Gas-slurry double-channel mixing pile drill bit

Abstract

The utility model particularly relates to a gas-slurry double-channel mixing pile drill bit, which belongs to the technical field of mixing pile application and comprises an extension drill rod, a high-pressure gas cavity sleeve is sleeved on the outer side of the lower end of the extension drill rod, a high-pressure output valve is mounted on the outer side of the high-pressure gas cavity sleeve, and a high-pressure gas conveying channel is arranged on the outer side of the extension drill rod. A high-pressure slurry conveying channel is formed in the middle of the extending drill rod, an impact drill bit is installed at the lower end of the extending drill rod, a conveying connecting structure is arranged at the upper end of the extending drill rod, and cutting energy attenuation of slurry in a soil layer is reduced through the combined effect of high-pressure gas and high-pressure slurry. The drill rod and the drill bit are low in refitting difficulty and high in applicability; gas overflows along the drill rod to slow down geological flow of a sand layer to bury the drill rod; a high-pressure gas outlet is additionally formed in the drill bit part, high-pressure gas impacts and cuts a soil body, and when the drill bit performs reinforcing action, high-pressure gas blades are matched with high-pressure slurry to stir a soil layer, so that the solidification range of the slurry and the soil layer is larger, and the stirring effect is denser and more uniform.

Description

Technical Field

[0001] The utility model specifically relates to an air-slurry double-channel mixing pile drill bit, belonging to the technical field of mixing pile application. Background Art

[0002] The cement mixing pile construction technology has the advantages of simple process, low cost, low pollution and short construction period, and is widely used in soft foundation treatment. According to the construction process and mechanical type of cement mixing piles, it is generally divided into three forms: single-axis, double-axis and three-axis. Single-axis mixing piles are widely used in foundation reinforcement due to their simple structure and flexible and convenient use. Due to the characteristics of loose soil and certain fluidity in the sand layer geology, the mixing piles are prone to greater resistance during the process of cutting the soil and drilling the upper body. During the on-site pile test, it was found that the sinking speed of the drill bit slowed down significantly after drilling about 1.2m into the sand layer. Continuing to drill down, the drill bit finally got stuck and could not continue to drill, and cement slurry overflowed at the drilling position. The treatment depth of the mixing pile did not meet the design requirements. The sand layer has high fluidity. When the drill bit drills to the designed elevation, the flowing sand layer will refill the borehole and exert a gradually increasing friction resistance on the drill bit and drill rod. At the same time, it will absorb the cutting force of the high-pressure slurry impact cutting the soil, causing the diameter of the entire soil reinforcement range to gradually shrink as the elevation decreases until the drill bit stops rotating. At this time, the inner wall of the borehole almost overlaps with the drill bit, and the reinforcement effect is not achieved.

[0003] This construction technology adds a new channel to the drill bit, uses an air compressor to integrate high-pressure gas (20 times atmospheric pressure on site) into the drill bit, and forms a high-pressure gas blade to cut the sand layer, while blocking the flowing sand layer from accumulating around the drill bit and drill rod to produce a large resistance that affects the construction process of the mixing pile. At the same time, it solves the problem that the radial diameter of the high-pressure rotary spraying of the mixing pile in general sand layer geology becomes smaller and smaller with the depth of the driving. Utility Model Content

[0004] The utility model aims to provide an air-slurry double-channel mixing pile drill bit to address the deficiencies of the prior art, so as to reduce the influence of the fluidity of the sand layer on the pile forming effect of the device.

[0005] The utility model achieves the above-mentioned purpose through the following technical scheme: an air-slurry dual-channel mixing pile drill bit, comprising an extended drill rod, a high-pressure gas chamber sleeve is sleeved on the outer side of the lower end of the extended drill rod, a high-pressure output valve is evenly inlaid and installed on the outer side of the high-pressure gas chamber sleeve, a high-pressure gas delivery channel is opened on the outer side of the extended drill rod, a high-pressure slurry delivery channel is opened in the middle of the extended drill rod, an impact drill bit is fixedly installed on the lower end of the extended drill rod, and a delivery connection structure is arranged on the upper end of the extended drill rod.

[0006] Preferably, in order to transmit high-pressure gas, the high-pressure gas delivery channel is respectively opened around the extended drill rod, one end of the high-pressure gas delivery channel passes through the upper end of the extended drill rod, and the lower end of the high-pressure gas delivery channel is interconnected with the interior of the high-pressure gas cavity sleeve.

[0007] Preferably, in order to improve the slurry delivery effect, the high-pressure slurry delivery channel is opened at the center position of the extended drill rod, and output connecting holes are opened around the lower end of the high-pressure slurry delivery channel, and the other end of the output connecting hole is interconnected with the interior of the high-pressure gas chamber sleeve.

