Road tunnel surrounding rock coring device
By designing bidirectional spiral drilling blades, retractable drill bits, and annular clamping parts, the problems of poor debris discharge, core breakage, and slippage in existing devices have been solved, thereby improving the integrity of the core and the success rate of core extraction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA FIRST HIGHWAY ENGINEERING CO LTD
- Filing Date
- 2026-02-05
- Publication Date
- 2026-04-17
AI Technical Summary
Existing highway tunnel core sampling equipment suffers from poor debris removal during drilling, cores are prone to breakage at the end of the sampling process, cores are prone to slipping when the drill rod is retracted, and the extraction method is prone to causing secondary damage.
It adopts a bidirectional spiral drilling blade design, a retractable drill bit and an annular clamping structure, combined with a core pushing mechanism with a drive cylinder pusher plate, to achieve efficient debris discharge, stable core cutting and firm clamping.
It improved the smoothness of cuttings removal, reduced drilling resistance, ensured the integrity of the core, reduced fractures and slippage, avoided secondary damage, and improved the success rate of core sampling.
Smart Images
Figure CN121875638A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of geological drilling technology, specifically to a core sampling device for surrounding rock of highway tunnels. Background Technology
[0002] In highway tunnel construction, the geological conditions of the surrounding rock directly determine the tunnel construction plan, the design of the support structure, and the overall safety and stability of the project. Therefore, core sampling of the surrounding rock is a crucial step in the quality control during the early geological exploration and construction phases of highway tunnel construction. Obtaining complete and undamaged rock cores allows for accurate analysis of core parameters such as lithological composition, structural density, fracture development, and compressive strength, providing vital geological data support for engineering decisions. However, existing highway tunnel core sampling devices still face several technical challenges in practical applications.
[0003] 1. Existing drilling devices mostly have drill bit designs in a single helical direction. During drilling, it is difficult to quickly and smoothly remove rock debris, which tends to accumulate at the contact surface between the drill rod and the surrounding rock, increasing drilling resistance and aggravating drill bit wear. At the same time, the backflow of debris may also scratch the obtained rock core and reduce the integrity of the rock core.
[0004] 2. In the final stage of core sampling, existing equipment generally uses direct extraction to remove the core, lacking a specialized lateral cutting mechanism. The connection between the core and the surrounding rock cannot be quickly and smoothly severed. During extraction, the core is subjected to uneven tensile and frictional forces, especially for structurally fragile or fractured cores, which are prone to breakage and fragmentation, resulting in the inability to obtain complete core samples and thus affecting the accuracy of geological parameter analysis.
[0005] 3. Some devices lack an effective core fixing structure, which makes it easy for the core to slip out of the core barrel during the drill pipe retraction process, resulting in core retrieval failure; while traditional core retrieval methods mostly rely on manual knocking or mechanical dragging, which is not only cumbersome to operate, but also easy to cause secondary damage to the core, affecting the accuracy of subsequent test results. Summary of the Invention
[0006] In view of the above-mentioned shortcomings in the prior art, the present invention provides a highway tunnel surrounding rock coring device that solves the problems of poor discharge of surrounding rock debris during drilling, easy breakage of rock cores due to the inability to cut laterally quickly and smoothly at the end of the coring process, easy slippage of rock cores when the drill rod is withdrawn, and easy secondary damage caused by the extraction method.
[0007] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: a core sampling device for surrounding rock of a highway tunnel, comprising a support frame, a core drilling rod, and a drive mechanism for driving the core drilling rod to rotate, wherein the support frame is provided with a feed mechanism for driving the core drilling rod to move toward the surrounding rock of the tunnel;
[0008] The core drill rod is a hollow cylindrical structure with an open front end. Inside the core drill rod, there is a core tube and a core pushing mechanism. The inner side wall of the front end of the core tube is provided with an inwardly protruding clamping part. The core pushing mechanism includes a pusher plate that can move along the axial direction of the core drill rod, which is used to push the rock core out of the core tube after the core is taken out.
