Locking mechanism for prestressed steel bars, and prefabricated concrete member and production method therefor

Abstract

The present invention relates to a locking mechanism for prestressed steel bars, characterized in that the locking mechanism comprises a sleeve, with a tapered hole and an internally threaded hole which are arranged in sequence from left to right and penetrate axially being provided inside the sleeve, and a sleeve external thread configured to be in threaded connection with an end plate being provided on the outer periphery of the sleeve; a tapered clamp, which is placed in and adapted to the tapered hole; and a top cylinder, with a through hole penetrating axially being provided therein and a top cylinder external thread being provided on the outer periphery thereof. When the clamp is placed in the tapered hole, the top cylinder is screwed into the internally threaded hole of the sleeve by means of the top cylinder external thread, an inner end of the top cylinder can directly or indirectly abut against a right end face of the clamp, and an internally toothed hole of the clamp and the through hole of the top cylinder penetrate axially so as to allow a prestressed steel bar to pass therethrough in sequence. The present locking mechanism can greatly improve the positioning accuracy of a prestressed steel bar locked by the tapered clamp. The present invention further relates to a prefabricated concrete member and a production method therefor.

Description

Prestressed steel bar locking mechanism, production method of precast concrete components and precast concrete components Technical Field

[0001] This invention belongs to the technical field of concrete foundation engineering for various building structural systems, and particularly relates to a locking mechanism for prestressed steel bars in precast concrete components. This invention also relates to a production method for precast concrete components using the aforementioned prestressed steel bar locking mechanism, and precast concrete components manufactured using the aforementioned method. Background Technology

[0002] Due to the high tensile strength of prestressed steel bars (for example, the design tensile strength of steel strand is 1320 MPa, and the maximum tensile strength can reach 1960 MPa), in recent years, Chinese enterprises and research institutions have conducted extensive research on the application of prestressed steel bars in precast concrete components. During the manufacturing process of these prestressed reinforced concrete precast components, conical clamps are typically used to lock the prestressed steel bars. The core technical challenges are how to conveniently and accurately connect and lock the prestressed steel bars to the conical clamps, and how to maximize the consistency of tension force on each prestressed steel bar.

[0003] For example, a Chinese invention patent with patent number ZL201410034851.8 (publication number CN103741672B) entitled "A pre-tensioned centrifugal concrete pile with steel strand and its manufacturing method" discloses a steel strand locking method: a conical hole is opened on the end plate, and a conical clamp assembly composed of multiple clamping plates is placed in each conical hole. The steel strand passes through the inner tooth hole of the clamp assembly and is locked on the end plate. This locking method is simple, but during the early stages of production, during the installation of the rebar cage (before the steel strands are tensioned), it is difficult to connect and fix the ends of the steel strands to the conical clamp assembly. Moreover, this connection is often very loose, requiring the use of a hammer to force the ends of the steel strands and the clamp assembly together into the conical holes on the end plate to achieve a tight connection and lock the steel strands to the end plate. This can lead to direct misalignment between the clamp assembly and the steel strands. Furthermore, when the ends of the steel strands extend into the clamp assembly, it can cause relative misalignment of the clamping plates and irregularity of the internal teeth, thus reducing the effectiveness of the internal teeth on the steel strands. The clamping force also results in low positioning accuracy of the clamping assemblies locking the steel strands. That is, the clamping and locking positions of each steel strand in the length direction of each clamping assembly are inconsistent and inconsistent, resulting in inconsistent tension of each steel strand, which seriously affects the mechanical properties of the pile body. Moreover, after the pile body is formed, the prestress of the prestressed steel bar locking end plate is inconsistent, which also affects the mechanical properties of the pile end. In addition, after the concrete pile is formed, the ends of the steel strands are firmly locked in the conical clamping assemblies under the action of prestress, and even if the inconsistent tension of each steel strand is found, it is difficult to make remedial corrections. Another example is the Chinese invention patent "Pre-tensioned Centrifugal Concrete Pile with Steel Strand and Manufacturing Method" (patent number ZL201410036904.X, publication number CN103758120B), which discloses a similar steel strand locking mechanism: the anchor ring has a stepped through hole, the larger part of which is a threaded hole, and the smaller part of which is a conical hole. A conical clamp assembly composed of multiple clamping plates is placed inside the conical hole. The steel strand is locked in the internal toothed hole of the clamp assembly. The anchor ring is connected to the end plate by a bolt connector, and the threaded section of the bolt extends into the threaded hole of the larger part of the anchor ring. This locking method is similar to the first method mentioned above. It also suffers from the problem that the conical clamp assembly and the end of the steel strand are difficult to lock together, the locking position accuracy is not high, and the clamping and locking positions of each clamp assembly on each steel strand in the length direction are inconsistent, affecting the mechanical properties of the pile itself and the pile end. Moreover, it is difficult to take remedial measures for inconsistent tension of the steel strand.

[0004] Chinese patent application CN104343118A discloses a tensioning device for manufacturing concrete piles with steel strands. The device has multiple first through holes on an anchor plate, with a first connecting seat detachably fixed within each hole. A first threaded through hole is provided on the first connecting seat, and a first push rod is threadedly connected within the first threaded through hole. The inner end of the first push rod abuts against the outer end face of a clamping assembly. The push rod pushes the steel strands to be flush with the outer end face of the clamping assembly. After centrifugation, no steel strands protrude from the end plate of the concrete pile. Chinese patent application CN110499754A also discloses a steel strand clamping component and a corresponding concrete pile. This component has an external thread on the outer wall of an anchor ring for direct connection to an end plate, and an internal threaded hole within the anchor ring for fixing a plug. A conical clamping assembly placed within the conical hole of the anchor ring locks the steel strands onto the end plate. These two inventions employ push rods and plugs respectively to abut against the ends of the clamping assemblies and steel strands, aiming to achieve uniform insertion lengths of each steel strand into each clamping assembly and thereby consistent tension on each steel strand. However, while the conical clamps in these two inventions improve the accuracy of locking the steel strands in position, in actual operation, there is always mutual friction and jamming between the steel strand ends and the clamping assemblies during insertion into the toothed holes of the clamping assemblies. Not every steel strand end and clamping assembly abuts against the push rod or plug uniformly as the invention expects. Often, some clamping assemblies or steel strand ends jam, resulting in different insertion lengths of the steel strands into the clamping assemblies. The clamping assemblies may also experience misalignment and deformation of the clamping plates, reducing the clamping force on the steel strands. Moreover, in actual production, it is difficult to guarantee that the cut length of each steel strand is uniform; each steel strand will have more or less length differences, which also makes it difficult for the invention to achieve consistent tension on each steel strand in practice. Therefore, these two inventions also suffer from the same defects as the two patents mentioned above: the conical clamp assembly is difficult to lock with the end of the steel strand, or the positional accuracy of the conical clamp assembly locking the reinforcing bar is not high, and the tension of each steel strand is inconsistent. Moreover, because the top rod and the plug block the end of the steel strand, it is difficult to detect and correct the problem of inconsistent tension of the steel strand.

