Axial composite type cutter, cutter head for heading machine and design method

Abstract

The application provides an axial composite cutter, a cutter head and a design method for a tunneling machine. The axial composite cutter comprises a cutter shaft and a cutter ring sleeved outside the cutter shaft, and the cutter ring is formed with an integrated composite cutter blade. The composite cutter blade is composed of a central vertical blade in the axial middle part and first and second inclined blades on both sides. The first inclined blade has a first inclination angle, a first effective blade width and a first shape factor, and the second inclined blade has a second inclination angle, a second effective blade width and a second shape factor. The numerical values of the first inclination angle and the second inclination angle are not equal, and the force sizes of the first inclined blade and the second inclined blade in the horizontal plane are equal and the directions thereof are opposite through the difference compensation of the first inclination angle and the second inclination angle, and the difference between the first effective blade width and the second effective blade width and the difference between the first shape factor and the second shape factor.

Description

Technical Field

[0001] This application relates to the field of shaft engineering machinery application equipment, and in particular to axial composite cutterheads, cutter heads and design methods for tunneling machines. Background Technology

[0002] Full-face shaft boring machines (MDMs) are key equipment for achieving mechanized and continuous shaft excavation. They primarily utilize disc cutters mounted on a cutterhead to compress, roll, and shear the rock mass, achieving rock breaking and shaft excavation. As the core rock-breaking component and main wear part of the cutterhead, the disc cutters' rock-breaking performance and service life directly affect the excavation efficiency, project cost, and operational safety of shaft construction. Statistics show that downtime due to cutter inspection, replacement, and maintenance accounts for approximately 30% of the total construction time, and related costs account for approximately 30% of the total construction cost. Therefore, improving the reliability and service life of the cutters is a crucial prerequisite for ensuring the efficient and continuous operation of MBMs.

[0003] To improve the efficiency of cuttings collection and removal during shaft excavation, some full-face shaft boring machines (TBMs) adopt a W-type cutterhead structure. This cutterhead has multiple inclined working faces, which utilize its structural slope to guide broken cuttings towards the cuttings collection area in the center of the cutterhead, facilitating subsequent cuttings collection and removal. Compared to a flat cutterhead, the W-type cutterhead has better cuttings collection capacity, which helps reduce cuttings accumulation on the working face, improves cuttings removal efficiency, and enhances the continuity of tunneling operations.

[0004] However, the intersection of adjacent inclined working faces of the W-type cutterhead forms a special corner region with a distinctly asymmetrical rock surface. When traditional symmetrical cutterheads are installed in this location, it is difficult for both sides of the cutter ring to maintain proper contact with the rock surface simultaneously, easily leading to problems such as one-sided contact, lateral load imbalance, and uneven stress. Prolonged exposure to such abnormal stress conditions exacerbates the wear of the cutter ring, bearings, and connecting components, causing instability in cutter operation. In severe cases, it can even lead to bearing failure, cutter ring loosening or detachment, affecting the rock-breaking effect in the corner region and the overall operational reliability of the W-type cutterhead. Current technologies address the severe cutter wear problem primarily by optimizing the cutter structure and arrangement, improving cutter materials, and adjusting tunneling parameters. However, they do not fully consider the matching relationship between the asymmetrical rock surface in the corner region of the W-type cutterhead and the traditional cutter structure, thus failing to fundamentally solve the problems of lateral load imbalance, uneven stress, and abnormal damage to the cutters in this region.

[0005] Therefore, it is necessary to design a new type of cutter structure suitable for the rock surface morphology and cutter stress characteristics in the corner area of ​​the W-type cutterhead, so that it can form reasonable contact with the asymmetrical inclined rock surface, optimize the load transfer and distribution, reduce lateral load, improve the stress stability and operational reliability of the cutter during rock breaking, thereby reducing the risk of abnormal damage to components such as cutter rings and bearings, extending the service life of the cutter, and ensuring the stable operation of the W-type cutterhead's slag collection, slag discharge, and continuous tunneling functions. Summary of the Invention

[0006] In view of this, this application provides an axial composite cutter for a tunneling machine to solve the technical problem that when traditional symmetrical cutter structures are installed on the transition surface of a W-shaped cutterhead, it is difficult to form ideal contact and load distribution with the asymmetrical inclined rock surface, resulting in lateral load imbalance and uneven stress, which in turn accelerates bearing failure and increases the risk of accidental detachment of the cutter ring. The application significantly improves the stress state of the cutter, enhances rock breaking stability and reliability, and extends the service life of the cutter.

