Preformed pile spigot joint

Abstract

The present application relates to a precast pile plug-in lock joint, comprising: an upper sleeve, a bottom end of which is provided with a plug rod, a bottom end of the plug rod is provided with a first connecting structure, an outer circumferential wall of the plug rod is provided with an outer lock piece capable of being elastically deformed in a radial direction, the outer lock piece is provided with a second connecting structure and a first combining surface; a lower sleeve, a top end of which is provided with an opening for inserting the plug rod, a bottom of the lower sleeve is provided with an inner lock piece capable of being elastically deformed in a radial direction, an inner wall of the inner lock piece is provided with a third connecting structure matched with the first connecting structure and a second combining surface matched with the first combining surface, and an inner wall of the lower sleeve is provided with a fourth connecting structure matched with the second connecting structure; after the plug rod is inserted into place, the first combining surface is attached to the second combining surface, so as to form double self-locking between the second connecting structure and the fourth connecting structure and between the third connecting structure and the first connecting structure when being pulled.

Description

Technical Field

[0001] This invention relates to the field of precast pile foundation technology, and particularly to the connection of precast components, especially to the precast pile interlocking joint. Background Technology

[0002] In reinforced concrete structure construction, the main methods of connecting reinforcing bars include lap splices, mechanical connections, and welding. Currently, the connection of reinforcing bars is frequently involved in the butt splicing of concrete piles. Especially for prestressed concrete piles, the reinforcing bars are constantly under high stress during service, thus placing higher reliability requirements on the connection structure between piles.

[0003] Currently, when splicing multi-section prestressed piles on-site, the connection between upper and lower pile sections is mainly achieved by welding the end plates of adjacent piles on-site. However, this welding connection method has the following drawbacks: the construction process is cumbersome and labor costs are high; it requires highly skilled operators who possess proficient welding skills to ensure connection quality; welding is time-consuming and has low construction efficiency; it is significantly affected by external weather conditions such as wind, rain, and low temperatures, which can easily lead to large fluctuations in welding quality and poor quality controllability, thus posing safety hazards to the connection area of ​​the precast pile head.

[0004] To overcome the quality risks associated with on-site welding, some projects have adopted mechanical connection methods to achieve welding-free installation of precast piles on-site. However, existing mechanical connection components require high precision from installers and high-quality concrete forming at the pile ends, and the cost of some mechanical connection solutions is even higher than that of traditional welding connections.

[0005] Chinese utility model patent CN218990142U discloses a mechanical connection structure aimed at solving the problem of discontinuous force transmission and unstable connection caused by the gap between the plug rod and the outer sleeve when existing mechanical connectors are subjected to vertical pull-out force and lateral shear force. The technical solution is as follows: a first fastening ring is provided at the external threaded connection end of the plug rod, which axially abuts against the first outer sleeve. A radial gap is reserved between the plug rod and the first outer sleeve, thereby ensuring that the plug rod and the outer sleeve remain tightly abutted under stress, forming a stable connection. This improves the tensile strength and anti-derailment performance of the mechanical connector, ensuring the connection stability and construction efficiency of the precast pile.

[0006] However, most mainstream mechanical connection structures on the market currently use a single elastic ring as the core locking element: the elastic deformation of the elastic ring allows the pin to be inserted, and the elastic recovery of the elastic ring locks the teeth on the pin. The effectiveness of this type of structure is highly dependent on the deformation capacity and service life of the elastic element. Once the elastic ring experiences fatigue, aging, breakage, or permanent deformation, the joint will fail, causing the entire connection to malfunction.

[0007] Therefore, it is necessary to provide a precast pile joint structure that can overcome the failure risk of the above-mentioned single elastic element, and achieve 100% effectiveness guarantee of the joint connection by introducing a forced constraint mechanism. Summary of the Invention

[0008] To address the aforementioned problems in the prior art, the present invention provides a precast pile interlocking joint.

