CN1599832A - earth drilling rig - Google Patents

Abstract

The invention relates to a drill and a method for down-the-hole drilling, said drill comprising a central pilot hole drill bit (20), a reamer bit (33) and a guide body (12) controlling said drill and mutually opposite drill pipes, said guide body (12), reamer bit (33) and pilot hole drill bit (20) being formed such that rotational energy is transmitted from said guide body (12) to the reamer bit (33) and from the reamer bit (33) to the pilot hole drill bit (20), but said transmission of both rotational energies does not involve any threaded connection. And a substantially radial displacement between the guide body (12) and the reamer (33). This arrangement also facilitates retraction of the reamer (33) without the need for the pilot hole bit to also rotate.

Description

In-ground drilling rig

technical field

The present invention relates to a drilling rig for down-the-hole drilling for drilling the ground and overlying rock formations, said drilling rig drilling a hole before a subsequent drill pipe.

Background technique

Previously known drilling rigs comprise a central pilot drill bit (pilot drill bit), a reamer drill (reamer) and a guide body (guide body) for guiding the drilling rig and mutually opposite drilling pipes, when all work in the drilling rig In this state the guide body has an axial mounting position on the drilling machine. The guide body is located inside the drill pipe and transmits rotational and impact energy to the cross-hole and pilot-hole bits. The drill bit may be located in a position centered with the guide body and the pilot drill bit, where the pilot drill bit and the drill bit can be guided by the drill pipe and protrude in an operable radial direction. position to drill a hole larger than the drill pipe. For example, reference is made to EP-A-36847 and SE-B-411139 for such drilling rigs.

In the case of such drilling rigs, when drilling hard ground or fractured rock, for example, the drill bit is inserted so tightly that sometimes there is a risk of losing the drilling tool. The difficulty here is that the guide body and pilot hole bit are prevented from rotating with the eccentric shaft hole of the jammed cross-boring bit. With the opposite rotation, the thread would loosen and separate from the drill pipe, making it impossible to bring the reaming bit back to the retracted position to be stowed through the drill pipe.

Furthermore, for example the threaded connection between the guide body and the part bearing the drill head is a weak point of the known drill. A known structure comprises a guide body, a shaft integral with said guide body and to be connected with a down-the-hole drilling hammer. A pilot hole drill pipe an external threaded plug is connected to the guide body, the threaded plug is received in an internal threaded hole of the guide body, and an enclosing drill bit is rotatably supported on the guide body by an intermediate member. hole drill. The damage that most often occurs in this case is the thread on the upper part of the threaded plug being damaged.

Some attempts have been made to avoid threaded connections in down-the-hole drilling rigs. EP-A-515538 describes a down-the-hole drilling machine in which no threaded connection is used between the guide body and the shaft of the pilot hole bit. According to this known structure, the drilling machine comprises a central pilot hole bit, a drill bit and a guide body to control the drilling machine and the drill pipes facing each other, and a shaft to be connected to a down-the-hole drilling impact On the tool, the shaft and the pilot hole bit form an integral unit, and the guide body is mounted on the shaft so that it can be removed, for example for replacing the cross-boring bit. However, according to this structure, the shaft of the guide body is still used by an external thread to fix the internal thread of the DTH hammer, which still has the possibility of thread loosening, especially if the drill bit is jammed when too tight. The drill is driven by the shaft of the pilot drill.

One of the main reasons why the threads of known structures (including said EP-A-515538) sometimes loosen is unless the pilot hole bit rotates the jammed counterboring bit in the opposite direction of rotation for drilling, Otherwise it cannot be recovered. Thus, it is readily understood that if the shaft of the drill and/or pilot drill is tightly gripped or prevented from turning freely in the opposite direction, the threads will loosen and cause the drill to be pulled apart.

In US-A-5787999 there is described a construction of a down-the-hole drilling machine comprising a guide body, a drill bit and a drill bit arm mounted between these two elements, said arm being able to extend into a working position and Lifted and retracted, for example by a drill pipe. However, these drill arms are relatively brittle and easily damaged. Also, drill cuttings, debris from the ground can easily get behind or in the middle of the arm, preventing said arm from returning to where it should rest, which again can cause the drill to be lost. Furthermore, according to this US specification the impact energy is transferred from the drill arm to the pilot drill bit (shoulder seat), which is certainly a disadvantage when subjected to high force connections.

Contents of the invention

Therefore, a first object of the present invention is to be able to retract the drill bit of a down-the-hole drilling machine without the need to turn said pilot hole drill bit.

Another object of the invention is to avoid screw connections.

