A drilling machine for annular holes

Abstract

This invention discloses a drilling machine for annular holes, comprising a support, a drive frame, and a stirring unit. The support has a support platform and a working hole penetrating the support platform, and an oscillator is mounted on the support surface of the support platform. The drive frame includes a drive wheel movably supported on the support surface; the drive wheel is connected to the oscillator. The stirring unit includes a hollow shaft, an annular body mounted at the lower end of the hollow shaft, and a spiral drill bit mounted at the lower end of the annular body. The hollow shaft and the annular body are coaxially arranged, and the support platform is freely fitted onto the hollow shaft through the working hole. The drive wheel is fitted onto the hollow shaft and held together by protruding teeth and grooves. The spiral drill bit includes a spiral drill bit and a motor connected together. The motor is installed in the motor cavity of the annular body. An inlet pipe and a slurry outlet pipe are fixedly mounted on the annular body, and the outlet of the inlet pipe and the slurry outlet pipe both penetrate downwards through the lower end face of the annular body. The drilling machine of this application can adapt to various construction methods and adjust the construction method as needed.

Description

Technical Field

[0001] This invention relates to a drilling machine for annular holes. Background Technology

[0002] In the construction of existing building structures, a large number of engineering piles and foundation treatment piles are required. In some construction areas, due to site requirements or surrounding environmental requirements, it is not possible to use a large number of precast round piles. Instead, they can only be combined with some cast-in-place piles or steel sheet piles to form composite piles. However, the end bearing capacity of steel sheet piles is relatively small, and their performance in some soft soil areas is poor, so they cannot be used as foundation piles. Even if cast-in-place piles are used, these cast-in-place piles are also used as independent pile bodies. Furthermore, the mixed construction of precast piles and cast-in-place piles is more difficult and results in lower construction efficiency.

[0003] Currently, it is sometimes necessary to re-pile in areas where pile construction has been completed to compensate for exploration or design defects, or to accommodate modifications to the building design. However, re-pile can only be carried out in areas deviating from the original bearing points, requiring corresponding enlargement of the pile cap and adjustments to the corresponding areas. Therefore, it is necessary to enlarge and reinforce existing precast concrete circular piles that have already been sunk to improve their bearing capacity.

[0004] Furthermore, in existing construction practices, cement-soil cylindrical piles are widely used in areas with less demanding requirements due to their lower construction costs. During construction, a cylindrical drill is typically used to inject cement slurry into the ground while drilling the pile hole. The cement slurry impacts and softens the soil, improving construction efficiency. However, the slow rotation speed of the cylindrical drill results in weak mixing; the cement slurry's mixing with the soil relies primarily on its impact force, failing to achieve uniform mixing. Therefore, to improve the uniformity of the cement slurry-soil mixture, the cylindrical drill needs to be raised and lowered multiple times within the pile hole after drilling to ensure even mixing and guarantee pile quality. This repeated raising and lowering of the cylindrical drill prevents a significant increase in the overall construction efficiency of cement-soil cylindrical piles.

[0005] Therefore, there is an urgent need for a drilling device for annular holes that can be applied to various working conditions. Summary of the Invention

[0006] To address the aforementioned problems, this application first proposes a drilling machine for annular holes, comprising a support, a drive frame, and a stirring unit; the support has a support platform, the upper surface of which is formed as a horizontally arranged support surface, and a working hole extending vertically through the support platform is formed therein; an oscillator is mounted on the support surface; the drive frame includes a drive wheel, which is movably supported on the support surface; the drive wheel is annular in shape and connected to the oscillator, which drives the drive wheel to reciprocate about a first axis as its central axis; the first axis extends vertically;

[0007] The stirring unit includes a hollow shaft extending vertically, an annular body fixedly installed at the lower end of the hollow shaft, and at least four augers installed at the lower end of the annular body. The hollow shaft and the annular body are coaxially arranged, and the central axes of the hollow shaft and the annular body are collinear with the first axis. The first inner cavity of the hollow shaft and the second inner cavity of the annular body together form a central channel extending vertically. The inner diameter of the central channel is the smaller of the inner diameter of the first inner cavity and the inner diameter of the second inner cavity. The support platform is freely fitted onto the hollow shaft through the working hole.

[0008] The drive wheel is mounted on a hollow shaft. One of the two types of teeth, a tooth and a groove, is provided on the inner circumferential surface of the drive wheel, and the other type of tooth and groove is provided on the outer circumferential surface of the hollow shaft. Both the tooth and groove extend vertically. The tooth extends into the groove. When the drive wheel reciprocates, it drives the hollow shaft to reciprocate synchronously, and also drives the stirring unit to reciprocate synchronously. The hollow shaft can reciprocate vertically relative to the drive wheel.

[0009] Each auger drill includes an auger drill bit and a motor. The auger drill bit is fixedly mounted on the output shaft of the motor. A motor cavity is provided in the annular body, and the motor is installed in the motor cavity. The auger drill bit is installed on the lower side of the annular body.

