TBM hob cutter ring machining method

Abstract

A TBM hob cutter ring machining method belongs to the technical field of TBM cutters, a TBM hob cutter ring comprises a cutter ring base body, a cutter hub mounting hole is formed in the middle of the cutter ring base body, two sets of flat top cutter rings and two sets of inserted tooth cutter rings are evenly distributed on the surface of the cutter ring base body in the circumferential direction of the cutter ring base body, and the two sets of flat top cutter rings and the two sets of inserted tooth cutter rings are arranged in a staggered mode. The top of the flat top cutter ring and the top of the inserted tooth cutter ring are located on the same circumferential curved surface; the TBM hobbing cutter ring machining method comprises the six steps of semi-finished product machining, rough machining, quenching treatment, tempering treatment, surface hardening treatment on an inserted tooth cutter ring and finish machining. The flat top cutter rings and the inserted tooth cutter rings are arranged in a staggered mode, so that rock cracks are fully expanded, the penetration degree is improved, the rock breaking specific energy is reduced, and the rock breaking efficiency is improved; and meanwhile, the wear resistance and the service life of the inserted cutter ring can be improved and prolonged through surface hardening treatment of the inserted cutter ring.

Description

Technical Field

[0001] The present invention belongs to the technical field of TBM cutters, and more specifically, relates to a method for machining a TBM hob cutter ring. Background Art

[0002] A TBM (Tunnel Boring Machine) is a factory - type assembly - line tunnel construction equipment that integrates construction processes such as tunneling, support, and muck removal. It is especially suitable for the construction of deep - buried long tunnels under complex geographical and geological conditions, and has the advantages of high tunneling speed, environmental protection, high efficiency, and high safety performance. It is widely used in tunnel projects such as railways, hydropower, transportation, mines, and municipal engineering, and is one of the key technologies in the field of tunnel construction.

[0003] For example, the opening of Shenzhen Metro Line 10 adopted TBM technology, which solved the complex geological and construction problems such as high rock formation hardness, and the need to pass under Chicken Ridge Mountain and the Xiamen - Shenzhen Railway. As one of the core components of the TBM, the hob plays a crucial role in rock breaking and tunneling. The hob is installed on the cutter head, and the hydraulic push rod pushes the cutter head to the tunneling face, pressing the hob tightly against the tunneling face. Under the thrust of the propulsion system and the torque of the cutter head system, the hob cuts the rock mass. When the thrust generated by the hydraulic rod is greater than the compressive strength of the rock mass on the tunneling face, the hob penetrates the rock, and multiple grooves are formed on the tunneling face by the extrusion of the hob. As the hydraulic system continues to push forward, the cracks deepen and expand continuously. Once the force applied by the equipment to the tunneling face is greater than the shear and tensile strength of the rock, the rock on the tunneling face will fall off, thus completing rock breaking.

[0004] However, there are some disadvantages in the existing hob cutter rings, namely, flat - top cutter rings and dome - top cutter rings. For example:

[0005] The flat - top cutter ring ( Figure 2 as shown) has a low penetration rate, slow propulsion speed, a large contact area with the rock, a high specific energy of rock breaking, excessive rock fragmentation, a large dense core area, an obvious slag retention effect, and is prone to typical three - body abrasive wear. As a result, serious plastic deformation or brittle fracture occurs on the surface of the cutter ring.

[0006] The dome - top cutter ring ( Figure 3 as shown) has weak crack propagation ability and is prone to local wear; the slag retention effect is obvious.

[0007] These series of disadvantages seriously affect the overall tunneling efficiency of the TBM. Therefore, it is necessary to design the structure of the hob cutter ring to overcome the above - mentioned disadvantages and improve the working efficiency of the TBM. Summary of the Invention

[0008] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a method for machining the cutter head of a TBM, which is used to solve the technical problem of low overall tunneling efficiency of the TBM in the prior art.

