A pressure reducing device for down-the-hole hammer

Abstract

This invention discloses a pressure-reducing device for down-the-hole (DHH) hammers, relating to the field of geological drilling technology. It mainly includes a connector; the first end of the connector is connected to the outlet of an air compressor, and the second end is connected to the DHH hammer. A one-way outlet is provided on the side wall of the connector. Part of the gas entering at the first end of the connector can flow out of the one-way outlet and into the borehole, while the other part can be used to drive the DHH hammer during drilling. This invention can reduce the pressure of water in the borehole on the DHH hammer, ensuring drilling efficiency.

Description

Technical Field

[0001] This invention relates to the field of geological drilling technology, and in particular to a pressure reducing device for down-the-hole hammers. Background Technology

[0002] Down-the-hole (DH) hammer drilling is a highly efficient drilling technique often used in formations with low water content, such as intact bedrock, due to its high efficiency and low cost. However, when drilling to greater depths, excessive water volume and pressure within the borehole can impair the DH hammer's operation or even render it inoperable. Several solutions exist to address this: First, increasing the air compressor pressure, typically achieved by using a booster pump. The booster pump increases the output pressure of compressed air to counteract the high water pressure within the borehole, thus maintaining the DH hammer's normal operation. Second, pumping out the water from the borehole using drainage equipment to reduce water pressure. Third, switching to other drilling techniques, such as circulating mud drilling. However, these methods all have significant drawbacks; both replacing and adding equipment require considerable time for equipment transport, installation, and commissioning. Prolonged setup times lead to extended drilling interruptions, significantly reducing drilling efficiency. This not only delays project progress but also increases drilling costs due to increased equipment investment and time expenditure. Therefore, a pressure-reducing device for down-the-hole hammers is urgently needed to address these technical problems. Summary of the Invention

[0003] The purpose of this invention is to provide a pressure reducing device for down-the-hole hammers to solve the problems existing in the prior art, thereby reducing the pressure of water in the borehole on the down-the-hole hammer and ensuring drilling efficiency.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] The present invention provides a pressure reducing device for a down-the-hole hammer, including a connector. The first end of the connector is used to connect to the air outlet of an air compressor, and the second end of the connector is used to connect to the down-the-hole hammer. A one-way outlet is provided on the side wall of the connector. Part of the gas entering the first end of the connector can flow out of the one-way outlet and enter the borehole, and the other part can be used to drive the down-the-hole hammer to drill.

[0006] In some embodiments, the connector includes a first connector and a second connector, and the second connector is internally provided with an impact device for impacting the down-the-hole hammer. The first connector is provided with the one-way outlet. The second connector includes an insertion part and a sleeve part. The insertion part is fixedly disposed inside the sleeve part and extends into the inner wall of the first connector. There is a flow gap between the insertion part and the inner wall of the first connector. The sleeve part is sleeved outside the first connector, and an air outlet is provided at the connection between the sleeve part and the first connector. The air outlet communicates with the one-way outlet. A one-way valve is provided at the one-way outlet. Gas can sequentially pass through the flow gap, the one-way valve, and the air outlet to exit the first connector and enter the borehole.

[0007] In some embodiments, a sealing gasket is also included, the inner wall of the air outlet is inclined, the sealing gasket includes a fixing part and a deflecting part, the fixing part is fixedly disposed on the first connector, the deflecting part can fit against the air outlet of the one-way valve, and the gas discharged from the one-way valve can blow the deflecting part to deflect.

[0008] In some embodiments, a gas-water separation block is also included, which is provided with a plurality of spiral grooves and is rotatably connected to the inside of the first end of the first connector. The inlet of the spiral groove is located close to the first end of the first connector, and the outlet of the spiral groove is located close to the first end of the second connector.

[0009] In some embodiments, the impact device includes a piston and an elastic element, the two ends of which are fixedly connected to the piston and the inner wall of the second end of the second connector, respectively. The piston is slidably disposed in the inner cavity of the second connector, and the air entering the first end of the second connector can push the piston to press against the second end of the second connector.