[0009] To achieve the above objectives, the present invention provides a precast pile interlocking joint, characterized in that it includes: The upper sleeve has an insertion rod at its bottom end. The bottom end of the insertion rod has a first connecting structure. The outer peripheral wall of the insertion rod has an external locking fastener that can be radially elastically deformed. The external locking fastener has a second connecting structure and a first mating surface. The lower sleeve has an opening at its top for inserting the rod, and an inner locking fastener that can be radially elastically deformed is provided at the bottom of the lower sleeve. The inner wall of the inner locking fastener is provided with a third connecting structure that matches the first connecting structure and a second mating surface that matches the first mating surface. The inner wall of the lower sleeve is provided with a fourth connecting structure that matches the second connecting structure. The connector is configured such that, during the insertion of the insert rod into the lower sleeve, the outer locking fastener is elastically contracted inward by radial compression from the inner wall of the lower sleeve, and the inner locking fastener is elastically expanded outward by radial compression from the insert rod. After the insertion rod is in place, the second connecting structure is connected to the fourth connecting structure, the third connecting structure is connected to the first connecting structure, and the first mating surface is in contact with the second mating surface, so as to form a double self-locking between the second connecting structure and the fourth connecting structure and between the third connecting structure and the first connecting structure when under tension.

[0010] Preferably, the first connecting structure, the second connecting structure, the third connecting structure, and the fourth connecting structure are selected from one or both of the following: toothed structure and threaded structure.

[0011] Preferably, the first connection structure, the second connection structure, the third connection structure, and the fourth connection structure are all connection structures that fit together along the axial direction of the joint.

[0012] Preferably, both the second connecting structure and the fourth connecting structure are reverse tooth structures.

[0013] Preferably, the insert rod is provided with an anti-interference groove to provide space for the external locking fastener to elastically deform inward.

[0014] Preferably, both the first mating surface and the second mating surface are inclined surfaces.

[0015] Preferably, a pad is provided at the bottom of the lower sleeve, and the inner locking fastener is installed on the pad.

[0016] Preferably, the pad is provided with an upward-facing boss, the outer diameter of which is smaller than the inner diameter of the inner locking fastener.

[0017] Preferably, the lower sleeve has a longitudinal through groove, the bottom of the lower sleeve is provided with a radial groove, the bottom of the inner locking fastener is provided with an outward protruding rib, the outward protruding rib is installed radially in the radial groove, and the outward protruding rib matches the longitudinal through groove.

[0018] Preferably, the external locking fastener has a threaded hole and a plurality of resilient locking tabs extending downward from the threaded hole, the threaded hole being used for screwing into the insert rod.

[0019] Preferably, the outer diameter of the outer locking fastener is larger than the inner diameter of the lower sleeve, and the inner diameter of the inner locking fastener is smaller than the outer diameter of the first connecting structure of the insert rod.

[0020] The beneficial effects of the precast pile interlocking joint provided by this invention are as follows: Double locking for high reliability: Utilizing a dual-locking structure with inner and outer locking fasteners. The outer locking fastener is located on the insertion rod of the upper sleeve, while the inner locking fastener is located at the bottom of the lower sleeve. During insertion, both the inner and outer locking fasteners undergo controllable elastic deformation, eliminating the need for traditional spring elements at the bottom of the insertion rod. This double locking mechanism effectively avoids the risk of the entire connector failing due to the failure of a single elastic element, significantly improving the redundancy and overall reliability of the connection structure.

[0021] Self-locking under load, with strength increasing with load: After insertion, the outer locking fastener engages with the fourth connecting structure (such as teeth) on the inner wall of the lower sleeve, and the inner locking fastener engages with the first connecting structure (such as teeth) at the bottom of the insertion rod. Simultaneously, the first mating surface of the outer locking fastener and the second mating surface of the inner locking fastener are in contact. When the joint is subjected to axial pull-out force, the meshing pressure of each connecting structure increases with the pull-out force, forming a self-locking reinforcement effect. The overall connection strength is higher than that of the static locking structure.

[0022] Self-locking and anti-loosening, adaptable to off-center load conditions: Both inner and outer locking fasteners are made of elastic materials and have a multi-tooth structure. When the joint is subjected to force, the locking fasteners can automatically deform and lock; even if the joint is locally tilted or subjected to off-center load during use, the elastic multi-tooth structure can still maintain effective engagement, ensuring connection stability and preventing loosening.