[0009] To achieve the above object and other related objects, the present invention provides a method for machining the cutter head of a TBM. The cutter head of the TBM includes a cutter head matrix, a cutter hub mounting hole is provided in the middle of the cutter head matrix, and two groups of flat cutter heads and two groups of insert cutter heads are evenly distributed along the circumferential direction of the outer edge of the cutter head matrix. The two groups of flat cutter heads and the two groups of insert cutter heads are arranged alternately, and the tops of the flat cutter heads and the insert cutter heads are on the same circumferential curved surface.

[0010] The machining method includes the following steps:

[0011] 1) Semi-finished product machining: Cast the material to prepare the cutter head blank, and machine it into two groups of flat cutter heads and two groups of insert cutter heads that are evenly distributed and arranged alternately on the outer edge of the cutter head blank.

[0012] 2) Rough machining: Use turning and milling equipment to perform rough machining on the cutter head blank to remove the excess allowance on the cutter head blank.

[0013] 3) Quenching treatment: Quench the cutter head after rough machining, and perform heat preservation treatment after quenching. Among them, the time of heat preservation treatment is 1-2 minutes of heat preservation per millimeter of cutter head thickness.

[0014] 4) Tempering treatment: Perform two tempering-heat preservation treatments on the quenched cutter head.

[0015] 5) Hardening treatment on the tooth edge surface of the insert cutter head: During the hardening treatment, use a high-temperature-resistant ceramic fiber board or graphite board to shield the flat cutter head.

[0016] 6) Finish machining

[0017] Preferably in any of the above solutions, the determination method of the tooth top spacing between two adjacent tooth edges in each group of insert cutter heads in 1) is coupled by the following three methods:

[0018] (1) Rock hardness classification adaptation

[0019] For hard rock formations, the tooth top spacing between two adjacent tooth edges is 30-50 mm;

[0020] For soft rock formations or high confining pressure working conditions, the tooth top spacing between two adjacent tooth edges is 20-40 mm;

[0021] (2) Tool structure matching

[0022] The minor axis of the tooth edge has a positive correlation adjustment relationship with the tooth top spacing, specifically:

[0023] For every 5 mm increase in the short axis of the tooth blade, the tooth tip spacing synchronously increases by 5 mm;

[0024] (3) Construction parameter constraints

[0025] When 2 ≤ a < 4, 10 < b ≤ 15;

[0026] When 4 < a ≤ 6, 6 < b ≤ 12;

[0027] When a = 4, 6 ≤ b ≤ 10;

[0028] Among them,

[0029] a is the penetration depth of the tooth blade;

[0030] b is the ratio of the tooth tip spacing to the penetration depth.

[0031] Preferably in any of the above solutions, in the above (3), the quenching temperature of the quenching treatment is 820 - 850 °C, and the quenching medium is oil or high-speed gas.

[0032] Preferably in any of the above solutions, in the above (4), the tempering temperature of the tempering treatment is 200 - 250 °C, and the holding time is 1 - 2 h.

[0033] Preferably in any of the above solutions, in the above (5), the hardening treatment method is carburizing the surface of the tooth blade of the insert cutter ring. Among them, the carburizing temperature of the carburizing treatment is 900 - 950 °C, the carburizing time is 2 - 6 h, and the carbon potential is 0.8% - 1.2%.

[0034] Preferably in any of the above solutions, in the above (5), the hardening treatment method is nitriding the surface of the tooth blade of the insert cutter ring. Among them, the nitriding temperature of the nitriding treatment is 500 - 550 °C, the nitriding time is 2 - 5 h, and the nitrogen potential is 0.3% - 0.6%.

[0035] As described above, a TBM hob cutter ring of the present invention has the following beneficial effects:

[0036] 1. In the present invention, through the staggered arrangement of the flat-top cutter ring and the insert cutter ring, the rock cracks are fully expanded, the penetration depth is increased, the specific energy of rock breaking is reduced, and the rock breaking efficiency is improved.

[0037] 2. In the present invention, the setting of the insert cutter ring reduces the contact area between the hob and the rock, reduces excessive rock fragmentation, and due to the special structure of the tooth blade, a good initial crack can be formed with a smaller cutter head thrust.

[0038] 3. In the present invention, the setting of the tooth gap of the insert cutter ring enables good discharge of the rock debris, reduces the rock debris stagnation effect, reduces three-body abrasive wear, reduces the risk of plastic deformation or brittle fracture of the hob, extends the service life of the hob, and improves the rock breaking efficiency.

