Drill rod for pile driver

Abstract

A drill rod for a pile driver comprises a drill rod body (7), a first joint (1) and a second joint (2) connected to the two ends of the drill rod body (7), wherein the first and second joints (1, 2) are respectively provided with a first through hole (100) and a second through hole (200), wherein the first joint (1) can be plugged into the second joint (2), and after plugging, the first and second through holes are connected and located at the plugging position of the first and second joints (1, 2); and further comprises a connecting sleeve (4) and at least two sealing members (3), wherein the connecting sleeve (4) is sleeved on the first joint (1) and has a connecting portion for the second joint (2) to be inserted and detachably connected to the second joint (2); and the sealing member (3) is used to seal the connecting sleeve (4) and the first and second joints (1, 2). Compared with the prior art, the drill rod of the present invention is easy to extend and can also prevent slurry leakage at the connection.

Description

Technical Field

[0001] The invention belongs to the technical field of pile drivers for construction, and in particular relates to a drill rod for a pile driver. Background Art

[0002] A pile driver is a mechanical device that can drive a drill bit into the ground to break rock and soil. While the drill bit is drilling holes, grouting is used to improve the soil. The improved soil can be used to form mixing piles, composite piles, etc.

[0003] The pile driver includes multiple sections of drill rods and drill bits. The drill rods and drill bits are axially connected with a conveying channel for concrete slurry to pass through. When the drill bit drills to a certain depth, if the drill rod is not long enough, it is necessary to increase or extend the drill rod to extend the drill rod before drilling further. Therefore, in order to ensure normal grouting and drilling operations, the drill rod extension technology is crucial. In the prior art, there are two ways to extend the drill rod: 1. Telescopic connection; 2. Pin connection.

[0004] For the pin-type connection, please refer to the invention patent "Material Conveying Pipe Mechanism of Power-Down Drill Pipe" (authorization announcement number CN106351216B) with application number CN201610938624.7. The disclosed mechanism includes a length adjustment rod, a power mechanism and a drill rod from top to bottom. The power mechanism is drivingly connected to the drill rod and can drive the drill rod to rotate circumferentially; the power mechanism and the length adjustment rod are connected by a plug-in connection structure, which includes a first connection block and a second connection block respectively screwed and fixed to the power mechanism and the length adjustment rod, the first connection block is inserted into the second connection block, the first connection block and the second connection block are fixedly connected by a pin connection structure, and when the first connection block and the second connection block are fixedly connected, a hollow insertion channel is formed in the middle of the plug-in connection structure. The pin connection structure includes a first pin hole located on the first connecting block and a second pin hole located on the second connecting block. When the first connecting block is inserted into the second connecting block, rotating the first connecting block or the second connecting block can make the positions of the first pin hole and the second pin hole correspond to each other, and the pin bolt is inserted into the first pin hole from the outside of the second pin hole to pin the first connecting block and the second connecting block together.

[0005] The plug-in connection structure in the above patent, that is, the joint can realize the connection and disassembly of multiple length adjustment rods, so as to facilitate the adjustment of the length of the length adjustment rod. However, there are the following disadvantages: 1. Since the joint is threadedly connected to the length adjustment rod, it is difficult to align the pin hole on the joint; 2. The pin hole and the pin require high precision; 3. It is difficult to align the joints on the two length adjustment rods; 4. The length adjustment rod is a hollow structure, and its wall thickness is generally thin. Since the joint is threadedly connected to the length adjustment rod, it is necessary to open an internal thread on the length adjustment rod, which makes the wall thickness of the connection between the length adjustment rod and the joint thinner and reduces the connection strength; 5. Since the joint is threadedly connected to the length adjustment rod, the shape of the connection between the joint and the length adjustment rod must be limited to a circle, so there are high requirements for shape and processing accuracy; 6. Leakage may occur at the pin; 7. When the connection structure is used for a rotary pile driver, shearing will occur at the pin, resulting in the pin breaking.

[0006] For telescopic connection, please refer to the invention patent application "Telescopic Drill Rod" with application number CN201610941633.1 (application publication number CN106401464A). The drill rod disclosed therein includes a drill rod mechanism and a drill bit mechanism fixed at the end of the drill rod mechanism. The drill rod mechanism can reciprocate along the axial direction to change the length of the drill rod mechanism, thereby forming a telescopic drill rod, which can automatically drill downward without adding external force, reducing the time of connecting the drill rod, and is convenient and quick to use. However, the drill rod structure has the following problems: the sealing of each telescopic drill rod connection is poor, and the telescopic section is large in volume, the amount of soil extrusion is large, it is difficult to extend it underground, and the resistance is large. Summary of the invention

[0007] The first technical problem to be solved by the present invention is to provide a drill rod for a pile driver which is convenient for extending the drill rod and can prevent leakage of slurry at the connection point, etc., in view of the current status of the prior art.

