Hydraulic percussion combined drill bit and drilling rig

Abstract

The utility model relates to hydraulic combined drill bit technical field especially relates to a kind of hydraulic impact combined drill bit and drilling machine, comprising: shield body;At least one hydraulic impact hammer, setting in shield body and reciprocating along the central axis direction of shield body;Cutterhead, coaxial setting is in the lower part of shield body;Threaded sleeve, with hydraulic impact hammer coaxial embedding in cutterhead;At least one impact drill bit, rotation is clamped in threaded sleeve and reciprocating along the central axis direction of threaded sleeve;Air chamber, at least the region where the impact end of mutual contact of hydraulic impact hammer and impact drill bit is wrapped, the internal pressure of air chamber is greater than the external pressure of air chamber.The utility model impact drill bit under the combined action of axial impact force of hydraulic impact hammer and combined drill bit rotary torque carries out axial rotation broken construction, more smoothly punch round, until pile hole construction is completed.Meanwhile, by double air chamber positive pressure sealing system, and supplemented by multistage dynamic and static sealing structure, provide clean working environment for impact area.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic combination drill bit technology, and in particular to a hydraulic impact combination drill bit and drilling machine. Background Technology

[0002] In the field of piling machinery, there are various methods for manufacturing and applying drill bits to drill through rock formations. Currently, the most widely used drill bit on the market is the rotary drilling rig bit. This bit is installed at the end of a freely extendable drill rod, has a cylindrical structure, and is equipped with alloy cutting teeth and a movable bottom cap. It exhibits significant drilling efficiency in sandy soil, gravel, and other strata. Additionally, auger drill bits and other types are also well-suited for these types of formations. However, when these drill bits are used in hard rock formations, their drilling efficiency decreases significantly.

[0003] In the past, both domestically and internationally, a combined pneumatic down-the-hole hammer was used to solve the problem of driving piles into rock. Since the working power medium of the pneumatic down-the-hole hammer is air, after the working medium drives the pneumatic hammer core and drill bit during operation, the air carries the drill cuttings out of the hole at the bottom of the hole and is not recovered. Therefore, when using the pneumatic combined down-the-hole hammer drill bit, the impactor and the impact drill bit below the pneumatic impactor are connected together by the threaded sleeve outside the impact drill bit to form a complete pneumatic impact unit. Then, the pneumatic impact unit is locked and fixed under the bottom plate and top plate of the pneumatic down-the-hole hammer impact unit for use.

[0004] Although the pneumatic combined down-the-hole hammer has the advantages of simple structure and convenient installation, it still has obvious limitations in practical engineering applications: First, it continuously emits a large amount of gas during operation, which can easily cause serious dust pollution and pollute the construction environment; Second, due to the lack of mud circulation for wall protection, the hole wall stability is poor when drilling in sandy soil or loose strata, which can easily lead to hole collapse accidents.

[0005] In traditional underwater or wet borehole operations, the impact zone of the impactor and drill bit is typically exposed directly or indirectly to external media (such as mud or seawater) rich in silt, rock cuttings, and corrosive ions. This exposure leads to a severe reduction in energy transfer efficiency. Specifically, water and mud, as incompressible or low-compressible fluids, infiltrate the impact contact surface at the moment of impact, forming a "liquid cushion" effect that significantly buffers and absorbs the impact stress wave. This results in a substantial reduction in the actual impact energy acting on the rock, severely weakening the efficiency of rock breaking by impact.