[0010] Viewed vertically, all the spiral drill bits are evenly arranged around the first axis and located within a virtual annular surface. Adjacent spiral drill bits are spaced apart. In the radial direction, the outer circumferential surfaces of the hollow shaft and the annular body do not extend outward beyond the outer edge of the virtual annular surface, and the inner circumferential surfaces of the hollow shaft and the annular body do not extend inward beyond the inner edge of the virtual annular surface. When the stirring part reciprocates, the drill holes formed by adjacent spiral drill bits can overlap each other.

[0011] A vertically extending inlet pipe and outlet pipe are fixedly installed on the annular body. Both the inlet and outlet pipes freely pass through the drive wheel and the working hole before being fixedly connected to the annular body. The inlet pipe has an inlet and an outlet, and the outlet pipe has an inlet and an outlet. Both the inlet and outlet penetrate downwards through the lower end face of the annular body, and neither extends downwards beyond the drill tip of the auger bit. The number of auger drill bits is controlled between 4 and 12.

[0012] This drilling machine is used for constructing cylindrical piles; or for expanding and reinforcing precast concrete piles such as hollow pipe piles, solid pipe piles, and solid round piles to form composite piles and improve bearing capacity; or for stirring the soil around the pile to be pulled out to reduce the bond between the pile and the surrounding soil, thereby reducing the pulling force.

[0013] When the drilling rig is in operation, it is installed in the preset position, and then the motor is started to make the auger drill bit rotate. At the same time, the mixing part rotates back and forth, and water is introduced into the pile hole through the liquid inlet pipe. The mixing action of the auger drill bit makes the cut soil form plain soil slurry. Due to the sealing effect of the annular body, the annular hole at the bottom of the annular body forms a relatively sealed cavity. Under the driving action of water pressure, the plain soil slurry is discharged from the annular hole through the slurry outlet pipe. The plain soil slurry not only outputs the cut soil from the annular hole, but also plays a role in protecting the wall, reducing cutting resistance, and improving construction efficiency.

[0014] When a drilling rig is used to construct cylindrical piles, after completing the annular hole, the auger bit is withdrawn from the annular hole. A reinforcing cage or prestressed tendons are then placed inside the annular hole, and concrete is poured to form a reinforced concrete cylindrical pile. Alternatively, only concrete, cement-soil, cement mortar, or other solidifying materials can be poured to form a plain cylindrical pile. Reinforced concrete cylindrical piles can be used as engineering piles, while plain cylindrical piles can replace existing solid piles used for foundation treatment, such as gravel piles, compaction piles, sand piles, and solid cement-soil piles. Of course, steel pipes or structural steel sections can also be inserted into the plain cylindrical pile to reinforce it.

[0015] When expanding the diameter of precast concrete cylindrical piles such as hollow pipe piles, solid pipe piles, and solid circular piles for reinforcement, the resulting annular hole is made to surround the precast concrete cylindrical pile, and a solidifiable material is poured into the annular hole to form a plain cylindrical pile or a steel-concrete cylindrical pile.

[0016] When used for pile extraction, it is only necessary to form an annular hole around the existing pile body, and then pull the pile body out of the ground.

[0017] The reciprocating rotation of the mixing section allows the boreholes formed by adjacent auger drill bits to overlap. The overlap length between the boreholes formed by adjacent auger drill bits can be adjusted as needed. When the boreholes are fully overlapped, the inner and outer walls of the annular hole are smooth circles. When the boreholes are only partially overlapped, irregular grooves will form on the inner and outer walls of the annular hole, giving the formed pipe pile greater lateral friction and improving the bearing capacity of the pipe pile.

[0018] In addition, when using solidifiable materials with good fluidity, such as cement soil and cement mortar, to construct the cylindrical pile, after drilling the annular hole, the auger bit is kept inside the annular hole, and then the solidifiable material is introduced into the annular hole through the liquid inlet pipe. At the same time, the auger bit is lifted upwards. While lifting, the rotation of the auger bit and the reciprocating rotation of the mixing part can be used to mix the solidifiable material, thereby improving the uniformity of the cylindrical pile quality.

[0019] Therefore, the drilling machine in this application can adapt to various construction methods and adjust the construction method as needed.

[0020] Furthermore, the distance between the outer circumferential surface of the annular body and the outer edge of the virtual annular surface is 10-30 mm, and the distance between the inner circumferential surface of the annular body and the inner edge of the virtual annular surface is 10-30 mm; the outer circumferential surface of the hollow shaft does not extend outward beyond the outer circumferential surface of the annular body, and the inner circumferential surface of the hollow shaft does not extend inward beyond the inner circumferential surface of the annular body. That is, the outer edge of the virtual annular surface extends outward beyond the outer circumferential surface of the annular body, and the inner edge of the virtual annular surface extends inward beyond the inner circumferential surface of the annular body.

[0021] When the drilling rig is used for pile extraction or diameter expansion reinforcement, this design can prevent the inner and outer circumferential surfaces of the annular body and the hollow shaft from touching the sidewall of the annular hole, thus affecting the stability of the annular hole. At the same time, it can make the annular hole below the annular body form a relatively sealed chamber, allowing the plain soil slurry to be smoothly discharged through the slurry outlet pipe.

