Mortise and tenon structure type reinforcing steel bar mechanical connection joint

Abstract

The invention discloses a tenon-and-mortise structure type reinforcing steel bar mechanical connection joint, and belongs to the technical field of reinforcing steel bar connection. The mechanical connection joint comprises an outer sleeve and a connection locking assembly arranged in the outer sleeve; the connecting and locking assembly comprises a tenon-and-mortise type clamping piece and a connecting clamping piece which are arranged in a split mode, the tenon-and-mortise type clamping piece is directly clamped on the surface of the reinforcing steel bar, and the connecting clamping piece is arranged between the tenon-and-mortise type clamping piece and the inner wall of the outer sleeve; the reinforcing steel bars do not need to be rotated or axially moved, the tenon-and-mortise type clamping pieces and the surfaces of the reinforcing steel bars are forced to form mechanical engagement through the radial restraining effect of the outer sleeve, and therefore axial force transmission of the two reinforcing steel bars is achieved. The reinforcing steel bar does not need to be moved or cut or plastically extruded, the original section of the reinforcing steel bar is kept, and the method has the advantages of being reliable in connection, convenient to construct and particularly suitable for assembly type modular construction.

Description

Technical Field

[0001] This invention belongs to the field of rebar connection technology, and specifically relates to a mechanical rebar connection joint. Background Technology

[0002] As the core load-bearing material in modern concrete structures, the reliability of steel reinforcement connections directly affects the overall structure's load-bearing capacity, seismic performance, and service life.

[0003] In various civil engineering projects such as building construction, bridge engineering, water conservancy facilities, and subway tunnels, there are a large number of steel bars that need to be connected on-site or in the factory. Therefore, the development of efficient, reliable, and convenient steel bar connection technology has always been a key focus of industry research and development.

[0004] Mechanical splices for reinforcing bars are key components for achieving rebar connections. Currently, they are mainly divided into two categories: threaded sleeves and extruded sleeves. However, both have certain limitations in practical applications. Threaded sleeve connections require cutting some longitudinal and transverse ribs at the ends of the reinforcing bars using a thread rolling machine before rolling the threads. This process reduces the effective cross-sectional area of ​​the reinforcing bars, creating weak points that may affect the mechanical properties of the joint area. In addition, it requires high precision in the processing of the reinforcing bars and is not suitable for all specifications or materials of reinforcing bars.

[0005] Although extrusion sleeve connection does not weaken the cross-section of the reinforcing bar, it requires the use of large-tonnage special extrusion equipment to forcefully radially extrude the sleeve to cause plastic deformation and interlock with the reinforcing bar. This process involves bulky equipment, requires high operating space and skilled personnel, and has low construction efficiency. In addition, the extruded sleeve and reinforcing bar cannot be disassembled, making it difficult to adjust the reinforcing bar spacing or axial deviation commonly encountered in construction.

[0006] In summary, existing mainstream mechanical connection technologies for reinforcing bars generally suffer from the following problems: they either require cutting and damaging the cross-section of the reinforcing bars, rely on large equipment and have complex processes, or lack adaptability and adjustability. Especially with the rapid development of prefabricated buildings, the requirements for on-site construction convenience and connection quality stability are increasing. Therefore, developing a new type of mechanical connection joint for reinforcing bars that does not require processing the reinforcing bar itself, does not damage its cross-section, is flexible and easy to construct, and has reliable connection has become an urgent technical problem to be solved in this field. Summary of the Invention

[0007] To address the problems of existing threaded sleeves requiring the cutting of reinforcing bars to weaken the cross-section, and extrusion sleeves relying on large equipment, being inconvenient to construct, and having poor adaptability, this invention provides a tenon-and-mortise structure mechanical connection joint for reinforcing bars. It aims to achieve a mechanical connection for reinforcing bars that does not damage the reinforcing bar itself, requires no complex processing, is applicable to various reinforcing bar fixing scenarios, is easy to construct, and provides a reliable connection.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A tenon-and-mortise type mechanical connection joint for connecting two axially opposed steel bars includes two outer sleeves and at least one set of connection locking components.

[0009] The outer sleeve has an axial through hole for the reinforcing bar to pass through; the connecting locking assembly is disposed in the axial through hole of the outer sleeve.