[0039] 4. In the present invention, the setting of the flat-top cutter head retains the good rock crack propagation ability of the traditional flat-top hob, improves the penetration rate, reduces the specific energy, and improves the rock-breaking efficiency.

[0040] 5. In the present invention, the tops of the flat-top cutter head and the insert cutter head are on a circumferential curved surface, making the contact between the hob and the rock smooth, reducing the impact, and improving the service life of the hob.

[0041] 5. In the present invention, hardening the tooth edge of the insert cutter head can improve the wear resistance and service life of the tooth edge of the insert cutter head, thereby increasing the quality of the cutter head of the hob. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It shows a schematic structural view of the present invention.

[0043] Figure 2 It shows a schematic view of a commonly used flat-top cutter head for TBM.

[0044] Figure 3 It shows a schematic view of a commonly used round-top cutter head for TBM.

[0045] Figure 4 It shows a front view of the present invention.

[0046] Figure 5 It shows a left view of the present invention.

[0047] Figure 6 It shows a top view of the present invention.

[0048] Figure 7 It shows a partially enlarged schematic view of the cutter head in the present invention.

[0049] Figure 8 It is a comparison chart of the proportion of specific energy for single-cutter rock-breaking in simulation.

[0050] Figure 9 It shows a comparison chart of the proportion of specific energy for double-cutter combined rock-breaking in simulation.

[0051] Figure 10 It shows a comparison chart of the proportion of rock-breaking volume for double-cutter combined rock-breaking in simulation.

[0052] Figure 11 It shows a comparison chart of the comprehensive stress at the end of the simulation hob.

[0053] Figure 12 It shows a stress nephogram of rock-breaking by the simulation flat-top hob.

[0054] Figure 13 It shows a stress nephogram of rock-breaking by the simulation insert hob.

[0055] Description of Component Labels

[0056] 1 - cutter ring matrix; 2 - cutter hub mounting hole; 3 - flat top cutter ring; 4 - inserted tooth cutter ring; 5 - round top cutter ring. Specific embodiments

[0057] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0058] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have substantial technical significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that the technical content disclosed by the present invention can cover. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration, and are not used to limit the scope for the implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope for the implementation of the present invention.

[0059] Embodiment 1

[0060] Please refer to Figure 1 、 4 -7. The present invention provides a TBM hob cutter ring, including a cutter ring matrix 1. A cutter hub mounting hole 2 is opened in the middle of the cutter ring matrix 1. Two groups of flat top cutter rings 3 and two groups of inserted tooth cutter rings 4 are evenly distributed along the circumferential direction of the outer edge of the cutter ring matrix 1. The two groups of flat top cutter rings 3 and the two groups of inserted tooth cutter rings 4 are arranged alternately, and the tops of the flat top cutter rings 3 and the inserted tooth cutter rings 4 are on the same circumferential curved surface.

[0061] When this embodiment is used, the TBM hob cutter ring includes a cutter ring matrix 1, a cutter hub mounting hole 2, a flat top cutter ring 3, and an inserted tooth cutter ring 4. The flat top cutter rings 3 and the inserted tooth cutter rings 4 are alternately and evenly distributed on the outer edge of the cutter ring matrix 1. That is, the cutter ring matrix 1 is a disk structure as a whole, and the outer edge of the cutter ring matrix 1 is composed of 1 / 4 flat top cutter ring 3, 1 / 4 inserted tooth cutter ring 4, 1 / 4 flat top cutter ring 3, and 1 / 4 inserted tooth cutter ring 4 arranged in sequence along the circumference. When the TBM using this cutter ring is working, the working of the hob is a periodic process from the initial rock breaking of the inserted tooth cutter ring 4 to the crack expansion of the flat top cutter ring 3, so as to reduce the specific energy of rock breaking, accelerate the propulsion speed, promote the discharge of rock slag, reduce the wear of the cutter ring, and improve the rock breaking efficiency. Specifically:

