A drilling and coring device and method for building pile foundations

Abstract

The application discloses a drilling and coring device for building pile foundation and a coring method, and belongs to the technical field of drilling devices. The drilling and coring device for building pile foundation comprises a mast and a power head slidingly assembled on the mast, and further comprises a rope, one end of the rope is connected with a clamp for clamping a drill rod, and the other end of the rope is connected with a winding drum of a winch. The clamp comprises a top plate and two chuck heads hingedly connected to the top plate, and the outer circular surface of the chuck head is provided with a half shaft. Compared with a traditional locking mechanism, the device utilizes the power of the power head for driving the drill rod to rotate, drives the inner ring plate and the extruding piece to operate in linkage, and automatically completes the unlocking of the chuck head and the release of the drill rod. The whole mechanism does not need workers to manually unlock from high places, and does not need to additionally configure an independent power source, and the structure is simple, and the overall structure of the clamp is effectively simplified.

Description

Technical Field

[0001] This invention relates to the field of drilling equipment technology, and in particular to a core drilling device and core sampling method for building pile foundations. Background Technology

[0002] After the construction of building pile foundations is completed, core drilling is usually required to sample and test the quality, integrity, and density of the pile concrete to determine whether the pile foundation meets the design and usage requirements. Core drilling operations require continuously extending the drill rod according to the drilling depth; therefore, the hoisting, connection, and disassembly of the drill rod are essential procedures in pile foundation core drilling operations.

[0003] Chinese patent CN208010298U discloses a drill pipe lifting device, including a lifting body and a pipe unloading joint slidably connected to the lifting body. The drill pipe is located on the side of the lifting body opposite to the pipe unloading joint, and the drill pipe is slidably connected to the lifting body. The end of the pipe unloading joint near the drill pipe has an anti-detachment part to prevent the pipe unloading joint from detaching from the lifting body. The lifting body has a locking component for locking the drill pipe onto the lifting body. The pipe unloading joint is connected to a power device for assembling and disassembling the pipe unloading joint and the drill pipe, allowing for quick connection of the pipe unloading joint to the drill string, improving connection speed. Reversing the power device allows for disassembly of the drill string. Furthermore, Chinese patent CN209324277U also discloses a structure for clamping the drill pipe using a rope and a hoisting mechanism.

[0004] However, in actual field operations, directly integrating the power components into the hoisting device, lifting gear, and other clamping mechanisms that move and rise with the rope not only significantly increases the overall size and number of parts of the clamping mechanism, resulting in a bulky equipment structure and increased difficulty in assembly and maintenance, but also makes it difficult to stably lay out the power oil and electrical circuits when the clamping mechanism is in a suspended state. This leads to unreliable and continuous power supply, and long-term use can easily result in malfunctions and component failures. In contrast, the purely manual unlocking clamping mechanism commonly used in the industry, while avoiding the structural complexity caused by external power, requires workers to climb to a height above the orifice for close-range unlocking. This not only involves a cumbersome and labor-intensive process, but also poses safety hazards such as falls and collisions when working at heights near edges.

[0005] Therefore, it is necessary to provide a core drilling device and core sampling method for building pile foundations to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to provide a core drilling device and core drilling method for building pile foundations, so as to solve the technical problems mentioned in the background art.

[0007] Based on the above ideas, the present invention provides the following technical solution: a core drilling device for building pile foundations, comprising a mast and a power head slidably assembled on the mast, and further comprising: A rope, one end of which is connected to a clamp for holding the drill rod, and the other end of which is connected to the drum of a winch; The clamp includes a top plate and two chucks hinged to the top plate. The outer surface of the chucks is provided with a half shaft. When the two chucks are in contact to clamp the drill rod, the two sets of half shafts are assembled to form a complete cylindrical structure. A knob is rotatably sleeved on one of the half shafts, and the knob is elastically connected to the half shaft in the circumferential direction. One of the chucks is elastically connected to a locking pin along its diameter. The side wall of the knob has a pin hole that mates with the locking pin. The knob and the chuck can be locked together by the engagement of the locking pin and the pin hole. The chuck has an inner ring plate on its inner side. The chuck clamps the drill rod against the inner ring plate. When the clamp is locked to the power head and the drill rod drives the inner ring plate to rotate synchronously, the locking pin on the knob can be released.