[0010] In some embodiments, the impact device further includes a valve seat, which is fixedly disposed inside the first connector. The valve seat has a frustum-shaped opening inside. The piston is frustum-shaped at one end near the first connector. The piston can extend into the interior of the valve seat and fit against the inner wall of the valve seat. A sealing gasket is provided at the fitting point between the piston and the valve seat, and the sealing gasket is fixedly disposed on the valve seat.

[0011] In some embodiments, a positioning sleeve is also included. The positioning sleeve has a through hole for gas to pass through. The positioning sleeve is fixedly disposed inside the first connector and located between the gas-water separator and the valve seat, and is used to provide positioning for the valve seat.

[0012] In some embodiments, a mounting base and a washer are also included, the mounting base being fixedly disposed inside the second end of the second connector, the elastic element being fixedly connected to the mounting base, and the washer being fixedly disposed at the end of the mounting base near the first end of the second connector.

[0013] In some embodiments, a balance pin is also included, which is slidably disposed at the end of the piston away from the second joint, and the sliding direction of the balance pin is perpendicular to the movement direction of the piston.

[0014] In some embodiments, the balance pin is a cylindrical pin.

[0015] The present invention achieves the following technical effects compared to the prior art:

[0016] The pressure reduction device for down-the-hole hammer provided by this invention includes a connector. The first end of the connector is used to connect to the air outlet of an air compressor, and the second end of the connector is used to connect to the down-the-hole hammer. A one-way outlet is provided on the side wall of the connector. Part of the gas entering from the first end of the connector can flow out of the one-way outlet and enter the borehole, while the other part can be used to drive the down-the-hole hammer to drill. The discharged air mixes with the water in the borehole. The density of the water after mixing is significantly lower than that before mixing, which leads to a decrease in water pressure. At this time, the water pressure in the upper part of the borehole is small and can no longer suppress the water below. The water below will move upward and partially discharge from the borehole. The water pressure in the borehole can be significantly reduced without the need for a water pump, ensuring that the drilling efficiency is not affected. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the pressure reducing device for down-the-hole hammer in some embodiments of the present invention;

[0019] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0020] Figure 3 This is a front view of the gas-liquid separator block in some embodiments of the present invention;

[0021] Figure 4 This is a top view of the gas-liquid separator block in some embodiments of the present invention;

[0022] Figure 5This is a schematic diagram illustrating the connection between the pressure reducing device for the down-the-hole hammer and the down-the-hole hammer in some embodiments of the present invention.

[0023] In the diagram: 101-Down-the-hole hammer; 1-Second connector; 2-Helical groove; 3-Piston; 4-Valve seat; 5-Sealing gasket; 6-Limit block; 7-First connector; 8-Air-water separator; 9-Spring; 10-Positioning sleeve; 11-Spring seat; 12-Balance pin; 13-First O-ring; 14-Second O-ring; 15-One-way valve; 16-Air outlet; 17-Washer; 18-Drill hole. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The purpose of this invention is to provide a pressure reducing device for down-the-hole hammers to solve the problems existing in the prior art, thereby reducing the pressure of water in the borehole on the down-the-hole hammer and ensuring drilling efficiency.

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] like Figures 1-5As shown, this invention provides a pressure-reducing device for a down-the-hole hammer, including a connector. The first end of the connector is connected to the outlet of an air compressor, and the second end is connected to the down-the-hole hammer 101. A one-way outlet from the inside out is provided on the side wall of the connector. Part of the gas entering from the first end of the connector can flow out of the one-way outlet and into the borehole, while the other part can be used to drive the down-the-hole hammer 101 to drill. Gas is discharged into the borehole 18 from the one-way outlet on the connector. The discharged air mixes with the water in the borehole 18. The density of the mixed water is significantly lower than before mixing, resulting in a decrease in water pressure. Generally, the pressure of the air entering is lower than the water pressure at the corresponding water level, meaning the air can dilute the water in the borehole to a certain extent. At this time, the water pressure in the upper part of the borehole 18 is low and can no longer suppress the water below. The water below will move upwards and partially discharge from the borehole 18. This significantly reduces the water pressure in the borehole 18 without the need for a pump. By timely reducing the excessively high water pressure in the borehole 18, the down-the-hole hammer 101 can continue to operate normally. To prevent the down-the-hole hammer 101 from malfunctioning or operating abnormally due to water pressure issues, and to reduce drilling interruptions caused by equipment failures and adjustments, drilling work can be carried out continuously, thereby ensuring overall drilling efficiency. Furthermore, the one-way outlet design ensures unidirectional gas discharge, preventing water or other impurities in the borehole 18 from flowing back into the joint and affecting the normal operation of the device.

