Shield cutter head and shield tunneling machine stone diameter limiting method suitable for complex stratum

Abstract

The invention relates to the technical field of tunnel construction equipment, in particular to a shield cutterhead suitable for a complex stratum and a shield tunneling machine stone diameter limiting method.The shield cutterhead comprises a diameter limiting plate installed between a cutterhead panel and spokes, the diameter limiting plate can be machined and replaced according to the size between the cutterhead panel and the spokes, and by installing the diameter limiting plate, the diameter limiting plate can be machined and replaced according to the size between the cutterhead panel and the spokes; the device can effectively control the particle size of stones entering the soil bin, reduce the frequency of settling and accumulating large-size stones and boulders after entering the soil bin, reduce the blockage of a screw conveyor, and effectively control the safety risk of shutdown of a shield tunneling machine due to the fact that the screw conveyor is blocked and cannot normally discharge slag. Therefore, the purpose that the shield tunneling machine keeps continuous and safe propelling in a complex upper-soft lower-hard stratum is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction equipment, and in particular to a shield cutter head and a shield machine stone diameter limiting method suitable for complex strata. Background Art

[0002] In recent years, with the increasing demand for transportation facilities construction in my country, a large number of tunnel projects have emerged, and the scale is getting larger and larger. At present, in most tunnel projects with complex geology, soft on top and hard on the bottom, broken rock layers are developed, and large rocks and boulders in the rock layers are very easy to enter the soil bin, resulting in problems such as storage bins, sinking bins, and screw machine blockage. After the shield machine is passively shut down, the screw machine must be unblocked before the bin is opened, the stones in the soil bin must be manually removed, and the tool must be repaired and replaced. This causes a lot of waste of manpower, material resources, and financial resources, and directly affects the progress of the entire project.

[0003] Therefore, how to control the entry of large rocks and boulders into the shield machine soil bin to reduce bin accumulation, sinking, and screw machine blockage is a problem that needs to be solved in tunnel construction. The Chinese patent with patent announcement number CN109184717B discloses a shield machine cutterhead, including a shield machine cutterhead shell, a receiving rotating rod and a connecting rotating disk. The shield machine cutterhead shell is composed of an outer diameter limiting cutterhead, an inner grinding cutterhead, a central cutterhead and a screening leak hole. The outer diameter limiting cutterhead, the inner grinding cutterhead and the central cutterhead are sequentially nested and installed in the inner cavity on the front side of the shield machine cutterhead shell from the outside to the inside. The outer diameter limiting cutterhead includes an outer diameter limiting tool and a guide chute. The shield machine cutterhead, through the stepped excavation and crushing components in the outer diameter limiting cutterhead, the inner grinding cutterhead and the central cutterhead, performs the first, second and third level excavation and crushing work of the tunnel in steps during the working shield machine driving the cutterhead, reduces the stress and torque of the crushing tools such as the outer diameter limiting tool, the main crushing tool and the block tool on the cutterhead during the excavation and crushing process, and reduces the wear rate of the crushing tool during the excavation process. The above device only contains three diameter limiting cutters, which cannot prevent large-sized stones between the spokes and the cutter head panel, and the load on the central cutter head is large, which is easy to damage the cutter. Therefore, it is urgent for those skilled in the art to solve the above technical problems. Summary of the invention

[0004] The invention aims to solve the problems of accumulation, sinking, screw machine blockage and waste of manpower, material and financial resources caused by large-volume stones and isolated stones entering the soil bin.

