Internal expansion method for fishing out a round drill rod that has fallen out of a hole during full hydraulic drilling of a cast-in-place pile

Abstract

The invention relates to a circular drill rod internal expansion type salvage method for a drill bit dropped in a fully hydraulically drilled hole of a cast-in-place pile, comprising the following steps: determining the position where the drill bit falls, lowering a drill bit salvage device to the drill rod; aligning the drill bit salvage device with the drill rod, and sliding blocks distributed on the drill bit salvage device penetrate into the drill rod along with the drill bit salvage device; pulling the drill bit salvage device upwards, and radially pressing the inner wall of the drill rod through the sliding blocks on the drill bit salvage device to connect the drill rod to the drill bit salvage device; and pulling the drill rod salvage device to salvage the dropped drill bit, wherein the entire salvage process is safe, convenient and reliable.

Description

Technical Field

[0001] The invention relates to the technical field of bored pile construction, in particular to a method for fishing a round drill rod with internal expansion when a drill bit is lost in a fully hydraulically drilled hole of a cast-in-place pile. Background Art

[0002] When drilling large rock-embedded cast-in-place piles using RCD drilling rigs, KTY drilling rigs, etc., large-diameter roller bits are often used for rock drilling. However, while the drill bit provides a large drilling force through the drill rod, it also bears a large resistance. In particular, when sand surges or rocks fall from the borehole wall, the resistance on the drill bit will increase significantly. When the force on the drill rod exceeds its torque strength, the following will occur: Figure 1 The drill bit is detached from the drill rod, the drill rod body is broken, and the drill bit or the drill bit carrying the broken drill rod falls to the bottom of the hole.

[0003] When the drill bit falls off, divers usually dive into the hole to connect the salvage hook to the drill bit, and then pull the salvage hook upward to fish the drill bit out. The working environment of the divers during the connection process is dangerous and the connection is difficult. Summary of the invention

[0004] Based on this, it is necessary to provide a drill bit salvage device to address the above technical problems.

[0005] A method for recovering a round drill rod with internal expansion when a drill bit falls out of a hole in a fully hydraulic bored pile, wherein a drill bit recovering device is used to recover the drill bit that falls out of the hole with the broken drill rod, and the method comprises the following steps:

[0006] Step S1: determining the falling position of the drill bit in the borehole, and lowering the drill bit salvage device into the drill bit to the drill rod;

[0007] Step S2: aligning the drill bit salvage device with the drill pipe and lowering it into the inside of the drill pipe, and sliding blocks distributed on the drill bit salvage device enter the inside of the drill pipe along with the drill bit salvage device;

[0008] Step S3: Pull the drill bit salvage device upward, and the slider on the drill bit salvage device moves downward until the inner wall of the drill pipe is radially pressed to fix the drill bit salvage device to the drill pipe;

[0009] Step S4: Pull the drill bit salvage device upward to retrieve the fallen drill bit from the drill hole.

[0010] When the drill bit is salvaged by the circular drill rod internal expansion method in the above-mentioned cast-in-place pile full hydraulic drilling hole,

[0011] First, determine the falling position of the drill bit in the borehole, lower the drill bit salvage device to the drill pipe, then insert the slider distributed on the drill bit salvage device into the drill pipe, then pull the drill bit salvage device upward to move the slider downward until it is pressed against the inner wall of the drill pipe to fix the drill bit salvage device to the drill pipe, and finally pull the drill bit salvage device upward to salvage the fallen drill bit from the borehole. The entire salvage process is safe, convenient and reliable.

[0012] Preferably, in step S1, before lowering the drill bit salvage device into the borehole, the deposits in the borehole are cleared first.

[0013] Preferably, in step S2, after the slider is lowered into the borehole along with the drill bit salvage device, it is further lowered by a set distance, and the slider radially abuts against the inner wall of the drill pipe under the action of its own gravity. Preferably, in step S3, the drill bit salvage device is repeatedly pulled upward in small amplitudes until the slider completely presses against the inner wall of the drill pipe.

