CN113172750B

CN113172750B - Tensioning device and tensioning process for enhanced precast pile

Info

Publication number: CN113172750B
Application number: CN202110391073.8A
Authority: CN
Inventors: 陈浩; 米涛; 谢晓钟; 陈昊
Original assignee: Jianhua Construction Materials China Co Ltd; Jiangsu Jianhua New Wall Material Co Ltd
Current assignee: Jianhua Construction Materials China Co Ltd; Jiangsu Jianhua New Wall Material Co Ltd
Priority date: 2021-04-12
Filing date: 2021-04-12
Publication date: 2022-06-28
Anticipated expiration: 2041-04-12
Also published as: CN113172750A

Abstract

The invention provides a tensioning device and a tensioning process for an enhanced precast pile. After a steel reinforcement cage with a plurality of double-headed main reinforcements arranged at two ends is placed into the cage, the reinforcement penetrating holes of the end plates at the head end and the tail end sequentially penetrate through 2 heads of the main reinforcements, the head penetrating holes of the head tensioning head plate and the tail penetrating holes of the tail tensioning tail plate at the head end and the tail end of the main reinforcements rotate for a certain angle, and the connection of the heads and the corresponding counter bores can be realized. According to the mode, after secondary heading processing is carried out on the two ends of all main ribs, the heading is assembled and clamped with the end plate and the tensioning plate respectively, the tensioning plate is not required to be connected through bolts, the process flow is simplified, and the labor intensity of workers is reduced.

Description

Tensioning device and tensioning process for enhanced precast pile

Technical Field

The invention relates to the field of production of prefabricated parts, in particular to a novel tensioning process of a prefabricated pile.

Background

The pre-tensioning method concrete prefabricated pile is used as a new building product and is widely applied to construction of various industries. In order to improve the bending resistance of a precast pile product, in the stage of manufacturing a steel reinforcement cage, end plates with a plurality of counter sink holes or sleeves with counter sinks are required to be installed at two ends of a precast pile die, upset heads in an enlarged head shape are processed at two ends of a plurality of longitudinal main reinforcements of the steel reinforcement cage, the same number of the upset heads at two sides are respectively clamped in the counter sinks of the end plates or the sleeves at two ends, then a tail end tensioning plate and the end plate at the tail end are fixedly connected by adopting tensioning bolts, and a head end tensioning plate and the end plate at the head end are fixedly connected. After the positions of the tail end tensioning plate and the end plate of the tail end are relatively fixed with the die, the hydraulic tensioning equipment is connected with the tensioning plate through other connecting pieces to stretch the main reinforcement of the reinforcement cage clamped in the end plates at the two ends or the sunken holes of the sleeve, and after the stretching is finished, the anchoring device is adopted to ensure that the reinforcement cage keeps the stretched state. And then pouring concrete into the mould, after the concrete is solidified, loosening the anchoring device, so that the reinforcement cage cemented with the concrete cannot rebound, and the prestress of the main reinforcement is kept all the time, thereby improving the bending resistance of the whole precast pile.

At present, according to the technology disclosed in the patent document of the "tubular pile tensioning mechanism" of the chinese patent application having the application number of 201610547088.8 and the application date of 2016, 7, 8, as shown in fig. 1 and fig. 2, a connecting bolt and the like need to be placed in the connecting channel 25 for connecting the axial main rib with the first tensioning plate assembly and the second tensioning plate assembly, which has the technical problem that:

the connecting bolts are required to be connected with the sleeves or the end plates for clamping the main reinforcement upset heads, and the connecting bolts are required to be recycled, so that the connecting bolts are required to be disassembled after concrete of the precast pile is solidified and formed, the tensioning assemblies on two sides are provided with the connecting bolts, the assembly and disassembly of the bolts not only reduce the production efficiency, but also increase the labor intensity of operators.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a novel tensioning process, and the problems of high labor intensity and low production efficiency in the prior art are effectively solved by designing novel structures of a tensioning plate and a main rib heading.

In order to solve the technical problem, the invention provides the technical scheme that the tensioning device of the enhanced precast pile comprises a precast pile die; the head end of the precast pile mould is connected with a tensioning baffle, and the inner wall of the precast pile mould is sequentially connected with a tensioning head plate, a head end plate, a tail end plate and a tensioning tail plate from the head end to the tail end; the tensioning screw penetrates through the tensioning baffle and is connected to the tensioning head plate, and the tensioning nut is connected to the tensioning screw; a traction device is arranged between the tension head plate and the head end plate; the head ends of the main ribs are respectively provided with a first head end heading and a second head end heading, and the tail end is provided with a first tail end heading and a second tail end heading;

A tensioning head plate counter bore is formed in the tensioning head plate, and a first heading head at the head end is clamped in the tensioning head plate counter bore; the head end plate is provided with a head end plate counter bore, and a head end second upset head is clamped in the head end plate counter bore; a tensioning tail plate counter bore is formed in the tensioning tail plate, and a first heading at the tail end is clamped in the tensioning tail plate counter bore; the tail end plate is provided with a tail end plate counter bore, and a tail end second heading is clamped in the tail end plate counter bore.

Preferably, the traction device comprises a traction device long rod, and the traction device long rod is sequentially provided with a pressure spring seat, a pressure spring, a traction device stop block and a magnet from the head end to the tail end; one end of the pressure spring is arranged on the pressure spring seat, and the other end of the pressure spring is pressed on the end surface of the head end of the tension head plate; the traction device stop block is arranged between the tension head plate and the head end plate and is connected through a traction device long rod penetrating through a traction device mounting hole in the tension head plate; one end of the magnet is connected to the tail end of the long rod of the traction device, and the other end of the magnet is connected to the head end plate during tensioning.

Preferably, the tensioning head plate is provided with tensioning screw mounting holes, traction device mounting holes, tensioning head plate rib penetrating holes, tensioning head plate transition grooves and tensioning head plate counter bores, wherein the number of the tensioning head plate rib penetrating holes is consistent with that of the main ribs; the tensioning head plate reinforcement penetrating hole, the tensioning head plate transition groove and the tensioning head plate counter bore are blind holes with sealed heads, the thickness L1 of the internal space of the tensioning head plate transition groove is smaller than the thickness L2 of the internal space of the tensioning head plate counter bore, and each tensioning head plate counter bore is used for clamping a first heading head at each head end;

The tensioning tail plate is provided with a tail plate hole, a tail plate sealing rubber plug, tensioning tail plate through rib holes, tensioning tail plate transition grooves and tensioning tail plate counter bores, the number of the tensioning tail plates is consistent with that of the main ribs; the tensioning tail plate transition groove is connected with a tensioning tail plate rib penetrating hole and a tensioning tail plate counter bore, the tensioning tail plate rib penetrating hole, the tensioning tail plate transition groove and the tensioning tail plate counter bore are blind holes with sealed tail ends, the thickness L3 of the inner space of the tensioning tail plate transition groove is smaller than the thickness L4 of the inner space of the tensioning tail plate counter bore, and each tensioning tail plate counter bore is used for clamping a first heading of each tail end; a tail plate sealing rubber plug is arranged in the tail plate hole;

the head end plate rib penetrating hole sealing plugs are arranged in the head end plate transition grooves and the head end plate rib penetrating holes; a head end plate rubber plug is arranged in the through hole in the middle of the head end plate;

and the tail end plate transition groove and the tail end plate rib penetrating hole are provided with a tail end plate rib penetrating hole sealing plug.

Preferably, a tail end radial sealing sleeve is arranged on a through hole in the middle of the tail end plate; the tail end radial sealing sleeve is of a cylindrical structure, a through hole is formed in the tail end radial sealing sleeve in a penetrating mode, a sinking platform is arranged on the outer diameter of the tail end radial sealing sleeve, and the sinking platform part with the smaller outer diameter is arranged in the through hole in the middle of the tail end plate.

Preferably, the diameter of the tensioning head plate bar penetrating hole is larger than that of the first heading head at the head end of the main bar, and a chamfer is arranged at the inlet of the tensioning head plate bar penetrating hole;

the diameter of the tensioning tail plate rib penetrating hole is larger than that of a first heading at the tail end of the main rib 10, and a chamfer is arranged at the inlet of the tensioning tail plate rib penetrating hole.

Preferably, a head end plate rubber plug is mounted in a through hole in the middle of the head end plate;

the head end second upset head is clamped in the head end plate counter bore;

the diameter of the head end plate tendon penetration hole is larger than the diameters of the first head and the second head 1 of the main tendon head;

the tail end second heading is clamped in the tail end plate counter bore;

the diameter of the tail end plate tendon penetrating hole is larger than the diameters of the first upsetting head and the second upsetting head at the tail end of the main tendon;

the depth of the tail end plate counter bore is larger than the thickness of the tail end second upsetting head, when the tail end second upsetting head transversely slides to the tail end plate counter bore position, then the tail end plate moves to the opposite direction of the head end first upsetting head, the tail end second upsetting head is firmly clamped in the tail end plate counter bore.

Preferably, the tensioning screw is connected with a hydraulic tensioning device.

Preferably, the distance between the first upset at the head end and the second upset at the head end is greater than 40mm, and the distance between the first upset at the tail end and the second upset at the tail end is also greater than 40 mm.

