A pressure chamber for rock mechanics testing

Abstract

The application provides a pressure chamber for rock mechanics testing, and relates to the technical field of rock mechanics experimental equipment.The pressure chamber for rock mechanics testing comprises a protective outer cylinder, one end of which is a closed end and the other end is an open end; a pressurizing inner cylinder coaxially arranged in the protective outer cylinder and in sealed sliding fit with the protective outer cylinder, the pressurizing inner cylinder having an axially-through pressurizing cavity, one end of the pressurizing inner cylinder being in abutment with the closed end, and an end face sealing device being arranged between the closed end and the end face of the pressurizing inner cylinder; a pressurizing pull rod comprising a pressurizing protective head and a first lifting mechanism, the pressurizing protective head being arranged in sealed sliding fit in the pressurizing cavity, the first lifting mechanism being connected with the pressurizing protective head and driving the pressurizing protective head to reciprocate along the axis of the pressurizing inner cylinder; and a second lifting mechanism connected with the pressurizing inner cylinder and the protective outer cylinder and driving the pressurizing inner cylinder to reciprocate along the axis of the protective outer cylinder. The pressure chamber for rock mechanics testing can be conveniently opened and closed while having good sealing effect.

Description

Technical Field

[0001] This invention relates to the field of rock mechanics experimental equipment technology, and in particular to a pressure chamber for rock mechanics testing. Background Technology

[0002] Triaxial rock mechanics testing is an experimental method used to study the mechanical properties of rocks under various environments. Through triaxial rock mechanics testing, engineers can obtain key parameters of rocks under different confining pressures, such as compressive strength, shear strength, elastic modulus, and Poisson's ratio. These parameters are crucial foundational data for fracturing design. Triaxial testing also allows engineers to gain a more accurate understanding of the mechanical properties of rocks, providing a scientific basis for fracturing design. Particularly for deep rocks under complex stress states, triaxial rock mechanics testing can simulate the mechanical properties of rocks under such complex stress states, making the experimental results closer to reality and improving the accuracy of fracturing design.

[0003] When conducting triaxial rock mechanics tests, it is necessary to simulate the high temperature and high pressure environment underground. Therefore, the pressure chamber used to place the rock needs to be easy to open and close while having a good sealing effect. However, after too many opening and closing cycles, traditional box-type pressure chambers will develop sealing gaps, leading to pressure leakage problems during testing.

[0004] For example, Chinese patent CN117110065A discloses a triaxial pressure chamber for cyclic load creep testing. The bottom of the confining pressure chamber is connected and sealed to a base, with a portion of the upper part of the base embedded within the confining pressure chamber. To prevent pressure leakage, an annular sealing ring is installed in the embedded portion to seal the confining pressure chamber, making it a sealed cavity. Simultaneously, the pressure chamber body and the base are tightly fixed together using quick-clamping clamps. After applying confining pressure, the pressure chamber body and the base may tend to detach; the quick-clamping clamps can fix them and withstand the tensile force generated by the pressure chamber body and the base. In the above-mentioned triaxial pressure chamber, a sealing ring is still used to achieve confining pressure sealing. After repeated closing and lifting over a long period, the sealing ring is very prone to deformation, thus losing its seal and potentially leaking pressure. Especially for applications requiring ultra-high pressure, the equipment structure is no longer sufficient to meet the experimental pressure requirements.

[0005] Another Chinese patent, CN109752252A, proposes a sealing device for a high confining pressure chamber of a triaxial apparatus. This device comprises a fixed base plate, a fixed top plate, a cylindrical plexiglass ring, and a shaped rubber ring to form a sealed pressure chamber, providing controllable confining pressure. The shaped rubber ring is added as the pressure increases to ensure a tight seal. However, the sealing performance of the gasket deteriorates rapidly with repeated use, rendering it unsuitable for ultra-high temperature and ultra-high pressure rock mechanics experiments due to its inability to meet the safety and usability requirements.

