Automatic pressure maintaining system for slurry balance shield tunneling machine, slurry balance shield tunneling machine

Abstract

The application discloses an automatic pressure maintaining system for a slurry balance shield tunneling machine and the slurry balance shield tunneling machine. The automatic pressure maintaining system detects the pressure value in the excavation bin in real time through an excavation bin pressure sensor and feeds back to a processor. The processor can calculate the current theoretical liquid level difference between the excavation bin and the air cushion bin based on the pressure value in the excavation bin and the pressure setting value of the air cushion bin. If the theoretical liquid level difference is within the allowable range, the pressure setting value of the air cushion bin remains unchanged. If the theoretical liquid level difference is not within the allowable range, the pressure setting value of the air cushion bin is adjusted so that the theoretical liquid level difference between the excavation bin and the air cushion bin is within the allowable range. The pressure setting value of the air cushion bin is associated with the actual pressure value of the excavation bin. When the pressure of the excavation bin fluctuates greatly, the pressure setting value of the air cushion bin is updated in time, the liquid level fluctuation range of the air cushion bin is reduced, and the pressure of the air cushion bin is kept stable.

Description

Technical Field

[0001] The present invention relates to the technical field of slurry shield machines, in particular to an automatic pressure maintaining system for a slurry shield machine, and further to a slurry shield machine using the automatic pressure maintaining system. Background Art

[0002] The biggest risk during the construction of a slurry shield is the instability and sudden change of the face pressure, that is, the pressure in the excavation chamber (i.e., slurry chamber) of the slurry shield machine is unstable. In order to ensure the stability of the shield excavation face, the face pressure must be kept as stable as possible. At present, there are two ways to control the stability of the face pressure, namely direct control slurry shield and indirect control slurry shield. Among them, the direct control slurry shield uses the speed of the mud pump and the opening of the valve to directly control the face pressure, while the indirect control slurry shield uses the pressure of the air buffer layer to control the mud water pressure, thereby indirectly balancing the face soil pressure. Figure 1 As shown in FIG, the working principle of the air pressure maintenance system of the existing indirect control slurry shield is: P1-P2=ρgΔh, where P1 represents the set pressure value of the air cushion chamber, P2 represents the actual pressure value of the slurry chamber, that is, the tunnel face pressure value, and Δh represents the theoretical liquid level difference between the slurry chamber and the air cushion chamber. The set pressure value P1 of the air cushion chamber does not change for a long time after being set. The air cushion chamber is controlled by the fuzzy PID operation of the controller to control the air intake and exhaust of the air cushion chamber so that the air cushion chamber pressure is dynamically balanced near the set pressure P1, thereby achieving constant value control of the air cushion chamber pressure. The actual liquid level difference between the slurry chamber and the air cushion chamber is controlled to be near the theoretical liquid level difference, thereby compensating for the pressure change of the slurry chamber. The actual liquid level difference is achieved by the driver manually controlling the slurry intake and discharge flow according to the excavation working conditions. Therefore, the pressure stability of the slurry chamber depends largely on the driver's experience in liquid level adjustment, and the control accuracy and reliability are poor. The driver needs to concentrate for a long time, which increases the difficulty of the construction workers' work. In addition, the theoretical liquid level difference Δh should be controlled between 1 / 3 and 2 / 3 of the shield diameter D. When the face pressure fluctuates greatly, if the driver fails to adjust the liquid level in time, the actual liquid level fluctuation range of the air cushion tank will exceed the allowable value. If the liquid level of the air cushion tank is too high, the compressed air pipeline will be backfilled, causing the tank to burst. If the liquid level of the air cushion tank is too low, it will affect the mud circulation efficiency, thereby affecting the construction efficiency.

[0003] Therefore, the air pressure maintenance system of the existing indirect control slurry shield only controls the actual pressure of the air cushion chamber near the set pressure of the air cushion chamber. The set pressure of the air cushion chamber does not change for a long time after being set, and there is no real-time correlation between it and the actual pressure of the slurry chamber. If the driver fails to adjust the liquid level in time, when the excavation surface pressure fluctuates greatly, it will cause the liquid level in the air cushion chamber to fluctuate beyond the allowable range, and the liquid level of the air cushion chamber will be unstable. In addition, the method of manually adjusting the liquid level difference according to the excavation working conditions by the driver also has the problems of poor adjustment accuracy and poor reliability. Therefore, it is difficult for the air pressure maintenance system of the existing indirect control slurry shield to control the slurry chamber pressure to remain stable. Summary of the Invention

[0004] The present invention provides an automatic pressure maintaining system for a slurry shield machine and a slurry shield machine, so as to solve the technical problem of unstable liquid level of an air cushion cabin in an air pressure maintaining system of an existing indirect control slurry shield.

[0005] According to one aspect of the present invention, there is provided an automatic pressure maintaining system for a slurry shield machine, comprising:

[0006] Excavation chamber pressure sensor, used to measure the pressure value of the excavation chamber;

[0007] a first analog-to-digital converter, electrically connected to the excavation chamber pressure sensor, for converting an analog signal output by the excavation chamber pressure sensor into an electrical signal;

[0008] Air cushion tank pressure transmitter, used to measure the pressure value of the air cushion tank;

[0009] The pneumatic pressure-maintaining PID controller is connected to the air cushion chamber pressure transmitter and is used to adjust the pressure setting value of the air cushion chamber and perform PID control on the pressure of the air cushion chamber according to the pressure setting value of the air cushion chamber and the measurement result of the air cushion chamber pressure transmitter;

[0010] The processor is electrically connected to the first analog-to-digital converter, and is used to calculate the current theoretical liquid level difference based on the pressure measurement value of the excavation chamber and the pressure setting value of the air cushion chamber, and automatically adjust the pressure setting value of the air cushion chamber when the current theoretical liquid level difference exceeds the allowable range to ensure that the theoretical liquid level difference is within the allowable range.