In order to solve the technical problem, the technical scheme is that the novel tensioning process of the reinforced precast pile by using the tensioning device of the reinforced precast pile comprises the following steps:

(1) after the main reinforcement is cut off in a fixed length, firstly, hot heading processing is carried out, and a head end second heading, a head end first heading, a tail end second heading and a tail end first heading are sequentially processed;

(2) performing roll welding processing on a plurality of processed main reinforcements and ring reinforcements to form a reinforcement cage structure;

(3) assembling the head end plate provided with the head end hoop and the reinforcement cage, firstly, enabling all head end first upsets which are uniformly distributed on the graduated circle to penetrate through the head end plate rib penetrating holes, then enabling the head end second upsets to penetrate through the head end plate rib penetrating holes, then, rotating the head end plate, enabling all main ribs to slide to the positions of the head end plate counter bores through the head end plate transition grooves, finally, pulling the head end plate back towards the direction of the head end first upsets, and enabling all head end second upsets to be clamped in the head end plate counter bores;

(5) assembling the tail end plate provided with the tail end hoop and a reinforcement cage, firstly, penetrating all tail end first upsets uniformly distributed on a graduated circle through a tail end plate rib penetrating hole, then penetrating tail end second upsets through the tail end plate rib penetrating hole, then, rotating the tail end plate, sliding all main ribs to the position of a tail end plate counter bore through each tail end plate transition groove, finally, pulling the tail end plate back towards the tail end first upsets, and clamping all tail end second upsets in the tail end plate counter bore;

(7) Integrally placing the reinforcement cages respectively sleeved with the head end plate and the tail end plate into a lower die of the precast pile die;

(8) assembling the tension head plate and the reinforcement cage, firstly, penetrating all head end first upsets uniformly distributed on the pitch circle through tension head plate reinforcement penetrating holes, then rotating the tension head plate, sliding all main reinforcements to the position of tension head plate counter bores through transition grooves of the tension head plate, finally, pulling the tension head plate back towards the direction of a tension screw rod, and clamping all head end first upsets in the tension head plate counter bores;

(9) mounting the sinking platform part with the smaller outer diameter of the tail end radial sealing sleeve in a through hole in the middle of the tail end plate; assembling the tensioning tail plate and the reinforcement cage, firstly, penetrating all tail end first upset heads uniformly distributed on a graduated circle through tensioning tail plate rib penetrating holes, then, rotating the tensioning tail plate, sliding all main ribs to the position of tensioning tail plate counter bores through all tensioning tail plate transition grooves, finally, pulling back the tensioning tail plate in the direction opposite to that of the tensioning head plate, clamping all tail end first upset heads into the tensioning tail plate counter bores, and then, enabling a tail end radial sealing sleeve to be in a compression state to seal a space between the tensioning tail plate and a tail end plate;

(10) Pressing down the pressure spring seat of each traction device towards the tail end direction of the precast pile mould to ensure that each magnet is tightly attached to the head end plate;

(11) covering an upper die of the precast pile die on a lower die, and locking connecting bolts of the upper die and the lower die, wherein the whole precast pile die is combined into a cylindrical whole;

(12) connecting the tensioning screw with tensioning equipment, wherein a reaction frame of the tensioning equipment is pressed on a tensioning baffle plate to start tensioning;

(13) under the action of hydraulic tension, the main rib between the tail end plate and the tensioning tail plate is lengthened, and a tail end second heading arranged in a tail end plate counter bore drives the tail end plate to move forwards;

(14) under the action of hydraulic tension, the tensioning screw and the tensioning head plate both move forwards, and because the head end plate is fixed in position, when the main rib is elongated, the second upset head at the head end can be separated from the counter bore of the head end plate; under the action of the tension force, the tension head plate moves forwards to gradually compress the pressure spring, when the rebound force of the pressure spring is greater than the power of the traction device for driving the head end plate to move forwards, the traction device pulls the head end plate to continuously move forwards under the action of the rebound force of the pressure spring because each magnet is attached to the head end plate, and the counter bore of the head end plate is ensured to be attached to the second upset head of the head end;

(15) When the set tension force is reached, the tensioning nut on the tensioning screw rod is screwed in towards the tensioning baffle plate until the tensioning nut is tightly attached to the end face of the tensioning baffle plate, the hydraulic tensioning device is separated from the tensioning screw rod, the tensioning nut plays a role in locking, the main rib cannot rebound, the prestress of the main rib is kept, and the whole tensioning process is completed.

Preferably, the method also comprises the following steps that after the steps are completed, the head end plate rib penetrating hole of each head end plate and the head end plate rib penetrating hole sealing plug are plugged into the transition groove of each head end plate, and then the head end plate rubber plug is plugged into the middle through hole of the head end plate;

and 6, after the step 5 is finished, plugging the tail end plate rib penetrating holes and the tail end plate transition grooves of the tail end plates into the tail end plate rib penetrating hole sealing plugs.

A novel tensioning process of an enhanced precast pile adopts a precast pile mould to perform tensioning; the precast pile mould is sequentially provided with a tensioning screw, a tensioning nut, a tensioning baffle, a tensioning head plate, a head end plate, a main rib, a tail end plate, a tensioning tail plate, a traction device, a head end first heading and a head end second heading from the head end to the tail end; a second heading at the tail end; a first upset head at the tail end;

The tensioning head plate is provided with a tensioning head plate counter bore, and the tensioning head plate counter bore is used for clamping a first heading head at each head end; the head end plate is provided with a head end plate counter bore, and a head end second upset head is clamped in the head end plate counter bore; a tensioning tail plate counter bore is formed in the tensioning tail plate; the counter bores of the tensioning tail plates are used for clamping the first heading heads at the tail ends; the tail end plate is provided with a tail end plate counter bore, a tail end second heading is clamped in the tail end plate counter bore, the traction device comprises a traction device long rod, a compression spring seat, a compression spring, a traction device stop block and a magnet, one section of the compression spring is pressed on the compression spring seat, and one end of the compression spring is pressed on the end face of the tension head plate; the compression spring seat and the traction device stop block are respectively arranged on two sides of the section of the tension head plate and are connected through a traction device long rod penetrating through a traction device mounting hole on the tension head plate; the end part of the other end of the long rod of the traction device, which is opposite to the compression spring seat, is provided with a magnet.

The tensioning head plate is provided with a tensioning screw mounting hole, a traction device mounting hole, a tensioning head plate reinforcement penetrating hole, a tensioning head plate transition groove and a tensioning head plate counter bore; the tensioning head plate transition groove is connected with a tensioning head plate reinforcement penetrating hole and a tensioning head plate counter bore, the tensioning head plate reinforcement penetrating hole, the tensioning head plate transition groove and the tensioning head plate counter bore are all blind holes, the thickness L1 of the internal space of the tensioning head plate transition groove is smaller than the thickness L2 of the internal space of the tensioning head plate counter bore, and the tensioning head plate counter bore is used for clamping a first heading at each head end;

The traction device mounting hole is provided with a traction device; the traction device comprises a traction device long rod, a compression spring seat, a compression spring, a traction device stop block and a magnet, wherein one section of the compression spring is pressed on the compression spring seat, and one end of the compression spring is pressed on the end surface of the tension head plate; the compression spring seat and the traction device stop block are respectively arranged on two sides of the section of the tension head plate and are connected through a traction device long rod penetrating through a traction device mounting hole in the tension head plate; the end part of the other end of the long rod of the traction device, which is opposite to the pressure spring seat, is provided with a magnet;

the tensioning tail plate is provided with a tail plate hole, a tail plate sealing rubber plug, a tensioning tail plate reinforcement penetrating hole, a tensioning tail plate transition groove and a tensioning tail plate counter bore; the tensioning tail plate transition groove is connected with a tensioning tail plate reinforcement penetrating hole and a tensioning tail plate counter bore, the tensioning tail plate reinforcement penetrating hole, the tensioning tail plate transition groove and the tensioning tail plate counter bore are blind holes, the thickness L3 of the internal space of the tensioning tail plate transition groove is smaller than the thickness L4 of the internal space of the tensioning tail plate counter bore, and each tensioning tail plate counter bore is used for clamping a first heading of each tail end; a tail plate sealing rubber plug is arranged in the tail plate hole;

the head end plate is provided with a head end plate counter bore, a head end plate transition groove and a head end plate rib penetrating hole, and a head end second upset head is clamped in the head end plate counter bore. The head end plate transition groove and the head end plate reinforcement penetrating hole are provided with a head end plate reinforcement penetrating hole sealing plug; a head end plate rubber plug is arranged in the through hole in the middle of the head end plate;

The tail end plate is provided with a tail end plate counter bore, a tail end plate transition groove and a tail end plate rib penetrating hole, and a tail end second heading is clamped in the tail end plate counter bore; a tail end plate rib penetrating hole sealing plug is arranged on the tail end plate transition groove and the tail end plate rib penetrating hole; a tail end radial sealing sleeve is arranged in the through hole in the middle of the tail end plate; the tail end radial sealing sleeve is of a cylindrical structure, a through hole is formed in the tail end radial sealing sleeve in a penetrating mode, the outer portion of the tail end radial sealing sleeve is a combination of step-shaped cylinders with different diameters, and the portion with the smaller diameter is installed in the through hole in the middle of the tail end plate.

The specific operation steps are as follows:

(1) after cutting the main bar in a fixed length, firstly carrying out hot heading processing, and sequentially processing a head end second heading, a head end first heading, a tail end second heading and a tail end first heading;

(2) performing roll welding processing on a plurality of main reinforcements and ring reinforcements to form a reinforcement cage structure;

(3) assembling the head end plate provided with the head end hoop and the reinforcement cage, firstly, enabling all head end first upsets which are uniformly distributed on a graduated circle to penetrate through the head end plate rib penetrating holes, then enabling head end second upsets to penetrate through the head end plate rib penetrating holes, then, rotating the head end plate, enabling all main ribs to slide to the positions of the head end plate counter bores through the head end plate transition grooves, finally, pulling the head end plate back towards the head end first upsets, and enabling all head end second upsets to be clamped in the head end plate counter bores;

(4) Plugging a head end plate rib penetrating hole sealing plug into each head end plate rib penetrating hole and each head end plate transition groove of the head end plates, and then plugging a head end plate rubber plug into a middle through hole of the head end plate;

(6) plugging a tail end plate rib penetrating hole sealing plug into each tail end plate rib penetrating hole and each tail end plate transition groove of the tail end plate, and then plugging a tail end radial sealing sleeve into a middle through hole of the tail end plate;

(7) putting the reinforcement cages respectively sleeved with the head end plate and the tail end plate into a lower die of the precast pile die 1;

(8) assembling the tension head plate and the reinforcement cage, firstly, penetrating all head end first upsets uniformly distributed on the graduated circle through tension head plate reinforcement penetrating holes, then, rotating the tension head plate, sliding all main reinforcements to the position of tension head plate counter bores through transition grooves of the tension head plate, finally, pulling the tension head plate back towards the direction of a tension screw rod, and clamping all head end first upsets in the tension head plate counter bores;