[0008] The second technical problem to be solved by the present invention is to provide a drill rod for a pile driver with good sealing between the first and second joints to further prevent slurry leakage in view of the current status of the prior art.

[0009] The third technical problem to be solved by the present invention is to provide a drill rod for a pile driver with high connection strength between a joint and a drill rod body in view of the current status of the prior art.

[0010] The technical solution adopted by the present invention to solve the above technical problems is: a drill rod for a pile driver, comprising a drill rod body, a first joint and a second joint connected to the two ends of the drill rod body, the first joint and the second joint are respectively provided with a first through hole and a second through hole connected to a pipe in the drill rod body, the first joint can be plugged into the second joint, and after plugging, the first through hole and the second through hole are connected and located at the plugging position of the first and second joints;

[0011] It also includes a connecting sleeve and at least one sealing member. The connecting sleeve is sleeved on the first joint and has a connecting portion into which the second joint can be inserted and detachably connected to the second joint. The sealing member is used to ensure sealing cooperation between the connecting sleeve and the first joint and the second joint.

[0012] In order to improve the sealing performance between the first and second joints, the improvement is that the first joint and the second joint are plugged into the plug through the jack, and the jack has a first plugging surface with a diameter gradually reduced along the plugging direction, and the plug has a second plugging surface matched with the first plugging surface. When the first joint is plugged into the second joint, there is a gap between the opposite end faces of the first joint and the second joint. The first plugging surface with a diameter gradually reduced has a guiding function to facilitate the rapid insertion of the plug; and the abutment and matching of the first plugging surface with a diameter gradually reduced and the second plugging surface can improve the sealing performance; and the existence of the gap allows the second plugging surface on the plug to further abut against the first plugging surface, further improving the sealing match between the two.

[0013] In order to further improve the sealing performance between the first plug-in surface and the second plug-in surface, it is further improved that the sealing member includes a third sealing ring, and the third sealing ring is arranged between the first plug-in surface and the second plug-in surface to make the two seal and cooperate to achieve a compact seal.

[0014] In order to leave space for the compaction and deformation of the third sealing ring, it is further improved that when the first plug-in surface and the second plug-in surface are in a sealed fit state, the height of the gap is ≥1 mm.

[0015] In the above scheme, in order to prevent external dust and other substances from entering the connecting sleeve and affecting the connection between the first and second joints, it is preferred that the sealing member also includes a first sealing ring and a second sealing ring. The first sealing ring is arranged on the connecting sleeve at a position corresponding to the first joint, and surrounds the first joint to seal the first joint and the connecting sleeve; the second sealing ring is arranged on the second joint, and surrounds the second joint to seal the second joint and the connecting sleeve.

[0016] It is further preferred that a retaining ring is provided on the second joint, and the second sealing ring is arranged between the connecting sleeve and the end surface opposite to the retaining ring, so that the upper and lower end surfaces of the second sealing ring are respectively sealedly connected with the connecting sleeve and the end surface opposite to the retaining ring, and the inner side wall of the second sealing ring is sealedly connected with the outer side wall of the second joint, thereby further improving the sealing performance.

[0017] When the first connector is plugged into the second connector, there is a gap between the end faces of the plug and the socket facing each other.

[0018] In the above solution, the drill pipe body is fixedly connected to the first joint and the second joint or detachably connected. The detachable connection can be achieved by threaded connection, clamping connection, etc.

[0019] In order to improve the connection strength between the joint and the drill pipe body and avoid reducing the strength of the drill pipe body due to processing connection structures such as threads and connection grooves on the drill pipe body, the improvement is that the first joint is welded and fixed to one end of the drill pipe body; the second joint is welded and fixed to the other end of the drill pipe body.

[0020] Finally, since the drill rod body is a rod-shaped structure with a smooth exterior, in order to better drive the drill rod body to move up and down, the drill rod body is convexly provided with at least one holding and pressing block for receiving external forces to move the drill rod body up and down.