[0022] Specifically, 2-5 swingers are installed on the support surface, each swinger including a hydraulic cylinder; corresponding to each hydraulic cylinder, a swing rod extending radially outward is fixedly installed on the drive wheel, and all the swing rods are evenly arranged around the first axis; along the circumferential direction of the drive wheel, each hydraulic cylinder is located on the same side of the circumferential direction of its corresponding swing rod.

[0023] For each swing arm, a limiting member is fixedly installed on the support surface. The limiting member is located on the radial outer side of the drive wheel. An arc-shaped groove is formed on each limiting member. The arc-shaped groove is formed by the side of the limiting member facing the drive wheel and being recessed radially away from the drive wheel. The arc-shaped grooves on all the limiting members are located in the same virtual annular groove. The central axis of the virtual annular groove coincides with the first axis. The radial outer end of the swing arm extends movably into the arc-shaped groove on the corresponding limiting member. The drive wheel is movably supported in the arc-shaped groove by the swing arm.

[0024] For each hydraulic cylinder, a guide rail assembly is fixedly installed on the support surface. Each guide rail assembly includes at least one guide rail. The hydraulic cylinder is slidably mounted on the guide rail of the corresponding guide rail assembly. The extension direction of the piston rod of the hydraulic cylinder is perpendicular to the guide rail of the installed guide rail assembly, and the piston rod is perpendicular to the first axis. The piston rod of the hydraulic cylinder is hinged to the corresponding rocker arm. When each guide rail assembly includes at least two guide rails, the guide rails in the same guide rail assembly are parallel to each other.

[0025] The drive wheel is movably supported in the arc-shaped groove by the rocker arm, so that the drive wheel is movably supported on the support surface by the limiting member.

[0026] Because the extension length of the hydraulic cylinder piston rod can be flexibly adjusted, the drilling machine can flexibly adjust the rotation angle of the hollow shaft to adjust the overlap rate. Furthermore, since the piston rod has minimal lag during reciprocating movement, the overlap rate during actual construction can be kept within the design range. Although stepper motors and servo motors also have the advantages of flexible adjustment and low lag, their larger output power results in a corresponding increase in motor size, leading to a larger drilling machine and making it inconvenient to move. Using a support platform as the mounting base for the hydraulic cylinder eliminates the need to fabricate a mounting base on the ground. This allows for rapid positioning and commencement of operations when moving the drilling machine, thus improving construction efficiency.

[0027] To maximize the torque exerted by the piston rod on the rocker arm, it is preferable that the piston rod is hinged to the radially outer end of the rocker arm. That is, the piston rod is hinged to the end of the rocker arm furthest from the drive wheel.

[0028] Specifically, the inner circumferential surface of the drive wheel is provided with an internal spline, and the outer circumferential surface of the hollow shaft is provided with an external spline that meshes with the internal spline. Both the drive wheel and the hollow shaft are formed using spline structures, which can ensure the torque between the two, prevent the key teeth from being damaged under large torque, ensure a stable connection between the two, and extend the service life of the equipment.

[0029] Specifically, the annular body includes an inner cylinder and an outer cylinder sleeved outside the inner cylinder. Both the inner and outer cylinders extend vertically and are radially spaced. A top cover, which is annular, is installed at the upper end of the inner and outer cylinders. The inner and outer radial ends of the top cover are sealed and fixedly installed on the inner and outer cylinders, respectively. A bottom cover, which is annular, is installed at the lower end of the inner and outer cylinders. The inner and outer radial ends of the bottom cover are sealed and detachably installed on the inner and outer cylinders, respectively. The space enclosed by the inner cylinder, outer cylinder, top cover, and bottom cover forms a receiving cavity.

[0030] The receiving cavity is formed as a motor cavity, and the motor is fixedly installed in the receiving cavity. The drive shaft of the motor extends vertically downwards and is sealed out of the base plate. The drill rod of the auger bit is fixedly connected to the drive shaft.

[0031] The receiving cavity forms the motor chamber for installing the motor. Utilizing the large operating space of the receiving cavity, it is convenient to install, debug, and replace the motor. At the same time, multiple motor mounting positions can be set on the base plate to install different combinations of motor groups as needed, so as to adjust the model, quantity, and distance of the auger drill bit.

[0032] Furthermore, a step portion protruding radially outward is provided at the lower end of the hollow shaft. This step portion has an annular, upward-facing step surface, on which the drive wheel can be detachably supported.

[0033] After the drilling machine completes drilling a ring hole, the hollow shaft is lifted upwards, allowing the drive wheel to rest on the step surface, thus lifting the entire drilling machine off the ground and moving it to the next working position. When the auger bit drills downwards to drill the ring hole, the step surface can move away from the drive wheel.

[0034] Furthermore, the drive frame also includes a positioning ring located above the drive wheel and fixedly mounted on the top of the hollow shaft. The inlet pipe and outlet pipe are fixedly mounted on this positioning ring. Both the inlet and outlet pipes are steel pipes. When the expanding pile driver is working, as the auger bit cuts the soil downwards, the positioning ring moves downwards synchronously and approaches the drive wheel. The maximum working depth of the auger bit is reached when the positioning ring abuts against the drive wheel. This design fully utilizes the length of the hollow shaft.

