High and low frequency vibration device and method for reinforcing and compacting composite goaf

Abstract

The invention provides a high and low frequency vibration device and method for reinforcing and compacting a composite goaf, and belongs to the technical field of mining operation and underground engineering construction. The problems that the reinforcement operation of the loose and broken stratum of the composite goaf is low in efficiency and difficult to carry out smoothly are solved. The device comprises a vibration head and an impactor connected with the vibration head, the vibration head comprises a center key column, a vibration base and a supporting disc, one end of the center key column makes contact with the vibration base, crank arms are evenly arranged on the periphery of the center key column, one end of each crank arm is connected with the vibration base, and the other end of each crank arm is connected with the supporting disc. The supporting disc is fixed on the central key column, a plurality of micro-vibrators are arranged on each crank arm, piezoelectric ceramics are arranged on the outer side of each micro-vibrator, and a vibrating reed is arranged on the outer side of the piezoelectric ceramics corresponding to the plurality of micro-vibrators on the same crank arm; the method is applied to goaf reinforcing operation.

Description

Technical Field

[0001] The present application relates to the field of mining and underground engineering construction technology, and in particular to a high- and low-frequency vibration device and method for reinforcing and compacting composite goaf areas. Background Art

[0002] As multiple coal seams continue to advance, the originally independent goafs are interconnected to form large-scale composite goafs. The internal rock structure is loose and broken, and there are many risks: cracks are developed inside the goafs, and air leakage is serious, which increases the possibility of spontaneous combustion of the remaining coal; the accumulation of a large number of loose rock blocks leads to extremely poor overall stability inside the goaf, which may cause accidents such as surface collapse; the existing goaf reinforcement technology has limitations and is difficult to meet the management needs. An efficient and accurate solution is urgently needed.

[0003] There are several traditional reinforcement methods: 1. Filling the goaf with waste rock, tailings and other materials to support the surrounding rock and reduce its deformation, thereby achieving the purpose of maintaining the stability of the goaf. However, the material transportation and filling process are complicated, and there are problems such as long transportation distance, high difficulty, and loose filling. In addition, the strength is limited and the implementation cost is high. 2. Injecting cement slurry into the goaf to improve the strength and stability of the internal space through the consolidation of the slurry. However, due to the complex air leakage channels in the composite goaf, it is easy to cause slurry loss and difficulty in reaching the reinforced area. In addition, the uneven diffusion of the slurry and insufficient consolidation strength will also affect the reinforcement effect. 3. Using pillars to support the roof to prevent the roof from collapsing, but it is difficult to ensure the support effect due to rock deformation and fragmentation. If the pillars themselves are damaged, they will lose their support function. Therefore, the development of a high- and low-frequency vibration device for the reinforcement and compaction of composite goafs to break through the current technical bottleneck of goaf space reinforcement has become a key issue that needs to be urgently addressed in the industry. Summary of the Invention

[0004] In order to solve the problem of low efficiency and difficulty in smoothly carrying out the reinforcement operation of loose and broken strata in composite goaf areas, the present application proposes a high- and low-frequency vibration device and method for reinforcing and compacting composite goaf areas.

[0005] The technical solution adopted in this application is: a high and low frequency vibration device for reinforcing and compacting composite goaf areas, including a vibration head and an impactor connected to the vibration head, the vibration head including a central key column, a vibration base and a support plate, one end of the central key column is in contact with the vibration base, and curved arms are evenly arranged around the central key column, one end of the curved arm is connected to the vibration base, and the other end of the curved arm is connected to the support plate, and the support plate is fixed on the central key column, and each curved arm is provided with a number of micro vibrators, and a piezoelectric ceramic is provided on the outside of each micro vibrator, and a vibration plate is provided on the outside of the piezoelectric ceramic corresponding to several micro vibrators on the same curved arm.

[0006] Furthermore, three curved arms are evenly arranged around the central key column, each curved arm includes two support rods and a conductor tile, one end of the two support rods is connected to the inner side of the conductor tile, the other end of one of the support rods is connected to the vibration base, and the other end of the other support rod is connected to the support plate, and several micro vibrators are fixed on the outside of the conductor tile.

[0007] Furthermore, the micro vibrator includes a coaxially arranged spring outer sleeve, a spring and a spring inner sleeve, one end of the spring is connected to the conductor tile, and the other end of the spring is connected to the piezoelectric ceramic.