[0009] The core drill rod includes a cylinder and a retractable drill bit located at the front end of the cylinder. The connection surface between the cylinder and the retractable drill bit is an inclined plane, and a slide rail is provided on the inclined plane. Spiral drill cutting blades are provided on the outer and inner walls of the cylinder. The retractable drill bit includes several circumferentially distributed cutting convex teeth. Adjacent cutting convex teeth are connected by a crank connecting rod. The connection surface between the cutting convex teeth and the cylinder is a wedge surface that matches the inclined plane. A spring is provided on the wedge surface, and the spring is connected to the track.
[0010] Furthermore, the aforementioned highway tunnel surrounding rock coring device includes a core pushing mechanism that further comprises a drive rod and a drive cylinder. One end of the drive rod is fixedly connected to the pusher plate, and the other end is connected to the output end of the drive cylinder. The drive cylinder is fixedly installed at the rear end of the core drilling rod.
[0011] Furthermore, in the aforementioned highway tunnel surrounding rock coring device, the front end of the cutting protrusion is provided with a diamond cutting edge, which is distributed in a serrated shape.
[0012] Furthermore, the aforementioned highway tunnel surrounding rock coring device includes a drive mechanism comprising a drive motor, a reduction gearbox, and a transmission gear set. The output end of the drive motor is connected to the input end of the reduction gearbox, and the output end of the reduction gearbox is connected to the coring drill rod via the transmission gear set.
[0013] Furthermore, the aforementioned highway tunnel surrounding rock core sampling device has a support frame including a base, columns, and a crossbeam. The columns are vertically fixed on both sides of the base, and the crossbeam is fixedly connected to the top of the two columns. The feeding mechanism is set on the crossbeam.
[0014] Furthermore, in the aforementioned highway tunnel surrounding rock coring device, the spiral drilling blades include outer wall blades and inner wall blades, with the spiral direction of the outer wall blades being opposite to that of the inner wall blades.
[0015] Furthermore, in the aforementioned highway tunnel surrounding rock coring device, the two ends of the crank connecting rod are movably connected to the adjacent cutting teeth via hinge joints.
[0016] Furthermore, in the aforementioned highway tunnel surrounding rock coring device, the diameter of the pusher plate is adapted to the inner diameter of the core cylinder, and the surface of the pusher plate is provided with an elastic buffer layer.
[0017] Furthermore, the aforementioned highway tunnel surrounding rock core sampling device has a ring-shaped protrusion structure for the clamping part, and its inner wall is provided with an anti-slip and wear-resistant layer.
[0018] Furthermore, the aforementioned highway tunnel surrounding rock coring device also includes a control system, which is electrically connected to the drive mechanism, the feeding mechanism, and the core pushing mechanism, and is used to control the start-up, shutdown, and operating parameters of each mechanism.
[0019] The beneficial effects of this invention are as follows:
[0020] 1. The outer and inner walls of the core drill pipe are each equipped with helical drilling blades, with the outer and inner blades having opposite helical directions. During drilling, the outer blades, through their reverse helical structure, quickly remove external rock debris, preventing debris accumulation at the contact surface between the drill pipe and the surrounding rock. The inner blades, through their reverse helical action, prevent internal debris from flowing back and damaging the formed core. This bidirectional helical cuttings removal design significantly improves the smoothness of cuttings removal, effectively reduces drilling resistance, minimizes drill bit wear, and ensures the integrity of the core surface.
[0021] 2. A retractable drill bit design is adopted. Through the engagement of the inclined plane and sliding rail between the cylinder and the cutting cams, as well as the linkage of the crank and connecting rod, the extension and retraction of the cutting cams are achieved. During drilling, the cutting cams extend outwards in a radial pattern, forming a larger cutting diameter to meet the requirements of efficient drilling. At the end of core sampling, the cutting cams retract inwards, reducing the overall diameter, allowing for rapid and stable lateral cutting of the connection between the core and the surrounding rock matrix. Compared to traditional direct extraction methods, this design avoids uneven tension and friction on the core, making it particularly suitable for structurally fragile or fractured cores, significantly reducing the probability of core breakage and fragmentation, and ensuring the acquisition of intact core samples.
