Shield machine, cutterhead and cutter changing device and method for coping with upper soft and lower hard stratum

Abstract

The application provides a cutter head, a cutter changing device and a method for coping with the upward floating of a shield machine in a soft upper and hard lower stratum, and belongs to the field of rail transit tunnel excavation and construction.The cutter head comprises a cutter head body, a main cutter beam assembly, a secondary cutter beam assembly and a web plate assembly.The main cutter beam assembly comprises cross-distributed cross beam assemblies and vertical beam assemblies.The secondary cutter beam assembly is arranged on both sides of the main cutter beam assembly close to one end of the cutter head edge.The web plate assembly is arranged at the cutter head edge and between two adjacent secondary cutter beam assemblies.Compared with a traditional cutter head, the application replaces six heavy-duty tear cutters and two wedge-toothed rollers and adds four heavy-duty tear cutters.Through the special design and mutual cooperation of the cutter installation position and angle, the mudstone at the lower part of the tunnel can be better cut, the cutter wear can be effectively prevented, the rock breaking and path keeping functions can be achieved as a whole, the cuttings can be smoothly put into the soil bin, the posture of the shield machine can be controlled, and the quality of the formed segments can be guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of tunnel excavation and construction for rail transit, and in particular relates to a cutterhead, cutter replacement device and method for dealing with the upward drift of a shield tunneling machine in soft upper and hard lower strata. Background Technology

[0002] With the rapid development of the civil engineering industry, building types are no longer limited to surface engineering; underground space engineering is also constantly developing and maturing. While underground space construction technology is maturing, modern urban underground rail transit is also continuously developing, with more and more cities building underground rail transit networks consisting of multiple subway lines. At the same time, during the construction of subway rail transit, tunnel excavation is often difficult due to special strata or complex geological conditions encountered in the engineering design route.

[0003] Currently, tunnel boring machines (TBMs) are commonly used excavation machinery in urban underground rail transit projects. A TBM has a full-face cutting cutterhead at its front end, and behind the cutterhead is a soil chamber to store the excavated soil. A conveyor is installed below the center line of the soil chamber, and an inlet / outlet is located at the other end of the conveyor to transport the excavated soil.

[0004] During the construction of urban subways, when tunnel boring machines (TBMs) encounter strata with a soft upper layer and a hard lower layer in the designed tunneling route, the cutting amount of the cutterhead on the upper and lower strata is inconsistent, often showing that the cutting amount in the lower part is less than that in the upper part. This leads to difficulties in TBM tunneling, difficulty in controlling the upward drift of the TBM's attitude, and inability to guarantee the quality of the formed tunnel. Once the TBM starts, the only solution to these problems in this situation is to open the cutterhead and change the cutterhead midway. However, stopping the machine for cutterhead changes consumes a lot of time, causing delays in the construction period, increasing construction costs, and potentially having a significant impact on the surrounding environment. Moreover, engineering accidents caused by ground instability due to stopping the machine for cutterhead changes are not uncommon. Therefore, the solution of this invention is to select appropriate cutterheads and make targeted cutterhead arrangements on the cutterhead by conducting geological exploration and analysis of the designed tunneling route with a soft upper layer and a hard lower layer before the TBM starts. This not only solves the problem of tunneling in strata with a soft upper layer and a hard lower layer, but also greatly reduces the possibility of opening the cutterhead and changing the cutterhead during tunneling, thus reducing potential risks. Even if there is a genuine need to change the cutting tools, it is done through mechanical devices, which reduces tool changing time, minimizes manual intervention, and improves tool changing efficiency and safety. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a cutterhead, cutter replacement device and method for dealing with the upward drift of a tunnel boring machine (TBM) in a soft-over-hard stratum, so as to solve the problem of upward drift of the TBM when facing a soft-over-hard stratum.

[0006] To achieve the above and other related objectives, the present invention provides a cutterhead, cutter replacement device and method for dealing with the upward drift of a tunnel boring machine in soft upper and hard lower strata.

[0007] The cutterhead for shield tunneling machines to cope with the upward drift of soft upper and hard lower strata includes a cutterhead body, a main cutter beam assembly, a secondary cutter beam assembly, and a web plate assembly. The main cutter beam assembly includes cross-shaped horizontal beam assemblies and vertical beam assemblies. The secondary cutter beam assemblies are located on both sides of the main cutter beam assembly near the edge of the cutterhead. The web plate assembly is located at the edge of the cutterhead and between two adjacent secondary cutter beam assemblies.

[0008] It also includes the first heavy-duty tearing cutter, the second heavy-duty tearing cutter, the third heavy-duty tearing cutter, the fourth heavy-duty tearing cutter, the fifth heavy-duty tearing cutter, the sixth heavy-duty tearing cutter, the seventh heavy-duty tearing cutter, the eighth heavy-duty tearing cutter, the ninth heavy-duty tearing cutter, the tenth heavy-duty tearing cutter, the first wedge hob, and the second wedge hob;

[0009] The first heavy-duty tearing blade is mounted on the edge of the secondary blade beam assembly on the upper right side of the vertical beam assembly at an angle of 36.3 degrees.

[0010] The second heavy-duty tearing blade is mounted on the edge of the secondary blade beam assembly on the lower left side of the crossbeam assembly at an angle of 70 degrees.

[0011] The third heavy-duty tearing blade is installed on the edge of the secondary blade beam assembly on the upper left side of the crossbeam assembly at an angle of 61.8 degrees.

[0012] The fourth heavy-duty tearing blade is installed on the edge of the secondary blade beam assembly on the upper left side of the vertical beam assembly at an angle of 50.2 degrees.

[0013] The fifth heavy-duty tearing blade is installed on the edge of the auxiliary blade beam assembly on the lower right side of the vertical beam assembly at an angle of 43.5 degrees.

[0014] The sixth heavy-duty tearing blade is installed on the lower edge of the vertical beam assembly at an angle of 56.3 degrees.

[0015] The seventh heavy-duty tearing blade is installed on the inner side of the upper edge of the lower right corner flange assembly of the cutter head body, and the installation angle is 0 degrees.

[0016] The eighth heavy-duty tearing blade is installed on the upper edge of the vertical beam assembly at an angle of 0 degrees.

[0017] The ninth heavy-duty tearing blade is installed on the inner side of the lower edge of the upper right corner flange assembly of the cutter head body, and the installation angle is 0 degrees.

[0018] The tenth heavy-duty tearing blade is installed on the inner side of the lower edge of the upper left corner flange assembly of the cutter head body, and the installation angle is 0 degrees.