[0028] In some embodiments, the connector includes a first connector and a second connector, and the second connector is provided with an impact device for impacting the down-the-hole hammer 101. The first connector is provided with a one-way outlet. The second connector 1 includes an extension portion and a sleeve portion. The extension portion is fixedly disposed inside the sleeve portion and extends into the inner wall of the first connector 7. There is a flow gap between the extension portion and the inner wall of the first connector 7. The sleeve portion is sleeved outside the first connector 7, and an air outlet 16 is provided at the connection between the sleeve portion and the first connector 7. The air outlet 16 communicates with the one-way outlet. The one-way outlet includes a receiving port and a one-way valve 15. The one-way valve is disposed inside the receiving port. Gas can be discharged from the first connector 7 and enter the borehole 18 by sequentially passing through the flow gap, the one-way valve 15 and the air outlet 16. The extension portion extends into the first connector 7 and forms a flow gap, providing a dedicated channel for gas discharge. This allows for smoother gas discharge compared to structures without a specific channel, more efficiently guiding the air compressed by the air compressor towards the one-way outlet. This enhances the mixing effect with the air and water inside the borehole 18, further improving the ability to reduce water pressure. Furthermore, the size of the flow gap can be set much smaller than the interface between the second connector 1 and the first connector 7, ensuring that the majority of the gas flows into the second connector 1 to support the normal operation of the down-the-hole hammer 101, while a small portion flows into the borehole 18 to reduce water pressure. A one-way valve 15 is installed at the one-way outlet to precisely control gas discharge, allowing only gas to flow from inside the first connector 7 into the borehole 18. This effectively prevents water, impurities, or pressure from flowing back into the first connector 7 from the borehole 18, ensuring stable internal air pressure. A stable air pressure environment helps maintain the normal operation of the down-the-hole hammer 101, avoiding malfunctions caused by pressure fluctuations and improving the stability and reliability of the entire drilling system.

[0029] It should be noted that there are other ways to achieve a one-way outlet, such as directly rotating and installing a sealing plate on the outside of the receiving port. The sealing plate covers the outside of the receiving port of the first connector. The water pressure on the outside cannot open it, and the air on the inside can force open the sealing plate and be discharged into the borehole.

[0030] It should also be noted that in this embodiment, the one-way valve 15 opens entirely by air pressure; when air is introduced, the one-way valve 15 opens to release gas. Furthermore, the one-way valve 15 can also be an electromagnetic one-way valve 15, etc. The electromagnetic one-way valve 15 can actively control the opening and closing of the valve body and can be manually adjusted, thus achieving one-way gas discharge as well. It should be noted that the first connector 7 and the second connector 1 can also be directly aligned and connected, and the second connector 1 no longer extends into the first connector 7.

[0031] In some embodiments, the pressure reducing device for the down-the-hole hammer further includes a sealing gasket 5. The inner wall of the air outlet 16 is inclined. The sealing gasket 5 includes a fixing part and a deflecting part. The fixing part is fixedly mounted on the first connector 7. The deflecting part can conform to the air outlet end of the one-way valve 15, and the gas discharged from the one-way valve 15 can blow the deflecting part to conform to the inner wall of the air outlet 16. When the deflecting part conforms to the receiving port, that is, when the deflecting part conforms to the air outlet end of the one-way valve, the gas does not flow out of the one-way valve 15. When the gas flows out of the one-way valve 15, the gas impacts the deflecting part and blows the deflecting part away from the air outlet end of the one-way valve 15. The inclined inner wall of the air outlet 16 and the cooperation of the sealing gasket 5 guide the airflow direction. The gas blows the deflecting part to conform to the inclined inner wall, so that the airflow enters the borehole 18 at an incline, preventing the gas from entering the hole vertically. Due to the high gas pressure, it would blow directly onto the hole wall, affecting the safety of the hole wall.

