Shield machine screw conveyor for safe excavation to prevent water and sand gushing

Abstract

The present invention provides a screw conveyor for a shield machine that can safely excavate the earth with water and sand gushing out. The screw conveyor includes a cylinder, a spiral stirring shaft, a slag gate, and a slag discharge control device installed at the gate. The slag discharge control device includes a connecting plate, a slag discharge sleeve, an impeller valve placed in the slag discharge sleeve, and an impeller valve driving device. A slag through hole is provided on the connecting plate, and a slag inlet and a slag outlet are provided on the slag discharge sleeve. The slag inlet of the slag discharge sleeve is sealed and docked with the slag through hole on the connecting plate, and is installed on the outside of the gate of the slag discharge gate through the connecting plate; the impeller valve divides the inner cavity of the slag discharge sleeve into at least two slag discharge cavities, and drives it to rotate through the impeller valve driving device. The present invention has a simple structure, is easy to use, has a good sealing effect, and can effectively control the amount of earth excavated, solving the problem of gushing when the screw conveyor is constructed in a water-rich sand layer or a pressurized water-sand layer geological layer environment.

Description

Technical Field

[0001] The invention belongs to the field of shield construction, and in particular relates to a screw conveyor for a shield machine capable of safely excavating the ground and preventing water and sand gushing. Background Art

[0002] In recent years, with the further development and utilization of underground space, shield construction is the safest construction method. For water-rich sand layers, slurry shields are usually selected, but due to geological changes in the entire section, construction site restrictions and other reasons, earth pressure balance shields are sometimes used. When the shield machine is advancing normally, the slag peeled off from the face enters the screw conveyor through the screw conveyor inlet, and is discharged into the slag of the slag battery car through the belt conveyor.

[0003] As a channel for transporting the slag out of the excavation bin of the earth pressure balance shield, the screw conveyor plays an important role in maintaining the balance of the excavation bin, the stability of the face and the safety of excavation. The gate of the screw conveyor is the main component to ensure the sealing of the screw conveyor. When there is a large amount of water in the soil layer, if the gate is not sealed well or cannot be closed in time, a gushing accident will occur, which may cause surface settlement or landslide, and the safety risk is high. At present, the gates of screw conveyors can generally be divided into single gates and double gates. The single gate has a simple structure and occupies a large space. The double gate opens left and right, occupies a small space, has a relatively fast relative speed, and opens from the middle to both sides. It has obvious advantages, but it is easy to get stuck. The slag passing through the gate opening will be deposited at the gate, and the slag will be stuck in the gap between the gate and the door frame. Therefore, when the two existing screw conveyor gates encounter water and sand gushing, the gushing sediment acts on the gate plate of the gate, increasing the resistance of the gate plate to close, and it cannot be closed normally, which is easy to cause gushing over square or even ground collapse. Another commonly used method is to transform the first-stage screw conveyor into a second-stage screw conveyor, but the cost is high. If water-rich strata are encountered, once water or sand gushing occurs, the sealing effect will not be good.

