CN220977976U - Pretension mechanical joint of multidentate card joint, precast concrete stake - Google Patents

Abstract

The utility model discloses a pre-tightening mechanical connector for clamping a multi-tooth clamping piece and a precast concrete pile, wherein the connector comprises a plunger rod with a plug; a large nut having a receiving cavity; a pretension nut having a pretension nut threaded connection portion and a pretension nut driving portion; a multi-tooth card assembly disposed within the pretension nut; when the multi-tooth card assembly is clamped on the plug, the driving part can drive the pre-tightening nut driving part from the lateral direction of the pre-tightening nut, so that the pre-tightening nut rotates and moves along the axial direction of the large nut, and the plug and the pre-tightening nut are locked in the axial direction of the large nut. The pre-tightening mechanical connector for the multi-tooth clamping piece disclosed by the utility model can effectively eliminate the axial gap among the plug, the multi-tooth clamping piece assembly and the pre-tightening nut, so that the joint of the precast concrete pile is not cracked and cracked when the joint is subjected to the acting forces such as drawing force, shearing force or bending force.

Description

Pretension mechanical joint of multidentate card joint, precast concrete stake

Technical Field

The utility model relates to the technical field of prefabricated parts, in particular to a pre-tightening mechanical connector for clamping a multi-tooth card and a prefabricated concrete pile.

Background

The common engineering piles (precast piles) are multi-section piles, and the existing precast concrete pile ends are generally connected with each other rapidly through mechanical joints.

The 5.1.7 th rule in the technical Standard of prestressed concrete pipe piles is that the crack control grade of the prestressed pipe pile is one grade for the prestressed pipe pile which has no crack under strict requirements; 5.1.8, when the axial center of the pile body of the specified pipe pile is pulled, the crack control grade is a first grade; when the tubular pile body is bent. The control grade of the tubular pile crack in the weak corrosion environment and above is two-level, and the control grade of the tubular pile crack in the medium and strong corrosion environment and above is one-level.

In the specification of concrete structural design, GB50010-2015, 3.4.4 specifies that the stress crack control class of the normal section of the structural member is classified into three classes, and the classification and requirements meet the following specifications:

First-order-members which are strictly required to be free of cracks, and when the members are subjected to tensile edge concrete according to load standard combination calculation, tensile stress is not generated.

And the second level, namely a component which is generally required to be free of cracks, and the tensile stress of the concrete at the tensile edge of the component is not larger than the standard value of the tensile strength of the concrete when calculated according to the load standard combination.

Three stages-means to allow cracking: for reinforced concrete components, the maximum crack width of the component should not exceed the maximum crack width limit specified in the specification table 3.4.5 when calculated by taking the long-term effect into account in the load quasi-permanent combination. When the prestressed concrete member is combined according to the load standard and the influence of long-term action is considered for calculation, the maximum crack width of the member should not exceed the maximum crack width limit value specified in 3.4.5 of the specification table; for the prestressed concrete member in the two-a environment, the load quasi-permanent combination is calculated, and the tensile stress of the member tensile edge concrete is not larger than the tensile strength standard value of the concrete. In the specification of 3.4.5 of the specification table, the prestressed concrete structure is specified to have a crack control level of one in three a and three b environments, a crack control level of two in two b environments, no crack is allowed to be generated in one and two crack control levels, a crack control level of three in two a environments, a limit of maximum crack width of 0.1mm is set, a crack control level of three in one environment, and a limit of maximum crack width of 0.2mm is set.

A first structural form of the existing mechanical joint is shown in fig. 23, and comprises a large nut 2, a small nut 21, a plug rod 1 and a connecting piece 90; insert rod one end and little nut threaded connection, the other end is equipped with the plug, and the connecting piece is equipped with a plurality of snap rings with big nut threaded connection, and the one end in the big nut is arranged in to the connecting piece, and the plug inserts from the one end of connecting piece and can with snap ring butt, realizes the joint of insert rod and connecting piece to can realize the quick-operation joint of two sections precast concrete stake through this mechanical joint, however, this kind of mechanical joint carries out precast concrete stake and connects and have following not enough: 1. when the mechanical joint is used for connecting the precast concrete piles, the condition that the inserted rod is inserted into the connecting piece is caused by the inclination of the pile end face and the like, when the condition that the inserted rod is inserted into the connecting piece is caused, all or part of the mechanical joint at the pile connecting end face can generate axial gaps when the precast concrete piles are subjected to acting forces such as pulling force, shearing force or bending force and the like, and then the axial gaps are correspondingly generated at the precast concrete pile connecting position, so that the precast concrete pile mechanical joint connecting position cracks to generate cracks, specifically, as shown in fig. 23, a schematic diagram of the inserted rod is shown, when the inserted rod is inserted into the connecting piece, the axial gaps delta h are formed between the end parts of the elastic snap rings and the blocking surfaces of the inserted rod, so that corresponding axial gaps are generated between the connecting end faces of the precast concrete piles under the action of external force, and the crack control level of the prestressed pipe pile which is specified in the 5.1.7 th section of the technical standard of prestressed concrete pipe piles is not required to be strictly generated is the first-level pipe pile; when the axis of the pile body of the pipe pile specified in the 5.1.8 th step is pulled, the crack control grade is a first grade; when the tubular pile body is bent. The control grade of the tubular pile crack in the weak corrosion environment and above is two-level, and the control grade of the tubular pile crack in the medium and strong corrosion environment and above is one-level; 2. because the large nut is connected with the connecting piece and the small nut is connected with the inserted link through threads, certain axial gaps exist in the threaded connection, when the mechanical joint is subjected to drawing force, the corresponding axial gaps are generated between the connecting end faces of the precast concrete piles due to the axial gaps in the threaded connection, and the size of cracks at the connecting positions of the precast concrete piles is further increased, so that the requirements for crack control in the technical standard of prestressed concrete pipe piles cannot be met when the precast concrete piles are used for connecting the precast concrete piles; 3. as shown in fig. 24, when the mechanical joint is used for connecting precast concrete piles, there is a problem that the plug of the insert rod is not inserted into the connecting piece, namely, when the insert rod is inserted into the connecting piece, the end part of the elastic snap ring does not enter into the annular groove of the insert rod, so that the insert rod and the connecting piece cannot be clamped, and the connection of the piles is failed.

