Air automatic pressure maintaining control system and control method of shield tunneling machine, and shield tunneling machine

Abstract

The application discloses an air automatic pressure maintaining control system and method of a shield tunneling machine and the shield tunneling machine. In the control system, a pneumatic controller outputs a pressure signal of P1-P3 according to a pressure value in a gas cushion cabin, so as to control the opening and closing states of a first pressure comparison valve and a second pressure comparison valve, and then control the opening and closing states of a first pneumatic ball valve and a second pneumatic ball valve, and further control the gas cushion cabin to switch between an air inlet state, an air exhaust state and a pressure maintaining state. The opening and closing of the pneumatic ball valves on the air exhaust pipeline and the air inlet pipeline are controlled by the two pressure comparison valves, and only one pneumatic regulating valve is used to realize the air inlet regulation and the air exhaust regulation of the gas cushion cabin, so that the cost of the air automatic pressure maintaining system is reduced. In addition, the range signal output by the pneumatic controller is converted into a single range signal, and no matter the air inlet process or the air exhaust process, the regulating range is [P1, P3], so that the range regulating amplitude of the pneumatic regulating valve is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic air pressure maintaining system of shield machine, in particular, relates to an automatic air pressure maintaining control system and method of shield machine, and further relates to a shield machine using the control system. BACKGROUND

[0002] During the process of shield machine tunneling, the shield body near the excavation face will bear certain stratum earth pressure and water pressure, in order to maintain the stability of the excavation face and prevent the uplift and subsidence of the ground surface, pressurized air is often used to maintain the stability of the excavation face, and the automatic air pressure maintaining system is a control system for achieving the above purpose by using pressurized air. Figure 1 As shown in the figure, the working process of the existing automatic air pressure maintaining system is as follows: the pneumatic controller receives the air cabin pressure sent by the transmitter and compares it with the set pressure, if the air cushion cabin pressure is greater than the set pressure of the pneumatic controller, the pneumatic controller outputs a signal pressure in the range of P1-P2, at this time the spring force of the counter-acting exhaust valve is greater than the gas pressure, the exhaust valve is opened, the spring force of the positive-acting air inlet valve is also greater than the gas pressure, the air inlet valve remains closed, the air cushion cabin gas is discharged, and the air cushion cabin pressure is reduced; if the air cushion cabin pressure is less than the set pressure of the pneumatic controller, the pneumatic controller outputs a signal pressure in the range of P2-P3, the spring force of the positive-acting air inlet valve is less than the gas pressure, the air inlet valve is opened, the spring force of the counter-acting exhaust valve is also less than the gas pressure, the exhaust valve is closed, the air compressor gas enters the air cushion cabin through the air inlet valve, and the air cabin pressure rises. Finally, the air cushion cabin pressure is equal to the set pressure, the signal pressure output by the pneumatic controller is equal to P2, and the two pneumatic regulating valves remain closed at the same time, achieving the purpose of pressure maintaining. Among them, the signals of the whole system are standard pressure gas, 0.2bar

[0003] Therefore, in order to distinguish the air inlet signal and the exhaust signal, the existing automatic air pressure maintaining system directly adopts a split range processing method, the signal pressure output by the pneumatic controller is directly output to the air inlet valve and the exhaust valve, the exhaust signal pressure is P1-P2, and the air inlet signal is P2-P3. However, the air inlet valve and the exhaust valve will not work at the same time, and the price of the pneumatic regulating valve is very expensive, thereby causing the cost of the automatic air pressure maintaining system to be high, and the control method directly adopting the split range processing reduces the stroke adjustment range of the pneumatic regulating valve. SUMMARY

[0004] The present application provides an automatic air pressure maintaining control system and method of shield machine, and a shield machine, to solve the technical problem of high cost of the existing automatic air pressure maintaining system.

[0005] According to one aspect of the present application, an air automatic pressure maintaining control system of a shield tunneling machine is provided, comprising a pressure transmitter, a pneumatic controller, a first pressure comparison valve, a second pressure comparison valve, an air compressor, a first pneumatic ball valve, a first one-way valve, a pneumatic regulating valve, a second pneumatic ball valve and a second one-way valve, the pressure transmitter is used to detect the pressure in the air cushion cabin, the output end of the air compressor is connected with the first end of the first pneumatic ball valve, the second end of the first pneumatic ball valve is connected with the first end of the pneumatic regulating valve and the output end of the first one-way valve respectively, the first end of the second pneumatic ball valve is connected with the outside, and the second end is connected with the second end of the pneumatic regulating valve and the input end of the second one-way valve respectively, the input end of the first one-way valve and the output end of the second one-way valve are connected with the air cushion cabin, the two ends of the first pressure comparison valve are connected with an external air source and the control end of the first pneumatic ball valve respectively, the two ends of the second pressure comparison valve are connected with an external air source and the control end of the second pneumatic ball valve respectively, the pneumatic controller is connected with the pressure transmitter, and is also connected with the control ends of the first pressure comparison valve, the second pressure comparison valve and the pneumatic regulating valve, is used to output a pressure to the control ends of the first pressure comparison valve, the second pressure comparison valve and the pneumatic regulating valve according to the detection result of the pressure transmitter, so as to control the opening and closing states of the first pressure comparison valve and the second pressure comparison valve, thereby controlling the opening and closing states of the first pneumatic ball valve and the second pneumatic ball valve, and further controlling the air cushion cabin to switch between the air inlet state, the air exhaust state and the pressure maintaining state, and simultaneously controlling the opening degree of the pneumatic regulating valve.