[0004] In order to prevent the shield machine screw conveyor from gushing, there are many patents for improving the excavation port of the screw conveyor, such as the utility model patent No. CN201620724889.2, a device for opening and closing the excavation gate of the shield machine screw conveyor, the invention patent No. CN201910321395.8, a winch-type automatic closing shield screw conveyor gate and its use method, the utility model patent No. CN2017217812975, a screw conveyor gate with an inclined gate plate, and other prior arts are all improvements on the gate of the screw conveyor. These improvements require improvements to the original structure of the screw conveyor, and the existing screw conveyor equipment needs to be updated, which is costly and has a relatively complex overall structure. For example, patent number CN20112052118521 discloses a screw conveyor gate safety device, specifically a connecting pipe is installed at the rear end of the screw conveyor gate, and a manual gate is installed on the connecting pipe. When encountering a large amount of pressure water surge, the excavation gate of the screw conveyor is manually closed. The manual gate is inconvenient to use and cannot control the excavation volume; patent number CN201911095616.0 discloses a shield screw conveyor with an anti-surge device, specifically including a screw conveyor and a belt conveyor, and also including an anti-surge device and a control circuit. The anti-surge device has a tubular body, an opening and closing gate, and a pneumatic control system. The anti-surge device of the patent has a complex structure, a large volume, and occupies a large space. It is not suitable for narrow areas and cannot control the excavation volume. In the process of shield construction, it is usually necessary to set the discharge flow of the screw conveyor according to the different strata to be excavated. Improper control of the discharge flow of the screw conveyor is very likely to cause ground subsidence, gushing and other problems, which seriously threatens the safety of shield construction. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a screw conveyor for a shield machine that can safely excavate water and sand and prevent gushing. The screw conveyor adds an excavation control device at the gate to control the speed of slag discharge and release the pressure in the screw conveyor, thereby solving the problem of gushing of traditional screw conveyors in water-rich sand layers and pressurized water-sand layers during shield construction.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a screw conveyor for a shield machine that is safe from water and sand gushing, comprising a screw conveyor barrel, a driving device, a spiral stirring shaft disposed in the screw conveyor barrel and a slag discharge gate disposed on the screw conveyor barrel, characterized in that a slag discharge control device is installed at the gate mouth of the slag discharge gate, the slag discharge control device comprises a connecting plate, a slag discharge sleeve, an impeller valve disposed in the slag discharge sleeve and an impeller valve driving device, a slag through hole is opened on the connecting plate, the slag discharge sleeve is a circular barrel structure, one end of which is provided with a driving device mounting seat, and the other end is provided with a sealing end cover, a sleeve slag inlet and a sleeve slag outlet are respectively opened on the barrel of the slag discharge sleeve, and the slag discharge sleeve is installed on the connecting plate , its slag inlet is sealed and docked with the slag through hole on the connecting plate, and is installed on the outer side of the gate of the slag gate through the connecting plate, and its slag through hole is sealed and docked with the slag outlet of the slag gate; the impeller valve includes a central rotating shaft, at least two rotating baffles distributed along the circumferential direction of the central rotating shaft, and impellers arranged at both ends of the at least two rotating baffles, the impeller valve is horizontally placed in the slag discharge sleeve, and the inner cavity of the slag discharge sleeve is divided into at least two slag discharge cavities, and the outer edge of the impeller and the edge of each rotating baffle are in sealing contact with the inner wall of the slag discharge sleeve; the impeller valve driving device is installed on one side of the slag discharge sleeve The drive device mounting seat, the output shaft of which is connected to the central rotating shaft of the impeller valve, drives the impeller valve to rotate in the slag discharge sleeve to control the slag discharge amount.

[0007] Further technical solution of the present invention: the impeller valve driving device is a hydraulic motor and is equipped with a hydraulic control system. The hydraulic control system adopts an open hydraulic control system, including an oil tank, a hydraulic plunger pump and an electromagnetic reversing valve. The hydraulic plunger pump is an axial variable plunger pump, driven by a four-pole motor and controlled by a proportional valve. The electromagnetic reversing valve is a two-way control valve. The input end of the hydraulic plunger pump is connected to the oil tank, and the output end is connected to the cylinder input end of the hydraulic motor through the electromagnetic reversing valve. The cylinder oil outlet pipe of the hydraulic motor returns to the oil tank through the electromagnetic reversing valve.

[0008] The preferred technical solution of the present invention is as follows: the length of the impeller valve is equal to the inner cavity length of the slag discharge sleeve, the outer diameter of the impeller is equal to the inner diameter of the slag discharge sleeve, and a first sealing ring is provided on the contact surface between the outer edges of the two impellers and the inner wall of the slag discharge sleeve; the rotating baffle is a square baffle with a thickness of 5 to 8 cm, one long side of which is fixed on the central rotating shaft, and the other long side is in contact with the inner wall of the slag discharge sleeve, and a sealing strip is provided on the contact surface, and the sealing strip is embedded in a sealing strip groove provided on the rotating baffle.

[0009] A more preferred technical solution of the present invention is as follows: the connecting plate adopts a square plate body with the same shape and size as the gate port of the slag discharge gate, a plurality of threaded connection holes are opened on the plate body, the area of ​​the slag through hole is 1 / 3 to 2 / 5 of the area of ​​the gate port, and is the same shape and size as the slag inlet of the sleeve, and a second sealing ring is provided on the joint surface between the slag through hole of the connecting plate and the slag discharge gate; a slag discharge outlet with an area larger than 1 / 2 of the gate port area is also opened on the plate body, and the slag discharge outlet and the sleeve slag outlet are both aligned with the slag belt conveyor.

