Rock core drilling tool capable of preventing broken rock from falling off
By introducing limiting support and clamping structures into the core drilling tool, the problem of core detachment was solved, enabling efficient and complete core sample collection, and improving the recovery rate and reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- QINGHAI PROVINCIAL SECOND GEOLOGICAL EXPLORATION INSTITUTE
- Filing Date
- 2025-07-12
- Publication Date
- 2026-05-19
AI Technical Summary
During core drilling, core samples are prone to detachment due to vibration and high-pressure cooling mud injection, resulting in substandard recovery rates and affecting subsequent experimental and testing results.
A core drilling tool was designed, comprising an inner tube, a snap ring seat, a sleeve seat, and an anti-fall-off device. The anti-fall-off device is equipped with a limiting support structure and a clamping structure, which prevent rock fragments from falling off through the limiting support plate and the clamping ring.
It effectively prevents rock fragments from falling off, improves the core recovery rate and reliability, ensures the integrity of core samples, and has a simple structure that is easy to manufacture and maintain.
Smart Images
Figure CN224260295U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of geological engineering and technology, specifically to a core drilling tool that prevents rock fragments from falling off. Background Technology
[0002] Core drilling is an important method used in geological exploration to obtain samples of underground rocks for various analyses and studies.
[0003] However, in geology, rock strata do not necessarily increase in density or hardness as they descend. During crustal movements, rock fracture zones often suddenly appear in certain areas. The rocks in these areas are relatively loose. When the circlip holds the core, it generates a large amount of holding force on the core. At the same time, the movement of the core out of the drill pipe generates a certain amount of vibration. In addition, there is high-pressure cooling mud between the inner and outer tubes, which forms a jet when it reaches the gap between the drill bit and the circlip seat, easily washing away the powdery core. As a result, the rock core at and below the circlip is washed away. Furthermore, broken cores inside the circlip seat are prone to falling out, failing to meet the requirements for coring.
[0004] In summary, this will result in the core recovery rate not meeting the requirements, affecting subsequent experimental and testing results.
[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content
[0006] The technical problem to be solved by this utility model is to overcome the above-mentioned problems and provide a core drilling tool that prevents rock fragments from falling off.
[0007] To solve the above-mentioned technical problems, the technical solution provided by this utility model is as follows: a core drilling tool for preventing rock fragments from falling off, comprising an inner tube, an inner tube assembly connected to the inner tube, and a retaining spring seat threadedly connected to the other end of the inner tube, wherein a retaining spring is provided inside the retaining spring seat, and further comprising:
[0008] Sleeve seat connected to snap ring seat;
[0009] An anti-fall-off device is installed inside a sleeve seat and includes a protective shell coaxial with the sleeve seat. The protective shell is provided with two limiting support structures and a clamping structure. The limiting support structures and the clamping structure work together to prevent rock fragments from falling out of the inner tube.
[0010] The limiting support structure includes several limiting support plates hinged to the protective shell;
[0011] The clamping structure includes several clamping rings and a connecting plate that connects the clamping rings to the protective shell.
[0012] Preferably, the sleeve seat is internally threaded to an externally threaded sleeve, and the externally threaded sleeve is fixedly connected to the inner tube.
[0013] Preferably, the limiting support structure further includes a plurality of rotating holes circumferentially opened on the inner wall of the protective shell, the limiting support plate being rotatably connected in the corresponding rotating holes, and a plurality of limiting blocks for limiting the rotation of the limiting support plate being fixedly connected on the inner wall of the protective shell.
[0014] Preferably, the limiting support plate is provided with an abutment groove, and an abutment block is provided in the rotating hole, the abutment block being fixedly connected to the inner wall of the sleeve seat.
[0015] Preferably, the clamping structure further includes a plurality of connecting holes formed on the inner wall of the protective shell, and the connecting plate is fixedly connected to the top wall of the connecting holes.
[0016] Preferably, the connecting hole is further provided with a protrusion that can push the connecting plate and the clamping ring to move.
[0017] The advantages of this utility model compared with the prior art are as follows:
[0018] An anti-detachment device is installed, which includes a limiting support structure and a clamping structure to effectively prevent rock fragments from falling out of the inner tube, ensuring the integrity of the rock core sample and improving the core recovery rate and reliability. At the same time, the tool has a simple structure, is easy to manufacture and maintain, and has high practical value. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a perspective view of the present invention.
[0021] Figure 2 This is a structural diagram of the present invention.
[0022] Figure 3 This is a partial enlarged view of the present invention at point A.
[0023] Figure 4 This is a structural diagram of the sleeve seat in this utility model.