[0006] Further, if the pressure output by the pneumatic controller is greater than P2+0.02bar, the second pressure comparison valve is opened, the first pressure comparison valve is closed, thereby controlling the first pneumatic ball valve to be opened and the second pneumatic ball valve to be closed, and the air cushion cabin is in the air inlet state;

[0007] If the pressure output by the pneumatic controller is less than P2-0.02bar, the second pressure comparison valve is closed, the first pressure comparison valve is opened, thereby controlling the first pneumatic ball valve to be closed and the second pneumatic ball valve to be opened, and the air cushion cabin is in the air exhaust state;

[0008] If the pressure output by the pneumatic controller is between [P2-0.02bar, P2+0.02bar], the second pressure comparison valve and the first pressure comparison valve are both closed, thereby controlling the first pneumatic ball valve and the second pneumatic ball valve to be closed, and the air cushion cabin is in the pressure maintaining state.

[0009] Further, a signal conversion device is further included, which is connected with the pneumatic controller and the pneumatic regulating valve respectively, is used to convert the range pressure output by the pneumatic controller into a single pressure and then output to the pneumatic regulating valve, so as to control the opening degree of the pneumatic regulating valve.

[0010] Further, the signal conversion device comprises a first pressure-displacement conversion component, a symmetrical cam, a pneumatic amplifier and a nozzle baffle, the pneumatic amplifier is connected with an external air source, the upper end of the nozzle baffle is hinged, the lower end is in a free state, the nozzle baffle is located in front of the nozzle of the pneumatic amplifier, by adjusting the distance between the nozzle baffle and the nozzle of the pneumatic amplifier, the back pressure of the pneumatic amplifier can be adjusted, thereby the output pressure of the pneumatic amplifier is adjusted, one end of the symmetrical cam is hinged, the other end abuts against the middle part of the nozzle baffle, one end of the first pressure-displacement conversion component is fixed, the other end is connected with the extension rod of the symmetrical cam, the first pressure-displacement conversion component is also connected with the pneumatic controller, for converting the pressure output by the pneumatic controller into displacement.

[0011] When the signal pressure output by the pneumatic controller is between [P2-0.02bar, P2+0.02bar], the first pressure-displacement conversion component does not stretch or shrink, the contact point between the symmetrical cam and the nozzle baffle is located at the maximum radius of the symmetrical cam, the distance between the nozzle baffle and the nozzle of the pneumatic amplifier is the farthest, the air pressure signal output by the pneumatic amplifier is the smallest, thereby the opening degree of the pneumatic regulating valve is the smallest.

[0012] When the signal pressure output by the pneumatic controller is not between [P2-0.02bar, P2+0.02bar], the first pressure-displacement conversion component stretches or shrinks and drives the symmetrical cam to rotate counterclockwise or clockwise, the radius at the contact point between the symmetrical cam and the nozzle baffle becomes smaller, thereby the nozzle baffle rotates counterclockwise, the distance between the nozzle baffle and the nozzle of the pneumatic amplifier decreases, the back pressure of the pneumatic amplifier increases, the output pressure of the pneumatic amplifier increases, thereby the opening degree of the pneumatic regulating valve increases.

[0013] Further, the signal conversion device further comprises a second pressure-displacement conversion component, the second pressure-displacement conversion component is connected with the output end of the pneumatic amplifier, and the movable end of the second pressure-displacement conversion component is connected with the lower end of the nozzle baffle, when the output pressure of the pneumatic amplifier becomes larger, the feedback is transmitted to the second pressure-displacement conversion component, the movable end of the second pressure-displacement conversion component stretches to drive the nozzle baffle to rotate clockwise, the distance between the nozzle baffle and the nozzle of the pneumatic amplifier is increased, thereby the feedback adjustment is realized.

[0014] Further, the signal conversion device further comprises an adjusting spring, one end of the adjusting spring is fixed, the other end is connected with the nozzle baffle, by adjusting the spring force of the adjusting spring, the rigidity of the nozzle baffle is adjusted.

[0015] Further, the first pressure-displacement conversion assembly and the second pressure-displacement conversion assembly are bellows or Bourdon tubes.

[0016] In addition, the application further provides an air automatic pressure maintaining control method of a shield tunneling machine, which adopts the air automatic pressure maintaining control system.

[0017] The pressure in the air cushion cabin is detected by a pressure transmitter;

[0018] A pressure is output to the control end of the first pressure comparison valve, the second pressure comparison valve and the pneumatic regulating valve according to the detection result of the pressure transmitter, so as to control the opening and closing states of the first pressure comparison valve and the second pressure comparison valve, thereby controlling the opening and closing states of the first pneumatic ball valve and the second pneumatic ball valve, and further controlling the air cushion cabin to switch between the air intake state, the air exhaust state and the pressure maintaining state, and controlling the opening degree of the pneumatic regulating valve.

[0019] Further, the application further comprises the following content: the output split-range pressure is converted into single-range pressure and then output to the pneumatic regulating valve, so as to control the opening degree of the pneumatic regulating valve.

[0020] In addition, the application further provides a shield tunneling machine, which adopts the air automatic pressure maintaining control system.