[0022] 3. The inner wall of the annular clamping part on the inner side of the front end of the coring cylinder is equipped with an anti-slip and wear-resistant layer, which can firmly hold the rock core during retraction, effectively preventing the rock core from slipping out of the coring cylinder. This solves the problem of rock core easy detachment during coring in traditional devices and significantly improves the success rate of coring. The core pushing mechanism drives the pusher plate to move axially through a drive cylinder. The diameter of the pusher plate is precisely matched with the inner diameter of the coring cylinder, and the surface is equipped with an elastic buffer layer. After coring, the pusher plate can smoothly and evenly push the rock core out of the coring cylinder, replacing the traditional method of manual knocking or mechanical dragging, avoiding secondary damage to the rock core and ensuring the original state of the rock core. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the structure of the device;
[0024] Figure 2 A schematic diagram of a core drilling rod in which the cutting protrusions are distributed radially.
[0025] Figure 3 A schematic diagram of the core drilling rod with the cutting teeth in a contracted state;
[0026] Figure 4 A schematic diagram of the connection structure between two adjacent cutting protrusions;
[0027] Figure 5 This is a schematic diagram of the core drill rod and core cylinder.
[0028] Figure 6 This is a schematic diagram of the cross-sectional structure of the coring drill pipe;
[0029] The components are: 1. Core drill rod, 2. Feed mechanism, 3. Core cylinder, 4. Clamping part, 5. Push plate, 6. Cylinder, 7. Retractable drill bit, 8. Cutting teeth, 9. Crank connecting rod, 10. Inclined surface, 11. Wedge surface, 12. Spring, 13. Drive rod, 14. Drive cylinder, 15. Slide rail, 16. Drilling blade, 17. Drive motor, 18. Gearbox, 19. Transmission gear set, 20. Base, 21. Column, 22. Crossbeam, 23. Outer wall blade, 24. Inner wall blade. Detailed Implementation
[0030] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.
[0031] like Figures 1-6 As shown, this embodiment discloses a core sampling device for highway tunnels, which solves the problems of poor discharge of surrounding rock debris during drilling, easy breakage of the rock core due to the inability to cut laterally quickly and smoothly during the final stage of core sampling, and easy slippage of the rock core during drill rod retraction, which can easily cause secondary damage. The device includes a support frame, a core drilling rod 1, a drive mechanism for driving the core drilling rod 1 to rotate, a feed mechanism 2 for driving the core drilling rod 1 towards the tunnel surrounding rock, a core cylinder 3 and a core pushing mechanism disposed inside the core drilling rod 1, and a control system for controlling the start and stop of each mechanism and the operating parameters. The control system is electrically connected to the drive mechanism, the feed mechanism 2 and the core pushing mechanism respectively.
[0032] The support frame includes a base 20, columns 21, and a crossbeam 22. Columns 21 are vertically fixed to both sides of the base 20, and the crossbeam 22 is fixedly connected to the tops of the two columns 21. The feeding mechanism 2 is mounted on the crossbeam 22. The base 20 is made of Q235 steel plate and is rectangular in shape. Adjustable support feet are provided at the four corners of the bottom of the base 20, with an adjustment range of 0-100mm, to adapt to uneven ground in the tunnel and ensure the stability of the support frame. The columns 21 are made of seamless steel pipe of 45# steel. The lower end of the column 21 is vertically fixed to the base 20 by welding, and the weld is reinforced with fillet welds to ensure connection strength. The crossbeam 22 is also made of Q235 steel plate, and both ends of the crossbeam 22 are fixedly connected to the tops of the two columns 21 by bolts.
[0033] The drive mechanism includes a drive motor 17, a reduction gearbox 18, and a transmission gear set 19. The output end of the drive motor 17 is connected to the input end of the reduction gearbox 18, and the output end of the reduction gearbox 18 is connected to the core drill rod 1 via the transmission gear set 19. The drive motor 17 is a three-phase asynchronous motor, characterized by stable operation and sufficient power output, providing sufficient power for the rotation of the core drill rod 1. The reduction gearbox 18 uses a hardened cylindrical gear reducer, which can effectively transmit torque and reduce vibration during transmission. The transmission gear set 19 includes a driving gear and a driven gear. The driving gear is fixed on the output shaft of the reduction gearbox 18, and the driven gear is fixed on the outer wall of the core drill rod 1. The driving gear and the driven gear mesh with each other. After carburizing and quenching treatment, the tooth surface hardness reaches HRC58-62, the tooth width is 50mm, and the module is 4, ensuring the smoothness and wear resistance of the gear transmission, realizing the effective transmission of power from the drive motor 17, and driving the core drill rod 1 to rotate at a set speed.