A second structural form of the conventional mechanical joint is shown in fig. 25, and includes a large nut 2, a small nut 21, a plug rod 1, an intermediate nut 91, an elastic member 92, and a snap ring 93; insert rod one end and little nut threaded connection, the other end is equipped with the plug, middle nut and big nut threaded connection, the one end that big nut was arranged in to the middle nut is equipped with the toper joint face, be equipped with elastic component and a plurality of snap ring in the holding intracavity of big nut, the elastic component is with a plurality of snap rings butt on the toper joint face of middle nut, the plug inserts and can compress the elastic component from the one end of middle nut, thereby make the plug pass the space that a plurality of snap rings enclose and carry out the snap ring joint between middle nut and plug, in order to realize the quick coupling of two sections precast concrete stake, however, use this kind of mechanical joint to carry out precast concrete stake connection and have following inadequately: 1. in the process of inserting the insert rod into the middle nut, there is a situation that the central axis x-x of the insert rod is not coaxial with the central axis y-y of the middle nut, so as shown in fig. 25, 26 and 27, when the insert rod is inserted into the middle nut, the snap ring on one side close to the axis of the insert rod is firstly contacted with the plug, and the snap ring on one side far from the axis of the insert rod is firstly contacted with the plug and compresses the spring under the action of the plug, and the snap ring on the upper side is contacted with the plug, so that the snap ring on one side as shown in fig. 26 possibly enters between the plug and the middle nut, and the snap ring on the other side cannot enter between the plug and the middle nut; or as shown in fig. 27, the clamping positions of the plurality of clamping rings, the plug and the middle nut are different, so that pile connection failure or low connection strength of the mechanical connector is caused, and when the precast concrete pile is subjected to acting forces such as pulling force, shearing force or bending force, axial sliding occurs between the inserted rod of the mechanical connector and the clamping rings, so that all or part of the mechanical connector at the pile connection end face can generate axial gaps, and the joint of the precast concrete pile mechanical connector is cracked to generate cracks; 2. after the plug is inserted into the middle nut and is clamped with the clamping ring, no wedge-shaped surface is formed among the plug, the clamping ring and the middle nut (the acting force between the plug and the clamping ring is very small), so that when the insert rod is subjected to the acting force such as drawing force, shearing force or bending force, the plug of the insert rod can squeeze the clamping ring, and further the clamping ring can slide axially relative to the plug, so that when the mechanical joint is adopted for connecting precast concrete piles, all or part of the mechanical joints at the pile connecting end surfaces can generate axial gaps when the mechanical joint is subjected to the acting force such as pulling force, shearing force or bending force, and then the corresponding axial gaps are generated at the precast concrete pile connecting positions, and the precast concrete pile mechanical joint is cracked to generate cracks; 3. as shown in fig. 27, the clamping surfaces of the clamping ring and the plug are tapered cylindrical surfaces, and the clamping positions of the clamping ring and the plug are uncertain, so that the clamping surfaces of the clamping ring and the plug are not completely attached when the clamping ring and the plug are clamped. As shown in fig. 28, the curves Q1 to Q5 in the drawing represent the curves of the cross-section radius at different positions of the clamping surface of the plug, and the curve J in the drawing represents the curves of the cross-section radius at a certain position of the clamping ring, as shown in the drawing, when the curve J is at the position Q1, the curve J is completely attached to the curve Q1, and when the curve J is at the position Q2 to Q5, the gap between the curve J and the curve Q is gradually increased, that is, when the clamping ring is at different positions of the plug, the clamping states of the clamping ring and the plug are different, that is, the clamping surface of the clamping ring and the clamping surface of the plug cannot be guaranteed to be completely attached. The clamping ring is in line contact with the plug, when the mechanical connector is subjected to the action force such as the drawing force, the shearing force or the bending force, axial sliding can be generated between the clamping ring and the plug or the clamping ring can be partially embedded into the plug (or the clamping ring is subjected to the action force to deform) so as to cause the mechanical connector to generate an axial gap, namely when the mechanical connector is used for connecting the precast concrete pile and is subjected to the action force such as the drawing force, the shearing force or the bending force, the corresponding axial gap can be generated between the connecting end surfaces of the precast concrete pile, so that the connecting part of the mechanical connector of the precast concrete pile is cracked to generate cracks; 4. because all pass through threaded connection between big nut and the middle nut and between little nut and the inserted bar, threaded connection also can have certain axial clearance, and then when mechanical joint receives effort such as drawing force, shearing force or bending force, threaded connection's axial clearance also can cause to produce corresponding axial clearance between precast concrete pile's the terminal surface of connection for precast concrete pile mechanical joint junction fracture produces the crack. The mechanical structure has the defects, so that when the mechanical joint is used for connecting precast concrete piles, the precast concrete pile connection is easy to be impossible to achieve the prestressed pipe pile which is specified in the 5.1.7 th item of the technical standard of prestressed concrete pipe piles in JGJ/T406-2017 and has no crack for strict requirements, and the crack control level is one level; when the axis of the pile body of the pipe pile specified in the 5.1.8 th step is pulled, the crack control grade is a first grade; when the tubular pile body is bent. The control grade of the tubular pile crack in the weak corrosion environment and above is two-level, and the control grade of the tubular pile crack in the medium and strong corrosion environment and above is one-level.

The existing mechanical joint has the problem of axial clearance, so that the prefabricated concrete pile is connected by adopting the mechanical joint, and when the prefabricated concrete pile is subjected to acting forces such as drawing force, shearing force and/or bending force, the gap can be generated by the mechanical joint connection mechanism of the prefabricated concrete pile, so that a crack is generated at the joint of the prefabricated concrete pile. The precast pile foundation belongs to underground hidden engineering, and the precast pile itself can not be repaired.

Building pile foundation potential safety hazard that concrete precast pile joint produced crack:

When the precast concrete pile bears bending resistance and shearing resistance, the axial clearance exists at the joint of the precast concrete pile, and the axial clearance of the mechanical joint can lead the joint of the precast concrete pile to generate cracks, thereby leading the pile and the pile not to be on the same axis and leading the connecting end surface of the pile to generate local eccentric stress; the concrete on the pile end face is damaged or broken, so that potential safety hazards exist on the building pile foundation.

When the precast concrete pile bears the tensile force, the axial gaps generated by the mechanical joints cannot be ensured to be completely consistent, and the design value of the axial center tensile bearing capacity of the pile body of the precast pile is considered according to the total number of main ribs (the number of the mechanical joints); the mechanical joints are broken one by one when being pulled, so that potential safety hazards exist on the building pile foundation.

When the precast concrete pile bears bending resistance, shearing resistance and tensile force, the joint of the precast concrete pile is cracked due to the generation of axial gaps, so that groundwater can invade and corrode a mechanical connector and/or a main rib of the precast pile, and the durability of the precast pile is difficult to ensure, specifically, the annual corrosion rate of a steel pile in the table 4.1.18 in the technical Specification of building pile foundation, JGJ94-2008 can be known, and the single-sided corrosion rate is 0.05-0.1 mm/y when the steel pile is positioned above the ground and is in an environment without corrosive gas or corrosive volatile medium; when the steel pile is positioned below the ground and above the water level, the single-sided corrosion rate is 0.05mm/y; when the steel pile is positioned below the ground and below the water level, the single-sided corrosion rate is 0.03mm/y; the steel pile is positioned below the ground and in a water level fluctuation zone, and the single-side corrosion rate is 0.1-0.3 mm/y; thus, it is known that when a precast concrete pile is cracked due to an axial gap of a mechanical joint, the mechanical joint and/or a main rib thereof is rapidly corroded, so that the durability of the precast pile is difficult to ensure, and the severity of the hazard thereof is nonverbal.

Disclosure of Invention

The utility model provides a multi-tooth clamping-connected pre-tightening mechanical joint, which aims at solving the problems that the axial clearance exists in the existing mechanical joint connection mechanism to cause the crack at the joint of a precast concrete pile to cause the corrosion of a main rib and/or the mechanical joint, the local compression of the pile end surface and the like, and solves the problem of potential safety hazard caused by the axial clearance after the existing mechanical joint connection.