[0008] As a further aspect of the present invention: the knob is circumferentially rotated and axially fixed in conjunction with the half-shaft.

[0009] As a further aspect of the present invention: the outer circular surface of the half-shaft is integrally formed with a limiting part along its circumferential direction, and the inner circular surface of the knob is provided with a limiting groove that slides with the limiting part. The limiting groove and the limiting part have T-shaped cross sections along the diameter direction of the half-shaft.

[0010] As a further aspect of the present invention: the projection of the inner ring plate along its own axis is an arc-shaped structure, and the inner ring plate is elastically fitted with the chuck along the circumferential direction of the chuck. The outer circular surface of the inner ring plate, near the pin, is recessed inward along the diameter direction to form a recessed portion. An extrusion member is fixedly connected to the recessed portion. An avoidance groove is provided at the end of the extrusion member near the pin. The end of the pin extending into the chuck is located at the avoidance groove. The outer circular surface of the pin extends outward along its diameter direction to form two sets of semi-circular stop portions. The bottom end of the avoidance groove is located between the two stop portions. The extrusion member is an arc-shaped plate structure. The center of the outer circular surface of the extrusion member is coaxially arranged with the center of the inner ring plate. The thickness of the inner circular surface of the extrusion member gradually increases in the direction away from the pin to form an extrusion portion.

[0011] As a further embodiment of the present invention: the outer circular surface of the chuck extends outward along its diameter to form a protrusion, and a positioning post is fixedly connected to the protrusion; a positioning sleeve that cooperates with the positioning post is fixedly connected to the top of the outer shell of the power head.

[0012] As a further aspect of the present invention: the outer circular surface of the half-shaft is integrally formed with a limiting part along its circumferential direction, and the inner circular surface of the knob is provided with a limiting groove that slides with the limiting part. The limiting groove and the limiting part have T-shaped cross sections along the diameter direction of the half-shaft.

[0013] As a further aspect of the present invention: the knob can be chamfered at the end of the clamp and near the chuck, so that interference between the knob and the locking pin can be avoided during the rotation of the knob.

[0014] As a further aspect of the present invention: the outer wall of the chuck is provided with a through guide groove along its circumference, and the guide block fixed to the inner ring plate passes through the guide groove and slides in cooperation with the guide groove.

[0015] As a further aspect of the present invention: the locking pin is configured as a semi-cylindrical shape and a slide bar is fixedly connected to the outer circular surface of the locking pin, and the locking pin is radially slidingly engaged with the clamp through the slide bar.

[0016] A core sampling method based on the aforementioned core drilling device for building pile foundations includes the following steps: S1. Place the drill rod to be connected between the two chucks, close the two chucks to make the two half shafts fit together, turn the knob across the outside of the two half shafts, and lock the knob by the cooperation of the locking pin and the pin hole to make the clamp clamp the drill rod. S2. Start the winch to wind up the rope, which will lift the clamp and drill rod upwards. Then slowly lower the rope so that the drill rod passes through the power head from top to bottom. S3. Drive the power head upward to lock the chuck with the power head and restrict the chuck's circumferential rotation; S4. The internal jaws of the power head clamp the drill rod and drive it to rotate. The drill rod simultaneously drives the inner ring plate to rotate circumferentially to unlock the knob and the half shaft.

[0017] Compared with existing technologies, the advantages of this invention are: compared with traditional locking mechanisms, this device utilizes the power of the power head to rotate the drill rod, driving the inner ring plate and the extrusion component to operate in conjunction, automatically completing the unlocking of the chuck and the release of the drill rod. The entire mechanism does not require personnel to climb to a height for manual unlocking, nor does it require an additional independent power source. Its structure is simple and effectively simplifies the overall construction of the clamp. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the bottom structure of the clamp of the present invention; Figure 3 This is a schematic diagram of the structure of the clamp and the power head of the present invention being connected; Figure 4 This is a schematic diagram of the three-dimensional structure of the clamp of the present invention; Figure 5 This is a schematic diagram of the initial state of the knob of the present invention; Figure 6 This is the present invention. Figure 5 A magnified structural diagram at point A; Figure 7 This is a schematic diagram of the guide block and guide groove of the present invention; Figure 8 This is a schematic diagram showing the relative positions of the extrusion member and the locking pin of the present invention; Figure 9 This is the present invention. Figure 8 A magnified structural diagram at point B; Figure 10 This is a schematic diagram of the fit between the extrusion part and the locking pin of the present invention.