[0034] The feed mechanism 2 is mounted on the crossbeam 22 and adopts a ball screw slide structure, including a ball screw, guide rails, a slide, and a feed motor. The guide rails are linear guide rails, with two parallel guide rails positioned on both sides of the ball screw and fixedly connected to the crossbeam 22. The length of the guide rails is the same as that of the ball screw. The slide is threaded to the ball screw and slides with the guide rails. The core drill rod 1 is fixedly connected to the slide via a bearing seat, allowing it to move along the guide rails with the slide. The feed motor is a servo motor, connected to one end of the ball screw via a coupling. The servo motor is equipped with a driver, enabling precise position and speed control. The feed speed of the feed mechanism 2 is adjustable from 0-50 mm / min, meeting the feed requirements under different core sampling conditions, and driving the core drill rod 1 to move smoothly towards the tunnel surrounding rock or back in the opposite direction.
[0035] The core drill rod 1 is a hollow cylindrical structure with an open front end, including a cylinder 6 and a retractable drill bit 7 set at the front end of the cylinder 6. The connection surface between the cylinder 6 and the retractable drill bit 7 is an inclined surface 10, and a slide rail 15 is set on the inclined surface 10. The outer wall and inner wall of the cylinder 6 are provided with helical drilling blades 16. The helical drilling blades 16 include an outer wall blade 23 and an inner wall blade 24. The helical direction of the outer wall blade 23 is opposite to that of the inner wall blade 24.
[0036] The cylinder 6 is made of seamless steel pipe with uniform wall thickness to ensure structural strength and rigidity. Slide rails 15 are mounted on the inclined surface 10 at the front end of the cylinder 6, with the inclined surface 10 forming a 30° angle with the axis of the cylinder 6. There are 10 slide rails 15, evenly distributed along the circumference of the cylinder 6. The cross-section of each slide rail 15 is T-shaped. The slide rails 15 are fixedly connected to the cylinder 6 by welding, and the weld joints are ground to ensure a smooth surface.
[0037] Both the outer wall cutting tool 23 and the inner wall cutting tool 24 are made of cemented carbide, featuring high hardness and high wear resistance. The outer wall cutting tool 23 has a helix angle of 20°, a right-hand helix direction, a width of 15mm, and a thickness of 5mm. It is fixed to the outer wall of the cylinder 6 by welding, with the cutting edge extending 5mm above the outer wall of the cylinder 6. The inner wall cutting tool 24 has a helix angle of 20°, a left-hand helix direction, a width of 15mm, and a thickness of 5mm. It is also fixed to the inner wall of the cylinder 6 by welding, with the cutting edge extending 5mm above the inner wall of the cylinder 6. The bidirectional helical drilling cutting tool 16 enables efficient removal of surrounding rock debris when the core drill rod 1 rotates, preventing debris accumulation and backflow.
[0038] The retractable drill bit 7 includes several circumferentially distributed cutting protrusions 8. Adjacent cutting protrusions 8 are connected by a crank connecting rod 9. The connection surface between the cutting protrusions 8 and the cylinder 6 is a wedge surface 11 that matches the inclined surface 10. A spring 12 is installed on the wedge surface 11, and the spring 12 is connected to the track. There are 10 cutting protrusions 8, evenly distributed along the circumference of the cylinder 6. The front end of each cutting protrusion 8 is provided with a diamond cutting edge, which is serrated and fixed to the cutting protrusion 8 by brazing to ensure a firm connection. The diamond cutting edge has high hardness and strong wear resistance, which can effectively improve cutting efficiency and adapt to surrounding rocks of different hardness.
