An expanded shell anchor head having a large expanded size and an anchor rod comprising the anchor head

Abstract

The application discloses an expanded-shell anchor head with large expansion size, which comprises an expanded-shell inner wedge with an inner cavity and two expanded-shell pieces capable of sliding along the expanded-shell inner wedge, and two inclined surfaces are symmetrically arranged on the two sides of the workbench and are inclined to the connecting part of the workbench, sliding grooves are respectively arranged on the two inclined surfaces, and the two sliding grooves are centrally symmetrically arranged through the axis of the work part; sliding blocks are arranged on the expanded-shell pieces and are in sliding cooperation with the sliding grooves. The application further discloses an anchor rod comprising the expanded-shell anchor head with large expansion size, which comprises an anchor rod body, and the expanded-shell anchor head is connected with the end of the anchor rod body. The maximum expansion size of the expanded-shell piece of the anchor head can reach three times of the diameter of the anchor head, the defect that the anchoring effect is not good or even cannot form support due to the small expansion size of the expanded-shell piece is avoided, and the size of the anchor head can be reduced due to the large surplus of the expanded-shell piece after expansion, so that the anchor rod and the anchor head can be conveniently put into the anchor hole.

Description

Technical Field

[0001] This invention relates to the field of anchoring device technology, and in particular to an expansion shell anchor head with a large expansion size and an anchor rod including the anchor head. Background Technology

[0002] In geotechnical engineering, including underground engineering, mining engineering, and foundation pit and slope engineering, a primary method of reinforcing strata or rock formations to prevent deformation, collapse, or instability that could jeopardize safety is the use of anchor bolts inserted into the rock strata for support. The high tensile strength of the anchor bolts, combined with the tight bond between the anchor bolt body and the surrounding grout, strengthens the strata, improving their overall integrity. This anchor bolt exerts various mechanical resistances, including shear, tensile, and compressive strength, to control deformation and achieve a stable and safe state. This technology has been developed for over a century, resulting in various anchor bolt support types and processes to adapt to different geological conditions and requirements.

[0003] Expansion shell anchor bolts: These bolts utilize the expansion shell force of the anchor head to create point anchoring force, resulting in anchoring force generated by non-bonded anchoring. Because the expansion shell force is generated through friction between the expansion shell and the borehole wall, it is only suitable for relatively good rock formations.

[0004] Existing expansion-shell anchor bolts theoretically have a maximum tensile distance of twice the anchor head diameter for the expansion shell plate on the anchor head, as detailed in documents such as CN200310108547.5 and CN201821364464.0. Taking a 39mm anchor head as an example, a 41-46mm drill bit is required to ensure smooth entry of the anchor bolt and anchor head into the anchor hole, thus the actual anchor hole diameter is 41-46mm. When the anchor hole length is greater than 3 meters, due to the influence of factors such as drilling path curvature and debris, a drill bit as large as possible (46mm) within the standard range is selected to ensure smooth insertion of the anchor bolt, thereby eliminating the influence of drilling deviation on anchor bolt insertion. Longer holes require drill bits with even larger diameters. When anchoring long boreholes, the diameter of the anchor hole is too large, resulting in the expansion shell anchor head being only slightly larger than the diameter of the anchor hole after the two expansion shell plates are fully opened. This leads to poor anchoring effect and poor load-bearing capacity. Only a small force is needed to make the anchor rod fall out of the anchor hole, thus failing to achieve the anchoring effect. In some cases, even after the two expansion shell plates are fully opened, the diameter is still smaller than the diameter of the anchor hole, making it impossible to form support. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an expandable shell anchor head with a large expansion size and an anchor rod including the anchor head. The maximum expansion size of the shell on the anchor head can reach three times the diameter of the anchor head, avoiding the shortcomings of small expansion shells resulting in poor anchoring effect or even failure to form support. Furthermore, due to the excellent expansion size of the shell, the anchor head has a large margin after expansion, thus allowing for a smaller anchor head size, facilitating the entry of the anchor rod and anchor head into the anchor hole. It also provides strong anchoring load-bearing capacity and helps save costs. The objective of this invention is achieved through the following technical solution: An inflatable shell anchor head with a large expansion size includes an internally hollow inflatable shell wedge and two inflatable shell plates that can slide along the inflatable shell wedge. The inflatable shell wedge includes a working part and a connecting part disposed at the lower part of the working part. The upper end of the working part is provided with a worktable, and there is a receiving cavity between the worktable and the connecting part for storing the expansion shell when it is retracted. The two sides of the worktable are symmetrically provided with inclined surfaces that slope towards the connecting part from the worktable. Each of the two inclined surfaces is provided with a sliding groove, and the two sliding grooves are arranged centrally symmetrically through the axis of the working part. The expansion shell is provided with a slider that slides in conjunction with the sliding groove, which passes through the central symmetry plane and is arranged side by side in the receiving cavity.

