A design method of multi-tooth rock breaking cutter of a cutter head of a cellular tunnel boring machine

Abstract

The application belongs to the technical field of tunneling construction equipment, and discloses a design method of a multi-tooth rock breaking cutter of a cutter head of a honeycomb type tunnel boring machine. The design method designs involute gear cutting tooth structure at the overall circumference of a cutter ring of a rolling cutter, and simultaneously uses radial force and shearing force generated by gear cutting to break rocks, so as to replace the traditional rolling cutter which only relies on the extrusion force and impact force of the cutter head to cut and break rocks, and to realize high-speed cutting construction of the tunnel boring machine. Meanwhile, the traditional solid connecting structure cutter shaft is improved to be a honeycomb type porous structure rolling cutter shaft. The honeycomb structure is composed of a series of hexagonal or other polygonal honeycomb structures arranged in the shaft body in a regular manner, and forms a continuous, uniform and periodic topological structure. The structure design improves the durability and stability of the cutter shaft under harsh working conditions on the premise of ensuring that the cutter shaft has sufficient strength and rigidity, thereby prolonging the service life of the cutter shaft.

Description

Technical Field

[0001] This invention belongs to the technical field of tunnel excavation equipment. In response to engineering problems such as slow excavation speed and severe vibration that easily damages the main load-bearing structure, a cutter head structure that improves the excavation rate and reduces vibration is designed. The invention adopts a novel involute hobbing tooth structure cutter head ring and honeycomb cutter shaft design method. Background Technology

[0002] Tunnel boring machines (TBMs), often referred to as the "crown jewel" of high-end equipment manufacturing, require a novel tooth-like cutterhead design to ensure safe and rapid tunneling. Traditional disc-shaped cutterheads and cutter shafts are key vulnerable structures of the TBM cutterhead. The cutterhead, a smooth plane, relies on the impact and compressive force generated by the rotating cutterhead to break up hard rock. However, this rock-breaking efficiency is insufficient for current tunneling needs and cannot adapt to complex geological conditions involving alternating hard rock, soft rock, and muddy water. The smooth cutterhead is easily encased in mud and sand, affecting tunneling speed and resulting in low construction efficiency.

[0003] In summary, to ensure safe tunneling, improve tunneling efficiency, reduce vibration damage, and lower construction costs, it is necessary to develop a design method for an involute hobbing cutter ring and honeycomb cutter shaft to meet the requirements of efficient, rapid, and stable tunneling for tunnel boring machines. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies in terms of low adaptability. Specifically, considering the characteristics of the cutterhead ring in tunnel boring machines, this invention proposes a novel involute gear cutterhead ring and honeycomb cutter shaft design method. This method designs an involute gear cutting tooth structure around the entire circumference of the cutterhead ring. The radial force and shear force generated by gear cutting are used simultaneously to break rock, replacing the traditional method of cutting rock solely through the extrusion and impact force of the cutterhead, thus enabling high-speed cutting operations for tunnel boring machines. Simultaneously, the traditional solid connection structure cutter shaft is improved by adopting a honeycomb porous structure cutter shaft. This honeycomb structure consists of a series of hexagonal or other polygonal hole units arranged according to specific rules inside the shaft, forming a continuous and uniform periodic topological structure. This structural design, while ensuring sufficient strength and rigidity of the cutter shaft, improves its durability and stability under harsh working conditions, thereby extending the service life of the cutter shaft.

[0005] The technical solution of the present invention:

[0006] A design method for a honeycomb-type tunnel boring machine cutterhead multi-tooth rock-breaking cutter involves creating involute hobbing cutting teeth on the cutting edge of the cutterhead ring to form a multi-tooth disc-shaped cutterhead, and adding a honeycomb structure at the cutter shaft to form a honeycomb-shaped porous cutter shaft. This cutter is suitable for various geological conditions, including hard rock, soft rock, and muddy water mixed strata, enabling rapid and precise cutting and tunneling operations, while also providing vibration reduction, damage resistance, and service life extension.

[0007] The steps are as follows:

[0008] (1) Design method of multi-tooth disc hob;

[0009] (1.1) Based on the tunneling parameters and cutter geometry parameters, the vertical force acting on the cutter during tunneling is calculated as follows:

[0010] (1)

[0011] Among them, F v Vertical force, unit: N; θ is the rock compressive strength, in MPa; θ is the cutting edge angle, in degrees (°); R is the roller radius, in mm; A is the cutting edge width, in mm; k is the elastic limit coefficient, between 1 and 2; L is the depth of penetration into the rock, in mm.

[0012] (1.2) The tooth height of the cutting teeth in the involute hobbing structure is determined as follows:

[0013] (2)

[0014] Where: h is the tooth height, in mm; t is the wear amount of the hob ring; g is the minimum vertical distance of the hob ring, in mm;

[0015] (1.3) With a vertical force F v The product of the tooth height h and the tooth root bending moment is used as the tooth root bending moment. Combined with the allowable bending stress of the hob cutter ring material, the minimum tooth thickness of the cutting tooth in an involute hobbing structure that meets the strength requirements is calculated using the tooth root bending strength check formula:

[0016] (3)

[0017] (4)

[0018] σ F ≤[σ FP (5)

[0019] Where, σ F σ is the tooth root stress, in MPa; FP Let F be the allowable bending stress of the hob cutter ring material, and let F be the ultimate tensile strength of the hob cutter ring, not exceeding 750 MPa; MB is the root bending moment, in N; B is the tooth width, i.e., the thickness of the hob cutter ring, in mm; S f The safety factor is between 2 and 3; S is the tooth thickness in mm.