(9) Assembling the tensioning tail plate and a reinforcement cage, firstly, penetrating all tail end first upset heads uniformly distributed on a graduated circle through tensioning tail plate rib penetrating holes, then, rotating the tensioning tail plate, sliding all main ribs to the position of a tensioning tail plate counter bore through each tensioning tail plate transition groove, finally, pulling back the tensioning tail plate in the direction opposite to that of the tensioning head plate, clamping all tail end first upset heads into the tensioning tail plate counter bore, and then, enabling a tail end radial sealing sleeve to be in a compression state to play a role in sealing a space between the tensioning tail plate and a tail end plate;

(11) an upper die of the precast pile die 1 covers the lower die, and connecting bolts of the upper die and the lower die are locked, so that the whole precast pile die becomes a cylindrical whole;

(12) connecting the tensioning screw with hydraulic tensioning equipment, wherein a reaction frame of the hydraulic tensioning equipment is pressed on a tensioning baffle plate to start tensioning;

(13) because the size of the tensioning tail plate is larger than the size of the radial section of the precast pile mould, the position of the tensioning tail plate is limited by the precast pile mould during tensioning, and the position of the tensioning tail plate is fixed;

(14) Under the action of hydraulic tension, the steel bar between the tail end plate and the tensioning tail plate is elongated, and a tail end second heading head arranged in a tail end plate counter bore drives the tail end plate to move forwards;

(15) under the effect of hydraulic tension, stretch-draw screw rod, stretch-draw head board all move forward, because head end plate position is fixed, after the rod iron is elongated, head end second upset head can break away from head end plate counter bore. Under the action of the tension force, the tension head plate moves forwards to gradually compress the pressure spring, and when the rebound force of the pressure spring is greater than the power for the traction device to pull the head end plate to move forwards, the traction device pulls the head end plate to continuously move forwards under the action of the rebound force of the pressure spring because each magnet is tightly attached to the head end plate, so that the counter bore of the head end plate is ensured to be tightly attached to the second heading of the head end.

(16) When the set tension force is reached, the tensioning nut on the tensioning screw is screwed in the direction of the tensioning baffle until the tensioning nut is tightly attached to the end face of the tensioning baffle, the hydraulic tensioning device is separated from the tensioning screw, the tensioning nut plays a role in locking, the main rib cannot rebound, and the prestress of the main rib is maintained;

(17) a pumped pump pipe is inserted into the inner cavity of the precast pile die from the tail plate hole, after the space between the tensioning head plate and the tensioning tail plate is filled with concrete, the pump pipe is pulled out, and the tail plate sealing rubber plug blocks a through hole in the middle of the tensioning tail plate to prevent the concrete from flowing out of the through hole;

(18) Centrifuging the precast pile mould, pulling out the tail plate sealing rubber plug, completely pouring cement paste in the inner cavity of the precast pile mould after centrifuging, and curing the mould by steam to solidify the concrete. At the moment, after the tensioning nut is reversely rotated by adopting the tensioning device, the main rib cannot rebound because the concrete is solidified, the prestress is maintained, and the bending resistance of the precast pile product is greatly enhanced.

(19) Loosening connecting bolts of an upper die and a lower die of the precast pile die, and removing the upper die of the precast pile die;

(20) reversely rotating the tensioning head plate, and sliding all the head end first heads to the positions of the tensioning head plate reinforcement penetrating holes from the tensioning head plate counter bores to ensure that the tensioning head plate is smoothly separated from the head end first heads; after the stretching head plate is detached, the rubber plug of the head end plate is detached, so that the head end plate can be conveniently reused next time;

(21) and reversely rotating the tensioning tail plate to slide all the first tail end upsetting heads from the tensioning tail plate counter bores to the positions of the tensioning tail plate reinforcement through holes, so that the tensioning tail plate is smoothly separated from the first tail end upsetting heads. After the tensioning tail plate is dismantled, the tail end radial sealing sleeve is dismantled, so that the tail end radial sealing sleeve can be conveniently reused next time;

(22) Lifting the formed precast pile, and cutting off the parts of the two ends of the main reinforcement, which protrude out of the second heading 1 at the head end and the second heading at the tail end, to obtain a precast pile finished product; thus, the whole tensioning production process flow is completed.

According to the novel tensioning process, the precast pile mould is divided into an upper mould and a lower mould, and the upper mould and the lower mould are fastened and connected into a cylindrical or square-tube-shaped whole through bolts;

and the tensioning tail plate and the tensioning baffle plate are respectively clung to the end surfaces of the head plate and the tail plate of the precast pile mould, so that a cavity structure is formed inside the precast pile mould.

The middle of the tensioning baffle is provided with a circular through hole, a tensioning screw penetrates through the circular through hole, a matched tensioning nut is screwed on the tensioning screw, one end of the tensioning screw penetrates through the circular through hole in the middle of the tensioning baffle, and the other end of the tensioning screw is screwed with a tensioning screw mounting hole in the middle of the tensioning head plate.

The middle part of the tension head plate is provided with a tension screw mounting hole, the end face of the tension head plate is uniformly provided with a traction device mounting hole, and the traction device mounting hole is a through hole.

The other end surface of the tension head plate is uniformly provided with a tension head plate reinforcement penetrating hole, a tension head plate transition groove and a tension head plate counter bore;

The stretching head plate reinforcement penetrating holes, the stretching head plate transition grooves and the stretching head plate counter bores are communicated with one another, and the number of the stretching head plate reinforcement penetrating holes is consistent with the number of the main reinforcements of the precast pile reinforcement cage;

the tensioning head plate rib penetrating hole, the tensioning head plate transition groove and the tensioning head plate counter bore are blind holes, and the depths of the blind holes are consistent relative to the end faces of the holes of the tensioning head plate blind holes.

The diameter of the tensioning head plate bar penetrating hole is larger than that of the first head of the main bar head end, and a chamfer with a large outside and a small inside is arranged at the entrance of the tensioning head plate bar penetrating hole so that the first head of the head end can better enter the tensioning head plate bar penetrating hole.

The tensioning head plate transition groove is used for connecting the tensioning head plate reinforcement penetrating hole and the tensioning head plate counter bore;

the size of the tensioning tail plate is larger than the section size of the precast pile mould, and one section of end face of the tensioning tail plate is tightly attached to the end face of the tail end of the precast pile mould.

The tail plate hole has been seted up at the middle part of stretch-draw tailboard, and the downthehole sealed rubber buffer of tailboard that has installed of tailboard flows when the sealed rubber buffer of tailboard can prevent that the concrete in the precast pile mould in the precast pile production process from not solidifying yet.

A tensioning tail plate reinforcement penetrating hole, a tensioning tail plate transition groove and a tensioning tail plate counter bore are uniformly formed in the end face, close to the side end face of the precast pile die, of the tensioning tail plate;

The tensioning tail plate reinforcement penetrating holes, the tensioning tail plate transition grooves and the tensioning tail plate counter bores are communicated with one another, the number of the tensioning tail plate reinforcement penetrating holes is consistent with the number of the main reinforcements of the precast pile reinforcement cage,

the tensioning tail plate rib penetrating hole, the tensioning tail plate transition groove and the tensioning tail head plate counter bore are blind holes, and the depths of the blind holes are consistent relative to the opening end faces of the blind holes of the tensioning tail plate.

The diameter of the tensioning tail plate rib penetrating hole is larger than that of the first head of the main rib tail end, and a chamfer with a large outer part and a small inner part is arranged at the inlet of the tensioning tail plate rib penetrating hole so that the first head of the tail end can better enter the tensioning tail plate rib penetrating hole.

The tensioning tail plate transition groove is used for connecting the tensioning tail plate reinforcement penetrating hole and the tensioning tail plate counter bore

The middle part of head end plate has been seted up head end plate rubber buffer mounting hole, has been installed the head end plate rubber buffer in the mounting hole, and head end plate rubber buffer can prevent that the concrete in the precast pile mould from flowing in the space between head end plate and the stretch-draw head board when not solidifying yet in the precast pile production process.

The end face of the head end plate is evenly provided with a head end plate counter bore, a head end plate transition groove and a head end plate rib penetrating hole.

The head end plate counter bore, the head end plate transition groove and the head end plate reinforcement hole are provided with the same number of main reinforcements as the number of the precast pile reinforcement cage;

The head end plate counter bore, the head end plate cross the aqueduct, the head end plate wears the muscle hole and is the through-hole, the step face counter bore has been seted up at the head end plate to the head end plate counter bore, and head end second upset joint is in the head end plate counter bore.

The diameter of the head end plate tendon penetrating hole is larger than the diameter of the main tendon head first upset head and the head end second upset head 1, so that the head end first upset head and the head end second upset head can better enter the head end plate tendon penetrating hole.

Just by the joint back firmly in the head end plate counter bore of head end second heading, the head end plate crosses the aqueduct, the head end plate wears the downthehole head end plate and wears muscle hole sealing plug of all having installed of muscle, the head end plate wears muscle hole sealing plug can cross the aqueduct with the head end plate, the head end plate is worn the inner space in muscle hole and is filled up, when preventing that the concrete in the precast pile mould from not solidifying yet in the precast pile production process, cross the aqueduct through the head end plate, the head end plate wears the muscle hole and flows out in the space between head end plate and the stretch-draw head board.

The tail end radial sealing sleeve mounting hole is formed in the middle of the tail end plate, the tail end radial sealing sleeve is arranged in the mounting hole, and the tail end radial sealing sleeve can prevent concrete in a precast pile mould from flowing out of a space between the tail end plate and the tensioning tail plate before solidification in the precast pile production process.

The tail end radial sealing sleeve is of a hollow cylindrical structure, and the diameter of the inner diameter through hole is consistent, so that the pump pipe can be smoothly inserted when the material is pumped and distributed.

The outer diameter of the tail end radial sealing sleeve is provided with a sinking platform, and the part with the smaller outer diameter is arranged in the middle of the tail end plate and provided with a tail end radial sealing sleeve mounting hole.

The end face of the tail end plate is evenly provided with a tail end plate counter bore, a tail end plate transition groove and a tail end plate rib penetrating hole.