[0019] The first wedge hob is installed on the edge of the secondary cutter beam assembly on the upper right side of the crossbeam assembly at an angle of 70 degrees.

[0020] The second wedge hob is mounted on the edge of the auxiliary cutter beam assembly on the lower right side of the crossbeam assembly at an angle of 66.2 degrees.

[0021] The installation angle is determined as follows: when installed perpendicular to the front of the cutter head, it is 0 degrees. With the vertical line on the front of the cutter head as the reference, the angle is positive when rotated clockwise.

[0022] Optionally, the wedge hob is mounted on the cutter head via a tool box;

[0023] The tool box includes a tool holder, end wedges and a middle wedge, with the outer side of the tool holder welded to the tool disc.

[0024] The tool holder is a through cavity structure. A positioning groove is provided on a set of opposing cavity walls of the cavity structure. Concave wedge grooves are provided on both sides of the positioning groove. The wedge hob is installed into the cavity structure along the positioning groove. The two end wedges are inserted obliquely from the middle to the sides into the gap between the wedge groove and the wedge hob and are fastened by end bolts. The middle wedge is inserted horizontally into the gap between the wedge hob and the two end wedges and is fastened by the middle bolt.

[0025] Among them, the cutter replacement device for shield tunneling machines that drift upwards in soft upper and hard lower strata includes a tailstock, a robotic arm and an end effector. The tailstock is fixedly installed in the air cushion chamber of the shield front shield. The robotic arm is connected between the tailstock and the end effector and has multiple degrees of freedom. The end effector extends into the rear end of the cutterhead along with the robotic arm and can detach and install cutters.

[0026] The wedge hob and toolbox described above are used;

[0027] The end effector includes a connecting seat, a sliding block, a gripper, a first disassembly / assembly part, and a second disassembly / assembly part;

[0028] The connecting seat is fixedly installed at the end of the robotic arm. The sliding block is slidably installed on the connecting seat and its sliding position can be adjusted. One end of the two sets of grippers is rotatably installed on the sliding block, while the other end is in a counter-clamping shape to clamp the wedge hob. The degree of clamping is adjusted and controlled by the tensioning device.

[0029] The two sets of the first disassembly and assembly parts are respectively arranged on both sides of the sliding block, and can extend and disassemble the central bolt and the central wedge;

[0030] The four sets of the second disassembly and assembly parts are respectively located at the four corners of the sliding block, and can extend and disassemble the end bolts and end wedges.

[0031] Optionally, the tensioning device includes:

[0032] Telescopic power source, active crossbar, passive crossbar and structural linkage;

[0033] The output shaft of the telescopic power source is located in the middle of the two sets of grippers. The active crossbar is fixedly connected to the output shaft and is perpendicular to the output shaft. The plane where the active crossbar and the output shaft are located is the symmetrical plane of the two sets of grippers. The two passive crossbars are respectively connected to the two grippers of each set and are parallel to the active crossbar. The two ends of the structural connecting rod are respectively rotatably connected between the active crossbar and the passive crossbar. When the telescopic power source extends or retracts, the two sets of grippers retract or open.

[0034] Optionally, the tensioning device further includes a locking rod, the locking rod being positioned in the same direction as the telescopic power source. One end of the locking rod is fixedly connected to the active crossbar, and the other end is provided with a locking head. When the telescopic power source retracts to tighten the grippers, the locking head is inserted into the middle of the ends of the two grippers.

[0035] Optionally, the first disassembly and assembly part includes a first power source and an annular transmission structure fixedly disposed on the sliding block, and a first disassembly and assembly rod. When the sliding block slides to the middle of the connecting seat, the axis of the first disassembly and assembly rod coincides with the axis of the middle bolt.

[0036] The ring transmission structure includes a rotating seat and a ring gear. The rotating seat is fixedly installed on the outer periphery of the sliding block, and the ring gear is rotatably installed on the rotating seat and driven by the first power source.

[0037] The first disassembly rod includes a first sleeve at the head end, a first rod body in the middle, and a telescopic drive device at the tail end. The telescopic drive device is fixedly installed on the sliding block by a first support column. The first rod body is rotatably and slidably installed in the telescopic drive device. The middle section of the first rod body is provided with teeth that mesh with the ring gear.

[0038] The first sleeve can be inserted into the countersunk hole of the central wedge to turn the central bolt and hold the central bolt and the central wedge in place.

[0039] Optionally, the second disassembly and assembly part includes a second power source, a transmission flexible shaft, and a second disassembly and assembly rod. When the sliding block slides to the upper and lower ends of the connecting seat, the axis of the second disassembly and assembly rod coincides with the axis of the end bolt.

[0040] The second disassembly rod includes a second sleeve assembly at the head end, a second rod body in the middle, and a telescopic drive device at the tail end. The telescopic drive device is fixedly installed on the sliding block by a second support column, and the second rod body is telescopically slidably connected to the telescopic drive device.

[0041] The second sleeve assembly includes a sleeve housing, a sleeve plate, and a telescopic airbag. The sleeve housing has a U-shaped opening structure, and the opening width matches the end wedge. The sleeve plate is slidably disposed at the opening. The telescopic airbag is disposed in the sleeve plate and the opening and adjusts the position of the sleeve plate. A sleeve is rotatably disposed on the sleeve plate. The tail end of the sleeve is connected to the second power source through the transmission flexible shaft. The head end of the sleeve can be inserted into the countersunk hole of the end wedge to tighten the end bolt and attract the end bolt and the end wedge.

[0042] Optionally, the connecting seat is arc-shaped, and an arc-shaped groove is provided on the connecting seat to divide the connecting seat into a sliding part and a connecting part. The sliding block is slidably connected to the sliding part, and the robotic arm is connected to the connecting part.

[0043] Optionally, when the gripper clamps the wedge hob, the sliding trajectory of the sliding block on the connecting seat is concentric with the wedge hob.