[0006] Furthermore, the sliding groove is a T-shaped groove or a dovetail groove, and the shape of the slider is adapted to the sliding groove.

[0007] Furthermore, the working part and the connecting part are an integrated structure.

[0008] Furthermore, the slider is connected to the expansion shell through a triangular connecting block, and the slider, connecting block and expansion shell are an integrated structure.

[0009] Furthermore, the connecting block is provided with a triangular relief groove.

[0010] Furthermore, the slider, connecting block, and expansion shell form a triangular cross-section, and the length of the base of the triangle formed by the slider, connecting block, and expansion shell is less than or equal to the diameter of the working part.

[0011] Furthermore, the top of the working part is conical.

[0012] An anchor bolt comprising an expansion shell anchor head with a large expansion size, comprising an anchor bolt body, wherein the expansion shell anchor head is connected to the end of the anchor bolt body.

[0013] Furthermore, the connecting part is coaxially provided with a threaded hole, and the expansion shell anchor head is threadedly connected to the anchor rod body through the threaded hole.

[0014] Furthermore, the threaded hole communicates with the receiving cavity to form a grouting channel.

[0015] The beneficial effects of this invention are: The anchor head of the present invention has an expansion shell with a maximum expansion size of up to three times the diameter of the anchor head, which avoids the shortcomings of small expansion shell with poor anchoring effect or even failure to form support. Furthermore, due to the excellent expansion size of the expansion shell, the anchor head has a large margin after expansion, so the size of the anchor head can be reduced, which facilitates the entry of the anchor rod and anchor head into the anchor hole. It also has strong anchoring bearing capacity, which helps to save costs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the expansion shell anchor head with a large expansion size in an embodiment of the present invention; Figure 2 This is an exploded view of the large-expansion shell anchor head in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the large-expansion shell anchor head in an embodiment of the present invention; Figure 4 This is a bottom view of the large-expansion shell anchor head in an embodiment of the present invention; Figure 5 As described in the embodiments of the present invention Figure 4 Sectional view along the BB direction; Figure 6 As described in the embodiments of the present invention Figure 4 C-axis sectional view; Figure 7 This is a schematic diagram of the overall structure of the anchor rod including the expansion shell anchor head with a large expansion size in an embodiment of the present invention; In the figure, 1. Inner wedge of the expansion shell; 2. Expansion shell plate; 3. Working part; 4. Connecting part; 5. Worktable; 6. Receiving cavity; 7. Inclined surface; 8. Sliding groove; 9. Sliding block; 10. Connecting block; 11. Lightening groove; 12. Anchor bolt body. Detailed Implementation

[0017] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] See Figures 1-7 The present invention provides a technical solution: Example