[0006] In existing technologies, although some attempts have been made to use simple isolation measures such as sealing rings and dust covers, these methods are not reliable enough in dynamic impact conditions with high pressure and high abrasive concentration underwater, and are difficult to effectively remove the intruded medium, thus failing to create a "clean space" for the impact area. Utility Model Content

[0007] To address at least one of the aforementioned technical problems, this utility model proposes a hydraulic impact combined drill bit and drilling rig to solve the problems of pollution to the construction environment, poor borehole wall stability, and reduced impact stress waves caused by water and other external media in the impact area.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of this utility model proposes a hydraulic impact combined drill bit, comprising: shield; At least one hydraulic impact hammer is disposed inside the shield body and reciprocates along the central axis of the shield body; The cutterhead is coaxially disposed at the lower part of the shield body; A threaded sleeve is coaxially embedded in the cutter head with the hydraulic impact hammer, and the threaded sleeve has a stepped receiving cavity with openings at both ends; At least one impact drill bit is coaxially disposed at the lower part of the hydraulic impact hammer. The impact drill bit is rotatably locked inside the threaded sleeve and reciprocates along the central axis of the threaded sleeve. The impact drill bit performs axial rotational crushing construction under the combined action of the axial impact force of the hydraulic impact hammer and the rotational torque of the combined drill bit. An air chamber, which at least covers the area where the hydraulic impact hammer and the impact drill bit are in contact, has an internal pressure greater than the external pressure to prevent external media from entering the air chamber.

[0009] Preferably, the combined drill bit further includes two interlocking semi-circular flanges, and the upper part of the impact drill bit is provided with a snap-fit ​​section along its axial direction. The two semi-circular flanges are sleeved on the snap-fit ​​section, and the height of the semi-circular flanges is less than the length of the snap-fit ​​section, so as to facilitate the reciprocating movement of the impact drill bit along the threaded sleeve.

[0010] Preferably, the air chamber comprises: The first air chamber is located inside the shield body and the cutterhead. The first air chamber surrounds the area where the hydraulic impact hammer and the impact drill bit are in contact. The pressure of the first air chamber is greater than the external pressure, which is used to prevent external media from entering the first air chamber and maintain the cleanliness of the area where the impact end is located. The second air chamber is disposed inside the cutter head and located below the first air chamber. The second air chamber at least partially encloses the impact drill bit located inside the cutter head, and the pressure in the second air chamber is greater than the pressure in the working area below the cutter head.

[0011] Preferably, the first air chamber is provided with a first air inlet communicating with an air source and a first air outlet located below the first air inlet for exhausting air, and the first air inlet and the first air outlet are located inside the shield body; The second air chamber is provided with a second air inlet that is connected to an air source, and the second air inlet is located inside the cutter head.

[0012] Preferably, a first sealing element is provided in the first air chamber along the central axis of the impact drill bit, and the upper part of the impact drill bit is slidably disposed relative to the first sealing element. The first sealing element isolates the first air chamber and the second air chamber into relatively independent air chambers.

[0013] Preferably, a second sealing element is embedded in the inner wall of the threaded outer sleeve, and a third sealing element is provided between the outer wall of the threaded outer sleeve and the cutter head.

[0014] Preferably, the impact drill bits located on the outer ring of the cutter head are arranged in a circular array around the center of the cutter head.

[0015] Preferably, the number of impact drill bits located on the outer ring of the cutterhead is 2-15.

[0016] Preferably, the combined drill bit further includes an oil collector and a drill rod arranged sequentially on the upper part of the shield body, and a central rotary joint is sleeved on the outside of the drill rod.

[0017] The second aspect of this utility model provides a drilling machine having a hydraulic impact combination drill bit as described in the first aspect.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. This utility model features an impact drill bit that can rotate relative to the cutterhead and the shield. Specifically, the hydraulic impact drill bit, driven by the power head on the ground drilling rig, rotates as a whole at the bottom of the hole, gradually impacting and breaking up all the rock on the entire cross-section of the hole to form a pile hole. When the hydraulic impact drill bit rotates and drills, the outermost alloy drill bit at the bottom of the cutterhead rotates under the action of rotational torsional force, along with the rotation of the overall hydraulic combined down-the-hole drill bit, thereby enabling the hole to be drilled more smoothly until the pile hole construction is completed.

