阅读说明：本技术 三轴变径搅拌钻杆 (Triaxial reducing stirring drill rod ) 是由 金俊杰 王一锋 黄丽莎 潘海翔 周鑫鑫 于 2021-07-17 设计创作，主要内容包括：本发明涉及建筑桩基工程的技术领域,公开了一种轴变径搅拌钻杆,包括驱动系统、机箱和钻杆,钻杆设有三根且转动连接于机箱,驱动系统设于机箱上,钻杆包括搅拌杆和钻头机构,钻头机构包括下钻组件和扩径组件；钻组件包括连接于钻杆的下钻头和固定连接于下钻头外侧壁的下钻叶片,扩径组件包括延伸叶片和顶出组件,下钻叶片远离下钻头的端面上开有引导孔,下钻头的顶面向下开有滑移孔,引导孔与滑移孔相通,延伸叶片滑移在引导孔中,顶出组件滑移在滑移孔中,延伸叶片的一端位于滑移孔中,且抵触于顶出组件。本申请的钻杆能够形成带有扩大头的三轴变径桩孔,从而使得最终形成的桩体在桩孔中的抗拔力提高,提高桩体在地面内的稳定性。(The invention relates to the technical field of building pile foundation engineering, and discloses a shaft reducing stirring drill rod, which comprises three driving systems, a case and drill rods, wherein the drill rods are rotatably connected to the case; the drilling assembly comprises a lower drill bit connected to the drill rod and a lower drilling blade fixedly connected to the outer side wall of the lower drill bit, the expanding assembly comprises an extending blade and an ejecting assembly, a guide hole is formed in the end face, away from the lower drill bit, of the lower drilling blade, a sliding hole is formed in the top face of the lower drill bit downwards, the guide hole is communicated with the sliding hole, the extending blade slides in the guide hole, the ejecting assembly slides in the sliding hole, and one end of the extending blade is located in the sliding hole and abuts against the ejecting assembly. The drill rod of this application can form the triaxial reducing stake hole that has the enlarged footing to make the uplift resistance of the pile body in the stake hole of final formation improve, improve the stability of pile body in ground.)

1. The utility model provides a triaxial reducing stirring drilling rod, includes actuating system (1), quick-witted case (2) and drilling rod (3), drilling rod (3) are equipped with three and rotate and connect in quick-witted case (2), and the line in three drilling rod (3) axle center constitutes equilateral triangle, actuating system (1) is located on quick-witted case (2) for drive drilling rod (3) rotate, its characterized in that: the drill rod (3) comprises a stirring rod (4) and a drill bit mechanism (5), and the drill bit mechanism (5) comprises a drilling assembly (51) and an expanding assembly (52); the down-drilling assembly (51) comprises a down-drilling bit (511) connected to the drill rod (3) and a down-drilling blade (512) fixedly connected to the outer side wall of the down-drilling bit (511), the diameter expanding assembly (52) comprises an extending blade (521) and an ejecting assembly (522), a guide hole (5121) is formed in the end face, away from the down-drilling bit (511), of the down-drilling blade (512), a sliding hole (5111) is formed in the top face of the down-drilling bit (511) downwards, the guide hole (5121) is communicated with the sliding hole (5111), the extending blade (521) slides in the guide hole (5121), the ejecting assembly (522) slides in the sliding hole (5111), and one end of the extending blade (521) is located in the sliding hole (5111) and abuts against the ejecting assembly (522).

2. The three-axis reducing stirring drill rod as recited in claim 1, wherein: the ejection assembly (522) comprises an ejection block (5221), a downward pressing compression spring (5222) and an upper pulling rope (5223), the ejection block (5221) slides in a sliding hole (5111), the ejection block is in a circular truncated cone shape with a large upper part and a small lower part, a guide rod (5224) is fixedly connected in the sliding hole (5111), the guide rod (5224) penetrates through the ejection block (5221) and is in sliding fit with the ejection block (5221), a limiting piece (5225) is fixedly connected to the top end of the guide rod (5224), the downward pressing compression spring (5222) is sleeved on the guide rod (5224), the downward pressing compression spring (5222) is squeezed between the limiting piece (5225) and the ejection block (5221), the upper pulling rope (5223) is connected to the ejection block (5221), the end part of the upper pulling rope penetrates out of the drill rod (3) upwards, and a winding machine rope (6) for winding the upper pressing compression spring (5223) is arranged on the case (2).

