Goaf roof pressure monitoring device and monitoring method thereof

Abstract

A goaf roof pressure monitoring device and a monitoring method thereof relate to the field of mine pressure monitoring, the goaf roof pressure monitoring device comprises a measuring unit, a fixing unit and a control unit, the measuring unit comprises a shell and a stepping motor capable of adjusting the pose of the shell, and the top of the shell comprises a horizontal center plate and a plurality of side inclined plates arranged around the edge of the horizontal center plate and facing the upper part of the outer side of the shell; the fixing unit comprises a plurality of anchor rods and locking pieces spirally arranged at the upper ends of the anchor rods, the stepping motors are lead screw type stepping motors, the multiple stepping motors are vertically arranged along the edge of the shell, the lead screw output ends of the stepping motors face downwards and are connected with one end of a transversely-arranged connecting plate through a rolling bearing, and the other end of the connecting plate is connected with the fixing unit. The other end of the connecting plate is located on the outer side of the shell and vertically provided with a positioning hole in clearance fit with the anchor rod, and the locking piece can be matched with the anchor rod to lock the connecting plate in the reserved groove. The problems that a traditional device is lack of data dimensions and cannot be leveled, cables are prone to being damaged, and all movable parts are difficult to maintain are solved.

Description

Technical Field

[0001] The present invention relates to the field of mine pressure monitoring, and particularly to a gob roof pressure monitoring device and a monitoring method thereof. Background Art

[0002] Mine pressure monitoring is a key link in mining engineering, especially crucial in the analysis of gob roof caving, the evaluation of roof cutting pressure relief effect, and the support design of gob-side entry retaining. Currently, traditional stress measurement methods (such as stress relief method, hydraulic fracturing method) have limitations such as being unable to monitor for a long time and unable to cover the caving rock strata area.

[0003] The prior art such as a stress monitoring method and device for a gob in Patent 2010200230138 can monitor the pressure in the gob, but has the following problems: First, the measurement device only collects the vertical pressure generated by roof caving through a single vertically arranged stress monitoring device, and cannot synchronously obtain horizontal extrusion stress or oblique shear stress data. This single-dimensional monitoring mode leads to the lack of key data in the analysis of the movement law of the caving rock strata of the roof, making it difficult to accurately judge the stability of the short-wall beam structure after roof cutting pressure relief. Second, the measurement device relies on a pressure equalizing pipeline to forcibly synchronize the movement of four hydraulic cylinders to maintain the horizontal of the bearing plate. However, it is difficult to ensure the horizontality of the installation plate, and the pressure equalizing pipeline cannot actively correct the inclination of the bearing plate, which leads to the difficulty in keeping the stress monitoring device horizontal, and thus leads to monitoring data errors. Third, the stress monitoring device is connected to the monitoring sub-station through independent data lines. The data lines need to be hung on the cable hooks on one side of the coal mining equipment and pay out the lines as the equipment moves. When multiple measurement devices need to be densely arranged in the working face, it will cause multiple groups of data lines to be intertwined, easily be squeezed and damaged, and it is difficult to troubleshoot faults. Moreover, the pay-out length of each measurement device needs to be controlled separately, significantly increasing the operation burden.

[0004] Fourth, the four hydraulic cylinders of the measurement device are exposed outside and connected to the hydraulic pump without any protection, and are easily damaged. The hydraulic cylinders and their connecting pipelines are completely exposed to the harsh environment of the gob. Without a protection structure, during the roof caving process, flying gangue is extremely likely to damage the seals or pipelines of the hydraulic cylinders, resulting in the failure of the hydraulic system and seriously reducing the long-term reliability of the measurement device. Summary of the Invention

[0005] To solve the technical problems in the above background art that the measurement device cannot synchronously obtain horizontal extrusion stress or oblique shear stress data and the stress monitoring device is difficult to be horizontal, the present invention provides a gob roof pressure monitoring device and a monitoring method thereof.

[0006] The technical solution of the present invention is as follows: A goaf roof pressure monitoring device includes a measuring unit, a fixing unit capable of fixing it in a reserved groove, and a control unit electrically connected to the measuring unit.