[0024] Figure 5 This is a schematic diagram of the anti-fall-off device in the sleeve seat of this utility model.
[0025] Figure 6 This is a partial structural diagram of the present invention under working condition 1.
[0026] Figure 7 This is a partial structural diagram of the present invention under operating condition two.
[0027] Figure 8 This is a partial structural diagram of the present invention under operating condition three.
[0028] As shown in the figure:
[0029] 1. Inner tube; 2. Inner tube assembly; 3. Snap ring seat; 4. Snap ring; 5. Sleeve seat; 6. Protective shell;
[0030] 7. Limiting support structure; 701. Limiting support plate; 702. Rotating hole; 703. Limiting block; 704. Abutting groove; 705. Abutting block;
[0031] 8. Clamping structure; 801. Clamping ring; 802. Connecting plate; 803. Connecting hole; 804. Protrusion;
[0032] 9. External threaded sleeve. Detailed Implementation
[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0034] Example 1:
[0035] like Figures 1 to 5 As shown, this utility model provides a core drilling tool that prevents rock fragments from falling off, including an inner tube 1, an inner tube assembly 2, a retaining spring seat 3, and a retaining spring 4;
[0036] The inner tube assembly 2 is fixedly connected to the top end of the inner tube 1, the snap ring seat 3 is threadedly connected to the bottom of the inner tube 1, and the snap ring 4 is disposed inside the snap ring seat 3. It should be understood that the core drilling tool used in this embodiment is the NQ model, and the components and connection methods of its various parts are well known to those skilled in the art; therefore, the specific structure and operating principle of the inner tube assembly 2 will not be described in detail here.
[0037] A 4 mm thick inner tube 1 is selected, and an external threaded sleeve 9 is welded to its bottom end. The connection between the two is then finely polished.
[0038] Next, a sleeve seat 5 is installed, with its inner wall threadedly connected to the external threaded sleeve 9. At the same time, an anti-detachment device is installed inside the external threaded sleeve 9. The anti-detachment device and the snap ring 4 on the snap ring seat 3 work together to reduce the occurrence of rock fragments falling out of the inner tube 1 and ensure the integrity of subsequent core experiments and tests.
[0039] Specifically, the anti-fall-off device includes a sleeve-shaped protective shell 6 located inside the sleeve base 5, wherein the protective shell 6 and the sleeve base 5 are coaxial. Furthermore, a clamping structure 8 and two limiting support structures 7 are arranged sequentially from top to bottom on the inner wall of the protective shell 6, with the two limiting support structures 7 arranged vertically.
[0040] The clamping structure 8 includes connecting holes 803 that are formed around the upper part of the inner wall of the protective shell 6. A zigzag connecting plate 802 is fixedly connected to the top wall of each connecting hole 803. The connecting plate 802 is made of polypropylene and has the ability to deform elastically, so that the bottom of the connecting plate 802 is located inside the protective shell 6. At the same time, an arc-shaped clamping ring 801 is fixedly connected to the bottom end of each connecting plate 802. The inner wall of the clamping ring 801 is fixedly connected with anti-slip texture. Next, a protrusion 804 is provided in each connecting hole 803. The top of the protrusion 804 is rounded on the side near the center of the protective shell 6. The protrusion 804 abuts against the connecting plate 802. The side of the protrusion 804 away from the protective shell 6 is fixedly connected to the inner wall of the sleeve seat 5. Since the connecting plate 802 is zigzag-shaped, when the protrusion 804 moves upward, it will abut against the connecting plate 802 and move towards the center of the protective shell 6. At the same time, the connecting plate 802 will drive the clamping ring 801 to move together.
[0041] Meanwhile, the limiting support structure 7 includes a rotating hole 702 on the inner wall of the protective shell 6. A limiting support plate 701 is installed within the rotating hole 702. Furthermore, the limiting support plate 701 is rotatably connected to the inner wall of the rotating hole 702 via a rotating shaft, and anti-slip textures are fixedly attached to the limiting support plate 701. Simultaneously, a limiting block 703 is provided below each rotating hole 702, and the limiting block 703 is fixedly connected to the inner wall of the protective shell 6. Thus, the limiting block 703 restricts the rotation range of the limiting support plate 701 to 0-90°. That is, when the limiting support plate 701 is kept horizontal, it can only rotate upwards and cannot rotate downwards. At the same time, the limiting block 703 also provides additional support for the limiting support plate 701.