The counter bores of the tail end plates, the transition grooves of the tail end plates and the reinforcement through holes of the tail end plates are arranged in the same number as the number of the main reinforcements of the reinforcement cage of the precast pile,

the counter bore of the tail end plate, the transition groove of the tail end plate and the rib penetrating hole of the tail end plate are all through holes,

the tail end plate counter bore is provided with a step face counter bore at the tail end plate, and a tail end second heading is clamped in the tail end plate counter bore.

The diameter of the tail end plate rib penetrating hole is larger than the diameters of the first tail end heading and the second tail end heading of the main rib, so that the first tail end heading and the second tail end heading can better enter the tail end plate rib penetrating hole.

The tail end plate transition groove is used for connecting the tail end plate counter bore and the tail end plate reinforcement through hole,

After the tail end second heading is firmly clamped in the tail end plate countersink, a tail end plate tendon penetrating hole sealing plug 8-4 is arranged in the tail end plate transition groove and the tail end plate tendon penetrating hole, the tail end plate tendon penetrating hole sealing plug can fill the inner space of the tail end plate transition groove and the tail end plate tendon penetrating hole 8-3, and when concrete 15 in a precast pile mould in the precast pile production process is not solidified, the concrete flows out of the space between the tail end plate 8 and the tensioning tail plate 5 through the tail end plate transition groove and the tail end plate tendon penetrating hole 8-3.

The size of the tensioning baffle plate is larger than the section size of the precast pile mould, and one section of end face of the tensioning baffle plate is tightly attached to the end face of the head end of the precast pile mould.

The middle of the tensioning baffle is provided with a through hole, and the size of the through hole is larger than the diameter of the tensioning screw, so that the tensioning screw can smoothly pass through the through hole. And after the tensioning screw rod penetrates through the through hole in the middle of the tensioning baffle, one end of the tensioning screw rod is screwed in the tensioning screw rod mounting hole of the tensioning head plate, and the other end of the tensioning screw rod is suspended in the air, so that the tensioning screw rod is conveniently connected with hydraulic tensioning equipment.

The tensioning nut is matched with the tensioning screw in a threaded manner, the tensioning nut is screwed on the tensioning screw, and when the hydraulic tensioning equipment stretches the main reinforcement of the reinforcement cage through the tensioning screw, the tensioning nut rotates and clings to the tensioning baffle. When the hydraulic tensioning equipment is separated from the tensioning screw rod, the tensioning nut plays a role in locking, so that the main rib cannot retract, and the prestress is maintained;

The main ribs are the main ribs of the reinforcement cage, and the number of the main ribs is the same as that of tension head plate counter bores of the tension head plate, tension tail plate counter bores of the tension tail plate, head end plate counter bores of the head end plate and tail end plate counter bores of the tail end plate;

the main rib is provided with a head end first upsetting head, a head end second upsetting head, a tail end second upsetting head and a tail end first upsetting head;

the first head end heading is clamped in a tensioning head plate counterbore of the tensioning head plate, the second head end heading is clamped in a head end plate counterbore of the head end plate, the second tail end heading is clamped in a tail end plate counterbore of the tail end plate, and the first tail end heading is clamped in a tensioning tail plate counterbore of the tensioning tail plate;

the head end plate is worn muscle hole sealing plug, tail end plate is worn muscle hole sealing plug, head end plate rubber buffer, tail end radial seal cover and is made for the sealing material, through the installation of alignment extrusion deformation, realizes its sealed effect.

The traction device consists of a traction device long rod, a compression spring seat, a compression spring, a traction device stop block and a magnet,

a long rod of the traction device between the pressure spring seat and the stop block of the traction device penetrates through a mounting hole of the traction device of the tension head plate and can freely move back and forth;

One end of the pressure spring is pressed on the pressure spring seat, the other end of the pressure spring is pressed on the end surface of the tension head plate, the diameter of the pressure spring seat is larger than that of the pressure spring, the diameter of the pressure spring is larger than that of a traction device mounting hole of the tension head plate,

the diameter of the traction device stop block on the other side of the tensioning head plate is larger than that of the traction device mounting hole of the tensioning head plate, and the structure ensures that the traction device can freely move back and forth in the traction device mounting hole of the tensioning head plate without falling off.

And when the tension head plate, the head end plate and the main ribs are completely installed, all the traction devices are pushed forwards until all the magnets cling to the end surface of the head end plate.

The invention has the beneficial effects that:

1. after secondary heading processing is carried out on the two ends of all main ribs, the heading is assembled and clamped with the end plate and the tensioning plate respectively, the problem that the tensioning plate and the end plate in the industry need to be connected through bolt fastening is solved, the workload of workers for frequently tightening and disassembling the connecting bolts can be solved, the labor intensity of the workers is greatly reduced, and meanwhile, the production efficiency is also improved.

2. The invention provides a novel tensioning process of a precast pile, which comprises a main bar with two upset heads at two ends, wherein the upset heads at the end parts of the main bar are clamped in counter bores of a tensioning plate, the upset head at the middle part is clamped in an end plate counter bore at one end, and meanwhile, a traction device is additionally arranged on a tensioning head plate to ensure that all the upset heads can be tightly clamped with the corresponding counter bores in the tensioning process of the main bar. Meanwhile, a sealing pad plug made of various flexible materials is arranged between the concrete distribution area and the non-concrete distribution area, so that the problems of concrete loss and mold pollution are effectively solved. After a steel reinforcement cage with a plurality of double-headed main reinforcements arranged at two ends is placed into the cage, the reinforcement penetrating holes of the end plates at the head end and the tail end sequentially penetrate through 2 heads of the main reinforcements, the head penetrating holes of the head tensioning head plate and the tail penetrating holes of the tail tensioning tail plate at the head end and the tail end of the main reinforcements rotate for a certain angle, and the connection of the heads and the corresponding counter bores can be realized. In the mode, after secondary heading processing is carried out on both ends of all main ribs, the heading is assembled and clamped with the end plate and the tensioning plate respectively. Because of the tensile force is all by the first upset head of head end, stretch-draw first upset head board and tail end, stretch-draw the tailboard on, under the prerequisite of guaranteeing reinforcing bar tensile force, can effectually keep the integrity of head end second upset head, tail end second upset head, because head end plate and tail end plate are not atress at the in-process of stretch-draw, consequently stopped with integrative head end plate of precast pile product and tail end plate by head end second upset head, the possibility that tail end second upset head pulled through to the effectual quality of guaranteeing the product.

3. The invention provides a novel tensioning process of a precast pile, which comprises a main rib with two upset heads at two ends, wherein the upset heads at the end parts of the main rib are clamped in counter bores of a tensioning plate, the upset head at the middle part is clamped in an end plate counter bore at one end, and meanwhile, a traction device is additionally arranged on a tensioning head plate to ensure that all the upset heads can be tightly clamped with the corresponding counter bores in the tensioning process of the main rib. Meanwhile, a sealing gasket plug made of various flexible materials is arranged between the concrete distribution area and the non-concrete distribution area, so that the problems of concrete loss and mold pollution are effectively solved. After a plurality of steel reinforcement cages with double-headed main reinforcements at two ends are placed in a cage, the reinforcement penetrating holes of the end plates at the head end and the tail end sequentially penetrate through 2 heads of the main reinforcements, the head penetrating holes of the head tensioning head plate and the tail penetrating holes of the tail tensioning tail plate at the head end and the tail end of the main reinforcements rotate for a certain angle, and the heads and the tail tensioning tail plate and the end plates at the head end and the tail end can be clamped with corresponding counter bores. According to the mode, after the two ends of all main ribs are subjected to secondary heading processing, the heading is assembled and clamped with the end plate and the tensioning plate respectively, the tensioning plate is not required to be connected through bolts, the process flow is simplified, and the labor intensity of workers is reduced.

The invention realizes that the tensioning plate is not required to be connected by bolts, simplifies the process flow and reduces the labor intensity of workers.

Drawings

FIG. 1 is a side view of a tensioned structure according to the present technique.

Fig. 2 is an a-direction view of the tension head plate.

Fig. 3 is a view of the tension head plate in the direction B.

Fig. 4 is a sectional view of the tension head plate in the direction of C.

Fig. 5 is a sectional view of the tension head plate in the direction D.

Fig. 6 is a sectional view of the tension head plate in the direction of E.

Fig. 7 is a J-view of the head end plate structure.

FIG. 8 is an M-direction view of a tensioned tailgate.

FIG. 9 is a cross-sectional view of the tensioning tailgate in the direction F.

FIG. 10 is a sectional view of the tension tailgate in the direction G.

FIG. 11 is a cross-sectional view taken in the direction H of the tensioning tailgate.

Fig. 12 is a K-direction view of the trailing end plate structure.

Fig. 13 is a side view of the draft gear.

In the figure:

1-prefabricating a pile mould; 2, stretching a screw rod; 3, tensioning the nut; 4, tensioning the head plate; 4-1-tensioning screw mounting holes; 4-2-a traction device mounting hole; 4-3-stretching the head plate to penetrate the rib hole; 4-stretching the head plate transition groove; 4-5-stretching the head plate counter bore; 5, tensioning the tail board; 5-1-tail plate hole; 5-2-sealing rubber plug of end plate; 5-3 stretching the tail plate through rib holes; 5-4-tensioning the tail plate transition groove; 5-5 stretching the tail plate counter bore; 6-head end plate; 6-1 — a head end plate counter bore; 6-2-a head end plate transition groove; 6-3, a head end plate rib penetrating hole; 6-4, sealing plug of head end plate through rib hole; 7-head end hoop; 8-tail end plate; 8-1-end plate counter bore; 8-2-a tail end plate transition groove; 8-3-a tail end plate rib penetrating hole; 8-4, a tail end plate rib hole penetrating sealing plug; 9-tail end hoop; 10-main reinforcement; 10-1-a first heading at the head end; 10-2-a second heading at the head end; 10-3-second heading at the tail end; 10-4-first heading at tail end; 11-head end plate rubber plug; 12-tail end radial seal cover; 13-a traction device; 13-1 — long rod of traction device; 13-2-compression spring seat; 13-3-compression spring; 13-4-a draft gear stop; 13-5-magnet; 14-stretching the baffle; 15-concrete.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present invention and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

According to the novel tensioning process disclosed by the invention, as shown in fig. 1, the precast pile mould 1 is divided into an upper mould and a lower mould, the upper mould and the lower mould are fastened and connected into a cylindrical or square cylindrical whole through bolts, and a tensioning tail plate 5 and a tensioning baffle plate 14 are respectively tightly attached to the end surfaces of a head plate and a tail plate of the precast pile mould 1, so that a cavity structure is formed in the interior of the precast pile mould. A circular through hole is formed in the middle of the tensioning baffle 14, a tensioning screw 2 penetrates through the circular through hole, a matched tensioning nut 3 is screwed on the tensioning screw 2, one end of the tensioning screw 2 penetrates through the circular through hole in the middle of the tensioning baffle 14, and the other end of the tensioning screw 2 is screwed with a tensioning screw mounting hole 4-1 in the middle of the tensioning head plate 4.

