A compound expansion prestressed anchor rod

Abstract

The present invention provides a compound expansion prestressed anchor rod, which relates to the field of anchor rod technology and solves the problems of insufficient initial anchoring force of anchor rods in rock anchor holes and poor anchoring effect in mudstone anchor holes. The invention comprises an expansion end connected to one end of an anchor rod body, the expansion end comprising an inner shell and an outer shell movably mounted on the inner shell, both the outer shell and the inner shell being provided with a plurality of expansion portions, the inner shell being movably mounted on the anchor rod body, the end of the anchor rod body being provided with a barb protrusion annularly, and the inner side of the expansion portion of the inner shell being provided with a barb groove group, the barb groove group being arranged in an inverted trapezoidal shape. The anchor rod body extends into the inner shell to expand and expand the expansion portion of the inner shell, thereby driving the expansion portion of the outer shell to expand and expand, thereby achieving a first expansion operation; the anchor rod body is pulled, so that the barb protrusion on the anchor rod body cooperates with the barb groove group to pull the inner shell outward, and the expanded expansion portion of the inner shell continues to expand the expansion portion of the outer shell, thereby achieving a second expansion operation, thereby increasing the friction between the anchor rod and the anchor hole and improving the anchoring effect.

Description

Technical Field

[0001] The present invention relates to the technical field of anchor rods, in particular to a compound expansion prestressed anchor rod. Background Art

[0002] In tunnels, foundation pits, mining, slopes and other projects that require prestressed anchoring support, various prestressed anchor cables and prestressed anchor rods are needed to perform multi-point anchoring of surrounding rocks that pose a potential threat to them, or to support and connect the mesh, concrete and other covering layers used to manage the surrounding rocks.

[0003] Prestressed anchor rods are rods anchored in the rock mass to reinforce the surrounding rock. The anchoring force works together with the surrounding rock's own restraining force. As an internal reinforcement method, it improves the mechanical properties of the original surrounding rock, making it a force-bearing structure that stabilizes itself and the internal mountain deformation. The anchor rods penetrate the stable section of the surrounding rock, connecting the rock blocks in series to play a reinforcing role, making the originally unstable surrounding rock tend to be stable.

[0004] To enhance anchoring effectiveness, existing anchor rods feature an expandable structure at their ends. Once the rod is lowered into the anchor hole, the expansion structure begins to expand and come into close contact with the inner wall of the hole, increasing friction between the two. However, existing anchor rods remain stationary after this initial expansion, resulting in only a small initial anchoring force in anchor holes in hard rock. In anchor holes in debris structures, the looseness of the debris prevents the expansion structure from maintaining close contact with the inner wall of the hole, significantly reducing the friction of the rod. Consequently, the anchoring force of existing anchor rods cannot meet the requirements of slope management. Summary of the Invention

[0005] In response to the problems of insufficient initial anchoring force of the above-mentioned anchor rods in the anchor holes of rocks and poor anchoring effect in the anchor holes of mud and stone, the purpose of the present invention is to provide a compound expansion prestressed anchor rod, which expands and expands the expanded part of the inner shell by extending the anchor rod body into the inner shell, thereby driving the expanded part of the outer shell to expand and expand, realizing the first expansion operation; then pulling the anchor rod body, so that the barb protrusions on the anchor rod body cooperate with the barb groove group to pull the inner shell to move outward, and at this time the expanded and expanded expanded part of the inner shell continues to expand the expanded part of the outer shell, realizing the second expansion, increasing the friction between the anchor rod and the anchor hole, and improving the anchoring effect.

[0006] The embodiments of the present invention are achieved through the following technical solutions:

[0007] A compound expansion prestressed anchor rod comprises an anchor rod body, one end of the anchor rod body is connected to an expansion end head, the expansion end head comprises an inner shell and an outer shell movably mounted on the inner shell, the outer shell and the inner shell are both provided with a plurality of expansion parts, the inner shell movably mounted on the anchor rod body, the end of the anchor rod body is annularly provided with a barb protrusion, the inner side of the expansion part of the inner shell is provided with a barb groove group that cooperates with the barb protrusion to limit the movement of the anchor rod body in the inner shell toward the top of the inner shell, the barb groove group is arranged in an inverted trapezoidal shape, and the outer side of the inner shell is provided with a first protrusion that limits the movement of the inner shell toward the bottom of the outer shell.

[0008] Preferably, the outer wall of the expansion portion of the inner shell is provided with an inclined surface inclined outward.

[0009] Preferably, the inner wall of the expanded portion of the outer shell is provided with an inclined surface adapted to the outer wall of the expanded portion of the inner shell.

[0010] Preferably, the inner wall of the shell is provided with a second protrusion that cooperates with the first protrusion, and the first protrusion and the second protrusion are both threads.

[0011] Preferably, through grooves are provided on both sides of the connection between the upper ends of the support portions of the outer shell and the inner shell.

[0012] Preferably, an annular groove is further provided at the connection of the upper end of the support portion of the shell.