3. The three-axis reducing stirring drill rod as recited in claim 1, wherein: fixedly connected with dog (5212) on the lateral wall of extension blade (521), it has the groove of stepping down (5122) that supplies dog (5212) to slide to open on the inside wall of bullport (5121), it has pressure spring (513) that resets to deviate from the lateral wall in the hole of sliding (5111) and to step down to extrude between the inside wall in groove (5122) to dog (5212).

4. The three-axis reducing stirring drill rod as recited in claim 3, wherein: the stop block (5212) on each extension blade (521) is respectively arranged on two opposite side walls, and the abdicating groove (5122) and the reset pressure spring (513) are matched with the stop block (5212).

5. The three-axis reducing stirring drill rod as recited in claim 2, wherein: it has let position mouth (5226) to open on the lateral wall of guide bar (5224), let position mouth (5226) along the radial guide bar (5224) that runs through (5224) of guide bar (5224), fixedly connected with passes on the top surface of ejecting block (5221) and lets position mouthful (5227) of go up stay cord (5223) fixed connection in go up stay cord (5227), it has the dodge hole that supplies stay cord (5223) to pass to open on spacing piece (5225), it has the rope threading hole (31) that supplies stay cord (5223) to pass to open on the axis of drilling rod (3).

6. The three-axis reducing stirring drill rod as recited in claim 1, wherein: the top surface of drill bit (511) is followed its circumference fixedly connected with a plurality of butt joint pieces down, the ground of drilling rod (3) is opened along its circumference has a plurality of butt joint hole (412), the butt joint piece inserts in butt joint hole (412), wear to be equipped with locking bolt (413) on the lateral wall of drilling rod (3), the screw rod position of locking bolt (413) gets into in butt joint hole (412) and threaded connection in butt joint piece.

7. The three-axis reducing stirring drill rod as recited in claim 2, wherein: one end of the extension blade (521) extending into the sliding hole (5111) is rotatably connected with a resistance reducing roller (5211), and the resistance reducing roller (5211) is abutted against the ejection block (5221).

8. The three-axis reducing stirring drill rod as recited in claim 1, wherein: and the lower drill blade (512) is fixedly connected with an injection pipe (7) communicated with the guide hole (5121), and the injection pipe (7) is in threaded connection with a blocking cover (71).

Technical Field

The invention relates to the technical field of building pile foundation engineering, in particular to a three-shaft reducing stirring drill rod.

Background

The construction of the triaxial mixing pile is a construction method for retaining soil and a waterproof curtain of a foundation pit enclosure, and the construction method mainly aims to solve the problems that adjacent piles of the biaxial cement-soil mixing pile are not completely lapped, the perpendicularity of a formed pile is difficult to guarantee, and the like.

At present, Chinese patent with publication number CN106089084A discloses a super triaxial mixing pile for pebble strata and a mixing method thereof, which comprises three drill rods, a drill bit assembly fixed at the bottom of the drill rods and a blade assembly connected on the drill rods, wherein the drill bit assembly is connected with a stepless speed change power head through the drill rods, the drill rods are connected with a pile frame through a supporting frame, the drill bit assembly comprises drill collars connected on the drill rods, drilling tools connected on the drill collars and hollow drill bits, and 3-4 alloy cutter heads are fixed on the drilling tools; the blade assembly is a plurality of groups of blades connected on the drill rod.

Although the triaxial mixing pile can drill with a larger rotating torque, only pile holes with the same inner diameter from the top end to the bottom end can be formed when the pile holes of the triaxial mixing pile are formed, and after a pile body is formed in the pile holes, the uplift resistance of the pile body is smaller, and the stability is poorer.

