Blasthole plugging device for blasting under mine

Abstract

The invention discloses a blast hole plugging device for blasting under a mine, and relates to the technical field of mine blasting, the blast hole plugging device comprises a plugging main body and a plurality of threaded rods, and threaded grooves matched with the threaded rods are formed in the circumferential direction of the plugging main body at equal intervals; a first cavity is formed in the plugging body, a piston plate is slidably mounted in the cavity, and a spring is fixed between the piston plate and the bottom of the cavity. An expansion bag is fixed to the outer side of the plugging body, a second cavity is formed in the inner side of the plugging body, and the first cavity communicates with the second cavity through a communicating hole. A movable plate is fixed to the top end of the second cavity, and the bottom ends of the movable rods are fixed to the piston plate. During use, the threaded rod is screwed into the threaded groove to extrude the movable plate, the piston plate is pushed by the movable rod to compress gas, and the gas enters the second cavity through the communicating hole to enable the expansion bag to expand to block the shot hole. The device is simple in structure, high in plugging stability, capable of being repeatedly used and suitable for various mine blasting shot hole plugging scenes.

Description

Technical Field

[0001] This invention relates to the field of mine blasting technology, specifically to a device for sealing blast holes in underground mines. Background Technology

[0002] In mining operations, blasting is the core process for breaking up rock masses, and the stability of the blast hole sealing directly determines the blasting effect and operational safety. Currently, underground blast hole sealing mainly relies on two methods: traditional manual filling with stemming material or simple mechanical sealing, but both have significant stability defects.

[0003] Traditional stemming methods rely on manual labor to fill the blast hole with clay stemming material in layers and tamp it down. Its stability depends entirely on the operator's experience and strength. In practice, gaps easily form between the stemming material and the inner wall of the blast hole. Furthermore, the stemming material itself has low strength and is easily broken or deformed under the impact of the blasting shock wave, leading to the failure of the sealing structure. This not only causes explosive energy leakage and reduced blasting efficiency but may also trigger safety accidents such as flying rocks and gas outbursts. At the same time, manual filling is inefficient and cannot meet the needs of large-scale blasting operations.

[0004] Existing simple mechanical plugging devices mostly employ a single expansion or mechanical support structure, resulting in insufficient stability. Some devices achieve plugging through airbag inflation, but the friction between the airbag and the inner wall of the borehole is limited, making them prone to displacement under axial impact during blasting. Other devices use radial struts for support, but the connection between the struts and the borehole is often a simple plug-in joint, lacking reliable limiting and locking structures, making them prone to loosening and detachment under vibration loads. Furthermore, these devices are difficult to adapt to boreholes of different diameters and depths, exhibiting poor versatility and further limiting the improvement of their plugging stability.

[0005] In summary, existing blast hole plugging technologies suffer from problems such as high reliance on manual labor, weak structural impact resistance, and poor adaptability, failing to meet the stringent requirements for plugging stability in mine blasting operations. Therefore, developing a blast hole plugging device that can reliably limit movement, has strong impact resistance, and adapts to different working conditions is crucial to solving the current problem of plugging stability. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a device for sealing blast holes in mines.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a blasting and sealing device for blast holes in a mine, comprising a sealing body and a plurality of threaded rods, wherein the sealing body is provided with a plurality of threaded grooves adapted to the threaded rods, and the plurality of threaded grooves are distributed at equal intervals on the circumference of the sealing body.

[0008] The sealing body has a first cavity inside, a piston plate is slidably installed inside the first cavity, and a spring is fixedly installed between the piston plate and the inner bottom surface of the first cavity.

[0009] An expansion bladder is fixedly installed on the sealing body, and a second cavity is formed on the sealing body and inside the expansion bladder. The first cavity is connected to the second cavity through multiple connecting holes.

[0010] A movable rod is slidably installed on the sealing body at each threaded groove, a movable plate is fixedly installed at the top of the second cavity, and the bottom end of the movable rod is fixedly connected to the piston plate.

[0011] Preferably, a protrusion is fixedly installed on the outer surface of the sealing body at the threaded groove.

[0012] Preferably, a narrow head is fixedly installed at the bottom end of the sealing body, and the diameter of the narrow head is smaller than the diameter of the sealing body.

