End constant-resistance yielding anchor rod

Abstract

The invention belongs to the technical field of surrounding rock reinforcement, and particularly relates to an end constant-resistance yielding anchor rod which comprises an anchoring section embedded in surrounding rock and a free section extending out of the surrounding rock. The surface of the free section is provided with groove threads, the gasket is arranged at the boundary of the anchoring section and the free section in a sleeving mode and tightly attached to the surface of surrounding rock, a lead screw shaft of the ball screw is the free section provided with the groove threads, the ball screw is sleeved with the constant-torque spring, the two ends of the shell are open, and the whole free section is sleeved with the shell; one end of the constant-torque spring is connected to the ball screw, and the other end is connected to the inner side of the shell. The constant-resistance anchor rod yielding is achieved through the constant-torque spring and the ball screw, the constant-resistance precision is high, standardized mechanical components are adopted, the precision is high, the service life is long, installation is easy, the yielding amount and the yielding process can be easily measured through a flexible rule, and convenience and reliability are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of surrounding rock reinforcement, and in particular relates to an end constant resistance and pressure-yielding anchor rod. Background Art

[0002] Anchor rods are an integral part of tunnel support, used to reinforce the surrounding rock of the tunnel so that the surrounding rock can support itself. Anchor rods are not only used in mining, but also in engineering technology to reinforce the main body of slopes, tunnels, and dams.

[0003] The existing common anchor rods either have no pressure-yielding function. In tunnel engineering applications, when the surrounding rock undergoes large deformation, the anchor rod will be broken and the anchor head will be damaged, making it impossible for the anchor rod to actively reinforce the surrounding rock; or the end-head pressure-yielding method is used, but the pressure-yielding effect is average. The end-head is too large and is easily separated from the shotcrete during the pressure-yielding process, causing serious damage to the primary support surface and poor integrity. In addition, the pressure-yielding process is concealed, and the pressure-yielding length of the anchor rod cannot be accurately known after burial, and it cannot be quickly and accurately known after the anchor rod is damaged. Summary of the invention

[0004] The purpose of the present invention is to propose a structure that can achieve constant resistance and pressure release at the end of the anchor rod, so that the anchor rod can achieve constant resistance and pressure release; and the outer shell of the anchor rod end is fixed to avoid damage to the spray mix and the anchor rod bonding part during the pressure release process; the hollow grouting function is retained, and the anchor rod end pressure release process is clearly visible, which is convenient for on-site construction identification.

[0005] The technical solution of the present invention is as follows:

[0006] An end constant resistance pressure-yielding anchor rod comprises an anchoring section buried in the surrounding rock and a free section extending out of the surrounding rock;

[0007] It also includes a gasket, a ball screw, a constant torque spring and a housing. The surface of the free section is provided with a groove thread. The gasket is sleeved at the boundary between the anchor section and the free section and is close to the surface of the surrounding rock. The screw shaft of the ball screw is the free section provided with a groove thread. The constant torque spring is sleeved on the ball screw. The housing has openings at both ends and is sleeved on the entire free section.

[0008] One end of the constant torque spring is connected to the ball screw, and the other end is connected to the inner side of the housing.

[0009] Furthermore, the end of the free section is a gradual anti-dropping enlarged head.

[0010] Furthermore, the cross-sectional diameter of the left opening of the shell is smaller than the cross-sectional diameter of the anti-falling enlarged head.

[0011] Furthermore, the anchor rod body is an internal hollow structure.

[0012] Furthermore, a scale is provided on the inner wall of the right end of the shell.

[0013] The beneficial technical effects of the present invention are as follows:

[0014] 1. The present invention realizes constant resistance anchor rod pressure release through constant torque spring and ball screw, has high constant resistance precision, adopts standardized mechanical components, has high precision, long service life and is easy to install.

[0015] 2. The anchor rod end of the present invention is small in size and is fixed by a shell. After implementation, the mixture can be sprayed directly around the anchor rod end, so that the pressure process will not cause the sprayed mixture to separate from the anchor rod end.