[0019] like Figures 1-7As shown, an expansion shell anchor head with a large expansion size includes an internally hollow expansion shell wedge 1 and two expansion shell plates 2 that can slide along the expansion shell wedge 1. The expansion shell wedge 1 includes a working part 3 and a connecting part 4 disposed at the lower part of the working part 3. The upper end of the working part 3 is provided with a worktable 5. Between the worktable 5 and the connecting part 4, there is a receiving cavity 6 for storing the expansion shell 2 when it is retracted. The two sides of the worktable 5 are symmetrically provided with inclined surfaces 7 that are inclined from the worktable 5 toward the connecting part 4. Each of the two inclined surfaces 7 is provided with a sliding groove 8. The two sliding grooves 8 are centrally symmetrically arranged, passing through the axis of the working part 3. Here, the sliding groove 8 passing through the axis means that the projection of the sliding groove 8 in the axial direction of the working part 3 intersects the axis of the working part 3.

[0020] The expansion shell 2 is provided with a slider 9 that slides in conjunction with the sliding groove 8. The sliding groove 8 passes through the central symmetry plane of the worktable and is arranged side by side in the receiving cavity. The sliding grooves are staggered and pass through the central symmetry plane of the worktable. This arrangement ensures that the stroke of each expansion shell is maximized to be close to the diameter of the working part.

[0021] like Figure 2 As shown, the sliding groove 8 is a T-shaped groove or a dovetail groove, and the shape of the slider 9 is adapted to the sliding groove 8. This design of the sliding groove 8, when in conjunction with the slider 9, not only guides the slider 9 but also limits its movement, ensuring that the slider 9 moves only along the length of the groove.

[0022] like Figure 2 As shown, the working part 3 and the connecting part 4 are an integrated structure.

[0023] like Figure 3 As shown, the slider 9 is connected to the expansion shell 2 via a triangular connecting block 10, and the slider 9, connecting block 10 and expansion shell 2 are an integrated structure.

[0024] like Figure 3 As shown, the connecting block 10 is provided with a triangular weight-reducing groove 11. The weight-reducing groove 11 can reduce the weight of the anchor head, reduce the use of raw materials, and save costs.

[0025] like Figure 3 As shown, the slider 9, connecting block 10 and expansion shell 2 form a triangular cross-section, and the length of the base of the triangle formed by the slider 9, connecting block 10 and expansion shell 2 is less than or equal to the diameter of the working part 3.

[0026] The top of the working part 3 is tapered. The tapered top facilitates the entry of the anchor rod into the anchor hole.

[0027] Working principle: After drilling an anchor hole in the stratum / rock, the drilling rig inserts the anchor rod with the expansion shell anchor head into the anchor hole until the expansion shell anchor head is in place. Once in place, the drilling rig drives the anchor rod to rotate, and the end of the expansion shell anchor head is pressed against the bottom of the anchor hole and thus limited (restricting the rotation of the expansion shell anchor head). Under the action of the drilling rig, the anchor rod rotates in the connecting part 4, causing the anchor rod to rotate and advance. The anchor rod pushes the expansion shell plate 2 to slide along the sliding groove. During the sliding process of the expansion shell plate 2, due to the action of the inclined surface 7 (wedge-shaped), the two expansion shell plates 2 are spread apart. The outer surface of the expansion shell plate 2 is in close contact with the wall of the anchor hole until they are squeezed together to form expansion force and friction force; when the drilling rig can no longer rotate the anchor rod body, the expansion shell anchor head is installed in place, and the anchoring force of the expansion shell anchor head is thus formed.

[0028] During the expansion process of the expansion shell 2, since the base length of the triangle formed by the slider 9, connecting block 10, and expansion shell 2 is the same as the diameter of the working part 3, the size of the entire anchor head when both expansion shells 2 are fully expanded can reach three times that of the unexpanded size (1.5 times that of a conventional anchor head). Because the anchor head is large after expansion, and has a large allowance after opening, a smaller anchor head can meet the anchoring requirements for anchor holes of the same diameter. Making the anchor head smaller facilitates the entry of the anchor head and anchor rod into the anchor hole. The large expansion size of the expansion shell 2 provides greater support force, stronger force application, and better anchoring effect.

