Anchor rod tensioning and twisting type high-pretightening-force construction device and method

Abstract

The anchor rod tensioning type high-pretightening-force construction device comprises a tensioning part and a screwing mechanism, the tensioning part is used for tensioning an anchor rod in a rock mass, the screwing mechanism is used for rotating a nut on the tensioned anchor rod, and after the nut is screwed in place, the tensioning part releases tensioning force. The tightening mechanism and the tensioning part are integrated in a solid mode, a light and small integrated structure is formed, carrying and operation are convenient, anchor rod high pre-tightening force applying operation can be conveniently conducted in complex environments such as a coal mine tunnel, and the safety and reliability of anchor rod supporting are improved.

Description

Technical Field

[0001] The present invention relates to a construction device and construction method for high pre-tightening force of bolt tension-twisting type. Background Art

[0002] In bolt support, the application of pre-tightening force has a decisive influence on the support effect. Affected by factors such as burial depth, the surrounding rock of coal mine roadways generally shows the characteristic of large deformation. Therefore, it is required that the support material has a certain deformation ability. Therefore, the deformation ability of the bolt body is of great significance for improving the support effect.

[0003] The rod body is made of bar materials such as steel bars, and the tail is pre-tightened by means of threaded connection. The outstanding advantage of this type of bolt is that the elongation rate of the rod body is large, and the cost of the tail nut used for pre-tightening is low. However, its disadvantage is that it is difficult to obtain a high active pre-tightening force, which affects the support effect: to obtain a large axial pre-tightening force of the bolt, it is necessary to apply a large pre-tightening torque to the tail nut. When the torque is too large, it may cause torsional failure of the rod body, and affected by the efficiency of the spiral structure, the conversion efficiency of torque to axial force is very low.

[0004] To solve the above problems, the present invention proposes a construction device and construction method for high pre-tightening force of bolt tension-twisting type. By using a hydraulic jack to tension the bolt body to obtain a large axial force, and then tightening the nut to maintain the axial force, a higher active support force of the bolt can be obtained. Summary of the Invention

[0005] The present invention provides a construction device and construction method for high pre-tightening force of bolt tension-twisting type to solve the problems existing in the above-mentioned prior art. The present invention solves the key technical problems existing in the deep coal mine roadway support system, especially the limitation of the traditional nut screwing pre-tightening method in applying large pre-tightening force.

[0006] The technical solutions adopted by the present invention are as follows:

[0007] A construction device for high pre-tightening force of bolt tension-twisting type, comprising:

[0008] A tensioning part, which is used to tension the bolt in the rock mass;

[0009] A screwing mechanism, which is used to rotate the nut on the tensioned bolt. After the nut is screwed in place, the tensioning part releases the tension force.

[0010] Furthermore, the screwing mechanism and the tensioning part are integrally solid.

[0011] Further, the tightening mechanism includes a rotary drive, a machine base, a linkage sleeve, and a drive sleeve. The rotary drive is fixed to the machine base. The linkage sleeve is driven by the rotary drive to rotate. The drive sleeve is engaged with the linkage sleeve. The linkage sleeve rotates and drives the drive sleeve to perform a combined axial and circumferential movement, and the drive sleeve drives the nut to rotate.

[0012] Further, axially arranged spline grooves are provided on the inner cavity surface of the linkage sleeve, splines adapted to the spline grooves are provided on the outer wall of the drive sleeve, and a hole adapted to the nut is provided in the axial direction of the drive sleeve, and the hole is a stepped hole.

[0013] Further, the tightening mechanism further includes a spring. The spring is arranged axially in the linkage sleeve along the axial direction of the linkage sleeve, and the drive sleeve is supported on the upper end surface of the spring.

[0014] Further, the tensioning part is a cable anchor tensioning tool with a conical anchor cup.

[0015] Further, three sliding grooves are provided on the inner wall of the housing of the cable anchor tensioning tool, and anti-rotation keys are provided on the outer wall of each anchor cup, and the anti-rotation keys are placed in the sliding grooves.

[0016] The present invention also discloses a construction method, and the steps are as follows:

[0017] S1: After the anchor bolt is installed in the rock mass according to the conventional construction process, the nut is threadedly connected to the anchor bolt and is preliminarily pre-tightened.

[0018] S2: The tightening mechanism is sleeved on the exposed end of the anchor bolt and abuts against the surface of the tray, and the linkage sleeve in the tightening mechanism is sleeved on the nut.

