Method for improving pre-pulling force of anchor rod
Technical Field
The invention belongs to the technical field of anchor rods, and particularly relates to a method for improving the pretensioning and pulling force of an anchor rod.
Background
The anchor rod is the most basic component of roadway support in the contemporary coal mine, and consolidates the surrounding rocks of the roadway together to support the surrounding rocks, so that the anchor rod is not only used for mines, but also used in engineering technology to carry out main body reinforcement on slopes, tunnels and dam bodies; the anchor rod is used as a tension member penetrating into the stratum, one end of the anchor rod is connected with an engineering structure, the other end of the anchor rod penetrates into the stratum, the whole anchor rod is divided into a free section and an anchoring section, the free section is an area for transmitting the tension at the head of the anchor rod to an anchoring body, and the anchor rod is used for applying prestress to the anchor rod.
The anchor rod is a rod piece system structure for reinforcing the rock-soil body, the defect that the tensile capacity of the rock-soil body is far lower than the compressive capacity is overcome through the longitudinal tension action of the anchor rod body, the cohesive force and the internal friction angle of the surrounding rock body are mainly improved from the mechanical point of view, the anchor rod is located in the rock-soil body to form a new composite body with the rock-soil body, and the anchor rod in the composite body is the key for solving the problem that the tensile capacity of the surrounding rock body is low, so that the bearing capacity of the rock-soil body is greatly enhanced.
The anchor rod is the most basic component of roadway support in the contemporary underground mining mine, and binds the surrounding rocks of the roadway together to enable the surrounding rocks to support the anchor rod, and the anchor rod is not only used for the mine, but also used in engineering technology to actively reinforce side slopes, tunnels, dam bodies and the like.
The anchor rod is divided into wood anchor rod, steel bar or steel wire rope mortar anchor rod, inverted wedge type metal anchor rod, pipe seam type anchor rod, resin anchor rod, fast hardening expansion cement anchor rod, double fast cement anchor rod and the like.
In the field practical application process, because the space of construction sites such as mines and the like is limited, large construction equipment is difficult to enter, sufficient drawing force cannot be applied to the anchor rod, and factors such as insufficient tensile strength of the anchor rod and poor shearing resistance are easy to lose efficacy, so that great potential safety hazards are brought to the safe production of construction sites such as mines and the like, normal production activities are seriously influenced, and great economic loss is brought to the coal mine enterprises.
In the supporting process of a modern mine roadway, anchor rod-guniting, anchor rod-protective net-anchor rope, anchor rod-grouting-protective net-anchor rope and other combined supporting forms are adopted according to different construction spaces and geological conditions, however, in the roadway with narrow space, complex geological conditions and serious roof breaking and floor separation, due to the fact that the strength of the anchor rod is insufficient, large-scale anchor rod drawing equipment cannot enter the roadway, the pre-drawing force of the anchor rod is insufficient, and an ideal stable anchoring effect cannot be achieved.
The existing anchoring process is a one-time anchoring process, the anchor rod is mainly fixed by guniting, grouting and other fixing methods when anchoring and supporting a roadway, and the anchor rod is permanently left in a supporting body after being fixed and cannot be pulled out for secondary utilization after production is finished, so that more production cost is saved; the anchor rod is inserted into a drilled hole which is drilled in advance when anchoring and supporting, then the anchor rod is subjected to prestress drawing by using hydraulic drawing equipment, and finally the anchor rod is fixed, so that the anchor rod is easy to slip in the anchor rod fixing process, the anchoring capability is reduced, and the production safety is influenced.
Disclosure of Invention
In order to make up for the defects of the prior art, the invention provides a method for improving the pretensioning and pulling force of an anchor rod, and the invention aims to solve the technical problems that: how to improve the pre-drawing force of the anchor rod.
