Variable-diameter blade type rotary drilling pipe for mixing pile

Abstract

The utility model relates to the technical field of engineering machinery, disclose a variable diameter with blade formula rotary drilling rod for mixing pile, including support pole part, work pole part, drive part. Support pole part adopts the same support outer tube nested connecting pipe, strengthens the overall bending resistance. The work pole part is detachably connected with the support pole part through the standardized hexagonal joint, the link pipe can be flexibly selected and matched to realize the variable diameter construction of different diameters, and different geological requirements are adapted to; The bottom of the mixing rod is provided with staggered mixing blades. The drive part includes a rotary support unit and a lifting execution unit, which realizes the rotation and lifting of the drill rod, and attenuates the vibration transmitted by the power head through the shock pad. The grouting pipe head, the skeleton oil seal and the coaxial grouting branch pipe form a closed slurry channel. After construction, the mixing rod is replaced with a drilling tool, and the equipment can be reused for rotary drilling operation. The drill rod solves the problems of single function, high cost and poor stratum adaptability of traditional equipment, realizes equipment reuse, variable diameter optimization and vibration control, and improves construction efficiency and economy.

Description

Technical Field

[0001] This utility model relates to the field of engineering machinery technology, specifically a variable diameter rotary drilling rod with blades for mixing piles. Background Technology

[0002] Concrete mixing piles are a common method for foundation treatment, and their construction quality is closely related to the performance of the equipment. Traditional mixing pile construction mainly relies on specialized mixing pile machines, which are usually equipped with non-removable integral mixing drill rods and matching power systems, resulting in significant limitations.

[0003] While existing specialized mixing pile machines can achieve the function of mixing and forming piles, their equipment procurement costs are high and their functions are limited. Especially in composite foundation construction scenarios, when the same project requires alternating implementation of mixing piles and rotary drilling grouting piles, construction units are forced to configure multiple specialized machines, resulting in high equipment idle rates and large capital occupation. Moreover, existing mixing pile equipment has limited functions and cannot be directly used for other pile foundation operations after completion, resulting in low equipment reuse rates and further increasing the overall project cost.

[0004] In addition, traditional mixing drill rods lack the ability to change diameter. When constructing in complex strata (such as when the diameter of the ground hole is limited), the single diameter of the drill rod often leads to insufficient mixing for different geological conditions or the existing rotary drilling rod size does not match the construction size, which affects the quality of pile formation and construction progress.

[0005] Therefore, a variable diameter rotary drilling rod with blades for mixing piles is proposed to address the current shortcomings. Summary of the Invention

[0006] In order to solve the problems of the prior art, this utility model provides a variable diameter rotary drilling rod with blades for mixing piles.

[0007] The technical problem to be solved by this utility model is to overcome the defects of the above-mentioned technology and provide a variable diameter rotary drilling rod with blades for mixing piles.

[0008] To solve the above-mentioned technical problems, the technical solution provided by this utility model is a variable diameter rotary drilling rod with blades for mixing piles, comprising: The support rod portion has a support outer tube and a connecting tube coaxially nested inside the support outer tube; The working rod is detachably connected to the bottom end of the connecting pipe via the first fixing part, and is used for mixing and stirring the injected concrete and soil. The drive unit has a rotating support unit connected to the outer support tube and a lifting execution unit connected to the rotating support unit. The drive unit is used to connect to the drilling rig lifting mechanism and realize the rotation of the support rod and the working rod relative to the lifting execution unit, as well as drive the lifting of the support rod and the working rod. The grouting pipe head is located inside the lifting execution unit. Its top end extends to the outside of the lifting execution unit for connecting to external grouting equipment, and its bottom end passes through the rotating support unit and is movably connected to the support rod. Multiple grouting sub-pipes are provided and are coaxially fixed inside the connecting pipe and the working rod. Adjacent grouting sub-pipes are coaxially connected, and the uppermost grouting sub-pipe is connected to the bottom end of the grouting pipe head.

[0009] As an improvement, a front flange is coaxially connected to the top of the outer support tube, and a flange stiffener plate connecting the front flange is provided around the outer support tube. A rear flange and a shock-absorbing pad are fitted on the outer support tube. The rear flange is located above the shock-absorbing pad and is connected to the flange stiffener plate. Flange plates are provided at both ends inside the outer support tube, and the connecting pipe is fixedly connected to the outer support tube through the flange plates.

[0010] As an improvement, the working rod portion includes: Multiple connecting pipes are provided, and adjacent connecting pipes are detachably connected by a second fixing part. The uppermost connecting pipe is detachably connected to the bottom end of the connecting pipe by the first fixing part. The stirring rod is detachably connected to the connecting pipe at the bottom end via a second fixing part, and the stirring blades are arranged in an alternating pattern on the lower part of the stirring rod.

