Stress monitoring device for overburden rock after coal mine goaf filling

Abstract

The utility model discloses a coal mine goaf filling post overburden stress monitoring device, install the device to the mine tunnel mining area ground, the inside center of main body bin is equipped with bottom clamping groove for installing elastomer to the main body bin, after mainboard and elastomer are installed, glue is injected in the main body bin to completely cover the welding point of mainboard and strain gauge bottom end, to achieve waterproof effect. After installation is completed, filling material is used to fill the mine tunnel mining area, and the roof contacts the filling body, when the roof bears stress and deforms, presses the elastomer downward, and any strain gauge of the elastomer senses the deformation output voltage of the elastomer, is transmitted to the ADC acquisition chip after the operation amplifier, is transmitted to the main control STM32F103C8T6 through IIC, and is transmitted to the external monitoring station through the 485 chip, and the 485 digital displacement signal is received by the monitoring station, the utility model discloses volume is small, and the bearing capacity is strong, and the installation is convenient, and the accurate monitoring of filling body's stress and deformation is convenient.

Description

Technical Field

[0001] This utility model relates to a monitoring device for filling bodies, and more particularly to a monitoring device for overburden stress after filling in coal mine goaf areas. Background Technology

[0002] Goaf (mining tunnel area) is a "cavity" created below the surface by human excavation or natural geological movement. The existence of goaf poses a great safety problem to the safe production of mines.

[0003] In existing technologies, backfill mining involves filling the goaf with backfill material. Because the backfill body is located in the high-temperature, high-pressure environment of a coal mine goaf and is a confined space, it can only be monitored remotely using equipment. Current traditional monitoring equipment, such as patent number 201210020613.2, has a strain gauge in the middle of the measuring rod to measure the strain of the backfill body. Its disadvantage is that it has weak load-bearing capacity and cannot accurately monitor the stress and deformation of backfill material weighing several tons or even tens of tons. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this utility model provides a device for monitoring the stress of overburden after filling in the goaf of a coal mine, and its technical solution is as follows: Each monitoring device includes a top plate and a bottom plate. The top plate has an integrally formed sliding chamber on its surface. The sliding chamber is a hollow rectangular structure with no bottom. Insert tongues extend horizontally outward from both sides of the bottom of the sliding chamber. A top block is provided in the middle of the lower surface of the top plate. The outer edge of the top block extends downward to form an additional space, which is a slot I. The main body compartment is integrally formed on the upper surface of the base plate. The main body compartment is a hollow rectangular structure without a top. Symmetrical folding ears are provided on both sides of the top of the main body compartment. Inside the main body compartment and on the base plate, there are several motherboard mounting holes and bottom slots. The motherboard mounting holes are located around the bottom slots and are used to install the motherboard. The edge of the bottom slots extends upwards, and the middle part is a downward slot II. It also includes an elastomer, which is a rectangular structure. During installation, the top and bottom of the elastomer are matched and installed with slot I and slot II, respectively. Strain gauges are longitudinally provided on the four sides of the elastomer.

[0005] Furthermore, during installation, the folded lugs and the latches are matched and installed, meaning the latches can be inserted into the inside of the two symmetrical folded lugs.

[0006] Furthermore, after the tongue is horizontally inserted into the folded ear, the top plate is pressed down so that the top plate and the sliding chamber are downward as a whole, so that the top of the elastomer is engaged in the top slot I inside the sliding chamber.

[0007] Furthermore, the elastomer is an aluminum block comprising a top, a bottom, and four sides.

[0008] Furthermore, each monitoring device is installed at the bottom of the mining tunnel area and is connected to an underground monitoring substation.

[0009] Furthermore, a cable outlet is provided on one side of the main compartment for leading out the strain gauge cables and connecting them to the strain gauge interface on the main board.

[0010] Furthermore, the motherboard is equipped with a 485 communication unit, an STM32 main controller, a signal unit, a power supply unit, and a signal amplification circuit. The power supply unit provides DC12V power to the device, and the power module outputs DC3.3V to power the internal functional modules. At the same time, the unit is equipped with a power protection circuit to achieve overvoltage, overcurrent, and reverse connection protection. If it is in an explosion-proof environment, it can also be adapted to an intrinsically safe power supply to ensure safe power supply.

[0011] Furthermore, the deformation output voltage of the four strain gauges senses the elastic body, which is then transmitted to the ADC acquisition chip after passing through the operational amplifier. It is then transmitted to the main controller STM32F103C8T6 via IIC, and finally transmitted to the external monitoring station via the 485 chip, where the monitoring station receives the 485 digital displacement signal.

