Multi-stage tool changer, normal pressure tool changing system and tool changing method

Abstract

The application provides a multi-stage tool changing device, an atmospheric pressure tool changing system and a tool changing method, wherein the rear end face of an inner cutter barrel located at the inner side of a cutter head is connected with an outer cutter barrel through a multi-stage pushing-out structure, and the multi-stage pushing-out structure is detachably connected with the inner cutter barrel and the outer cutter barrel through first fasteners; additional sealing members are sequentially assembled between the inner cutter barrel and the mounting seat at the rear side of original sealing members, and the number of the additional sealing members is not less than the number of limiting members, and the distance between any adjacent additional sealing members is not less than the thickness of the limiting members. After the tool head is worn, at least one limiting member between the inner cutter barrel and the outer cutter barrel is disassembled, and the inner cutter barrel is moved to the outer side of the cutter head by a corresponding distance in the axial direction, at which time the additional sealing members block the mud and water on the outer side of the cutter head. The application can realize multi-stage pushing-out of one tool head and reach the digging distance of the original multiple tools, and the tool changing frequency is greatly reduced, and meanwhile, the multi-stage sealing structure is supplemented, so that the isolation of the external high-pressure mud and water environment can be ensured after the tool head is pushed out for multiple times.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machines, and more specifically to a cutterhead changing device for tunnel boring machines. Background Technology

[0002] With the rapid advancement of urbanization and the continuous expansion of urban scale, the pressure on surface transportation is increasing daily. To address this contradiction, the development and utilization of underground space has become an inevitable trend of the times. Currently, underground space development is moving towards deeper, longer, and larger-scale projects, resulting in a large number of long-distance, large-diameter tunnel projects, especially major infrastructure projects such as river-crossing tunnels.

[0003] For long-distance, large-diameter tunnel construction under complex geological conditions, atmospheric pressure shield tunneling machines have become an ideal and widely used excavation equipment due to their unique advantages. The atmospheric pressure cutterhead changer, as one of the core components of the atmospheric pressure cutterhead, is designed to replace worn cutters under atmospheric pressure while ensuring personnel safety, thereby maintaining the shield machine's continuous excavation capability.

[0004] However, in practical applications, existing atmospheric pressure cutterhead changing devices and cutterhead technologies still face severe challenges. Due to the complex and variable underground geological conditions, especially when traversing highly abrasive strata or major risk sources such as riverbeds, the wear rate of tunneling tools accelerates significantly. To ensure tunneling efficiency and safety, frequent shutdowns for cutterhead replacement are necessary.

[0005] This frequent cutterhead replacement has led to a series of serious problems: First, frequent equipment downtime significantly extends the overall construction period; second, the extended period directly increases project costs; and more importantly, when traversing major risk sources such as riverbeds and fault fracture zones, frequent downtime significantly increases project risks and poses a huge threat to construction safety. Therefore, the industry urgently hopes to minimize the number of cutterhead replacements and extend the single tunneling distance to minimize downtime and achieve rapid and safe passage through risk areas.

[0006] In summary, how to effectively reduce the cutter replacement frequency of atmospheric pressure tunnel boring machines (TBMs) in complex geological formations, extend cutter life and continuous tunneling distance, so as to improve the overall working efficiency of TBMs and reduce engineering costs and risks, has become a key technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] Purpose of the invention: The purpose of this invention is to address the shortcomings of existing technologies by providing a multi-stage tool changing device, an atmospheric pressure tool changing system, and a tool changing method. This enables multi-stage tool changing operations to be completed under atmospheric pressure without removing the tool cylinder or opening and closing the gate, thereby reducing the number of tool changes and lowering the tool changing frequency.

[0008] Technical Solution: The multi-stage tool changing device of the present invention includes a tool disc, a mounting base, an outer tool cylinder, an inner tool cylinder, a tool head, and an initial sealing element. The outer tool cylinder is fixed on the tool disc by the mounting base axially connected to it. The inner tool cylinder slides coaxially within the outer tool cylinder and the mounting base. The tool head is mounted on the front end face of the inner tool cylinder located outside the tool disc. The initial sealing element is assembled between the inner tool cylinder and the mounting base to block mud and water from entering the outer side of the tool disc. The device also includes: The multi-stage ejection structure includes at least one limiting member stacked in layers. The rear end face of the inner cutter cylinder located inside the cutter disc is connected to the outer cutter cylinder through the multi-stage ejection structure. The multi-stage ejection structure is detachably connected to the inner cutter cylinder and the outer cutter cylinder respectively through a first fastener. A multi-stage sealing structure includes at least one additional seal, which is sequentially assembled between the inner knife cylinder and the mounting base on the rear side of the original seal, and the number of additional seals is not less than the number of limiting elements, and the distance between any adjacent additional seals is not less than the thickness of the limiting elements. After the cutter head wears out, at least one limiting member between the inner and outer cutter cylinders is removed, and the inner cutter cylinder is moved axially and outwards from the cutter disc by a corresponding distance. At this time, the additional sealing member blocks the mud and water outside the cutter disc.