[0005] A shield cutterhead suitable for complex strata, comprising a cutterhead panel, spokes and a diameter limiting plate; the diameter limiting plate is welded and reinforced on the cutterhead panel and the spokes, and is used to prevent large-volume crushed stone and boulders from entering the soil bin behind the shield cutterhead, the diameter limiting plate comprises diameter limiting plate 1, diameter limiting plate 2, diameter limiting plate 3 and diameter limiting plate 4, one side of the diameter limiting plate 1 is welded on both sides of the cutterhead panel to prevent the outermost stones and boulders from entering the soil bin; the two sides of the diameter limiting plate 2 are respectively welded and reinforced at the spokes and the cutterhead panel, and are located below the diameter limiting plate 1; the diameter limiting plate 3 is welded and reinforced on one side on the inner side of the cutterhead panel, and is located below the diameter limiting plate 2; the diameter limiting plate 4 is welded and reinforced on one side at the center of the spoke to limit the stones and boulders in the center of the cutterhead panel from entering the soil bin.

[0006] By adopting the above technical scheme, by limiting the size of large stones entering the soil bin, the problems of accumulation and sinking caused by the accumulation of large stones can be significantly reduced, the frequency of opening the bin to clean stones can be reduced, and the construction efficiency can be improved. Limiting the large stones from entering the soil bin can help avoid the blockage of the screw conveyor due to excessively large stones, keep the slag discharge system unobstructed, reduce the number of shutdowns for maintenance, and ensure the continuous operation of the shield machine. By controlling the particle size of the stones entering the soil bin, the risk of equipment damage caused by large stones is reduced, and the safety hazards of operators during manual cleaning are reduced. The presence of the diameter limiting plate reduces the direct impact on the tool and other internal components, thereby extending the service life of these components and reducing the maintenance costs required for frequent replacement of tools or repair of other components. Due to the reduction in downtime caused by handling large stones, the overall construction progress is accelerated, the working efficiency of the shield machine is improved, and the tunnel construction period is shortened. The design of the diameter limiting plate is relatively simple, easy to process and install, and can be easily replaced or adjusted when necessary, thereby improving the maintainability of the equipment.

[0007] Furthermore, a total of 8 diameter limiting plates are provided, and both sides of the diameter limiting plate 2 are respectively welded and reinforced at the spokes and the cutter disc panel, and are located below the diameter limiting plate 1. A total of 8 diameter limiting plates are provided. The overall curvature of the diameter limiting plate 2 is 15°-20°, and its shape is similar to a rectangle. The diameter limiting plate 3 is welded and reinforced on one side on the inner side of the cutter disc panel, and is located below the diameter limiting plate 2. A total of 8 diameter limiting plates are provided for the diameter limiting plates 3, and a total of 4 diameter limiting plates are provided for the diameter limiting plates 4.

[0008] By adopting the above technical solution, by arranging multiple diameter limiting plates at different positions of the cutter disc panel, effective coverage of the entire cutter disc area can be achieved, ensuring that large rocks entering the soil bin from all directions are effectively blocked. The diameter limiting plates 1, 2, 3, and 4 are respectively located at different levels of the cutter disc, forming a multi-level protection net, which further improves the interception effect of large rocks. The diameter limiting plate 1 is installed on the outermost side and is mainly used to block the outermost large rocks and boulders. This is the first line of defense for stones to enter the soil bin. The diameter limiting plate 2 is located below the diameter limiting plate 1 and has a certain curvature (15°-20°), which helps to guide smaller stones to move to the center and prevent medium-sized stones from directly entering the soil bin. The diameter limiting plate 3 is located below the diameter limiting plate 2, further refining the screening of stones to ensure that only small stones that meet the requirements can enter the soil bin. The diameter limiting plate 4 is aimed at the center area of ​​the cutter disc and is specifically used to limit the stones in this area from entering the soil bin, forming the last line of defense. The number and layout design of the diameter limiting plates take into account the stability of the overall structure. Multiple evenly distributed limit plates can enhance the overall rigidity and impact resistance of the cutter disc. The arc design of the limit plate 2 also helps to disperse stress and reduce the risk of damage caused by excessive force on a single point. Since the limit plates are designed in blocks, if any one of them is worn or damaged, it can be replaced individually without replacing the entire system.

