SU1740681A1 - Expanding tubular anchor and its manufacturing method - Google Patents

Abstract

The invention relates to mining. The goal is to simplify the design of the expandable tubular anchor and increase its operational reliability. The expanding tubular anchor includes pipe (T) 1 with sealed ends. For participation 0.9-0.98 of length T1 inside its cavity is crushed with the possibility of straightening a longitudinal fold 3. The sealed ends of T1 are made in the form of twists (C) 5. The anchor is equipped with a backing washer 10. In the manufacture of the anchor, an extended stock cu T1 and seal its ends. The sealing of the ends T1 is carried out by heating them at the site of sealing to the plastic state of the material T1. Then, the heated ends are twisted into tight strands with simultaneous longitudinal stretching at location 5. The heating of ends T1 at locations C 5 is carried out to 750-950 ° C. When installing the anchor in the well 11 into the cavity 7 T1 is injected through the hole 6 by means of a hydraulic pump fluid (water). In this case, under the action of the pressure of the fluid, the fold 3 expands, the diameter T1 increases, and it is pressed in the borehole 11. 2 s. and 1 z. p. f-ly, 13 ill. with s

Description

The invention relates to mining, namely anchoring,

A known construction of a tubular expansion anchor includes a pipe with an axial fold, placed inside with the possibility of straightening under pressure. The protruding end of the tube has an axial hole and is open, and the inner one is sealed by means of a weld.

The known anchor is manufactured according to a technique that includes forming a longitudinal fold in a section of a steel pipe and then sealing one end of the pipe by welding.

The disadvantage of this design. The anchor and its manufacturing technology is the low reliability of the anchor. This is due to the fact that the brewing of the end of the pipe occurs at 2000 ° C, which causes the burning of carbon and other reinforcing components from the steel. As a result, the strength of the pipe sections adjacent to the weld seam sharply decreases and in the process of hydraulic expansion of the anchor, carried out by pressure up to 30 MPa, the pipe breaks in these sections until the end of the installation process of the anchor. In addition, during the thrust of the anchor, accompanied by the opening of the longitudinal hole along the length of the pipe, including in the area of the brewed end, significant deformations of the weld occur, which is an additional reason for the anchor to rupture during its hydrospray.

Closest to the invention is a tubular anchor, made in the form of a metal pipe with a longitudinal fold, both ends of which are provided with reinforcing sleeves, one of which has an annular shoulder radial opening for supplying liquid inside the pipe. Both ends of the pipe are sealed with welds.

The manufacture of such an anchor is carried out by deforming a deep longitudinal recess on a pipe, due to which the initial diameter of the pipe is reduced. After the recess is formed, reinforcing sleeves are mounted on the ends of the pipe, followed by sealing of the ends by welding. A collar is seated in one of the sleeves under the bearing washer and a radial hole is provided to feed the liquid into the anchor. When hydraulic anchor is in the well, reinforcing sleeves prevent opening of the notch at the pipe ends and prevent welds from deformation.

The disadvantage of this solution is the complexity of the manufacturing technology of the anchor, since it includes additional operations for the production of bushings, the formation of a collar on one of them and their fitting onto the ends of the pipe. For making

bushings require pipes whose diameter is less than the diameter of the pipes used to manufacture the anchor itself. Consequently, such structures and technologists for the manufacture of anchors are coupled with

0 additional consumption of raw materials of various grades. In addition, the application for sealing the ends of the welding anchor reduces the strength of the pipe near the welds and thereby reduces the reliability of operation.

5 anchors,

The purpose of the invention is to simplify the technology of manufacturing anchors and increase their reliability by using a pipe itself for sealing the ends of the material.

This goal is achieved by the fact that in a known expandable tubular anchor comprising a pipe with sealed ends and a longitudinal fold positioned inside the U section, 9-0.98 of the length of the pipe with the possibility of straightening under pressure, according to the invention, the pipe is provided with hermetic twists placed at both its ends.

In addition, in the known method of manufacturing tubular spacer anchors, including forming a longitudinal fold on a pipe and sealing its ends, according to the invention, sealing the ends of the pipe 5 is performed by heating to a ductile condition and twisting to break at the twisting points. The heating temperature of the twist points is within 750-950 ° C. In the process of twisting place

0 strands stretch along the pipe axis.

