CN116220012A

CN116220012A - Reverse circulation construction device for bridge bored pile

Info

Publication number: CN116220012A
Application number: CN202310351827.6A
Authority: CN
Inventors: 陈治玉; 朱必洲; 徐文江; 朱明业; 刘晓东; 胡建; 姜春燕; 董莉莉
Original assignee: Third Engineering Co Ltd of China Railway 16th Bureau Group Co Ltd
Current assignee: Third Engineering Co Ltd of China Railway 16th Bureau Group Co Ltd
Priority date: 2023-03-29
Filing date: 2023-03-29
Publication date: 2023-06-06

Abstract

The utility model relates to a bridge drilling bored concrete pile reverse circulation construction device belongs to the bridge field, and it includes the foundation ditch pile casing, the coaxial drill way department of locating the stake hole that inlays of foundation ditch pile casing, coaxial wear to be equipped with the thick liquid drilling rod in the stake hole, the subaerial mud pit of having seted up of stake hole side, fixedly connected with drainage tube on the foundation ditch pile casing, the one end and the mud pit intercommunication of drainage tube, the other end and foundation ditch pile casing inner chamber and stake hole intercommunication, be equipped with drainage mechanism on the foundation ditch pile casing, drainage mechanism is used for making mud dash to the thick liquid drilling rod from the foundation ditch pile casing, be provided with the water pump on the drainage tube. The utility model provides a mud after making getting into the stake hole dashes to the thick liquid drilling rod, and thick liquid drilling rod alright be as drainage rod guide mud decline, and the washing effort of decline in-process mud to stake hole inner wall is lower, has certainly reduced the probability that the soil property collapses in the degree.

Description

Reverse circulation construction device for bridge bored pile

Technical Field

The application relates to the field of bridge construction, in particular to a reverse circulation construction device for a bored pile of a bridge.

Background

The bridge pile head, i.e. the bridge pile foundation, is the part of the bridge lower structure contacted with the foundation, bears the whole load transmitted by the bridge upper structure, and transmits the load of the bridge lower structure and the whole load to the foundation so as to ensure the safety and normal use of the full bridge.

In the related art, a bridge pile foundation is a concrete bored pile, and the bored pile is a pile formed by forming a pile hole in foundation soil by means of mechanical boring, steel pipe soil squeezing, manual excavation or the like on an engineering site, and placing a reinforcement cage and pouring concrete in the pile hole. The foundation pit is arranged on the ground and is positioned beside the pile hole, a sedimentation tank is arranged and communicated with the foundation pit, the sedimentation tank is used for containing slurry, and the sedimentation tank is divided into a positive circulation rotary drilling hole and a reverse circulation rotary drilling hole according to the slag discharging mode in the hole forming process of the bored pile.

The reverse circulation rotary drilling hole is driven by a drilling machine rotary device to rotationally cut and break rock and soil by a drill rod and a drill bit, the circulating wall-protecting slurry is pumped by means of pumping, gas lifting, spraying and the like, the entrained drilling slag is pumped out of the hole from the inner cavity of the drill rod and flows into a sedimentation tank, and the sediment and the filtered drilling slag flow back into the pile hole.

For reverse circulation rotary drilling, the clear Kong Nijiang continuously flows downwards from the position between the drill rod and the pile hole wall, has a continuous scouring effect on the soil property of the pile hole wall, and generates continuous acting force on the soil property, so that the risk of hole wall collapse is increased compared with that of forward circulation rotary drilling.

Disclosure of Invention

In order to improve the problems, the application provides a reverse circulation construction device for a bored pile of a bridge.

The application provides a bridge drilling bored concrete pile reverse circulation construction equipment adopts following technical scheme:

the utility model provides a bridge drilling bored concrete pile reverse circulation construction device, includes the foundation ditch pile casing, the coaxial drill way department of locating the stake hole that inlays of foundation ditch pile casing, downthehole coaxial slip drilling rod that wears to be equipped with of stake, the subaerial mud pit of having seted up of stake hole, fixedly connected with drainage tube on the foundation ditch pile casing, the one end and the mud pit intercommunication of drainage tube, the other end and foundation ditch pile casing inner chamber and stake hole intercommunication, be equipped with drainage mechanism on the foundation ditch pile casing, drainage mechanism is used for making mud dash to the slip drilling rod from the foundation ditch pile casing, be provided with the water pump on the drainage tube.