[0010] Once the ends of the two reinforcing bars are in place, the radial constraint of the connecting locking assembly by the outer sleeve causes the connecting locking assembly to mechanically engage with the surfaces of the two reinforcing bars, thereby enabling the transmission of axial force between the reinforcing bars.

[0011] Specifically, the connection locking assembly includes a mortise and tenon clamp and a connecting clamp, which are separately arranged. The mortise and tenon clamp is used to directly engage with the surface of the reinforcing bar, while the connecting clamp is disposed between the mortise and tenon clamp and the inner wall of the outer sleeve.

[0012] Furthermore, the tenon-and-mortise type clamp consists of at least two pieces for each steel bar, spliced ​​along the circumference of the steel bar, with grooves or tooth-like structures on its inner surface for engaging with the ribs on the surface of the steel bar to enhance the mechanical interlocking effect; the connecting clamp is a ring-shaped structure, with its inner wall contour matching the outer contour of the spliced ​​tenon-and-mortise type clamp, used to tighten the tenon-and-mortise type clamp.

[0013] To achieve reliable radial constraint, the inner wall of the outer sleeve and the outer wall of the connecting clamp are fitted with a tapered surface, a threaded fit, or an interference fit.

[0014] In a preferred embodiment, the inner wall of the outer sleeve is provided with an inner conical surface, and the outer wall of the connecting clip is provided with a matching outer conical surface. When the outer sleeve moves or is tightened along the axial direction, radial clamping force can be applied to the connecting clip and tenon-type clip inside through the mating surface, so that they tightly hug the reinforcing bar.

[0015] To connect two steel bars, the tenon-and-mortise type clamps in the connection locking assembly are set in two sets, corresponding to the ends of the two steel bars to be connected respectively. The connection clamps in the connection locking assembly can be designed as a ring-shaped or combined double-cone sleeve structure after combination, or as an integral double-cone sleeve structure, or as an independent ring-shaped piece.

[0016] In addition, to facilitate control of the installation position, limiting structures can be provided on the inner walls of both ends of the outer sleeve or on the connecting locking assembly.

[0017] Compared with the prior art, the present invention has the following significant advantages: 1. Force is transmitted through the mechanical interlocking of the tenon and mortise clamps with the surface of the reinforcing bar, eliminating the need for cutting, thread rolling, or local plastic extrusion of the reinforcing bar, thus fully preserving the original cross-sectional area and mechanical properties of the reinforcing bar.

[0018] 2. All components can be pre-fitted onto the reinforcing bars. On-site assembly only requires pushing or tightening the outer sleeve, eliminating the need for large-scale specialized thread rolling equipment. This allows for flexible construction and reduces labor intensity.

[0019] 3. The components are clearly defined in terms of function. The tenon and mortise clamps, connecting clamps and outer sleeves can all be produced in standardized factories and supplied commercially. They are particularly suitable for the rapid connection of steel reinforcement modules in prefabricated construction, which reduces on-site workload and helps improve project quality and construction efficiency.

[0020] In summary, this invention provides a new solution for efficient, reliable, and construction-friendly mechanical connection of reinforcing bars. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the mortise and tenon structure rebar mechanical connection joint of the present invention during the assembly process; Figure 2 This is a schematic diagram of the mortise and tenon structure steel bar mechanical connection joint of the present invention in the final tightening state.

[0022] Figure 3 This is a three-dimensional exploded structural diagram of the outer sleeve, connecting clip, and tenon-and-mortise clip in this invention.

[0023] The markings in the diagram are as follows: 1. Reinforcing bar; 2. Outer sleeve; 3. Connecting clamp; 4. Mortise and tenon clamp. Detailed Implementation

[0024] To enhance understanding of the present invention, the invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only for explaining the invention and do not constitute a limitation on the scope of protection of the invention.

[0025] like Figure 1 , Figure 2 and Figure 3 As shown, the tenon and mortise structure rebar mechanical connection joint provided by the present invention is mainly used to reliably connect two rebars 1 with their ends axially opposite. The core design of this mechanical connection joint is that, through the ingenious combination of multi-layer components and radial constraints, a high-strength mechanical connection can be formed without moving or processing the rebar body.