[0009] Furthermore, the diameter limiting plate one is a rectangle with a length of 350 cm and a width of 300 cm minus an arc with a radius of 800 cm, and a thickness of 80 cm; the diameter limiting plate two is 836 cm long, 300 cm wide, and 60 cm thick; the diameter limiting plate three is a rectangle with a length of 560 cm and a width of 300 cm minus an arc with a radius of 800 cm, and a thickness of 60 cm; the size of the diameter limiting plate three is consistent with that of the diameter limiting plate one.

[0010] By adopting the above technical solution, the design of the diameter limiting plate 1 (350cm x 300cm rectangle minus an arc with a radius of 800cm, thickness 80cm) and the diameter limiting plate 3 (560cm x 300cm rectangle minus an arc with a radius of 800cm, thickness 60cm) can form an effective opening by subtracting an arc portion with a large radius, allowing smaller stones to pass through while blocking larger stones. The rectangular design of the diameter limiting plate 2 (836cm x 300cm, thickness 60cm) has no arc portion, which can provide a larger plane area to further refine the screening of stones. The thickness of the diameter limiting plate 1 is 80cm, which is thicker than the other diameter limiting plates, which increases its compressive resistance and wear resistance when subjected to impact. Since it is the first line of defense, directly facing the large rocks outside, it needs higher strength. The thickness of the two and three limit plates is 60cm. Although thin, they are located inside the cutterhead and are relatively less directly impacted. This design not only ensures sufficient strength, but also reduces the overall weight and improves the operating efficiency of the shield machine. The one and three limit plates have the same arc design, which is particularly suitable for the edge and center area of ​​the cutterhead, and can better guide the stones to move inward while preventing large stones from entering the soil bin. The rectangular design of the two limit plates is suitable for the middle layer, which helps to evenly distribute the pressure of the stones and provides a wider range of protection. Through the design of multi-layer limit plates, the stones are gradually broken and screened, and only small stones that meet the requirements enter the soil bin. This can improve the efficiency of the slag discharge system and reduce the possibility of blockage. The standardized size design of the limit plates makes them easier to process and manufacture, reducing production costs.

[0011] The present invention also includes a stone diameter limiting method for a shield machine applicable to complex strata, which uses a shield cutter head applicable to complex strata to prevent large stones from entering the shield machine soil bin, thereby avoiding the shield machine from freezing and crashing, and includes the following steps: Step 1: Before construction, conduct a detailed geological survey and analysis of the stratum that the tunnel passes through. If the stratum is found to be a complex stratum with soft top and hard bottom, a diameter limiting plate is installed on the shield cutterhead; Step 2: Cut out the appropriate diameter limiting plate according to the size of the shield machine; Step 3: Weld the diameter limiting plate to the cutter head panel or spoke; Step 4: Start the shield machine and conduct trial excavation at a low speed to observe the working status of the diameter limiting plate and its effect on the control of stone particle size; Step 5: Gradually increase the excavation speed and start tunnel construction.

[0012] By adopting the above scheme, the design of the diameter limiting plate can effectively prevent large-volume stones from entering the soil bin, reduce the problems of accumulation and sinking caused by the accumulation of large stones, reduce the frequency of opening the bin to clean the stones, and improve the construction efficiency. By limiting the large stones from entering the soil bin, it helps to avoid the screw conveyor from being blocked by too large stones, keep the slag discharge system unobstructed, reduce the number of shutdowns for maintenance, and ensure the continuous operation of the shield machine. By controlling the particle size of the stones entering the soil bin, the risk of equipment damage caused by large stones is reduced, and the safety hazards of operators during manual cleaning are reduced. The existence of the diameter limiting plate reduces the direct impact on the cutter and other internal components, thereby extending the service life of these components and reducing the maintenance costs required for frequent replacement of cutters or repair of other components. Due to the reduction of downtime caused by handling large stones, the overall construction progress is accelerated, the working efficiency of the shield machine is improved, and the tunnel construction period is shortened. The design of the diameter limiting plate is relatively simple, easy to process and install, and can be easily replaced or adjusted when necessary, which improves the maintainability of the equipment. The size and layout of the diameter limiting plate can be adjusted according to different geological conditions and construction requirements to adapt to a variety of complex formation environments.