[0019] Meanwhile, by setting up air chambers inside the shield and cutterhead to maintain a pressure higher than that of the external environment (e.g., underwater environment), an airtight barrier is formed to actively repel sewage and / or silt. This effectively ensures that the impact areas of the hydraulic impact hammer and the impact drill bit are completely enveloped in a relatively clean and dry working environment. Because the hydraulic impact hammer avoids the buffering effect of water when striking the impact drill bit, the impact stress wave of the hydraulic impact hammer can be transmitted to the impact drill bit with near-loss, improving the efficiency of energy transfer. At the same time, by preventing silt from entering the impact area, the impact surfaces of the hydraulic impact hammer and the impact drill bit are relatively clean, reducing wear caused by silt.

[0020] 2. This utility model, through the redundant sealing design of the first and second air chambers, ensures that in extreme cases, if the second air chamber near the working face experiences pressure fluctuations or slight leakage, causing water or sediment from the working environment to enter the first air chamber, the positive pressure environment of the second air chamber makes it difficult for water or sediment to enter the second air chamber, thereby further improving the reliability of the drill bit in the clean environment of the underwater operation area. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a hydraulic impact combined drill bit; Figure 2 This is a schematic diagram of the impact unit structure of a hydraulic impact combined drill bit; Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 This is an assembly drawing of the threaded sleeve and the impact drill bit in this utility model; Figure 5 This is a top view of the semi-circular flange in this utility model; Figure 6 This is a schematic diagram of the drill bit body in this utility model; Figure 7 This is a bottom view of the cutter head in this utility model; In the diagram: 10, shield body; 20, cutterhead; 30, hydraulic impact hammer; 40, impact drill bit; 401, snap-fit ​​section; 402, cutting section; 50, air chamber; 501, first air chamber; 5011, first air inlet; 5012, first air outlet; 502, second air chamber; 5021, second air inlet; 60, semi-circular flange; 70, first seal; 80, threaded sleeve; 801, second seal; 802, third seal; 90, oil collector; 100, drill rod; 110, central rotary joint. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions in this utility model, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments in this utility model, and not all of the embodiments in this utility model.

[0023] Example 1 Please refer to Figures 1-7 As shown, a hydraulic impact combination drill bit includes: Shield 10; At least one hydraulic impact hammer 30 is disposed inside the shield body 10 and reciprocates along the central axis of the shield body 10; The cutterhead 20 is coaxially positioned at the lower part of the shield body 10; The threaded sleeve 80 is coaxially embedded in the cutter head 20 with the hydraulic impact hammer 30, and the threaded sleeve 80 has a stepped receiving cavity with openings at both ends. At least one impact drill bit 40 is coaxially disposed at the lower part of the hydraulic impact hammer 30. The impact drill bit 40 is rotatably locked inside the threaded sleeve 80 and reciprocates along the central axis of the threaded sleeve 80. The impact drill bit 40 performs axial rotational crushing construction under the combined action of the axial impact force of the hydraulic impact hammer 30 and the rotational torque of the combined drill bit. The air chamber 50 at least covers the area where the hydraulic impact hammer 30 and the impact drill bit 40 are in contact. The internal pressure of the air chamber 50 is greater than the external pressure of the air chamber 50 to prevent external media from entering the air chamber 50.

[0024] In this embodiment, an impact drill bit 40 is set up that can rotate relative to the cutterhead 20 and the shield 10. Specifically, the hydraulic impact combined drill bit is driven by the power head on the ground drilling rig and rotates as a whole at the bottom of the hole, gradually impacting and breaking up all the rock on the entire cross section of the hole to form a pile hole. When the hydraulic impact combined drill bit is rotating and drilling, the outermost alloy drill bit at the bottom of the cutterhead 20 rotates under the action of rotational torsion force, along with the rotation of the overall hydraulic combined down-the-hole drill bit, thereby achieving a smoother drilling of the hole until the pile hole construction is completed.