[0005] Another problem with the existing prestressed steel bar locking method is that once the end of the prestressed steel bar is locked by the conical clamp, it no longer extends. Therefore, the existing technology cannot be used for the long-line production (i.e., two or more concrete piles can be produced simultaneously in the same long mold) of concrete piles with end plates, thus limiting its application scope. Furthermore, the end plate holes corresponding to the steel strands of the concrete piles in the above invention cannot be connected to other components.

[0006] In summary, the locking mechanism for prestressed steel bars in the aforementioned prior art still needs further improvement. Summary of the Invention

[0007] The first technical problem to be solved by the present invention is to provide a locking mechanism for prestressed steel bars that is structurally reasonable, can easily lock the prestressed steel bars of precast concrete components with a conical clamp assembly (clamp), and can greatly improve the positional accuracy of the prestressed steel bars locked by the conical clamp. This locking mechanism can also be used to manufacture prestressed concrete components with end plates using the long-line method.

[0008] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: a locking mechanism for prestressed steel bars in precast concrete components, characterized in that:

[0009] The sleeve includes a tapered hole and an internally threaded hole arranged sequentially from left to right and axially extending therethrough. The internally threaded hole is located to the right of the tapered hole. The diameter of the tapered hole gradually increases from left to right. The outer periphery of the sleeve has an external thread for threaded connection with an end plate.

[0010] A conical clamp can be placed inside the conical hole and its outer circumferential surface is adapted to the conical hole. The center of the clamp has an internal toothed hole for locking the prestressed steel bars, and the peripheral wall of the internal toothed hole has locking teeth.

[0011] The top cylinder has an axially penetrating hole, and its outer periphery is provided with an external thread for threaded connection with the internal threaded hole of the sleeve. When the clamp is placed in the tapered hole, the top cylinder is screwed into the internal threaded hole of the sleeve through its external thread, and the inner end of the top cylinder can directly or indirectly abut against the right end face of the clamp. The internal toothed hole of the clamp and the penetrating hole of the top cylinder are axially connected to allow prestressed steel bars to pass through sequentially. The clamp can be composed of two or more clamping pieces spliced ​​together, or it can be a single integral tapered clamp with elasticity.

[0012] Preferably, with the sleeve threadedly connected to the end plate, the outer end of the sleeve is flush with or lower than the outer end face of the end plate. The outer end of the sleeve does not protrude from the end plate, thus not affecting piling and pile splicing.

[0013] As an improvement, the aforementioned sleeve is in the shape of a stepped shaft, with the external thread of the sleeve located on the outer circumference of the small shaft portion on the right side of the sleeve. The shoulder of the sleeve abuts against the inner end face of the end plate. The abutment between the shoulder of the sleeve and the inner end face of the end plate serves as an installation indicator. When the sleeve is screwed into the end plate, the abutment between the shoulder of the sleeve and the end plate indicates that the sleeve has been installed in place, eliminating the need to observe whether the sleeve protrudes from the end plate, making the installation more user-friendly.

[0014] To facilitate screwing the top cylinder into the sleeve, the top cylinder has a connecting portion and a head. The connecting portion is a threaded post for connecting with the internal threaded hole, and the head is polygonal with an outer diameter larger than that of the connecting portion. This facilitates screwing the top cylinder into the internal threaded hole of the sleeve when used with a wrench.

[0015] A further improvement is made: the thread direction of the internal threaded hole on the sleeve is opposite to the thread direction of the external thread on the sleeve. This ensures that during the screwing into of the top sleeve, the rotation of the top sleeve will not cause the sleeve to unscrew out of the threaded connection hole on the end plate.

[0016] Compared with existing technologies, the beneficial technical effects of this locking mechanism are as follows:

[0017] 1. Because the top cylinder of this invention has an axially penetrating through hole, the end of the prestressed steel bar of the precast concrete component can pass through the conical hole of the sleeve and emerge from the through hole of the top cylinder, and can be fixed and stabilized in advance. In the subsequent process of simply inserting the conical clamp into the conical hole of the sleeve, there is no need to consider the fit of the prestressed steel bar end. There is absolutely no risk of the prestressed steel bar end causing jamming, interference, or misalignment of the internal toothed hole of the conical clamp. This avoids problems such as reduced clamping force caused by disturbance and misalignment of the prestressed steel bar end to the conical clamp, and there is no need to consider whether the length of the prestressed steel bar end extending into the conical clamp is consistent. After the prestressed steel bars pass through the perforation of the top cylinder, they can be pre-tensioned uniformly. With the prestressed steel bars fixed and tensioned after passing through the perforation of the top cylinder, the prestressed steel bars are stable and immobile. The top cylinder can be gradually screwed into the internal threaded hole of the sleeve through the external thread of the top cylinder. The inner end of the top cylinder can stably and gradually abut against the conical clamp located in the conical hole of the sleeve. There is no interaction between the top cylinder and the end of the prestressed steel bar, and there is no slippage or loosening of the prestressed steel bar. Therefore, the conical clamp can synchronously and gradually sink in the conical hole and gradually clamp the prestressed steel bars located in the inner toothed hole of the clamp, so that the clamping position and clamping force of the conical clamp on each prestressed steel bar are always consistent. Therefore, this invention can conveniently, systematically, controllably, and reliably lock prestressed steel bars with conical clamps, and can greatly improve the accuracy of locking the position of prestressed steel bars with conical clamps. It effectively solves the technical problems of difficulty in locking the conical clamp assembly with prestressed steel bars or loose connection and inconsistent clamping position of the steel bars in the prior art. This allows the tension of each prestressed steel bar in the concrete component to remain highly consistent, greatly improving the mechanical properties of the concrete component itself and its ends. Based on this, precast concrete components with ultra-high mechanical properties can be produced.

