CN109538266B

CN109538266B - Flexible anchor rod

Info

Publication number: CN109538266B
Application number: CN201910073743.4A
Authority: CN
Inventors: 张农; 谢正正; 魏群
Original assignee: Jiangsu Fengzhi Mining Technology Co ltd; China University of Mining and Technology CUMT
Current assignee: Jiangsu Fengzhi Mining Technology Co ltd; China University of Mining and Technology CUMT
Priority date: 2019-01-25
Filing date: 2019-01-25
Publication date: 2023-10-03
Anticipated expiration: 2039-01-25
Also published as: WO2020151161A1; CA3156369A1; CA3156369C; CN109538266A

Abstract

The invention discloses a flexible anchor rod, which is suitable for the field of coal mine roadway support engineering. Comprises a flexible anchor rod body, a tray, a fixed torque nut, an antifriction washer and an anti-torsion aligning ball head; the flexible anchor rod body comprises a connecting sleeve, a steel strand, a limiting cylinder and a friction-increasing wire spring, wherein the connecting sleeve, the steel strand and the wire spring are reliably fixed in an extrusion mode, and the limiting cylinder is sleeved on the connecting sleeve; the tray blocks through spacing post and rock mass surface and prevents rotatory during pretension, and anti-torsion aligning bulb realizes through first arch and tray between circumference spacing, realizes through the second arch and the flexible stock body between circumference spacing, and then prevents the stock body and rotate along with the nut during pretension. The support device is not limited by the height of a roadway, the support effect is effectively enhanced, the problem of rod body torsion during flexible anchor rod pre-tightening is solved by the special anti-torsion structure, the pre-tightening force is improved, the construction speed is improved by the anchor rod through spiral pre-tightening, and the support efficiency is high.

Description

Flexible anchor rod

Technical Field

The invention relates to a flexible anchor rod, which is particularly suitable for the field of coal mine roadway support engineering.

Background

At present, the anchor bolt support technology is commonly used in coal mine roadways in China, and is firstly used in rock roadways with relatively stable surrounding rocks, and later, the anchor bolt support technology can adapt to various roadways with severe conditions such as soft broken surrounding rock roadways, mining influence roadways and the like by improving the rigidity and strength of anchor bolt materials. The anchor bolt support mainly uses anchor bolts to be driven into preset drilling holes of surrounding rocks of a roadway, and combines the surrounding rock body crushed at a shallow part with the stable rock body at a deep part, so that the purposes of controlling the deformation of the roadway and realizing the safety and stability of the roadway are achieved.

The importance of anchors in anchor bolt support systems has made the variety of anchors numerous. Along with the complexity of roadway conditions, the small-aperture resin anchoring pre-stressed anchor cable is also developed and applied to the coal mine field, and in a word, the diversity of the anchor rod and anchor cable forms is suitable for the complex field conditions of the coal mine in China. However, due to the limitation of the roadway height, the length of the anchor rod can only be maintained at about 2m, the thickness of an anchor rod anchoring area can also be only 2m, and the method is not suitable for the complex geological conditions of the current roadway. Although the anchor cable can be long enough, compared with the anchor rod, the anchor cable installation procedure is relatively complex, the later stage of the anchor cable installation procedure is needed to stretch by using the pump body, so that the tunneling speed of a coal roadway is restricted, meanwhile, the longer the anchor cable length is, the larger the required pretightening force is, the pretightening force cannot be applied on site, the limited pretightening force cannot effectively strengthen an anchor cable anchoring area, and the roadway deformation cannot be controlled well. Therefore, there is an urgent need to develop a bolt that is bendable and can be installed rapidly.

Disclosure of Invention

Technical problems: aiming at the defects of the technology, the flexible anchor rod is provided, the rod body can be bent to adapt to complex geological environment, the pump body is not required to be stretched, the installation is rapid, and the supporting effect is good.