[0008] Preferably, in order to maintain the conveying of raw materials during the rotation of the extended drill rod, the conveying connection structure includes a mounting nut, a connecting thread is provided on the outer surface of the upper end of the extended drill rod, the mounting nut and the connecting thread are rotatably engaged with each other, and a connecting bearing is fixedly installed inside the mounting nut.

[0009] Preferably, in order to improve the gas delivery effect, a positioning and connecting box is fixedly installed inside the connecting bearing, and a gas outlet connecting ring is inlaid and installed at the lower end of the positioning and connecting box.

[0010] Preferably, in order to prevent gas leakage, an annular sealing groove is opened on the outer side of the upper end of the extended drill rod, a sealing rubber ring is fixedly installed on the lower surface of the annular sealing groove, the high-pressure gas delivery channel passes through the sealing rubber ring, and the air outlet connecting ring and the annular sealing groove are slidably engaged with each other.

[0011] Preferably, in order to communicate with an external gas delivery device, an air intake connection hole is opened on one side of the upper end of the positioning and communicating box, and an air flow delivery pipe is embedded and installed inside the air intake connection hole.

[0012] Preferably, in order to improve the mud conveying efficiency, a mud input hole is opened at the center position of the positioning connecting box, a mud inlet pipe is embedded in the inside of the mud input hole, and a positioning connecting slot is opened at the upper end of the high-pressure slurry conveying channel, and the positioning connecting slot and the mud inlet pipe are slidably engaged with each other.

[0013] The beneficial effects of the utility model are as follows: the combined effect of high-pressure gas and high-pressure slurry reduces the energy attenuation of slurry cutting in the soil layer; the modification difficulty of the drill rod and drill bit is small and the applicability is strong; the gas overflows along the drill rod to slow down the geological flow of the sand layer and bury the drill rod; a high-pressure gas outlet is added to the drill bit part, and after the high-pressure gas reaches the drill bit, it impacts and cuts the soil at a very high speed. When the drill bit is performing the reinforcement action, the high-pressure gas blade cooperates with the high-pressure slurry to stir the soil layer, which can generate greater impact energy than simply using high-pressure slurry, achieves a larger consolidation range of the slurry and the soil layer, and has a denser and more uniform stirring effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the utility model;

[0015] Figure 2 It is a side sectional structural schematic diagram of the utility model;

[0016] Figure 3 This is a schematic diagram of the internal structure of the extended drill rod portion of the utility model;

[0017] Figure 4 It is a structural schematic diagram of the extended drill rod part in the utility model;

[0018] Figure 5 It is a structural schematic diagram of the conveying connection structure part in the utility model.

[0019] In the figure: 1. Extended drill pipe; 2. High-pressure gas chamber sleeve; 3. High-pressure output valve; 4. High-pressure gas delivery channel; 5. High-pressure slurry delivery channel; 6. Impact drill bit; 7. Delivery connection structure; 701. Mounting nut; 702. Connecting bearing; 703. Positioning connecting box; 704. Air outlet connecting ring; 705. Sealing rubber ring; 706. Air flow delivery pipe; 707. Mud inlet pipe. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] See also Figure 1-Figure 5 As shown, an air-slurry dual-channel mixing pile drill bit comprises an extended drill rod 1, a high-pressure gas chamber sleeve 2 is sleeved on the outer side of the lower end of the extended drill rod 1, a high-pressure output valve 3 is evenly inlaid and installed on the outer side of the high-pressure gas chamber sleeve 2, a high-pressure gas delivery channel 4 is opened on the outer side of the extended drill rod 1, a high-pressure slurry delivery channel 5 is opened in the middle of the extended drill rod 1, an impact drill bit 6 is fixedly installed on the lower end of the extended drill rod 1, and a delivery connection structure 7 is provided on the upper end of the extended drill rod 1.

[0022] The high-pressure gas delivery channel 4 is respectively opened around the extended drill pipe 1, one end of the high-pressure gas delivery channel 4 passes through the upper end of the extended drill pipe 1, and the lower end of the high-pressure gas delivery channel 4 is interconnected with the interior of the high-pressure gas chamber sleeve 2 to facilitate the transmission of high-pressure gas.

[0023] The high-pressure slurry delivery channel 5 is opened at the center of the extended drill pipe 1. Output connection holes are opened around the lower end of the high-pressure slurry delivery channel 5. The other end of the output connection hole is interconnected with the interior of the high-pressure gas chamber sleeve 2 to improve the slurry delivery effect.