[0011] Furthermore, it also includes an electrical converter, a pneumatic motor and a pressure regulating device. The electrical converter is electrically connected to the processor and is used to convert the electrical control signal output by the processor into a pneumatic control signal. The pressure regulating device is used to output the pneumatic signal to the pneumatic pressure-maintaining PID controller to adjust the pressure setting value of the air cushion chamber. The pneumatic motor is respectively connected to the electrical converter and the pressure regulating device and is used to control the size of the pneumatic signal output by the pressure regulating device according to the pneumatic control signal output by the electrical converter.

[0012] Furthermore, the pressure regulating device includes an air source, a reversing mechanism, a manual pressure regulating device and an automatic pressure regulating device. The manual pressure regulating device is used to manually adjust the output air signal size before excavation. The automatic pressure regulating device is connected to the pneumatic motor and is used to automatically adjust the output air signal size during excavation. The manual pressure regulating device and the automatic pressure regulating device are arranged in parallel and connected to the air source through the reversing mechanism. The reversing mechanism is used to control the manual pressure regulating device to be connected to the air source or the automatic pressure regulating device to be connected to the air source.

[0013] Furthermore, the manual pressure regulating device and the automatic pressure regulating device both include:

[0014] A base, used as a support, having a gas source cavity, an input hole for inputting gas, and an output hole for outputting gas, wherein the input hole is connected to the reversing mechanism and the gas source cavity respectively, and the output hole is connected to the pneumatic pressure-maintaining PID controller;

[0015] an amplifier for amplifying gas flow, mounted on the base, comprising an input chamber, an output chamber, and a first regulating assembly, wherein the input chamber is connected to the input hole, the output chamber is connected to the output hole, and the first regulating assembly is used to change the gas pressure of the output chamber in response to changes in the pressure of the input chamber;

[0016] an adjustment mechanism mounted on the base, comprising an adjustment chamber, a second adjustment assembly, a floating plate, and a nozzle communicating with the input chamber and the adjustment chamber, wherein the second adjustment assembly is used to adjust the distance between the first end of the floating plate and the nozzle orifice, thereby adjusting the air pressure within the adjustment chamber;

[0017] A feedback component is provided on the base and is communicated with the regulating chamber and the output chamber respectively, and is used to make the air pressure output by the output chamber act on the second end of the floating plate to regulate the air pressure in the regulating chamber.

[0018] Furthermore, the amplifier also includes a first cover plate, the base has a first mounting cavity located on the gas source cavity, and the first cover plate sealing cover is arranged on the first mounting cavity; the first adjustment component includes a diaphragm component arranged in the first mounting cavity, and the diaphragm component is used to separate the first mounting cavity into the input cavity and the output cavity.

[0019] Furthermore, the base includes a valve seat installed on the air source cavity, which is used to separate the air source cavity and the first installation cavity; the first adjusting assembly also includes a valve core and a first elastic member, the first elastic member is installed between the bottom of the air source cavity and the valve core, and the first elastic member is used to keep the valve core in contact with the valve hole of the valve seat; the diaphragm assembly is used to move toward the output cavity when the pressure in the input cavity increases, thereby moving the valve core, thereby opening the valve hole or increasing the gap between the valve core and the valve hole, and the diaphragm assembly is also used to move toward the input cavity when the pressure in the input cavity decreases, thereby resetting the valve core under the action of the first elastic member, thereby reducing the gap between the valve core and the valve hole or closing the valve hole.

[0020] Furthermore, the adjustment mechanism includes a second elastic member, a first end of the second elastic member is connected to the first end portion of the floating plate, a second end of the second elastic member is fixedly connected to the base, and the extension and contraction direction of the second elastic member is perpendicular or nearly perpendicular to the floating plate; a traction beam is fixedly provided above the first end of the floating plate; the second adjustment assembly includes a traction block provided above the floating plate and an adjusting screw provided through the traction block and arranged along the length direction of the floating plate and parallel to the floating plate, the traction block is connected to the traction beam through a third elastic member, the adjusting screw is used to drive the traction block to move toward the second end of the floating plate, so as to apply traction to the traction beam through the third elastic member, thereby driving the first end of the floating plate away from the nozzle, and the adjusting screw is also used to drive the traction block to move toward the first end of the floating plate, so as to cancel the traction of the traction beam, so that the first end of the floating plate is reset under the elastic force of the second elastic member in the stretched state and moves toward the nozzle.

[0021] Furthermore, it also includes:

[0022] The pneumatic air inlet regulating valve is installed on the air inlet pipe of the air cushion chamber to control the air inlet of the air cushion chamber;

[0023] The pneumatic exhaust regulating valve is installed on the exhaust pipe of the air cushion chamber to control the exhaust of the air cushion chamber;

[0024] The pneumatic pressure maintaining PID controller is connected to the pneumatic air inlet regulating valve and the pneumatic exhaust regulating valve respectively, and is used to control the working status of the pneumatic air inlet regulating valve and the pneumatic exhaust regulating valve according to the pressure measurement value and the pressure setting value of the air cushion chamber, so as to control the actual pressure value of the air cushion chamber to be consistent with the set value.

[0025] Furthermore, a muffler is provided at the end of the exhaust pipe of the air cushion chamber.

[0026] In addition, the present invention also provides a slurry shield machine that adopts the automatic pressure maintaining system as described above.

