A tunnel boring machine capable of excavating structures with a large inner surface and a small outer surface.

Abstract

This invention discloses a tunnel boring device capable of excavating structures with a larger internal structure and a smaller external structure, belonging to the field of tunnel construction technology. It includes a rod body, a universal coupling, a main shaft, a drilling bit, a drill bit support, an electric expansion joint, a fixed base, a first fixed support rod, and a second fixed support rod. A rotation drive device is installed inside the rod body, connected to the main shaft via the universal coupling. The main shaft is rotatably connected to the drilling bit via bearings, and the drilling bit is simultaneously rotatably mounted on the outer end of the drill bit support. An electric expansion joint and the first fixed support rod are fixedly installed on the rod body near the drill bit support, arranged on opposite sides of the universal coupling. The outer ends of the electric expansion joint and the first fixed support rod are respectively hinged to the fixed base and the second fixed support rod. The fixed base and the second fixed support rod are simultaneously fixed to the drill bit support near the rod body. This invention solves the technical problems of poor anchoring reliability and cumbersome construction process of traditional circular drill bits.

Description

Technical Field

[0001] This invention belongs to the field of tunnel construction technology, specifically relating to a tunnel excavation device capable of excavating a tunnel with a large inner structure and a small outer structure. Background Technology

[0002] In tunnel support construction, the coordinated anchoring of anchor bolts and concrete is a core technology for ensuring the stability of the surrounding rock. Traditional tunnel excavation uses fixed-diameter circular drill bits, resulting in a uniform cylindrical structure in the excavated borehole. The bond between the anchor bolt and the concrete and soil relies solely on static friction at the contact surface. This traditional structure has several technical drawbacks: First, the static friction is easily attenuated by deformation, vibration, and changes in temperature and humidity of the surrounding rock, leading to anchor bolt loosening, reduced anchoring force, and in severe cases, support failure. Second, the smooth cylindrical surface cannot form a mechanical interlocking effect, and the concrete has weak shear resistance after solidification, making it prone to interface slippage under long-term loads. Therefore, there is an urgent need for a tunnel excavation device capable of excavating structures with a larger inner diameter and a smaller outer diameter, which can solve the technical problems of poor anchoring reliability and cumbersome construction process associated with traditional circular drill bits. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a tunnel excavation device that can excavate a structure with a large inner diameter and a small outer diameter, which can solve the technical problems of poor anchoring reliability and cumbersome construction process of traditional circular drill bits.

[0004] To achieve the above objectives, the present invention provides the following technical solution: This invention discloses a tunnel boring device capable of excavating structures with a larger inner structure and a smaller outer structure. It includes a rod body, a universal coupling, a main shaft, a drilling bit, a drill bit support, an electric expansion joint, a fixed base, a first fixed support rod, and a second fixed support rod. A rotation drive device is installed inside the rod body, connected to the main shaft via the universal coupling. The main shaft is rotatably connected to the drilling bit via bearings. The drilling bit is simultaneously rotatably mounted on the outer end of the drill bit support. An electric expansion joint and the first fixed support rod are fixedly installed on the rod body near the drill bit support. The electric expansion joint and the first fixed support rod are arranged on opposite sides of the universal coupling. The outer ends of the electric expansion joint and the first fixed support rod are respectively hinged to the fixed base and the second fixed support rod. The fixed base and the second fixed support rod are simultaneously fixed to the drill bit support near the rod body. The electric expansion joint can drive the drill bit support and the drilling bit to deflect around the hinge point of the first and second fixed support rods.

[0005] Furthermore, the drill bit support is a cylindrical structure. Water spray holes and water suction holes are evenly opened along the circumference of the circumferential wall of the drill bit support. The water spray holes and water suction holes are connected to one end of the water inlet pipe and the water outlet pipe through the water spray channel and the water suction channel opened inside the drill bit support, respectively. The other end of the water inlet pipe and the water outlet pipe passes through the inside of the rod body and is connected to the water tank. A water pump is connected to both the water inlet pipe and the water outlet pipe.

[0006] Furthermore, the water tank is equipped with both a clean water zone and a wastewater zone, with the wastewater zone located above the clean water zone. A filter membrane is installed between the clean water zone and the wastewater zone.

