A hard rock tunnel boring machine with an arched crown and straight wall cross-section

Abstract

The top-arc straight-wall cross-section hard rock tunnel boring machine provided by the present invention includes a machine body, a main beam arranged in the middle of the machine body and moving synchronously with the machine body and extending backward, a circular main cutter head rotatably arranged at the front end of the machine body, a main drive arranged in the machine body and located between the main cutter head and the main beam for driving the main cutter head to rotate, and an auxiliary cutter head. The main cutter head is used to excavate a circular cross-section, the upper half of the circular cross-section forms a top arc, the auxiliary cutter head is in a drum shape and is located at the rear end of the machine body, the auxiliary cutter head is swingably connected to both sides of the bottom of the main beam, its swing angle is ≥90°, its swing plane is parallel to the circular cross-section, and its swing radius is variable. When the main cutter head advances forward, the auxiliary cutter head excavates the lower half of the circular cross-section by swinging back and forth and cooperating with the change of the swing radius to shape a straight wall. This tunnel boring machine does not waste the tunnel earthwork excavation volume, can adapt to hard rock formation tunneling, is simple and convenient to transform, has high tunneling efficiency, and good operation reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel boring machines, and particularly relates to an arch-top straight-wall section hard rock tunnel boring machine. Background Art

[0002] A tunnel boring machine is a new and advanced tunnel construction machine that uses rotary cutters to excavate, simultaneously break the surrounding rock in the tunnel and drive, forming the entire tunnel section. In China, the tunnel boring machine used for soft soil strata is customarily called a shield, and the tunnel boring machine used for rock strata is called a TBM.

[0003] As a construction tool for rock stratum excavation, tunnel boring machines (TBMs) have been widely used in industries such as railways, highways, water conservancy, municipal engineering, and coal. The excavation sections of traditional tunnel boring machines (TBMs) are all circular. However, from the perspective of the space utilization rate of the tunnel section, the most suitable tunnel section for projects such as railways and highways is the "gateway" shape. The existing excavation method is to backfill after excavating a circular section. As Figure 1 shown, although this method can preserve the integrity of the cutter head of the tunnel boring machine (TBM) and adapt to the tunneling of hard rock strata with a compressive strength above 100 MPa, the subsequent backfilling operation is time-consuming and laborious. At the same time, a tunnel boring machine (TBM) with a larger diameter also needs to be used for tunneling, resulting in a large waste of tunnel earthwork excavation volume.

[0004] To solve this problem, tunnel boring machines with the ability to excavate special-shaped sections have emerged on the market. These tunnel boring machines are basically realized by two structures:

[0005] First, replace the large-diameter main cutter head with multiple small-diameter cutter heads, and use the excavation trajectories of the multiple small-diameter cutter heads to fit the special-shaped section. Since the structure of the small-diameter cutter head is relatively thin and the support strength is low, it is difficult to adapt to the tunneling of hard rock strata with a relatively high compressive strength. It has only appeared in the Baicheng Tunnel of the Meng-Hua Railway in actual applications, and the compressive strength of the excavated strata is lower than 70 MPa.

[0006] Second, set a telescopic profiling cutter beam on the large-diameter main cutter head, and then set a part of the hob on the profiling cutter beam. When the main cutter head rotates, use the telescopic movement of the profiling cutter beam to fit the special-shaped section. However, the profiling cutter beam occupies a large space on the main cutter head, changing the original integral design of the main cutter head and reducing its strength. At the same time, the method of excavating the special-shaped section and the original circular section simultaneously during tunneling does not reduce the pressure on the profiling cutter beam and the main cutter head, resulting in that this type of tunnel boring machine is also difficult to adapt to the tunneling operation of hard rock strata.

[0007] In addition, both of these two tunnel boring machines need to change the original shape of the main cutter head, making it difficult to retain the originally strong tunneling ability in hard rock formations. At the same time, the transformation process is time-consuming and laborious. After the transformation, the components for driving, transmission, and control at the main cutter head increase significantly, and the installation positions are crowded, resulting in very inconvenient debugging and maintenance, seriously affecting the tunneling efficiency and the reliability of operation. Summary of the Invention

[0008] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an arc-top straight-wall section hard rock tunnel boring machine that does not waste the amount of tunnel earth excavation, can adapt to tunneling in hard rock formations, is simple and convenient to transform, has high tunneling efficiency, and good operation reliability.