[0010] A better technical solution of the present invention: the impeller valve includes four rotating baffles, which are evenly spaced along the circumferential direction of the central rotating shaft, and combined with the impellers at both ends to divide the inner cavity of the slag discharge sleeve into four slag discharge cavities of the same size and fan-shaped cross-sections, and the diameters of the sleeve slag inlet and the sleeve slag outlet are both smaller than the cross-sectional arc length of each slag discharge cavity.

[0011] The better technical solution of the present invention is as follows: bearing holes are respectively opened on the drive device mounting seat and the sealing end cover, and rolling bearings are installed accordingly, the two ends of the central rotating shaft respectively extend out of the slag discharge sleeve and are rotatably connected to the rolling bearings on the corresponding sides, and are sealed at the connection point by the bearing cover, and the shaft end passing through the drive device mounting seat is connected to the output shaft of the impeller valve drive device.

[0012] A further technical solution of the present invention is as follows: a lubrication cavity is provided between the impellers at both ends of the impeller valve and the closed structures at both ends of the slag discharge sleeve, a first lubrication oil circuit is provided in the central rotating shaft, and a second lubrication oil circuit connecting the lubrication cavity and the first lubrication oil circuit is provided at a position near the impeller of each rotating baffle, the first lubrication oil circuit runs through the central rotating shaft, and sealing heads are provided at both ends.

[0013] A preferred technical solution of the present invention is that the first sealing ring and the sealing strip are both polyurethane sealing strips.

[0014] A more preferred technical solution of the present invention is as follows: a circle of sealing ring groove is provided at the outer edge of the slag through hole at the connection surface between the connecting plate and the slag discharge gate, and the second sealing ring adopts a polyurethane sealing strip and is embedded in the groove.

[0015] A more preferred technical solution of the present invention: the first lubricating oil circuit is arranged on the central axis of the central rotating shaft, and its diameter is 1 to 1.3 cm; the diameter of the second lubricating oil circuit is 0.6 to 0.9 cm; the oil tank adopts the oil tank of the hydraulic system of the shield machine.

[0016] Beneficial effects of the present invention:

[0017] (1) The present invention solves the problem of gushing of conventional screw conveyors during shield construction in water-rich sand layers and pressurized water-sand layers by adding an excavation control device at the gate of the screw conveyor and controlling the excavation amount;

[0018] (2) The unearthing control device in the present invention can be directly installed at the gate of the screw conveyor by bolts, which will not have any impact on the gate structure of the screw conveyor and does not require any improvement to the existing screw conveyor. It can be directly installed and disassembled according to needs, which is convenient and simple to use. Even if a fault occurs, it can be removed separately for maintenance, cleaning or replacement without replacing the entire machine, thereby reducing production costs;

[0019] (3) The unearthing control device of the present invention adopts the structure of an impeller valve and is controlled by a hydraulic control system. By controlling the electrical signal, the speed of rotation of the impeller valve is controlled, and the speed of slag discharge is controlled. Regardless of the rotation speed of the impeller valve, the pressure in the screw conveyor can be released through the rotation of the blades, which greatly solves the problem of gushing and avoids the problem of ground collapse.

[0020] (4) The unearthing device of the present invention comprises an impeller valve and an outer sleeve, wherein the impeller valve and the outer sleeve are tightly matched, which can ensure the normal rotation of the impeller valve and the sealing effect between the impeller valve and the sleeve wall;

[0021] The invention has the advantages of simple structure, convenient use, good sealing effect, and can effectively control the amount of excavated soil. It has high continuous construction efficiency, low cost and high economy, convenient production and assembly of the device, strong promotion ability, and solves the problem of gushing when the screw conveyor is constructed in the environment of water-rich sand layer and pressurized water-sand layer geological layer, thereby improving the construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of the slag discharge control device in the present invention;

[0024] Figure 3 is a bottom view of the slag discharge control device of the present invention;

[0025] Figure 4 yes Figure 2 Middle AA section view;

[0026] Figure 5 yes Figure 2 Middle BB section view;

[0027] Figure 6 is a hydraulic control diagram of the impeller valve driving device of the present invention;

[0028] Figure 7 It is a structural schematic diagram of the connecting plate in the present invention;

[0029] Figure 8It is a structural schematic diagram of the slag discharge sleeve in the present invention;

[0030] Fig. 9 is a longitudinal cross-sectional view of the slag discharge sleeve in the present invention;

[0031] Fig.10 It is a structural schematic diagram of the impeller valve in the present invention;

[0032] Fig.11 is a longitudinal cross-sectional view of the impeller valve of the present invention;

[0033] Fig.12 yes Fig.11 Middle EE section view;

[0034] Fig.13 It is a schematic diagram of the structure of the drive device mounting seat in the present invention;

[0035] Fig.14 It is a schematic diagram of the structure of the sealing end cover in the present invention;

[0036] Fig.15 is a cross-sectional view of the drive device mounting seat;

[0037] Fig.16 It is a cross-sectional view of the sealing end cover.