A third object of the invention is to obtain an operationally reliable drilling rig for down-the-hole drilling which is insensitive to incoming cuttings and other debris.

A further object of the present invention is to design a drilling rig for down-the-hole drilling consisting of as few components as possible.

Yet another object of the present invention is to provide a drilling rig with improved characteristics for remediation in the event of jamming and at the same time ensuring improved control flexibility in the working and retracted positions of said drilling tool.

Extension and retraction are positively controlled. If a shaft break occurs and the pilot and counterbores leave the raised hole, they are caught by the drill rotating in the same direction as the working position.

These and other objects, which are obvious to an expert, can be considered to be realized in a surprising manner by means of a drilling rig designed according to the characterizing parts of claim 1 . The drill rig in the preferred embodiments of the invention is defined by the independent claims.

Description of drawings

A preferred embodiment of the present invention will be described schematically below with reference to the accompanying drawings, but this embodiment is not intended to be limited, and the brief description is as follows:

Figure 1 shows a cross-sectional view of a guide body passing through a drill pipe in a pilot hole drill bit, viewed from the side, and shows a cross-sectional view of the reamer concentrically opposite said guide body in a retracted position.

Figure 2 shows a corresponding view of the drill collar with the pilot hole bit and the extension reamer in the operative position, below the bore of the drill pipe.

Fig. 3 shows the sectional view of the pilot hole drill bit and the reamer drill in Fig. 1 at 3-3.

Figure 4 shows a sectional view of the pilot hole drill and reamer drill in Figure 2 at 4-4.

Figure 5 shows a side view of the pilot hole bit with camshaft, cam and shaft.

FIG. 6 is a top view of the pilot hole drill shown in FIG. 5 .

FIG. 7 shows a side view of the guide shown in FIGS. 1 and 2 .

Fig. 8 is a cross-sectional view at 8-8 of the guide body shown in Fig. 7 .

Figure 9 shows a side view of the reamer shown in Figures 1 and 2 .

Fig. 10 is a sectional view of the reamer shown in Fig. 9 at 10-10.

Fig. 11 is a sectional view of the reamer shown in Fig. 9 at 11-11.

FIG. 12 shows a bottom view from 12-12 of FIG. 5 .

Detailed ways

Figure 1 shows the drill bit and reamer 33 in the retracted (non-operating) position. Said guide body 12 (see also FIG. 7 ) is connected in a conventional manner within a drill pipe 13 to a continuous drill rod by a device which rotates with the guide body clockwise as indicated in the embodiment and is received in the The impact energy of a down-the-hole drilling hammer or a left-handed top hammer connected in a torsionally rigid manner between the drill rod and the guide body 12 . The drill pipe and its components are of conventional type and therefore not shown in the figures. The guide body 12 has a cylindrical guide portion 47 which is mounted concentrically and rotates coaxially with the drill shaft 16 guided by the bore of the drill pipe 13 . As shown in the embodiment, by driving the down-the-hole drill hammer, the drill pipe includes a welded drill pipe collar 14 (casing shoe), which forms an annular collar 15 inside the drill pipe 13, and a guide body The guide hole 19 formed by the guide portion 47 of 12. Furthermore, said guide body 12 has a rear shoulder 17 which rests against said collar 15 in operation, so that a portion of the impact energy of the down-the-hole drill hammer is transmitted to said drill pipe 13 to drive it downwards.

The pilot hole drill 20 (see also FIGS. 5 and 6 ) comprises a shaft 21 and a cam 22 integrated into a camshaft 42 and a working drill 48 . The length L of the shaft 21 measured from the bit flat 23 to its top surface 24 (together with the camshaft 42 ) is greater than the diameter D of the shaft 21 . The top end surface 24 of the shaft 21 is perpendicular to the longitudinal axis 16 to receive the impact energy and has such a length that a groove 59 is formed between the lower surface of the guide body and the upper surface of the reamer opposed thereto. The shaft 21 also has a radial groove 26 to receive a flexible sliding pin 30 (see also FIG. 8 ). The shaft 21 is mounted rotatably in a central bore 28 of the guide body. The shaft 21 terminates at the top in a recess 25 which seals off the shaft at 180 degrees parallel to the cam. Furthermore, said guide body 12 has at its lower end a shoulder 27 with two parallel planes 27A, 27B, the position of which is shown in FIG. 8 . These planes contact each other with two parallel planes 36A, 36B of the two shoulders 36', 36" (see FIGS. 9 and 10) of the reamer near the bottom hole of the hole 28. Between the guide body 12 and the reamer The advantage of this connection between 33 is that it is very cheap and easy to replace parts, said reamer being very easily damaged in operation.