[0014] Preferably, the drill bit salvage device comprises a salvage rod and a plurality of convex strips distributed on the periphery of the salvage rod and with a slider moving up and down, the plurality of convex strips are arranged at intervals along the periphery of the salvage rod, and the convex strips are arranged along the axial extension of the salvage rod;

[0015] Slide rails for guiding the movement of the slider are respectively arranged on both sides of the convex strip, the slide rails are arranged extending along the length direction of the convex strip, the slider is movably connected to the slide rails, and along the top-to-bottom direction, the slide rails are arranged outwardly away from the salvage rod; the slider has a pressing surface arranged outwardly, and the pressing surfaces of the multiple sliders are spaced and enclosed to form an outer peripheral surface;

[0016] In step S2, when the plurality of sliders enter the interior of the drill rod, the plurality of sliders are squeezed and move upward along the slide rail, the diameter of the peripheral surface enclosed by the plurality of sliders is reduced, and the pressing surface of the slider moves relative to the inner wall of the drill rod;

[0017] In step S3, when the drill bit salvage device moves upward, the slider moves downward along the slide rail under the action of gravity, the diameter of the outer surface enclosed by the multiple sliders expands, and the pressing surface of the slider is pressed and fixedly connected to the inner wall of the drill pipe.

[0018] Preferably, a salvage tube is arranged around the outside of the salvage rod, a avoidance groove is provided on the wall of the salvage tube, the avoidance groove is arranged along the axial extension of the salvage rod, the slider passes through the avoidance groove, the pressing surface of the slider is exposed outside the salvage tube, and a guide head is provided at the bottom of the salvage tube.

[0019] Preferably, a connecting piece is provided at the upper end of the drill bit salvage rod, and the connecting piece is connected by an external driving device to drive the drill bit salvage device to move upward or downward.

[0020] Preferably, the external driving device is a drilling rig that matches the drill bit, and the connecting piece is a cylindrical flange, and the cylindrical flange is detachably connected to the drilling rig.

[0021] Preferably, the internal expansion salvage device comprises a plurality of connecting rods, and the connecting rods are detachably connected to the salvage rod and the drilling tool.

[0022] Preferably, an image acquisition device is provided at the lower end of the drill bit salvage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a diagram of the drill bit falling;

[0024] Figure 2 This is a flowchart for fishing an internal expansion drill bit;

[0025] Figure 3 It is a schematic diagram of the first state of the drill bit salvage device;

[0026] Figure 4 for Figure 3 Section view in the AA direction;

[0027] Figure 5 for Figure 3 Partial schematic diagram;

[0028] Figure 6 is a schematic diagram of the drill bit salvage device in the second state;

[0029] Figure 7 for Figure 6 Cross-sectional view along BB direction.

[0030] Figure Number:

[0031] 10-Drill bit salvage device;

[0032] 100-salvage body; 110-salvage rod; 120-slide rail; 121-upper end of slide rail; 122-lower end of slide rail; 123-convex strip; 1231-first side surface; 1232-second side surface; 130-sliding block; 131-butting surface; 132-connecting portion; 1321-extension plate; 1322-sliding claw; 133-guide surface; 140-salvage tube; 141-tube wall; 142-avoidance groove; 1421-upper groove wall; 1422-lower groove wall; 143-guide head; 150-limiting body;

[0033] 200-connector; 210-cylindrical flange; 220-reinforcement rib;

[0034] 300-drill rod; 310-inner hole;

[0035] 400-drill bit; 500-drilling. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0039] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0041] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0042] Combination Figure 2-7 It can be seen that the present invention discloses a method for salvaging a circular drill rod with internal expansion when a drill bit falls out of a hole in a fully hydraulically bored pile, wherein a drill bit salvage device is used to salvage the drill bit that falls with the broken drill rod, and the method comprises the following steps:

[0043] Step S1: determine the falling position of the drill bit in the borehole, and lower the drill bit salvage device into the borehole to the drill pipe;

[0044] Before using the drill bit salvage device 10 to salvage the drill bit 400, it is first necessary to determine the position where the drill bit 400 has fallen in the borehole, and then lower the drill bit salvage device 10 into the borehole near the drill rod 300 to facilitate the connection of the drill bit salvage device 10 to the drill rod 300, thereby achieving the salvage of the fallen drill bit 400.

[0045] Specifically, when the drill rod 300 breaks and falls to the bottom of the borehole 500 together with the drill bit 410, the drill bit 400 is usually located at the bottom and the drill rod 300 connected to the drill bit 400 is located above the drill bit 400. Therefore, the determination of the falling position of the drill bit 400 is mainly used to determine the specific position of the broken part of the drill rod 300. Among them, an external information collection device can be used to determine the specific position of the broken drill rod 300, or an information collection device can be set at the bottom of the drill bit salvage device 10 to dynamically determine the relative position of the drill bit salvage device 10 and the broken part of the drill rod as the drill bit salvage device 10 is lowered.

