Pressurizing device for indoor soil test

Abstract

The utility model relates to the field of indoor soil test equipment, and discloses a pressurizing device for an indoor soil test, which comprises a base, a pressure unit, a control unit and a driving unit for driving the pressure unit to work, the pressure unit comprises a shell and a piston rod; the bottom of the shell is provided with a pipeline connector connected with an external pressure container. The piston rod is sleeved with the shell. A pressure medium for providing pressure is filled between the piston rod and the bottom of the shell; the base is provided with a pressure sensor for detecting the pressure of the pressure medium; the control unit is electrically connected with the driving unit and the pressure sensor. After the pressure device reaches a target pressure value, the pressure can be kept stable, and the test accuracy is improved.

Description

Technical Field

[0001] The utility model relates to the field of indoor geotechnical test equipment, in particular to a pressurizing device used for indoor geotechnical test. Background Art

[0002] At present, the stress systems used in indoor geotechnical tests include air compressors, weights, head differences, AC motor-driven mechanical gearbox speed regulation, etc. These stress systems have a low degree of automation, and the test process requires a lot of manual operation. There are generally problems such as poor accuracy, small range, and data conversion. The hydraulic triaxial instrument commonly used in China by Nantu has a low degree of automation, poor pressure stability accuracy, and an error range of ±10kPa, which will cause large errors in the measurement of shear strength and pore pressure values ​​of soft soil under small confining pressure. The pneumatic triaxial instrument of Beijing Huakan uses an air source as the confining pressure source, and the measurement of axial pressure is converted using water as the medium. The test accuracy and system stability are poor. General geotechnical tests in domestic laboratories cannot provide data indicators close to the on-site environment, and expert experience is still needed to judge the data.

[0003] CN202211390634.3 discloses a true triaxial test device and method for deep well drilling, including a pressure chamber, a drilling assembly, a pressurizing assembly, a heating assembly and at least six locking assemblies; the pressure chamber is used to accommodate a sample and hydraulic oil; the drilling assembly includes a drill bit; the pressurizing assembly includes a push rod piston, which is inserted into the pressure chamber and can move along its own axis; the heating assembly is used to heat the hydraulic oil; every two locking assemblies are a group, and the two locking assemblies are connected to form an oblique line segment, which intersects at its own midpoint and forms a circular array along the axis of the drill bit. The present invention fixes irregular samples by multi-point clamping and hydraulic force, and simulates the drilling of the drill bit in a complex formation environment by hydraulic pressurization and heating hydraulic oil. However, the pressurizing assembly of the test device moves through the push rod piston, reducing the space of the pressure chamber, thereby increasing the pressure. When the pressure reaches the target value, due to certain changes in the environment and the motor, the pressure value may be unstable, thereby affecting the results of the test.

[0004] The technical problem to be solved by the utility model is: how to maintain the stability of the pressure after the pressure-adding device reaches the target pressure value. Utility Model Content

[0005] The main purpose of the utility model is to provide a pressurizing device for indoor geotechnical tests. By arranging a pressure sensor in the shell, the pressure of the pressure medium is detected in real time. When the pressure is low or high, the control unit controls the driving unit to move the piston rod, thereby adjusting the pressure and maintaining the pressure stable.

[0006] To achieve the above objectives, the technical solutions adopted in this application are:

[0007] A pressurizing device for indoor geotechnical testing comprises a base, a pressure unit, a control unit and a driving unit for driving the pressure unit to work; the pressure unit comprises a shell and a piston rod; the bottom of the shell is provided with a pipeline interface connected to an external pressure vessel; the piston rod is sleeved inside the shell; the space between the piston rod and the bottom of the shell is filled with a pressure medium for providing pressure; the base is provided with a pressure sensor for detecting the pressure of the pressure medium; the control unit is electrically connected to the driving unit and the pressure sensor respectively.