[0007] Furthermore, a rubber sleeve is installed at the steering structure between the rod body and the drill bit support. The two ends of the rubber sleeve are fixedly connected to the rod body and the drill bit support, respectively. The universal coupling, electric expansion joint, fixed seat, first fixed support rod, and second fixed support rod are all located inside the rubber sleeve.

[0008] Furthermore, the tunneling drill bit is a cone-shaped rotating structure with multiple sets of frustoconical alloy teeth on the outer side along the axial direction, and multiple sets of chip removal grooves are evenly distributed on the outer side of the tunneling drill bit in the circumferential direction.

[0009] Furthermore, the tunneling drill bit is evenly spaced around the circumference with deflection tools, which include a grooved rail, a drill bit, and an elastic spring. One end of the grooved rail is fixedly connected to the tunneling drill bit. The grooved rail extends along the length of the chip removal groove, and the groove of the grooved rail corresponds to the chip removal groove of the tunneling drill bit. The drill bit is slidably mounted on the grooved rail, and the end of the drill bit away from the tunneling drill bit extends out from the grooved rail. An elastic spring connects the drill bit and the grooved rail.

[0010] Furthermore, multiple elastic paddles are evenly spaced along the length of the bottom of the chip removal groove corresponding to the groove rail, and a spring steel block is fixed between two adjacent elastic paddles. A protrusion is fixed at the bottom of the drill bit, and the protrusion contacts the elastic paddle.

[0011] The beneficial effects of this invention are as follows: The present invention discloses a tunnel boring device capable of excavating structures with a larger inner diameter and a smaller outer diameter. By installing an electric expansion joint between the rod body and the drill bit support, the radial direction of the drilling bit can be changed, thereby excavating structures with a larger inner diameter and a smaller outer diameter, meeting the needs of tunnel construction in actual processes.

[0012] This invention achieves a stepped formation of "cavity one (outer small diameter) → cavity two (middle diameter) → cavity three (inner large diameter)" through the synergistic action of the directional drive mechanism and the support positioning component. After the concrete solidifies, it forms a mechanical interlocking structure similar to an "inverted cone anchor bolt", which greatly improves the anchoring force compared to traditional circular holes and effectively resists the effects of surrounding rock deformation and vibration. Attached Figure Description

[0013] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration: Figure 1 This is a schematic diagram of the structure of Example 1; Figure 2 This is a schematic diagram of the rubber sleeve structure; Figure 3 This is a structural diagram of the excavated tunnel. Figure 4 This is a structural diagram of the three chambers; Figure 5 This is a schematic diagram of the structure of Example 2; Figure 6 for Figure 5 Enlarged view of point A in the middle; Figure 7 This is a schematic diagram of the elastic lever.

[0014] The following are the markings in the attached diagram: 1. Rod body; 2. Universal coupling; 3. Main shaft; 4. Drill bit; 5. Drill bit support; 6. Electric expansion joint; 7. Fixed base; 8. First fixed support rod; 9. Second fixed support rod; 10. Rotary drive device; 11. Water spray hole; 12. Water inlet pipe; 13. Water outlet pipe; 14. Water tank; 15. Clean water area; 16. Sewage area; 17. Filter membrane; 18. Rubber sleeve; 19. Chip removal trough; 20. Track rail; 21. Drill cutter; 22. Elastic tension spring; 23. Elastic lever; 24. Spring steel block; 25. Protrusion; 26. Rock stratum; 27. Excavated tunnel; 28. Tunnel 1; 29. ​​Tunnel 2; 30. Tunnel 3; 31. Detailed Implementation

