Deburring structure for a hold-on core and method of using the same

Abstract

This invention relates to the chip removal structure and usage method of a pressure-holding core sampler, comprising an outer tube, a pressure-holding controller, a core tube, and a stroke-extending sleeve for scraping coal chips from the outer wall of the core tube. The pressure-holding controller and the stroke-extending sleeve are installed inside the outer tube. The pressure-holding controller includes a valve seat and a valve cover. The stroke-extending sleeve includes a first section and a second section. The first section is installed inside the outer tube and located below the valve seat, and the second section can be inserted into the valve seat. Multiple annular grooves are formed along the axial direction on the inner walls of the first and second sections for storing coal chips. During the upward lifting of the core tube, the stroke-extending sleeve removes coal chips from the outer wall of the core tube and increases the stroke for the coal chips to fall. It also provides space for easily falling coal chips, thereby reducing the amount of coal chips falling at the pressure-holding controller and preventing coal chips from entering the valve cover and valve seat sealing surfaces of the pressure-holding controller. This reduces incomplete closure problems caused by impurities on the sealing surface and improves the closure stability of the pressure-holding controller.

Description

Technical Field

[0001] This invention relates to the field of pressure-holding core extractor technology, and more particularly to the chip removal structure of the pressure-holding core extractor and its usage method. Background Technology

[0002] The pressure-maintaining gas core sampler is a gas and coal sample collection device with a pressure-maintaining function. Its main operating method involves loading the pressure-maintaining gas sampler into the external drilling tool and continuing drilling 300mm into the working face. Then, the core sampler and external drilling tool are lifted. A hydraulically driven retrieval nozzle acts on the central rod, indirectly lifting the core tube. The pressure-maintaining controller closes, and the core tube is then transported to the surface in a sealed, pressure-maintaining environment for testing.

[0003] A Chinese patent document with publication number CN109458147A discloses a core sampling device, including a core drilling tool, a core catcher, a core tube, a drilling rig outer cylinder, a flap valve, and an inner rod for lifting the core tube. The lower end of the inner rod extends into the core cylinder and can move a certain distance axially relative to the core cylinder. The flap valve includes a valve seat and a sealing valve cover. The valve seat is coaxially mounted on the inner wall of the drilling rig outer cylinder, and one end of the sealing valve cover is movably connected to the upper outer wall of the valve seat. When the core tube is located in the valve seat, the sealing valve cover opens 90°. When the core tube is lifted to a certain height by the inner rod, the sealing valve cover returns to the top surface of the valve seat and seals against the valve seat.

[0004] However, during operation, coal dust will adhere to the core tube. As the core tube is lifted upwards, the coal dust may fall onto the valve seat sealing surface, which will adversely affect the sealing performance of the pressure holding controller and thus affect the pressure holding performance of the coring equipment. Summary of the Invention

[0005] This application provides a chip removal structure for a pressure-holding core extractor and its usage method to solve the above-mentioned technical problems.

[0006] This application is achieved through the following technical solution:

[0007] The chip removal structure of the pressure-holding coring device provided in this application includes an outer tube, a pressure-holding controller, a core tube, and an extension sleeve. The pressure-holding controller and the extension sleeve are installed inside the outer tube. The pressure-holding controller includes a valve seat and a valve cover, with a sealing surface on the top of the valve seat that matches the valve cover. The core tube can pass through the valve seat and the extension sleeve. When the core tube is located in the valve seat, the valve cover is open and located in the annular space between the core tube and the outer tube. When the core tube is lifted to a certain height, the valve cover and the valve seat are closed. The extension sleeve is used to scrape coal chips off the outer wall of the core tube. The extension sleeve includes a first section and a second section. The outer diameter of the first section is larger than that of the second section. The first section is installed inside the outer tube and located below the valve seat. The second section is operably inserted into the valve seat. The upper end face of the extension sleeve can exceed the sealing surface of the valve seat. The inner walls of the first section and the second section have multiple annular grooves along the axial direction for storing coal chips.

[0008] In particular, the inner diameters of the first and second segments are equal.

[0009] Specifically, the cross-section of the annular groove is a trapezoidal groove with a narrowing opening.

