CN114412377A - Mine drill pipe - Google Patents

Abstract

The present disclosure provides a mining drill pipe, which relates to the technical field of drill pipes. The mining drill pipe comprises: a main body of the drill pipe, a first sealing joint and a second sealing joint located at both ends of the main body of the drill pipe; the first sealing joint is in the shape of a truncated cone, and the side wall of the first sealing joint is in the direction close to the main body of the drill pipe The upper part has an outer cone surface section, a male thread section and a first stepped surface in sequence; the second sealing joint has a circular truncated through hole, and the inner wall of the circular truncated through hole has a second stepped surface, an inner cone in the direction away from the main body of the drill pipe. Face and female thread segments. In the embodiment of the present disclosure, when two mining drill pipes are connected, multiple seals can be formed, which improves the sealing performance of the connection of the mining drill pipes, thereby reducing the pressure loss of the high-pressure fluid, and ensuring that the high-pressure fluid can operate at a higher The pressure is delivered to the bottom of the drilled hole to ensure the effect of reaming. In addition, due to the good sealing performance of the connection between the two adjacent mining drill pipes, the leakage of high-pressure fluid can be avoided and the occurrence of safety accidents can be avoided.

Description

Mine drill pipe

technical field

The present disclosure relates to the technical field of drill pipes, and in particular, to a mining drill pipe.

Background technique

Since gas outburst is the main unsafe factor in coal mining, which seriously affects the safety of coal mining, it is a mandatory regulation for coal mining in my country to extract first and then mine. However, advanced drilling is required for drainage, and the larger the hole diameter, the better the pressure relief effect of the coal seam, and the higher the gas drainage rate and drainage volume.

In actual production, under the premise that the torque of the drilling rig is determined, it is difficult to increase the hole diameter of the drilled hole by increasing the size of the drill bit and the size of the drill pipe. Therefore, in the related art, hydraulic punching technology is used for hole reaming, so as to increase the hole diameter of the hole. Among them, the hydraulic punching technology refers to transporting high-pressure fluid along the mine drill pipe to the bottom of the hole, and injecting the high-pressure fluid to the hole wall through the nozzle at the drill bit to cut and break the coal seam on the hole wall, so as to achieve hole reaming of a technology. After hydraulic punching, the hole diameter of the drilled hole can be increased from 113 to 203 mm to 460 to 1440 mm.

However, when the hole is enlarged by the hydraulic punching technology, the inventor found that the hole diameter after the hole expansion cannot achieve the expected effect.

It should be noted that the information disclosed in the above Background section is only for enhancement of understanding of the background of the present disclosure, and therefore may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.

SUMMARY OF THE INVENTION

The purpose of the present disclosure is to provide a mining drill pipe, which can improve the sealing performance of the drill pipe string and ensure the hole reaming effect during the hydraulic punching operation.

According to one aspect of the present disclosure, a mining drill pipe is provided, comprising: a drill pipe main body and a first sealing joint and a second sealing joint located at both ends of the drill pipe main body;

The first sealing joint has a truncated structure, the large diameter end of the first sealing joint is close to the main body of the drill pipe and the small diameter end is far away from the main body of the drill pipe, and the side wall of the first sealing joint is close to the main body of the drill pipe. The direction of the main body of the drill pipe is sequentially provided with an outer conical surface section, a male thread section and a first stepped surface;

The second sealing joint has a truncated through hole, the large diameter end of the truncated through hole is far away from the main body of the drill pipe, and the small diameter end is close to the main body of the drill pipe, and the inner wall of the circular truncated through hole is far away from the main body of the drill pipe. The direction of the main body of the drill pipe is sequentially provided with a second step surface, an inner cone surface section and a female thread section;

Wherein, the end face of the small diameter end of the first sealing joint can fit with the second stepped surface of the second sealing joint, and the outer cone surface section of the first sealing joint can be fitted with the inner cone of the second sealing joint The face section can fit, the male thread section of the first sealing joint can be threadedly connected with the female threaded section of the second sealing joint, and the first step surface of the first sealing joint can be threaded with the second sealing joint The end face close to the large diameter end of the circular truncated through hole is fitted.

