Connecting device of multi-layer bidirectional mutual shearing type stirring drill bit

Abstract

The invention relates to the technical field of mixing piles, in particular to a connecting device of a multi-layer bidirectional mutual shearing type mixing drill bit, which comprises an outer drill pipe, an inner drill pipe and a first limiting ring, the inner drill pipe is rotatably sleeved in the outer drill pipe, the bottom end of the inner drill pipe is positioned below the outer drill pipe, and the first limiting ring is arranged in the inner drill pipe. The first limiting ring is arranged on the inner drilling pipe in a sleeving mode and located at the bottom of the outer drilling pipe, and a plurality of inner cutter heads are fixedly connected to the surface of the first limiting ring in the circumferential direction; under the action of the second limiting mechanism and the reverse transmission mechanism, the upper end and the lower end of the outer cutter head generate power transmission, so that the transmission integrity of the outer cutter head is guaranteed, and the stress concentration during working of the outer cutter head is reduced; and the inner stirring cutter and the outer stirring cutter can be directly and axially detached along the sleeving position by detaching the contact drill bit, so that the detaching time spent in the overhaul and maintenance process is shortened, and the convenience degree of equipment maintenance is improved.

Description

Technical Field

[0001] The invention relates to the technical field of mixing piles, and in particular to a connecting device for a multi-layer bidirectional mutual shearing type mixing drill bit. Background Art

[0002] Cement-soil mixing piles are a method used to reinforce saturated soft clay foundations. They use cement as a curing agent and a special mixing machine to force the soft soil and curing agent to mix deep in the foundation. A series of physical and chemical reactions between the curing agent and the soft soil are used to harden the soft soil into a high-quality foundation with integrity, water stability and a certain strength.

[0003] The patent document with publication number CN117005393A discloses a multi-layer shear mixing pile drilling rig, including a drilling rig body, a power unit, a drill rod assembly, a drill bit assembly, a faucet, a grouting unit and a suspension device; the power unit includes a single motor and a gear set; the drill rod assembly includes an inner drill rod and an outer drill rod, and a grouting channel is provided inside the inner drill rod; the drill bit assembly includes an inner tube, an outer tube, an outer mixing frame, a mixing wing plate, and a drilling wing plate.

[0004] At present, when reinforcing soft clay foundation, shear mixing piles are usually used to carry out bidirectional mixing of the soft clay foundation, and a curing agent is added during the mixing process. The drill bit, inner mixing blade and outer mixing blade of the traditional shear mixing pile need to be fixed separately, which takes a lot of disassembly time during maintenance, affecting the convenience of equipment maintenance. The inner mixing blade and the outer mixing blade are driven in reverse by the inner rod and the outer rod respectively, and the outer mixing blade is limited only by the bottom end of the outer rod during rotation, which affects the integrity of the outer mixing blade transmission and reduces the fatigue resistance of the outer mixing blade. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings existing in the above-mentioned technology and to propose a connecting device for a multi-layer bidirectional shearing type stirring drill bit.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: a connecting device of a multi-layer bidirectional mutual shearing type stirring drill bit, comprising an outer drill pipe, an inner drill pipe and a first limiting ring, wherein the inner drill pipe is rotatably sleeved inside the outer drill pipe, the bottom end of the inner drill pipe is located below the outer drill pipe, the first limiting ring is sleeved on the inner drill pipe and located at the bottom of the outer drill pipe, a plurality of inner cutter discs are fixedly connected to the surface of the first limiting ring along the circumferential direction, and a first limiting mechanism is connected between the inner drill pipe and the first limiting ring; The first limiting ring is sleeved with a second limiting ring, and the second limiting ring is fixedly connected to a plurality of outer cutter discs along the circumferential direction, and a second limiting mechanism is connected between the outer cutter disc and the outer drill pipe, and the second limiting mechanism includes a plurality of arc plates and a plurality of limiting baffles, and the plurality of arc plates are respectively fixedly connected to the top ends of the corresponding outer cutter discs, and the plurality of limiting baffles are fixedly connected to the bottom of the outer drill pipe along the circumferential direction, and the arc plate is located between two adjacent limiting baffles, and the surface of the first limiting ring is provided with a plurality of strip-shaped through grooves, and support strips are arranged inside the strip-shaped through grooves, and the strip-shaped through grooves are located between the second limiting ring and the corresponding arc plates, and a movable telescopic mechanism is connected to the support strip; A reverse transmission mechanism is connected between the first limiting ring and the second limiting ring, a contact drill bit is commonly provided at the bottom of the first limiting ring and the second limiting ring, a positioning mechanism is connected between the contact drill bit and the inner drill tube, a first drainage hole and a second drainage hole are respectively provided on the inner drill tube and the first limiting ring, and the first drainage hole and the second drainage hole are communicated with each other.

