Drill hole stress meter based on square drill hole and drill bit

Abstract

The utility model relates to a drill hole stress meter based on a square drill hole and a drill bit, and belongs to the technical field of coal stress monitoring. The borehole stress meter comprises a square-column-shaped pressure-bearing seat, a first oil bag and a second oil bag are installed on the side face and the top face of the pressure-bearing seat respectively, a first pressure-bearing plate is installed on the upper side of the first oil bag, and a second pressure-bearing plate is installed on the outer side face of the second oil bag. According to the borehole stress meter designed by the utility model, the square-column-shaped pressure-bearing seat and the square drill hole are designed, so that the stress meter can be ensured to be in a horizontal state during installation, and the accuracy of monitoring stress change can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of mine rock mass stress monitoring, in particular to a drilling stress meter based on a square drilling hole and a matching drilling drill bit. Background Art

[0002] Rock burst is a dynamic phenomenon characterized by sudden, sharp, and violent destruction of coal and rock masses around mine shafts and mining areas due to the release of deformation energy. It is essentially caused by the sudden release of a large amount of elastic energy. In recent years, with the exhaustion of shallow coal resources, the depth of deep mining (underground mining with a depth greater than 600m) has continued to increase, the mine pressure has intensified, and disasters such as rock burst have occurred frequently. And with the continuous increase in mining depth, this disaster has become more and more serious. Rock burst has become one of the most serious dynamic disasters faced by coal mines.

[0003] The rock burst problem is essentially a stress problem of the coal rock mass. Therefore, for rock burst monitoring, "stress" is the most reliable physical quantity. The borehole stress gauge is currently the most widely used stress monitoring device. Existing borehole stress gauges are mostly oil pressure stress gauges based on circular boreholes. Due to the depth of the borehole, it is difficult to ensure a flat installation during the installation process. At the same time, when the stress gauge is installed in place, the pressure clamp of the stress gauge will be offset and rotated during the pressure replenishment and oil filling process, causing the oil bag to lose its restraint, affecting the monitoring and analysis of the vertical stress of the coal body, resulting in low measurement accuracy and sensitivity of the stress gauge. Moreover, once the oil bag is crushed during use, it will lose its function and can only be re-drilled and installed. In view of the above shortcomings, the present application aims to propose a stress gauge based on a square borehole and a corresponding matching drilling drill bit. Summary of the invention

[0004] In order to solve the problems in the prior art, this utility model patent designs a drilling stress gauge and a drilling drill bit based on square drilling holes to solve the problem that the existing drilling stress gauge is difficult to ensure horizontal installation affecting the measurement accuracy and the stress gauge fails due to oil bag explosion during use.

[0005] The technical solution adopted by the utility model is: the drilling stress gauge includes a square columnar pressure-bearing seat, the top surface and the side surface of the pressure-bearing seat are respectively installed with a first oil bag and a second oil bag, the upper side of the first oil bag is installed with a first pressure plate, and the outer side surface of the second oil bag is installed with a second pressure plate.

[0006] Furthermore, strain gauges are embedded and installed along the center line on the outer side surfaces of the first pressure-bearing plate and the second pressure-bearing plate, and the strain gauge signals are connected to the drilling stress sensor of the drilling stress gauge.

[0007] Furthermore, a strain gauge is also embedded on the front end surface of the pressure bearing seat, and the signal is connected to the drilling stress sensor.

[0008] Furthermore, the outer side surfaces of the first pressure-bearing plate and the second pressure-bearing plate are both planes and are parallel to the top surface and the side surfaces of the pressure-bearing seat respectively. The top surface and one side surface of the pressure-bearing seat are respectively provided with arc-shaped grooves. The first oil bag and the second oil bag are respectively tightly fitted and fixed in their corresponding grooves. The inner side surfaces of the first pressure-bearing plate and the second pressure-bearing plate are also respectively provided with arc-shaped grooves and are respectively tightly fitted and fixed to the first oil bag and the second oil bag.

[0009] The utility model patent also provides a drilling drill bit for installing a drilling stress gauge based on a square drilling hole as described above, wherein the drilling drill bit includes a square hole drill bit, the shape of the square hole drill bit is a Lello triangle shape, and the rear end of the square hole drill bit is connected to a drill rod, and the drill rod is a universal coupling.