[0021] Compared with the prior art, the advantages of the present invention are: by adopting a connecting sleeve to be set outside the first and second joints to connect the first and second joints, the original connection mode of the first and second joints is changed, and the situation of leakage of slurry and tearing of the plug-type joint at the plug is better avoided; and the connecting sleeve is set outside the first and second joints and sealed by a sealing member, which can better protect the joint and prevent external dust and other substances from entering the connecting sleeve to affect the connection of the joint; and the connecting sleeve can be detachably connected to the second joint by means of threaded connection, etc., which is convenient for installation and disassembly. The structure is reasonable and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure after the connecting sleeve is connected to the first and second joints;

[0024] Figure 3 is a schematic structural diagram of a second joint in an embodiment of the present invention;

[0025] Figure 4 is a top view of the second joint in an embodiment of the present invention;

[0026] Figure 5 for Figure 4 Cross-sectional view along the BB direction;

[0027] Figure 6 is a cross-sectional view of the second joint in another direction in an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the structure of the first joint in an embodiment of the present invention;

[0029] Figure 8 is a bottom view of the first joint in an embodiment of the present invention;

[0030] Fig. 9 for Figure 8 Sectional view along AA direction;

[0031] Fig.10 This is a schematic diagram of the structure of a support ring in an embodiment of the present invention;

[0032] Fig.11 is a cross-sectional view of a support ring in an embodiment of the present invention;

[0033] Fig.12 It is a schematic diagram of the structure of the connecting sleeve in an embodiment of the present invention;

[0034] Fig.13 It is a structural schematic diagram of a first joint equipped with a connecting sleeve in an embodiment of the present invention;

[0035] Fig.14 for Figure 2 Enlarged view of part C in the middle. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below with reference to the accompanying drawings.

[0037] like Figures 1 to 14 The above is a preferred embodiment of the drill rod of the present embodiment, which includes a drill rod body 7, a first joint 1 connected to the lower end of the drill rod body 7, a second joint 2 connected to the upper end of the drill rod body 7, a connecting sleeve 4 and a sealing member 3 sleeved on the first joint 1, and the sealing member 3 includes a first sealing ring 31, a second sealing ring 32 and a third sealing ring 33.

[0038] The drill rod body 7 is a rod-shaped structure, in which a pipe 71 is provided along the axial direction for the pipeline medium (concrete slurry) to flow. At least one holding block 72 is provided on the drill rod body 7 for receiving external force to move the drill rod body 7 up and down. At the same time, the inner wall of the drill rod body 7 is a square structure (of course, other structures such as round and polygonal structures can also be used).

[0039] The first connector 1 and the second connector 2 are connected by the cooperation of the jack and the plug, respectively, as follows:

[0040] like Figures 7 to 11 and Fig.13As shown, the first joint 1 includes a first joint body 10 and a support ring 5. The first joint 1 is provided with a first through hole 100 connected to the pipe 71 in the drill pipe body 7, and the second joint 2 is provided with a second through hole 200 connected to the pipe 71 in the drill pipe body 7. The first joint 1 can be plugged into the second joint 2. After the first joint 1 and the second joint 2 are plugged together, the first through hole 100 and the second through hole 200 are connected and are located at the plug-in position of the first joint 1 and the second joint 2.

[0041] In this embodiment, the drill pipe also includes a connecting sleeve 4 and at least one sealing member 3. The connecting sleeve 4 is sleeved on the first joint 1 and has a connecting portion into which the second joint 2 can be inserted and detachably connected to the second joint 2. The connecting portion is the second connecting portion. The sealing member 3 is used to make the connecting sleeve 4 seal with the first joint 1 and the second joint 2.

[0042] The first port 101 of the first through hole 100 is used for inserting the plug 21 on the second joint 2, and the second port 102 corresponds to the pipeline 71 in the drill pipe body 7 for the pipeline medium to flow. The first through hole 100 includes: a first guide section 100a, a calibration section 100b and a flow section 100c in sequence along the insertion direction, wherein the caliber of the first guide section 100a gradually decreases along the insertion direction for the plug 21 on the second joint 2 to slide in (i.e., the caliber of the first plug-in surface 111 of the first guide section 100a gradually decreases along the plug-in direction); the calibration section 100b is connected with the small-caliber end of the above-mentioned first guide section 100a, and is used to define the insertion position of the plug 21 on the second joint 2, that is, the first guide section 100a and the calibration section 100b are jacks for inserting the plug 21; the flow section 100c is connected with the calibration section 100b, and is used to communicate with the second through hole 200 in the second joint 2 when the second joint 2 is inserted into the first joint 1, so as to allow the pipeline medium to flow.