[0011] As an improvement, the first fixing part and the second fixing part have the same structure, both including: An internal hexagonal connector is provided at the top of the connecting pipe or the top of the stirring rod; An external hexagonal connector is located at the bottom end of the connecting pipe or the bottom end of the connecting tube. The external hexagonal connector is inserted into the internal hexagonal connector and fixedly connected by bolts.

[0012] As an improvement, the lifting execution unit includes: The connecting cover has a hollow cylindrical structure with an open bottom, and its upper end is used to connect to the drilling rig lifting mechanism. The follower frame has an annular ring at one end that is fixedly connected to the bottom of the connecting cover, and the other end is slidably connected to the drilling rig mast.

[0013] As an improvement, the rotating support unit includes: The outer bearing has its outer ring fixedly connected to the front flange by bolts, and its inner ring is fixedly connected to the annular ring by bolts on the same axis. The inner bearing is coaxially mounted with the outer bearing, and its outer ring is fixedly connected to the front flange by bolts.

[0014] As an improvement, the grouting pipe head includes: The main grouting pipe head has an inverted J-shaped structure, and its outlet end extends to the outside of the connecting cover. The main grouting pipe head is provided with a connecting plate that is fixedly connected to the inner ring of the inner bearing. The bottom end of the main grouting pipe head is rotatably connected to the front flange. The front flange is provided with a skeleton oil seal that mates with the bottom end of the main grouting pipe head. The air inlet pipe head is inclined and connected to the main grouting pipe head; The connecting cover is provided with a through hole for the outlet end of the main grouting pipe and the air inlet pipe to pass through.

[0015] As an improvement, the grouting branch pipe is coaxially arranged in the central through hole of the connecting pipe and the stirring rod, and the two ends of the grouting branch pipe extend into the corresponding internal hexagonal joint and external hexagonal joint respectively and are sealed and connected to their internal channels.

[0016] As an improvement, the outer support tube is provided with a pressure locking block circumferentially below the shock-absorbing pad. The pressure locking block extends axially along the outer support tube and is used to cooperate with the drive keyway of the drilling rig power head to transmit torque.

[0017] The advantages of this utility model compared with the prior art are as follows: 1. By employing a coaxial nesting design between the supporting outer pipe and the connecting pipe, and utilizing flange plates to achieve rigid connection and collaborative load-bearing, the bending stiffness, torsional strength, and axial load-bearing capacity of the drill rod are significantly enhanced. This structure effectively overcomes the shortcomings of traditional single-pipe drill rods that are prone to bending and deformation during deep hole construction, ensuring that the drill rod maintains a stable working state under complex loads, thereby improving construction safety and pile quality.

[0018] 2. The working rod section features a plug-in, detachable connection between an internal hexagonal connector and an external hexagonal connector, enabling rapid assembly and disassembly of the connecting pipe and precise alignment, ensuring efficient torque transmission and verticality control. Furthermore, by selecting connecting pipes of different diameters, it can flexibly adapt to soft soil layers (reducing the diameter to lower drilling resistance) and hard soil layers (increasing the diameter to enhance pile bearing capacity), solving the problems of poor geological adaptability and low construction efficiency caused by the fixed diameter of traditional drill rods, and optimizing geological response capabilities.

[0019] 3. The outer bearing decouples the rotation of the support rod from that of the lifting actuator, keeping the connecting cover stationary when the drill rod rotates; the inner bearing fixes the grouting pipe head and, together with the skeleton oil seal, forms a rotary seal to prevent the grouting pipe from tangling. Combined with the shock-absorbing pads installed on the outer support pipe, the vibration energy transmitted by the power head is effectively attenuated, reducing the risk of component damage and improving the system's operational stability and lifespan.

[0020] 4. The support rod and working rod adopt a standard rotary drilling rod structure. They are detachably connected by the first and second fixing parts. After construction, the mixing rod can be quickly replaced according to the construction needs, realizing the reuse of mixing pile formation and other functions, reducing the need for special equipment configuration, reducing procurement costs and idle rate, and improving the overall utilization rate and economy of the equipment.

[0021] 5. The grouting branch pipes are coaxially installed inside the connecting pipe and the working rod, and form a continuous and closed grout delivery path through the sealed connection of the internal channels of the hexagonal joint; combined with the rotary sealing design of the grouting pipe head and the skeleton oil seal, grout leakage is effectively prevented, ensuring stable delivery of concrete under complex working conditions and improving the uniformity and quality control of pile formation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a variable diameter rotary drilling rod with blades for mixing piles according to this utility model.

[0023] Figure 2 This is a schematic diagram of the support rod and drive unit in a variable diameter rotary drilling rod with blades for mixing piles according to this utility model.