[0027] The present invention has the following effects:

[0028] The automatic pressure maintaining system for a slurry shield machine of the present invention detects the pressure value in the excavation chamber in real time through the excavation chamber pressure sensor and feeds it back to the processor. The processor can calculate the current theoretical liquid level difference between the excavation chamber and the air cushion chamber based on the pressure value in the excavation chamber and the pressure setting value of the air cushion chamber. If the theoretical liquid level difference is within the allowable range, the pressure setting value of the air cushion chamber is kept unchanged. If the theoretical liquid level difference is not within the allowable range, the pressure setting value of the air cushion chamber is adjusted to make the theoretical liquid level difference between the excavation chamber and the air cushion chamber within the allowable range, thereby realizing the association between the pressure setting value of the air cushion chamber and the actual pressure value of the excavation chamber. When the pressure of the excavation chamber fluctuates greatly, the pressure setting value of the air cushion chamber is updated in time, thereby reducing the amplitude of the liquid level fluctuation of the air cushion chamber, which is conducive to ensuring that the pressure of the air cushion chamber remains stable.

[0029] In addition, the slurry shield machine of the present invention also has the above advantages.

[0030] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0032] Figure 1 It is a schematic diagram of the principle of the air pressure maintenance system of the existing indirect control slurry shield.

[0033] Figure 2 It is a schematic diagram of the principle of an automatic pressure maintaining system for a slurry shield machine according to a preferred embodiment of the present invention.

[0034] Figure 3 It is a schematic diagram of the principle of the pressure regulating device of the preferred embodiment of the present invention.

[0035] Figure 4 It is a structural schematic diagram of a manual pressure regulating device / automatic pressure regulating device according to a preferred embodiment of the present invention.

[0036] Figure 5 Schematic diagram of the structure of an amplifier according to a preferred embodiment of the present invention.

[0037] Figure 6 It is a structural schematic diagram of the adjustment mechanism of a preferred embodiment of the present invention.

[0038] Figure 7It is a structural diagram of the feedback component of the preferred embodiment of the present invention.

[0039] Figure 8 This is a schematic diagram of the structural principle of a manual pressure regulating device / automatic pressure regulating device according to a preferred embodiment of the present invention.

[0040] Description of Reference Numerals

[0041] 1. Excavation chamber pressure sensor; 2. First analog-to-digital converter; 3. Pneumatic pressure-maintaining PID controller; 4. Processor; 5. Liquid level sensor; 6. Second analog-to-digital converter; 7. Flow sensor; 8. Air cushion chamber pressure transmitter; 9. Pneumatic inlet regulating valve; 10. Pneumatic exhaust regulating valve; 100. Excavation chamber; 200. Air cushion chamber; 300. Air compressor; 11. Electrical converter; 12. Pneumatic motor; 13. Pressure regulating device; 14. Muffler; 131. Air source; 132. Reversing mechanism; 133. Manual pressure regulating device; 134. Automatic pressure regulating device; 21. Amplifier; 211. Orifice; 212. Hose; 213. First cover plate; 214. Diaphragm assembly Component; 215, spring piece; 216, valve seat; 217, first sealing ring; 218, valve core; 219, first elastic component; 22, adjusting mechanism; 221, mounting seat; 222, mounting plate; 223, traction block; 224, nozzle; 225, floating plate; 226, third elastic component; 227, traction beam; 228, adjusting screw; 229, retaining ring; 2210, knob; 2211, nut; 2212, limiting rod; 2213, second elastic component; 23, input hole; 24, feedback assembly; 241, second cover plate; 242, first diaphragm; 243, second sealing ring; 25, base; 26, output hole; 27, input cavity; 28, output cavity; 29, gas source cavity. DETAILED DESCRIPTION

[0042] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0043] It is understandable that Figures 2 to 8As shown, a preferred embodiment of the present invention provides an automatic pressure-maintaining system for a slurry shield machine, comprising an excavation chamber pressure sensor 1, a first analog-to-digital converter 2, an air cushion chamber pressure transmitter 8, a pneumatic pressure-maintaining PID controller 3, and a processor 4. The excavation chamber pressure sensor 1 is used to measure the pressure value of the excavation chamber 100 (i.e., the slurry chamber). The first analog-to-digital converter 2 is electrically connected to the excavation chamber pressure sensor 1 and the processor 4, respectively, and is used to convert the analog signal output by the excavation chamber pressure sensor 1 into an electrical signal and transmit the electrical signal to the processor 4. The air cushion chamber pressure transmitter 8 is used to measure the pressure value of the air cushion chamber 200. The pneumatic pressure-maintaining PID controller 3 is connected to the air cushion chamber pressure transmitter 8 and is used to adjust the pressure setting value of the air cushion chamber 200. The air cushion chamber pressure transmitter 8 outputs a gas signal to the pneumatic pressure-maintaining PID controller 3. The pneumatic pressure-maintaining PID controller 3 performs PID control on the pressure of the air cushion chamber 200 based on the pressure setting value of the air cushion chamber 200 and the measurement result of the air cushion chamber pressure transmitter 8. The processor 4 is configured to calculate a current theoretical liquid level difference based on the pressure measurement value of the excavation chamber 100 and the pressure setting value of the air cushion chamber 200, and automatically adjust the pressure setting value of the air cushion chamber 200 to bring the theoretical liquid level difference within the allowable range when the current theoretical liquid level difference exceeds the allowable range. The processor 4 may be a single-chip microcomputer or an FPGA. It can be understood that the processor 4 obtains the pressure value P2 in the excavation chamber 100 in real time through the excavation chamber pressure sensor 1, and then obtains the set pressure value P1 of the air cushion chamber 200. Then, based on the formula: P1-P2=ρgΔh, the current theoretical liquid level difference Δh between the excavation chamber 100 and the air cushion chamber 200 can be calculated. If Δh is between 1 / 3 and 2 / 3 of the shield diameter D, the pressure setting value of the air cushion chamber 200 is kept unchanged. If it is not between 1 / 3 and 2 / 3 of the shield diameter D, it means that the pressure setting value of the air cushion chamber 200 is unreasonable at this time and needs to be adjusted so that the theoretical liquid level difference between the excavation chamber 100 and the air cushion chamber 200 is between 1 / 3 and 2 / 3 of the shield diameter D. For example, the theoretical liquid level difference Δh is set to 1 / 2 of the shield diameter D, and the new pressure setting value of the air cushion chamber 200 can be calculated based on Δh, the actual pressure value P2 in the excavation chamber 100 and the above formula.

