebars). Even if there is a slight deviation in the position or uncertainty in the spacing between the two rebars when inserted into the sleeve, the nut can adapt to these changes by sliding, thereby ensuring that the rebars can be butt-jointed. This rebar butt connection structure, by employing a sliding and rotatable nut and an easy-to-operate side opening, can tolerate a certain amount of installation error, eliminating the need for strict control of the distance between rebars as in traditional methods. This rebar butt connection structure effectively solves the problem of requiring precise control of the distance between rebars in traditional connection methods, not only simplifying the construction process and reducing the requirements for positioning accuracy, but also greatly improving assembly efficiency, making on-site operations simpler and faster. Attached Figure Description
[0017] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein:
[0018] Figure 1 A schematic diagram of the sleeve structure of this application is shown;
[0019] Figure 2 schematically shownFigure 1 Cross-sectional view at point A in the diagram;
[0020] Figure 3 schematically shown Figure 1 Cross-sectional view at point B in the diagram;
[0021] Figure 4 The diagram schematically illustrates a first-state structural schematic of a steel bar butt connection structure provided in this application;
[0022] Figure 5 A schematic diagram of the second state of a steel bar butt connection structure provided in this application is shown.
[0023] Figure 6 A schematic diagram of another steel bar butt connection structure provided in this application is shown.
[0024] Figure 7 A three-dimensional structural diagram of another steel bar butt connection structure provided in this application is shown schematically.
[0025] Figure 8 A schematic diagram of another steel bar butt connection structure provided in this application is shown.
[0026] Figure 9 A schematic diagram of the structure of the nut at the first angle of this application is shown.
[0027] Figure 10 A schematic diagram of the structure of the nut at the second angle of this application is shown.
[0028] Figure 11 A schematic diagram of the third angle of the nut in this application is shown.
[0029] Figure 12 A cross-sectional view of the steel bar butt connection structure of this application in its working state is schematically shown.
[0030] Explanation of icon numbers:
[0031] 1. Sleeve; 11. First cylinder; 12. Second cylinder; 13. Receiving cavity; 14. Insertion port; 15. Side opening; 131. Concave spherical surface; 2. Nut; 21. Convex spherical surface; 3. Part to be connected; 4. Pressing part; 5. First groove; 6. Second groove; 7. Locking pin; 8. Wrench. Detailed Implementation
[0032] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
[0033] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains.
[0034] The inventors discovered that because the reinforcing bars are fixed within the concrete of the precast component, necessary rotational adjustments are difficult to make, hindering the implementation of traditional mechanical threaded sleeve connections and increasing the complexity and difficulty of the assembly process. To address this issue, the industry has attempted to use grouting sleeve technology to achieve effective connection of the reinforcing bars. However, this method not only involves concealed engineering work, making grouting connection quality monitoring difficult, but also places extremely high demands on the positioning accuracy of the precast component. It requires ensuring that the reinforcing bars are accurately inserted into the sleeve and that the distance between the two reinforcing bars precisely matches the requirements of the grouting sleeve.
[0035] The first aspect of this application provides a steel bar butt connection structure, such as Figures 1-7 As shown, it includes: a sleeve 1, with insertion ports 14 at both ends that communicate with the receiving cavity 13 inside the sleeve 1 and have an inner diameter smaller than the cavity diameter of the receiving cavity 13, and the side wall of the sleeve 1 has a side opening 15 extending axially; two nuts 2, which are slidably disposed in the receiving cavity 13 and partially exposed in the side opening 15, the side opening 15 being used to insert a tool to make the nuts 2 rotate in the receiving cavity 13, and the central axis of the inner hole of the two nuts 2 being parallel or coincident with the central axis of the receiving cavity 13.