According to any one of the mining drill rods of the present disclosure, the first stepped surface has a conical structure.

According to any one of the mining drill pipes of the present disclosure, the included angle between the generatrix of the first step surface and the axial direction of the drill pipe body is greater than or equal to 70° and less than or equal to 85°.

According to any one of the mining drill pipes of the present disclosure, the first step surface is a plane structure, and the plane where the first step surface is located is not perpendicular to the axial direction of the main body of the drill pipe.

According to any one of the mining drill pipes of the present disclosure, the second stepped surface is conical, and the included angle between the generatrix of the second stepped surface and the axial direction of the main body of the drill pipe is greater than or equal to 50° and less than or equal to 85°.

According to any one of the mining drill pipes of the present disclosure, the included angle between the generatrix of the outer conical surface section and the axial direction of the drill pipe body is greater than or equal to 5° and less than or equal to 7°.

According to any one of the mining drill pipes of the present disclosure, the included angle between the generatrix of the outer conical surface section and the axial direction of the main body of the drill pipe is greater than the angle between the generatrix of the inner conical surface section and the main body of the drill pipe The included angle between the axial directions, and the difference between the two is greater than or equal to 1° and less than 5°.

According to any one of the mining drill pipes of the present disclosure, the diameter of the small end of the outer conical surface segment is smaller than the diameter of the small end of the inner conical surface segment, and the difference between the two is greater than or equal to 0.5 mm and less than or equal to 3mm.

According to any one of the mining drill pipes of the present disclosure, the side wall of the first sealing joint is provided with a first annular sealing surface on the side of the male threaded section close to the outer conical surface section, and the truncated cone-shaped A second annular sealing surface is provided on the inner wall of the through hole on the side of the female thread segment close to the inner cone surface segment;

The mining drill pipe further includes a first sealing ring, the first annular sealing surface or the second annular sealing surface has a first sealing groove, and the first sealing ring is located in the first sealing groove and is for sealing the gap between the first annular sealing surface and the second annular sealing surface.

According to any one of the mining drill pipes of the present disclosure, a side wall of the first sealing joint is provided with a third annular sealing surface on the side of the male threaded section close to the first stepped surface, and the circular frustum-shaped sealing surface has a third annular sealing surface. A fourth annular sealing surface is provided on the inner wall of the through hole on the side of the female thread segment away from the inner cone surface segment;

The mining drill pipe further includes a second sealing ring, the third annular sealing surface or the fourth annular sealing surface has a second sealing groove, and the second sealing ring is located in the second sealing groove and is to seal the gap between the third annular sealing surface and the fourth annular sealing surface.

According to any one of the mining drill pipes of the present disclosure, the third annular sealing surface and/or the fourth annular sealing surface has a first stress relief groove.

The embodiments of the present disclosure include at least the following technical effects:

In the embodiment of the present disclosure, when two mining drill pipes are connected, multiple seals can be formed, which improves the sealing performance of the connection between two adjacent mining drill pipes, thereby reducing the pressure loss of the high-pressure fluid and ensuring that the high-pressure fluid can It is delivered to the bottom of the drilled hole with high pressure to ensure the effect of reaming. In addition, due to the good sealing performance of the connection between the two adjacent mining drill pipes, the leakage of high-pressure fluid can be avoided and the occurrence of safety accidents can be avoided.

It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description serve to explain the principles of the disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 is a schematic cross-sectional structure diagram of a mining drill pipe according to an embodiment of the present disclosure.

FIG. 2 is a schematic cross-sectional structural diagram of a first sealing joint provided by an embodiment of the present disclosure.

3 is a schematic cross-sectional structural diagram of a second sealing joint provided by an embodiment of the present disclosure.

4 is a schematic cross-sectional structural diagram of another first sealing joint provided by an embodiment of the present disclosure.