The utility model adopts the following technical means:

a pre-tightening mechanical joint for clamping a multi-tooth card, which comprises a clamping plate,

The plug is arranged at one end of the inserted link, and a first tooth is arranged on the outer wall of the plug;

The large nut is internally provided with a containing cavity;

The pre-tightening nut is internally provided with an insertion cavity, a multi-tooth card accommodating groove is formed in the insertion cavity, and the outer wall of the pre-tightening nut is provided with a pre-tightening nut threaded connection part and a pre-tightening nut driving part; the pre-tightening nut threaded connection part is arranged in the large nut and is in threaded connection with the accommodating cavity, and at least part of the pre-tightening nut driving part is positioned outside the accommodating cavity;

The multi-tooth card assembly is arranged in the multi-tooth card accommodating groove and comprises a plurality of circumferentially spliced cards and an elastic ring sleeved outside the cards and provided with radial elasticity, a plurality of cards enclose a clamping cavity, the cards can expand and contract in the multi-tooth card accommodating groove, the inner wall of each card is provided with a second tooth, and the plug can be inserted into the clamping cavity and is clamped with the second tooth so as to realize the clamping of the plug and the multi-tooth card assembly;

When the multi-tooth card assembly is clamped with the plug, the driving part can drive the pre-tightening nut driving part from the lateral direction of the pre-tightening nut, so that the pre-tightening nut rotates and moves along the axial direction of the large nut, and the plug and the pre-tightening nut are locked in the axial direction of the large nut.

Further, the driving part of the pre-tightening nut is provided with driving teeth, the driving part is a screw rod, and the screw rod is provided with engaging teeth which can be engaged with the driving teeth.

Further, the driving teeth are straight teeth parallel to the axis of the pre-tightening nut or inclined teeth forming a certain angle with the axis of the pre-tightening nut.

Further, in the process of inserting the plug into the clamping cavity, the maximum outer diameter of the plurality of cards when being opened is smaller than or equal to the inner diameter of the multi-tooth card accommodating groove;

the minimum inner diameter of the plurality of cards when open is less than or equal to the minimum inner diameter of the insertion cavity.

Further, the inner wall of one side of the multi-tooth card accommodating groove close to the plug insertion end is a first abutting surface, a second abutting surface is arranged on one side of the card facing the plug insertion end, and when the plug and the pre-tightening nut are locked in the axial direction of the large nut, the first abutting surface and the second abutting surface are mutually abutted.

Further, the first abutment surface and the second abutment surface are both tapered surfaces.

Further, the first teeth and the second teeth are saw tooth type teeth or pagoda type teeth.

Further, before the plug and the multi-tooth card assembly are locked in the axial direction of the large nut, the threaded connection between the pre-tightening nut and the large nut is loose-fit threaded connection.

Further, after the plug and the multi-tooth card assembly are locked in the axial direction of the large nut, the tensile strength of the connection of the plug and the multi-tooth card assembly is larger than or equal to that of any one of the main rib, the large nut and the small nut.

Further, the device also comprises a small nut used for being connected with the inserted link base of the inserted link.

The invention relates to a precast concrete pile, which comprises a precast concrete pile body, a main rib and a pre-tightening mechanical connector clamped by a multi-tooth clamping piece, wherein the pre-tightening mechanical connector is arranged on the precast concrete pile body;

The main rib is arranged in the precast concrete pile body, one end of the precast concrete pile body is provided with the large nut, and the pretension nut and the multi-tooth card assembly are arranged in the large nut;

the inserted link is arranged at the other end of the precast concrete pile body;

The end part of the precast concrete pile body is provided with a driving part accommodating groove;

When two adjacent precast concrete piles are connected, one end of the driving part accommodating groove is communicated with the outer wall of the precast concrete pile body, the other end of the driving part accommodating groove extends to the end part of the pre-tightening nut, so that after the driving part is inserted into the driving part accommodating groove from the outer wall of the precast concrete pile body, the driving part can interact with the driving part of the pre-tightening nut, the pre-tightening nut can rotate and move along the axial direction of the large nut, and the plug and the pre-tightening nut are locked in the axial direction of the large nut.

Further, the one end that precast concrete stake body was equipped with the inserted bar still is equipped with little nut, big nut with the one end of little nut respectively with the both ends of main muscle are connected, the inserted bar with the other end threaded connection of little nut.

Further, the driving part remains in or moves out of the driving part accommodating groove after the driving part drives the pre-tightening nut to rotate and locks the plug and the pre-tightening nut in the axial direction of the large nut.

Further, structural adhesive is also injected into the connecting end face of the precast concrete pile body and the pretension mechanical connector clamped by the multi-tooth clamping piece.

Compared with the prior art, the pretension mechanical connector for clamping the multi-tooth card has the following beneficial effects: the pre-tightening mechanical joint for the multi-tooth clamping connection disclosed by the utility model has the advantages that the pre-tightening nut driving part is arranged on the pre-tightening nut, and after the plug is inserted into the cavity, the pre-tightening nut driving part is driven by the driving part from the side direction of the pre-tightening nut, so that the pre-tightening nut moves along the axial direction of the large nut, the plug and the pre-tightening nut are locked in the axial direction of the large nut, the axial gaps among the plug, the multi-tooth clamping component and the pre-tightening nut are effectively eliminated, and further, as the pre-tightening nut, the inserted rod and the multi-tooth clamping component are locked in the axial direction, a certain axial acting force (tightening force) is generated in the axial direction in the locking process, and under the action of the axial acting force, the axial gaps among the pre-tightening nut, the inserted rod, the large nut, the multi-tooth clamping component and the small nut can be effectively eliminated, so that when the mechanical joint disclosed by the utility model is used for connecting a concrete pile, the precast pile is subjected to the action force such as a tensile force, a shearing force or a bending force, and a crack is not generated at the precast pile, and the precast pile crack can meet the requirements of a precast pile-G406, and the precast pile can meet the related requirements of the technology. And the problem that gaps are generated in the connection of the precast concrete piles due to the fact that gaps are generated in the connection mechanism of the existing mechanical connectors, cracks are generated at the joints of the precast concrete piles, and potential safety hazards exist in the foundation of the building piles is solved.