[0012] The beneficial effects of this utility model are as follows: This utility model is a monitoring device for overburden stress after filling in coal mine goaf areas. Before filling, several of these devices are installed on the ground of the mining area according to requirements. The main body has a bottom slot in the center for installing the elastomer inside. After the main board and elastomer are installed, glue is injected into the main body until it completely covers the welding points of the main board and the bottom of the strain gauges to achieve a waterproof effect. After installation, the mining area is filled with filling material. The top plate contacts the filling body. When the top plate is subjected to force and deformation, it presses down on the elastomer. Any strain gauge of the elastomer senses the deformation of the elastomer and outputs a voltage. After passing through an operational amplifier, it is transmitted to an ADC acquisition chip, then to the main controller STM32F103C8T6 via IIC, and finally to an external monitoring station via a 485 chip. The monitoring station receives the 485 digital displacement signal. Compared with the prior art, this utility model is small in size, has strong bearing capacity, is easy to install, and facilitates accurate monitoring of the force and deformation of the filling body. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 for Figure 1 Schematic diagram of the split structure; Figure 3 for Figure 1 Sectional front view; Figure 4 for Figure 3 Sectional side view; Figure 5 for Figure 3 Sectional view (top view); Figure 6 for Figure 1 Schematic diagram of the structure of a mining tunnel area; Figure 7 This is a schematic cross-sectional view of the top plate and sliding compartment. Figure 8 for Figure 7 Side view; Figure 9 for Figure 7 Top view; Figure 10 This is a schematic cross-sectional view of the base plate and main compartment. Figure 11 for Figure 10 Side view; Figure 12 for Figure 10 Top view; Figure 13 This is a block diagram of the motherboard structure. Figure 14 This is a schematic diagram of the motherboard circuit connection structure of this utility model; As shown in the figure, 1 is the mining area, 2 is the filling body, 3 is the roof plate, 4 is the bottom plate, 5 is the sliding chamber, 6 is the main chamber, 7 is the folded lug, 8 is the tongue, 9 is the cable outlet, 10 is the top block, 11 is the bottom slot, 12 is the main board fixing hole, 13 is the sliding groove, 14 is the elastomer, 15 is the strain gauge, 16 is the glue injection, 17 is the slot I, 18 is the slot II, and 19 is the mounting hole. Detailed Implementation

[0014] As shown in the figure, this utility model is a monitoring device for overburden stress after filling the goaf in a coal mine. It includes a roof plate 3, a sliding chamber 5, an elastic body 14, a main chamber 6, and a bottom plate 4. First, several of these devices are installed on the ground of the mining area 1 in the mine tunnel, and these devices are connected to the underground monitoring substation using connecting wires. Then, the mining area in the mine tunnel is filled with a filling body 2 (the filling body is made of fly ash).

[0015] Installation process: The four corner mounting holes 19 of the base plate 4 are preferably fixed to the ground of the mining area using expansion bolts. A main body compartment 6 is welded onto the base plate (the base plate and main body compartment can be integrally connected, with the outer edge of the base plate larger than the outer edge of the main body compartment). A cable outlet 9 is located on the lower center of one side of the main body compartment. Main board mounting holes 12 are located at the four corners of the interior of the main body compartment for installing the main board (the main board is hollow in the center and surrounded by several module units, such as…). Figure 13(As shown). A bottom groove 11 is located at the center of the base plate (the edge of this groove faces upwards, forming groove II18, which is identical in shape to the bottom of the elastomer and is installed accordingly; the bottom of the elastomer is inserted into groove II18). The elastomer 14 is installed into the main chamber. After the main board and elastomer are installed, glue 16 is injected into the main chamber until it completely covers the welding points between the main board and the bottom of the strain gauges to achieve a waterproof effect. Four strain gauges 15 are attached to the center of the four sides of the elastomer to detect displacement caused by deformation. Symmetrical folded ears 7 are provided at the top of the main chamber (the folded ears provide additional space, i.e., a sliding groove 13, which allows the tongue 8 to be inserted horizontally during installation). The design of the folded ears and tongues facilitates the overall insertion of the sliding chamber into the main chamber and prevents the sliding chamber from sliding out of the main chamber when the filling material is subjected to force and deformation.

[0016] The sliding chamber 5 has a top plate 3 (which can be designed as a single piece, with the outer edge of the top plate larger than the outer edge of the sliding chamber) at its top. This plate is used to directly contact the filling material and bear pressure. A top block 10 is integrally formed in the center of the top plate, with its lower edge extending downwards to form a slot I17. The elastomer 14 is a 40×40×100mm aluminum block, including a top, bottom, and four sides, which can be integrally formed (the reason for using an aluminum block is twofold: firstly, its material is lightweight and easy to install; secondly, it is easily deformed under pressure). Strain gauges 15 are longitudinally provided on the four sides of the elastomer 14 to detect the deformation of the aluminum block under stress. During installation, after the bottom plate and main chamber are fixed, the bottom of the elastomer is inserted into the slot I17. The top plate is then installed, and the sliding chamber's tongue is inserted into the folded lug. After the entire sliding chamber enters the main chamber, the top plate is pressed down, causing it to face downwards, so that the top of the elastomer is inserted into the slot I17, stabilizing the elastomer. Pressing is then stopped, and assembly is complete.