[0024] Figure 3 This is a top view of the support rod and drive unit in a variable diameter rotary drilling rod with blades for mixing piles according to this utility model.

[0025] Figure 4 yes Figure 3 Sectional view at point AA.

[0026] Figure 5 yes Figure 4 A magnified view of a section at point B.

[0027] Figure 6 This is a front view of the connecting pipe in a variable diameter rotary drilling rod with blades for mixing piles according to this utility model.

[0028] Figure 7 yes Figure 6 Sectional view at point CC.

[0029] Figure 8 This is a schematic diagram of the structure of the mixing rod in a variable diameter rotary drilling rod with blades for mixing piles according to this utility model.

[0030] Figure 9 This is a schematic diagram of the external hexagonal joint in a variable diameter rotary drilling rod with blades for mixing piles according to this utility model.

[0031] Figure 10 This is a schematic diagram of the internal hexagonal joint in a variable diameter rotary drilling rod with blades for mixing piles according to this utility model.

[0032] As shown in the figure: 1. Support rod; 11. Support outer tube; 12. Connecting pipe; 13. Front flange; 14. Flange stiffener; 15. Rear flange; 16. Vibration damping pad; 17. Flange plate; 18. Pressure locking block; 2. Working rod section; 21. Connecting pipe; 22. Second fixing part; 23. Stirring rod; 24. Stirring blade; 3. First fixing part; 31. Internal hexagonal connector; 32. External hexagonal connector; 4. Drive unit; 41. Rotary support unit; 411. Outer bearing; 412. Inner bearing; 42. Lifting actuator; 421. Connecting cover; 422. Follower frame; 423. Annular ring; 5. Grouting pipe head; 51. Main grouting pipe head; 52. Connecting plate; 53. Skeleton oil seal; 54. Air inlet pipe head; 6. Grouting pipes. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the utility model embodiments clearer, the technical solutions of the utility model embodiments will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. The components of the utility model embodiments described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0034] In the description of the embodiments of the utility model, it should be noted that if terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," or "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, they are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the utility model. Furthermore, terms such as "first," "second," and "third" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0035] Furthermore, the use of terms such as "horizontal," "vertical," and "sag" does not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0036] In the description of the utility model embodiments, "a plurality of" means at least two.

[0037] In the description of the embodiments of the utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the utility model according to the specific circumstances.

[0038] As shown in the attached figures, a variable-diameter rotary drilling rod with blades for mixing piles includes: The support rod part 1, as the support structure of the drill rod, has a support outer tube 11 and a connecting tube 12 coaxially nested inside the support outer tube 11, forming a concentric double-axis structure to ensure the overall load-bearing capacity of the drill rod, while providing installation space for the grouting branch pipe 6. Specifically, the hollow cylindrical steel pipe supporting the outer tube 11 directly bears the torque transmitted by the drill rig's power head, the axial pressure during drilling, the tension during lifting, and the bending moment during operation, ensuring the overall rigidity and strength of the drill rod.

[0039] The connecting pipe 12 is also a hollow cylindrical steel pipe with a diameter smaller than the inner diameter of the supporting outer pipe 11. It shares the load with the supporting outer pipe 11, which can enhance the load-bearing capacity and bending stiffness of the drill rod and prevent the long drill rod from bending excessively during construction.

[0040] The top end of the outer support tube 11 is coaxially connected to a front flange 13, providing an installation and connection surface for the rotating support unit 41. The outer support tube 11 is provided with a flange stiffener 14 for connecting the front flange 13 around its circumference. The front flange 13 is circumferentially connected to the outer support tube 11 through the flange stiffener 14, which can enhance the connection strength and structural stability between the front flange 13 and the outer support tube 11, ensuring a reliable connection between the support rod 1 and the rotating support unit 41. At the same time, the load borne by the front flange 13 can be transferred to the tube wall of the outer support tube 11 to avoid stress concentration.

[0041] A rear flange 15 and a shock-absorbing pad 16 are fitted on the outer support pipe 11. The rear flange 15 is located above the shock-absorbing pad 16 and is fixedly connected to the other end of the flange stiffener 14, further enhancing the rigidity of the flange stiffener 14 itself and the connection strength with the outer support pipe 11. The shock-absorbing pad 16 absorbs the vibration transmitted by the drilling rig power head.

[0042] It absorbs and attenuates the vibration and impact loads transmitted from the drilling rig's power head during operation, protecting the support rod 1 and the rotating support unit 41 from damage caused by severe vibration, and improving the service life of the components.