[0062] By jointly adjusting the layout of the hob on the cutter head, the propulsion pressure of the cutter head, and related parameters, all the hobs work in a periodic process from the insert cutter ring 4 to the flat-top cutter ring 3. When the insert cutter ring 4 is working, the propulsion pressure of the cutter head decreases. At this time, due to the special structure of the insert cutter ring 4, a relatively small propulsion pressure can also form better initial cracks in the rock. When the flat-top cutter ring 3 is working, the propulsion pressure of the cutter head increases. At this time, taking advantage of the large penetration of the flat-top cutter ring 3, the initial cracks in the rock are further expanded. Due to the presence of the inserts, the contact area between the hob and the rock is reduced, and the gaps between the inserts are beneficial to the discharge of rock chips.

[0063] In this embodiment, the tooth profile of the tooth edge in the flat-top cutter ring 3 is formed by rotating an ellipse along its major axis. The tops of the flat-top cutter ring 3 and the insert cutter ring 4 are on the same circumferential surface, ensuring smooth contact between the hob and the rock and reducing impact.

[0064] In this embodiment, the inner side of the cutter ring base 1 is a cylindrical annular inner wall. The cylindrical annular inner wall forms a cutter hub mounting hole 2, and the cylindrical annular inner wall is chamfered to facilitate the installation of the hob hub.

[0065] In this embodiment, the cutter ring base 1 is made of H13 steel or DC-53 steel.

[0066] In this embodiment, the flat-top cutter ring 3 and the insert cutter ring 4 are subjected to heat treatment or surface strengthening treatment. Among them, heat treatment includes but is not limited to quenching and tempering, and multi-phase strengthening heat treatment. Surface strengthening treatment includes but is not limited to laser cladding, coating technology, and surface quenching.

[0067] As a further description of the above embodiment, each group of the insert cutter rings 4 is composed of 9 evenly arranged tooth edges. The gaps between adjacent tooth edges are beneficial to the discharge of rock chips, reducing the rock chip clogging effect, reducing three-body abrasive wear, reducing the risk of plastic deformation or brittle fracture of the hob, extending the service life of the hob, and improving the rock-breaking efficiency.

[0068] Of course, the number of tooth edges on the insert cutter ring 4 is not limited to 9, and can be adjusted accordingly according to the actual situation. For example, each group of the insert cutter rings 4 is composed of 8-10 evenly arranged tooth edges.

[0069] As a further description of the above embodiment, the two ends of the flat-top cutter ring 3 are rounded to effectively avoid stress concentration.

[0070] Please refer to Figures 8 - 10, under the same penetration depth, the contact area between a conventional flat-top hob and the rock is relatively large, resulting in a relatively uniform pressure distribution per unit area. However, the overall cutting force required also increases accordingly. This relatively large cutting force leads to more energy consumption during the rock-breaking process. Meanwhile, during the rock-breaking process, the flat-top cutter head has a relatively strong crack propagation ability, which means that under the same penetration depth, the flat-top cutter head can more effectively propagate cracks and break a larger volume of rock. Although this helps improve the rock-breaking efficiency, it also means that more energy is required to achieve this process, resulting in a relatively high specific energy for rock breaking.

[0071] Although the specific energy for rock breaking of a common dome hob is relatively lower compared to that of a flat-top hob, during the rock-breaking process, its crack propagation ability is relatively weak, resulting in a relatively smaller volume of rock fragments generated. This means that under the same penetration depth, the dome hob breaks a relatively smaller volume of rock and has a relatively lower rock-breaking efficiency. At the same time, the contact area and the stress concentration range between the dome hob and the rock are relatively small, and local wear is likely to occur during long-term use, causing a greater change in the radius of the dome hob. This will lead to uneven wear of the cutter head during use and affect its service life.

[0072] As can be seen from the figure, under the same penetration depth, whether it is a single cutter or a combination of two cutters, the proportion of the specific energy for rock breaking of the flat-top hob and the dome hob is greater than that of the insert hob; while the rock-breaking volume ratio of the insert hob is 2.4 times that of the flat-top hob and 5 times that of the dome hob. It can be concluded that under the same penetration depth, the insert hob has a large rock-breaking volume and a low specific energy for rock breaking.