The technical scheme adopted by the invention for solving the technical problems is as follows: the invention relates to a method for improving the pretensioning force of an anchor rod, which is characterized by comprising the following steps of: the method comprises the following steps:
s1, drilling an anchor rod hole on the roadway through the anchor rod drilling machine;
s2, rolling a rectangular steel wire mesh into a cylinder shape, and placing the cylinder shape into the anchor rod hole in the S1; so that the steel wire mesh is tightly attached to the inner wall of the anchor rod hole;
s3, placing the anchor rod into a space formed by the steel wire mesh in the S2;
s4, adjusting the anchor rod to enable the anchor rod to be fixed on the inner wall of the steel wire mesh;
the node of one surface of the steel wire mesh is provided with a pricker which is vertical to the plane of the steel wire mesh, and when the steel wire mesh is rolled into a cylinder shape and placed in the anchor rod hole, the pricker is pricked into the inner wall of the anchor rod hole;
the anchor rod adopted in the process comprises an outer rod, an inner rod, a support rod and a pushing unit; the anchor rod is inserted into a pre-drilled hole, the outer rod reaches the bottom of a drilled hole, the inner rod is pulled outwards, the inner rod moves outwards, the inner rod drives the pushing unit to be pushed outwards through the supporting rod, the pushing unit can clamp the inner wall of the drilled hole, the friction force between the outer rod and the inner wall of the drilled hole is increased, and the stable fastening and anchoring function of the anchor rod is realized.
Preferably, the top of the inner rod is provided with a recovery unit which comprises a cylinder barrel, a piston rod and an oil inlet pipe, the invention is characterized in that the cylinder barrel is positioned at the top of the inner cavity of the outer rod, the cylinder barrel is of a cylindrical tubular structure, the top of the cylinder barrel is fixedly connected with the outer rod, a piston is arranged in the cylinder barrel and can slide along the inner wall of the cylinder barrel, a piston rod is arranged at the bottom of the piston, the piston is fixedly connected with the piston rod, the bottom of the piston rod is fixedly connected with the inner rod, and the right side of the bottom of the cylinder barrel is connected with an oil inlet pipe. Thereby driving the support rod to enable the pushing unit to contract towards the inside of the anchor rod, reducing the pressure of the pushing unit on the wall of the drilling hole, and then reduce the stock and the frictional force of drilling wall to pull out the stock from the drilling very easily, carry out the reutilization, practice thrift the cost, improve the utilization ratio of stock.
Preferably, the hemispherical salient points are arranged at one end, located on the outer wall of the outer rod, of the push-out unit, the hardness of the salient points is increased after heat treatment, the push-out unit can be tightly compacted with the inner wall of a drill hole after being pushed out outwards, the inner wall of the drill hole is generally rough rock, the hardness of the hemispherical salient points is improved after heat treatment, the hemispherical salient points are better embedded into the inner wall of the drill hole under the action of pressure, the friction force between the anchor rod and the inner wall of the drill hole is increased, and the pulling resistance strength.
Preferably, one end of the inner rod, which is located outside the drill hole, is provided with a self-locking unit, the self-locking unit comprises a pawl, ratchets, a return spring and a base, the base is sleeved outside the inner rod, the part of the inner rod, which is located on the base, is uniformly provided with a plurality of ratchets, the pawl is arranged in the base, one end of the pawl is hinged with the base, the other end of the pawl is meshed with the ratchets, the middle of the pawl is provided with the return spring, the other end of the return spring is fixedly connected with the base, and the return spring is a compression spring.