Through adopting above-mentioned technical scheme, the mud after getting into the stake hole dashes to the thick liquid drilling rod, and then the thick liquid drilling rod just can be as drainage rod guide mud decline, then the washing effort of mud to stake hole inner wall is lower in the decline in-process, has reduced the probability that the soil property collapses in certain degree.

Preferably, the foundation pit pile casing comprises an outer cylinder and an inner cylinder which are coaxially and fixedly connected with each other, a drainage gap is formed between the outer cylinder and the inner cylinder, a plurality of drainage holes are formed in the inner cylinder, the plurality of drainage holes are distributed in an annular array mode by taking the axis of the foundation pit pile casing as the center, the drainage mechanism comprises drainage plates, the drainage plates are located on one side, facing the slurry pumping drill rod, of the inner cylinder, and the drainage plates are located below the drainage holes.

Preferably, the drainage plate is hinged with the inner cylinder, the hinge shaft of the drainage plate and the inner cylinder is positioned below the drainage hole, and a torsion spring is arranged on the hinge shaft of the drainage plate and the inner cylinder and applies upward overturning torsion force to the drainage plate.

Through adopting above-mentioned technical scheme, after mud was spouted from the drainage hole, the drainage plate had carried out further guide to the mud flow, reduced the probability of mud and stake hole inner wall contact, under the effect of torsional spring, the mud flow was gone out from the drainage hole and is required certain pressure, has improved the pressure of the liquid self-contained in the success entering stake hole, has further reduced the probability that mud flows down along stake hole inner wall.

Preferably, a seam membrane is fixedly connected between the adjacent drainage plates, the seam membrane is an elastic geomembrane, and a containing groove for the seam membrane to exist is formed in the side edge of each drainage plate.

Through adopting above-mentioned technical scheme, at the in-process that the drainage board overturned, connect and clearance seal through seam membrane all the time between two adjacent drainage boards, reduce the probability that mud oozes from here, also can improve the synchronism in each drainage board working process simultaneously.

Preferably, the axis of drainage tube is parallel with the horizontal direction, the axial of drainage tube is the tangent line of inner tube outer wall in stake hole axial direction's projection, drainage mechanism still includes the homogenate subassembly, the homogenate subassembly is used for improving the mud and flows to the drainage hole in foundation ditch casing circumference ascending distribution uniformity degree.

Through adopting above-mentioned technical scheme, after mud gets into the drainage space, mud just rotates in the drainage space under the guide of inner tube outer wall and urceolus inner wall, improves the filling degree of mud in the drainage space.

Preferably, the homogenizing component comprises a flow equalizing rotor, the flow equalizing rotor is coaxially and rotationally connected with the foundation pit pile casing, the flow equalizing rotor comprises a flow equalizing annular plate and a plurality of power sailboards, the flow equalizing annular plate is positioned in a drainage gap and is coaxial with the foundation pit pile casing, the plurality of power sailboards are annularly arranged in an array manner and are fixedly connected to the flow equalizing annular plate, the projection of the drainage tube on the horizontal direction is positioned in the height range of the power sailboards, and a plurality of slurry passing holes which are communicated with the thickness of the drainage tube are formed in the flow equalizing annular plate.

Through adopting above-mentioned technical scheme, the impact force that produces after mud fluid rushes into drainage space can act on the power sailboard as thrust, drives the directional rotation of rotor that flow equalizes, and mud between accuse pressure ring plate and the flow equalizing ring plate can pass through the pulp passage and flow downwards and continue simultaneously, and pivoted rotor that flow equalizes can improve the uniform velocity degree in different angular orientations when mud rotates in the drainage space.

Preferably, the face of the power sailboard is perpendicular to the face of the current-sharing annular plate, one side, away from the current-sharing annular plate, of each power sailboard is fixedly connected with the same pressure-controlling annular plate at the same time, the shape of the pressure-controlling annular plate is consistent with that of the current-sharing annular plate, and each power sailboard is provided with a uniform pressure hole.

By adopting the technical scheme, due to the existence of the uniform pressure holes, when the injection power of the slurry is continuously improved, the hydraulic pressure between each power sailboard tends to be equal, and the flow distribution of the slurry along the circumference of the uniform flow rotor is more balanced when the slurry permeates downwards.