[0046] By clarifying the falling position of the drill bit 400, on the one hand, the specific depth of the drill bit 400 can be determined, and on the other hand, a suitable driving device can be selected according to the depth of the drill bit 400 to lower the drill bit salvage device 10 to avoid the depth being unable to meet the salvage requirements of the drill bit salvage device 10.

[0047] Step S2: aligning the drill bit salvage device with the drill pipe and lowering it into the inside of the drill pipe, and sliding blocks distributed on the drill bit salvage device enter the inside of the drill pipe along with the drill bit salvage device;

[0048] When the drill bit salvage device 10 moves downward to the vicinity of the drill rod 300, align the drill bit salvage device 10 with the inner hole 310 of the drill rod, and continue to lower the drill bit salvage device 10 into the drill rod 300, so that the slider 13 distributed on the drill bit salvage device 10 enters the inside of the drill rod, and then the connection between the drill bit salvage device 10 and the drill bit 400 can be achieved.

[0049] Specifically, the sliders 130 are circumferentially distributed on the periphery of the drill bit salvage device 10 and slide up and down relative to the slide rail 120. The diameter of the outer surface formed by the pressure surfaces of the multiple sliders 130 gradually increases as the sliders 130 slide downward. When the slider 130 is located at the uppermost end, the diameter of the outer surface formed by the pressure surfaces thereof is smaller than the diameter of the inner hole 310 of the drill rod. When the slider 130 is located at the lowermost end, the diameter of the outer surface formed by the pressure surfaces thereof is larger than the diameter of the inner hole 310 of the drill rod. Before the slider 130 is lowered to the opening of the drill rod inner hole 310 along with the drill bit salvage device 10, the slider 130 is located at the lowest position under the action of its own gravity, and the diameter of the outer surface formed by the intervals between the pressure surfaces of the slider is larger than the diameter of the opening of the inner hole 310; as the depth of the drill bit salvage device 10 extending into the drill rod 300 increases, the slider 130 is lowered to the opening of the inner hole 310, and the drill rod 300 prevents the slider 130 from sliding downward and slides upward relative to the drill bit salvage device 10 until the slider 130 slides upward relative to the drill bit salvage device 10 until the diameter of the outer surface formed by the intervals between the pressure surfaces of the slider 130 is equal to or slightly smaller than the diameter of the drill rod inner hole 310, and the slider 130 slides into the drill rod along with the drill bit salvage device 10.

[0050] Step S3: Pull the drill bit salvage device upward, and the slider on the drill bit salvage device moves downward until it radially presses against the inner wall of the drill pipe, so as to fix the drill bit salvage device to the drill pipe;

[0051] When the drill bit salvage device 10 is pulled upward, the slider 130 remains stationary or moves downward relative to the drill bit salvage device 10 due to its own gravity and the friction with the wall of the inner hole 310 of the drill rod. During the downward movement of the slider 130 relative to the drill bit salvage device 10, the diameter of the outer surface formed by the interval between the pressing surfaces of the slider 130 increases. The drill bit salvage device 10 presses the slider 130 against the drill rod 300, so that the drill rod 300 is connected to the drill bit salvage device 10 as a whole through the slider 130.

[0052] Step S4: Pull the drill bit salvage device upward to retrieve the fallen drill bit.

[0053] After the drill bit salvage device 10 is connected to the drill rod 300 , the fallen drill bit 400 can be salvaged by pulling the drill bit salvage device 10 upward.

[0054] During the drilling process of the drill bit 400 driven by the drill rod 300, the bottom of the borehole 500 is usually covered with fallen rocks, soil, etc. The broken drill rod 300 and the drill bit 400 that fall to the bottom of the borehole 500 are usually trapped in the mud and sand at the bottom of the borehole 500. When the drill bit 400 is salvaged, the mud and sand around the drill rod 300 and the drill bit 400, on the one hand, hinder the connection between the drill bit salvage device 10 and the drill rod 300, and on the other hand, the resistance of the surrounding mud and sand to the drill bit 400 increases the load-bearing capacity of the drill bit salvage device 10, making the salvage more difficult. In view of the above technical problems, before lowering the drill bit salvage device 10, it is necessary to first clear the deposits in the borehole 500 so that there is no deposit around the broken drill rod 300 and the drill bit 400 to hinder the connection between the drill bit salvage device 10 and the drill rod 300. At the same time, when the drill bit salvage device 10 pulls the drill rod 300 upward, it only needs to bear the gravity of the broken drill rod 300 and the drill bit 400 to remove the drill bit 400 from the borehole 500.