[0021] The application has the following effects:

[0022] The air automatic pressure maintaining control system of the shield tunneling machine, the pneumatic controller outputs a P1-P3bar pressure signal according to the pressure value in the air cushion cabin detected by the pressure transmitter, so as to control the opening and closing states of the first pressure comparison valve and the second pressure comparison valve, thereby controlling the opening and closing states of the first pneumatic ball valve and the second pneumatic ball valve. When the first pressure comparison valve is controlled to be closed and the second pressure comparison valve is controlled to be opened, the second pneumatic ball valve is controlled to be closed and the first pneumatic ball valve is controlled to be opened, the compressed air output by the air compressor enters the air cushion cabin in sequence through the first pneumatic ball valve, the pneumatic regulating valve and the second check valve, the air cushion cabin is in the air intake state, and the compressed air pushes against the first check valve; when the first pressure comparison valve is controlled to be opened and the second pressure comparison valve is controlled to be closed, the second pneumatic ball valve is controlled to be opened and the first pneumatic ball valve is controlled to be closed, the compressed air output by the air compressor cannot enter, the air in the air cushion cabin is exhausted in sequence through the first check valve, the pneumatic regulating valve and the second pneumatic ball valve, and the air cushion cabin is in the air exhaust state; and when the first pressure comparison valve and the second pressure comparison valve are both controlled to be closed, the second pneumatic ball valve and the first pneumatic ball valve are both closed, the air cushion cabin cannot intake air or exhaust air, and the air cushion cabin is in the pressure maintaining state. The application uses two pressure comparison valves to control the opening and closing of the pneumatic ball valves on the air exhaust pipeline and the air intake pipeline, and only one pneumatic regulating valve is used to realize the air intake regulation and the air exhaust regulation of the air cushion cabin, thereby reducing the cost of the air automatic pressure maintaining system.

[0023] In addition, the air automatic pressure maintaining control method of the shield tunneling machine and the shield tunneling machine have the above advantages.

[0024] In addition to the above described objects, features and advantages, the present application has other objects, features and advantages. The present application will be further described in detail with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which form a part of this application, are intended to provide further understanding of the application and are incorporated herein in

[0026] Figure 1 is a schematic diagram of the principle of the existing air automatic pressure maintaining system.

[0027] Figure 2 is a schematic diagram of the principle of the air automatic pressure maintaining control system of the shield tunneling machine of the preferred embodiment of the present application.

[0028] BRIEF DESCRIPTION OF DRAWINGS

[0029] 1, air cushion cabin; 2, pressure transmitter; 3, pneumatic controller; 4, first pressure comparison valve; 5, second pressure comparison valve; 6, air compressor; 7, first pneumatic ball valve; 8, first check valve; 9, pneumatic regulating valve; 10, second pneumatic ball valve; 11, muffler; 12, second check valve; 13, signal conversion device; 14, pneumatic amplifier; 15, nozzle baffle; 16, adjusting spring; 17, symmetrical cam; 18, first pressure-displacement conversion assembly; 19, second pressure-displacement conversion assembly. DETAILED DESCRIPTION

[0030] The embodiments of the present application will be described in detail below with reference to the drawings, but the present application can be implemented in various different ways as defined and covered below.

[0031] As Figure 2As shown, the preferred embodiment of the present application provides an automatic air pressure maintaining control system for a shield tunneling machine, comprising a pressure transmitter 2, a pneumatic controller 3, a first pressure comparison valve 4, a second pressure comparison valve 5, an air compressor 6, a first pneumatic ball valve 7, a first one-way valve 8, a pneumatic regulating valve 9, a second pneumatic ball valve 10 and a second one-way valve 12, wherein the pressure transmitter 2 is used to detect the pressure in the air cushion cabin 1, the output end of the air compressor 6 is connected with the first end of the first pneumatic ball valve 7, the second end of the first pneumatic ball valve 7 is connected with the first end of the pneumatic regulating valve 9 and the output end of the first one-way valve 8 respectively, the first end of the second pneumatic ball valve 10 is connected with the outside, and the second end is connected with the second end of the pneumatic regulating valve 9 and the input end of the second one-way valve 12 respectively, the input end of the first one-way valve 8 and the output end of the second one-way valve 12 are connected with the air cushion cabin 1, the two ends of the first pressure comparison valve 4 are connected with an external air source and the control end of the first pneumatic ball valve 7 respectively, the two ends of the second pressure comparison valve 5 are connected with an external air source and the control end of the second pneumatic ball valve 10 respectively, the on-off of the second pneumatic ball valve 10 is controlled by the first pressure comparison valve 4, and the on-off of the first pneumatic ball valve 7 is controlled by the second pressure comparison valve 5. The pneumatic controller 3 is connected with the pressure transmitter 2, and is also connected with the control ends of the first pressure comparison valve 4, the second pressure comparison valve 5 and the pneumatic regulating valve 9, and is used to output a pressure to the control ends of the first pressure comparison valve 4, the second pressure comparison valve 5 and the pneumatic regulating valve 9 according to the detection result of the pressure transmitter 2, so as to control the opening and closing states of the first pressure comparison valve 4 and the second pressure comparison valve 5, thereby controlling the opening and closing states of the first pneumatic ball valve 7 and the second pneumatic ball valve 10, and further controlling the air cushion cabin 1 to switch between the air inlet state, the air exhaust state and the pressure maintaining state, while controlling the opening degree of the pneumatic regulating valve 9.