[0032] In some embodiments, the pressure reducing device for the down-the-hole hammer further includes a gas-liquid separator 8. The gas-liquid separator 8 has multiple spiral grooves 2 located between a one-way outlet and the first end of the first connector. Gas first flows through the spiral grooves 2, exits from the spiral grooves 2, and then passes through the one-way outlet. The gas-liquid separator 8 is rotatably connected to the interior of the first end of the first connector 7, with the inlet of the spiral grooves 2 located close to the first end of the first connector 7, and the outlet of the spiral grooves 2 located close to the first end of the second connector 1. The multiple spiral grooves 2 on the gas-liquid separator 8 utilize the principle of centrifugal force to achieve efficient gas-liquid separation. Since the air compressor discharges gas containing some water, the water vapor can affect the operation of the impact device. The water-water separator 8 removes this water. When the water-containing gas mixture enters the first end of the first connector 7, the gas-water separator 8 rotates, causing the gas mixture to rotate at high speed within the spiral groove 2. The water, due to its higher density, is thrown against the groove wall and flows along it to the outlet 16, while the majority of the gas concentrates at the center of the spiral groove 2 and moves towards the outlet. This effectively separates the gas and water, improving the purity of the gas entering the impact device and ensuring the stable operation of the down-the-hole hammer 101. Furthermore, the rotating connection of the gas-water separator 8 increases the kinetic energy of the gas during the separation process. As the gas-water separator 8 rotates, the gas is accelerated within the spiral groove 2. When the separated gas enters the second connector 1 and flows towards the impact device, it possesses higher energy, enhancing the impact force of the impact device on the down-the-hole hammer 101 and improving the drilling efficiency of the drilling 18 to some extent.

[0033] In some embodiments, the impact device includes a piston 3 and an elastic element. The two ends of the elastic element are fixedly connected to the inner walls of the second end of the piston 3 and the second connector 1, respectively. The piston 3 is slidably disposed within the inner cavity of the second connector 1. Air entering from the first end of the second connector 1 can push the piston 3 to press against the second end of the second connector 1. When the air entering from the first end of the second connector 1 pushes the piston 3, the gas pressure can be directly converted into the mechanical energy of the piston 3, thereby exerting a pressing effect on the second end of the second connector 1, driving the down-the-hole hammer 101 to vibrate. The elastic element provides good buffering. During the movement of the piston 3, when encountering complex resistance or instantaneous impact within the borehole 18, the elastic element can absorb some energy, preventing damage to the piston 3 and the second connector 1 due to excessive impact force. Simultaneously, the buffering effect of the elastic element makes the movement of the piston 3 more stable, ensuring the stability of the force exerted by the impact device on the down-the-hole hammer 101, and also helping the piston 3 to reset.

[0034] In some embodiments, the impact device further includes a valve seat 4, which is fixedly disposed inside the first connector 7. The valve seat 4 has a frustum-shaped opening inside. The end of the piston 3 near the first end of the second connector 1 is a frustum-shaped piston with its small end near the large end of the valve seat opening, and its large end near the second end of the second connector. The piston 3 can extend into the interior of the valve seat 4 and fit against the frustum-shaped opening on the inner wall of the valve seat 4. A sealing gasket, preferably a first O-ring 13, is provided at the contact point between the piston 3 and the valve seat 4, and the first O-ring 13 is fixedly disposed on the valve seat 4. The frustum-shaped contact design between the valve seat 4 and the piston 3 is similar to a conical sealing structure, which inherently provides a good sealing foundation. On this basis, the first O-ring 13 fixedly disposed on the valve seat 4 further enhances the sealing effect. This double sealing guarantee effectively prevents gas leakage and ensures that the gas pressure entering the second connector 1 to drive the piston 3 is stable, providing a solid gas pressure guarantee for the efficient operation of the impact device. The presence of the first O-ring 13 not only improves the sealing performance, but also reduces the wear between the piston 3 and the valve seat 4. During the frequent movement of the piston 3, the first O-ring 13 plays a buffering and lubricating role, reducing the direct friction between the sealing valve seat 4 and the valve cone surface, avoiding sealing failure and equipment damage caused by excessive wear, thereby extending the service life of each component of the impact device.