[0009] In one implementation, the limiting member is constructed as a ring, and the inner diameter of the limiting member matches the outer diameter of the inner blade cylinder.

[0010] In one implementation, the annular component is composed of radially divided arc-shaped components, each arc-shaped component being connected to the inner and outer cutter cylinders respectively via a first fastener.

[0011] In one implementation, a gate assembly is provided between the outer cutter barrel and the mounting base to isolate the high-pressure environment outside the cutter head from the normal-pressure environment inside. The gate assembly includes a gate plate and a sealing strip. The gate plate is axially fixed to the outer knife cylinder and the mounting base, and the gate plate is tightly fitted with the inner wall of the outer knife cylinder by the sealing strip.

[0012] In one implementation, the number of additional seals is the same as the number of limiting elements, and the distance between adjacent additional seals is equal to the thickness of a single limiting element.

[0013] An atmospheric pressure tool changing system includes a multi-stage tool changing device and a tool head wear detection module. The tool head wear detection module detects the wear degree of the tool head in real time. When the wear height of the tool head reaches the thickness of the limiting component, the multi-stage tool changing device removes at least one limiting component between the inner and outer tool cylinders and moves the inner tool cylinder a corresponding distance to the outside of the tool disc. At this time, an additional sealing component blocks the mud and water outside the tool disc.

[0014] In one implementation, the tool wear detection module includes a wear sensor, a signal transmission element, and a host computer; The wear sensor is mounted on the cutter head and is used to detect the degree of wear of the cutter head in real time. The signal transmission element connects the wear sensor and the host computer, and is used to transmit the wear degree signal of the cutter head to the host computer; The host computer is located in the monitoring room and is used to process and display the wear level signal.

[0015] In one implementation, the signal transmission element transmits signals in a wired and / or wireless manner.

[0016] In one implementation, the wear sensor is configured as a resistance sensor.

[0017] A method for changing a tool in a multi-stage tool changer involves the following steps: When the tool wear detection module detects that the wear of the tool head has reached a preset threshold, the first fastener between the inner and outer tool cylinders is removed, and several limiting members with a stacked thickness adapted to a set height are taken out. The inner tool cylinder is then moved axially a corresponding distance to the outside of the tool disc, and the remaining limiting members are connected to the inner and outer tool cylinders respectively through the first fastener. At this point, the tool head is pushed out to complete the tool change. When the tool wear detection module detects that the tool head is worn again and the wear amount reaches a preset threshold, the operator repeats the above operation to complete the multi-stage tool change.

[0018] Beneficial Effects: This invention, through its multi-stage ejection structure, allows a single cutter head to be ejected in multiple stages, achieving the same tunneling distance as multiple cutters, significantly reducing the number of cutter head replacements. Furthermore, the multi-stage sealing structure ensures continued isolation from the external high-pressure slurry environment even after multiple cutter head ejections. In addition, traditional cutter head replacement requires stopping the machine, opening the gate, removing the old cutter head, installing the new cutter head, and closing the gate—a complex process. This invention only requires removing the limiting components inside the machine and ejecting the cutter head, making the operation simple and quick, eliminating the need to open the gate and greatly reducing downtime. Since cutter head replacement does not require opening the gate, high-risk operations such as sealing unlocking and reinstallation under high pressure and high-risk environments are avoided, greatly improving construction safety. By significantly reducing the number of gate openings and closings, the service life and reliability of the machine can be effectively extended. Attached Figure Description

[0019] Figure 1 (1) is a schematic diagram of the initial state structure of the two-stage tool changer in the embodiment. Figure 1 (2) for Figure 1 (1) Sectional view of section AA; Figure 2 (1) is a schematic diagram of the cutter head and inner cutter cylinder. Figure 2 (2) for Figure 2 (1) Sectional view of section BB; Figure 3 (1) is a schematic diagram of the mounting base. Figure 3 (2) for Figure 3 (1) Sectional view of section CC; Figure 4 (1) is a schematic diagram of the inner knife cylinder structure. Figure 4 (2) for Figure 3 (1) Sectional view of section DD; Figure 5 This is a schematic diagram of the tool wear detection module; Figure 6 (1) and (2) are respectively a cross-sectional view and a side view of the limiting member of the present invention, which is constructed as two semi-circular parts; Figure 7 (1) and (2) are process diagrams of the ejectable special cutter head of the present invention from its original state to the first wear of 30mm; Figure 7 (3) A radial sectional view of the inner cutter barrel after the first wear of 30mm; Figure 7 (4) for Figure 7 (3) Sectional view of section B1-B1; Figure 8 (1)-(3) are flow charts showing the first ejection process of the ejectable tool changer of the present invention. Figure 8 (4) for Figure 8 (3) Sectional view of section A1-A1; Figure 9 (1) and (2) are process diagrams of the ejectable special cutter head of the present invention from its original state to the second wear of 30mm; Figure 9 (3) A radial sectional view of the inner cutter barrel after the second wear of 30 mm; Figure 9 (4) for Figure 9 (3) Sectional view of section B2-B2; Figure 10 (1)-(3) are flow charts showing the second ejection process of the ejectable tool changer of the present invention. Figure 10 (4) for Figure 10 (3) Sectional view of section A2-A2. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of this application.

