Bidirectional stirring drill bit with front-arranged outer drill rod for stirring drilling

Abstract

The utility model discloses a bidirectional stirring drill bit with a front outer drill rod for stirring and drilling, which belongs to the field of pile foundation construction equipment and comprises an inner mandrel, an outer frame, a sealing sleeve, an outer stirring blade, an inner stirring blade, a drill tip, an upper guniting port and a lower guniting port. The outer stirring blades and the inner stirring blades are distributed alternately, the upper guniting opening is formed in the joint of the uppermost inner stirring blade and the inner core shaft and located on the back-to-soil side of the inner stirring blades, the lower guniting opening is formed in the joint of the lowermost outer stirring blade and the inner core shaft and located on the back-to-soil side of the lowermost outer stirring blade, and drilling teeth are arranged on the lowermost outer stirring blade. And the lower end of the inner mandrel is welded with the drill tip. According to the utility model, the upper and lower guniting ports are arranged, only the lower guniting port works in the downward drilling process, only the upper guniting port works in the lifting drilling process, and the mixing uniformity of solidified materials and soil is ensured in the construction process.

Description

Technical Field

[0001] The utility model belongs to the field of pile foundation construction equipment, and specifically relates to a bidirectional stirring drill bit for front stirring drilling of an outer drill rod. Background Art

[0002] Soft soil refers to fine-grained soil with high natural water content, large porosity, high compressibility and low shear strength deposited in coastal areas, lakes, valleys and riverbanks. More and more highways, railways and ports will inevitably pass through soft soil foundation areas during construction. Strengthening the foundation strength through cement soil mixing piles is a common improvement measure. Bidirectional mixing piles use cement / curing agent as curing material. Through special mixing machinery and slurry pumps, soft soil and curing materials are forced to mix deep in the foundation. A series of physical and chemical reactions between curing materials and soft soil are used to harden the soft soil into a composite foundation with integrity, water stability and high foundation bearing capacity.

[0003] At present, the biggest problem in two-way mixing construction is that the spraying medium (cement slurry or powdered material) is not mixed evenly with the soil layer, which affects the overall strength of the pile body. The reason is that the spraying ports are all set at the bottom. During the drilling and mixing process, the slurry and the soil are stirred by multiple layers of intersecting blades, and the slurry is mixed relatively completely; but when the drill is lifted, the slurry is still located at the bottom of the drill bit. Although there are one or two layers of blades stirring, the slurry sprayed out by the drill still causes the slurry to fill the gaps and aggregate, which leads to uneven strength of the pile body after hardening, and even the strength of the pile center is much higher than the strength of the pile edge.

[0004] Based on this, it is very necessary for the utility model to fundamentally improve the design of the existing mixing pile drill bit, otherwise it will inevitably limit the applicability of the two-way mixing process. Based on this, the utility model proposes a two-way mixing drill bit for mixing drilling with an outer drill rod in front. Summary of the invention

[0005] In view of the above technical problems existing in the prior art, the utility model proposes a bidirectional mixing drill bit for front mixing drilling with an outer drill rod, which overcomes the shortcomings of the prior art. By setting two upper and lower grouting ports, only the lower grouting port works when the drill is lowered, and only the upper grouting port works when the drill is raised, thus ensuring the uniformity of mixing of the solidified material and the soil during the construction process.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A bidirectional stirring drill bit for stirring drilling with an outer drill rod in front, comprising an inner core shaft, an outer frame, a sealing sleeve, an outer stirring blade, an inner stirring blade, a drill tip, an upper grouting port, and a lower grouting port; the inner core shaft is connected to the inner drill rod through a flange, the inner stirring blade is welded to the inner core shaft, the outer stirring blade is welded to the outer frame, the outer stirring blade and the inner stirring blade are alternately distributed, the upper part of the outer frame is connected to the outer drill rod through the outer stirring blade, the lower part of the outer frame is in contact with the inner core shaft through a wear-resistant sleeve, the bottommost outer stirring blade is provided with drill teeth, and the lower end of the inner core shaft is welded to the drill tip.