[0013] Preferably, an anti-slip annular groove is provided on the outer wall of the expanded portion of the housing.

[0014] Preferably, one end of the anchor rod body away from the expansion end head is connected to a connector, and a baffle located below the connector is movably sleeved on the anchor rod body.

[0015] Preferably, the anchor rod body is threadedly connected to the connecting head.

[0016] Preferably, a base is provided below the inner shell, and a through slot connecting the upper and lower end surfaces of the base is provided on the side wall of the base, a screw connected to the inner shell is provided in the through slot, and the head of the screw is clamped on the lower end surface of the base.

[0017] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0018] The anchor rod body is extended into the inner shell to expand the expanded part of the inner shell, thereby driving the expanded part of the outer shell to expand and expand, realizing the first expansion operation; then the anchor rod body is pulled, so that the barb protrusions on the anchor rod body cooperate with the barb groove group to pull the inner shell to move outward. At this time, the expanded expanded part of the inner shell continues to expand the expanded part of the outer shell, realizing the second expansion, increasing the friction between the anchor rod and the anchor hole, and improving the anchoring effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A schematic diagram of the main structure provided by an embodiment of the present invention;

[0021] Figure 2 A schematic cross-sectional view of an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of the expansion end head provided in an embodiment of the present invention being expanded;

[0023] Figure 4 This is a schematic diagram of the three-dimensional structure of the expansion end provided by an embodiment of the present invention.

[0024] Icons: 1-connector; 2-baffle; 3-anchor rod body; 31-barbed protrusion; 4-expansion end; 41-outer shell; 42-annular groove; 43-through groove; 44-anti-slip annular groove; 45-inner shell; 46-barbed groove group; 47-first protrusion; 48-second protrusion; 5-base; 6-screw. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0027] The following combination Figures 1-4 The present invention is described in detail.

[0028] Example

[0029] A compound expansion prestressed anchor rod, comprising an anchor rod body 3, one end of the anchor rod body 3 is connected to an expansion end head 4, the expansion end head 4 comprises an inner shell 45 and an outer shell 41 movably mounted on the inner shell 45, the outer shell 41 and the inner shell 45 are both provided with a plurality of expansion parts, the inner shell 45 is movably mounted on the anchor rod body 3, the end of the anchor rod body 3 is annularly provided with a barb protrusion 31, the inner side of the expansion part of the inner shell 45 is provided with a barb groove group 46 that cooperates with the barb protrusion 31 to limit the movement of the anchor rod body 3 in the inner shell 45 toward the top of the inner shell 45, the barb groove group 46 is arranged in an inverted trapezoidal shape, and the outer side of the inner shell 45 is provided with a first protrusion 47 that limits the movement of the inner shell 45 toward the bottom of the outer shell 41.

[0030] In the anchor hole of rock or mudstone, through the two expansion processes of the outer shell 41, the outer shell 41 is further closely contacted with the inner wall of the anchor hole, thereby improving the anchoring force and enhancing the anchoring effect.

[0031] The inverted trapezoidal barb groove group 46 causes the expanded portion of the inner shell 45 to be expanded by the anchor body 3 during the downward movement of the anchor body 3. The first protrusion 47 is used to prevent the inner shell 45 from moving downward with the anchor body 3 during the downward movement of the anchor body 3, ensuring that the anchor body 3 can extend into the barb groove group 46 of the inner shell 45 under the support of the outer shell 41.

[0032] The anchor rod body 3 is made of precision-rolled threaded steel and its tensile strength is 2-3 times that of traditional anchor rods.

[0033] The outer wall of the expanded portion of the inner shell 45 is provided with an outwardly inclined slope, which allows the expanded portion of the inner shell 45 to expand further relative to the outer shell 41, thereby increasing the expansion and expansion degree of the outer shell 41.

[0034] The inner wall of the expansion portion of the outer shell 41 is provided with an inclined surface that matches the outer wall of the expansion portion of the inner shell 45. The inner wall of the expansion portion of the outer shell 41 is also provided with an inclined surface, so that the expansion portion of the inner shell 45 is better fitted on the expansion portion of the outer shell 41, ensuring the supporting strength of the expansion portion of the outer shell 41.

[0035] The inner wall of the outer shell 41 is provided with a second protrusion 48 that cooperates with the first protrusion 47. Both the first protrusion 47 and the second protrusion 48 are threaded. Since the inner shell 45 has a structure with a small upper end and a large lower end, when the inner shell 45 and the outer shell 41 are assembled, the outer shell 41 can only be inserted into the inner shell 45 from the top down, and the first protrusion 47 restricts the upward and downward movement of the outer shell 41. Therefore, by providing the first protrusion 47 and the second protrusion 48 with a threaded structure, the second protrusion 48 of the outer shell 41 is caused to pass through the first protrusion 47 during the insertion process. After the second protrusion 48 passes through the first protrusion 47, during the relative upward and downward movement of the outer shell 41 and the inner shell 45, the second protrusion 48 cooperates with the first protrusion 47 to restrict the outer shell 41 and the inner shell 45 from separating from each other. This design facilitates the assembly of the inner shell 45 and the outer shell 41 and prevents the inner shell 45 and the outer shell 41 from separating from each other, thereby preventing the expansion end 4 from being unusable. At the same time, it also ensures that the anchor body 3 can move normally into the inner shell 45.