FIG. 5 is a schematic cross-sectional structural diagram of another second sealing joint provided by an embodiment of the present disclosure.

Reference number:

1. Main body of drill pipe; 2. First sealing joint; 3. Second sealing joint; 4. First sealing ring; 5. Second sealing ring;

21. Outer cone surface section; 22. Male thread section; 23. First step surface; 24. First annular sealing surface; 25. Third annular sealing surface; 241. First sealing groove;

31, the second step surface; 32, the inner cone surface section; 33, the female thread section; 34, the second annular sealing surface; 35, the fourth annular sealing surface; 351, the second sealing groove.

Detailed ways

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments, however, can be embodied in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements/components/etc; the terms "include" and "have" are used to indicate an open-ended is meant to be inclusive and means that additional elements/components/etc may be present in addition to the listed elements/components/etc; the terms "first", "second" and "third" etc. only Used as a marker, not a limit on the number of its objects.

In the related art, when hydraulically punching a borehole, a plurality of mining drill pipes need to be sequentially connected to obtain a drill pipe string, and then the high-pressure fluid is transported along the drill pipe string to the bottom of the drill hole. The inventor found that although the initial pressure is controlled at 20MPa or even higher when the high-pressure fluid is delivered, the pressure of the high-pressure fluid when it reaches the bottom of the borehole is only about 12MPa, so that the effect of hole expansion is not obvious. After careful research, the inventor found that when the high-pressure fluid was transported along the drill pipe string, due to the poor sealing performance of the connection between two adjacent mining drill pipes, the pressure loss of the high-pressure fluid was too large, causing the high-pressure fluid to reach the drill pipe. The pressure is lower at the bottom of the hole.

Embodiments of the present disclosure provide a mining drill pipe. As shown in FIG. 1 , the mining drill pipe includes: a drill pipe main body 1 , a first sealing joint 2 and a second sealing joint 3 located at both ends of the drill pipe main body 1 .

The drill pipe main body 1 , the first sealing joint 2 and the second sealing joint 3 all have through holes along their respective centerline directions, and after the three are connected, their respective centerline directions coincide. The main body 1 of the drill pipe, the first sealing joint 2 and the second sealing joint 3 are of an integral structure, and of course, they can also be fixedly connected by welding, or fixedly connected by other means.

As shown in FIG. 2 , the first sealing joint 2 has a circular truncated structure. The large diameter end of the first sealing joint 2 is close to the main body 1 of the drill pipe and the small diameter end is far away from the main body 1 of the drill pipe. The side wall of the first sealing joint 2 is close to the drill pipe main body 1 . In the direction of the rod main body 1 , an outer cone surface segment 21 , a male thread segment 22 and a first stepped surface 23 are sequentially arranged. As shown in FIG. 3 , the second sealing joint 3 has a truncated through hole, the large diameter end of the truncated through hole is far away from the drill rod main body 1 and the small diameter end is close to the drill rod main body 1 , and the inner wall of the circular truncated through hole is far from the drill rod main body. 1 has a second stepped surface 31 , an inner cone surface segment 32 and a female thread segment 33 in sequence.

The end face of the small diameter end of the first sealing joint 2 can fit with the second stepped surface 31 of the second sealing joint 3 , and the outer cone surface section 21 of the first sealing joint 2 can be fitted with the inner cone surface section of the second sealing joint 3 . 32 can fit, the male thread section 22 of the first sealing joint 2 can be threadedly connected with the female thread section 33 of the second sealing joint 3, the first step surface 23 of the first sealing joint 2 can be close to the circular frustum of the second sealing joint 3 The end face of the large diameter end of the through hole is attached.

For the mining drill pipes disclosed in the embodiments of the present disclosure, in actual use, a plurality of mining drill pipes are connected in sequence. When connecting a plurality of mining drill rods, for any two adjacent mining drill rods, the first sealing joint 2 and the second sealing joint 2 of the first mining drill rod in the adjacent two mining drill rods are The second sealing joint 3 of the mining drill pipe is connected in a sealing manner. Therefore, in actual use, the first sealed joint 2 of the first mining drill pipe and the second sealed joint 3 of the second mining drill pipe among the two adjacent mining drill pipes will be described.