[0007] Preferably, the first limiting mechanism includes a plurality of first limiting strips and a plurality of strip grooves, the plurality of first limiting strips are fixedly connected to the inner wall of the first limiting ring along the circumferential direction, the plurality of strip grooves are circumferentially opened on the surface of the inner drill tube and located at the bottom of the outer drill tube, and the first limiting strips are located inside the corresponding strip grooves.

[0008] Preferably, the positioning mechanism includes a plug-in hole, which is opened at the top of the contact drill bit, and a plurality of second limit strips are fixedly connected to the interior of the plug-in hole along the circumferential direction, the bottom end of the inner drill tube is located inside the plug-in hole, and a plurality of the second limit strips are respectively located inside the corresponding strip grooves, and a plurality of positioning bolts are circumferentially arranged on the side surface of the contact drill bit, and the threaded ends of the positioning bolts all penetrate the contact drill bit and extend to the interior of the plug-in hole and are then threadedly connected to the inner drill tube.

[0009] Preferably, the reverse transmission mechanism includes an annular groove, which is opened on the inner side of the bottom of the second limiting ring, and an inner gear ring is fixedly connected to the inner wall of the annular groove, and an outer gear ring is fixedly connected to the top of the contact drill bit and is rotatably connected to a plurality of transmission gears, and the transmission gear and the outer gear ring are both located inside the annular groove, and the inner gear ring and the outer gear ring are both meshed with the transmission gear.

[0010] Preferably, the movable telescopic mechanism includes a plurality of arc grooves, each of which is opened inside the first limiting ring, and each of the arc grooves is communicated with the corresponding strip-shaped through-grooves, and each of the arc grooves is fixedly connected to a first limiting pin inside the first limiting pin, and a first connecting ring is slidably inserted on the first limiting pin, and the first connecting ring is fixedly connected to the corresponding support bar, and a first spring is sleeved on the first limiting pin, and the first spring is fixedly connected between the corresponding first connecting ring and one end of the arc groove, and a plurality of plug-in grooves are opened at the bottom of the inner side of the first limiting ring, and the plug-in grooves are communicated with the corresponding strip-shaped through-grooves, and a plurality of extrusion strips are fixedly connected to the top of the contact drill bit, and the extrusion strips are respectively located in the corresponding plug-in grooves and the top of the extrusion strip is located in the corresponding strip-shaped through-grooves, and the adjacent ends of the extrusion strip and the support strip are each provided with a guiding inclined surface.

[0011] Preferably, a plurality of spherical grooves are circumferentially formed at the bottom of the second limiting ring, balls are rollingly connected inside the spherical grooves, an annular groove is formed at the top of the contact drill bit, and the bottoms of the balls are located inside the annular groove.

[0012] Preferably, a piston is slidably connected to the inside of the inner drill tube, the first drainage hole is located on the side of the piston, a plurality of second limit pins are fixedly connected to the bottom of the piston, second limit pins are slidably inserted with second connecting rings, the second connecting rings are fixedly connected to the inside of the inner drill tube, the second limit pins are sleeved with second springs, the second springs are fixedly connected between the piston and the corresponding second connecting rings, and a movable air intake mechanism is connected to the inner drill tube.

[0013] Preferably, the movable air intake mechanism includes a connecting hole, which is opened on the inner drill tube, the bottom end of the connecting hole is connected to the interior of the inner drill tube, the bottom end of the connecting hole is located below the piston, and the top end of the connecting hole is located above the inner drill tube and connected to the outside of the inner drill tube.

[0014] Preferably, the outer cutter disc and the inner cutter disc are both arranged to be inclined, and the inclination directions of the outer cutter disc and the inner cutter disc are opposite.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The contact drill bit and the inner drill pipe are fixed by the positioning mechanism, so that the contact drill bit supports and limits the first limit ring and the second limit ring, and the inner mixing blade and the outer mixing blade can be directly disassembled axially along the sleeve position by disassembling the contact drill bit, thereby reducing the disassembly time spent in the inspection and maintenance process and improving the convenience of equipment maintenance.

[0016] 2. The second limit ring rotates in the opposite direction with the outer cutter disc, and drives the inner gear ring to rotate in the opposite direction, so that multiple transmission gears mesh and rotate between the outer gear ring and the inner gear ring. When the outer cutter disc stirs the soil inside and produces vertical torsion under the action of external force, the rotation frequency of the upper and lower ends of the outer cutter disc changes, and the rotation of the outer gear ring is driven by the rotation of the contact drill bit, and the meshing action of multiple transmission gears makes the outer gear ring transmit the power under the meshing action, and the second limit ring is rotated, thereby ensuring that the upper and lower ends of the outer cutter disc are effectively transmitted, reducing the stress concentration caused by single-direction transmission, and improving the fatigue resistance of the outer cutter disc.