[0044] The method for changing the cutterhead when the tunnel boring machine floats upwards in soft upper and hard lower strata employs the cutterhead changing device described above, and includes the following steps:

[0045] Preparation steps: The cutter head rotates, and the tool to be replaced enters the tool changing working area;

[0046] Disassembly steps: The robotic arm moves, the end effector reaches behind the target tool, the gripper opens and inserts into the tool box to clamp the tool, and the sliding block slides to the middle of the connecting seat; the first disassembly part extends and removes the middle bolt and the middle wedge, and after removal, the first disassembly part moves backward carrying the middle bolt and the middle wedge; the sliding block slides to one side, and the second disassembly rod on the other side extends and removes the end bolt and the end wedge, and after removal, moves backward carrying the end bolt and the end wedge; the sliding block slides to the other side and removes the remaining end bolt and end wedge, then moves backward;

[0047] Tool placement and retrieval: The gripper of the end effector clamps the tool, the robotic arm moves to remove the old tool and place it in the tool recycling position, and takes out a new tool from the new tool position, returns to the tool removal position, and puts the tool into the tool box;

[0048] Tool installation steps: Reverse the sub-steps in the tool removal steps to complete the installation of the new tool;

[0049] When the robotic arm moves, the end effector disengages from the cutter head, the cutter head rotates, and the next tool to be replaced arrives at the tool changing work area. The above steps are repeated to change the tool.

[0050] As described above, the cutterhead, cutter replacement device, and method of the present invention for dealing with the upward drift of a tunnel boring machine in soft upper and hard lower strata have at least the following beneficial effects:

[0051] The tunnel boring machine (TBM) can maintain a good posture when excavating in strata with soft upper layers and hard lower layers, and will not experience upward drift. Specifically, based on the traditional cutter arrangement, this invention designs and replaces 8 cutters at the edge of the cutterhead, and welds 4 more cutters. These cutters include wedge-tooth hobs and heavy-duty tearing cutters. Through the special design and coordinated action of the cutter installation position and angle parameters, it can better cut the mudstone in the lower part of the tunnel, effectively prevent cutter wear, and play an overall role in rock breaking and diameter maintenance. This allows the excavated soil to enter the soil chamber smoothly, while the posture of the TBM is controlled, and the quality of the tunnel segments is guaranteed. Attached Figure Description

[0052] Figure 1 The image shown is a front view of the cutter head of the present invention.

[0053] Figure 2 The diagram shows the wedge hob and toolbox of the present invention.

[0054] Figure 3 The diagram shown is a schematic of the tool changing device of the present invention.

[0055] Figure 4 The diagram shown is a schematic of the end effector of the present invention.

[0056] Figure 5 The diagram shown is a schematic of the end effector of the present invention.

[0057] Figure 6 The diagram shown is a schematic of the end effector of the present invention.

[0058] Figure 7 The diagram shown is a schematic diagram of the wedge block in the middle of the end effector of the present invention.

[0059] Figure 8 The diagram shown is a schematic of the end effector of the present invention with the upper side wedge removed.

[0060] Figure 9 The diagram shows the end-side wedge block removed from the end effector of the present invention.

[0061] Figure 10 The diagram shows the arrangement of the cutterhead changing device of the present invention in a tunnel boring machine.

[0062] Figure 11 The diagram shows the working position of the tool changing device of the present invention.

[0063] The components include: front shield 1, cutter head body 2, cutter holder 20, positioning groove 201, wedge groove 2010, end side wedge block 21, end side bolt 210, middle wedge block 22, middle bolt 220, main cutter beam assembly 3, crossbeam assembly 30, vertical beam assembly 31, sixth heavy-duty tearing cutter 311, eighth heavy-duty tearing cutter 312, secondary cutter beam assembly 4, first heavy-duty tearing cutter 40, second heavy-duty tearing cutter 41, third heavy-duty tearing cutter 42, fourth heavy-duty tearing cutter 43, fifth heavy-duty tearing cutter 44, first wedge hob 45, second wedge hob 46, wing plate assembly 5, seventh heavy-duty tearing cutter 51, ninth heavy-duty tearing cutter 52, tenth heavy-duty tearing cutter 53, and tail. 6. Seat 7. Robotic arm 8. End effector 8. Connecting seat 80. Sliding block 81. Gripper 82. First disassembly / assembly part 83. First power source 830. Ring transmission structure 831. Rotating seat 8311. Ring gear 8312. First disassembly / assembly rod 832. First sleeve 8321. First rod body 8322. Second disassembly / assembly part 84. Transmission flexible shaft 840. Second sleeve assembly 841. Sleeve housing 8411. Sleeve plate 8412. Telescopic airbag 8413. Second rod body 842. Tightening / loosening device 85. Telescopic power source 850. Active crossbar 851. Passive crossbar 852. Structural connecting rod 853. Locking rod 854. Locking head 855. Detailed Implementation

[0064] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0065] Please see Figures 1 to 11 It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0066] The following embodiments are for illustrative purposes only. These embodiments can be combined and are not limited to the content shown in any single embodiment below.

[0067] The following are embodiments of the cutterhead, cutter replacement device, and method for dealing with the upward drift of a tunnel boring machine in soft upper and hard lower strata provided by the present invention.

[0068] One example of how to handle the upward drift of the cutterhead by the tunnel boring machine in soft upper and hard lower strata is described in the following embodiment. Figure 1 The invention includes a cutter head body 2, a main cutter beam assembly 3, a secondary cutter beam assembly 4, and a web plate assembly 5. The main cutter beam assembly 3 includes a cross-shaped horizontal beam assembly 30 and a vertical beam assembly 31. The secondary cutter beam assembly 4 is located on both sides of the main cutter beam assembly 3 near the edge of the cutter head. The web plate assembly 5 is located on the edge of the cutter head and between two adjacent secondary cutter beam assemblies 4. In addition to traditional tearing blades, scrapers, and wear detectors, the main improvement of this invention for the cutter head is that it also includes a first heavy-duty tearing blade 40, a second heavy-duty tearing blade 41, a third heavy-duty tearing blade 42, a fourth heavy-duty tearing blade 43, a fifth heavy-duty tearing blade 44, a sixth heavy-duty tearing blade 311, a seventh heavy-duty tearing blade 51, an eighth heavy-duty tearing blade 312, a ninth heavy-duty tearing blade 52, a tenth heavy-duty tearing blade 53, a first wedge-tooth hob 45, and a second wedge-tooth hob 46.