[0007] To achieve the above objectives, this application provides the following technical solution: Axial compound cutter cutters for tunneling machines include: The cutter shaft is fixed in place. The cutter ring is rotatably fitted onto the cutter shaft; An integral composite blade is integrally formed on the blade ring. The integral composite blade consists of a central vertical blade located in the axial center of the blade shaft and a first inclined blade and a second inclined blade located on both sides of the central vertical blade along the axial direction. The first inclined blade has a first set of parameters, and the second inclined blade has a second set of parameters; The first parameter set includes a first tilt angle, a first effective cutting width, and a first shape factor; the second parameter set includes a second tilt angle, a second effective cutting width, and a second shape factor. The first tilt angle is the angle between the first tilting blade and the vertical direction, and the second tilt angle is the angle between the second tilting blade and the vertical direction. The values ​​of the first tilt angle and the second tilt angle are not equal. The first effective cutting width is the width of the part of the first inclined cutting edge that contacts the rock mass, the second effective cutting width is the width of the part of the second inclined cutting edge that contacts the rock mass, the first shape factor is the influence coefficient of the cutting edge cross-sectional shape of the first inclined cutting edge on the rock mass breaking resistance, and the second shape factor is the influence coefficient of the cutting edge cross-sectional shape of the second inclined cutting edge on the rock mass breaking resistance. The first parameter group and the second parameter group are configured to: compensate for the difference between the first tilt angle and the second tilt angle by combining the difference between the first effective cutting edge width and the second effective cutting edge width and the difference between the first shape factor and the second shape factor, so that the force on the first tilting edge and the second tilting edge in the horizontal direction is equal in magnitude and opposite in direction.

[0008] Optionally, in the aforementioned axial composite cutter for a tunneling machine, the product of the first effective cutting width, the first shape factor, and a sine value twice the first inclination angle constitutes the first horizontal component of the rock mass's force on the first inclined cutting edge, and the product of the second effective cutting width, the second shape factor, and a sine value twice the second inclination angle constitutes the second horizontal component of the rock mass's force on the second inclined cutting edge. The first horizontal component and the second horizontal component are equal in magnitude and opposite in direction.

[0009] Optionally, in the above-mentioned axial composite cutter for a tunneling machine, the first inclination angle θ L Less than the second tilt angle θ R ; The first effective cutting width is greater than the second effective cutting width; The first shape factor is greater than the second shape factor.

[0010] Optionally, in the above-mentioned axial composite cutter for tunneling machines, 8°≤θ L ≤15°, 30°≤θ R ≤45°; The first effective cutting width is 1 to 1.3 times the second effective cutting width; The first inclined blade has a flat-topped cross-sectional shape, and the first shape factor is 1.0; The cutting edge cross-section of the second inclined blade is a circular arc cross-section or a parabolic cross-section, and the second shape factor is 0.7-0.8.

[0011] Optionally, in the axial compound cutter for a tunneling machine described above, the radial dimension of the central vertical cutting edge is greater than the radial dimensions of the first inclined cutting edge and the second inclined cutting edge along the radial direction of the cutter shaft.

[0012] Optionally, in the aforementioned axial composite hobbing cutter for tunneling machines, the integrated composite cutting edge and the cutter ring are integrally forged, cast, or integrally formed by powder metallurgy.

[0013] A cutterhead, wherein the cutterhead is a W-type cutterhead, and the W-type cutterhead includes the axial compound hobbing cutter for a tunneling machine as described in any of the preceding claims.

[0014] Optionally, in the above-mentioned cutter head, the W-shaped cutter head includes an outer inclined surface, an inner inclined surface, and a transition surface connecting the outer inclined surface and the inner inclined surface. The angle between the outer inclined surface and the horizontal plane is greater than the angle between the inner inclined surface and the horizontal plane, and the axial composite hob is disposed on the transition surface.

[0015] The design method for an axial composite cutter for a tunneling machine, applicable to the axial composite cutter for a tunneling machine described in any of the above-mentioned claims, includes: S1: Determine the first dip angle and the second dip angle based on the geometric parameters of the rock mass; S2: With the goal of equalizing the first horizontal component force and the second horizontal component force, the first effective cutting width and the second effective cutting width are determined based on the fact that the first effective cutting width is 1 to 1.3 times the second effective cutting width, the first tilt angle, and the second tilt angle. S3: Configure the first shape factor and the second shape factor so that the first horizontal component force and the second horizontal component force are equal; Wherein, the first tilt angle is the angle between the first tilting blade and the vertical direction, the second tilt angle is the angle between the second tilting blade and the vertical direction, and the values ​​of the first tilt angle and the second tilt angle are not equal; The first effective cutting width is the width of the part of the first inclined cutting edge that contacts the rock mass, the second effective cutting width is the width of the part of the second inclined cutting edge that contacts the rock mass, the first shape factor is the influence coefficient of the cutting edge cross-sectional shape of the first inclined cutting edge on the rock mass breaking resistance, and the second shape factor is the influence coefficient of the cutting edge cross-sectional shape of the second inclined cutting edge on the rock mass breaking resistance.

[0016] Optionally, in the above-described design method for an axial composite cutter for a tunneling machine, the distance from the vertical plane containing the tip of the first inclined blade to the midpoint of the axial direction of the cutter shaft is adjusted, the distance from the vertical plane containing the tip of the second inclined blade to the midpoint of the axial direction of the cutter shaft is adjusted, and the distance from the vertical plane containing the central vertical blade to the midpoint of the axial direction of the cutter shaft is adjusted, so that the algebraic sum of the torques generated by the vertical components of the first inclined blade, the second inclined blade, and the central vertical blade relative to the midpoint of the cutter shaft is zero, so that the integrated composite cutter blade satisfies torque balance.