[0036] In one possible case, such as Figure 1 , Figure 4 , Figure 5 , Figure 6 , Figure 7As shown, this rebar butt connection structure can be applied to, but is not limited to, the rebar in precast components. The sleeve 1 in this rebar butt connection structure is used to accommodate the nuts 2, and it has a receiving cavity 13. The receiving cavity 13 can be a cylindrical sleeve 1, a sleeve 1 with a square or rectangular cross-section, etc. The cylindrical sleeve 1 mates with the circular receiving cavity 13. The circular receiving cavity 13 facilitates the sliding of the two nuts 2 within the receiving cavity 13 to accommodate the distance between the two parts to be connected 3, which can be the rebar in the precast component. Two insertion ports 14 are provided at opposite ends of the sleeve 1 for inserting the two parts to be connected 3. The inner diameter of the insertion port 14 is smaller than the cavity diameter of the receiving cavity 13; for example, if the cavity diameter of the receiving cavity 13 is 6 cm, the inner diameter of the insertion port 14 can be 4 cm. The shape of the insertion port 14 can be arbitrary, such as circular, square, or other irregular shapes. Two axially extending side openings 15 are formed on the side wall of the sleeve 1. The width of the side openings 15 can be any width, such as 5cm, 8cm, etc. The length of the side openings 15 along the central axis of the receiving cavity 13 can cover part or all of the length of the sleeve 1. The side openings 15 are used for inserting a tool to rotate the nut 2. The rotating tool can be a wrench 8. The two nuts 2 are made of high-strength stainless steel and are slidably disposed in the receiving cavity 13 of the sleeve 1. The central axis of their inner holes coincides with the central axis of the receiving cavity 13, ensuring that the nuts 2 can slide smoothly in the receiving cavity 13. The nuts 2 can slide along the axial direction of the sleeve 1 and rotate around their own central axis. The nuts 2 can slide in opposite directions along the axial direction of the receiving cavity 13 according to the distance between the two connecting parts, so that the two nuts 2 are threadedly connected to the two connecting parts 3 respectively. Insert the two parts 3 to be connected into the insertion ports 14 at both ends of the sleeve 1. Use the side opening 15 to insert a tool and rotate the nut 2 to thread it onto the part 3. After connection, the opposite sides of the two nuts 2 abut against the cavity wall where the insertion ports 14 of the receiving cavity 13 are located. Cement can then be injected into the space between the two nuts 2 or a top pressure rod can be inserted to ensure that the two parts 3 can withstand both tensile force and compressive force along the axial direction of the receiving cavity 13.
[0037] In this design, the sleeve 1 contains a nut 2 that can slide axially and rotate around its own central axis, allowing the nut 2 to be flexibly adjusted according to the actual position of the parts to be connected 3 (such as reinforcing bars). Even if there is a slight deviation in the position or uncertainty in the spacing between the two reinforcing bars when they are inserted into the sleeve 1, the nut 2 can adapt to these changes by sliding, thereby ensuring that the reinforcing bars can be butt-jointed. By using a sliding and rotatable nut 2 and an easy-to-operate side opening 15, a certain amount of installation error can be tolerated, eliminating the need for strict control of the distance between the reinforcing bars as in traditional methods. This reinforcing bar butt connection structure effectively solves the problem of needing to precisely control the distance between reinforcing bars in traditional connection methods, simplifies the construction process, reduces the requirements for positioning accuracy, and greatly improves assembly efficiency, making on-site operations simpler and faster.
[0038] In some embodiments, the inner walls at both ends of the receiving cavity 13 are provided with pressure-bearing surfaces, which are concave spherical surfaces 131 that are recessed away from the receiving cavity 13, and the opposite side of the two nuts 2 is a convex spherical surface 21 that is adapted to the concave spherical surface 131; the outer diameter of the nuts 2 is different from the cavity diameter of the receiving cavity 13.