[0043] The support ring 5 and the first joint body 10 can be integrally formed, or connected by a detachable connection method such as a snap-on connection. In this embodiment, in order to improve the connection strength and facilitate loading and unloading, the connection structure between the support ring 5 and the first joint body 10 is as follows: a first step 14 is annularly recessed on the outer side wall of the lower end portion of the first joint body 10 (i.e., the end corresponding to the position of the first port 101), and the first step 14 has a first horizontal plane parallel to the lower end face of the first joint body 10, and a first vertical plane perpendicular to the first horizontal plane, and an external thread 11 is provided on the first vertical plane. The above-mentioned support ring 5 is sleeved on the first step 14, and its vertical cross-section is L-shaped, including a vertical connecting portion and a transverse supporting portion. The connecting portion is sleeved on the first step 14 and has an internal thread 51 that cooperates with the external thread 11 to be threadedly connected with the first joint body 10. After the support ring 5 is assembled on the first step 14, the top surface of the connecting portion of the support ring 5 abuts against the first horizontal plane for limiting the position, and the outer side wall of the connecting portion is connected with the outer side wall of the first joint body 10. The supporting portion is annularly protruded on the first joint body 10 to form a limiting step.

[0044] Since the support ring 5 and the first joint body 10 are threadedly connected, in order to prevent the two from rotating relative to each other, in this embodiment, a semi-threaded hole 12 is provided on the external thread 11 of the first joint body 10, and a corresponding semi-threaded hole 52 is provided on the internal thread 51 of the support ring 5. After the support ring 5 is connected to the first joint body 10, the two semi-threaded holes form a complete threaded hole for the screw 9 to be inserted, and the support ring 5 can be effectively prevented from rotating relative to the first joint body 10 after the screw 9 is inserted. In this embodiment, there are two semi-threaded holes on both the external thread 11 and the internal thread 51, and they are evenly distributed. Of course, there can also be only one or more semi-threaded holes, or other anti-rotation structures can be used, as long as the support ring 5 can be positioned on the first joint body 10 to prevent the two from rotating relative to each other.

[0045] At the same time, since the first joint 1 and the second joint 2 are plugged in through the cooperation of the jack and the plug 21, and the jack has a first plugging surface 111 with a gradually decreasing diameter along the plugging direction, and the plug 21 has a second plugging surface 211a that matches the first plugging surface 111, when the first joint 1 is plugged in the second joint 2, there is a gap X between the opposite end faces of the first joint 1 and the second joint 2, and the gap X is used to ensure the compaction sealing effect of the third sealing ring 33a to avoid leakage between the first plugging surface 111 and the second plugging surface 211a. Therefore, after the plug 21 is inserted into the jack, the two can still rotate in the circumferential direction. In order to prevent the two from rotating, the present embodiment is provided with a semi-positioning hole 13 on the external thread 11 of the first joint body 10, and the same semi-positioning hole 53 is correspondingly provided on the internal thread 51 of the support ring 5. After the support ring 5 is connected to the first joint body 10, the two semi-positioning holes form a complete positioning hole for inserting one end of the positioning pin. After the one end of the positioning pin is inserted, the relative rotation of the first and second joints 1 and 2 can be effectively prevented. In the present embodiment, there are two semi-positioning holes on the external thread 11 and the internal thread 51, and they are evenly distributed. Of course, there may be only one or more semi-positioning holes, or other positioning structures may be used, as long as the second joint 2 can be positioned on the first joint 1 to prevent the two from rotating relative to each other.

[0046] The connection structure between the first joint body 10 and the drill rod body 7 is as follows: the cross section of the upper end of the first joint body 10 (i.e., the end corresponding to the position of the second port 102) is circular as a whole, and is inserted into the drill rod body 7; in order to facilitate processing and ensure accuracy, a cutting surface N matching the inner wall of the drill rod body 7 is formed on the outer wall of the upper end of the first joint body 10, and one or more welding holes 15 are provided on the cutting surface N, and the welding holes 15 are used to fill flux so that the first joint body 10 is welded and fixed on the drill rod body 7. In actual operation, the first joint body 10 and the drill rod body 7 can be connected by buried welding. Of course, the connection structure between the first joint body 10 and the drill rod body 7 is not limited to welding and fixing, and can also be connected by other means such as threaded connection. At the same time, the outer diameter of the upper end of the first joint body 10 is relatively large, so as to form a step structure with the middle part of the first joint body 10, so that an I-shaped structure with large ends and small middle is formed between the upper end, the middle part and the support ring 5 on the lower end of the first joint body 10.