[0008] Furthermore, the piezoelectric ceramics include positive piezoelectric ceramics and negative piezoelectric ceramics, and at least one positive piezoelectric ceramic and one negative piezoelectric ceramic are respectively provided on a plurality of micro vibrators on a same vibration plate.

[0009] Furthermore, the vibration head is threadedly connected to the impactor.

[0010] Furthermore, a reserved hole for the impactor is provided inside the impactor, and the other end of the central key column is inserted into the reserved hole for the impactor.

[0011] Furthermore, a sleeve is fixed on the vibration base, and the central key column moves back and forth in the sleeve.

[0012] Furthermore, the vibration head and the central key column are coaxially arranged.

[0013] A high- and low-frequency vibration method for reinforcing and compacting a composite goaf area comprises the following steps: Step 1: Insert the high- and low-frequency vibration device for composite goaf reinforcement and densification into a reserved borehole in the goaf to perform impact vibration operation. During the process of inserting the device into the bottom of the hole, the vibration head is in a retracted state; Step 2: When the vibrating head reaches the bottom of the hole, the vibrating base is in close contact with the rock at the bottom of the hole. The vibrating head begins to open due to the extrusion of the axial force. The impactor provides the power of impact vibration and the vibrating head starts to work. Step 3: The vibrating head, under the action of the impactor, performs low-frequency and large-amplitude vibration to crush the larger rocks, while the micro-vibrator performs high-frequency and small-amplitude vibration to compact and reinforce the smaller rocks; Step 4: The positive piezoelectric ceramic converts the mechanical energy generated by the vibrating plate into electrical energy. The spring and conductive tile inside the micro vibrator transmit the electrical energy to the negative piezoelectric ceramic. The negative piezoelectric ceramic converts the electrical energy into mechanical energy, driving the micro vibrator to vibrate continuously, providing power for the vibrating plate to vibrate at a high frequency and small amplitude, thereby compacting and reinforcing the smaller rock blocks. Step 5: The impactor continues to impact and vibrate, and repeat steps 3 to 4.

[0014] Furthermore, the low frequency vibration range is 10-20 Hz, and the high frequency vibration range is 50-100 Hz.

[0015] The beneficial effects of this application compared to the prior art are: 1. The vibration head and the impactor of this application are connected by threads, which makes the operation stable and reliable under the impact and vibration environment, and is simple and convenient to disassemble and assemble, saving time and cost, and facilitating regular maintenance and replacement of equipment; 2. This application uses positive and negative piezoelectric ceramics to achieve rapid energy conversion and transmission, providing continuous and stable power for the micro vibrator to perform high-frequency vibration, and has the advantages of energy saving, environmental protection and high efficiency.

[0016] 3. The high- and low-frequency vibration device for composite goaf reinforcement and compaction proposed in this application performs vibration operations in the goaf. The impactor drives the vibration head to perform low-frequency and large-amplitude vibrations to crush larger rock blocks, and the micro-vibrator drives the vibration plate to perform high-frequency and small-amplitude vibrations to further crush and compact smaller rock blocks, thereby improving the stability of the internal space of the goaf. Compared with traditional goaf reinforcement technology, the device has strong environmental adaptability, the reinforcement effect can be increased by 1 to 2 times, and the construction period is greatly shortened, thereby improving the efficiency of goaf reinforcement operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present application will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic structural diagram of the vibration device of this application; Figure 2 for Figure 1 Cross-sectional view of AA; Figure 3 Schematic diagram of the operation process of the device of this application in the goaf Figure 1 ; Figure 4 Schematic diagram of the operation process of the device of this application in the goaf Figure 2 ; Figure 5 This is a schematic diagram of the relationship between the vibration frequency, amplitude and time of the device of this application; Figure 6 Schematic diagram of internal energy conversion of the device of this application.

