Small-opening panel-type tunnel boring machine cutterhead and tunnel boring machine including the same

Abstract

The present invention provides a small-opening panel-type tunnel boring machine cutterhead and a tunnel boring machine including the same, belonging to the technical field of tunnel engineering construction; including a panel, a cutter and an adjustable sealing plate assembly; a plurality of slag discharge holes are provided on the panel, and the aperture size of a single slag discharge hole is smaller than the particle size through which a slurry pump can pass; and the cross section of a single slag discharge hole is set to be a square, and the vertical section of a single slag discharge hole is set to be a conical trumpet-shaped structure with a small front and a large rear; a cutter is installed on the side end face of the panel close to the tunneling direction; and the adjustable sealing plate assembly is arranged on the end of the panel away from the cutter. By arranging an opening adjustable sealing plate assembly, when the cutterhead of the small-opening panel-type tunnel boring machine is tunneling in a formation with poor stability such as sand, the outer opening is blocked by the sealing plate, and the cutterhead opening rate is reduced to improve the balancing ability of the cutterhead to the face; when the cutterhead is tunneling in a formation with good stability such as clay, the sealing plate is adjusted to increase the cutterhead opening rate to prevent the cutterhead from sticking and improve the cutterhead slag discharge efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel engineering construction, and relates to a small-opening panel-type tunnel boring machine cutter head and a tunnel boring machine comprising the same. Background Art

[0002] As urban underground space is continuously developed and utilized. In this process, the role of mechanical construction is becoming more and more obvious. Shields and pipe jacking machines have been widely used in tunnel projects such as municipal, subway, highway and railway. The existing small-diameter tunnel boring machines below 5 meters have limited space, and the arrangement of spiral machines is limited under the earth pressure mode. In addition, the spiral slag is discontinuous compared to the mud and water slag. The mud and water slag is directly transported to the slag box without waiting for the slag truck. Therefore, small-diameter tunnel boring machines mostly use mud and water slag. The existing small-diameter cutterheads are usually equipped with cone crushing structures, that is, the cutterhead legs cooperate with the shield cone plate to rotate and crush the slag, and the soil bin slag enters the mud pipe through the shield screen plate holes and is output; in order to adapt to different geological environments across the country, designers have designed cutterheads of various forms. This diverse design allows shield machines to adapt to different engineering geological conditions. Existing shield machines have spoke-type, panel-type, composite-type cutterhead structures. When the actual project is in sand, clay, silt and other strata, the existing cutterhead is usually designed with a large opening to prevent the cutterhead from forming mud cakes. However, in strata with poor stability such as soft plastic clay, the cutterhead with a large opening structure cannot provide support for the face, and the face is very easy to be unstable, resulting in surface settlement in the excavation interval. In addition, the slag enters the soil bin in blocks and forms mud balls after stirring, which can easily cause the shield screen plate holes to be blocked, requiring repeated flushing and dredging for a long time, and the slag discharge efficiency is low. In addition, the flushing and dredging process can easily cause the face to collapse. Therefore, in the construction of sand, clay, silt and other strata, how to solve the problems of face stability and slag discharge efficiency of the cutterhead and soil bin is a technical problem that technicians in this field currently need to solve.