[0019] S3: Operate the tensioning part, and the tensioning part tensions the anchor bolt to a certain force value.

[0020] S4: Start the rotary drive in the tightening mechanism, and then drive the nut to rotate through the linkage sleeve to achieve high-torque pre-tightening; repeat S3-S4 until the tension force value reaches the planned value.

[0021] S5: Loosen the tensioning part, remove the device, and complete the high-torque pre-tightening.

[0022] The present invention has the following beneficial effects:

[0023] 1) The present invention first performs tensioning through the tensioning part, can obtain a large axial force, effectively solves the limitation that it is difficult to obtain a high active pre-tightening force by the traditional method of screwing the nut for pre-tightening, improves the support effect of the anchor bolt, and has important significance for improving the support conditions of high-stress and large-deformation surrounding rocks such as deep coal mine roadways.

[0024] 2) After obtaining a relatively large axial force through tensioning, use the tightening mechanism to tighten the nut, so that the nut presses the tray against the rock mass, thereby realizing the maintenance of the axial force, ensuring that the bolt can continuously and stably provide support force for the surrounding rock, and enhancing the reliability of the support system.

[0025] 3) The tightening mechanism is integrally solid with the tensioning part, forming a portable and compact integrated structure, which is convenient to carry and operate, and can conveniently apply the pre-tightening force of the bolt in complex environments such as coal mine roadways, improving the work efficiency.

[0026] 4) The linkage sleeve and the drive sleeve in the tightening mechanism are in spline fit. When the linkage sleeve rotates, it can drive the drive sleeve to perform a combined axial and circumferential movement, and then drive the nut to rotate. The transmission efficiency is high, the nut can be quickly tightened, the operation time can be reduced, and the construction progress can be improved.

[0027] 5) The tensioning part adopts a cable tensioning tool with a conical anchor cup, and by setting an anti-torsion structure on the outer wall of the anchor cup, the torsion of the bolt during tensioning is effectively restricted, ensuring the accurate transmission of the tensile force, improving the accuracy and effect of the pre-tightening force application, and avoiding problems such as pre-tightening force loss or nut damage caused by bolt torsion. Description of the Drawings

[0028] Figure 1 It is a schematic diagram of the use of the present invention.

[0029] Figure 2 is Figure 1 a partial plan sectional view of

[0030] Figure 3 It is a structural diagram of the present invention.

[0031] Figure 4 It is a structural diagram of the present invention.

[0032] Figure 5 It is an exploded view of the tensioning part.

[0033] Figure 6 It is a structural diagram of the drive sleeve.

[0034] Figure 7 It is a structural diagram of a rotation-preventing key arranged on the outer wall of the anchor cup in the cable tensioning tool. Detailed Embodiment

[0035] The present invention will be further described below with reference to the drawings.

[0036] Such as Figures 1 to 4, a construction device with high pre-tightening force for bolt tensioning and twisting according to the present invention includes a tensioning part 1 and a screwing mechanism 2. The screwing mechanism 2 is integrally fixed with the tensioning part 1. The tensioning part 1 is used for tensioning the bolt 100 in the rock mass, and the screwing mechanism 2 is used for rotating the nut 110 on the tensioned bolt 100. After the nut 110 is screwed in place (the tray 120 is abutted against the rock mass), the tensioning part 1 releases the tensile force.

[0037] As Figure 5 , the screwing mechanism 2 includes a rotary drive 21, a machine base 22, a linkage sleeve 23 and a drive sleeve 24. The rotary drive 21 is fixed to the machine base 22, the output end of the rotary drive 21 is fixed to the linkage sleeve 23, the linkage sleeve 23 is rotatably arranged on the machine base 22, the linkage sleeve 23 is driven to rotate by the rotary drive 21, and the drive sleeve 24 drives the nut 110 to rotate.

[0038] As Figure 6 , axially arranged spline grooves 231 are provided on the inner cavity surface of the linkage sleeve 23, splines adapted to the spline grooves 231 are provided on the outer wall of the drive sleeve 24, and a hexagonal hole adapted to the nut is provided in the axial direction of the drive sleeve 24, and this hole is a stepped hole.