[0017] This application utilizes independently adjustable first and second parameter sets for the first and second inclined blades, respectively. The first parameter set includes a first inclination angle, a first effective cutting width, and a first shape factor, while the second parameter set includes a second inclination angle, a second effective cutting width, and a second shape factor. These two parameter sets are configured such that the first and second inclination angles are unequal, enabling the two inclined blades to geometrically match the rock surfaces at different inclination angles on either side of the conical cutterhead's cone-shaped corner. Simultaneously, by compensating for the differences between the first and second effective cutting widths and the first and second shape factors, the first and second inclined blades experience equal but opposite forces in the horizontal direction, achieving self-balancing of the cutter in the horizontal direction. This invention eliminates harmful lateral loads caused by rock surface asymmetry from a mechanical perspective, significantly reducing abnormal bearing loads and extending bearing life. The first and second inclined blades, while balancing forces, participate in coordinated rock breaking, forming a coordinated rock breaking mechanism of "central main breaking + lateral expansion," resulting in a more uniform load distribution. This effectively avoids loosening and detachment of the cutter ring caused by alternating loads under high impact and high vibration conditions, greatly improving the operational reliability and durability of the cutter. Furthermore, the horizontally self-balancing forces of the two inclined blades prevent ineffective blade slippage and energy loss due to eccentric loading, allowing the cutterhead thrust to be converted into rock breaking work more efficiently, significantly improving the effective penetration and rock breaking energy efficiency ratio of the cutter. In summary, this application has achieved significant beneficial effects in extending cutter life, improving rock breaking efficiency, and reducing construction costs. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 A schematic diagram of the axial composite hob provided in this application; Figure 2 The front view of the axial compound hob provided in this application; Figure 3 A front view of the axial composite hob in working condition provided in this application; Figure 4 This is a schematic diagram of the structure of the W-type cutter head provided in this application.

[0020] icon: 1. Cutter shaft; 2. Cutter ring; 3. One-piece composite cutting edge; 4. Central vertical cutting edge; 5. First inclined cutting edge; 6. Second inclined cutting edge; 7. Rock mass. Detailed Implementation

[0021] This application provides an axial composite cutter for a tunneling machine, which solves the technical problem that in the prior art, when a traditional symmetrical cutter is installed on the transition surface of a W-shaped cutterhead, it is difficult to form an ideal contact and load distribution with an asymmetrical inclined rock surface, resulting in lateral load imbalance and uneven stress, which in turn accelerates bearing failure and increases the risk of accidental detachment of the cutter ring. The application significantly improves the stress state of the cutter, enhances rock breaking stability and reliability, and extends the service life of the cutter.

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] like Figures 1-4 As shown, this application proposes an axial composite cutter for a tunneling machine. The axial composite cutter includes a fixedly mounted cutter shaft 1, a cutter ring 2 rotatably fitted outside the cutter shaft 1, and an integrally formed composite cutting edge 3 on the cutter ring 2. Specifically, the integrally formed composite cutting edge 3 is integrally formed on the outer circumference of the cutter ring 2. The integrally formed composite cutting edge 3 consists of a central vertical cutting edge 4 located at the axial center of the cutter shaft 1, and first inclined cutting edges 5 and second inclined cutting edges 6 located on either side of the central vertical cutting edge 4 along the axial direction. The first inclined cutting edge 5 has a first set of parameters, and the second inclined cutting edge 6 has a second set of parameters. The first set of parameters includes a first inclination angle, a first effective cutting width, and a first shape factor; the second set of parameters includes a second inclination angle, a second effective cutting width, and a second shape factor. The first inclination angle is the angle between the first inclined cutting edge 5 and the vertical direction, and the second inclination angle is the angle between the second inclined cutting edge 6 and the vertical direction. The values ​​of the first inclination angle and the second inclination angle are not equal. The first effective cutting width is the width of the contact portion between the first inclined cutting edge 5 and the rock mass 7, and the second effective cutting width is the width of the contact portion between the second inclined cutting edge 6 and the rock mass 7. The first shape factor is the influence coefficient of the cutting edge cross-sectional shape of the first inclined cutting edge 5 on the rock mass 7 breaking resistance, and the second shape factor is the influence coefficient of the cutting edge cross-sectional shape of the second inclined cutting edge 6 on the rock mass 7 breaking resistance. The first and second parameter sets are configured such that, by unequal first and second inclination angles, and by compensating for the differences between the first and second effective cutting widths and the first and second shape factors, the forces on the first inclined cutting edge 5 and the second inclined cutting edge 6 in the horizontal direction are equal in magnitude and opposite in direction, thus balancing the forces on the cutter in the horizontal direction.