Drawings

FIG. 1 is an axial view of a pre-tensioned mechanical joint of a multi-tooth card joint of the present disclosure;

FIG. 2 is a front view of a multi-tooth card-retaining pre-tension mechanical joint of the present disclosure;

FIG. 3 is a cross-sectional view of a pre-tensioned mechanical joint of the disclosed multi-tooth card-lock;

FIG. 4 is a schematic diagram of a pretensioned mechanical connector for a multiple tooth card of the present utility model when the plug and the clamping spring are not axially locked after the plug is inserted into the pretensioned nut;

FIG. 5 is an enlarged view of a portion of FIG. 4 at A;

FIG. 6 is a schematic view of a pre-tightening mechanical joint for multi-tooth card locking after a plug is axially locked with a locking spring after the plug is inserted into a pre-tightening nut;

FIG. 7 is a partial enlarged view at B in FIG. 6;

FIG. 8 is a schematic view of the structure of a pretension nut of a pretension mechanical joint of the multi-tooth card-lock according to the present utility model;

FIG. 9 is a cross-sectional view of a pretension nut of a pretension mechanical joint of the multi-tooth card-joint disclosed by the utility model;

FIG. 10 is a top view of a pretension nut of a pretension mechanical joint of the disclosed multi-tooth card-joint;

FIG. 11 is a front view of the drive components of the multi-tooth card-lock pretensioned mechanical joint of the present disclosure;

FIG. 12 is a right side view of the drive member of the multi-tooth card-lock pretension mechanical joint of the present disclosure;

FIG. 13 is a front view of a multi-tooth card assembly of the pre-tensioned mechanical joint of the disclosed multi-tooth card-lock;

FIG. 14 is a cross-sectional view of a multi-tooth card assembly of the pre-tensioned mechanical joint of the disclosed multi-tooth card-lock;

FIG. 15 is a front view of a large nut of a multi-tooth card-clamped pre-tightening mechanical joint of the present disclosure;

FIG. 16 is a cross-sectional view of a large nut of a multi-tooth card-clamped pre-tightening mechanical joint of the present disclosure;

FIG. 17 is a block diagram of a plunger of a pretensioned mechanical joint of the multi-tooth card-lock of the present disclosure;

FIG. 18 is a schematic structural view of a precast concrete pile connection with a multi-tooth card-clamped pre-tensioned mechanical joint of the present disclosure, where the number of piles is two;

FIG. 19 is a cross-sectional view of a precast concrete pile connection having a multi-tooth card-clamped pre-tensioned mechanical joint of the present disclosure;

FIG. 20 is an enlarged view of a portion of FIG. 19 at D;

FIG. 21 is an end view of a precast concrete pile connection having a multi-tooth card-clamped pre-tensioned mechanical joint of the present disclosure;

FIG. 22 is an enlarged view of a portion of FIG. 21 at F;

FIG. 23 is a block diagram of a prior art first mechanical connector showing the plug in an over-inserted condition;

FIG. 24 is a block diagram of a prior art first mechanical connector showing a plug in a underinserted condition;

FIG. 25 is a schematic illustration of a prior art second mechanical joint in which the axis of the insert rod is not collinear with the axis of the intermediate nut;

FIG. 26 is a block diagram of a second prior art mechanical joint in which the plug of the bayonet is first contacted with the lower card such that the lower card cannot enter between the plug and the middle nut;

FIG. 27 is a block diagram of a second prior art mechanical joint showing a plurality of cards captured at different positions of a plug and an intermediate nut;

Fig. 28 is a schematic view showing a state in which a card of a conventional second mechanical connector contacts a plug engagement surface.

In the figure:

1. A rod; 10. a plug; 11. a first tooth; 12. a plunger base; 2. a large nut; 20. a receiving chamber; 21. a small nut; 3. a multi-tooth card assembly; 30. a card; 31. an elastic ring; 32. a clamping cavity; 33. a second tooth; 34. a second abutment surface; 4. pre-tightening the nut; 40. an insertion cavity; 41. a first abutment surface; 42. a multi-tooth card receiving slot; 43. a plug insertion end; 45. a pretension nut threaded connection; 46. a pretension nut driving section; 461. a drive tooth; 6. a driving part; 60. a screw rod; 600. a bite tooth; 8. prefabricating concrete piles; 80. prefabricating a concrete pile body; 81. a main rib; 82. the driving part accommodating groove.

Detailed Description

The utility model discloses a pretension mechanical connector for clamping a multi-tooth card, which is shown in fig. 1, 2 and 3, and comprises a plunger rod 1, wherein one end of the plunger rod 1 is provided with a plug 10, and the outer wall of the plug is provided with a first tooth 11, as shown in fig. 17;

a large nut 2, wherein a containing cavity 20 is arranged in the large nut 2, as shown in fig. 15 and 16;

The pre-tightening nut 4 is internally provided with an insertion cavity 40, a multi-tooth card accommodating groove 42 is arranged in the insertion cavity 40, and the outer wall of the pre-tightening nut 4 is provided with a pre-tightening nut threaded connection part 45 and a pre-tightening nut driving part 46; the pre-tightening nut threaded connection part 45 is arranged in the large nut 2 and is in threaded connection with the accommodating cavity 20, and at least part of the pre-tightening nut driving part 46 is positioned outside the accommodating cavity 20;

The multi-tooth card assembly 3, the multi-tooth card assembly 3 is disposed in the multi-tooth card accommodating groove 42, as shown in fig. 13 and 14, the multi-tooth card assembly 3 includes a plurality of circumferentially spliced cards 30 and an elastic ring 31 sleeved outside the cards 30 and having radial elasticity, the elastic ring 31 is made of an elastic material, an opening is formed on the annular ring, so that the elastic ring can be opened or contracted, in this embodiment, the cards have 3 sheets, the number of the cards can be selected according to needs, a groove structure is formed on the outer side wall of the cards, so that the elastic ring is sleeved in the groove of the outer wall of the cards, a plurality of the cards 30 enclose a clamping cavity 32, and a plurality of the cards 30 can be opened and contracted in the multi-tooth card accommodating groove 42, the inner wall of the cards 30 is provided with a second tooth 33, and the plug 10 can be inserted into the clamping cavity 32 and the first tooth 11 and the second tooth 33 are clamped to realize the clamping of the plug 10 and the multi-tooth card assembly 3;

When the multi-tooth card assembly 3 is clamped with the plug 10, the driving part 6 can drive the pre-tightening nut driving part 46 from the lateral direction of the pre-tightening nut 4, so that the pre-tightening nut 4 rotates and moves along the axial direction of the large nut 2, and the plug 10 and the pre-tightening nut 4 are locked in the axial direction of the large nut 2.