[0069] The first heavy-duty tearing blade 40 is installed on the edge of the secondary blade beam assembly 4 on the upper right side of the vertical beam assembly 31 at an angle of 36.3 degrees; the second heavy-duty tearing blade 41 is installed on the edge of the secondary blade beam assembly 4 on the lower left side of the horizontal beam assembly 30 at an angle of 70 degrees; the third heavy-duty tearing blade 42 is installed on the edge of the secondary blade beam assembly 4 on the upper left side of the horizontal beam assembly 30 at an angle of 61.8 degrees; the fourth heavy-duty tearing blade 43 is installed on the edge of the secondary blade beam assembly 4 on the upper left side of the vertical beam assembly 31 at an angle of 50.2 degrees; the fifth heavy-duty tearing blade 44 is installed on... The auxiliary cutter beam assembly 4 is mounted on the lower right side of the vertical beam assembly 31 at an angle of 43.5 degrees; the sixth heavy-duty tearing cutter 311 is mounted on the lower edge of the vertical beam assembly 31 at an angle of 56.3 degrees. All six heavy-duty tearing cutters have a height of 187.7 mm. On traditional shield tunneling cutters, these six positions were originally occupied by smooth roller cutters. Smooth roller cutters have poor cutting performance on the lower rock mass and are prone to clogging the cutter box during mudstone excavation, reducing the cutter head opening ratio. As a result, not all the cut mudstone from the lower part of the shield can enter the soil chamber, causing the shield to drift upwards. This invention replaces these with heavy-duty tearing cutters. Compared to ordinary tearing cutters, heavy-duty tearing cutters are larger in size, have a thicker wear-resistant layer, and deeper tooth marks. When cutting mudstone, smooth roller cutters cannot operate normally because they do not reach the required starting thrust. However, the heavy-duty tearing cutters used as replacements have lower thrust requirements and can forcefully cut mudstone. Combined with the specific tunneling parameters described later, they can effectively cut the lower mudstone. Because the heavy-duty tearing cutter has a thicker wear-resistant layer and is more effective at breaking mudstone than ordinary smooth single-edged cutters, it can better cut the mudstone in the lower part of the tunnel, allowing the excavated soil to enter the soil chamber, thereby controlling the shield's attitude and ensuring the quality of the formed segments.

[0070] The seventh heavy-duty tearing cutter 51 is installed on the inner side of the upper edge of the lower right corner flange assembly 5 of the cutterhead body 2 at an angle of 0 degrees; the eighth heavy-duty tearing cutter 312 is installed on the upper edge of the vertical beam assembly 31 at an angle of 0 degrees; the ninth heavy-duty tearing cutter 52 is installed on the inner side of the lower edge of the upper right corner flange assembly 5 of the cutterhead body 2 at an angle of 0 degrees; the tenth heavy-duty tearing cutter 53 is installed on the inner side of the lower edge of the upper left corner flange assembly 5 of the cutterhead body 2 at an angle of 0 degrees. These four heavy-duty tearing cutters have the same cutter model as the six heavy-duty tearing cutters mentioned above, but the difference lies in the installation method. The six heavy-duty tearing cutters mentioned above are replaced using replaceable cutter boxes, while these four heavy-duty tearing cutters are directly welded to the edge of the cutterhead. The height of these four welded heavy-duty tearing cutters is the same as that of the heavy-duty tearing cutters installed in the cutter boxes, which is 187.7 mm. Their function is also the same: while enhancing the overall cutting ability of the shield cutterhead in cutting mudstone, they can also play a role in maintaining the diameter and protecting the edge of the cutterhead.

[0071] The first wedge hob 45 is mounted on the edge of the secondary cutter beam assembly 4 on the upper right side of the crossbeam assembly 30 at an angle of 70 degrees; the second wedge hob 46 is mounted on the edge of the secondary cutter beam assembly 4 on the lower right side of the crossbeam assembly 30 at an angle of 66.2 degrees. The wedge hobs can be 17-inch single-edged hobs with a wedge-shaped cutting edge of 120 degrees and a cutting height matching the aforementioned heavy-duty tearing cutter. The outer ring is welded with a carbide tooth ring, and the carbide teeth are hemispherical. Besides being larger in size, they have a thicker wear-resistant layer and deeper tooth marks. The carbide teeth increase the friction with mudstone, embedding themselves into the mudstone surface to reduce the thrust required for the hob to start rotating. Simultaneously, the carbide teeth on the wedge hob's cutter ring significantly enhance the rock-breaking effect. Overall, the wedge hobs function to break rocks and maintain diameter, and mounting them on the edge of the cutter head effectively prevents tool wear.

[0072] During the aforementioned cutter installation process, the installation angle is determined as follows: 0 degrees when installed perpendicular to the cutterhead front; clockwise rotation is considered positive, using the vertical line of the cutterhead front as a reference. At the edge of the cutterhead, the cutterhead front may be curved; in this case, the curved section is used as the cutterhead front. This solution addresses the issue of shield machine attitude drift during excavation in soft-over-hard strata, facilitates vertical attitude control during tunneling, and alleviates problems such as muck removal difficulties and cutter wear. It also reduces shield thrust and torque during cutting, achieving low-energy tunneling.

[0073] In actual shield tunneling applications, the cutters are first installed on the cutterhead according to the above scheme. After the shield machine is lowered into the shaft and before it advances, the advancing speed in the solid concrete body is determined based on the existing design data of the shield starting point, namely its concrete strength and the width of the solid concrete body.

[0074] For example, when advancing through the solidified foundation at the starting end, the thrust of the tunnel boring machine (TBM) gradually increases from 4500KN to 9000KN, the cutterhead torque gradually increases from 560KN·m to 2500KN·m, and the tunneling speed is controlled at 10-30mm / min. That is, the thrust and cutterhead torque of the TBM should not be too large, and the tunneling speed should not be too fast.

[0075] When tunneling through gravel and sand layers or rounded gravel strata, the tunnel boring machine (TBM) can maintain a tunneling speed of 60-70 mm / min and a rotation speed of 1.5 r / min, with the cutterhead torque controlled at around 3500 kN·m and the total thrust controlled at around 14000 kN. When tunneling through strata with a soft upper layer and a hard lower layer, the TBM's tunneling speed, thrust, and torque should be lower than the normal tunneling parameters.

[0076] After the tunnel boring machine (TBM) enters the soft-over-hard stratum, it continues to excavate at a speed of 40-60 mm / min and a rotational speed of 1.5-2.0 r / min until it reaches a depth of approximately 1.5m where the lower mudstone intrudes into the tunnel section. The cutterhead torque is controlled at 2000-3000 kN·m, and the total thrust is controlled at 10000-14000 kN.

[0077] After the tunnel boring machine (TBM) has advanced to a depth of 1.5m where the lower mudstone has intruded into the tunnel, the TBM should reduce its excavation speed. This allows for more effective cutting of the lower mudstone and also enables better control and adjustment of the TBM's attitude. Specific excavation parameters are as follows: the TBM excavation speed should be maintained at 30-50 mm / min, with a rotational speed below 1.5 r / min; the total thrust should be controlled at 9000-11000 KN; and the cutterhead torque should be controlled below 2500 KN·m. During actual tunneling, the TBM thrust, cutterhead torque, cutterhead rotational speed, and excavation speed can be appropriately controlled and adjusted according to the site conditions.