[0024] It should be noted that the first shape factor is the influence coefficient of the cutting edge cross-sectional shape of the first inclined blade 5 on the rock mass 7 breaking resistance, and the second shape factor is the influence coefficient of the cutting edge cross-sectional shape of the second inclined blade 6 on the rock mass 7 breaking resistance. The value of the influence coefficient is equal to the ratio of the normal rock-breaking reaction force of the first inclined blade 5 or the second inclined blade 6 under the same conditions to the normal rock-breaking reaction force of the flat-top cross-section blade.

[0025] When the cutter head is installed and in operation, the cutter shaft 1 is fixed at both ends to the cutter holders of the tunneling machine cutterhead. The cutterhead drives the entire cutter head to revolve around the center of the shaft and applies a downward thrust. The thrust is transmitted to the cutter ring 2 and its integrated composite cutting edge 3 through the cutter shaft 1, bearings, etc., causing the integrated composite cutting edge 3 to press into the rock mass 7. In asymmetrical rock surface areas such as the transition surface of the W-shaped cutterhead (discussed later), since the rock surface itself is asymmetrically inclined, the asymmetrically designed first inclined edge 5 and second inclined edge 6 on the integrated composite cutting edge 3 can form good geometric matching and contact with the rock surfaces on both sides with different inclination angles. During the rolling process of the cutter ring 2 around the fixed cutter shaft 1, the first inclined edge 5 and the second inclined edge 6, together with the central vertical edge 4 located in the center, jointly compress and shear the rock mass 7. By carefully configuring the first and second parameter sets, i.e., the first and second inclination angles are not equal, and introducing difference compensation between the first and second effective cutting widths and the first and second shape factors, the harmful lateral load caused by the asymmetry of the rock surface can be offset from the root. This makes the horizontal force exerted by the rock mass 7 on the first and second inclined cutting edges 5 equal in magnitude and opposite in direction, thereby significantly improving the overall stress state of the hob and jointly solving the technical problems of hob easy eccentric load, easy bearing damage, and easy detachment of the cutter ring 2 under asymmetric rock surface conditions.

[0026] It should be noted that both the first inclined blade 5 and the second inclined blade 6 cut perpendicularly into the slope of the corresponding rock mass 7.

[0027] In practical applications, the overall movement and collaborative rock-breaking process of this axial composite roller cutter are as follows: Under the continuous pushing pressure of the cutter head and the rolling pressure of the roller cutter, the rock mass 7 is simultaneously penetrated by the central vertical blade 4, the first inclined blade 5, and the second inclined blade 6 because the rock surface is curved. The central vertical blade 4 is located in the axial middle of the cutter ring 2 and serves as the main rock-breaking blade among the three blades, undertaking the primary task of rock breaking. The first inclined blade 5 and the second inclined blade 6 are located on both sides of the central vertical blade 4, and their inclination angles correspond to the inclination angles of the rock surface at their respective locations. The inclined blades on both sides cut into the rock mass 7 in a direction matching the inclination angle of their respective rock surfaces, providing auxiliary cutting and crack propagation to the rock mass 7 on both sides of the breaking zone of the central vertical blade 4. Because the inclination angles, effective cutting widths, and shape factors of the first and second inclined blades 5 and 6 are configured with differential compensation, the horizontal force components generated by them when cutting rock are equal in magnitude and opposite in direction. This achieves self-balancing of the horizontal force inside the cutter head, avoiding ineffective slippage and energy loss caused by eccentric loading, and making the thrust of the cutter head more efficiently converted into rock breaking work. The three blades are continuously distributed along the circumference of the cutter ring, and alternately repeat the synergistic rock breaking cycle of "central crushing + bilateral expansion" during the continuous rotation of the cutter head, achieving efficient and stable crushing of asymmetric inclined rock surfaces.

[0028] It should be noted that the horizontal component forces acting on the first inclined blade 5 and the second inclined blade 6 are in opposite directions; for ease of description, the first inclined blade 5 is regarded as the left inclined blade in the following description, and the second inclined blade 6 is regarded as the right inclined blade in the following description.

[0029] The mechanism of the equality of the above-mentioned horizontal components is further explained. The product of the first effective cutting edge width, the first shape factor, and the sine value twice the first dip angle constitutes the first horizontal component of the rock mass 7 on the first inclined cutting edge 5; the product of the second effective cutting edge width, the second shape factor, and the sine value twice the second dip angle constitutes the second horizontal component of the rock mass 7 on the second inclined cutting edge 6; the first horizontal component and the second horizontal component are equal.

[0030] Specifically, the first inclined cutting edge 5 and the second inclined cutting edge 6 penetrate the rock mass 7 to the same depth h. The normal rock reaction force on the first inclined cutting edge 5 and the second inclined cutting edge 6 is proportional to their vertical stiffness. for: (1) in, Represents L or R, where L represents the first inclined blade 5 and R represents the second inclined blade 6; Represents the normal reaction force; This represents the equivalent resistance coefficient of the corresponding side rock mass 7 (or the unit contact stiffness of rock mass 7). This represents the effective cutting width of the inclined cutting edge on that side. This represents the equivalent indentation depth of the inclined cutting edge on that side; The shape factor represents the shape of the blade on that side of the inclined blade.