[0006] In view of this, based on years of experience in production and design in this and related fields, the inventor has designed a pressure chamber for rock mechanics testing through repeated experiments, in order to solve the problems existing in the prior art. Summary of the Invention

[0007] The purpose of this invention is to provide a pressure chamber for rock mechanics testing that is easy to open and close while having a good sealing effect.

[0008] To achieve the above objectives, the present invention proposes a pressure chamber for rock mechanics testing, wherein the pressure chamber for rock mechanics testing comprises:

[0009] The protective outer cylinder has a closed end and an open end;

[0010] A pressure inner cylinder is coaxially inserted inside the protective outer cylinder and is in a sealing sliding fit with the protective outer cylinder. The pressure inner cylinder has an axially penetrating pressure cavity. One end of the pressure inner cylinder abuts against the closed end, and an end face sealing device is provided between the closed end and the end face of the pressure inner cylinder.

[0011] A pressure rod includes a pressure protection head and a first lifting mechanism. The pressure protection head is slidably and sealed within the pressure chamber. The first lifting mechanism is connected to the pressure protection head and drives the pressure protection head to reciprocate along the axis of the pressure inner cylinder.

[0012] The second lifting mechanism connects the pressurized inner cylinder and the protective outer cylinder and drives the pressurized inner cylinder to reciprocate along the axis of the protective outer cylinder.

[0013] Compared with the prior art, the present invention has the following features and advantages:

[0014] The pressure chamber for rock mechanics testing proposed in this invention features a superimposed sleeve structure formed by the sealed cooperation of the pressurized inner cylinder and the protective outer cylinder. Compared to a single-layer structure, this superimposed sleeve structure better ensures the airtightness of the pressure chamber, avoids pressure leakage, and facilitates improved accuracy of rock pressure and high-temperature resistance test data. Furthermore, the end-face sealing device located between the closed end and the end face of the pressurized inner cylinder further reduces the possibility of pressure leakage through gaps, enabling the pressure chamber to withstand higher pressures.

[0015] The pressure chamber for rock mechanics testing proposed in this invention allows for sample retrieval by a second lifting mechanism that drives the inner pressure cylinder outward, separating it from the outer protective cylinder. During this process, the inner pressure cylinder separates entirely from the outer protective cylinder, ensuring the seal between the inner pressure cylinder and the protective head remains unaffected. This further prevents pressure leakage and improves the accuracy of rock pressure and high-temperature resistance test data. Attached Figure Description

[0016] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.

[0017] Figure 1 This is a schematic diagram of the right front axial view of the pressure chamber for rock mechanics testing proposed in this invention;

[0018] Figure 2 This is a schematic diagram of the overall disassembled structure of the pressure chamber for rock mechanics testing proposed in this invention;

[0019] Figure 3 This is a schematic diagram of the cross-sectional structure of the protective outer cylinder and the pressurized inner cylinder of the pressure chamber for rock mechanics testing proposed in this invention.

[0020] Figure 4 yes Figure 3 Enlarged structural diagram at point A in the middle;

[0021] Figure 5 This is a schematic diagram showing the disassembled structure of the pressure rod and the second lifting mechanism in this invention;

[0022] Figure 6 This is a cross-sectional view of the pressure tie rod in this invention;

[0023] Figure 7 This is an assembly diagram of the pressure-pressurizing tie rod, the pressure-pressurizing inner cylinder, and the protective outer cylinder of the present invention;

[0024] Figure 8 This is a schematic diagram of the top cross-sectional structure of the pressurized inner cylinder in this invention.