[0017] 3. After moving outward, one side of the support strip is located between the second limit ring and the corresponding arc plate, thereby supporting the second limit ring and the arc plate to prevent the outer mixing knife from being vertically stressed and deformed inward during rotation. When the contact drill bit is disassembled downward, the extrusion strip is separated from between the support strip and the inner drill pipe, so that the support strip returns to the inside of the strip through-groove under the elastic extension of the first spring, ensuring that the movement of the arc plate is not blocked by the support strip, and ensuring that the outer mixing knife can be disassembled normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 For the present invention Figure 1 A schematic diagram of the structure enlargement at point A; Figure 3 It is a schematic diagram of the first cross-sectional structure of the present invention; Figure 4 For the present invention Figure 3 A schematic diagram of the structure at B in FIG. Figure 5 For the present invention Figure 3 A schematic diagram of the structure at position C in FIG. Figure 6 It is a schematic diagram of the second cross-sectional structure of the present invention; Figure 7 It is a third cross-sectional structural schematic diagram of the present invention; Figure 8 For the present invention Figure 7 A schematic diagram of the structure at D in FIG. Fig. 9 It is a schematic diagram of the fourth cross-sectional structure of the present invention; Fig.10 For the present invention Fig. 9 A schematic diagram of the structure at position E in FIG. Fig.11 It is a schematic diagram of the matching structure of the outer drill pipe and the inner drill pipe of the present invention; Fig.12It is a schematic diagram of the matching structure of the second limiting ring, the outer cutter disc and the arc plate of the present invention; Fig.13 For the present invention Fig.12 A magnified schematic diagram of the structure at F in FIG. Fig.14 It is a schematic diagram of the matching structure of the first limiting ring and the inner cutter disc of the present invention; Fig.15 It is a schematic diagram of the contact drill bit structure of the present invention.

[0019] In the figure: 1, outer drill pipe; 2, inner drill pipe; 3, first limit ring; 4, inner cutter disc; 5, second limit ring; 6, outer cutter disc; 7, contact drill bit; 8, first drainage hole; 9, second drainage hole; 10, first limit strip; 11, strip groove; 12, arc plate; 13, limit baffle; 14, plug-in hole; 15, second limit strip; 16, positioning bolt; 17, annular groove; 18, inner gear ring; 19, outer gear ring; 20, transmission gear; 21, strip through groove; 22, support strip; 23, arc groove; 24, first limit pin; 25, first connecting ring; 26, first spring; 27, plug-in groove; 28, extrusion strip; 29, spherical groove; 30, ball; 31, annular groove; 32, piston; 33, second limit pin; 34, second connecting ring; 35, second spring; 36, connecting hole. DETAILED DESCRIPTION