[0035] It should be noted that a second O-ring 14 for buffering and sealing is provided at multiple locations where the valve seat 4 extends into and abuts against the first connector 7. Each second O-ring 14 is arranged along the circumference of the valve seat, and multiple second O-rings 14 are arranged along the axial direction of the valve seat.

[0036] In some embodiments, the pressure-reducing device for the down-the-hole hammer further includes a positioning sleeve 10. The positioning sleeve 10 has a through hole for gas passage. It is fixedly installed inside the first connector 7 and located between the gas-water separator 8 and the valve seat 4, providing positioning for the valve seat 4. During equipment installation, the positioning sleeve 10 provides a precise positioning reference for the valve seat 4 and reliable positioning support, ensuring the valve seat 4 maintains a stable position during operation and preventing displacement or shaking due to vibration, impact, or other factors. The stable position of the valve seat 4 ensures a tight fit with the piston 3, maintaining the normal operation of the impact device.

[0037] It should be noted that, since the valve seat 4 extends into the interior of the first connector 7 and is fixedly connected, in order to ensure the stability of the valve seat 4, a limiting block 6 can also be set on the inner wall of the first connector 7, and a corresponding contact point can be set on the valve seat 4. Specifically, the contact point can be a groove, and the limiting block 6 abuts against the groove on the valve seat 4 to prevent the valve seat 4 from shifting.

[0038] In some embodiments, the impact device further includes a mounting base and a washer. The mounting base is fixedly disposed inside the second end of the second connector, the elastic element is fixedly connected to the mounting base, and the washer is fixedly disposed at the end of the mounting base near the first end of the second connector. Specifically, the mounting base is a spring seat 11, the elastic element is a spring 9, the spring seat 11 is fixedly disposed inside the second end of the second connector 1, the spring 9 is fixedly connected to the spring seat 11 and disposed above the spring seat 11, and the washer 17 is fixedly disposed at the end of the spring seat 11 near the first end of the second connector 1. The fixed connection between the spring seat 11 and the spring 9 allows the spring 9 to play a more stable buffering role during operation. When the piston 3 is subjected to complex resistance or instantaneous impact from the borehole 18, the spring 9 distributes the force evenly through the spring seat 11, effectively absorbing energy and preventing the piston 3 and the second connector 1 from being damaged by excessive impact force, providing more reliable protection for the impact device and ensuring the continuous operation of drilling. Washer 17 is mounted on spring seat 11, and spring 9 passes through washer 17. Piston 3 can impact washer 17. When piston 3 impacts washer 17, washer 17 and spring 9 provide a dual buffering effect. Spring 9 first buffers and disperses energy, while washer 17 itself has a certain degree of elasticity, which can further absorb the impact force of piston 3, reducing the damage to the entire device caused by the instantaneous impact of piston 3, and ensuring stable operation of the equipment.

[0039] In some embodiments, the pressure-reducing device for the down-the-hole hammer further includes a cylindrical balance pin 12. The balance pin 12 is slidably disposed at the end of the piston 3 away from the second joint 1, and the sliding direction of the balance pin 12 is perpendicular to the movement direction of the piston 3. During the reciprocating motion of the piston 3, the balance pin 12 slides inside the piston 3. When a lateral force is generated, the balance pin 12 will generate an interaction force with the mating surface inside the piston 3. The direction of this interaction force is opposite to the direction of the lateral force and the magnitude is equal (according to the principle of force balance), thereby effectively canceling the lateral force. For example, when the piston 3 is subjected to a rightward lateral force, the balance pin 12 will give the piston 3 a leftward reaction force, making the resultant force of the piston 3 in the horizontal direction zero, ensuring that the piston 3 will not deviate due to the lateral force, and ensuring that the piston 3 always moves stably along the axial direction, providing a stable and continuous impact force for the impact device.