[0043] Furthermore, the outer support tube 11 is provided with a pressure locking block 18 circumferentially below the shock-absorbing pad 16. The pressure locking block 18 extends axially along the outer support tube 11, and the upper end of the pressure locking block 18 passes through the rear flange 15 and the shock-absorbing pad 16. It is used to cooperate with the drive keyway of the drilling rig power head to transmit torque, so as to realize the rotation drive of the support rod 1 through the power head.

[0044] During use, vibration and impact are generated in the working area where the power head keyway engages with the pressure locking block 18. They are then diffused into the wall of the support outer tube 11 through the connection between the pressure locking block 18 and the support outer tube 11, and transmitted upward along the tube wall to the outer wall surface of the support outer tube 11 that contacts the shock-absorbing pad 16. This causes periodic compression deformation of the shock-absorbing pad 16, and internal friction is generated inside the elastic material of the shock-absorbing pad 16, which converts the mechanical energy of the vibration into heat energy and dissipates it, thereby attenuating the vibration energy that continues to be transmitted upward.

[0045] Flange plates 17 are provided at both ends of the inner support outer tube 11. The flange plates 17 are annular plates and are fixedly connected to the support outer tube 11 by welding. The connecting pipe 12 is fixedly connected to the support outer tube 11 through the flange plates 17, and the two ends of the connecting pipe 12 are fixed to the flange plates 17 by welding.

[0046] The working rod 2 is detachably connected to the bottom end of the connecting pipe 12 via the first fixing part 3, and is used to mix and stir the injected concrete and soil to form a mixing pile; Working rod 2 includes: Multiple connecting pipes 21 are provided. In specific implementation, the number of connecting pipes 21 is set according to the actual situation to adapt to the construction needs of mixing piles at different depths. In this embodiment, there are two connecting pipes 21. Adjacent connecting pipes 21 are detachably connected through the second fixing part 22, which can realize the coaxial series connection of multiple connecting pipes 21 to achieve the required construction depth. The uppermost connecting pipe 21 is detachably connected to the bottom end of the connecting pipe 12 through the first fixing part 3.

[0047] The stirring rod 23 is a hollow cylindrical steel pipe located at the lowest end of the working rod part 2. It is detachably connected to the lowest end connecting pipe 21 through the second fixing part 22. The stirring rod 23 has stirring blades 24 arranged in a staggered pattern on the lower part of the circumference. Specifically, the stirring blades 24 are arranged in multiple groups along the axial direction of the stirring rod 23 at intervals. Each group of stirring blades 24 consists of two symmetrically arranged on both sides of the stirring rod 23 and arranged in a cross pattern.

[0048] During rotation, the mixing blades 24 cut and agitate the soil, and thoroughly and evenly mix the concrete slurry flowing from the bottom with the soil to form a concrete-soil mixing pile that meets the requirements. The staggered arrangement of the mixing blades 24 can improve the uniformity and efficiency of mixing.

[0049] The first fixing part 3 and the second fixing part 22 have the same structure, both including: An internal hexagonal connector 31 is located at the top of the connecting pipe 21 or the top of the stirring rod 23; The external hexagonal connector 32 is located at the bottom end of the connecting pipe 12 or the bottom end of the connecting pipe 21. The external hexagonal connector 32 is inserted into the internal hexagonal connector 31 and fixedly connected by bolts.

[0050] During use, the mating connection between the external hexagonal connector 32 and the internal hexagonal connector 31 enables reliable, quick, and detachable connection between the support rod 1 and the working rod 2, as well as between the various sections inside the working rod 2. It also enables precise alignment between the connecting pipes 21 and between the connecting pipe 21 and the stirring rod 23, ensuring the verticality of the drilling process.

[0051] Meanwhile, both the external hexagonal joint 32 and the internal hexagonal joint 31 have internal channels that penetrate axially.

[0052] During implementation, the working rod 2 can be modified by selecting connecting pipes 21 of different diameters to adapt to construction needs under different geological conditions. For example, in soft soil layers, a smaller diameter connecting pipe 21 can be used for drilling to reduce drilling resistance; while in hard soil layers, a larger diameter connecting pipe 21 can be used to increase the pile's bearing capacity and improve construction efficiency. By modifying the diameter of the connecting pipe 21, the drill rod can cope with complex geological conditions and improve construction quality.

[0053] In this embodiment, the connecting pipe 12 in the support rod part 1 and the rod body of the working rod part 2 are both existing rotary drilling rods. In actual use, after the mixing pile construction is completed, the mixing rod 23 can be replaced to connect the connecting rod 22 with the drilling tool for drilling operation.