[0032] It can be understood that the air automatic pressure maintaining control system of the tunneling machine in the embodiment, the pneumatic controller 3 outputs a pressure signal of P1~P3bar according to the pressure value in the air cushion cabin 1 detected by the pressure transmitter 2, to control the opening and closing state of the first pressure comparison valve 4 and the second pressure comparison valve 5, thereby controlling the opening and closing state of the first pneumatic ball valve 7 and the second pneumatic ball valve 10. When the first pressure comparison valve 4 is controlled to be closed and the second pressure comparison valve 5 is controlled to be opened, the second pneumatic ball valve 10 is closed and the first pneumatic ball valve 7 is opened, and the compressed air output by the air compressor 6 enters the air cushion cabin 1 in sequence through the first pneumatic ball valve 7, the pneumatic regulating valve 9 and the second one-way valve 12, the air cushion cabin 1 is in the air inlet state, and the compressed air pushes against the first one-way valve 8; when the first pressure comparison valve 4 is controlled to be opened and the second pressure comparison valve 5 is controlled to be closed, the second pneumatic ball valve 10 is opened and the first pneumatic ball valve 7 is closed, and the compressed air output by the air compressor 6 cannot enter, the air in the air cushion cabin 1 is discharged in sequence through the first one-way valve 8, the pneumatic regulating valve 9 and the second pneumatic ball valve 10, and the air cushion cabin 1 is in the air exhaust state; and when the first pressure comparison valve 4 and the second pressure comparison valve 5 are both controlled to be closed, the second pneumatic ball valve 10 and the first pneumatic ball valve 7 are both closed, the air cushion cabin 1 cannot intake and exhaust air, and the air cushion cabin 1 is in the pressure maintaining state. At the same time, the pressure output by the pneumatic controller 3 can control the opening degree of the pneumatic regulating valve 9, thereby controlling the air flow in the air inlet process and the air exhaust process. The present application uses two pressure comparison valves to control the opening and closing of the pneumatic ball valves on the air exhaust pipeline and the air inlet pipeline respectively, and only one pneumatic regulating valve 9 is used to realize the air inlet regulation and the air exhaust regulation of the air cushion cabin 1, thereby reducing the cost of the air automatic pressure maintaining system.

[0033] It can be understood that if the pressure output by the pneumatic controller 3 is greater than P2+0.02bar, the second pressure comparison valve 5 is opened and the first pressure comparison valve 4 is closed, thereby controlling the first pneumatic ball valve 7 to be opened and the second pneumatic ball valve 10 to be closed, and the air cushion cabin 1 is in the air inlet state;

[0034] If the pressure output by the pneumatic controller 3 is less than P2-0.02bar, the second pressure comparison valve 5 is closed and the first pressure comparison valve 4 is opened, thereby controlling the first pneumatic ball valve 7 to be closed and the second pneumatic ball valve 10 to be opened, and the air cushion cabin 1 is in the air exhaust state;

[0035] If the pressure output by the pneumatic controller 3 is between [P2-0.02bar, P2+0.02bar], the second pressure comparison valve 5 and the first pressure comparison valve 4 are both closed, thereby controlling the first pneumatic ball valve 7 and the second pneumatic ball valve 10 to be closed, and the air cushion cabin 1 is in the pressure maintaining state.

[0036] Specifically, the upper critical opening pressure of the first pressure comparison valve 4 is P2-0.02 bar, when the pressure value output by the pneumatic controller 3 to the control end of the first pressure comparison valve 4 is less than P2-0.02 bar, i.e. the output pressure of the pneumatic controller 3 is between [P1, P2-0.02 bar], the first pressure comparison valve 4 will open, otherwise it will close; while the lower critical opening pressure of the second pressure comparison valve 5 is P2+0.02 bar, when the pressure value output by the pneumatic controller 3 to the control end of the second pressure comparison valve 5 is greater than P2+0.02 bar, i.e. the output pressure of the pneumatic controller 3 is between [P2+0.02 bar, P3], the second pressure comparison valve 5 will open, otherwise it will close.

[0037] Therefore, when the pressure output by the pneumatic controller 3 is greater than P2+0.02 bar, the second pressure comparison valve 5 opens, the input pressure gas of the external air source (4 bar) drives the first pneumatic ball valve 7 to open, while the first pressure comparison valve 4 closes, the pressure gas of the external air source (4 bar) cannot be delivered to the control end of the second pneumatic ball valve 10, and the second pneumatic ball valve 10 is in a closed state, at this time, the compressed air output by the air compressor 6 is input into the hovercraft cabin 1 through the first pneumatic ball valve 7, the pneumatic regulating valve 9 and the intake branch of the second one-way valve 12, and the hovercraft cabin 1 is in an air intake state. When the pressure output by the pneumatic controller 3 is less than P2-0.02 bar, the first pressure comparison valve 4 opens, the pressure gas of the external air source (4 bar) is delivered to the control end of the second pneumatic ball valve 10 to drive it to open, while the second pressure comparison valve 5 closes, the pressure gas of the external air source (4 bar) cannot be delivered to the control end of the first pneumatic ball valve 7, and the first pneumatic ball valve 7 is in a closed state, at this time, the compressed air output by the air compressor 6 cannot enter, and the pressure air in the hovercraft cabin 1 is sequentially discharged to the outside through the first one-way valve 8, the pneumatic regulating valve 9 and the exhaust branch of the second pneumatic ball valve 10, and the hovercraft cabin 1 is in an exhaust state. When the pressure output by the pneumatic controller 3 is between [P2-0.02 bar, P2+0.02 bar], at this time, the first pressure comparison valve 4 and the second pressure comparison valve 5 are both closed, the pressure gas of the external air source (4 bar) cannot be delivered to the control end of the first pneumatic ball valve 7 and the second pneumatic ball valve 10, and the first pneumatic ball valve 7 and the second pneumatic ball valve 10 are both closed, the hovercraft cabin 1 cannot intake and exhaust air, and is in a pressure maintaining state.

