Sealing structure for through cable drill rod core joint

Abstract

The utility model relates to the field of drilling equipment for soft coal seams, in particular to a sealing structure for a through cable drill rod core joint, which comprises an annular sealing groove, the annular sealing groove comprises a mounting part and a pressure relief part, a sealing piece is sleeved in the mounting part to ensure the sealing performance of the butt joint of an inner joint and an outer joint, and the pressure relief part is arranged on the adjacent side of the mounting part. The mounting part is positioned on the reverse side of the inserting direction; the pressure relief part comprises a deformation containing groove and a pressure relief groove, the deformation containing groove is axially arranged and used for containing the axial deformation of the sealing piece, the pressure relief groove is formed in the bottom face of the deformation containing groove, and the pressure relief groove structure should guarantee that when the sealing piece deforms and enters the pressure relief part, sealing failure is caused by the fact that the radial size of the position where the pressure relief groove is located is increased. In addition, an axial pre-jacking protrusion is arranged at the position, corresponding to the pressure relief portion, of the installation portion, and the sealing piece has initial elastic tension due to the arrangement of the pre-jacking protrusion.

Description

Technical Field

[0001] The utility model relates to the technical field of underground drilling, in particular to a sealing structure for a core joint of a cable drill rod. Background Art

[0002] Existing directional cable drill pipe cores are connected via internal and external connectors on either side of their insulating casing. The internal connector is equipped with a circular double sealing ring that forms a seal when plugged into the external connector. However, during actual downhole docking, once the double sealing rings form a seal, the water inside the connector cannot be drained. At this point, the two connectors have not yet reached their final docking position, causing water pressure to gradually increase during the subsequent docking process, increasing resistance and preventing proper docking. Furthermore, excessive pressure within the connector can easily cause it to rupture, weakening or even losing electrical signals, thereby increasing maintenance costs. Summary of the Invention

[0003] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide a sealing structure for a cable drill pipe core joint, which can balance the pressure difference between the inside and outside of the joint when plugged in, eliminate damage to the joint caused by the pressure difference, and reduce maintenance costs.

[0004] The technical solution adopted by this utility model is:

[0005] A sealing structure for a cable drill pipe core joint includes an annular sealing groove, which includes a mounting portion and a pressure relief portion. The mounting portion includes a sealing member that can effectively seal in the mounting portion, and the pressure relief portion is adjacent to the mounting portion and is located on the opposite side of the mounting portion in the insertion direction.

[0006] The pressure relief part includes a deformation accommodating groove and a pressure relief groove, wherein the deformation accommodating groove is axially arranged to accommodate the axial deformation of the seal; the pressure relief groove is arranged on the bottom surface of the deformation accommodating groove, and the pressure relief groove structure should ensure that when the seal is deformed and enters the pressure relief part, the radial dimension of the pressure relief groove increases, resulting in sealing failure.

[0007] An axial pre-lift protrusion is provided at a position of the mounting portion corresponding to the pressure relief portion.

[0008] The transition between the axial surface of the pre-top protrusion and the axial surface of the mounting portion is a continuous arc surface.

[0009] The pressure relief groove is an axial guide groove opened at the bottom of the deformation accommodating groove, and the guide groove communicates the mounting part and the pressure relief part.

[0010] The sealing structure of the first inner joint includes a first annular sealing groove, a first deformation accommodating groove, and a first pressure relief groove. The first annular sealing groove is an annular groove cut circumferentially along the central axis. An O-ring is sleeved in the first annular sealing groove. The first deformation accommodating groove is adjacent to the first annular sealing groove. The first deformation accommodating groove faces the opposite direction of the insertion direction. The first deformation accommodating groove is a U-shaped groove. The opening of the U-shaped groove is connected to the first annular sealing groove. The bottom of the U-shaped groove is flush with the bottom of the first deformation accommodating groove. The first pressure relief groove is arranged at the bottom of the U-shaped groove. The first pressure relief groove is an elongated hole groove. The elongated hole groove intersects with the bottom of the first annular sealing groove to form a guide groove.

