阅读说明：本技术 地壳钻孔体积式应变仪 (Earth crust drilling volume type strain gauge ) 是由 李海亮 马京杰 于 2020-05-08 设计创作，主要内容包括：本发明公开了一种地壳钻孔体积式应变仪,设于地下钻孔内,感受腔(7)内设两个以上的MEMS压力传感器(12),MEMS压力传感器(12)固定于金属柱芯(8)或隔板(11)的下表面上；所述的测量腔(5)上顶部设有独立的顶腔(13),顶腔(13)内设电路模块(14),MEMS压力传感器(12)的连接线穿过隔板(11)与测量腔(5)顶板(16)绝缘连接电路模块(14),电路模块(14)通过外接电缆(15)与地面电子线路连接。压力传感器采用MEMS数字芯片,精度高,功耗小,有效地解决了传统工艺在膜片破裂后上下腔导通的技术难题,延长了应变仪的使用寿命,无需多次频繁的维修,节约人力成本,体积小,安装简单。(The invention discloses a ground shell borehole volume type strain gauge which is arranged in an underground borehole, wherein more than two MEMS pressure sensors (12) are arranged in a sensing cavity (7), and the MEMS pressure sensors (12) are fixed on the lower surface of a metal column core (8) or a partition plate (11); the measuring cavity (5) is provided with an independent top cavity (13) at the top, a circuit module (14) is arranged in the top cavity (13), a connecting line of the MEMS pressure sensor (12) penetrates through the partition plate (11) and is connected with the circuit module (14) in an insulation mode with a top plate (16) of the measuring cavity (5), and the circuit module (14) is connected with a ground electronic circuit through an external cable (15). The pressure sensor adopts the MEMS digital chip, has high precision and low power consumption, effectively solves the technical problem of the conduction of the upper cavity and the lower cavity after the diaphragm is broken in the traditional process, prolongs the service life of the strain gauge, does not need frequent maintenance, saves the labor cost, and has small volume and simple installation.)

1. The utility model provides a ground shell bores pore volume formula strain gauge, locates in the underground borehole, its characterized in that: the measuring device comprises a cylinder body (10), wherein a partition plate (11) is arranged in the cylinder body (10) to divide the cylinder body (10) into an upper cavity and a lower cavity, the upper cavity is a measuring cavity (5), and the lower cavity is a sensing cavity (7); a metal column core (8) is arranged in the sensing cavity (7), and silicone oil (9) is filled in the sensing cavity (7); the lower part of the measuring cavity (5) is filled with silicon oil (9), and the upper part of the measuring cavity is filled with argon (2); the partition plate (11) is provided with an electromagnetic valve (4) which is used for communicating or sealing a silicone oil passage between the measuring cavity (5) and the sensing cavity (7);

more than two MEMS pressure sensors (12) are arranged in the sensing cavity (7), and the MEMS pressure sensors (12) are fixed on the lower surface of the metal column core (8) or the partition plate (11);

the measuring cavity (5) is provided with an independent top cavity (13) at the top, a circuit module (14) is arranged in the top cavity (13), a connecting line of the MEMS pressure sensor (12) penetrates through the partition plate (11) and is connected with the circuit module (14) in an insulation mode with a top plate (16) of the measuring cavity (5), and the circuit module (14) is connected with a ground electronic circuit through an external cable (15).

2. The earth borehole volumetric strain gauge according to claim 1, wherein the MEMS pressure sensor (12) comprises two, three, four, five or six.

3. The earth boring volumetric strain gauge according to claim 1 or 2, characterized in that the MEMS pressure sensors (12) are each connected independently using mutually independent shielded wires as connecting wires.

4. The earth crust drilling volumetric strain gauge according to claim 1 or 2, characterized in that a resistance wire (6) is arranged in the sensing cavity (7), and a connecting wire of the resistance wire (6) passes through the partition plate (11) and is connected with an external cable (15) in an insulated manner with a top plate (16) of the measuring cavity (5).

5. A crustal drilling volumetric strain gauge according to claim 1 or 2, characterized in that said cylindrical body (10) is provided at its lower end with a lower cone (17).

Technical Field

The invention relates to the technical field of mechanical and electronic measurement structures, in particular to a ground shell drilling volume type strain gauge applied to the field of borehole body strain observation such as earthquake precursor strain observation, mine and other engineering measurement.

Background

At present, a probe of a crustal drilling strain observation instrument is generally placed in bedrock of a crustal with a depth of tens of meters in a drill hole, and the strain change of the surface layer of the crustal is observed. The observation object includes: and (4) bulk strain. The observation principle of the volume type strain gauge for drilling the crust is as follows: when the deformable container containing the incompressible liquid is subjected to a change in pressure, the level of the liquid at the upward outlet changes accordingly. At present, a body strain observation instrument used for a borehole strain observation platform network.