It is the combination of twists on the pipe, as a means of sealing its ends, with a set of technological operations and temperature regimes for their implementation and

5 provide ease of manufacture of the anchor, as well as the strength and reliability required for operation.

Sealing the pipe with a twist yields cone-shaped ends at its ends.

0 harnesses and a series of small corrugations (folds) that significantly increase the rigidity of the twisting points and perform the same functions as the reinforcement sleeves of the prototype. Stretching the twisting points heated to ductile state during the twisting process until their rupture increases the density of the twists. and reliable sealing of pipe ends without welding. At the same time, the claimed temperature limits for twisting places (750–950 ° C) are only

The pipe material is softened for quality sealing and does not cause (as in the known solutions) a decrease in its strength.

Figure 1 shows the anchor introduced into the well to inflate, a general view; figure 2 - the same, after inflate; on fig.Z - the moment of submission of the workpiece to the site Forming; figure 4 - blank, cross-section; Fig. 5 shows the workpiece after the formation of the longitudinal fold; fig.b-too, a cross-section; 7 - the workpiece after crimping the sides of the fold; on Fig - the same cross section; figure 9 - the time of drilling holes in the non-profiled section of the workpiece; in fig. 10 - the same, cross section; in fig. 11 - the moment of fixation of the middle part of the workpiece at the sealing area; on Fig - the moment of heating of the ends of the workpiece with the help of inductors of TVC; in fig. 13- the moment of twisting the ends of the workpiece with their simultaneous axial stretching.

The anchor (Figures 1 and 2) consists of a thin pipe 1, made of a soft metal with a thickness of 1.5-3 mm. The length of the pipe 1, with the exception of the non-profiled section 2, is made deeply longitudinal or screw fold 3, due to which the diameter of the pipe is reduced compared to the original. In section 2, pipe 1 has a non-profiled (initial) diameter with a smooth transition 4 to a pipe diameter reduced by fold 3. Pipe 1 has twists 5 at both ends, due to which its internal cavity is sealed. In the non-profiled section 2 of the pipe 1, an opening 6 is made for supplying fluid under pressure to the cavity 7. The walls of pipe 1 in sections of stranding 5 have a series of small inclined corrugations (folds) 8. smoothly turning into tightly twisted bundles 9. The anchor is completed with support washer 10, which is held at junction 4 of pipe 1.

As a variant, when fastening rocks with lateral shear movements, the anchor is provided with a return seal, which is performed by a cement-sand plug or non-return valve inside pipe 1 (not shown).

The manufacturing techniques for the anchors (Figures 3-13) are as follows. The pre-cut tubes are cut into measured sections, where a longitudinal fold is formed on the pipe by stamping or rolling. The sequence of operations for forming the fold by punching is shown in FIGS. 3-10 and includes: laying the workpiece under the stamp (FIGS. 3 and 4); Embossing fold effort P1

(figure 5 and 6); compression of the pipe to a smaller diameter force P2 (Fig.7 and 8); drilling hole (Fig.9 and 10).

With the formed fold, the billet is fed to the Sealing section, where twisting is performed at the ends of the pipes (Fig. 11-13). For this, the billet is clamped with a force P3 in the middle part (Fig. 11), then using high frequency current inductors (HDTV) Hi and heat the ends of the billet to 750-950 ° C (Fig. 12). After warming up the ends of the workpiece, torques MBr and MBr are applied to them. f, as well as axial tensile forces P01 and P011 (fig. 13). Under the action of these moments and tensile forces, the areas of the workpiece softened from heating are twisted into tight strands, and with continued rotation and stretching, breaks occur in the middle of each of these areas. The final steps in the proposed method of manufacturing anchors are to control the quality of their manufacture and the application of an anti-corrosion coating. These operations include: selective testing of the quality of the packing of the ends of the anchor by supplying them with liquid (water) under a pressure of 27.5-30 MPa until they are completely inflated; checking the straightness of anchors by pattern; Calibration of anchor in outer diameter.