[0011] The sealing structure of the second inner joint includes a second annular sealing groove and a second deformation accommodating pressure relief groove. The second annular sealing groove is arranged at the outer edge of the head of the second inner joint. The second annular sealing groove is an annular groove cut circumferentially along the central axis. An O-ring is sleeved in the second annular sealing groove. The second deformation accommodating pressure relief groove is adjacent to the second annular sealing groove. The second deformation accommodating pressure relief groove is a through groove formed by cutting radially downward along the outer circle of the second inner joint. The bottom surface of the through groove is a plane. The bottom surface of the through groove is lower than the bottom surface of the second annular sealing groove. The bottom of the through groove intersects with the bottom of the second annular sealing groove to form a guide groove.

[0012] The sealing structure of the third inner joint includes a third annular sealing groove, a third deformation accommodating groove, and a third pressure relief groove. The third annular sealing groove is arranged at the head of the third inner joint, and is an annular groove cut circumferentially along the central axis. The third annular sealing groove is provided with a pre-top protruding part in the opposite direction of the third inner joint insertion direction. The pre-top protruding part is a circular arc protrusion. The third annular sealing groove and the circular arc protrusion constitute a special-shaped sealing groove with a protrusion. The O-ring is sleeved in the special-shaped sealing groove. The special-shaped sealing groove is adjacent to the third deformation accommodating groove. The third deformation accommodating groove is in the opposite direction of the insertion direction. The third deformation accommodating groove is an arc-shaped groove. The arc-shaped groove matches the circular arc protrusion. The third pressure relief groove is arranged at the bottom of the arc-shaped groove. The arc-shaped guide groove structure is formed from the bottom of the special-shaped sealing groove downwardly sloping to the bottom of the third deformation accommodating groove, which is the third pressure relief groove. The third pressure relief groove connects the special-shaped sealing groove with the third deformation accommodating groove.

[0013] The transitions among the third annular sealing groove, the arc protrusion, the third deformation accommodating groove, and the third pressure relief groove are all continuous arc surface smooth transitions.

[0014] Beneficial effects of the utility model:

[0015] When the cam is in the airtight position, the sealing member is pressed against the sealing member, and the sealing member is pressed against the sealing member, so that the sealing member is in the airtight position, and the sealing member is pressed against the sealing member. At this time, the water pressure difference inside and outside the joint is basically balanced, eliminating the weakening or loss of electrical signals caused by joint rupture, thereby reducing maintenance costs. In addition, an axial pre-top protrusion is provided at the position of the pressure relief portion corresponding to the installation portion. The setting of the pre-top protrusion gives the seal an initial elastic tension. As the insertion force increases, the elastic tension value of the seal continues to increase, the resilience of the seal increases, the return effect is better, and the sealing of the internal and external joints is better guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites preferred embodiments and is accompanied by the accompanying drawings. However, the embodiments in the drawings do not constitute any limitation to the present invention. For ordinary technicians in this field, other drawings can be obtained based on the following drawings without paying any creative work.

[0017] Figure 1 This is a schematic diagram of the internal and external connector insertion;

[0018] Figure 2 Schematic diagram of the first inner joint structure;

[0019] Figure 3 is a partial cross-sectional schematic diagram of the first inner joint sealing structure;

[0020] Figure 4 Schematic diagram of the second inner joint structure;

[0021] Figure 5 It is a partial cross-sectional schematic diagram of the second inner joint sealing structure;

[0022] Figure 6 Schematic diagram of the third inner joint structure;

[0023] Figure 7 It is a partial cross-sectional schematic diagram of the third inner joint sealing structure.