The male threaded section 22 of the first sealing joint 2 is threadedly connected with the female threaded section 33 of the second sealing joint 3. At this time, the first stepped surface 23 of the first sealing joint 2 and the second sealing joint 3 are far away from the corresponding drill pipe main body 1. The end face of the first sealing joint 2 is fitted (the first step surface 23 is sealed), the outer cone surface section 21 of the first sealing joint 2 is fitted with the inner cone surface section 32 of the second sealing joint 3 (cone sealing), and the The second stepped surface 31 is in contact with the end surface of the first sealing joint 2 away from the corresponding drill pipe main body 1 (the second stepped surface 31 is sealed), thereby realizing multiple sealing between two adjacent mining drill pipes and improving the relative The sealing performance of the connection between the two adjacent mining drill pipes reduces the pressure loss of the high-pressure fluid, ensures that the high-pressure fluid can be delivered to the bottom of the borehole at a higher pressure, and ensures the effect of reaming. In addition, due to the good sealing performance of the connection between the two adjacent mining drill pipes, the leakage of high-pressure fluid can be avoided and the occurrence of safety accidents can be avoided.

Wherein, when the first sealing joint 2 and the second sealing joint 3 are tightened, the first sealing joint 2 and the second sealing joint 3 may appear to be in pressing contact, that is, the first step of the first sealing joint 2 The surface 23 is press-fitted with the end face of the second sealing joint 3 away from the corresponding drill pipe main body 1, the outer conical surface section 21 of the first sealing joint 2 is press-fitted with the inner cone surface section 32 of the second sealing joint 3, The second step surface 31 of the second sealing joint 3 is pressed and fitted with the end face of the first sealing joint 2 away from the corresponding drill pipe main body 1, so that interference contact can be formed at each fitting position, and the safety of each fitting position is improved. sealing effect.

In the embodiment of the present disclosure, when the first stepped surface 23 of the first sealing joint 2 is in contact with the end surface of the second sealing joint 3 away from the corresponding drill pipe body 1 , the end surfaces of the first stepped surface 23 and the second sealing joint 3 are both It is a plane structure, so that the first step surface 23 is sealed by laminating two planes.

Of course, when forming the first step surface 23 for sealing, in order to further ensure the sealing effect and at the same time improve the torsional strength of the mining drill pipe, in some embodiments, as shown in FIG. 2 or FIG. 4 , the first step surface 23 is Correspondingly, as shown in FIG. 3 or FIG. 5 , the corresponding end face on the second sealing joint 3 is also a conical structure. In this way, the contact area between the first step surface 23 of the first sealing joint 2 and the corresponding end surface of the second sealing joint 3 can be increased, thereby improving the sealing effect, reducing the probability of puncture leakage, and improving the torsion resistance of the mining drill pipe. strength.

Wherein, the large diameter end of the first stepped surface 23 is close to the main body 1 of the drill pipe to ensure that the first sealing joint 2 can smoothly extend into the circular frustum-shaped through hole of the second sealing joint 3 . The included angle between the generatrix of the first stepped surface 23 and the axial direction of the drill pipe body 1 is greater than or equal to 70° and less than or equal to 80°. For example, the generatrix of the first stepped surface 23 and the axial direction of the drill pipe body 1 The angle between them is 72°, 74°, 76° or 78°. In this way, in addition to ensuring the contact area between the first step surface 23 and the corresponding end face of the second sealing joint 3, it can also avoid the situation that the first sealing joint 2 or the second sealing joint 3 is partially thin and easily damaged. prolong the service life of mining drill pipe.