[0020] In the diagram: 1. Mast; 2. Power head; 201. Positioning sleeve; 3. Rope; 4. Chuck; 402. Pin; 403. Boss; 404. Half shaft; 4041. Limiting part; 405. Guide groove; 5. Clamping assembly; 6. Top plate; 7. Drill rod; 8. Knob; 801. Groove; 802. Chamfer; 803. Pin hole; 9. Elastic element; 10. Positioning pin; 11. Stop; 12. Inner ring plate; 1201. Guide block; 13. Limiting spring; 14. Locking pin; 1401. Sliding strip; 1402. Stop; 15. Extrusion part; 1501. Extrusion part; 1502. Clearance groove; 16. Tension spring. Detailed Implementation

[0021] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0022] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0023] like Figures 1 to 10As shown, a drilling rig includes a body and a mast 1 mounted on one side of the body. The mast 1 is hinged to the body. Specifically, a base is fixedly mounted on the body, and a connecting shaft is fixedly connected to the mast 1. This connecting shaft is rotatably engaged with the base via bearings. The mast 1 can be laid flat to facilitate the overall relocation of the equipment, and when erected, its tilt angle can be adjusted to regulate the drilling angle. A hydraulic rod is also provided between the body and the mast 1. The cylinder of the hydraulic rod is hinged to the body, and the telescopic end of the hydraulic rod is hinged to the mast 1. The telescopic movement of the hydraulic rod drives the mast 1 to switch its posture and adjust its angle.

[0024] A power head 2 is slidably mounted on the mast 1. Specifically, a slide rail is fixedly connected to the mast 1, and a slider that slides with the slide rail is fixedly connected to the power head 2. A drive unit is installed at the top of the mast 1. The drive unit can be a hydraulic rod, and the telescopic end of the hydraulic rod is connected to the power head 2 to drive the power head 2 to move relative to the mast 1.

[0025] The power head 2 has a through mounting hole, through which the drill rod 7 passes. The power head 2 contains slips, which are driven by a matching drive mechanism to radially retract and grip the drill rod 7. When the power head 2 is running, the slips can drive the drill rod 7 to rotate synchronously. The power head 2 in this design is a mature structure used in core drilling rigs and will not be described in detail here.

[0026] A guide pulley is fixedly installed at the top of the mast 1, and the rope 3 is wound around the outside of the guide pulley to form a reversing structure. One end of the rope 3 is equipped with a clamp for holding the drill rod 7, and the other end extends to the machine body and is connected to the drum of the winch. When performing the drill rod 7 docking operation, first securely attach the drill rod 7 to be installed to the clamp, start the winch, and the drum winds up the rope 3, using the guiding action of the pulley to lift the clamp and the drill rod 7 upward together. After the drill rod 7 is raised to the designated height, continue to operate the winch to lower the rope 3, so that the drill rod 7 to be installed passes through the power head 2, until the lower end of the drill rod 7 is precisely docked with the drill rod 7 already installed below, thus completing the installation of the entire drill rod 7. For details, please refer to [reference needed]. Figure 3 As shown.

[0027] Normally, after the two drill pipe sections 7 are joined together, workers need to disconnect the clamp from the drill pipe 7. To address the problems of traditional clamps requiring personnel to climb to heights, posing high operational risks, and being inconvenient to operate, this solution improves the clamp structure, as follows: The clamp includes a top plate 6 and chucks 4 respectively located on both sides of the bottom of the top plate 6. Each chuck 4 is a cylindrical component with a semi-circular axial projection. The chucks 4 are hinged to the top plate 6. After the two chucks 4 rotate downwards and come into contact with each other, they form a complete cylindrical cavity, thereby clamping the drill rod 7 located at the center of the cavity. Furthermore, locking screws are radially mounted on each chuck 4, which can be tightened by screwing to further reinforce the clamping and improve the reliability of holding the drill rod 7.