Preferably, the flow equalizing ring plate is provided with a speed regulating hole, the flow equalizing ring plate is movably connected with a speed regulating plate at the speed regulating hole, the plate surface of the speed regulating plate is attached to the plate surface of the flow equalizing ring plate, the speed regulating plate is movable to control the closing or opening of the speed regulating hole, and the homogenate assembly further comprises a control member for controlling the movement of the speed regulating plate.

Preferably, the speed regulation plate is in sliding connection with the flow equalization ring plate, the sliding direction is the radial direction of the flow equalization ring plate, the control piece is a centrifugal spring, the expansion direction of the centrifugal spring is the radial direction of the flow equalization ring plate, one end of the centrifugal spring is fixedly connected with the flow equalization ring plate, and the other end of the centrifugal spring is fixedly connected with the speed regulation plate.

Through adopting above-mentioned technical scheme, when needs improve mud velocity of flow, improve the power of water pump, fluid pressure increases, and the rotor rotational speed that flow equalizes improves, and under the effect of centrifugal force, the speed regulating plate has the trend of keeping away from the inner tube and remove, and centrifugal spring is compressed, and the speed regulating hole is opened, and the higher rotational speed, the degree that the speed regulating hole was opened just is bigger, and the speed that mud passed through the flow equalizing annular plate is also higher.

In summary, the present application includes at least one of the following beneficial technical effects:

1. through the arrangement of the drainage mechanism, the slurry entering the pile hole is flushed towards the slurry pumping drill rod, and then the slurry pumping drill rod can serve as the drainage rod to guide the slurry to descend, so that the flushing acting force of the slurry on the inner wall of the pile hole in the descending process is lower, and the probability of soil collapse of the hole wall is reduced to a certain extent;

2. through the setting of homogenate subassembly, the rotor that flow equalizes takes place to rotate continually by the in-process that mud impacted, and the existence of even pressure hole makes the hydraulic pressure between each dynamic sailboard tend to be equal, and the mud volume distribution in the circumference in drainage space is more even promptly, and then mud can reach the drainage hole after the circulation board that flow equalizes downwards, and from each drainage hole spun mud volume, velocity of flow also tend to be equal, then the mud flow in the entering stake hole is also more stable.

Drawings

Fig. 1 is a schematic cross-sectional view of a construction structure used for embodying a reverse circulation construction device for a bored pile of a bridge in an embodiment of the present application.

Fig. 2 is a schematic structural diagram for embodying a drainage mechanism in an embodiment of the present application.

Fig. 3 is a schematic structural diagram of a flow equalizing rotor according to an embodiment of the present application.

Fig. 4 is a schematic structural view of the drainage plate according to the embodiment of the present application when lifted.

Fig. 5 is a schematic structural diagram for showing the drainage plate when all the drainage plates are punched out in the embodiment of the present application.

Reference numerals illustrate: 1. pile holes; 11. a slurry pool; 12. a slurry pumping drill rod; 2. a foundation pit pile casing; 21. an outer cylinder; 22. an inner cylinder; 221. drainage holes; 23. a drainage tube; 231. a water pump; 3. a drainage mechanism; 31. a drainage plate; 311. a receiving groove; 32. a seaming film; 4. a homogenizing assembly; 41. a flow equalizing rotor; 411. a flow equalizing ring plate; 412. a pressure control ring plate; 413. a power sailboard; 414. uniformly pressing the holes; 415. a pulp passing hole; 416. a speed regulating hole; 42. a speed regulating plate; 43. the spring is centrifuged.

Detailed Description

The present application is described in further detail below in conjunction with figures 1-5.

The embodiment of the application discloses reverse circulation construction device of bridge bored pile, as shown in fig. 1, including foundation ditch pile casing 2 and drainage mechanism 3. The ground is provided with a vertical pile hole 1, a mud pit 11 is dug beside the pile hole 1, the mud pit 11 is communicated with the pile hole 1, mud for cleaning the pile hole 1 is contained in the mud pit 11, a mud pumping drill rod 12 is coaxially arranged in the pile hole 1 in a penetrating way, the lower end of the mud pumping drill rod 12 is connected with a drill bit (not shown in the figure) for rotary drilling, and in the drilling and cleaning processes, the mud pumping drill rod 12 continuously pumps the mud at the bottom of the pile hole 1 to the outside; the foundation pit casing 2 is embedded in the pile hole 1 and is positioned at an orifice, and the drainage mechanism 3 is used for enabling slurry to flow through the foundation pit casing 2 from the slurry pool 11 and to be flushed towards the slurry pumping drill rod 12.