[0013] Furthermore, in step 3, the diameter limiting plate one is welded on one side to make it firmly connected to both sides of the cutter disc panel, the two sides of the diameter limiting plate two are respectively welded to the spokes and the cutter disc panel, the diameter limiting plate three is welded on one side to the inner side of the cutter disc panel and placed under the diameter limiting plate two, and the diameter limiting plate four is welded on one side to the center of the spoke.

[0014] By adopting the above technical solution, through multi-point welding, the connection between the diameter limit plate and the cutter disc panel and the spokes is more firmly established, which improves the stability of the overall structure. The combination of single-sided welding and double-sided welding ensures that the diameter limit plate can withstand forces from all directions at different positions. The diameter limit plate 1 is welded on both sides of the cutter disc panel, directly facing the large rocks outside, forming the first line of defense, effectively preventing large rocks from entering the soil bin. The diameter limit plate 2 is located below the diameter limit plate 1, further refining the screening of stones to prevent medium-sized stones from entering. The diameter limit plate 3 is located below the diameter limit plate 2, continuing to refine the screening to ensure that only those that meet the requirements Only small stones can enter the soil bin. The diameter limit plate four is located at the center of the spokes. It is specially used to limit the stones in the center area of ​​the cutter disc from entering the soil bin, forming the last line of defense. The design of multi-layer diameter limit plates can evenly distribute the pressure of stones on the cutter disc and reduce the risk of damage caused by excessive force at a single position. The double-sided welding design of the diameter limit plate two helps to disperse stress and improve its impact resistance. Since the diameter limit plate is designed in blocks, if a certain block is worn or damaged, it can be replaced separately without replacing the entire system. In complex strata with soft top and hard bottom, stones at different positions may enter the soil bin in different ways. The design of multi-layer diameter limit plates can better adapt to these changes and provide a more stable construction environment. The size and shape of the diameter limit plates can be adjusted according to actual geological conditions, which increases the flexibility of the system.

[0015] Furthermore, in step 4, the shield machine starts excavation from a minimum speed of 0.5 mm / min, gradually increases to 2.0 mm / min, and increases the speed by 0.5 mm / min every thirty seconds to observe the material situation in the soil bin, the slag discharge efficiency, and the overall operation status of the shield machine.

[0016] By adopting the above technical solution, by gradually increasing the excavation speed, the working state of the diameter limit plate at different speeds and its control effect on the stone particle size can be observed in more detail, which is helpful to find potential problems, such as stone jamming, poor slag discharge, etc., so as to take timely measures. The low-speed start and gradual acceleration method reduce the risks that may be caused by sudden high-speed excavation, such as cutter head jamming or screw conveyor blockage, and provide operators with more time to monitor and adjust to ensure that the shield machine operates in a safe state. By gradually increasing the speed, the best excavation speed that best suits the current geological conditions can be found, which helps to determine the best torque, thrust and other excavation parameters to achieve the best construction efficiency and equipment performance. The speed is increased by 0.5 mm / min every thirty seconds, which can provide frequent feedback to help operators respond quickly to any abnormal situation, monitor the material situation in the soil bin, the slag discharge efficiency and the overall operation of the shield machine in real time, and ensure that everything is under control. By gradually accelerating, problems can be discovered and solved in time before they occur, avoiding long-term downtime due to sudden failures, reducing additional costs caused by equipment damage or downtime, and improving overall construction efficiency.

[0017] Furthermore, in step 5, after the shield machine is started normally, it is stopped for inspection every 50-100 meters to understand the wear of the diameter limit plate under specific geological conditions. If the welding points between the diameter limit plate and the cutterhead panel or spokes are damaged, the diameter limit plate is reinforced or replaced.