[0044] It can be understood that the automatic pressure maintaining system for the slurry shield machine of this embodiment detects the pressure value in the excavation chamber 100 in real time through the excavation chamber pressure sensor 1 and feeds it back to the processor 4. The processor 4 can calculate the current theoretical liquid level difference between the excavation chamber 100 and the air cushion chamber 200 based on the pressure value in the excavation chamber 100 and the pressure setting value of the air cushion chamber 200. If the theoretical liquid level difference is within the allowable range, the pressure setting value of the air cushion chamber 200 is kept unchanged. If the theoretical liquid level difference is not within the allowable range, the pressure setting value of the air cushion chamber 200 is adjusted to make the theoretical liquid level difference between the excavation chamber 100 and the air cushion chamber 200 within the allowable range, thereby realizing the association between the pressure setting value of the air cushion chamber 200 and the actual pressure value of the excavation chamber 100. When the pressure of the excavation chamber 100 fluctuates greatly, the pressure setting value of the air cushion chamber 200 will be updated in time, thereby reducing the liquid level fluctuation amplitude of the air cushion chamber 200, which is conducive to ensuring that the pressure of the air cushion chamber 200 remains stable.

[0045] Optionally, the automatic pressure maintaining system also includes a liquid level sensor 5 and a second analog-to-digital converter 6, and the second analog-to-digital converter 6 is electrically connected to the liquid level sensor 5 and the processor 4 respectively. The liquid level sensor 5 is used to measure the liquid level value of the air cushion chamber 200, and the second analog-to-digital converter 6 is used to convert the analog signal output by the liquid level sensor 5 into an electrical signal and output it to the processor 4. The processor 4 is also used to control the slurry inlet and outlet flow according to the real-time liquid level value of the air cushion chamber 200, so that the actual liquid level difference between the excavation chamber 100 and the air cushion chamber 200 is maintained near the theoretical liquid level difference, and the pressure of the excavation chamber 100 can be automatically controlled to remain stable. It can be understood that during the advancement process, the excavation chamber 100 is always in a full-bin state. After measuring the actual liquid level value of the air cushion chamber 200, the actual liquid level difference between the excavation chamber 100 and the air cushion chamber 200 can be calculated. If the actual liquid level difference is less than the theoretical liquid level difference, the mud pump speed and the valve opening are increased to increase the slurry inlet and discharge flow, thereby increasing the actual liquid level difference. If the actual liquid level difference is greater than the theoretical liquid level difference, the mud pump speed and the valve opening are reduced to reduce the slurry inlet and discharge flow, thereby increasing the actual liquid level difference, and finally making the actual liquid level difference equal to the theoretical liquid level difference.

[0046] Preferably, the automatic pressure maintaining system also includes a flow sensor 7 electrically connected to the processor 4 for measuring the inlet and outlet flow rates. The processor 4 is also used to perform feedback adjustment on the inlet and outlet flow rates according to the detection results of the flow sensor 7. In addition, when the current theoretical liquid level difference does not exceed the range, the processor 4 is also used to calculate the current actual liquid level difference based on the current liquid level value of the air cushion tank 200, and calculate the change time required for the current actual liquid level difference to change to exceed the allowable range based on the inlet and outlet flow measurement results and the current actual liquid level difference. If the required change time exceeds the preset time threshold, the pressure setting value of the air cushion tank 200 is automatically adjusted. If the required change time does not exceed or equal to the preset time threshold, the pressure setting value of the air cushion tank 200 is maintained unchanged. In this control mode, the liquid level difference change trend analysis is performed based on the inlet and outlet flow rates, and the early prediction of the liquid level difference exceeding the standard is achieved, thereby improving the timeliness of the control strategy.

[0047] Optionally, the automatic pressure maintaining system also includes an electrical converter 11, a pneumatic motor 12 and a pressure regulating device 13. The electrical converter 11 is electrically connected to the processor 4 and is used to convert the electrical control signal output by the processor 4 into an air control signal. The pressure regulating device 13 is used to output the air signal to the pneumatic pressure maintaining PID controller 3 to adjust the pressure setting value of the air cushion chamber 200. The pneumatic motor 12 is respectively connected to the electrical converter 11 and the pressure regulating device 13 and is used to control the size of the air signal output by the pressure regulating device 13 according to the air control signal output by the electrical converter 11.

[0048] The pressure regulating device 13 includes an air source 131, a reversing mechanism 132, a manual pressure regulating device 133, and an automatic pressure regulating device 134. The manual pressure regulating device 133 is used to manually adjust the output air signal before excavation. The automatic pressure regulating device 134 is connected to the pneumatic motor 12 and is used to automatically adjust the output air signal during excavation. The manual pressure regulating device 133 and the automatic pressure regulating device 134 are arranged in parallel and connected to the air source 131 through the reversing mechanism 132. The reversing mechanism 132 is used to control the connection between the manual pressure regulating device 133 and the air source 131 or the connection between the automatic pressure regulating device 134 and the air source 131, thereby achieving switching between manual and automatic settings. The reversing mechanism 132 can be a pneumatic reversing valve, and the pneumatic pressure maintaining PID controller 3 controls the pneumatic reversing valve for reversing.