[0021] In the description of the embodiments of this application, it should be noted that the terms "inner" and "outer," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of this application. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0023] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0024] Currently, tunnel engineering is developing towards longer distances and larger diameters, especially with the increasing number of major projects such as river-crossing tunnels. For such projects, atmospheric pressure tunnel boring machines (TBMs) have become an ideal choice due to their unique advantages. The atmospheric pressure cutterhead replacement device is one of the core components of the atmospheric pressure cutterhead. Its original design purpose is to replace worn cutters under atmospheric pressure while ensuring personnel safety, thus ensuring continuous tunneling. However, in practical applications, existing technologies still have significant shortcomings: due to the complex and variable underground geological conditions, especially when crossing highly abrasive strata or major risk sources such as riverbeds, the cutter wear rate accelerates significantly, leading to frequent cutter replacements.

[0025] Frequent cutterhead changes bring a series of problems: First, multiple shutdowns for cutterhead changes significantly extend the overall construction period; second, the extended period directly increases project costs; and more importantly, frequent shutdowns when traversing major risk areas significantly increase project risks and threaten construction safety. Therefore, the industry urgently needs technical solutions to reduce the number of cutterhead changes and extend the single tunneling distance, minimizing downtime and enabling rapid and safe passage through risk areas. Thus, how to effectively reduce the frequency of cutterhead changes for atmospheric pressure tunnel boring machines (TBMs) in complex geological formations, improve cutter life and continuous tunneling capability, thereby increasing the overall working efficiency of the TBM and reducing project costs and risks, has become a pressing technical problem for those skilled in the art.

[0026] Based on this, the present invention provides a multi-stage tool changing device, such as... Figure 1 As shown, the outer cutter barrel 5 is fixed to the cutter head 12 by a mounting base 2 axially connected to it, and the inner cutter barrel 4 is correspondingly and slidably mounted coaxially in the outer cutter barrel 5 and the mounting base 2; as Figure 2 As shown, the cutter head 1 is installed on the front end face of the inner cutter cylinder 4 located outside the cutter disc 12, and the original seal 10 is assembled between the inner cutter cylinder 4 and the mounting base 2 to block the mud and water outside the cutter disc 12.

[0027] Generally, the cutterhead 12 is a rotary support structure at the front end of the tunnel boring machine, and it has several mounting holes for installing the cutterhead replacement device. The cutterhead 12 is connected to the shield body through a rotary drive, and rotates during tunnel boring machine excavation, driving various cutters mounted on it to cut and break the rock and soil at the excavation face.

[0028] In addition, the outer cutter barrel 5 and the inner cutter barrel 4 are typically configured as hollow, cylindrical steel structures to house and protect the cutting tools. The outer cutter barrel 5 is a hollow cylindrical structure and can be fixed to the cutter head 12 via the mounting base 2. The mounting base 2 is generally a precision-machined metal base, such as... Figure 3 As shown, it is fixedly connected to the mounting hole of the cutterhead 12. Specifically, the mounting base 2 is preferably fixed to the cutterhead 12 by welding to ensure that the connection strength is sufficient to withstand the huge load during the tunneling process. Figure 3 In the diagram, L1 represents the overall height of mounting base 2.

[0029] The outer cutterhead 5 is coaxially and fixedly connected to the mounting base 2. The rear end of the outer cutterhead 5 is open to accommodate and operate internal components, and the front end is also open for fixed connection with the mounting base 2. The front end face of the outer cutterhead 5 fits tightly with the mounting base 2 and is fixed by fasteners (such as bolts) or welding to ensure that it does not undergo axial or circumferential displacement during tunneling operations. It should be noted that, unless otherwise stated, in this embodiment, "rear end," "rear side," etc., can all be used to refer to the end and side near the internal operating space of the tunnel boring machine, and "front end," "front side," "outer side," etc., can all be used to refer to the end and side near the excavation face.

