Anti-sloughing drilling tool for upper drill hole of weak rock tunnel

Abstract

The utility model discloses an anti-sloughing drilling tool for drilling holes in the upper portion of a weak rock tunnel, which comprises a drill bit, a drill rod, an anchor sealing structure and a spray hole, and the anchor sealing structure is connected to the lower portion of the drill rod. The anchor sealing structure comprises a fixed chassis, a movable sash, a positioning pin shaft, a first pin shaft, a swinging connecting rod and a second pin shaft; movable sashes are hinged to the head end of the swing connecting rod through pin shafts, the movable sashes are distributed in a petal shape, one corner of each movable sash is connected with a positioning pin shaft, the positioning pin shafts are fixed to the fixed base plate, and the movable sashes can rotate around the positioning pin shafts; when the fixed chassis rotates, the position of the positioning pin shaft is fixed, and the swing connecting rod and the second pin shaft push the movable sash to rotate around the positioning pin shaft, so that the movable sash is closed and opened; when the movable fan is completely opened, the drill rod can pass through the hole in the center of the fixed chassis, and when the movable fan is completely closed, the hole in the center of the fixed chassis is blocked.

Description

Technical Field

[0001] This utility model belongs to the field of drilling tool technology, specifically relating to a drilling tool for preventing collapse in the upper part of tunnels in weak rock. Background Technology

[0002] During the construction of tunnels and underground projects, geological disasters such as collapses, rock bursts, and sudden water and mud inrushes are frequently encountered, seriously threatening the safe construction of tunnels and underground projects. Among these, tunnel surrounding rock collapse is one of the most common geological disasters in jointed hard rock tunnels. It is characterized by strong concealment, suddenness, destructiveness, and catastrophic potential. The disaster process involves the gradual destruction of jointed rock mass and the large-scale collapse of dangerous block groups, making prevention and control extremely difficult and causing serious economic and property losses and casualties every year.

[0003] With the increasing number of tunnel projects in my country, the probability of tunnels with deep burial, high ground stress, large deformation, and complex geology is increasing. Tunnels in weak rock are characterized by high construction difficulty, complex ground stress structure, susceptibility to plastic failure, and strong fluidity, resulting in poor surrounding rock stability. This has always been a key challenge for tunnel construction, support, and maintenance both domestically and internationally.

[0004] Among the existing patents related to construction technology, the application publication number "CN115434737A" describes a device and method for preventing the collapse of anchor bolt drilling holes in soft rock tunnels. This method can prevent the collapse of the holes to a certain extent. However, when grouting after drilling the upper part of a soft rock tunnel, the cement grout in the hole may fall off due to its own weight during the grouting process, resulting in insufficient cement grout being injected into the upper part of the hole. At the same time, the cement grout may also fall off due to its own weight during the sealing of the anchor. This patent does not take this into full consideration. Utility Model Content

[0005] This utility model provides a drilling tool for preventing collapse during drilling in the upper part of a tunnel in weak rock. The purpose is to address the technical problem that cement grout may fall off during grouting in the upper part of a tunnel in weak rock, making it difficult to complete the sealing and anchoring.

[0006] Therefore, the present invention adopts the following technical solution:

[0007] A drilling tool for preventing collapse in the upper part of tunnels in weak rock includes a drill bit, a drill rod, a sealing and anchoring structure and a blowhole, wherein the sealing and anchoring structure is connected to the lower part of the drill rod;

[0008] The sealing and anchoring structure includes a fixed base, a movable fan, a positioning pin, a first pin, a swing connecting rod, and a second pin. The fixed base is disc-shaped with a circular hole in the center. The inner diameter of the circular hole is equal to the outer diameter of the drill rod, and the drill rod passes through the circular hole.

[0009] Multiple swing links are connected to the upper surface of the fixed chassis. The multiple swing links are located at the edge of the fixed chassis and are arranged in a ring. The tail end of the swing link is hinged to a first pin, which is vertically fixed to the fixed chassis. The head end of the swing link is hinged to a movable fan through a pin. Each movable fan is distributed in a petal shape. A positioning pin is connected to one corner of the movable fan, which is fixed to the fixed chassis. The movable fan can rotate around the positioning pin.