[0055] After the slider 130 enters the drill rod 300 along with the drill bit salvage 10, in order to avoid pulling the drill bit salvage 10 upward, the slider 130 slides upward along with the drill bit salvage 10 relative to the drill rod 300, and the slider 130 slides out from the inner hole 310 of the drill rod 300. In step S2, the slider 130 is lowered into the inner hole 310 along with the drill bit salvage 10 and then continues to be lowered by a set distance. Preferably, in order to make the slider 130 stably pressed against the wall of the inner hole 310 of the drill rod, when the drill bit salvage 10 is pulled upward, the drill bit salvage 10 can be repeatedly pulled upward in a small amplitude. That is, after pulling upward for a certain distance, it is lowered for a certain distance, and then pulled upward for a certain distance again, and it is repeatedly pulled several times until the slider 130 is completely and firmly pressed against the wall of the inner hole 310 of the drill rod, so that the drill bit salvage 10 is connected to the drill rod 300 as a whole through the slider 130.

[0056] After the drill bit salvage device 10 salvages the drill bit 400 inside the borehole 500 to the ground, the drilling tool needs to be separated from the drill bit salvage device 10. Specifically, a cutting tool can be used to cut the drill bit salvage device 10 from the drilling tool to separate the drill bit 400 from the drilling tool.

[0057] When a drill bit salvage device is used to salvage the drill bit, the drill bit salvage device used is as follows:

[0058] The drill bit salvage device 10 comprises a salvage body 100 connected to a dropped drill bit 400 and a connecting body 200 connecting the salvage body 100 to an external driving device. After the salvage body 100 is connected to the drill bit 400, the external driving device pulls the salvage body 100 carrying the drill bit 400 out of the borehole 500 through the salvage body 100, and the drill bit 400 dropped into the borehole 500 can be salvaged, and the entire salvage process of the drill bit 400 is safe, convenient, and efficient. Specifically, the salvage body 100 includes a salvage rod 110, a plurality of convex strips 123 distributed on the periphery of the salvage rod 110 and for a slider to move up and down, the convex strips 123 extending along the axial direction of the salvage rod 110 and arranged at intervals along the periphery of the salvage rod 110, and slide rails 120 guiding the movement of a slider 130 are respectively provided on both sides of the convex strips 123, the slide rails 120 extending along the length direction of the convex strips 123 and tilted outwardly away from the salvage rod 110 in a top-down direction of the salvage rod 110, wherein the slider 130 is slidably connected to the slide rails 120, and a plurality of abutment surfaces 131 of the sliders 130 arranged outwardly are spaced apart to enclose a peripheral surface. In the process of using the drill bit salvage device 10 to salvage the drill bit, when the drill bit salvage device 10 is lowered into the drill rod 300, that is, in step S2, multiple sliders 130 enter the drill rod 300 along with the salvage rod, and the multiple sliders 130 are squeezed and move upward along the slide rail 120, and the diameter of the outer peripheral surface enclosed by the multiple sliders 130 is reduced, that is, the abutting surface 131 of the slider and the inner wall of the drill rod are relatively movable; when the drill bit salvage device 10 is pulled upward, that is, in step S3, the drill bit salvage device 10 moves upward, and the slider 130 moves downward along the slide rail 120 under the action of its own gravity, and the diameter of the outer peripheral surface enclosed by the multiple sliders 130 is expanded, and the abutting surface 131 of the slider and the inner wall of the drill rod 300 are pressed and fixedly connected. One side of the connecting body 200 is connected to an external driving device, and the other side is connected to the salvage body 100 . The external driving device can salvage the salvage body 100 connected to the drill bit 400 from the drill hole 500 through the salvage body 100 .