[0030] Furthermore, the inner cutter cylinder 4 is coaxially and slidably mounted within the internal cavity of the outer cutter cylinder 5 and the mounting base 2, such as... Figure 4 As shown, the outer diameter of the inner cutter cylinder 4 matches the inner diameter of the outer cutter cylinder 5 and the mounting base 2, forming a precise sliding fit between the inner and outer parts. The rear end of the inner cutter cylinder 4 extends to the rear opening of the outer cutter cylinder 5, facilitating operations by operators or cutter-changing robots inside the tunnel boring machine, while its front end is used to install the cutter head 1. Figure 4 In the diagram, L3 represents the length of the machined surface of the inner tool barrel 4. This machined surface is set as the first mating surface that mates with the mounting base 2. Correspondingly, as shown in the diagram... Figure 3 As shown, the inner wall of the mounting base 2 needs to be constructed with a second mating surface that is adapted to the first mating surface, and the length L3 of the first mating surface should be equal to the length L2 of the second mating surface.

[0031] Based on the structure of the outer cutter cylinder 5 and the inner cutter cylinder 4, the cutter head 1 is installed on the front end face of the inner cutter cylinder 4. Specifically, the cutter head 1 can be detachably fixed to the inner cutter cylinder 4 through the connecting pin 7, to ensure that the cutter head 1 remains stable when subjected to huge tunneling loads, while facilitating subsequent replacement or maintenance. The type of cutter head 1 can be selected according to geological conditions, such as disc cutter, toothed cutter, or scraper.

[0032] Based on this, the original seal 10 is sandwiched between the inner cutterhead 4 and the mounting base 2. In some examples, the original seal 10 is at least one O-ring, which is installed in a sealing groove opened on the outer wall of the inner cutterhead 4 and / or in a sealing groove opened on the inner wall of the mounting base 2. The sealing groove should be opened on the first mating surface and / or the second mating surface. When the inner cutterhead 4 is installed in the mounting base 2, the original seal 10 is deformed by the inner and outer walls of the two, forming a circumferential seal. This sealing structure is used to prevent high-pressure slurry from the outside of the cutterhead 12 from seeping into the normal pressure operating space inside the tunnel boring machine from the mating gap between the inner cutterhead 4 and the mounting base 2, providing basic safety assurance for tunneling operations.

[0033] With the above structure, when the tunnel boring machine is tunneling normally, the cutterhead 12 drives the mounting base 2 and the entire cutter replacement device to rotate. The cutter head 1 cuts the rock and soil under the action of thrust. All tunneling loads are transmitted to the inner cutter cylinder 4 through the cutter head 1, and then to the cutterhead 12 through the outer cutter cylinder 5 and the mounting base 2. The original seal 10 plays an isolation role throughout the process to prevent mud and water from seeping into the cylinder.

[0034] To improve tool changing efficiency, this invention, based on the above structure, also includes a multi-stage ejection structure and a multi-stage sealing structure. The multi-stage ejection structure includes at least one stacked limiting member. The rear end face of the inner tool cylinder 4 located inside the tool disc 12 is connected to the outer tool cylinder 5 via the multi-stage ejection structure, and the multi-stage ejection structure is detachably connected to both the inner tool cylinder 4 and the outer tool cylinder 5 via first fasteners 13. The multi-stage sealing structure includes at least one additional sealing member 11, which is sequentially assembled between the inner tool cylinder 4 and the outer tool cylinder 5 behind the original sealing member 10. The number of additional sealing members 11 is not less than the number of limiting members, and the distance between any adjacent additional sealing members 11 is not less than the thickness of the limiting member.

[0035] Based on the multi-stage ejection and multi-stage sealing structure, after the cutter head 1 wears, the first fastener 13 used to fix the inner cutter cylinder 4 and the outer cutter cylinder 5 is opened. Depending on the degree of wear, at least one limiting member between the inner and outer cutter cylinders 5 is removed, and the inner cutter cylinder 4 is moved axially outwards from the cutter disc 12 by a corresponding distance, and then the inner cutter cylinder 4 and the outer cutter cylinder 5 are fixed again by the first fastener 13. At this time, the additional sealing member 11 at the front end blocks the mud and debris on the outside of the cutter disc 12, preventing wear on the machined surface of the mounting base 2.

[0036] As can be seen, the multi-stage ejection structure is set on the rear end face of the inner cutter cylinder 4 to limit the extreme position of the inner cutter cylinder 4's movement towards the front end. When the cutter head 1 wears down, as long as the corresponding number of limiting members are removed, the inner cutter cylinder 4 can move a corresponding distance towards the front end of the cutter disc 12. At the same time, it is fixed to the outer cutter cylinder 5 by the first fastener 13, forming a stable cutter head 1 fixing structure. After the limiting members are removed, if the original sealing member 10 moves with the inner cutter cylinder 4 and may not be able to fit tightly with the inner wall of the outer cutter cylinder 5, the gap between the inner cutter cylinder 4 and the outer cutter cylinder 5 is sealed by the remaining additional sealing member 11 near the cutter head 1.