[0020] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0021] like Figures 1 to 15 A connecting device of a multi-layer bidirectional mutual shearing type stirring drill bit is shown, comprising an outer drill pipe 1, an inner drill pipe 2 and a first limiting ring 3, wherein the inner drill pipe 2 is rotatably sleeved inside the outer drill pipe 1, and the bottom end of the inner drill pipe 2 is located below the outer drill pipe 1, the first limiting ring 3 is sleeved on the inner drill pipe 2 and located at the bottom of the outer drill pipe 1, a plurality of inner cutter discs 4 are fixedly connected to the surface of the first limiting ring 3 along the circumferential direction, and a first limiting mechanism is connected between the inner drill pipe 2 and the first limiting ring 3; The first limiting ring 3 is sleeved with a second limiting ring 5, and a plurality of outer cutter discs 6 are fixedly connected to the second limiting ring 5 along the circumferential direction. A second limiting mechanism is connected between the outer cutter disc 6 and the outer drill pipe 1, and the second limiting mechanism includes a plurality of arc plates 12 and a plurality of limiting baffles 13. The plurality of arc plates 12 are respectively fixedly connected to the top of the corresponding outer cutter disc 6 and slidably fit on the surface of the first limiting ring 3, and the plurality of limiting baffles 13 are fixedly connected to the bottom of the outer drill pipe 1 along the circumferential direction and slidably fit on the surface of the first limiting ring 3. The arc plate 12 is located between two adjacent limiting baffles 13, and a plurality of strip-shaped through grooves 21 (such as Fig.14As shown), a support bar 22 is provided inside the strip-shaped through groove 21, the strip-shaped through groove 21 is located between the second limiting ring 5 and the corresponding arc-shaped plate 12, and a movable telescopic mechanism is connected to the support bar 22; A reverse transmission mechanism is connected between the first limiting ring 3 and the second limiting ring 5. A contact drill bit 7 is provided at the bottom of the first limiting ring 3 and the second limiting ring 5. A positioning mechanism is connected between the contact drill bit 7 and the inner drill pipe 2. The inner drill pipe 2 and the first limiting ring 3 are respectively provided with a first drainage hole 8 and a second drainage hole 9 (such as Figure 4 As shown), the first drainage hole 8 and the second drainage hole 9 are connected; when working, the prior art usually uses shear mixing piles to perform bidirectional mixing on the soft clay foundation when reinforcing the soft clay foundation, and adds a curing agent during the mixing process. The drill bit, inner mixing knife and outer mixing knife of the traditional shear mixing pile need to be fixed separately, so that a lot of disassembly time is spent in the maintenance process, which affects the convenience of equipment maintenance. The inner mixing knife and the outer mixing knife are respectively driven in reverse by the inner rod and the outer rod. The outer mixing knife is limited only by the bottom end of the outer rod during the rotation process, which affects the integrity of the outer mixing knife transmission and reduces the fatigue resistance of the outer mixing knife. The technical solution can solve the above problems, and the specific working method is as follows: the top of the outer drill pipe 1 and the inner drill pipe 2 are reversely driven by the power equipment The outer drill pipe 1 and the inner drill pipe 2 are driven in the opposite direction and move vertically downward along the soft clay foundation. When the outer drill pipe 1 and the inner drill pipe 2 rotate in the opposite direction, the first limiting mechanism and the positioning mechanism make the first limiting ring 3 and the contact drill bit 7 rotate synchronously with the inner drill pipe 2. The first limiting ring 3 drives the multiple inner cutter discs 4 to rotate synchronously, and the outer cutter disc 6 rotates synchronously with the outer drill pipe 1 through the second limiting mechanism. At the same time, the first limiting ring 3 and the second limiting ring 5 rotate in the opposite direction through the reverse transmission mechanism, so that when the inner cutter disc 4 and the outer cutter disc 6 rotate in the opposite direction, the second limiting mechanism and the reverse transmission mechanism make the upper and lower ends of the outer cutter disc 6 generate power transmission, thereby ensuring the integrity of the transmission of the outer cutter disc 6, thereby reducing the stress concentration of the outer cutter disc 6 when working, and improving the fatigue resistance of the outer cutter disc 6; During maintenance and overhaul, the positioning between the contact drill bit 7 and the inner drill pipe 2 is released by releasing the positioning mechanism and removing the contact drill bit 7. At the same time, the contact drill bit 7 cancels the support for the bottom of the first limiting ring 3 and the second limiting ring 5. Then, the second limiting ring 5 is axially removed downward along the sleeve position of the first limiting ring 3. The second limiting ring 5 drives the outer cutter disc 6 to move downward synchronously from between the two adjacent inner cutter discs 4, and releases the limiting effect between the outer cutter disc 6 and the outer drill pipe 1. Finally, the first limiting ring 3 is taken out axially downward along the sleeve of the inner drill pipe 2 and the limiting function of the first limiting mechanism is released, so that the inner cutter disc 4 is disassembled, and the contact drill bit 7 and the inner drill pipe 2 are fixed by the positioning mechanism, so that the contact drill bit 7 supports and limits the first limiting ring 3 and the second limiting ring 5, and the inner cutter disc 4 and the outer cutter disc 6 can be directly disassembled axially along the sleeve position by disassembling the contact drill bit 7, thereby reducing the disassembly time spent in the inspection and maintenance process and improving the convenience of equipment maintenance; The rotation of the outer drill pipe 1 drives multiple limit baffles 13 to rotate synchronously, and the arc plate 12 is limited by two adjacent limit baffles 13, so that the arc plate 12 rotates synchronously with the outer drill pipe 1 and drives the corresponding outer cutter disc 6 to rotate. When the outer cutter disc 6 is disassembled, the second limit ring 5 is moved axially downward along the sleeve position of the first limit ring 3, and the second limit ring 5 drives multiple outer cutter discs 6 and the arc plate 12 to move downward synchronously, and the outer cutter disc 6 and the arc plate 12 move through between the adjacent inner cutter discs 4, thereby completing the disassembly of the outer cutter disc 6. Through the action of the movable telescopic mechanism, one side of the support bar 22 is located between the second limit ring 5 and the corresponding arc plate 12 after moving outward, thereby supporting the second limit ring 5 and the arc plate 12 to prevent the outer mixing knife from being vertically stressed and deformed toward the inside during rotation.

[0022] As a further embodiment of the present invention, the first limiting mechanism includes a plurality of first limiting strips 10 and a plurality of strip grooves 11 (such as Fig.10 As shown in the figure, a plurality of first limiting strips 10 are fixedly connected to the inner wall of the first limiting ring 3 along the circumferential direction, a plurality of strip grooves 11 are circumferentially opened on the surface of the inner drill pipe 2 and located at the bottom of the outer drill pipe 1, and the first limiting strips 10 are located inside the corresponding strip grooves 11; during operation, the first limiting strips 10 are limited by the strip grooves 11 opened on the inner drill pipe 2, so that when the inner drill pipe 2 rotates, the first limiting ring 3 rotates synchronously with the inner drill pipe 2, and the plurality of inner cutter discs 4 are driven to rotate synchronously through the first limiting ring 3, and when the first limiting ring 3 moves axially downward along the inner drill pipe 2, the first limiting strip 10 moves downward from the corresponding strip grooves 11, thereby axially removing the first limiting ring 3 from the inner drill pipe 2.