[0010] Compared with the prior art, the advancement of the borehole stress gauge based on square boreholes designed by the utility model patent lies in: first, the application of the borehole stress gauge of the utility model is based on square boreholes, and the stress concentration coefficient of square boreholes is greater than that of circular holes. By changing the stress concentration coefficient of the boreholes, the monitoring accuracy and sensitivity of the stress gauge are enhanced; secondly, the borehole stress adopts a square columnar pressure-bearing seat, so that the stress gauge does not have the problem of being unable to be installed flat due to improper operation during installation, so that the stress gauge can accurately monitor the vertical stress changes from the vertical and horizontal directions when used, and ensure the accuracy of the monitoring results; in addition, because the cross-sectional shape of the borehole is a regular square, oil bags are set on the top and side surfaces of the borehole stress gauge, and strain gauges are set on the end surface, so that the monitoring direction of the stress gauge is extended from the traditional unidirectional stress monitoring in the vertical direction to the three-directional stress monitoring in the vertical, horizontal and axial directions; finally, strain gauges are embedded on the outer surface of the pressure plate of the borehole stress gauge. Even if the oil bag is burst by stress during use, the strain gauge can still play a monitoring role to ensure the continuous and effective monitoring of the borehole stress gauge. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the split structure of the borehole stress gauge based on a square drilled hole.

[0012] Figure 2 It is a schematic diagram of the side view split structure of the borehole stress gauge based on square drilled holes.

[0013] Figure 3 This is a schematic diagram of the application of a borehole strain gauge based on a square drilled hole.

[0014] Figure 4 It is a schematic diagram of the front view structure of the drilling drill bit.

[0015] Figure 5It is a schematic diagram of the side view structure of a drilling drill bit.

[0016] In the figure, 1 is a pressure seat, 2 is a first oil bag, 3 is a second oil bag, 4 is a first pressure plate, 5 is a second pressure plate, 6 is an oil pipe, 7 is a groove, 8 is a strain gauge, 10 is a square hole, 11 is a drilling stress gauge, 12 is an oil delivery steel pipe, 13 is a one-way manual pump, 14 is a drilling stress sensor, 15 is a three-way valve, 16 is a rock mass, 21 is a square hole drill bit, and 22 is a drill rod. DETAILED DESCRIPTION

[0017] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments. The technical solutions in the embodiments of the utility model are clearly and completely described, and the described embodiments are only embodiments of a part of the invention, not all of it. Based on the embodiments in the invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the invention. Example 1

[0018] like Figure 1-3 As shown, the utility model patent designs an embodiment of a drilling stress gauge based on a square drilled hole. In this embodiment, the drilling stress gauge includes a square columnar pressure seat 1, and the top surface and the right side surface of the pressure seat 1 are respectively installed with a first oil bag 2 and a second oil bag 3, a first pressure plate 4 is installed on the upper side of the first oil bag 2, and a second pressure plate 5 is installed on the outer side of the second oil bag 3. The rear ends of the first oil bag 2 and the second oil bag 3 are both connected with oil pipes 6, and the oil pipes 6 are connected to the drilling stress sensor 14 through the oil delivery steel pipe 12. Two groups of oil pressure sensors are arranged on the drilling stress sensor 14, which are used to monitor the pressure changes of the first oil bag 2 and the second oil bag 3, respectively. The two groups of oil pressure sensors are respectively provided with three-way valves 15 connected to the oil delivery steel pipe 12 and the one-way manual pump 13.