[0040] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A pressure-reducing device for a down-the-hole hammer, characterized in that: The device includes a connector. The first end of the connector is used to connect to the outlet of an air compressor, and the second end is used to connect to a down-the-hole hammer. A one-way outlet is provided on the side wall of the connector. Part of the gas entering from the first end of the connector can flow out of the one-way outlet and enter the borehole, while the other part can be used to drive the down-the-hole hammer. The connector includes a first connector and a second connector. The second connector has an impact device inside for impacting the down-the-hole hammer. The first connector has the one-way outlet. The second connector includes an insertion part and a sleeve part. The insertion part is fixedly disposed inside the sleeve part and extends into the inner wall of the first connector. A flow gap exists between the insertion part and the inner wall of the first connector. The sleeve part is sleeved outside the first connector, and an air outlet is provided at the connection between the sleeve part and the first connector. The air outlet communicates with the one-way outlet. A one-way valve is provided at the one-way outlet. Gas can sequentially pass through the flow gap, the one-way valve, and the air outlet to exit the first connector and enter the borehole.

2. The pressure-reducing device for a down-the-hole hammer according to claim 1, characterized in that: It also includes a sealing gasket, the inner wall of the air outlet is inclined, the sealing gasket includes a fixing part and a deflecting part, the fixing part is fixedly disposed on the first connector, the deflecting part can fit against the air outlet of the one-way valve, and the gas discharged from the one-way valve can blow the deflecting part to deflect.

3. The pressure-reducing device for a down-the-hole hammer according to claim 1, characterized in that: It also includes a gas-water separator block, which is provided with multiple spiral grooves and is rotatably connected to the inside of the first end of the first connector. The inlet of the spiral groove is located close to the first end of the first connector, and the outlet of the spiral groove is located close to the first end of the second connector.

4. The pressure reducing device for a down-the-hole hammer according to claim 3, characterized in that: The impact device includes a piston and an elastic element. The two ends of the elastic element are fixedly connected to the piston and the inner wall of the second end of the second connector, respectively. The piston is slidably disposed in the inner cavity of the second connector. The air entering the first end of the second connector can push the piston to press against the second end of the second connector.

5. The pressure-reducing device for a down-the-hole hammer according to claim 4, characterized in that: The impact device also includes a valve seat, which is fixedly disposed inside the first connector. The valve seat has a frustum-shaped opening inside. The piston is frustum-shaped at one end near the first connector. The piston can extend into the valve seat and fit against the inner wall of the valve seat. A sealing gasket is provided at the fitting point between the piston and the valve seat, and the sealing gasket is fixedly disposed on the valve seat.

6. The pressure-reducing device for a down-the-hole hammer according to claim 5, characterized in that: It also includes a positioning sleeve, which has a through hole for gas to pass through. The positioning sleeve is fixedly installed inside the first connector and is located between the gas-water separator and the valve seat, and is used to provide positioning for the valve seat.

7. The pressure reducing device for a down-the-hole hammer according to claim 4, characterized in that: It also includes a mounting base and a washer. The mounting base is fixedly disposed inside the second end of the second connector. The elastic element is fixedly connected to the mounting base. The washer is fixedly disposed at the end of the mounting base near the first end of the second connector.

8. The pressure reducing device for a down-the-hole hammer according to claim 4, characterized in that: It also includes a balance pin, which is slidably disposed at the end of the piston away from the second joint, and the sliding direction of the balance pin is perpendicular to the movement direction of the piston.

9. The pressure-reducing device for a down-the-hole hammer according to claim 8, characterized in that: The balance pin is a cylindrical pin.

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