[0024] The conveying connection structure 7 includes a mounting nut 701, a connecting thread is provided on the outer surface of the upper end of the extended drill rod 1, and the mounting nut 701 and the connecting thread are rotatably engaged with each other, a connecting bearing 702 is fixedly installed inside the mounting nut 701, so as to maintain the conveying of raw materials during the rotation of the extended drill rod 1, a positioning connecting box 703 is fixedly installed inside the connecting bearing 702, and an air outlet connecting ring 704 is inlaid on the lower end of the positioning connecting box 703, an annular sealing groove is provided on the outer side of the upper end of the extended drill rod 1, and a sealing rubber ring 705 is fixedly installed on the lower surface of the annular sealing groove, and the high-pressure gas conveying channel 4 passes through the sealing rubber ring 705, and the air outlet connecting ring 704 and the annular sealing groove are slidably engaged with each other, so as to improve the gas conveying effect, and an air inlet connecting hole is provided on one side of the upper end of the positioning connecting box 703, and an air flow conveying pipe 706 is inlaid inside the air inlet connecting hole, so as to communicate with the external gas conveying device.

[0025] A mud input hole is provided at the center of the positioning connecting box 703, and a mud inlet pipe 707 is embedded in the inside of the mud input hole. A positioning connection slot is provided at the upper end of the high-pressure slurry conveying channel 5, and the positioning connection slot and the mud inlet pipe 707 are slidably engaged with each other to improve the mud conveying efficiency.

[0026] When the device is in use, the user places the device in an appropriate position, fixes the mud inlet pipe 707 and the external high-pressure slurry pump in communication with each other, fixes the airflow delivery pipe 706 and the external air compressor in communication with each other, and adds a high-pressure output valve 3 to the drill bit. After the high-pressure gas reaches the drill bit, it impacts and cuts the soil at a very high speed. The air knife enters the high-pressure gas chamber sleeve 2 through the air inlet through the compressed air. After the airflow passes through the narrow and thin nozzle, a balanced airflow sheet is formed in a specific direction. Since the high-pressure gas chamber sleeve 2 has a very high compression ratio for the high-pressure airflow, the airflow velocity loss is minimized and the pressure is maximized, thereby generating an airflow sheet with strong impact force. When the drill bit performs reinforcement action, the high-pressure gas blade cooperates with the high-pressure slurry to stir the soil layer, which can generate greater impact energy than simply using high-pressure slurry, achieving a larger consolidation range of the slurry and the soil layer, and a denser and more uniform stirring effect.

[0027] A dual-channel combined grouting pipe structure is used. When the grouting pipe is drilled into the predetermined depth of the soil layer along with the drill bit, a jet flow of two media, high-pressure slurry and air, is simultaneously ejected through the high-pressure output valve 3 on the side of the bottom of the pipe to impact and destroy the soil. That is, a high-pressure generating device such as a high-pressure mud pump is used to eject a slurry of about 6KPa, which is ejected from the high-pressure output valve 3 at a high speed. Under the combined action of the high-pressure slurry and its outer ring airflow, the energy for destroying the soil is significantly increased, and finally a larger consolidated body is formed in the soil, overcoming the greater resistance caused by the sand layer to the lifting process of the impact drill bit 6, thereby avoiding drill jamming. The high porosity of sandy formations leads to large mud consumption and serious mud loss. Therefore, when constructing large-diameter mixing piles in sandy geology, higher requirements are placed on the viscosity and concentration of the mud to ensure that it can effectively emulsify and suspend sand particles to prevent sand particles from flowing and carrying. The friction resistance of sandy formations is large, and the drilling torque and pull-back force will increase, which may cause the impact drill bit 6 and the drill rod to be easily worn, greatly increasing the construction difficulty and the support process cannot be completed normally. The combination of high-pressure gas and slurry can greatly reduce the resistance of the sand layer. The sandy formation has strong sedimentation and adsorption capacity and abundant groundwater, which may cause the mud to be diluted and increase the risk of burying drill pipes. Due to the fluidity of gravel sand and coarse sand in the mud, it is easy to form blockages in the borehole, squeezing and burying the laid pipes. In this solution, the soil is destroyed by cutting with high-pressure gas, which can avoid the buried pipe phenomenon caused by the fluidity of the sand layer.

[0028] The present invention has low modification difficulty and strong operability. A dual-channel drill rod is used for drilling. When the grouting pipe is drilled into the predetermined depth of the soil layer along with the drill bit, a coaxial double nozzle on the side of the bottom of the pipe is used to simultaneously eject a jet flow of two media, high-pressure slurry and air, to impact and destroy the soil. That is, a high-pressure generating device such as a high-pressure mud pump is used to eject a slurry of about 20KPa and a high-pressure gas of 0.9Mpa-1.2Mpa pressure, which are ejected from the inner nozzle at high speed. Under the combined action of the high-pressure slurry and its outer ring airflow, the energy for destroying the soil body is significantly increased, and finally a larger consolidated body is formed in the soil. Overcome the greater resistance caused by the sand layer to the drill bit during the lifting process to avoid drill jamming. The sandy stratum has a high porosity, resulting in a large mud consumption and serious mud loss.