[0018] 2. Secondary tensioning of prestressed steel bars can correct potential inconsistencies in prestressed steel bar tension within concrete members, ensuring high mechanical properties. Whether the inconsistency in tension arises from length differences during initial cutting of prestressed steel bars or from other occasional factors during production, the locking mechanism of this invention can compensate for and correct these issues. Specifically, during production, each prestressed steel bar extends outside the top cylinder through a perforation. Jacks can be used to clamp the outer bars, and each bar can be individually tensioned to a uniform tension before being released. Conical clamps automatically lock the bars. Alternatively, after pile formation, each bar extending outside the end plate can be individually tensioned to a uniform tension using jacks. Therefore, the locking mechanism of this invention can ultimately ensure consistent tension in all prestressed steel bars, thereby guaranteeing the mechanical properties of the concrete member itself and its ends.

[0019] 3. After the concrete component is formed, the top sleeve of the present invention can be unscrewed from the sleeve for reuse, and the internal threaded hole of the empty sleeve can be used as a connection hole to connect with other components. It can be used for mechanical splicing or connection with tensioning plate and anchor plate without the need to set additional threaded connection holes for mechanical splicing or connection on the end plate. Under the premise of a certain end plate area, as many prestressed steel bars as possible can be arranged, providing the possibility for high-density reinforcement of concrete components.

[0020] 4. The top cylinder of the present invention has an axially penetrating hole, and the same prestressed steel bar can continuously penetrate the top cylinder on multiple end plates without affecting the top cylinder pressing the conical clamp into the conical hole of the end plate, thereby conveniently and reliably locking the conical clamp into the prestressed steel bar, providing the possibility for the long-line method (two or more concrete components can be produced in the same long mold) to produce concrete components with end plates.

[0021] The aforementioned locking mechanism is generally applicable to locking prestressed steel bars in various types of precast concrete components, including centrifugally formed round piles, square piles, and irregularly shaped piles, as well as vibration-formed square piles, H-shaped piles, and irregularly shaped piles. It can also be used to lock prestressed steel bars in bridge concrete components, and has a wide range of applications.

[0022] The second technical problem to be solved by the present invention is to address the shortcomings of the prior art by using the above-mentioned locking mechanism to lock the prestressed steel bars in the production method of concrete piles. This production method can conveniently and reliably achieve precise locking of the prestressed steel bars by the conical clamp, and can also perform secondary tensioning of each prestressed steel bar.

[0023] The first technical solution adopted by the present invention to solve the second technical problem mentioned above is: a method for producing concrete piles, characterized in that: multiple locking mechanisms, multiple end plates, and multiple prestressed steel bars are used; the end plates are distributed on the mold; each sleeve is connected to the end plate through an external thread; each top cylinder is connected to the internal thread hole of the sleeve through an external thread; each prestressed steel bar is passed through the conical hole of the corresponding sleeve and the through hole of the top cylinder; the two ends of each prestressed steel bar are fixed; the prestressed steel bars are tensioned; each top cylinder is unscrewed from the internal thread hole of the sleeve; the clamp is inserted into the sleeve; each top cylinder is then screwed into the internal thread hole of the sleeve; the top cylinder is tightened and the clamp is pressed against the conical hole of the sleeve; after pouring concrete, a concrete pile is formed. After cutting the prestressed steel bars outside the end plates, the concrete pile can be hoisted out of the mold; the conical clamp is generally composed of multiple clamping plates, such as two, three, or four plates, etc., or it may be a single integral conical clamp with elasticity. In this method, "multiple," "multiple roots," and "multiple blocks" refer to two or more items.

[0024] Preferably, the sleeve is pre-connected to the end plate and the top cylinder is connected to the internal threaded hole of the sleeve, and then the end plate with the sleeve and top cylinder installed is placed in the mold. This avoids the sleeve and top cylinder slipping on the steel strands during the insertion and tensioning of the prestressed steel bars, making the process more efficient. Of course, initially, the sleeve and top cylinder may not be connected to the end plate. After the prestressed steel bars pass through the threaded holes on the end plate, the sleeve and top cylinder, which were previously fitted onto the prestressed steel bars, are then installed onto the end plate. Alternatively, the sleeve may be connected to the end plate first, and the top cylinder may be screwed into the internal threaded hole of the sleeve after the steel bars have passed through the sleeve and end plate. These are all feasible. Here, the top cylinder is only shallowly screwed into the internal threaded hole of the sleeve to facilitate subsequent unscrewing of the top cylinder for installation of the fixture.

[0025] After the concrete pile is formed, the prestressed steel bars outside the end plate are cut off, and the top cylinder is removed. The top cylinder can be reused.

[0026] To facilitate secondary single-strand tensioning of the prestressed steel bars after cutting, after the concrete pile is formed, each prestressed steel bar is cut while retaining a section of prestressed steel bar outside the end plate. The length of the prestressed steel bar remaining outside the end plate is generally no less than 20cm. Before or after cutting the prestressed steel bars, the top cylinder is screwed out of the internal threaded hole of the sleeve, the top cylinder is removed, and then each prestressed steel bar is tensioned a second time. After tensioning, the prestressed steel bars protruding from the end plate are cut off. Secondary tensioning further ensures that the prestress of each prestressed steel bar is consistent when locked to the end plate.

[0027] As described above regarding the beneficial effects of the locking mechanism, this production method for concrete piles allows for convenient, standardized, controllable, and reliable locking of prestressed steel bars using conical clamps. It significantly improves the accuracy of the conical clamps in locking the prestressed steel bars, effectively solving the technical problems of difficulty in locking the conical clamp assembly to the prestressed steel bars, loose connections, and inconsistent clamping positions in existing technologies. This ensures that the tension of each prestressed steel bar in the concrete member remains highly consistent, greatly enhancing the mechanical properties of the concrete member itself and its ends. This allows for the production of precast concrete piles with ultra-high mechanical properties. Furthermore, because the steel bars can pass through the perforations in the top cylinder and protrude beyond the end plate, after the pile body is formed and the steel bars are cut, the exposed steel bars can be tensioned again to ensure consistent tension. This ensures that the prestress of each prestressed steel bar is consistent when locking the end plate, improving the mechanical properties of the pile ends and solving the problem of inconsistent prestress when locking the end plate due to the retraction of some steel bars within the conical holes after cutting.