[0073] Please refer to Figure 11 , as can be seen from the figure, the stress concentration of the insert cutter head 4 is obvious, while the flat-top cutter head 3 does not have such a situation. Therefore, arranging two groups of flat-top cutter heads 3 and insert cutter heads 4 alternately can reduce the working time of the insert cutter head 4 and avoid long-term stress concentration.

[0074] Please refer to Figures 12 - 13 , as can be seen from the two stress nephograms, during the rock-breaking process of the flat-top cutter head 3, the stress extends downward more strongly, which makes the rock cracks more likely to extend downward, that is, the flat-top cutter head 3 has good crack propagation ability and a large penetration depth; while during the rock-breaking process of the insert cutter head 4, the stress diffuses evenly in all directions, making the rock cracks less likely to extend downward, that is, the pure insert cutter head 4 has poor crack propagation ability and a small penetration depth.

[0075] Meanwhile, the pure insert hob has relatively poor formation adaptability and is prone to tooth breakage in hard rock formations. The cutter teeth may fall off due to impact loads and vibrations. The fallen cutter teeth will not only reduce the rock-breaking efficiency but may also cause further damage to the hob. By adopting the design of a composite hob, when the insert hob is working, the thrust of the cutter head can be adjusted to reduce the possibility of tool fracture.

[0076] In summary, in the embodiments of the present invention, through the reasonable design of the cutting edge shape and distribution of the TBM cutter head, the layout of the cutter head on the cutter disc, the propulsion pressure of the cutter disc, and related parameters are jointly adjusted, and the advantages of large penetration of the flat-top cutter head and small specific energy of the round-top cutter head are flexibly utilized, so that the specific energy of rock breaking during the operation of the TBM is reduced, the rock breaking volume is increased, and at the same time, the alternating work of the inserted tooth cutter head 4 and the flat-top cutter head 3 reduces the risk of increased wear caused by stress concentration at the tooth part, and improves the rock breaking efficiency.

[0077] Embodiment 2

[0078] A processing method for a TBM cutter head includes the following steps:

[0079] 1) Semi-finished product processing: Cast an H13 steel to prepare a cutter head blank, and use a mold or mechanical forming process to process the cutter head blank into a shape with four groups of alternately arranged flat-top cutter heads and inserted tooth cutter heads evenly distributed on the outer edge of the cutter head blank;

[0080] In this process, the cutter head blank includes a cutter head base body 1. The cutter head base body 1 is a disc structure as a whole. A cutter hub mounting hole 2 is opened in the middle of the cutter head base body 1. The outer edge of the cutter head base body 1 is composed of a 1 / 4 flat-top cutter head 3, a 1 / 4 inserted tooth cutter head 4, a 1 / 4 flat-top cutter head 3, and a 1 / 4 inserted tooth cutter head 4 arranged in sequence along the circumference. The vertex of the inserted tooth cutter head 4 and the flat-top cutter head 3 are on the same circumferential curved surface. And the annular inner wall of the cutter hub mounting hole 2 is chamfered, and the two ends of the flat-top cutter head 3 are rounded.

[0081] 2) Rough machining: Use turning and milling equipment to perform rough machining on the cutter head blank, remove the excess allowance on the cutter head blank, and prepare for subsequent finish machining;

[0082] 3) Quenching treatment: Quench the rough-machined cutter head. The quenching temperature is 820 °C. After quenching, perform heat preservation treatment. Among them, the heat preservation treatment time is 1 minute for every millimeter of cutter head thickness. The quenching medium is high-speed gas cooling to improve the hardness and wear resistance of the cutter head;

[0083] 4) Tempering treatment: Temper the quenched cutter head. The tempering temperature is 200 °C, and the heat preservation time after tempering is 1 h; Perform two temperings to eliminate quenching stress and improve the toughness and stability of the cutter head.

[0084] 5) Hardening treatment on the tooth edge surface of the inserted tooth cutter head: During the hardening treatment, use a high-temperature-resistant graphite plate to shield the flat-top cutter head to ensure that the flat-top cutter head is isolated from the hardening treatment medium to ensure that the flat-top cutter head will not be hardened.