[0035] The positioning ring ensures that the inlet pipe and outlet pipe extend vertically between the positioning ring and the annular body, preventing tilting. When the drilling machine is operating, the annular body remains above the drive wheel, effectively preventing the inlet and outlet pipes from impacting the annular hole's periphery and affecting its stability when unrestrained.

[0036] Furthermore, to facilitate the lifting and moving of the drilling machine, a lifting hole is provided at the top of the hollow shaft.

[0037] Furthermore, when the mixing section reciprocates, the overlap rate of the boreholes formed by adjacent auger bits is 20-100%. The overlap rate refers to the ratio of the overlap length between the boreholes formed by two adjacent auger bits to the borehole diameter. For example, if the borehole diameter is 320mm, and the overlap length between the boreholes formed by two adjacent auger bits is 80mm, then the overlap rate is 80 / 320 = 25%. When the overlap rate is 100%, the inner and outer walls of the annular hole are smooth. When the overlap rate is less than 100%, the inner and outer walls of the annular hole have numerous grooves, resulting in corresponding grooves on the inner and outer walls of the formed pile, which improves the friction of the pile and enhances its bearing capacity. Attached Figure Description

[0038] Figure 1 It is a 3D diagram of a drilling machine.

[0039] Figure 2 This is the front view of the drilling machine.

[0040] Figure 3 yes Figure 2 Top view.

[0041] Figure 4 yes Figure 2 A view from the center AA direction.

[0042] Figure 5 yes Figure 2 A view from the center (BB direction).

[0043] Figure 6 yes Figure 2 A view directed towards the center (CC).

[0044] Figure 7 yes Figure 6 Enlarged view of section D.

[0045] Figure 8 yes Figure 6 Enlarged view of section E in the middle.

[0046] Figure 9 This is a diagram showing the positional relationship between the virtual annular surface where the auger bit is located and the stirring section.

[0047] Figure 10 This is a schematic diagram of the working state of a drilling machine. Detailed Implementation

[0048] A drilling machine, please refer to Figures 1-8 It includes a support 10, a drive frame 20, and a stirring unit 40. The support 10 includes a leg 11 and a generally square support platform 12 fixedly mounted on the top of the leg. Of course, the support platform can also be circular, rectangular, or other shapes.

[0049] The upper surface of the support platform 12 is formed as a support surface 121, which is horizontally arranged. A working hole 122 is provided on the support platform 12, penetrating the upper and lower surfaces of the support platform 12.

[0050] The stirring unit 40 includes a hollow shaft 41 extending vertically. An annular body 42 is fixedly installed at the lower end of the hollow shaft, and eight spiral drill bits 50 are installed at the lower end of the annular body 42. The central axes of the hollow shaft and the annular body are both collinear with a first axis 91, i.e., the hollow shaft and the annular body are coaxially arranged, and the first axis 91 extends vertically. The first inner cavity of the hollow shaft and the second inner cavity of the annular body together form a central channel 412 extending vertically. A support platform is freely fitted onto the hollow shaft through the working hole. A lifting hole 413 is provided at the top end of the hollow shaft 41, and the lifting hole 413 penetrates the shaft wall of the hollow shaft 41 radially.

[0051] In this embodiment, the inner diameter of the first inner cavity is the same as the inner diameter of the second inner cavity, and the inner diameter of the central channel 412 is either the inner diameter of the first inner cavity or the inner diameter of the second inner cavity.

[0052] It is understood that in other embodiments, when the inner diameter of the first inner cavity is greater than the inner diameter of the second inner cavity, the inner diameter of the central channel is the inner diameter of the second inner cavity; when the inner diameter of the first inner cavity is less than the inner diameter of the second inner cavity, the inner diameter of the central channel is the inner diameter of the first inner cavity. That is, the smaller of the inner diameter of the first inner cavity and the inner diameter of the second inner cavity is used as the inner diameter of the central channel.

[0053] In this embodiment, the annular body 42 includes an inner cylinder 421 and an outer cylinder 422 sleeved outside the inner cylinder 421. Both the inner and outer cylinders extend vertically and are radially spaced. In this embodiment, the inner and outer cylinders are coaxially arranged, and their central axes are collinear with the first axis. Please refer to [link to relevant documentation]. Figure 7 A first inner flange 426 is installed radially inward at the upper end of the inner cylinder, and a first outer flange 424 is installed radially outward at the upper end of the outer cylinder. The top cover 428 is annular, and its radially inner and radially outer ends are detachably and securely bolted to the upper sides of the first inner flange 426 and the first outer flange 424, respectively. In other words, the radially inner and radially outer ends of the top cover are securely and sealingly fixed to the upper ends of the inner and outer cylinders, respectively.

