Variable-diameter stepped heading machine cutterhead and heading method

Abstract

The invention discloses a variable-diameter stepped tunneling machine cutterhead and a tunneling method, and relates to the technical field of tunneling machine equipment, the variable-diameter stepped tunneling machine cutterhead comprises a connecting structure used for connecting the cutterhead and a main drive of a tunneling machine, a center body used for installing cutterhead plates and the cutterhead plates used for tunneling; the cutterhead plate comprises a first-stage tunneling part used for foundation tunneling or first tunneling and a second-stage tunneling part used for expansion tunneling or later tunneling. The variable-diameter stepped tunnel boring machine cutterhead has the beneficial effects that the variable-diameter stepped tunnel boring machine cutterhead is mainly used for tunnel construction under hard rock extreme geological conditions; for a stepped structure, the cutter head can be excavated in a hard rock stratum in a grading manner, and large disturbance to tunnel stratum stress is avoided; for a variable-diameter structure, tunneling is conducted by changing the diameter of the cutter head, the problems that the cutter head is clamped and embraced in a soft and broken stratum can be avoided, and finally safe and efficient tunneling of tunnel construction is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel boring machine equipment, and in particular to a variable-diameter stepped tunnel boring machine cutter head and a tunneling method. Background Art

[0002] With the further development of underground space, tunnels are increasingly being used in railway, highway, and water conservancy projects. The extremely complex geology of the Hengduan Mountains in southwestern my country often leads to tunnel construction problems such as collapse, soft rock deformation, and mud and water inrush, which can cause tunnel boring machines to become stuck. For example, in the Southwest my country Water Diversion Project, weak geology caused the tunnel's surrounding rock radius to shrink by more than one meter, significantly delaying construction and increasing costs.

[0003] The traditional tunnel boring machine excavation method is to use the entire cutterhead to excavate the tunnel at one time. For example, the diameter of a water conservancy project tunnel is generally over 9 meters. When excavating in super-hard rock and high-stress strata, the full-section excavation causes a temporary imbalance in ground stress, which is very likely to cause excavation risks such as rock bursts. When excavating in soft rock with large deformation and broken strata, the machine is very likely to get stuck due to the convergence and deformation of the surrounding rock during the excavation process. After the excavation is completed, the surrounding rock further converges, causing the tunnel diameter to be greatly reduced. In order to meet the engineering design requirements, secondary manual excavation is required, which greatly increases the engineering risk and cost.

[0004] In order to solve the problems of low tunnel construction efficiency, machine jamming during the process, and large deformation of surrounding rock convergence after tunnel construction under extremely complex geological conditions, the traditional solution mainly relies on manual excavation to achieve tunnel excavation relief. However, if the operation is not carried out, the risk is high and the operation efficiency is low. Summary of the Invention

[0005] The purpose of the present invention is to provide a variable diameter stepped tunnel boring machine cutterhead in order to solve the above problems. In soft rock with large deformation and broken strata, the pre-expansion of the tunnel is achieved by changing the cutterhead diameter to ensure the safe construction of the tunnel boring machine and the tunnel quality meets the engineering design standards. At the same time, the stepped cutterhead is more conducive to improving the tunnel excavation efficiency under extremely hard rock conditions.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0007] A variable diameter stepped tunnel boring machine cutterhead, comprising:

[0008] Connecting structure, used to connect the cutterhead to the main drive of the tunnel boring machine;

[0009] A central body, one end of which is connected to the main drive of the roadheader through the connecting structure and is used to install the cutterhead plate; and

[0010] a cutterhead segment, which is arranged on the central body and is used for excavation;

[0011] Wherein, the cutter head plate includes:

[0012] A first-stage excavation, which is arranged in the middle of the end of the central body away from the tunnel boring machine housing and is used for basic excavation or preliminary excavation; and

[0013] The secondary excavation has one end rotatably connected to the middle circumference of the central body. The secondary excavation can swing backward around the end connected to the central body to realize a variable diameter cutterhead. The secondary excavation is used to expand excavation or post-excavation.

[0014] Preferably, the connection structure includes a connection flange on the central body, and the connection flange is connected to a flange on a rotating shaft of the tunnel boring machine.

[0015] Preferably: the central body includes an annular beam, a rear corbel beam fixedly installed on the side of the annular beam close to the connecting structure, and a front corbel beam fixedly installed on the side of the annular beam away from the connecting structure, the first-level excavation is fixedly installed on the end of the front corbel beam away from the annular beam, and the second-level excavation is rotatably connected to the annular beam.