[0039] In one possible case, such as Figures 4-7 As shown, the inner walls at both ends of the sleeve 1 are provided with concave spherical surfaces 131 recessed away from the receiving cavity 13 as bearing surfaces. That is, the bearing surfaces can be part of the inner walls at both ends of the receiving cavity 13, and each concave spherical surface 131 is provided with an insertion port 14. The insertion port 14 is located on the bearing surface, ensuring that the reinforcing bar can pass smoothly through and enter the receiving cavity 13. Since the insertion port 14 itself is also part of the concave spherical surface 131, this allows the reinforcing bar to obtain a certain degree of support and guidance during insertion, which helps to improve the accuracy and stability of insertion. The opposite sides of the two nuts 2 are provided with convex spherical surfaces 21 that are adapted to the concave spherical surfaces 131. After the connection between the two nuts 2 and the part to be connected 3 is completed, the opposite sides of the two nuts 2 abut against the concave spherical surfaces 131 respectively. The fit between the concave spherical surfaces 131 and the convex spherical surfaces 21 allows the nuts 2 to be freely tilted and adjusted within a small range to accommodate the eccentricity or misalignment between the reinforcing bars. Even if the central axis of the reinforcing bar is not perfectly aligned, the nuts 2 can automatically adjust their position and angle to compensate for the deviation and ensure a stable connection. Furthermore, the large and uniformly distributed contact area between the concave spherical surface 131 and the convex spherical surface 21 helps to disperse the force applied to the nut 2, reducing local stress concentration and improving the stability and durability of the connection. The outer diameter of the nut 2 is slightly smaller than the diameter of the receiving cavity 13, ensuring that it can slide and rotate freely within the cavity.
[0040] In some embodiments, the inner diameters of the two nuts 2 are different to accommodate the different diameters of the parts to be connected 3.
[0041] In one possible scenario, to accommodate connecting parts 3 of different diameters, the inner diameters of the two nuts 2 can be different. For example, one nut 2 may have an inner diameter of 3cm, suitable for smaller diameter reinforcing bars; the other nut 2 may have an inner diameter of 4cm, suitable for larger diameter reinforcing bars. The appropriate nut 2 can be flexibly selected for installation according to actual needs.
[0042] In some embodiments, the inner wall of the receiving cavity 13 is provided with a left-hand threaded section and a right-hand threaded section, which are movably connected to the right-hand external thread and the left-hand external thread provided on the outer surface of the two nuts 2, respectively.
[0043] In one possible scenario, the inner wall of the receiving cavity 13 is provided with two sections of threads in different directions: a left-hand thread section and a right-hand thread section. The left-hand thread section is located near the insertion port 14 at one end, while the right-hand thread section is located near the insertion port 14 at the other end. The outer peripheral surfaces of the two nuts 2 are respectively provided with right-hand external threads and left-hand external threads, and each nut 2 can be threadedly connected to its corresponding thread section. By installing one nut 2 with a right-hand external thread on the right-hand thread section of the receiving cavity 13 and the other nut 2 with a left-hand external thread on the left-hand thread section of the receiving cavity 13, a bidirectional and stable connection can be achieved. That is, the thread on the inner wall of each nut 2 is threadedly connected to the part 3 to be connected, and the thread on the outer peripheral surface is threadedly connected to the cavity wall of the receiving cavity 13. When subjected to tension and pressure along the axial direction of the receiving cavity 13, the tension and pressure are effectively distributed on the threads of the two nuts 2 due to the tight connection between the threads on the outer surfaces of the two nuts 2 and the threads of the receiving cavity 13, thereby improving the stability of the entire steel bar butt connection structure.
[0044] In some embodiments, the side opening 15 extends axially through the sleeve 1 and communicates with the insertion port 14, so that the side opening 15 forms a C-shaped opening.
[0045] In one possible case, such as Figure 1 , Figure 7As shown, the side opening 15 extends axially through the entire sleeve 1 along the receiving cavity and communicates with the insertion ports 14 at both ends, forming a C-shaped opening. This means there is an open channel from one end of the sleeve 1 to the other, through which the interior of the receiving cavity 13 can be directly seen, allowing tools or parts 3 to be connected to enter. Because the side opening 15 extends axially through the sleeve 1 and communicates with the insertion ports 14, forming a C-shaped opening, even when the distance between two parts 3 to be connected is very small, the parts 3 can be directly inserted into the receiving cavity 13 through the side opening 15 and connected to the nut 2. For example, in confined spaces, through the C-shaped opening, workers can directly insert reinforcing bars or other parts 3 to be connected from the side of the sleeve 1 and use tools to adjust the position of the nut 2 through the side opening 15 to ensure they are correctly aligned with the parts 3. The C-shaped opening not only improves operational flexibility but also simplifies the construction process. Construction workers do not need to precisely align the insertion port 14. They can first determine the positions of the two parts 3 to be connected, then insert the parts 3 into the sleeve 1 through the side opening 15. Next, they can adjust the two nuts 2 according to the distance between the two parts 3, causing the two nuts 2 to slide opposite each other along the axial direction of the receiving cavity 13 and connect with the parts 3 by threads, thus reducing the difficulty of construction. Furthermore, tools can be easily accessed through the side opening 15 to rotate and adjust the nuts 2, ensuring a stable and reliable connection.