[0026] The entire mechanical connection joint mainly consists of two outer sleeves 2 and a set of connection locking components (the three-dimensional shape of each component can be seen in the figure). Figure 3 The outer sleeve 2 is typically a cylindrical metal part with a through axial hole in the center to facilitate fitting onto the reinforcing bar 1 and the connecting locking assembly. The connecting locking assembly includes a mortise and tenon clamp 4 and a connecting clamp 3, which work together to clamp and connect the reinforcing bar 1.

[0027] The specific assembly and connection process is as follows: First, before the steel bars are in place, the outer sleeve 2 is inserted onto the steel bars 1 to be connected.

[0028] Subsequently, after the reinforcing bar is in place, two tenon-and-mortise clamps 4 are combined radially and fitted onto the surface of the predetermined position at the end of the reinforcing bar 1. The inner surface of the tenon-and-mortise clamps 4 is machined with grooves or tooth-like structures that match the shape of the transverse ribs on the surface of the reinforcing bar 1, thereby forming a mechanical interlocking tenon and mortise when they are fitted together. This is the key interface for transmitting axial force and does not damage the parent material of the reinforcing bar at all.

[0029] Next, the connecting clip 3 is fitted onto the outside of the assembled mortise and tenon clip 4. The connecting clip 3 is ring-shaped after assembly, and its inner wall contour is closely matched with the outer contour of the assembled mortise and tenon clip 4, which plays a role in initial clamping and integration.

[0030] Finally, by moving the outer sleeve 2 axially, the inner wall of the outer sleeve 2 applies radial inward pressure to the internal connecting clip 3. Since the connecting clip 3 and the inner wall of the outer sleeve 2 preferably adopt a conical surface fit, the axial movement can be efficiently converted into a strong radial clamping force. This clamping force is transmitted to the tenon-and-mortise type clip 4 through the connecting clip 3, forcing it to fit tightly against the surface of the tenon-and-mortise steel bar 1, ultimately forming a strong connection. Figure 2 The state shown.

[0031] In a preferred embodiment of the present invention, the connecting clip 3 corresponding to the connecting locking component is designed as three identical double-conical sleeve structures. The structure is thick in the middle and thin at both ends, and the outer surface is two symmetrical conical surfaces, which can simultaneously cooperate with the inner conical surfaces at both ends of the outer sleeve 2. The outer surface is a straight line. This design not only simplifies the shape of the parts and facilitates processing, but also ensures that when the outer sleeve 2 is tightened, the steel bars 1 on both sides are locked synchronously and symmetrically, and the force is more balanced.

[0032] To further ensure connection accuracy and facilitate construction positioning, annular shoulders can be provided on the inner walls at both ends of the outer sleeve 2 as a limiting structure, or steps can be provided on the end faces of the connecting clip 3 and the tenon-and-mortise clip 4. This limiting structure can ensure the position of the tenon-and-mortise type steel bar mechanical connection joint relative to the steel bar 1, so that the force is completely transmitted through the mechanical interlocking surface.

[0033] The improvements of this invention are mainly reflected in the fact that it eliminates the steel bar threading process required for traditional threaded sleeves, and also avoids the large hydraulic equipment and irreversible plastic deformation process required for radial extrusion sleeves. Instead, it achieves non-destructive connection through the assembly of detachable standardized components and controllable radial elastic constraints. Construction requires only simple tools and allows for fine-tuning before final locking. It also has more relaxed requirements for the alignment of on-site steel bars, making it particularly suitable for the rapid and high-quality connection of prefabricated modular steel bars in prefabricated construction.

[0034] Implementation Example To enable those skilled in the art to better understand the present invention, a specific implementation example is provided below.

[0035] In this example, two HRB400 grade ribbed steel bars with a diameter of 25mm are to be connected. The design and material selection of each component of the tenon and mortise structure steel bar mechanical connection joint are as follows: The outer sleeve 2 is made of 40Cr alloy steel precision forging. It is cylindrical with a total length of about 200mm. The inner hole is a bidirectional inner conical surface that is larger at both ends and slightly smaller in the middle, with a taper of about 1:10. At the openings at both ends, there is a ring groove with a depth of 2mm as an installation limiting structure.