The pre-tightening mechanical joint with the clamping ring in clamping connection is disclosed by the utility model, as the pre-tightening nut 4 is provided with the pre-tightening nut driving part 46, as shown in fig. 4 and 6, the pre-tightening nut driving part 46 can be used for locking the plug 10 of the inserted rod 1 and the pre-tightening nut 2 in the axial direction of the large nut 2 (shown by arrow B in fig. 4) after the plug 10 of the inserted rod 1 is inserted into the multi-tooth card accommodating groove 42 and is radially clamped with the multi-tooth card assembly 3 arranged in the multi-tooth card accommodating groove 42, the driving part 6 is driven from the side of the pre-tightening nut 4, as shown in fig. 4, in particular, after the plug is inserted into the multi-tooth card assembly in the pre-tightening nut, a certain axial clearance L exists between the multi-tooth card assembly 3 and the plug 10, as shown in fig. 5, the driving part 6 rotates under the action of external force, so that the pre-tightening nut 4 can radially rotate (shown by arrow B in fig. 4) and axially move along the large nut 2 (shown by arrow C in fig. 4), that after the plug 10 of the inserted rod 1 is clamped with the multi-tooth card assembly 3, the pre-tightening nut 4 can move along the axial clearance L between the pre-tightening nut 4 and the pre-tightening nut 4 in the axial direction as shown by the axial clearance L; further, because the pretension nut, the inserted bar and the multi-tooth card assembly are locked in the axial direction, in the locking process, due to the fact that a screwing moment (screwing force) is generated between the pretension nut and the large nut, the screwing force enables the pretension nut, the inserted bar and the multi-tooth card assembly to generate a certain axial acting force in the axial direction, under the action of the axial acting force, axial gaps among the pretension nut, the inserted bar, the large nut, the multi-tooth card assembly, the small nut and other components can be effectively eliminated, for example, gaps between the pretension nut and the large nut (axial gaps of threaded connection of an area shown by E2 in FIG. 6), gaps between the inserted bar base of the inserted bar and the threaded connection of the small nut (axial gaps of threaded connection of an area shown by E1 in FIG. 6), gaps between the inserted bar and the multi-tooth card assembly and the like, and therefore, when the mechanical joint disclosed by the utility model is adopted for prefabricating a concrete pile, the prefabricated pile connection is subjected to the acting force such as a pulling force, a shearing force or a bending force, the prefabricated pile connection is not cracked and generates cracks, and even if the mechanical joint disclosed by the utility model is used for prefabricating pile connection, the pile can meet the requirements of a high-shear stress resistance and a relative to a pipe and a high-shear stress resistance of a prefabricated pile, and a pipe and a relative a pipe joint, and a high-shear stress resistance requirement can be achieved by the utility model, and a relative a pile can be achieved by the prefabricated pile, and a mechanical joint, and a joint can be controlled by the utility model. And the problem that gaps are generated in the connection of the precast concrete piles due to the fact that gaps are generated in the connection mechanism of the existing mechanical connectors, cracks are generated at the joints of the precast concrete piles, and potential safety hazards exist in the foundation of the building piles is solved.

Meanwhile, the multi-tooth card accommodating groove is formed in the insertion cavity of the pre-tightening nut, so that the multi-tooth card assembly can be directly arranged in the multi-tooth card accommodating groove of the pre-tightening nut, and the two parts form an assembly, so that the subsequent installation of the mechanical connector is facilitated, the installation difficulty is reduced, and the cost is saved. Meanwhile, the multi-tooth card assembly and the pre-tightening nut are simple in structure, and cost is further reduced. Preferably, the ends of the plug are hemispherical, parabolic or frustoconical to facilitate radial expansion of the multi-tooth card assembly.

Further, as shown in fig. 8 and 10, the driving teeth 461 are provided on the pretensioned nut driving portion 46, the driving member 6 is a screw 60, and the screw 60 is provided with engagement teeth 600 capable of engaging with the driving teeth 461.

Specifically, in this embodiment, since the driving teeth 461 are disposed on the driving portion 46 of the pre-tightening nut, the driving teeth 461 may be straight teeth parallel to the axis of the pre-tightening nut 4 or inclined teeth forming a certain angle with the axis of the pre-tightening nut, or straight teeth as shown in fig. 8, so that the driving member 6 may be a screw 60, as shown in fig. 11 and 12, a meshing tooth 600 capable of meshing with the driving teeth 461 is disposed on the screw 60, a driving member accommodating groove 82 communicating with the outer wall of the pile is disposed at one end of the pre-tightening nut, the other end of the driving member accommodating groove 82 extends to the end of the large nut 2, the screw 60 can be inserted between two sections of pre-tightening nuts through the driving member accommodating groove 82, and the screw 60 can be driven to rotate at the outer side wall of the pre-tightening nut, and the screw 60 is provided with an inner hexagonal hole, a linear groove or a cross groove and other structure, so that the screw rotation can be driven by a tool, the screw rotation can be driven by the driving teeth on the pre-tightening driving portion to rotate, thereby realizing the pre-tightening of the pre-tightening nut, the axial clearance between the pre-tightening nut and the axial clearance card and the axial clearance between the pre-tightening nut and the plug and the axial clearance component and the plug component. The screw rod tooth structure drives the pre-tightening nut to rotate, so that the screw rod tooth structure has the advantages of simple structure, large stroke, capability of moving the pre-tightening nut in a small space, locking performance guarantee, and convenience in operation and control of axial locking force between the inserted rod and the pre-tightening nut. The adoption of the straight tooth structure has the advantage of being convenient to process, and the adoption of the helical tooth structure has the advantages that the screw rod can apply larger circumferential driving force to the pre-tightening nut, so that the pre-tightening nut can be rotated conveniently to realize axial movement. The driving teeth can be directly formed on the pre-tightening nut driving part in a machining way, or can be of an independent structure, namely, the pre-tightening nut driving part is sleeved with an intermediate sleeve, the intermediate sleeve is provided with driving teeth (a structure similar to a gear is formed), and the intermediate sleeve is connected with the pre-tightening nut driving part through a key and other structures.

Further, in the process of inserting the plug 10 into the clamping cavity 32, the maximum outer diameter of the plurality of cards 30 when being opened is equal to or smaller than the inner diameter of the multi-tooth card accommodating groove 42, the minimum inner diameter of the plurality of cards 30 when being opened is smaller than or equal to the minimum inner diameter of the insertion cavity 40, the maximum outer diameter of the plurality of cards 30 when being opened is equal to the inner diameter of the multi-tooth card accommodating groove 42, so that the outer wall of the multi-tooth card assembly can be attached to the inner wall of the pretension nut, the pretension nut provides radial supporting force for the multi-tooth card assembly and limits the cards of the multi-tooth card assembly, meanwhile, the minimum inner diameter (the diameter surrounded by the tooth tops of the second tooth) of the cards 30 when being opened is smaller than or equal to the minimum inner diameter of the insertion cavity 40, as shown in fig. 9, the insertion cavity 40 of the pretension nut has a stepped hole structure, the aperture near the insertion end of the inserted link is relatively smaller, the aperture far from the insertion end of the inserted link is relatively larger, the portion far from the aperture of the insertion end of the inserted link forms a multi-tooth card accommodating groove, a plurality of card components are arranged in the multi-tooth card accommodating groove, the minimum inner diameter (the diameter surrounded by the tooth tops of the second teeth) of the card 30 is smaller than or equal to the minimum inner diameter of the insertion cavity 40 when the card 30 is opened, that is, the minimum inner diameter (the diameter surrounded by the tooth tops of the second teeth) of the card 30 is smaller than or equal to the aperture near the insertion end of the inserted link when the card 30 is opened, because the minimum inner diameter of the card 30 is smaller than or equal to the minimum inner diameter of the insertion cavity 40, the card plays a role in limiting and guiding the plug in the plug insertion process, the inserted link is smaller than the minimum inner diameter of the insertion cavity during the insertion process of the multi-tooth card components and/or after the insertion of the card components, and then make inserted bar and pretension nut have clearance (contactless) in radial direction, reduced or eliminated the effort between parts such as inserted bar and the pretension nut promptly to the drive part is rotated from side direction drive pretension nut, makes pretension nut along big nut axial motion, thereby locks plug and snap ring in big nut axial direction.