[0016] 3. The anchor rod pressure relief amount and pressure relief process in the present invention can be easily measured by a tape measure, which is convenient and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the end constant resistance pressure anchor structure in an embodiment of the present invention;

[0018] Figure 2 It is a cross-sectional schematic diagram of the free section of the anchor rod in an embodiment of the present invention.

[0019] Figure markings: 1-anchoring section, 2-free section, 3-gasket, 4-groove thread, 5-ball screw, 6-constant torque spring, 7-housing, 8-anti-falling enlarged head, 9-anchor rod body. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0021] Please refer to Figure 1 The present invention provides an end constant resistance pressure anchor rod, wherein the anchor rod body 9 includes an anchoring section 1 buried in the surrounding rock and a free section 2 extending out of the surrounding rock, and a groove thread 4 is engraved on the surface of the free section 2.

[0022] The yield anchor rod is also provided with a gasket 3, a ball screw 5, a constant torque spring 6 and a housing 7.

[0023] The ball screw 5 and the constant torque spring 6 are both standardized mechanical components, and the device cross section is as follows: Figure 2 shown.

[0024] The gasket 3 is sleeved at the boundary between the anchor section 1 and the free section 2, close to the surface of the surrounding rock. The screw shaft of the ball screw 5 is the free section 2 with a groove thread 4. The constant torque spring 6 is sleeved on the ball screw 5. The housing 7 is sleeved on the entire free section 2. The connection method can be welding, bolting, etc.

[0025] One end of the constant torque spring 6 is connected to the ball screw 5 , and the other end is connected to the inner side of the housing 7 .

[0026] Example:

[0027] On the basis of the above-mentioned scheme, the end structure of the free section 2 described in this embodiment is set as a gradual anti-falling enlarged head 8, and the cross-sectional diameter of the outer shell 7 with the left opening is smaller than the cross-sectional diameter of the anti-falling enlarged head 8, ensuring that it will not fall off the free section 2. The entire anchor rod body 9 adopts an internal hollow structure, retaining the hollow grouting function of the traditional ordinary anchor rod.

[0028] The pressure relief amount can be measured by directly inserting a measuring tape, and can even be directly observed due to the characteristic of the right opening of the housing 7.

[0029] Principle of the device: The device adopts groove thread 4 + ball screw 5 on the free section 2 of the anchor rod body 9 to realize the anchor rod pressure release, so that the anchor rod pressure release process is converted into the inward rotation process of the ball screw 5, and the constant torque spring 6 is connected with the ball screw 5 to realize constant resistance in the anchor rod pressure release process.

[0030] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. An end constant resistance pressure-yielding anchor rod, comprising an anchoring section (1) buried in the surrounding rock and a free section (2) extending out of the surrounding rock, characterized in that: It also includes a gasket (3), a ball screw (5), a constant torque spring (6) and a housing (7); the surface of the free section (2) is provided with a groove thread (4); the gasket (3) is sleeved at the boundary between the anchor section (1) and the free section (2) and is in close contact with the surface of the surrounding rock; the screw shaft of the ball screw (5) is the free section (2) provided with the groove thread (4); the constant torque spring (6) is sleeved on the ball screw (5); and the housing (7) has openings at both ends and is sleeved on the entire free section (2); One end of the constant torque spring (6) is connected to the ball screw (5), and the other end is connected to the inner side of the housing (7).

2. The end constant resistance pressure relief anchor rod according to claim 1, characterized in that: The end of the free section (2) is a gradual anti-dropping enlarged head (8).

3. The end constant resistance pressure relief anchor rod according to claim 2, characterized in that: The cross-sectional diameter of the left opening of the shell (7) is smaller than the cross-sectional diameter of the anti-falling enlarged head (8).

4. The end constant resistance pressure relief anchor rod according to claim 1, characterized in that: The anchor rod body (9) is an internal hollow structure.

5. The end constant resistance pressure relief anchor rod according to claim 1, characterized in that: The inner wall of the right end of the housing (7) is provided with a scale.

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