[0018] In the figure: 1 is the impactor, 2 is the center key column, 3 is the support rod, 4 is the vibration base, 5 is the conductor tile, 6 is the micro vibrator, 7 is the piezoelectric ceramic, 8 is the spring outer sleeve, 9 is the spring, 10 is the spring inner sleeve, 11 is the positive piezoelectric ceramic, 12 is the negative piezoelectric ceramic, 13 is the support plate, 14 is the vibration plate, 15 is the vibration head, 16 is the composite goaf, 17 is the reserved drill hole, 18 is the curved arm, and 19 is the reserved hole for the impactor. DETAILED DESCRIPTION

[0019] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate relative positions or positional relationships, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second" and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0020] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0021] like Figures 1 to 6 As shown, the present application provides a high- and low-frequency vibration device for composite goaf reinforcement and densification, including a vibration head 15 that penetrates into the goaf 16 and an impactor 1 that is threadedly connected to the vibration head 15. A central key column 2 is provided inside the vibration head 15, and one end of the central key column 2 penetrates into the impactor reserved hole 19, and the other end extends into the sleeve fixed on the vibration base 4, so that the central key column 2 can move back and forth in the sleeve of the vibration base 4. Three curved arms 18 and conductor tiles 5 are evenly arranged around the central key column 2, and the vibration head 15 and the central key column 2 are coaxially arranged. Two support rods 3 are provided on the curved arm 18, and the two support rods 3 are bolted to the inner side of the conductor tile 5. One end of the curved arm 18 is connected to the support plate 13, and the other end is connected to the vibration base 4. The curved arm 18 is bolted to the support plate 13 and the vibration base 4. The support plate 13 is fixed on the central key column 2. Several microvibrators 6 are arranged outside the conductive tile 5. These microvibrators 6 include a spring outer sleeve 8, a spring inner sleeve 10, and a spring 9. The spring outer sleeve 8, spring inner sleeve 10, and spring 9 are coaxially arranged. One end of the spring 9 is connected to the outside of the conductive tile 5, and the other end is connected to the piezoelectric ceramic 7. The piezoelectric ceramic 7 includes several positive piezoelectric ceramics 11 and negative piezoelectric ceramics 12. One end of the piezoelectric ceramic 7 is connected to the spring 9, and the other end is connected to the inside of the vibrating plate 14.

[0022] A gap is left between the vibrating pieces 14 connecting the positive and negative piezoelectric ceramics.

[0023] This application also proposes a high- and low-frequency vibration method for reinforcing and compacting a composite goaf, using the above-mentioned vibration device. The method comprises the following steps: Step 1: Insert the high and low frequency vibration device for composite goaf reinforcement and densification into the reserved borehole 17 in the goaf 16 to perform impact vibration operation, such as Figure 3 As shown, during the process of sending the device to the bottom of the hole, the vibrating head 15 is in a retracted state; Step 2: Figure 3 As shown, when the vibration head 15 reaches the bottom of the hole, the vibration base 4 is in close contact with the rock at the bottom of the hole, and the vibration head 15 begins to open due to the squeezing of the axial force. The impactor 1 provides the power of impact vibration, and the vibration head 15 starts to work; Step 3: Figure 4 、 Figure 5 As shown, under the action of the impactor 1, the vibration head 15 performs low-frequency and large-amplitude vibration to crush the larger rock blocks, while the micro-vibrator 6 performs high-frequency and small-amplitude vibration to compact and reinforce the smaller rock blocks.

[0024] Step 4: Figure 6 As shown, the positive piezoelectric ceramic 11 converts the mechanical energy generated by the vibrating plate 14 into electrical energy. The spring 9 inside the micro vibrator 6 and the conductive tile 5 transmit the electrical energy to the negative piezoelectric ceramic 12. The negative piezoelectric ceramic 12 converts the electrical energy into mechanical energy, driving the micro vibrator 6 to vibrate continuously, providing power for the vibrating plate 14 to vibrate at a high frequency and a small amplitude, thereby compacting and reinforcing the smaller rock blocks. Step 5: The impactor 1 continues the impact and vibration operation, and repeats steps 3 to 4.

[0025] The impactor 1 and vibrating head 15 of this application work together to effectively compact and reinforce the interior space of the goaf 16. Compared to traditional filling, grouting, and pillar methods, this application's approach, based on the interaction between the positive and negative piezoelectric ceramics 11 and 12, along with high- and low-frequency vibration, offers significant results, low cost, and strong environmental adaptability. This significantly improves reinforcement efficiency and reduces energy consumption. Experiments have shown that the reinforcement effect can be increased by 1 to 2 times.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A high and low frequency vibration device for reinforcing and compacting composite goaf, characterized by: The invention comprises a vibration head (15) and an impactor (1) connected to the vibration head (15), wherein the vibration head (15) comprises a central key column (2), a vibration base (4) and a support plate (13), wherein one end of the central key column (2) contacts the vibration base (4), and curved arms (18) are evenly arranged around the central key column (2), wherein one end of the curved arm (18) is connected to the vibration base (4), and the other end of the curved arm (18) is connected to the support plate (13), and the support plate (13) is fixed on the central key column (2), wherein each curved arm (8) is provided with a plurality of micro vibrators (6), and a piezoelectric ceramic (7) is provided on the outer side of each micro vibrator (6), and a vibration plate (14) is provided on the outer side of the piezoelectric ceramic (7) corresponding to the plurality of micro vibrators (6) on the same curved arm (8).