Further, the inner wall of the side of the multi-tooth card accommodating groove 42, which is close to the plug insertion end 43, is a first abutting surface 41, and the side of the card 30, which faces the plug insertion end 43, is provided with a second abutting surface 34, when the plug 10 and the pretension nut 4 are locked in the axial direction of the large nut 2, the first abutting surface 41 and the second abutting surface 34 abut against each other, at this time, the first abutting surface and the second abutting surface are completely abutted, the gap between the multi-tooth card assembly and the plug is eliminated, and when the mechanical joint disclosed by the utility model is used for prefabricating a concrete pile, the pile joint has higher pulling resistance, bending resistance and shearing resistance, so that when the mechanical joint disclosed by the utility model is used for prefabricating the concrete pile, the related requirements on crack level control in the technical standards of prestressed concrete pipe pile, JGJ/T406-2017, can be met. And the problem that gaps are generated in the connection of the precast concrete piles due to the fact that gaps are generated in the connection mechanism of the existing mechanical connectors, cracks are generated at the joints of the precast concrete piles, and potential safety hazards exist in the foundation of the building piles is solved.

Further, the first abutting surface 41 and the second abutting surface 34 are both tapered surfaces, and as the first abutting surface and the second abutting surface are both tapered surfaces, when the pretension nut and the multi-tooth card assembly are axially locked, the first abutting surface 41 generates an acting force perpendicular to the second abutting surface 34, the generated acting force can be decomposed into a force perpendicular to the card and in a direction in which the card is tightened inwards, and a force downwards vertically, so that the inner wall of the pretension nut and the multi-tooth card assembly form a holding force, the connection strength of the pretension nut and the multi-tooth card assembly is enhanced, and the pulling resistance, the bending resistance and the shearing resistance can also be enhanced.

Further, the first teeth 11 and the second teeth 33 are saw teeth or pagoda teeth, so that the connection between the inserted bar and the multi-tooth card assembly is tighter and firmer, and the connection effect of the inserted bar and the multi-tooth card assembly is ensured.

Further, the threaded connection between the pre-tightening nut 4 and the large nut 2 is loose-fit threaded connection before the plug 10 and the multi-tooth card assembly are locked in the axial direction of the large nut 2.

Specifically, the tolerance of the internal thread on the inner wall of the accommodating cavity of the large nut and the external thread on the outer wall of the pre-tightening nut can be reasonably selected according to the requirement, so that the threaded connection between the pre-tightening nut and the large nut is loose-fit threaded connection, and the acting force between the pre-tightening nut and the large nut is relatively small before the plug and the multi-tooth card assembly are locked, so that the driving component can conveniently drive the pre-tightening nut to rotate from the lateral direction, the pre-tightening nut moves along the axial direction of the large nut, and the plug and the multi-tooth card assembly are locked in the axial direction of the large nut.

Further, after the plug 10 and the multi-tooth card assembly 3 are locked in the axial direction of the large nut 2, the tensile strength of the connection between the plug and the multi-tooth card assembly is greater than or equal to that of any one of the main rib, the large nut and the small nut. Preferably, after the plug 10 and the multi-tooth card assembly 3 are locked in the axial direction of the large nut 2, the plug and the multi-tooth card assembly are connected without ductile deformation when bearing a drawing force of 11.7 Mpa.

According to the utility model, after the plug 10 and the multi-tooth card assembly 3 are locked in the axial direction of the large nut 2, the tensile strength of the connection between the plug and the clamping ring is larger than or equal to that of any one of the main rib, the large nut and the small nut, and the pre-fabricated concrete pile with the multi-tooth card assembly clamped by the pre-fabricated concrete pile is free from ductile deformation when being subjected to a drawing force of 11.7Mpa after the plug is connected with the multi-tooth card assembly, so that the large nut, the small nut, the inserted bar, the multi-tooth card assembly and the pre-fabricated nut cannot generate ductile deformation before the main rib is subjected to the drawing force which causes ductile deformation, and therefore no crack or gap is generated between the connecting end surfaces of the two pre-fabricated piles, and the multi-tooth card clamped pre-fabricated mechanical joint disclosed by the utility model can be reliably connected without being damaged before the main rib is ductile and is pulled off, and the connection performance of the pre-fabricated concrete pile by adopting the multi-tooth card clamped by the pre-fabricated mechanical joint disclosed by the utility model is further ensured. Specifically, in a national construction standard design atlas (atlas number: 20G 361) of precast concrete square piles, the relation between the model of the pile and the prestressed main rib is specified in detail in a prestressed concrete square pile reinforcement and mechanical property table, for example, the main rib of the pile prestressed main rib with the pile section of 600x600 is specified to be 24 phi ^D 12.6.6; the pile section model and the pile shaft axial tension bearing capacity design value Nt (kN) are specified in detail in the pile shaft axial compression resistance and the positive section bending bearing capacity of the prestressed concrete square pile, the B-shaped pile with the pile section of 600x600 is specified in the table, the pile shaft axial tension bearing capacity design value is 2544kN, and the tension bearing capacity design value of the prestressed main rib of the precast pile is 2544/24=10.6kN can be calculated according to the data; 10.6x1.1=11.66=11.7 kN, namely the pretension mechanical joint for the multi-tooth card joint disclosed by the utility model has no ductile deformation of the main rib of the precast concrete pile and the pretension mechanical joint for the multi-tooth card joint in the pulling force of 11.7kN, and all parts of the mechanical joint have no slippage, so that gaps are not generated between the connecting end surfaces of the precast concrete pile, and the connecting performance of the precast concrete pile is ensured.

Further, a small nut 21 for connection with the plunger base 12 of the plunger 1 is included.

Specifically, in this embodiment, the insert rod 1 is fixed at one end of the precast concrete pile through the small nut 21, the large nut 2 is fixed at the other end of the precast concrete pile, the large nut 2 and the small nut 21 are respectively and fixedly connected with two ends of the main rib in the precast concrete pile, the large nut is internally provided with a positioning sleeve, a pre-tightening nut and other components, and two adjacent precast concrete piles can be quickly connected through the pre-tightening mechanical joint disclosed by the application.

Example 2

Fig. 18, 19, 20, 21 and 22 show a precast concrete pile according to the present disclosure, including a precast concrete pile body 80, a main rib 81, and a pre-tightening mechanical joint of the multi-tooth card-locking of the present disclosure;

The main rib 81 is arranged in the precast concrete pile body 80, one end of the precast concrete pile body 80 is provided with the large nut 2, and the large nut 2 is internally provided with the pre-tightening nut 4 and the multi-tooth card assembly 3;

the other end of the precast concrete pile body 80 is provided with the inserted link 1;

the end of the precast concrete pile body 80 is provided with a driving part accommodating groove 82;

When two adjacent precast concrete piles are connected, one end of the driving member accommodating groove 82 is communicated with the outer wall of the precast concrete pile body 80, and the other end of the driving member accommodating groove extends to the end of the pre-tightening nut 4, so that after the driving member 6 is inserted into the driving member accommodating groove 82 from the outer wall of the precast concrete pile body 80, the driving member 6 can interact with the pre-tightening nut driving part 46, so that the pre-tightening nut 4 rotates and moves axially along the large nut 2, and the plug 10 and the pre-tightening nut 4 are locked in the axial direction of the large nut 2.