[0025] Meanwhile, by setting up air chambers 50 inside the shield body 10 and cutterhead 20 to maintain a pressure higher than that of the external environment (e.g., underwater environment), an airtight barrier is formed to actively repel sewage and / or silt. This effectively ensures that the impact areas of the hydraulic impact hammer 30 and the impact drill bit 40 are completely enveloped in a relatively clean and dry working environment. Because the hydraulic impact hammer 30 avoids the buffering effect of water when striking the impact drill bit 40, the impact stress wave of the hydraulic impact hammer 30 can be transmitted to the impact drill bit 40 with near-loss, improving the efficiency of energy transfer. At the same time, by preventing silt from entering the impact area, the impact surfaces of the hydraulic impact hammer 30 and the impact drill bit 40 are relatively clean, reducing wear caused by silt.

[0026] Please refer to Figure 4 , Figure 5 and Figure 6 As shown, in a preferred embodiment, the combined drill bit also includes two interlocking semi-circular flanges 60. The upper part of the impact drill bit 40 is provided with a snap-fit ​​section 401 along its axial direction. The two semi-circular flanges 60 are sleeved on the snap-fit ​​section 401. The height of the semi-circular flanges 60 is less than the length of the snap-fit ​​section 401, so that the impact drill bit 40 can reciprocate along the threaded sleeve 80.

[0027] In this embodiment, by setting up interlocking semi-circular flanges 60, after the threaded outer sleeve 80 is fitted onto the outside of the impact drill bit 40, the flange can be spliced ​​and assembled through the gap between the impact drill bit 40 and the threaded outer sleeve 80. The semi-circular flange 60 is fitted onto the snap-fit ​​section 401 to achieve the movable snap-fit ​​of the threaded outer sleeve 80 onto the impact drill bit 40.

[0028] Meanwhile, when the drill bit wears out, the semi-circular flange 60 can be removed through the gap, allowing for the disassembly of the threaded outer sleeve 80 from the impact drill bit 40. Therefore, the disassembly and assembly efficiency of the impact drill bit 40 is effectively improved.

[0029] It should be noted that in this embodiment, the snap-fit ​​section 401 is formed by a boss spaced apart on the upper part of the impact drill bit 40. This ensures that the rod part of the upper part of the impact drill bit 40 that contacts the hydraulic impact hammer 30 has a sufficient diameter to meet the strength requirements of the impact drill bit 40.

[0030] In this embodiment, the height of the semicircular flange 60 is less than the length of the snap-fit ​​section 401, so that the impact drill bit 40, under the limiting action of the semicircular flange 60, has a certain axial reciprocating stroke within the length range of the snap-fit ​​section 401.

[0031] Meanwhile, the spliced ​​semi-circular flange 60 is embedded between the threaded sleeve 80 and the impact drill bit 40, which provides radial and axial constraints on the impact drill bit 40. This allows axial movement while ensuring the radial stability of the impact drill bit 40, thereby ensuring that the hydraulic impact hammer 30 and the upper part of the impact drill bit 40 are directly impacted.

[0032] Please refer to Figure 2 and Figure 4 As shown, in a preferred embodiment, the air chamber 50 includes: The first air chamber 501 is located inside the shield body 10 and the cutter head 20. The first air chamber 501 encloses the area where the hydraulic impact hammer 30 and the impact drill bit 40 are in contact. The pressure of the first air chamber 501 is greater than the external pressure, which is used to prevent external media from entering the first air chamber 501 and maintain the cleanliness of the area where the impact end is located. The second air chamber 502 is disposed inside the cutter head 20 and located below the first air chamber 501. The second air chamber 502 at least partially encloses the impact drill bit 40 located inside the cutter head 20. The pressure of the second air chamber 502 is greater than the pressure of the working area at the lower part of the cutter head 20. Understandably, the redundant sealing design of the first air chamber 501 and the second air chamber 502 means that in extreme cases, if the second air chamber 502, which is close to the working face, experiences pressure fluctuations or slight leakage, water or sediment from the working environment may enter the first air chamber 501. Under the positive pressure environment of the second air chamber 502, it is difficult for external media such as water or sediment to enter the second air chamber 502, thereby further improving the reliability of the drill bit in the clean environment of the underwater operation area.