As shown in fig. 1 and 2, the foundation pit casing 2 comprises an outer cylinder 21 and an inner cylinder 22 which are coaxially and fixedly connected with each other, the inner wall of the inner cylinder 22 is flush with the wall of the pile hole 1, and an annular drainage gap is formed between the outer cylinder 21 and the inner cylinder 22; the outer wall of the outer cylinder 21 is fixedly connected with a drainage tube 23, one end of the drainage tube 23 is communicated with the drainage gap, the other end of the drainage tube is communicated with the mud pit 11, the drainage tube 23 is also connected with a water pump 231, and the water pump 231 is used for enabling mud in the mud pit 11 to transmit power into the drainage gap through the drainage tube 23. The axis of the drainage tube 23 is parallel to the horizontal direction, and the projection of the axis of the drainage tube 23 on the axial direction of the pile hole 1 is a tangent line of the outer wall of the inner cylinder 22, namely, when the slurry enters the drainage gap, the slurry rotates in the drainage gap under the guidance of the outer wall of the inner cylinder 22 and the inner wall of the outer cylinder 21. A plurality of drainage holes 221 are formed in the inner barrel 22 and are positioned near the bottom of the pile hole 1, the plurality of drainage holes 221 are distributed in an annular array with the axis of the foundation pit casing 2 as the center, and mud in the drainage gap finally enters the pile hole 1 through the drainage holes 221.

As shown in fig. 2, 3 and 4, the drainage mechanism 3 includes a homogenizing component 4, where the homogenizing component 4 is used to improve the uniformity of distribution of slurry in the circumferential direction of the foundation pit casing 2 when the slurry flows to the drainage hole 221, the homogenizing component 4 includes a flow equalizing rotor 41, where the flow equalizing rotor 41 is composed of a pressure-controlling ring plate 412, a flow equalizing ring plate 411 and a plurality of power sailboards 413, the flow equalizing ring plate 411 is located in the drainage gap and is coaxially and rotatably connected with the foundation pit casing 2, the shape of the pressure-controlling ring plate 412 is identical to that of the flow equalizing ring plate 411, and the two plate surfaces are parallel to each other; the power sailboards 413 are annularly arranged and fixedly connected to the upper plate surface of the current-sharing annular plate 411, the plate surface of the power sailboards 413 is perpendicular to the plate surface of the current-sharing annular plate 411, and one end, away from the current-sharing annular plate 411, of the power sailboards 413 is fixedly connected with the lower plate surface of the current-sharing annular plate 411. The flow equalizing ring plate 411 is provided with a plurality of slurry passing holes 415, each slurry passing hole 415 is annularly arranged into a circle by taking the axis of the flow equalizing ring plate 411 as the center, the projection of the drainage tube 23 in the horizontal direction is positioned in the height range of the power sailboard 413, namely, the impact force generated after slurry fluid rushes into the drainage gap can act on the power sailboard 413 as thrust force to drive the flow equalizing rotor 41 to rotate directionally, and meanwhile, the slurry between the pressure controlling ring plate 412 and the flow equalizing ring plate 411 can continuously flow downwards through the slurry passing holes 415; due to the existence of the uniform pressure holes 414, when the injection power of the slurry is continuously improved, the hydraulic pressure among the power sailboards 413 tends to be equal, and the flow distribution of the slurry along the circumference of the uniform flow rotor 41 is more uniform when the slurry permeates downwards.

