Host machine of expanding heading machine and expanding heading machine

Abstract

The invention provides a main machine of an expanding heading machine and the expanding heading machine, and belongs to the technical field of tunneling equipment. The expanding heading machine main machine comprises a main drive and an expanding cutter head which is controlled by the main drive to rotate so as to cut segments of an existing tunnel and excavate a stratum, and further comprises a segment stabilizing device which is used for being arranged in the existing tunnel so as to stabilize a tunnel face, and the expanding cutter head comprises an annular cutter head body. The duct piece stabilizing device is connected to a center partition plate of the main drive through a transition mechanism penetrating through a center hole of the cutterhead body. The duct piece stabilizing device is integrated in the main machine, in the tunneling process, the duct piece stabilizing device synchronously advances along with the main machine, a tractor does not need to be arranged, the construction cost can be reduced, and the problems that due to the tractor, the tractor cannot enter a tunnel when the diameter of the tunnel is small, and construction is inconvenient are solved. And meanwhile, steps needing mutual coordination operation do not exist, construction is simpler, the segment stabilizing device can effectively maintain the stability of the tunnel face all the time, and the construction safety is higher.

Description

Technical Field

[0001] The invention relates to a main engine of a diameter-expanding tunnel boring machine and the diameter-expanding tunnel boring machine, belonging to the technical field of tunnel boring equipment. Background Art

[0002] With the development of the city, when some existing tunnels such as subway tunnels, cable tunnels and drainage tunnels cannot meet the use requirements due to disrepair, quality degradation or small design size, it is necessary to maintain the existing tunnels or re-plan and construct new tunnel lines. However, simple tunnel maintenance cannot completely solve the quality problems, and re-planning the route will incur high design and construction costs.

[0003] In this regard, the utility model patent with the authorization announcement number CN208502773U discloses a shield machine suitable for excavation of existing tunnels. The shield machine includes a pressure-maintaining system in the front and a main engine system in the rear. The pressure-maintaining system includes a tractor, a pressure-maintaining assembly and a steel sleeve. The tractor is hinged to the front end of the steel sleeve. The pressure-maintaining assembly includes a sealing system, a support system and a grease injection port arranged on the side wall of the steel sleeve. The main engine system includes a shield body, an expansion cutter disc, a main drive, a partition, a screw conveyor, etc., wherein the expansion cutter disc is used to cut the existing pipe segment and the stratum. A pressurized excavation chamber is formed between the steel sleeve and the partition. The cut slag flows into the excavation chamber and then is discharged out of the tunnel through the screw conveyor. After the main engine system excavates a certain distance, the tractor drags the steel sleeve forward. During the excavation process of the main engine system, in order to prevent the steel sleeve from shifting forward under the pressure of the excavation chamber, the inner wall of the existing pipe segment can be pressed against by the support system to ensure the stability of the steel sleeve.

[0004] The above-mentioned steel sleeve can ensure the stability of the tunnel face during the excavation of the main engine system and constitute a segment stabilization device. However, since the steel sleeve needs to be equipped with a tractor, the construction cost increases, and when the diameter of the existing tunnel is relatively small, the tractor cannot enter at all, causing construction inconvenience. At the same time, the pressure maintenance system and the main engine system are independent of each other, but the two need to coordinate operations, resulting in complicated procedures. Once there is a deviation in coordination, the steel sleeve moves forward too much and will not be able to effectively maintain the stability of the tunnel face, which also poses construction risks. Summary of the invention

[0005] The object of the present invention is to provide a main engine of a diameter expansion tunneling machine to solve the problems in the prior art that a segment stabilization device requires a special tractor, which increases the construction cost, and when the diameter of the existing tunnel is relatively small, the tractor cannot enter at all, causing construction inconvenience, and the existing segment stabilization device and the main engine system are independent of each other, and the two need to coordinate operations, resulting in complicated procedures, and when there is a deviation in coordination, the segment stabilization device cannot effectively maintain the stability of the face; the object of the present invention is also to provide a diameter expansion tunneling machine to solve the above problems.