[0008] Compared with the prior art, this solution has the following beneficial effects:

[0009] The pressurizing device of this case is provided with a pressure sensor. When working, the pressure sensor feeds back the current pressure value to the control unit in real time. By comparing the difference between the real-time pressure value of the pressure sensor and the target pressure value, if the difference is large, the control unit controls the driving unit to advance rapidly, thereby increasing the pressure rapidly. As the difference becomes smaller, the control unit controls the driving unit to slow down the speed of the driving unit until the difference is small enough to be within the pressure range and the target pressure value is reached. After reaching the target pressure value, the pressure sensor detects the pressure in real time and feeds back to the control unit. The control unit adjusts the pressure by controlling the driving unit to stabilize the pressure within the target value range.

[0010] Secondly, a pressure unit is added. Instead of directly pushing the piston to pressurize the pressure chamber, the pressure chamber is connected through a pipe interface. This can achieve modularization and facilitate the later damage of components without the need for overall replacement, thereby reducing the cost of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the pressurizing device of Example 1;

[0012] Figure 2 This is a cross-sectional view of the pressurizing device of Example 1. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. The components of the present application implemented as described and shown in the drawings here can be arranged and designed in various different configurations.

[0014] Example 1

[0015] refer to Figure 1-2A pressurizing device for indoor geotechnical testing comprises a base 1, a pressure unit 2, a control unit 3 and a driving unit 4 for driving the pressure unit 2 to work; the pressure unit 2 comprises a shell 21 and a piston rod 22; a pipe interface 23 connected to an external pressure vessel is provided at the bottom of the shell 21; the piston rod 22 is sleeved inside the shell 21; a pressure medium for providing pressure is filled between the piston rod 22 and the bottom of the shell 21; the base 1 is provided with a pressure sensor 11 for detecting the pressure of the pressure medium; the control unit 3 is electrically connected to the driving unit 4 and the pressure sensor 11 respectively.

[0016] The pressurizing device is used in indoor geotechnical tests and belongs to the stress system therein. It is connected to an external pressure chamber through the pressurizing device. The external pressure chamber and the outer shell 21 are filled with pressure medium. The space where the pressure medium exists is reduced by pushing the piston rod 22, thereby increasing the pressure in the external pressure chamber, and then performing pressure-related tests on the samples in the pressure chamber.

[0017] In this embodiment, the pressure medium can be gas or liquid, and the pressure medium used in this solution is degassed water. The control unit 3 is a microprocessor, and this solution uses a microprocessor manufactured by NXP and model LPC1820FET100. Other microprocessors can also be selected according to needs.

[0018] The specific working process of the pressurizing device is as follows: the pipeline interface 23 of the pressurizing device is connected to the pressure chamber of the external device and filled with degassed water. The staff inputs the target pressure value into the control unit 3, and the control unit 3 sends a feed signal to the drive unit 4. The drive unit 4 pushes the piston rod 22 to move forward, and the piston rod 22 compresses the space where the degassed water is located, so that the volume of the degassed water changes, so that a continuous pressure is generated in the pressure chamber of the external device. The pressure sensor 11 detects the pressure of the degassed water in real time and transmits the detected pressure value to the control unit 3. The control unit 3 calculates the difference between the detected pressure value and the target pressure value. When the difference is large, the drive unit 4 pushes the piston rod 22 to move at a faster speed; when the difference is small, the drive unit 4 pushes the piston rod 22 to move at a slower speed until the difference is zero; after the pressure reaches the target pressure value, the pressure sensor 11 continues to detect the pressure of the degassed water. When the pressure changes, the drive unit 4 pushes the piston rod 22 to dynamically adjust the pressure of the degassed water, so that the pressure value is kept within the target pressure value range during the test. After the pressure is stable, relevant tests are performed on the samples in the pressure chamber of the external device.

[0019] In this way, during the entire test process, the degassed water can be kept within the target pressure value, thereby improving the accuracy of the test. Moreover, automatic control by the control unit 3 reduces the workload of the staff and improves efficiency.

[0020] Preferably, the driving unit 4 includes a motor 41 , a screw rod 42 and a slider 43 ; the screw rod 42 is fixedly connected to the power output end of the motor 41 ; the slider 43 is slidably connected to the screw rod 42 ; and the free end of the piston rod 22 is fixed to the slider 43 .