[0013] Preferably, a fixing rod is fixedly installed inside the sealing body and located within the second cavity.

[0014] Preferably, a threaded sleeve is threadedly installed on the outer surface of the threaded rod, and a pressure plate is fixedly installed on the bottom end of the threaded sleeve.

[0015] Preferably, the included angle between the threaded groove and the sealing body is 20°-40°.

[0016] Compared with the prior art, the present invention provides a device for sealing blast holes in mines, which has the following beneficial effects:

[0017] 1. The device utilizes the diameter difference between the narrow head and the sealing body to create a stepped support, which, combined with the locking and limiting action of the protruding head and the blast hole groove, achieves initial fixation of the sealing body. The threaded connection between the threaded rod and the threaded groove, along with the adhesion and fixation of the pressure plate to the rock wall, constructs a dual locking structure in both the radial and axial directions. The expansion bladder, after expansion, adheres tightly to the inner wall of the blast hole, further enhancing friction. The synergistic effect of these multiple stabilization mechanisms effectively resists blast shock waves and vibration loads, preventing displacement or loosening of the sealing body. The sealing stability is improved by more than 60% compared to traditional devices.

[0018] 2. When the threaded rod is screwed in, it pushes the piston plate through the movable rod to compress the gas, causing the expansion bladder to expand evenly and fit tightly against the inner wall of the borehole, sealing without gaps. The spring return design ensures that the expansion bladder can contract after blasting, resulting in a high reusability of the device. At the same time, the fixed rod enhances the structural strength of the second chamber, preventing the expansion bladder from deforming under pressure. The sealing layer and sealing sleeve ensure stable gas pressure, preventing a decrease in sealing force due to gas leakage, and significantly improving the long-term sealing stability and reliability.

[0019] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Specific embodiments of the present invention are given in detail below with reference to the accompanying drawings. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0021] Fig. 1 This is a schematic diagram of the structure of the present invention;

[0022] Fig. 2 This is a cross-sectional structural diagram of the present invention.

[0023] In the diagram: 1. Blocking body; 2. Expansion bladder; 3. Narrow head; 4. Threaded rod; 5. Protruding head; 6. Threaded groove; 7. First cavity; 8. Piston plate; 9. Spring; 10. Second cavity; 11. Connecting hole; 12. Fixed rod; 13. Movable rod; 14. Movable plate; 15. Threaded sleeve; 16. Pressure plate. Detailed Implementation

[0024] The following is in conjunction with the appendix Figs. 1-2 The principles and features of the present invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0025] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] Please combine Figs. 1-2 As shown, this invention provides a device for sealing blast holes in mines. The device includes a sealing body 1 and a threaded rod 4. The sealing body 1 is forged from 45# steel, and is cylindrical in shape with a diameter of 8-15cm and a length of 20-30cm, possessing sufficient strength to withstand blasting impact. A narrow head 3 is welded and fixed to the bottom end of the sealing body 1. The narrow head 3 has a frustum-shaped structure, with a diameter 2-4cm smaller than that of the sealing body 1 and a height of 2-5cm. This structural design allows the narrow head 3 to guide the device to quick positioning when the sealing body 1 is inserted into the blast hole. Simultaneously, utilizing the diameter difference between the sealing body 1 and the narrow head 3, a stepped support surface is formed after the blast hole is enlarged, achieving initial axial positioning of the sealing body 1 within the blast hole.

[0028] Four threaded grooves 6 are evenly spaced along the circumference of the sealing body 1, with a central angle of 90° between adjacent threaded grooves 6. The included angle between the threaded groove 6 and the radial direction of the sealing body 1 is set to 30°. The depth of the threaded groove 6 is 5-8 cm, and the inner diameter is 3-4 cm. Fine threads are machined in the groove for mating with the threaded rod 4. On the outer surface of the sealing body 1 corresponding to the opening of each threaded groove 6, a protrusion 5 is bolted and fixed to the sealing body 1 at the opening of the threaded groove 6.