[0015] Example 1, as Figures 1-4 As shown, the present invention discloses a tunnel boring device capable of excavating a structure with a large inner surface and a small outer surface, comprising a rod body 1, a universal coupling 2, a main shaft 3, a drilling bit 4, a drill bit support 5, an electric telescopic device 6, a fixed base 7, a first fixed support rod 8, and a second fixed support rod 9. The rod body 1 is a long rod-shaped structure, and a rotation drive device 10 is installed inside the rod body 1. The rotation drive device 10 is a geared motor. The rotation drive device 10 is connected to the main shaft 3 through the universal coupling 2. The main shaft 3 is rotatably connected to the drilling bit 4 through a bearing. The drilling bit 4 is rotatably mounted on the outer end of the drill bit support 5. The geared motor drives the drilling bit 4 to rotate through the main shaft 3. The drill bit support 5 provides a support platform for the drilling bit 4. An electric expansion joint 6 and a first fixed support rod 8 are fixedly installed on one end of the rod body 1 near the drill bit support 5. The electric expansion joint 6 and the first fixed support rod 8 are arranged on both sides of the universal coupling 2. The outer ends of the electric expansion joint 6 and the first fixed support rod 8 are respectively hinged to the fixed seat 7 and the second fixed support rod 9. Similarly, the fixed seat 7 and the second fixed support rod 9 are arranged on both sides of the main shaft 3. The axes of the electric expansion joint 6, the first fixed support rod 8, the fixed seat 7, the second fixed support rod 9, and the main shaft 3 are all located in the same plane. The fixed seat 7 and the second fixed support rod 9 are simultaneously fixed to the end of the drill bit support 5 near the rod body 1. The electric expansion joint 6 can drive the drill bit support 5 and the drilling bit 4 to rotate around the hinge fulcrum of the first fixed support rod 8 and the second fixed support rod 9. A self-lubricating bearing is provided at the hinge of the first fixed support rod 8 and the second fixed support rod 9 to reduce rotational wear.

[0016] The diameter of the drill bit support 5 is the same as the diameter of the rod 1. When a change of direction is required for tunneling, the electric expansion joint 6 extends; when straight tunneling is required or the device needs to be reset, the electric expansion joint 6 retracts, driving the front-end tunneling drill bit 4 back to a straight state. The electric expansion joint 6 is linked to the power system of the tunnel excavation equipment and is equipped with an independent control module. It can adjust the extension amount wirelessly to achieve remote and precise control of the drill bit diameter.

[0017] In this embodiment, the drill bit support 5 is a cylindrical structure. Water spray holes 11 and water suction holes 12 are evenly distributed along the circumferential direction on the circumferential wall of the drill bit support 5. The water spray holes 11 and water suction holes 12 are connected to one end of the inlet pipe 13 and the outlet pipe 14 respectively through water spray channels and water suction channels opened inside the drill bit support 5. The other ends of the inlet pipe 13 and the outlet pipe 14 pass through the inside of the rod body 1 and connect to the water tank 15. Water pumps are connected to both the inlet pipe 13 and the outlet pipe 14. The water tank 15 contains both a clean water zone 16 and a wastewater zone 17. The wastewater zone 17 is located above the clean water zone 16, and a filter membrane 18 is installed between the clean water zone 16 and the wastewater zone 17. Using this structure, functions such as cooling and lubrication, active mud suction, mud-water filtration, and clean water circulation can be achieved without the need for additional cooling equipment or slag removal devices, reducing equipment switching frequency and greatly improving construction efficiency.

[0018] The suction hole 12 actively draws in the mud-water mixture, preventing wastewater from flowing out and polluting the working environment; the water purification and circulation system achieves a water resource utilization rate of over 90%, significantly reducing construction water consumption. The drilling bit 4 and spindle 3 are detachably connected, and the filter membrane 18 can be disassembled and cleaned separately, reducing maintenance costs and downtime.

[0019] In this embodiment, a rubber sleeve 19 is installed at the steering structure between the rod body 1 and the drill bit support 5. Both ends of the rubber sleeve 19 are fixedly connected to the rod body 1 and the drill bit support 5, respectively. The universal coupling 2, electric expansion joint 6, fixed seat 7, first fixed support rod 8, and second fixed support rod 9 are all located inside the rubber sleeve 19. The rubber sleeve 19 can comprehensively block the erosion of the internal transmission components of the steering drive mechanism by mud, water, and soil particles in the construction environment, significantly improving the durability of the device in complex soil and rock construction environments and extending its overall service life.

[0020] In this embodiment, the tunneling drill bit 4 is a cone-shaped rotating body structure. Multiple sets of frustoconical alloy teeth are opened on the outer side of the tunneling drill bit 4 along the axial direction. Multiple sets of chip removal grooves 20 are evenly opened on the outer side of the tunneling drill bit 4 in the circumferential direction, which can facilitate tunnel construction.