The technical scheme is as follows: the flexible anchor rod comprises a flexible anchor rod body, a tray, a fixed torque nut, an antifriction washer and an anti-torsion aligning ball head, wherein the tray is arranged at the tail part of the flexible anchor rod body, the fixed torque nut is used for fixing the tray, and the antifriction washer and the anti-torsion aligning ball head are arranged between the tray and the fixed torque nut;

the flexible anchor rod body comprises steel strands, the steel strands tail ends are arranged in the connecting sleeve, the connecting sleeve comprises a tail end and a head end, a boss of an annular structure is arranged at a transition section between the tail end and the head end, a limiting cylinder is arranged on the boss, the face of the boss, which faces the head end, is a vertical end face, the face, which faces the tail end, of the boss is a conical face, the outer cylindrical face of the tail end is threaded, the tail end is provided with symmetrically arranged rectangular grooves which are axially arranged along the connecting sleeve, the head end is provided with an inner cylindrical hole connected with the steel strands, the steel strands are inserted into the cylindrical hole of the connecting sleeve, an annular groove is formed in the bottom of the inner cylindrical hole, and a friction increasing spring is arranged between the steel strands and the cylindrical hole, and fastening between the steel strands and the connecting sleeve is realized by extruding the outer cylindrical face of the head end of the connecting sleeve.

The limiting cylinder comprises a limiting cylinder conical cylinder body, the limiting cylinder conical cylinder body comprises a large opening and a small opening, a flanging is arranged on the large opening of the limiting cylinder conical cylinder body, an annular bayonet is arranged on the small opening, the inner diameter of the annular bayonet is smaller than the outer diameter of the boss by 0.5-2 mm, the limiting cylinder is sleeved by the tail end of the connecting sleeve, the annular bayonet deforms and is clamped on the vertical end face of the boss beyond the conical end face of the boss, and the limiting cylinder is made of hard plastic materials.

The tray comprises a tray body and stop posts, the tray body consists of a flanging part and an arch part, the appearance of the flanging part is circular, a conical hole is formed in the center of the arch part, the large end of the conical hole faces the top end of the arch part, a plurality of grooves which are uniformly distributed along the circumference are formed in the conical surface of the conical hole, the number of the grooves is 4-8, and the stop posts are fixed with the flanging part through welding or interference connection.

The anti-torsion aligning ball head comprises a cambered surface and a plane, wherein the cambered surface comprises a plurality of conical surfaces, a bulge I is arranged between every two conical surfaces, the radius of each conical surface is identical to that of each conical hole, the width and the height of the bulge I are smaller than those of the grooves, the quantity of the bulges I is identical to that of the grooves, when the flexible anchor rod is pre-tensioned, the bulge I is embedded into the grooves to ensure that the anti-torsion ball head is fixed with the circumferential direction between the tray, the center of the anti-torsion aligning ball head is provided with a round hole, a bulge II distributed on the opposite side is arranged in the round hole, the section of the bulge II is of a rectangular structure, the width of the bulge II is smaller than that of the rectangular groove by 0.5-1 mm, and the height of the bulge II is smaller than that of the rectangular groove by 0.5-1 mm, and the bulge II is embedded into the rectangular groove to limit the flexible anchor rod body to twist.

The beneficial effects are that: due to the adoption of the technical scheme, compared with the prior art, the invention has the following advantages:

(1) The anchor rod body formed by the steel stranded wires is convenient to bend, the problem that the length of the anchor rod is limited by the height of a roadway is solved, a thick-layer anchoring rock beam needs to be constructed along with the continuous increase of the starting depth of coal, the deformation of the roadway can be controlled only by a high-strength long anchor rod, the breaking load and the breaking length of the flexible anchor rod are 2 times higher than those of a common anchor rod, and the flexible anchor rod can be effectively adapted to complex mine environments;

(2) The flexible anchor rod body is connected with the connecting sleeve in an extrusion way, the strength of the joint of the two parts can reach 95% or more of the strength of the rod body, and the requirements of complex environments on site can be met;

(3) The flexible anchor rod is pre-tightened and installed through the fixed torque nut, a pump body is not required to be used for tensioning, compared with a lock tensioning installation mode of a steel strand, the fixed torque nut can be used for realizing quick installation, the anchor rod supporting speed is greatly improved, the propulsion speed of a roadway is further improved, the working efficiency is effectively improved, and meanwhile, the pump body is not required to be carried, and the labor consumed by equipment transportation is also saved;

(4) The limiting cylinder in the flexible anchor rod can accurately position the installation position of the anchor rod, even if the depth of an anchor rod hole is too large, the limiting cylinder is used for restraining the outer side of a rock body, the installation length of the flexible anchor rod connecting sleeve can be ensured, the flexible anchor rod cannot be invalid, the reliability is high, the uniform anchor rod exposure length is ensured, and the quality standardization of the coal mine anchor rod support is realized;

(5) The structure of tray, aligning bulb and adapter sleeve in the flexible stock has solved flexible stock and has followed nut pivoted troublesome problem when the jumbolter pretension, adds antifriction packing ring's effect for the flexible stock can exert great pretightning force, realizes bigger stock pretightning force, retrains the deformation in tunnel better.