[0010] Optionally, the extended stroke sleeve has a rubber ring on its inner wall that contacts the core tube.

[0011] Specifically, a spring is provided between the outer tube and the extended stroke sleeve to provide axial elastic force. The spring is used to push the extended stroke sleeve away from the valve seat. When the core tube is located inside the extended stroke sleeve, the extended stroke sleeve and the core tube remain relatively stationary due to the friction between them, and the spring is compressed between the outer tube and the extended stroke sleeve.

[0012] Specifically, the outer tube includes a first outer tube and a second outer tube, with the upper end of the first outer tube connected to the lower end of the second outer tube, the pressure holding controller installed inside the second outer tube, and the stroke extension sleeve installed inside the first outer tube.

[0013] Optionally, the upper end of the first outer tube has an inner step, the lower end of the valve seat abuts against the inner step, and the upper end of the spring abuts against the inner step.

[0014] Specifically, at the connection between the first and second segments, the outer step is formed, and when the core tube is located inside the extended stroke sleeve, the spring is compressed between the inner step of the first outer tube and the outer step of the extended stroke sleeve.

[0015] Optionally, permanent magnets are installed on both the valve seat and the valve cover.

[0016] The method of using the chip removal structure of the pressure-holding core extractor provided in this application includes the following steps:

[0017] In the initial state: the core tube passes through the inner hole of the extension sleeve and valve seat 3. The extension sleeve cooperates with the spring and the core tube. The spring is in a compressed state. The friction between the extension sleeve and the core tube resists the spring force. The extension sleeve, outer tube and core tube remain relatively stationary. The upper end face of the extension sleeve exceeds the sealing surface of the valve seat. The valve cover is opened and located in the annulus between the core tube and the outer tube.

[0018] In operation: The corer completes coal sample collection, the core tube moves upward under external force, the extension sleeve begins to remove coal dust, and a large amount of coal dust falls into the lower end of the extension sleeve and the internal space of the outer tube; after the lower end of the core tube enters the interior of the extension sleeve, the friction of the extension sleeve continues to scrape off the coal dust on the outer tube of the core tube, and at this time the coal dust falling out of the core tube falls into the annular groove of the extension sleeve;

[0019] As the core tube continues to move upward, after the lower end of the core tube passes the upper end of the extension sleeve, the lower end of the core tube has also passed the valve seat. The frictional force given to the extension sleeve by the core tube disappears, and the extension sleeve moves downward under the elastic force of the spring, removing the coal dust accumulated below the extension sleeve.

[0020] The core tube continues to move upwards, and the valve cover closes.

[0021] Compared with the prior art, this application has the following beneficial effects:

[0022] 1. In the process of lifting the core tube upwards, the extended-stroke sleeve can remove coal dust from the outer wall of the core tube and increase the stroke of the coal dust falling. It also reserves space for the easily falling coal dust, thereby reducing the falling of coal dust at the pressure holding controller and preventing coal dust from entering the valve cover and valve seat sealing surface of the pressure holding controller. This reduces the problem of incomplete closure caused by impurities on the sealing surface and improves the closure stability of the pressure holding controller.

[0023] 2. The extended stroke sleeve has a stepped external structure. Its thinner section can pass through the pressure holding controller. The main purpose is to prevent coal dust from falling from the sealing surface of the valve cover and valve seat of the pressure holding controller at the lower end of the core tube, thereby preventing coal dust from falling on the contact surface of the valve cover and valve seat.

[0024] 3. The extended stroke sleeve of this application can move downward under the action of the spring, thereby clearing the coal dust below the pressure holding controller, reducing the accumulation of coal dust below the pressure holding controller, and preventing excessive accumulation of coal dust from causing the valve cover to fail to close.

[0025] 4. Using this application, most of the coal dust is blocked below the extended stroke bushing, and the remaining coal dust is stored in the annular groove of the extended stroke bushing. This can solve the problem of coal dust accumulation at the lower end of the pressure holding controller, reduce the accumulation of coal dust at the pressure holding controller, reduce the amount of dust entering the valve cover and valve seat contact surface, thereby improving the sealing performance of the pressure holding controller and ensuring the pressure holding performance of the core extractor.