[0025] Explanation of reference numerals in the attached figures

[0026] 100. Pressure chamber; 1. Protective outer cylinder; 101. Fixed base; 102. Annular groove; 103. Rock placement seat; 2. Elastic sealing gasket; 3. Second lifting mechanism; 4. Pressurized inner cylinder; 401. Annular protrusion; 402. Inner ring boss; 403. Heating chamber hole; 404. Inner ring stop; 405. Fixed top plate; 406. Rotary shaft limit seat; 5. Pressurized pull rod; 501. Pressurized protective head; 502. Air pressure connecting pipe; 503. Temperature and pressure monitoring gauge; 504. Lifting control tooth groove; 505. Fixed top ring; 6. Drive motor; 601. Spinning drill bit; 7. Lifting motor; 701. Drive worm gear; 8. Lifting control worm wheel. Detailed Implementation

[0027] The details of the present invention can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, and these should all be considered to fall within the scope of the invention.

[0028] like Figure 1 As shown, the present invention proposes a pressure chamber 100 for rock mechanics testing. The pressure chamber 100 for rock mechanics testing includes a protective outer cylinder 1, a pressure inner cylinder 4, a pressure rod 5, and a second lifting mechanism 3. One end of the protective outer cylinder 1 is a closed end, and the other end of the protective outer cylinder 1 is an open end. The pressure inner cylinder 4 is coaxially inserted inside the protective outer cylinder 1 and slides in cooperation with the protective outer cylinder 1. The pressure inner cylinder 4 has an axially penetrating pressure cavity. One end of the pressure inner cylinder 4 abuts against the closed end, and an end face sealing device is provided between the closed end and the end face of the pressure inner cylinder 4. The pressure rod 5 includes a pressure protective head 501 and a first lifting mechanism. The pressure protective head 501 is slidably disposed in the pressure cavity. The first lifting mechanism is connected to the pressure protective head 501 and drives the pressure protective head 501 to reciprocate along the axis of the pressure inner cylinder. The second lifting mechanism connects the pressure inner cylinder 4 and the protective outer cylinder 1 and drives the pressure inner cylinder 4 to reciprocate along the axis of the protective outer cylinder 1.

[0029] The pressure chamber 100 for rock mechanics testing proposed in this invention features a superimposed sleeve structure formed by the sealed cooperation of the pressurized inner cylinder 4 and the protective outer cylinder 1. Compared to a single-layer structure, the superimposed sleeve structure better ensures the sealing performance of the pressure chamber 100, avoids pressure leakage problems, and facilitates improved accuracy of rock pressure and high-temperature resistance test data. Furthermore, the end-face sealing device located between the closed end and the end face of the pressurized inner cylinder 4 further reduces the possibility of pressure leakage through gaps, enabling the pressure chamber 100 to withstand higher pressures and making it feasible to conduct mechanical testing on rocks under ultra-high temperature and ultra-high pressure environments.

[0030] The pressure chamber 100 for rock mechanics testing proposed in this invention allows for the separation of the inner pressure cylinder 4 from the outer protective cylinder 1 by moving the inner pressure cylinder 4 outward through a second lifting mechanism when it is necessary to open the pressure chamber 100 for rock sample loading or unloading. During this process, the inner pressure cylinder 4 is completely separated from the outer protective cylinder 1, and the sealing performance between the inner pressure cylinder 4 and the pressure protective head 501 remains unaffected, further preventing pressure leakage in the pressure chamber 100 and improving the accuracy of rock pressure and high temperature resistance test data.

[0031] In an optional embodiment of the present invention, the end-face sealing device has at least one first sealing structure, which includes an annular groove 102 and an annular protrusion 401. The annular groove 102 is formed on the inner end face of the closed end, and the annular protrusion 401 is disposed on the end face of the pressurized inner cylinder 4. The annular protrusion 401 can be embedded in the annular groove 102 and seal the annular groove 102. With the above structure, after the pressurized inner cylinder 4 is inserted into the protective outer cylinder 1, the annular protrusion 401 located on the end face of the pressurized inner cylinder 4 is aligned and inserted into the annular groove 102. Through the sealing cooperation between the outer wall of the annular protrusion 401 and the inner wall of the annular groove 102, the annular groove 102 is sealed, thereby achieving the sealing of the pressurized cavity.