[0010] When the fixed chassis rotates, the position of the positioning pin remains unchanged. The swing linkage and the second pin push the movable fan to rotate around the positioning pin, thereby realizing the opening and closing of the movable fan. When the movable fan is fully open, the drill rod can pass through the hole in the center of the fixed chassis. When the movable fan is fully closed, the hole in the center of the fixed chassis is blocked.

[0011] Furthermore, the swing linkage is an arc-shaped rod, and the movable fan is crescent-shaped.

[0012] Furthermore, the support structure is a ring structure, fixedly connected to the upper part of the drill pipe, and the support structure is close to the drill bit;

[0013] The support structure includes a movable ring, a support cylinder, a transition ring, and a connecting ring. The support structure is equipped with rolling bearings, which are sleeved on the drill rod so that the outside of the support structure does not rotate when the drill rod rotates.

[0014] The positional relationship of the components in the support structure is as follows: the inner wall of the movable ring is tightly attached to the support ring of the support structure. The movable ring has multiple circular holes along the circumferential direction. A solid connecting ring is hung on each circular hole. A support cylinder is hung on each solid connecting ring. The support cylinder is vertically downward and tightly attached to the drill pipe wall. A transition ring is set at the lower part of the support cylinder. The support ring is spliced ​​together from 8 hollow rings. A pull ring line is set at the support ring to lock the support ring. The pull ring line is set outside the hole. During grouting, the pull ring is pulled down, the upper part of the support ring opens, and the four components spread out and open, so that the support structure opens.

[0015] The transition ring is the circular part of the hinge. The upper part is movable and can be opened by pulling down the ring, while the lower part is fixed. The transition ring has a groove that matches the hollow circular ring, which limits the support structure to a horizontal position and prevents cement grout from falling due to its own weight.

[0016] The beneficial effects of this utility model are as follows:

[0017] 1. This utility model utilizes a support structure, the transition ring of which is a solid circular ring structure. During grouting, the support structure opens, and the transition ring limits the support structure to a horizontal position, thus preventing cement grout from falling due to its own weight. Furthermore, a ring of support cylinders is evenly arranged along the outer wall of the support structure. During grouting, the support cylinders provide secondary support to the support structure, further preventing cement grout from falling due to its own weight.

[0018] 2. This utility model utilizes its sealing and anchoring structure, with its fixed connecting rod located at the upper left corner of the movable fan, so that the movable fan can only rotate around this fixed point. The movable fan and the connecting plate are connected through the movable connecting rod, and the movable connecting rod is connected through the connecting plate, so that the movable fan closes and opens when the handle is rotated, thereby further preventing cement slurry from falling due to its own weight after grouting the upper part of the tunnel.

[0019] 3. This utility model features an integrated drilling and grouting structure. During drilling, when the borehole reaches the designed height and the drill is withdrawn, grouting is performed simultaneously, avoiding the need for separate grouting after withdrawal. This effectively reduces the probability of tunnel collapse during drill withdrawal. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the support structure of this utility model when it is not open;

[0021] Figure 2 This is a schematic diagram of the open state of the support structure of this utility model;

[0022] Figure 3 This is a schematic diagram of the support structure of this utility model;

[0023] Figure 4 This is a schematic diagram of the lower hinge structure of the support structure of this utility model;

[0024] Figure 5 This is a schematic diagram of the single-piece hollow ring structure of the support structure of this utility model;

[0025] Figure 6 This is a schematic diagram of the sealing and anchoring structure of this utility model in the open state;

[0026] Figure 7 This is a schematic diagram of the sealing and anchoring structure of this utility model in an unopened state;

[0027] In the diagram: 1. Drill bit; 2. Support structure; 3. Drill rod; 4. Anchoring structure; 5. Spray hole; 6. Movable ring; 7. Support cylinder; 8. Transition ring; 9. Connecting ring; 10. Fixed chassis; 11. Movable fan; 12. Positioning pin; 13. Swinging link; 14. Swinging link; 15. Second pin; 16. Pull rope; 17. Nut; 18. Groove. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0029] like Figure 1 and 2 As shown, a drilling tool for preventing collapse during drilling in the upper part of tunnels in weak rock includes a drill bit 1, a support structure 2, a drill rod 3, a sealing and anchoring structure 4, and a blowhole 5. The support structure 2 is a ring-shaped structure, fixedly connected to the upper part of the drill rod 3, and the support structure 2 is close to the drill bit 1. The support structure 2 includes a movable ring 6, a support cylinder 7, a transition ring 8, and a connecting ring 9. A rolling bearing is installed inside the support structure 2, and the rolling bearing is sleeved on the drill rod 3, so that when the drill rod 3 rotates, the outside of the support structure 2 does not rotate with it.