[0023] High tolerance and reduced installation accuracy requirements: The elasticity of the inner and outer locking components and the multi-tooth connection structure allow the connector to automatically compensate for axial or angular deviations between the insertion rod and the lower sleeve through elastic deformation, achieving reliable insertion and locking. Compared to rigid connections or single elastic ring solutions, this invention significantly reduces the accuracy requirements for on-site installation alignment.

[0024] Compact structure and high functional integration: the external locking fastener is integrated into the plug rod and uses reverse tooth engagement to achieve one-way locking, the internal locking fastener engages with the bottom of the plug rod with multiple teeth, the groove in the middle of the plug rod provides deformation avoidance, the pad plate ensures axial positioning, and all components work together to achieve efficient and reliable connection. Attached Figure Description

[0025] Figure 1 This is an exploded view of the first embodiment of the precast pile interlocking joint of the present invention.

[0026] Figure 2 This is a schematic diagram of the structure of the first embodiment of the precast pile interlocking joint of the present invention before insertion.

[0027] Figure 3 This is a schematic diagram of the first embodiment of the precast pile interlocking joint of the present invention during insertion.

[0028] Figure 4 This is a schematic diagram of the structure of the first embodiment of the precast pile interlocking joint of the present invention after insertion.

[0029] Figure 5 This is an exploded view of a second embodiment of the precast pile interlocking joint of the present invention.

[0030] Figure 6 This is a schematic diagram of the second embodiment of the precast pile interlocking joint of the present invention after insertion. Detailed Implementation

[0031] To more clearly describe the technical content of the present invention, the following description is provided in conjunction with specific embodiments.

[0032] Example 1 like Figures 1 to 4 The diagram shows a first embodiment of the precast pile interlocking joint of the present invention. The precast pile interlocking joint includes an upper sleeve 2, a lower sleeve 7, an insertion rod 3, an outer locking fastener 4, an inner locking fastener 5, and a pad 6. The upper pier head steel rod 1 is installed inside the upper sleeve 2, and the lower pier head steel rod 8 is installed inside the lower sleeve 2. The upper pier head steel rod 1, the lower pier head steel rod 8, and the upper and lower sleeves are pre-embedded at the pile head position during the pipe pile fabrication process, requiring no additional assembly during on-site construction.

[0033] A plug rod 3 is fixedly installed at the bottom end of the upper sleeve 2, and the two together form the upper component of the connector. A first connecting structure 10 is provided at the bottom end of the plug rod 3. An external locking fastener 4 that can be radially elastically deformed is provided on the outer peripheral wall of the plug rod 3. The external locking fastener 4 is provided with a second connecting structure 9 and a first mating surface 14.

[0034] The lower sleeve 7 has an opening at its top for inserting the insertion rod 3. The bottom of the lower sleeve 7 is provided with an inner locking member 5 that can deform radially. The inner wall of the inner locking member 5 is provided with a third connecting structure 12 and a second mating surface 15, wherein the third connecting structure 12 matches the first connecting structure 10, and the second mating surface 15 matches the first mating surface 14. The inner wall of the lower sleeve 7 is provided with a fourth connecting structure 11, which matches the second connecting structure 9.

[0035] A pad 6 is also fixedly installed at the bottom of the lower sleeve 7. The pad 6 is placed inside the lower sleeve 7 and located on the upper surface of the pier head of the steel bar. The inner locking fastener 5 is installed on the pad 6. The boss of the pad 6 provides radial and axial limit for the installation position of the inner locking fastener 5. The above components together form the lower assembly of the joint.

[0036] The outer diameter of the external locking fastener 4 when it opens is greater than the inner diameter of the lower sleeve 7, and the inner diameter of the internal locking fastener 5 is smaller than the outer diameter of the first connecting structure of the insert rod 3.