[0038] In the figure: 1—screw conveyor barrel, 2—driving device, 3—screw stirring shaft, 4—slag gate, 5—slag control device, 50—connecting plate, 5000—slag through hole, 5001—threaded connection hole, 5002—slag discharge port, 5003—sealing ring groove, 51—slag sleeve, 52—impeller valve, 5200—central rotating shaft, 5201—rotating baffle, 5202—impeller, 5203—lubricating chamber, 5204—first lubricating oil circuit, 5205—slag discharge sleeve, 5206—slag discharge port, 5207—slag discharge port, 5208—slag discharge port, 5209—slag discharge port, 5210—slag discharge port, 5211—slag discharge port, 5212—slag discharge port, 5213—slag discharge port, 5214—slag discharge port, 5215—slag discharge port, 5216—slag discharge port, 5217—slag discharge port, 5218—slag discharge port, 5219—slag discharge port, 5220—slag discharge port, 5221 —Second lubricating oil circuit, 5206—sealing head, 53—impeller valve driving device, 54—sealing end cover, 55—driving device mounting seat, 56—sleeve slag inlet, 57—sleeve slag outlet, 58—sealing strip, 5800—sealing strip slot, 59—first sealing ring, 510—second sealing ring, 511—oil tank, 512—hydraulic piston pump, 513—electromagnetic reversing valve, 514—hydraulic piston pump, 515—four-pole motor, 516—proportional valve, 517—rolling bearing, 518—bearing cover. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. Figures 1 to 16The accompanying drawings of the embodiments are drawn in a simplified manner and are only used to clearly and concisely illustrate the embodiments of the present invention. The technical solutions shown in the following drawings are specific solutions of the embodiments of the present invention and are not intended to limit the scope of the invention claimed for protection. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0041] The embodiment provides a screw conveyor for a shield machine for safe excavation against water and sand gushing, such as Figure 1 As shown, it includes a screw conveyor barrel 1, a driving device 2, a screw stirring shaft 3 placed in the screw conveyor barrel 1 and a slag gate 4 placed on the screw conveyor barrel 1. The screw stirring shaft 3 is provided with stirring blades. The driving device 2 drives the slag to be transported from the slag inlet of the screw conveyor barrel 1 to the slag outlet. A slag gate 4 is provided at the slag outlet. The slag gate 4 controls the slag discharge, and the slag is sent to the belt conveyor and output through the belt conveyor. The screw conveyor in the present invention also includes a slag discharge control device 5 arranged outside the slag gate 4. Figures 2 to 4 As shown, the slag discharge control device 5 includes a connecting plate 50, a slag discharge sleeve 51, an impeller valve 52 disposed in the slag discharge sleeve 51, and an impeller valve driving device 53. A slag through hole 5000 is provided on the connecting plate 50, and a sleeve slag inlet 56 and a sleeve slag outlet 57 are symmetrically provided on the cylinder body of the slag discharge sleeve 51. The slag discharge sleeve 51 is installed on the connecting plate 50, and its slag inlet is sealed and docked with the slag through hole 5000 on the connecting plate 50. Figure 1 As shown, the slag discharge control device 5 is installed on the outside of the slag discharge gate 4 through the connecting plate 50, and its slag through hole 5000 is sealed and connected with the slag discharge port of the slag discharge gate 4. Figure 5 As shown, the impeller valve 52 is horizontally placed in the slag discharge sleeve 51, and divides the inner cavity of the slag discharge sleeve 51 into four slag discharge chambers 5100. The outer edge of the impeller valve 52 is in sealing contact with the inner wall of the slag discharge sleeve 51; the impeller valve driving device 53 is installed on one side of the slag discharge sleeve 51, and its output shaft is connected to the central rotating shaft 5200 of the impeller valve 52, driving the impeller valve 52 to rotate in the slag discharge sleeve 51 to control the slag discharge amount.