As shown in fig. 2, a tension screw mounting hole 4-1 is formed in the middle of the tension head plate 4, traction device mounting holes 4-2 are equally formed in the end face of the tension head plate 4, and the traction device mounting holes 4-2 are through holes. The number of the traction device mounting holes 4-2 is more than or equal to 2, and the traction device mounting holes are circumferentially and symmetrically arranged. As shown in fig. 3, the other end surface of the tension head plate 4 is uniformly provided with tension head plate reinforcement penetrating holes 4-3, tension head plate transition grooves 4-4 and tension head plate counter bores 4-5; the tension head plate reinforcement penetrating holes 4-3, the tension head plate transition grooves 4-4 and the tension head plate counter bores 4-5 are communicated with one another, the number of the tension head plate reinforcement penetrating holes is consistent with the number of main ribs 10 of the precast pile reinforcement cage, the tension head plate reinforcement penetrating holes 4-3, the tension head plate transition grooves 4-4 and the tension head plate counter bores 4-5 are blind holes, and the depth of the blind holes is consistent relative to the end face of the blind holes of the tension head plate 4. The diameter of the tensioning head plate bar penetrating hole 4-3 is larger than that of the first upset head 10-1 at the head end of the main bar 10, and as shown in fig. 5, a chamfer with a large outside and a small inside is arranged at the inlet of the tensioning head plate bar penetrating hole 4-3, so that the first upset head 10-1 at the head end can better enter the tensioning head plate bar penetrating hole 4-3. The tensioning head plate transition groove 4-4 is used for connecting a tensioning head plate reinforcement penetrating hole 4-3 and a tensioning head plate counter bore 4-5, a head end first upset head 10-1 enters the tensioning head plate reinforcement penetrating hole 4-3 and then slides transversely, can smoothly pass through the tension head plate transition groove 4-4, at the moment, because the tension head plate transition groove 4-4 is of a structure with a small inside and a big outside, the opening width of the sliding groove is larger than the diameter of the main rib 10 and smaller than the diameter of the first upset head 10-1 at the head end, the thickness L1 of the internal space of the tension head plate transition groove 4-4 is slightly larger than that of the first upset head 10-1 at the head end, therefore, when the head end first upset head 10-1 is in the tension head plate transition groove 4-4, the head end first upset head is limited in the groove and can only slide along two directions of the tension head plate reinforcement through hole 4-3 and the tension head plate counter bore 4-5. The thickness L2 of the inner space of the tension head plate counter bore 4-5 is larger than the thickness L1 of the inner space of the tension head plate transition groove 4-4, so when the head end first upset head 10-1 enters the position of the tension head plate counter bore 4-5, and then the head end plate 6 moves towards the direction opposite to the direction of the head end first upset head 10-1, the head end first upset head 10-1 is firmly clamped in the tension head plate counter bore 4-5.

As shown in fig. 8, the size of the tensioning tail plate 5 is larger than the cross-sectional size of the precast pile mold 1, and a section of the end surface of the tensioning tail plate 5 is tightly attached to the end surface of the tail end of the precast pile mold 1. The middle part of the tensioning tail plate 5 is provided with a tail plate hole 5-1, a tail plate sealing rubber plug 5-2 is arranged in the tail plate hole 5-1, and the tail plate sealing rubber plug 5-2 can prevent the concrete 15 in the precast pile mould from flowing out when not solidified in the precast pile production process. A tensioning tail plate reinforcement penetrating hole 5-3, a tensioning tail plate transition groove 5-4 and a tensioning tail plate counter bore 5-5 are uniformly formed in the end face, close to the side end face of the precast pile mould, of the tensioning tail plate 5; the tensioning tail plate reinforcement penetrating holes 5-3, the tensioning tail plate transition grooves 5-4 and the tensioning tail plate counter bores 5-5 are communicated with one another, the number of the tensioning tail plate reinforcement penetrating holes is consistent with the number of the main ribs 10 of the precast pile reinforcement cage, the tensioning tail plate reinforcement penetrating holes 5-3, the tensioning tail plate transition grooves 5-4 and the tensioning tail head plate counter bores 5-5 are blind holes, and the depth of the blind holes is consistent relative to the end face of the blind hole opening of the tensioning tail plate 4. The diameter of the tensioning tail plate rib penetrating hole 5-3 is larger than that of the first upset head 10-4 at the tail end of the main rib 10, and as shown in fig. 5, a chamfer with a large outside and a small inside is arranged at the inlet of the tensioning tail plate rib penetrating hole 5-3, so that the first upset head 10-4 at the tail end can better enter the tensioning tail plate rib penetrating hole 5-3. The tensioning tail plate transition groove 5-4 is used for connecting the tensioning tail plate reinforcement penetrating hole 5-3 and the tensioning tail plate counter bore 5-5, the first upset head 10-4 at the tail end slides transversely after entering the tensioning tail plate reinforcement penetrating hole 5-3, can smoothly pass through the tensioning tail plate transition groove 5-4, at the moment, because the tensioning tail plate transition groove 5-4 is of a structure with a small inside and a large outside, the opening width of the sliding groove is larger than the diameter of the main rib 10 and smaller than the diameter of the first upset head 10-4 at the tail end, the thickness L1 of the internal space of the tensioning tail plate transition groove 5-4 is slightly larger than that of the first upset head 10-4 at the tail end, therefore, when the first upset head 10-4 at the tail end is in the tensioning tail plate transition groove 5-4, the first upset head is limited in the groove and can only slide along two directions of the tensioning head plate reinforcement through hole 5-3 and the tensioning tail plate counter bore 5-5. The thickness L2 of the inner space of the tension tail plate counter bore 5-5 is larger than the thickness L1 of the inner space of the tension head plate transition groove 4-4, so when the first tail end upset head 10-4 enters the position of the tension tail plate counter bore 5-5 and then the tail end plate 8 moves towards the direction opposite to the direction of the first tail end upset head 10-4, the first tail end upset head 10-4 is firmly clamped in the tension tail plate counter bore 5-5.

As shown in fig. 7, 11 mounting holes of head end plate rubber buffer have been seted up at the middle part of head end plate 6, have been equipped with head end plate rubber buffer 11 in the mounting hole, and head end plate rubber buffer 11 can prevent to flow out in the space between head end plate 6 and stretch-draw head plate 4 when concrete 15 in precast pile mould 1 in the precast pile production process has not solidified yet. The end face of the head end plate 6 is evenly provided with a head end plate counter bore 6-1, a head end plate transition groove 6-2 and a head end plate tendon penetration hole 6-3. The number of the head end plate counter bores 6-1, the head end plate transition grooves 6-2 and the head end plate reinforcement through holes 6-3 is the same as the number of the main reinforcements 10 of the precast pile reinforcement cage, the head end plate counter bores 6-1, the head end plate transition grooves 6-2 and the head end plate reinforcement through holes 6-3 are all through holes, the head end plate counter bores 6-1 are provided with step face counter bores in the head end plate 6, and the head end second upset heads 10-2 are clamped in the head end plate counter bores 6-1. The diameter of the head end plate tendon penetration hole 6-3 is larger than the diameters of the first head end 10-1 and the second head end 10-2 of the main tendon 10, so that the first head end 10-1 and the second head end 10-2 can better enter the head end plate tendon penetration hole 6-3. The head end plate transition groove 6-2 is used for connecting a head end plate counter bore 6-1 and a head end plate rib penetrating hole 6-3, the head end first upset 10-1 and the head end second upset 10-2 sequentially penetrate the head end plate rib penetrating hole 6-3 and then transversely slide, and can smoothly pass through the head end plate transition groove 6-2, at the moment, because the opening width of the head end plate transition groove 6-2 is larger than the diameter of the main rib 10 and smaller than the diameters of the head end first upset 10-1 and the head end second upset 10-2, when the head end plate second upset 10-2 passes through the head end plate transition groove 6-2, the head end second upset is limited in the groove and can only slide along two directions of the head end plate counter bore 6-1 and the head end plate rib penetrating hole 6-3. The depth of the head end plate counter bore 6-1 is larger than the thickness of the head end second upset head 10-2, when the head end second upset head 10-2 transversely slides to the position of the head end plate counter bore 6-1, and then the head end plate 6 moves towards the direction opposite to the direction of the head end first upset head 10-1, the head end second upset head 10-2 is firmly clamped in the head end plate counter bore 6-1. After the head end second upset head 10-2 is firmly clamped in the head end plate counter bore 6-1, head end plate reinforcing hole sealing plugs 6-4 are respectively arranged in the head end plate transition groove 6-2 and the head end plate reinforcing hole 6-3, and the head end plate reinforcing hole sealing plugs 6-4 can fill the inner spaces of the head end plate transition groove 6-2 and the head end plate reinforcing hole 6-3, so that the situation that concrete 15 in a precast pile die in the precast pile production process does not solidify yet is prevented from flowing out of the space between the head end plate 6 and the tensioning head plate 4 through the head end plate transition groove 6-2 and the head end plate reinforcing hole 6-3.