Disclosure of Invention

In order to form the triaxial reducing pile hole with the enlarged head, the uplift resistance of the finally formed pile body in the pile hole is improved, and the stability of the pile body in the ground is improved, the application provides a triaxial reducing stirring drill rod

The application provides a pair of triaxial reducing stirring drilling rod adopts following technical scheme:

a three-shaft reducing stirring drill rod comprises a driving system, a case and drill rods, wherein the three drill rods are rotatably connected to the case, the connecting lines of the axes of the three drill rods form an equilateral triangle, the driving system is arranged on the case and used for driving the drill rods to rotate, each drill rod comprises a stirring rod and a drill bit mechanism, and each drill bit mechanism comprises a drilling assembly and an expanding assembly; the down-drilling assembly comprises a down-drilling bit connected to a drill rod and a down-drilling blade fixedly connected to the outer side wall of the down-drilling bit, the diameter expanding assembly comprises an extending blade and an ejecting assembly, a guide hole is formed in the end face, far away from the down-drilling bit, of the down-drilling blade, a sliding hole is formed in the top face of the down-drilling bit downwards, the guide hole is communicated with the sliding hole, the extending blade slides in the guide hole, the ejecting assembly slides in the sliding hole, and one end of the extending blade is located in the sliding hole and abuts against the ejecting assembly.

By adopting the technical scheme, when the drilling operation is carried out, the extension blade is positioned in the drilling-down blade, the drilled holes are holes with the same inner diameter from top to bottom, when the drilling depth reaches the design requirement, the driving system stops working, at the moment, the ejection assembly ejects the extension blade out, so that the total length of the blade is prolonged, then the driving system is started again, the driving system enables the drill rod to continue to drill down, and because the total length of the blade is prolonged, the inner diameter of the drilled pile hole is increased, and finally the enlarged head part is formed. When the pile rod is formed at the later stage, the enlarged head part is formed at the bottom, so that the uplift resistance of the finally formed pile body in the pile hole is improved, and the stability of the pile body in the ground is improved.

Optionally, the ejection assembly includes an ejection block, a downward-pressing pressure spring and an upper pull rope, the ejection block slides in the sliding hole, the ejection block is in a shape of a circular truncated cone with a large top and a small bottom, a guide rod is fixedly connected in the sliding hole, the guide rod penetrates through the ejection block and is in sliding fit with the ejection block, a limit plate is fixedly connected to the top end of the guide rod, the downward-pressing pressure spring is sleeved on the guide rod, the downward-pressing pressure spring is extruded between the limit plate and the ejection block, the upper pull rope is connected to the ejection block, the end portion of the upper pull rope penetrates out of the drill rod upwards, and a winding machine for winding the upper pull rope is arranged on the case.

By adopting the technical scheme, when the extension blade needs to be ejected, the upper pull rope is released by the winding machine, the ejection block is driven to move downwards by the elastic force of the downward pressing pressure spring, and the extension blade is ejected gradually in the downward moving process of the ejection block due to the fact that the ejection block is in the shape of a circular truncated cone with a large upper part and a small lower part.

Optionally, fixedly connected with dog on the lateral wall of extension blade, it has the groove of stepping down that supplies the dog to slide to open on the inside wall of bullport, the dog deviates from and pushes away the pressure spring that resets between the lateral wall in the hole of sliding and the inside wall in groove of stepping down.

Through adopting above-mentioned technical scheme, creep into at the enlarged footing and accomplish the back, the rolling machine rolls up last stay cord, and the elasticity that resets the pressure spring this moment impels extension blade to move towards the underdrill blade in, until extension blade gets into under the drill blade completely to this realizes collecting of extension blade.

Optionally, one stop block is arranged on each of two opposite side walls of each extending blade, and the abdicating groove and the reset pressure spring are arranged in pair with the stop blocks.

Through adopting above-mentioned technical scheme, the dog and the pressure spring that resets of extension blade both sides cooperate jointly, have improved the stability of extension blade at the in-process that resets.

Optionally, it has the mouth of stepping down to open on the lateral wall of guide bar, the mouth of stepping down runs through the guide bar along the radial of guide bar, fixedly connected with passes the go-between of the mouth of stepping down on the top surface of ejecting piece, go up stay cord fixed connection in the go-between, it has the hole of stepping down that supplies the stay cord to pass to open on the spacing piece, it has the wire rope handling hole that supplies the stay cord to pass to open on the axis of drilling rod.

Through adopting above-mentioned technical scheme, the setting of stepping down mouth and go-between can let the axis department that goes up the stay cord and follow ejecting block pull out to this pulling out that makes ejecting block is more stable.

Optionally, the top surface of the lower drill bit is fixedly connected with a plurality of butt-joint pieces along the circumferential direction of the drill bit, the ground of the drill rod is provided with a plurality of butt-joint holes along the circumferential direction of the drill rod, the butt-joint pieces are inserted into the butt-joint holes, the side wall of the drill rod is provided with a locking bolt in a penetrating manner, and the screw rod part of the locking bolt enters the butt-joint holes and is in threaded connection with the butt-joint pieces.