[0021] In this embodiment, the drive unit 4 uses a combination of a motor 41 and a screw rod 42. The motor 41 drives the screw rod 42 to rotate, so that the slider 43 moves linearly, and the slider 43 pushes the piston rod 22 to move horizontally. The screw rod 42 and the motor 41 can improve the accuracy of the moving distance of the piston rod 22, and cooperate with the pressure sensor 11 to accurately control the pressure value of the pressure chamber of the peripheral device.

[0022] Preferably, the base 1 is provided with a fixing seat 12 ; the fixing seat 12 is provided with a bearing 13 ; and the screw rod 42 is fixedly connected to the bearing 13 .

[0023] In this embodiment, there are two fixing seats 12, and both ends of the screw rod 42 are respectively connected to the fixing seats 12, so that the screw rod 42 remains stable during rotation, avoiding the screw rod 42 from shaking, which causes the piston rod 22 to be subjected to radial force, thereby increasing the service life of the piston rod 22.

[0024] Preferably, the base 1 is provided with a slide rail 14 ; the slider 43 is slidably connected to the slide rail 14 .

[0025] In this embodiment, the slider 43 is connected to the slide rail 14. During the movement of the slider 43, due to the limiting effect of the slide rail 14, the slider 43 can only maintain horizontal movement. This not only prevents the piston rod 22 from being affected by the gravity of the slider 43, but also maintains the horizontal movement of the piston rod 22, thereby preventing the leakage of degassed water in the outer shell 21.

[0026] Preferably, a piston 24 is provided at the end of the piston rod 22 ; a sealing ring 25 is provided on the outer periphery of the piston 24 ; and the sealing ring 25 is pressed against the inner wall of the housing 21 .

[0027] In this embodiment, the degassed water exists between the piston 24 and the pipe interface 23 and fills the external pressure chamber. The sealing ring 25 can prevent the degassed water from flowing into other positions of the housing 21 and affecting the pressurization effect.

[0028] Preferably, a valve 26 is provided on the pipeline interface 23 .

[0029] In this embodiment, the valve 26 can be closed when not in use, thereby ensuring that the pressurizing device is filled with degassed water, so that the pressurization is more stable when the piston rod 22 is pushed.

[0030] Preferably, the base 1 is provided with a switch button 15 and an interface 16 for data transmission; the interface 16 and the switch button 15 are both electrically connected to the control module.

[0031] In this embodiment, the staff sets the target pressure value or reads related data through the interface 16 .

[0032] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A pressurizing device for indoor geotechnical testing, characterized in that: It includes a base, a pressure unit, a control unit and a driving unit for driving the pressure unit to work; the pressure unit includes a shell and a piston rod; the bottom of the shell is provided with a pipeline interface connected to an external pressure container; the piston rod is sleeved inside the shell; the space between the piston rod and the bottom of the shell is filled with a pressure medium for providing pressure; the base is provided with a pressure sensor for detecting the pressure of the pressure medium; the control unit is electrically connected to the driving unit and the pressure sensor respectively.

2. The pressurizing device for indoor geotechnical testing according to claim 1, characterized in that: The driving unit comprises a motor, a screw rod and a slider; the screw rod is fixedly connected to the power output end of the motor; the slider is slidably connected to the screw rod; and the free end of the piston rod is fixed to the slider.

3. The pressurizing device for indoor geotechnical testing according to claim 2, characterized in that: The base is provided with a fixing seat; the fixing seat is provided with a bearing; the screw rod is fixedly connected to the bearing.

4. The pressurizing device for indoor geotechnical testing according to claim 2, characterized in that: The base is provided with a slide rail; the slider is slidably connected to the slide rail.

5. The pressurizing device for indoor geotechnical testing according to claim 1, characterized in that: A piston is arranged at the end of the piston rod; a sealing ring is arranged on the outer periphery of the piston; and the sealing ring is pressed against the inner wall of the outer shell.

6. The pressurizing device for indoor geotechnical testing according to claim 1, characterized in that: A valve is arranged on the pipeline interface.

7. The pressurizing device for indoor geotechnical testing according to claim 1, characterized in that: The base is provided with a switch button and an interface for data transmission; the interface and the switch button are both electrically connected to the control module.

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