[0023] As a further embodiment of the present invention, the positioning mechanism includes a plug hole 14 (such as Figure 6As shown in the figure, the plug-in hole 14 is opened at the top of the contact drill bit 7, and a plurality of second limit strips 15 are fixedly connected to the inside of the plug-in hole 14 along the circumferential direction. The bottom end of the inner drill pipe 2 is located inside the plug-in hole 14, and the plurality of second limit strips 15 are respectively located inside the corresponding strip grooves 11. A plurality of positioning bolts 16 are circumferentially arranged on the side of the contact drill bit 7, and the threaded ends of the positioning bolts 16 all penetrate the contact drill bit 7 and extend to the inside of the plug-in hole 14 and are then threadedly connected to the inner drill pipe 2. When working, the bottom end of the inner drill pipe 2 is inserted into the plug-in hole 1 4, and the second limiting strip 15 is limited by the strip groove 11, and then the contact drill bit 7 is threadedly fixed on the inner drill pipe 2 by the positioning bolt 16, so that the inner drill pipe 2 can drive the contact drill bit 7 to rotate synchronously, and after the contact drill bit 7 is positioned on the bottom end of the inner drill pipe 2, the bottoms of the first limiting ring 3 and the second limiting ring 5 are supported and limited by the contact drill bit 7. When the contact drill bit 7 is released from the inner drill pipe 2, the first limiting ring 3 and the second limiting ring 5 lose the support and limitation at the bottom and are axially disassembled.

[0024] As a further embodiment of the present invention, the reverse transmission mechanism includes an annular groove 17 (such as Figure 8 As shown in the figure, the annular groove 17 is opened on the inner side of the bottom of the second limiting ring 5, and an inner gear ring 18 is fixedly connected to the inner wall of the annular groove 17. An outer gear ring 19 is fixedly connected to the top of the contact drill bit 7 and is rotatably connected to a plurality of transmission gears 20. The transmission gears 20 and the outer gear ring 19 are both located inside the annular groove 17, and the inner gear ring 18 and the outer gear ring 19 are both meshed with the transmission gear 20. During operation, the inner drill pipe 2 drives the contact drill bit 7 to rotate unidirectionally, so that the outer gear ring 19 rotates synchronously with the contact drill bit 7. When the outer gear ring 19 rotates unidirectionally, the second limiting ring 5 rotates in the opposite direction with the outer cutter head 6, and drives the inner gear ring 18 to rotate in the opposite direction. As a result, multiple transmission gears 20 mesh and rotate between the outer gear ring 19 and the inner gear ring 18. When the outer cutter disc 6 stirs the soil inside and generates vertical twisting under the action of external force, the upper and lower ends of the outer cutter disc 6 are prone to torsional deformation under the condition of uneven driving force, and the rotation of the contact drill bit 7 drives the outer gear ring 19 to rotate, and the meshing action of multiple transmission gears 20 causes the inner gear ring 18 to rotate under the meshing action, and drives the second limit ring 5 to rotate, thereby ensuring effective transmission at the upper and lower ends of the outer cutter disc 6, reducing stress concentration caused by single-direction transmission, and improving the fatigue resistance of the outer cutter disc 6.

[0025] As a further embodiment of the present invention, the movable telescopic mechanism includes a plurality of arc grooves 23, and the plurality of arc grooves 23 are all opened inside the first limiting ring 3 (such as Fig.10As shown in the figure, the arc grooves 23 are all connected with the corresponding bar-shaped through grooves 21, and the interior of the arc grooves 23 is fixedly connected with a first limiting pin 24, and a first connecting ring 25 is slidably inserted on the first limiting pin 24, and the first connecting ring 25 is fixedly connected to the corresponding support bar 22. A first spring 26 is sleeved on the first limiting pin 24, and the first spring 26 is fixedly connected between the corresponding first connecting ring 25 and one end of the arc groove 23. A plurality of plug-in grooves 27 (as shown in the figure) are provided at the bottom of the inner side of the first limiting ring 3 Figure 8 and Fig.14 As shown, the insertion slots 27 are all connected to the corresponding strip-shaped through slots 21, and a plurality of extrusion strips 28 (as shown) are fixedly connected to the top of the contact drill bit 7. Figure 8 and Fig.15 As shown in the figure, the extrusion strips 28 are respectively located in the corresponding plug-in grooves 27 and the top ends of the extrusion strips 28 are located in the corresponding strip-shaped through-grooves 21. The adjacent ends of the extrusion strips 28 and the support strips 22 are provided with guiding inclined surfaces. When working, the first connecting rings 25 on both sides of the support strips 22 are extruded by the elastic extension of the first springs 26, so that the support strips 22 are completely located in the corresponding strip-shaped through-grooves 21. When the contact drill bit 7 moves axially upward and is positioned by the action of the positioning mechanism, the contact drill bit 7 is located at the bottom of the first limiting ring 3 and the second limiting ring 5. When the contact drill bit 7 moves toward the bottom of the first limiting ring 3 and the second limiting ring 5, the extrusion strip 28 at the top of the contact drill bit 7 moves upward along the corresponding plug-in groove 27, and one end of the extrusion strip 28 moves toward the corresponding strip-shaped through-grooves 21. The extrusion strips 28 are moved to the corresponding strip-shaped through-grooves 21. The end adjacent to 28 and the support bar 22 is contacted and squeezed by the guiding inclined surface, so that the support bar 22 moves along the corresponding strip-shaped through-groove 21 toward the outside of the first limiting ring 3, and drives the first connecting ring 25 to move synchronously, thereby squeezing the first spring 26 to produce compression deformation. After moving outward, one side of the support bar 22 is located between the second limiting ring 5 and the corresponding arc plate 12, thereby supporting the second limiting ring 5 and the arc plate 12 to prevent the outer stirring knife from being vertically stressed and deforming inward during rotation. When the contact drill bit 7 is disassembled downward, the extrusion bar 28 is disengaged from the support bar 22 and the inner drill pipe 2, so that the support bar 22 returns to the inside of the strip-shaped through-groove 21 under the elastic extension action of the first spring 26, ensuring that the movement of the arc plate 12 is not blocked by the support bar 22, and ensuring that the outer stirring knife can be disassembled normally.