[0018] By adopting the above technical solution, through regular inspection, the wear, cracks or other damage of the diameter limit plate and its welding points can be discovered early, and measures can be taken in time to reinforce or replace them, so as to avoid small problems from turning into major failures and reduce the risk of unexpected downtime. Regular inspection helps to ensure that the diameter limit plate is always in good working condition, prevent large stones caused by failure of the diameter limit plate from entering the soil bin, thereby avoiding the jam of the shield machine or the blockage of the screw conveyor, ensuring the safety of the operators and reducing the risk of accidents caused by equipment failure. Through regular inspection and maintenance, the excessive wear of the diameter limit plate and other related components can be effectively reduced, the service life of the shield machine and its components can be extended, and the need for frequent replacement of parts can be reduced. Regular inspection and maintenance can ensure that the shield machine operates in the best condition, reduce downtime caused by equipment failure, maintain continuous and efficient excavation, and improve the overall construction progress and efficiency.

[0019] Beneficial effects of the present invention: 1. The present invention significantly reduces the problems of silo accumulation and sinking caused by the accumulation of large stones by limiting the size of large stones entering the soil bin, reduces the frequency of opening the bin to clean the stones, and thus improves the construction efficiency. The design of the diameter limiting plate effectively prevents large stones from entering the soil bin, reduces the risk of the screw conveyor being blocked by oversized stones, keeps the slag discharge system unobstructed, reduces the number of shutdowns for maintenance, and ensures the continuous operation of the shield machine. By controlling the particle size of the stones entering the soil bin, the risk of equipment damage caused by large stones is reduced, and the safety hazards of operators performing manual cleaning are reduced; 2. The existence of the diameter limiting plate of the present invention reduces the direct impact on the cutter and other internal components, thereby extending the service life of these components and reducing the maintenance cost required for frequent replacement of cutters or repair of other components. Through regular inspections (stopping for inspection every 50-100 meters), wear, cracks or other damage to the diameter limiting plate and its welding points can be discovered early, and measures can be taken in time to reinforce or replace them, avoiding small problems from turning into major failures and reducing the risk of unexpected downtime. Regular inspections and maintenance can ensure that the shield machine operates in the best condition, reduce downtime caused by equipment failure, maintain continuous and efficient excavation, and improve the overall construction progress and efficiency; 3. The present invention forms a multi-level protection net by arranging multiple diameter limiting plates at different positions of the cutter head panel, ensuring that large rocks entering the soil bin from all directions are effectively blocked. The diameter limiting plates 1, 2, 3 and 4 are respectively located at different levels of the cutter head, further improving the interception effect of large rocks. The size and shape of the diameter limiting plates can be adjusted according to the actual geological conditions, increasing the flexibility of the system and being able to better adapt to the complex formation environment with soft upper and hard lower parts. The design of the diameter limiting plates is relatively simple and easy to process and install. It can be easily replaced or adjusted when necessary, improving the maintainability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a schematic diagram of the plane installation of the diameter limiting plate of the present invention; Figure 2 This is a schematic diagram of the installation of the diameter limiting plate of the present invention. Figure 1 ; Figure 3 This is a schematic diagram of the installation of the diameter limiting plate of the present invention. Figure 2 ; Figure 4 It is a flow chart of the method of the present invention.