[0024] In the figure: 1-inner joint, 2-outer joint, 3-seal, 4-first inner joint, 401-first annular sealing groove, 402-first deformation accommodating groove, 403-first pressure relief groove, 5-second inner joint, 501-second annular sealing groove, 502-second deformation accommodating pressure relief groove, 6-third inner joint, 601-third annular sealing groove, 602-third deformation accommodating groove, 603-third pressure relief groove, 604-arc protrusion. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention.

[0026] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0027] like Figure 1 As shown, a core joint for a cable drill pipe includes an inner joint 1, an outer joint 2, and a seal 3. The inner joint 1 and the outer joint 2 are cylindrical structures. The inner joint 1 and the outer joint 2 are plugged into each other. The head of the inner joint 1 is provided with a sealing structure, which forms a seal after being plugged into the outer joint to isolate the inside of the joint from the outside. The head of the inner joint 1 is provided with a sealing structure including an annular sealing groove, which is provided on the outer cylindrical surface of the head of the inner joint 1. The annular sealing groove includes a mounting portion and a pressure relief portion. The mounting portion is used to sleeve the sealing member 3. The pressure relief portion is adjacent to the mounting portion and is located on the opposite side of the insertion direction of the mounting portion. The pressure relief portion includes a deformation accommodating groove and a pressure relief groove. When the inner joint 1 is inserted into the outer joint 2, the sealing member 3 sleeved on the mounting portion undergoes elastic deformation due to the insertion thrust. The deformation accommodating groove is used to accommodate the axial deformation of the seal. The pressure relief groove is provided on the bottom surface of the deformation accommodating groove, which is an axial guide groove opened at the bottom of the deformation accommodating groove. The guide groove communicates the mounting portion and the pressure relief portion. When the seal is deformed and enters the pressure relief portion, the seal fails due to the increase in radial size at the location of the pressure relief groove.

[0028] When the inner joint 1 and the outer joint 2 are plugged into each other, the seal 3 on the upper sleeve of the inner joint 1 and the outer joint 2 first form a seal. As the plugging thrust increases, the seal 3 elastically deforms, and the deformed part enters the deformation accommodating groove. The pressure relief groove on the bottom of the deformation accommodating groove temporarily invalidates the seal formed by the inner joint 1 and the outer joint 2, allowing the water inside the joint to be discharged. The water pressure inside and outside the joint is balanced, and the inner joint 1 continues to be inserted into the outer joint 2. The elastically deformed part of the seal 3 rebounds, and the inner joint 1 and the outer joint 2 form a seal again, isolating the environment inside the joint from the environment outside the joint. The insertion of the inner joint 1 and the outer joint 2 is completed. At this time, the water pressure difference inside and outside the joint is basically balanced, eliminating the weakening or loss of the electrical signal caused by the joint rupture, thereby reducing maintenance costs.

[0029] The elastic deformation of the seal 3 is a minute effective elastic deformation.

[0030] In the following embodiments, the sealing member 3 provided in the annular sealing groove is an O-ring.

[0031] Example 1

[0032] like Figure 2 、 Figure 3 As shown, the sealing structure of the first inner joint 4 includes a first annular sealing groove 401, a first deformation accommodating groove 402, and a first pressure relief groove 403. The first annular sealing groove 401 is provided at the outer edge of the head of the first inner joint 4. The first annular sealing groove 401 is an annular groove cut circumferentially along the central axis. An O-ring is sleeved in the first annular sealing groove 401. The size of the first annular sealing groove 401 matches the O-ring. The first annular sealing groove 401 is adjacent to the first deformation accommodating groove 402. The first deformation accommodating groove 402 Reverse to the insertion direction, the first deformation accommodating groove 402 is a U-shaped groove, the opening of the U-shaped groove is connected to the first annular sealing groove 401, the bottom of the U-shaped groove is flush with the bottom of the first deformation accommodating groove 402, and the first pressure relief groove 403 is set at the bottom of the U-shaped groove. The first pressure relief groove 403 is an elongated hole groove, which intersects with the bottom of the first annular sealing groove 401 to form a guide groove, which plays a role in guiding flow, and when the O-ring is set in the first annular sealing groove 401, it cannot destroy the sealing of the O-ring to the joint.