[0003] In view of the shortcomings of the above-mentioned technical status, some technicians in this field have conducted relevant research. For example, patent CN216429613U proposes a "cutting disc for a pipe jacking machine to avoid soil accumulation and blockage", which includes a connecting sleeve, a panel is provided on the front of the connecting sleeve, a fishtail knife is provided at the center of the front of the panel, edge rollers are provided on both sides of the front of the panel, and a number of split components are provided between the fishtail knife and the edge rollers. By setting up multiple sets of cutting knives, the soil layer can be cut in many aspects and at a deep level, thereby ensuring the uniformity of the cut soil and preventing the accumulation of soil blocks from causing blockage; however, stones with larger particle sizes need to be fully crushed and cut by the rollers. Due to the small overall opening rate, the opening cannot be changed in different strata. In soft plastic clay and other strata, mud cakes are easily formed. There is a lack of effective stirring measures on the back of the cutter disc, which is prone to blocking the shield sieve plate holes. The overall excavation efficiency in clay and other strata is low. Patent CN218030192U proposed "A shield machine cutterhead suitable for hard plastic clay", including a central cutter box arranged at the center of the cutterhead, and the central cutter box is sequentially provided with concentric inner ring plates, middle ring plates and outer ring plates outward, and four main spokes are connected between the central cutter box and the outer ring plate, and each main spoke and the back of the secondary spoke are connected with a supporting bracket, which is inclined inward and a connecting flange is fixed at the end of the supporting bracket; this scheme has strong structural stability and strong slag improvement ability. Due to the large overall opening, this scheme reduces the risk of mud cake on the cutterhead; but the cutterhead with a large opening structure cannot provide support for the face, and the face is very easy to be unstable, resulting in surface settlement in the excavation interval; Patent CN 213269894U proposed "A Cutterhead for Pipe Jacking Machine", which includes a crushing chamber, a chamber for accommodating the cutterhead at the front end of which is provided with a shell on the outside; a cutterhead, which is located in the chamber, and the cutterhead is rotatably installed in the chamber through a positioning ring, and the front end of the cutterhead is radially formed with a plurality of spokes, and the free end of the spoke is provided with a retaining ring that fits the opening of the chamber. This scheme has a high opening rate, no pressure difference, and a stable overall structure. The connection between the spoke and the retaining ring forms an arc surface, and the cutting surface of the circumferential cutter has the same arc as the arc surface, which can better cut the soil at the edge of the cutterhead. However, this scheme also cannot provide support for the face due to the large opening structure. When the cutterhead is excavating in sandy soil and other strata, landslides and other unstable face situations are prone to occur. The slag enters the soil bin in blocks and forms mud balls after stirring, which easily causes the shield screen plate holes to be blocked, resulting in low slag discharge efficiency. The cutterhead has low excavation efficiency in soft plastic clay, silt and other strata. Summary of the invention

[0004] In order to address the deficiencies in the prior art, the present invention provides a small-opening panel-type tunnel boring machine cutter disc and a tunnel boring machine comprising the same, which are intended to solve the problems of poor face stability and low slag discharge efficiency of the cutter disc and soil bin in construction in sandy, clay, silt and other strata of the existing cutter disc.

[0005] The present invention provides a small-opening panel-type tunnel boring machine cutterhead, a small-opening panel-type tunnel boring machine cutterhead, comprising a panel, a cutter and an adjustable sealing plate assembly;

[0006] A plurality of slag discharge holes are arranged on the panel, and the aperture size of a single slag discharge hole is smaller than the particle size through which the slurry discharge pump can pass; and the cross section of a single slag discharge hole is arranged to be a square, and the vertical section of a single slag discharge hole is arranged to be a conical trumpet-shaped structure with a small front and a large rear;

[0007] A cutter is installed on the side end surface of the panel close to the excavation direction;

[0008] The adjustable sealing plate assembly is arranged on one end of the panel away from the tool; and the adjustable sealing plate assembly comprises a bottom plate and a sealing plate; the bottom plate is arranged on one end of the panel away from the tool, and the sealing plate is connected to the bottom plate.

[0009] Optionally, a plurality of slag discharge holes are arranged in a plurality of rows along both sides of the running track of the tool and are spaced apart from each other.

[0010] Optionally, the cutting tool includes a fishtail center knife, a cutting knife and an edge cutting knife; the fishtail center knife is arranged at the central part of the panel, the cutting knife is provided with a plurality of pieces arranged at intervals from each other, and the distance between two adjacent cutting knives is smaller than the width of the cutting knife; the edge cutting knife is provided with a plurality of pieces evenly arranged on the panel, and the outer edges of the plurality of edge cutting knives overlap with the outer circumference of the panel.

[0011] Optionally, the fishtail center cutter includes a plurality of cutting heads, and the plurality of cutting heads are arranged from near to far from the center of the panel.

[0012] Optionally, the spacing between two adjacent groups of cutting heads is set to 50mm-150mm, and the distance between one group of cutting heads closest to the center of the panel and the center of the panel is set to be within 50mm.

[0013] Optionally, a line connecting the cutting bits disposed on both sides of the central axis of the panel is disposed at an angle less than or equal to 25° to the central axis of the panel.

[0014] Optionally, the plurality of cutters are linearly evenly distributed, and the number of arms of the cutter distribution is an even number.

[0015] Optionally, the number of the edge cutters is less than the number of arms on which the cutters are distributed.