[0008] Preferably, if the upper shotcrete port and the lower shotcrete port are arranged on the same slurry channel, the switching of the upper shotcrete port and the lower shotcrete port is realized by a conversion device, and the conversion device changes the opening and closing states of the upper shotcrete port and the lower shotcrete port by external force; if the upper shotcrete port and the lower shotcrete port are arranged on different slurry channels, the switching of the upper shotcrete port and the lower shotcrete port is realized by a conversion device, and the conversion device switches the connection between different slurry channels and the upper shotcrete port and the lower shotcrete port by external force; the external force exerted on the conversion device includes manual operation, the rotation of the drill rod in different directions drives the conversion device, and the force of the external structure connected to the conversion device is transmitted to the conversion device.

[0009] Preferably, the angle between the inner stirring blade and the first and fourth quadrants in the horizontal plane is 10°~50°, and the angle between the outer stirring blade and the second and third quadrants in the horizontal plane is 10°~50°; the projection height of the inner stirring blade on the vertical plane is A, the projection height of the outer stirring blade on the vertical plane is B, and the distance between the inner drill rod blade and the outer drill rod blade is 0.5-2.0 times the maximum value between A and B.

[0010] Preferably, the shortest distance between the free end of the inner stirring blade and the outer frame is 0.025-0.25 times the length of the inner stirring blade; the shortest distance between the free end of the outer stirring blade and the inner core shaft is 0.025-0.25 times the length of the outer stirring blade.

[0011] Preferably, the outer frame is formed by welding two rectangular plate structures, and the angle between the two rectangular plate structures is 30° to 150°.

[0012] Preferably, the number of the outer frames is two or three, and the outer frames are evenly distributed.

[0013] Preferably, the sealing sleeve is fixed on the outer drill rod, and the sealing sleeve is in close contact with the inner drill rod.

[0014] Preferably, the upper spray port is arranged at the intersection of the uppermost inner stirring blade and the inner core shaft and on the back side of the inner stirring blade, and the lower spray port is arranged at the intersection of the lowermost outer stirring blade and the inner core shaft and on the back side of the lowermost outer stirring blade.

[0015] Beneficial technical effects brought by the utility model:

[0016] (1) By setting two upper and lower grouting ports, only the lower grouting port works when the drill is lowered, and only the upper grouting port works when the drill is lifted. The sprayed slurry can be stirred by multiple layers of blades, ensuring the uniformity of the mixing of the solidified material and the soil during the construction process. (2) The outer drill rod pre-mixing drilling refers to the blade at the bottom that breaks the soil, that is, the bottom outer mixing blade is directly connected to the outer frame. The outer mixing blade rotates and breaks the soil through the drive of the outer drill rod. The advantage of this is that the outer drill rod uses a relatively low speed to achieve a small speed and high torque, thereby achieving a better drilling effect. At the same time, the inner drill rod rotates quickly, and the uniformity of mixing is further guaranteed. (3) The upper and lower grouting ports are both set on the back side of the blade. For example, when the inner drill rod rotates clockwise, the inner mixing blade is at an angle. When breaking the soil, the upper side of the blade is in direct contact with the soil and belongs to the soil facing side. On the contrary, the other side belongs to the back side. The soil is lifted by the soil facing side, resulting in a cavity formed at the back side of the blade. The grouting port is set on the back side to facilitate the slurry to directly fill the cavity without being directly squeezed to other positions. (4) The angle between the mixing blade and the horizontal plane is to ensure a certain amount of cutting soil, lift the soil to form a cavity to facilitate slurry filling, and also to ensure that the blade is subject to less resistance during the mixing process. (5) The distance between the free end of the blade and the shaft, as well as the distance between the two layers of blades, are set for the optimal cutting distance to ensure that the soil can be mixed more evenly. (6) The outer frame is set in a "V"-shaped angle. Firstly, it is to ensure that the outer frame can form a ground-breaking state during the process of drilling down and drilling up in opposite directions. Secondly, the outer frame is the part that directly contacts the original soil. The "V"-shaped structure reduces the direct contact between the outer frame and the original soil, thereby reducing frictional resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The utility model is a schematic diagram of the overall structure of a bidirectional stirring drill bit for stirring drilling with an outer drill rod in front.

[0018] Figure 2 This is a structural diagram of the inner and outer frames of a bidirectional stirring drill bit for stirring drilling with an outer drill rod in front of the utility model.