As shown in fig. 12, a tail end radial sealing sleeve 12 is provided in the middle of the tail end plate 8, a tail end radial sealing sleeve 12 is provided in the mounting hole, and the tail end radial sealing sleeve 12 can prevent the concrete 15 in the precast pile mold 1 from flowing out into a space between the tail end plate 8 and the tension tail plate 5 when the concrete is not yet solidified in the precast pile production process. The tail end radial sealing sleeve 12 is of a hollow cylindrical structure, and the diameter of the inner diameter through hole is consistent, so that a pump pipe can be inserted smoothly when the material is distributed by pumping. The outer diameter of the tail end radial sealing sleeve 12 is provided with a sinking platform, and the part with the smaller outer diameter is arranged in the middle of the tail end plate 8 and provided with a mounting hole of the tail end radial sealing sleeve 12. The end face of the tail end plate 8 is evenly provided with a tail end plate counter bore 8-1, a tail end plate transition groove 8-2 and a tail end plate tendon penetration hole 8-3. The number of the tail end plate counter bore 8-1, the number of the tail end plate transition grooves 8-2 and the number of the tail end plate reinforcement through holes 8-3 are the same as the number of the main reinforcements 10 of the precast pile reinforcement cage, the tail end plate counter bore 8-1, the tail end plate transition grooves 8-2 and the tail end plate reinforcement through holes 8-3 are through holes, the tail end plate counter bore 8-1 is provided with a step face counter bore in the tail end plate 8, and a tail end second heading 10-3 is clamped in the tail end plate counter bore 8-1. The diameter of the tail end plate tendon penetrating hole 8-3 is larger than the diameters of the first tail end heading 10-4 and the second tail end heading 10-3 of the main tendon 10, so that the first tail end heading 10-4 and the second tail end heading 10-3 can better enter the tail end plate tendon penetrating hole 8-3. The tail end plate transition groove 8-2 is used for connecting a tail end plate counter bore 8-1 and a tail end plate through rib hole 8-3, a first tail end heading 10-4 and a second tail end heading 10-3 sequentially pass through the tail end plate through rib hole 8-3 and then transversely slide, and can smoothly pass through the tail end plate transition groove 8-2, at the moment, because the opening width of the tail end plate transition groove 8-2 is larger than the diameter of the main rib 10 and smaller than the diameters of the first tail end heading 10-4 and the second tail end heading 10-3, when the second tail end heading 10-3 is in the tail end plate transition groove 8-2, the second tail end heading is limited in the groove and can only slide along two directions of the tail end plate counter bore 8-1 and the tail end plate through rib hole 8-3. The depth of the tail end plate counter bore 8-1 is larger than the thickness of the tail end second upsetting head 10-3, when the tail end second upsetting head 10-3 transversely slides to the tail end plate counter bore 8-1 position, and then the tail end plate 8 moves towards the direction opposite to the head end first upsetting head 10-1, the tail end second upsetting head 10-3 is firmly clamped in the tail end plate counter bore 8-1. After the second tail end heading 10-3 is firmly clamped in the tail end plate counter bore 8-1, the tail end plate transition groove 8-2 and the tail end plate reinforcement hole 8-3 are both provided with a tail end plate reinforcement hole sealing plug 8-4, and the tail end plate reinforcement hole sealing plug 8-4 can fill the inner space of the tail end plate transition groove 8-2 and the tail end plate reinforcement hole 8-3, so that the concrete 15 in the precast pile die in the precast pile production process is prevented from flowing out to the space between the tail end plate 8 and the tensioning tail plate 5 through the tail end plate transition groove 8-2 and the tail end plate reinforcement hole 8-3 when not solidified.

As shown in fig. 1, the size of the tension baffle 14 is larger than the cross-sectional size of the precast pile mold 1, and a section of the end face of the tension baffle 14 is closely attached to the end face of the head end of the precast pile mold 1. The middle of the tensioning baffle 14 is provided with a through hole, and the size of the through hole is larger than the diameter of the tensioning screw rod 2, so that the tensioning screw rod 2 can smoothly pass through the through hole. After the tensioning screw 2 penetrates through the through hole in the middle of the tensioning baffle plate 14, one end of the tensioning screw is screwed in the tensioning screw mounting hole 4-1 of the tensioning head plate 4, and the other end of the tensioning screw 2 is suspended in the air, so that the hydraulic tensioning device can be conveniently connected. The tensioning nut 3 is matched with the tensioning screw 2 in a threaded manner, the tensioning nut 3 is screwed on the tensioning screw 2, and when the hydraulic tensioning equipment stretches the steel reinforcement cage main reinforcement 10 through the tensioning screw 2, the tensioning nut 3 rotates and clings to the tensioning baffle 14. When the hydraulic tensioning equipment is separated from the tensioning screw rod 2, the tensioning nut 3 plays a role in locking, so that the main rib 10 cannot retract, and the prestress is maintained;

the main ribs 10 are the main ribs of the reinforcement cage, and the number of the main ribs is the same as the number of tension head plate counter bores 4-5 of the tension head plate 4, the number of tension tail plate counter bores 5-5 of the tension tail plate 5, the number of head end plate counter bores 6-1 of the head end plate 6 and the number of tail end plate counter bores 8-1 of the tail end plate 8; the main rib 10 is provided with a first head end upset 10-1, a second head end upset 10-2, a second tail end upset 10-3 and a first tail end upset 10-4; the first head end upset 10-1 is clamped in a tension head plate counter bore 4-5 of the tension head plate 4, the second head end upset 10-2 is clamped in a head end plate counter bore 6-1 of the head end plate 6, the second tail end upset 10-3 is clamped in a tail end plate counter bore 8-1 of the tail end plate 8, and the first tail end upset 10-4 is clamped in a tension tail plate counter bore 5-5 of the tension tail plate 5;

The head end plate rib penetrating hole sealing plug 6-4, the tail end plate rib penetrating hole sealing plug 8-4, the head end plate rubber plug 11 and the tail end radial sealing sleeve 12 are all made of sealing materials, and the sealing effect is achieved through alignment, extrusion and deformation installation.

The traction device 13 consists of a traction device long rod 13-1, a pressure spring seat 13-2, a pressure spring 13-3, a traction device stop block 13-4 and a magnet 13-5, wherein the traction device long rod 13-1 between the pressure spring seat 13-2 and the traction device stop block 13-4 penetrates through a traction device mounting hole 4-2 of the tension head plate 4 and can freely move back and forth; one end of the pressure spring 13-3 is pressed on the pressure spring seat 13-2, the other end of the pressure spring is pressed on the end face of the tension head plate 4, the diameter of the pressure spring seat 13-2 is larger than that of the pressure spring 13-3, the diameter of the pressure spring 13-3 is larger than that of the traction device mounting hole 4-2 of the tension head plate 4, the diameter of the traction device stop block 13-4 on the other side of the tension head plate 4 is larger than that of the traction device mounting hole 4-2 of the tension head plate 4, and the traction device 13 can freely move back and forth in the traction device mounting hole 4-2 of the tension head plate 4 and cannot fall off. In the process of tensioning, as the main reinforcement 10 is elongated, the tensioning screw 2, the tensioning head plate 4, the head end first upset head 10-1 and the head end second upset head 10-2 all move towards the tensioning baffle 14, and as the head end plate 6 is placed in the precast pile mould 1, the head end second upset head 10-2 can be separated from the head end plate 6 in the process of moving forwards, in order to ensure that the head end second upset head 10-2 is effectively clamped in the head end plate counter bore 6-1 of the head end plate 6, the head end plate 6 must also move forwards during tensioning. The traction device 13 penetrates through the partial head end of the tension head plate 4 and is provided with the magnets 13-5, after the tension head plate 4, the head end plate 6 and the main ribs 10 are installed, the traction devices 13 are pushed forwards until all the magnets 13-5 are tightly attached to the end face of the head end plate 6, and the magnets 13-5 and the head end plate 6 are tightly bonded together under the action of the attraction force of the magnets 13-5. When the tension head plate 4 moves forwards, the compression spring 13-3 is compressed by pressure, the reaction force is applied to the long device rod 13-1 through the compression spring seat 13-2, so that the traction device 13 is ensured to move forwards, and simultaneously, the long device rod 13-1, the magnet 13-5 and the head end plate 6 form a whole, so that the head end plate 6 moves forwards along with the whole. The head end plate counter bore 6-1 of the head end plate 6 can be tightly attached to the second head 10-2 of the head end, and the phenomenon that the second head 10-2 of the head end is separated can not occur.

The invention relates to a novel tensioning process, which comprises the following operation steps:

1. after the main reinforcement 10 is cut off in a fixed length, firstly, hot upsetting is carried out, and a head end second upsetting head 10-2, a head end first upsetting head 10-1, a tail end second upsetting head 10-3 and a tail end first upsetting head 10-4 are sequentially processed;

2. performing roll welding processing on a plurality of main reinforcements 10 and the annular reinforcements to form a reinforcement cage structure;

3. assembling a head end plate 6 provided with a head end hoop 7 and a reinforcement cage, firstly, penetrating all head end first upsets 10-1 uniformly distributed on a graduated circle through head end plate through rib holes 6-3, then penetrating head end second upsets 10-2 through head end plate through rib holes 6-3, then rotating the head end plate 6, sliding all main ribs 10 to the positions of head end plate counter bores 6-1 through all head end plate through aqueducts 6-2, and finally pulling the head end plate 6 back towards the head end first upsets 10-1 direction, wherein all head end second upsets 10-2 are blocked in the head end plate counter bores 6-1;

4. plugging a head end plate tendon-penetrating hole sealing plug 6-4 into each head end plate tendon-penetrating hole 6-3 and each head end plate transition groove 6-2 of the head end plate 6, and then plugging a head end plate rubber plug 11 into a middle through hole of the head end plate 6;

5. assembling a tail end plate 8 provided with a tail end hoop 9 and a reinforcement cage, firstly, penetrating all tail end first upsets 10-4 uniformly distributed on a graduated circle through tail end plate rib penetrating holes 8-3, then penetrating tail end second upsets 10-3 through the tail end plate rib penetrating holes 8-3, then rotating the tail end plate 8, sliding all main ribs 10 to the positions of tail end plate counter bores 8-1 through tail end plate transition grooves 8-2, and finally pulling the tail end plate 8 back towards the tail end first upsets 10-4 direction, wherein all tail end second upsets 10-3 are clamped in the tail end plate counter bores 8-1;