[0028] To lock and fix the two clamps 4, the outer circular surface of the clamps 4 extends radially outward to form a semi-shaft 404, the axial projection of which is semi-circular. When the two clamps 4 are in contact with each other, the two semi-shafts 404 are assembled into a complete cylindrical structure. A knob 8 is rotatably fitted on one of the semi-shafts 404. The knob 8 is circumferentially rotatable and axially fixed with the semi-shaft 404, and the knob 8 is circumferentially elastically connected to the semi-shaft 404. After the two clamps 4 are closed, rotating the knob 8 so that it spans across the outside of the assembled semi-shafts 404 completes the locking of the two clamps 4. Further integration Figure 4 , Figure 5 As shown, the knob 8 is cylindrical in shape, with a slot 801 axially formed on its outer circumference. The arc of the slot 801 along the circumference of the knob 8 is greater than π. Initially, the knob 8 is fitted onto the outside of one of the half-shafts 404. After the two clamps 4 are in contact with each other and the two half-shafts 404 are joined to form a complete cylinder, rotating the knob 8 moves it to the engagement position of the two half-shafts 404, as shown. Figure 4 As shown. At this time, the two chucks 4 are locked by the cooperation between the knob 8 and the half-shaft 404, and the drill rod 7 is firmly clamped at the central axis of the two chucks 4. Compared with the traditional bolt and screw locking structure, this solution can quickly complete the locking and unlocking operation of the chucks 4 by means of the cooperation between the knob 8 and the half-shaft 404. At the same time, the overall structural strength is higher, which can ensure the clamping stability of the chucks 4 on the drill rod 7.

[0029] To achieve the positioning and locking of the knob 8, this design includes a locking pin 14 installed on the outer circular surface of the chuck 4 near its straight edge. The locking pin 14 elastically slides with the chuck 4 along the axial direction of the half-shaft 404; a pin hole 803 adapted to the locking pin 14 is provided on the end face of the knob 8 facing the chuck 4. When the knob 8 is rotated between the two half-shafts 404 and the pin hole 803 is aligned with the locking pin 14, the locking pin 14 pops out under elastic action and engages with the pin hole 803, completing the locking of the knob 8 and the half-shaft 404, thereby achieving the locking and fixing of the two chucks 4.

[0030] Furthermore, the locking pin 14 is generally semi-cylindrical, with a slide bar 1401 axially fixed on its outer surface. Along the axial direction of the semi-shaft 404, the collet 4 and the boss 403 are provided with a sliding groove for the locking pin 14 to slide, and the inner wall of the sliding groove is also machined with a T-shaped groove that matches the slide bar 1401. The projections of the slide bar 1401 and the T-shaped groove along the axial direction of the semi-shaft 404 are both T-shaped structures, which can effectively prevent the locking pin 14 from coming out of the collet 4.

[0031] Combination Figures 5 to 10 As shown, an inner ring plate 12 is fitted onto the inner circular side of the chuck 4. The axial projection of the inner ring plate 12 is arc-shaped, and the inner ring plate 12 is elastically connected to the chuck 4 circumferentially. (Refer to...) Figure 8 , Figure 10 A recess is formed radially inward on the outer surface of the inner ring plate 12 near the locking pin 14, and a pressing member 15 is fixed to the inner ring plate 12 at the recess. Figure 8 As can be seen, the end of the extrusion piece 15 facing the locking pin 14 has a relief groove 1502, and the end of the locking pin 14 extending into the chuck 4 is located in the relief groove 1502. When the inner ring plate 12 rotates circumferentially relative to the chuck 4, it can push the locking pin 14 to move axially, releasing the lock between the knob 8 and the half shaft 404; then the two chucks 4 can open outwards, releasing the drill rod 7.

[0032] Combination Figure 8 , Figure 9 As shown, the outer circular surface of the locking pin 14 extends radially outward to form two sets of semi-annular stop portions 1402. (As...) Figure 9 As shown, the bottom end of the clearance groove 1502 on the extruded part 15 is located between the two stop portions 1402. Combined with... Figure 10 The extrusion piece 15 has an overall arc-shaped plate structure, with the center of its outer circle coinciding with the center of the inner ring plate 12. The thickness of the inner circle of the extrusion piece 15 gradually increases in the direction away from the locking pin 14, forming an extrusion section 1501. When the inner ring plate 12 drives the extrusion piece 15 to rotate circumferentially relative to the chuck 4, the extrusion section 1501 presses against the stop section 1402, thereby pushing the locking pin 14 to move axially, causing the end of the locking pin 14 to disengage from the pin hole 803, thus unlocking the knob 8 from the half shaft 404.