In other embodiments, the first stepped surface 23 is a plane structure, and the plane where it is located is not perpendicular to the axial direction of the main body 1 of the drill pipe. Accordingly, the corresponding end surface on the second sealing joint 3 is also a plane structure, and the plane where it is located The plane is parallel to the plane where the first stepped surface 23 is located. In this way, the contact area between the first step surface 23 of the first sealing joint 2 and the end surface of the second sealing joint 3 can be increased, thereby improving the sealing effect and at the same time improving the torsional strength of the mining drill pipe.

Wherein, the included angle between the plane where the first stepped surface 23 is located and the axial direction of the drill rod main body 1 is greater than or equal to 70° and less than or equal to 80°. In this way, in addition to ensuring the contact area between the first step surface 23 and the corresponding end face of the second sealing joint 3, it can also avoid the situation that the first sealing joint 2 or the second sealing joint 3 is partially thin and easily damaged. prolong the service life of mining drill pipe.

In the embodiment of the present disclosure, when the second stepped surface 31 of the second sealing joint 3 is in contact with the end surface of the first sealing joint 2 away from the corresponding drill pipe body 1 , the second stepped surface 31 and the corresponding end surface of the first sealing joint 2 For the fit condition, please refer to the above-mentioned fit of the first step surface 23 and the corresponding end surface of the second sealing joint 3 to increase the second step surface 31 of the second sealing joint 3 and the corresponding end surface of the first sealing joint 2 The contact area of the end face reduces the probability of puncture leakage, thereby improving the sealing effect and at the same time improving the torsional strength of the mining drill pipe.

For example, as shown in FIG. 3 or FIG. 5 , the second stepped surface 31 has a conical shape, and correspondingly, as shown in FIG. 2 or FIG. 4 , the corresponding end surface of the first sealing joint 2 is also a conical structure.

Wherein, the included angle between the generatrix of the second step surface 31 and the axial direction of the drill rod main body 1 is greater than or equal to 50° and less than or equal to 85°. Preferably, the included angle between the generatrix of the second step surface 31 and the axial direction of the drill rod body 1 is greater than or equal to 50° and less than or equal to 60°. For example, the included angle between the generatrix of the second step surface 31 and the axial direction of the drill rod body 1 is 52°, 54°, 56° or 58°. In this way, in addition to ensuring the contact area between the second step surface 31 and the corresponding end surface of the first sealing joint 2, it can also avoid the situation that the first sealing joint 2 or the second sealing joint 3 is partially thin and easily damaged. prolong the service life of mining drill pipe.

In some embodiments, the included angle between the generatrix of the outer conical surface section 21 and the axial direction of the drill rod body 1 is greater than or equal to 5° and less than or equal to 7°. For example, the included angle between the generatrix of the outer conical surface section 21 and the axial direction of the drill rod body 1 is 6°.

Wherein, the included angle between the generatrix of the inner conical surface section 32 and the axial direction of the drill rod main body 1 is greater than the included angle between the generatrix of the outer conical surface section 21 and the axial direction of the drill rod main body 1, and the angle between the two The difference is greater than or equal to 1° and less than 5°. For example, the included angle between the generatrix of the inner conical surface section 32 and the axial direction of the drill rod main body 1 is 9°, so that the first sealing joint 2 can be ensured to extend into the frustum-shaped through hole of the second sealing joint 3, and It is ensured that the outer conical surface section 21 of the first sealing joint 2 and the inner conical surface section 32 of the second sealing joint 3 can fit tightly, so as to ensure that the conical surface between the first sealing joint 2 and the second sealing joint 3 is tightly sealed. sealing effect.

Wherein, the diameter of the small end of the outer cone segment 21 is smaller than the diameter of the small end of the inner cone segment 32, and the difference between the two is greater than or equal to 0.5 mm and less than or equal to 3 mm. For example, the diameter of the small end of the outer conical surface segment 21 is 1 mm, 2 mm, etc. smaller than the diameter of the small end of the inner conical surface segment 32 .