[0009] To achieve the above object, the technical solution adopted by the present invention is that an arc-top straight-wall section hard rock tunnel boring machine includes:

[0010] A cylindrical body;

[0011] A main beam provided in the middle of the body and extending backward, and the main beam moves synchronously with the body;

[0012] A circular main cutter head rotatably provided at the front end of the body, the front surface of the main cutter head is provided with rotatable main hob cutters, the main cutter head is used to excavate a circular cross-section, and the upper half of the circular cross-section constitutes the arc top in the arc-top straight-wall section;

[0013] A main drive provided in the body and located between the main cutter head and the main beam, and the main drive is used to drive the main cutter head to rotate;

[0014] And, a sub-cutter head;

[0015] The sub-cutter head is in the shape of a drum, the outer wall of the sub-cutter head is provided with rotatable sub-hob cutters, the sub-cutter head is located at the rear end of the body, the sub-cutter head is swingably connected to both sides of the bottom of the main beam, the swing angle of the sub-cutter head is ≥90°, the swing plane of the sub-cutter head is parallel to the circular cross-section, the swing radius of the sub-cutter head is variable, and when the main cutter head tunnels forward, the sub-cutter head excavates the lower half of the circular cross-section by swinging back and forth and cooperating with the change of the swing radius to trim out the straight wall in the arc-top straight-wall section.

[0016] Preferably, the sub-cutter head includes support plates located at the front and rear sides, a drum rotatably mounted on the support plates, a sub-drive for driving the drum to rotate, and a telescopic arm. A swing seat that can swing is provided on the main beam, the swing axis line of the swing seat extends in the front-rear direction, one end of the telescopic arm is connected to the support plate, and the other end is connected to the swing seat.

[0017] Further preferably, both ends of the telescopic arm are respectively rotatably connected to the support plate and the swing seat, and the rotation planes of the telescopic arm relative to the support plate and the swing seat are both perpendicular to the circular cross-section.

[0018] Further preferably, the rotation angles of the telescopic arm relative to the support plate and the swing seat are ±3°.

[0019] Further preferably, a first driving member for driving the telescopic arm to expand and contract is provided inside the telescopic arm, and the first driving member changes the swing radius of the secondary cutter head by driving the telescopic arm to expand and contract.

[0020] Further preferably, the first driving member includes a telescopic hydraulic cylinder. During the process of changing the swing radius of the secondary cutter head, the telescopic arm first extends and then contracts.

[0021] Further preferably, during the process of changing the swing radius of the secondary cutter head, the telescopic amplitude of the telescopic arm located on the front side is smaller than that of the telescopic arm located on the rear side, so that the drum is in an inclined state with the front end close to the main beam and the rear end far from the main beam.

[0022] Further preferably, a second driving member for driving the swing seat to swing is further provided on the main beam, and the second driving member includes a swing hydraulic cylinder.

[0023] Preferably, the secondary hob is a disc hob. When the secondary cutter head excavates the lower half of the circular cross-section, the secondary hob cuts the rock by using the principle of squeezing rock breaking and finally forms the straight wall.

[0024] Preferably, the arc-top straight-wall section hard rock tunnel boring machine further includes a muck collection and conveying device, and the muck collection and conveying device is used to collect the rock debris cut by the secondary cutter head and transport it outside the tunnel. The muck collection and conveying device includes a belt conveyor.

[0025] Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art:

[0026] 1. First, use the main cutter head to excavate the circular cross-section, and then use the secondary cutter head to excavate the lower half of the circular cross-section, and then shape the arc-top straight-wall section. In this way, there is no need to change the overall structure of the main cutter head, the integrity of the main cutter head can be retained, and the performance of the main cutter head is not affected. At the same time, the excavation surface corresponding to the secondary cutter head is actually an open surface, which can greatly reduce the pressure on the secondary cutter head and adapt to the tunneling operation in hard rock formations with a compressive strength of more than 100 MPa.

[0027] 2. It can achieve the one-time excavation and forming of the arc-top straight-wall section. The selection of the main cutter head diameter can be more reasonable, and there is no need for backfilling operations, without wasting the tunnel earthwork excavation volume, effectively shortening the construction period and reducing the construction cost.

[0028] 3. Since the auxiliary cutter head is located at the rear end of the machine body and is swing-connected to both sides of the bottom of the main beam, it has no relation with the main cutter head. It can simply and conveniently transform the existing tunnel boring machine with a circular section. The components added during the transformation are few, the debugging and maintenance are convenient, and the tunneling efficiency and reliability after the transformation are high. Brief Description of the Drawings

[0029] Figure 1 It is a schematic diagram of the operation of backfilling after excavating a circular section in the prior art.