[0078] When the shield cutterhead first enters the soft-over-hard stratum and contacts the lower mudstone and continues to advance, pay close attention to the data collected by the earth pressure sensor on the cutterhead, as well as the total thrust, cutterhead torque, and rotational speed of the shield machine. If the values ​​suddenly increase, far exceeding the data from the sand layer, and the thrust and torque of the shield increase significantly, it can be further determined that the heavy tearing cutter and wedge-tooth cutter on the secondary cutter beam and the cutterhead have contacted the lower mudstone. Then, the aforementioned tunneling method for when the lower mudstone intrudes into the tunnel should be adopted.

[0079] The above-mentioned solution proposes a targeted and feasible solution to the problem of tunneling through soft upper and hard lower strata in actual engineering projects. Specifically, it proposes the core principles and implementation plan for solving this problem in the field of tunnel boring machines by optimizing the cutter arrangement of the shield cutterhead. Furthermore, this solution, combined with the above-mentioned working methods, has been successfully applied in the construction of Nanchang Rail Transit.

[0080] For further information, please refer to Figure 2 The wedge hob is mounted on the cutter head via a tool box. The tool box includes a tool holder 20, end wedges 21, and a central wedge 22. The outer side of the tool holder 20 is welded to the cutter head; the tool holder 20 is a through-cavity structure. Figure 2 To facilitate viewing the internal structure of the cutterhead, the external structure is concealed. A positioning groove 201 is provided on one set of opposing cavity walls of the cutterhead cavity structure. Concave wedge grooves 2010 are provided on both sides of the positioning groove 201. The wedge hob is inserted into the cavity structure along the positioning groove 201. Two end wedges 21 are inserted obliquely from the center to the sides into the gap between the wedge grooves 2010 and the wedge hob, and are secured by end bolts 210. A central wedge 22 is horizontally inserted into the gap between the wedge hob and the two end wedges 21 and is secured by a central bolt 220. The cutterhead body has multiple cutter box positions. The cutter boxes can be inserted into these positions, and the cutters are installed in them. The outer side of the cutter protrudes from the surface of the tunnel boring machine cutterhead, while the inner side allows for cutter replacement. In the above embodiment, this design allows for convenient replacement of the cutters after wear.

[0081] This embodiment describes a cutterhead changing device for tunnel boring machines (TBMs) that experience upward drift in soft-over-hard strata. Please refer to [link to relevant documentation]. Figure 3 and Figure 10-11 The system includes a tailstock 6, a robotic arm 7, and an end effector 8. The tailstock 6 is fixedly installed in the air cushion chamber of the front shield 1 of the tunnel boring machine. The robotic arm 7 is connected between the tailstock 6 and the end effector 8 and has multiple degrees of freedom. The end effector 8 extends into the rear end of the cutterhead along with the robotic arm 7 and can assemble and disassemble the cutter. This embodiment uses the wedge-tooth hob and cutter box as described above. The end effector 8 includes a connecting seat 80, a sliding block 81, grippers 82, a first disassembly / assembly part 83, and a second disassembly / assembly part 84. The connecting seat 80 is fixedly installed at the end of the robotic arm 7. The sliding block 81 is slidably installed on the connecting seat 80, and its sliding position can be adjusted. There are many specific implementation methods, which are not shown in the figure. One end of the two sets of grippers 82 is rotatably installed on the sliding block 81, while the other end is in an opposing clamping shape to clamp the wedge-tooth hob. The degree of clamping is adjusted and controlled by the tensioning device 85. Two sets of first disassembly parts 83 are respectively provided on both sides of the sliding block 81, which can extend and disassemble the middle bolt 220 and the middle wedge 22; four sets of second disassembly parts 84 are respectively provided on the four corners of the sliding block 81, which can extend and disassemble the end bolt 210 and the end wedge 21.

[0082] In the above embodiments, the working principle of the wedge hob replacement is as follows:

[0083] Preparation steps: When the tool on the tool turret needs to be replaced, the tool turret rotates to allow the tool to be replaced to move into the tool replacement working area, which is the working space of the end effector 8. (See reference...) Figure 10 and Figure 11 ;

[0084] Disassembly procedure: The robotic arm 7 moves, the end effector 8 reaches behind the target tool, the gripper 82 opens and inserts into the tool holder to clamp the tool, and the sliding block 81 slides to the middle of the connecting seat 80; Figure 7 As shown, the first disassembly / assembly part 83 extends and disassembles the central bolt 220 and the central wedge 22. After disassembly, the first disassembly / assembly part 83 retracts carrying the central bolt 220 and the central wedge 22. The first disassembly / assembly part 83 can be configured to have an adsorption, magnetic, or clamping mechanism to achieve the above-mentioned effects; the sliding block 81 slides to one side, for example, downwards, as... Figure 8 As shown, at this time, the second disassembly rod on the other side (upper side) extends and removes the upper end bolt 210 and end wedge 21. After removal, it moves backward carrying the end bolt 210 and end wedge 21; the sliding block 81 slides to the other side, as shown. Figure 9 As shown, remove the remaining end bolt 210 and end wedge 21 on one side and then back up;

[0085] Tool placement and retrieval: The gripper 82 of the end effector 8 clamps the tool, the robotic arm 7 moves to remove the old tool and place it in the tool recycling position, and takes out the new tool from the new tool position, returns to the tool removal position on the tool turret, and puts the tool into the tool box;

[0086] Tool installation steps: Reverse the sub-steps of the tool removal steps to complete the installation of the new tool;

[0087] The robotic arm 7 moves, causing the end effector 8 to disengage from the cutter head. The cutter head rotates, and the next tool to be replaced arrives at the tool changing work area, which is the preparation step state described above. The above steps are repeated to change tools until all tools have been replaced, and then the robotic arm retracts.

[0088] The aforementioned tool changing device, combined with the tool changing method, can improve the efficiency of tool changing, realize automatic mechanical tool changing, and avoid the need for personnel to enter the chamber to operate when tool changing is required. This not only improves the efficiency of tool changing but also enhances the safety of construction.