[0016] Optionally, the blades of the cutter and the edge cutter are both configured as horn-shaped structures.

[0017] Optionally, the edge cutter is configured as a trapezoidal structure as a whole.

[0018] As a further solution of the present invention, the small opening panel type roadheader cutter head also includes a flange, a leg, a stirring rod, a support ring and a reinforcing rib plate;

[0019] The panel is connected to the legs via flanges;

[0020] The stirring rod is arranged in the form of a fan-shaped sieve plate, and one end of the stirring rod is fixedly connected to an end of the panel away from the cutter;

[0021] The support ring is provided with a plurality of pieces respectively welded on the peripheral area of ​​one end surface of the panel away from the cutter, and the plurality of support rings cooperate with the shield body in the tunnel boring machine to form a labyrinth structure;

[0022] The reinforcing rib plate is welded to the supporting ring and the panel at the same time.

[0023] The present invention also provides a tunnel boring machine, comprising a shield body, a main drive arranged in the shield body, and a small-opening panel-type tunnel boring machine cutter head as described above;

[0024] The small-opening panel-type tunnel boring machine cutterhead is connected to a main drive.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The present invention provides an open adjustable sealing plate assembly at one end of the panel away from the cutter. When the cutter head of the small-opening panel-type tunnel boring machine is excavating in a stratum with poor stability such as sand, the outer opening is blocked by the sealing plate to reduce the cutter head opening rate and improve the cutter head's ability to balance the tunnel face. When the cutter head is excavating in a stratum with good stability such as clay, the sealing plate is adjusted to increase the cutter head opening rate to prevent the cutter head from sticking and improve the cutter head slag discharge efficiency. Through the above measures, the cutter head can be adapted to excavation in different strata.

[0027] (2) The present invention designs the edge cutters into a trapezoidal structure and arranges them around the cutter disc in a form of larger outside and smaller inside. During the cutting process, the slag is gathered toward the center of the cutter disc to facilitate slag discharge.

[0028] (3) The present invention sets a number of rows of square trumpet-shaped slag discharge holes with a size slightly smaller than the particle size passing through the slurry pump on both sides of the panel tool trajectory, thereby limiting the particle size and preventing hole clogging. After being cut by the tool, the slag enters the soil bin directly through the slag discharge holes without the need for secondary crushing. After entering the soil bin, the slag is directly discharged through the slurry discharge pipe, thereby improving the slag discharge efficiency of the cutter disc and the soil bin.

[0029] (4) The blade disc stirring rod is designed as a fan-shaped sieve plate to replace the traditional columnar structure to improve the stirring rate. At the same time, small square holes are opened on the stirring rod. The soil slag in the soil bin passes through the sieve holes of the stirring rod to form noodle-like lumps, which are then directly discharged through the slurry discharge pipe, which can further improve the slag discharge efficiency of the soil bin slag.

[0030] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0032] Figure 1 It is a schematic front view of a small-opening panel-type tunnel boring machine cutterhead in an embodiment of the present invention;

[0033] Figure 2 yes Figure 1 Side view of

[0034] Figure 3 yes Figure 1 Schematic diagram of the structure of the middle slag discharge hole (where the arrow indicates the excavation direction);

[0035] Figure 4 yes Figure 1 Structural schematic diagram of the adjustable sealing plate;

[0036] Figure 5 yes Figure 4 Schematic diagram of the AA section (where the arrow indicates the excavation direction);

[0037] Figure 6 yes Figure 1 Schematic diagram of the structure of the middle cutter;

[0038] Figure 7 yes Figure 1 Schematic diagram of the structure of the middle and side cutter;

[0039] Figure 8 yes Figure 1 Schematic diagram of the structure of the fishtail center knife;

[0040] Fig. 9 It is a schematic diagram of the opening adjustment of a cutter head of a small-opening panel-type tunnel boring machine in an embodiment of the present invention.