[0016] Preferably, the first-stage excavation includes a circular front cutterhead.

[0017] Preferably, the secondary excavation includes a plurality of variable diameter cutterhead blocks, and one end of the variable diameter cutterhead block away from the annular beam is rotatably connected to the connecting structure through an adjusting cylinder.

[0018] Preferably, the number of the variable diameter cutter disc blocks is 6-8.

[0019] Preferably, the secondary excavation further comprises a connecting block for filling the gap between adjacent variable diameter cutterhead blocks, and the connecting block is fixedly connected to the variable diameter cutterhead blocks by fixing bolts.

[0020] Preferably, the side surface of the annular beam away from the first-level excavation side corresponds to the mounting bracket of the variable diameter cutter head block, and the variable diameter cutter head block is rotatably connected to the bracket via a rotating shaft.

[0021] Preferably, when the secondary excavation is parallel to the primary excavation, it is a stepped cutterhead; when the secondary excavation swings backward, it is a variable diameter cutterhead.

[0022] A tunneling method using the above-mentioned variable-diameter stepped tunnel boring machine cutterhead, in hard rock formations, the variable-diameter cutterhead block of the secondary tunneling is kept parallel to the front small cutterhead of the primary tunneling, forming a stepped cutterhead, the front small cutterhead first performs basic tunneling on the central area of ​​the tunnel, and the variable-diameter cutterhead blocks then cooperate to perform expansion tunneling on the surrounding rock formations; in soft and broken formations, the variable-diameter cutterhead block of the secondary tunneling is swung backward around the end connected to the center body to a set position by adjusting the oil cylinder, forming a variable-diameter cutterhead, and tunneling is carried out using the variable diameter. At the same time, the gaps between adjacent variable-diameter cutterhead blocks are filled by special connecting blocks fixed with consolidation bolts.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: the variable diameter stepped tunnel boring machine cutterhead disclosed by the present invention is mainly aimed at tunnel construction under extreme geological conditions of hard rock; for the stepped structure, the cutterhead can realize graded excavation in hard rock strata, avoiding causing large disturbance to the tunnel stratum stress; for the variable diameter structure, by changing the cutterhead diameter during excavation, the cutterhead can avoid being stuck or held in soft and broken strata, ultimately ensuring safe and efficient tunnel construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 It is a schematic diagram of the maximum diameter structure of a variable diameter stepped tunnel boring machine cutter head according to the present invention.

[0026] Figure 2 It is a schematic diagram of the minimum diameter structure of a variable diameter stepped tunnel boring machine cutter head according to the present invention.

[0027] Figure 3 It is a schematic diagram of the internal structure of a variable diameter stepped tunnel boring machine cutter head according to the present invention.

[0028] Figure 4 It is a side view of a variable diameter stepped roadheader cutterhead according to the present invention.

[0029] Figure 5 It is an AA sectional view of a variable diameter stepped tunnel boring machine cutter head according to the present invention.

[0030] Figure 6 It is a three-dimensional isometric view of a variable diameter stepped tunnel boring machine cutterhead according to the present invention.

[0031] The following are the descriptions of the reference numerals:

[0032] 1. Front cutterhead; 2. Front corbel; 3. Variable diameter cutterhead block; 4. Adjusting cylinder; 5. Rear corbel; 6. Connecting flange; 7. Main drive bearing; 8. Tunnel boring machine housing; 9. Piston connecting shaft; 10. Piston support; 11. Cylinder connecting shaft; 12. Cylinder support; 13. Connecting block; 14. Fixing bolts; 16. Rotating shaft; 17. Bracket; 18. Annular beam. DETAILED DESCRIPTION

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood based on specific circumstances.

[0035] The present invention will be further described below in conjunction with the accompanying drawings:

[0036] like Figures 1-6As shown, a variable diameter stepped tunnel boring machine cutterhead includes a connecting structure, a center body and a cutterhead plate. The connecting structure is used to connect the cutterhead to the tunnel boring machine main drive; one end of the center body is connected to the tunnel boring machine main drive through the connecting structure for mounting the cutterhead plate; the cutterhead plate is set on the center body for tunneling; the cutterhead plate includes a primary tunneling plate and a secondary tunneling plate; the primary tunneling plate is set in the middle position of the end of the center body away from the tunnel boring machine housing 8, and is used for basic tunneling or preliminary tunneling; one end of the secondary tunneling plate is rotatably connected to the middle circumference of the center body, and the secondary tunneling plate can swing backward around the end connected to the center body to realize a variable diameter cutterhead, and the secondary tunneling plate is used for expansion tunneling or post-tunneling.