[0037] like Figure 2 and Figure 3 As shown, during the downward insertion of the insert rod 3 into the lower sleeve 7, because the inner diameter of the lower sleeve 7 is smaller than the outer diameter of the outer locking fastener 4 when it naturally opens outward, the outer locking fastener 4 is radially compressed by the inner wall of the lower sleeve 7 and elastically contracts inward, causing its second connecting structure 9 to slide downward tightly against the inner wall of the lower sleeve 7. Simultaneously, because the inner diameter of the inner locking fastener 5 is smaller than the outer diameter of the insert rod 3's head, the inner locking fastener 5 is radially compressed by the insert rod 3 and elastically expands outward. This coordinated elastic deformation of the inner and outer locking fasteners ensures that the upper component of the connector can overcome the diameter difference and smoothly insert into the lower component.

[0038] like Figure 4As shown, when the insertion rod 3 is inserted to the predetermined depth, the outer locking fastener 4 elastically resets radially outward, and the second connecting structure 9 combines with the fourth connecting structure 11 on the inner wall of the lower sleeve 7 to form the first locking; the inner locking fastener 5 elastically resets radially inward, and the third connecting structure 12 combines with the first connecting structure 10 at the head end of the insertion rod 3 to form the second locking; at the same time, the first mating surface 14 of the outer locking fastener 4 and the second mating surface 15 of the inner locking fastener 5 fit together. After the overall connection is completed, when the joint is subjected to axial pull-out force, the insertion rod 3 together with the inner locking fastener 5 is pulled upward, and the mating surfaces of the inner and outer locking fasteners are pressed together. After the outer locking fastener 4 is subjected to force, it fits more tightly with the first locking of the lower sleeve 7. The overall connection strength increases with the increase of the pull-out force, forming a self-locking effect of "the more you pull, the tighter it gets".

[0039] Therefore, the precast pile plug-in type connector provided by the present invention, after being inserted into place, has the outer locking fastener engaging with the fourth connecting structure (such as teeth) on the inner wall of the lower sleeve, and the inner locking fastener engaging with the first connecting structure (such as teeth) at the bottom end of the plug rod. At the same time, the first mating surface of the outer locking fastener and the second mating surface of the inner locking fastener are in contact, and the three form a mutually pressing and locking state. When the connector is subjected to axial pull-out force, the meshing points of each connecting structure are in a mutually pressing and locking state, and each connecting structure cannot deform and loosen, forming a self-locking reinforcement effect. The overall connection strength is higher than that of the static locking structure.

[0040] In this embodiment, the first connecting structure 10, the second connecting structure 9, the third connecting structure 12, and the fourth connecting structure 11 are all toothed structures. Among them, the second connecting structure 9 and the fourth connecting structure 11 adopt a reverse toothed structure, which is unidirectionally inclined along the axial direction, making it easy for the insertion rod 3 to enter when inserted, and forming a self-locking stop when pulled out.

[0041] It is understood that in other embodiments, the above-described connection structure is not limited to a toothed structure. For example, the first to fourth connection structures can all adopt a fully threaded structure, achieving connection and locking through threaded engagement; or a hybrid structure can be adopted, with a combination of threaded upper part and toothed lower part in a single connection structure. Any structural form that can achieve axial engagement connection falls within the protection scope of this invention.

[0042] An anti-interference groove 13 is provided in the middle of the insertion rod 3. The groove is located on the outer surface of the insertion rod 3, providing clearance space for the outer locking fastener 4 to elastically deform inward, avoiding interference between the outer locking fastener 4 and the body of the insertion rod 3 during the shrinkage process, and ensuring smooth elastic deformation.

[0043] like Figure 1 and Figure 2As shown, the external locking fastener 4 has a threaded hole and multiple elastic locking tabs extending downward from the threaded hole, forming an elastic structure that naturally opens outward. The threaded hole is used for screwing into the insertion rod 3. By connecting the external locking fastener 4 to the insertion rod 3, the external locking fastener 4 is simultaneously inserted into the lower sleeve along with the insertion rod 3, making the deformation of the external locking fastener controllable and the relative position of the inner and outer locking fasteners controllable throughout the insertion process, thereby simplifying the entire locking joint structure.