[0007] As the core technical concept of the present invention, the measuring unit includes a housing and a stepping motor capable of adjusting its pose. The housing includes an upper housing and a lower housing. The upper housing includes a horizontal center plate and multiple side inclined plates arranged around its edge facing the upper side outside the housing. Measuring ports with pressure sensors are provided on both the side inclined plates and the center plate.

[0008] Further, the fixing unit includes multiple anchor rods and locking members spirally provided at their upper ends. The stepping motor is a lead screw type stepping motor. A plurality of them are arranged vertically along the edge of the housing, and their lead screw output ends face downward and are connected to the anchor rods through a connecting plate. The connecting plate is arranged horizontally. One end is rotatably connected to the lead screw output end of the stepping motor through a rolling bearing, and the other end is located outside the housing and is provided with a positioning hole with a clearance fit with the anchor rod. The locking member can cooperate with the anchor rod to lock the connecting plate in the reserved groove. A gyroscope sensor communicatively connected to the stepping motor is also provided inside the housing.

[0009] As a preferred embodiment, both the stepping motor and the gyroscope sensor are arranged inside the housing. A cable sheath is also provided on one side of the housing. The signal lines and power lines of the pressure sensor, gyroscope sensor, and stepping motor are led out along the inside of the housing to the cable sheath.

[0010] The above arrangement of both the stepping motor and the gyroscope sensor inside the housing improves the service life of the stepping motor and the gyroscope sensor. And through the setting of the cable sheath, it can effectively prevent the signal lines and power lines from being exposed outside and being damaged by extrusion or being intertwined with soil, stones, etc. This is beneficial for troubleshooting and operation.

[0011] As a preferred embodiment, the detection surface of the pressure sensor passes through the measuring port and is flush with the outer surface of the corresponding center plate or side inclined plate, and the upper housing is a hollow frustum of a pyramid structure.

[0012] Further, multiple support plates are also provided inside the upper housing, which are respectively arranged parallel to the lower sides of the center plate and the four side inclined plates. Each pressure sensor is installed on the support plate corresponding to the center plate or side inclined plate, and the gyroscope sensor is installed on the lower side of the support plate corresponding to the center plate.

[0013] Preferably, the housing is a steel housing, and both the pressure sensor and the gyroscope sensor are installed on the support plate through metal glue.

[0014] To further protect the signal lines and power lines, a plastic hose is also sleeved outside the cable sheath, and the cable sheath is arranged in a snake shape inside the plastic hose.

[0015] As a preferred embodiment, the lower housing is a rectangular box structure, and there are four stepping motors located at the four corners inside the lower housing, and the screw output ends thereof pass through the lower housing and are connected to the connecting plate.

[0016] The present invention also provides a monitoring method using the goaf roof pressure monitoring device described above, including the following steps: S1: Excavate a reserved groove in the floor rock stratum; S2. Pre-fix the measuring unit in the reserved groove; Specifically: S2.1. Place the measuring unit flat at the pre-installation position in the reserved groove; S2.2. Anchor each anchor rod of the fixing unit in the reserved groove through the positioning holes on each connecting plate; S2.3. Install a locking member at the upper end of each anchor rod to pre-lock the corresponding connecting plate at the bottom of the reserved groove; S3. Real-time collect the data of the gyroscope sensor, control the corresponding stepping motor to level the measuring unit, and then adjust the locking member to lock the connecting plate in the reserved groove; S4. Fill the reserved groove around the measuring unit with buffer materials; S5. Lay steel plates above the reserved grooves on both sides of the measuring unit; S6. Real-time collect the data of each pressure sensor and analyze the vertical and horizontal pressure distributions of the roof rock stratum.