[0042] The embodiment provides a screw conveyor for a shield machine that is safe to excavate and prevent water and sand gushing. The impeller valve driving device 53 is a hydraulic motor and is equipped with a hydraulic control system. Figure 6 As shown, the hydraulic control system adopts an open hydraulic control system, through an external electrical signal, including an oil tank 511, a hydraulic piston pump 512 and an electromagnetic reversing valve 513. The hydraulic piston pump 514 is an axial variable piston pump, driven by a 55KW four-pole motor 515, with a driving speed of 1470r / min. The four-pole motor 515 is connected to the control end of the hydraulic piston pump 514 through auxiliary parts such as a mold cover and a coupling. The hydraulic piston pump 514 is controlled by a proportional valve 516. The working voltage of the proportional valve 516 is 24V, and the control circuit is 200mA-600mA. The electromagnetic reversing valve 513 is a two-way control valve, which performs two-way rotation switching. The input end of the hydraulic piston pump 512 is connected to the oil tank 511, and the output end is connected to the oil cylinder input end of the hydraulic motor through the electromagnetic reversing valve 513. The oil cylinder outlet pipe of the hydraulic motor returns to the oil tank 511 through the electromagnetic reversing valve 513. The oil tank 5011 adopts the oil tank of the hydraulic system of the shield machine. The open hydraulic plunger pump in the hydraulic control system is driven by a four-pole motor 515. The S port of the hydraulic plunger pump 512 sucks oil from the shield machine oil tank 5011, and the oil enters the pressure oil inlet A port of the impeller valve driving device 53 (hydraulic motor) after the oil is discharged through the A port, driving the hydraulic motor to rotate, and the low-pressure oil of the hydraulic motor returns to the shield machine oil tank 5011 through the B port. The present invention drives the hydraulic motor to rotate the impeller valve 52 through the electronically controlled hydraulic system, and adjusts the current size to control the flow of the hydraulic valve group according to the needs to control the speed of the impeller valve 52. The faster the speed of the impeller valve 52, the higher the efficiency of the slag discharge system, and the control is performed according to actual needs.

[0043] The slag discharge control device 5 provided in the embodiment has a specific structure of the connecting plate 50 as follows: Figure 7As shown, a square plate body with the same shape and size as the gate of the slag gate 4 is adopted, and a plurality of threaded connection holes 5001 are opened on the plate body, which can be conveniently bolted to the slag gate 4 of the screw conveyor. The area of ​​the slag through hole 5000 is about 1 / 3 of the area of ​​the gate, and is the same in shape and size as the sleeve slag inlet 56. A circle of sealing ring groove 5003 is provided on the outer edge of the slag through hole 5000, and a second sealing ring 510 made of polyurethane sealing strip is embedded in the sealing ring groove 5003. When the connecting plate 50 is connected to the slag gate 4 of the screw conveyor, sealing can be performed through the second sealing ring 510. A slag discharge outlet 5002 with an area larger than 1 / 2 of the gate area is also provided on the connecting plate. When excavation is smooth, there is no need to disassemble the slag discharge control device 5, and the gate can be completely opened directly. The material can be discharged directly through the slag discharge outlet 5002 and the slag can be directly discharged onto the slag belt conveyor, which can save the time for disassembly and assembly of the slag discharge control device 5.

[0044] The slag discharge sleeve 51 of the slag discharge control device 5 provided in the embodiment is as follows: Figure 8 and Fig. 9 As shown, it is a circular cylindrical structure, and flange connection plates are respectively provided at both ends of the slag discharge sleeve 51. Fig.13 and Fig.14 As shown, the drive device mounting seat 55 and the sealing end cover 54 are also provided with bolt connection holes, the drive device mounting seat 55 can be sealed with the flange connection plate at one end of the slag discharge sleeve 51, and the sealing end cover 54 can be sealed with the flange connection plate at the other end of the slag discharge sleeve 51. Fig.15 and Fig.16 As shown, bearing holes are respectively provided on the drive device mounting seat 55 and the sealing end cover 59. Figure 4 As shown, a rolling bearing 517 is installed in the bearing hole on each side, and the two ends of the central rotating shaft 5200 of the impeller valve 52 extend out of the slag discharge sleeve 51 and are rotatably connected to the rolling bearing 517 on the corresponding side, and are sealed at the connection by a bearing cover 518. The connection is sealed by a bearing seal to ensure its sealing effect. One end of the central rotating shaft 5200 of the impeller valve 52 is the active end, which is installed with the hydraulic motor through the keyway and spline of the shaft, and the hydraulic motor end cover is installed, and the hydraulic motor is installed. The other end is the passive end, which is sealed and connected with the sealing end cover 54 through the bearing cover 518 and the bearing seal. In the embodiment, the inner ring size of the slag discharge sleeve 51 is made according to the outer size of the impeller valve 52, and the impeller valve 52 can be installed in the slag discharge sleeve 51 to achieve clearance fit, and the impeller valve 52 and the slag discharge sleeve 51 are sealed by a sealing connection to achieve a sealing effect. The top of the slag discharge sleeve 51 is connected to the earth discharge port of the screw machine, which does not affect the opening and closing of the spiral slag discharge gate 4. A polyurethane sealing strip is installed at the connection plate between the slag discharge sleeve 51 and the screw machine to prevent mud from leaking out.