[0047] In order to reduce the weight of the first joint body 10 , in this embodiment, at least one weight-reducing hole 16 for reducing weight is axially disposed on the first joint body 10 , and each weight-reducing hole 16 is separated from the first through hole 100 .

[0048] At the same time, a receiving groove 17 coaxially distributed with the first through hole 100 is opened on the lower end surface of the first joint body 10, and the receiving groove 17 is connected to the large-diameter end of the first guide section 100a, and the diameter of the receiving groove 17 is larger than the diameter of the first guide section 100a to receive the fallen pipeline medium.

[0049] like Figure 2 , 12 As shown in Figures 13, the connecting sleeve 4 is sleeved on the first joint body 10 and can move up and down in the middle part of the first joint body 10. Specifically, the connecting sleeve 4 includes a body 40, a first connecting part and a second connecting part. The body 40 is a cylindrical structure with openings at both ends, wherein the first opening 40a is used for inserting the first joint body 10, and the second opening 40b is used for inserting the second joint 2. The first connecting part is arranged on the body 40 at a position close to the first opening 40a, and includes a convex edge 44 convexly arranged on the inner wall of the body 40. The convex edge 44 is an annular structure distributed circumferentially along the inner wall of the body 40, and extends inwardly along the radial direction of the body 40, and is used to support on the support ring 5 of the first joint 1, and can move up and down between the support ring 5 and the upper end of the first joint body 10 (i.e., the middle part of the first joint body 10), so as not to slip off the first joint 1. A step 45 for accommodating the first sealing ring 31 is provided on the end surface of the body 40 corresponding to the first opening 40a (the first sealing ring 31 is provided on the step 45 at a position corresponding to the first joint 1, and surrounds the first joint 1, and is used to seal the first joint 1 and the connecting sleeve 4). The second connecting portion includes a thread 41 provided on the inner wall of the body 40, which can be threadedly connected with the outer wall of the second joint 2. In order to prevent the second joint 2 from rotating relative to the inner wall of the body 40, a rotation-stopping structure is provided on the body 40. The rotation-stopping structure includes a threaded hole 42 provided on the body 40 for the locking screw 43 to pass through. After passing through the threaded hole 42, the locking screw 43 can abut against the outer wall of the second joint 2 to prevent the second joint 2 from rotating relative to the body 40. In order to facilitate the rotation of the body 40 and connect it to the second joint 2, at least one tool hole 46 for inserting a tool such as a wrench to drive the body 40 to rotate is provided on the outer wall of the body 40. The tool hole 46 is not connected to the inner wall of the body 40.

[0050] In this embodiment, the first sealing ring 31 is arranged on the connection sleeve 4 at a position corresponding to the first joint 1, and surrounds the first joint 1, and is used to seal the first joint 1 and the connection sleeve 4; the second sealing ring 32 is arranged on the second joint 2, and surrounds the second joint 2, and is used to seal and connect the second joint 2 and the connection sleeve 4. When the first sealing ring 31 seals the first joint 1 and the connection sleeve 4 and the second sealing ring 32 seals the second joint 2 and the connection sleeve 4, it is difficult for soil to enter the connection sleeve 4.

[0051] Preferably, a retaining ring 23 is provided on the second joint 2, and the second sealing ring 32 is arranged between the connecting sleeve 4 and the end surface opposite to the retaining ring 23. In addition to being used to limit the retaining ring 23, the retaining ring 23 on the second joint 2 can also provide a clamping surface for the claw mechanism.