[0085] 6) Finish machining, determine the surface finish, dimensional accuracy, and shape accuracy of the cutter head, so as to meet the use requirements.

[0086] As a further description of the above embodiments, the method for determining the tooth tip distance between two adjacent tooth edges in each group of inserted tooth cutter rings in (1) is coupled by the following three methods:

[0087] (1) Rock hardness classification adaptation

[0088] For hard rock formations, including but not limited to granite and basalt, the tooth tip distance between two adjacent tooth edges is 30 - 50 mm;

[0089] For soft rock formations or high confining pressure working conditions, including but not limited to mudstone and shale, the tooth tip distance between two adjacent tooth edges is 20 - 40 mm;

[0090] (2) Tool structure matching

[0091] The minor axis of the tooth edge has a positive correlation adjustment relationship with the tooth tip distance, specifically:

[0092] When the minor axis of the tooth edge increases by 5 mm, the tooth tip distance synchronously increases by 5 mm;

[0093] (3) Construction parameter constraints

[0094] When 2 ≤ a < 4, 10 < b ≤ 15;

[0095] When 4 < a ≤ 6, 6 < b ≤ 12;

[0096] When a = 4, 6 ≤ b ≤ 10;

[0097] Among them,

[0098] a is the penetration of the tooth edge;

[0099] b is the ratio of the tooth tip distance to the penetration.

[0100] Specifically, the tooth profile of the inserted tooth cutter ring is formed by rotating an ellipse along its major axis, and the tooth tip falls on the circumference of the flat-top cutter ring. The setting of the tooth tip distance between two adjacent tooth edges is based on the above three methods for parameter coupling, that is:

[0101] In the hard rock formation, the penetration of the tooth edge is 2 mm, and the tooth tip distance is 30 mm.

[0102] In the soft rock formation or high confining pressure working condition, the penetration of the tooth edge is 2 mm, and the tooth tip distance is 20 mm.

[0103] In the hard rock formation, the penetration of the tooth edge is 4 mm, and the tooth tip distance is 32 mm.

[0104] In the soft rock formation or high confining pressure working condition, the penetration of the tooth edge is 4 mm, and the tooth tip distance is 24 mm.

[0105] In the hard rock formation, the penetration of the tooth edge is 5 mm, and the tooth tip distance is 40 mm.

[0106] In soft rock formations or under high confining pressure conditions, the penetration depth of the tooth edge is 5 mm, and the distance between the tooth tips is 35 mm.

[0107] Of course, the determining factors for the distance between the tooth tips include, but are not limited to, the coupling of the above three parameters. In actual application, factors such as the cutter head thrust can be considered to make corresponding adjustments to the distance between the tooth tips.

[0108] As a further description of the above embodiment, in the above (5), the hardening treatment method is carburizing the surface of the tooth edge of the insert cutter ring. Among them, the carburizing temperature for the carburizing treatment is 930 °C, the carburizing time is 4 h, and the carbon potential is 1%.

[0109] Embodiment III

[0110] A method for machining a TBM hob cutter ring includes the following steps:

[0111] 1) Semi-finished product machining: Cast a DC-53 steel to prepare a cutter ring blank, and use a mold or mechanical forming process to machine the cutter ring blank into a shape with four groups of alternately arranged flat-top cutter rings and insert cutter rings evenly distributed on the outer edge of the cutter ring blank;

[0112] In this process, the cutter ring blank includes a cutter ring base body 1. The cutter ring base body 1 is a disk structure as a whole. A cutter hub mounting hole 2 is opened in the middle of the cutter ring base body 1. The outer edge of the cutter ring base body 1 is composed of 1 / 4 flat-top cutter rings 3, 1 / 4 insert cutter rings 4, 1 / 4 flat-top cutter rings 3, and 1 / 4 insert cutter rings 4 arranged in sequence along the circumference. The vertices of the insert cutter rings 4 and the flat-top cutter rings 3 are on the same circumferential curved surface. And chamfer the annular inner wall of the cutter hub mounting hole 2, and round the two ends of the flat-top cutter rings 3.