[0037] Here, as the cutter head 1 gradually wears down during the tunneling process, the distance the inner cutter cylinder 4 extends towards the front end of the cutterhead 12 is determined according to the degree of wear, while the number of limiting components that need to be removed is determined according to the moving distance of the inner cutter cylinder 4. It is easy to conclude that the moving distance of the inner cutter cylinder 4 is equal to the total thickness of the removed limiting components. The moving distance of the inner cutter cylinder 4 can restore the working height of the cutter head 1, allowing the tunnel boring machine to continue tunneling.

[0038] It is conceivable that, in order to ensure a sealing structure remains between the inner and outer cutter cylinders 5 even after any limiting component is removed, the number of additional sealing components 11 is no less than the number of limiting components, and the distance between any adjacent additional sealing components 11 is no less than the thickness of the limiting component. Under this structure, as the limiting components are reduced until they are completely removed, there will always be remaining additional sealing components 11 to replace the original sealing components, effectively contacting the outer cylinder and isolating the inside from the outside, ensuring that external high-pressure mud and water will not rush in.

[0039] The device with the above structure is called a multi-stage tool changer because it can perform multiple pushes without opening the gate to change the tool.

[0040] In order to facilitate the dismantling of the multi-stage ejection structure and the ejection of the inner cutter cylinder 4, it is necessary to explain the connection method between the limiting member and the rear end face of the inner cutter cylinder 4 and the outer cutter cylinder 5.

[0041] In some embodiments, the inner cutter cylinder 4 includes a first cylinder and a first rear end face. The outer diameter of the first rear end face is larger than the outer diameter of the first cylinder, meaning the first rear end face acts as a shoulder of the first cylinder, supporting and restricting the multi-stage ejection structure. Correspondingly, the outer cutter cylinder 5 includes a second cylinder and a second rear end face. The inner diameters of the second cylinder and the second rear end face must be consistent to ensure that the inner cylinder can fit against and penetrate the interior of the outer cylinder. Furthermore, the outer diameter of the second rear end face is larger than the outer diameter of the second cylinder, meaning the second rear end face acts as a shoulder of the second cylinder, providing another restriction on the multi-stage ejection structure. In this case, the two ends of the multi-stage ejection structure abut against the front end of the first rear end face and the rear end of the second rear end face, respectively. Therefore, the thickness of the multi-stage ejection structure determines the relative position of the inner cutter cylinder 4 and the outer cutter cylinder 5, that is, the extension distance of the cutter head 1 fixed on the inner cutter cylinder 4 relative to the outer cutter cylinder 5.

[0042] To accommodate the structures of the inner cutter cylinder 4 and the outer cutter cylinder 5, the limiting component is constructed as a ring, with its inner diameter matching the outer diameter of the inner cutter cylinder 4. Therefore, the inner circumferential surface of the limiting component contacts the outer circumferential surface of the inner cutter cylinder 4, providing auxiliary radial support and guidance for the inner cutter cylinder 4. When the inner cutter cylinder 4 is subjected to eccentric loads or radial impacts during tunneling, the ring component can share some of the radial force, preventing the inner cutter cylinder 4 from tilting or jamming, ensuring its smooth movement along the predetermined axis. Furthermore, the ring structure significantly increases the contact area between the limiting component and the first rear end face of the inner cutter cylinder 4 and the second rear end face of the outer cylinder, avoiding point contact or localized stress concentration. Additionally, the ring component is fitted onto the outside of the first cylinder of the inner cutter cylinder 4, naturally aligning during installation and requiring no additional adjustment for accurate positioning.

[0043] In some examples, each limiting member can adopt a split structure design, with the annular member composed of radially divided arc-shaped members. Each arc-shaped member is connected to the inner cutter cylinder 4 and the outer cutter cylinder 5 respectively by a first fastener 13. The purpose of the split design is to facilitate disassembly and assembly operations in confined spaces. Each arc-shaped member is fixedly connected to the inner cutter cylinder 4 and the outer cutter cylinder 5 by its own first fastener 13. When disassembly is required, each arc-shaped member can be removed radially from the side without disassembling other components.

[0044] In this embodiment, as Figure 6 As shown, each limiting component is constructed from two radially opposed semi-annular parts, that is, the two semi-annular parts form a two-lobed structure divided along the diameter direction. When removing the limiting component, it can be removed radially from both sides. To facilitate the installation of the semi-annular parts, an assembly gap t is reserved between the two semi-annular parts to facilitate radial disassembly and assembly, compensate for manufacturing errors, and reserve space for thermal expansion, thereby improving operational convenience and assembly accuracy.