[0054] The drive unit 4 has a rotating support unit 41 connected to the supporting outer tube 11 and a lifting execution unit 42 connected to the rotating support unit 41. The drive unit 4 is used to connect the drilling rig lifting mechanism and realize the rotation of the support rod part 1 and the working rod part 2 relative to the lifting execution unit 42, as well as drive the lifting of the support rod part 1 and the working rod part 2. The lifting actuator 42 includes: The connecting cover 421 has a hollow cylindrical structure with an open bottom. Its upper end is used to connect to the drilling rig lifting mechanism. Specifically, the top of the connecting cover 421 is provided with a lifting lug that is connected to the drilling rig lifting mechanism and is directly connected to the wire rope of the drilling rig lifting mechanism.

[0055] Meanwhile, the hollow structure of the connecting cover 421 provides installation space for the grouting pipe head 5.

[0056] The follower frame 422 has an annular ring 423 fixedly connected to the bottom of the connecting cover 421 at one end, and is slidably connected to the drilling rig mast at the other end.

[0057] The connecting cover 421 is connected to the drilling rig lifting mechanism. Driven by the lifting mechanism, the connecting cover 421 is raised and lowered on the drilling rig, which in turn drives the support rod 1 and the working rod 2 to rise and fall. The follower frame 422, which is fixedly connected to the connecting cover 421, slides along the mast to ensure the straightness of the raising and lowering.

[0058] In practice, the lifting actuator 42 transmits lifting force through the fixed connection between the connecting cover 421 and the follower frame 422. At the same time, the follower frame 422 and the mast guide rail form a moving pair to form free circumferential movement, which can ensure the vertical movement of the drill rod under complex working conditions.

[0059] The rotating support unit 41 includes: The outer bearing 411 has its outer ring fixedly connected to the front flange 13 by bolts, and its inner ring fixedly connected to the annular ring 423 by bolts, thereby realizing the rotational connection between the support rod 1 and the follower frame 422. Since the follower frame 422 is fixedly connected to the connecting cover 421, the support rod 1 and the lifting actuator 42 are rotated through the outer bearing 411, thus ensuring that the lifting actuator 42 is stationary when the support rod 1 and the working rod 2 rotate, that is, allowing the support rod 1 and the working rod 2 to rotate freely relative to the lifting actuator 42.

[0060] The inner bearing 412 is coaxially arranged with the outer bearing 411, and its outer ring is fixedly connected to the front flange 13 by bolts, so as to realize the coaxial rotation of the grouting pipe head 5 and the front flange 13.

[0061] Grouting pipe head 5 is installed inside the lifting execution unit 42, and its top end extends to the outside of the lifting execution unit 42 to connect to external grouting equipment, so as to introduce the concrete slurry delivered by the external grouting equipment into the grouting branch pipe inside the drill rod.

[0062] The bottom end of the grouting pipe head 5 passes through the rotating support unit 41 and is movably connected to the support rod part 1; in this embodiment, the grouting pipe head 5 passes through the inner bearing 412 and is connected to its inner bearing ring.

[0063] Grouting pipe head 5 includes: The main grouting pipe head 51 has an inverted J-shaped structure, and its outlet end extends to the outside of the connecting cover 421. The bottom end of the main grouting pipe head 51 is rotatably connected to the front flange 13, providing a transition channel for the grout from the external equipment to the working rod 2. The front flange 13 is provided with a skeleton oil seal 53 that mates with the bottom end of the main grouting pipe head 51. In this embodiment, the vertical bottom end of the main grouting pipe head 51 passes through the skeleton oil seal 53 and fits tightly with the inner lip of the skeleton oil seal 53. To ensure its sealing effect, there are multiple skeleton oil seals 53 and they are spaced apart along the axial direction of the front flange 13.

[0064] When the support rod 1 rotates, the inner lip of the skeleton oil seal 53 is tightly attached to the outer wall of the bottom end of the main grouting pipe head 51, preventing grout from leaking from the gap between the rotating front flange 13 and the stationary main grouting pipe head 51.

[0065] The main grouting pipe head 51 is provided with a connecting plate 52 that is fixedly connected to the inner ring of the inner bearing 412. Specifically, the connecting plate 52 is welded to the pipe body of the main grouting pipe head 51, and the connecting plate 52 is rigidly connected to the inner ring of the inner bearing 412 by bolts. The air inlet pipe head 54 is inclined and connected to the main grouting pipe head 51; The connecting cover 421 is provided with a through hole for the outlet end of the main grouting pipe head 51 and the air inlet pipe head 54 to pass through; By engaging the through hole with the outlet end of the main grouting pipe head 51, the upper part of the main grouting pipe head 51 can be fixed on the connecting cover 421. At the same time, by connecting the connecting plate 52 on the main grouting pipe head 51 with the inner ring of the inner bearing 412, the grouting pipe head 5 can remain stationary relative to the rotating front flange 13, and a rotational seal can be achieved through the skeleton oil seal 53.