[0021] Example 2, as Figure 5-7As shown, unlike Embodiment 1, in this embodiment, deflection tools are evenly spaced along the circumference of the tunneling drill bit 4. The deflection tools include a groove rail 21, a drill bit 22, and an elastic spring 23. One end of the groove rail 21 is fixedly connected to the tunneling drill bit 4. The groove rail 21 extends along the length of the chip removal groove 20, and the groove opening of the groove rail 21 corresponds to the chip removal groove 20 of the tunneling drill bit 4. The drill bit 22 is slidably mounted on the groove rail 21, with one end of the drill bit 22 extending from the groove rail 21 away from the tunneling drill bit 4. An elastic spring 23 connects the drill bit 22 and the groove rail 21. By providing additional deflection tools, this invention can assist drilling when the tunneling drill bit 4 changes direction. The drill bit 22 can also move along the length of the groove rail 21, reducing the occurrence of jamming and other problems, and improving the smoothness of the device's construction process.

[0022] In this embodiment, multiple elastic paddles 24 are evenly spaced along the length of the bottom of the chip removal groove 20 corresponding to the groove rail 21. A spring steel block 25 is fixed between two adjacent elastic paddles 24. A protrusion 26 is fixed to the bottom of the drill bit 22, and the protrusion 26 contacts the elastic paddles 24. By setting the elastic paddles 24, the present invention can buffer and dampen the drill bit 22 when it moves back and forth under the driving action of the rock, soil and elastic tension spring 23 during drilling, further improving the smoothness of the device during use.

[0023] The construction process of this invention is as follows: Device positioning and initialization: Determine the tunneling point through construction surveying, fix the device at the output end of the tunnel excavation equipment, start the control module to initialize the electric expansion joint 6, and keep the tunneling drill bit 4 in a straight line; check the sealing of the water circulation filtration system, inject clean water into the clean water area 16, and ensure that the water spray hole 11 and water suction hole 12 are unobstructed.

[0024] Formation of Cavern 29: The drive motor of the main shaft 3 is started, driving the drilling bit 4 to rotate at a speed of 800-1200 r / min. Simultaneously, the water circulation system is started, and the water inlet pipe 13 transports clean water from the clean water zone 16 to the water spray hole 11, which sprays out at a flow rate of 5-8 L / min to cool the drill bit and wet the mud and sand. The drilling bit 4 first advances in a straight rotation. After advancing a certain distance, the telescopic rod is adjusted by the control module to make the drilling bit 4 gradually turn, thereby forming cavern 29 in the rock stratum 27. At the same time, the water suction hole 12 actively sucks up the mud-water mixture under negative pressure and transports it to the sewage zone 17 through the water outlet pipe 14.

[0025] Formation of Cavern 2 30: After the formation of Cavern 1 29, the drilling bit 4 continues to rotate. The electric expansion joint 6 is activated through the control module, driving the expansion rod to gradually retract. The first fixed support rod 8 and the second fixed support rod 9 rotate around the hinge point back to a collinear state, driving the drilling bit 4 back to a straight state. Then, the propulsion device continues to advance a certain distance. The expansion rod is adjusted through the control module to make the drilling bit 4 gradually turn, thus forming Cavern 2 30. The mud-water mixture is continuously pumped through the suction hole 12 to the sewage area 17. After being filtered by the filter membrane 18, the clean water flows into the clean water area 16 for recycling.

[0026] Formation of Cavern 31: Repeat the above operation to finally form a stepped mechanical interlocking structure similar to an "inverted cone anchor bolt" with a larger inner diameter and a smaller outer diameter in the rock layer 27, which is "Cavern 1 29 → Cavern 2 30 → Cavern 3 31" to meet the requirements of high-strength anchoring.

[0027] Anchoring operation and device reset: After the excavation of the last cavern is completed, the main shaft 3 and water circulation system are shut down, the electric expansion joint 6 is controlled to retract, and the device is withdrawn; anchor rods are inserted into the excavated cavern 28, and early-strength concrete is poured in. After the concrete solidifies, it forms a mechanical interlock with the stepped cavern, and the anchoring force of the anchor rods is improved compared with traditional circular holes.

[0028] Key parameter control The telescopic device has a stepless adjustment accuracy of ±0.1mm; Spindle 3 rotation speed: 800-1500r / min, suitable for different hardness soil and rock masses; Water flow rate from spray hole 11: 5-8 L / min; negative pressure from suction hole 12: -10 to -15 kPa. Filter membrane 18: filtration accuracy: 50μm, water resource recycling rate ≥90%.