[0026] 5. This application has a simple structure, can complete pipe wall chip removal in a narrow space, is easy to reset, and is convenient to use. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of the embodiments of this application and form part of this application, do not constitute a limitation on the embodiments of the present invention.

[0028] Figure 1 This is a cross-sectional view of the chip removal structure and usage method of the pressure-holding core extractor in the initial state of the embodiment;

[0029] Figure 2 This is a cross-sectional view of the chip removal structure and usage method of the pressure-holding core extractor during operation in the embodiment;

[0030] Figure 3 This is a cross-sectional view of the chip removal structure and usage method of the pressure-holding core extractor in the final state of the embodiment;

[0031] Figure 4 Cross-sectional view of the extended-stroke sleeve in the embodiment;

[0032] Figure 5 A cross-sectional view of the first outer tube in the embodiment. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. It should also be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments; similar or identical parts between embodiments can be referred to interchangeably.

[0036] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0037] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0038] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0039] like Figures 1-3 As shown, the chip removal structure of the pressure-holding coring device disclosed in this embodiment includes an outer tube, a pressure-holding controller, a core tube 5, and an extension sleeve 6. The pressure-holding controller and the extension sleeve 6 are coaxially mounted inside the outer tube. The center of the extension sleeve 6 allows the core tube 5 to pass through, and the extension sleeve 6 is used to scrape coal chips off the outer wall of the core tube 5.

[0040] like Figure 2 As shown, the pressure holding controller includes a valve seat 3 and a valve cover 4. The top of the valve seat 3 has a sealing surface that matches the valve cover 4. When the core tube 5 is located in the valve seat 3, the valve cover 4 is open and located in the annulus between the core tube 5 and the outer tube. When the core tube 5 is lifted to a certain height, the valve cover 4 flips up to close with the valve seat 3. This is conventional technology in the field and will not be described in detail here.

[0041] In one possible design, the valve seat 3 is provided with multiple permanent magnets 31 along the circumference, and the valve cover 4 is also provided with permanent magnets 31. The permanent magnets 31 on the valve seat 3 can attract the permanent magnets 31 on the valve cover 4, thereby increasing the sealing pressure and improving the sealing stability.

[0042] The extended stroke sleeve 6 includes a first section 61 and a second section 62. The outer diameter of the first section 61 is larger than the outer diameter of the second section 62. The first section 61 fits with the inner wall of the outer tube and is located below the pressure holding controller. The second section 62 is operablely inserted into the valve seat 3. The inner walls of the first section 61 and the second section 62 have multiple annular grooves 63 along the axial direction. The annular grooves 63 are used to store coal dust.

[0043] In particular, the inner diameters of the first segment 61 and the second segment 62 are equal.

[0044] It is worth noting that the number and size of the annular grooves 63 can be set reasonably according to the needs.

[0045] In one possible design, the annular groove 63 has a trapezoidal cross-section with a narrowing opening. The trapezoidal design prevents coal dust from moving between different areas.

[0046] In one possible design, the first segment 61 has four annular grooves 63. Since more coal dust falls in the lower segment, the width of the two lower annular grooves 63 is greater than the width of the two upper annular grooves 63, which is used to store different amounts of coal dust at different distances from the lower end of the pressure holding controller.

[0047] Specifically, the two lower annular grooves 63 of the first segment 61 are the same size, and the two upper annular grooves 63 are the same size but slightly smaller than the lower annular groove 63.

[0048] In one possible design, the inner wall of the extended-stroke sleeve 6 is used to contact the core tube 5. A rubber ring 8 is provided on the contact surface of the inner wall of the extended-stroke sleeve 6 where it contacts the core tube 5. The rubber ring 8 is used to increase friction and clean coal dust from the wall of the core tube 5. Optionally, the frictional force of the rubber ring 8 on the second section 62 is greater than that of the rubber ring 8 on the first section 61.

[0049] In one possible design, there is a spring 7 between the outer tube and the extended stroke sleeve 6 to provide axial elastic force, which pushes the extended stroke sleeve 6 away from the valve seat 3.