[0038] It can be understood that in other embodiments of the present application, the upper critical opening pressure of the first pressure comparison valve 4 and the lower critical opening pressure of the second pressure comparison valve 5 can also be set according to actual needs, but the lower critical opening pressure of the second pressure comparison valve 5 must be greater than the upper critical opening pressure of the first pressure comparison valve 4, for example, the upper critical opening pressure of the first pressure comparison valve 4 is set to P2-0.01 bar, and the lower critical opening pressure of the second pressure comparison valve 5 is set to P2+0.03 bar.

[0039] In addition, the first end of the second pneumatic ball valve 10 is also connected with a silencer 11 for reducing or eliminating the noise generated by the air cushion cabin 1 during exhaust.

[0040] It can be understood that when the air pressure signal output by the pneumatic controller 3 directly controls the opening degree of the pneumatic regulating valve 9, the inlet stroke signal of the pneumatic regulating valve 9 is [P2+0.02 bar, P3], and the exhaust stroke signal is [P1, P2-0.02 bar], that is, the air pressure signal output by the pneumatic controller 3 is still a split-range signal, and the stroke adjustment range of the pneumatic regulating valve 9 is poor. Therefore, as a preferred, the air automatic pressure maintaining control system further comprises a signal conversion device 13 connected with the pneumatic controller 3 and the pneumatic regulating valve 9 respectively, for converting the split-range pressure output by the pneumatic controller 3 into a single-range pressure and outputting to the pneumatic regulating valve 9 to control the opening degree of the pneumatic regulating valve 9, and through the signal conversion device 13, the split-range pressure is converted into a single-range pressure, so that the adjustment stroke of the pneumatic regulating valve 9 is [P1, P3] in both the inlet process and the exhaust process, greatly improving the stroke adjustment range of the pneumatic regulating valve 9.

[0041] Specifically, the signal conversion device 13 comprises a first pressure-displacement conversion assembly 18, a symmetrical cam 17, a pneumatic amplifier 14 connected with an external air source (1.4 bar), and a nozzle baffle 15, the upper end of which is hinged and the lower end of which is free. The nozzle baffle 15 is located in front of the nozzle of the pneumatic amplifier 14, and the back pressure of the pneumatic amplifier 14 can be adjusted by adjusting the distance between the nozzle baffle 15 and the nozzle of the pneumatic amplifier 14, so as to adjust the output pressure of the pneumatic amplifier 14. One end of the symmetrical cam 17 is hinged and the other end abuts against the middle part of the nozzle baffle 15, wherein the radius of the symmetrical cam 17 is the largest at the distal end of the symmetry axis, gradually decreases from the distal end of the symmetry axis to both sides, and the decrease amplitudes of both sides are consistent. The proximal end of the symmetrical cam 17 is hinged and the distal end abuts against the middle part of the nozzle baffle 15. When the symmetrical cam 17 rotates, the contact point of the symmetrical cam 17 with the nozzle baffle 15 changes. Due to the change of the contact point, the nozzle baffle 15 rotates with the change of the contact point until it abuts against the symmetrical cam 17 again. One end of the first pressure-displacement conversion assembly 18 is fixed and the other end is connected with the extension rod of the symmetrical cam 17. The first pressure-displacement conversion assembly 18 is also connected with the pneumatic controller 3, and is used to convert the pressure output by the pneumatic controller 3 into displacement. The open end of the first pressure-displacement conversion assembly 18 is fixed and the sealing section is connected with the extension rod of the symmetrical cam 17. The open end of the first pressure-displacement conversion assembly 18 is connected with the pneumatic controller 3. When the pneumatic controller 3 outputs pressure gas into the first pressure-displacement conversion assembly 18, the first pressure-displacement conversion assembly 18 will perform telescopic displacement, thereby driving the symmetrical cam 17 to rotate around the hinge point.

[0042] When the signal pressure output by the pneumatic controller 3 is between [P2-0.02 bar, P2+0.02 bar], the first pressure-displacement conversion assembly 18 does not perform telescopic displacement, that is, the pressure output by the pneumatic controller 3 is in the balanced pressure interval. At this time, the contact point of the symmetrical cam 17 with the nozzle baffle 15 is located at the maximum radius of the symmetrical cam 17, that is, the contact point is located at the distal end of the symmetrical cam 17. The distance between the nozzle baffle 15 and the nozzle of the pneumatic amplifier 14 is the farthest, and the air pressure signal output by the pneumatic amplifier 14 is the smallest, for example, the air pressure output by the pneumatic amplifier 14 is P1, thereby controlling the opening of the pneumatic regulating valve 9 to be the smallest.

[0043] When the signal pressure outputted by the pneumatic controller 3 is not in [P2-0.02bar, P2+0.02bar], the first pressure-displacement conversion assembly 18 extends or contracts and drives the symmetrical cam 17 to rotate counterclockwise or clockwise, the radius of the contact point between the symmetrical cam 17 and the nozzle baffle 15 becomes smaller, so that the nozzle baffle 15 rotates counterclockwise, the distance between the nozzle baffle 15 and the nozzle of the pneumatic amplifier 14 decreases, the back pressure of the pneumatic amplifier 14 increases, the output pressure of the pneumatic amplifier 14 increases, and the opening of the pneumatic regulating valve 9 controlled thereby increases.