Through adopting above-mentioned technical scheme, when carrying out drill bit and the connection of drilling rod down, will insert the butt joint piece in the butt joint hole, then utilize locking bolt locking to this realization is down the drill bit and is connected with dismantling between the drilling rod, and the maintenance or the change in the later stage of being convenient for.

Optionally, one end of the extension blade extending into the sliding hole is rotatably connected with a resistance reducing roller, and the resistance reducing roller abuts against the ejection block.

Through adopting above-mentioned technical scheme, fall and hinder the gyro wheel and can reduce the frictional force between extension blade and the ejecting piece, improved the smooth and easy degree when relative movement each other.

Optionally, the lower drilling blade is fixedly connected with an injection pipe communicated with the guide hole, and a blocking cover is connected to the inner thread of the injection pipe.

Through adopting above-mentioned technical scheme, the filling hole is convenient for clear up drill bit inside down, and when needs were cleared up, the staff twisted out the shutoff lid to insert the injection pipe with the water pipe, rivers can get into down in the drill bit through the injection pipe, with this realization to the inside washing of drill bit down. Meanwhile, the worker can inject lubricating oil into the lower drill bit through the injection pipe, so that the extension blades and the ejection block can slide more smoothly.

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

1. the combination of the drilling assembly and the expanding assembly can form a pile hole with a large lower part and a small upper part, so that when a pile rod is formed at the later stage, an expanding head part is formed at the bottom, the uplift resistance of the finally formed pile body in the pile hole is improved, and the stability of the pile body in the ground is improved.

2. When the extension blade needs to be ejected, the upper pull rope is released by the winding machine, the ejection block is driven to move downwards by the elasticity of the downward pressing pressure spring, and the extension blade is ejected gradually because the ejection block is in a circular truncated cone shape with a large upper part and a small lower part in the downward moving process;

3. after the drilling of the expanded head is completed, the winding machine winds the upper pull rope, and at the moment, the elastic force of the reset pressure spring enables the extension blade to move towards the inner side of the lower drill blade until the extension blade completely enters the lower drill blade, so that the extension blade is collected.

Drawings

Fig. 1 is a schematic structural diagram for embodying the present application.

Fig. 2 is an exploded schematic view for showing a connection relationship between two adjacent unit sections.

Fig. 3 is a schematic structural view for embodying a drill-down assembly.

Fig. 4 is a cross-sectional view for embodying an ejector assembly.

FIG. 5 is a cross-sectional view for illustrating the internal structure of a downhole blade.

Description of reference numerals: 1. a drive system; 2. a chassis; 3. a drill stem; 31. a stringing hole; 4. a stirring rod; 41. a unit section; 411. a plug-in sheet; 4111. a threaded hole; 412. a butt joint hole; 413. locking the bolt; 5. a drill bit mechanism; 51. a drill-down assembly; 511. a lower drill bit; 5111. a sliding hole; 512. Drilling down the blade; 5121. a guide hole; 5122. a yielding groove; 513. resetting the pressure spring; 52. a diameter expanding assembly; 521. an extension blade; 5211. resistance reducing rollers; 5212. a stopper; 522. ejecting the assembly; 5221. ejecting a block; 5222. pressing down the pressure spring; 5223. pulling a rope upwards; 5224. a guide bar; 5225. a limiting sheet; 5226. a let position port; 5227. a connecting ring; 6. a winding machine; 7. an injection pipe; 71. and (6) sealing and blocking the cover.

Detailed Description

The present application is described in further detail below with reference to the attached figures 1-3

The embodiment of the application provides a triaxial reducing stirring drilling rod, it can form the enlarged footing at the hole bottom position in stake hole at the in-process of boring the quincuncial pile hole down to this quincuncial pile who makes final formation has the withdrawal resistance.

Referring to fig. 1, triaxial reducing stirring drilling rod includes actuating system 1, quick-witted case 2 and drilling rod 3, and drilling rod 3 is equipped with three, and three drilling rods 3 rotate to be connected in the lower surface of quick-witted case 2, and actuating system 1 is three motor, and the motor passes through bolted connection on quick-witted case 2, every motor with every drilling rod 3 one-to-one, the output shaft of motor passes through the cooperation of gear in order to drive drilling rod 3 and rotates.