[0022] Among them, 1-cutter head panel; 2-spoke; 3-diameter limiting plate; 31-diameter limiting plate one; 32-diameter limiting plate two; 33-diameter limiting plate three; 34-diameter limiting plate four. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0024] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0025] like Figure 1 , Figure 2 and Figure 3As shown, a shield cutterhead suitable for complex formations, the cutterhead panel 1 and the spokes 2 constitute the basic frame of the shield cutterhead, wherein the cutterhead panel 1 is the main component, used to install the diameter limiting plate and other components, and the spokes 2 connect the center and edge of the cutterhead, provide structural support for the cutterhead, and serve as the welding basis for the diameter limiting plate. The diameter limiting plate 3 includes four types, namely, diameter limiting plate 1 31, diameter limiting plate 2 32, diameter limiting plate 3 33 and diameter limiting plate 4 34, which are arranged according to position and have different sizes and shapes. The diameter limiting plate 31 is welded and reinforced on both sides of the cutter head panel 1 on one side. Its function is to prevent the outermost stones and isolated stones from entering the soil bin. A total of 8 pieces are set. The size is a rectangle with a length of 350 cm and a width of 300 cm minus an arc with a radius of 800 cm, and a thickness of 60 cm; the diameter limiting plate 2 32 is welded and reinforced on both sides of the spoke 2 and the cutter head panel 1, respectively, and is located below the diameter limiting plate 31. It further refines the screening of stones and prevents medium-sized stones from entering the soil bin. A total of 8 pieces are set. The size is 836 cm long, 300 cm wide, and 60 cm thick. The overall curvature is 19°, and the shape is similar to a rectangle. The diameter limiting plate 33 is welded and reinforced on one side on the inner side of the cutter head panel 1, located below the diameter limiting plate 2 32, and the screening is continued to be refined to ensure that only small stones that meet the requirements can enter the soil bin. A total of 8 pieces are set, with a size of a rectangle of 560cm long and 300cm wide minus an arc with a radius of 800cm, and a thickness of 60cm; the diameter limiting plate 4 34 is welded and reinforced on one side at the center of the spoke 2 to control the stones and boulders in the central area of ​​the cutter head panel to enter the soil bin. A total of 4 pieces are set, with a size of a rectangle of 350cm long and 300cm wide minus an arc with a radius of 800cm, and a thickness of 60cm. Through this multi-level diameter limiting plate design, the present invention can effectively control the particle size of the stones entering the soil bin, reduce the frequency of accumulation and sinking caused by large-volume stones and boulders entering the soil bin, and reduce the safety risk of the shield machine being shut down due to the inability to discharge slag normally, thereby achieving the purpose of maintaining continuous and safe advancement of the shield machine in complex soft and hard strata.

[0026] like Figure 4 As shown, a stone diameter limiting method for a shield machine applicable to complex strata comprises the following steps: Step 1: Before construction, conduct a detailed geological survey and analysis of the stratum that the tunnel passes through. If the stratum is found to be a complex stratum with soft top and hard bottom, a diameter limiting plate is installed on the shield cutterhead; Step 2: Cut out the appropriate diameter limiting plate according to the size of the shield machine; Step 3: Weld the diameter limiting plate to the cutter head panel or spoke; Step 4: Start the shield machine and conduct trial excavation at a low speed to observe the working status of the diameter limiting plate and its effect on the control of stone particle size; Step 5: Gradually increase the excavation speed and start tunnel construction.