The reamer 33 shown in FIG. 2 is in its extended working position and its one-piece design is shown in FIGS. 9 , 10 and 11 . In Fig. 10 it is possible to see the recess 34 and the flat 35 positioned for right-hand rotation of the cam 22 (viewed from above), forming an underside that should be adjacent to the flat 23 of the pilot hole bit. In the case of a drilling tool with counterclockwise movement, the recess 34 should be in a position which is a mirror image of FIG. 10 , so that it can also work when using an identically guided drill bit 20 . FIG. 11 shows the top of the reamer, which has two parallel shoulders 36 whose longitudinal surfaces run parallel to the longitudinal extension of the oval recess 37 . When the reamer 33 is extended, the surfaces 36A, 36B slide into the two planes 27A, 27B of the guide body, so that the movement of the reamer is radial, by displacement, the cam 22 moves into the recess 34 from the retracted position to the extended position.

In Fig. 1, the pilot hole drill bit 20 hangs freely in the guide body 12 through a transverse hole 38 (see Fig. 8) which passes through and enters an annular radial The flexible sliding pin is inserted into the radial groove and supports the rotatable shaft 21 and the guide body together. In a small hole substantially perpendicular to said bore 38 , a tubular pin 31 is inserted for locking said sliding pin 30 . The locking pin/plug 31 is preferably made of a material that is less dense than the retainer 12 . The locking pin 31 is desirably made of elastic material such as urethane rubber or plastic polymer (PAG). By using the locking pin 31 of low density material, the risk of the locking pin 31 being damaged or coming out is greatly reduced. This solution principle can therefore be more favorable for the operational reliability of the drilling tool. It should be understood that this newly named scheme is not intended to be limited to only this type of drill bit, but that the principles can be applied to the locking of interacting components of other types of drill bits.

It should be clear from FIG. 1 that a flushing channel 43 , 44 is provided centrally within the drill head, the diameter of which is adapted to the desired flushing medium and/or flow rate. The flushing channel 43 in the guide body 12 leads through and into a flushing channel 44 in the pilot hole drill 20 . The cylindrical recesses 43A and 44A are respectively located in the passage area of the flushing passages 43 , 44 between the guide body 12 and the pilot hole bit 20 . Said recess has a substantially uniform outer diameter and is able to accommodate a sealing bush 50 made of a suitable material, preferably plastic. In the approximate middle of the recess 44A of the pilot hole drill there is provided a groove 44B for engagement with a correspondingly formed annular projection 51 of the sealing bush 50 . Due to this, the sealing bush 50 can be securely caught at the concave portion 44A of the pilot hole drill 20 and fixed. The function of the sealing bush 50 is to seal the upper joint between the pilot hole drill bit 20 and the guide body 12 . This thus prevents flushing medium from leaking out of the connection into the connection.

As shown in FIG. 5 , it is advantageous to use said sealing bush 50 to regulate the flushing of the flushing medium by selecting a sealing bush with the desired diameter R50 . The bit thus has seal bushings that accept many different internal diameters, enabling optimum flushing to be achieved quickly and easily.

According to FIG. 2 , the pilot hole drill 20 and the reamer drill 33 are in working positions. The drill collar 14 with the seat 15 transmits impact energy from the shoulder 17 located behind the collar 15 (when driving using a top impactor, since there is no drill collar and the guide body 12 is not used when it is guided against the actual inside of the drill pipe) in the axial direction of the drill pipe inside the drill pipe, in which case the length of the guide body 12 beyond the drill pipe collar 14 The protruding portion of the front end of the or drill pipe 13 should reach a distance from there to the plane 39 of the upper part of the reamer approximately equal to or less than the length of the shoulder 17. When the edge excavation reamer tooth 49 rests on a hard foundation, the flat surface 39 is pressed towards the underside of the guide body and the impact energy is transferred to the reamer tooth 49, according to FIG. 4 , by The reamer drill 22 of the cam 22 is fixedly staying in the extended position, and the reamer drill bit 33 is supported in the hole 28 at its rear by the shaft 21 and on the opposite side by the carbide teeth 46 of the pilot drill bit in a tighter position. The teeth (as shown in Figures 4 and 12) are supported to provide a back pressure from the borehole wall. FIG. 6 demonstrates that the pilot hole drill 20 is advantageously equipped with a plurality of edge teeth 58 .

The reamer protrudes from the central shaft 16 at a radius and upon rotation provides a circular hole which is larger than the diameter of the outer enclosure of the drill pipe 13 . The pilot hole bit is positioned in the recess 34 of the reamer via the camshaft 42 with the cam 22 (Fig. 5), and in the recess 25 of the shaft (Figs. 5 and 6) and in the support shoulder 18 (Figure 8) Get its rotation.