[0042] In addition, each limiting support plate 701 has an abutment groove 704 on its top. The inner wall of the abutment groove 704 is shaped such that, when the limiting support plate 701 is horizontal, the bottom wall of the abutment groove 704 gradually becomes shallower on the side away from the center of the protective shell 6 and towards the center of the protective shell 6. At the same time, an abutment block 705 is provided in the rotation hole 702. The side of the abutment block 705 away from the limiting support plate 701 is fixedly connected to the inner wall of the sleeve seat 5, while the other end of the abutment block 705 is arc-shaped. When the limiting support plate 701 rotates upward and is in close contact with the inner wall of the protective shell 6, the abutment block 705 is located in the abutment groove 704 and abuts against the inner wall of the abutment groove 704.
[0043] Thus, according to the shape of the inner wall of the abutment groove 704, when the limiting support plate 701 is tightly attached to the inner wall of the protective shell 6 and the abutment block 705 is displaced upward in the rotating hole 702, it will push the limiting support plate 701 to rotate towards the side closer to the limiting block 703.
[0044] Therefore, in the specific implementation process of this embodiment, after the core drilling tool has completed the core drilling, the inner tube assembly 2 moves downward together with the inner tube 1, the snap ring seat 3 and the sleeve seat 5. The core first passes through the sleeve seat 5 and continues to move upward. During this process, it pushes several limiting support plates 701 to rotate away from the limiting block 703, and finally moves through the snap ring seat 3 into the inner tube 1.
[0045] Next, the inner tube assembly 2 drives the inner tube 1 to move upward inside the outer tube. When the retaining spring 4 holds the rock core, the inner tube assembly 2 drives the inner tube 1 to rotate. The retaining spring 4 clamps and pulls the rock core off the original rock layer, completing the cutting process. It should be noted that during this process, the limiting support plate 701 only adheres to the rock core and will not interfere with the process of twisting the rock core off the original rock layer.
[0046] Finally, the inner tube assembly 2 drives the inner tube 1 and the rock core inside it to move upward.
[0047] Example 2:
[0048] However, in reality, a situation may arise where there are loose areas in the rock layer. When the retaining spring 4 engages with the rock core, it will come into contact with these loose areas. Additionally, as the inner tube assembly 2 moves the inner tube 1 and its contents upwards, significant vibrations are generated. Simultaneously, high-pressure cooling mud exists between the inner and outer tubes, spraying out in a jet pattern at the gap between the drill bit and the retaining spring seat 3. This can easily wash away the powdery rock core, causing the rock core inside the retaining spring 4 to loosen and fracture. Consequently, rock fragments fall from the inner tube 1, compromising the recovery rate and failing to meet sampling requirements. To explain the detailed working principle of the anti-drop device and the retaining spring 4, and how the anti-drop device solves the above problems, this utility model also provides a second embodiment.
[0049] Against this backdrop, when the retaining spring 4 clamps the rock core and pulls it off from the rock layer, some rock will remain at the bottom of the rock core on the rock layer, making the total length of the bottom of the rock core uncontrollable. This will result in several different working conditions.
[0050] Operating Condition 1: Figure 6 As shown, the rock core fractures at clamping structure 8, which is located above the two limiting support structures 7. The limiting support plates 701 on both limiting support structures 7 are in a horizontal state. When the rock core held by the retaining spring 4 breaks, the rock core below the retaining spring 4 will fall onto several limiting support plates 701 on the upper layer, increasing the weight of the entire anti-fall device and causing the protective shell 6 to move downwards.
[0051] As a result, the protrusion 804 inside the connecting hole 803 will move upward, pushing the connecting plate 802 and the clamping ring 801 to move towards the center of the protective shell 6. Finally, several clamping rings 801 will clamp onto the outer wall of the rock core, while the upper limiting support plate 701 will abut against the bottom of the rock core, so that the broken rock core will not fall out of the inner tube 1.
[0052] Operating Condition 2: (e.g.) Figure 7 As shown, the rock core fractures at the upper limiting support structure 7, that is, the rock core passes between several upper limiting support plates 701. The limiting support plates 701 on the lower limiting support structure 7 are in a horizontal state, while the limiting support plates 701 on the upper limiting support structure 7 are attached to the outer wall of the rock core. Once the rock core at the retaining spring 4 breaks, the broken rock core falls onto the lowest limiting support plate 701, increasing the weight of the entire anti-fall device and causing the protective shell 6 to move downwards.