[0026] As a further embodiment of the present invention, the bottom of the second limiting ring 5 is provided with a plurality of spherical grooves 29 (such as Fig.13 As shown, the ball 30 is rollingly connected inside the spherical groove 29, and an annular groove 31 is opened on the top of the contact drill bit 7 (as shown in FIG. Fig.15As shown in the figure), the bottom of the balls 30 are all located inside the annular groove 31; when working, the bottom of the first limiting ring 3 and the second limiting ring 5 are supported by the contact drill bit 7, and the second limiting ring 5 and the contact drill bit 7 rotate in opposite directions, and the balls 30 inside the spherical groove 29 contact the inside of the annular groove 31, and multiple balls 30 roll during the process of the second limiting ring 5 and the contact drill bit 7 rotating in opposite directions, thereby effectively reducing the contact friction between the contact drill bit 7 and the second limiting ring 5, and extending the service life of the equipment.

[0027] As a further embodiment of the present invention, a piston 32 (such as Figure 4 As shown in the figure, the first drainage hole 8 is located on the side of the piston 32, and a plurality of second limiting pins 33 are fixedly connected to the bottom of the piston 32. The second limiting pins 33 are slidably inserted with second connecting rings 34, and the second connecting rings 34 are fixedly connected to the inside of the inner drill pipe 2. The second limiting pins 33 are sleeved with second springs 35, and the second springs 35 are fixedly connected between the piston 32 and the corresponding second connecting rings 34. The inner drill pipe 2 is connected with a movable air intake mechanism. When working, the first drainage hole 8 is blocked by the piston 32, so that when the inner drill pipe 2 and the first limiting ring 3 rotate in the soil, the soft clay cannot be moved along the second drainage holes 9 and the first drainage holes in sequence. The liquid hole 8 enters the inner drill pipe 2. When the concrete for curing is pumped into the inner drill pipe 2, the hydraulic pressure generated by the pumping squeezes the piston 32 downward, and causes the second limit pin 33 at the bottom of the piston 32 to slide along the corresponding second connecting ring 34, thereby squeezing the second spring 35 to produce compression deformation, and causing the piston 32 to move below the first drainage hole 8, so that the concrete can be discharged along the first drainage hole 8 and the second drainage hole 9, and mixed in the soft clay for curing. After the concrete stops being pumped, the piston 32 returns to its initial position through the elastic extension of the second spring 35, and blocks the first drainage hole 8 again.

[0028] As a further embodiment of the present invention, the movable air intake mechanism includes a communication hole 36, which is opened on the inner drill pipe 2 (such as Figure 4 and Figure 5As shown in the figure, the bottom end of the communicating hole 36 is connected to the inside of the inner drill pipe 2, the bottom end of the communicating hole 36 is located below the piston 32, and the top end of the communicating hole 36 is located above the inner drill pipe 2 and is connected to the outside of the inner drill pipe 2; during operation, when the piston 32 moves downward, the gas located below the piston 32 enters the inside of the communicating hole 36 along the bottom end of the communicating hole 36 under the squeezing action of the piston 32, and is discharged from the top end of the communicating hole 36, thereby ensuring the normal movement of the piston 32, and by setting the top end of the communicating hole 36 above the inner drill pipe 2, the inside of the communicating hole 36 is prevented from entering the soil and being blocked. When the piston 32 returns to its position, the external gas enters the inside of the communicating hole 36 along the top end of the communicating hole 36, and re-enters the inner drill pipe 2 along the bottom end of the communicating hole 36.