In the embodiment of the present disclosure, both the male thread section 22 on the first sealing joint 2 and the female thread section 33 on the second sealing joint 3 may be hardened, so as to improve the threaded teeth on the male thread section 22 and the female thread section 33 Hardness, breakage occurs when the thread teeth of the male thread segment 22 and the thread teeth of the female thread segment 33 are pressed against each other.

The hardening treatment includes but is not limited to quenching treatment and nitriding treatment. For example, the first sealing joint 2 and the second sealing joint 3 are made of 35CrMo steel. At this time, oil quenching at 850°C and tempering at 550°C can be used to seal the male thread section 22 of the first sealing joint 2 and the second sealing joint. The female thread section 33 of the joint 3 is hardened.

In some embodiments, both the thread teeth of the male thread segment 22 and the thread roots of the thread teeth of the female thread segment 33 are processed by cold rolling, and the surface of the thread teeth is coated with sealing grease, so as to improve the first sealing joint 2 and the The sealing performance of the threaded connection between the second sealing joints 3 prevents high-pressure fluid from immersing in the gap between the male thread segment 22 and the female thread segment 33 .

In some embodiments, the male thread segment 22 and the female thread segment 33 use double-shouldered rectangular tapered threads, the front end of the thread has a large chamfer structure, and the thread pitch adopts a segmented thread pitch. In this way, after the first sealing joint 2 and the second sealing joint 3 are connected by thread, the pre-tightening force of the thread is greater than the pressure of the medium in the cavity, which improves the sealing performance of the thread connection. Service life of threaded segment 22 and female thread segment 33.

In some embodiments, the thread of the male thread segment 22 and the start thread of the thread of the female thread segment 33 are chamfered, so as to avoid stress concentration on the thread, improve the service life of the thread, and thereby improve the The service life of the first sealing joint 2 and the second sealing joint 3.

Wherein, the included angle between the chamfer of the starting tooth and the axial direction of the main body 1 of the drill rod is greater than 55°. For example, the angle between the chamfer of the starting tooth and the axial direction of the main body 1 of the drill rod is 60°, 70°, 80°, and so on.

In the embodiment of the present disclosure, combined with the above description, after the first sealing joint 2 is extended into the second sealing joint 3 and screwed, a quadruple seal can be formed, that is, the first step surface 23 seal, the thread segment seal, the conical surface seal and the third seal The second step surface 31 is sealed.

In order to further improve the sealing performance after the first sealing joint 2 and the second sealing joint 3 are connected, in some embodiments, as shown in FIG. 4 , the side wall of the first sealing joint 2 is located close to the male thread section 22 One side of the outer conical surface section 21 has a first annular sealing surface 24, and the inner wall of the circular truncated through hole is located on the side of the female thread section 33 close to the inner conical surface section 32 has a second annular sealing surface 34; the mining drill pipe also includes The first sealing ring 4, the first annular sealing surface 24 or the second annular sealing surface 34 has a first sealing groove 241 (as shown in FIG. 4, the first sealing groove 241 is located on the first annular sealing surface 24), the first sealing The ring 4 is located in the first sealing groove 241 and is used to seal the gap between the first annular sealing surface 24 and the second annular sealing surface 34 .

In this way, after the first sealing joint 2 extends into the circular frustum-shaped through hole of the second sealing joint 3, the first sealing ring 4 can be squeezed by the first annular sealing surface 24 and the second annular sealing surface 34, so that the A reseal can be further formed between the first annular sealing surface 24 and the second annular sealing surface 34, thereby further improving the sealing effect. Wherein, the first sealing ring 4 may be a polypropylene sealing ring or a polytetrafluoroethylene sealing ring.

The cross-section of the first sealing groove 241 is rectangular, and the rectangular cross-section includes inner corner chamfering and outer corner chamfering, and the inner corner chamfering radius is larger than the outer corner chamfering radius. For example, the corner radius of the inner corner chamfer is 1 mm, and the corner radius of the outer corner chamfer is 0.2 mm.

Wherein, the distance between the first sealing groove 241 and the second step surface 31 is greater than or equal to 5 mm and less than or equal to 8 mm. For example, the distance between the first sealing groove 241 and the second stepped surface 31 is 7 mm.