[0030] Figure 2 It is a schematic cross-sectional view during the tunneling of the first embodiment of the present invention.

[0031] Figure 3 It is Figure 1 The rear view schematic diagram of , and for easy observation, components such as the main drive and the main cutter head are hidden.

[0032] Figure 4 It is Figure 1 The structural schematic diagram at the auxiliary cutter head in , at this time, the telescopic arm is in the extended state.

[0033] Figure 5 It is the structural schematic diagram at the auxiliary cutter head in the second embodiment of the present invention.

[0034] Figure 6 It is the structural schematic diagram at the auxiliary cutter head in the third embodiment of the present invention.

[0035] Wherein: 10. Machine body; 20. Main beam; 21. Swing seat; 22. Second driving member; 30. Main cutter head; 31. Main hob; 32. Circular section; 40. Main drive; 50. Auxiliary cutter head; 51. Auxiliary hob; 52. Support plate; 53. Drum; 54. Auxiliary drive; 55. Telescopic arm; 551. First driving member; 60. Muck collection and conveying device; 71. Arc top; 72. Straight wall; 80. Backfill area. Detailed Embodiment

[0036] The following elaborates on the preferred embodiments of the present invention in detail with reference to the drawings, so that the advantages and features of the present invention are more easily understood by those skilled in the art, thereby making the protection scope of the present invention more clearly defined.

[0037] Embodiment 1

[0038] As Figures 2 to 4As shown in the figure, the top-arc straight-wall section hard rock tunnel boring machine provided by the present invention includes: a machine body 10, a main beam 20, a main cutter head 30, a main drive 40, and a secondary cutter head 50. Among them, the machine body 10 is in a cylindrical shape; the main beam 20 is a propulsion main beam, which is arranged in the middle of the machine body 10 and extends backward, and the main beam 20 moves synchronously with the machine body 10; the main cutter head 30 is circular, and the main cutter head 30 is rotatably arranged at the front end of the machine body 10. A plurality of rotatable main rolling cutters 31 are provided on the front surface of the main cutter head 30. The rotation direction of the main rolling cutter 31 is determined according to the position where the main rolling cutter 31 is located, so as to extend the service life as much as possible while ensuring the rock-breaking effect. The main cutter head 30 is used to excavate a circular section 32, and the upper half of the circular section 32 constitutes the arc top 71 in the top-arc straight-wall section; the main drive 40 is arranged in the machine body 10 and is located between the main cutter head 30 and the main beam 20. The main drive 40 is used to drive the main cutter head 30 to rotate, and the main drive 40 can drive the main cutter head 30 to rotate by existing methods such as motors, speed reducers, and gear combinations; the secondary cutter head 50 is in a drum shape, and rotatable secondary rolling cutters 51 are provided on the outer wall of the secondary cutter head 50. The secondary cutter head 50 is located at the rear end of the machine body 10. There are two groups of secondary cutter heads 50, and these two groups of secondary cutter heads 50 are swingably connected to both sides of the bottom of the main beam 20 and are symmetrically arranged. The swing plane of the secondary cutter head 50 is parallel to the circular section 32, and the swing radius of the secondary cutter head 50 is variable. When the main cutter head 30 advances forward, the secondary cutter head 50 excavates the lower half of the circular section 32 by swinging back and forth and cooperating with the change of the swing radius to shape the straight wall 72 in the top-arc straight-wall section. The swing angle of the secondary cutter head 50 is very important. If this angle is too large, it will affect the overall tunneling efficiency. If this angle is too small, it is difficult to shape the straight wall 72. Preferably, this angle is 90°-100°. In this embodiment, this angle is 95°. Specifically, the secondary cutter head 50 has a first limit position and a second limit position. When the secondary cutter head 50 swings to the vertical downward direction and continues to swing 2.5° in the direction close to the other secondary cutter head 50, the secondary cutter head 50 reaches the first limit position. When the secondary cutter head 50 swings to the horizontal direction and continues to swing upward 2.5°, the secondary cutter head 50 reaches the second limit position.

[0039] The advantages of such a setting are as follows:

[0040] 1. There is no need to change the overall structure of the main cutter head, which can retain the integrity of the main cutter head and does not affect the performance of the main cutter head. At the same time, the actual excavation surface corresponding to the secondary cutter head is an open surface, which can greatly reduce the pressure borne by the secondary cutter head and adapt to the tunneling operation in hard rock formations with a compressive strength of more than 100 MPa.

[0041] 2. It can realize the one-time excavation and forming of the top-arc straight-wall section. The selection of the diameter of the main cutter head can be more reasonable, and there is no need to carry out backfilling operations, which does not waste the tunnel earthwork excavation volume, effectively shortens the construction period, and reduces the construction cost.