[0029] When constructing large-diameter mixing piles in sandy geology, higher requirements are placed on the viscosity and concentration of the mud to ensure that the sand can be effectively emulsified and suspended to prevent the sand from flowing and being carried. The friction resistance of the sandy stratum is large, and the drilling torque and pull-back force will increase, which may cause the drill bit and drill rod to be easily worn. This greatly increases the difficulty of construction and the support process cannot be completed normally. The combination of high-pressure gas and slurry can greatly reduce the resistance of the sand layer. The sandy stratum has strong sedimentation and adsorption capacity, and there is abundant groundwater, which may cause the mud to thin out and increase the risk of burying drill pipes. Due to the fluidity of gravel sand and coarse sand in the mud, it is easy to form blockages in the borehole, squeezing and burying the laid pipes. In this solution, the soil is cut and destroyed by high-pressure gas, which can avoid the phenomenon of buried pipes caused by the fluidity of the sand layer.

[0030] Two channels are independently set up. Compared with the original large-diameter mixing pile construction machinery and equipment, only the gas channel and the high-pressure gas generating device need to be added, and the rest of the parts do not need to be significantly adjusted to complete the equipment combination.

[0031] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0032] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An air-slurry dual-channel mixing pile drill bit, comprising an extended drill rod (1), characterized in that: A high-pressure gas chamber sleeve (2) is sleeved on the outer side of the lower end of the extended drill rod (1), a high-pressure output valve (3) is evenly inlaid and installed on the outer side of the high-pressure gas chamber sleeve (2), a high-pressure gas delivery channel (4) is opened on the outer side of the extended drill rod (1), a high-pressure slurry delivery channel (5) is opened in the middle of the extended drill rod (1), an impact drill bit (6) is fixedly installed on the lower end of the extended drill rod (1), and a delivery connection structure (7) is provided on the upper end of the extended drill rod (1).

2. The air-slurry dual-channel mixing pile drill bit according to claim 1, characterized in that: The high-pressure gas delivery channel (4) is respectively opened around the extended drill rod (1), one end of the high-pressure gas delivery channel (4) passes through the upper end of the extended drill rod (1), and the lower end of the high-pressure gas delivery channel (4) is connected to the interior of the high-pressure gas chamber sleeve (2).

3. The air-slurry dual-channel mixing pile drill bit according to claim 1, characterized in that: The high-pressure slurry delivery channel (5) is opened at the center position of the extended drill rod (1), and output connection holes are opened around the lower end of the high-pressure slurry delivery channel (5), and the other end of the output connection hole is interconnected with the interior of the high-pressure gas chamber sleeve (2).

4. The air-slurry dual-channel mixing pile drill bit according to claim 1, characterized in that: The conveying connection structure (7) comprises a mounting nut (701), the upper end outer surface of the extended drill rod (1) is provided with a connecting thread, the mounting nut (701) and the connecting thread are rotatably engaged with each other, and a connecting bearing (702) is fixedly installed inside the mounting nut (701).

5. The air-slurry dual-channel mixing pile drill bit according to claim 4, characterized in that: A positioning and connecting box (703) is fixedly installed inside the connecting bearing (702), and an air outlet connecting ring (704) is inlaid and installed at the lower end of the positioning and connecting box (703).

6. The air-slurry dual-channel mixing pile drill bit according to claim 5, characterized in that: An annular sealing groove is provided on the outer side of the upper end of the extended drill rod (1), a sealing rubber ring (705) is fixedly mounted on the lower surface of the annular sealing groove, the high-pressure gas delivery channel (4) passes through the sealing rubber ring (705), and the gas outlet connecting ring (704) and the annular sealing groove are slidably engaged with each other.

7. The air-slurry dual-channel mixing pile drill bit according to claim 5, characterized in that: An air intake connection hole is provided on one side of the upper end of the positioning and connecting box (703), and an air flow conveying pipe (706) is embedded and installed inside the air intake connection hole.

8. The air-slurry dual-channel mixing pile drill bit according to claim 7, characterized in that: A mud input hole is provided at the center of the positioning connection box (703), a mud introduction pipe (707) is embedded in the mud input hole, and a positioning connection slot is provided at the upper end of the high-pressure slurry delivery channel (5), and the positioning connection slot and the mud introduction pipe (707) are slidably engaged with each other.

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