[0029] As a further implementation scheme of the present invention, the outer cutter disc 6 and the inner cutter disc 4 are both inclined, and the inclination directions of the outer cutter disc 6 and the inner cutter disc 4 are opposite; during operation, the outer cutter disc 6 and the inner cutter disc 4 are inclinated in the opposite direction, so that the outer cutter disc 6 and the inner cutter disc 4 produce a shearing effect on the soil during the reverse rotation process, thereby improving the mixing effect of the curing agent and the soft clay.

[0030] Working principle of the present invention: The top ends of the outer drill pipe 1 and the inner drill pipe 2 are driven in reverse by a power device and move vertically downward along the soft clay foundation. When the outer drill pipe 1 and the inner drill pipe 2 rotate in reverse, the first limiting mechanism and the positioning mechanism cause the first limiting ring 3 and the contact drill bit 7 to rotate synchronously with the inner drill pipe 2. The first limiting ring 3 drives multiple inner cutter discs 4 to rotate synchronously, and the outer cutter disc 6 rotates synchronously with the outer drill pipe 1 through the action of the second limiting mechanism. At the same time, the first limiting ring 3 and the second limiting ring 5 rotate in reverse through the action of the reverse transmission mechanism. When the inner cutter disc 4 and the outer cutter disc 6 rotate in reverse, the second limiting mechanism and the reverse transmission mechanism cause power transmission to be generated at both the upper and lower ends of the outer cutter disc 6, thereby ensuring the integrity of the transmission of the outer cutter disc 6, thereby reducing the stress concentration of the outer cutter disc 6 during operation and improving the fatigue resistance of the outer cutter disc 6. During maintenance and overhaul, the positioning between the contact drill bit 7 and the inner drill pipe 2 is released by releasing the positioning mechanism and removing the contact drill bit 7. At the same time, the contact drill bit 7 cancels the support for the bottom of the first limiting ring 3 and the second limiting ring 5. Then, the second limiting ring 5 is axially removed downward along the sleeve position of the first limiting ring 3. The second limiting ring 5 drives the outer cutter disc 6 to move downward synchronously from between the two adjacent inner cutter discs 4, and releases the limiting effect between the outer cutter disc 6 and the outer drill pipe 1. Finally, the first limiting ring 3 is taken out axially downward along the sleeve of the inner drill pipe 2 and the limiting effect of the first limiting mechanism is released, so that the inner cutter disc 4 is disassembled, and the contact drill bit 7 and the inner drill pipe 2 are fixed by the positioning mechanism, so that the contact drill bit 7 supports and limits the first limiting ring 3 and the second limiting ring 5, and the inner mixing blade and the outer mixing blade can be directly disassembled axially along the sleeve position by disassembling the contact drill bit 7, thereby reducing the disassembly time spent in the inspection and maintenance process and improving the convenience of equipment maintenance; The rotation of the outer drill pipe 1 drives multiple limit baffles 13 to rotate synchronously, and the arc plate 12 is limited by two adjacent limit baffles 13, so that the arc plate 12 rotates synchronously with the outer drill pipe 1 and drives the corresponding outer cutter disc 6 to rotate. When the outer cutter disc 6 is disassembled, the second limit ring 5 is moved axially downward along the sleeve position of the first limit ring 3, and the second limit ring 5 drives multiple outer cutter discs 6 and the arc plate 12 to move downward synchronously, and the outer cutter disc 6 and the arc plate 12 move through between the adjacent inner cutter discs 4, thereby completing the disassembly of the outer cutter disc 6. Through the action of the movable telescopic mechanism, one side of the support bar 22 is located between the second limit ring 5 and the corresponding arc plate 12 after moving outward, thereby supporting the second limit ring 5 and the arc plate 12 to prevent the outer mixing knife from being vertically stressed and deformed toward the inside during rotation.

[0031] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions only describe the principles of the present invention. The present invention may have various changes and improvements without departing from the spirit and scope of the present invention, and these changes and improvements fall within the scope of the present invention to be protected, and the scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A connection device for a multi-layer bidirectional shearing stirring drill bit, comprising an outer drill pipe, an inner drill pipe and a first limiting ring, characterized in that: The inner drill pipe is rotatably sleeved inside the outer drill pipe, the bottom end of the inner drill pipe is located below the outer drill pipe, the first limiting ring is sleeved on the inner drill pipe and located at the bottom of the outer drill pipe, a plurality of inner cutter discs are fixedly connected to the surface of the first limiting ring along the circumferential direction, and a first limiting mechanism is connected between the inner drill pipe and the first limiting ring; The first limiting ring is sleeved with a second limiting ring, and a plurality of outer cutter discs are fixedly connected to the second limiting ring along the circumferential direction, and a second limiting mechanism is connected between the outer cutter disc and the outer drill pipe, and the second limiting mechanism includes a plurality of arc plates and a plurality of limiting baffles, and the plurality of arc plates are respectively fixedly connected to the top ends of the corresponding outer cutter discs, and the plurality of limiting baffles are fixedly connected to the bottom of the outer drill pipe along the circumferential direction, and the arc plate is located between two adjacent limiting baffles, and a plurality of strip-shaped through grooves are opened on the surface of the first limiting ring, and support strips are arranged inside the strip-shaped through grooves, and the strip-shaped through grooves are located between the second limiting ring and the corresponding arc plates, and a movable telescopic mechanism is connected to the support strips; A reverse transmission mechanism is connected between the first limiting ring and the second limiting ring, a contact drill bit is commonly provided at the bottom of the first limiting ring and the second limiting ring, a positioning mechanism is connected between the contact drill bit and the inner drill tube, a first drainage hole and a second drainage hole are respectively provided on the inner drill tube and the first limiting ring, and the first drainage hole and the second drainage hole are communicated with each other.