[0029] The anchor head of the present invention has an expansion shell 2 whose maximum expansion size can reach three times the diameter of the anchor head, which avoids the shortcomings of small expansion shell 2, poor anchoring effect or even failure to form support. Moreover, due to the excellent opening size of the expansion shell 2, the anchor head has a large margin after opening, so the size of the anchor head can be reduced, which facilitates the entry of the anchor rod and anchor head into the anchor hole. It also has strong anchoring bearing capacity, which helps to save costs. Example

[0030] like Figure 7 As shown, an anchor bolt including an expansion shell anchor head with a large expansion size includes an anchor bolt body 12, wherein the expansion shell anchor head is connected to the end of the anchor bolt body 12.

[0031] The connecting part 4 is coaxially provided with a threaded hole, and the expansion shell anchor head is threadedly connected to the anchor body 12 through the threaded hole.

[0032] The connecting part 4 is directly connected to the external thread of the anchor rod body 12 through the threaded hole, which facilitates the assembly and disassembly of the anchor head and the anchor rod body 12.

[0033] Furthermore, the threaded hole communicates with the receiving cavity 6 to form a grouting channel. When permanent support is required, the anchor bolt body is a hollow anchor bolt. After the anchor head expands, the grouting channel communicates with the internal channel of the hollow anchor bolt, and grout is injected into the anchor hole through the internal channel of the hollow anchor bolt. After the grout solidifies, permanent support is formed.

[0034] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A large-expansion-size inflatable anchor head, comprising an internally hollow inflatable wedge and two inflatable plates that can slide along the internal wedge, characterized in that: The inner wedge of the expansion shell includes a working part and a connecting part disposed at the lower part of the working part; The upper end of the working part is provided with a worktable, and there is a receiving cavity between the worktable and the connecting part for storing the expansion shell when it is retracted. The two sides of the worktable are symmetrically provided with inclined surfaces that slope towards the connecting part from the worktable. Each of the two inclined surfaces is provided with a sliding groove, and the two sliding grooves are arranged centrally symmetrically through the axis of the working part. The expansion shell is provided with a slider that slides with the sliding groove, and the sliding groove passes through the central symmetry plane and is arranged side by side in the receiving cavity; The slider is connected to the expansion shell through a triangular connecting block, and the slider, connecting block and expansion shell are an integrated structure; The slider, connecting block, and expansion shell form a structure with a triangular cross-section; Because the length of the base of the triangle formed by the slider, connecting block and expansion shell during the expansion shell expansion process is the same as the diameter of the working part, the size of the entire anchor head reaches three times that when the two expansion shells are fully expanded.

2. The expansion-shell anchor head with a large expansion size according to claim 1, characterized in that: The sliding groove is a T-shaped groove or a dovetail groove, and the shape of the slider is adapted to the sliding groove.

3. The expansion-shell anchor head with a large expansion size according to claim 1, characterized in that: The working part and the connecting part are an integrated structure.

4. The expansion-shell anchor head with a large expansion size according to claim 1, characterized in that: The connecting block is provided with a triangular light-reducing groove.

5. The expansion-shell anchor head with a large expansion size according to claim 1, characterized in that: The top of the working part is conical.

6. An anchor bolt comprising an expansion shell anchor head with a large expansion size as described in any one of claims 1-5, characterized in that: It includes an anchor bolt body, and the expansion shell anchor head is connected to the end of the anchor bolt body.

7. The anchor bolt according to claim 6, characterized in that: The connecting part is coaxially provided with a threaded hole, and the expansion shell anchor head is threadedly connected to the anchor rod body through the threaded hole.

8. The anchor bolt according to claim 7, characterized in that: The threaded hole communicates with the receiving cavity to form a grouting channel.

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