[0019] Among them, 1-inner core shaft, 2-outer frame, 3-sealing sleeve, 4-outer stirring blade, 5-inner stirring blade, 6-drill tip, 7-upper spraying port, 8-lower spraying port, 9-wear-resistant sleeve, 10-drill tooth, 11-inner drill rod, 12-outer drill rod. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments: Embodiment 1:

[0021] like Figure 1~2As shown, a bidirectional stirring drill bit for front-end stirring drilling with an outer drill rod comprises an inner core shaft 1, an outer frame 2, a sealing sleeve 3, an outer stirring blade 4, an inner stirring blade 5, a drill tip 6, an upper grouting port 7, and a lower grouting port. By setting two upper and lower grouting ports, only the lower grouting port works when the drill is lowered, and only the upper grouting port works when the drill is lifted. The slurry sprayed out can be stirred by multiple layers of blades, and the uniformity of mixing of the solidified material and the soil is ensured during the construction process. The inner core shaft 1 is connected to the inner drill rod 11 through a flange, the inner stirring blade 5 is welded to the inner core shaft 1, the outer stirring blade 4 is welded to the outer frame 2, the outer stirring blade 4 and the inner stirring blade 5 are alternately distributed, the upper part of the outer frame 2 is connected to the outer drill rod 12 through the outer stirring blade 4, and the lower part of the outer frame 2 is in contact with the inner core shaft 1 through the wear-resistant sleeve 9. The upper grouting port 7 is arranged at the intersection of the uppermost inner stirring blade 5 and the inner core shaft 1 and on the back side of the inner stirring blade 5, and the lower grouting port is arranged at the lowermost outer stirring blade 5. At the intersection of the mixing blade 4 and the inner core shaft 1 and on the back side of the bottom outer mixing blade 4, the upper and lower grouting ports are both set on the back side of the blade. For example, when the inner drill rod 11 rotates clockwise, the inner mixing blade 5 is at an oblique angle. When breaking the soil, the upper side of the blade is in direct contact with the soil and belongs to the soil-facing side. On the contrary, the other side belongs to the back side. The soil is lifted by the soil-facing side, resulting in the formation of a cavity at the back side of the blade. The grouting port is set on the back side to facilitate the slurry to directly fill the cavity without being directly squeezed to other positions. The bottom outer mixing blade 4 is provided with a drill tooth 10. The front mixing drilling of the outer drill rod 12 refers to the blade that breaks the soil at the bottom, that is, the bottom outer mixing blade 4 is directly connected to the outer frame 2. The outer mixing blade 4 is rotated and broken by the drive of the outer drill rod 12. The advantage of this is that the outer drill rod 12 uses a relatively low rotation speed to achieve a small rotation speed and a large torque, thereby achieving a better drilling effect. At the same time, the inner drill rod 11 rotates quickly, and the uniformity of mixing is further guaranteed. The lower end of the inner core shaft 1 is connected to the drill tip 6 by welding.

[0022] Preferably, if the upper shotcrete port 7 and the lower shotcrete port 8 are arranged on the same slurry channel, the switching of the upper shotcrete port 7 and the lower shotcrete port 8 is realized by a conversion device, and the conversion device changes the opening and closing states of the upper shotcrete port 7 and the lower shotcrete port 8 by external force; if the upper shotcrete port 7 and the lower shotcrete port 8 are arranged on different slurry channels, the switching of the upper shotcrete port 7 and the lower shotcrete port 8 is realized by a conversion device, and the conversion device switches the connection between different slurry channels and the upper shotcrete port 7 and the lower shotcrete port 8 by external force; the external force exerted on the conversion device includes manual operation, the rotation of the drill rod in different directions drives the conversion device, and the force of the external structure connected to the conversion device is transmitted to the conversion device.

[0023] Preferably, the angle between the inner stirring blade 5 and the first and fourth quadrants in the horizontal plane is 10°~50°, and the angle between the outer stirring blade 4 and the second and third quadrants in the horizontal plane is 10°~50°; the angle between the stirring blade and the horizontal plane is to ensure a certain cutting of the soil body, lift the soil body to form a cavity to facilitate slurry filling, and also to ensure that the resistance encountered by the blade during the stirring process is small. The projection height of the inner stirring blade 5 on the vertical plane is A, the projection height of the outer stirring blade 4 on the vertical plane is B, and the distance between the inner drill rod 11 blade and the outer drill rod 12 blade is 0.5-2.0 times the maximum value between A and B.