[0113] 2) Rough machining: Use turning and milling equipment to perform rough machining on the cutter ring blank, remove the excess allowance on the cutter ring blank, and prepare for subsequent finish machining;

[0114] 3) Quenching treatment: Perform quenching treatment on the rough-machined cutter ring. The quenching temperature is 850 °C. After quenching, perform heat preservation treatment. Among them, the heat preservation treatment time is 2 min for each millimeter of the cutter ring thickness. The quenching medium is oil cooling to improve the hardness and wear resistance of the hob cutter ring;

[0115] 4) Tempering treatment: Perform tempering treatment on the quenched cutter ring. The tempering temperature is 250 °C, and the heat preservation time after tempering is 2 h; Usually, tempering is performed twice to eliminate quenching stress and improve the toughness and stability of the cutter ring.

[0116] 5) Hardening treatment is carried out on the tooth edge surface of the inserted tooth cutter ring: During the hardening treatment process, the flat-top cutter ring is shielded with a high-temperature-resistant ceramic fiber board to ensure that the flat-top cutter ring is isolated from the hardening treatment medium, so as to ensure that the flat-top cutter ring will not be hardened.

[0117] 6) Finish machining to determine the surface finish, dimensional accuracy and shape accuracy of the cutter ring, so as to meet the usage requirements.

[0118] As a further description of the above embodiment, the determination method of the tooth tip spacing between two adjacent tooth edges in each group of inserted tooth cutter rings in the above 1) is coupled by the following three methods:

[0119] (1) Rock hardness grading adaptation

[0120] For hard rock formations, including but not limited to granite and basalt, the tooth tip spacing between two adjacent tooth edges is 30 - 50 mm;

[0121] For soft rock formations or high confining pressure working conditions, including but not limited to mudstone and shale, the tooth tip spacing between two adjacent tooth edges is 20 - 40 mm;

[0122] (2) Tool structure matching

[0123] There is a positive correlation adjustment relationship between the minor axis of the tooth edge and the tooth tip spacing. Specifically:

[0124] When the minor axis of the tooth edge increases by 5 mm, the tooth tip spacing increases synchronously by 5 mm;

[0125] (3) Construction parameter constraints

[0126] When 2 ≤ a < 4, 10 < b ≤ 15;

[0127] When 4 < a ≤ 6, 6 ≤ b < 12;

[0128] When a = 4, 6 ≤ b ≤ 10;

[0129] Among them,

[0130] a is the penetration degree of the tooth edge;

[0131] b is the ratio of the tooth tip spacing to the penetration degree.

[0132] Specifically, the tooth profile of the inserted tooth cutter ring is formed by rotating an ellipse along its major axis, and the tooth tip falls on the circumference of the flat-top cutter ring. The setting of the tooth tip spacing between two adjacent tooth edges is based on the coupling of the above three parameters, that is:

[0133] In the hard rock formation, the penetration degree of the tooth edge is 3 mm, and the tooth tip spacing is 45 mm.

[0134] In the soft rock formation or high confining pressure working condition, the penetration degree of the tooth edge is 3 mm, and the tooth tip spacing is 33 mm.

[0135] In hard rock formations, the penetration depth of the tooth edge is 4 mm, and the tooth tip spacing is 40 mm.

[0136] In soft rock formations or high confining pressure conditions, the penetration depth of the tooth edge is 4 mm, and the tooth tip spacing is 36 mm.

[0137] In hard rock formations, the penetration depth of the tooth edge is 6 mm, and the tooth tip spacing is 48 mm.

[0138] In soft rock formations or high confining pressure conditions, the penetration depth of the tooth edge is 6 mm, and the tooth tip spacing is 36 mm.

[0139] Of course, the determining factors of the tooth tip spacing include, but are not limited to, the coupling of the above three parameters. In the actual application process, factors such as the cutter head thrust can be considered to make corresponding adjustments to the tooth tip spacing.

[0140] As a further description of the above embodiment, in the above (5), the hardening treatment method is nitriding the surface of the tooth edge of the insert cutter ring. Among them, the nitriding temperature of the nitriding treatment is 530 °C, the nitriding time is 3 h, and the nitrogen potential is 0.5%.