[0054] Please see Figure 8A second inner flange 427 is installed radially inward at the lower end of the inner cylinder, and a second outer flange 425 is installed radially outward at the lower end of the outer cylinder. The bottom cover 429 is annular, and its radially inner and radially outer ends are detachably and securely fixed to the lower sides of the second inner flange 427 and the second outer flange 425 using bolts. In other words, the radially inner and radially outer ends of the bottom cover are detachably and securely installed at the lower ends of the inner and outer cylinders, respectively. The space enclosed by the inner cylinder, outer cylinder, top cover, and bottom cover forms a receiving cavity 423.

[0055] A stepped portion 44 protruding radially outward is provided at the lower end of the hollow shaft 41. This stepped portion is a cylinder extending vertically, with its upper and lower ends welded to the lower end of the hollow shaft 41 and the top cover 428, respectively. The inner diameter of the cylinder is larger than the inner diameter of the hollow shaft, and the outer diameter of the cylinder is larger than the outer diameter of the hollow shaft but smaller than the outer diameter of the annular body. A stepped surface 43 is provided between the stepped portion 44 and the hollow shaft, and this stepped surface is an annular shape facing upward.

[0056] When the hollow shaft is lifted upwards, the drive wheel 21 can be supported on the stepped surface 43. When the hollow shaft moves downwards, the drive wheel can leave the stepped surface 43. That is, the drive wheel can be separably supported on the stepped surface.

[0057] Each auger drill 50 includes an auger drill bit 52 and a motor 51. The motor is fixedly installed in the receiving cavity. Corresponding to each motor, a motor shaft hole is opened on the bottom cover. The output shaft 511 of the motor 51 passes through the motor shaft hole, exits the bottom cover 429, and connects to the drill rod 521 of the auger drill bit 52, so that the auger drill bit is installed on the lower side of the annular body. A helical blade 522 is welded on the outer circumferential surface of the drill rod 521, and the drill tip 523 of the drill rod 52 faces downward. That is, in this embodiment, the receiving cavity is also formed as a motor cavity. It can be understood that in another embodiment, the annular body can be a solid structure, and then a motor cavity is provided in the annular body for each motor.

[0058] The packing flange 512 is fitted onto the output shaft 511 and is sealed on the bottom cover. An O-ring 513 is installed between the packing flange and the output shaft to seal the gap between the packing flange and the output shaft.

[0059] Please also refer to Figure 9 Eight spiral drill bits 52 are evenly arranged around the first axis. Figure 9 For clarity, the first axis 91 is represented by a small circle. Viewed vertically, all the auger bits are located within a virtual annular surface 420, with adjacent auger bits spaced apart. Furthermore, viewed vertically, in the radial direction, the outer circumferential surfaces of the hollow shaft and the annular body do not extend beyond the outer edge of the virtual annular surface, while the inner circumferential surfaces of the hollow shaft and the annular body do not extend beyond the inner edge of the virtual annular surface.

[0060] Specifically, in this embodiment, the inner diameter DA of the virtual annular surface 420 is 605 mm, the outer diameter DB of the virtual annular surface 420 is 1245 mm, the inner diameter DC of the annular body 42 is 630 mm, and the outer diameter DD of the annular body is 1210 mm. The inner circumferential surface of the hollow shaft is coplanar with the inner circumferential surface of the annular body, that is, the inner diameter of the central channel is 650 mm. The outer circumferential surface of the annular body extends outward beyond the outer circumferential surface of the hollow shaft. Figure 9 In the diagram, 101 represents the inner edge of the virtual annular surface 420, 102 represents the outer edge of the virtual annular surface 420, 4201 represents the inner circumferential surface of the annular body 42, and 4202 represents the outer circumferential surface of the annular body 42.

[0061] It is understood that in other embodiments, the outer peripheral surface of the hollow shaft and the outer peripheral surface of the annular body may both be located on the same circular surface as the outer edge of the virtual annular surface, and the inner peripheral surface of the hollow shaft and the inner peripheral surface of the annular body may both be located on another circular surface as the inner edge of the virtual annular surface.

[0062] The drive frame 20 includes drive wheels 21 and positioning rings 22 spaced vertically. Both the drive wheels and positioning rings are annular. The drive wheels are fitted onto a hollow shaft, and the positioning rings 22 are located above the drive wheels and welded to the top of the hollow shaft. Five vertically extending steel pipes are connected to the positioning rings 22. The five steel pipes include one liquid inlet pipe 241, one slurry outlet pipe 242, and three sheathing pipes 23. The five steel pipes are welded to the positioning rings 22. Corresponding to the five steel pipes, five through holes 212 are provided on the drive wheels, and each of the five steel pipes can freely pass through one through hole.

[0063] The inlet pipe 241 has an inlet and a outlet, and the outlet pipe 242 has an outlet and an outlet. Both the inlet pipe 241 and the outlet pipe 242 penetrate the annular body vertically and extend out of the bottom cover 429 in a sealed manner, so that the outlet and the inlet both extend downward out of the bottom cover. In this embodiment, the outlet and the inlet are flush with the lower end face of the bottom cover, and the inlet and the outlet extend upward out of the positioning ring. The upper openings of the three sheath pipes all extend upward out of the positioning ring, and the lower openings of the three sheath pipes all extend into the receiving cavity.