[0017] Depending on the actual situation, 201 stainless steel can be used for the bottom plate, main compartment, top plate, sliding compartment, etc., which has certain high temperature resistance and high pressure resistance characteristics.

[0018] The system power supply unit provides DC 12V power to this sensor, and the power module outputs DC 3.3V to power the internal functional modules. This unit is also equipped with power protection circuitry to provide overvoltage, overcurrent, and reverse connection protection. In explosion-proof environments, an intrinsically safe power supply can be adapted for safe power supply. Four strain gauges (preferably connected in series, so any one gauge can be used) sense the deformation of the elastic body and output voltage. This voltage is then transmitted through an operational amplifier to an ADC acquisition chip (ADS1110A0IDBVR), and then via IIC to the main controller STM32F103C8T6. Finally, it is transmitted to an external monitoring station via a 485 chip (RSM3485PHT). The monitoring station receives the 485 digital displacement signal for accurate monitoring of the force and deformation of the filling material.

[0019] The above description represents the preferred embodiment of this utility model. Any substitutions, combinations, or modifications made by those skilled in the art under the guidance of this patent without departing from the scope of protection of the claims of this patent shall also be within the scope of protection of this patent.

Claims

1. A monitoring device for overburden stress after backfilling in a coal mine goaf, comprising an underground monitoring substation and multiple monitoring devices, characterized in that, Each monitoring device includes a top plate (3) and a bottom plate (4). The lower surface of the top plate (3) is integrally provided with a sliding chamber (5). The sliding chamber (5) is a rectangular structure with a hollow interior and no bottom. The two sides of the bottom of the sliding chamber (5) extend outward horizontally with tongues (8). The middle of the lower surface of the top plate (3) is provided with a top block (10). The outer edge of the top block (10) extends downward to form an additional space, which is a slot I (17). The base plate (4) has an integral main compartment (6) on its upper surface. The main compartment (6) is a rectangular structure with a hollow interior and no top. Symmetrical folding ears (20) are provided on both sides of the top of the main body compartment (6); inside the main body compartment (6) and on the bottom plate (4), there are several main board fixing holes (12) and bottom slots (11). The main board fixing holes (12) are located around the bottom slots (11) and are used to install the main board; the edge of the bottom slots (11) extends upward and the middle part is a downward slot II (18). It also includes an elastomer (14), which is a rectangular structure. During installation, the top and bottom of the elastomer are matched and installed with slot I (17) and slot II (18) respectively. Strain gauges (15) are provided longitudinally on the four sides of the elastomer.

2. The overburden stress monitoring device after filling the coal mine goaf as described in claim 1, characterized in that, During installation, the folding lugs (20) and the tongue (8) are matched and installed, that is, the tongue (8) can be inserted into the inside of the two symmetrical folding lugs (20).

3. The overburden stress monitoring device after filling the coal mine goaf as described in claim 1, characterized in that, After the tongue is horizontally inserted into the folded ear, press the top plate so that the top plate and the sliding chamber are downward as a whole, so that the top of the elastomer can be inserted into the top slot I inside the sliding chamber.

4. The overburden stress monitoring device after filling the coal mine goaf as described in claim 1, characterized in that, The elastomer is an aluminum block containing a top, a bottom, and four sides.

5. The overburden stress monitoring device after filling the coal mine goaf as described in claim 1, characterized in that, Each monitoring device is installed at the bottom of the mining area and is connected to an underground monitoring substation.

6. The overburden stress monitoring device after filling the coal mine goaf as described in claim 1, characterized in that, A cable outlet (9) is provided on one side of the main compartment for leading out the strain gauge cable and connecting it to the strain gauge interface on the main board.

7. The overburden stress monitoring device after filling the coal mine goaf as described in claim 1, characterized in that, The motherboard is equipped with a 485 communication unit, an STM32 main controller, a signal unit, a power supply unit, and a signal amplification circuit. The power supply unit provides DC12V power to the device, and the power module outputs DC3.3V to power the internal functional modules. At the same time, the unit is equipped with a power protection circuit to achieve overvoltage, overcurrent, and reverse connection protection. If it is in an explosion-proof environment, it can also be adapted to an intrinsically safe power supply to ensure safe power supply.

8. The overburden stress monitoring device after filling the coal mine goaf as described in claim 7, characterized in that, The four strain gauges sense the deformation of the elastic body and output voltage. After passing through an operational amplifier, the voltage is transmitted to the ADC acquisition chip, then to the main controller STM32F103C8T6 via IIC, and finally to the external monitoring station via the 485 chip. The monitoring station receives the 485 digital displacement signal.

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