As shown in fig. 1, the conventional earth crust drilling volume type strain gauge structurally comprises an oblong cylinder, a partition plate is arranged in the middle of the oblong cylinder to divide the upper chamber into a measuring chamber 5 and a sensing chamber 7, a metal column core 8 is arranged in the sensing chamber 7, silicone oil 9 is filled in the sensing chamber 7, and a pressure sensor 3 and an electromagnetic valve 4 are arranged in the measuring chamber and filled with the silicone oil 9 and argon 2. The pressure sensor 3 and the electromagnetic valve 4 are connected with an external cable, and the external cable extends out through the end cap 1 to be connected with a ground electronic circuit. The pressure P of the measuring chamber 5 is measured due to the presence of argon 2₀Substantially constant, but with the sensing chamber 7, the pressure P of the silicone oil 9 being such that the volume of the chamber varies slightly as a result of the external force₁I.e. a significant change will occur. The pressure sensor 3 is used for sensing the difference between the pressures of the measuring chamber 5 and the sensing chamber 7, namely P₁-P₀But actually P₀Is substantially unchanged (P is produced already₀Set to one atmosphere, i.e., about 0.1MPa), the information reflected by the pressure sensor 3 is only the pressure change of the sensing chamber 7. The electrical output e of the pressure sensor 3 is proportional to the volumetric strain Δ V1/V1 of the long cylinder. Two pressure sensors 3 are typically employed, with the intention that one is damaged and the other activated.

The solenoid valve 4, which can be opened when it is energized, communicates the measurement chamber 5 with the sensing chamber 7, the pressure difference between the two chambers becomes zero, P₁＝P₀And due to P₀Is a constant standard pressure (one atmosphere), so that the pressure of the silicon oil 9 in the sensing cavity 7 can be restored to the original standard pressure when the electromagnetic valve 4 is opened. When the solenoid valve 4 is opened, the silicone oil 9 in a liquid state may be in a small amount (e.g., 0.003 cm)³Magnitude) for only about 0.2s, so that the solenoid valve 4 is closed (de-energized) for the majority of the time.

When the body strain of the bedrock of the crust of the earth changes to 6 × 10^-6In the magnitude range, the ground electronic circuit can automatically open the electromagnetic valve 4 once to restore the working point of the pressure sensor 3 to the zero position (P)₁≈P₀The zero output of the electronic circuit is close to 0V).

The working principle is as follows: the structure is that an oblong elastic cylinder is filled with silicon oil, when the elastic cylinder is extruded or stretched by surrounding rocks, the pressure of the silicon oil liquid in the cylinder is changed, and the strain state of the rocks can be known to be compression or stretching through the increase or decrease of the hydraulic pressure. When the voltage is increased towards the positive direction, the curve is compressed, namely the positive pressure is changed upwards; when the voltage value changes towards the negative direction, the curve is stretched, namely the negative direction is tensile, and the curve changes downwards.

Disclosure of Invention

The invention aims to provide a ground shell drill hole volume type strain gauge, which prolongs the service life of the strain gauge, does not need frequent maintenance for many times, saves the labor cost, and has small volume and simple installation.

The purpose of the invention is realized by the following technical scheme:

a kind of crust bores the pore type strain gauge, locate in underground bore hole, including the cylinder 10, the inner baffle 11 of cylinder 10 divides cylinder 10 into upper chamber and lower chamber, the upper chamber is the measuring chamber 5, the lower chamber is the feeling chamber 7; a metal column core 8 is arranged in the sensing cavity 7, and the sensing cavity 7 is filled with silicon oil 9; the lower part of the measuring cavity 5 is filled with silicon oil 9, and the upper part is filled with argon 2; the partition plate 11 is provided with an electromagnetic valve 4 which is used for communicating or sealing a silicone oil passage between the measuring cavity 5 and the sensing cavity 7;

more than two MEMS pressure sensors 12 are arranged in the sensing cavity 7, and the MEMS pressure sensors 12 are fixed on the lower surface of the metal column core 8 or the partition plate 11;

an independent top cavity 13 is arranged at the top of the measuring cavity 5, a circuit module 14 is arranged in the top cavity 13, a connecting wire of the MEMS pressure sensor 12 penetrates through the partition plate 11 and is connected with a top plate 16 of the measuring cavity 5 in an insulating mode to be connected with the circuit module 14, and the circuit module 14 is connected with a ground electronic circuit through an external cable 15.

The MEMS pressure sensor 12 may include two, three, four, five, or six.

The MEMS pressure sensors 12 each use a mutually independent shielding line as a connection line, and are connected independently.

And a resistance wire 6 is arranged in the sensing cavity 7, and a connecting wire of the resistance wire 6 penetrates through the partition plate 11 and is connected with a top plate 16 of the measuring cavity 5 in an insulated manner to form an external cable 15.

The lower end of the cylinder body 10 is provided with a lower cone 17.

According to the technical scheme provided by the invention, the plurality of MEMS pressure sensors are installed on the ground auger pore volume type strain gauge provided by the embodiment of the invention, and the pressure sensors adopt MEMS digital chips, so that the precision is high, the power consumption is low, the technical problem of conducting the upper cavity and the lower cavity after the diaphragm is broken in the traditional process is effectively solved, the service life of the strain gauge is prolonged, frequent maintenance is not needed for many times, the labor cost is saved, the size is small, and the installation is simple.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a prior art earth boring volumetric strain gauge;

fig. 2 is a schematic structural diagram of a volume strain gauge for earth boring according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.