[0032] In an optional example of this embodiment, the inner wall surface of the annular groove 102 is an arc surface, and the inner wall surface of the annular protrusion 401 is also an arc surface, which further facilitates the sealing between the annular groove 102 and the annular protrusion 401.

[0033] In an optional example of this embodiment, the end face sealing device also has a second sealing structure, which includes a matching elastic sealing gasket 2 and an inner ring boss 402. The elastic sealing gasket 2 is disposed on the inner end face of the closed end. The inner wall of the end of the pressurized inner cylinder 4 protrudes inward to form the inner ring boss 402. The inner ring boss 402 can press against the elastic sealing gasket 2, further reducing the possibility of pressure leakage from the gap, so that the pressure chamber 100 can withstand higher pressure.

[0034] In an optional embodiment, a rock placement seat 103 for placing a rock sample is provided on the inner end face of the closed end, and the elastic sealing gasket 2 is annular and embedded between the rock placement seat 103 and the annular groove 102. With the above structure, the rock placement seat 103 plays a limiting role for the elastic sealing gasket 2, preventing the sealing performance from being affected by the displacement of the elastic sealing gasket 2.

[0035] In one alternative example, the top of the rock placement seat 103 is curved to facilitate the placement of the rock sample.

[0036] In an optional embodiment of the present invention, a fixed top plate 405 is provided at the other end of the pressurized inner cylinder 4. The fixed top plate 405 is arranged radially along the pressurized inner cylinder 4, and both ends of the fixed top plate 405 protrude out of the protective outer cylinder 1 respectively. The first lifting mechanism and the second lifting mechanism are respectively arranged on the fixed top plate 405.

[0037] In an optional embodiment, the protective outer cylinder 1 is provided with two fixed bases 101. The two fixed bases 101 are symmetrically arranged on the outer wall of the closed end and are aligned with the fixed top plate 405. The second lifting mechanism includes two lifting cylinders, which are symmetrically arranged on both sides of the protective outer cylinder 1. One end of each lifting cylinder is fixed to the fixed base 101, and the other end of each lifting cylinder is fixed to the fixed top plate 405. The second lifting mechanism can control the position of the pressurized inner cylinder 4 and the protective outer cylinder 1, thereby fitting the pressurized inner cylinder 4 into the protective outer cylinder 1. The cooperation between the pressurized inner cylinder 4 and the protective outer cylinder 1 forms an overlapping sleeve structure, which can better ensure the sealing of the pressure chamber.

[0038] In an optional example, the telescopic rod of the lifting cylinder is fixedly connected to the fixed top plate 405, and the cylinder body of the lifting cylinder is fixedly connected to the fixed base 101. The position of the pressurized inner cylinder 4 can be controlled by changing the telescopic rod.

[0039] In one alternative example, the lifting cylinder is an electric lifting cylinder, a pneumatic lifting cylinder, or a hydraulic lifting cylinder.

[0040] In an optional example of this embodiment, the first lifting mechanism includes a pull rod body and two drive components. The pull rod body is coaxially arranged with the pressure inner cylinder 4. One end of the pull rod body is fixedly connected to the pressure protection head 501, and the other end of the pull rod body passes through the fixed top plate 405 and slides in cooperation with the fixed top plate 405. The two drive components are respectively located on both sides of the pull rod body. The drive components include a lifting motor 7 and a worm gear transmission. The lifting motor 7 is fixedly connected to the fixed top plate 405 and is connected to the pull rod body through the worm gear transmission, driving the pull rod body to reciprocate along its axis. With the above structure, the movement of the pull rod body is synchronously controlled by the two drive components, so that the pressure pull rod 5 and the pressure protection head 501 can reciprocate under high pressure, thereby enabling better testing of the mechanical properties of the rock.