[0089] Please refer to this embodiment. Figure 5 and Figure 7The tensioning device 85 includes: a telescopic power source 850, an active crossbar 851, a passive crossbar 852, and a structural connecting rod 853. The output shaft of the telescopic power source 850 is located in the middle of the two sets of grippers 82 and can be located inside the sliding block 81. The active crossbar 851 is fixedly connected to the output shaft and is perpendicular to the output shaft. The plane where the active crossbar 851 and the output shaft are located is the symmetrical plane of the two sets of grippers 82. The active crossbar 851 and the output shaft of the telescopic power source 850 form a "T" shape. The two passive crossbars 852 are respectively connected to the two grippers 82 of each set and are parallel to the active crossbar 851. The two ends of the structural connecting rod 853 are rotatably connected between the active crossbar 851 and the passive crossbar 852. When the telescopic power source 850 extends or retracts, the two sets of grippers 82 retract or open.

[0090] In the above embodiment, the opening and closing of the gripper 82 is achieved by the extension and retraction of the telescopic power source 850. The telescopic power source 850 is located in the middle and has strong structural stability. During operation, the upper and lower grippers 82 close or open synchronously, and the point of force application is located in the middle of the gripper 82. When the gripper 82 holds the tool, the lever arm of the tool's weight is shorter, and the stability of the entire gripper structure is stronger.

[0091] Furthermore, such as Figure 5 As shown, the tensioning device 85 also includes a locking rod 854. The locking rod 854 is positioned in the same direction as the telescopic power source 850. One end of the locking rod 854 is fixedly connected to the active crossbar 851, and the other end is equipped with a locking head 855. When the telescopic power source 850 retracts to tighten the grippers 82, the locking head 855 inserts into the middle of the ends of the two grippers 82. The outer side of the locking head 855 can be covered with an elastic material such as rubber. When the locking head 855 retracts to clamp the tool, it simultaneously engages with the ends of the two grippers 82, creating an interaction force between them. Simultaneously, the ends of the two grippers 82 are also subjected to the direct force of the telescopic power source 850, pushing them to tighten. Overall, the force transmission path is more diverse, the interaction forces can be shared, and the power effect and structural stability are further enhanced.

[0092] This embodiment can be referred to. Figure 4-6 The first disassembly / assembly part 83 includes a first power source 830 and a ring transmission structure 831 fixedly disposed on the sliding block 81, and a first disassembly / assembly rod 832. When the sliding block 81 slides to the middle of the connecting seat 80, that is, when the first disassembly / assembly part 83 is disassembled, the first disassembly / assembly part 83 is disassembled. Figure 7At the indicated position, the axis of the first disassembly rod 832 coincides with the axis of the central bolt 220. The ring transmission structure 831 includes a rotating seat 8311 and a ring gear 8312. The rotating seat 8311 is fixedly installed on the outer periphery of the sliding block 81, and the ring gear 8312 is rotatably installed on the rotating seat 8311 and driven by the first power source 830. The first disassembly rod 832 includes a first sleeve 8321 at the head end, a first rod body 8322 in the middle, and a telescopic drive device at the tail end. The telescopic drive device is fixedly installed on the sliding block 81 through a first support column. The first rod body 8322 is rotatably and slidably installed in the telescopic drive device. Both can be piston structures, and the extension or retraction is controlled by the air pressure pipe on the telescopic drive device. The middle section of the first rod body 8322 is provided with teeth that mesh with the ring gear 8312. The first sleeve 8321 can be inserted into the countersunk hole of the central wedge 22 to turn the central bolt 220 and hold the central bolt 220 and the central wedge 22. This can be achieved by installing an electromagnet on the first sleeve 8321, or other methods such as pneumatic or electric clamping can be used. After the middle bolt and the middle wedge are removed, they will be temporarily fixed to the first sleeve 8321. After the new tool is installed, they can be reinstalled in the same way, which can greatly simplify the tool replacement process and improve the tool replacement efficiency.

[0093] The second disassembly / assembly section 84 includes a second power source, a transmission flexible shaft 840, and a second disassembly / assembly rod. When the sliding block 81 slides to the upper and lower ends of the connecting seat 80, as... Figure 8 As shown in Figure 9, after the second disassembly rod extends, its axis coincides with the axis of the end bolt 210. The second disassembly rod includes a second sleeve assembly 841 at the head end, a second rod body 842 in the middle, and a telescopic drive device at the tail end. The telescopic drive device is fixedly installed on the sliding block 81 via a second support column. The telescopic movement can be electric or pneumatic. The second rod body 842 is slidably connected to the telescopic drive device. The second sleeve assembly 841 includes a sleeve housing 8411, a sleeve plate 8412, and a telescopic airbag 8413. The sleeve housing 8411 has a "U"-shaped opening structure, and the opening width matches the end wedge block 21. The sleeve plate 8412 is slidably arranged at the opening. The telescopic airbag 8413 is arranged in the sleeve plate 8412 and the opening and adjusts the position of the sleeve plate 8412. A sleeve is rotatably arranged on the sleeve plate 8412, and the tail end of the sleeve is connected to the second power source via a transmission flexible shaft 840. A flexible drive shaft is a type of shaft that transmits power via steel wire and is flexible. The flexible drive shaft 840 drives the sleeve to rotate, and the head end of the sleeve can be inserted into the countersunk hole of the end wedge 21 to tighten the end bolt 210 and attract the end bolt 210 and the end wedge 21. The end bolt 210 attracts the end bolt 210 and the end wedge 21. After the end bolt 210 falls off the tool box, the telescopic airbag 8413 contracts to pull both into the sleeve housing 8411.

[0094] For further information, please refer to Figure 7-8 The connecting seat 80 is arc-shaped, and an arc-shaped groove is provided on the connecting seat 80 to divide the connecting seat 80 into a sliding part and a connecting part. The sliding block 81 is slidably connected to the sliding part, and the robotic arm 7 is connected to the connecting part. When the gripper 82 clamps the wedge hob, the sliding trajectory of the sliding block 81 on the connecting seat 80 is concentric with the wedge hob.

[0095] The tail end of the sliding block 81 is located in the arc-shaped groove of the connecting seat 80, which is divided into an upper groove and a lower groove. Both the upper and lower grooves are equipped with telescopic structures. One end of the telescopic structure acts on the tail end of the sliding block 81, and the other end acts on the upper and lower ends of the arc-shaped groove. Specifically, the telescopic structure can be a hydraulic bladder or an arc-shaped hydraulic cylinder. By differentiating the telescopic states of the two telescopic structures located on both sides, the angular position of the sliding block 81 on the connecting seat 80 can be controlled.