[0033] In addition, when a large amount of water is discharged from the first air chamber 501 to the ground, it indicates that the sealing performance of the drill bit may be reduced. The drill bit can be inspected at an appropriate time to ensure that the drilling work can proceed smoothly.

[0034] It is understandable that the second air chamber 502 is not provided with a separate air outlet, mainly because there is an inevitable small gap between the rod and the threaded sleeve below. The gas is discharged from the small gap on the periphery, which can form an air curtain seal and prevent water from entering the second air chamber 502 from the small gap to a certain extent.

[0035] Please refer to Figure 2 As shown, in order to facilitate the delivery of gas into the air chamber, in this embodiment, the first air chamber 501 is provided with a first air inlet 5011 connected to the gas source and a first air outlet 5012 located below the first air inlet 5011 for exhausting gas. The first air inlet 5011 and the first air outlet 5012 are located inside the shield body 10; the second air chamber 502 is provided with a second air inlet 5021 connected to the gas source. The second air inlet 5021 is located inside the cutter head 20.

[0036] Please refer to Figure 2 As shown, in order to improve the sealing performance of the impact drill bit 40, a first sealing element 70 is provided in the first air chamber 501 along the central axis of the impact drill bit 40. The upper part of the impact drill bit 40 is slidably disposed relative to the first sealing element 70, thereby isolating the first air chamber 501 and the second air chamber 501 into relatively independent air chambers.

[0037] It is understandable that during dynamic movement, the upper part of the impact drill bit 40 (the rod portion of the impact drill bit 40) may bring external media (such as water or mud) into the first air chamber 502. By providing a first seal 70 within the first air chamber 501, the rod portion of the impact drill bit 40 is physically divided into two working areas: a smooth section that directly impacts the hydraulic impact hammer 30 (located within the first air chamber 501) and a lower section located outside the first air chamber 50 that comes into contact with more impurities. This effectively prevents the brought-in external media from directly entering the first air chamber 501, further improving the reliability of maintaining the cleanliness of the first air chamber 501 and ensuring the cleanliness of the impact surface where the hydraulic impact hammer 30 contacts the impact drill bit 40. In this embodiment, the first seal 70 is cylindrical.

[0038] Please refer to Figure 2 and Figure 3 As shown, in a preferred embodiment, a second sealing element 801 is embedded in the inner wall of the threaded sleeve 80, and a third sealing element 802 is provided between the outer wall of the threaded sleeve 80 and the cutter head 20.

[0039] Understandably, the threaded sleeve 80 provides a long-stroke mechanical guide for the impact drill bit 40, ensuring its linear motion and thus guaranteeing the accuracy of the impact between the hydraulic impact hammer 30 and the impact drill bit 40, and ensuring efficient transmission of impact force. Simultaneously, the threaded sleeve 80 effectively prevents direct contact between the impact drill bit 40 and the cutter head 20, avoiding potential wear of the cutter head 20 over long-term use. The replaceability of the threaded sleeve 80 facilitates maintenance and improves the overall service life of the drill bit.

[0040] Simultaneously, a dynamic seal is achieved between the impact drill bit 40 and the threaded outer sleeve 80 through a second sealing element 801 (such as a Step seal or a Glyd ring), and a static seal is achieved between the threaded outer sleeve 80 and the mounting hole of the cutter head 20 through a third sealing element 802 (such as an O-ring). This effectively prevents high-pressure gas or media from the external working environment from directly entering the second gas chamber 502 through the gap between the threaded outer sleeve 80 and the mounting hole of the cutter head 20.

[0041] Please refer to Figure 7 As shown, in this embodiment, several impact drill bits 40 located on the outer ring of the cutterhead 20 are arranged in a circular array around the center of the cutterhead 20. The number of impact drill bits 40 located on the outer ring of the cutterhead 20 is 2-15, preferably 6. Obviously, the number of impact drill bits 40 can be selected according to actual construction needs, and this application does not limit it.