[0049] Wherein, the manual pressure regulating device 133 and the automatic pressure regulating device 134 both include:

[0050] The base 25 is used as a support. The base 25 has a gas source cavity 29, an input hole 23 for inputting gas, and an output hole 26 for outputting gas. The input hole 23 is connected to the reversing mechanism 132 and the gas source cavity 29 respectively. The output hole 26 is connected to the pneumatic pressure-maintaining PID controller 3.

[0051] Amplifier 21 is used to amplify gas flow and is mounted on base 25. It has an input chamber 27, an output chamber 28, and a first regulating assembly. Input chamber 27 is connected to input hole 23, and output chamber 28 is connected to gas source chamber 29 and output hole 26, respectively. Output chamber 28 is used to output gas. The first regulating assembly is used to adjust the gas pressure of output chamber 28 in response to the pressure of input chamber 27.

[0052] The regulating mechanism 22 is mounted on the base 25 and includes a regulating chamber, a nozzle 224 connecting the input chamber 27 and the regulating chamber, a floating plate 225, and a second regulating assembly. The nozzle 224 has its nozzle orifice facing the first end of the surface of the floating plate 225. The second regulating assembly is used to adjust the distance between the first end of the floating plate 225 and the nozzle orifice of the nozzle 224, thereby adjusting the air pressure within the regulating chamber.

[0053] The feedback component 24 is disposed on the base 25 and is connected to the regulating chamber and the output chamber 28 respectively. It is used to apply the air pressure output by the output chamber 28 to the second end of the floating plate 225 to adjust the air pressure of the regulating chamber and further adjust the air pressure of the input chamber 27.

[0054] The operating principle of this pressure regulating device is as follows: This pressure regulating device is installed in an automatic pressure maintaining system, with its input port 23 connected to the reversing mechanism 132, and its output port 26 outputting a gas signal to the pneumatic pressure maintaining PID controller 3. After airflow enters the input port 23, it is split into two paths: one path is filled into the gas source chamber 29, and the other path is filled into the input chamber 27. At this time, the air pressure in the input chamber 27 increases. As the pressure in the input chamber 27 increases, the first regulating component adjusts the air path between the output chamber 28 and the gas source chamber 29 (i.e., increases the air path between the output chamber 28 and the gas source chamber 29), ensuring that the output chamber 28 has air pressure, enabling the output of a gas signal. The second regulating component adjusts the distance between the first end of the floating plate 225 and the nozzle 224, thereby adjusting the air pressure in the regulating chamber and, consequently, the air pressure in the input chamber 27. The first regulating component adjusts the air pressure in the output chamber 28 in response to changes in the air pressure in the input chamber 27, achieving stepless regulation of the output pressure and high control accuracy. During the regulation process, the air pressure in the input chamber 27 may be relatively too low, while the air pressure in the output chamber 28 may be relatively too high. At this time, the air pressure in the output chamber 28 acts on the second end of the floating plate 225 through the feedback component 24, causing it to move, thereby adjusting the air pressure in the regulation chamber, thereby increasing the air pressure in the input chamber 27 in a coordinated manner, ensuring that the air pressure remains stable during the regulation process. Conversely, when the air pressure in the input chamber 27 is relatively too high and the air pressure in the output chamber 28 is relatively too low, the force exerted by the feedback component 24 on the second end of the floating plate 225 is reduced, and the air pressure in the regulation chamber is adjusted according to the feedback, maintaining the air pressure stable during the regulation process, and the output pressure is stable, which is highly reliable. In addition, this device is a purely mechanical precision pressure regulation device that is not affected by external electrical signals, has a compact structure, has high regulation accuracy, stable output pressure, and achieves stepless regulation, with a wide range of applications.