[0028] The second technical solution adopted by the present invention to solve the second technical problem mentioned above is as follows: a method for producing concrete piles, characterized in that: multiple locking mechanisms, multiple end plates, and multiple prestressed steel bars are used; the end plates are distributed on a mold; each sleeve is connected to the end plate through an external thread; one end of each prestressed steel bar is passed through the conical hole, internal thread hole, and through hole of the corresponding sleeve on each end plate; the top sleeve is fitted onto the prestressed steel bar but not connected to the sleeve; both ends of the prestressed steel bars are fixed; the prestressed steel bars are tensioned; a clamp is inserted into the sleeve; the top sleeve is screwed into the internal thread hole of the sleeve; the top sleeve is tightened and the clamp is pressed against the conical hole of the sleeve; after pouring concrete, a concrete pile is formed.

[0029] Furthermore, after the concrete pile is formed, each prestressed steel bar is cut off while retaining a section of prestressed steel bar outside the end plate. Before or after cutting the prestressed steel bar, the top cylinder is screwed out of the internal thread hole of the sleeve, the top cylinder is removed, and then each prestressed steel bar is tensioned a second time. After tensioning is completed, the prestressed steel bar exposed outside the end plate is cut off.

[0030] The difference between this solution and the first technical solution is that the sleeve is fixed to the end plate before the prestressed steel bars are inserted. The top cylinder is movably sleeved on the prestressed steel bars and is not initially connected to the sleeve. The top cylinder is then screwed into the inner threaded hole of the sleeve after the clamp is installed into the sleeve. This eliminates one step of unscrewing the top cylinder out of the sleeve, thus improving production efficiency.

[0031] The two production methods described above can be applied to producing one precast concrete pile with one mold, or to producing concrete piles in a long line, where one mold can produce two or more concrete piles at a time.

[0032] The third technical problem solved by this invention is to address the shortcomings of existing technologies by using the above-mentioned locking mechanism to lock prestressed steel bars in the long-line production process (i.e., one mold can produce two or more concrete piles at the same time) to produce concrete piles. This production method can easily achieve precise locking of prestressed steel bars and clamps, and can achieve secondary tensioning of each prestressed steel bar before the pile body is formed, thereby ensuring the mechanical properties of the concrete pile body and pile end.

[0033] The technical solution adopted to solve the third technical problem is as follows: a method for producing concrete piles, wherein one mold can produce multiple concrete piles simultaneously, characterized in that: multiple prestressed steel bar locking mechanisms, multiple end plates, and multiple prestressed steel bars are used, with the end plates distributed on the mold; each sleeve is connected to the end plate via an external thread, and each top cylinder is connected to the internal thread hole of the sleeve via an external thread; each prestressed steel bar is passed through the corresponding through holes in the sleeve and top cylinder on each end plate, and the two ends of each prestressed steel bar are fixed; for each prestressed steel bar... The prestressed steel bars are tensioned for the first time. The top cylinder is screwed out of the internal threaded hole of the sleeve, the clamp is inserted into the sleeve, and then the top cylinder is screwed into the internal threaded hole of the sleeve. The top cylinder is tightened and the clamp is pressed into the conical hole of the sleeve. The prestressed steel bars between the outer end faces of two adjacent end plates are cut off, and then the two adjacent end plates are connected by a connector. Alternatively, the two adjacent end plates are connected by a connector first and then the prestressed steel bars between the outer end faces of the two adjacent end plates are cut off. Then, the prestressed steel bars are tensioned as a whole at one end of the mold. After pouring concrete, a concrete pile is formed.

[0034] The difference between this method and the previous two methods is that this scheme performs secondary tensioning of the prestressed steel bars before molding. The first tensioning is to 25% of the design tensile strength of the prestressed steel bars to straighten them, facilitating the locking mechanism to fix the prestressed steel bars to the end plate via the conical clamps. This also ensures that the positions of each prestressed steel bar locked by each conical clamp are consistent, thereby ensuring consistent tension for each prestressed steel bar in subsequent applications. The second tensioning is performed to the set value to meet the design requirements of the concrete pile.

[0035] Preferably, the sleeve is pre-connected to the end plate, and the top cylinder is connected to the internal threaded hole of the sleeve, and then the end plate with the sleeve and top cylinder installed is placed in the mold.

[0036] A connector is essentially a connection structure that connects two adjacent end plates, and its structural form can vary. Alternatively, the connector includes two connecting plates for connecting to the two adjacent end plates respectively, and a connector for fixing the two connecting plates. The connecting plates have connecting holes corresponding to the positions of the sleeves. The top cylinder passes through the connecting holes and is screwed into the internal threaded hole of the sleeve. The connecting plate is fixed to the end plate through the head at the outer end of the top cylinder. Alternatively, the end plate may have additional bolt holes, and the connecting plate and end plate are connected by bolts.

[0037] The fourth technical problem to be solved by the present invention is to provide a concrete pile that has a reasonable structure, is convenient for mechanical splicing, has better mechanical properties such as bending and shear resistance, and can increase the reinforcement density, in order to overcome the shortcomings of the prior art.

[0038] The technical solution adopted by the present invention to solve the fourth technical problem mentioned above is as follows: a concrete pile, comprising a pile body, prestressed steel bars inside the pile body, and an end plate at the end of the pile body, characterized in that: it further comprises a sleeve, wherein the sleeve has a tapered hole and an internally threaded hole arranged axially from left to right, the internally threaded hole being located on the right side of the tapered hole, the diameter of the tapered hole gradually increasing from left to right, the outer periphery of the sleeve having an external thread, and the sleeve being threadedly connected to the end plate through the external thread; a tapered clamp located inside the tapered hole and its outer circumferential surface being adapted to the tapered hole, the center of the clamp having an internal toothed hole, the peripheral wall of the internal toothed hole having locking teeth, the prestressed steel bars being locked by the internal toothed hole; the end of the prestressed steel bar being accommodated in the internally threaded hole of the sleeve, and an annular space being formed between the prestressed steel bar and the inner wall of the internally threaded hole, the right end of the internally threaded hole being open, the internally threaded hole being usable for threaded connection with other components or the annular space being filled with sealing material.

[0039] The aforementioned piles are formed by centrifugal molding or vibration molding, and the cross-section of the piles is circular, square, H-shaped, or irregular.

[0040] The end plate is also provided with threaded holes for connecting other components.

[0041] The sealing material filling the annular space can be epoxy resin or concrete.

[0042] The second technical solution adopted by the present invention to solve the fourth technical problem mentioned above is: a concrete pile, including a pile body, prestressed steel bars inside the pile body and an end plate at the end of the pile body, which is manufactured according to the aforementioned production method.