[0042] 3. It can simply and conveniently transform the existing tunnel boring machine with a circular cross-section. The components added during the transformation are few, the debugging and maintenance are convenient, and the tunneling efficiency and reliability after the transformation are high.

[0043] In this embodiment, the auxiliary cutter head 50 includes support plates 52 located on the front and rear sides, a roller 53 rotatably mounted on the support plates 52, an auxiliary drive 54 for driving the roller 53 to rotate, and a telescopic arm 55. The auxiliary hob 51 is rotatably arranged on the outer wall of the roller 53. The rotation direction of the auxiliary hob 51 is determined according to the position where the auxiliary hob 51 is located, so as to extend the service life as much as possible while ensuring the rock-breaking effect. The auxiliary drive 54 is arranged on the side of the support plate 52 away from the roller 53. The auxiliary drive 54 can adopt the cooperation of a motor and a reducer to drive the roller 53 to rotate. One end of the telescopic arm 55 is connected to the support plate 52, and the other end is connected to the swing seat 21. The swing seat 21 is swingably arranged on the main beam 20. The swing axis line of the swing seat 21 extends in the front-rear direction to realize the swing connection between the auxiliary cutter head 50 and the main beam 20. Further, a second drive member 22 for driving the swing seat 21 to swing is also provided on the main beam 20. The second drive member 22 is a swing-type hydraulic cylinder.

[0044] In this embodiment, a first drive member 551 for driving the telescopic arm 55 to expand and contract is arranged inside the telescopic arm 55. The first drive member 551 realizes the change of the swing radius of the auxiliary cutter head 50 by driving the telescopic arm 55 to expand and contract. Further, the first drive member 551 is a telescopic hydraulic cylinder. During the change of the swing radius of the auxiliary cutter head 50, the telescopic arm 55 first extends and then contracts.

[0045] In this embodiment, the auxiliary hob 51 is a disc hob. When the auxiliary cutter head 50 excavates the lower half of the circular cross-section 32, the auxiliary hob 51 cuts the rock using the principle of extrusion rock breaking and finally forms a straight wall 72.

[0046] In this embodiment, the arc-top straight-wall cross-section hard-rock tunnel boring machine further includes a muck collection and conveying device 60. The muck collection and conveying device 60 is used to collect the rock debris cut by the auxiliary cutter head 50 and transport it outside the tunnel. The muck collection and conveying device 60 is a belt conveyor.

[0047] It should be noted that due to the limitation of the swing angle of the auxiliary cutter head 50, there is a protruding part at the connection between the straight wall 72 and the circular cross-section 32. The size of this protruding part is small and can be removed before the subsequent segment assembly operation, or directly flattened by the segment during the segment assembly, which will not affect the finally formed arc-top straight-wall cross-section.

[0048] Embodiment Two

[0049] As Figure 5As shown, Example 2 is basically the same as Example 1, except that in Example 2, both ends of the telescopic arm 55 are rotatably connected to the support plate 52 and the swing seat 21 respectively. The rotation plane of the telescopic arm 55 relative to the support plate 52 and the rotation plane of the telescopic arm 55 relative to the swing seat 21 are both perpendicular to the circular cross-section 32.

[0050] The advantage of this setting is that it can make the roller 53, the telescopic arm 55, and the main beam 20 form a parallelogram mechanism. When the secondary cutter head 50 excavates the lower half of the circular cross-section 32, if it encounters an area where the hardness suddenly increases, the parallelogram mechanism can be deformed to swing the roller 53 backward and upward, so as to avoid this area and prevent damage to the secondary cutter head 50, the secondary hob 51, and the telescopic arm 55, ensuring the tunneling efficiency.

[0051] The rotation angle of the telescopic arm 55 relative to the support plate 52 and the swing seat 21 should not be too large or too small. If it is too large, the secondary cutter head 50 is likely to swing backward and upward excessively under the action of inertia, affecting the excavation effect of the lower half of the circular cross-section 32. If it is too small, it is difficult to play the role of avoidance. In this embodiment, this angle is ±3°.

[0052] It should be noted that after passing through the area where the hardness suddenly increases, if the resistance in the front-back direction received by the secondary hob 51 is small, the parallelogram mechanism can be reset by its own weight and in cooperation with the swing of the secondary cutter head 50. If the resistance in the front-back direction received by the secondary hob 51 is large, it can be forcibly reset by setting a return torsion spring at the rotational connection of the end of the telescopic arm 55, etc.