[0029] The threaded rod 4 is a connecting and limiting component of the device, made of high-strength threaded steel, with a length of 15-25cm. Its outer diameter matches the inner diameter of the threaded groove 6. One end is machined with an external thread matching the threaded groove 6, and the outer surface of the other end is also machined with threads, and a threaded sleeve 15 is threadedly installed thereon. A pressure plate 16 is welded to the bottom end of the threaded sleeve 15. The pressure plate 16 is a circular steel plate with a diameter of 6-8cm and a thickness of 1-1.5cm, and its surface is roughened to increase friction. The position of the pressure plate 16 can be adjusted by rotating the threaded sleeve 15, so that the pressure plate 16 fits tightly against the outer rock wall of the blast hole, enhancing the installation stability of the threaded rod 4.

[0030] The sealing body 1 has a first cavity 7 axially formed inside, serving as a gas pressure generation source. The first cavity 7 is a cylindrical cavity with a diameter of 4-5 cm and a depth of 10-15 cm, and its axis coincides with the axis of the sealing body 1. A piston plate 8 is slidably installed inside the first cavity 7. The piston plate 8 is a circular metal plate with a diameter that is clearance-fitted to the inner diameter of the first cavity 7 (clearance ≤ 0.1 mm). Its outer surface is covered with a 0.5 cm thick nitrile rubber sealing layer to ensure airtightness with the cavity wall. A spring 9 is fixedly installed between the center of the lower surface of the piston plate 8 and the inner bottom surface of the first cavity 7. The spring 9 is a cylindrical helical compression spring, which holds the piston plate 8 at the upper position of the first cavity 7 in its natural state.

[0031] An expansion bladder 2 is fixedly installed around the circumference of the outer wall of the sealing body 1. The expansion bladder 2 is made of multi-layer nylon reinforced rubber with a thickness of 1.5-2cm, and its two ends are tightly fixed to the sealing body 1 by metal clamps to prevent gas leakage. Inside the sealing body 1 and inside the expansion bladder 2, there is an annular second cavity 10.

[0032] To enhance the structural strength of the second cavity 10, a fixing rod 12 is welded axially along the sealing body 1 inside it. The fixing rod 12 is a cylindrical steel rod with a length consistent with the height of the second cavity 10, and its two ends are welded and fixed to the upper and lower walls of the second cavity 10, respectively. The first cavity 7 and the second cavity 10 are connected by four connecting holes 11. The connecting holes 11 are evenly distributed inside the sealing body 1, with a diameter of 1-1.5 cm. One end of the hole connects to the upper side wall of the first cavity 7, and the other end connects to the inner side wall of the second cavity 10, ensuring that the gas in the first cavity 7 can quickly enter the second cavity 10.

[0033] A movable rod 13 is slidably installed in each threaded groove 6. The movable rod 13 is a cylindrical steel rod with its axis parallel to the axis of the threaded groove 6. A movable plate 14, which is a circular metal plate, is fixed to the top of the movable rod 13 by bolts. The bottom end of the movable rod 13 is welded and fixed to the corresponding position on the upper surface of the piston plate 8, so as to realize the synchronous movement of the movable rod 13 and the piston plate 8.

[0034] Working principle: Step 1: Based on the diameter of the narrow head 3, use drilling equipment to process the diameter of the main body of the blast hole to match the diameter of the narrow head 3; enlarge the hole at the end of the blast hole near the roadway, and after enlargement, the hole diameter is consistent with the diameter of the sealing body 1, forming a stepped surface; around the circumference of the enlarged blast hole, corresponding to the positions of the four threaded grooves 6, open four side holes (one or more side holes are sufficient), the diameter of the side holes is adapted to the outer diameter of the threaded rod 4, the inclination angle is the same as the angle of the threaded groove 6 (30°), and they are connected to the enlarged blast hole; at the same time, on the inner wall of the enlarged blast hole, a semi-circular groove is opened corresponding to the position of the protrusion 5.

[0035] Step Two: Installation of the Sealing Body: Align the end of the sealing body 1 with the narrow head 3 with the blast hole and slowly insert it into the blast hole until the bottom end face of the sealing body 1 is in close contact with the stepped surface inside the blast hole. At this time, the protruding head 5 is precisely embedded in the groove of the blast hole enlargement section, realizing the radial limitation of the sealing body 1 and preventing it from rotating inside the blast hole. At the same time, the diameter difference between the sealing body 1 and the narrow head 3 forms axial support, eliminating the need for additional fixing structures.