[0096] To achieve better clamping, the tool is wedged using a method where side wedges are inserted obliquely to engage with a central wedge. This makes the tool disassembly and installation angles during tool changes more complex. Existing technologies typically employ manual tool changes. In this embodiment, a sliding block, along with two sets of disassembly / installation rods, allows for disassembly and installation from two different angles. Throughout the process, the robotic arm only needs to remain in its original position; the angle changes are automatically adjusted by the end effector, significantly reducing the robotic arm's repeatability requirements and improving disassembly efficiency. Simultaneously, when the grippers clamp the tool, the two sets of gripper holding parts are concentric with the tool's axis. Therefore, when the grippers slide up and down on the connecting seat 80, it's equivalent to the entire end effector rotating around the tool's axis. This facilitates position adjustment of each disassembly component and positioning at various angles. Furthermore, it allows the cantilevered robotic arm end to connect to the tool disc via the tool, preventing prolonged cantilever operation during disassembly and thus improving the stability and reliability of the entire tool changing device.

[0097] In summary, the present invention effectively overcomes the various shortcomings of the prior art, produces beneficial technical effects, and has made significant progress.

[0098] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A cutterhead for a tunnel boring machine (TBM) to cope with upward drift in soft-over-hard strata, comprising a cutterhead body (2), a main cutter beam assembly (3), a secondary cutter beam assembly (4), and a web assembly (5), wherein the main cutter beam assembly (3) comprises a cross-shaped crossbeam assembly (30) and a vertical beam assembly (31), the secondary cutter beam assembly (4) is disposed on both sides of the main cutter beam assembly (3) near the edge of the cutterhead, and the web assembly (5) is disposed on the edge of the cutterhead and located between two adjacent secondary cutter beam assemblies (4), characterized in that: It also includes the first heavy-duty tearing cutter (40), the second heavy-duty tearing cutter (41), the third heavy-duty tearing cutter (42), the fourth heavy-duty tearing cutter (43), the fifth heavy-duty tearing cutter (44), the sixth heavy-duty tearing cutter (311), the seventh heavy-duty tearing cutter (51), the eighth heavy-duty tearing cutter (312), the ninth heavy-duty tearing cutter (52), the tenth heavy-duty tearing cutter (53), the first wedge hob (45), and the second wedge hob (46); The first heavy-duty tearing blade (40) is mounted on the edge of the secondary blade beam assembly (4) on the upper right side of the vertical beam assembly (31) at an angle of 36.3 degrees; The second heavy-duty tearing blade (41) is mounted on the edge of the sub-blade beam assembly (4) on the lower left side of the crossbeam assembly (30) at an angle of 70 degrees; The third heavy-duty tearing blade (42) is installed on the edge of the secondary blade beam assembly (4) on the upper left side of the crossbeam assembly (30) at an angle of 61.8 degrees; The fourth heavy-duty tearing blade (43) is installed on the edge of the auxiliary blade beam assembly (4) on the upper left side of the vertical beam assembly (31) at an angle of 50.2 degrees. The fifth heavy-duty tearing blade (44) is installed on the edge of the auxiliary blade beam assembly (4) on the lower right side of the vertical beam assembly (31) at an angle of 43.5 degrees. The sixth heavy-duty tearing blade (311) is mounted on the lower edge of the vertical beam assembly (31) at an angle of 56.3 degrees; The seventh heavy-duty tearing blade (51) is installed on the inner side of the upper edge of the lower right corner flange assembly (5) of the cutter head body (2) at an angle of 0 degrees. The eighth heavy-duty tearing blade (312) is mounted on the upper edge of the vertical beam assembly (31) at an angle of 0 degrees; The ninth heavy-duty tearing blade (52) is installed on the inner side of the lower edge of the upper right corner flange assembly (5) of the cutter head body (2) at an angle of 0 degrees. The tenth heavy-duty tearing blade (53) is installed on the inner side of the lower edge of the upper left corner flange assembly (5) of the cutter head body (2) at an angle of 0 degrees. The first wedge hob (45) is installed on the edge of the secondary cutter beam assembly (4) on the upper right side of the crossbeam assembly (30) at an angle of 70 degrees. The second wedge hob (46) is installed on the edge of the auxiliary cutter beam assembly (4) on the lower right side of the crossbeam assembly (30) at an angle of 66.2 degrees. The installation angle is determined as follows: when installed perpendicular to the front of the cutter head, it is 0 degrees. With the vertical line on the front of the cutter head as the reference, the angle is positive when rotated clockwise.

2. The cutterhead for shield tunneling machines to drift upwards in soft-over-hard strata as described in claim 1, characterized in that: The wedge hob is mounted on the cutter head via a cutter box; The tool box includes a tool holder (20), an end wedge (21), and a middle wedge (22), with the outer side of the tool holder (20) welded to the tool disc; The tool holder (20) is a through cavity structure. A positioning groove (201) is provided on one set of opposing cavity walls of the cavity structure. Concave wedge grooves (2010) are provided on both sides of the positioning groove (201). The wedge hob is installed into the cavity structure along the positioning groove (201). The two end wedges (21) are inserted obliquely from the middle to the sides into the gap between the wedge groove (2010) and the wedge hob and are fastened by end bolts (210). The middle wedge (22) is inserted horizontally into the gap between the wedge hob and the two end wedges (21) and is fastened by the middle bolt (220).

3. A cutter replacement device for shield tunneling machines that drift upwards in soft-over-hard strata, comprising a tailstock (6), a robotic arm (7), and an end effector (8), wherein the tailstock (6) is fixedly installed in the air cushion chamber of the front shield (1) of the shield tunneling machine, the robotic arm (7) is connected between the tailstock (6) and the end effector (8) and has multiple degrees of freedom, and the end effector (8) extends into the rear end of the cutterhead along with the robotic arm (7) and is capable of assembling and disassembling cutters, characterized in that: Applied to the wedge hob and toolbox as described in claim 2; The end effector (8) includes a connecting seat (80), a sliding block (81), a gripper (82), a first disassembly / assembly part (83), and a second disassembly / assembly part (84); The connecting seat (80) is fixedly installed at the end of the robotic arm (7). The sliding block (81) is slidably installed on the connecting seat (80) and its sliding position can be adjusted. One end of each of the two sets of grippers (82) is rotatably installed on the sliding block (81) and the other end is in a counter-clamping position to clamp the wedge hob. The degree of clamping is adjusted and controlled by the tensioning device (85). The two sets of the first disassembly and assembly parts (83) are respectively provided on both sides of the sliding block (81) and can extend and disassemble the central bolt (220) and the central wedge (22). The four sets of the second disassembly parts (84) are respectively located at the four corners of the sliding block (81), and can extend and disassemble the end bolts (210) and end wedges (21).