Drawings

Fig. 1 is a cross-sectional view of a flexible anchor body of the present invention.

Fig. 2 is an enlarged partial cross-sectional view of the flexible anchor body of the present invention.

Fig. 3 is a cross-sectional view of a connection sleeve of the flexible anchor body of the present invention.

Fig. 4 is a schematic view of the outer shape of the connecting sleeve of the flexible anchor body of the present invention.

Fig. 5 is a cross-sectional view of the stopper tube of the present invention.

Fig. 6 is a schematic illustration of the flexible anchor of the present invention in an unpressurized state.

Fig. 7 is a cross-sectional view of the flexible anchor of the present invention after pretensioning.

Fig. 8 is a schematic view of a rock bolt hole for rock mass construction according to the present invention.

Fig. 9 is a schematic view of a pallet of the present invention.

FIG. 10 is a schematic view of an anti-twist and aligning ball of the present invention.

Fig. 11 is a schematic view of a constant torque nut of the present invention.

In the figure: A. a rock mass; a1, a rock mass free face; a2, a macroporous section; a3, a small hole section; B. a flexible anchor body; b1, steel strands, B2, friction-increasing springs, B3, a limiting cylinder, B3a, flanging, B3B, annular bayonets, B3C, a conical cylinder body of the limiting cylinder, B4, a connecting sleeve, B4a, a tail end, B4B, a head end, B4C, a cylindrical hole, B4d, an annular groove, B4e, a boss, B4f, a rectangular groove, C, a tray, C1, a tray body, C1a, a conical hole, C1B, a flanging part, C1C, an arch part, C1d, a groove, C2 and a stop post; D. a fixed torque nut; d1, a nut body, D2, a fixed torque baffle, E, an antifriction washer, F, an anti-torsion aligning ball head, F1, a conical surface, F2, a bulge I, F3, a bulge II, F4 and a round hole.

Detailed Description

Specific embodiments of the invention are further described below with reference to the accompanying drawings:

as shown in fig. 1, 2, 3 and 4, the flexible anchor rod comprises a flexible anchor rod body B, a tray C, a fixed torque nut D, an antifriction washer E and an anti-torsion aligning ball head F, wherein the tray C is arranged at the tail part of the flexible anchor rod body B, the fixed torque nut D is used for fixing the tray C, and the antifriction washer E and the anti-torsion aligning ball head F are arranged between the tray C and the fixed torque nut D;

the flexible anchor rod body B comprises a steel strand B1, the tail end of the steel strand B1 is arranged in a connecting sleeve B4, the connecting sleeve B4 comprises a tail end B4a and a head end B4B, a boss B4e of an annular structure is arranged at the transition section between the tail end B4a and the head end B4B, a limit cylinder B3 is arranged on the boss B4e, the face of the boss B4e, which faces the head end B4B, is a vertical end face, the face of the boss B4e, which faces the tail end B4a, is a conical face, threads are arranged on the outer cylindrical surface of the tail end B4a, the tail end B4a is provided with symmetrically arranged rectangular grooves B4f which are axially arranged along the connecting sleeve B4, the head end B4B is provided with an inner cylindrical hole B4c connected with the steel strand B1, threads are arranged on the inner wall of the inner cylindrical hole B4c, an annular groove B4d is arranged at the bottom of the hole, the steel strand B1 is inserted into the cylindrical hole B4c of the connecting sleeve B4, a wire expansion spring B2 is arranged between the steel strand B1 and the cylindrical hole B4c, and the connecting sleeve B4B is fastened by extruding the outer cylindrical surface of the connecting sleeve B4B.

As shown in fig. 5, the limiting cylinder B3 includes a limiting cylinder conical cylinder B3c, the limiting cylinder conical cylinder B3c includes a large opening and a small opening, the large opening on the limiting cylinder conical cylinder B3c is provided with a flange B3a, the small opening is provided with an annular bayonet B3B, the inner diameter of the annular bayonet B3B is smaller than the outer diameter of the boss B4e by 0.5-2 mm, the limiting cylinder B3 is sleeved by the tail end B4a of the connecting sleeve B4, the annular bayonet B3B deforms and passes over the conical end face of the boss B4e to be clamped on the vertical end face of the boss B4e, and the limiting cylinder B3 is made of hard plastic material.