6. Plugging each tail end plate tendon penetration hole 8-3 and each tail end plate transition groove 8-2 of the tail end plate 8 into a tail end plate tendon penetration hole sealing plug 8-4, and then plugging a tail end radial sealing sleeve 12 into a middle through hole of the tail end plate 8;

7. putting the reinforcement cages respectively sleeved with the head end plate 6 and the tail end plate 8 into a lower die of the precast pile die 1;

8. assembling a tension head plate 4 and a reinforcement cage, firstly, penetrating all head end first upset heads 10-1 uniformly distributed on a graduated circle through tension head plate reinforcement through holes 4-3, then, rotating the tension head plate 4, sliding all main reinforcements 10 to the position of tension head plate counter bores 4-5 through tension head plate transition grooves 4-4, finally, pulling back the tension head plate 4 towards a tension screw 2, and clamping all head end first upset heads 10-1 in the tension head plate counter bores 4-5;

9. assembling a tensioning tail plate 5 and a reinforcement cage, firstly, penetrating all tail end first upset heads 10-4 uniformly distributed on a graduated circle through tensioning tail plate reinforcement through holes 5-3, then, rotating the tensioning tail plate 5, sliding all main reinforcements 10 to the position of tensioning tail plate counter bores 5-5 through all tensioning tail plate transition grooves 5-4, finally, pulling back the tensioning tail plate 5 in the direction opposite to that of the tensioning head plate 4, clamping all tail end first upset heads 10-4 in the tensioning tail plate counter bores 5-5, and then, enabling a tail end radial sealing sleeve 12 to be in a compression state, and sealing the space between the tensioning tail plate 5 and a tail end plate tensioning 8;

10. Pressing down the pressure spring seat 13-2 of each traction device 13 towards the tail end direction of the precast pile mould 1 to ensure that each magnet 13-5 is tightly attached to the head end plate 6;

11. an upper die of the precast pile die 1 covers the lower die, and connecting bolts of the upper die and the lower die are locked, so that the whole precast pile die 1 becomes a cylindrical whole;

12. connecting the tensioning screw 2 with a hydraulic tensioning device, wherein a reaction frame of the hydraulic tensioning device is pressed against the tensioning baffle 14, and tensioning is started;

13. because the size of the tensioning tail plate 5 is larger than the size of the radial section of the precast pile mould 1, the position of the tensioning tail plate 5 is limited by the precast pile mould 1 during tensioning, and the position is fixed and unchanged.

14. Under the action of hydraulic tension, the steel bar 10 between the tail end plate 8 and the tensioning tail plate 5 is lengthened, and a tail end second heading 10-3 arranged in a tail end plate counter bore 8-1 drives the tail end plate to move forwards;

15. under the action of hydraulic tension, the tension screw 2 and the tension head plate 4 both move forwards, and because the position of the head end plate 6 is fixed, when the steel bar 10 is elongated, the second head 10-2 of the head end can be separated from the counter bore 6-1 of the head end plate. Under the action of the tension force, the tension head plate 4 moves forwards to gradually compress the compression spring 13-3, when the rebound force of the compression spring 13-3 is larger than the power of the traction device 13 for driving the head end plate 6 to move forwards, the traction device 13 pulls the head end plate 6 to continuously move forwards under the action of the rebound force of the compression spring 13-3 as the magnets 13-5 are tightly attached to the head end plate 6, and the counter bore 6-1 of the head end plate and the second head heading 10-2 are ensured to be tightly attached together.

16. When the set tension force is reached, the tensioning nut 3 on the tensioning screw rod 2 is screwed in towards the direction of the tensioning baffle 14 until the tensioning nut 3 is tightly attached to the end face of the tensioning baffle 14, the hydraulic tensioning device is separated from the tensioning screw rod 2, the tensioning nut 3 plays a role in locking, the main rib 10 cannot rebound, and the prestress of the main rib 10 is maintained;

17. a pumped pump pipe is inserted into the inner cavity of the precast pile mould 1 from the tail plate hole 5-1, after the space between the tensioning head plate 4 and the tensioning tail plate 5 is filled with concrete 15, the pump pipe is pulled out, and the tail plate sealing rubber plug 5-2 blocks a through hole in the middle of the tensioning tail plate 5 to prevent the concrete 15 from flowing out of the through hole;

18. centrifuging the precast pile mould, wherein the concrete 15 in the precast pile mould 1 is of a hollow cylindrical structure, pulling out the tail plate sealing rubber plug 5-2, completely pouring cement paste in the inner cavity of the precast pile mould after centrifuging is finished, and curing the mould by steam, so that the concrete 15 is solidified. At this time, after the tension nut 3 is rotated reversely by adopting the tension releasing device, the main reinforcement 10 can not rebound because the concrete 15 is solidified, the prestress is maintained, and the bending resistance of the precast pile product is greatly enhanced.

19. Loosening connecting bolts of an upper die and a lower die of the precast pile die 1, and then removing the upper die of the precast pile die 1;

20. And reversely rotating the tensioning head plate 4, and sliding all the head end first upsets 10-1 from the tensioning head plate counter bores 4-5 to the positions of the tensioning head plate reinforcement penetrating holes 4-3 to ensure that the tensioning head plate 4 is smoothly separated from the head end first upsets 10-1. After the stretching head plate 4 is detached, the head end plate rubber plug 11 is detached, so that the head end plate rubber plug can be reused next time;

21. and reversely rotating the tensioning tail plate 5 to slide all the first tail end upsetting heads 10-4 from the tensioning tail plate counter bores 5-5 to the positions of the tensioning tail plate reinforcement through holes 5-3, so as to ensure that the tensioning tail plate 5 is smoothly separated from the first tail end upsetting heads 10-4. After the tensioning tail plate 5 is disassembled, the tail end radial sealing sleeve 12 is disassembled, so that the next recycling is facilitated;

22. and (3) hoisting the formed precast pile, and cutting off all parts of the two ends of the main reinforcement 10, which protrude out of the second upset heads 10-2 at the head end and 10-3 at the tail end, so as to obtain a precast pile finished product. Thus, the whole tensioning production process flow is completed.

This mode can all carry out secondary upset head processing back with whole main muscle both ends, again with end plate, stretch-draw board assembly joint, has realized need not to assemble the head tailboard through bolted connection's mode dismouting, has simplified process operation flow, simultaneously greatly reduced staff's intensity of labour.

It should be understood that although the specification has been described in terms of various embodiments, not every embodiment includes every single embodiment, and such description is for clarity purposes only, and it will be appreciated by those skilled in the art that the specification as a whole can be combined as appropriate to form additional embodiments as will be apparent to those skilled in the art.

The above-listed detailed description is only a specific description of possible embodiments of the present invention, and they are not intended to limit the scope of the present invention, and equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included in the scope of the present invention.

Claims

1. The tensioning device for the reinforced precast pile is characterized by comprising a precast pile mould (1); the head end of the precast pile mould (1) is connected with a tensioning baffle (14), and the inner wall of the precast pile mould (1) is sequentially connected with a tensioning head plate (4), a head end plate (6), a tail end plate (8) and a tensioning tail plate (5) from the head end to the tail end; the tensioning screw (2) penetrates through the tensioning baffle (14) to be connected to the tensioning head plate (4), and the tensioning nut (3) is connected to the tensioning screw (2); a traction device (13) is arranged between the tension head plate (14) and the head end plate (6); the head ends of the main ribs (10) are respectively provided with a first head end upset head (10-1) and a second head end upset head (10-2), and the tail ends are respectively provided with a first tail end upset head (10-4) and a second tail end upset head (10-3);

A tension head plate counter bore (4-5) is formed in the tension head plate (4), and a head end first heading (10-1) is clamped in the tension head plate counter bore (4-5); the head end plate (6) is provided with a head end plate counter bore (6-1), and a head end second heading (10-2) is clamped in the head end plate counter bore (6-1); a tensioning tail plate counter bore (5-5) is formed in the tensioning tail plate (5), and a first heading (10-4) at the tail end is clamped in the tensioning tail plate counter bore (5-5); the tail end plate (8) is provided with a tail end plate counter bore (8-1), and a tail end second heading (10-3) is clamped in the tail end plate counter bore (8-1);

a stretching head plate reinforcement penetrating hole (4-3), a stretching head plate transition groove (4-4) and a stretching head plate counter bore (4-5) are arranged on the stretching head plate (4); the tensioning tail plate (5) is provided with a tail plate hole (5-1), a tensioning tail plate transition groove (5-4) and a tensioning tail plate counter bore (5-5); the head end plate is provided with a transition groove (6-2) and a head end plate rib penetrating hole (6-3); the tail end plate is provided with a tail end plate transition groove (8-2) and a tail end plate rib penetrating hole (8-3).

2. A tensioning device for an enhanced precast pile according to claim 1, wherein the traction device (13) comprises a long traction device rod (13-1), and the long traction device rod (13-1) is provided with a pressure spring seat (13-2), a pressure spring (13-3), a traction device stop block (13-4) and a magnet (13-5) in sequence from the head end to the tail end; one end of the pressure spring (13-3) is arranged on the pressure spring seat (13-2), and the other end of the pressure spring is pressed on the end face of the head end of the tension head plate (4); the traction device stop block (13-4) is arranged between the tension head plate (4) and the head end plate (6) and is connected through a traction device long rod (13-1) penetrating through a traction device mounting hole (4-2) on the tension head plate (4); one end of the magnet (13-5) is connected with the tail end of the long rod (13-1) of the traction device, and the other end is connected with the head end plate (6) during tensioning.