[0043] Compared with the prior art, the advantages of this precast concrete component are as follows: The concrete pile of this invention is produced using the above-mentioned locking mechanism. The ends of the prestressed steel bars are accommodated in the internal threaded hole of the sleeve, so that the tension of each prestressed steel bar in the pile body is consistent, and the locking force of each prestressed steel bar locking end plate is consistent, thereby improving the mechanical properties of the concrete pile body and pile ends, such as bending resistance, shear resistance, and pull-out resistance. An annular space is formed between the prestressed steel bar and the inner wall of the internal threaded hole. The right end of the internal threaded hole is open, so it can be used for mechanical pile splicing or connection with other components. At the same time, when the internal threaded hole of the sleeve also serves as a connection hole for mechanical pile splicing or connection with other components, it is not necessary to set a separate connection hole on the end plate, thereby increasing the distribution density of prestressed steel bars in a limited end plate area to produce concrete piles with higher mechanical properties. Attached Figure Description

[0044] Figure 1 is a cross-sectional view of an embodiment of the locking mechanism;

[0045] Figure 2 is a three-dimensional schematic diagram of the sleeve in an embodiment of the locking mechanism;

[0046] Figure 3 is a cross-sectional view of the sleeve in an embodiment of the locking mechanism;

[0047] Figure 4 is a three-dimensional schematic diagram of the top cylinder in an embodiment of the locking mechanism;

[0048] Figure 5 is a cross-sectional view of the top cylinder in an embodiment of the locking mechanism;

[0049] Figure 6 is a three-dimensional structural diagram of the clamp in the embodiment of the locking mechanism;

[0050] Figure 7 is an exploded perspective view of the clamp in an embodiment of the locking mechanism;

[0051] Figure 8 is a structural schematic diagram of the first embodiment of the production method;

[0052] Figure 9 is a structural schematic diagram of the second embodiment of the production method (first connector type);

[0053] Figure 10 is a structural schematic diagram of the second embodiment of the production method (second connector type);

[0054] Figure 11 is a structural schematic diagram of the second embodiment of the production method (third connector type);

[0055] Figure 12 is a structural schematic diagram of the second embodiment of the production method (fourth connector type);

[0056] Figure 13 is a structural schematic diagram of the second embodiment of the production method (the fifth type of connector);

[0057] Figure 14 is a three-dimensional schematic diagram of an embodiment of a concrete pile;

[0058] Figure 15 is a partial cross-sectional view of an embodiment of a concrete pile. Detailed Implementation

[0059] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0060] Figures 1 to 7 show preferred embodiments of the locking mechanism for prestressed steel bars in precast concrete components.

[0061] A locking mechanism for prestressed steel bars in a precast concrete component, wherein the precast concrete component may be a concrete pile or a concrete slab, and the prestressed steel bars 2 are steel strands or steel bars, etc.

[0062] Sleeve 1 has a tapered hole 1a and an internally threaded hole 1b arranged sequentially from left to right and extending axially. The internally threaded hole 1b is located to the right of the tapered hole 1a. The diameter of the tapered hole 1a gradually increases from left to right. The outer periphery of sleeve 1 has an external thread 1c for threaded connection with end plate 3. The direction of rotation of the internally threaded hole 1b on sleeve 1 is opposite to the direction of rotation of the external thread 1c on sleeve 1.

[0063] A conical clamp 5 is placed inside the conical hole 1a, and its outer peripheral surface is adapted to the conical hole 1a. The center of the clamp 5 has an internal toothed hole 51 for locking the prestressed steel bar 2, and the peripheral wall of the internal toothed hole 51 has locking teeth 52. The clamp 5 is formed by assembling two or three clamping pieces, and the outer peripheral surface of the clamp 5 forms a conical surface 53 that matches the conical hole 1a.

[0064] The top cylinder 6 has an axially penetrating through hole 6a, and its outer periphery is provided with an external thread 6b for threaded connection with the internal threaded hole 1b of the sleeve 1. When the clamp 5 is placed in the tapered hole 1a, the external thread 6b of the top cylinder is connected to the internal threaded hole 1b of the sleeve 1, and the inner end of the top cylinder 6 can directly or indirectly abut against the right end face of the clamp 5. The internal toothed hole 51 of the clamp 5 and the through hole 6a of the top cylinder 6 are axially penetrating to allow the prestressed steel bars 2 to pass through sequentially. The top cylinder 6 has a connecting part 61 and a head 62. The connecting part 61 is a threaded column for connection with the internal threaded hole 1b, and the head 62 is a polygon for easy engagement with a wrench, and the outer diameter of the head 62 is larger than the outer diameter of the connecting part 61.

[0065] With the sleeve 1 threadedly connected to the end plate 3, the outer end of the sleeve 1 is flush with or lower than the outer end face of the end plate 3. In this embodiment, the sleeve 1 is in the shape of a stepped shaft, the external thread 1c of the sleeve is provided on the outer periphery of the small shaft part on the right side of the sleeve 1, and the shoulder 11 of the sleeve 1 abuts against the inner end face of the end plate 3.

[0066] This locking mechanism is used to lock the straightened prestressed steel bars 2 onto the end plate. Specifically, each sleeve 1 is first connected to the end plate 3 through the external thread 1c of the sleeve. One end of each prestressed steel bar 2 is passed through the conical hole 1a, the internal threaded hole 1b of the corresponding sleeve 1 on the end plate 3, and the through hole 6a of the top cylinder 6. The two ends of each prestressed steel bar 2 are fixed. Then, the prestressed steel bars are tensioned. They can be tensioned to about 25% of the tensile strength of the prestressed steel bars first, or they can be tensioned to the design value in one go. The clamp 5 is connected in series with the prestressed steel bars 2 and inserted into the conical hole 1a of the sleeve 1. The top cylinder 6 is screwed into the internal threaded hole 1b of the sleeve 1. The top cylinder 6 is tightened and the clamp 5 is gradually pressed into the conical hole 1a of the sleeve 1. The clamp 5 can then tightly fix and lock the prestressed steel bars 2. The locking mechanism of this invention allows the conical clamp to easily lock the prestressed steel bars. This locking mechanism enables standardized operation during production, is less susceptible to human error or other factors, and significantly improves the accuracy of the conical clamp in locking the prestressed steel bars. It effectively solves the technical problems of difficulty in locking the conical clamp assembly to the prestressed steel bars, loose connections, and inconsistent clamping positions in existing technologies. This ensures that the tension of each prestressed steel bar in the concrete component remains highly consistent, greatly improving the mechanical properties of the concrete component itself and its ends. Based on this, precast concrete components with ultra-high mechanical properties can be produced, ensuring product quality and performance.