[0044] For example, when the signal pressure outputted by the pneumatic controller 3 is between [P1, P2-0.02bar], the first pressure-displacement conversion assembly 18 contracts, thereby driving the symmetrical cam 17 to rotate clockwise, the contact point between the symmetrical cam 17 and the nozzle baffle 15 moves from the far end to the upper arc, the nozzle baffle 15 rotates counterclockwise until it again abuts against the symmetrical cam 17, the distance between the nozzle baffle 15 and the nozzle of the pneumatic amplifier 14 decreases, the back pressure of the pneumatic amplifier 14 increases, the output pressure of the pneumatic amplifier 14 increases, and the opening of the pneumatic regulating valve 9 controlled thereby increases. When the signal pressure outputted by the pneumatic controller 3 is P1, the contraction amplitude of the first pressure-displacement conversion assembly 18 is the largest, the rotation amplitude of the symmetrical cam 17 and the nozzle baffle 15 is the largest, the distance between the nozzle baffle 15 and the nozzle of the pneumatic amplifier 14 is the smallest, the back pressure of the pneumatic amplifier 14 is the largest, the output pressure of the pneumatic amplifier 14 is P3, and the opening of the pneumatic regulating valve 9 controlled thereby is the largest.

[0045] Or, when the signal pressure outputted by the pneumatic controller 3 is between [P2+0.02bar, P3], the first pressure-displacement conversion assembly 18 extends, thereby driving the symmetrical cam 17 to rotate counterclockwise, the contact point between the symmetrical cam 17 and the nozzle baffle 15 moves from the far end to the lower arc, the nozzle baffle 15 rotates counterclockwise until it again abuts against the symmetrical cam 17, the distance between the nozzle baffle 15 and the nozzle of the pneumatic amplifier 14 decreases, the back pressure of the pneumatic amplifier 14 increases, the output pressure of the pneumatic amplifier 14 increases, and the opening of the pneumatic regulating valve 9 controlled thereby increases. When the signal pressure outputted by the pneumatic controller 3 is P3, the extension amplitude of the first pressure-displacement conversion assembly 18 is the largest, the rotation amplitude of the symmetrical cam 17 and the nozzle baffle 15 is the largest, the distance between the nozzle baffle 15 and the nozzle of the pneumatic amplifier 14 is the smallest, the back pressure of the pneumatic amplifier 14 is the largest, the output pressure of the pneumatic amplifier 14 is P3, and the opening of the pneumatic regulating valve 9 controlled thereby is the largest.

[0046] Further preferably, the signal conversion device 13 further comprises a second pressure-displacement conversion component 19, which is connected with the output end of the pneumatic amplifier 14, and the movable end of the second pressure-displacement conversion component 19 is connected with the lower end of the nozzle baffle 15. Specifically, the open end of the second pressure-displacement conversion component 19 is fixed, the movable end is connected with the lower end of the nozzle baffle 15, when the pressure gas output by the pneumatic amplifier 14 enters the second pressure-displacement conversion component 19, the second pressure-displacement conversion component 19 performs the telescopic action, thereby driving the nozzle baffle 15 to rotate. When the output pressure of the pneumatic amplifier 14 is increased and fed back to the second pressure-displacement conversion component 19, the movable end of the second pressure-displacement conversion component 19 is extended to drive the nozzle baffle 15 to rotate clockwise, thereby increasing the distance between the nozzle baffle 15 and the nozzle of the pneumatic amplifier 14, so as to realize the feedback regulation and improve the control precision. Similarly, when the output pressure of the pneumatic amplifier 14 is decreased and fed back to the second pressure-displacement conversion component 19, the movable end of the second pressure-displacement conversion component 19 is retracted to drive the nozzle baffle 15 to rotate counterclockwise, thereby reducing the distance between the nozzle baffle 15 and the nozzle of the pneumatic amplifier 14. The first pressure-displacement conversion component 18 and the second pressure-displacement conversion component 19 are bellows or Bourdon tubes, and since the pressure value output by the pneumatic controller 3 is not large, in order to ensure the control precision, the bellows is preferably adopted.

[0047] Further preferably, the signal conversion device 13 further comprises an adjusting spring 16, one end of the adjusting spring 16 is fixed, and the other end is connected with the nozzle baffle 15, and the rigidity of the nozzle baffle 15 is adjusted by adjusting the spring force of the adjusting spring 16, thereby adjusting the sensitivity of the entire signal conversion device 13.

[0048] It can be understood that one end of the adjusting spring 16 is fixed, and the other end is connected with the nozzle baffle 15, and the rigidity of the nozzle baffle 15 can be adjusted by controlling the spring force of the adjusting spring 16, thereby the damping of the rotation of the nozzle baffle 15 can be adjusted, which is equivalent to adjusting the sensitivity of the entire signal conversion device 13, so as to meet different sensitivity requirements.

[0049] In addition, another embodiment of the present application also provides an air automatic pressure maintaining control method of a shield tunneling machine, preferably adopting the air automatic pressure maintaining control system as described above, and the method comprises the following contents:

[0050] The pressure in the air cushion cabin 1 is detected by the pressure transmitter 2;

[0051] According to the detection result of the pressure transmitter 2, a pressure is output to the control end of the first pressure comparison valve 4, the second pressure comparison valve 5 and the pneumatic regulating valve 9, so as to control the opening and closing state of the first pressure comparison valve 4 and the second pressure comparison valve 5, thereby controlling the opening and closing state of the first pneumatic ball valve 7 and the second pneumatic ball valve 10, and further controlling the switching between the air intake state, the air exhaust state and the pressure maintaining state of the air cushion cabin 1, and controlling the opening degree of the pneumatic regulating valve 9.