[0064] In this embodiment, the cable enters the receiving cavity through three sheathed tubes 23 and is then connected to each motor.

[0065] A rocker arm 32 is symmetrically arranged on both sides of the drive wheel 21. The rocker arm is fixedly connected to the outer circumferential surface of the drive wheel and extends outward along the radial direction of the drive wheel. That is, the two rocker arms are evenly arranged around the first axis.

[0066] Two oscillators 30 are mounted on the support surface, each corresponding to a swing rod 32. The two oscillators have the same structure, and each oscillator 30 includes a hydraulic cylinder 35.

[0067] It is understood that in other embodiments, when the number of pendulum rods is 3, 4, or 5, the corresponding number of oscillators is 3, 4, or 5.

[0068] For each hydraulic cylinder, a guide rail assembly is fixedly installed on the support surface. Each guide rail assembly includes two parallel guide rails 356. In this embodiment, the guide rails are T-shaped. The cylinder barrel 351 of the hydraulic cylinder 35 has a front end plate 354 and a rear end plate 355 at its two ends, respectively. The cylinder barrel 351 is horizontally arranged. A sliding member 357 is installed at the lower end of the front end plate and the rear end plate, respectively. The sliding member 357 has a groove that can be engaged with the guide rail. The two sliding members are slidably engaged with a T-shaped guide rail through the groove, so that the hydraulic cylinder can reciprocate along the length direction of the T-shaped guide rail. The extension direction of the piston rod of the hydraulic cylinder is perpendicular to the installed T-shaped guide rail, and the piston rod is perpendicular to the first axis.

[0069] For each swing arm 32, a limiting member 34 is fixedly installed on the support surface. The limiting member is located radially outward of the drive wheel 21, and an arc-shaped groove 341 is formed on the limiting member. The arc-shaped groove 341 is formed by the limiting member 34 being recessed radially away from the drive wheel 21 on the side facing the drive wheel. The arc-shaped groove 341 has a circular arc bottom that protrudes radially outward. The radially outer end of the swing arm 32 is a hemispherical end 321 that extends movably into the arc-shaped groove. All the arc-shaped grooves are located within the same virtual annular groove, and the central axis of the virtual annular groove coincides with the first axis. The drive wheel is movably supported in the arc-shaped groove by the swing arm, so that the drive wheel is movably supported on the support surface by the limiting member. It can be understood that in another embodiment, the end can also be spherical.

[0070] Along the circumferential direction of the drive wheel, all hydraulic cylinders are located on the same side of the circumferential direction of their corresponding rocker arms. A hinge rod 33 is fixedly installed at the outer end of the rocker arm facing the corresponding hydraulic cylinder. This hinge rod 33 is hinged to the piston rod 353 of the hydraulic cylinder via a pin. For clarity, the pin is not shown in the attached drawing; only the pin hole 331 for inserting the pin is shown. That is, the piston rod 353 is indirectly hinged to the drive wheel 21 via the hinge rod 33 and the rocker arm 32.

[0071] In this embodiment, an internal spline 211 is provided on the inner circumferential surface of the oscillating wheel, and an external spline 411 that meshes with the internal spline 211 is provided on the outer circumferential surface of the hollow shaft. The key teeth and keyways of both the internal spline 211 and the external spline 411 extend vertically, allowing the hollow shaft to reciprocate vertically relative to the drive wheel. The key teeth of both the internal spline 211 and the external spline 411 are formed as convex teeth, and the keyways are formed as grooves. That is, the inner circumferential surface of the drive wheel has convex teeth, and the outer circumferential surface of the hollow shaft has a groove for the convex teeth to extend into. Alternatively, the inner circumferential surface of the drive wheel has a groove, and the outer circumferential surface of the hollow shaft has convex teeth for extending into the groove.

[0072] Driven by the piston rod, the drive wheel can reciprocate around the first axis as the central axis, and drive the hollow shaft to reciprocate synchronously, and make the stirring part reciprocate synchronously, while the hydraulic cylinder moves back and forth along the T-shaped guide rail.

[0073] In this embodiment, eight identical spiral drill bits are used. The drill tips 523 of all eight drill bits are located on a circle with a diameter of 925 mm. Each spiral drill bit has a diameter of 550 mm. When the stirring unit reciprocates, the angle of reciprocating rotation is 45°, allowing the holes formed by adjacent spiral drill bits to overlap, forming a complete annular hole. That is, in this embodiment, the overlap rate between the holes formed by adjacent spiral drill bits is 100%. It can be understood that in other embodiments, adjusting the angle of reciprocating rotation can also make the overlap rate between the holes formed by adjacent spiral drill bits 20%, 30%, 40%, 50%, 80%, or other ratios between 20% and 100%. The overlap rate refers to the ratio of the overlap length between the holes formed by two adjacent auger drill bits to the diameter of the hole. For example, in this embodiment, the diameter of the hole is 320mm. When the holes formed by two adjacent auger drill bits completely overlap, that is, the overlap length is 320mm, the overlap rate is 320 / 320 = 100%.