Referring to fig. 1 and 2, the drill rod 3 includes a stirring rod 4 and a drill bit mechanism 5, the stirring rod 4 is composed of a plurality of unit sections 41, the upper surface of each unit section 41 is fixedly connected with a plurality of insertion pieces 411 along the circumferential direction thereof, the lower surface of each unit section 41 is provided with a butt-joint hole 412 for the insertion of the plurality of insertion pieces 411, and after the insertion pieces 411 are inserted into the butt-joint hole 412, two adjacent unit sections 41 abut against each other.

Referring to fig. 2, locking bolts 413 are inserted into the side walls of the unit segments 41 near the bottom ends thereof, the number and positions of the locking bolts 413 correspond to those of the docking holes 412, and the locking bolts 413 enter the docking holes 412. Each plug piece 411 is provided with a threaded hole 4111 corresponding to the locking bolt 413, and after the locking bolt 413 enters the butt-joint hole 412, the locking bolt is screwed into the plug piece 411 through the threaded hole 4111.

Referring to fig. 3 and 4, the drill bit mechanism 5 includes a drill-down assembly 51 and an expanding assembly 52. The lower drilling assembly 51 comprises a lower drill bit 511 connected to the bottom end of the drill rod 3 and lower drilling blades 512 fixedly connected to the outer side wall of the lower drill bit 511, wherein the lower drilling blades 512 are distributed at equal intervals along the circumference of the lower drill bit 511, and each lower drilling blade 512 is inclined at the same angle. The insertion pieces 411 are fixedly connected to the top end of the lower drill 511 along the circumferential direction thereof, and after the insertion pieces are inserted into the butt holes 412, the connection between the lower drill 511 and the unit section 41 is realized by fastening the locking bolts 413.

Referring to fig. 4, the expanding assembly 52 includes an extending blade 521 and an ejecting assembly 522, a guide hole 5121 is formed on the end surface of the lower drill blade 512 away from the lower drill 511, a sliding hole 5111 is formed downward on the top surface of the lower drill 511, and the guide hole 5121 communicates with the sliding hole 5111. The extension blade 521 slides in the guide hole 5121, the ejection assembly 522 slides in the sliding hole 5111, and one end of the extension blade 521 extends into the sliding hole 5111 and abuts against the ejection assembly 522.

Referring to fig. 4, the ejection assembly 522 includes an ejection block 5221, a downward pressing spring 5222, and an upper pull cord 5223. The ejector block 5221 slides in the slide hole 5111, and has a circular truncated cone shape with a large top and a small bottom. One end of the extension blade 521 extending into the sliding hole 5111 is rotatably connected with a resistance reducing roller 5211, and the resistance reducing roller 5211 abuts against the outer side wall of the ejection block 5221. A guide rod 5224 is fixedly connected in the sliding hole 5111, the guide rod 5224 is positioned on the axis of the lower drill 511, and the guide rod 5224 passes through the ejection block 5221 and is in sliding fit with the ejection block 5221.

Referring to fig. 4, a limit piece 5225 is fixedly connected to the top end of the guide rod 5224, and a downward pressing spring 5222 is fitted over the guide rod 5224 and pressed between the limit piece 5225 and the ejector block 5221. The side wall of the guide rod 5224 is provided with a yielding hole 5226, the yielding hole 5226 penetrates through the guide rod 5224 along the radial direction of the guide rod 5224, the limiting piece 5225 is provided with a yielding hole communicated with the yielding hole 5226, and the axis of the drill rod 3 is provided with a rope penetrating hole 31 communicated with the yielding hole.

Referring to fig. 1 and 4, a connection ring 5227 penetrating through the abdicating hole 5226 is fixedly connected to the top surface of the ejector rod, one end of the upper pulling rope 5223 is fixedly connected to the connection ring 5227, the other end of the upper pulling rope 5223 penetrates out of the case 2 after sequentially passing through the abdicating hole 5226, the abdicating hole and the rope threading hole 31, a winding machine 6 is connected to the case 2 through bolts, and the upper pulling rope 5223 penetrates out of the case 2 and is connected to the winding end of the winding machine 6.