[0045] Based on the above scheme, N limiting components can be stacked accordingly to accommodate the required number of stages N. This structure is compact and occupies little axial space. The thickness of each limiting component is the extension distance of that stage. Let the thickness of the i-th limiting component be Ti. Then, when the limiting component is removed, the inner cutter cylinder 4 can be extended forward a distance equal to Ti, thereby restoring the extension height of the cutter head 1 to the required working height.

[0046] In some examples, such as Figure 7-10 As shown, the multi-stage ejection structure includes a first limiting member 8 and a second limiting member 9 stacked together, thus enabling up to two stages of ejection of the cutter head 1. Taking a two-stage ejection as an example, in the initial state, both the first limiting member 8 and the second limiting member 9 are installed between the inner cutter cylinder 4 and the outer cylinder. When a first-stage ejection is required, the operator first removes the first fastener 13 to release the axial lock between the inner cutter cylinder 4 and the outer cylinder; then, the two semi-annular parts of the first limiting member 8 are radially pulled out from both sides; subsequently, the first fastener 13 is reinstalled and locked, causing the inner cutter cylinder 4 to move forward a distance T1 relative to the outer cylinder, completing the first-stage ejection. When a second-stage ejection is required, the above operation is repeated, removing the second limiting member 9, causing the inner cutter cylinder 4 to continue moving forward a distance T2.

[0047] With the structure described in the embodiment, the operator does not need to completely disassemble the inner cutter cylinder 4. He only needs to remove the first fastener 13 on the normal pressure side inside the tunnel boring machine and remove the limiting parts that need to be removed in sections. This allows the inner cutter cylinder 4 and the cutter head 1 to be pushed forward step by step. The operation is simple and quick, and the efficiency of cutter replacement is significantly improved.

[0048] For example, the first fastener 13 is configured as a bolt, which axially penetrates the multi-stage ejection structure, with its head abutting against the rear end face of the inner cutter cylinder 4, and its shank passing through each layer of limiting members and engaging with the threaded hole on the rear end face of the outer cylinder to lock it in place.

[0049] In some embodiments, the original seal 10 and the additional seal 11 are constructed as O-rings to prevent mud and sand from the excavation face from entering the cutter barrel and causing wear on the cutter mounting seat 2. They also serve as the first seal for the mud and water chamber and the multi-stage cutter changing device.

[0050] In some embodiments, the number of additional seals 11 is equal to the number of limiting members, the distance between adjacent additional seals 11 is equal to the thickness of the limiting members, and whenever a limiting member is removed, the foremost additional seal 11 can take over to seal the mud and water in the same position.

[0051] In order to achieve reliable isolation between the pressurized side of the high-pressure slurry chamber at the excavation face and the atmospheric pressure side of the internal operating space of the tunnel boring machine, and to ensure the safety of the cutterhead replacement operation, the outer cutterhead 5 is generally fixedly connected to the mounting base 2 through the gate assembly 3. The gate assembly 3 includes a gate plate and a sealing strip. The gate plate is axially connected and fixed to the outer cutterhead 5 and the mounting base 2 respectively. The plate surface of the gate plate can movably and radially close the interior of the outer cutterhead 5, and the gate plate is tightly fitted with the inner wall of the outer cutterhead 5 by a sealing strip.

[0052] The inner wall of the outer cylinder is provided with a gate slot for installing the gate plate, so that the gate plate can be inserted into or removed from the slot from the operating side inside the tunnel boring machine in a direction perpendicular or approximately perpendicular to the axial direction of the inner cutter cylinder 4.

[0053] When the gate plate is fully inserted into the working position along the gate slot, its body cuts off the internal channel of the entire outer cylinder. At this time, the sealing strip installed around the gate plate forms a tight compression contact with the inner wall of the gate slot and the inner wall of the outer cylinder. The sealing strip is usually made of highly elastic, wear-resistant materials, such as polyurethane or nitrile rubber, to maintain good sealing performance under high pressure.

[0054] Therefore, when the gate plate is closed, it forms a reliable dynamic sealing interface with the outer cylinder through the sealing strip, completely isolating the front and rear ends of the outer cylinder. This means that even if the inner cutter cylinder 4 at the front end is partially or completely removed, the slurry pressure of the high-pressure chamber connected to the front end of the outer cylinder cannot leak into the operating space inside the tunnel boring machine through the internal channels of the outer cylinder, thus achieving the purpose of safely disassembling and installing the inner cutter cylinder 4 and the cutters under normal pressure.