[0033] The outer surface of the chuck 4 extends outward along its diameter to form a protrusion, and a positioning post 10 is fixedly connected to the protrusion. The positioning post 10 is arranged axially along the chuck 4. A positioning sleeve 201 is fixedly connected to the top of the outer shell of the power head 2. The inner diameter of the positioning sleeve 201 is larger than the diameter of the positioning post 10. When the rope 3 lifts the clamp and the power head 2 approaches the clamp in the vertical direction, the positioning post 10 can be inserted into the positioning sleeve 201, thereby restricting the circumferential rotation of the chuck 4. At this time, when the pressing member 15 rotates synchronously with the drill rod 7, the knob 8 can be unlocked from the half shaft 404.

[0034] In summary, when performing the drill rod 7 docking operation, first, control the winch drum to release the rope 3. The operator places the end of the drill rod 7 to be docked between the two chucks 4, so that the two chucks 4 face each other and clamp the drill rod 7. Rotate the knob 8 until it is between the two half shafts 404; when the locking pin 14 is aligned with the pin hole 803 on the side wall of the knob 8, the locking pin 14 elastically inserts into the pin hole 803, thereby locking the knob 8 and the half shaft 404, and thus locking the two chucks 4. The drill rod 7 is then adjusted to align vertically with the mounting hole of the power head 2. The rope 3 is then lowered, causing the clamp and drill rod 7 to descend together, allowing the drill rod 7 to pass through the mounting hole of the power head 2. The hydraulic mechanism then drives the power head 2 upwards, bringing it closer to the clamp. The clamp is rotated using the drill rod 7, causing the positioning pin 10 on the chuck 4 to roughly align with the positioning sleeve 201 at the top of the power head 2. As the power head 2 continues to ascend, the positioning pin 10 inserts into the positioning sleeve 201, providing circumferential restraint to the chuck 4 and preventing it from rotating with the drill rod 7. When the internal jaws of the power head 2 clamp the drill rod 7 and cause it to rotate, the inner ring plate 12, which is in close contact with the drill rod 7, rotates circumferentially relative to the chuck 4. The pressing part 1501 of the pressing member 15 presses against the stop part 1402 on the locking pin 14, pushing the locking pin 14 to move axially, causing its end to exit the pin hole 803, thus releasing the lock between the knob 8 and the half shaft 404. After unlocking, the knob 8 can rotate circumferentially around the half shaft 404, turning completely to the outside of one side of the half shaft 404, and the two chucks 4 then open outward around the top plate 6, releasing the clamping of the drill rod 7.

[0035] Compared to traditional locking mechanisms, this device utilizes the power head 2 to rotate the drill rod 7, which in turn drives the inner ring plate 12 and the pressing component 15 to operate in conjunction, automatically unlocking the chuck 4 and releasing the drill rod 7. The entire mechanism eliminates the need for manual unlocking by personnel climbing to a height, and also eliminates the need for an additional independent power source. Its simple structure effectively simplifies the overall construction of the clamp.

[0036] Combination Figures 4-5 As shown, the outer circular surface of the chuck 4 protrudes outward along its diameter to form a boss 403. When the two chucks 4 are deflected downward and fit together, the two bosses 403 can fit together and form a circular structure along the axis of the half shaft 404. The half shaft 404 can be set at the end of the boss 403.

[0037] Furthermore, a block-shaped stop 11 is fixedly provided at the end of the boss 403. When the knob 8 is rotated between the two half shafts 404 to lock the chuck 4, the stop 11 can limit the knob 8, restricting its rotation limit position, effectively improving the convenience and efficiency of operation.

[0038] Combination Figure 4As shown, the chuck 4 equipped with the knob 8 has a protrusion fixed to the end of its boss 403. An elastic element 9 is connected between the protrusion and the knob 8. The elastic element 9 can be a spring, so that the knob 8 and the half shaft 404 form a circumferential elastic connection. When the locking pin 14 separates from the pin hole 803, the knob 8 can automatically reset by rotating circumferentially relative to the half shaft 404 under the elastic force of the elastic element 9, thereby causing the two chucks 4 to deflect outward and release the drill rod 7.