[0052] It can be understood that, according to the air automatic pressure maintaining control method of the shield tunneling machine, a P1-P3bar pressure signal is output according to the pressure value in the air cushion cabin 1 detected by the pressure transmitter 2, so as to control the opening and closing state of the first pressure comparison valve 4 and the second pressure comparison valve 5, thereby controlling the opening and closing state of the first pneumatic ball valve 7 and the second pneumatic ball valve 10. When the first pressure comparison valve 4 is controlled to be closed and the second pressure comparison valve 5 is controlled to be opened, the second pneumatic ball valve 10 is closed and the first pneumatic ball valve 7 is opened, the compressed air output by the air compressor 6 passes through the first pneumatic ball valve 7, the pneumatic regulating valve 9 and the second one-way valve 12 in sequence and enters the air cushion cabin 1, and the air cushion cabin 1 is in the air intake state, and the compressed air pushes against the first one-way valve 8; when the first pressure comparison valve 4 is controlled to be opened and the second pressure comparison valve 5 is controlled to be closed, the second pneumatic ball valve 10 is opened and the first pneumatic ball valve 7 is closed, and the compressed air output by the air compressor 6 cannot enter, the air in the air cushion cabin 1 is exhausted through the first one-way valve 8, the pneumatic regulating valve 9 and the second pneumatic ball valve 10 in sequence, and the air cushion cabin 1 is in the air exhaust state; and when the first pressure comparison valve 4 and the second pressure comparison valve 5 are both controlled to be closed, the second pneumatic ball valve 10 and the first pneumatic ball valve 7 are both closed, the air cushion cabin 1 cannot intake or exhaust air, and the air cushion cabin 1 is in the pressure maintaining state. Meanwhile, the output pressure can also control the opening degree of the pneumatic regulating valve 9, so as to control the air flow during the air intake process and the air exhaust process. The present application uses two pressure comparison valves to control the opening and closing of the pneumatic ball valves on the air exhaust pipeline and the air intake pipeline, and only one pneumatic regulating valve 9 is used to realize the air intake regulation and the air exhaust regulation of the air cushion cabin 1, thereby reducing the cost of the air automatic pressure maintaining system.

[0053] In addition, the air automatic pressure maintaining control method further comprises the following contents:

[0054] The split-range pressure is converted into a single-range pressure and then output to the pneumatic regulating valve 9, so as to control the opening degree of the pneumatic regulating valve 9.

[0055] In addition, another embodiment of the present application further provides a shield tunneling machine, which preferably adopts the air automatic pressure maintaining control system as described above.

[0056] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. An air automatic pressure maintaining control system of a shield tunneling machine, characterized in that, The system comprises a pressure transmitter (2), a pneumatic controller (3), a first pressure comparison valve (4), a second pressure comparison valve (5), an air compressor (6), a first pneumatic ball valve (7), a first one-way valve (8), a pneumatic regulating valve (9), a second pneumatic ball valve (10) and a second one-way valve (12), the pressure transmitter (2) is used for detecting the pressure in the air cushion cabin (1), the output end of the air compressor (6) is connected with the first end of the first pneumatic ball valve (7), the second end of the first pneumatic ball valve (7) is connected with the first end of the pneumatic regulating valve (9) and the output end of the first one-way valve (8) respectively, the first end of the second pneumatic ball valve (10) is connected with the outside, the second end is connected with the second end of the pneumatic regulating valve (9) and the input end of the second one-way valve (12) respectively, the input end of the first one-way valve (8) and the output end of the second one-way valve (12) are connected with the air cushion cabin (1), the two ends of the first pressure comparison valve (4) are connected with an external air source and the control end of the first pneumatic ball valve (7) respectively, the two ends of the second pressure comparison valve (5) are connected with an external air source and the control end of the second pneumatic ball valve (10) respectively, the pneumatic controller (3) is connected with the pressure transmitter (2), and is also connected with the control end of the first pressure comparison valve (4), the second pressure comparison valve (5) and the pneumatic regulating valve (9), is used for outputting a pressure to the control end of the first pressure comparison valve (4), the second pressure comparison valve (5) and the pneumatic regulating valve (9) according to the detection result of the pressure transmitter (2), so as to control the opening and closing states of the first pressure comparison valve (4) and the second pressure comparison valve (5), thereby controlling the opening and closing states of the first pneumatic ball valve (7) and the second pneumatic ball valve (10), and further controlling the air cushion cabin (1) to switch between the air inlet state, the air exhaust state and the pressure maintaining state, and simultaneously controlling the opening degree of the pneumatic regulating valve (9).

2. The air automatic pressure maintaining control system of the shield tunneling machine according to claim 1, wherein, if the pressure output by the pneumatic controller (3) is greater than P2+0.02bar, the second pressure comparison valve (5) is opened, the first pressure comparison valve (4) is closed, thereby controlling the first pneumatic ball valve (7) to be opened and the second pneumatic ball valve (10) to be closed, and the air cushion cabin (1) is in the air inlet state; if the pressure output by the pneumatic controller (3) is less than P2-0.02bar, the second pressure comparison valve (5) is closed, the first pressure comparison valve (4) is opened, thereby controlling the first pneumatic ball valve (7) to be closed and the second pneumatic ball valve (10) to be opened, and the air cushion cabin (1) is in the air exhaust state; if the pressure output by the pneumatic controller (3) is between [P2-0.02bar, P2+0.02bar], the second pressure comparison valve (5) and the first pressure comparison valve (4) are both closed, thereby controlling the first pneumatic ball valve (7) and the second pneumatic ball valve (10) to be closed, and the air cushion cabin (1) is in the pressure maintaining state.