[0024] Preferably, the shortest distance between the free end of the inner stirring blade 5 and the outer frame 2 is 0.025-0.25 times the length of the inner stirring blade 5; the shortest distance between the free end of the outer stirring blade 4 and the inner core shaft 1 is 0.025-0.25 times the length of the outer stirring blade 4. The distance between the free end of the blade and the shaft, and the distance between the two layers of blades are set for the optimal cutting distance to ensure that the soil can be stirred more evenly.

[0025] Preferably, the outer frame 2 is welded by two rectangular plate structures, and the angle between the two rectangular plate structures is 30° to 150°. The outer frame 2 is set in the form of a "V"-shaped angle, firstly to ensure that the outer frame 2 can form a ground-breaking state during the process of drilling down and drilling up in opposite directions, and secondly, the outer frame 2 is the part that directly contacts the in-situ soil, and the "V"-shaped structure reduces the direct contact between the outer frame 2 and the in-situ soil, thereby reducing the frictional resistance.

[0026] Preferably, the number of the outer frames 2 is two or three, and the outer frames 2 are evenly distributed.

[0027] Preferably, the sealing sleeve 3 is fixed on the outer drill rod 12 , and the sealing sleeve 3 is in close contact with the inner drill rod 11 . Embodiment 2:

[0028] like Figure 1~2 As shown, a bidirectional stirring drill bit for stirring drilling with an outer drill rod in front comprises an inner core shaft 1, an outer frame 2, a sealing sleeve 3, an outer stirring blade 4, an inner stirring blade 5, a drill tip 6, an upper grouting port 7, and a lower grouting port; the inner core shaft 1 is connected to the inner drill rod 11 through a flange, the inner stirring blade 5 is welded to the inner core shaft 1, the outer stirring blade 4 is welded to the outer frame 2, the outer stirring blade 4 and the inner stirring blade 5 are alternately distributed, the upper part of the outer frame 2 is connected to the outer drill rod 12 through the outer stirring blade 4, the lower part of the outer frame 2 is in contact with the inner core shaft 1 through a wear-resistant sleeve 9, the bottommost outer stirring blade 4 is provided with a drill tooth 10, and the lower end of the inner core shaft 1 is welded to the drill tip 6.

[0029] Preferably, if the upper shotcrete port 7 and the lower shotcrete port 8 are arranged on the same slurry channel, the switching of the upper shotcrete port 7 and the lower shotcrete port 8 is realized by a conversion device, and the conversion device changes the opening and closing states of the upper shotcrete port 7 and the lower shotcrete port 8 by external force; if the upper shotcrete port 7 and the lower shotcrete port 8 are arranged on different slurry channels, the switching of the upper shotcrete port 7 and the lower shotcrete port 8 is realized by a conversion device, and the conversion device switches the connection between different slurry channels and the upper shotcrete port 7 and the lower shotcrete port 8 by external force; the external force applied to the conversion device includes manual operation, that is, the conversion device is arranged on the drilling rig or in the background, and when the shotcrete position needs to be changed, the conversion device is manually turned. The conversion device is used to switch the grouting position; the drill pipe rotates in different directions to drive the conversion device, that is, the conversion device is installed at the drill pipe joint, and the clockwise and counterclockwise rotation of the drill pipe drives the conversion device to rotate clockwise or counterclockwise, and the rotation in two directions causes the conversion device to be connected to different slurry channels, thereby realizing the change of the upper and lower grouting positions; the external structure connected to the conversion device is subjected to force and transmitted to the conversion device, that is, the conversion device is connected to a force-bearing blade, and the blade is subjected to resistance in different directions when drilling and lifting the drill, thereby driving the conversion structure to rotate, thereby realizing the connection of the conversion device with different slurry channels, or opening and closing different grouting ports.

[0030] Preferably, the angle between the inner stirring blade 5 and the first and fourth quadrants in the horizontal plane is 30°, and the angle between the outer stirring blade 4 and the second and third quadrants in the horizontal plane is 30°; the projection height of the inner stirring blade 5 on the vertical plane is A, the projection height of the outer stirring blade 4 on the vertical plane is B, and the distance between the blades of the inner drill rod 11 and the blades of the outer drill rod 12 is 1.2 times the maximum value between A and B.

[0031] Preferably, the shortest distance between the free end of the inner stirring blade 5 and the outer frame 2 is 0.1 times the length of the inner stirring blade 5 ; the shortest distance between the free end of the outer stirring blade 4 and the inner core shaft 1 is 0.1 times the length of the outer stirring blade 4 .