[0039] The screwing mechanism 2 further includes a spring 25. The spring 25 is arranged in the linkage sleeve 23 along the axial direction of the linkage sleeve 23, and the drive sleeve 24 is supported on the upper end surface of the spring 25. The lower end surface of the spring 25 is supported on the tensioning part 1, or a stepped surface is provided on the tensioning part 1, and the lower end surface of the spring 25 is supported on the stepped surface. The spring 25 does not rotate together with the drive sleeve 24.

[0040] The purpose of setting the spring 25 is that when the initial device is assembled with the nut, the nut may not be exactly aligned with the hexagonal hole on the drive sleeve 24. At this time, the upper top device is used and the spring 25 is in a compressed state. The spring 25 abuts the drive sleeve 24 against the misaligned drive sleeve 24, and then the linkage sleeve 23 is rotated. Under the action of the spring force, after the nut 110 is aligned with the hexagonal hole on the drive sleeve 24, a "click" sound will be heard, and the nut 110 falls into the drive sleeve 24 and cooperates with the hexagonal hole.

[0041] As Figure 7 , the tensioning part 1 in the present invention is a cable tensioning tool with a conical anchor cup 11. Three sliding grooves 11 are provided on the inner wall of the shell of the cable tensioning tool, and anti-rotation keys 12 are provided on the outer wall of each anchor cup 11. The anti-rotation keys 12 are placed in the sliding grooves 11. The three anchor cups 11 hold the bolt tightly. When screwing the nut, the cooperation between the anti-rotation keys 12 and the sliding grooves 11 can prevent the bolt from rotating together with the nut.

[0042] The surrounding rock in deep underground coal mines often exhibits characteristics of high stress and large deformation, and local instability is likely to occur in traditional support methods. Using high-preload bolts can fully stimulate the bonding and frictional effects between the anchored body and the surrounding rock, thereby achieving "active support" and effectively improving the overall stress state of the support system. The tail of the bolt is pre-tensioned by tensioning, and after reaching the predetermined tensile value, the bolt nut is tightened and locked, and then the tensioning mechanism is removed to complete the application of high preload to the bolt.

[0043] The whole invention is divided into a tensioning part and a tightening part, namely a tensioning part 1 and a tightening mechanism 2.

[0044] The power of the tightening part comes from the rotary drive 21. The rotary drive 21 transmits the power to the linkage sleeve 23. The linkage sleeve 23 is connected to the drive sleeve 24 by splines. The inside of the drive sleeve 24 is hexagonal, and the bolt nut 110 is placed therein, so that the nut is tightened when rotating circumferentially. While the nut is being tightened, the spring acts on the floating sleeve to ensure that when the nut moves upward, the floating sleeve and the nut do not move, ensuring the stability of the preload.

[0045] The tightening mechanism 2 uses a hydraulic-driven cable tensioning tool. The principle of the cable tensioning tool will not be elaborated here as it is prior art. During the tightening process, due to the action of friction, the nut drives the bolt to have a tendency to twist, which will affect the preload. To solve this problem, the present invention designs an anti-torsion structure: improvements are made to the structure that restricts the circumferential rotation of the bolt. The inner wall of the anchor cup has thread teeth, which can restrict the rotation of the bolt and increase the friction when pulling downward. At the same time, the anchor cup is in three pieces and can be tightened to wrap the bolt when transported downward. A rotation stop key 12 is provided on the outer wall of the anchor cup to restrict the rotation of the anchor cup.

[0046] Based on the device of the present invention, its specific construction method is as follows:

[0047] I. Preparation work:

[0048] According to the conventional construction process, drill holes in the rock mass, install the anchoring agent and stir evenly, insert the bolt 100 into the hole, and preliminarily pre-tighten the nut 110 through conventional pre-tightening means such as a bolt drilling rig.

[0049] Check whether the tensioning part 1 and the tightening mechanism 2 of the device are in good condition to ensure that components such as the rotary drive 21, the machine base 22, the linkage sleeve 23, and the drive sleeve 24 can work normally.

[0050] Put the tightening mechanism 2 on the exposed end of the bolt 100 and press it against the surface of the tray, so that the linkage sleeve 23 is sleeved on the nut 110. At the same time, connect and fix the tensioning part 1 and the tightening mechanism 2 to ensure the stability of the overall structure.

[0051] II. Tensioning and tightening process:

[0052] Start the tensioning part 1, and tension the anchor bolt 100 through the tensioning part 1, gradually increasing the tension force to a certain value. During the tensioning process, closely observe the change of the tension force to ensure that the tension force increases evenly and stably.