[0017] The beneficial effects of the present invention compared with the prior art are as follows: 1. Through the special design of the upper housing structure and the combined action with the pressure sensor, the synchronous monitoring of vertical and horizontal pressures is realized, and multiple inclined side plates are distributed in a surrounding manner, covering different directions, filling the key data gaps in the analysis of the movement law of the caving rock stratum of the roof; 2. Through the closed-loop control system of the stepping motor and the gyroscope sensor, and the coordinated leveling mechanism of the fixing unit and the stepping motor, the housing is easy to adjust and maintain horizontal, thereby improving the accuracy of the monitoring data; 3. Through the setting of the cable sheath, it can effectively prevent each signal wire and power wire from being exposed outside and being damaged by extrusion or being intertwined with mud, stones, etc., which is not only conducive to troubleshooting of the circuit, but also convenient for wiring operation; 4. Both the stepping motor and the gyroscope sensor are arranged inside the housing, which improves the service life of the stepping motor and the gyroscope sensor, and further improves the long-term reliability of the measuring unit. Description of the Drawings

[0018] In the drawings: Figure 1Schematic diagram of the installation of a goaf roof pressure monitoring device in a reserved groove in this embodiment; Figure 2 Internal structure schematic diagram of a goaf roof pressure monitoring device in this embodiment; Figure 3 Usage schematic diagram of a goaf roof pressure monitoring device in this embodiment; Figure 4 is Figure 3 Top view of a goaf roof pressure monitoring device in (hiding the coal mining equipment, rotated 90° to the right); The components represented by each reference numeral in the figure are: 1. Reserved groove; 2. Coal mining equipment; 21. Scraper conveyor; 22. Coal cutter; 23. Fully mechanized mining support; 3. Measuring unit; 31. Housing; 311. Central plate; 312. Side inclined plate; 313. Support plate; 32. Adjusting mechanism; 321. Stepper motor; 322. Gyroscope sensor; 33. Pressure sensor; 34. Connecting plate; 35. Cable sheath; 36. Plastic hose; 37. Thickened bottom plate; 4. Fixing unit; 41. Anchor bolt; 42. Locking nut; 5. Steel plate; 6. Buffer material; 7. Anchor agent. Detailed implementation mode

[0019] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the drawings.

[0020] Embodiment: In combination with Figure 1 and Figure 2 , this embodiment provides a goaf roof pressure monitoring device, including a measuring unit 3, a fixing unit 4 that can fix it in a reserved groove 1 on the floor rock formation, and a control unit electrically connected to the measuring unit 3.

[0021] Specifically, the measuring unit 3 includes a housing 31 and an adjusting mechanism 32 inside it. The adjusting mechanism 32 includes a stepper motor 321 that can adjust the pose of the housing 31. The housing 31 includes an upper housing 31 and a lower housing 31. The upper housing 31 includes a horizontally arranged central plate 311 and multiple side inclined plates 312 that surround the edge of the central plate 311 and face the upper side outside the housing 31.

[0022] Measurement ports are provided on both the side inclined plate 312 and the central plate 311, and pressure sensors 33 are respectively provided corresponding to each measurement port. The detection surface of the pressure sensor 33 passes through the measurement port and is flush with the outer surface of the corresponding central plate 311 or side inclined plate 312.

[0023] Among them, the central plate 311 measures the vertical pressure, and the side inclined plate 312 can decompose the horizontal pressure component of the caving rock stratum of the roof through an inclined angle (such as 45 degrees), realizing the synchronous monitoring of vertical and horizontal pressures. Moreover, multiple side inclined plates 312 are distributed in a surrounding manner, covering different directions, filling the key data missing in the analysis of the movement law of the caving rock stratum of the roof.

[0024] Combined with Figure 2 , the upper housing 31 is a hollow frustum of a pyramid structure.

[0025] Inside the upper housing 31, there are also multiple support plates 313 respectively arranged in parallel under the central plate 311 and the four side inclined plates 312, and each pressure sensor 33 is installed on the support plate 313 corresponding to the central plate 311 or the side inclined plate 312.

[0026] Combined with Figure 1 , the fixing unit 4 includes multiple anchor bolts 41 and locking parts spirally arranged at their upper ends. The stepping motor 321 is a lead screw type stepping motor 321, and multiple are arranged vertically along the edge of the housing 31, and its lead screw output end faces downward and is connected to the anchor bolt 41 through a connecting plate 34.

[0027] The connecting plate 34 is arranged horizontally. One end is rotatably connected to the lead screw output end of the stepping motor 321 through a rolling bearing, and the other end is located outside the housing 31 and is vertically provided with a positioning hole for clearance fit with the anchor bolt 41. The locking part can cooperate with the anchor bolt 41 to lock the connecting plate 34 in the reserved groove 1. The adjusting mechanism 32 also includes a gyroscope sensor 322 arranged inside the housing 31 and communicatively connected to the stepping motor 321.