[0042] Understandably, when the fixed outer ring cutting section 402 is rotating and excavating, its cutting angle is fixed relative to the rock strata. When encountering rock strata or gravel with uneven hardness, it is prone to jamming and overload. The tool may be "jawed" by hard points or cracks, resulting in a sudden increase in torque, which may cause equipment overload or damage. At the same time, the continuous friction at the fixed contact point causes severe wear on one side of the tool, resulting in uneven wear and premature failure, shortening the service life of the drill bit.

[0043] In this embodiment, the rotatable cutting part 402 can rotate when it encounters resistance, automatically adjusting the contact angle between its cutting edge and the rock layer to find the rock-breaking position and posture with the least resistance. At the same time, cutting is performed at multiple contact points, so that the entire cutting part 402 participates in the cutting action, and the total wear can be evenly distributed, improving the overall service life of the cutting part 402.

[0044] Meanwhile, the uniformly distributed drill bit in a ring ensures that the load is balanced on the circumference of the cutter head 20, guaranteeing that each cutting part 402 bears a basically the same load. When the cutter head 20 rotates, the dynamic balance is good and there will be no obvious eccentric vibration.

[0045] It should be noted that since the force that drives the percussion drill bit to rotate comes from the resistance of the surrounding rock wall, the direction of rotation of the percussion drill bit is opposite to the direction of rotation of the cutterhead and the shield.

[0046] Please refer to Figure 1 As shown, the combined drill bit also includes an oil collector 90 and a drill rod 100 arranged sequentially on the upper part of the shield body 10, and a central rotary joint 110 is sleeved on the outside of the drill rod 100.

[0047] It should be noted that during drill bit operation, the cutterhead 20 and shield 10 need to rotate for cutting, while the internal hydraulic impact hammer 30 requires continuous high-pressure oil drive. The drill rod 100, connecting the drill bit to the surface platform, also rotates with the entire drill string or remains fixed. The central rotary joint 110 allows relative rotation between the drill rod 100 (or housing) and the hydraulic lines inside the drill bit, while maintaining continuous and leak-free high-pressure hydraulic oil supply.

[0048] The oil collector 90, as a cavity or collection device installed on the upper part of the shield 10, typically has an internal pressure lower than the external water pressure (or is designed to create a negative pressure). It can actively collect and gather any possible leaking oil, and guide it back to the oil treatment system or a dedicated container on the surface platform through a dedicated circuit. By monitoring the amount of oil recovered by the oil collector 90, the health status of the core seals of the hydraulic system can be indirectly assessed, enabling predictive maintenance.

[0049] The structure and working principle of the conventional components in this embodiment are existing technologies and will not be described in detail here.

[0050] This application utilizes a dual-chamber positive pressure sealing system, supplemented by multi-stage dynamic and static sealing structures, to provide a protected, clean working environment for the high-load moving parts of the underwater hydraulic impact drill bit 40. This fundamentally solves the problems of efficiency reduction, accelerated wear, and poor reliability caused by water and sand intrusion in traditional underwater drilling tools.

[0051] Example 2 This embodiment provides a drilling rig with the hydraulic impact combined drill bit of Embodiment 1. It is understood that by carrying a drill bit that rotates with the cutterhead and shield, the drilled hole can meet the roundness and quality requirements of the construction; simultaneously, by carrying a drill bit with a double-chamber seal, underwater tunneling operations can be completed efficiently. The type of drilling rig in this application is not limited, such as tracked drilling rigs, platform-fixed drilling rigs, etc.