[0027] Before construction, a detailed geological survey and analysis is carried out on the stratum that the tunnel passes through to determine the stratum type. If the stratum is measured to be a complex stratum that is soft on the top and hard on the bottom, a diameter limiting plate 3 is installed on the shield cutter head panel 1, and the diameter limiting plate 3 is cut according to the size of the shield machine. According to the specific size of the shield machine, a suitable diameter limiting plate 3 is cut. The diameter limiting plate 3 includes four types: diameter limiting plate 1 31, diameter limiting plate 2 32, diameter limiting plate 3 33 and diameter limiting plate 4 34. The diameter limiting plate 1 31 is welded and reinforced on one side on both sides of the cutter head panel 1 to control the size of the outermost stones and boulders entering the soil bin. A total of 8 pieces are set. The diameter limiting plate 2 32 is welded and reinforced on both sides at the spoke 2 and the cutter head panel 1 respectively, and is located below the diameter limiting plate 1 31. A total of 8 pieces are set. The diameter limiting plate 33 is welded and reinforced on one side on the inner side of the cutter head panel 1, and is located below the diameter limiting plate 2 32. A total of 8 pieces are set. The diameter limiting plate 4 34 is welded and reinforced on one side at the center of the spoke 2 to control the size of the stones and boulders in the central area of ​​the cutter head panel entering the soil bin. A total of 4 pieces are set. Start the shield machine at low speed and conduct trial excavation at low speed with an initial speed of 0.5 mm / min. Gradually accelerate and gradually increase the excavation speed by 0.5 mm / min every thirty seconds until it reaches 2.0 mm / min. During this process, observe the working status of the diameter limit plate 3 and its control effect on the stone particle size, including the material situation in the soil bin, the slag discharge efficiency and the overall operation status of the shield machine. After confirming that the diameter limit plate 3 is working normally, gradually increase the excavation speed and start the formal tunnel construction. After normal startup, carry out a shutdown inspection every 50-100 meters to understand the wear of the diameter limit plate performance under specific geological conditions. If damage is found at the welding point between the diameter limit plate 3 and the cutter head panel 1 or the spoke 2, reinforce or replace the diameter limit plate 3. By limiting the size of large stones entering the soil bin, the problems of storage and sinking caused by the accumulation of large stones are significantly reduced, the frequency of opening the bin to clean up stones is reduced, and the construction efficiency is improved. The design of the diameter limit plate 3 effectively prevents The entry of large rocks into the soil bin reduces the risk of the screw conveyor being blocked by overly large rocks, keeps the slag discharge system unobstructed, reduces the number of shutdowns for maintenance, and ensures the continuous operation of the shield machine. The presence of the diameter limiting plate 3 reduces the direct impact on the cutter and other internal components, thereby extending the service life of these components and reducing the maintenance costs required for frequent replacement of cutters or repairs of other components. Through regular inspection and maintenance, the wear, cracks or other damage of the diameter limiting plate 3 and its welding points can be discovered early, and measures can be taken in time to reinforce or replace them, avoiding small problems from turning into major failures and reducing the risk of unexpected shutdowns. By arranging multiple diameter limiting plates 3 at different positions of the cutter head panel 1, a multi-level protection is formed to ensure that large rocks entering the soil bin from all directions are effectively blocked.

[0028] Working principle: First, by adjusting the size of the diameter limiting plate 3, the particle size of the stones entering the soil bin can be effectively controlled, and large-volume stones and isolated stones can be effectively blocked outside the soil bin. After being ground by the cutter head for many times, they can enter the soil bin, reducing the frequency of bin opening and reducing the risk of bin opening, reducing the safety risk of shield machine shutdown due to failure to discharge slag normally, saving costs, and improving construction efficiency. At the same time, it has the advantages of simple structure, strong operability, and easy processing. It can be used directly after welding reinforcement is completed. Thereby achieving the purpose of maintaining continuous and safe advancement of the shield machine in complex soft upper and hard lower strata.

[0029] It should be noted that the above specific implementations are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art should understand that various modifications, equivalent substitutions, changes, etc. can be made to the present invention. However, as long as these changes do not deviate from the spirit of the present invention, they should be within the scope of protection of the present invention. In addition, some terms used in the specification and claims of this application are not restrictive, but are only for the convenience of description.

Claims

1. A shield cutterhead suitable for complex strata, characterized in that: The invention comprises a cutter head panel (1), spokes (2) and a diameter limiting plate; the diameter limiting plate is welded and reinforced on the cutter head panel (1) and the spokes (2) to prevent large-volume crushed stones and isolated stones from entering the soil bin behind the shield cutter head; the diameter limiting plate comprises a diameter limiting plate 1 (31), a diameter limiting plate 2 (32), a diameter limiting plate 3 (33) and a diameter limiting plate 4 (34); one side of the diameter limiting plate 1 (31) is welded to both sides of the cutter head panel (1) to prevent the outermost stones and isolated stones from entering the soil bin behind the shield cutter head; The two sides of the second diameter limiting plate (32) are respectively welded and reinforced at the spokes (2) and the cutter head panel (1), and are located below the first diameter limiting plate (31); the third diameter limiting plate (33) is welded and reinforced on one side at the inner side of the cutter head panel (1), and is located below the second diameter limiting plate (32); the fourth diameter limiting plate (34) is welded and reinforced on one side at the center of the spoke (2), so as to limit the stones and isolated stones in the center of the cutter head panel (1) from entering the soil bin.