[0059] During the drill bit salvage process, the drill bit salvage device 10 is first aligned with the drill rod 300 and placed into the borehole 500 until it is lowered to the vicinity of the drill rod 300, so that the drill bit salvage device 10 is connected to the drill rod 300; then the salvage rod 110 is aligned with the inner hole 310 of the drill rod 300 and penetrates into the inner hole 310. During the process of the salvage rod 110 extending into the drill rod 300, the slider 130 first moves upward along the slide rail 120 for a certain distance and then moves downward along the slide rail 120 until it is firmly abutted against the drill rod 300, thereby realizing the connection between the salvage body 100 and the drill rod 300; finally, the external driving device pulls the connecting body 200 upward, thereby pulling the salvage body 100 and the drill bit 400 connected to each other out of the borehole 500, and completing the salvage of the drill bit 400. Specifically, since the slider 130 is affected by its own gravity, when the salvage rod 110 penetrates into the inner hole 310 of the drill rod, its initial position of the slider 130 is located at the bottom of the slide rail 120. Before the slider 130 is lowered to the opening of the inner hole 310 of the drill rod along with the drill rod 300, the slider 130 is located at the lowest position under the action of its own gravity, and the diameter of the outer surface formed by the interval between the pressure surfaces of the slider 130 is larger than the diameter of the opening of the inner hole 310. As the drill bit salvage device 10 is lowered to an increasing depth inside the drill rod 300, the slider 130 is lowered to the opening of the inner hole 310, and the drill rod 300 prevents the slider 130 from sliding downward and slides upward relative to the drill bit salvage device 10, until the slider 130 slides upward relative to the drill bit salvage device 10 until the diameter of the outer surface formed by the interval between the pressure surfaces of the slider 130 is equal to or slightly smaller than the diameter of the inner hole 310 of the drill rod, and the slider 130 slides into the drill rod 300 along with the drill bit salvage device 10. When the drill bit salvage device 10 is pulled upward, the slider 130 remains stationary or moves downward relative to the salvage rod 110 due to its own gravity and the friction between the slider abutment surface 131 and the wall of the drill rod inner hole 310. During the downward movement of the slider 130 relative to the salvage rod 110, the diameter of the outer surface formed by the interval between the abutment surfaces 131 of the slider 130 increases, and the slide rail 120 presses the slider 130 against the drill rod 300, so that the drill rod 300 is connected to the drill bit salvage device 10 as a whole through the slider 130.

[0060] When the salvage rod 110 is used to penetrate the borehole 500 to connect the drill bit 400, a thin solid salvage rod is often used to reduce the mass of the salvage body 100 while ensuring the tensile strength of the salvage body 100. However, in the process of the salvage rod 110 penetrating the borehole 500 to connect the drill rod 300, the diameter of the salvage rod 110 provided with the slide rail 120 is significantly smaller than the diameter of the inner hole 310. When the salvage rod penetrates the inner hole 310, it is easy to shake relative to the drill rod 300, making it difficult for the slider 130 to align and abut with the wall of the inner hole 310 of the drill rod, which affects the salvage efficiency and the connection stability between the salvage rod 110 and the drill rod 300 is poor. In view of the above problems, a salvage tube 140 is provided on the outer periphery of the salvage rod 110 to match the inner hole 310 (e.g., there is a gap of 10-50 cm between the salvage tube 140 and the inner wall of the inner hole 310), and a clearance groove 142 is provided on the wall of the salvage tube 140 for the slider 130 to slide relative to the slide rail 120. When the slider 130 slides along the slide rail 120, the abutting surface 131 of the slider is exposed outside the clearance groove 142 and abuts against the drill rod 300. Specifically, the salvage tube 140 can be fixedly or detachably connected to the outer wall of the salvage rod 110, and the salvage rod 110 is located in the salvage tube 140 as a whole, wherein the diameter of the salvage tube 140 is set according to the diameter of the inner hole 310 of the drill rod, for example, the diameter of the salvage tube 140 is slightly smaller than the inner hole 310 of the drill rod so that the slider 130 exposed outside the salvage tube 140 can slide in. By using a thinner salvage rod 110 and arranging an overshot tube 140 outside the salvage rod 110 that matches the inner hole 310, the weight of the salvage body 100 can be reduced while ensuring the stability of the salvage rod 110 penetrating into the drill pipe 300.