Preferably, the pushing unit comprises a pushing block, a top rod, a first sliding hole and a second sliding hole, a plurality of first sliding holes are uniformly formed in the outer wall of the outer rod, the bottom of each first sliding hole is provided with the second sliding hole, each second sliding hole is a through hole, the diameter of each first sliding hole is larger than that of each second sliding hole, the pushing block is sleeved in each first sliding hole, the top rod is sleeved in each second sliding hole, the right end of the top rod is hinged with the support rod, and a closed cavity formed by the pushing block and the top rod is filled with hydraulic oil; when the push rod is pushed out outwards under the action of the support rod, the thrust is transmitted to the push-out block through hydraulic oil, the thrust is amplified through the Pascal principle, and the outward thrust of the push-out block is increased, so that the push-out block obtains larger push-out force by the inner rod with smaller pull force, the friction force between the anchor rod and a drill hole is further enhanced, the anchoring stability is increased, the strength requirements of the inner rod and the support rod can be reduced, the material consumption is reduced, and the material cost is saved; the pascal principle is: after any point in incompressible static fluid is subjected to pressure increment generated by external force, the pressure increment is instantaneously transmitted to each point of the static fluid, the Pascal law can only be used in the liquid, due to the liquidity of the liquid, the pressure change generated by a certain part of the static fluid in a closed container constantly transmits the pressure in all directions, the pressure is equal to the acting pressure divided by the stressed area, a certain pressure is exerted on one piston in a hydraulic system according to the Pascal law, the same pressure increment must be generated on the other piston, if the area of the second piston is one tenth of the area of the first piston, the force acting on the second piston is increased to ten times of that of the first piston, the pressures on the two pistons are equal, if two pistons with different sizes are arranged in a fluid system, small thrust is exerted on the small piston, and the pressure transmission in the fluid is realized, a large thrust is generated on the large piston.
Preferably, the pushing block is provided with a limiting unit, the limiting unit comprises a limiting chute and a limiting block, the upper portion of the pushing block is provided with the limiting chute, the limiting chute is internally provided with the limiting block, the limiting chute can slide along the limiting block, and the limiting block is fixedly arranged on the outer rod.
The invention has the following beneficial effects:
1. the steel wire mesh is matched with the special anchor rod, so that the friction force between anchor rod pre-anchoring holes of the anchor rod is improved, the pre-pulling force of the anchor rod is further improved, the anchor rod pre-pulling device has a good using effect, and the steel wire mesh pre-pulling device is easy to disassemble and assemble, so that the steel wire mesh pre-pulling device can be quickly disassembled and assembled for use.
2. According to the method for improving the pre-pulling force of the anchor rod, the inner rod is pulled outwards, the inner rod drives the ejector rod to be pushed outwards through the support rod, the pushing force is transmitted to the pushing block through hydraulic oil, the pushing force is amplified through the Pascal principle, the outward pushing force of the pushing block is increased, the anchoring stability is increased, the strength requirements of the inner rod and the support rod can be reduced, materials are reduced, and the material cost is saved.
3. According to the method for improving the pre-pulling force of the anchor rod, pressure oil is driven into the cylinder barrel through the oil inlet pipe, the pressure oil pushes the piston to move upwards, the piston drives the piston rod and the inner rod to move upwards, so that the support rod is driven to enable the push-out unit to retract into the anchor rod, the pressure of the push-out unit on the wall of a drilled hole is reduced, the friction force between the anchor rod and the wall of the drilled hole is further reduced, the anchor rod is easily pulled out of the drilled hole for secondary utilization, the cost is saved, and the utilization rate of the anchor rod is improved.
Drawings
The invention will be further explained with reference to the drawings.
FIG. 1 is a front view of a rock bolt employed in the present invention;
FIG. 2 is an enlarged view at A in FIG. 1;
FIG. 3 is a left side view of the ejector block;
FIG. 4 is a block diagram of the self-locking unit;
in the figure: the device comprises an outer rod 1, an inner rod 2, a support rod 3, a pushing unit 4, a recovery unit 5, a cylinder 51, a piston 52, a piston rod 53, an oil inlet pipe 54, a salient point 41, a self-locking unit 6, a pawl 61, a ratchet 62, a return spring 63, a base 64, a pushing block 42, a push rod 43, a first sliding hole 44, a second sliding hole 45, a limiting unit 7, a limiting sliding groove 71 and a limiting block 72.
Detailed Description
In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.