4. The cutterhead changing device for dealing with the upward drift of a tunnel boring machine in soft upper and hard lower strata as described in claim 3, characterized in that, The tensioning device (85) includes: a telescopic power source (850), an active crossbar (851), a passive crossbar (852), and a structural connecting rod (853); The output shaft of the telescopic power source (850) is located in the middle of the two sets of grippers (82). The active crossbar (851) is fixedly connected to the output shaft and is perpendicular to the output shaft. The plane where the active crossbar (851) and the output shaft are located is the symmetrical plane of the two sets of grippers (82). The two passive crossbars (852) are respectively connected to the two grippers (82) of each set and are parallel to the active crossbar (851). The two ends of the structural connecting rod (853) are respectively rotatably connected between the active crossbar (851) and the passive crossbar (852). When the telescopic power source (850) extends or retracts, the two sets of grippers (82) retract or open.

5. The cutterhead changing device for dealing with the upward drift of a tunnel boring machine in soft upper and hard lower strata as described in claim 4, characterized in that, The tensioning device (85) also includes a locking rod (854). The locking rod (854) is set in the same direction as the telescopic power source (850). One end of the locking rod (854) is fixedly connected to the active crossbar (851), and the other end is provided with a locking head (855). When the telescopic power source (850) retracts and tightens the gripper (82), the locking head (855) is inserted into the middle of the ends of the two grippers (82).

6. The cutterhead changing device for dealing with the upward drift of a tunnel boring machine in soft upper and hard lower strata as described in claim 3, characterized in that: The first disassembly and assembly part (83) includes a first power source (830) and a ring transmission structure (831) fixedly disposed on the sliding block (81), and a first disassembly and assembly rod (832). When the sliding block (81) slides to the middle of the connecting seat (80), the axis of the first disassembly and assembly rod (832) coincides with the axis of the middle bolt (220). The ring transmission structure (831) includes a rotating seat (8311) and a ring gear (8312). The rotating seat (8311) is fixedly installed on the outer periphery of the sliding block (81), and the ring gear (8312) is rotatably installed on the rotating seat (8311) and driven by the first power source (830). The first disassembly rod (832) includes a first sleeve (8321) at the head end, a first rod body (8322) in the middle, and a telescopic drive device at the tail end. The telescopic drive device is fixedly installed on the sliding block (81) by a first support column. The first rod body (8322) is rotatably and slidably installed in the telescopic drive device. The middle section of the first rod body (8322) is provided with teeth and meshes with the ring gear (8312). The first sleeve (8321) can be inserted into the countersunk hole of the middle wedge (22) to turn the middle bolt (220) and attract the middle bolt (220) and the middle wedge (22).

7. The cutterhead changing device for dealing with the upward drift of a tunnel boring machine in soft upper and hard lower strata as described in claim 3, characterized in that: The second disassembly and assembly part (84) includes a second power source, a transmission flexible shaft (840), and a second disassembly and assembly rod. When the sliding block (81) slides to the upper and lower ends of the connecting seat (80), the axis of the second disassembly and assembly rod coincides with the axis of the end bolt (210). The second disassembly rod includes a second sleeve assembly (841) at the head end, a second rod body (842) in the middle, and a telescopic drive device at the tail end. The telescopic drive device is fixedly installed on the sliding block (81) by a second support column, and the second rod body (842) is telescopically slidably connected to the telescopic drive device. The second sleeve assembly (841) includes a sleeve housing (8411), a sleeve plate (8412), and a telescopic airbag (8413). The sleeve housing (8411) has a "U"-shaped opening structure, and the opening width matches the end wedge (21). The sleeve plate (8412) is slidably disposed at the opening. The telescopic airbag (8413) is disposed in the sleeve plate (8412) and the opening and adjusts the position of the sleeve plate (8412). A sleeve is rotatably disposed on the sleeve plate (8412). The tail end of the sleeve is connected to the second power source through the transmission flexible shaft (840). The head end of the sleeve can be inserted into the countersunk hole of the end wedge (21) to tighten the end bolt (210) and attract the end bolt (210) and the end wedge (21).

8. The cutterhead changing device for dealing with the upward drift of a tunnel boring machine in soft upper and hard lower strata as described in claim 3, characterized in that, The connecting seat (80) is arc-shaped, and an arc-shaped groove is provided on the connecting seat (80) to divide the connecting seat (80) into a sliding part and a connecting part. The sliding block (81) is slidably connected to the sliding part, and the robotic arm (7) is connected to the connecting part.

9. The cutterhead changing device for dealing with the upward drift of a tunnel boring machine in soft upper and hard lower strata as described in claim 8, characterized in that, When the gripper (82) clamps the wedge hob, the sliding path of the sliding block (81) on the connecting seat (80) is concentric with the wedge hob.

10. A method for changing cutterheads to address the upward drift of a tunnel boring machine in soft-over-hard strata, characterized in that... The tool changing device as described in claim 3 includes the following steps: Preparation step: The tool disc rotates, and the tool to be changed arrives at the tool changing working area; Disassembly steps: The robotic arm (7) moves, the end effector (8) reaches behind the target tool, the gripper (82) opens and inserts into the tool box to clamp the tool, and the sliding block (81) slides to the middle of the connecting seat (80); The first disassembly part (83) extends and disassembles the central bolt (220) and the central wedge (22). After disassembly, the first disassembly part (83) retracts carrying the central bolt (220) and the central wedge (22). The sliding block (81) slides to one side, and the second disassembly rod on the other side extends and disassembles the end bolt (210) and the end wedge (21). After disassembly, it moves backward carrying the end bolt (210) and the end wedge (21). The sliding block (81) slides to the other side and removes the end bolt (210) and end wedge (21) on the remaining side before retracting; tool release: the gripper (82) of the end effector (8) clamps the tool, the robotic arm (7) moves to remove the old tool and place it in the tool recycling position, and takes out a new tool from the new tool position, returns to the tool removal position, and puts the tool into the tool box; Tool installation step: Reverse the sub-steps in the tool removal step to complete the installation of the new tool; the robotic arm (7) moves, the end effector (8) disengages from the tool disc, the tool disc rotates, the next tool to be replaced arrives at the tool replacement work area, and the above steps are repeated to replace the tool.

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