As shown in fig. 2, 3 and 4, the flow equalizing ring plate 411 is further provided with a plurality of speed adjusting holes 416, the plurality of speed adjusting holes 416 are also annularly arranged to form a circle by taking the axis of the flow equalizing ring plate 411 as the center, the formed circle is positioned at the outer edge of the circle formed by the slurry passing holes 415, and the speed adjusting holes 416 can also allow slurry to cross the flow equalizing ring plate 411. The lower plate surface of the flow equalizing ring plate 411 is slidably connected with a speed regulating plate 42 at a speed regulating hole 416, the sliding direction is radial of the flow equalizing ring plate 411, the plate surface of the speed regulating plate 42 is attached to the plate surface of the flow equalizing ring plate 411, and the homogenizing component 4 further comprises a control member for controlling the movement of the speed regulating plate 42; in this embodiment, the control member is a centrifugal spring 43, the expansion direction of the centrifugal spring 43 is also radial to the flow equalizing ring plate 411, one end of the centrifugal spring is fixedly connected with the flow equalizing ring plate 411, and the other end is fixedly connected with the speed regulating plate 42. Under the natural state, the speed regulating plate 42 plugs the speed regulating hole 416, when the flow rate of slurry needs to be increased, the power of the water pump 231 is increased, the fluid pressure is increased, the rotation speed of the flow equalizing rotor 41 is increased, under the action of centrifugal force, the speed regulating plate 42 has a tendency of moving away from the inner cylinder 22, the centrifugal spring 43 is compressed, the speed regulating hole 416 is opened, and the higher the rotation speed is, the greater the degree of opening the speed regulating hole 416 is, and the higher the speed of slurry passing through the flow equalizing ring plate 411 is.

As shown in fig. 1, 4 and 5, the drainage mechanism 3 further comprises a drainage plate 31, the drainage plate 31 is hinged to one side of the inner barrel 22 facing the pulp pumping drill pipe 12, and the hinge shaft of the drainage plate is positioned below the drainage hole 221; in this embodiment, the number of drainage holes 221 and drainage plates 31 is eight and corresponds to each other one by one. And install torsional spring (not shown in the figure) on the articulated shaft of drainage plate 31 and inner tube 22, the torsional spring applys the torsion of upwards overturning to drainage plate 31, under the natural state, drainage plate 31 keeps laminating with inner tube 22 inner wall and seals drainage hole 221, thereby mud is impacted to drainage plate 31 and is made its upset downwards when spouting mud in drainage hole 221, when each drainage plate 31 overturns to the mutual butt of side, all drainage plates 31 just splice into an annular board, this board plays further guide effect to follow the mud that spouts from drainage hole 221, make mud dash more smoothly to the thick liquid pipe that draws, reduce the probability that mud contacted with this stake hole 1 inner wall. In order to reduce the condition that mud passes through gaps between adjacent drainage plates 31, accommodating grooves 311 are formed in the side edges of each drainage plate 31, a seam membrane 32 is fixedly connected between every two adjacent drainage plates 31, the seam membrane 32 is an elastic geomembrane, two ends of the seam membrane are respectively and fixedly connected to the bottoms of the accommodating grooves 311, connection and gap sealing are always achieved between every two adjacent drainage plates 31 through the seam membrane 32 in the process of overturning the drainage plates 31, and meanwhile synchronism in the working process of each drainage plate 31 can be improved.

The implementation principle of the reverse circulation construction device for the bridge bored pile provided by the embodiment of the application is as follows:

after the water pump 231 is started, mud in the mud pit 11 is pumped into the foundation pit pile casing 2, the mud is uniformly distributed along the circumference of the foundation pit pile casing 2 and is sprayed to the mud pumping drill pipe 12 under the action of the flow equalizing component, the mud flows downwards along the mud pumping drill pipe 12 under the adsorption action of liquid, the downflowing liquid is hardly told to contact with the inner wall of the pile hole 1 in the whole process, and the risk of collapse of the soil structure of the inner wall of the pile hole 1 is reduced.

The foregoing are all preferred embodiments of the present application, and are not intended to limit the scope of the present application in any way, therefore: all equivalent changes in structure, shape and principle of this application should be covered in the protection scope of this application.

Claims

1. The utility model provides a bridge drilling bored concrete pile reverse circulation construction device, includes foundation ditch pile casing (2), the drill way department of locating stake hole (1) is inlayed to foundation ditch pile casing (2) coaxial, coaxial string of being equipped with in stake hole (1) draws thick liquid drilling rod (12), and mud pit (11), its characterized in that have been seted up on the subaerial by stake hole (1): fixedly connected with drainage tube (23) on foundation ditch pile casing (2), the one end and the mud pit (11) intercommunication of drainage tube (23), the other end and foundation ditch pile casing (2) inner chamber and stake hole (1) intercommunication, be equipped with drainage mechanism (3) on the foundation ditch pile casing (2), drainage mechanism (3) are used for making mud dash to take out thick liquid drilling rod (12) from foundation ditch pile casing (2), be provided with water pump (231) on drainage tube (23).