[0039] The two ends of the crank connecting rod 9 are movably connected to the adjacent cutting teeth 8 through hinge joints, enabling the cutting teeth 8 to rotate flexibly during the extension and retraction process and ensuring the coordination of the movement of each cutting tooth 8. The spring 12 provided on the wedge surface 11 is a cylindrical helical compression spring 12. One end of the spring 12 is fixedly connected to the wedge surface 11 of the cutting tooth 8, and the other end is fixedly connected to the slide rail 15. In its natural state, the spring 12 pushes the cutting teeth 8 to extend outward along the slide rail 15, so that the retractable drill bit 7 is radially distributed to meet the drilling requirements; when retraction is required, under the action of external force, the cutting teeth 8 move inward along the slide rail 15, and the spring 12 is compressed.
[0040] The core barrel 3 is installed inside the core drill rod 1 and is arranged coaxially with it. The core barrel 3 is made of 304 stainless steel. The front end of the core barrel 3 is flush with the front end of the core drill rod 1, and the rear end is fixedly connected to the core drill rod 1 via a bracket. The bracket is bolted for easy disassembly and replacement of the core barrel 3. The inner side wall of the front end of the core barrel 3 has an inwardly protruding clamping part 4. The clamping part 4 is an annular protrusion structure, and its inner wall is provided with an anti-slip and wear-resistant layer. The anti-slip and wear-resistant layer is made of polyurethane material and is fixed to the inner wall of the clamping part 4 by adhesive. The surface of the anti-slip and wear-resistant layer is provided with anti-slip texture, which can enhance the clamping force on the rock core, prevent the rock core from slipping during retraction, and avoid damage to the rock core.
[0041] The core pushing mechanism includes a pusher plate 5, a drive rod 13, and a drive cylinder 14, all of which are axially movable along the core drill rod 1. One end of the drive rod 13 is fixedly connected to the pusher plate 5, and the other end is drively connected to the output end of the drive cylinder 14. The drive cylinder 14 is fixedly located at the rear end of the core drill rod 1. The pusher plate 5 is made of nylon and its diameter is matched to the inner diameter of the core cylinder 3. An elastic buffer layer is provided on the surface of the pusher plate 5. The elastic buffer layer is made of rubber and is fixedly connected to the pusher plate 5 by vulcanization. The elastic buffer layer can buffer and protect the core during the pushing process, preventing the core from being damaged by rigid impact.
[0042] The drive rod 13 is made of round steel, specifically 45# steel. One end of the drive rod 13 is fixedly connected to the pusher plate 5 via a thread, and the other end is connected to the output end of the drive cylinder 14 via a coupling. The drive cylinder 14 is a standard cylinder, which is fixed to the rear end of the core drill rod 1 by a bracket. The bracket is welded to the core drill rod 1. The drive cylinder 14 can provide a stable thrust, driving the pusher plate 5 to move axially along the core drill rod 1, pushing the rock core out of the core cylinder 3.
[0043] The control system includes a controller, a touch screen, sensors, and control circuitry. The controller is a PLC, characterized by high reliability, simple programming, and strong expandability. The touch screen is a human-machine interface (HMI) touch screen, connected to the PLC controller via a communication cable. It is used for parameter setting, status display, and operation control. Operators can use the touch screen to set parameters such as the speed of the drive motor 17, the feed speed of the feed mechanism 2, and the working pressure of the drive cylinder 14. Simultaneously, they can view the real-time operating status of each mechanism, such as the operating current of the drive motor 17, the position of the feed mechanism 2, and the rotational speed of the core drill rod 1.
[0044] The sensors include a speed sensor, a position sensor, and a pressure sensor. The speed sensor is a Hall effect speed sensor, installed on the output shaft of the drive motor 17, used to detect the speed of the drive motor 17 and transmit the signal to the controller. The position sensor is a photoelectric position sensor, installed on the guide rail of the feed mechanism 2, used to detect the position of the slide, and to achieve precise position control of the feed mechanism 2. The pressure sensor is a diffused silicon pressure sensor, installed at the air inlet of the drive cylinder 14, used to detect the working pressure of the drive cylinder 14, and to ensure the smoothness of the core pushing process. The control circuit uses copper core cable, model RVV. The appropriate wire diameter is selected according to the power and current requirements of each component. The control circuit is arranged through cable trays to ensure neatness and safety. The control system is electrically connected to the drive mechanism, feed mechanism 2, and core pushing mechanism through the control circuit to achieve coordinated operation of each mechanism.