Said guide body 12 has an axial, preferably straight, flushing groove 40 which terminates at the rear between the shoulders 17 and has a discharge hole 41 acting to the rear and connected to the inner bottom plane. It includes holes 28 . The flushing grooves 40 end blocked before they reach the front edge of the guide body 12 and part of said grooves open on the plane 27 .

In drilling, a major portion of the drilling work is sustained by the wear of the pilot hole bit, since the drilling takes place in an area slightly smaller than the inside diameter of the drill collar 14 or drill pipe 13 . The reaming drill 33 just carries out radial extension after the hole of drill pipe or drill collar is positioned at the end plane of guide body 12, and the plane of pilot hole drill bit installation tooth is pressed to ground and its holding force and frictional force are significantly greater than Friction on the opposite end planes of the shaft 21 , the pilot hole bit remains steady as the guide body and the reamer rotate relative to the shaft 21 and camshaft 42 . The radial ends of the cams 22 come into position at the ends of the coincident holes 37 and recesses 34 . The back of the cam 22 forms a camshaft 42 which bears against the opposite end of the bore 37 and prevents the reamer from vibrating movement during operation. When the reamer 33 is withdrawn, the direction of rotation is reversed and the above-mentioned radial movement is repeated by the reamer, whose shoulders 36', 36" slide so that the sliding planes 36A, 36B Resting on the parallel planes 27A, 27B of the guide body ensures the retraction and maintenance of the reamer in the position according to FIG. 3 .

The flushing medium, which may comprise the steam outlet of the down-the-hole drill hammer, is supplied through the drill rod to the passage 43 of the guide body (Fig. 7) and through passage 44 forward into the pilot hole bit, which opens through the passage branch, On the one hand into the camshaft 43 and the opening 45 of the cam 22 respectively, and on the other hand into the front surface of the pilot hole bit on which the teeth are mounted. The guide body has an outlet hole 41 close to the hole 28 of the bottom surface. As mentioned above, on the pilot hole bit with cam 44 there are a plurality of flush holes 45 which run radially into the camshaft 42 and cam 22 to provide an extreme pressure on the recess 34 to prevent the entry of cuttings and other debris. . The flushing medium partially flows out of the front face 35 of the reamer.

As will be apparent from the above description, the design of drilling rigs for down-the-hole drilling hammers has been improved in which threaded connections can be completely eliminated. It gives a level of operational reliability hitherto unattainable. Furthermore, the continuous transmission of power from the guide body to the reamer, and from the reamer to the pilot hole bit means that the reamer can be retracted with a half turn without turning the pilot hole bit. This convenience ensures retraction of the reamer in a crowded working position, which was hitherto impossible due to the drive of the reamer by the pilot hole drill according to the prior art.

It should be understood that the above description is only a preferred embodiment and that for an expert there is still room for numerous improvements which fall within the scope of the claims. In light of the above-described embodiment, it should be noted that the shaft 21 and the operating drill bit 48 are an integral unit. However, within the framework of the invention it is possible to separate the shaft and the drill head but to be connected to each other in a torsionally rigid manner, for example by means of molecular linkages. Furthermore, it should be understood that the connection 27, 36 between the guide body and the reamer 33 can be reversed so that the reamer 33 is provided with a central shoulder instead of the guide body 12 and two laterally arranged shoulders are provided on the guide body 12. shoulders. It should be clear that sealing bushes 50 arranged in the respective recesses of the flushing passage are not necessary. In certain cases it may be desirable, for example, to arrange recesses only on the pilot hole bit 20, or even not to have recesses, but to use only grooves or other suitable means on the pilot hole 20 to keep the bushing in place at the joint. Also, it should be understood that another sliding connection 30 could be used, such as a ball having a diameter suitable for the slots 26,38. It will also be appreciated that flush holes 41 may be placed on many planes other than those described above, and that it may be advantageous to place them higher than liner 50 in certain circumstances.

It should also be known that the displacement of the reaming drill is not necessarily along a straight sliding plane, and can also reach a certain range relative to the reaming drill 33 of the guide body 12 through a curved sliding plane, a certain rotation, but This displacement is still to be considered substantially radially relative to said guide body. Furthermore, it should be understood that the basic principles according to the invention can also be applied to power transmission threaded connections.

Said abstract is also an integral part of this description.