[0028] In order to reduce the thickness of the connecting plate 34 while meeting the use strength of the connecting plate 34, a thickened bottom plate 37 is fixedly connected to one end of the connecting plate 34 connected to the stepping motor 321, and the lead screw output end of the stepping motor 321 is rotatably connected to the thickened bottom plate 37 through a rolling bearing.

[0029] Among them, the locking part is a locking nut 42. During installation, the locking nut 42 is screwed to fix the connecting plate 34 in the reserved groove 1, and the gyroscope sensor 322 monitors the levelness of the housing 31, controls the lead screw of the stepping motor 321 to adjust the pose of the housing 31, until the leveling of the housing 31 is completed and the locking nut 42 locks the connecting plate 34 in the reserved groove 1, solving the problem of data deviation caused by the inclination of the traditional device during installation.

[0030] The stepping motor 321 and the gyroscope sensor 322 are both arranged inside the housing 31. One side of the housing 31 is also provided with a cable sheath 35, and the signal lines and power lines of the pressure sensor 33, the gyroscope sensor 322 and the stepping motor 321 are led out along the inside of the housing 31 into the cable sheath 35.

[0031] Specifically combined withFigure 2 For the lower housing 31, it is a rectangular box structure, and the top surface of the lower housing 31 coincides with the bottom surface of the upper housing 31.

[0032] The gyroscope sensor 322 is installed on the lower side of the support plate 313 corresponding to the center plate 311.

[0033] There are four stepping motors 321 located at the four corners inside the lower housing 31, and the lead screw output ends thereof pass through the lower housing 31 and are connected to the connecting plate 34.

[0034] The housing 31 is a steel housing 31, and the pressure sensor 33 and the gyroscope sensor 322 are both installed on the support plate 313 by metal glue.

[0035] The arrangement of both the stepping motor 321 and the gyroscope sensor 322 inside the housing 31 improves the service life of the stepping motor 321 and the gyroscope sensor 322. And through the arrangement of the cable sheath 35, it can effectively prevent each signal wire and power wire from being exposed outside and being damaged by extrusion or being intertwined with soil, stones, etc., which is conducive to fault troubleshooting and operation.

[0036] In this embodiment, the cable sheath 35 includes a polyvinyl chloride protective layer and a steel tape armor protective layer arranged from the inside to the outside, and an insulating filler arranged between the polyvinyl chloride protective layer and each signal wire and power wire.

[0037] Combined with Figure 4 , a plastic hose 36 is also sleeved outside the cable sheath 35. Through the double protection of the cable sheath 35 and the plastic hose 36, the impact of falling roof gravel or other damages on each signal wire and power wire is resisted, so as to improve the service life.

[0038] The cable sheath 35 is arranged in a snake shape inside the plastic hose 36 to reserve the length of each signal wire or power wire and avoid pulling and breaking each signal wire or power wire due to the deformation of the rock stratum.