[0036] Step 3: Insert the threaded rods 4 into the corresponding side holes, aligning the threaded end of the threaded rod 4 with the threaded groove 6. Rotate the threaded rod 4 clockwise to gradually screw it into the threaded groove 6 and form a threaded connection. As the threaded rod 4 is screwed in, its bottom end contacts the upper surface of the movable plate 14 and applies downward pressure, pushing the movable plate 14 downward along the axis of the threaded groove 6. The movable plate 14 drives the movable rod 13 to move downward synchronously. The movable rod 13 pushes the piston plate 8 to overcome the elastic force of the spring 9 and slide downward along the inner wall of the first cavity 7. During the downward movement of the piston plate 8, it compresses the air in the first cavity 7, increasing the air pressure in the cavity. The high-pressure air flows rapidly into the second cavity 10 through the four connecting holes 11.

[0037] Step 4: After the second chamber 10 is filled with high-pressure air, the expansion bladder 2 expands outward under the air pressure until the outer surface of the expansion bladder 2 is tightly fitted with the inner wall of the blast hole, forming an annular sealing surface, thus effectively sealing the blast hole. At this time, stop rotating the threaded rod 4, and rotate the threaded sleeve 15 at the other end of the threaded rod 4, causing the pressure plate 16 to move downward and tightly fit against the rock wall surface outside the blast hole. The friction between the pressure plate 16 and the rock wall further fixes the threaded rod 4, ensuring the stability of the entire device during the blasting process.

[0038] Step 5: After the blasting is complete, rotate the threaded rod 4 counterclockwise to gradually withdraw it from the threaded groove 6. As the threaded rod 4 withdraws, the pressure on the movable plate 14 disappears, and the piston plate 8 returns to its original position under the elastic force of the spring 9, drawing the air in the second chamber 10 back into the first chamber 7 through the connecting hole 11. The expansion bladder 2, having lost its air pressure support, contracts and returns to its original shape. Finally, remove the sealing body 1 from the blast hole to complete the dismantling of the device.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A device for sealing off a blast hole for blasting in a mine, characterised in that: The utility model provides a sealing body (1) and a plurality of threaded rods (4), a plurality of threaded grooves (6) are set on the sealing body (1) and are matched with threaded rods (4), and a plurality of threaded grooves (6) are distributed in the circumferential direction of the sealing body (1) at equal intervals. A first cavity (7) is formed in the sealing body (1), a piston plate (8) is slidably installed in the first cavity (7), and a spring (9) is fixedly installed between the piston plate (8) and the inner bottom surface of the first cavity (7). An expansion bag (2) is fixedly installed on the sealing body (1), a second cavity (10) is formed in the sealing body (1) and located on the inner side of the expansion bag (2), and the first cavity (7) is in communication with the second cavity (10) through a plurality of communication holes (11). An activity rod (13) is slidably installed on the sealing body (1) and located at each threaded groove (6), an activity plate (14) is fixedly installed at the top of the second cavity (10), and the bottom end of the activity rod (13) is fixedly connected with the piston plate (8).

2. The device for sealing blast holes in underground mine blasting according to claim 1, characterized in that: A convex head (5) is fixedly installed on the outer surface of the sealing body (1) and located at the threaded groove (6).

3. The device for sealing blast holes in underground mine blasting according to claim 1, characterized in that: A narrow head (3) is fixedly installed at the bottom end of the sealing body (1), and the diameter of the narrow head (3) is smaller than the diameter of the sealing body (1).

4. The device according to claim 1, characterized in that: A fixed rod (12) is fixedly installed in the sealing body (1) and located in the second cavity (10).

5. The device according to claim 1, characterized in that: A threaded sleeve (15) is threadedly installed on the outer surface of the threaded rod (4), and a pressing plate (16) is fixedly installed on the bottom end of the threaded sleeve (15).

6. The device according to claim 1, characterized in that: The included angle between the threaded groove (6) and the sealing body (1) is 20°-40°.

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