[0045] The impeller valve 52 of the slag discharge control device 5 provided in the embodiment is as follows: Figures 10 to 12 As shown, it includes a central rotating shaft 5200, four rotating baffles 5201 distributed along the circumferential direction of the central rotating shaft 520, and impellers 5202 arranged at both ends of the four rotating baffles 5201. The impeller valve 52 is made of Q345 steel, and its length is equal to the inner cavity length of the slag discharge sleeve 51. The outer diameter of the impeller 5202 is equal to the inner diameter of the slag discharge sleeve 51, and a first sealing ring 59 is provided on the contact surface between the outer edges of the two impellers 5202 and the inner wall of the slag discharge sleeve 51. Four rotating baffles 5201 are evenly spaced along the circumferential direction of the central rotating shaft 5200, and a 90° angle is formed between two adjacent rotating baffles 5201. The four rotating baffles 5201 are combined with the impellers 5202 at both ends to divide the inner cavity of the slag discharge sleeve 51 into four slag discharge chambers 5100 of the same size and fan-shaped cross-sections. The diameters of the sleeve slag inlet 56 and the sleeve slag outlet 57 are both smaller than the arc length of the cross-section of each slag discharge chamber 5100, which can ensure that the slag can enter each slag discharge chamber 5100. The rotating baffle 5201 is a square baffle, which is integrated with the central rotating shaft 5200, has a thickness of about 6 cm and a length of 82 cm, one of which is fixed on the central rotating shaft 5200, and the other is in contact with the inner wall of the slag discharge sleeve 51, and a sealing strip 58 is provided on the contact surface, and the sealing strip 58 is embedded in the sealing strip card slot 5800 provided on the rotating baffle 5201. The first sealing ring 59 and the sealing strip 58 are both made of polyurethane sealing strips.

[0046] In order to make the impeller valve 52 rotate smoothly in the slag discharge sleeve 51, grooves are provided on the outer sides of the impellers 5202 at both ends of the impeller valve 52 in the embodiment, such as Figure 4 and Fig.12 As shown, after the impeller valve 52 is installed on the slag discharge sleeve 51, the grooves on the two end surfaces respectively form a lubrication cavity 5203 with the closed structures at the two ends of the slag discharge sleeve 51, and a first lubrication oil passage 5204 with a diameter of 1.2 cm is provided on the central axis of the central shaft 5200, and a second lubrication oil passage 5205 connecting the lubrication cavity 5203 and the first lubrication oil passage 5204 is provided at the position of each rotating baffle 5201 near the impeller 5202, and the first lubrication oil passage 5204 runs through the central shaft 5200, and a plugging head 5206 is provided at both ends, and the plugging head 5206 is connected by a thread, which can be easily opened to inject lubrication oil into the lubrication oil passage. The diameter of the second lubrication oil passage 5205 is 0.8 cm, and the angle between the second lubrication oil passage on each rotating baffle 5201 and the central shaft 5200 is 60°. The total length of the impeller valve in the embodiment is about 1.5 meters, the length of the cavity and the impeller sealing part is about 1 meter, and the length of the shaft extending from the left and right sides is about 50 centimeters.