The invention relates to a method for improving the pretensioning and pulling force of an anchor rod, which is characterized by comprising the following steps of: the method comprises the following steps:
s1, drilling an anchor rod hole on the roadway through the anchor rod drilling machine;
s2, rolling a rectangular steel wire mesh into a cylinder shape, and placing the cylinder shape into the anchor rod hole in the S1; so that the steel wire mesh is tightly attached to the inner wall of the anchor rod hole;
s3, placing the anchor rod into a space formed by the steel wire mesh in the S2;
s4, adjusting the anchor rod to enable the anchor rod to be fixed on the inner wall of the steel wire mesh;
the node of one surface of the steel wire mesh is provided with a pricker which is vertical to the plane of the steel wire mesh, and when the steel wire mesh is rolled into a cylinder shape and placed in the anchor rod hole, the pricker is pricked into the inner wall of the anchor rod hole;
as shown in fig. 1 to 4, the anchor rod used in the above process comprises an outer rod 1 and an inner rod 2, and further comprises a support rod 3 and a pushing unit 4; the anchor rod comprises an outer rod 1, an inner rod 2, a plurality of support rods 3 and a plurality of pushing units 4, wherein the outer rod 1 is of a hollow cylindrical structure, the top of the outer rod 1 is conical, the plurality of pushing units 4 are uniformly arranged in the wall of the outer rod 1 along the circumferential direction, the pushing units 4 can transversely slide along the wall of the outer rod 1, the inner rod 2 penetrates through the inner rod 1, the inner rod 2 can axially slide along the outer rod 1, the support rods 3 are arranged between each pushing unit 4 and the inner rod 2, the support rods 3, the inner rod 2 and the pushing units 4 are connected through hinges, and the length of each support rod 3 is larger than the distance between the inner wall of the outer rod 1 and the inner rod 2.
As a specific embodiment of the invention, the top of the inner rod 2 is provided with the recovery unit 5, the recovery unit 5 comprises a cylinder 51, a piston 52, a piston rod 53 and an oil inlet pipe 54, the cylinder 51 is positioned at the top of the inner cavity of the outer rod 1, the cylinder 51 is in a cylindrical tubular structure, the top of the cylinder 51 is fixedly connected with the outer rod 1, the piston 52 is arranged in the cylinder 51, the piston 52 can slide along the inner wall of the cylinder 51, the piston rod 53 is arranged at the bottom of the piston 52, the piston 52 is fixedly connected with the piston rod 53, the bottom of the piston rod 53 is fixedly connected with the inner rod 2, the right side of the bottom of the cylinder 51 is connected with the oil inlet pipe 54, the invention pumps pressure oil into the cylinder 51 through the oil inlet pipe 54, the pressure oil pushes the piston 52 to move upwards, the piston 52 drives the piston rod 53 and the inner rod 2 to move, and then reduce the stock and the frictional force of drilling wall to pull out the stock from the drilling very easily, carry out the reutilization, practice thrift the cost, improve the utilization ratio of stock.
As a specific embodiment of the invention, one end of the push-out unit 4, which is positioned on the outer wall of the outer rod 1, is provided with the hemispherical convex point 41, and the hardness of the convex point 41 is increased after heat treatment.
As a specific embodiment of the invention, one end of the inner rod 2 positioned outside the drill hole is provided with a self-locking unit 6, the self-locking unit 6 comprises a pawl 61, ratchets 62, a return spring 63 and a base 64, the outer side of the inner rod 2 is sleeved with the base 64, the part of the inner rod 2 positioned on the base 64 is uniformly provided with a plurality of ratchets 62, the base is internally provided with the pawl 61, one end of the pawl 61 is hinged with the base 64, the other end of the pawl 61 is engaged with the ratchets 62, the middle part of the pawl 61 is provided with the return spring 63, the other end of the return spring 63 is fixedly connected with the base 64, and the return spring 63 is a compression spring, when the inner rod 2 is pulled outwards, the pawl 61 and the ratchets 62 are relatively displaced, the pawl 61 is matched with the return spring 63 to enable the pawl 61 to be tightly attached to the ratchets 62, the, the anti-pulling strength of the anchor rod is reduced.