[0032] Preferably, the outer frame 2 is formed by welding two rectangular plate structures, and the angle between the two rectangular plate structures is 45°.

[0033] Preferably, the number of the outer frames 2 is two or three, and the outer frames 2 are evenly distributed.

[0034] Preferably, the sealing sleeve 3 is fixed on the outer drill rod 12 , and the sealing sleeve 3 is in close contact with the inner drill rod 11 .

[0035] Preferably, the upper spray port 7 is arranged at the intersection of the uppermost inner stirring blade 5 and the inner core shaft 1 and on the back side of the inner stirring blade 5, and the lower spray port is arranged at the intersection of the lowermost outer stirring blade 4 and the inner core shaft 1 and on the back side of the lowermost outer stirring blade 4.

[0036] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention also fall within the protection scope of the present invention.

Claims

1. A bidirectional stirring drill bit for front stirring drilling with an outer drill rod, characterized in that: It includes an inner core shaft, an outer frame, a sealing sleeve, an outer stirring blade, an inner stirring blade, a drill tip, an upper spraying port, and a lower spraying port; the inner core shaft is connected to the inner drill rod through a flange, the inner stirring blade is welded to the inner core shaft, the outer stirring blade is welded to the outer frame, the outer stirring blade and the inner stirring blade are alternately distributed, the upper part of the outer frame is connected to the outer drill rod through the outer stirring blade, the lower part of the outer frame is in contact with the inner core shaft through a wear-resistant sleeve, the bottom outer stirring blade is provided with drill teeth, and the lower end of the inner core shaft is welded to the drill tip.

2. A bidirectional stirring drill bit for external drill rod front stirring drilling according to claim 1, characterized in that: If the upper shotcrete port and the lower shotcrete port are arranged on the same slurry channel, the switching between the upper shotcrete port and the lower shotcrete port is realized by a conversion device, and the conversion device changes the opening and closing states of the upper shotcrete port and the lower shotcrete port through external force; if the upper shotcrete port and the lower shotcrete port are arranged on different slurry channels, the switching between the upper shotcrete port and the lower shotcrete port is realized by a conversion device, and the conversion device switches the connection between different slurry channels and the upper shotcrete port and the lower shotcrete port through external force; the external force applied to the conversion device includes manual operation, the rotation of the drill rod in different directions drives the conversion device, and the force of the external structure connected to the conversion device is transmitted to the conversion device.

3. A bidirectional stirring drill bit for external drill rod pre-stirring drilling according to claim 1, characterized in that: The angle between the inner stirring blade and the first and fourth quadrants in the horizontal plane is 10°~50°, and the angle between the outer stirring blade and the second and third quadrants in the horizontal plane is 10°~50°; the projection height of the inner stirring blade on the vertical plane is A, the projection height of the outer stirring blade on the vertical plane is B, and the distance between the inner drill pipe blade and the outer drill pipe blade is 0.5-2.0 times the maximum value between A and B.

4. A bidirectional stirring drill bit for external drill rod front stirring drilling according to claim 1, characterized in that: The shortest distance between the free end of the inner stirring blade and the outer frame is 0.025-0.25 times the length of the inner stirring blade; the shortest distance between the free end of the outer stirring blade and the inner core shaft is 0.025-0.25 times the length of the outer stirring blade.

5. The bidirectional stirring drill bit for external drill rod front stirring drilling according to claim 1, characterized in that: The outer frame is formed by welding two rectangular plate structures, and the angle between the two rectangular plate structures is 30°~150°.

6. A bidirectional stirring drill bit for external drill rod front stirring drilling according to claim 1, characterized in that: The number of the outer frames is two or three, and the outer frames are evenly distributed.

7. A bidirectional stirring drill bit for external drill rod front stirring drilling according to claim 1, characterized in that: The sealing sleeve is fixed on the outer drill rod, and the sealing sleeve is in close contact with the inner drill rod.

8. The bidirectional stirring drill bit for external drill rod front stirring drilling according to claim 1, characterized in that: The upper spraying port is arranged at the intersection of the uppermost inner stirring blade and the inner core shaft and on the back soil side of the inner stirring blade, and the lower spraying port is arranged at the intersection of the lowermost outer stirring blade and the inner core shaft and on the back soil side of the lowermost outer stirring blade.

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