[0044] Example 2 like Figures 5 to 6 The image shows a second embodiment of the precast pile interlocking connector of the present invention. The main difference between the second and first embodiments lies in the installation and fixing method of the inner locking fastener. In the second embodiment, the lower sleeve has a longitudinal through groove 18, a radial groove 16 at the bottom, and an outwardly protruding rib 17 at the bottom, which matches the longitudinal through groove 18. During installation, the outwardly protruding rib 17 of the inner locking fastener matches the longitudinal through groove 18. First, the inner locking fastener is placed into the bottom of the lower sleeve 7 along the longitudinal through groove 18 until it is in place. Then, the inner locking fastener is rotated by an angle so that the outwardly protruding rib and the longitudinal through groove are not on the same axis. This arrangement prevents the inner locking fastener from falling out of the lower sleeve.

[0045] In this specification, the invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and variations can be made without departing from the spirit and scope of the invention. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

Claims

1. A precast pile interlocking joint, characterized in that, include: The upper sleeve has an insertion rod at its bottom end. The bottom end of the insertion rod has a first connecting structure. The outer peripheral wall of the insertion rod has an external locking fastener that can be radially elastically deformed. The external locking fastener has a second connecting structure and a first mating surface. The lower sleeve has an opening at its top for inserting the rod, and an inner locking fastener that can be radially elastically deformed is provided at the bottom of the lower sleeve. The inner wall of the inner locking fastener is provided with a third connecting structure that matches the first connecting structure and a second mating surface that matches the first mating surface. The inner wall of the lower sleeve is provided with a fourth connecting structure that matches the second connecting structure. The connector is configured such that, during the insertion of the insert rod into the lower sleeve, the outer locking fastener is elastically contracted inward by radial compression from the inner wall of the lower sleeve, and the inner locking fastener is elastically expanded outward by radial compression from the insert rod. After the insertion rod is in place, the second connecting structure is connected to the fourth connecting structure, the third connecting structure is connected to the first connecting structure, and the first mating surface is in contact with the second mating surface, so as to form a double self-locking between the second connecting structure and the fourth connecting structure and between the third connecting structure and the first connecting structure when under tension.

2. The precast pile interlocking joint according to claim 1, characterized in that, The first connection structure, the second connection structure, the third connection structure, and the fourth connection structure are selected from one or both of the following: toothed structure and threaded structure.

3. The precast pile interlocking joint according to claim 1, characterized in that, The first, second, third, and fourth connection structures are all connection structures that fit together along the axial direction of the joint.

4. The precast pile interlocking joint according to claim 1, characterized in that, Both the second connecting structure and the fourth connecting structure are reverse tooth structures.

5. The precast pile interlocking joint according to claim 1, characterized in that, The insertion rod is provided with an anti-interference groove to provide space for the external locking fastener to elastically deform inward.

6. The precast pile interlocking joint according to claim 1, characterized in that, Both the first and second mating surfaces are inclined surfaces.

7. The precast pile interlocking joint according to claim 1, characterized in that, A pad is provided at the bottom of the lower sleeve, and the inner locking fastener is installed on the pad.

8. The precast pile interlocking joint according to claim 7, characterized in that, The pad is provided with an upward-facing boss, the outer diameter of which is smaller than the inner diameter of the inner locking fastener.

9. The precast pile interlocking joint according to claim 1, characterized in that, The lower sleeve has a longitudinal through groove, and the bottom of the lower sleeve is provided with a radial groove. The bottom of the inner locking fastener is provided with an outward protruding rib, which is installed radially in the radial groove and matches the longitudinal through groove.

10. The precast pile interlocking joint according to claim 1, characterized in that, The external locking fastener has a threaded hole and a plurality of elastic locking tabs extending downward from the threaded hole, the threaded hole being used for screwing into the insertion rod.

11. The precast pile interlocking joint according to claim 1, characterized in that, The outer diameter of the external locking fastener is larger than the inner diameter of the lower sleeve, and the inner diameter of the internal locking fastener is smaller than the outer diameter of the first connecting structure of the insertion rod.

Images