When the pile hole of the three-axis mixing pile is drilled downwards, the driving force of the driving system 1 causes the three drill rods 3 to rotate together, and the drilling-downwards blades 512 at the tail ends of the drill rods 3 can gradually enter the ground due to the inclined arrangement, so that the pile hole is formed. When the depth of the pile hole reaches the calibrated depth, the driving system 1 stops working, and meanwhile, the winding machine 6 unwinds the upper pull rope 5223, and at the moment, the elastic force of the lower pressing spring 5222 urges the ejection block 5221 to move downwards, and because the ejection block 5221 is in a circular truncated cone shape with a large upper part and a small lower part, the extension blade 521 gradually penetrates out of the lower drill blade 512 through the guide hole 5121, so that the length of the lower drill blade 512 is extended.

And then the driving system 1 is started again, the driving system 1 causes the drilling-down blade 512 to drill down the pile hole again, and the total length of the drilling-down blade 512 is prolonged, so that the inner diameter of the drilled pile hole is larger, and after the pile body is formed by later pouring, an enlarged head part is formed at the bottom, so that the triaxial mixing pile has larger pulling resistance.

Referring to fig. 4 and 5, a stopper 5212 is fixedly coupled to an outer sidewall of the extending blade 521, and one stopper 5212 is fixedly coupled to each of opposite sidewalls of the extending blade 521. The inner side wall of the guide hole 5121 is provided with a yielding groove 5122 for the block 5212 to slide, and the yielding grooves 5122 correspond to the block 5212 in number and position one to one. A return compression spring 513 is extruded between the side wall of each block 5212, which faces away from the sliding hole 5111, and the inner side wall of the abdicating groove 5122.

After the enlarged hole at the bottom of the pile hole is drilled, the worker closes the driving system 1, and winds the upper pulling rope 5223 by using the winding machine 6, so that the ejection block 5221 moves upwards. At this time, the elastic force of the return compression spring 513 is released, and the elastic force is released to the stopper 5212, thereby urging the extension blade 521 to move into the guide hole 5121. When the extension blade 521 completely enters the guide hole 5121, the worker closes the winder 6 and immediately takes out the drill rod 3 from the pile hole.

Referring to fig. 5, in addition, soil easily enters into the lower drill 511 through a gap between the extension blade 521 and the inner sidewall of the guide hole 5121 during drilling, so that an injection pipe 7 communicating with the guide hole 5121 is fixedly coupled to the lower drill blade 512, and a plugging cap 71 is threadedly coupled to the injection pipe 7, in order to facilitate cleaning of the inside of the lower drill 511. When the lower drill bit 511 needs to be cleaned, a worker unscrews the plugging cover 71 and inserts a water pipe into the injection pipe 7, and water flow can enter the lower drill bit 511 through the injection pipe 7, so that the interior of the lower drill bit 511 can be cleaned. Meanwhile, the worker can inject the lubricant into the lower drill 511 through the injection pipe 7, so that the extension blades 521 and the ejector block 5221 can slide more smoothly.

The specific implementation principle of the embodiment of the application is as follows:

when the pile hole of the triaxial mixing pile is drilled downwards, the driving system 1 drives the three drill rods 3 to rotate, and the drilling-downwards blades 512 at the tail ends of the drill rods 3 gradually enter the ground to form the pile hole. When the depth of the pile hole reaches the calibrated depth, the driving system 1 stops working, and the winding machine 6 unwinds the upper pull rope 5223, at this time, the elastic force of the lower pressing spring 5222 urges the ejection block 5221 to move downwards, and since the ejection block 5221 is in a circular truncated cone shape with a large upper part and a small lower part, the extension blade 521 gradually penetrates out of the lower drill blade 512 through the guide hole 5121, so that the length of the lower drill blade 512 is extended.

Then the drive system 1 is started again, and the drive system 1 causes the drill-down blade 512 to drill down the pile hole again, and the total length of the blade is extended, so that the inner diameter of the drilled pile hole is larger. After the enlarged hole at the bottom of the pile hole is drilled, the worker closes the driving system 1, and winds the upper pulling rope 5223 by using the winding machine 6, so that the ejection block 5221 moves upwards. At this time, the elastic force of the return compression spring 513 is released, and the elastic force is released to the stopper 5212, thereby urging the extension blade 521 to move into the guide hole 5121. When the extension blade 521 completely enters the guide hole 5121, the worker closes the winder 6 and immediately takes out the drill rod 3 from the pile hole.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.