2. The shield cutterhead suitable for complex strata according to claim 1, characterized in that: The diameter limiting plate one (31) is provided with 8 pieces in total. The two sides of the diameter limiting plate two (32) are respectively welded and reinforced at the spokes (2) and the cutter head panel (1), and are located below the diameter limiting plate one (31). A total of 8 pieces are provided. The overall curvature of the diameter limiting plate two (32) is 15°-20°, and its shape is similar to a rectangle. The diameter limiting plate three (33) is welded and reinforced on one side on the inner side of the cutter head panel (1), and is located below the diameter limiting plate two (32). A total of 8 pieces of the diameter limiting plate three (33) are provided. A total of 4 pieces of the diameter limiting plate four (34) are provided.

3. The shield cutterhead suitable for complex strata according to claim 2, characterized in that: The diameter limiting plate 1 (31) is a rectangle with a length of 350 cm and a width of 300 cm minus an arc with a radius of 800 cm, and a thickness of 80 cm; the diameter limiting plate 2 (32) is 836 cm long, 300 cm wide, and 60 cm thick; the diameter limiting plate 3 (33) is a rectangle with a length of 560 cm and a width of 300 cm minus an arc with a radius of 800 cm, and a thickness of 60 cm; the size of the diameter limiting plate 3 (33) is consistent with that of the diameter limiting plate 1 (31).

4. A stone diameter limiting method for a shield machine suitable for complex strata, characterized in that: Using the shield cutterhead suitable for complex strata as described in any one of claims 1 to 3 to limit the size of stones entering the shield machine soil bin comprises the following steps: Step 1: Before construction, conduct a detailed geological survey and analysis of the stratum that the tunnel passes through. If the stratum is found to be a complex stratum with soft top and hard bottom, a diameter limiting plate is installed on the shield cutterhead; Step 2: Cut out the appropriate diameter limiting plate according to the size of the shield machine; Step 3: Weld the diameter limiting plate to the cutter head panel or spoke; Step 4: Start the shield machine and conduct trial excavation at a low speed to observe the working status of the diameter limiting plate and its effect on the control of stone particle size; Step 5: Gradually increase the excavation speed and start tunnel construction.

5. The stone diameter limiting method for a shield machine suitable for complex strata as claimed in claim 4, characterized in that: In step 3, the diameter limiting plate 1 is welded on one side so that it is firmly connected to both sides of the cutter head panel (1), the two sides of the diameter limiting plate 2 (32) are welded to the spokes (2) and the cutter head panel (1) respectively, the diameter limiting plate 3 (33) is welded on one side to the inner side of the cutter head panel (1) and placed under the diameter limiting plate 2 (32), and the diameter limiting plate 4 (34) is welded on one side to the center of the spoke (2).

6. The stone diameter limiting method for a shield machine suitable for complex strata as claimed in claim 4, characterized in that: In step 4, the shield machine starts excavation from a minimum speed of 0.5 mm / min, gradually increases to 2.0 mm / min, and increases the speed by 0.5 mm / min every thirty seconds. The material situation in the soil bin, the slag discharge efficiency, and the overall operating status of the shield machine are observed.

7. The stone diameter limiting method for a shield machine suitable for complex strata as claimed in claim 4, characterized in that: In step 5, after the shield machine is started normally, it is stopped for inspection every 50-100 meters to understand the wear of the diameter limiting plate under specific geological conditions. If the welding point between the diameter limiting plate and the cutterhead panel (1) or the spoke (2) is damaged, the diameter limiting plate is reinforced or replaced.

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