[0067] The left and right directions in this application are based on the direction shown in Figure 1. They are introduced to facilitate the description of the relative positional relationships of various parts and structures. They do not limit the direction of each component or part to be fixed. The visual direction may be different in multiple perspectives and different scenes, but their relative positional relationships are determined.

[0068] Figure 8 shows the first embodiment of a method for producing precast concrete components using the aforementioned locking mechanism.

[0069] A method for producing precast concrete components includes multiple locking mechanisms as described above, multiple end plates 3, and multiple prestressed steel bars 2. The end plates 3 are distributed on a mold 9. Each sleeve 1 is connected to the end plate 3 via an external sleeve thread 1c. Each top cylinder 6 is connected to the internal threaded hole 1b of the sleeve 1 via an external top cylinder thread 6b. Each prestressed steel bar 2 is passed through the corresponding conical hole 1a of the sleeve 1 and the through hole 6a of the top cylinder 6 on each end plate 3. The two ends of each prestressed steel bar 2 are fixed, typically directly or indirectly fixed to the two ends of the prestressed steel bar with a reaction wall. The prestressed steel bars 2 are tensioned. The top cylinder 6 is unscrewed from the internal threaded hole 1b of the sleeve 1. A clamp 5 is inserted into the sleeve 1, and then each top cylinder 6 is screwed into the internal threaded hole 1b of the sleeve 1. The top cylinder 6 is tightened, and the clamp 5 is pressed tightly into the conical hole 1a of the sleeve 1. After pouring concrete, a concrete pile is formed. After the concrete pile is formed, the prestressed steel bars outside the end plate are cut off, and the concrete pile can be lifted out of the mold. The top cylinder 6 is then removed for reuse or as a connector.

[0070] Specifically, the sleeve 1 can be pre-threaded onto the end plate 3, and the external thread 6b of the top cylinder can be connected into the internal threaded hole 1b of the sleeve 1. Then, the end plate 3, with the sleeve 1 and the top cylinder 6 installed, can be placed into the mold 9. This pre-installation of the sleeve and top cylinder onto the end plate makes production more organized, avoiding excessive scattering of components that could affect production efficiency or lead to omissions. Of course, when initially connecting the top cylinder into the internal threaded hole of the sleeve, it does not need to be screwed in too tightly, to facilitate subsequent unscrewing of the top cylinder from the internal threaded hole of the sleeve to install the tapered clamp.

[0071] After the concrete pile is formed, each prestressed steel bar 2 can be cut off while retaining a section of prestressed steel bar 2 outside the end plate 3. Before or after cutting the prestressed steel bar 2, the top cylinder 6 is screwed out of the internal threaded hole 1b of the sleeve 1 again. The top cylinder 6 is then removed, and each prestressed steel bar 2 is tensioned a second time. After tensioning is completed, the prestressed steel bar 2 exposed outside the end plate 3 is cut off. The tensioning equipment is either a tensioning machine or a jack, both of which are existing technologies and will not be described in detail here.

[0072] Alternatively, one end of each prestressed steel bar 2 can be passed through the conical hole 1a, the internal threaded hole 1b of the corresponding sleeve 1 on each end plate 3, and the through hole 6a of the top cylinder 6. The top cylinder 6 is sleeved on the prestressed steel bar 2 without being connected to the sleeve 1 beforehand. After the conical clamp is placed in the conical hole of the sleeve, the top cylinder 6 is screwed into the internal threaded hole 6a of the sleeve. The advantage of this method is that, compared with the above production method, the process of screwing the top cylinder into and then out of the internal threaded hole of the sleeve can be omitted, thus saving steps.

[0073] Figures 9 to 13 show a second embodiment of the production method of concrete piles using the aforementioned locking mechanism.

[0074] A method for producing precast concrete components, wherein a single mold 9 can simultaneously produce multiple concrete piles, includes multiple prestressed steel bar locking mechanisms as described in the previous embodiments, multiple end plates 3, and multiple prestressed steel bars 2. The end plates 3 are distributed on the mold 9, and each sleeve 1 is connected to the end plate 3 via an external thread 1c. Each top cylinder 6 is connected to the internal threaded hole 1b of the sleeve 1 via an external thread 1c. Each prestressed steel bar 2 is passed through the corresponding through holes 6a of the sleeve 1 and top cylinder 6 on each end plate 3, and both ends of the passed-through prestressed steel bar 2 are fixed. Each prestressed steel bar 2 is then subjected to a single-bar initial tensioning to secure it. Straighten to facilitate the installation of tapered clamps to lock the prestressed steel bars. Unscrew the top cylinder 6 out of the internal threaded hole 1b of the sleeve 1, insert the clamp 5 into the sleeve 1, and then screw the top cylinder 6 into the internal threaded hole 1b of the sleeve 1. Tighten the top cylinder 6 and press the clamp 5 into the tapered hole 1a of the sleeve 1. Cut the prestressed steel bars 2 between the outer end faces of two adjacent end plates 3, and then connect the two adjacent end plates 3 through the connector 7, or first connect the two adjacent end plates 3 with the connector 7 and then cut the prestressed steel bars 2 between the outer end faces of the two adjacent end plates 3. Then tension each prestressed steel bar 2 as a whole at one end of the mold 9. After pouring concrete, the concrete pile is formed. After the concrete pile is formed, cut the prestressed steel bars outside the end plates, and the concrete pile can be lifted out of the mold. The top cylinder (6) is then removed for reuse or as a connector.

[0075] Specifically, the sleeve 1 can be pre-threaded onto the end plate 3, and the external thread 6b of the top cylinder can be connected into the internal thread hole 1b of the sleeve 1. Then, the end plate 3 with the sleeve 1 and the top cylinder 6 installed can be placed into the mold 9. As described above, this will make production more orderly.

[0076] As shown in Figure 9, the connector 7 includes two connecting plates 7a for connecting to two adjacent end plates 3 respectively, and a connector 7b for fixing the two connecting plates 7a. The connecting plates 7a are provided with connecting holes 7a1 corresponding to the positions of each sleeve 1. The top cylinder 6 passes through the connecting hole 7a1 and is screwed into the internal thread hole 1b of the sleeve 1. The connecting plate 7a is fixed to the end plate 3 through the head of the outer end of the top cylinder 6. Here, the top cylinder 6 not only plays the role of pressing the conical clamp inside the sleeve, but also plays the role of connecting and fixing the connecting plate 7a to the end plate 3. This method does not require a separate connecting hole for connecting the end plate 3 and the connecting plate 7a on the end plate, but uses the internal thread hole of the sleeve as the connecting hole. It also does not require a special connecting bolt, but uses the top cylinder 6 instead of the connecting bolt.