[0045] The specific working process of this device is as follows:
[0046] 1. Installation and Debugging of the Device: Place the support frame in a suitable position inside the tunnel. Adjust the adjustable support feet at the bottom of the base 20 to keep the support frame level and stable. Then check the connection of each component to ensure that the bolts are tight, the welds are firm, and the connections are not loose. Set the speed of the drive motor 17 to 500 r / min, the feed speed of the feed mechanism 2 to 20 mm / min, and the working pressure of the drive cylinder 14 to 0.6 MPa via the touch screen. Start the control system and perform no-load operation debugging. Check the operating status of the drive mechanism, feed mechanism 2, and core pushing mechanism to ensure that each mechanism operates smoothly without abnormal noise, the core drill rod 1 rotates flexibly, the feed mechanism 2 is accurately positioned, and the pusher plate 5 moves smoothly.
[0047] 2. Core Sampling Operation: After debugging, the drive mechanism is started. The drive motor 17 drives the core drill rod 1 to rotate through the reduction gearbox 18 and the transmission gear set 19. After the rotation speed of the core drill rod 1 reaches the set value, the feed mechanism 2 is started, driving the core drill rod 1 towards the surrounding rock of the tunnel to begin drilling. During drilling, the cutting teeth 8 of the retractable drill bit 7 extend outward in a radial pattern under the action of the spring 12. The diamond cutting edge cuts the surrounding rock. The right-hand spiral outer wall blade 23 on the outer wall of the cylinder 6 discharges the debris from the outside of the surrounding rock outward, preventing debris from accumulating at the contact surface between the drill rod and the surrounding rock. The left-hand spiral inner wall blade 24 on the inner wall of the cylinder 6 prevents internal debris from flowing back and avoids scratching the formed rock core. The bidirectional spiral chip removal design ensures smooth chip removal and reduces drilling resistance.
[0048] 3. Core Cutting and Retraction: Once the core reaches the set depth, the control system stops the feed mechanism 2 and simultaneously reduces the rotational speed of the core drill rod 1 to 100 r / min. Then, the control system sends a signal to retract the cutting teeth 8 of the retractable drill bit 7 inwards. The cutting teeth 8 move along the slide rail 15 at the front end of the cylinder 6. Adjacent cutting teeth 8 are linked by the crank connecting rod 9 to achieve synchronous retraction. During retraction, the cutting teeth 8 rapidly and smoothly cut the connection between the core and the surrounding rock, severing the connection. While the cutting teeth 8 are cutting laterally, the clamping part 4 at the front end of the core cylinder 3 retracts synchronously under the thrust of the cutting teeth 8. The clamping part 4 firmly holds the core through the anti-slip and wear-resistant layer, preventing the core from falling out.
[0049] After the cutting is completed, the control system controls the feed mechanism 2 to run in reverse, driving the core drill rod 1 to retract. During the retraction process, the clamping part 4 inside the core tube 3 continues to hold the rock core to prevent the rock core from slipping.
[0050] 4. Core Removal: After the coring drill rod 1 retracts to its initial position, the control system stops the drive mechanism and then activates the core pushing mechanism. The drive cylinder 14 operates, pushing the drive rod 13 and the pusher plate 5 along the axial direction of the coring drill rod 1. The pusher plate 5 moves smoothly within the coring cylinder 3, pushing the core out of the cylinder. The elastic buffer layer on the surface of the pusher plate 5 protects the core from damage. After core removal, the control system resets the drive cylinder 14, and the pusher plate 5 returns to its initial position, completing one coring operation.
[0051] This device employs bidirectional spiral-distributed drill bit 16, with the outer wall bit 23 and inner wall bit 24 spiraling in opposite directions. This achieves efficient removal of surrounding rock debris, avoiding damage to the core caused by debris accumulation and backflow, reducing drilling resistance, and minimizing drill bit wear. The retractable drill bit 7 design enables rapid and stable lateral cutting of the connection between the core and the surrounding rock matrix during the final stage of core extraction, avoiding core breakage and fragmentation problems caused by traditional extraction methods and ensuring the integrity of the core. The clamping part 4 at the front end of the core cylinder 3, combined with an anti-slip and wear-resistant layer, effectively prevents the core from slipping during retraction, improving the core extraction success rate. The core pushing mechanism, driven by the drive cylinder 14, drives the pusher plate 5 to smoothly push out the core, replacing the traditional manual knocking or mechanical dragging methods. This avoids secondary damage to the core, preserves the original state of the core, and provides accurate and reliable core samples for subsequent geological parameter analysis, meeting the quality control needs of geological exploration and construction during highway tunnel construction.