[0041] in:

[0042] 1. Panel, 2. Knife, 21. Fishtail center knife, 22. Cutter, 221. First blade, 23. Side cutter, 231. Second blade, 3. Flange, 4. Leg, 5. Stirring rod, 6. Support ring, 7. Reinforcement rib plate, 8. Adjustable sealing plate assembly, 81. Bottom plate, 82. Sealing plate, 83. Fastening connectors. DETAILED DESCRIPTION

[0043] In order to make the above-mentioned purposes, features and advantages of the present invention more clear and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. It should be noted that the drawings of the present invention are all simplified and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the implementation of the present invention; the "number" mentioned in the present invention is not limited to the specific number in the examples in the accompanying drawings; the directions or positional relationships indicated by "front", "middle", "back", "left", "right", "up", "down", "top", "bottom", "middle", etc. mentioned in the present invention are based on the directions or positional relationships shown in the drawings of the present invention, and do not indicate or imply that the devices or components referred to must have a specific direction, nor can they be understood as limitations on the present invention.

[0044] Example:

[0045] See also Figures 1 to 9 As shown, a small-opening panel-type tunnel boring machine cutterhead provided by the present invention comprises a panel 1, a cutter 2, a flange 3, a leg 4, a stirring rod 5, a support ring 6, a reinforcing rib plate 7 and an adjustable sealing plate assembly 8;

[0046] A cutter 2 is installed on the side end surface of the panel 1 close to the excavation direction;

[0047] The cutter 2 includes a fishtail center cutter 21, a cutter 22 and a side cutter 23; the fishtail center cutter 21 is arranged at the center of the panel 1, and is used to penetrate into the soil first and cut, and improve the fluidity and stirring effect of the soil; the cutter 22 is provided with a plurality of pieces spaced apart from each other, and the distance between two adjacent cutters 22 is less than the width of the cutter 22, so as to ensure that the cutter 22 can cut the entire cross section; the side cutter is provided with a plurality of pieces evenly arranged on the panel 1, and the outer edges of the plurality of side cutters 23 overlap with the outer circumference of the panel 1;

[0048] The panel 1 is connected to the legs 4 via the flange 3;

[0049] The stirring rod 5 is configured in the form of a fan-shaped sieve plate, and one end of the stirring rod 5 is fixedly connected to an end of the panel 1 away from the cutter 2;

[0050] The support ring 6 is welded to the peripheral area of ​​one end surface of the panel 1 away from the cutter 2, and the support ring 6 and the shield body form a labyrinth structure to reduce the mud in the soil bin from flowing into the outside of the shield body from the incision ring position.

[0051] The reinforcing rib plate 7 is welded to the support ring 6 and the panel 1 to enhance the overall rigidity and strength of the cutter disc.

[0052] The adjustable sealing plate assembly 8 is arranged on the end of the panel 1 away from the tool 2; and the adjustable sealing plate assembly 8 includes a base plate 81, a sealing plate 82 and a fastening connector 83; the base plate 81 is welded to the upper part of the end of the panel 1 away from the tool 2, and the sealing plate 82 is connected to the base plate 81 by a fastening connector 83; when the cutter head of the small-opening panel-type tunnel boring machine is excavating in a stratum with poor sand stability, the outer opening is blocked by the sealing plate, the cutter head opening rate is reduced to improve the cutter head's balancing ability on the tunnel face; when the cutter head is excavating in a stratum with good clay stability, the sealing plate is adjusted to increase the cutter head opening rate to prevent the cutter head from sticking and improve the cutter head slag discharge efficiency.

[0053] Preferably, a plurality of slag discharge holes are provided on the panel 1, and the plurality of slag discharge holes are arranged in multiple rows spaced apart from each other along both sides of the running track of the cutter 2. Further preferably, the slag discharge holes close to the cutter 2 are preferably provided in two rows, so as to meet the larger opening rate of the cutter disc while ensuring the strength of the overall structure of the cutter disc.

[0054] Preferably, the aperture size of a single slag discharge hole is smaller than the particle size that the slurry discharge pump can pass through, so as to avoid clogging of the slurry discharge pump. Further preferably, the cross section of a single slag discharge hole is set to be square, so that after the slag contacts the panel 1, the slag discharge hole can scrape the slag, which is beneficial to the overall cutting and slag discharge effect of the cutter head; the vertical section of a single slag discharge hole is set to a conical trumpet-shaped structure with a small front and a large back, so as to limit the particle size and prevent clogging.

[0055] Preferably, the cutter 2 and the panel 1 are connected to each other by welding.

[0056] Preferably, the fishtail center knife 21 includes a plurality of cutting heads, and the plurality of cutting heads are arranged from near to far from the center of the panel 1 .