The utility model discloses a clasp clamped pre-tightening mechanical joint, which is characterized in that a pre-tightening nut driving part is arranged on a pre-tightening nut, the pre-tightening nut driving part can be driven by a driving part from the lateral direction of the pre-tightening nut after a plug of a plunger rod is inserted into an insertion cavity of the pre-tightening nut in the middle and is radially clamped with a multi-tooth card assembly arranged in a containing cavity, so that the pre-tightening nut rotates and moves along the axial direction of a large nut, thereby locking the plug and the pre-tightening nut in the axial direction of the large nut, namely, after the plug of the plunger rod is clamped with the multi-tooth card assembly, the pre-tightening nut can move along the axial direction of the large nut under the driving of the driving part, thereby eliminating the axial gaps among the plug of the plunger rod, the multi-tooth card assembly and the pre-tightening nut through the axial movement of the pre-tightening nut, in the locking process, a certain axial acting force is generated by the pretension nut, the inserted bar, the large nut, the multi-tooth card assembly, the small nut and other parts in the axial direction, and under the action of the axial acting force, the axial gaps among the pretension nut, the inserted bar, the large nut, the multi-tooth card assembly, the small nut and other parts can be effectively eliminated, for example, the gap between the pretension nut and the threaded connection of the large nut, the gap between the inserted bar base of the inserted bar and the threaded connection of the small nut, the gap between the inserted bar plug and the multi-tooth card assembly and the like, so that when the mechanical joint disclosed by the utility model is adopted for connecting precast concrete piles, the precast concrete piles can not crack and generate cracks even if the mechanical joint disclosed by the utility model is used for connecting precast concrete piles, the pile connection has higher pull-out resistance, the bending resistance and the shearing resistance can meet the related requirements on crack level control in the technical standard of prestressed concrete pipe piles JGJ/T406-2017 when the mechanical joint disclosed by the utility model is used for connecting precast concrete piles. And the problem that gaps are generated in the connection of the precast concrete piles due to the fact that gaps are generated in the connection mechanism of the existing mechanical connectors, cracks are generated at the joints of the precast concrete piles, and potential safety hazards exist in the foundation of the building piles is solved.

Further, a small nut 21 is further disposed at one end of the precast concrete pile body 80, where the insert rod 1 is disposed, one ends of the large nut 2 and the small nut 21 are respectively connected with two ends of the main rib 81, and the insert rod 1 is in threaded connection with the other end of the small nut 21. The mechanical connectors are arranged at the two ends of the main rib, so that the main rib and the mechanical connectors are coaxial, the main rib and the mechanical connectors are positioned on the same axis when being stressed, and the pulling resistance of the pile is improved. The driving part holding groove 82 also can set up the one end that is equipped with little nut at precast concrete stake, when driving part holding groove 82 sets up the one end that is equipped with little nut at precast concrete stake, this precast concrete stake is equipped with the one end tip of little nut and is equipped with pretension nut accommodation hole to when precast pile connection about being convenient for, in this hole was arranged in on pretension nut's upper portion, driving part holding groove 82 one end and precast concrete stake intercommunication, the other end and driving part holding groove 82 intercommunication, and then can make driving part drive pretension nut rotate.

Further, after the driving member 6 drives the pretensioning nut 4 to rotate and locks the plug 10 with the pretensioning nut 4 in the axial direction of the large nut 2, the driving member 6 remains in or moves out of the driving member receiving groove 82.

Specifically, when precast concrete pile connects, can drive a plurality of pretension nuts on the precast concrete pile respectively in proper order through a lead screw and rotate to realize the axial locking of all mechanical joints, eliminate axial clearance, improve the resistance to plucking ability of stake, and the lead screw can used repeatedly, has saved use cost. And when the screw rod drives the pretension nut to rotate and realize axial locking, the screw rod is reserved in the accommodating groove of the driving part, namely, the screw rod is not taken out from the accommodating groove of the driving part, and a plurality of screw rod structures are arranged between two precast concrete piles, so that the compression resistance of the end part of the precast pile is further improved.

Further, structural glue is injected into the connecting end face of the precast concrete pile body 80 and the pre-tightening mechanical joint clamped by the multi-tooth clamping piece, and the structural glue can fill, bond and seal various grooves of the connecting end face, the mechanical joint and the end face, so that the connection performance and the corrosion resistance between piles are further improved.

Example 3

The connecting method of the precast concrete pile comprises the following steps:

The end, provided with the inserted link, of the precast concrete pile moves towards the end, provided with the pre-tightening nut, of the adjacent precast concrete pile, and the plug of the inserted link is inserted into the insertion cavity of the pre-tightening nut to realize the clamping connection between the plug and the multi-tooth card assembly;

The driving part is inserted into the outer wall of the precast concrete pile, and the driving part drives the pre-tightening nut driving part, so that the pre-tightening nut rotates and moves along the axial direction of the large nut, and the plug and the pre-tightening nut are locked in the axial direction of the large nut.

The following two situations exist when the driving component (screw rod) drives the pretension nut to rotate: 1. when the acting force generated by the threaded connection between the pre-tightening nut and the large nut is smaller, namely the connection between the pre-tightening nut and the large nut is looser, the screw rod is meshed with the driving teeth on the driving part of the pre-tightening nut and drives the pre-tightening nut to start rotating and axially move along the large nut, after the pre-tightening nut realizes axial locking between the multi-tooth card assembly and the plug, the pre-tightening nut stops rotating, at the moment, the screw rod moves into the driving part accommodating groove under the action of the driving tooth structure until the end part of the screw rod is abutted to the end part of the accommodating groove, at the moment, when the screw rod is continuously driven, the pre-tightening force is generated by the interaction between the screw rod and the driving teeth on the inserting rod, so that the pre-tightening force is generated at the connecting part of the precast concrete pile, buckling deformation is not generated when a certain acting force is applied after the pile connection, and the connecting strength of the precast concrete pile is improved; 2. when the effort that threaded connection produced between pretension nut and the big nut is great, be connected compactly between pretension nut and the big nut promptly, the in-process that the lead screw got into the drive component holding tank, lead screw and drive tooth meshing, the unable drive pretension nut of drive tooth structure rotates this moment, the drive tooth carries out to the drive component holding tank internal motion under the effect of tooth structure, until lead screw tip and holding tank tip butt back, the lead screw begins to drive the pretension nut through tooth structure and rotates in order to realize the axial locking between many teeth card subassembly and the plug, thereby the axial clearance between the plug of inserted bar, many teeth card subassembly and the pretension nut has been eliminated through the axial motion of pretension nut, the intensity of precast pile connection has been guaranteed. Further, because the pretension nut, the inserted bar and the multi-tooth card assembly are locked in the axial direction, a tightening force is generated between the pretension nut and the large nut in the locking process, so that a certain axial acting force can be generated by the pretension nut, the inserted bar and the multi-tooth card assembly in the axial direction, and under the action of the axial acting force, axial gaps among the pretension nut, the inserted bar, the large nut, the multi-tooth card assembly, the small nut and other components can be effectively eliminated, such as a gap between the pretension nut and the large nut in threaded connection, a gap between the inserted bar base of the inserted bar and the small nut in threaded connection, a gap between a plug of the inserted bar and the multi-tooth card assembly and the like, the connection performance of a mechanical joint is further improved, and the pulling resistance performance of a precast concrete pile after being connected through the pretension mechanical joint of the multi-tooth joint is improved.