[0019] The top surface and right side surface of the pressure seat 1 are respectively provided with arc-shaped grooves 7 along the length direction, and the first oil bag 2 and the second oil bag 3 are respectively tightly fitted and fixed in the corresponding grooves 7. The inner side surfaces of the first pressure plate 4 and the second pressure plate 5 are also respectively provided with arc-shaped grooves 7 along the length direction, and are respectively tightly fitted with the first oil bag 2 and the second oil bag 3. The outer side surfaces of the first pressure plate 4 and the second pressure plate 5 are both planes, and grooves are respectively provided on the outer side surfaces of the two along the center line of the length direction, and strain gauges 8 are respectively embedded in the grooves. In addition, the front end surface of the pressure seat 1 is also grooved and embedded with strain gauges 8. The three groups of strain gauges 8 are respectively connected to the signal transmitter of the drilling stress sensor 14 through signal cables. When assembling the first pressure plate 4 and the second pressure plate 5, it is necessary to ensure that their plate surfaces are parallel to the top surface and the right side surface of the pressure seat 1 respectively, and then use steel wire ropes to bundle and fix them near the two ends. The steel wire ropes are arranged along the bundling grooves on the pressure column and the two pressure plates, and do not exceed the outer planes of the pressure column and the pressure plates, and are sealed into a whole with black heat shrink adhesive. Example 2

[0020] like Figure 3 , 4 As shown, the utility model patent designs an embodiment of a matching punching drill bit for the installation of the above-mentioned drilling stress gauge. In this embodiment, the punching drill bit includes a square hole drill bit 21, and the shape of the square hole drill bit 21 is a Lello triangle. The Lello triangle, also known as an equal-width curve, is a special geometric shape characterized in that its width remains unchanged in any direction. The unique properties of this shape enable it to be used to manufacture special drill bits that can drill square holes. The working principle of the Lello triangle drill bit is based on its fixed width curve characteristics. When the drill bit rotates, its motion trajectory forms a square, thereby drilling a square hole in the material. The rear end of the square hole drill bit 21 is connected to a drill rod 22, which is a universal coupling.

[0021] When the borehole stress gauge based on the square borehole disclosed in the utility model patent is used, the square borehole 10 is first opened at the monitoring point selected on the tunnel rock mass 16 using the drilling drill bit provided in Example 2. To facilitate the placement of the borehole stress gauge 11, the size of the square borehole 10 is slightly larger than the borehole stress gauge 11. Then, a push rod is used to push the borehole stress gauge 11 to the bottom of the square borehole 10, and then a one-way manual pump 13 is used to pressurize the two oil bags respectively, so that the two pressure plates are tightly fitted with the inner walls of the square borehole 10 respectively.

[0022] The above contents are only preferred embodiments of the present invention and cannot be used to limit the scope of implementation of the present invention. That is, any simple equivalent changes and modifications made according to the claims and description of the present invention are still within the scope of the present invention.

Claims

1. A borehole stress gauge based on a square borehole, characterized in that: The drilling stress gauge includes a square columnar pressure seat, the top surface and side surface of the pressure seat are respectively installed with a first oil bag and a second oil bag, the upper side of the first oil bag is installed with a first pressure plate, and the outer side surface of the second oil bag is installed with a second pressure plate.

2. A drilling stress gauge based on a square drilled hole according to claim 1, characterized in that: Strain gauges are embedded and installed along the center line on the outer side surfaces of the first pressure-bearing plate and the second pressure-bearing plate, and the strain gauge signals are connected to the drilling stress sensor of the drilling stress gauge.

3. A drilling stress gauge based on a square drilled hole according to claim 2, characterized in that: A strain gauge is also embedded on the front end surface of the pressure bearing seat, and is connected to the drilling stress sensor by signal.

4. A drilling stress gauge based on a square drilling hole according to claim 3, characterized in that: The outer side surfaces of the first pressure-bearing plate and the second pressure-bearing plate are both planes and are parallel to the top surface and the side surfaces of the pressure-bearing seat respectively.

5. A drilling stress gauge based on a square drilling hole according to claim 4, characterized in that: The top surface and one side surface of the pressure-bearing seat are respectively provided with arc-shaped grooves, and the first oil bag and the second oil bag are respectively tightly fitted and fixed in their respective grooves. The inner side surfaces of the first pressure-bearing plate and the second pressure-bearing plate are also respectively provided with arc-shaped grooves, which are respectively tightly fitted and fixed to the first oil bag and the second oil bag.

6. A drilling drill bit for installing a drilling stress gauge based on a square drilling hole as claimed in claim 5, characterized in that: The punching drill bit comprises a square hole drill bit, the outer shape of the square hole drill bit is a Lello triangle shape, the rear end of the square hole drill bit is connected to a drill rod, and the drill rod is a universal coupling.

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