[0039] Combination Figure 1 As shown, a clamping assembly 5 is installed at the bottom of the mast 1. This clamping assembly 5 adopts an existing wellhead slip-type clamping structure and is mainly used for radial clamping and positioning of the drill rod 7 that is lowered into the formation. During operation, the clamping assembly 5 retracts and grips the drill rod 7, restricting the rotation and axial movement of the drill rod 7, keeping the lower drill rod 7 in a stable position, and providing reliable support for the hoisting, insertion, and joint docking operations of the upper drill rod 7. After docking is completed, the clamping assembly 5 releases the drill rod 7, thereby releasing the restriction and ensuring the normal progress of subsequent drilling operations. This clamping assembly 5 is a mature technology used in core drilling rigs, and will not be described in detail here.

[0040] Combination Figure 4 As shown, a base is fixed to the outer circular surface of the chuck 4, and pins 402 are fixed to both sides of the base. A hinge seat is fixed to the outer circular surface of the top plate 6. The pins 402 are hinged to the hinge seat, so that the chuck 4 can rotate around the axis of the pins 402.

[0041] Combination Figure 5 As shown, the outer circular surface of the half-shaft 404 is integrally formed with a limiting part 4041 along its circumference. The inner circular surface of the knob 8 is provided with a limiting groove that slides with the limiting part 4041. The limiting groove and the limiting part 4041 have T-shaped cross sections along the diameter direction of the half-shaft 404, thereby preventing the knob 8 from separating from the half-shaft 404.

[0042] Combination Figure 6 As shown, the knob 8 is provided with chamfers 802 at both ends near the chuck 4. When the knob 8 is rotated to move circumferentially relative to the half shaft 404, the chamfers 802 compress the end of the locking pin 14, so that after the locking pin 14 is aligned with the pin hole 803, the locking pin 14 can pop out under elastic force and insert into the pin hole 803.

[0043] One end of the limiting part 4041, which engages with the knob 8, is radially recessed inward to form a recessed surface a. This recessed surface a forms a beveled guide structure, which reduces the frictional resistance between the knob 8 and the limiting part 4041 during the rotation of the knob 8 into the two half-shafts 404, allowing the knob 8 to be easily and smoothly screwed into the locking position. Through this beveled structure, during the continuous tightening of the knob 8, the circumferential rotational force of the knob 8 can be converted into radial compressive force, achieving a labor-saving locking effect of small rotation and large clamping force.

[0044] Combination Figure 7 As shown, the outer wall of the chuck 4 has a through guide groove 405 along its circumference. A guide block 1201 fixed on the inner ring plate 12 passes through the guide groove 405 and slides within it. A housing is fixed to the outer surface of the chuck 4, which covers the outside of the guide block 1201. A limit spring 13 is connected between the inner end face of the housing and the guide block 1201. This device relies on the power head 2 to drive the drill rod 7 to rotate, thereby driving the inner ring plate 12 to rotate circumferentially. Therefore, a limit spring 13 with high stiffness can be selected to ensure the stability of the locking state between the locking pin 14 and the knob 8.

[0045] A rubber pad can be provided on the inner wall of the inner ring plate 12. When the two chucks 4 are deflected downwards and fit together, the rubber pad can be pressed against the outer surface of the drill rod 7, which is beneficial for fixing the drill rod 7.

[0046] Combination Figure 10 As shown, a tension spring 16 connects the inner stop 1402 to the inner wall of the chuck 4. When the pressing part 1501 and the stop 1402 are misaligned, the locking pin 14 can automatically reset under the elastic force of the tension spring 16, preparing for the next clamping operation.

[0047] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A core drilling device for building pile foundations, comprising a mast (1) and a power head (2) slidably mounted on the mast (1), characterized in that, Also includes: Rope (3), one end of which is connected to a clamp for holding the drill rod (7), and the other end of which is connected to the drum of the winch; The clamp includes a top plate (6) and two chucks (4) hinged to the top plate (6). The outer surface of the chucks (4) is provided with a half shaft (404). When the two chucks (4) are fitted together to clamp the drill rod (7), the two sets of half shafts (404) are assembled to form a complete cylindrical structure. A knob (8) is rotatably sleeved on one of the half shafts (404), and the knob (8) is circumferentially elastically connected to the half shaft (404). One of the chucks (4) is elastically connected to a locking pin (14) along its diameter. The side wall of the knob (8) is provided with a pin hole (803) that mates with the locking pin (14). The knob (8) and the chuck (4) can be locked by the engagement of the locking pin (14) and the pin hole (803). The chuck (4) has an inner ring plate (12) on its inner side. The chuck (4) clamps the drill rod (7) against the inner ring plate (12). When the clamp is locked with the power head (2) and the drill rod (7) drives the inner ring plate (12) to rotate synchronously, the locking state of the latch (14) on the knob (8) can be released.