The foregoing is only a preferred embodiment of the present utility model, but the scope of the present utility model is not limited thereto, and any person skilled in the art, who is within the scope of the present utility model, should make equivalent substitutions or modifications according to the technical scheme of the present utility model and the inventive concept thereof, and should be covered by the scope of the present utility model.

Claims (14)

1. The utility model provides a pretension mechanical joint of multidentate card joint which characterized in that: comprising the steps of (a) a step of,

The plug comprises a plug rod (1), wherein one end of the plug rod (1) is provided with a plug (10), and the outer wall of the plug is provided with a first tooth (11);

the large nut (2) is internally provided with a containing cavity (20);

The device comprises a pre-tightening nut (4), wherein an insertion cavity (40) is formed in the pre-tightening nut (4), a multi-tooth card accommodating groove (42) is formed in the insertion cavity (40), and a pre-tightening nut threaded connection part (45) and a pre-tightening nut driving part (46) are arranged on the outer wall of the pre-tightening nut (4); the pre-tightening nut threaded connection part (45) is arranged in the large nut (2) and is in threaded connection with the accommodating cavity (20), and at least part of the pre-tightening nut driving part (46) is positioned outside the accommodating cavity (20);

The multi-tooth card assembly (3), the multi-tooth card assembly (3) is arranged in the multi-tooth card accommodating groove (42), the multi-tooth card assembly (3) comprises a plurality of circumferentially spliced cards (30) and elastic rings (31) sleeved outside the cards (30) and having radial elasticity, a plurality of the cards (30) enclose into a clamping cavity (32), the cards (30) can be expanded and contracted in the multi-tooth card accommodating groove (42), second teeth (33) are arranged on the inner wall of the cards (30), and the plug (10) can be inserted into the clamping cavity (32) and clamped with the second teeth (33) to realize the clamping of the plug (10) and the multi-tooth card assembly (3);

When the multi-tooth card assembly (3) is clamped with the plug (10), the driving part (6) can drive the pre-tightening nut driving part (46) from the lateral direction of the pre-tightening nut (4) so that the pre-tightening nut (4) rotates and moves along the axial direction of the large nut (2), and the plug (10) and the pre-tightening nut (4) are locked in the axial direction of the large nut (2).

2. The multi-tooth card-retaining pre-tensioned mechanical coupling of claim 1 wherein: the pre-tightening nut driving part (46) is provided with driving teeth (461), the driving part (6) is a screw rod (60), and the screw rod (60) is provided with engaging teeth (600) which can be engaged with the driving teeth (461).

3. The multi-tooth card-retaining pre-tensioned mechanical coupling of claim 2 wherein: the driving teeth (461) are straight teeth parallel to the axis of the pre-tightening nut (4) or inclined teeth forming a certain angle with the axis of the pre-tightening nut.

4. A multi-tooth card-retaining pre-tensioning mechanical joint according to any one of claims 1 to 3, characterized in that: in the process of inserting the plug (10) into the clamping cavity (32), the maximum outer diameter of the plurality of cards (30) when being opened is smaller than or equal to the inner diameter of the multi-tooth card accommodating groove (42);

the minimum inner diameter of the plurality of cards (30) when expanded is less than or equal to the minimum inner diameter of the insertion cavity (40).

5. The multi-tooth card-retaining pre-tensioned mechanical coupling of claim 4 wherein: the inner wall of one side of the multi-tooth card accommodating groove (42) close to the plug insertion end (43) is a first abutting surface (41), one side of the card (30) facing the plug insertion end (43) is provided with a second abutting surface (34), and when the plug (10) and the pre-tightening nut (4) are locked in the axial direction of the large nut (2), the first abutting surface (41) and the second abutting surface (34) are mutually abutted.

6. The multi-tooth card-retaining pre-tensioned mechanical coupling of claim 5 wherein: the first abutment surface (41) and the second abutment surface (34) are both tapered surfaces.

7. The multi-tooth card-retaining pre-tensioned mechanical coupling of claim 1 wherein: the first teeth (11) and the second teeth (33) are saw tooth teeth or pagoda teeth.

8. The multi-tooth card-retaining pre-tensioned mechanical coupling of claim 1 wherein: before the plug (10) and the multi-tooth card assembly are locked in the axial direction of the large nut (2), the pre-tightening nut (4) and the large nut (2) are in loose fit threaded connection.

9. The multi-tooth card-retaining pre-tensioned mechanical coupling of claim 1 wherein: after the plug (10) and the multi-tooth card assembly (3) are locked in the axial direction of the large nut (2), the tensile strength of the connection of the plug and the multi-tooth card assembly is larger than or equal to that of any one of the main rib, the large nut and the small nut.

10. The multi-tooth card-retaining pre-tensioned mechanical coupling of claim 1 wherein: the novel socket also comprises a small nut (21) which is used for being connected with the socket rod base (12) of the socket rod (1).

11. A precast concrete pile, characterized in that: comprising a precast concrete pile body (80), a main rib (81), a pre-tightening mechanical joint for clamping the multi-tooth card according to any one of claims 1 to 10;

the main rib (81) is arranged in the precast concrete pile body (80), one end of the precast concrete pile body (80) is provided with the large nut (2), and the large nut (2) is internally provided with the pre-tightening nut (4) and the multi-tooth card assembly (3);

the other end of the precast concrete pile body (80) is provided with the inserted link (1);

The end part of the precast concrete pile body (80) is provided with a driving part accommodating groove (82);

When two adjacent precast concrete piles are connected, one end of the driving part accommodating groove (82) is communicated with the outer wall of the precast concrete pile body (80), the other end of the driving part accommodating groove extends to the end of the pre-tightening nut (4), so that after the driving part (6) is inserted into the driving part accommodating groove (82) from the outer wall of the precast concrete pile body (80), the driving part (6) can interact with the pre-tightening nut driving part (46), the pre-tightening nut (4) rotates and moves axially along the large nut (2), and the plug (10) and the pre-tightening nut (4) are locked in the axial direction of the large nut (2).

12. A precast concrete pile according to claim 11, characterized in that: the precast concrete pile is characterized in that a small nut (21) is further arranged at one end of the precast concrete pile body (80) provided with the inserted link (1), one end of the large nut (2) and one end of the small nut (21) are respectively connected with two ends of the main rib (81), and the inserted link (1) is in threaded connection with the other end of the small nut (21).

13. A precast concrete pile according to claim 12, characterized in that: the driving part (6) drives the pre-tightening nut (4) to rotate and locks the plug (10) and the pre-tightening nut (4) in the axial direction of the large nut (2), and the driving part (6) is kept in or moved out of the driving part accommodating groove (82).

14. A precast concrete pile according to claim 13, characterized in that: structural adhesive is also injected into the connecting end face of the precast concrete pile body (80) and the pretension mechanical connector clamped by the multi-tooth clamping piece.