[0030] The positional relationship of the components in support structure 2 is as follows: the inner wall of the movable ring 6 is tightly attached to the support ring of support structure 2. The movable ring 6 has multiple circular holes along its circumferential direction, and a solid connecting ring 9 is hung on each circular hole. A support cylinder 7 is hung on each solid connecting ring 9. The support cylinder 7 is vertically downward and tightly attached to the wall of the drill rod 3. A transition ring 8 is set at the lower part of the support cylinder 7. The support ring is composed of 8 hollow rings spliced ​​together, and a pull ring line is provided at the support ring to lock the support ring. The pull ring line is set outside the hole. During grouting, pulling down the pull ring opens the upper part of the support ring, causing the four components to spread and open, thus opening the support structure. The transition ring is the circular part of the hinge. The upper part is movably connected by pulling down the pull ring to open the upper part, and the lower part is fixedly connected. The transition ring 8 is provided with a groove 18 that matches the hollow ring, limiting the support structure 2 to a horizontal position to prevent cement grout from falling due to its own weight.

[0031] A ring of supporting cylinders 7 is evenly arranged around the outer wall of the supporting structure 2. During grouting, the supporting cylinders 7 provide secondary support to the supporting structure 2, further preventing cement grout from falling due to its own weight. When the supporting ring can no longer support the grout falling from the top due to its own weight, the lower part of the supporting cylinder 7 will move closer to the drill rod 3 until it is in close contact with the outer wall of the drill rod 3. At this time, a triangle is formed between the supporting ring, the supporting cylinder 7, and the drill rod 3, which makes the supporting structure more stable and the supporting performance stronger.

[0032] The connecting ring 9 connects the movable ring located on the outer wall of the drill pipe 3 to the supporting cylinder 7, so that when the supporting structure 2 is opened, this end of the supporting cylinder 7 is movably connected to the movable ring 6, and the other end hangs down naturally.

[0033] The sealing and anchoring structure 4 includes a fixed base plate 10, a movable fan 11, a positioning pin 12, a first pin 13, a swing connecting rod 14, and a second pin 15. During drilling, the support structure 2 is in close contact with the drill rod 3. When grouting is performed while retracting the drill, the support structure 2 opens to prevent cement grout from falling due to its own weight when grouting the upper tunnel. When the retraction of the drill is about to end, the sealing and anchoring structure 4 seals the anchor simultaneously to prevent cement grout from falling due to its own weight.

[0034] The anchoring structure 4 includes a fixed base 10, a movable fan 11, a positioning pin 12, a first pin 13, a swing link 14, and a second pin 15. The connection relationship between the components is as follows: the fixed base 10 is disc-shaped with a circular hole in the center. The inner diameter of the circular hole is equal to the outer diameter of the drill rod 3, and the drill rod 3 passes through the circular hole. Multiple swing links 14 are connected to the upper surface of the fixed base 10. The multiple swing links 14 are located at the edge of the fixed base 10 and arranged in a ring. The tail end of the swing link 14 is hinged to the first pin 13, which is vertically fixed to the fixed base 10. The head end of the swing link 14 is hinged to the movable fan 11 through a pin. Each movable fan 11 is distributed in a petal shape. A positioning pin 12 is connected to one corner of the movable fan 11. The positioning pin 12 is fixed to the fixed base 10, and the movable fan 11 can rotate around the positioning pin 12. When the fixed base 10 rotates, the position of the positioning pin 12 remains fixed. The swing link 14 and the second pin 15 push the movable fan 11 to rotate around the positioning pin 12, thereby realizing the closing and opening of the movable fan 11. When the movable fan 11 is fully open, the drill rod 3 can pass through the hole in the center of the fixed base 10. When the movable fan 11 is fully closed, the hole in the center of the fixed base 10 is blocked. This effectively avoids the grouting fluid in the upper anchor drill hole 3 of the tunnel falling due to its own weight during the time of manual anchor sealing.