[0053] During the descent, several limiting support plates 701 on the upper side abut against the outer wall of the rock core. Because the limiting support plates 701 have anti-slip textures, the rock core will cause the limiting support plates 701 to continue rotating downwards. During this process, the limiting support plates 701 compress the rock core. Since the limiting support plates 701 are wrapped around the inner wall of the protective shell 6, the compression of the multiple limiting support plates 701 effectively limits and fixes the broken rock core. Simultaneously, the protrusion 804 moves upwards, pushing the connecting plate 802 and the clamping ring 801 towards the center of the protective shell 6. Ultimately, the clamping rings 801 clamp the outer wall of the rock core, preventing the broken rock core from falling out of the inner tube 1.
[0054] Operating Condition 3: (e.g.) Figure 8As shown, the core fracture occurs at the lower limiting support structure 7. More specifically, the core is simultaneously located between several limiting support plates 701 on both the upper and lower sides. In this way, the upper and lower limiting support plates 701 are attached to the outer wall of the core.
[0055] When the rock core breaks, several limiting support plates 701 on the upper and lower sides abut against the outer wall of the rock core. The rock core then drives the limiting support plates 701 to continue rotating downwards, causing the upper and lower limiting support plates 701 to simultaneously compress the rock core. Since the limiting support plates 701 are wrapped around the inner wall of the protective shell 6, the compression of the multiple limiting support plates 701 effectively limits and fixes the broken rock core. Simultaneously, the protrusion 804 moves upwards, pushing the connecting plate 802 and the clamping ring 801 towards the center of the protective shell 6. Ultimately, the clamping rings 801 clamp the outer wall of the rock core, preventing the broken rock core from falling out of the inner tube 1.
[0056] In summary, regardless of which of the three operating conditions mentioned above occurs, at least two or more limiting structures (including clamping structure 8 and limiting support structure 7) are used to limit and fix the rock core, thereby reducing the possibility of the rock core falling out of the inner tube 1 and the sleeve seat 5. Since the rock core inside the sleeve seat 5 is limited and fixed, any broken rock core at the snap ring 4 will also be blocked, preventing it from falling out of the core drilling tool due to vibration and water flow impact. Furthermore, the overall structure is simple, the operating principle is simple, suitable for large-scale promotion, and it is a modification of existing products, resulting in a lower overall cost.
[0057] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.
[0058] The detailed description of known functions and components is omitted in this disclosure. To ensure the compatibility of the equipment, the operating methods used are consistent with the parameters of commercially available instruments.
Claims
1. A core drilling tool for preventing rock fragments from falling off, comprising an inner tube (1), an inner tube assembly (2) connected to the inner tube (1), and a retaining ring seat (3) threadedly connected to the other end of the inner tube (1), wherein a retaining ring (4) is provided inside the retaining ring seat (3), characterized in that, Also includes: Sleeve seat (5) connected to snap ring seat (3); The anti-fall device is installed inside the sleeve seat (5) and includes a protective shell (6) coaxial with the sleeve seat (5). The protective shell (6) is provided with two limiting support structures (7) and clamping structures (8). The limiting support structures (7) and clamping structures (8) work together to prevent rock fragments from falling out of the inner tube (1). Among them, the limiting support structure (7) includes several limiting support plates (701) hinged to the protective shell (6); The clamping structure (8) includes several clamping rings (801) and a connecting plate (802) that connects the clamping rings (801) to the protective shell (6).
2. A core drilling tool for preventing rock fragments from falling off, as described in claim 1, characterized in that: The sleeve seat (5) is internally threaded to an externally threaded sleeve (9), which is fixedly connected to the inner tube (1).
3. A core drilling tool for preventing rock fragments from falling off, as described in claim 1, characterized in that: The limiting support structure (7) also includes a plurality of rotating holes (702) circumferentially opened on the inner wall of the protective shell (6), the limiting support plate (701) is rotatably connected in the corresponding rotating hole (702), and a plurality of limiting blocks (703) for limiting the rotation of the limiting support plate (701) are fixedly connected on the inner wall of the protective shell (6).
4. A core drilling tool for preventing rock fragments from falling off, as described in claim 3, characterized in that: The limiting support plate (701) is provided with an abutment groove (704), and an abutment block (705) is provided in the rotating hole (702). The abutment block (705) is fixedly connected to the inner wall of the sleeve seat (5).
5. A core drilling tool for preventing rock fragments from falling off, as described in claim 1, characterized in that: The clamping structure (8) also includes several connecting holes (803) opened on the inner wall of the protective shell (6), and the connecting plate (802) is fixedly connected to the top wall of the connecting holes (803).
6. A core drilling tool for preventing rock fragments from falling off, as described in claim 5, characterized in that: The connecting hole (803) is also provided with a protrusion (804) that can push the connecting plate (802) and the clamping ring (801) to move.