[0077] Alternatively, as shown in Figures 10-12, bolt holes are provided on the end plate 3, and the connecting plate 7a is connected to the end plate 3 by bolts 8. Alternatively, as shown in Figure 13, the connecting piece 7b is directly connected to both end plates 3.

[0078] In all the above production methods, after the concrete pile is formed, the prestressed steel bars that protrude from the end plate must be ground flat so that the ends of the prestressed steel bars are flush with or slightly lower than the outer end face of the end plate, so as not to affect the pile driving construction.

[0079] Figures 14 and 15 show examples of precast concrete components.

[0080] It includes the pile body 4, the prestressed steel bars 2 inside the pile body 4, and the end plate 3 at the end of the pile body 4.

[0081] Sleeve 1 has a tapered hole 1a and an internal threaded hole 1b arranged axially from left to right. The internal threaded hole 1b is located to the right of the tapered hole 1a. The diameter of the tapered hole 1a gradually increases from left to right. The outer circumference of sleeve 1 has an external thread 1c. Sleeve 1 is threadedly connected to end plate 3 through the external thread 1c.

[0082] A conical clamp 5 is located inside the conical hole 1a and its outer circumferential surface is adapted to the conical hole 1a. The clamp 5 has an internal toothed hole 51 at its center and a retaining tooth 52 on the peripheral wall of the internal toothed hole 51. The prestressed steel bar 2 is locked by the internal toothed hole 51.

[0083] The end of the prestressed steel bar 2 is accommodated in the internal threaded hole 1b of the sleeve 1, and an annular space Q is formed between the prestressed steel bar 2 and the inner wall of the internal threaded hole 1b. The internal threaded hole 1b can be used to connect with other components by threads, and the annular space Q can also be filled with sealing material to seal the end of the steel bar.

[0084] The pile body 4 is formed by centrifugal molding or vibration molding, and the cross-section of the pile body 4 is circular, square, H-shaped, or irregular. Threaded holes for connecting other components may also be provided on the end plate 3.

[0085] The sealing material can be epoxy resin or concrete.

[0086] The aforementioned precast concrete components can be manufactured using the aforementioned production methods.

[0087] It should be noted that in the description of this embodiment, the terms "front," "rear," "left," "right," "inner," "outer," "upper," and "lower," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are merely for the convenience of describing the invention 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. Therefore, they should not be construed as limitations on the invention. The terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A prestressed steel bar locking mechanism for precast concrete components, characterized in that: include Sleeve (1), the sleeve (1) has a tapered hole (1a) and an internal threaded hole (1b) arranged sequentially from left to right and axially penetrating inside the sleeve (1), the internal threaded hole (1b) is located to the right of the tapered hole (1a), the diameter of the tapered hole (1a) gradually increases from left to right, and the outer periphery of the sleeve (1) has a sleeve external thread (1c) for threaded connection with the end plate (3); A conical clamp (5) can be placed in the conical hole (1a) and its outer peripheral surface is adapted to the conical hole (1a). The center of the clamp (5) has an internal toothed hole (51) for locking the prestressed steel bar (2), and the peripheral wall of the internal toothed hole (51) has a locking tooth (52). The top cylinder (6) has an axially penetrating through hole (6a) and the outer periphery of the top cylinder (6) is provided with a top cylinder external thread (6b) for threaded connection with the internal threaded hole (1b) of the sleeve (1); when the clamp (5) is placed in the tapered hole (1a), the top cylinder is screwed into the internal threaded hole (1b) of the sleeve (1) through the top cylinder external thread (6b) and the inner end of the top cylinder (6) can directly or indirectly abut against the right end face of the clamp (5). The internal toothed hole (51) of the clamp (5) and the through hole (6a) of the top cylinder (6) are axially penetrating so that the prestressed steel bars (2) can pass through in sequence.

2. The locking mechanism according to claim 1, characterized in that: With the sleeve (1) threadedly connected to the end plate (3), the right end of the sleeve (1) is flush with or lower than the outer end face of the end plate (3).

3. The locking mechanism according to claim 2, characterized in that: The sleeve (1) is in the shape of a stepped shaft, and the external thread (1c) of the sleeve is provided on the outer periphery of the small shaft part on the right side of the sleeve (1). The shoulder (11) of the sleeve (1) abuts against the inner end face of the end plate (3).

4. The locking mechanism according to claim 1, characterized in that: The top cylinder (6) has a connecting part (61) and a head (62). The connecting part (61) is a threaded column for connecting with the internal threaded hole (1b). The head (62) is polygonal and its outer diameter is larger than that of the connecting part.

5. The locking mechanism according to claim 1, characterized in that: The thread direction of the internal threaded hole (1b) on the sleeve (1) is opposite to the thread direction of the external thread (1c) on the sleeve (1).

6. A method for producing precast concrete components, characterized in that: Using multiple locking mechanisms as described in any one of claims 1 to 5, multiple end plates (3), and multiple prestressed steel bars (2), the end plates (3) are distributed on the mold (9). Each sleeve (1) is connected to the end plate (3) through the sleeve external thread (1c), and each top cylinder (6) is connected to the internal thread hole (1b) of the sleeve (1) through the top cylinder external thread (6b). Each prestressed steel bar (2) is passed through the conical hole (1a) of the corresponding sleeve (1) and the top cylinder. (6) Through the hole (6a), fix the two ends of each prestressed steel bar (2) that has been threaded through; tension the prestressed steel bar (2); unscrew each of the top cylinders (6) out of the internal thread hole (1b) of the sleeve (1), put the clamp (5) into the sleeve (1), and then screw each of the top cylinders (6) into the internal thread hole (1b) of the sleeve (1), tighten the top cylinder (6) and press the clamp (5) against the conical hole (1a) of the sleeve (1); after pouring concrete, form a concrete pile.

7. The method for producing precast concrete components according to claim 6, characterized in that: The sleeve (1) is connected to the end plate (3) in advance and the top cylinder is connected to the internal thread hole (1b) of the sleeve (1). Then the end plate (3) with the sleeve (1) and the top cylinder (6) installed is placed in the mold (9).