[0066] Multiple grouting branch pipes 6 are provided and are coaxially fixedly installed in the connecting pipe 12 and the working rod part 2. Adjacent grouting branch pipes 6 are coaxially connected, and the uppermost grouting branch pipe 6 is connected to the bottom end of the grouting pipe head 5.

[0067] The grouting branch pipe 6 is coaxially arranged in the central through hole of the connecting pipe 21 and the mixing rod 23. The two ends of the grouting branch pipe 6 extend into the corresponding internal hexagonal joint 31 and external hexagonal joint 32 respectively and are sealed and connected with their internal channels, forming a continuous and closed grout delivery channel from the bottom of the grouting pipe head 5 to the bottom of the mixing rod 23, so that the grout can be continuously delivered between the sections of the drill rod, and then the concrete grout is delivered to the mixing area at the bottom of the working rod 2.

[0068] Meanwhile, to ensure the fixed installation of the grouting branch pipe 6 in the connecting pipe 21 or the stirring rod 23, the two ends of the grouting branch pipe 6 are provided with connecting flange plates, and the grouting branch pipe 6 is fixedly connected to the connecting pipe 21 or the stirring rod 23 through the connecting flange plates.

[0069] During implementation, adjacent grouting pipes 6 are coaxially sealed and connected at the internal channels of the inner hexagonal joint 31 and the outer hexagonal joint 32. To ensure their sealing performance, both the inner hexagonal joint 31 and the outer hexagonal joint 32 are equipped with sealing rings that mate with the ends of the grouting pipes 6.

[0070] In specific implementation of this utility model: 1) Power transmission and rotary drive: The drive keyway of the drilling rig power head cooperates with the pressure locking block 18 on the support rod 1, and the torque generated by the rotation of the power head is directly transmitted to the support outer tube 11 through the pressure locking block 18.

[0071] The outer support pipe 11 transmits torque to the connecting pipe 12 through the flange plate 17. The bottom end of the connecting pipe 12 is connected to the inner hexagonal joint 31 at the top of the uppermost connecting pipe 21 through the outer hexagonal joint 32 of the first fixing part 3 and fixed with bolts to realize the transmission of torque.

[0072] Adjacent connecting pipes 21 are connected and fixed to transmit torque through the external hexagonal connector 32 and internal hexagonal connector 31 of the second fixing part 22. The lowermost connecting pipe 21 is connected to the internal hexagonal connector 31 at the top of the stirring rod 23 through the external hexagonal connector 32 of the second fixing part 22 to transmit torque.

[0073] Ultimately, the torque drives the stirring rod 23 and its lower circumferentially staggered stirring blades 24 to rotate.

[0074] In the process of power transmission and rotational drive The concentric double-axis structure formed by the supporting outer tube 11 and the connecting tube 12 enhances the rigidity, strength, and bending resistance of the drill pipe, ensuring stable operation during drilling and hoisting and preventing excessive bending. The connection between the external hexagonal joint 32 and the internal hexagonal joint 31 ensures precise alignment between the sections and reliable torque transmission.

[0075] 2) Axial force transmission and drilling / lifting: During drilling: The power head of the drilling rig applies downward axial pressure, which is transmitted to the support outer pipe 11 through the pressure locking block 18, and then to the mixing rod 23 and mixing blade 24 through the connecting pipe 12, the first fixing part 3, the connecting pipe 21, and the second fixing part 22, so that the drill bit cuts into the soil.

[0076] During lifting: The drilling rig lifting mechanism is connected to the lifting lug at the top of the connecting cover 421 by a steel wire rope, which applies an upward pulling force and fixes the connecting cover 421 to the follower frame 422.

[0077] The follower frame 422 is connected to the front flange 13 of the support rod part 1 via the outer bearing 411. Therefore, the lifting force is used to lift the support rod part 1 and the working rod part 2 through the connecting cover 421, thereby lifting the drill rod.

[0078] During axial force transmission and drilling / lifting, the follower frame 422 is slidably connected to the drilling rig mast to ensure the straightness of the drill rod during lifting and lowering. The outer bearing 411 allows the support rod 1 and the working rod 2 to rotate freely, while the connecting cover 421 and the follower frame 422 remain relatively stationary during lifting / lowering.

[0079] 3) Vibration attenuation: The vibration and impact loads generated when the power head is working are produced at the mating point between the power head keyway and the pressure locking block 18.

[0080] Vibration is transmitted to the wall of the outer support pipe 11 through the pressure locking block 18. The vibration is transmitted upward along the wall of the outer support pipe 11 to the outer wall surface in contact with the damping pad 16. The damping pad 16 is subjected to periodic compression deformation. Internal friction is generated inside the elastic material of the damping pad 16, which converts the mechanical energy of the vibration into heat energy and dissipates it. This effectively attenuates the vibration energy that continues to be transmitted upward, and prevents the front flange 13, the rotating support unit 41 and the grouting pipe head 5 connected to it from being damaged by severe vibration, thereby improving the service life of the components.