[0052] like Figure 2 , 13 As shown in Figures 14, in order to enable the connecting sleeve 4 to slide on the first joint 1 and always maintain a sealed state with the first joint 1, the structure of the first sealing ring 31 on the connecting sleeve 4 plays an important role. In this embodiment, the first sealing ring 31 includes a first sealing portion 311 and a second sealing portion 312 which are integrally connected inside and outside. The first sealing portion 311 is supported on the step 45 of the connecting sleeve 4 and is sealed with the connecting sleeve 4. The second sealing portion 312 is sleeved on the first joint 1 and is sealed with the first joint 1. The second sealing portion 312 is a hook-shaped structure with its opening facing away from the first joint 1. It includes a connecting end 312a connected to the first sealing portion 311 and a free end 312b that can rotate relative to the connecting end 312a under the action of an external force, and the free end 312b is arranged in the direction where the second joint 2 is located. In this embodiment, in order to further improve the sealing performance, a resilient member (spring ring 313) is further provided on the first sealing ring 31, and a spring groove G for accommodating the spring ring 313 is provided on the inner side of the second sealing portion 312 in an annular direction. The spring ring 313 is accommodated in the spring groove G, so that the second sealing portion 312 always has a tendency to move closer to the first joint 1, and further seals the first joint 1. When the first sealing ring 31 moves axially along the first joint 1 toward the direction where the second joint 2 is located, the sealing part of the second sealing portion 312 that cooperates with the first joint 1 always has a tendency to move in the opposite direction to form a compact seal, thereby ensuring that it always cooperates with the first joint 1 in a sealed manner during the movement process; when the first sealing ring 31 moves in the opposite direction, the second sealing portion 312 can move along the first joint 1, thereby facilitating movement without a large resistance, and when moving in the opposite direction, the second sealing portion 312 also always sticks to the first joint 1 to form a seal.

[0053] like Figures 2~6As shown, the second joint 2 includes a second joint body 20 and a plug 21 protruding from the second joint body 20, and the second joint body 20 and the plug 21 have a second through hole 200 axially extending therethrough, and one end of the second through hole 200 close to the plug 21 is used to connect to the first joint 1, and the other end of the second through hole 200 is used to correspond to the pipe 71 in the drill pipe body 7 for the flow of the pipeline medium; the plug 21 corresponds to the shape of the jack, and includes a second guide section 21a and a positioning section 21b, wherein the second guide section 21a is located at the tail of the plug 21, and the diameter of its second plug surface 211a gradually decreases toward the head direction of the plug 21, so as to adjust the position of the first joint 1 on the second joint 2; the positioning section 21b is located at the head of the plug 21, and is connected to the small head end of the second guide section 21a to limit the position of the first joint 1 on the second joint 2. In this way, when the plug 21 is plugged into the jack, the plug 21 slides in along the first guide section 100a in the jack to achieve the matching of the positioning section 21b on the plug 21 and the calibration section 100b in the jack, and after the two are plugged in, the second through hole 200 on the plug 21 is connected with the flow section 100c of the first through hole 100 in the first connector 1 to allow the pipeline medium to flow. In this embodiment, the second guide section 21a of the plug 21 is a truncated cone structure as a whole; the positioning section 21b is a columnar structure coaxially distributed with the second guide section 21a, and the diameter of its plug-in surface 211b corresponds to the diameter of the small end port in the second guide section 21a. The shapes of the first guide section 100a and the calibration section 100b in the jack match the shapes of the second guide section 21a and the positioning section 21b in the plug 21, respectively.

[0054] Since the second guide section 21a and the first guide section 100a are truncated cone structures, they have a good sealing effect when they are pressed tightly. However, in order to further improve the sealing performance, the third sealing ring 33 is used to make the first plug-in surface 111 and the second plug-in surface 211a seal and cooperate. In this embodiment, at least one annular groove 212 for accommodating the third sealing ring 33 is circumferentially provided on the plug 21, specifically: the second guide section 21a of the plug 21 is axially distributed with two (or one, three or more) first annular grooves 212a for accommodating the third sealing ring 1 33a to achieve compaction sealing with the plug hole; the positioning section 21b is axially distributed with two second annular grooves 212b for accommodating the third sealing ring 2 33b to achieve vertical sealing with the plug hole. Each third sealing ring 1 33a is sleeved on the first annular groove 212a, and each third sealing ring 2 33b is sleeved on the second annular groove 212b. After the plug 21 with the third sealing ring 33 is inserted into the socket, the compaction seal and vertical seal of the plug 21 and the socket can be better achieved at the same time, ensuring that the pipeline medium will not flow out from the gap between the plug 21 and the socket during operation to cause leakage.

[0055] In this embodiment, in order to further ensure the sealing performance of the plug 21 and the socket, when the first connector 1 equipped with the third sealing ring 33 is plugged into the second connector 2 and the two are in a sealed fit state (that is, the first plug-in surface 111 and the second plug-in surface 211a are in a sealed fit state), there is a gap X between the opposite end surfaces of the first and second connectors 1 and 2, and the height of the gap X is ≥1mm. The gap X leaves space for the compaction deformation of the third sealing ring 33a; when the first connector 1 is plugged into the second connector 2, there is a gap Y between the opposite end surfaces of the plug 21 and the socket.