[0055] In summary, this invention, through its multi-stage ejection and sealing structures, enables tool changing operations under normal pressure without removing the inner tool cylinder 4 or closing the gate plate. This not only effectively isolates the pressurized chamber from the normal pressure side during tool changing but also simplifies the sealing path and improves isolation reliability and operational convenience because the gate acts directly on the outer cylinder channel.

[0056] An atmospheric pressure tool changing system includes a multi-stage tool changing device and a tool head wear detection module. The tool head wear detection module detects the wear degree of the tool head 1 in real time. When the wear height of the tool head 1 reaches the thickness of the limiting component, the multi-stage tool changing device removes at least one limiting component between the inner and outer tool cylinders 5 and moves the inner tool cylinder 4 to the outside of the tool disc 12 by a corresponding distance. At this time, the additional sealing component 11 blocks the mud and water outside the tool disc 12.

[0057] Specifically, such as Figure 5 As shown, the tool wear detection module includes a wear sensor 6, a signal transmission element, and a host computer 18. The wear sensor 6 is installed on the multi-stage tool changer, while the host computer 18 is installed in the driver's cab. The signal transmission element enables signal transmission between the two.

[0058] In some embodiments, the wear sensor 6 is disposed on the cutter head 1, and the sensor 6 is configured as a resistive sensor 6. The resistive sensor 6 can be fixed at a predetermined wear detection position of the cutter head 1, or installed on the inner cutter cylinder 4 at a detection point associated with the wear of the cutter head 1, for real-time sensing of changes in the amount of wear of the cutter head 1.

[0059] Optionally, the signal transmission element can be wired and / or wireless. In some examples, the wireless signal transmission element includes a connector, a wireless signal transmitter 15, and a data receiver 16. The wear sensor 6 is electrically connected to the connector via a signal transmission line 14, and the connector is further electrically connected to the wireless signal transmitter 15. The wireless signal transmitter 15 is fixedly mounted at the rear of the cutter head 12 or the inner cutter cylinder 4, and is used to convert the collected wear signal into a radio signal and transmit it outward. As a preferred embodiment, a data receiver 16 is also provided inside the pressure chamber to receive the signal emitted by the wireless signal transmitter 15 and convert it into an electrical signal.

[0060] A host computer 18 is located in the driver's cab and electrically connected to a data receiver 16 for processing and displaying wear level signals. Preferably, the data receiver 16 is located in the driver's cab and receives signals from a wireless transmitter 15, converting them into electrical signals. The host computer 18, electrically connected to the data receiver 16, receives wear data from the pressure chamber and performs calculations. For example, the host computer 18 can be configured as a PLC 17, equipped with a touchscreen display, for displaying the current wear value of the cutter head 1 in real time, either digitally or graphically.

[0061] In the above embodiments, the workflow of the tool wear detection module is as follows: First, during the tunnel boring machine's excavation process, the resistive sensor 6 detects the wear of the cutter head 1 in real time and generates a resistance value change signal corresponding to the amount of wear. This signal is transmitted to the connector through the signal transmission line 14, and then converted into a radio signal by the wireless signal transmitter 15 and transmitted outward.

[0062] Next, the data receiver 16 receives the radio signals emitted by the wireless signal transmitter 15, converts them into electrical signals, and transmits them to the host computer 18 in the driver's cab. The host computer 18 processes the received signals and parses out the detailed wear data of the cutter head 1.

[0063] Finally, the wear data processed by the host computer 18 is transmitted to the touch screen display and displayed in real time on the screen in numerical or graphical form. By observing the touch screen display, the operator can monitor the wear status of the cutter head 1 in real time.

[0064] Based on the aforementioned tool wear detection module, this invention can also provide a tool changing method for a multi-stage tool changing device based on real-time wear data. Specifically, when the tool wear detection module detects that the wear of tool 1 reaches a first preset threshold, the system issues a prompt signal, indicating to the operator that a first-stage ejection operation can be performed. For example, the first preset threshold corresponds to the thickness T1 of the first limiting member.

[0065] The operator then removed the first fastener 13 on the atmospheric pressure side inside the tunnel boring machine, took out the first limiting piece, and then re-tightened the first fastener 13, causing the inner cutter cylinder 4 to be pushed forward a distance T1. At this time, the extension height of the cutter head 1 returned to the initial working height H0, and the tunnel boring machine could continue tunneling.

[0066] When the cutter head wear detection module detects that the cutter head 1 is worn again and the cumulative wear reaches the second preset threshold, the system issues a secondary push-out prompt signal. For example, the second preset threshold corresponds to the sum of the thicknesses of the two limiting members, T1 + T2. The operator repeats the above operation, removes the second limiting member, and allows the inner cutter cylinder 4 to continue pushing forward a distance T2, restoring the extension height of the cutter head 1 back to the initial working height H0.