[0006] In order to achieve the above-mentioned purpose, the main engine of the expansion tunnel boring machine in the present invention adopts the following technical scheme: A main engine of an expanding tunnel boring machine includes a main drive and an expanding cutterhead that is controlled to rotate by the main drive to cut existing tunnel segments and excavate strata, and also includes a segment stabilizing device for being arranged in the existing tunnel to stabilize the tunnel face. The expanding cutterhead includes an annular cutterhead body, and the segment stabilizing device is connected to the central partition of the main drive through a transition mechanism that passes through the central hole of the cutterhead body.

[0007] The beneficial effect of the above technical solution is that: the present invention belongs to a combined invention, which mainly integrates the segment stabilization device directly on the main engine of the expansion tunneling machine. To achieve integration, the expansion cutterhead is set to include a ring-shaped cutterhead body. Since the existing tunnel is a hollow structure, it does not affect the cutting of the existing tunnel segments. The segment stabilization device is connected to the central partition of the main drive through a transition mechanism that penetrates the central hole of the cutterhead body, thereby utilizing the central hole of the cutterhead body to facilitate the transition mechanism to pass through, realize the connection between the segment stabilization device and the central partition of the main drive, and then realize the integration of the segment stabilization device on the main engine of the expansion tunneling machine. In this way, during the excavation process of the main engine, the segment stabilization device moves forward synchronously with the main engine, and no tractor is required, which can reduce the construction cost and solve the problem that the tractor cannot enter the tunnel when the tunnel diameter is relatively small due to the tractor, which is inconvenient for construction. At the same time, the segment stabilization device moves forward synchronously with the main engine, and there is no step that needs to coordinate operations with each other, so the construction is simpler, and the segment stabilization device can always effectively maintain the stability of the face, and the construction safety is higher.

[0008] Furthermore, the transition mechanism includes a front fixing ring fixed on the segment stabilizing device and a rear fixing ring fixed on the central partition plate. The front fixing ring and the rear fixing ring are sleeved and rotatably matched through a ball joint structure. A telescopic adjustment device for adjusting the angle of the segment stabilizing device is connected between the front fixing ring and the rear fixing ring or between the segment stabilizing device and the rear fixing ring.

[0009] Furthermore, the rear fixing ring includes a fixing part fixed on the central partition and a matching part connected to the fixing part and sleeved with the front fixing ring and rotatably matched, and the rear end of the telescopic adjustment device is connected to the fixing part.

[0010] Furthermore, the telescopic adjustment device is provided with four parts: upper, lower, left and right.

[0011] Furthermore, the transition mechanism is detachably connected to the central partition.

[0012] Furthermore, the segment stabilizing device includes a cylindrical body and a sealing device fixed on the outer peripheral surface of the cylindrical body and used for contacting the existing tunnel segment.

[0013] Furthermore, the segment stabilizing device also includes a conical body connected to the front end of the cylindrical body and a front end plate connected to the front end of the conical body.

[0014] Furthermore, the segment stabilizing device also includes a rear end plate connected to the rear end of the cylindrical body, and the front end of the transition mechanism is connected to the rear end plate.

[0015] Furthermore, the cutter head body is equipped with cutting tools for cutting existing tunnel segments and excavation tools for excavating strata, and the cutting tools located on different circumferences are arranged to protrude forward gradually as the diameter of the circumferences decreases.

[0016] Furthermore, the cutting surface formed by each cutting tool is a concave arc surface.

[0017] Furthermore, the excavation surface formed by each excavation tool is a vertical surface and is tangent to the cutting surface formed by each cutting tool.

[0018] In order to achieve the above-mentioned purpose, the diameter expansion tunneling machine in the present invention adopts the following technical scheme: A diameter expansion tunneling machine includes a main machine and rear supporting equipment. The main machine includes a main drive and an expansion cutterhead that is controlled by the main drive to rotate to cut existing tunnel segments and excavate strata. It also includes a segment stabilizing device that is arranged in the existing tunnel to stabilize the tunnel face. The expansion cutterhead includes an annular cutterhead body, and the segment stabilizing device is connected to the central partition of the main drive through a transition mechanism that passes through the central hole of the cutterhead body.