[0035] The sealing structure 4 is tightly attached to the outer wall of the drill rod 3. When the fixed base plate 10 rotates clockwise, the movable fan 11 opens to place the anchor rod and perform secondary grouting. When the fixed base plate 10 rotates counterclockwise, the movable fan 11 closes to prevent cement grout from falling due to its own weight.

[0036] The positioning pin 12 is located at the upper left corner of the movable fan 11, so that the movable fan 11 can only rotate around this fixed position. The movable fan 11 and the swing linkage 14 are connected by the second pin 15, and then the first pin 13 is connected by the swing linkage 14. This enables the movable fan 11 to close and open when the fixed chassis 10 rotates, and further prevents the cement slurry from falling due to its own weight after grouting the upper part of the tunnel.

Claims

1. A drilling tool for preventing collapse during drilling in the upper part of tunnels in weak rock, characterized in that, The drill bit, the drill pipe, the anchor sealing structure and the jet orifice are included, and the anchor sealing structure is connected to the lower part of the drill pipe; The anchor sealing structure includes a fixed base plate, a movable fan, a positioning pin shaft, a first pin shaft, a swing link and a second pin shaft; the fixed base plate is disc-shaped, a circular hole is formed in the center of the fixed base plate, the inner diameter of the circular hole is equal to the outer diameter of the drill pipe, and the drill pipe is inserted into the circular hole; A plurality of swing links are connected to the upper surface of the fixed base plate, the plurality of swing links are arranged in a ring shape at the edge of the fixed base plate, the tail end of each swing link is hingedly connected to a first pin shaft, the first pin shaft is vertically fixed to the fixed base plate, the head end of each swing link is hingedly connected to a movable fan through a pin shaft, each movable fan is distributed in a petal shape, one corner of each movable fan is connected to a positioning pin shaft, and the positioning pin shaft is fixed to the fixed base plate; each movable fan can rotate around the positioning pin shaft; When the fixed base plate rotates, the position of the positioning pin shaft remains unchanged, the swing link and the second pin shaft push the movable fan to rotate around the positioning pin shaft, so that the movable fan is closed and opened; when the movable fan is completely opened, the drill pipe can pass through the hole in the center of the fixed base plate, and when the movable fan is completely closed, the hole in the center of the fixed base plate is blocked.

2. The anti-sloughing drilling tool for the upper drilling of a weak rock tunnel according to claim 1, characterized in that, The swing link is a circular arc-shaped rod, and the movable fan is in a crescent shape.

3. The drill tool for preventing collapse in upper drilling of a weak rock tunnel according to claim 1, wherein The support structure is a ring structure, is fixedly connected to the upper part of the drill pipe, and is close to the drill bit; The support structure includes a movable ring, a support cylinder, a transition ring and a connecting ring, a rolling bearing is arranged in the support structure, and the rolling bearing is sleeved on the drill pipe, so that the outer part of the support structure does not rotate when the drill pipe rotates; The positional relationship of the components in the support structure is that the inner wall of the movable ring is close to the support ring of the support structure, a plurality of circular holes are formed in the movable ring in the circumferential direction, a solid connecting ring is hung on each circular hole, a support cylinder is hung on each solid connecting ring, the support cylinder is vertically downward and close to the wall of the drill pipe, and a transition ring is arranged at the lower part of the support cylinder; the support ring is composed of eight hollow rings, and a pull ring line is arranged at the support ring to lock the support ring; the pull ring line is arranged outside the hole, when grouting, the pull ring is pulled down, the upper part of the support ring is opened, four components are expanded and opened, and the support structure is opened; The transition ring is a hinge ring part, the upper part is movably connected, the lower part is fixedly connected, a groove matched with the hollow ring is arranged on the transition ring, the limit of the support structure is limited to a horizontal position, and the transition ring plays a preventive role to prevent the cement slurry from falling due to gravity.

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