[0039] Combined with Figure 3 , the present invention also provides a monitoring method using the above gob roof pressure monitoring device, including the following steps: S1: Excavate a reserved groove 1 in the floor rock stratum; Specifically, a reserved groove 1 can be cut in the floor rock stratum of the working face by using the coal cutter 22 of the coal mining equipment 2 at the pre-installation position, and the setting direction of the reserved groove 1 is set to be away from the coal mining advancing direction of the coal mining equipment 2, and preferably the setting direction of the reserved groove 1 is perpendicular to the coal mining advancing direction of the coal mining equipment 2; In some cases, after the excavation of the reserved groove 1 is completed, it is also necessary to use tools such as shovels to clean the gravel or sand at the bottom of the reserved groove 1 and roughly level the bottom of the reserved groove 1 with a shovel. S2. Fix the measuring unit 3 preliminarily in the reserved groove 1; Specifically: S2.1. Place the measuring unit 3 flat at the pre-installation position in the reserved groove 1; S2.2. Anchor each anchor rod 41 of the fixing unit 4 in the reserved groove 1 through the positioning holes on each connecting plate 34; S2.3. Install a locking member at the upper end of each anchor rod 41 to preliminarily lock the corresponding connecting plate 34 to the bottom of the reserved groove 1; S3. Collect the data of the gyroscope sensor 322 in real time, control the corresponding stepping motor 321 to level the measuring unit 3, and then adjust the locking member to lock the connecting plate 34 in the reserved groove 1; S4. Fill the reserved groove 1 around the measuring unit 3 with buffer material 6; The buffer material 6 includes crushed stones, fine sand or soil, and after filling, it is compacted, and attention should be paid not to disturb the monitoring device during the compaction process; S5. Lay steel plates 5 above the reserved groove 1 on both sides of the measuring unit 3; Specifically, lay steel plates 5 above the reserved groove 1 on both sides of the measuring unit 3 corresponding to the positions of the foot frames of the fully-mechanized supports 23 of the coal mining equipment 2 to assist the scraper conveyor 21 and the fully-mechanized support 23 to pass through the position of the reserved groove 1. When laying the steel plates 5, attention should be paid to avoiding directly above the installation position of the monitoring device; S6. Collect the data of each pressure sensor 33 in real time and analyze the vertical and horizontal pressure distributions of the roof strata.

[0040] In step 4, before filling the reserved groove 1 around the measuring unit 3 with the buffer material 6, lead out each signal wire and power wire in the housing 31 along the inside of the housing 31 to the cable sheath 35. At the same time, sleeved a plastic hose 36 outside the cable sheath 35, and arrange the cable sheath 35 in a serpentine shape in the plastic hose 36, and then connect it to the underground ring network.

[0041] In some cases, the adjustment range of the stepping motor 321 in step 3 may not be sufficient to cover the inclination of the measuring unit 3. Based on this, step 2.2 specifically includes: Step S2.2.1: After placing the measuring unit 3 flat at the pre-installation position in the reserved groove 1, collect the initial inclination angle of the measuring unit 3 through the gyroscope sensor 322, and compare the initial inclination angle with the preset angle; If the initial inclination angle is greater than the preset angle, then drill a hole along the opposite direction of the initial inclination angle by a preset angle through the positioning hole on the connecting plate 34 for the corresponding anchor rod 41, and anchor the anchor rod 41 in the drilled hole; Step S2.2.2: If the initial inclination angle is less than or equal to the preset angle, drill and anchor the anchor rod 41 vertically through the positioning holes on the connecting plate 34. Among them, the preset angle is determined by the following method: According to the lead screw stroke of each stepping motor 321 and the spacing of each anchor rod 41, calculate the maximum inclination angle at which the measuring unit 3 can be leveled, and add 5° to the maximum inclination angle as the preset angle.

[0042] For example, the initial inclination angle of the measuring unit 3 is 12°, and the preset angle is 10° (determined by adding 5° to the maximum leveling angle of 5°). Execute step S2.2.1: Install the anchor rod 41 at an inclination of 10° in the opposite direction of the inclination (drill to the right if it is inclined to the left), so that the stepping motor 321 only needs to adjust the remaining inclination of 2° subsequently.

[0043] For another example, if the initial inclination angle of the measuring unit 3 is 8° and the preset angle is 10°, then step S2.2.2 is executed, and the anchor rod 41 is directly vertically anchored (such as the anchor rod 41 shown Figure 1 ), and the subsequent stepping motor 321 can fully cover the leveling requirements of the measuring unit 3.

[0044] Among them, the anchor rod 41 is filled and anchored in the drilled hole by the anchoring agent 7, and preferably a resin anchoring agent 7. The fluidity and curing strength of the resin anchoring agent 7 can adapt to the inclined drilling, and the drilling depth is not less than 1 meter to ensure the anti-pulling performance of the anchor rod 41.