2. The core drilling device for building pile foundations according to claim 1, characterized in that: The knob (8) is circumferentially rotated and axially fixed with the half shaft (404).

3. The core drilling device for building pile foundations according to claim 1, characterized in that: The outer circular surface of the half shaft (404) is integrally formed with a limiting part (4041) along its circumferential direction. The inner circular surface of the knob (8) is provided with a limiting groove that slides with the limiting part (4041). The limiting groove and the limiting part (4041) have T-shaped cross sections along the diameter direction of the half shaft (404).

4. The core drilling device for building pile foundations according to claim 1, characterized in that: The inner ring plate (12) has an arc-shaped projection along its own axis and is elastically fitted with the clamp (4) along the circumferential direction of the clamp (4). The outer circular surface of the inner ring plate (12) and the side near the locking pin (14) are recessed inward along the diameter direction to form a recessed part. A pressing member (15) is fixedly connected to the recessed part. The end of the pressing member (15) near the locking pin (14) is provided with a relief groove (1502). The end of the locking pin (14) extending into the clamp (4) is located in the relief groove (1502). At position 02), the outer circular surface of the locking pin (14) extends outward along its diameter to form two sets of semi-annular stop portions (1402), and the bottom end of the relief groove (1502) is located between the two stop portions (1402); the extrusion member (15) is an arc-shaped plate structure, and the center of the outer circular surface of the extrusion member (15) is coaxially arranged with the center of the inner ring plate (12). The thickness of the inner circular surface of the extrusion member (15) gradually increases in the direction away from the locking pin (14) and forms an extrusion portion (1501).

5. A core drilling device for building pile foundations according to claim 4, characterized in that: The outer surface of the chuck (4) extends outward along its diameter to form a protrusion, and a positioning post (10) is fixedly connected to the protrusion. The top of the outer shell of the power head (2) is fixedly connected to a positioning sleeve (201) that cooperates with the positioning post (10).

6. A core drilling device for building pile foundations according to claim 2, characterized in that: The outer circular surface of the half shaft (404) is integrally formed with a limiting part (4041) along its circumferential direction. The inner circular surface of the knob (8) is provided with a limiting groove that slides with the limiting part (4041). The limiting groove and the limiting part (4041) have T-shaped cross sections along the diameter direction of the half shaft (404).

7. A core drilling device for building pile foundations according to claim 1, characterized in that: The knob (8) can be chamfered (802) on the side near the clamp (4) and at both ends. When the knob (8) is offset from the locking pin (14), interference between the knob (8) and the locking pin (14) during rotation can be avoided.

8. A core drilling device for building pile foundations according to claim 1, characterized in that: The outer wall of the chuck (4) is provided with a through guide groove (405) along its circumference. The guide block (1201) fixed to the inner ring plate (12) passes through the guide groove (405) and slides with the guide groove (405).

9. A core drilling device for building pile foundations according to claim 1, characterized in that: The locking pin (14) is set as a semi-cylindrical shape and a slide bar (1401) is fixed to the outer surface of the locking pin (14). The locking pin (14) slides radially with the clamp (4) through the slide bar (1401).

10. A core sampling method based on the core drilling device for building pile foundations according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Place the drill rod (7) to be connected between the two chucks (4), close the two chucks (4) to make the two half shafts (404) fit together, turn the knob (8) across the outside of the two half shafts (404), and lock the knob (8) by the cooperation of the locking pin (14) and the pin hole (803) to clamp the drill rod (7). S2. Start the winch to wind up the rope (3), which will lift the clamp and drill rod (7) upward. Then slowly lower the rope (3) so that the drill rod (7) passes through the power head (2) from top to bottom. S3. Drive the power head (2) to move upward, so that the chuck (4) locks with the power head (2) and restricts the chuck (4) from rotating in the circumferential direction; S4. The internal slips of the power head (2) clamp the drill rod (7) and drive the drill rod (7) to rotate. The drill rod (7) synchronously drives the inner ring plate (12) to rotate circumferentially to unlock the knob (8) and the half shaft (404).

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