[0050] In one possible design, the outer tube includes a first outer tube 1 and a second outer tube 2. The upper end of the first outer tube 1 is threaded to the lower end of the second outer tube 2. The pressure holding controller is installed inside the second outer tube 2. The first section 61 of the stroke-increasing sleeve 6 is installed inside the first outer tube 1.

[0051] In one possible design, such as Figure 5As shown, the upper end of the first outer tube 1 has an inner step 11, which is used to determine the axial position of the lower end of the valve seat 3 and to install the spring 7. The valve seat 3 is installed inside the second outer tube 2, and its lower end abuts against the inner step 11.

[0052] In one possible design, such as Figure 4 , Figure 5 As shown, the first segment 61 is clearance-fitted with the first outer tube 1, which can support the axial movement of the extended stroke sleeve 6 on the inner wall of the first outer tube 1, ensuring that it does not cause eccentric movement; the outer step 64 formed at the connection between the first segment 61 and the second segment 62 can be used to hold the lower end of the spring 7; in the initial state, the spring 7 is compressed between the inner step 11 of the first outer tube 1 and the outer step 64 of the extended stroke sleeve 6.

[0053] The working principle of this embodiment:

[0054] In the initial state: such as Figure 1 As shown, the core tube 5 passes through the inner hole of the extension sleeve 6 and the valve seat 3. The extension sleeve 6 cooperates with the spring 7 and the core tube 5. The spring 7 is in a compressed state. The friction between the extension sleeve 6 and the core tube 5 resists the elastic force of the spring 7. The extension sleeve 6, the outer tube, and the core tube 5 remain relatively stationary. At this time, the upper end face of the second section 62 of the extension sleeve 6 exceeds the sealing surface of the valve seat 3. The valve cover 4 is opened and located in the annulus between the core tube 5 and the first outer tube 2.

[0055] In operation: The core sampler completes coal sample collection, and the core tube 5 moves upward under the action of external force. The rubber ring 8 of the extension sleeve 6 begins to remove coal dust. At this time, a large amount of coal dust falls into the lower end of the extension sleeve 6 and the internal space of the first outer tube 1. After the lower end of the core tube 5 enters the interior of the extension sleeve 6, the friction of the multiple rubber rings 8 of the extension sleeve 6 continues to scrape off the coal dust on the outer tube of the core tube 5, while the coal dust that falls out of the core tube 5 falls into the annular groove 63 of the extension sleeve 6.

[0056] like Figure 2 As shown, the core tube 5 continues to move upward. After the lower end of the core tube 5 passes the upper end of the extension sleeve 6, the lower end of the core tube 5 has passed the valve seat 3. The frictional force given by the core tube 5 to the extension sleeve 6 disappears. Under the elastic force of the spring 7, the extension sleeve 6 moves downward to remove the coal dust accumulated below the extension sleeve 6.

[0057] like Figure 3 As shown, the core tube 5 continues to move upward, and the valve cover 4 closes, forming a sealed space at its upper end. The complete pressure-holding space is not shown in this embodiment, but it has pressure-holding capability under actual conditions. This is a conventional technology in the field and will not be described in detail here.

[0058] Elastic reset: Reinstall the core tube 5, remove the debris from the inside of the first outer tube 1 and clean it thoroughly. Clean the extended stroke sleeve 6 and reinstall it in its initial position.

[0059] The extended-stroke bushing of this application allows for chip removal from the core tube wall in confined spaces, and also clears coal dust accumulation below the pressure holding controller, preventing excessive coal dust buildup from causing the valve cover to fail to close, thus improving the closing stability of the pressure holding controller. This application directly isolates the falling coal dust from the lower end face of the core tube from direct contact with the valve cover and valve seat sealing surfaces, improving the sealing performance of the pressure holding controller and ensuring the pressure holding performance of the core sampler.