As shown in fig. 9, the tray C includes a tray body C1 and stop posts C2, the tray body C1 is composed of a flanging portion C1b and an arch portion C1C, the shape of the flanging portion C1b is circular, a tapered hole C1a is provided in the center of the arch portion C1C, the large end of the tapered hole C1a faces the top end of the arch portion C1C, a plurality of grooves C1d uniformly distributed along the circumference are provided on the tapered surface of the tapered hole C1C, the number of the grooves C1d is 4-8, and the stop posts C2 are fixed with the flanging portion C1b through welding or interference connection.

As shown in FIG. 10, the anti-torsion aligning ball head F comprises an arc surface and a plane, wherein the arc surface comprises a plurality of conical surfaces F1, a protrusion I F2 is arranged between every two conical surfaces F1, the radius of each conical surface F1 is the same as that of each conical hole C1a, the width and the height of each protrusion I F2 are smaller than those of each groove C1d, the number of the protrusions I F2 is the same as that of the grooves C1d, when the flexible anchor rod is pre-tensioned, the protrusions I F2 are embedded into the grooves C1d to ensure the circumferential fixation between the anti-torsion ball head F and the tray C, the center of the anti-torsion aligning ball head F is provided with a round hole F4, protrusions II F3 distributed on opposite sides are arranged in the round hole, the cross section of each protrusion II F3 is of a rectangular structure, the width of each protrusion II F3 is smaller than that of each rectangular groove B4F by 0.5-1 mm, the height of each protrusion II F3 is smaller than that of each rectangular groove B4F by 0.5-1 mm, and the protrusions II F3 are embedded into the rectangular grooves B4F to limit the torsion of the flexible anchor rod body B.

As shown in fig. 11, the fixed torque nut D includes a nut body D1 and a fixed torque baffle D2

As shown in fig. 6 and 7, a flexible anchor construction method comprises the following steps:

step a, constructing a step anchor rod hole in a rock mass A, wherein the step anchor rod hole close to an excavation surface A1 is a large hole section A2, the rest step anchor rod holes are small hole sections A3, the diameter of the large hole section A2 is 4-10 mm larger than the diameter of the extruded head end B4B, and the depth of the large hole section A2 meets the condition that the flange of a limiting cylinder B3 is tightly attached to the excavation surface A1 after a flexible anchor rod body B is inserted into the anchor rod hole;

b, placing an anchoring agent into the anchor rod stepped hole, pushing the flexible anchor rod body B against the anchoring agent, pushing the anchoring agent into the bottom of the anchor rod stepped hole by utilizing the front part of the flexible anchor rod body B, driving the flexible anchor rod body B to rotate together with the anti-torsion aligning ball head F by utilizing the rotation fixed torque nut D of the anchor rod drilling machine, pushing the flexible anchor rod by the anchor rod drilling machine while rotating to uniformly stir the anchoring agent, rotating and pushing until the turned edge of the limiting cylinder B3 is tightly attached to the face A1 adjacent to the excavation face, stopping rotating the anchor rod drilling machine, and staying for 30 seconds to wait for the anchoring agent to solidify;

step c: the anchor rod drilling machine is started to drive the fixed torque nut D to rotate and damage the fixed torque structure of the fixed torque nut D, the fixed torque nut D is enabled to be screwed in continuously along the connecting sleeve B4 and tightly press the antifriction washer E, the anti-torsion aligning ball head F and the tray C, the stop column C2 on the tray C is clamped on the digging surface A1 to prevent the tray C from rotating, at the moment, the bulge I F2 on the aligning ball head F is clamped with the groove C1D on the tray C, the anti-torsion aligning ball head F is further prevented from rotating, the rotation of the connecting sleeve B4 is limited by the anti-torsion aligning ball head F through the bulge II F3, the rotation of the flexible anchor rod body B is limited, and the flexible anchor rod body B does not rotate when the anchor rod drilling machine applies pretightening force, and pretightening force is 60-100 kN.

Step d: and d, backing down the anchor rod drilling machine, and repeating the steps a-c to construct the next flexible anchor rod.