[0029] This invention solves the problems of poor anchoring reliability, construction pollution, and low efficiency of traditional circular drill bits through innovative designs such as stepped inner-large and outer-small structure forming, multi-functional integration, and water circulation filtration. The device has a compact structure, is easy to operate, and has low maintenance costs. It can be widely used in engineering scenarios such as tunnel support, slope reinforcement, and foundation anchoring, and has significant engineering practical value and promotion prospects.

Claims

1. A tunnel boring machine capable of excavating a structure with a large inner surface and a small outer surface, characterized in that: The device includes a rod body, a universal coupling, a main shaft, a tunneling drill bit, a drill bit support, an electric expansion joint, a fixed base, a first fixed support rod, and a second fixed support rod. A rotation drive device is installed inside the rod body, which is connected to the main shaft via the universal coupling. The main shaft is rotatably connected to the tunneling drill bit via bearings. The tunneling drill bit is simultaneously rotatably mounted on the outer end of the drill bit support. An electric expansion joint and the first fixed support rod are fixedly installed on one end of the rod body near the drill bit support. The electric expansion joint and the first fixed support rod are arranged on both sides of the universal coupling. The outer ends of the electric expansion joint and the first fixed support rod are respectively hinged to the fixed base and the second fixed support rod. The fixed base and the second fixed support rod are simultaneously fixed to the end of the drill bit support near the rod body. The electric expansion joint can drive the drill bit support and the tunneling drill bit to deflect around the hinge point of the first and second fixed support rods.

2. The tunnel boring machine capable of excavating a structure with a large inner surface and a small outer surface according to claim 1, characterized in that: The drill bit support is a cylindrical structure. Water spray holes and water suction holes are evenly distributed along the circumference of the circumferential wall of the drill bit support. The water spray holes and water suction holes are connected to one end of the water inlet pipe and the water outlet pipe through the water spray channel and the water suction channel opened inside the drill bit support, respectively. The other end of the water inlet pipe and the water outlet pipe passes through the inside of the rod body and is connected to the water tank. A water pump is connected to both the water inlet pipe and the water outlet pipe.

3. A tunnel boring machine capable of excavating a structure with a large inner surface and a small outer surface, as described in claim 2, is characterized in that: The water tank is equipped with both a clean water zone and a wastewater zone. The wastewater zone is located above the clean water zone, and a filter membrane is installed between the clean water zone and the wastewater zone.

4. A tunnel boring machine capable of excavating a structure with a large inner surface and a small outer surface, as described in claim 3, is characterized in that: A rubber sleeve is installed at the steering structure between the rod body and the drill bit support. The two ends of the rubber sleeve are fixedly connected to the rod body and the drill bit support, respectively. The universal coupling, electric expansion joint, fixed seat, first fixed support rod, and second fixed support rod are all located inside the rubber sleeve.

5. A tunnel boring machine capable of excavating a structure with a large inner surface and a small outer surface, as described in claims 1-4, characterized in that: The tunneling drill bit is a cone-shaped rotating structure. Along the axial direction, multiple sets of frustoconical alloy teeth are opened on the outer side of the tunneling drill bit, and multiple sets of chip removal grooves are evenly opened on the outer side of the tunneling drill bit in the circumferential direction.

6. A tunnel boring machine capable of excavating a structure with a large inner surface and a small outer surface, as described in claim 5, is characterized in that: The tunneling drill bit is equipped with deflection tools evenly spaced along its circumference. The deflection tools include a grooved rail, a drill bit, and an elastic spring. One end of the grooved rail is fixedly connected to the tunneling drill bit. The grooved rail extends along the length of the chip removal groove. The groove of the grooved rail corresponds to the chip removal groove of the tunneling drill bit. The drill bit is slidably mounted on the grooved rail. The end of the drill bit away from the tunneling drill bit extends out of the grooved rail. An elastic spring connects the drill bit and the grooved rail.

7. A tunnel boring machine capable of excavating a structure with a large inner surface and a small outer surface, as described in claim 6, is characterized in that: The bottom of the chip removal groove corresponding to the groove rail is fixed with multiple elastic paddles evenly spaced along its length. A spring steel block is fixed between two adjacent elastic paddles. A protrusion is fixed to the bottom of the drill bit, and the protrusion contacts the elastic paddles.

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