[0019] The beneficial effect of the above technical solution is that: the present invention belongs to an improved invention creation, and the main engine is further limited. The main engine sets the expanded diameter cutter disc to include a ring-shaped cutter disc body. Since the existing tunnel is a hollow structure, it will not affect the cutting of the existing tunnel segment. The segment stabilization device is connected to the central partition of the main drive through a transition mechanism that passes through the center hole of the cutter disc body, thereby utilizing the center hole of the cutter disc body to facilitate the transition mechanism to pass through, realize the connection between the segment stabilization device and the central partition of the main drive, and then realize the integration of the segment stabilization device on the main engine. In this way, during the excavation process of the main engine, the segment stabilization device moves forward synchronously with the main engine, and no tractor is required, which can reduce the construction cost and solve the problem that the tractor cannot enter the tunnel when the tunnel diameter is relatively small due to the tractor, which is inconvenient for construction. At the same time, the segment stabilization device moves forward synchronously with the main engine, and there is no need to coordinate the operation steps, so the construction is simpler, and the segment stabilization device can always effectively maintain the stability of the face, and the construction safety is higher.

[0020] Furthermore, the transition mechanism includes a front fixing ring fixed on the segment stabilizing device and a rear fixing ring fixed on the central partition plate. The front fixing ring and the rear fixing ring are sleeved and rotatably matched through a ball joint structure. A telescopic adjustment device for adjusting the angle of the segment stabilizing device is connected between the front fixing ring and the rear fixing ring or between the segment stabilizing device and the rear fixing ring.

[0021] Furthermore, the rear fixing ring includes a fixing part fixed on the central partition and a matching part connected to the fixing part and sleeved with the front fixing ring and rotatably matched, and the rear end of the telescopic adjustment device is connected to the fixing part.

[0022] Furthermore, the telescopic adjustment device is provided with four parts: upper, lower, left and right.

[0023] Furthermore, the transition mechanism is detachably connected to the central partition.

[0024] Furthermore, the segment stabilizing device includes a cylindrical body and a sealing device fixed on the outer peripheral surface of the cylindrical body and used for contacting the existing tunnel segment.

[0025] Furthermore, the segment stabilizing device also includes a conical body connected to the front end of the cylindrical body and a front end plate connected to the front end of the conical body.

[0026] Furthermore, the segment stabilizing device also includes a rear end plate connected to the rear end of the cylindrical body, and the front end of the transition mechanism is connected to the rear end plate.

[0027] Furthermore, the cutter head body is equipped with cutting tools for cutting existing tunnel segments and excavation tools for excavating strata, and the cutting tools located on different circumferences are arranged to protrude forward gradually as the diameter of the circumferences decreases.

[0028] Furthermore, the cutting surface formed by each cutting tool is a concave arc surface.

[0029] Furthermore, the excavation surface formed by each excavation tool is a vertical surface and is tangent to the cutting surface formed by each cutting tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A side view of a main machine of a diameter expansion tunneling machine according to an embodiment of the present invention; Figure 2 It is a front view of the cutter head in the embodiment of the main engine of the expansion boring machine of the present invention; Figure 3 for Figure 1 The enlarged view of point A in the middle; Figure 4 for Figure 3 CC section view in the figure; Figure 5 for Figure 1Enlarged view of point B in the middle.

[0031] In the figure: 1. shield body; 2. main drive; 2-1. center partition; 3. expanded diameter cutterhead; 3-1. cutterhead body; 3-2. cutting tool; 3-3. excavation tool; 3-4. bracket; 4. sealing assembly; 5. thrust cylinder; 6. segment assembler; 7. slag discharger; 8. segment stabilizing device; 8-1. cylindrical body; 8-2. conical body; 8-3. front end plate; 8-4. rear end plate; 8-5. sealing device; 9. existing tunnel segment; 10. expanded diameter tunnel segment; 11. front fixing ring; 12. fixing part; 13. mating part; 14. articulated cylinder. DETAILED DESCRIPTION

[0032] In response to the technical problems existing in the prior art, the basic concept of the present invention is to directly integrate the segment stabilization device into the main engine of the expansion tunneling machine, so that the segment stabilization device moves forward synchronously with the main engine, without the need for a traction vehicle and without the problem of coordinated operations.

[0033] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0034] Embodiment 1 of the main engine of the expansion boring machine in the present invention: like Figure 1 As shown, the main body of the expansion tunneling machine includes a shield body 1, a main drive 2 installed on the shield body 1, and an expansion cutter head 3 that is controlled by the main drive 2 to rotate to cut existing tunnel segments 9 and excavate strata, wherein the existing tunnel segments 9 are equivalent to hard rock and the strata are equivalent to soft rock. The main body of the expansion tunneling machine also includes a slag discharge device 7 for slag discharge, and the slag discharge device 7 can specifically be a slurry discharge pipe or a screw conveyor. The main body of the expansion tunneling machine also includes a segment assembler 6 for assembling the expansion tunnel segments 10 and a propulsion cylinder 5 for pushing the expansion cutter head 3 forward for excavation, the front end of the propulsion cylinder 5 is connected to the shield body 1, and the rear end is used to abut against the expansion tunnel segments 10.