[0046] In some embodiments, the area occupied by the C-shaped opening on the cross-section of the sleeve 1 is less than one-quarter of the cross-sectional area of the sleeve 1.
[0047] In one possible case, such as Figure 1 As shown, the C-shaped opening occupies less than one-quarter of the cross-sectional area of sleeve 1. This ensures that sleeve 1 has sufficient structural strength to support and fix components such as reinforcing bars, while also providing the necessary operating space so that tools can easily enter and operate nut 2. High construction efficiency and ease of operation are achieved without sacrificing structural strength.
[0048] In some embodiments, the sleeve 1 includes a first cylindrical body 11 and a second cylindrical body 12 that are detachably connected.
[0049] In one possible case, such as Figure 8As shown, the sleeve 1 includes a first cylinder 11 and a second cylinder 12. One end of each cylinder has matching internal and external threads, allowing for a tight connection between them by rotating one cylinder. Alternatively, one end of the first cylinder 11 has an outwardly protruding buckle, while one end of the second cylinder 12 has a corresponding groove. During installation, the connection is completed by aligning the buckle of the first cylinder 11 with the groove of the second cylinder 12. Alternatively, the connecting ends of the first cylinder 11 and the second cylinder 12 are provided with flanges, which are fixed together by bolts or pins. The first cylinder 11 and the second cylinder 12 are connected in a detachable manner, allowing for the selection of two appropriately sized first cylinders 11 and 12 based on the distance between the two parts 3 to be connected on site. This enhances the flexibility and adaptability of the rebar butt connection structure and significantly improves construction efficiency.
[0050] In some embodiments, the steel bar butt connection structure further includes: a top pressure member 4, which is disposed in the receiving cavity 13 and located between two nuts 2. The top pressure member 4 can generate axial expansion at a preset temperature, so that its two ends abut against the two nuts 2 respectively, and the opposite sides of the two nuts 2 abut against the two bearing surfaces respectively, so as to lock the two parts 3 to be connected.
[0051] In one possible case, such as Figure 6 As shown, the pressing component 4 can be made of a material capable of axial expansion at a preset temperature, such as a shape memory alloy, a thermally expanding material, or other composite material with similar properties. After the two components 3 to be connected are connected to the two nuts 2, the pressing component 4 can be placed between the two nuts 2. To ensure that the two ends of the pressing component 4 abut against the two nuts 2 respectively, the pressing component 4 can be heated to cause it to expand axially along the receiving cavity 13, generating axial thrust. At this time, the convex spherical surface 21 of the nut 2 is tightly fitted with the bearing surface, and the cooperation between the pressing component 4 and the bearing surface ensures that the nut 2 will not easily loosen, enhancing the stability of the overall connection.
[0052] In some embodiments, the outer periphery of the nut 2 is circular and a plurality of first slots 5 are provided on its outer peripheral wall at intervals along its circumference.
[0053] In one possible case, such as Figures 9-12As shown, a plurality of first slots 5 are provided circumferentially on the outer peripheral wall of the nut 2 to allow tools (such as wrenches 8 or other special tools) to be inserted and apply torque, thereby rotating the nut 2 for adjustment or tightening. Different numbers of first slots 5 can be provided according to actual needs, such as 4, 6, or 8, evenly distributed on the outer peripheral wall of the nut 2 to facilitate operation from different angles. The shape of the slots can be circular, rectangular, trapezoidal, or other shapes suitable for tool insertion. Furthermore, the outer periphery of the nut 2 is circular, fitting tightly with the circular receiving cavity 13 to ensure smooth rotation of the nut 2 within the cavity.