[0074] It is understood that in other embodiments, it is not necessary to use a splined drive wheel and a hollow shaft. It is only necessary to provide grooves or protrusions on a local outer peripheral surface of the hollow shaft and provide corresponding protrusions or grooves in the corresponding area of ​​the inner peripheral surface of the drive wheel, so that the hollow shaft can perform corresponding reciprocating rotation under the drive of the drive wheel.

[0075] The following describes the use of this drilling rig, specifically using pile extraction as an example. Please refer to [link / reference needed]. Figure 10 The specific steps for pile extraction are as follows:

[0076] (1) Install the drilling machine on the construction surface and make the pile body 90° aligned with the center hole.

[0077] (2) Start the motor to drive the spiral drill bit to rotate, and simultaneously start the hydraulic cylinder to drive the mixing part to reciprocate around the first axis to cut the soil around the pile body and form an annular hole 80.

[0078] While the soil is being cut, water is injected into the cut soil through the inlet pipe to form a soil slurry. Due to the sealing effect of the annular structure, the annular hole below the annular structure forms a relatively closed chamber. Under the pressure of the water, the soil slurry is discharged from the annular hole through the outlet pipe. In this embodiment, the water pressure is 0.7 MPa. When the soil slurry cannot be discharged from the annular hole smoothly, a slurry pump needs to be connected to the top of the outlet pipe to assist in discharging the soil slurry from the annular hole.

[0079] (3) When the depth of the annular hole extends downward beyond the lower end face of the pile, stop cutting the soil, remove the drilling machine, and then pull the pile out from the ground.

[0080] Because the drilling rig removes the soil surrounding the pile, it essentially eliminates the bond between the pile and the surrounding soil, leaving only a small amount of soil adhering to the pile. During pile extraction, the greatest resistance is not the pile itself, but rather the fact that the pile remains underground for a considerable period—ranging from 3-6 months to 1-2 years—causing the underground soil to adhere tightly to the pile. Therefore, extraction requires overcoming the frictional force between the pile and the soil, which is typically 4-5 times the pile's own weight, and sometimes as high as 8 times. Removing the surrounding soil significantly reduces the lifting force required for extraction. Although drilling a ring hole incurs some cost, it still substantially reduces the cost of pile extraction. By creating a ring hole around the pile, the extraction cost is only 20-40% of existing extraction costs.

[0081] When enlarging and reinforcing the pile, after drilling the annular hole, fluid, solidifiable materials such as cement-soil, cement mortar, and fine aggregate concrete are introduced into the annular hole through the inlet pipe. The slurry inside the annular hole continues to be discharged outwards through the outlet pipe. Simultaneously, the auger drill bit is lifted upwards, ultimately forming a plain cylindrical pile surrounding the pile body. This plain cylindrical pile, together with the original pile body, forms a composite pile. During the lifting of the auger drill bit, the rotation of the auger bit and the reciprocating oscillation of the mixing section are maintained, stirring the solidifiable materials and further improving the uniformity of the plain cylindrical pile.

[0082] Alternatively, after drilling the annular hole, the drilling machine can be removed, and then a steel cage and prestressed tendons can be lowered into the annular hole before concrete is poured to form a reinforced concrete cylinder pile. Or, only solidifiable materials such as concrete, cement soil, and cement mortar can be poured to form a plain cylinder pile, thus forming a composite pile.

[0083] When the above construction is carried out in other areas where there are no piles, steel-concrete cylindrical piles or plain cylindrical piles can be formed.

Claims

1. A drilling machine for annular holes, characterized in that, The device includes a support, a drive frame, and a stirring unit. The support has a support platform with its upper surface forming a horizontal support surface. A working hole extending vertically through the support platform is provided on the support platform, and a swing device is mounted on the support surface. The drive frame includes a drive wheel that is movably supported on the support surface. The drive wheel is annular and connected to the swing device, which drives the drive wheel to reciprocate about a first axis extending vertically. The stirring unit includes a hollow shaft extending vertically, an annular body fixedly installed at the lower end of the hollow shaft, and at least four augers installed at the lower end of the annular body. The hollow shaft and the annular body are coaxially arranged, and the central axes of the hollow shaft and the annular body are collinear with the first axis. The first inner cavity of the hollow shaft and the second inner cavity of the annular body together form a central channel extending vertically. The inner diameter of the central channel is the smaller of the inner diameter of the first inner cavity and the inner diameter of the second inner cavity. The support platform is freely fitted onto the hollow shaft through the working hole. The drive wheel is mounted on a hollow shaft. One of the two types of teeth, a tooth and a groove, is provided on the inner circumferential surface of the drive wheel, and the other type of tooth and groove is provided on the outer circumferential surface of the hollow shaft. Both the tooth and groove extend vertically. The tooth extends into the groove. When the drive wheel reciprocates, it drives the hollow shaft to reciprocate synchronously, and also drives the stirring unit to reciprocate synchronously. The hollow shaft can reciprocate vertically relative to the drive wheel. Each auger drill includes an auger drill bit and a motor. The auger drill bit is fixedly mounted on the output shaft of the motor. A motor cavity is provided in the annular body, and the motor is installed in the motor cavity. The auger drill bit is installed on the lower side of the annular body. Viewed vertically, all the spiral drill bits are evenly arranged around the first axis and located within a virtual annular surface. Adjacent spiral drill bits are spaced apart. In the radial direction, the outer circumferential surfaces of the hollow shaft and the annular body do not extend outward beyond the outer edge of the virtual annular surface, and the inner circumferential surfaces of the hollow shaft and the annular body do not extend inward beyond the inner edge of the virtual annular surface. When the stirring part reciprocates, the drill holes formed by adjacent spiral drill bits can overlap each other. A liquid inlet pipe and a slurry outlet pipe extending vertically are fixedly installed on the annular body. Both the liquid inlet pipe and the slurry outlet pipe freely pass through the drive wheel and the working hole and are then fixedly connected to the annular body. The liquid inlet pipe has a liquid inlet and a liquid outlet, and the slurry outlet pipe has a slurry inlet and a slurry outlet. Both the liquid inlet and the slurry outlet penetrate downward through the lower end face of the annular body, and neither the liquid inlet nor the slurry outlet extends downward beyond the drill tip of the auger bit.