[0033] In this embodiment, two groups of first annular sealing grooves 401 are provided, and two groups of first deformation accommodating grooves 402 and first pressure relief grooves 403 are provided, and are circumferentially opposite to each other.

[0034] When the first inner joint 4 and the outer joint 2 are plugged into each other, initially, the O-ring forms a sealing state between the first inner joint 4 and the outer joint 2, and the first inner joint 4 continues to be inserted. As the insertion force increases, the O-ring elastically deforms, and the deformed part enters the first deformation accommodating groove 402. The first pressure relief groove 403 destroys the sealing state between the first inner joint 4 and the outer joint 2, and the water pressure inside the joint and the water pressure inside the joint return to a balanced state. The insertion thrust decreases, and the deformed part of the O-ring rebounds. The first inner joint 4 and the outer joint 2 form a sealing state again, isolating the environment inside the joint from the environment outside the joint, and the insertion of the first inner joint 4 and the outer joint 2 is completed.

[0035] Example 2

[0036] like Figure 4 、 Figure 5 As shown, the sealing structure of the second inner joint 5 includes a second annular sealing groove 501 and a second deformation accommodating pressure relief groove 502. The second annular sealing groove 501 is provided on the outer edge of the head of the second inner joint 5. The second annular sealing groove 501 is an annular groove cut circumferentially along the central axis. An O-ring is sleeved in the second annular sealing groove 501. The size of the second annular sealing groove 501 matches the O-ring. The second annular sealing groove 501 is adjacent to the second deformation accommodating pressure relief groove 502. The second deformation accommodating pressure relief groove 502 is along the outer edge of the second inner joint 5. A through groove is formed by cutting radially downwardly of the circle, and the bottom surface of the through groove is a plane. The bottom surface of the through groove is lower than the bottom surface of the second annular sealing groove 501. The area formed by the through groove and the outer circle side of the second inner joint 5 is the O-ring deformation accommodating area, and the area where the through groove is lower than the bottom of the second annular sealing groove 501 is the pressure relief area. The bottom of the through groove intersects with the bottom of the second annular sealing groove 501 to form a guide groove, which plays a role in guiding flow, and when the O-ring is sleeved in the second annular sealing groove 501, the size of the pressure relief area cannot destroy the sealing of the O-ring to the joint.

[0037] In this embodiment, two groups of second annular sealing grooves 501 are provided, and two groups of second deformation accommodating and pressure relief grooves 502 are provided, and are circumferentially opposite to each other.

[0038] When the second inner joint 5 is plugged into the outer joint 2, initially, the O-ring forms a sealing state between the second inner joint 5 and the outer joint 2, and the second inner joint 5 continues to be inserted. As the insertion force increases, the O-ring elastically deforms, and the deformed part enters the deformation accommodating area of ​​the second deformation accommodating pressure relief groove 502. The pressure relief area of ​​the second deformation accommodating pressure relief groove 502 destroys the sealing state between the second inner joint 5 and the outer joint 2, and the water pressure inside the joint and the water pressure inside the joint return to a balanced state. The insertion thrust decreases, and the deformed part of the O-ring rebounds, and the second inner joint 5 and the outer joint 2 form a sealing state again, isolating the environment inside the joint from the environment outside the joint, and the insertion of the second inner joint 5 and the outer joint 2 is completed.