Claims

1. A flexible anchor rod, characterized in that: the anti-torsion self-aligning device comprises a flexible anchor rod body (B), a tray (C), a fixed torque nut (D), an anti-friction washer (E) and an anti-torsion self-aligning ball head (F), wherein the tray (C) is arranged at the tail part of the flexible anchor rod body (B), the fixed torque nut (D) is used for fixing the tray (C), and the anti-friction washer (E) and the anti-torsion self-aligning ball head (F) are arranged between the tray (C) and the fixed torque nut (D);

the flexible anchor rod body (B) comprises a steel strand (B1), the tail end of the steel strand (B1) is arranged in a connecting sleeve (B4), the connecting sleeve (B4) comprises a tail end (B4 a) and a head end (B4B), a transition section between the tail end (B4 a) and the head end (B4B) is provided with a boss (B4 e) with an annular structure, a limiting cylinder (B3) is arranged on the boss (B4 e), the surface of the boss (B4 e) facing the head end (B4B) is a vertical end surface, the surface of the boss (B4 e) facing the tail end (B4 a) is a conical surface, threads are arranged on the outer cylindrical surface of the tail end (B4 a), rectangular grooves (B4 f) which are symmetrically arranged and axially arranged along the connecting sleeve (B4) are arranged, the head end (B4B) is provided with inner cylindrical holes (B4 c) connected with the steel strand (B1), the bottoms of the inner cylindrical holes (B4 c) are provided with annular grooves (B4 d), the steel strand (B1) is inserted into the cylindrical holes (B4 c) of the connecting sleeve (B4B) and the cylindrical springs (B1) are arranged between the steel strand (B4B) and the outer cylindrical surface (B4B) in a mode, and the steel strand (B4B) is compressed tightly and the cylindrical surface (B) is arranged between the steel strand (B4B) and the connecting sleeve and the steel strand (B) and the cylindrical spring (B) in the cylindrical spring (B) and the cylindrical wire (B) through the cylindrical wire;

the tray (C) comprises a tray body (C1) and stop posts (C2), the tray body (C1) consists of a flanging part (C1 b) and an arch part (C1C) which are circular in appearance, a conical hole (C1 a) is formed in the center of the arch part (C1C), the large end of the conical hole (C1 a) faces the top end of the arch part (C1C), a plurality of grooves (C1 d) which are uniformly distributed along the circumference are formed in the conical surface of the conical hole (C1 a), the number of the grooves (C1 d) is 4-8, and the stop posts (C2) are fixed with the flanging part (C1 b) through welding or interference connection;

the anti-torsion aligning ball head (F) comprises an arc surface and a plane, wherein the arc surface comprises a plurality of conical surfaces (F1), a bulge I (F2) is arranged between every two conical surfaces (F1), the radius of each conical surface (F1) is identical to that of each conical hole (C1 a), the width and the height of each bulge I (F2) are smaller than those of the corresponding grooves (C1 d), the number of the bulges I (F2) is identical to that of the corresponding grooves (C1 d), when the flexible anchor rod is pre-tensioned, the bulges I (F2) are embedded into the grooves (C1 d) to ensure that the circumferential direction between the anti-torsion aligning ball head (F) and the tray (C) is fixed, the center of each anti-torsion aligning ball head (F) is provided with a round hole (F4), the bulges II (F3) distributed on opposite sides are arranged in the round hole, the cross section of each bulge II (F3) is of a rectangular structure, the width of each bulge II (F3) is smaller than that of each rectangular groove (B4F) by 0.5-1 mm, the height of each bulge II (F3) is smaller than that of each rectangular groove (B4F) by 0.5-1 mm, and each bulge II (F3) is embedded into each flexible anchor rod body (B) and is limited by each rectangular groove (1 mm);

the fixed torque nut (D) comprises a nut body (D1) and a fixed torque baffle plate (D2).

2. A flexible anchor rod as claimed in claim 1, wherein: the limiting cylinder (B3) comprises a limiting cylinder conical cylinder body (B3 c), the limiting cylinder conical cylinder body (B3 c) comprises a large opening and a small opening, a flanging (B3 a) is arranged on the large opening of the limiting cylinder conical cylinder body (B3 c), an annular bayonet (B3B) is arranged on the small opening, the inner diameter of the annular bayonet (B3B) is smaller than the outer diameter of the boss (B4 e) by 0.5-2 mm, the limiting cylinder (B3) is sleeved in by the tail end (B4 a) of the connecting sleeve (B4), the annular bayonet (B3B) deforms and is clamped on the vertical end face of the boss (B4 e) beyond the conical end face of the boss (B4 e), and the limiting cylinder (B3) is made of hard plastic materials.