[0061] Furthermore, in order to prevent the slider 130 from sliding out of the end of the slide rail 120 when sliding to the end of the slide rail 120, thereby affecting the normal use of the salvage body 100, a stopper 150 is provided at the end of the slide rail 120. When the slider 130 slides to the end of the slide rail 120, the stopper 150 prevents the slider 130 from continuing to slide upward or downward to prevent the slider 130 from detaching from the slide rail 120. Specifically, the stopper 150 is a stopper block whose width dimension is greater than the width of the end of the slide rail and / or whose height dimension is greater than the height of the end of the slide rail, or the stopper 150 is a protrusion provided at the end of the slide rail 120 that can prevent the slider 130 from sliding. Preferably, the limiting body 150 is located at the upper end portion 121 of the slide rail, and the lower end portion 122 of the slide rail is partially located in the overshot tube 140, wherein the limiting body 150 can prevent the slider 130 that has slid to the upper end portion 121 of the slide rail from continuing to slide upward and disengage from the slide rail 120, the upper groove wall 1421 of the avoidance groove abuts against the lower end portion of the slider 130 exposed in the avoidance groove 142, and the lower groove wall 1422 of the avoidance groove prevents the slider 130 from continuing to slide downward, and the limiting body 150 at the upper end of the slide rail 120 and the lower groove wall 1422 of the avoidance groove limit the sliding stroke of the slider 130; or, the limiting body 150 is located at the lower end portion 122 of the slide rail, and the upper end portion 121 of the slide rail is located inside the overshot tube 140, wherein the limiting body 150 can prevent the slider 130 that has slid to the lower end portion 122 of the slide rail from continuing to slide downward and disengage from the slide rail 120, and the upper groove wall 1421 of the avoidance groove abuts against the lower end portion of the slider 130 exposed in the avoidance groove The groove wall 1421 abuts against the upper end of the slider 130 exposed in the avoidance groove, and the upper groove wall 1421 of the avoidance groove prevents the slider 130 from continuing to slide upward, and the limiting body 150 at the lower end of the slide rail 120 and the upper groove wall 1421 of the avoidance groove limit the sliding stroke of the slider 130; or, the limiting body 150 is located at both ends of the slide rail, and the limiting body 150 prevents the slider 130 from sliding upward or downward, wherein the limiting body 150 includes a first limiting body and a second limiting body, the first limiting body is located at the upper end 121 of the slide rail, and the second limiting body is located at the lower end 122 of the slide rail, the first limiting body prevents the slider that slides to the upper end 121 of the slide rail from continuing to slide upward and disengage from the slide rail 120, and the second limiting body prevents the slider 130 that slides to the lower end 122 of the slide rail from continuing to slide downward and disengage from the slide rail 120, thereby limiting the stroke of the slider 130.

[0062] In one embodiment, a guide head 143 is provided at the bottom of the overshot tube 140, and the guide head 143 extends along the axis direction of the overshot tube 140 and contracts radially inward. Specifically, the guide head 143 can be a cone, a cylinder, a polygonal pyramid or a prism with a lower diameter smaller than an upper diameter. When the salvage body 100 penetrates into the inner hole 310 of the drill pipe, the inwardly inclined outer surface of the guide head 143 guides the overshot tube 140 to slide into the inner hole 310 and align with the drill pipe 300 axially and radially, so that the salvage body can penetrate into the interior of the drill pipe 300.

[0063] In one embodiment, the convex strips 123 distributed on the outer wall of the fishing rod 110 include a first side surface 1231 and an oppositely disposed second side surface 1232, and the slide rail 120 is disposed on the first side surface 1231 and the second side surface 1232 of the convex strip 123. The slide rail 120 is a protrusion or a groove disposed on the first side surface 1231 and / or the second side surface 1232, that is, the slide rail 120 disposed on the first side surface 1231 is a protrusion, and the slide rail 120 disposed on the second side surface 1232 is a protrusion, or the slide rail 120 disposed on the first side surface 1231 is a protrusion, and the slide rail 120 disposed on the second side surface 1232 is a groove, or the slide rail 120 disposed on the first side surface 1231 is a groove, and the slide rail 120 disposed on the second side surface 1232 is a groove. Specifically, preferably, in order to ensure the stability of the slider 130 sliding up and down relative to the slide rail 120, the first side surface 1231 and the second side surface 1232 are respectively provided with grooves, and a sliding claw 1322 is provided on the side of the slider 130 close to the fishing rod 110, and the sliding claw 1322 slides in the groove when the slider moves up and down relative to the slide rail 120. Specifically, the slider 130 includes an abutting surface 131 abutting against the hole wall of the inner hole 310 and a connecting portion 132 slidably connected to the slide rail 120, wherein the connecting portion 132 includes an extension plate 1321 extending from the inner side of the slider 130 toward the direction close to the slide rail 120 and a sliding claw 1322 extending from the end of the extension plate 1321 toward the groove, wherein the sliding claw 1322 is adapted to the shape of the groove and slides in the groove, and the slider 130 is slidably connected to the slide rail 120 by sliding the corresponding sliding claw 1322 into the grooves on both sides of the slide rail. Furthermore, to ensure the smoothness of the sliding block 130 relative to the slide rail 120 and the stability of the abutment against the inner hole wall, the connecting portion 132 of the sliding block fits with the contact surface of the slide rail, and the abutment surface 131 of the sliding block fits with the inner hole wall.