2. The reverse circulation construction device for the bored pile of the bridge according to claim 1, wherein: the foundation pit pile casing (2) comprises an outer cylinder (21) and an inner cylinder (22) which are coaxially and fixedly connected with each other, a drainage gap is formed between the outer cylinder (21) and the inner cylinder (22), a plurality of drainage holes (221) are formed in the inner cylinder (22), the drainage holes (221) are distributed in an annular array mode by taking the axis of the foundation pit pile casing (2) as the center, the drainage mechanism (3) comprises drainage plates (31), the drainage plates (31) are located on one side, facing the slurry pumping drill rod (12), of the inner cylinder (22), and the drainage plates (31) are located below the drainage holes (221).

3. The reverse circulation construction device for the bored pile of the bridge according to claim 2, wherein: the drainage plate (31) is hinged with the inner cylinder (22), the hinge shaft of the drainage plate (31) and the hinge shaft of the inner cylinder (22) are positioned below the drainage hole (221), and torsion springs are arranged on the hinge shaft of the drainage plate (31) and the hinge shaft of the inner cylinder (22) and apply upward overturning torsion force to the drainage plate (31).

4. A reverse circulation construction device for a bored pile of a bridge according to claim 3, wherein: a joint film (32) is fixedly connected between the adjacent drainage plates (31), the joint film (32) is an elastic geomembrane, and accommodating grooves (311) for the joint film (32) to exist are formed in the side edges of the drainage plates (31).

5. The reverse circulation construction device for the bored pile of the bridge according to claim 2, wherein: the axis of drainage tube (23) is parallel with the horizontal direction, the axial of drainage tube (23) is the tangent line of inner tube (22) outer wall in stake hole (1) axial direction's projection, drainage mechanism (3) still include homogenate subassembly (4), homogenate subassembly (4) are used for improving the mud and flow to drainage hole (221) in foundation ditch casing (2) circumference ascending distribution uniformity degree.

6. The reverse circulation construction device for the bored pile of the bridge according to claim 5, wherein: the utility model provides a homogenizing subassembly (4) is including rotor (41) that flow equalizes, rotor (41) that flow equalizes and foundation ditch protect a section of thick bamboo (2) coaxial rotation and be connected, rotor (41) that flow equalizes is including flow equalizing ring board (411) and a plurality of power sailboard (413), flow equalizing ring board (411) are located drainage space and with foundation ditch protect a section of thick bamboo (2) coaxial, a plurality of power sailboard (413) annular array arranges and fixed connection on flow equalizing ring board (411), the projection of drainage tube (23) on the horizontal direction is located the altitude range of power sailboard (413), a plurality of thick liquid holes (415) that link up self thickness have been seted up on flow equalizing ring board (411).

7. The reverse circulation construction device for the bored pile of the bridge as set forth in claim 6, wherein: the face of power sailboard (413) is perpendicular with the face of flow equalizing annular plate (411), each power sailboard (413) keep away from one side of flow equalizing annular plate (411) and fixedly connected with same accuse pressure annular plate (412) simultaneously, the shape of accuse pressure annular plate (412) is unanimous with flow equalizing annular plate (411), each power sailboard (413) is last all to have seted up even pressure hole (414).

8. The reverse circulation construction device for the bored pile of the bridge, according to claim 7, is characterized in that: the utility model discloses a flow equalizing device, including flow equalizing ring plate (411), speed adjusting hole (416) have been seted up on flow equalizing ring plate (411), flow equalizing ring plate (411) are gone up and in speed adjusting hole (416) department swing joint has speed adjusting plate (42), the face of speed adjusting plate (42) is laminated with the face of flow equalizing ring plate (411), speed adjusting plate (42) activity is in order to control the closure or opening of speed adjusting hole (416), homogenate subassembly (4) still including the control piece that is used for controlling speed adjusting plate (42) activity.

9. The reverse circulation construction device for the bored pile of the bridge according to claim 8, wherein: the speed regulation plate (42) is in sliding connection with the flow equalization annular plate (411), the sliding direction is the radial direction of the flow equalization annular plate (411), the control piece is a centrifugal spring (43), the expansion direction of the centrifugal spring (43) is the radial direction of the flow equalization annular plate (411), one end of the centrifugal spring (43) is fixedly connected with the flow equalization annular plate (411), and the other end of the centrifugal spring is fixedly connected with the speed regulation plate (42).