[0057] Further preferably, according to the different diameter sizes of the cutter head of the small opening panel type tunnel boring machine, the spacing between two adjacent groups of cutting heads is set to 50mm-150mm, and the distance between one group of cutting heads closest to the center of the panel 1 and the center of the panel 1 is set to within 50mm.

[0058] Further preferably, the line connecting the cutting bits disposed on both sides of the central axis of the panel 1 forms an angle of less than or equal to 25° with the central axis of the panel 1 .

[0059] Preferably, a plurality of cutters 22 are linearly and evenly distributed, the tracks of adjacent cutters overlap to achieve full cross-section coverage of the prop, and the number of arms distributed by the cutters 22 is an even number (in this embodiment, the number of arms is preferably set to 4 or 6 evenly distributed). Further preferably, since the slag discharge holes are only set on both sides of the track of the tool 2, the slag enters the soil bin directly through the slag discharge holes after being cut by the tool 2 to prevent hole blockage, when the number of arms distributed by the cutters 22 is 4 or 6, the overall opening rate of the cutter disc is small, which can improve the balance ability of the cutter disc on the face; when the cutter disc is excavating in a stratum with good stability, the number of arms distributed by the cutters 22 can be increased (such as set to 8 or more evenly distributed) to appropriately increase the cutter disc opening rate, prevent the cutter disc from sticking and improve the slag discharge efficiency of the cutter disc; according to different engineering geological conditions, when the cutter disc needs to adapt to a stratum with poor stability, the number of arms distributed by the cutters 22 can be reduced.

[0060] Preferably, the number of the edge cutters 23 is less than the number of arms in which the cutters 22 are distributed.

[0061] Preferably, a first blade 221 is provided at two diagonal positions on the cutting surface of the cutter 22, and the two first blades 221 are connected to the body of the cutter 22 to form a ram's horn structure with a low middle and high ends; a second blade 231 is provided at two diagonal positions on the cutting surface of the side cutter 23, and the two second blades 231 are connected to the body of the side cutter 23 to form a ram's horn structure with a low middle and high ends; forward and reverse bidirectional rotation cutting can be achieved.

[0062] Further preferably, the edge cutter 23 is configured as a trapezoidal structure as a whole and is arranged in a form of being larger outside and smaller inside, so that the slag is gathered toward the center of the cutter disc during the cutting process to facilitate slag discharge.

[0063] As a further embodiment of the present invention, the tool 2 includes other structures besides the structure described above, and the other structures refer to the prior art.

[0064] Preferably, a sufficient contact length is set on the side of the stirring rod 5 close to the cutter head panel 1, so that there is a sufficient root welding length between the stirring rod 5 and the panel 1 to ensure the welding strength.

[0065] Further preferably, the stirring range of the stirring rod 5 on one side of the slurry discharge pipe completely covers the slurry discharge area, and the size of the square hole set on the stirring rod 5 is consistent with the size of the slag discharge hole set on the panel 1. On the premise of ensuring the structural strength of the stirring rod 5, as many square holes as possible are set to ensure the stirring rate while ensuring the fluidity of the soil slag in the soil bin.

[0066] Further preferably, the stirring rod 5 is arranged as close to the periphery as possible with a certain gap reserved between it and the inner side of the shield body, so as to avoid the sedimentation of the soil bin and the accumulation of slag in the lower part of the soil bin.

[0067] Preferably, a groove is provided on the back side of the outer opening of the panel 1, and the bottom plate 81 is welded to the outer side of the opening of the groove on the back side of the panel 1, and sufficient installation space for the sealing plate 82 is reserved between the panel 1 and the bottom plate 81; the sealing plate 82 has reserved traction parts to enable left and right movement on the opening side.

[0068] Further preferably, the reserved traction member that moves left and right can be set to a manual, electric or pneumatic structure such as a wire rope, a slide rail, etc., but is not limited to it.

[0069] As a further embodiment of the present invention, the small-opening panel-type tunnel boring machine cutter head includes other structures in addition to the above-mentioned structure, and the other structures refer to the prior art.