[0064] Furthermore, a guide surface 133 is provided at the bottom of the slider 130, and the slider 130 can smoothly slide into the inside of the drill rod 300 through the guide surface 133. Figure 5 As shown, an inclined guide surface 133 is provided at the intersection of the bottom surface of the slider and the outer side surface of the slider, and the angle between the guide surface 133 and the extending direction of the outer side surface of the slider is selected to be in the range of 0-90°, preferably 30°.

[0065] In one embodiment, the salvage body 100 is fixedly connected to the connecting body 200 or detachably connected to the connecting body 200. Specifically, the salvage body 100 is fixedly connected to the connecting body 200 by welding or other connection methods, or the salvage body 100 is detachably connected to the connecting body 200 by bolts, screws, threaded connections or other methods. Preferably, in order to ensure the stability and safety of the connection of the connecting body 200 by pulling the salvage body 100 upward through an external driving device, the salvage body 100 is a cylindrical flange 210, and the salvage body 100 is fixedly connected to the cylindrical flange 210, that is, the salvage rod 110 and the salvage tube 140 are fixedly connected to the cylindrical flange 210. Furthermore, when the external driving device pulls the salvage rod 110 carrying the drill bit 400 upward through the connecting body 200, the connecting body 200 bears the weight of the salvage body 100 and the dropped drill bit 400. In order to avoid breakage at the connection between the connecting body 200 and the salvage body 100, reinforcing ribs 220 are provided between the cylindrical flange 210 and the salvage tube 140. The reinforcing ribs 220 are circumferentially distributed between the cylindrical flange 210 and the salvage tube 140. The connecting strength between the connecting body 200 and the salvage body 100 is improved by the reinforcing ribs 220.

[0066] When the drill bit salvage device 10 penetrates into the borehole 500 to connect with the drill rod 300, it is difficult to align the drill bit salvage device 10 with the drill rod 300 because the position of the lower end of the drill bit salvage device 10 and the inner hole 310 of the drill rod is difficult to determine. In view of the above technical problems, an image acquisition device is provided at the lower end of the drill bit salvage device 10, which can acquire the position of the inner hole 310 of the drill rod and transmit and display it to the operator. The operator adjusts the position of the drill bit salvage device 10 according to the position of the inner hole 310 of the drill rod. After adjusting the alignment between the lower end of the drill bit salvage device and the inner hole 310 of the drill rod, the drill bit salvage device 10 is moved downward so that the drill bit salvage device 10 penetrates into the inner hole 310 of the drill rod and connects with the drill rod 300. Furthermore, when the depth of the borehole 500 is relatively deep, the light at the bottom of the borehole 500 is relatively poor, and the clarity of the image transmitted by the image acquisition device is relatively poor, and the position of the inner hole 310 of the drill rod cannot be accurately determined. The image acquisition device is equipped with a lighting device, and the lighting device increases the brightness of the bottom of the borehole 500, thereby improving the clarity of the image transmitted by the image acquisition device. Preferably, the image acquisition device is a camera, and the lighting device is an LED lamp, and the LED lamp is charged by a lithium battery. The image acquisition device transmits the image to the user terminal by wireless or wired means, and the user terminal can be a computer, a drilling rig display screen, or a user's mobile device.