[0055] In this embodiment, the amplifier 21 also includes a first cover plate 213, the base 25 has a first mounting cavity located on the gas source cavity 29, and the first cover plate 213 is sealed and covered on the first mounting cavity; the first adjustment component includes a diaphragm component 214 arranged in the first mounting cavity, and the diaphragm component 214 is used to separate the first mounting cavity into an input cavity 27 and an output cavity 28; the diaphragm component 214 is a three-layer structure consisting of a diaphragm-metal body-diaphragm, which divides the first mounting cavity into an input cavity 27 and an output cavity 28. It can be understood that the gas introduced into the input hole 23 is divided into two paths and inputted into the gas source cavity 29 and the input cavity 27 respectively, and the output cavity 28 is connected to the output hole 26 and the feedback component 24; when the pressure in the input cavity 27 increases, the diaphragm component 214 moves toward the output cavity 28, and when the pressure decreases, the diaphragm component 214 moves toward the input cavity 27. Furthermore, the base 25 includes a valve seat 216 installed on the air source chamber 29, which is used to separate the air source chamber 29 and the first installation chamber. The valve seat 216 is fixedly arranged in the base 25, and a first sealing ring 217 is provided on the valve seat 216. A spring 215 is provided between the diaphragm assembly 214 and the valve seat 216, which is used to limit the downward movement range of the diaphragm assembly 214; the first adjusting assembly also includes a valve core 218 and a first elastic member 219, and the first elastic member 219 is installed between the valve core 218 and the bottom of the air source chamber 29. The first elastic member 219 is used to keep the valve core 218 against the valve hole of the valve seat 216, so as to reset the valve core 218; the diaphragm assembly 214 is used to move toward the output chamber 28 when the pressure in the input chamber 27 increases, thereby moving the valve core 218, thereby opening the valve hole or increasing the gap between the valve core 218 and the valve hole.For example, when gas is first input into the input hole 23, gas is filled into both the gas source chamber 29 and the input chamber 27. The gas pressure in the input chamber 27 increases, causing the diaphragm assembly 214 to move toward the output chamber 28, driving the valve core 218 to move and compress the first elastic member 219 and open the valve hole. The gas in the gas source chamber 29 is output to the output chamber 28, and the pressure in the output chamber 28 increases until the pressure between the input chamber 27 and the output chamber 28 is balanced. At this time, the regulating mechanism 22 is adjusted to reduce the gap between the floating plate 225 and the nozzle 224, thereby reducing the gas pressure in the regulating chamber and increasing the gas pressure in the input chamber 27, causing the diaphragm assembly 214 to move toward the output chamber 28, increasing the gas pressure in the input chamber 27 and increasing the output gas pressure. Similarly, the diaphragm assembly 214 is also used to move toward the input chamber 27 when the pressure in the input chamber 27 decreases, thereby causing the valve core 218 to move in the first elastic member 219. The regulating mechanism 22 adjusts the gap between the floating plate 225 and the nozzle 224 to increase the air pressure in the regulating chamber, and the air pressure in the input chamber 27 decreases. The diaphragm assembly 214 moves toward the input chamber 27. The valve core 218 is reset under the action of the first elastic member 219. The gap between the valve core 218 and the valve hole is reduced, thereby reducing the size of the air path between the air source chamber 29 and the output chamber 28. The air pressure in the output chamber 28 decreases, and the output air pressure decreases. If there is no air flow input to the input hole 23, there is no air pressure in the input chamber 27. The valve core 218 is reset under the action of the first elastic member 219 and drives the diaphragm assembly 214 to move, the valve hole is closed, and no air pressure is output from the output chamber 28. Optionally, a release hole is provided on the side wall of the diaphragm assembly 214 for releasing excess air pressure after pressure stabilization, that is, after the adjustment is completed, the air pressure in the input chamber 27 and the output chamber 28 tends to be stable, and the excess air pressure enters the diaphragm assembly 214 from the output chamber 28 and is released to the atmosphere through the release hole to maintain the stability of the device during use.

[0056] In this embodiment, the adjustment mechanism 22 includes a second elastic member 2213, a first end of the second elastic member 2213 is connected to the first end of the floating plate 225, and the second end of the second elastic member 2213 is fixedly connected to the base 25. The extension and contraction direction of the second elastic member 2213 is perpendicular or perpendicular to the floating plate 225; a traction beam 227 is fixedly provided above the first end of the floating plate 225; the second adjustment assembly includes a traction block 223 provided above the floating plate 225 and an adjustment screw 228 provided through the traction block 223 and arranged along the length direction of the floating plate 225 and parallel to the floating plate 225. The traction block 223 is connected to the traction beam 227 through the third elastic member 226, and the adjustment screw 228 is used to drive the traction block 223 toward the floating plate 225. The adjusting screw 228 is further used to drive the traction block 223 to move toward the first end of the floating plate 225 to cancel the traction of the traction beam 227, thereby causing the first end of the floating plate 225 to reset under the elastic force of the second elastic member 2213 in the stretched state and move toward the nozzle 224; by applying traction to the traction beam 227 through the third elastic member 226 via the axial movement of the adjusting screw 228, the traction force on the traction beam 227 is further converted into traction on the floating plate 225. When the adjusting screw 228 moves over a large range, it only drives the floating plate 225 to move slightly, thereby realizing precise pressure adjustment.

[0057] In this embodiment, the adjustment mechanism 22 further comprises a mounting seat 221 mounted on the base 25. The nozzle 224 is mounted on the bottom of the mounting seat 221 and connected to the top surface of the mounting seat 221. Mounting plates 222 are provided on both sides of the mounting seat 221. The second adjustment assembly further comprises a limiting rod 2212, which is arranged perpendicular to the axial direction of the adjustment screw 228. A limiting groove for receiving the limiting rod 2212 is defined on the mounting plate 222 along the length of the floating plate 225, and / or a limiting groove for receiving the limiting rod 2212 is defined on the floating block along the length of the floating plate 225. The adjustment chamber is formed between the mounting seat 221 and the floating plate 225.

[0058] The second elastic member 2213 is an L-shaped elastic piece that connects the floating plate 225 and the mounting base 221. A nut 2211 is fixed to the mounting base 221 for threaded connection with the first end of the adjusting screw 228. The second end of the adjusting screw 228 is provided with a retaining ring 229 for sealing. In the manual pressure adjustment device 133, the second end of the adjusting screw 228 is provided with a knob 2210 to facilitate rotation. In the automatic pressure adjustment device 134, the second end of the adjusting screw 228 is connected to the output of the pneumatic motor 12 via a coupling.

[0059] The third elastic member 226 in this embodiment is a spring, and both ends of the third elastic member 226 are respectively connected to the traction beam 227 and the limiting rod 2212;

[0060] In this embodiment, the regulating mechanism 22 includes two throttling holes 211 opened on the first cover plate 213. The throttling holes 211 are connected to the input chamber 27. The two throttling holes 211 are used to connect the input hole 23 and the nozzle 224 through the leather tube 212 respectively to amplify the gas flow input to the input chamber 27 and the regulating chamber.