[0047] When the present invention is used, the slag discharge control device 5 can be installed to the slag discharge port of the screw conveyor as needed. The installation is done by bolts, which is convenient for disassembly, and will not affect the normal opening and closing of the slag discharge gate 4 after installation. After the slag discharge control device 5 is installed, the opening and closing degree of the slag discharge gate 4 is adjusted so that the slag discharge port is less than or equal to the slag through hole 5000 on the connecting plate of the slag discharge control device 5, and the discharge can be carried out normally. The slag is transported to the discharge gate 4 through the spiral stirring shaft 3, and then directly enters each slag discharge cavity 5100 of the slag discharge control device 5 for slag discharge. The rotation speed of the impeller valve 52 of the slag discharge control device 5 can be controlled according to the speed of slag discharge of the screw conveyor, thereby controlling its discharge speed. Regardless of the rotation speed of the impeller valve, the pressure in the screw machine can be released through the rotation of the blades, which greatly solves the problem of gushing and avoids the problem of ground collapse. The screw conveyor in the present invention is mainly used for soil layers with high water content such as water-rich sand layers and pressurized water-sand layers to prevent gushing. When excavation is smooth and there is no need to prevent gushing, there is no need to disassemble the slag control device 5. The gate door can be fully opened directly to discharge the material directly through the slag discharge port 5002 on the connecting plate 50, and the slag can be directly discharged onto the slag belt conveyor, which can save the time for disassembling and assembling the slag control device 5.

[0048] The present invention can control the rotation speed of the impeller valve and the slag discharge speed by controlling the electrical signal, and release the pressure in the screw machine through the rotation of the impeller blades, thereby greatly solving the problem of gushing and avoiding the problem of ground collapse. It is also safe and reliable, has high continuous construction efficiency, low cost and high economy, is easy to produce and assemble, and has strong popularization potential.

[0049] In summary, the above is an embodiment of the present invention, but the present invention is not limited to the above embodiment. As long as the technical effect of the present invention is achieved by any same or similar means, it should fall within the scope of protection of the present invention.

Claims

1. A screw conveyor for a shield machine for safe excavation against water and sand gushing, comprising a screw conveyor barrel (1), a driving device (2), a screw stirring shaft (3) disposed in the screw conveyor barrel (1), and a slag discharge gate (4) disposed on the screw conveyor barrel (1), characterized in that: A slag discharge control device (5) is installed at the gate of the slag discharge gate (4). The slag discharge control device (5) comprises a connecting plate (50), a slag discharge sleeve (51), an impeller valve (52) disposed in the slag discharge sleeve (51), and an impeller valve driving device (53). A slag through hole (5000) is provided on the connecting plate (50). The slag discharge sleeve (51) is a circular cylindrical structure, one end of which is provided with a driving device mounting seat (55), and the other end is provided with a sealing end cover (54). A sleeve slag inlet (56) and a sleeve slag outlet (57) are respectively provided on the cylinder of the slag discharge sleeve (51). The slag discharge sleeve (51) is installed on the connecting plate (50), and its slag inlet is sealedly connected to the slag through hole (5000) on the connecting plate (50). The slag discharge sleeve (51) is installed on the outside of the gate of the slag discharge gate (4) through the connecting plate (50). The slag through hole (5000) is connected to the slag discharge gate. The slag outlet of the door (4) is sealed and docked; the impeller valve (52) comprises a central rotating shaft (5200), at least two rotating baffles (5201) distributed along the circumferential direction of the central rotating shaft (5200), and impellers (5202) arranged at both ends of the at least two rotating baffles (5201); the impeller valve (52) is horizontally placed in the slag discharge sleeve (51) and divides the inner cavity of the slag discharge sleeve (51) into at least two slag discharge cavities (5100); and the outer edge of the impeller (5202) and the edge of each rotating baffle (5201) are in sealing contact with the inner wall of the slag discharge sleeve (51); the impeller valve driving device (53) is mounted on a driving device mounting seat (55) on one side of the slag discharge sleeve (51), and its output shaft is connected to the central rotating shaft (5200) of the impeller valve (52), so as to drive the impeller valve (52) to rotate in the slag discharge sleeve (51) to control the slag discharge amount; The impeller valve driving device (53) is a hydraulic motor and is equipped with a hydraulic control system. The hydraulic control system adopts an open hydraulic control system, including an oil tank (511), a hydraulic plunger pump (514) and an electromagnetic reversing valve (513). The hydraulic plunger pump (514) is an axial variable plunger pump, driven by a four-pole motor (515) and controlled by a proportional valve (516). The electromagnetic reversing valve (513) is a two-way control valve. The input end of the hydraulic plunger pump (514) is connected to the oil tank (511), and the output end is connected to the input end of the oil cylinder of the hydraulic motor through the electromagnetic reversing valve (513). The oil outlet pipe of the oil cylinder of the hydraulic motor returns to the oil tank (511) through the electromagnetic reversing valve (513).