3. A tensioning device for an enhanced precast pile according to claim 1, wherein the tensioning head plate (4) is provided with tensioning screw mounting holes (4-1), traction device mounting holes (4-2), tensioning head plate reinforcement through holes (4-3), tensioning head plate transition grooves (4-4) and tensioning head plate counter bores (4-5) in the number consistent with that of the main reinforcements (10); the tensioning head plate reinforcement penetrating hole (4-3), the tensioning head plate transition groove (4-4) and the tensioning head plate counter bore (4-5) are blind holes with sealed heads, the thickness L1 of the inner space of the tensioning head plate transition groove (4-4) is smaller than the thickness L2 of the inner space of the tensioning head plate counter bore (4-5), and each tensioning head plate counter bore (4-5) is used for clamping a first heading (10-1) of each head end;

the tensioning tail plate (5) is provided with tail plate holes (5-1), tail plate sealing rubber plugs (5-2), tensioning tail plate through rib holes (5-3), tensioning tail plate transition grooves (5-4) and tensioning tail plate counter bores (5-5), wherein the number of the tensioning tail plate through rib holes is consistent with that of the main ribs (10); the tensioning tail plate transition groove (5-4) is connected with a tensioning tail plate reinforcement penetrating hole (5-3) and a tensioning tail plate counter bore (5-5), the tensioning tail plate reinforcement penetrating hole (5-3), the tensioning tail plate transition groove (5-4) and the tensioning tail plate counter bore (5-5) are blind holes with sealed tail ends, the thickness L3 of the inner space of the tensioning tail plate transition groove (5-4) is smaller than the thickness L4 of the inner space of the tensioning tail plate counter bore (5-5), and the tensioning tail plate counter bore (5-5) is used for clamping a first heading (10-4) of each tail end; a tail plate sealing rubber plug (5-2) is arranged in the tail plate hole (5-1);

Head end plate rib penetrating hole sealing plugs (6-4) are arranged in the head end plate transition grooves (6-2) and the head end plate rib penetrating holes (6-3); a head end plate rubber plug (11) is arranged in a through hole in the middle of the head end plate (6);

and a tail end plate rib penetrating hole sealing plug 8-4 is arranged on the tail end plate transition groove (8-2) and the tail end plate rib penetrating hole (8-3).

4. A tensioning device for an enhanced precast pile according to any one of claims 1 to 3, characterized in that a tail end radial sealing sleeve (12) is arranged on a through hole in the middle of the tail end plate (8); the tail end radial sealing sleeve (12) is of a cylindrical structure, a through hole is formed in the tail end radial sealing sleeve, a sinking platform is arranged on the outer diameter of the tail end radial sealing sleeve, and the sinking platform part with the smaller outer diameter is arranged in the through hole in the middle of the tail end plate (8).

5. A tensioning device for an enhanced precast pile according to claim 1, wherein: the diameter of the tensioning head plate bar penetrating hole (4-3) is larger than that of a first heading (10-1) at the head end of the main bar (10), and a chamfer is arranged at the inlet of the tensioning head plate bar penetrating hole (4-3);

the diameter of the tensioning tail plate tendon penetrating hole (5-3) is larger than that of the first upset head (10-4) at the tail end of the main tendon (10), and a chamfer is arranged at the inlet of the tensioning tail plate tendon penetrating hole (5-3).

6. A tensioning device for an enhanced precast pile according to claim 3, wherein: a head end plate rubber plug (11) is arranged in a through hole in the middle of the head end plate (6);

the head end second heading (10-2) is clamped in the head end plate counter bore (6-1);

the diameter of the head end plate tendon penetration hole (6-3) is larger than the diameters of a first head end (10-1) and a second head end (10-2) of the main tendon (10);

the tail end second heading (10-3) is clamped in the tail end plate counter bore (8-1);

the diameter of the tail end plate tendon penetrating hole (8-3) is larger than the diameters of a first tail end heading (10-4) and a second tail end heading (10-3) of the main tendon (10);

the depth of the tail end plate counter bore (8-1) is larger than the thickness of the tail end second upsetting head (10-3), when the tail end second upsetting head (10-3) transversely slides to the position of the tail end plate counter bore (8-1), and then the tail end plate (8) moves towards the direction opposite to the direction of the head end first upsetting head (10-1), the tail end second upsetting head (10-3) is firmly clamped in the tail end plate counter bore (8-1).

7. A tensioning device for a reinforced precast pile according to claim 1, wherein: the tensioning screw (2) is connected with a hydraulic tensioning device.

8. A tensioning device for an enhanced precast pile according to claim 1, wherein: the distance between the first heading end (10-1) and the second heading end (10-2) is larger than 40mm, and the distance between the first tail end (10-4) and the second tail end (10-3) is also larger than 40 mm.

9. A novel tensioning process of an enhanced precast pile using a tensioning device of the enhanced precast pile according to any one of claims 1 to 8, comprising the steps of:

(1) after the main reinforcement (10) is cut off in a fixed length, firstly, hot heading processing is carried out, and a head end second heading (10-2), a head end first heading (10-1), a tail end second heading (10-3) and a tail end first heading (10-4) are sequentially processed;

(2) performing roll welding on a plurality of processed main reinforcements (10) and the annular reinforcements to form a reinforcement cage structure;

(3) assembling a head end plate (6) provided with a head end hoop (7) with a reinforcement cage, firstly, enabling all head end first upsets (10-1) which are uniformly distributed on a graduated circle to penetrate through head end plate rib penetrating holes (6-3), then enabling head end second upsets (10-2) to penetrate through the head end plate rib penetrating holes (6-3), then rotating the head end plate (6), enabling all main ribs (10) to slide to the positions of the head end plate counter bores (6-1) through head end plate transition grooves (6-2), and finally pulling the head end plate (6) back towards the head end first upsets (10-1), and enabling all head end second upsets (10-2) to be clamped in the head end plate counter bores (6-1);

(5) Assembling a tail end plate (8) provided with a tail end hoop (9) and a reinforcement cage, firstly, penetrating all tail end first upsets (10-4) uniformly distributed on a graduated circle through tail end plate rib penetrating holes (8-3), then penetrating tail end second upsets (10-3) through the tail end plate rib penetrating holes (8-3), then rotating the tail end plate (8), sliding all main ribs (10) to the positions of tail end plate counter bores (8-1) through tail end plate transition grooves (8-2), and finally pulling back the tail end plate (8) towards the tail end first upsets (10-4), wherein all tail end second upsets (10-3) are clamped in the tail end plate counter bores (8-1);

(7) putting the reinforcement cages respectively sleeved with the head end plate (6) and the tail end plate (8) into a lower die of the precast pile die (1) integrally;

(8) assembling the tension head plate (4) and a reinforcement cage, firstly, penetrating all head end first upset heads (10-1) uniformly distributed on a pitch circle through tension head plate reinforcement penetrating holes (4-3), then rotating the tension head plate (4), sliding all main ribs (10) to positions of tension head plate counter bores (4-5) through all tension head plate transition grooves (4-4), finally, pulling the tension head plate (4) back towards a tension screw (2), and clamping all head end first upset heads (10-1) in the tension head plate counter bores (4-5);

(9) Mounting a sinking platform part with a smaller outer diameter of the tail end radial sealing sleeve (12) in a through hole in the middle of the tail end plate (8); assembling a tensioning tail plate (5) and a reinforcement cage, firstly, penetrating all tail end first upsets (10-4) uniformly distributed on a pitch circle through tensioning tail plate rib penetrating holes (5-3), then, rotating the tensioning tail plate (5), sliding all main ribs (10) to the positions of tensioning tail plate counter bores (5-5) through all tensioning tail plate transition grooves (5-4), finally, pulling the tensioning tail plate (5) back to the direction opposite to that of the tensioning head plate (4), clamping all tail end first upsets (10-4) in the tensioning tail plate counter bores (5-5), and sealing a space between the tensioning tail plate (5) and a tail end plate (8) when a tail end radial sealing sleeve (12) is in a compression state;

(10) pressing down the pressure spring seat (13-2) of each traction device (13) towards the tail end direction of the precast pile mould (1) to ensure that each magnet (13-5) is tightly attached to the head end plate (6);

(11) covering an upper die of the precast pile die (1) on a lower die, and locking connecting bolts of the upper die and the lower die, wherein the whole precast pile die (1) is combined into a cylindrical whole;

(12) Connecting the tensioning screw (2) with tensioning equipment, wherein a reaction frame of the tensioning equipment is pressed against a tensioning baffle (14) to start tensioning;

(13) under the action of hydraulic tension, a main rib (10) between the tail end plate (8) and the tensioning tail plate (5) is lengthened, and a tail end second heading (10-3) arranged in a tail end plate counter bore (8-1) drives the tail end plate (8) to move forwards;

(14) under the action of hydraulic tension, the tensioning screw (2) and the tensioning head plate (4) both move forwards, and because the position of the head end plate (6) is fixed, when the main rib (10) is elongated, the second head heading (10-2) of the head end can be separated from the counter bore (6-1) of the head end plate; under the action of tension force, the tension head plate (4) moves forwards to gradually compress the compression spring (13-3), when the rebound force of the compression spring (13-3) is greater than the power of the traction device (13) for pulling the head end plate (6) to move forwards, the traction device (13) pulls the head end plate (6) to continuously move forwards under the action of the rebound force of the compression spring (13-3) as each magnet (13-5) is tightly attached to the head end plate (6), and the head end counter bore end plate (6-1) and the head end second upset head (10-2) are ensured to be tightly attached together;

(15) When the set tension force is reached, the tensioning nut (3) on the tensioning screw (2) is screwed in towards the tensioning baffle (14) until the tensioning nut (3) is tightly attached to the end face of the tensioning baffle (14), the hydraulic tensioning device is separated from the tensioning screw (2), the tensioning nut (3) plays a role in locking, the main rib (10) cannot rebound, the prestress of the main rib (10) is kept, and the whole tensioning process is completed.

10. A novel tensioning process of a reinforced precast pile of a tensioning device of a reinforced precast pile according to claim 9, characterized by further comprising the steps (4) and (6),

(4) after the step (3) is finished, plugging a head end plate tendon penetrating hole sealing plug (6-4) into each head end plate tendon penetrating hole (6-3) and each head end plate transition groove (6-2) of the head end plate (6), and then plugging a head end plate rubber plug (11) into a middle through hole of the head end plate (6);

(6) and (5) after the step (5) is finished, plugging rib penetrating holes (8-3) of each tail end plate of the tail end plate (8) and sealing plugs (8-4) of the rib penetrating holes of the tail end plates into transition grooves (8-2) of each tail end plate.