[0031] Since the inclined blades (left and right inclined blades) form an angle with the vertical direction, then: (2) Substituting equation (2) into equation (1), (3) Horizontal component for: (4) Substituting equation (4) into equation (3), (5) Using the double-angle formula: (6) Substituting equation (6) into equation (5), (7) If the lithology of the rock mass 7 corresponding to the left and right inclined cutting edges is the same, and the penetration depth is the same, then All terms are omitted as common terms, resulting in the simplified engineering formula: (8) Therefore, during operation, the magnitude of the normal rock reaction force on each inclined cutting edge is related to the effective cutting edge width, the equivalent rock resistance coefficient, the equivalent indentation depth, and the shape factor. Since the inclined cutting edge forms an angle with the vertical indentation direction, the normal reaction force will have a horizontal component, i.e., a horizontal force. Through geometric projection and the double-angle formula, the magnitude of this horizontal component is proportional to the product of the effective cutting edge width, the shape factor, and the sine of twice the indentation angle of that side.

[0032] Because the values ​​of the first and second tilt angles are not equal, although this will lead to... The natural differences exist, but this solution compensates for these differences by differentiating the effective blade width and shape factor of the inclined blades on the left and right sides, ultimately making the product of the three factors representing the first horizontal component force and the second horizontal component force tend to be equal.

[0033] By using this mechanical principle to configure parameters, the structural design can be precisely guided from the theoretical derivation level. This ensures that the force balance of the cutter under asymmetric rock surface conditions does not depend on a complex real-time adjustment system. The structure is simple and highly reliable, and it can fundamentally eliminate lateral loads to the greatest extent, protect the bearings, and extend the service life of the cutter body.

[0034] Preferably, the preferred direction for the above parameter configuration is illustrated by example. First tilt angle θ LLess than the second tilt angle θ R The first effective cutting width is greater than the second effective cutting width; the first shape factor is greater than the second shape factor. Corresponding to the general geometric characteristic of the rock surface being steep on the outside and gentle on the inside at the transition surface of the W-shaped cutterhead, the first inclined cutting edge 5 corresponding to the gentler inner rock surface is set to a smaller inclination angle, while the second inclined cutting edge 6 corresponding to the steeper outer rock surface is set to a larger inclination angle. Because a smaller inclination angle would lead to… The value is small, thus giving this side a smaller horizontal force component coefficient ( This refers to the horizontal force component coefficient on the corresponding side. To compensate for this difference, the first effective cutting width is set to be greater than the second effective cutting width to increase its base force. At the same time, the first shape factor is set to be greater than the second shape factor to increase its equivalent rock-breaking resistance per unit width. Through this synergistic combination of "small angle + wide cutting surface + high resistance cutting edge" and "large angle + narrow cutting surface + low resistance cutting edge", the difference in horizontal force components on both sides can be effectively reduced and compensated along the correct direction, providing a clear and feasible parameter adjustment path for achieving the final force balance.

[0035] In a more specific embodiment, the above parameters are further quantified and defined. The range of the first tilt angle is 8° ≤ θ. L ≤15°, the range of the second tilt angle is 30°≤θ R ≤45°. The first effective cutting width is 1 to 1.3 times the second effective cutting width. The cutting edge cross-section of the first inclined cutting edge 5 is a flat-topped cross-section with a first shape factor of 1.0; the cutting edge cross-section of the second inclined cutting edge 6 is a circular arc cross-section or a parabolic cross-section with a second shape factor of 0.7-0.8.

[0036] The determination of this specific parameter range follows a systematic self-balancing design method of "three-level joint adjustment," the core logic of which is to gradually eliminate the initial stress imbalance caused by angle differences through graded adjustment. First, in the first-level adjustment, the inclination angle range of the left and right inclined blades is locked according to the rock surface geometry parameters of the W-shaped cutterhead transition surface in actual engineering.

[0037] To minimize the difference in horizontal force coefficients at the source, within the allowable range of the process, the lower limit of the second dip angle corresponding to the steeper rock surface is set to 30°, and the upper limit of the first dip angle corresponding to the gentler rock surface is set to 15°. At this point, the initial imbalance ratio of the horizontal forces on both sides (calculated based on sin2) is approximately 1.73.

[0038] Secondly, in the second-stage adjustment, a coarse adjustment is made by introducing blade width compensation. Within the range of 1 to 1.3 times that allows for structural strength and wear resistance, the effective blade width of the first inclined blade 5 is increased. For example, if the first effective blade width is 1.3 times that of the second effective blade width, then after this adjustment, the imbalance ratio can be significantly reduced from 1.73 to approximately 1.33. Finally, in the third-stage adjustment, a fine residual correction is performed using the shape factor. To achieve the final balance from 1.33 to 1.0, the unit width reaction force of the second inclined blade 6 needs to be reduced to approximately 0.75 times that of the previous stage.