[0035] The main machine of the expansion tunnel boring machine also includes a segment stabilizing device 8 for being arranged in the existing tunnel to stabilize the tunnel face. Figure 1 , Figure 3 and Figure 5 As shown, the segment stabilizing device 8 includes a cylindrical body 8-1 and a sealing device 8-5 fixed on the outer peripheral surface of the cylindrical body 8-1 and used to contact the existing tunnel segment 9. Therefore, the segment stabilizing device 8 has a pressure maintaining function, which can isolate the existing tunnel from the tunnel face, stabilize the tunnel face, and is conducive to the efficient rock breaking and slag discharge of the expanding cutter head 3.

[0036] The segment stabilizer 8 also includes a conical cylinder 8-2 connected to the front end of the cylindrical cylinder 8-1 and a front end plate 8-3 connected to the front end of the conical cylinder 8-2. The conical cylinder 8-2 has a guiding function, which facilitates the segment stabilizer 8 to enter the existing tunnel when starting. The segment stabilizer 8 also includes a rear end plate 8-4 connected to the rear end of the cylindrical cylinder 8-1. The overall structure is simple and easy to process and manufacture.

[0037] Combination Figure 1 and Figure 2 As shown, the expansion cutterhead 3 includes an annular cutterhead body 3-1, and the cutterhead body 3-1 is fixed to the main drive 2 through a bracket 3-4. The segment stabilizing device 8 is connected to the central partition 2-1 of the main drive 2 through a transition mechanism that penetrates the center hole of the cutterhead body 3-1. Since the existing tunnel is a hollow structure, the annular cutterhead body 3-1 does not affect the cutting of the existing tunnel segment 9. Instead, the center hole of the cutterhead body 3-1 can be used to facilitate the connection between the segment stabilizing device 8 and the central partition 2-1 through the transition mechanism, thereby realizing the integration of the segment stabilizing device 8 on the main machine of the expansion tunneling machine. In this way, during the excavation process of the main machine, the segment stabilizing device 8 moves forward synchronously with the main machine, and no tractor is required, which can reduce the construction cost and solve the problem that the tractor cannot enter the tunnel when the diameter is relatively small due to the tractor, which is inconvenient for construction. At the same time, the segment stabilizing device 8 moves forward synchronously with the main machine, and there is no step that needs to coordinate the operation with each other, so the construction is simpler, and the segment stabilizing device 8 can always effectively maintain the stability of the face, and the construction safety is higher.

[0038] The transition mechanism is located in the central area of ​​the enlarged cutter disc 3, such as Figure 3 As shown, the transition mechanism includes a front fixing ring 11 fixed on the rear end plate 8-4 and a rear fixing ring fixed on the center partition 2-1. The rear fixing ring includes a fixing portion 12 fixed on the center partition 2-1 and a matching portion 13 connected to the fixing portion 12 and sleeved with the front fixing ring 11 and rotatably matched. The matching portion 13 extends into the front fixing ring 11, and the outer peripheral surface of the matching portion 13 includes a spherical surface, so that the spherical surface realizes the ball joint match with the front fixing ring 11. A telescopic adjustment device for adjusting the angle of the pipe segment stabilizing device 8 is connected between the rear end plate 8-4 and the fixing portion 12. The telescopic adjustment device in this embodiment is an articulated oil cylinder 14, and is combined with Figure 4 As shown, four articulated cylinders 14 are provided, namely, upper, lower, left and right. By means of the different elongations of the articulated cylinders 14, the angle of the segment stabilizing device 8 can be adjusted to meet the construction requirements of the segment stabilizing device 8 for going up and down slopes and turning left and right.