[0037] The connection structure includes a connection flange 6 on the central body, which is connected to a flange on the rotating shaft 16 of the tunnel boring machine. A main drive bearing 7 is installed at a position of the tunnel boring machine corresponding to the rotating shaft 16 of the tunnel boring machine.

[0038] The central body includes an annular beam 18, six rear corbel beams 5 fixedly installed on the side of the annular beam 18 close to the connecting structure, and six front corbel beams 2 fixedly installed on the side of the annular beam 18 away from the connecting structure. The first-level excavation is fixedly installed on the end of the front corbel beam 2 away from the annular beam 18. The first-level excavation includes a circular front small cutter head 1.

[0039] The secondary excavation is rotatably connected to the annular beam 18. The secondary excavation includes 6 variable diameter cutter head blocks 3. The end of the variable diameter cutter head block 3 away from the annular beam 18 is rotatably connected to the connecting structure through the adjusting cylinder 4; the variable diameter cutter head block 3 is installed with a piston support 10 corresponding to the adjusting cylinder 4, and one end of the adjusting cylinder 4 is rotatably connected to the piston support 10 through the piston connecting shaft 9; a cylinder support 12 is installed on the connecting flange 6 corresponding to the adjusting cylinder 4, and the other end of the adjusting cylinder 4 is rotatably connected to the cylinder support 12 through the cylinder connecting shaft 11.

[0040] The secondary excavation also includes a connecting block 13 used to fill the gap between adjacent variable diameter cutter head blocks 3. The size of the connecting block 13 corresponds to the size of the gap between the two adjacent variable diameter cutter head blocks 3. The connecting block 13 of the corresponding size is installed according to the gap between the two adjacent variable diameter cutter head blocks 3. The connecting block 13 is fixedly connected to the variable diameter cutter head block 3 by a fixing bolt 14 to fix the variable diameter cutter head block 3. During excavation, the variable diameter cutter head block 3 and the connecting block 13 form mutual support to prevent the hydraulic cylinder from being subjected to radial load during the excavation process.

[0041] The annular beam 18 is mounted on a bracket 17 corresponding to the variable diameter cutter disc block 3 on the side away from the first-level excavation side. The variable diameter cutter disc block 3 is rotatably connected to the bracket 17 via a rotating shaft 16. The outer diameter of the front small cutter disc 1 is ≥ the outer diameter of the annular beam 18 to ensure that the front projection surface is the front small cutter disc 1 and the variable diameter cutter disc block 3 when excavating forward.

[0042] When the secondary excavation is parallel to the primary excavation, a "stepped" cutterhead is formed (e.g. Figure 1 As shown); the second stage excavation swings backward, which is a variable diameter cutterhead. When it reaches the set limit position, the variable diameter cutterhead is in the shape of a truncated cone (as shown Figure 2 As shown), the maximum diameter of the variable diameter cutter head at the limit position is set to be slightly larger than the diameter of the tunnel boring machine housing 8. For example, if the diameter of the tunnel boring machine housing 8 is 9 meters, the maximum diameter of the variable diameter cutter head at the limit position is set.

[0043] Working principle: The use of the variable diameter stepped tunnel boring machine cutterhead needs to switch the working mode in combination with different geological conditions: in hard rock formations, the variable diameter cutterhead block 3 of the secondary excavation is kept parallel to the front small cutterhead 1 of the primary excavation to form a stepped cutterhead. The front small cutterhead 1 first performs basic excavation on the central area of ​​the tunnel, and the variable diameter cutterhead block 3 then cooperates to expand the excavation of the surrounding rock formations, reducing the disturbance of the stress of the hard rock formation through graded excavation; in soft and broken formations, the variable diameter cutterhead block 3 of the secondary excavation is swung backward around the end connected to the center body to the set position by adjusting the oil cylinder 4 to form a variable diameter cutterhead, and excavation is carried out using a variable diameter (9.1 meters-10.4 meters) to prevent the cutterhead from being stuck or held. At the same time, the gap between adjacent variable diameter cutterhead blocks 3 is fixed and filled by a special connecting block through a consolidation bolt 14 to ensure structural stability during excavation, ultimately achieving safe and efficient tunnel construction.