[0054] In addition, such as Figure 8 As shown, the side wall of the sleeve 1 is provided with a second slot 6 corresponding to a plurality of first slots 5 and penetrating the side wall of the sleeve 1 radially along the receiving cavity 13; a plurality of locking pins 7, whose diameter is adapted to the diameter of the first slots 5, are used to insert into the first slots 5 and the second slots 6 to lock the nut 2 in the receiving cavity 13. The first slots 5 are provided on the outer peripheral wall of the nut 2, while the second slots 6 are provided on the side wall of the sleeve 1, and their positions correspond one-to-one. After the nut 2 is connected to the part to be connected 3 and its convex spherical surface abuts against its concave spherical surface, the first slots 5 and the second slots 6 are aligned, and the position of the nut 2 can be fixed by inserting the locking pins 7. After the locking pins 7 are inserted into the first slots 5 and the second slots 6, the nut 2 can be effectively locked in the current position to prevent it from loosening or displacing when subjected to tension or pressure.
[0055] In some embodiments, the axial length of the receiving cavity 13 is at least 5 times the thickness of the nut 2.
[0056] In one possible case, such as Figure 8 As shown, to ensure that the nut 2 has sufficient room to move within the receiving cavity 13 for flexible adjustment and operation, the axial length of the receiving cavity 13 can be at least 5 times the thickness of the nut 2. For example, if the thickness of the nut 2 is 2 cm, the length of the receiving cavity 13 should be at least 10 cm. This rebar butt connection structure not only improves the operational flexibility and adaptability of the nut 2, but also significantly enhances construction efficiency and connection reliability.
[0057] It should be noted that in the description of this specification, the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model; the terms "connection," "installation," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.
[0058] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0059] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A steel bar butt connection structure, characterized in that, include: The sleeve has insertion ports at both ends that communicate with the receiving cavity inside the sleeve and have an inner diameter smaller than the cavity diameter, and the side wall of the sleeve has a side opening extending axially. Two nuts are slidably disposed within the receiving cavity and partially exposed through the side opening. The side opening is used to insert a tool to rotate the nuts within the receiving cavity. The central axis of the inner bore of the two nuts is parallel to or coincides with the central axis of the receiving cavity.
2. The steel bar butt connection structure according to claim 1, characterized in that, The inner walls at both ends of the receiving cavity are provided with pressure-bearing surfaces, which are concave spherical surfaces that are recessed away from the receiving cavity. The opposite sides of the two nuts are convex spherical surfaces that are adapted to the concave spherical surfaces. The outer diameter of the nut is different from the diameter of the receiving cavity.
3. The steel bar butt connection structure according to claim 1, characterized in that, The two nuts have different inner diameters to accommodate components of different diameters.
4. The steel bar butt connection structure according to claim 1, characterized in that, The inner wall of the receiving cavity is provided with a left-hand thread section and a right-hand thread section, which are movably connected to the right-hand external thread and the left-hand external thread provided on the outer surface of the two nuts, respectively.
5. The steel bar butt connection structure according to claim 1, characterized in that, The side opening extends axially through the sleeve and connects to the insertion port, so that the side opening forms a C-shaped opening.
6. The steel bar butt connection structure according to claim 5, characterized in that, The area occupied by the C-shaped opening on the cross-section of the sleeve is less than one-quarter of the cross-sectional area of the sleeve.
7. The steel bar butt connection structure according to claim 1, characterized in that, The sleeve includes a first cylinder and a second cylinder that are detachably connected.
8. The steel bar butt connection structure according to claim 2, characterized in that, Also includes: A pressure member is disposed in the receiving cavity and located between the two nuts. The pressure member can generate axial expansion at a preset temperature, so that its two ends abut against the two nuts respectively, and the opposite sides of the two nuts abut against the two bearing surfaces respectively, so as to lock the two parts to be connected.
9. The steel bar butt connection structure according to claim 1, characterized in that, The nut has a circular outer periphery and multiple first slots spaced circumferentially on its outer wall.
10. The steel bar butt connection structure according to claim 1, characterized in that, The axial length of the receiving cavity is at least 5 times the thickness of the nut.