[0039] Among them, a sealing component 4 is provided at the ball joint matching position of the matching part 13 and the front fixing ring 11 to prevent the entry of debris. The fixing part 12 and the matching part 13 together form the rear fixing ring, which is convenient for the processing and manufacturing of the rear fixing ring and the connection of the articulated oil cylinder 14. At the same time, a total of four articulated oil cylinders 14 are provided, which has a simple structure and low configuration cost under the premise of meeting the adjustment requirements. In addition, the fixing part 12 is detachably connected to the central partition 2-1, which is convenient for installation and easy to disassemble after the construction is completed.

[0040] Combination Figure 2 and Figure 5 As shown, the cutter head body 3-1 is equipped with a cutting tool 3-2 for cutting the existing tunnel segment 9 and an excavation tool 3-3 for excavating the stratum. The cutting tool 3-2 and the excavation tool 3-3 in this embodiment are both roller cutters. The cutting tools 3-2 located on different circumferences are gradually protruded forward as the diameter of the circumference is continuously reduced, so that the cutting surface formed by each cutting tool 3-2 is not a vertical surface, but gradually transitions from back to front. Compared with the vertical cutting surface, this tool arrangement form increases the number of cutting tools 3-2. Therefore, when cutting the existing tunnel segment 9 with relatively high hardness, more tools can be used to share the load, which is beneficial to the service life of the tool, the uniform load of the main drive, and the stable cutting of the cutter head.

[0041] Furthermore, the cutting surface formed by each cutting tool 3-2 is a concave arc surface, so that the transition is smoother. At the same time, the excavation surface formed by each excavation tool 3-3 is a vertical surface and is tangent to the cutting surface formed by each cutting tool 3-2. In this way, the transition between the cutting tool 3-2 and the excavation tool 3-3 is relatively smooth, and there is no large turning point, which avoids uneven force on the tool at the transition position and affects the service life.

[0042] Through the above settings, the cutting tool 3-2 is densely arranged, so that the cutting tool 3-2 can better break the existing tunnel segment 9 with relatively high hardness, and realize stable and efficient excavation of the expanded diameter cutter head 3 in two obviously different strata, avoiding the use of conventional cutter heads that cause abnormal overloading of the main drive, abnormal wear of the tool, and difficulty in achieving stable excavation.

[0043] In summary, the main engine of the expanding tunnel boring machine provided by the present invention provides a new solution for the expansion and reconstruction of existing tunnels, and can solve the problems of high construction safety risks and high construction costs in the prior art. The main engine of the expanding tunnel boring machine provided by the present invention has a wide range of applications and can be used in many fields such as the "large-scale push, small tunnel first and station later" station method construction and municipal pipeline networks.

[0044] In other embodiments of the main body of the expansion tunneling machine: even if the excavation surface formed by each excavation tool is a vertical surface, it may not be tangent to the cutting surface formed by each cutting tool, but intersect with it. Of course, the excavation surface formed by each excavation tool may not be a vertical surface, but an inclined surface, and intersect with the cutting surface formed by each cutting tool.

[0045] In other embodiments of the main engine of the expansion tunneling machine: the cutting surface formed by each cutting tool can also be a conical surface.

[0046] In other embodiments of the main engine of the expansion tunneling machine: depending on the specific conditions of the stratum, the excavation tool used for excavating the stratum can also be a scraper.

[0047] In other embodiments of the main engine of the expansion tunnel boring machine: the cutting surfaces formed by the cutting tool for cutting the existing tunnel segments and the excavation tool for excavating the strata can both be vertical surfaces.

[0048] In other embodiments of the main engine of the expansion tunneling machine: the segment stabilization device may not include the rear end plate, and in this case the transition mechanism is connected to the inner circumference of the cylindrical body.

[0049] In other embodiments of the main engine of the expansion tunneling machine: the segment stabilizing device may not include a conical cylinder, and in this case the front end of the cylindrical cylinder is directly connected to the vertically arranged front end plate.

[0050] In other embodiments of the main engine of the expansion tunneling machine: the segment stabilization device may not include a sealing device, and the outer peripheral surface of the cylindrical barrel is in contact with the existing tunnel segment.

[0051] In other embodiments of the main body of the expansion tunnel boring machine: the transition mechanism can be welded and fixed to the central partition plate and is no longer detachably connected.

[0052] In other embodiments of the main engine of the expansion tunnel boring machine: the telescopic adjustment device can also be replaced by a cylinder or an electric push rod.

[0053] In other embodiments of the main body of the expanding tunnel boring machine: eight telescopic adjustment devices can also be set, distributed in eight positions: up, down, left, right, upper left, upper right, lower left and lower right.