Claims
1. A device for coring the surrounding rock of a highway tunnel, characterized in that, It includes a support frame, a core drill rod (1) and a drive mechanism for driving the core drill rod (1) to rotate. The support frame is provided with a feed mechanism (2) for driving the core drill rod (1) to move toward the surrounding rock of the tunnel. The core drill rod (1) is a hollow cylindrical structure with an open front end. The core drill rod (1) is equipped with a core tube (3) and a core pushing mechanism. The inner side wall of the front end of the core tube (3) is provided with an inwardly protruding clamping part (4). The core pushing mechanism includes a pusher plate (5) that can move along the axial direction of the core drill rod (1) and is used to push the rock core out of the core tube (3) after the core is taken. The core drill rod (1) includes a cylinder (6) and a retractable drill bit (7) set at the front end of the cylinder (6). The connection surface between the cylinder (6) and the retractable drill bit (7) is an inclined plane (10), and a slide rail (15) is provided on the inclined plane (10). The outer and inner walls of the cylinder (6) are provided with spiral drill cutting blades (16). The retractable drill bit (7) includes a number of circumferentially distributed cutting teeth (8). Adjacent cutting teeth (8) are connected by a crank connecting rod (9). The connection surface between the cutting teeth (8) and the cylinder (6) is a wedge surface (11) that matches the inclined plane (10). A spring (12) is provided on the wedge surface (11), and the spring (12) is connected to the track.
2. The highway tunnel host rock coring device according to claim 1, characterized in that, The core pushing mechanism also includes a drive rod (13) and a drive cylinder (14). One end of the drive rod (13) is fixedly connected to the push plate (5), and the other end is connected to the output end of the drive cylinder (14). The drive cylinder (14) is fixedly installed at the rear end of the core drill rod (1).
3. The highway tunnel surrounding rock coring device according to claim 1, characterized in that, The cutting tooth (8) has a diamond cutting edge at its front end, and the diamond cutting edge is distributed in a serrated shape.
4. The highway tunnel host rock coring device of claim 1, wherein, The drive mechanism includes a drive motor (17), a reduction gearbox (18), and a transmission gear set (19). The output end of the drive motor (17) is connected to the input end of the reduction gearbox (18), and the output end of the reduction gearbox (18) is connected to the core drill rod (1) through the transmission gear set (19).
5. The highway tunnel host rock coring device of claim 1, wherein, The support frame includes a base (20), columns (21) and a crossbeam (22). The columns (21) are vertically fixed on both sides of the base (20), and the crossbeam (22) is fixedly connected to the top of the two columns (21). The feeding mechanism (2) is set on the crossbeam (22).
6. The highway tunnel host rock coring device of claim 1, wherein, The spiral drilling blade (16) includes an outer wall blade (23) and an inner wall blade (24), wherein the spiral direction of the outer wall blade (23) is opposite to that of the inner wall blade (24).
7. The highway tunnel surrounding rock coring device according to claim 1, characterized in that, The two ends of the crank connecting rod (9) are movably connected to the adjacent cutting teeth (8) through hinge joints.
8. The highway tunnel surrounding rock coring device according to claim 2, characterized in that, The diameter of the pusher plate (5) is adapted to the inner diameter of the core tube (3), and the surface of the pusher plate (5) is provided with an elastic buffer layer.
9. The highway tunnel host rock coring device of claim 1, wherein, The clamping part (4) is an annular protrusion structure, and its inner wall is provided with an anti-slip and wear-resistant layer.
10. The highway tunnel host rock coring device of claim 1, wherein, The device also includes a control system, which is electrically connected to the drive mechanism, the feed mechanism (2) and the core pusher mechanism respectively, and is used to control the start-up and stop and operating parameters of each mechanism.