[0070] The specific process of using the above-mentioned small opening panel tunnel boring machine cutter head to work is as follows:

[0071] When the cutterhead is excavating in a stratum with poor stability such as sand, the sealing plate moves toward the opening side and is connected and fixed to the panel through a fastening connector to seal the outer opening of the cutterhead, thereby reducing the cutterhead opening rate and improving the balancing ability of the cutterhead on the tunnel face;

[0072] When the cutterhead is excavating in a relatively stable stratum such as clay, the fastening connectors between the sealing plate and the face plate are removed, the sealing plate is moved away from the opening side and connected to the bottom plate through the fastening connectors, so as to increase the opening rate of the cutterhead, prevent the cutterhead from sticking and improve the slag removal efficiency of the cutterhead.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A small opening panel type tunnel boring machine cutter head, characterized in that: It comprises a panel (1), a cutter (2), an adjustable sealing plate assembly (8) and a stirring rod (5); A plurality of slag discharge holes are provided on the panel (1), the aperture size of each slag discharge hole being smaller than the particle size through which the slurry discharge pump can pass; and the cross section of each slag discharge hole is set to be a square, and the vertical section of each slag discharge hole is set to be a conical trumpet-shaped structure with a small front and a large rear; A cutter (2) is installed on the side end surface of the panel (1) close to the excavation direction; The adjustable sealing plate assembly (8) is arranged on an end of the panel (1) away from the tool (2); and the adjustable sealing plate assembly (8) comprises a bottom plate (81) and a sealing plate (82); the bottom plate (81) is arranged on an end of the panel (1) away from the tool (2), and the sealing plate (82) is connected to the bottom plate (81); The stirring rod (5) is arranged in the form of a fan-shaped sieve plate, and one end of the stirring rod (5) is fixedly connected to an end of the panel (1) away from the knife (2).

2. The small opening panel type tunnel boring machine cutter head according to claim 1, characterized in that: A plurality of slag discharge holes are arranged in a plurality of rows at intervals along both sides of the running track of the cutter (2).

3. The small opening panel type tunnel boring machine cutter head according to claim 2, characterized in that: The cutting tool (2) comprises a fishtail center knife (21), a cutting knife (22) and a side cutting knife (23); the fishtail center knife (21) is arranged at the center of the panel (1); the cutting knife (22) is provided with a plurality of pieces arranged at intervals from each other, and the distance between two adjacent cutting knives (22) is smaller than the width of the cutting knife (22); the side cutting knife (23) is provided with a plurality of pieces evenly arranged on the panel (1), and the outer edges of the plurality of side cutting knives (23) overlap with the outer circumference of the panel (1).

4. The small opening panel type tunnel boring machine cutter head according to claim 3, characterized in that: The fishtail center knife (21) comprises a plurality of cutting heads, and the plurality of cutting heads are arranged in an arrangement from near to far from the center of the panel (1).

5. The small opening panel type tunnel boring machine cutter head according to claim 4, characterized in that: The spacing between two adjacent groups of cutting heads is set to 50 mm-150 mm, and the distance between one group of cutting heads closest to the center of the panel (1) and the center of the panel (1) is set to be within 50 mm; The connecting line between the cutting bits arranged on both sides of the central axis of the panel (1) is arranged at an angle of less than or equal to 25° with the central axis of the panel (1).

6. The small-opening panel-type tunnel boring machine cutterhead according to claim 5, characterized in that: The plurality of cutters (22) are linearly evenly distributed, and the number of arms of the cutters (22) is an even number; The number of the edge cutters (23) is smaller than the number of arms on which the cutters (22) are distributed.

7. The small opening panel type tunnel boring machine cutter head according to claim 6, characterized in that: The blades of the cutting knife (22) and the edge cutting knife (23) are both arranged in a horn-shaped structure. The edge cutter (23) is configured as a trapezoidal structure as a whole.

8. The small-opening panel-type tunnel boring machine cutterhead according to any one of claims 5 to 7, characterized in that: It also includes a flange (3), a leg (4), a support ring (6) and a reinforcing rib plate (7); The panel (1) is connected to the legs (4) via a flange (3); The support ring (6) is provided with a plurality of pieces respectively welded to the peripheral area of ​​one end surface of the panel (1) away from the cutter (2), and the plurality of support rings (6) cooperate with the shield body in the tunnel boring machine to form a labyrinth structure; The reinforcing rib plate (7) is welded to the supporting ring (6) and the panel (1) at the same time.

9. A tunnel boring machine, characterized in that: It comprises a shield body, a main drive arranged in the shield body and a cutter head of a small-opening panel-type tunnel boring machine as claimed in claim 8; The small-opening panel-type tunnel boring machine cutterhead is connected to a main drive.

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