2. The drilling machine according to claim 1, characterized in that, The distance between the outer circumferential surface of the annular body and the outer edge of the virtual annular surface is 10-30 mm, and the distance between the inner circumferential surface of the annular body and the inner edge of the virtual annular surface is 10-30 mm; the outer circumferential surface of the hollow shaft does not extend outward beyond the outer circumferential surface of the annular body, and the inner circumferential surface of the hollow shaft does not extend inward beyond the inner circumferential surface of the annular body.

3. The drilling machine according to claim 1, characterized in that, Two to five swingers are mounted on the support surface, each swinger including a hydraulic cylinder; corresponding to each hydraulic cylinder, a swing arm extending radially outward is fixedly mounted on the drive wheel, and all the swing arms are evenly arranged around the first axis; along the circumferential direction of the drive wheel, each hydraulic cylinder is located on the same side of the circumferential direction of its corresponding swing arm. For each swing arm, a limiting member is fixedly installed on the support surface. The limiting member is located on the radial outer side of the drive wheel. An arc-shaped groove is formed on each limiting member. The arc-shaped groove is formed by the side of the limiting member facing the drive wheel and being recessed radially away from the drive wheel. The arc-shaped grooves on all the limiting members are located in the same virtual annular groove. The central axis of the virtual annular groove coincides with the first axis. The radial outer end of the swing arm extends movably into the arc-shaped groove on the corresponding limiting member. The drive wheel is movably supported in the arc-shaped groove by the swing arm. For each hydraulic cylinder, a guide rail assembly is fixedly installed on the support surface. Each guide rail assembly includes at least one guide rail. The hydraulic cylinder is slidably mounted on the guide rail of the corresponding guide rail assembly. The extension direction of the piston rod of the hydraulic cylinder is perpendicular to the guide rail of the installed guide rail assembly, and the piston rod is perpendicular to the first axis. The piston rod of the hydraulic cylinder is hinged to the corresponding rocker arm. When each guide rail assembly includes at least two guide rails, the guide rails in the same guide rail assembly are parallel to each other.

4. The drilling machine according to claim 3, characterized in that, The piston rod is hinged to the radial outer end of the rocker arm.

5. The drilling machine according to claim 1, characterized in that, The inner circumferential surface of the drive wheel is provided with an internal spline, and the outer circumferential surface of the hollow shaft is provided with an external spline that meshes with the internal spline.

6. The drilling machine according to claim 1, characterized in that, The annular body includes an inner cylinder and an outer cylinder sleeved outside the inner cylinder. Both the inner and outer cylinders extend vertically and are radially spaced. A top cover, which is annular, is installed at the upper end of the inner and outer cylinders. The inner and outer radial ends of the top cover are sealed and fixedly installed on the inner and outer cylinders, respectively. A bottom cover, which is annular, is installed at the lower end of the inner and outer cylinders. The inner and outer radial ends of the bottom cover are sealed and detachably installed on the inner and outer cylinders, respectively. The space enclosed by the inner cylinder, outer cylinder, top cover, and bottom cover forms a receiving cavity. The receiving cavity is formed as a motor cavity, and the motor is fixedly installed in the receiving cavity. The drive shaft of the motor extends vertically downwards and is sealed out of the base plate. The drill rod of the auger bit is fixedly connected to the drive shaft.

7. The drilling machine according to claim 1, characterized in that, A step portion protruding radially outward is provided at the lower end of the hollow shaft. The step portion has an annular upward-facing step surface, on which the drive wheel can be detachably supported.

8. The drilling machine according to claim 1, characterized in that, The drive frame also includes a positioning ring located on the upper side of the drive wheel and fixedly mounted on the top of the hollow shaft. The inlet pipe and the outlet pipe are fixedly mounted on the positioning ring.

9. The drilling machine according to claim 1, characterized in that, A lifting hole is provided at the top of the hollow shaft.

10. The drilling machine according to claim 1, characterized in that, When the mixing section reciprocates, the overlap rate of the boreholes formed by adjacent auger bits is 20-100%.

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