[0039] Therefore, the first inclined blade 5 is configured with a high-resistance flat-top cross-section, and its shape factor is set to a baseline value of 1.0; the second inclined blade 6 is configured with a low-resistance circular or parabolic cross-section, and its shape factor is typically in the range of 0.7 to 0.8. By changing the shape of the cutting edge cross-section to precisely control the rock breaking resistance, a perfect balance of the horizontal components of force on both sides on the cutter can ultimately be achieved.

[0040] By adopting the above-mentioned three-level adjustment mechanism of "tilt angle matching - blade width compensation - blade shape correction", the ratio of the first horizontal component force to the second horizontal component force can be precisely adjusted to a near 1:1 equilibrium state without changing the overall working mode of the hob. This achieves force self-balancing, effectively eliminates harmful lateral load caused by asymmetrical rock surfaces, significantly reduces the risk of abnormal ablation of bearing end face and uneven wear and detachment of cutter ring 2, and significantly improves the service life and operational reliability of the hob under complex corner working conditions.

[0041] In one embodiment, along the radial direction of the cutter shaft 1, the radial dimension of the central vertical cutting edge 4 is greater than that of the first inclined cutting edge 5 and the second inclined cutting edge 6. By designing the central vertical cutting edge 4 to have the maximum radial protrusion height, the integrated composite cutting edge 3 is matched with the rock surface of the rock mass 7, meaning that the central vertical cutting edge 4, the first inclined cutting edge 5, and the second inclined cutting edge 6 simultaneously penetrate the rock mass, enabling all three to work together to break the rock. This three-blade stepped collaborative rock-breaking configuration, compared to a three-blade flush design, can significantly reduce the overall pushing force required for rock breaking, improve rock-breaking efficiency, and at the same time avoid the inclined cutting edge from prematurely bearing excessive frontal impact load, which is beneficial for protecting the cutting edge and extending tool life.

[0042] In one embodiment, the one-piece composite blade 3 and the blade ring 2 are integrally forged, cast, or formed by powder metallurgy. These one-piece forming processes ensure that the central vertical blade 4, the first inclined blade 5, the second inclined blade 6, and the blade ring 2 body form a continuous and dense metal structure without any connecting interfaces, thus eliminating the weak joint surfaces present in traditional welded or mechanically assembled structures.

[0043] This integrated structure allows the stress to be continuously and evenly transmitted between the cutter ring 2 and the cutting edge when the cutter is subjected to huge alternating impact loads and bending moments generated during rock breaking. This completely avoids the possibility of fatigue cracks caused by stress concentration at welds or assembly interfaces, thus eliminating the major risk of separation and detachment of the cutting edge from the cutter ring 2. This greatly enhances the overall structural integrity, load-bearing capacity, and reliability of the cutter under harsh working conditions.

[0044] Furthermore, as some optional implementation methods, the parameters and structural details described above should not be construed as limiting the scope of protection of this application. For example, although the specific values ​​of the inclination angle, cutting edge width, and shape factor in the foregoing embodiments are preferred for achieving perfect balance under specific rock surface geometry conditions, those skilled in the art will understand that in actual engineering, based on the physical and mechanical properties of the specific rock mass 7 and the cutterhead structure dimensions, the multiple range of the first effective cutting edge width and the second effective cutting edge width, as well as the specific values ​​of the first and second shape factors, can be flexibly combined within their reasonable ranges, as long as the ultimate goal of balancing the first and second horizontal components is met. The specific value ranges given in the foregoing embodiments are not fixed in their selected thresholds, but are determined comprehensively based on the balance target, structural strength, and wear resistance life requirements. When the parameters of the rock mass 7 or the structural boundary conditions change, those skilled in the art can re-obtain the specific value ranges of each parameter when the balance conditions are met through conventional means such as finite element simulation, bench experiments, or field testing, and use them as new selected thresholds. In addition to integral forging, casting and powder metallurgy, the manufacturing of the one-piece composite blade 3 can also adopt other processes that enable the blade and the blade ring 2 to achieve metallurgical bonding or high-strength non-detachable connection, such as hot isostatic pressing, laser cladding, electron beam welding, etc. These should all be regarded as alternatives to one-piece molding.

[0045] This application also provides a cutterhead, which is a W-type cutterhead, including the axial compound hobbing cutter for a tunneling machine described in any of the foregoing embodiments.