Further, when the first annular sealing surface 24 and the second annular sealing surface 34 press the first sealing ring 4, in order to ensure the pressing effect on the first sealing ring 4, the first annular sealing surface 24 and/or the second annular sealing surface The annular sealing surface 34 has a second stress relief groove. In this way, the stress can be released through the second stress release groove, so as to avoid the situation that the stress concentration hinders the deformation of the first sealing ring 4 .

In other embodiments, as shown in FIG. 5 , a third annular sealing surface 25 is provided on the side wall of the first sealing joint 2 on the side of the male threaded section 22 close to the first stepped surface 23 , and the inner wall of the conical through hole has a third annular sealing surface 25 . The upper side of the female thread segment 33 away from the inner cone surface segment 32 has a fourth annular sealing surface 35; the mining drill pipe also includes a second sealing ring 5, and the third annular sealing surface 25 or the fourth annular sealing surface 35 has a second annular sealing surface 35; The sealing groove 351 (as shown in FIG. 5, the second sealing groove 351 is located on the fourth annular sealing surface 35), the second sealing ring 5 is located in the second sealing groove 351, and is used to seal the third annular sealing surface 25 and the first sealing surface 25. The gap between the four annular sealing surfaces 35 .

The distance between the second sealing groove 351 and the first stepped surface 23 is 5-10 mm.

Further, when the third annular sealing surface 25 and the fourth annular sealing surface 35 squeeze the first sealing ring 4, in order to ensure the extrusion effect of the second sealing ring 5, the third annular sealing surface 25 and/ Or the fourth annular sealing surface 35 has a first stress relief groove. In this way, the stress can be released through the first stress release groove, so as to avoid the situation that the stress concentration hinders the deformation of the second sealing ring 5 .

In combination with the contents described in the above embodiments, for example, the diameter of the mining drill pipe provided by the embodiment of the present disclosure is 89 mm, and the length of the mining drill pipe is 36 mm longer than that of the conventional technology, and the length of the mining drill pipe is increased by 36 mm. , so as to process the outer cone surface section 21 and the inner cone surface section 32 on the mining drill pipe including the first sealing joint 2 and the second sealing joint 3, wherein the outer cone surface section 21 and the inner cone surface section 32 are along the drill pipe. The axial length of the main body 1 is all 5mm, the included angle between the generatrix of the outer conical surface section 21 and the axial direction of the drill pipe main body 1 is 8 degrees, and the included angle between the generatrix of the inner conical surface section 32 and the axial direction of the drill pipe main body 1 is 8 degrees. The diameter of the small end of the outer cone surface section 21 is 62mm, and the diameter of the small end of the inner diameter cone section is 63mm; the first sealing groove 241 is processed on the first annular sealing surface 24 of the first sealing joint 2, and the first sealing The width of the groove 241 is 3.5mm, the depth is 2mm, the distance to the first step surface 23 is 7mm, the inner corner chamfering radius of the first sealing groove 241 is 1mm, and the outer corner chamfering radius is 0.2mm; The second sealing groove 351 is machined on the fourth annular sealing surface 35 of the second sealing groove. The width of the second sealing groove 351 is 3.5mm, the depth is 2mm, and the distance to the second step surface 31 is 7mm. The radius is 1mm, and the outer corner chamfer radius is 0.2mm.

The internal pressure resistance of the drill pipe string formed by the above-mentioned multiple mining drill pipes can reach more than 35 MPa, so as to meet the requirement that high-pressure fluid is transported to the bottom of the borehole at a relatively high pressure.

Other embodiments of the present disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or techniques in the technical field not disclosed by the present disclosure . The specification and examples are to be regarded as exemplary only, with the true scope and spirit of the disclosure being indicated by the appended claims.