[0081] 4) Concrete slurry delivery and sealing: An external grouting device connects concrete grout to the outlet end of the main grouting head 51 via a hose, allowing the concrete grout to flow into the main grouting head 51. The vertical bottom end of the main grouting head 51 passes through multiple skeleton oil seals 53 within the front flange 13.

[0082] The inner lip of the skeleton oil seal 53 fits tightly against the outer wall of the bottom end of the main grouting pipe head 51, forming a rotary dynamic seal. When the support rod 1 drives the front flange 13 to rotate, the skeleton oil seal 53 can effectively prevent concrete grout from leaking from the gap between the rotating front flange 13 and the stationary main grouting pipe head 51.

[0083] The main grouting pipe head 51 is bolted to the inner ring of the inner bearing 412 via the connecting plate 52. The outer ring of the inner bearing 412 is bolted to the front flange 13. Meanwhile, the connecting cover 421 is provided with a through hole for the outlet end of the main grouting pipe head 51 to pass through, so as to ensure that the grouting pipe head 51 remains stationary relative to the rotating front flange 13.

[0084] Concrete flows out from the bottom of the main grouting pipe head 51 and enters the uppermost grouting branch pipe 6. The grouting branch pipe 6 is coaxially fixed in the connecting pipe 12 and the working rod part 2 (that is, fixed in the central through hole of the connecting pipe 21 and the mixing rod 23, and fixed by the connecting flange plates at both ends).

[0085] When the working rod 2 is composed of multiple segments, adjacent grouting pipes 6 are coaxially connected at the internal channels of the inner hexagonal joint 31 and the outer hexagonal joint 32. At the same time, sealing rings are provided at the internal channels of the inner hexagonal joint 31 and the outer hexagonal joint 32 to prevent concrete grout from leaking at the connection.

[0086] The concrete grout flows sequentially through the grouting branch pipe 6 in the connecting pipe 12, the internal channels of the inner hexagonal joint 31 and the outer hexagonal joint 32 of the first fixing part 3, the grouting branch pipe 6 in each connecting pipe 21, the internal channels of the inner hexagonal joint 31 and the outer hexagonal joint 32 of the second fixing part 22, and finally flows into the grouting branch pipe 6 inside the mixing rod 23.

[0087] Finally, the concrete slurry flows out from the grouting pipe 6 outlet at the bottom of the mixing rod 23.

[0088] During the concrete grout delivery and sealing process, the skeleton oil seal 53 achieves high-pressure rotary sealing; the inner bearing 412 supports and keeps the grouting pipe head 5 stationary; the internal channels of the grouting branch pipe 6 and the hexagonal joint form a continuous and sealed grout delivery channel that runs through the length of the drill rod; the air inlet pipe head 54 can assist in grouting and prevent pipe blockage.

[0089] 5) Mixing and piling: During the rotation and upward lifting of the drill rod, the mixing blades 24 at the lower part of the mixing rod 23 rotate to cut and turn the soil.

[0090] At the same time, the concrete slurry (concrete paste) flowing out from the bottom of the mixing rod 23 is sheared and mixed by the rotating mixing blades 24, and is fully and evenly mixed with the soil that is being turned over.

[0091] The staggered arrangement of the stirring blades 24 can improve the efficiency and uniformity of stirring.

[0092] As the drill rod continues to rotate and mix and slowly rises, a uniform, continuous concrete-soil mixing pile body that meets the design requirements is formed in the stratum.

[0093] 6) Variable diameter construction: Combining different diameter connecting pipes 21: Soft soil layers: Use smaller diameter connecting pipes 21. Smaller diameter drill pipes encounter less resistance during drilling, reducing the required torque and axial pressure, improving drilling efficiency and drill bit life, and reducing equipment load.

[0094] Hard soil or gravel layers: Use larger diameter connecting pipes 21. Larger diameter drill rods and mixing result in a larger pile cross-section, increasing the bearing capacity of a single pile.

[0095] The diameter change is achieved through standardized hexagonal connectors (31, 32) of the first fixing part 3 and the second fixing part 22, enabling quick and reliable connection and disassembly. Connecting pipes 21 of different diameters can be flexibly combined as long as the hexagonal connectors at both ends are of the same specification.

[0096] The internal grouting branch pipe 6 is also adapted to the connecting pipe 21 of different diameters, and the continuity and sealing of the grouting channel after the diameter change are ensured by the sealing ring of the internal channel of the hexagonal joint.