[0056] In this embodiment, the drill rod body 7 is fixedly connected or detachably connected to the first joint 1 and the second joint 2. Since the wall thickness of the drill rod body 7 is relatively thin, the first joint 1 is welded and fixed to one end of the drill rod body 7, and the second joint 2 is welded and fixed to the other end of the drill rod body 7. Of course, the drill rod body 7 and the first joint 1 and the second joint 2 can also be detachably connected, and the detachable connection can be achieved by threaded connection, clamping, etc.

[0057] When the first and second joints 1 and 2 are separated, a small amount of pipeline medium will fall out of the first joint 1. In order to receive the small amount of pipeline medium that falls out and not affect the sealing connection between the first and second joints 1 and 2, the second plug-in surface 211a of the second guide section 21a of the plug 21 is recessed with at least one first receiving groove 213 for receiving the pipeline medium that falls out of the first joint 1. Each first receiving groove 213 is axially distributed between two adjacent annular grooves 212; and the end surface of the second joint body 20 on which the plug 21 is convexly provided is recessed with at least one second receiving groove 22 for receiving the pipeline medium that falls out of the first joint 1. The small amount of pipeline medium that falls out first enters the first receiving groove 213 near the positioning section 21b, and after the first receiving groove 213 is filled, it enters the first receiving groove 213 of the next level, and finally enters the second receiving groove 22 on the second joint body 20. However, it should be noted that the first and second joints 1 and 2 are cleaned after use, and the first and second receiving grooves 213 and 22 and the receiving groove 17 in the first joint 1 are only for prevention, and generally speaking, there will not be a lot of pipeline medium. The purpose of providing the receiving groove 17 in the first joint 1 is to prevent the pipeline medium from being retained in the first and second receiving grooves 213 and 22 of the second joint 2, so that the pipeline medium in the first and second receiving grooves 213 and 22 of the second joint 2 is difficult to clean.

[0058] At the same time, the second joint body 20 is provided with a limiting hole 24 for inserting the other end of the positioning pin, one end of the positioning pin is inserted on the first joint 1, and the limiting hole 24 is provided on the end face of the second joint body 20 opposite to the first joint 1. And similar to the first joint 1, in order to reduce the weight of the second joint 2, this embodiment is axially provided with at least one weight-reducing hole 25 for reducing weight on the second joint body 20, and each weight-reducing hole 25 is separated from the second through hole 200. At the same time, in order to facilitate the insertion of the pipe 71 in the drill rod body 7 into the second through hole 200, the other end of the second through hole 200 is a step structure with a diameter from large to small toward the head direction of the plug 21, which is used for inserting the pipe 71 in the drill rod body 7.

[0059] The connection structure between the second joint body 20 and the drill rod body 7 is as follows: the cross section of the lower end of the second joint body 20 (i.e., the end of the second joint body 20 away from the plug 21) is circular as a whole, and is inserted into the drill rod body 7; and in order to facilitate processing and ensure accuracy, a cutting surface M that matches the inner wall of the drill rod body 7 is formed on the outer side wall of the lower end of the second joint body 20, and one or more welding holes 26 are provided on the cutting surface M, and the welding holes 26 are used to fill flux so that the second joint body 20 can be welded and fixed on the drill rod body 7. Of course, the second joint body 20 can also be connected to the drill rod body 7 by a detachable connection method such as a threaded connection or a snap connection.

[0060] In order to be threadedly connected with the connecting sleeve 4, an outer wall of the upper end of the second joint body 20 (i.e., the end of the second joint body 20 close to the plug 21) is provided with an outer thread 27 for assembling the connecting sleeve 4, and an abutment groove 28 for the locking screw 43 to abut is provided on the outer wall of the second joint body 20, and the abutment groove 28 is located below the outer thread 27. The locking screw 43 can abut on the abutment groove 28 after passing through the threaded hole 42 on the connecting sleeve 4. In this embodiment, a retaining ring 23 is circumferentially provided between the abutment groove 28 and the lower end of the second joint body 20, and the second sealing ring 32 (a conventional O-ring is selected) is arranged on the retaining ring 23, which is used to form a sealing match with the end face of the body 40 of the connecting sleeve 4 corresponding to the second opening 40b, that is, after the second joint body 20 is threadedly connected with the connecting sleeve 4, the second sealing ring 32 seals and connects the second joint body 20 with the connecting sleeve 4. And when the lower end of the second joint body 20 is inserted in the drill rod body 7, the retaining ring 23 is supported on the end face of the drill rod body 7 to limit the insertion position, and the outer diameter of the retaining ring 23 is larger than the outer diameter of the drill rod body 7, so that the retaining ring 23 is exposed on the drill rod body. In this way, the retaining ring 23 can also cooperate with the claw on the pile driver for the claw to be engaged.