[0052] The above description is a specific implementation of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A hydraulic impact combination drill bit, characterized in that, include: shield(10); At least one hydraulic impact hammer (30) is disposed inside the shield body (10) and reciprocates along the central axis of the shield body (10); The cutter head (20) is coaxially disposed at the lower part of the shield body (10); The threaded sleeve (80) is coaxially embedded in the cutter head (20) with the hydraulic impact hammer (30), and the threaded sleeve (80) has a stepped receiving cavity with openings at both ends; At least one impact drill bit (40) is coaxially disposed at the lower part of the hydraulic impact hammer (30). The impact drill bit (40) is rotatably locked inside the threaded sleeve (80) and reciprocates along the central axis of the threaded sleeve (80). The impact drill bit (40) performs axial rotational impact crushing construction under the combined action of the axial impact force of the hydraulic impact hammer (30) and the rotational torque of the combined drill bit. An air chamber (50) at least covers the area where the hydraulic impact hammer (30) and the impact drill bit (40) are in contact. The internal pressure of the air chamber (50) is greater than the external pressure of the air chamber (50) to prevent external media from entering the air chamber (50).

2. The hydraulic impact combined drill bit according to claim 1, characterized in that, The combined drill bit also includes two interlocking semi-circular flanges (60). The upper part of the impact drill bit (40) is provided with a snap-fit ​​section (401) along its axial direction. The two semi-circular flanges (60) are sleeved on the snap-fit ​​section (401). The height of the semi-circular flanges (60) is less than the length of the snap-fit ​​section (401) so that the impact drill bit (40) can reciprocate along the threaded sleeve (80).

3. The hydraulic impact combined drill bit according to claim 1, characterized in that, The air chamber (50) includes: The first air chamber (501) is disposed in the shield body (10) and the cutter head (20). The first air chamber (501) encloses the area where the hydraulic impact hammer (30) and the impact drill bit (40) are in contact. The pressure of the first air chamber (501) is greater than the external pressure, which is used to prevent external media from entering the first air chamber (501) and maintain the cleanliness of the area where the impact end is located. The second air chamber (502) is disposed inside the cutter head (20) and located below the first air chamber (501). The second air chamber (502) at least partially encloses the impact drill bit (40) located inside the cutter head (20). The pressure of the second air chamber (502) is greater than the pressure of the working area at the lower part of the cutter head (20).

4. The hydraulic impact combination drill bit according to claim 3, characterized in that, The first air chamber (501) is provided with a first air inlet (5011) connected to an air source and a first air outlet (5012) located below the first air inlet (5011) for exhausting air. The first air inlet (5011) and the first air outlet (5012) are located inside the shield body (10). The second air chamber (502) is provided with a second air inlet (5021) connected to the air source, and the second air inlet (5021) is located inside the cutter head (20).

5. The hydraulic impact combination drill bit according to claim 3, characterized in that, A first sealing element (70) is provided in the first air chamber (501) along the central axis of the impact drill bit (40). The upper part of the impact drill bit (40) is slidably disposed relative to the first sealing element (70). The first sealing element (70) isolates the first air chamber (501) and the second air chamber (502) into relatively independent air chambers.

6. The hydraulic impact combined drill bit according to claim 1, characterized in that, The inner wall of the threaded sleeve (80) is provided with a second sealing element (801), and a third sealing element (802) is provided between the outer wall of the threaded sleeve (80) and the cutter head (20).

7. The hydraulic impact combination drill bit according to claim 1, characterized in that, The impact drill bits (40) located on the outer ring of the cutter head (20) are arranged in a ring array around the center of the cutter head (20).

8. The hydraulic impact combination drill bit according to claim 5, characterized in that, The number of impact drill bits (40) located on the outer ring of the cutter head (20) is 2-15.

9. The hydraulic impact combination drill bit according to any one of claims 1-8, characterized in that, The combined drill bit also includes an oil collector (90) and a drill rod (100) arranged sequentially on the upper part of the shield body (10), and a central rotary joint (110) is sleeved on the outside of the drill rod (100).

10. A drilling rig, characterized in that, Includes the hydraulic impact combination drill bit as described in any one of claims 1-9.

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