[0054] In other embodiments of the main body of the expansion tunnel boring machine: the rear fixing ring no longer includes two parts, for example, the rear end of the matching part is directly fixed to the central partition, and the rear end of the telescopic adjustment device is connected to the inner wall of the matching part.

[0055] In other embodiments of the main body of the expanding tunnel boring machine: the front end of the telescopic adjustment device can also be connected to the inner wall of the front fixing ring.

[0056] In other embodiments of the main body of the expansion tunnel boring machine: the front fixing ring can extend into the interior of the rear fixing ring, and the outer peripheral surface of the front fixing ring includes a spherical surface to achieve a ball joint fit with the rear fixing ring.

[0057] In other embodiments of the main engine of the expansion tunneling machine: the transition mechanism can be a rigid non-adjustable mechanism, for example, the transition mechanism is a rigid connecting frame, the front end of the rigid connecting frame is fixed to the pipe segment stabilization device, and the rear end is fixed to the central partition.

[0058] The embodiment of the expanding tunnel boring machine in the present invention is as follows: the expanding tunnel boring machine includes a main machine and supporting equipment. The structure of the main machine is the same as the main machine of the expanding tunnel boring machine in any of the above embodiments, and will not be repeated here.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. A main machine of a diameter expansion tunneling machine, characterized in that: It includes a main drive and an expanded diameter cutterhead that is controlled by the main drive to rotate to cut existing tunnel segments and excavate strata, and also includes a segment stabilizing device that is arranged in the existing tunnel to stabilize the tunnel face. The expanded diameter cutterhead includes an annular cutterhead body, and the segment stabilizing device is connected to the central partition of the main drive through a transition mechanism that passes through the central hole of the cutterhead body.

2. The main machine of the expansion boring machine according to claim 1, characterized in that: The transition mechanism includes a front fixing ring fixed on the segment stabilizing device and a rear fixing ring fixed on the central partition. The front fixing ring and the rear fixing ring are sleeved and rotatably matched through a ball joint structure. A telescopic adjustment device for adjusting the angle of the segment stabilizing device is connected between the front fixing ring and the rear fixing ring or between the segment stabilizing device and the rear fixing ring.

3. The main machine of the expansion boring machine according to claim 2, characterized in that: The rear fixing ring comprises a fixing part fixed on the central partition plate and a matching part connected to the fixing part and sleeved with the front fixing ring and rotatably matched. The rear end of the telescopic adjustment device is connected to the fixing part.

4. The main machine of the expansion boring machine according to claim 2, characterized in that: The telescopic adjustment device is provided with four parts: upper, lower, left and right.

5. The main machine of the expansion boring machine according to any one of claims 1 to 4, characterized in that: The transition mechanism is detachably connected to the central partition.

6. The main machine of the expansion boring machine according to any one of claims 1 to 4, characterized in that: The segment stabilizing device comprises a cylindrical body and a sealing device which is fixed on the outer peripheral surface of the cylindrical body and is used for contacting with the existing tunnel segment.

7. The main machine of the expansion boring machine according to claim 6, characterized in that: The pipe segment stabilizing device also includes a conical cylinder connected to the front end of the cylindrical cylinder and a front end plate connected to the front end of the conical cylinder.

8. The main machine of the expansion boring machine according to claim 6, characterized in that: The pipe segment stabilizing device also includes a rear end plate connected to the rear end of the cylindrical body, and the front end of the transition mechanism is connected to the rear end plate.

9. The main machine of the expansion boring machine according to any one of claims 1 to 4, characterized in that: The cutterhead body is equipped with cutting tools for cutting existing tunnel segments and excavation tools for excavating strata. The cutting tools located on different circumferences are gradually protruded forward as the diameter of the circumferences decreases.

10. The main machine of the expansion boring machine according to claim 9, characterized in that: The cutting surface formed by each cutting tool is a concave arc surface.

11. The main machine of the expansion boring machine according to claim 10, characterized in that: The excavation surface formed by each excavation tool is a vertical surface and is tangent to the cutting surface formed by each cutting tool.

12. A diameter expansion tunneling machine, comprising a main machine and a supporting device, characterized in that: The main machine is the main machine of the expansion boring machine as described in any one of claims 1 to 11.

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