2. The screw conveyor for safe excavation of a shield machine against water and sand gushing according to claim 1, characterized in that: The length of the impeller valve (52) is equal to the length of the inner cavity of the slag discharge sleeve (51); the outer diameter of the impeller (5202) is equal to the inner diameter of the slag discharge sleeve (51); and a first sealing ring (59) is provided on the contact surface between the outer edges of the two impellers (5202) and the inner wall of the slag discharge sleeve (51); the rotating baffle (5201) is a square baffle with a thickness of 5 to 8 cm, one long side of which is fixed on the central rotating shaft (5200) and the other long side is in contact with the inner wall of the slag discharge sleeve (51); and a sealing strip (58) is provided on the contact surface, and the sealing strip (58) is embedded in a sealing strip slot (5800) provided on the rotating baffle (5201).

3. A screw conveyor for safe excavation of shield machine against water and sand gushing according to claim 1 or 2, characterized in that: The connecting plate (50) is a square plate body with the same shape and size as the gate of the slag discharge gate (4), and a plurality of threaded connection holes (5001) are provided on the plate body. The area of ​​the slag through hole (5000) is 1 / 3 to 2 / 5 of the area of ​​the gate, and is the same shape and size as the sleeve slag inlet (56). A second sealing ring (510) is provided on the interface between the slag through hole (5000) of the connecting plate (50) and the slag discharge gate (4). A slag discharge outlet (5002) with an area larger than 1 / 2 of the gate area is also provided on the plate body, and the slag discharge outlet (5002) and the sleeve slag discharge outlet (57) are both aligned with the slag belt conveyor.

4. A screw conveyor for safe excavation of a shield machine against water and sand gushing according to claim 1 or 2, characterized in that: The impeller valve (52) comprises four rotating baffles (5201), which are evenly spaced along the circumferential direction of the central rotating shaft (5200) and are combined with the impellers (5202) at both ends to divide the inner cavity of the slag discharge sleeve (51) into four slag discharge cavities (5100) of the same size and fan-shaped cross-sections. The diameters of the sleeve slag inlet (56) and the sleeve slag outlet (57) are both smaller than the arc length of the cross-section of each slag discharge cavity (5100).

5. A screw conveyor for safe excavation of shield machine against water and sand gushing according to claim 1 or 2, characterized in that: Bearing holes are respectively provided on the drive device mounting seat (55) and the sealing end cover (54), and rolling bearings (517) are installed correspondingly. The two ends of the central rotating shaft (5200) respectively extend out of the slag discharge sleeve (51) and are rotationally connected to the rolling bearings (517) on the corresponding sides. The connection is sealed by a bearing cover (518), and the shaft end passes through the drive device mounting seat (55) and is connected to the output shaft of the impeller valve drive device (53).

6. The screw conveyor for safe excavation of a shield machine against water and sand gushing according to claim 1, characterized in that: A lubrication cavity (5203) is provided between the impellers (5202) at both ends of the impeller valve (52) and the closed structures at both ends of the slag discharge sleeve (51); a first lubrication oil path (5204) is provided in the central rotating shaft (5200); a second lubrication oil path (5205) connecting the lubrication cavity (5203) and the first lubrication oil path (5204) is provided at a position adjacent to the impeller (5202) of each rotating baffle (5201); the first lubrication oil path (5204) passes through the central rotating shaft (5200) and is provided with plugging heads (5206) at both ends.

7. The screw conveyor for safe excavation of a shield machine against water and sand gushing according to claim 2, characterized in that: The first sealing ring (59) and the sealing strip (58) are both polyurethane sealing strips.

8. The screw conveyor for safe excavation of a shield machine against water and sand gushing according to claim 3, characterized in that: A sealing ring groove (5003) is provided at the outer edge of the slag through hole (5000) at the connection surface between the connection plate (50) and the slag discharge gate (4), and the second sealing ring (510) is a polyurethane sealing strip embedded in the groove.

9. The screw conveyor for safe excavation of a shield machine against water and sand gushing according to claim 6, characterized in that: The first lubricating oil circuit (5204) is arranged on the central axis of the central rotating shaft (5200) and has a diameter of 1 to 1.3 cm. The diameter of the second lubricating oil circuit (5205) is 0.6 to 0.9 cm. The oil tank (511) adopts the oil tank of the hydraulic system of the shield machine.

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