[0036] The connecting locking assembly includes a connecting clip 3 and a tenon-and-mortise clip 4. The connecting clip 3 adopts a double-cone sleeve structure and is made of 40Cr alloy steel. Its outer conical surface matches the inner conical surface of the outer sleeve 2, and its inner wall is cylindrical. The tenon-and-mortise clip 4 consists of four pieces, two pieces per set, and is made of high-carbon spring steel. Its inner surface is precisely machined with grooves that conform to the rib pattern of Φ25 steel bars to form a tenon-and-mortise effect. Its outer surface is precisely imprinted with tooth-like patterns to increase interlocking friction.

[0037] During construction, first, insert the outer sleeve 2 into the reinforcing bar. After the reinforcing bar is in place, combine the four tenon-and-mortise clamps 4 in pairs and hold the ends of the two reinforcing bars about 40mm from the end face.

[0038] Next, assemble the connecting clip 3 to hold the tenon-and-mortise clip in the appropriate position.

[0039] Finally, move the outer sleeve 2 to fit tightly onto the connecting clamp 3, and use a special installation tool to bring the two ends of the outer sleeve 2 axially closer together.

[0040] As the outer sleeve 2 moves, its inner wall presses against the outer wall of the connecting clip 3, generating strong radial pressure. This force forces the teeth on the outer surface of the tenon-and-mortise clip 4 to tightly engage with the connecting clip 3, and the inner wall to press tightly against the surface of the reinforcing bar, thereby achieving high-strength locking.

[0041] Mechanical performance tests showed that the joint could meet the standard value of the tensile strength of the reinforcing bar base material, and the failures all occurred in the reinforcing bar area outside the joint.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tenon-and-mortise type mechanical connection joint for connecting two axially opposite steel bars, characterized in that, include: Outer sleeve and connecting locking assembly; The outer sleeve has an axial through hole for the reinforcing bar to pass through; The connection locking component is disposed within the axial through hole of the outer sleeve; The connection locking component is configured such that, through the mortise and tenon joint and the radial constraint of the outer sleeve, the connection locking component and the surfaces of the two reinforcing bars form a mechanical engagement, thereby realizing the axial force transmission of the two reinforcing bars.

2. The tenon-and-mortise structure mechanical connection joint for reinforcing bars according to claim 1, characterized in that, The connection locking assembly includes a separate mortise and tenon clamp and a connecting clamp; The tenon-and-mortise type clamp directly fits onto the surface of the reinforcing bar, and the connecting clamp is disposed between the tenon-and-mortise type clamp and the inner wall of the outer sleeve.

3. The tenon-and-mortise structure mechanical connection joint for reinforcing bars according to claim 2, characterized in that, The tenon-and-mortise type clamp consists of at least two pieces, spliced ​​together along the circumference of the reinforcing bar, and its inner surface is provided with grooves or tooth-like structures that engage with the ribs on the surface of the reinforcing bar.

4. The tenon-and-mortise structure mechanical connection joint for reinforcing bars according to claim 3, characterized in that, The connecting clip has a ring-shaped structure, and its inner wall contour is adapted to the outer contour of the tenon-and-mortise clip.

5. The tenon-and-mortise structure mechanical connection joint for reinforcing bars according to claim 2, characterized in that, The inner wall of the outer sleeve and the outer wall of the connecting clip are fitted with a tapered surface, a threaded fit, or an interference fit.

6. The tenon-and-mortise structure mechanical connection joint for reinforcing bars according to claim 5, characterized in that, The inner wall of the outer sleeve is provided with an inner conical surface, and the outer wall of the connecting clip is provided with a matching outer conical surface.

7. The tenon-and-mortise structure mechanical connection joint for reinforcing bars according to any one of claims 2 to 6, characterized in that, The connection locking assembly consists of two sets of tenon-and-mortise type clamps, each corresponding to the end of one of the two reinforcing bars to be connected.

8. The tenon-and-mortise structure mechanical connection joint for reinforcing bars according to claim 7, characterized in that, The connecting clips in the connecting locking assembly are either ring-shaped, combined double-cone sleeve structures, integrally formed double-cone sleeve structures, or independent ring-shaped pieces.

9. The tenon-and-mortise structure mechanical connection joint for reinforcing bars according to claim 1, characterized in that, Limiting structures are provided on the inner walls of both ends of the outer sleeve or on the connecting locking assembly.

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