[0061] In this embodiment, the base 25 has a second mounting cavity that communicates with the output cavity 28. The feedback assembly 24 includes a second cover plate 241 sealed against the second mounting cavity and a first diaphragm 242 disposed within the second mounting cavity. A second sealing ring 243 is disposed on the lower surface of the first diaphragm 242. The first diaphragm 242 is configured to move in response to changes in the air pressure in the output cavity 28 and the regulating cavity, thereby controlling the movement of the second end of the floating plate 225 to adjust the air pressure in the output cavity 28 and the regulating cavity, thereby ensuring more stable output pressure following feedback control. The first diaphragm 242 has the same structure as the diaphragm assembly 214.

[0062] It can be understood that the structures of the manual pressure regulating device 133 and the automatic pressure regulating device 134 are basically the same. The only difference between the two is that the adjusting screw 228 of the manual pressure regulating device 133 is provided with a knob 2210, and the size of the output gas signal needs to be adjusted by manually rotating the adjusting screw 228, while the adjusting screw 228 of the automatic pressure regulating device 134 is driven by the pneumatic motor 12, and the size of the output gas signal is adjusted by controlling the rotation of the pneumatic motor 12.

[0063] It can be understood that during the shield machine's initial launch, based on the shield machine's initial launch conditions, the reversing mechanism 132 is switched to communicate with the manual pressure regulating device 133, thereby switching the pressure regulating device 13 to a manual setting mode. The operator manually rotates the knob 2210 to adjust the distance between the first end of the floating plate 225 and the nozzle 224 to manually adjust the output pressure. The pneumatic pressure-maintaining PID controller 3 then sets the pressure value output by the manual pressure regulating device 133 as the pressure setting value of the air cushion chamber 200, thereby manually setting the pressure setting value of the air cushion chamber 200. After the shield machine's initial launch conditions stabilize, the reversing mechanism 132 is controlled to switch to communicate with the automatic pressure regulating device 134, thereby switching the pressure regulating device 13 to an automatic setting mode. When the pressure setting value of the air cushion chamber 200 needs to be adjusted, the processor 4 calculates the new pressure setting value and outputs an electrical control signal to the electrical converter 11, converts the electrical control signal into an air control signal, and drives the pneumatic motor 12 to rotate, thereby driving the adjusting screw 228 to rotate a certain angle to automatically adjust the distance between the first end of the floating plate 225 and the nozzle 224, thereby adjusting the output pressure of the automatic pressure regulating device 134, and the pneumatic pressure maintaining PID controller 3 sets the pressure value output by the automatic pressure regulating device 134 as the pressure setting value of the air cushion chamber 200, thereby realizing the automatic setting of the pressure setting value of the air cushion chamber 200.

[0064] In addition, the automatic pressure-maintaining system also includes a pneumatic air intake regulating valve 9 and a pneumatic air exhaust regulating valve 10, both of which are connected to a pneumatic pressure-maintaining PID controller 3. The pneumatic air intake regulating valve 9 is arranged on the air intake pipe of the air cushion chamber 200 and is connected to the air compressor 300, and is used to control the air intake of the air cushion chamber 200. The pneumatic air exhaust regulating valve 10 is arranged on the air exhaust pipe of the air cushion chamber 200, and is used to control the exhaust of the air cushion chamber 200. The pneumatic pressure-maintaining PID controller 3 is used to control the working state of the pneumatic air intake regulating valve 9 and the pneumatic air exhaust regulating valve 10 according to the pressure measurement value and the pressure setting value of the air cushion chamber 200, so as to control the actual pressure value of the air cushion chamber 200 to be consistent with the set value. In addition, a muffler 14 is provided at the end of the exhaust pipe of the air cushion chamber 200 to reduce the noise pollution caused by exhaust.

[0065] In addition, another embodiment of the present invention further provides a slurry shield machine, which preferably adopts the automatic pressure maintaining system as described above.

[0066] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An automatic pressure maintaining system for a slurry shield machine, characterized in that: include: An excavation chamber pressure sensor (1) is used to measure the pressure value of the excavation chamber (100); A first analog-to-digital converter (2) is electrically connected to the excavation chamber pressure sensor (1) and is used to convert the analog signal output by the excavation chamber pressure sensor (1) into an electrical signal; An air cushion chamber pressure transmitter (8) for measuring the pressure value of the air cushion chamber (200); a pneumatic pressure-maintaining PID controller (3) connected to the air cushion chamber pressure transmitter (8) for adjusting the pressure setting value of the air cushion chamber (200) and performing PID control on the pressure of the air cushion chamber (200) according to the pressure setting value of the air cushion chamber (200) and the measurement result of the air cushion chamber pressure transmitter (8); A processor (4) is electrically connected to the first analog-to-digital converter (2), and is used to calculate a current theoretical liquid level difference based on the pressure measurement value of the excavation chamber (100) and the pressure setting value of the air cushion chamber (200), and automatically adjust the pressure setting value of the air cushion chamber (200) when the current theoretical liquid level difference exceeds an allowable range, so that the theoretical liquid level difference is within the allowable range; It also includes an electrical converter (11), a pneumatic motor (12) and a pressure regulating device (13), wherein the electrical converter (11) is electrically connected to the processor (4) and is used to convert the electrical control signal output by the processor (4) into a pneumatic control signal, and the pressure regulating device (13) is used to output the pneumatic signal to the pneumatic pressure-maintaining PID controller (3) to adjust the pressure setting value of the air cushion chamber (200), and the pneumatic motor (12) is respectively connected to the electrical converter (11) and the pressure regulating device (13) and is used to control the size of the pneumatic signal output by the pressure regulating device (13) according to the pneumatic control signal output by the electrical converter (11); The pressure regulating device (13) comprises an air source (131), a reversing mechanism (132), a manual pressure regulating device (133) and an automatic pressure regulating device (134); the manual pressure regulating device (133) is used to manually adjust the size of the output air signal before excavation; the automatic pressure regulating device (134) is connected to the pneumatic motor (12) and is used to automatically adjust the size of the output air signal during excavation; the manual pressure regulating device (133) and the automatic pressure regulating device (134) are arranged in parallel and connected to the air source (131) via the reversing mechanism (132); the reversing mechanism (132) is used to control the manual pressure regulating device (133) to be in communication with the air source (131) or the automatic pressure regulating device (134) to be in communication with the air source (131); The manual pressure regulating device (133) and the automatic pressure regulating device (134) both include: A base (25) is used as a support, and the base (25) has a gas source cavity (29), an input hole (23) for inputting gas, and an output hole (26) for outputting gas, wherein the input hole (23) is connected to the reversing mechanism (132) and the gas source cavity (29), respectively, and the output hole (26) is connected to the pneumatic pressure-maintaining PID controller (3); an amplifier (21) for amplifying gas flow, mounted on the base (25), comprising an input chamber (27), an output chamber (28), and a first regulating assembly, wherein the input chamber (27) is connected to the input hole (23), the output chamber (28) is connected to the output hole (26), and the first regulating assembly is used to change the gas pressure of the output chamber (28) in response to the pressure change of the input chamber (27); an adjusting mechanism (22) mounted on the base (25), comprising an adjusting chamber, a second adjusting assembly, a floating plate (225), and a nozzle (224) communicating with the input chamber (27) and the adjusting chamber, wherein the second adjusting assembly is used to adjust the distance between the first end of the floating plate (225) and the nozzle hole of the nozzle (224), thereby adjusting the air pressure in the adjusting chamber; A feedback component (24) is provided on the base (25) and is respectively connected to the regulating chamber and the output chamber (28), and is used to allow the air pressure output by the output chamber (28) to act on the second end of the floating plate (225) to regulate the air pressure in the regulating chamber.