[0041] In an optional example, a rotating shaft limiting seat 406 is provided on the fixed top plate 405 to align with the worm gear drive. The worm gear drive includes a lifting control worm wheel 8 and a drive worm 701 that mesh with each other. Both the drive worm 701 and the lifting control worm wheel 8 are rotatably mounted on the rotating shaft limiting seat 406. The outer wall of the pull rod body has a lifting control tooth groove 504 arranged parallel to the axis of the pull rod body. The lifting control worm wheel 8 meshes with the lifting control tooth groove 504. The drive worm 701 is connected to the output shaft of the lifting motor 7. With the above structure, the two lifting motors 7 can rotate synchronously. By meshing the drive worm 701 and the lifting control worm wheel 8, and by changing the meshing position of the lifting control worm wheel 8 with the lifting control tooth groove 504 on the outer wall of the pull rod body, the movement of the pull rod body can be controlled.

[0042] In one optional example, two lifting control slots 504 are symmetrically arranged on the left and right sides of the pull rod body, and each lifting control slot 504 is arranged along the length direction of the pull rod body, and each lifting control slot 504 is a helical tooth structure.

[0043] In an optional example, the tie rod body has an axially extending cavity, and a drive motor 6 is provided at the other end of the tie rod body. The output shaft of the drive motor 6 passes through the cavity and the pressure protection head 501, and the output shaft is in a sealed sliding fit with the tie rod body. A spinning drill bit 601 is provided at the end of the output shaft. With the above structure, the drive motor 6 drives the spinning drill bit 601 to rotate, and the spinning drill bit 601 contacts the rock to simulate the wear and tear caused by underground movement under high pressure and high temperature, thereby achieving comprehensive detection.

[0044] Preferably, the bottom of the spinning drill bit 601 is provided with six inclined alloy scrapers in a circular array.

[0045] Furthermore, the end of the pull rod body is provided with a fixing top ring 505 for mounting the drive motor 6.

[0046] In an optional example, the fixed top plate 405 is a rectangular plate, one surface of which is fixedly connected to the top of the pressurized inner cylinder 4. The fixed top plate 405 has a through hole for the pull rod body to pass through, and two rotating shaft limiting seats 406 are symmetrically arranged on both sides of the through hole.

[0047] In an optional embodiment of the present invention, the pressure protection head 501 is provided with a pneumatic connecting pipe 502, one end of which is connected to the pressure chamber, and the other end of which can be connected to a gas source. Using the above structure, pressure is continuously supplied to the pressure chamber through the pneumatic connecting pipe 502.

[0048] In an optional embodiment of the present invention, a plurality of temperature and pressure monitoring gauges 503 are provided inside the pressurized protective head 501 to detect the temperature and pressure inside the pressurized chamber. This allows for synchronous monitoring while the pressure in the air pressure connecting pipe 502 is adjusted in real time, so as to better test the mechanical properties of the rock. Furthermore, the design of multiple temperature and pressure monitoring gauges 503 can better ensure the accuracy of the data.

[0049] In an optional example of this implementation, six temperature and pressure gauges 503 are mounted in a ring array on the top of the pressure protection head 501.

[0050] In another optional embodiment of the present invention, the pressurized protective head 501 is provided with a plurality of temperature monitoring meters and a plurality of pressure monitoring meters. The temperature monitoring meters are used to detect the temperature inside the pressurized chamber, and the pressure monitoring meters are used to detect the pressure inside the pressurized chamber.

[0051] In another optional embodiment of the present invention, an inner ring block 404 is provided at the top of the pressurized inner cylinder 4, and the pressurized protective head 501 is in the shape of a disc, with the outer side of the top end face of the pressurized protective head 501 being stuck at the bottom of the inner ring block 404 at the top of the inner wall of the pressurized inner cylinder 4.