[0039] Example 3

[0040] like Figure 6 、 Figure 7 As shown, the sealing structure of the third inner joint 6 includes a third annular sealing groove 601, a third deformation accommodating groove 602, and a third pressure relief groove 603. The third annular sealing groove 601 is arranged at the head of the third inner joint 6. The third annular sealing groove 601 is an annular groove cut circumferentially along the central axis. The third annular sealing groove 601 is provided with a pre-top protruding portion in the opposite direction of the insertion direction of the third inner joint 6. The pre-top protruding portion is an arc protrusion 604. There is a continuous arc surface between the groove wall of the third annular sealing groove 601 and the arc protrusion 604, and the arc surfaces transition smoothly. The third annular sealing groove 601 and the arc protrusion 604 form a special-shaped sealing groove with a protrusion. The O-ring is sleeved in the special-shaped sealing groove. The arc protrusion 604 causes the O-ring to have a certain elastic deformation when it is initially installed, so that the O-ring forms an initial elastic tension. A third deformation accommodating groove 602 is arranged adjacent to the special-shaped sealing groove, and the third deformation accommodating groove 602 faces in the opposite direction of the insertion direction. The third deformation accommodating groove 602 is an arc-shaped groove, and the arc-shaped groove matches the arc protrusion 604. A third pressure relief groove 603 is arranged at the bottom of the arc-shaped groove. The third pressure relief groove 603 is an arc-shaped guide groove, which is inclined downward from the bottom of the special-shaped sealing groove to the bottom of the third deformation accommodating groove 602 to form an arc-shaped guide groove structure as the third pressure relief groove 603. The arc-shaped guide groove with an inclined surface connects the special-shaped sealing groove with the three deformation accommodating grooves 602; and when the O-ring is sleeved in the special-shaped sealing groove, the arc-shaped guide groove with an inclined surface cannot destroy the sealing of the O-ring to the joint.

[0041] The transitions among the third annular sealing groove 601 , the arc protrusion 604 , the third deformation accommodating groove 602 , and the third pressure relief groove 603 are all continuous arc-surface smooth transitions.

[0042] In this embodiment, two groups of special-shaped sealing grooves are provided, and two groups of third deformation accommodating grooves 602 and third pressure relief grooves 603 are provided, and are arranged opposite to each other in the circumferential direction.

[0043] When the third inner joint 6 is plugged into the outer joint 2, the O-ring initially exerts an initial elastic tension under the action of the arc-shaped protrusion 604. The O-ring forms a seal between the third inner joint 4 and the outer joint 2. As the third inner joint 6 continues to be inserted, as the insertion force increases, the O-ring elastically deforms, and the deformed portion enters the third deformation accommodating groove 602. The third pressure relief groove 603 destroys the seal between the third inner joint 6 and the outer joint 2, and the water pressure within the joint returns to equilibrium. The insertion thrust decreases, and the deformed portion of the O-ring rebounds, re-establishing a seal between the third inner joint 6 and the outer joint 2, isolating the internal and external environments of the joint. The insertion of the third inner joint 6 and the outer joint 2 is complete.

[0044] Since the O-ring forms initial elastic tension in the initial state, as the insertion force increases, the elastic tension value of the O-ring continues to increase, and the rebound force of the O-ring will be greater than that of the first and second embodiments, resulting in a better return effect.

[0045] In the third embodiment, the third annular sealing groove 601 and the arc protrusion 604 form a special-shaped sealing groove structure with a protrusion, which can be applied to the first annular sealing groove 401 and the second annular sealing groove 501 in the first and second embodiments.

Claims

1. A sealing structure for a cable drill pipe core joint, comprising an annular sealing groove, characterized in that: The annular sealing groove includes a mounting portion and a pressure relief portion, wherein: Mounting part: The seal can effectively seal in the mounting part; Pressure relief part: adjacent to the mounting part, located on the opposite side of the mounting part's insertion direction; The pressure relief portion includes a deformation accommodating groove and a pressure relief groove, wherein: The deformation accommodating groove is axially arranged to accommodate the axial deformation of the sealing member; The pressure relief groove is arranged on the bottom surface of the deformation accommodating groove. The pressure relief groove structure should ensure that when the seal is deformed and enters the pressure relief part, the radial dimension of the pressure relief groove increases, resulting in sealing failure.

2. A sealing structure for a cable drill pipe core joint according to claim 1, characterized in that: The mounting portion is provided with an axial pre-lift protrusion at a position corresponding to the pressure relief portion.