2. The automatic pressure maintaining system for a slurry shield machine according to claim 1, characterized in that: The amplifier (21) further includes a first cover plate (213), the base (25) has a first mounting cavity located on the gas source cavity (29), and the first cover plate (213) is sealed and provided on the first mounting cavity; the first regulating assembly includes a diaphragm assembly (214) provided in the first mounting cavity, and the diaphragm assembly (214) is used to separate the first mounting cavity into the input cavity (27) and the output cavity (28).

3. The automatic pressure maintaining system for a slurry shield machine according to claim 2, characterized in that: The base (25) includes a valve seat (216) installed on the gas source cavity (29) for separating the gas source cavity (29) and the first installation cavity; the first regulating assembly also includes a valve core (218) and a first elastic member (219), the first elastic member (219) being installed between the bottom of the gas source cavity (29) and the valve core (218), the first elastic member (219) being used to keep the valve core (218) against the valve hole of the valve seat (216); the diaphragm assembly (21 4) is used to move toward the output chamber (28) when the pressure in the input chamber (27) increases, thereby moving the valve core (218), thereby opening the valve hole or increasing the gap between the valve core (218) and the valve hole. The diaphragm assembly (214) is also used to move toward the input chamber (27) when the pressure in the input chamber (27) decreases, thereby causing the valve core (218) to reset under the action of the first elastic member (219), thereby reducing the gap between the valve core (218) and the valve hole or closing the valve hole.

4. The automatic pressure maintaining system for a slurry shield machine according to claim 1, wherein: The adjusting mechanism (22) includes a second elastic member (2213), a first end of the second elastic member (2213) is connected to the first end of the floating plate (225), a second end of the second elastic member (2213) is fixedly connected to the base (25), and the extension and contraction direction of the second elastic member (2213) is perpendicular to or tends to be perpendicular to the floating plate (225); a traction beam (227) is fixedly provided above the first end of the floating plate (225); the second adjusting assembly includes a traction block (223) provided above the floating plate (225) and an adjusting screw (228) passing through the traction block (223) and arranged along the length direction of the floating plate (225) and parallel to the floating plate (225), the traction block (223) is connected to the traction beam (227) through a third elastic member (226); the adjusting screw (228) is used to drive the traction block (223) to move toward the second end of the floating plate (225), so as to apply traction to the traction beam (227) through the third elastic member (226), thereby driving the first end of the floating plate (225) away from the nozzle (224); the adjusting screw (228) is also used to drive the traction block (223) to move toward the first end of the floating plate (225), so as to cancel the traction on the traction beam (227), thereby causing the first end of the floating plate (225) to reset under the elastic force of the second elastic member (2213) in a stretched state and move toward the nozzle (224).

5. The automatic pressure maintaining system for a slurry shield machine according to claim 1, characterized in that: Also includes: A pneumatic air intake regulating valve (9) is provided on the air intake pipeline of the air cushion chamber (200) and is used to control the air intake of the air cushion chamber (200); A pneumatic exhaust regulating valve (10) is provided on the exhaust pipeline of the air cushion chamber (200) and is used to control the exhaust of the air cushion chamber (200); The pneumatic pressure-maintaining PID controller (3) is connected to the pneumatic air inlet regulating valve (9) and the pneumatic air exhaust regulating valve (10) respectively, and is used to control the working states of the pneumatic air inlet regulating valve (9) and the pneumatic air exhaust regulating valve (10) according to the pressure measurement value and the pressure setting value of the air cushion chamber (200), so as to control the actual pressure value of the air cushion chamber (200) to be consistent with the setting value.

6. The automatic pressure maintaining system for a slurry shield machine according to claim 5, characterized in that: A muffler (14) is provided at the end of the exhaust pipe of the air cushion chamber (200).

7. A slurry shield machine, characterized in that: An automatic pressure maintaining system as described in any one of claims 1 to 6 is adopted.

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