[0053] When the tension force reaches a certain value, start the tightening mechanism 2. The rotary drive 21 drives the linkage sleeve 23 to rotate. The linkage sleeve 23 drives the drive sleeve 24 to perform a combined axial and circumferential movement through the spline fit with the drive sleeve 24, thereby driving the nut 110 to rotate. During the rotation of the nut 110, apply a large pre-tightening torque to gradually tighten the nut 110.

[0054] Repeat the above tensioning and tightening operations. After each tensioning, perform tightening, and gradually increase the tension force value until the tension force reaches the planned value. During the repetition process, pay attention to observing the tightening situation of the nut 110 and the stress state of the anchor bolt 100 to ensure that the nut 110 can be tightened smoothly and the anchor bolt 100 is not damaged.

[0055] When the tension force value reaches the planned value, slowly release the tensioning part 1 to release the tension force. During the release process, pay attention to maintaining the clamping state of the tightening mechanism 2 on the nut 110 to prevent the nut 110 from loosening.

[0056] Remove the device from the anchor bolt 100 to complete the high-torque pre-tightening construction. When removing the device, be careful to avoid causing unnecessary damage to the anchor bolt 100 and the surrounding rock mass.

[0057] The above is only the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. The construction device with high pre-tightening force by bolt tension and torsion, characterized in that: Comprising: A tensioning part (1) for tensioning the anchor bolt (100) in the rock mass; A screwing mechanism (2) for rotating the nut (110) on the tensioned anchor bolt (100). After the nut (110) is screwed in place, the tensioning part (1) releases the tensile force.

2. The bolt tension-torsion type high pre-tightening force construction device according to claim 1, characterized in that: The screwing mechanism (2) is integrally solid with the tensioning part (1).

3. The bolt tension-torsion type high pre-tightening force construction device according to claim 1, characterized in that: The screwing mechanism (2) includes a rotary drive (21), a machine base (22), a linkage sleeve (23) and a drive sleeve (24). The rotary drive (21) is fixed to the machine base (22). The linkage sleeve (23) is driven by the rotary drive (21) to rotate. The drive sleeve (24) cooperates with the linkage sleeve (23). The linkage sleeve (23) rotates and drives the drive sleeve (24) to perform a composite movement in the axial and circumferential directions, and the drive sleeve (24) drives the nut (110) to rotate.

4. The bolt tension and torsion type high pre-tightening force construction device according to claim 3, characterized in that: Axially arranged spline grooves (231) are provided on the inner cavity surface of the linkage sleeve (23). Splines adapted to the spline grooves (231) are provided on the outer wall of the drive sleeve (24). A hole adapted to the nut is provided in the axial direction of the drive sleeve (24), and the hole is a stepped hole.

5. The bolt tension-torsion type high pre-tightening force construction device according to claim 3, characterized in that: The screwing mechanism (2) further includes a spring (25). The spring (25) is arranged axially in the linkage sleeve (23), and the drive sleeve (24) is supported on the upper end surface of the spring (25).

6. The bolt tension-torsion type high pre-tightening force construction device according to claim 1, characterized in that: The tensioning part (1) is a cable anchor tensioning tool with a conical anchor cup (11).

7. The bolt tension-torsion type high pre-tightening force construction device according to claim 6, wherein: Three sliding grooves (11) are provided on the inner wall of the housing of the cable anchor tensioning tool. Anti-rotation keys (12) are provided on the outer wall of each anchor cup (11), and the anti-rotation keys (12) are placed in the sliding grooves (11).

8. A construction method of the device according to any one of claims 1-7, characterized in that: Including the following steps: S1: After the anchor bolt (100) is installed in the rock mass according to the conventional construction process, the nut (110) is threadedly connected to the anchor bolt (100) and preliminarily pre-tightened; S2: The screwing mechanism (2) is sleeved on the exposed end of the anchor bolt and abuts against the surface of the tray. The linkage sleeve (23) in the screwing mechanism (2) is sleeved on the nut (110); S3: Operate the tensioning part (1), and the tensioning part (1) tensions the anchor bolt to a certain force value; S4: Start the rotary drive (21) in the screwing mechanism (2), and then drive the nut (110) to rotate through the linkage sleeve (23) to achieve high-torque pre-tightening; Repeat S3 - S4 until the tensile force value reaches the planned value; S5: Loosen the tensioning part (1), remove the device, and complete the high-torque pre-tightening.

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