3. The automatic air pressure maintaining control system of the tunneling machine according to claim 1, wherein, The signal conversion device (13) is connected with the pneumatic controller (3) and the pneumatic regulating valve (9) respectively, and is used for converting the split-range pressure output by the pneumatic controller (3) into single-range pressure and then outputting the single-range pressure to the pneumatic regulating valve (9) to control the opening degree of the pneumatic regulating valve (9).

4. The automatic air pressure maintaining control system of the tunneling machine according to claim 3, wherein, The signal conversion device (13) comprises a first pressure-displacement conversion assembly (18), a symmetrical cam (17), a pneumatic amplifier (14) and a nozzle baffle (15). The pneumatic amplifier (14) is connected with an external air source. The upper end of the nozzle baffle (15) is hinged, and the lower end is in a free state. The nozzle baffle (15) is located in front of the nozzle of the pneumatic amplifier (14). By adjusting the distance between the nozzle baffle (15) and the nozzle of the pneumatic amplifier (14), the back pressure of the pneumatic amplifier (14) can be adjusted, so that the output pressure of the pneumatic amplifier (14) is adjusted. One end of the symmetrical cam (17) is hinged, and the other end abuts against the middle part of the nozzle baffle (15). One end of the first pressure-displacement conversion assembly (18) is fixed, and the other end is connected with the extension rod of the symmetrical cam (17). The first pressure-displacement conversion assembly (18) is also connected with the pneumatic controller (3) and is used for converting the pressure output by the pneumatic controller (3) into displacement. When the signal pressure output by the pneumatic controller (3) is between [P2-0.02bar, P2+0.02bar], the first pressure-displacement conversion assembly (18) does not expand or contract, the contact point of the symmetrical cam (17) and the nozzle baffle (15) is located at the maximum radius of the symmetrical cam (17), the distance between the nozzle baffle (15) and the nozzle of the pneumatic amplifier (14) is the farthest, and the air pressure signal output by the pneumatic amplifier (14) is the smallest, so that the opening degree of the pneumatic regulating valve (9) is the smallest. When the signal pressure output by the pneumatic controller (3) is not between [P2-0.02bar, P2+0.02bar], the first pressure-displacement conversion assembly (18) expands or contracts and drives the symmetrical cam (17) to rotate counterclockwise or clockwise. The radius of the contact point of the symmetrical cam (17) and the nozzle baffle (15) becomes smaller, so that the nozzle baffle (15) rotates counterclockwise, the distance between the nozzle baffle (15) and the nozzle of the pneumatic amplifier (14) decreases, the back pressure of the pneumatic amplifier (14) increases, the output pressure of the pneumatic amplifier (14) increases, and the opening degree of the pneumatic regulating valve (9) increases.

5. The automatic air pressure maintaining control system of the tunneling machine according to claim 4, wherein, The signal conversion device (13) further comprises a second pressure-displacement conversion assembly (19) connected with the output end of the pneumatic amplifier (14), and the active end of the second pressure-displacement conversion assembly (19) is connected with the lower end of the nozzle baffle (15). When the output pressure of the pneumatic amplifier (14) becomes larger, it is fed back to the second pressure-displacement conversion assembly (19), and the active end of the second pressure-displacement conversion assembly (19) is extended to drive the nozzle baffle (15) to rotate clockwise, so as to increase the distance between the nozzle baffle (15) and the nozzle of the pneumatic amplifier (14), thereby realizing feedback regulation.

6. The automatic air pressure maintaining control system of the tunneling machine according to claim 5, wherein, The signal conversion device (13) further comprises an adjusting spring (16) with one end fixed and the other end connected with the nozzle baffle (15), and the rigidity of the nozzle baffle (15) is adjusted by adjusting the spring force of the adjusting spring (16).

7. The automatic air pressure maintaining control system of the tunneling machine according to claim 5, wherein, The first pressure-displacement conversion assembly (18) and the second pressure-displacement conversion assembly (19) are bellows or Bourdon tubes.

8. An air automatic pressure maintaining control method of a shield tunneling machine, using the air automatic pressure maintaining control system according to any one of claims 1 to 7, characterized by, The following is included: The pressure in the air cushion cabin (1) is detected by a pressure transmitter (2); According to the detection result of the pressure transmitter (2), a pressure is output to the control end of the first pressure comparison valve (4), the second pressure comparison valve (5) and the pneumatic regulating valve (9), so as to control the opening and closing state of the first pressure comparison valve (4) and the second pressure comparison valve (5), thereby controlling the opening and closing state of the first pneumatic ball valve (7) and the second pneumatic ball valve (10), and further controlling the air cushion cabin (1) to switch between the air inlet state, the air exhaust state and the pressure maintaining state, while controlling the opening degree of the pneumatic regulating valve (9).

9. The air automatic pressure maintaining control method of a shield tunneling machine according to claim 8, wherein, The following is also included: The output stroke pressure is converted into single stroke pressure and then output to the pneumatic regulating valve (9) to control the opening degree of the pneumatic regulating valve (9).

10. A tunneling machine characterized by, An air automatic pressure maintaining control system is adopted. An air automatic pressure maintaining control system is adopted.

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