2. The high- and low-frequency vibration device for composite goaf reinforcement and densification according to claim 1 is characterized in that: Three curved arms (18) are evenly arranged around the central key column (2), each curved arm (18) includes two support rods (3) and a conductor tile (5), one end of each of the two support rods (3) is connected to the inner side of the conductor tile (5), the other end of one of the support rods (3) is connected to the vibration base (4), and the other end of the other support rod (3) is connected to the support plate (13), and a plurality of micro vibrators (6) are fixed on the outer side of the conductor tile (5).

3. The high- and low-frequency vibration device for composite goaf reinforcement and densification according to claim 2, characterized in that: The micro vibrator (6) comprises a coaxially arranged spring outer sleeve (8), a spring (9) and a spring inner sleeve (10), one end of the spring (9) is connected to the conductor tile (5), and the other end of the spring (9) is connected to the piezoelectric ceramic (7).

4. The high- and low-frequency vibration device for composite goaf reinforcement and densification according to claim 3 is characterized in that: The piezoelectric ceramic (7) includes a positive piezoelectric ceramic (11) and a negative piezoelectric ceramic (12), and at least one positive piezoelectric ceramic (11) and one negative piezoelectric ceramic (12) are respectively provided on a plurality of micro vibrators (6) on a same vibration plate (14).

5. The high- and low-frequency vibration device for composite goaf reinforcement and densification according to claim 4, characterized in that: The vibration head (15) is threadedly connected to the impactor (1).

6. The high- and low-frequency vibration device for composite goaf reinforcement and densification according to claim 5, characterized in that: An impactor reserved hole (19) is provided inside the impactor (1), and the other end of the center key column (2) is inserted into the impactor reserved hole (19).

7. The high- and low-frequency vibration device for composite goaf reinforcement and densification according to claim 1 is characterized in that: A sleeve is fixed on the vibration base (4), and the central key column (2) moves back and forth in the sleeve.

8. A high- and low-frequency vibration device for composite goaf reinforcement and densification according to any one of claims 1 to 7, characterized in that: The vibration head (15) and the central key column (2) are coaxially arranged.

9. A high- and low-frequency vibration method for reinforcing and compacting composite goaf, characterized by: The following steps are involved: Step 1: Insert the high- and low-frequency vibration device for composite goaf reinforcement and densification as described in any one of claims 1 to 8 into a reserved borehole (17) in the goaf (16) to perform impact vibration operation. During the process of inserting the device into the bottom of the hole, the vibration head (15) is in a retracted state; Step 2: When the vibrating head (15) reaches the bottom of the hole, the vibrating base (4) is in close contact with the rock at the bottom of the hole, the vibrating head (15) begins to open due to the squeezing of the axial force, the impactor (1) provides the power of impact vibration, and the vibrating head (15) starts to operate; Step 3: The vibrating head (15) performs low-frequency and large-amplitude vibration under the action of the impactor (1) to crush the larger rock blocks, while the micro-vibrator (6) performs high-frequency and small-amplitude vibration to compact and reinforce the smaller rock blocks; Step 4: The positive piezoelectric ceramic (11) converts the mechanical energy generated by the vibration plate (14) into electrical energy, and the internal spring (9) and the conductor tile (5) of the micro vibrator (6) transmit the electrical energy to the negative piezoelectric ceramic (12). The negative piezoelectric ceramic (12) converts the electrical energy into mechanical energy, driving the micro vibrator (6) to vibrate continuously, providing power for the vibration plate (14) to vibrate at a high frequency and a small amplitude, thereby compacting and reinforcing the smaller rock blocks; Step 5: The impactor (1) continues the impact and vibration operation, and repeats steps 3 to 4.

10. The high- and low-frequency vibration method for composite goaf reinforcement and densification according to claim 9, characterized in that: The range of low-frequency vibration is 10-20 Hz, and the range of high-frequency vibration is 50-120 Hz.

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