[0141] In summary, in the present invention, the flat-top cutter rings and the insert cutter rings are arranged alternately, enabling the full expansion of rock cracks, increasing the penetration depth, reducing the specific energy of rock breaking, and improving the rock breaking efficiency. At the same time, the surface hardening treatment of the insert cutter rings can improve the wear resistance and service life of the insert cutter rings. Therefore, the present invention effectively overcomes various disadvantages in the prior art and has high industrial utilization value.

[0142] The above embodiments are only illustrative of the principles and effects of the present invention and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A TBM hob cutter ring processing method, characterized in that: The TBM hob cutter ring comprises a cutter ring base (1), a cutter hub mounting hole (2) is provided in the middle of the cutter ring base (1), two groups of flat-top cutter rings (3) and two groups of insert tooth cutter rings (4) are evenly distributed along the circumference of the outer edge of the cutter ring base (1), the two groups of flat-top cutter rings (3) and the two groups of insert tooth cutter rings (4) are arranged alternately, and the tops of the flat-top cutter rings (3) and the insert tooth cutter rings (4) are on the same circumferential curved surface; The processing method comprises the following steps: 1) Semi-finished product processing: casting the material to prepare a cutter ring blank, and processing it into two groups of flat-top cutter rings (3) and two groups of toothed cutter rings (4) with the outer edges of the cutter ring blanks evenly and staggeredly arranged; 2) Rough machining: Use turning and milling equipment to rough-process the cutter ring blank to remove excess margin on the cutter ring blank; 3) Quenching treatment: the cutter ring after rough machining is quenched, and then subjected to heat preservation treatment, wherein the heat preservation time is 1 to 2 minutes per millimeter of cutter ring thickness; 4) Tempering treatment: The quenched knife ring is subjected to two tempering and heat preservation treatments; 5) Hardening the tooth edge surface of the toothed cutter ring (4): During the hardening process, the flat-top cutter ring (3) is shielded with a high-temperature resistant ceramic fiber board or graphite board; 6) Finishing.

2. The TBM hob cutter ring processing method according to claim 1, characterized in that: The method for determining the tooth top spacing between two adjacent tooth edges in each group of insert cutter rings (4) in 1) is to couple the following three methods: (1) Rock hardness classification and adaptation For hard rock formations, the tooth tip spacing between two adjacent tooth edges is 30 to 50 mm; For soft rock formations or high confining pressure conditions, the tooth tip spacing between two adjacent tooth edges is 20 to 40 mm; (2) Tool structure matching The short axis of the tooth blade and the tooth top spacing are positively correlated, specifically: For every 5mm increase in the short axis of the tooth blade, the tooth top spacing will increase by 5mm simultaneously; (3) Construction parameter constraints When 2≤a<4, 10<b≤15; When 4<a≤6, 6<b≤12; When a=4, 6≤b≤10; in, a is the penetration of the tooth edge; b is the ratio of the tooth tip spacing to the penetration.

3. The TBM hob cutter ring processing method according to claim 1, characterized in that: In the above 3), the quenching temperature of the quenching treatment is 820-850° C., and the quenching medium is oil or high-speed gas.

4. The TBM hob cutter ring processing method according to claim 1, characterized in that: In the above 4), the tempering temperature of the tempering treatment is 200-250° C., and the holding time is 1-2 hours.

5. The TBM hob cutter ring processing method according to claim 1, characterized in that: In the above 5), the hardening treatment method is to perform carburizing treatment on the tooth edge surface of the insert cutter ring (4), wherein the carburizing temperature of the carburizing treatment is 900-950° C., the carburizing time is 2-6 hours, and the carbon potential is 0.8%-1.2%.

6. The TBM hob cutter ring processing method according to claim 1, characterized in that: In the above 5), the hardening treatment method is to perform nitriding treatment on the tooth edge surface of the insert cutter ring (4), wherein the nitriding temperature of the nitriding treatment is 500-550° C., the nitriding time is 2-5 hours, and the nitrogen potential is 0.3%-0.6%.

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