Claims (15)

1. A drilling machine for down-the-hole drilling, wherein the drilling machine will drill a hole before the follow-up drill pipe (13), said drilling machine includes a central pilot hole drill bit (20), a drill bit (33) and a control station The guide body (12) and the drill pipe of the drilling machine are characterized in that: the guide body (12), the drill bit (33) and the pilot hole drill bit (20) are formed so that the rotational energy is generated by the guide body (12) to and from the counterbore bit (33) to the pilot hole bit (20) such that there is a substantially radial displacement between the guide body (12) and the coamer bit (33). 2. Drilling machine according to claim 1, characterized in that: the guide body (12) has at least one sliding plane (27A; 27B), and the enclosing drill bit (33) has at least one sliding surface (36A; 36B) shoulder (36'; 36") to at least partially rest and slide against said sliding plane (27A; 27B), so that through said sliding plane (27A; 27B) and sliding surface (36A; 36B) to transmit the rotational motion of the guide body to the undercounter bit, and the sliding plane and sliding surface may allow mutual sliding to facilitate radial extension and retraction of the undercounter bit, respectively (33). 3. The drilling machine according to claim 1 or 2, characterized in that: the pilot hole drill bit (20) has a radially protruding cam (22), which is suitable for accommodating the cam in the bracket drill bit (33). A recess (34) of (22) engages in such a way as to transmit a rotational movement from said reaming bit (33) to the pilot hole bit (20). 4. The drilling machine according to claim 3, characterized in that: the concave part (34) of the bracket drill bit (33) is designed to allow the cam (22) and the concave part (34) to rotate mutually, when the bracket When the concave part (34) of the drill bit (33) rotates around the cam (22) from the first position to the second position, the drill bit (33) moves from a radially extended position to a radially retracted position. 5. Drilling machine according to any one of the preceding claims, characterized in that: said pilot hole drill bit (20) comprises a shaft (21) rotatably connected to said guide body (12) by a sliding connection, preferably In the form of an annular sliding pin (30), the pilot bit is held stationary while the guide body and the counter bit are rotated in the retracted and extended positions of the counter bit, respectively. 6. Drilling machine according to claim 4 and/or 5, characterized in that the guide body (12) and the drill bit (33) rotate approximately half a turn when the drill bit is retracted and extended. 7. Drilling machine according to any one of the preceding claims, characterized in that: said drill bit (33) has a substantially elliptical through hole (37) except said recess (34), and said The through hole (37) together with said recess (34) forms a substantially polygonal shape with three sides (FIG. 10). 8. Drilling machine according to any one of the preceding claims, characterized in that the reaming bit (33) has a plurality of edge cutting teeth (40) and the pressure against these teeth during operation is along the direction of the pilot hole bit. A tighter profile (46) on the opposite edge of (20, 48) compensates to some extent. 9. Drilling machine according to any one of the preceding claims, characterized in that: the hole of the drill pipe (13) has a drill pipe collar (14), its upper end has a seat (15), and the upper end of the guide body (12) There is a shoulder (17) which during operation rests on the seat (15) so that the drill pipe (13) is driven down into the hole. 10. Drilling machine according to claim 2, characterized in that: said sliding surface (36A; 36B) and sliding plane (27A; 27B) respectively have the same curvature, preferably said sliding surface and sliding plane are respectively straight flat. 11. The drilling machine of claim 1, wherein neither of said two transfers of rotational energy includes any threaded connection. 12. Drilling machine according to claim 1, characterized in that: flushing passages (43, 44) are set concentrically inside the drill bit, wherein the flushing passages (43, 44) extend to the pilot hole drill bit ( 20), a sealing bushing (50) is arranged in the passing area of the flushing passage (43, 44) between the guide body (12) and the pilot hole drill bit (20). 13. Drilling machine as claimed in claim 12, characterized in that: at least one recess (43A, 44A) is set in the passing area of the flushing passage (43, 44) between the guide body (12) and the pilot hole drill bit (20), the most Well two, wherein said recesses (43A, 44A) have substantially the same diameter as said sealing bush (50) outer diameter. 14. Drilling machine according to claim 5, characterized in that said sliding connection (30) is fitted by means of a lower density than the pin body (31) of the material used for the fastener/guide body (12) Locked on the guide body (12). 15. Down-the-hole drilling method using a drilling rig to drill a hole before the subsequent drill pipe (13), said drilling rig comprising a central pilot hole bit (20), a wrapping bit (33) and a guide for controlling said drilling rig Body (12) and drill pipe, it is characterized in that: described guide body (12), enclosing drill bit (33) and pilot hole drill bit (20) are formed so that the rotational energy is transferred from described guide body (12) to enclosing drill bit (33) and from the cross-boring bit (33) to the pilot-hole bit (20), but neither transfer of rotational energy involves any threaded connection.

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