[0097] During variable diameter construction, the variable diameter design enables the drill rod to flexibly cope with complex and ever-changing geological conditions, optimizing construction efficiency and economy while ensuring pile quality.

[0098] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A variable-diameter rotary drilling rod with blades for mixing piles, characterized in that, include: The support rod portion has a support outer tube and a connecting tube coaxially nested inside the support outer tube; The working rod is detachably connected to the bottom end of the connecting pipe via the first fixing part, and is used for mixing and stirring the injected concrete and soil. The drive unit has a rotating support unit connected to the outer support tube and a lifting execution unit connected to the rotating support unit. The drive unit is used to connect to the drilling rig lifting mechanism and realize the rotation of the support rod and the working rod relative to the lifting execution unit, as well as drive the lifting of the support rod and the working rod. The grouting pipe head is located inside the lifting execution unit. Its top end extends to the outside of the lifting execution unit for connecting to external grouting equipment, and its bottom end passes through the rotating support unit and is movably connected to the support rod. Multiple grouting sub-pipes are provided and are coaxially fixed inside the connecting pipe and the working rod. Adjacent grouting sub-pipes are coaxially connected, and the uppermost grouting sub-pipe is connected to the bottom end of the grouting pipe head.

2. The variable diameter rotary drilling rod with blades for mixing piles according to claim 1, characterized in that: The top end of the supporting outer tube is coaxially connected to a front flange. The supporting outer tube is provided with flange stiffeners that connect to the front flange around its circumference. A rear flange and a shock-absorbing pad are fitted on the supporting outer tube. The rear flange is located above the shock-absorbing pad and is connected to the flange stiffeners. Flange plates are provided at both ends inside the supporting outer tube. The connecting pipe is fixedly connected to the supporting outer tube through the flange plates.

3. A variable-diameter rotary drilling rod with blades for mixing piles according to claim 2, characterized in that, The working rod portion includes: Multiple connecting pipes are provided, and adjacent connecting pipes are detachably connected by a second fixing part. The uppermost connecting pipe is detachably connected to the bottom end of the connecting pipe by the first fixing part. The stirring rod is detachably connected to the connecting pipe at the bottom end via a second fixing part, and the stirring blades are arranged in an alternating pattern on the lower part of the stirring rod.

4. A variable-diameter rotary drilling rod with blades for mixing piles according to claim 3, characterized in that, The first fixing part and the second fixing part have the same structure, both including: An internal hexagonal connector is provided at the top of the connecting pipe or the top of the stirring rod; An external hexagonal connector is located at the bottom end of the connecting pipe or the bottom end of the connecting tube. The external hexagonal connector is inserted into the internal hexagonal connector and fixedly connected by bolts.

5. A variable-diameter rotary drilling rod with blades for mixing piles according to claim 4, characterized in that, The lifting execution unit includes: The connecting cover has a hollow cylindrical structure with an open bottom, and its upper end is used to connect to the drilling rig lifting mechanism. The follower frame has an annular ring at one end that is fixedly connected to the bottom of the connecting cover, and the other end is slidably connected to the drilling rig mast.

6. A variable-diameter rotary drilling rod with blades for mixing piles according to claim 5, characterized in that, The rotary support unit includes: The outer bearing has its outer ring fixedly connected to the front flange by bolts, and its inner ring is fixedly connected to the annular ring by bolts on the same axis. The inner bearing is coaxially mounted with the outer bearing, and its outer ring is fixedly connected to the front flange by bolts.

7. A variable-diameter rotary drilling rod with blades for mixing piles according to claim 6, characterized in that, The grouting pipe head includes: The main grouting pipe head has an inverted J-shaped structure, and its outlet end extends to the outside of the connecting cover. The main grouting pipe head is provided with a connecting plate that is fixedly connected to the inner ring of the inner bearing. The bottom end of the main grouting pipe head is rotatably connected to the front flange. The front flange is provided with a skeleton oil seal that mates with the bottom end of the main grouting pipe head. The air inlet pipe head is inclined and connected to the main grouting pipe head; The connecting cover is provided with a through hole for the outlet end of the main grouting pipe and the air inlet pipe to pass through.

8. A variable-diameter rotary drilling rod with blades for mixing piles according to claim 4, characterized in that: The grouting branch pipe is coaxially arranged in the central through hole of the connecting pipe and the stirring rod. The two ends of the grouting branch pipe extend into the corresponding internal hexagonal joint and external hexagonal joint respectively and are sealed and connected with their internal channels.

9. A variable-diameter rotary drilling rod with blades for mixing piles according to claim 2, characterized in that: The outer support tube is provided with a pressure locking block circumferentially below the shock-absorbing pad. The pressure locking block extends axially along the outer support tube and is used to cooperate with the drive keyway of the drilling rig power head to transmit torque.

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