[0060] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. The chip removal structure of a pressure-holding core extractor, characterized in that: include: outer tube; The pressure holding controller is installed inside the outer pipe. The pressure holding controller includes a valve seat (3) and a valve cover (4). The top of the valve seat (3) has a sealing surface that matches the valve cover (4). The core tube (5) can pass through the valve seat (3) and the extended stroke sleeve (6). When the core tube (5) is in the valve seat (3), the valve cover (4) is open and located in the annulus between the core tube (5) and the outer tube. When the core tube (5) is lifted to a certain height, the valve cover (4) and the valve seat (3) are closed. The extended stroke sleeve (6) is used to scrape coal dust off the outer wall of the core tube (5). The extended stroke sleeve (6) includes a first section (61) and a second section (62). The outer diameter of the first section (61) is larger than the outer diameter of the second section (62). The first section (61) is installed inside the outer tube and located below the valve seat (3). The second section (62) is operably inserted into the valve seat (3). The upper end face of the extended stroke sleeve (6) can exceed the sealing surface of the valve seat (3). The inner walls of the first section (61) and the second section (62) have multiple annular grooves (63) along the axial direction, which are used to store coal dust. The cross-section of the annular groove (63) is a trapezoidal groove with a narrowing opening; The inner wall of the extended stroke sleeve (6) that contacts the core tube (5) is provided with a rubber ring (8); A spring (7) is provided between the outer tube and the extended stroke sleeve (6) to provide axial elastic force. The spring (7) is used to push the extended stroke sleeve (6) away from the valve seat (3). When the core tube (5) is located inside the extended stroke sleeve (6), the extended stroke sleeve (6) and the core tube (5) remain relatively stationary due to the friction between them, and the spring (7) is compressed between the outer tube and the extended stroke sleeve (6). The outer tube includes a first outer tube (1) and a second outer tube (2). The upper end of the first outer tube (1) is connected to the lower end of the second outer tube (2). The pressure holding controller is installed inside the second outer tube (2), and the stroke extension sleeve (6) is installed inside the first outer tube (1). The upper end of the first outer tube (1) has an inner step (11), the lower end of the valve seat (3) abuts against the inner step (11), and the upper end of the spring (7) abuts against the inner step (11); An outer step (64) is formed at the connection between the first segment (61) and the second segment (62). When the core tube (5) is located inside the extended stroke sleeve (6), the spring (7) is compressed between the inner step (11) of the first outer tube (1) and the outer step (64) of the extended stroke sleeve (6). Both the valve seat (3) and the valve cover (4) are equipped with permanent magnets (31).

2. The chip removal structure of the pressure-holding core extractor according to claim 1, characterized in that: The inner diameters of the first segment (61) and the second segment (62) are equal.

3. The method of using the chip removal structure of the pressure-holding core extractor according to claim 1 or 2, characterized in that: Includes the following steps: In the initial state: the core tube (5) passes through the inner hole of the extension sleeve (6) and the valve seat (3). The extension sleeve (6) cooperates with the spring (7) and the core tube (5). The spring (7) is in a compressed state. The friction between the extension sleeve (6) and the core tube (5) resists the elastic force of the spring (7). The extension sleeve (6), the outer tube, and the core tube (5) remain relatively stationary. The upper end face of the extension sleeve (6) exceeds the sealing surface of the valve seat (3). The valve cover (4) is opened and located in the annulus between the core tube (5) and the outer tube. In working condition: The core sampler completes coal sample collection, the core tube (5) moves upward under the action of external force, the extension sleeve (6) begins to remove shavings, and a large amount of coal shavings fall into the lower end of the extension sleeve (6) and the internal space of the outer tube; after the lower end of the core tube (5) enters the interior of the extension sleeve (6), the friction of the extension sleeve (6) continues to scrape off the coal shavings on the outer wall of the core tube (5), and at this time the coal shavings falling out of the core tube (5) fall into the annular groove (63) of the extension sleeve (6); The core tube (5) continues to move upward. After the lower end of the core tube (5) passes the upper end of the extension sleeve (6), the lower end of the core tube (5) has also passed the valve seat (3). The frictional force given to the extension sleeve (6) by the core tube (5) disappears. The extension sleeve (6) moves downward under the elastic force of the spring (7) to remove the coal dust accumulated below the extension sleeve (6). The core tube (5) continues to move upward, and the valve cover (4) closes.

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