Claims (11)

1. A mining drill pipe, characterized in that, comprising: a drill pipe main body and a first sealing joint and a second sealing joint located at both ends of the drill pipe main body; The first sealing joint has a truncated structure, the large diameter end of the first sealing joint is close to the main body of the drill pipe and the small diameter end is far away from the main body of the drill pipe, and the side wall of the first sealing joint is close to the main body of the drill pipe. The direction of the main body of the drill pipe is sequentially provided with an outer conical surface section, a male thread section and a first stepped surface; The second sealing joint has a truncated through hole, the large diameter end of the truncated through hole is far away from the main body of the drill pipe, and the small diameter end is close to the main body of the drill pipe, and the inner wall of the circular truncated through hole is far away from the main body of the drill pipe. The direction of the main body of the drill pipe is sequentially provided with a second step surface, an inner cone surface section and a female thread section; Wherein, the end face of the small diameter end of the first sealing joint can fit with the second stepped surface of the second sealing joint, and the outer cone surface section of the first sealing joint can be fitted with the inner cone of the second sealing joint The face section can fit, the male thread section of the first sealing joint can be threadedly connected with the female threaded section of the second sealing joint, and the first step surface of the first sealing joint can be threaded with the second sealing joint The end face close to the large diameter end of the circular truncated through hole is fitted. 2 . The mining drill pipe according to claim 1 , wherein the first stepped surface has a conical structure. 3 . 3. The mining drill pipe according to claim 2, wherein the included angle between the generatrix of the first step surface and the axial direction of the main body of the drill pipe is greater than or equal to 70° and less than or equal to 85° °. 4 . The mining drill pipe according to claim 1 , wherein the first stepped surface is a plane structure, and the plane where the first step surface is located is not perpendicular to the axial direction of the main body of the drill pipe. 5 . 5 . The mining drill pipe according to claim 1 , wherein the second stepped surface is conical, and the included angle between the generatrix of the second stepped surface and the axial direction of the main body of the drill pipe is 5 . Greater than or equal to 50° and less than or equal to 85°. 6 . The mining drill pipe according to claim 1 , wherein the included angle between the generatrix of the outer conical surface section and the axial direction of the drill pipe main body is greater than or equal to 5° and less than or equal to 7. 7 . °. 7 . The mining drill pipe according to claim 6 , wherein the included angle between the generatrix of the outer conical surface section and the axial direction of the main body of the drill pipe is greater than that between the generatrix of the inner conical surface section and the axial direction of the main body of the drill pipe. 8 . The included angle between the axial directions of the main body of the drill pipe, and the difference between the two is greater than or equal to 1° and less than 5°. 8 . The mining drill pipe according to claim 7 , wherein the diameter of the small end of the outer conical surface section is smaller than the diameter of the small end of the inner conical surface section, and the difference between the two is greater than or equal to 0.5 mm and less than or equal to 3mm. 9. The mining drill pipe according to any one of claims 1-8, wherein the side wall of the first sealing joint is located on the side of the male thread section close to the outer cone surface section with a first sealing joint. an annular sealing surface, and a second annular sealing surface is provided on the inner wall of the truncated through hole on the side of the female thread segment close to the inner cone surface segment; The mining drill pipe further includes a first sealing ring, the first annular sealing surface or the second annular sealing surface has a first sealing groove, and the first sealing ring is located in the first sealing groove and is for sealing the gap between the first annular sealing surface and the second annular sealing surface. 10. The mining drill pipe according to any one of claims 1-8, wherein the side wall of the first sealing joint is located on the side of the male thread section close to the first stepped surface with a first Three annular sealing surfaces, the inner wall of the circular truncated through hole has a fourth annular sealing surface on the side of the female thread segment away from the inner conical surface segment; The mining drill pipe further includes a second sealing ring, the third annular sealing surface or the fourth annular sealing surface has a second sealing groove, and the second sealing ring is located in the second sealing groove and is to seal the gap between the third annular sealing surface and the fourth annular sealing surface. 11. The mining drill pipe of claim 10, wherein the third annular sealing surface and/or the fourth annular sealing surface has a first stress relief groove.

Images