[0052] In an optional embodiment of the present invention, a heating chamber hole 403 is provided in the side wall of the pressurized inner cylinder 4, and a heating tube is installed inside the heating chamber hole 403 to heat the pressurized inner cylinder 4, so as to better simulate the high temperature environment underground.

[0053] Please refer to Figures 1 to 8 The following describes in detail the specific implementation process of the pressure chamber 100 for rock mechanics testing proposed in this invention, with reference to an embodiment.

[0054] By placing the rock on the top arc-shaped rock placement seat 103, and then controlling the position of the pressurized inner cylinder 4 and the protective outer cylinder 1 by changing the top telescopic end of the second lifting mechanism 3, the pressurized inner cylinder 4 is fitted into the protective outer cylinder 1. The cooperation between the pressurized inner cylinder 4 and the protective outer cylinder 1 forms an overlapping sleeve structure, which can better ensure the sealing of the pressure chamber, avoid pressure leakage problems, and facilitate the improvement of the accuracy of the demonstration pressure and high temperature resistance test data.

[0055] The annular protrusion 401 at the bottom of the pressurized inner cylinder 4 matches the annular groove 102 at the bottom of the inner side of the protective outer cylinder 1. The bottom of the inner wall of the pressurized inner cylinder 4 is provided with an annular inner ring protrusion 402. The inner wall of the inner ring protrusion 402 fits against the outer wall of the rock placement seat 103 fixed at the bottom of the protective outer cylinder 1. Furthermore, an elastic sealing gasket 2 is embedded in the bottom end face of the outer side of the rock placement seat 103 of the protective outer cylinder 1, which can further reduce the possibility of pressure leakage through gaps and enable the pressure chamber to withstand higher pressure. A heating chamber hole 403 is provided in the side wall of the pressurized inner cylinder 4. A heating tube is installed inside the heating chamber hole 403, which can heat the cavity formed by the pressurized inner cylinder 4 and the protective outer cylinder 1, and better simulate the underground high pressure and high temperature environment.

[0056] The synchronous rotation of the two lifting motors 7 drives the worm gear 701 and the lifting control worm wheel 8 to mesh. The lifting control worm wheel 8 changes the meshing position of the lifting control tooth groove 504 on the outer wall of the pressure rod 5, thus controlling the sliding of the pressure rod 5. This allows the pressure protection head 501 at the bottom of the pressure rod 5 to move downwards under high pressure. The air pressure connecting pipe 502 at the top of the pressure protection head 501 continuously supplies pressure to the cavity formed by the inner pressure cylinder 4 and the outer protective cylinder 1. The top of the pressure protection head 501 is... The ring array is equipped with six temperature and pressure monitoring gauges 503, which can perform synchronous monitoring when the pressure of the air pressure connecting pipe 502 is adjusted in real time. This allows for better testing of the mechanical properties of the rock. The design of multiple temperature and pressure monitoring gauges 503 can better ensure the accuracy of the data. By installing a drive motor 6 on the top ring 505 fixed at the top of the pressure rod 5, the drive motor 6 controls the rotation of the spinning drill bit 601 to contact the rock, so as to simulate the wear problem caused by underground movement under high pressure and high temperature, thereby achieving comprehensive testing.

[0057] The detailed explanations of the above embodiments are intended only to explain the present invention so as to facilitate a better understanding of the present invention. However, these descriptions should not be construed as limiting the present invention for any reason. In particular, the various features described in different embodiments can be arbitrarily combined with each other to form other embodiments. Unless there is an explicit description to the contrary, these features should be understood to be applicable to any embodiment, and not limited to the described embodiments.