[0046] Specifically, the W-shaped cutterhead includes an outer inclined surface, an inner inclined surface, and a transition surface connecting the outer and inner inclined surfaces. The angle between the outer inclined surface and the horizontal plane is greater than the angle between the inner inclined surface and the horizontal plane. The axial composite cutter is disposed on this transition surface. According to this embodiment, during tunneling, the cutter located on the transition surface faces an asymmetrical rock surface formed by the intersection of inner and outer inclined surfaces with different inclination angles. By installing the axial composite cutter of this application in this critical position, its asymmetrical integrated composite cutting edge 3 can achieve perfect geometric matching and adaptive contact with the asymmetrical rock surface below the transition surface. During the process of the cutter revolving with the cutterhead and rolling and breaking the rock, the cutter smoothly and efficiently breaks the rock in the transition area through its self-balancing force characteristics. The W-type cutterhead with this configuration solves the bottleneck problems of uneven load, uneven wear, and short life caused by the unbalanced force of traditional symmetrical cutters at this point. It enables the entire W-type cutterhead to advance efficiently and stably at the rock-breaking boundary, significantly improving the tunneling efficiency of the shaft boring machine and the working reliability of the cutterhead system under complex cross-sections.

[0047] This application also provides a design method for an axial composite cutter for a tunneling machine, applicable to the axial composite cutter described in any of the foregoing embodiments. The method includes the following steps.

[0048] S1: Based on the geometric parameters of rock mass 7, determine the first dip angle and the second dip angle. That is, according to the specific inclination shape of the rock surface at the W-shaped cutterhead transition surface in the target construction stratum, first determine the rock surface dip angle that the first dip edge 5 and the second dip edge 6 need to match, and then select the specific values ​​of the first dip angle and the first dip angle.

[0049] S2: With the goal of equalizing the first and second horizontal force components, the first and second effective cutting widths are determined based on the first effective cutting width being 1 to 1.3 times the second effective cutting width, the first tilt angle, and the second tilt angle. Under the condition of a determined tilt angle, based on the equality of the horizontal force components and within the limiting range of the cutting width ratio, the first and second effective cutting widths that can compensate for the difference in horizontal force components to the greatest extent are calculated, thereby achieving coarse adjustment balance of the hob in the horizontal direction.

[0050] S3: Configure the first shape factor and the second shape factor to make the first horizontal component force and the second horizontal component force equal. After the blade width compensation, calculate the amount of residual resistance adjustment required to achieve perfect balance, and select or design the blade edge cross-sectional shape (such as flat top, arc or parabola) of the inclined blades on both sides so that their shape factors meet the balance conditions, thereby achieving precise correction of the lateral force.

[0051] This step-by-step design method provides engineers with a clear and quantifiable design process, avoiding blind trial and error. It enables the efficient and accurate development of customized axial composite cutters, ensuring that the designed cutters achieve the predetermined goals of self-balancing, high-efficiency rock breaking, and long service life under given asymmetric rock surface conditions.

[0052] Furthermore, the distance from the vertical plane where the tip of the first inclined blade 5 is located to the midpoint of the axial direction of the cutter shaft 1 is adjusted, the distance from the vertical plane where the tip of the second inclined blade 6 is located to the midpoint of the axial direction of the cutter shaft 1 is adjusted, and the distance from the vertical plane where the central vertical blade 4 is located to the midpoint of the axial direction of the cutter shaft is adjusted, so that the algebraic sum of the torques generated by the vertical components of the first inclined blade 5, the second inclined blade 6, and the central vertical blade 4 relative to the midpoint of the cutter shaft 1 is zero, so that the integrated composite blade 3 satisfies the torque balance condition.

[0053] It should be noted that the middle position of the axial direction of the cutter shaft 1 refers to the position at half the axial length of the cutter shaft 1.

[0054] In practical implementation, once the installation positions of the first inclined blade 5 and the second inclined blade 6 are determined, if their torques are unbalanced, a balancing torque can be provided by adjusting the axial position of the central vertical blade 4. Specifically, the axial position of the central vertical blade 4 can be finely adjusted relative to the first inclined blade 5 and the second inclined blade 6 so that the resultant torque of the central vertical blade 4 and the second inclined blade 6 equals the torque of the first inclined blade 5, thereby achieving overall torque balance. This adjustment method makes the cutter's balancing system more flexible and allows for adaptive configuration according to different rock surface geometry and load conditions.

[0055] This ensures that the entire hob achieves mechanical balance in both the horizontal and vertical directions.

[0056] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0057] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0058] It should also be noted that in the apparatus, equipment, and housing of this application, the components or steps can be disassembled and / or reassembled. These disassemblies and / or reassemblies should be considered as equivalent solutions of this application.