2. A connection device for a multi-layer bidirectional shearing stirring drill bit according to claim 1, characterized in that: The first limiting mechanism includes a plurality of first limiting strips and a plurality of strip grooves. The plurality of first limiting strips are fixedly connected to the inner wall of the first limiting ring along the circumferential direction. The plurality of strip grooves are circumferentially opened on the surface of the inner drill pipe and located at the bottom of the outer drill pipe. The first limiting strips are located inside the corresponding strip grooves.

3. A connection device for a multi-layer bidirectional shearing stirring drill bit according to claim 2, characterized in that: The positioning mechanism includes a plug-in hole, which is opened at the top of the contact drill bit. A plurality of second limit strips are fixedly connected to the inside of the plug-in hole along the circumferential direction. The bottom end of the inner drill tube is located inside the plug-in hole. The plurality of second limit strips are respectively located inside the corresponding strip grooves. A plurality of positioning bolts are circumferentially arranged on the side surface of the contact drill bit. The threaded ends of the positioning bolts all penetrate the contact drill bit and extend to the inside of the plug-in hole and are then threadedly connected to the inner drill tube.

4. A connection device for a multi-layer bidirectional shearing stirring drill bit according to claim 3, characterized in that: The reverse transmission mechanism includes an annular groove, which is opened on the inner side of the bottom of the second limiting ring. An inner gear ring is fixedly connected to the inner wall of the annular groove. An outer gear ring is fixedly connected to the top of the contact drill bit and is rotatably connected to multiple transmission gears. The transmission gear and the outer gear ring are both located inside the annular groove, and the inner gear ring and the outer gear ring are both meshed with the transmission gear.

5. The connection device of a multi-layer bidirectional shearing stirring drill bit according to claim 1, characterized in that: The movable telescopic mechanism includes a plurality of arc grooves, which are all provided inside the first limiting ring, and the arc grooves are all connected with the corresponding strip-shaped through-grooves. A first limiting pin is fixedly connected inside the arc grooves, and a first connecting ring is slidably inserted on the first limiting pin, and the first connecting ring is fixedly connected to the corresponding support strip. A first spring is sleeved on the first limiting pin, and the first spring is fixedly connected between the corresponding first connecting ring and one end of the arc groove. A plurality of plug-in grooves are provided at the bottom of the inner side of the first limiting ring, and the plug-in grooves are all connected with the corresponding strip-shaped through-grooves. A plurality of extrusion strips are fixedly connected to the top of the contact drill bit, and the extrusion strips are respectively located inside the corresponding plug-in grooves and the top ends of the extrusion strips are located inside the corresponding strip-shaped through-grooves. A guiding slope is provided at the adjacent ends of the extrusion strip and the support strip.

6. A connection device for a multi-layer bidirectional shearing stirring drill bit according to claim 4, characterized in that: The bottom of the second limiting ring is provided with a plurality of spherical grooves along the circumferential direction, and balls are rollingly connected inside the spherical grooves. An annular groove is provided on the top of the contact drill bit, and the bottoms of the balls are located inside the annular groove.

7. A connection device for a multi-layer bidirectional shearing stirring drill bit according to claim 1, characterized in that: A piston is slidably connected to the inside of the inner drill tube, and the first drainage hole is located on the side of the piston. A plurality of second limit pins are fixedly connected to the bottom of the piston. Second connecting rings are slidably inserted on the second limit pins, and the second connecting rings are fixedly connected to the inside of the inner drill tube. Second limit pins are sleeved with second springs, and the second springs are fixedly connected between the piston and the corresponding second connecting rings. A movable air intake mechanism is connected to the inner drill tube.

8. A connection device for a multi-layer bidirectional shearing type stirring drill bit according to claim 7, characterized in that: The movable air intake mechanism comprises a connecting hole, which is arranged on the inner drill tube, the bottom end of the connecting hole is connected with the inside of the inner drill tube, the bottom end of the connecting hole is located below the piston, and the top end of the connecting hole is located above the inner drill tube and connected with the outside of the inner drill tube.

9. A connection device for a multi-layer bidirectional shearing stirring drill bit according to claim 8, characterized in that: The outer cutter disc and the inner cutter disc are both inclined, and the inclination directions of the outer cutter disc and the inner cutter disc are opposite.

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