[0067] Similarly, based on the number N of the ejectable cutter head, N limiting components with thicknesses of T1, T2...TN are set, and the number and spacing of the additional sealing components 11 correspond to the number and thickness of the limiting components. This allows for N ejections without opening the gate assembly 3. After each ejection, the extension height of the cutter head 1 returns to the initial working height H0, thus significantly extending the continuous tunneling distance after a single cutter change while ensuring sealing performance, reducing the number of gate openings and closings, and improving construction efficiency.

[0068] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A multi-stage tool changing device, comprising a tool disc, a mounting base, an outer tool cylinder, an inner tool cylinder, a tool head, and an initial sealing element, wherein the outer tool cylinder is fixed on the tool disc via a mounting base axially connected thereto, the inner tool cylinder slides coaxially within the outer tool cylinder and the mounting base, the tool head is mounted on the front end face of the inner tool cylinder located outside the tool disc, and the initial sealing element is assembled between the inner tool cylinder and the mounting base to block mud and water from entering the outer side of the tool disc; characterized in that, Also includes: The multi-stage ejection structure includes at least one limiting member stacked in layers. The rear end face of the inner cutter cylinder located inside the cutter disc is connected to the outer cutter cylinder through the multi-stage ejection structure. The multi-stage ejection structure is detachably connected to the inner cutter cylinder and the outer cutter cylinder respectively through a first fastener. A multi-stage sealing structure includes at least one additional seal, which is sequentially assembled between the inner knife cylinder and the mounting base on the rear side of the original seal, and the number of additional seals is not less than the number of limiting elements, and the distance between any adjacent additional seals is not less than the thickness of the limiting elements. After the cutter head wears out, at least one limiting member between the inner and outer cutter cylinders is removed, and the inner cutter cylinder is moved axially and outwards from the cutter disc by a corresponding distance. At this time, the additional sealing member blocks the mud and water outside the cutter disc.

2. The multi-stage tool changing device according to claim 1, characterized in that, The limiting member is constructed as a ring, and the inner diameter of the limiting member matches the outer diameter of the inner blade cylinder.

3. The multi-stage tool changing device according to claim 2, characterized in that, The annular component is composed of radially divided arc-shaped components, each of which is connected to the inner and outer cutter cylinders via a first fastener.

4. The multi-stage tool changer according to claim 1, characterized in that, A gate assembly is provided between the outer cutter barrel and the mounting base to isolate the high-pressure environment outside the cutter head from the normal-pressure environment inside. The gate assembly includes a gate plate and a sealing strip. The gate plate is axially fixed to the outer knife cylinder and the mounting base, and the gate plate is tightly fitted with the inner wall of the outer knife cylinder by the sealing strip.

5. The multi-stage tool changing device according to claim 1, characterized in that, The number of additional seals is the same as the number of limiting elements, and the distance between adjacent additional seals is equal to the thickness of a single limiting element.

6. A normal pressure tool changing system as described in claim 1, characterized in that, It includes a multi-stage tool changing device and a tool head wear detection module. The tool head wear detection module detects the wear degree of the tool head in real time. When the wear height of the tool head reaches the thickness of the limiting component, the multi-stage tool changing device removes at least one limiting component between the inner and outer tool cylinders and moves the inner tool cylinder to the outside of the tool disc by a corresponding distance. At this time, the additional sealing component blocks the mud and water outside the tool disc.

7. The atmospheric pressure tool changing system according to claim 1, characterized in that, The tool wear detection module includes a wear sensor, a signal transmission element, and a host computer; The wear sensor is mounted on the cutter head and is used to detect the degree of wear of the cutter head in real time. The signal transmission element connects the wear sensor and the host computer, and is used to transmit the wear degree signal of the cutter head to the host computer; The host computer is located in the monitoring room and is used to process and display the wear level signal.

8. The atmospheric pressure tool changing system according to claim 7, characterized in that, The signal transmission element can transmit signals in a wired and / or wireless manner.

9. The atmospheric pressure tool changing system according to claim 7, characterized in that, The wear sensor is configured as a resistance sensor.

10. A tool changing method for a multi-stage tool changing device as described in claim 6, characterized in that: When the tool wear detection module detects that the wear of the tool head has reached a preset threshold, the first fastener between the inner and outer tool cylinders is removed, and several limiting components with a stacked thickness adapted to the set height are taken out. The inner tool cylinder is moved axially a corresponding distance to the outside of the tool disc, and the remaining limiting components are connected to the inner and outer tool cylinders respectively through the first fastener. At this time, the tool head is pushed out to complete the tool change. When the tool wear detection module detects that the tool head is worn again and the wear amount reaches the preset threshold, the operator repeats the above operation to complete the multi-stage tool change.

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