[0044] The front cutterhead 1, front corbel 2, reducer block 3, adjustment cylinder 4, rear corbel 5, connecting flange 6, main drive bearing 7, and tunnel boring machine housing 8 are all commonly used standard components or components known to those skilled in the art. Their structures and principles can be learned from technical manuals or through conventional experimental methods by those skilled in the art, and therefore will not be described in detail here.

[0045] The basic principles, main features and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and improvements, and these changes and improvements shall fall within the scope of the invention claimed for protection.

Claims

1. A variable diameter stepped roadheader cutterhead, comprising: Connecting structure, used to connect the cutterhead to the main drive of the tunnel boring machine; The central body is used to install the cutterhead plate, and one end of the central body is connected to the main drive of the tunnel boring machine through the connecting structure; as well as a cutterhead segment, used for excavation, which is arranged on the central body; It is characterized in that: the cutter head plate includes: A first-stage excavation is provided at a middle position of one end of the central body away from the tunnel boring machine housing (8) and is used for basic excavation or preliminary excavation; and The secondary excavation has one end rotatably connected to the middle circumference of the central body. The secondary excavation can swing backward around the end connected to the central body to realize a variable diameter cutterhead. The secondary excavation is used to expand excavation or post-excavation.

2. The variable diameter stepped roadheader cutterhead according to claim 1, characterized in that: The connection structure comprises a connection flange (6) on the central body, and the connection flange (6) is connected to a flange on a rotating shaft (16) of a tunnel boring machine.

3. The variable diameter stepped roadheader cutterhead according to claim 1, characterized in that: The central body comprises an annular beam (18), a rear corbel beam (5) fixedly mounted on one side of the annular beam (18), and a front corbel beam (2) fixedly mounted on the other side of the annular beam (18); the first-stage excavation is fixedly mounted on the front corbel beam (2), and the second-stage excavation is rotatably connected to the annular beam (18).

4. The variable diameter stepped roadheader cutterhead according to claim 3, characterized in that: The first-stage excavation comprises a circular front cutterhead (1).

5. The variable diameter stepped roadheader cutterhead according to claim 3, characterized in that: The secondary excavation includes a plurality of variable diameter cutterhead blocks (3), and one end of the variable diameter cutterhead block (3) away from the annular beam (18) is rotatably connected to the connecting structure through an adjusting oil cylinder (4).

6. The variable diameter stepped roadheader cutterhead according to claim 1, characterized in that: The number of the variable diameter cutter disc blocks (3) is 6-8.

7. The variable diameter stepped roadheader cutterhead according to claim 5, characterized in that: The secondary excavation also includes a connecting block (13) for filling the gap between adjacent variable diameter cutterhead blocks (3), and the connecting block (13) is fixedly connected to the variable diameter cutterhead blocks (3) via fixing bolts (14).

8. The variable diameter stepped roadheader cutterhead according to claim 5, characterized in that: A mounting bracket (17) is provided on the annular beam (18), and the variable diameter cutter head block (3) is rotatably connected to the bracket (17) via a rotating shaft (16).

9. The variable diameter stepped roadheader cutterhead according to claim 1, characterized in that: When the secondary excavation is parallel to the primary excavation, it is a stepped cutterhead; when the secondary excavation swings backward to a set limit position, it is a variable diameter cutterhead.

10. A tunneling method using a variable diameter stepped tunnel boring machine cutterhead according to any one of claims 1 to 9, characterized in that: In hard rock formations, the variable diameter cutterhead block (3) of the secondary excavation is kept parallel to the front small cutterhead (1) of the primary excavation, forming a stepped cutterhead. The front small cutterhead (1) first performs basic excavation on the central area of ​​the tunnel, and the variable diameter cutterhead block (3) then cooperates to perform expansion excavation on the surrounding rock formations. In soft and broken formations, the variable diameter cutterhead block (3) of the secondary excavation is swung backward around one end connected to the center body to a set position by adjusting the oil cylinder (4), forming a variable diameter cutterhead, and excavation is performed using the variable diameter. At the same time, the gap between adjacent variable diameter cutterhead blocks (3) is fixed and filled by a special connecting block through a fixing bolt (14).

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