[0036] The upper end connection of the outer shell 41 and the inner shell 45 is provided with through slots 43 on both sides. The through slots 43 are provided on both sides of the connection of the open portion to reduce the force required to bend the open portion and prevent the open portion from being deformed and damaged due to the inability to bend outward.

[0037] The upper end connection of the expansion part of the shell 41 is also provided with an annular groove 42. Because the shell 41 needs to withstand a large force, the wall thickness of the shell 41 is relatively thick. Therefore, in order to facilitate the expansion part of the shell 41 to bend outward, the annular groove 42 is provided to reduce the wall thickness of the expansion part connection.

[0038] The outer wall of the expanded portion of the housing 41 is provided with an anti-slip annular groove 44. The anti-slip annular groove 44 can cooperate with the concave-convex structure of the inner wall of the anchor hole to increase the effect of clamping and fixing, especially for anchor holes in mudstone structures, the anti-slip annular groove 44 can play a better role.

[0039] The end of the anchor rod body 3 away from the expansion end 4 is connected to a connector 1, and a baffle 2 is movably sleeved on the anchor rod body 3 and located below the connector 1. The connector 1 is connected to the pull rope structure of the protective net, and the baffle 2 is provided to limit the installation position of the connector 1.

[0040] The anchor rod body 3 is threadedly connected to the connector 1. The threaded connection of the connector 1 is also convenient for replacement.

[0041] A base 5 is provided below the inner shell 45. A through slot is defined in the sidewall of the base 5, connecting the upper and lower end surfaces of the base 5. A screw 6 connected to the inner shell 45 is provided in the through slot, with the head of the screw 6 being engaged with the lower end surface of the base 5. The base 5 is provided primarily to block debris from entering the anchor hole below the anchor rod, preventing debris from entering the inner shell 45 through the lower end opening and affecting the movement of the anchor rod body 3. The screw 6 is used to support the base 5.

[0042] After the anchor rod is lowered into place, the head of the screw 6 is driven to disengage from the through slot of the base 5 by the outward opening movement of the expanded portion of the inner shell 45 , thereby ensuring the normal expansion of the inner shell 45 .

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A compound expansion prestressed anchor rod, comprising an anchor rod body (3), one end of the anchor rod body (3) being connected to an expansion end head (4), characterized in that: The expansion end (4) includes an inner shell (45) and an outer shell (41) movably mounted on the inner shell (45), the outer shell (41) and the inner shell (45) are both provided with a plurality of expansion parts, the inner shell (45) is movably mounted on the anchor rod body (3), the end of the anchor rod body (3) is provided with a barb protrusion (31) in an annular shape, the inner side of the expansion part of the inner shell (45) is provided with a barb groove group (46) that cooperates with the barb protrusion (31) to limit the anchor rod body (3) from moving inside the inner shell (45) toward the top of the inner shell (45), the barb groove group (46) is arranged in an inverted trapezoidal shape, and the outer side of the inner shell (45) is provided with a first protrusion (47) that limits the inner shell (45) from moving toward the bottom of the outer shell (41); The outer wall of the opening portion of the inner shell (45) is provided with an inclined surface inclined outward; The inner wall of the opening portion of the outer shell (41) is provided with an inclined surface adapted to the outer wall of the opening portion of the inner shell (45); The inner wall of the housing (41) is provided with a second protrusion (48) that cooperates with the first protrusion (47), and both the first protrusion (47) and the second protrusion (48) are screw threads.

2. A compound expansion prestressed anchor rod according to claim 1, characterized in that: Through slots (43) are provided on both sides of the connection between the upper ends of the support portions of the outer shell (41) and the inner shell (45).

3. A compound expansion prestressed anchor rod according to claim 1, characterized in that: An annular groove (42) is also provided at the connection point of the upper end of the support portion of the housing (41).

4. A compound expansion prestressed anchor rod according to claim 1, characterized in that: An anti-slip annular groove (44) is provided on the outer wall of the support portion of the housing (41).

5. The compound expansion prestressed anchor rod according to claim 1, characterized in that: One end of the anchor rod body (3) away from the expansion end head (4) is connected to a connector (1), and a baffle (2) located below the connector (1) is movably sleeved on the anchor rod body (3).

6. A compound expansion prestressed anchor rod according to claim 5, characterized in that: The anchor rod body (3) is threadedly connected to the connecting head (1).

7. The compound expansion prestressed anchor rod according to claim 1, characterized in that: A base (5) is provided below the inner shell (45), and a through slot communicating with the upper and lower end surfaces of the base (5) is provided on a side wall of the base (5). A screw (6) connected to the inner shell (45) is provided in the through slot, and the head of the screw (6) is clamped on the lower end surface of the base (5).

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