[0067] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for recovering a round drill rod that has fallen out of a fully hydraulically drilled bored pile hole by internal expansion, wherein the drill bit that has fallen out of the broken drill rod is recovered by a drill bit recoverer, and the method is characterized in that: The following steps are involved: Step S1: determine the falling position of the drill bit in the borehole, and lower the drill bit salvage device into the borehole to the drill pipe; Step S2: aligning the drill bit salvage device with the drill pipe and lowering it into the inside of the drill pipe, and sliding blocks distributed on the drill bit salvage device enter the inside of the drill pipe along with the drill bit salvage device; The sliders are circumferentially distributed around the periphery of the drill bit salvage device and slide up and down relative to the slide rail. The diameter of the peripheral surface formed by the intervals between the pressure surfaces of the multiple sliders gradually increases as the slider slides downward. The diameter of the peripheral surface formed by the intervals between the pressure surfaces of the slider at the uppermost end is smaller than the diameter of the inner hole of the drill rod. The diameter of the peripheral surface formed by the intervals between the pressure surfaces of the slider at the lowermost end is larger than the diameter of the inner hole of the drill rod. Step S3: Pull the drill bit salvage device upward, and the slider on the drill bit salvage device moves downward until Compressing the inner wall of the drill pipe radially to fix the drill bit salvage device to the drill pipe; Step S4: Pull the drill bit salvage device upward to retrieve the fallen drill bit from the drill hole; The drill bit salvage device comprises a salvage rod and a plurality of convex strips distributed on the periphery of the salvage rod and for the slider to move up and down, wherein the plurality of convex strips are arranged at intervals along the periphery of the salvage rod, and the convex strips are arranged to extend along the axial direction of the salvage rod; Slide rails for guiding the movement of the slider are respectively arranged on both sides of the convex strip, the slide rails are arranged extending along the length direction of the convex strip, the slider is movably connected to the slide rails, and along the top-to-bottom direction, the slide rails are arranged outwardly away from the salvage rod; the slider has a pressing surface arranged outwardly, and the pressing surfaces of the multiple sliders are spaced and enclosed to form an outer peripheral surface; In step S2, when the plurality of sliders enter the interior of the drill rod, the plurality of sliders are squeezed and move upward along the slide rail, the diameter of the peripheral surface enclosed by the plurality of sliders is reduced, and the pressing surface of the slider moves relative to the inner wall of the drill rod; The convex strip includes a first side surface and an oppositely arranged second side surface, the first side surface and the second side surface are respectively provided with a groove, and a sliding claw is provided on a side of the slider close to the salvage rod, and the sliding claw slides in the groove when the slider moves up and down relative to the slide rail; In step S3, when the drill bit salvage device moves upward, the slider moves downward along the slide rail under the action of gravity, the diameter of the outer peripheral surface enclosed by the plurality of sliders expands, and the pressing surface of the slider is pressed and fixedly connected to the inner wall of the drill pipe; A salvage tube is arranged around the outside of the salvage rod, a wall of the salvage tube is provided with an avoidance groove, the avoidance groove is arranged along the axial direction of the salvage rod, the slider passes through the avoidance groove, the pressing surface of the slider is exposed outside the salvage tube, and a guide head is provided at the bottom of the salvage tube; A limiting body is provided at the end of the slide rail, and when the slider slides to the end of the slide rail, the limiting body prevents the slider from sliding further upward or downward; An inclined guide surface is provided at the intersection of the bottom surface of the slider and the outer side surface of the slider, and the slider smoothly slides into the drill rod through the inclined guide surface; In the step S2, after the slider is lowered into the borehole along with the drill bit salvage device, it is further lowered by a set distance, and the slider radially abuts against the inner wall of the drill pipe under the action of its own gravity; In step S3, the drill bit salvage device is repeatedly pulled upward in small amplitudes until the slider is completely pressed against the inner wall of the drill pipe; An image acquisition device is provided at the lower end of the drill bit salvage device.

2. The method for recovering a round drill rod from a hole in a fully hydraulic bored pile according to claim 1, characterized in that: In the step S1, before lowering the drill bit salvage device into the borehole, the deposits in the borehole are cleared.

3. The method for recovering a round drill rod from a hole in a fully hydraulic bored pile according to claim 1, characterized in that: A connecting piece is provided at the upper end of the drill bit fishing rod, and the connecting piece is connected by an external driving device to drive the drill bit fishing device to move upward or downward.

4. The method for recovering a round drill rod from a hole in a fully hydraulic bored pile according to claim 3 is characterized in that: The external driving device is a drilling rig matched with the drill bit, and the connecting piece is a cylindrical flange, which is detachably connected to the drilling rig.

5. The method for recovering a round drill rod from a hole in a fully hydraulic bored pile according to claim 4 is characterized in that: The internal expansion drill bit salvage device comprises a plurality of connecting rods, and the connecting rods are detachably connected to the salvage rods.

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