8. The method for producing precast concrete components according to claim 6, characterized in that: After the concrete pile is formed, the prestressed steel bars outside the end plate are cut off and the top cylinder (6) is removed.

9. The method for producing precast concrete components according to claim 6, characterized in that: After the concrete pile is formed, each prestressed steel bar (2) is cut off while retaining a section of prestressed steel bar (2) outside the end plate (3). Before or after cutting the prestressed steel bar (2), the top cylinder (6) is screwed out of the internal thread hole (1b) of the sleeve (1), the top cylinder (6) is removed, and then each prestressed steel bar (2) is tensioned a second time. After the tensioning is completed, the prestressed steel bar (2) exposed outside the end plate (3) is cut off.

10. A method for producing precast concrete components, characterized in that: Using multiple locking mechanisms as described in any one of claims 1 to 5, multiple end plates (3), and multiple prestressed steel bars (2), the end plates (3) are distributed on the mold (9). Each sleeve (1) is connected to the end plate (3) through the sleeve external thread (1c). One end of each prestressed steel bar (2) is passed through the conical hole (1a), internal thread hole (1b) of the corresponding sleeve (1) on each end plate (3), and the through hole (6a) of the top cylinder (6). The top cylinder (6) is fitted onto the prestressed steel bars (2) but not connected to the sleeve (1); the two ends of each prestressed steel bar (2) are fixed; the prestressed steel bars (2) are tensioned; the clamp (5) is inserted into the sleeve (1), the top cylinder (6) is screwed into the internal threaded hole (1b) of the sleeve (1), the top cylinder (6) is tightened, and the clamp (5) is pressed against the conical hole (1a) of the sleeve (1); after pouring concrete, a concrete pile is formed.

11. The method for producing precast concrete components according to claim 10, characterized in that: After the concrete pile is formed, each prestressed steel bar (2) is cut off while retaining a section of prestressed steel bar (2) outside the end plate (3). Before or after cutting the prestressed steel bar (2), the top cylinder (6) is screwed out of the internal thread hole (1b) of the sleeve (1). The top cylinder (6) is removed and each prestressed steel bar (2) is tensioned a second time. After tensioning is completed, the prestressed steel bar (2) exposed outside the end plate (3) is cut off.

12. A method for producing precast concrete components, wherein one mold (9) can simultaneously produce multiple concrete piles, characterized in that: Using multiple locking mechanisms as described in any one of claims 1 to 5, multiple end plates (3), and multiple prestressed steel bars (2), the end plates (3) are distributed on the mold (9). Each sleeve (1) is connected to the end plate (3) through the external thread (1c) of the sleeve. Each top cylinder (6) is connected to the internal thread hole (1b) of the sleeve (1) through the external thread of the top cylinder (6). Each prestressed steel bar (2) is passed through the corresponding through hole (6a) of the sleeve (1) and top cylinder (6) on each end plate (3), and the two ends of each prestressed steel bar (2) are fixed. Each prestressed steel bar (2) is tensioned for the first time, and the top cylinder (6) is unscrewed from the sleeve (1). The internal threaded hole (1b) of the sleeve (1) is used to insert the clamp (5) into the sleeve (1), and then the top cylinder (6) is screwed into the internal threaded hole (1b) of the sleeve (1). The top cylinder (6) is tightened and the clamp (5) is pressed into the conical hole (1a) of the sleeve (1). The prestressed steel bars (2) between the outer end faces of two adjacent end plates (3) are cut off, and then the two adjacent end plates (3) are connected by the connector (7). Alternatively, the two adjacent end plates (3) can be connected by the connector (7) first and then the prestressed steel bars (2) between the outer end faces of the two adjacent end plates (3) are cut off. Then, the prestressed steel bars (2) are tensioned as a whole at one end of the mold (9). After pouring concrete, the concrete pile is formed.

13. The method for producing precast concrete components according to claim 12, characterized in that: The sleeve (1) is connected to the end plate (3) in advance, and the top cylinder is connected to the internal thread hole (1b) of the sleeve (1). Then the end plate (3) with the sleeve (1) and the top cylinder (6) installed is placed in the mold (9).

14. The method for producing precast concrete components according to claim 12, characterized in that: The connector (7) includes two connecting plates (7a) for connecting to two adjacent end plates (3) respectively, and a connector (b) for fixing the two connecting plates (7a); the connecting plate (7a) is provided with a connecting hole (7a1) corresponding to the position of each sleeve (1), the top cylinder (6) passes through the connecting hole (7a1) and is screwed into the internal thread hole (1b) of the sleeve (1), and the connecting plate is fixed to the end plate (3) by the head of the outer end of the top cylinder (6), or, the end plate (3) is provided with a bolt hole (31), and the connecting plate (7a) and the end plate (3) are connected by bolts (8).

15. A precast concrete component, comprising a pile body (4), prestressed steel bars (2) within the pile body (4), and an end plate (3) at the end of the pile body (4), characterized in that: Also includes Sleeve (1), the sleeve (1) has a tapered hole (1a) and an internal threaded hole (1b) arranged axially from left to right. The internal threaded hole (1b) is located to the right of the tapered hole (1a). The diameter of the tapered hole (1a) gradually increases from left to right. The outer periphery of the sleeve (1) has an external thread (1c). The sleeve (1) is threadedly connected to the end plate (3) through the external thread (1c). A conical clamp (5) is located inside the conical hole (1a) and its outer peripheral surface is adapted to the conical hole (1a). The clamp (5) has an internal toothed hole (51) at its center and a retaining tooth (52) on the peripheral wall of the internal toothed hole (51). The prestressed steel bar (2) is locked by the internal toothed hole (51). The end of the prestressed steel bar (2) is accommodated in the internal threaded hole (1b) of the sleeve (1), and an annular space (Q) is formed between the prestressed steel bar (2) and the inner wall of the internal threaded hole (1b). The right end of the internal threaded hole (1b) is open. The internal threaded hole (1b) can be used to connect with other components by threads or the annular space (Q) can be filled with sealing material.

16. The precast concrete component according to claim 15, characterized in that: The pile body (4) is formed by centrifugal molding or vibration molding, and the cross-section of the pile body (4) is circular, square, H-shaped or irregular.

17. The concrete pile according to claim 15, characterized in that: The end plate (3) is provided with threaded holes that can be used to connect other components.

18. A precast concrete component, comprising a pile body (4), prestressed steel bars within the pile body (4), and an end plate (3) at the end of the pile body (4), characterized in that: Manufactured by the production method according to any one of claims 6-14.

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