[0059] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0060] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0061] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. An axial compound cutter for a tunneling machine, characterized in that, include: The cutter shaft is fixed in place. The cutter ring is rotatably fitted onto the cutter shaft; An integral composite blade is integrally formed on the blade ring. The integral composite blade consists of a central vertical blade located in the axial center of the blade shaft and a first inclined blade and a second inclined blade located on both sides of the central vertical blade along the axial direction. The first inclined blade has a first set of parameters, and the second inclined blade has a second set of parameters; The first parameter set includes a first tilt angle, a first effective cutting width, and a first shape factor; the second parameter set includes a second tilt angle, a second effective cutting width, and a second shape factor. The first tilt angle is the angle between the first tilting blade and the vertical direction, and the second tilt angle is the angle between the second tilting blade and the vertical direction. The values ​​of the first tilt angle and the second tilt angle are not equal. The first effective cutting width is the width of the part of the first inclined cutting edge that contacts the rock mass, the second effective cutting width is the width of the part of the second inclined cutting edge that contacts the rock mass, the first shape factor is the influence coefficient of the cutting edge cross-sectional shape of the first inclined cutting edge on the rock mass breaking resistance, and the second shape factor is the influence coefficient of the cutting edge cross-sectional shape of the second inclined cutting edge on the rock mass breaking resistance. The first parameter group and the second parameter group are configured to compensate for the difference between the first tilt angle and the second tilt angle by combining the difference between the first effective cutting width and the second effective cutting width and the difference between the first shape factor and the second shape factor, so that the force on the first tilted blade and the second tilted blade in the horizontal direction is equal in magnitude and opposite in direction.

2. The axial composite hobbing cutter for a tunneling machine according to claim 1, characterized in that, The product of the first effective cutting edge width, the first shape factor, and the sine value twice the first dip angle constitutes the first horizontal component of the rock mass on the first inclined cutting edge. The product of the second effective cutting edge width, the second shape factor, and the sine value twice the second dip angle constitutes the second horizontal component of the rock mass on the second inclined cutting edge. The first horizontal component and the second horizontal component are equal in magnitude and opposite in direction.

3. The axial composite hobbing cutter for a tunneling machine according to claim 2, characterized in that, The first tilt angle θ L Less than the second tilt angle θ R ; The first effective cutting width is greater than the second effective cutting width; The first shape factor is greater than the second shape factor.

4. The axial composite cutter for a tunneling machine according to claim 3, characterized in that, 8°≤θ L ≤15°,30°≤θ R ≤45°; The first effective cutting width is 1 to 1.3 times the second effective cutting width; The first inclined blade has a flat-topped cross-sectional shape, and the first shape factor is 1.0; The cutting edge cross-section of the second inclined blade is a circular arc cross-section or a parabolic cross-section, and the second shape factor is 0.7-0.

8.

5. The axial composite cutter head for a tunneling machine according to claim 1, characterized in that, Along the radial direction of the cutter axis, the radial dimension of the central vertical cutting edge is greater than the radial dimensions of the first inclined cutting edge and the second inclined cutting edge.

6. The axial composite cutter head for a tunneling machine according to claim 1, characterized in that, The integrated composite blade and the blade ring are integrally forged, cast, or formed by powder metallurgy.

7. A cutter head, characterized in that, The cutterhead is a W-type cutterhead, and the W-type cutterhead includes the axial composite roller cutter for a tunneling machine as described in any one of claims 1-6.

8. The cutter head according to claim 7, characterized in that, The W-shaped cutter head includes an outer inclined surface, an inner inclined surface, and a transition surface connecting the outer inclined surface and the inner inclined surface. The angle between the outer inclined surface and the horizontal plane is greater than the angle between the inner inclined surface and the horizontal plane. The axial composite hob is disposed on the transition surface.

9. A design method for an axial composite hobbing cutter used in a tunneling machine, characterized in that, An axial compound cutter for a tunneling machine as described in any one of claims 1-6, comprising: S1: Determine the first dip angle and the second dip angle based on the geometric parameters of the rock mass; S2: With the goal of equalizing the first horizontal component force and the second horizontal component force, the first effective cutting width and the second effective cutting width are determined based on the fact that the first effective cutting width is 1 to 1.3 times the second effective cutting width, the first tilt angle, and the second tilt angle. S3: Configure the first shape factor and the second shape factor so that the first horizontal component force and the second horizontal component force are equal; Wherein, the first tilt angle is the angle between the first tilting blade and the vertical direction, the second tilt angle is the angle between the second tilting blade and the vertical direction, and the values ​​of the first tilt angle and the second tilt angle are not equal; The first effective cutting width is the width of the part of the first inclined cutting edge that contacts the rock mass, the second effective cutting width is the width of the part of the second inclined cutting edge that contacts the rock mass, the first shape factor is the influence coefficient of the cutting edge cross-sectional shape of the first inclined cutting edge on the rock mass breaking resistance, and the second shape factor is the influence coefficient of the cutting edge cross-sectional shape of the second inclined cutting edge on the rock mass breaking resistance.

10. The design method for an axial composite hobbing cutter for a tunneling machine according to claim 9, characterized in that, Adjust the distance from the vertical plane where the tip of the first inclined blade is located to the midpoint of the axial direction of the cutter shaft, adjust the distance from the vertical plane where the tip of the second inclined blade is located to the midpoint of the axial direction of the cutter shaft, and adjust the distance from the vertical plane where the central vertical blade is located to the midpoint of the axial direction of the cutter shaft, so that the algebraic sum of the torques generated by the vertical components of the first inclined blade, the second inclined blade, and the central vertical blade relative to the midpoint of the cutter shaft is zero, so that the integrated composite blade satisfies torque balance.

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