As a specific embodiment of the present invention, the pushing unit 4 includes a pushing block 42, a push rod 43, a first sliding hole 44 and a second sliding hole 45, a plurality of first sliding holes 44 are uniformly formed on the outer wall of the outer rod 1, a second sliding hole 45 is formed at the bottom of the first sliding hole 44, the second sliding hole 45 is a through hole, the diameter of the first sliding hole 44 is larger than that of the second sliding hole 45, the pushing block 42 is sleeved in the first sliding hole 44, the push rod 43 is sleeved in the second sliding hole 45, the right end of the push rod 43 is hinged to the support rod 3, and a closed cavity formed by the pushing block 42 and the push rod 43 is filled with hydraulic oil, in the present invention, when the push rod 43 is pushed outwards under the action of the support rod 3, the pushing force is transmitted to the pushing block 42 through the hydraulic oil, the pushing force is amplified through pascal principle, the outward pushing force of the pushing block 42 is increased, so that the pushing block 42 obtains a larger pushing force with a smaller pulling force by the inner rod 2, and the friction force of the, increase the firm degree of anchoring, also can reduce interior pole 2 and 3 intensity requirements of vaulting pole, reduce the material, material saving cost, the pascal principle is: after any point in incompressible static fluid is subjected to pressure increment generated by external force, the pressure increment is instantaneously transmitted to each point of the static fluid, the Pascal law can only be used in the liquid, due to the liquidity of the liquid, the pressure change generated by a certain part of the static fluid in a closed container constantly transmits the pressure in all directions, the pressure is equal to the acting pressure divided by the stressed area, a certain pressure is exerted on one piston in a hydraulic system according to the Pascal law, the same pressure increment must be generated on the other piston, if the area of the second piston is one tenth of the area of the first piston, the force acting on the second piston is increased to ten times of that of the first piston, the pressures on the two pistons are equal, if two pistons with different sizes are arranged in a fluid system, small thrust is exerted on the small piston, and the pressure transmission in the fluid is realized, a large thrust is generated on the large piston.
As a specific embodiment of the invention, the pushing-out block 42 is provided with a limiting unit 7, the limiting unit 7 comprises a limiting sliding groove 71 and a limiting block 72, the upper part of the pushing-out block 42 is provided with the limiting sliding groove 71, the limiting block 72 is arranged in the limiting sliding groove 71, the limiting sliding groove 71 can slide along the limiting block 72, and the limiting block 72 is fixedly arranged on the outer rod 1.
When the device works, the anchor rod is inserted into a hole which is drilled in advance, the anchor rod is fixed after the outer rod 1 reaches the bottom of the drilled hole, the inner rod 2 is pulled out by using hydraulic equipment, the inner rod 2 is pulled out outwards, the inner rod 2 drives the ejector rod 43 to be pushed out outwards through the support rod 3, the thrust is transmitted to the push-out block 42 through hydraulic oil, the thrust is amplified through the Pascal principle, the outward thrust of the push-out block 42 is increased, the hardness of the hemispherical convex points 41 of the push-out block 42 is improved after heat treatment, the hemispherical convex points 41 are better embedded into the inner wall of the drilled hole under the action of pressure, the friction force between the anchor rod and the inner wall of the drilled hole is increased, meanwhile, the hemispherical convex points 41 of the push-out block 42 push the pricked needles on the steel wire mesh towards the inner wall of the drilled hole, the stability is further improved, the hemispherical convex points 41 can be positioned in meshes of, the movable stroke of the pushing-out block 42 is limited, the pushing-out block 42 is prevented from sliding down from the first sliding hole 44 due to overlarge stroke, when the inner rod 2 is pulled outwards, the pawl 61 and the ratchet 62 are displaced relatively, the pawl 61 is enabled to be tightly attached to the ratchet 62 due to the cooperation of the pawl 61 and the return spring 63, the pawl 61 is constantly meshed with the ratchet 62, the inner rod 2 is automatically locked, the inner rod 2 is prevented from contracting inwards after pulling is stopped, the pressure of the pushing-out unit 4 on the inner wall of a drill hole is reduced, the pulling-out strength of the anchor rod is reduced, pressure oil is pumped into the cylinder barrel 51 through the oil inlet pipe 54, the piston 52 is pushed upwards by the pressure oil, the piston 52 drives the piston rod 53 and the inner rod 2 to move upwards, the supporting rod 3 is driven to enable the pushing-out unit 4 to contract inwards of the anchor rod, the pressure of the pushing-out unit 4, the cost is saved, and the utilization rate of the anchor rod is improved.
The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.