3. The sealing structure for a cable drill pipe core joint according to claim 2, characterized in that: The axial surface of the pre-top protrusion and the transition between it and the axial surface of the mounting portion are both continuous arc surfaces.

4. A sealing structure for a cable drill pipe core joint according to any one of claims 1 to 3, characterized in that: The pressure relief groove is an axial guide groove opened at the bottom of the deformation accommodating groove, and the guide groove communicates the mounting portion and the pressure relief portion.

5. The sealing structure for a cable drill pipe core joint according to claim 4, characterized in that: The sealing structure comprises a first annular sealing groove (401), a first deformation accommodating groove (402), and a first pressure relief groove (403). The first annular sealing groove (401) is an annular groove cut circumferentially along the central axis. An O-ring is sleeved in the first annular sealing groove (401). The first deformation accommodating groove (402) is adjacent to the first annular sealing groove (401). The first deformation accommodating groove (402) faces the opposite direction of the insertion direction. The first deformation accommodating groove (402) is a U-shaped groove. The opening of the U-shaped groove is connected to the first annular sealing groove (401). The bottom of the U-shaped groove is flush with the bottom of the first deformation accommodating groove (402). The first pressure relief groove (403) is provided at the bottom of the U-shaped groove. The first pressure relief groove (403) is an elongated hole groove. The elongated hole groove intersects with the bottom of the first annular sealing groove (401) to form a guide groove.

6. The sealing structure for a cable drill pipe core joint according to claim 4, characterized in that: The sealing structure comprises a second annular sealing groove (501) and a second deformation accommodating pressure relief groove (502). The second annular sealing groove (501) is arranged at the outer edge of the head of the second inner joint (5). The second annular sealing groove (501) is an annular groove cut circumferentially along the central axis. An O-type sealing ring is sleeved in the second annular sealing groove (501). The second deformation accommodating pressure relief groove (502) is arranged adjacent to the second annular sealing groove (501). The second deformation accommodating pressure relief groove (502) is a through groove formed by cutting radially downward along the outer circle of the second inner joint (5). The bottom surface of the through groove is a plane. The bottom surface of the through groove is lower than the bottom surface of the second annular sealing groove (501). The bottom of the through groove intersects with the bottom of the second annular sealing groove (501) to form a guide groove.

7. The sealing structure for a cable drill pipe core joint according to claim 4, characterized in that: The sealing structure comprises a third annular sealing groove (601), a third deformation accommodating groove (602), and a third pressure relief groove (603). The third annular sealing groove (601) is provided at the head of the third inner joint (6), and is an annular groove cut circumferentially along the central axis. The third annular sealing groove (601) is provided with a pre-top protruding portion in the opposite direction of the insertion direction of the third inner joint (6). The pre-top protruding portion is a circular arc protrusion (604). The third annular sealing groove (601) and the circular arc protrusion (604) form a special-shaped sealing groove with a protrusion. The O-ring is set on the special-shaped sealing groove. In the sealing groove, a third deformation accommodating groove (602) is arranged adjacent to the special-shaped sealing groove, the third deformation accommodating groove (602) faces the opposite direction of the insertion direction, the third deformation accommodating groove (602) is a section of arc-shaped groove, the arc-shaped groove matches and corresponds to the arc convex block (604), and a third pressure relief groove (603) is arranged at the bottom of the arc-shaped groove. An arc-shaped guide groove structure is formed from the bottom of the special-shaped sealing groove downwardly sloping to the bottom of the third deformation accommodating groove (602), which is the third pressure relief groove (603). The third pressure relief groove (603) connects the special-shaped sealing groove with the third deformation accommodating groove (602).

8. The sealing structure for a cable drill pipe core joint according to claim 7, characterized in that: The transitions between the third annular sealing groove (601), the arc convex block (604), the third deformation accommodating groove (602), and the third pressure relief groove (603) are all continuous arc-surface smooth transitions.

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