[0061] The process of connecting the first and second joints 1 and 2 is as follows: plug the first joint 1 and the second joint 2 together and fix them with a positioning pin, then rotate the connecting sleeve 4 so that the connecting sleeve 4 moves in the direction of the second joint 2 and is threadedly connected with the second joint 2, then tighten the locking screw 43 so that the locking screw 43 is against the second joint 2, and finally the connection and fixation of the first and second joints 1 and 2 are achieved, so that two adjacent drill rods can be connected, and the length of the drill rod is extended. When the first and second joints 1 and 2 need to be disassembled, first loosen the locking screw 43, then rotate the connecting sleeve 4 in the opposite direction, and after the connecting sleeve 4 is separated from the second joint 2, remove the positioning pin, and then pull the second joint 2 out of the first joint 1 to separate the two.

[0062] The above are only preferred embodiments of the present invention. The scope of protection of the invention shall be based on the scope defined by the claims. Several improvements and modifications made by those skilled in the art without departing from the spirit and scope of the present invention should also be regarded as the scope of protection of the present invention.

Claims

1. A drill rod for a pile driver, comprising a drill rod body (7), a first joint (1) and a second joint (2) connected to two ends of the drill rod body (7), wherein the first joint (1) and the second joint (2) are respectively provided with a first through hole (100) and a second through hole (200) connected to a pipe (71) in the drill rod body (7), and the first joint (1) can be plugged into the second joint (2), and after the plugging, the first through hole (100) and the second through hole (200) are connected; Features It also comprises a connecting sleeve (4) and at least one sealing member (3); the connecting sleeve (4) is sleeved on the first joint (1) and has a connecting portion capable of being inserted into the second joint (2) and detachably connected to the second joint (2); the sealing member (3) is used to achieve sealing cooperation between the connecting sleeve (4) and the first joint (1) and the second joint (2); The first connector (1) and the second connector (2) are plugged into the plug (21) via a plug hole, and the plug hole has a first plugging surface (111) whose diameter gradually decreases along the plugging direction, and the plug (21) has a second plugging surface (211a) that matches the first plugging surface (111), and when the first connector (1) is plugged into the second connector (2), there is a gap (X) between the opposite end surfaces of the first connector (1) and the second connector (2); The sealing member (3) further comprises a first sealing ring (31) and a second sealing ring (32); the first sealing ring (31) is arranged on the connecting sleeve (4) at a position corresponding to the first joint (1), surrounds the first joint (1), and is used to seal the first joint (1) and the connecting sleeve (4); the second sealing ring (32) is arranged on the second joint (2), surrounds the second joint (2), and is used to seal the second joint (2) and the connecting sleeve (4); The second joint (2) is provided with a retaining ring (23), and the second sealing ring (32) is arranged between the end faces of the connecting sleeve (4) and the retaining ring (23) that are opposite to each other.

2. The drill pipe according to claim 1, characterized in that: The sealing member (3) comprises a third sealing ring (33), and the third sealing ring (33) is arranged between the first plug-in surface (111) and the second plug-in surface (211a) so as to seal the two.

3. The drill pipe according to claim 2, characterized in that: When the first plug-in surface (111) and the second plug-in surface (211a) are in a sealed fit state, the height of the gap (X) is ≥1 mm.

4. The drill pipe according to claim 1, characterized in that: When the first connector (1) is plugged into the second connector (2), a gap (Y) is provided between the end faces of the plug and the socket facing each other.

5. The drill pipe according to claim 1, characterized in that: The drill rod body (7) is fixedly connected or detachably connected to the first joint (1) and the second joint (2).

6. The drill rod according to claim 5, characterized in that: The first joint (1) is welded and fixed to one end of the drill rod body (7); and the second joint (2) is welded and fixed to the other end of the drill rod body (7).

7. The drill pipe according to claim 1, characterized in that At least one holding and pressing block (72) is convexly provided on the drill rod body (7) and is used to receive external force and move the drill rod body up and down.

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