[0053] Example 3

[0054] As Figure 6 shown, Example 3 is basically the same as Example 2, except that in Example 3, during the process of the change of the swing radius of the secondary cutter head 50, the telescopic amplitude of the telescopic arm 55 located on the front side is smaller than the telescopic amplitude of the telescopic arm 55 located on the rear side, making the roller 53 in an inclined state where the front end is close to the main beam 20 and the rear end is far from the main beam 20. The advantage of this setting is that it can make the secondary hobs 51 distributed along the front-back direction on the roller 53 cut the rock step by step, making the single cutting amount of all secondary hobs 51 roughly equivalent, thereby extending their service life. The inclination angle (relative to the axis line of the main beam 20) of this inclined state needs to be determined comprehensively according to the length of the roller 53 and the telescopic amplitude of the telescopic arm 55 located on the rear side, and usually does not exceed 5°.

[0055] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly. It cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. An arc-top straight-wall cross-section hard-rock tunnel boring machine, comprising: Cylindrical body; A main beam provided in the middle of the body and extending backward, the main beam moving synchronously with the body; A circular main cutter head rotatably provided at the front end of the body, a rotatable main hob provided on the front surface of the main cutter head, the main cutter head being used to excavate a circular cross-section, the upper half of the circular cross-section constituting the arch crown of the arch crown straight wall cross-section; A main drive provided in the body and located between the main cutter head and the main beam, the main drive being used to drive the main cutter head to rotate; And a secondary cutter head; It is characterized in that: The secondary cutter head is in a drum shape, a rotatable secondary hob is provided on the outer wall of the secondary cutter head, the secondary cutter head is located at the rear end of the body, the secondary cutter head is swingably connected to both sides of the bottom of the main beam, the swing angle of the secondary cutter head ≥ 90°, the swing plane of the secondary cutter head is parallel to the circular cross-section, the swing radius of the secondary cutter head is variable, when the main cutter head advances forward, the secondary cutter head excavates the lower half of the circular cross-section by swinging back and forth and cooperating with the change of the swing radius to shape the straight wall in the arch crown straight wall cross-section; The secondary cutter head includes support plates located at the front and rear sides, a drum rotatably mounted on the support plates, a secondary drive for driving the drum to rotate, and a telescopic arm. A swing seat is provided on the main beam and can swing, the swing axis of the swing seat extends in the front-rear direction, one end of the telescopic arm is connected to the support plate, and the other end is connected to the swing seat; A first driving member for driving the telescopic arm to expand and contract is provided in the telescopic arm, and the first driving member realizes the change of the swing radius of the secondary cutter head by driving the telescopic arm to expand and contract; During the change of the swing radius of the secondary cutter head, the telescopic amplitude of the telescopic arm located at the front side is smaller than that of the telescopic arm located at the rear side, so that the drum is in an inclined state with the front end close to the main beam and the rear end far from the main beam.

2. The arc-top straight-wall cross-section hard-rock tunnel boring machine according to claim 1, characterized in that: Both ends of the telescopic arm are respectively rotatably connected to the support plate and the swing seat, and the rotation plane of the telescopic arm relative to the support plate and the rotation plane of the telescopic arm relative to the swing seat are both perpendicular to the circular cross-section.

3. The arc-top straight-wall cross-section hard-rock tunnel boring machine according to claim 2, characterized in that: The rotation angle of the telescopic arm relative to the support plate and the swing seat is ±3°.

4. The arc-top straight-wall cross-section hard-rock tunnel boring machine according to claim 1, characterized in that: The first driving member includes a telescopic hydraulic cylinder. During the change of the swing radius of the secondary cutter head, the telescopic arm first extends and then contracts.

5. The arc-top straight-wall cross-section hard-rock tunnel boring machine according to claim 1, characterized in that: A second driving member for driving the swing seat to swing is also provided on the main beam, and the second driving member includes a swing hydraulic cylinder.

6. The arc-top straight-wall cross-section hard-rock tunnel boring machine according to claim 1, characterized in that: The secondary hob is a disc hob. When the secondary cutter head excavates the lower half of the circular cross-section, the secondary hob cuts the rock by using the principle of squeezing rock breaking and finally forms the straight wall.

7. The arc-top straight-wall cross-section hard-rock tunnel boring machine according to claim 1, characterized in that: The arch crown straight wall cross-section hard rock tunnel boring machine further includes a muck collection and conveying device for collecting the rock debris cut by the secondary cutter head and transporting it outside the tunnel, and the muck collection and conveying device includes a belt conveyor.

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