Anticorrosive protection provides for various methods of coating, for example immersion of anchors in an oil bath.

If it is necessary to fold the pipe 1 along a helical line, the sequence of operations is as follows. A blank with a formed longitudinal (straight) fold 3 in the sealing area is clamped with a RE force. To the ends of the workpiece, the torques MBr and MBr11 directed in different directions are applied. Under the influence of torques, the pipe 1 in the fold 3 is twisted at an angle of 90-120 ° C per 1 m length of pipe 1, after which, without stopping the process of twisting, they turn on heating (inducers l / li and Ah) and apply axial forces Ro and Ro and complete the process of sealing the pipe 1,

As applied to pipes with a diameter of 45 mm with a wall thickness of 1.4-2 mm GOST 10704-76 of steel 10 GOST 1050-74, as the most acceptable for the manufacture of anchors of the proposed design, the numerical values of the parameters of technological operations are: Pi 80-90 kN 1 m pipe length; Pa 130-150 kN per 1 m pipe length; Рз 2-4 кН.

m

Mer MVr 0.1-0.25 kNm; P0 PO. 0.2-0.5 kN. The parameters of high frequency inductors l / li1 and I21 are equal and are: current frequency 8 kHz, power 150 kW.

According to the embodiment of an anchor with a reverse hydrolock, before sealing the preform, a sand-cement mixture is poured into the pipe 1 or a check valve is installed that blocks the opening 6. Subsequently, the preform is sealed by the subsequent method.

Anchor set as follows.

A loaded anchor washer 10 anchor is inserted into a well 11 previously drilled in the rock until the washer stops against the rock. The diameter of the well should ensure the free introduction of the anchor and should be 4-6 mm smaller than the original diameter of the pipe 1. The section 2 of the pipe 1 protruding from the well through the hole 6 is connected to a hydraulic pump (not shown) that develops the pressure of the liquid (water) 25 -30 MPa. Under the action of water pressure, the pipe 1 is plastically deformed in the radial directions and due to the expansion of the fold 3 increases in diameter. At the same time, the outer surface of the pipe 1 comes into tight contact with the surface of the borehole 11. After reaching the pressure developed by the hydraulic pump in the pipe 1, it is turned off, and the pressurized water is released from the cavity 7 through the opening 6. The anchor is installed. In an embodiment of an anchor with a reverse hydraulic lock, after it is inflated, water remains in the cavity 7 of the pipe 1, creating a constant backwater inside it, preventing the wall of the pipe from seeing in the lateral direction.

Unlike analogs, the proposed anchor has a simpler design. Manufacturing is carried out at a less complex than the known solutions technology, with a smaller number of operations and does not require additional raw materials. Wherein

Temperatures offered for sealing the ends of the anchor and sparing material for the pipe material provide higher sealing strength.

Thus, when the temperature of the heating of the twist points to 750-950 ° C is minimized, the negative effect of the scaling and decarburization of the pipe material on the quality and reliability is minimized.

At the same time, this temperature provides the plasticity of steel necessary for sealing and its subsequent normalization. This helps to increase the reliability of the anchor.

Tests of the proposed design and manufacturing technology of the anchor showed its operability and high reliability. At the same time, the labor and material costs for the manufacture of the anchor are reduced by 1822%.

Claims (3)

1. A retaining tubular anchor comprising a pipe with sealed ends and a longitudinal fold defined inside the cavity of the pipe in a section 0.9-0.98 of its length with the possibility of straightening, characterized in that, in order to simplify the design and increase the operational reliability of the anchor, sealed pipe ends are made in the form of twists. 2. A method of manufacturing an expandable tubular anchor, comprising forming a longitudinal fold on the pipe and sealing its ends, characterized in that the sealing of the pipe ends is carried out by heating the ends at the sealing place to a plastic state pipe material and twisting of the heated ends into tight bundles with simultaneous longitudinal stretching at the places of twisting. 3. A method according to claim 2, characterized in that the ends of the pipe in places of stranding are heated to 750 t950 ° C. 1740681 14Z & 4: U /// I K ////; Tl Uj F FIG. /five