Claims

1. A goaf roof pressure monitoring device, characterized in that, It includes a measuring unit (3), a fixing unit (4) capable of fixing it in a reserved groove (1), and a control unit electrically connected to the measuring unit (3); The measuring unit (3) includes a housing (31) and a stepping motor (321) capable of adjusting its position and posture; The housing (31) includes an upper housing (31) and a lower housing (31). The upper housing (31) includes a horizontal center plate (311) and multiple side inclined plates (312) arranged around its edge facing the upper side outside the housing (31). Measuring ports with pressure sensors (33) are provided on both the side inclined plates (312) and the center plate (311); The fixing unit (4) includes multiple anchor rods (41) and locking members spirally arranged at their upper ends. The stepping motor (321) is a lead screw type stepping motor. Multiple are vertically arranged along the edge of the housing (31), and its lead screw output end faces downward and is connected to the anchor rod (41) through a connecting plate (34). The connecting plate (34) is horizontally arranged. One end is rotatably connected to the lead screw output end of the stepping motor (321) through a rolling bearing, and the other end is located outside the housing (31). A positioning hole with a clearance fit with the anchor rod (41) is vertically provided. The locking member can cooperate with the anchor rod (41) to lock the connecting plate (34) in the reserved groove (1); A gyroscope sensor (322) communicatively connected to the stepping motor (321) is also provided inside the housing (31); 2. The gob roof pressure monitoring device according to claim 1, characterized in that, The stepping motor (321) and the gyroscope sensor (322) are both arranged inside the housing (31). A cable sheath (35) is also provided on one side of the housing (31); The signal lines and power lines of the pressure sensor (33), the gyroscope sensor (322), and the stepping motor (321) are all led out along the inside of the housing (31) into the cable sheath (35); 3. The gob roof pressure monitoring device according to claim 1, characterized in that The detection surface of the pressure sensor (33) passes through the measuring port and is flush with the outer surface of the corresponding center plate (311) or side inclined plate (312); 4. The gob roof pressure monitoring device according to claim 1, characterized in that, The upper housing (31) is a hollow frustum of a pyramid structure; 5. The gob roof pressure monitoring device according to claim 4, characterized in that, Multiple support plates (313) respectively parallel to the lower sides of the center plate (311) and the four side inclined plates (312) are also provided inside the upper housing (31); Each pressure sensor (33) is installed on the support plate (313) corresponding to the center plate (311) or the side inclined plate (312); 6. The gob roof pressure monitoring device according to claim 5, wherein, The gyroscope sensor (322) is installed on the lower side of the support plate (313) corresponding to the center plate (311); 7. The gob roof pressure monitoring device according to claim 6, characterized in that, The housing (31) is a steel housing, and the pressure sensor (33) and the gyroscope sensor (322) are both installed on the support plate (313) through metal glue; 8. The gob roof pressure monitoring device according to claim 2, wherein A plastic hose (36) is also sleeved outside the cable sheath (35), and the cable sheath (35) is arranged in a snake shape inside the plastic hose (36); 9. The gob roof pressure monitoring device according to claim 2, characterized in that, The lower housing (31) is a rectangular box structure. Four stepping motors (321) are provided at the four corners inside the lower housing (31), and their lead screw output ends pass through the lower housing (31) and are connected to the connecting plate (34); 10. A monitoring method using the gob roof pressure monitoring device according to any one of claims 1-9, characterized in that, It includes the following steps: S1: Excavate a reserved groove (1) in the floor rock formation; S2. Pre-fix the measuring unit (3) in the reserved groove (1); Specifically: S2.

1. Place the measuring unit (3) flat at the pre-installation position in the reserved groove (1); S2.

2. Anchor each anchor rod (41) of the fixing unit (4) in the reserved groove (1) through the positioning holes on each connecting plate (34); S2.

3. Install a locking member at the upper end of each anchor rod (41) to pre-lock the corresponding connecting plate (34) at the bottom of the reserved groove (1); S3. Collect the data of the gyroscope sensor (322) in real time, control the corresponding stepping motor (321) to level the measuring unit (3), and then adjust the locking member to lock the connecting plate (34) in the reserved groove (1); S4. Fill the reserved groove (1) around the measuring unit (3) with buffer material (6); S5. Lay steel plates (5) above the reserved groove (1) on both sides of the measuring unit (3); S6. Collect the data of each pressure sensor (33) in real time and analyze the vertical and horizontal pressure distributions of the roof rock stratum.

Images