Claims

1. A pressure chamber for rock mechanics testing, characterized in that, The pressure chamber for rock mechanics testing includes: The protective outer cylinder has a closed end and an open end; A pressure inner cylinder is coaxially inserted inside the protective outer cylinder and is in a sealing sliding fit with the protective outer cylinder. The pressure inner cylinder has an axially penetrating pressure cavity. One end of the pressure inner cylinder abuts against the closed end, and an end face sealing device is provided between the closed end and the end face of the pressure inner cylinder. A pressure rod includes a pressure protection head and a first lifting mechanism. The pressure protection head is slidably and sealed within the pressure chamber. The first lifting mechanism is connected to the pressure protection head and drives the pressure protection head to reciprocate along the axis of the pressure inner cylinder. The second lifting mechanism connects the pressurized inner cylinder and the protective outer cylinder and drives the pressurized inner cylinder to reciprocate along the axis of the protective outer cylinder.

2. The pressure chamber for rock mechanics testing as described in claim 1, characterized in that, The end face sealing device has at least the following features: The first sealing structure includes an annular groove and an annular protrusion. The annular groove is formed on the inner end face of the closed end, and the annular protrusion is disposed on the end face of the pressurized inner cylinder. The annular protrusion can be embedded in the annular groove and close the annular groove.

3. The pressure chamber for rock mechanics testing as described in claim 2, characterized in that, The end face sealing device also has: The second sealing structure includes a matching elastic sealing gasket and an inner ring boss. The elastic sealing gasket is disposed on the inner end face of the closed end. The inner wall of the pressurized inner cylinder protrudes inward at its end to form the inner ring boss. The end face of the inner ring boss can press against the elastic sealing gasket.

4. The pressure chamber for rock mechanics testing as described in claim 3, characterized in that, A rock placement seat for placing rock samples is provided on the inner end face of the closed end, and the elastic sealing gasket is annular and embedded between the rock placement seat and the annular groove.

5. The pressure chamber for rock mechanics testing as described in claim 1, characterized in that, A fixed top plate is provided at the other end of the pressurized inner cylinder. The fixed top plate is arranged radially along the pressurized inner cylinder, and both ends of the fixed top plate protrude from the protective outer cylinder. The first lifting mechanism and the second lifting mechanism are respectively arranged on the fixed top plate.

6. The pressure chamber for rock mechanics testing as described in claim 5, characterized in that, The protective outer cylinder is provided with two fixed bases, which are symmetrically arranged on the outer wall of the closed end. The second lifting mechanism includes two lifting cylinders, which are symmetrically arranged on both sides of the protective outer cylinder. One end of each lifting cylinder is fixed on the fixed base, and the other end of each lifting cylinder is fixed on the fixed top plate.

7. The pressure chamber for rock mechanics testing as described in claim 5, characterized in that, The first lifting mechanism includes: The pull rod body is arranged along the axis of the pressurized inner cylinder. One end of the pull rod body is fixedly connected to the pressurized protective head, and the other end of the pull rod body passes through the fixed top plate and slides with the fixed top plate. Two drive components are respectively located on both sides of the pull rod body. The drive components include a lifting motor and a worm gear transmission. The lifting motor is fixed to the fixed top plate. The lifting motor is connected to the pull rod body through the worm gear transmission and drives the pull rod body to reciprocate along the axis of the pressurized inner cylinder.

8. The pressure chamber for rock mechanics testing as described in claim 7, characterized in that, The pull rod body has an axially penetrating connecting cavity, and a drive motor is provided at the other end of the pull rod body. The output shaft of the drive motor passes through the connecting cavity, and the output shaft is sealed and rotated with the pull rod body. A spinning drill bit is provided at the end of the output shaft.

9. The pressure chamber for rock mechanics testing as described in claim 1, characterized in that, The pressurized protective head is equipped with a pneumatic connecting pipe. One end of the pneumatic connecting pipe is connected to the pressurized chamber, and the other end of the pneumatic connecting pipe can be connected to a gas source.

10. The pressure chamber for rock mechanics testing as described in claim 1, characterized in that, The pressure protection head is equipped with: Multiple temperature sensors are used to detect the temperature inside the pressurization chamber; Multiple pressure gauges are used to detect the pressure inside the pressurization chamber.

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