[0020] (1.4) Determine the tooth groove width based on the minimum tooth thickness and the rock compressive strength grade;

[0021] (6)

[0022] Where e is the tooth groove width, in mm; K e K is the surrounding rock coefficient. For Class I and Class II rocks, K e The value ranges from 0.5 to 0.75; for Class III, Class IV, and Class V rocks, K... e The value range is 1-1.25;

[0023] (1.5) Based on the hob ring radius R, the hob ring wear amount t, the minimum tooth thickness S, and the tooth groove width e, the number of teeth on the hob ring is determined as follows:

[0024] (7)

[0025] Where Z represents the number of teeth on the cutter ring, in units of teeth;

[0026] (2) Design method for hobbing cutter shaft with honeycomb porous structure;

[0027] The cutter shaft is replaced with a hob cutter shaft with a honeycomb porous structure; the honeycomb porous structure is composed of a series of polygonal hole units arranged regularly inside the hob cutter shaft, forming a continuous and uniform periodic topological structure.

[0028] (2.1) Calculate the honeycomb geometry using the critical shear buckling stress:

[0029] (8)

[0030] (9)

[0031] in, The critical shear buckling stress of the honeycomb structure is expressed in MPa. The shear buckling coefficient is taken as 5.35; This represents the elastic modulus of the honeycomb structure material itself, expressed in MPa. Poisson's ratio for honeycomb structure materials; J represents the cell wall thickness in mm, ranging from 1 mm to 2 mm; J represents the connection width between cell structures in mm. The width of the honeycomb structure is in mm.

[0032] (2.2) Finally, the number of cells in the cutter shaft honeycomb structure was determined to be:

[0033] (10)

[0034] in, C represents the number of honeycomb structures, in units; C represents the width of the cutter shaft, in mm.

[0035] The beneficial effects of this invention are as follows: This invention creates multi-tooth disc-shaped cutter cutters by opening involute hobbing teeth on the cutting edge of the cutter ring, changing the traditional smooth cutting edge structure of the cutter ring. This increases radial and shear forces during tunnel excavation, making it better adaptable to various geological and construction environments. This improvement not only optimizes the working performance of the cutter but also provides key component technical support for the efficient, vibration-reduced, and long-life operation of tunnel excavation equipment. This invention also designs a honeycomb-shaped porous structure cutter shaft. While ensuring sufficient strength and rigidity, it significantly reduces the overall mass of the cutter shaft, achieving a lightweight goal and helping to reduce equipment operating inertia and drive energy consumption. Simultaneously, the inherent high specific strength and excellent compressive and fatigue resistance of the honeycomb structure can effectively disperse and absorb the complex alternating stress and vibration energy generated during excavation, improving the durability and stability of the cutter shaft under harsh working conditions. Furthermore, the honeycomb structure inside the cutter shaft helps to block crack propagation paths, thereby extending the service life of the cutter shaft. Attached Figure Description

[0036] Figure 1 Axonometric drawing of a multi-tooth disc cutter for a tunnel boring machine with oblique honeycomb cutter;

[0037] Figure 2 This is a front view of a multi-tooth disc cutter head of a beveled honeycomb tunnel boring machine.

[0038] Figure 3 Axonometric drawing of a multi-tooth disc cutter for a tangential honeycomb tunnel boring machine;

[0039] Figure 4 This is a front view of a multi-tooth disc cutter head of a tangential honeycomb tunnel boring machine.

[0040] Figure 5 This is a magnified view of a multi-tooth disc hob.

[0041] Figure 6 Axonometric view of a tangential honeycomb-shaped knife axis;

[0042] Figure 7 Axonometric drawing of a beveled honeycomb cutter shaft;

[0043] In the diagram: 1-1 Obliquely cut honeycomb porous structure roller cutter shaft; 1-2 Obliquely cut honeycomb structure tunnel boring machine roller cutter body; 1-3 Obliquely cut honeycomb structure tunnel boring machine multi-tooth disc type roller cutter ring; 2-1 Positively cut honeycomb porous structure roller cutter shaft; 2-2 Positively cut honeycomb structure tunnel boring machine roller cutter body; 2-3 Positively cut honeycomb structure tunnel boring machine multi-tooth disc type roller cutter ring. Detailed Implementation

[0044] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0045] Example

[0046] (a) For a 19-inch hobbing cutter ring: cutting edge angle θ = 90°, rock compressive strength =83 MPa; the radius of the hobbing cutter ring R=241 mm, the cutting width A=20 mm, the elastic limit coefficient k=1, the depth of penetration into the rock L=30 mm; the wear amount of the hobbing cutter ring t=20 mm; the minimum vertical distance of the hobbing cutter ring g=57 mm; σ FP Allowable stress, not exceeding 750 MPa; tooth width B = 20 mm; safety factor S f =2; surrounding rock coefficient Ke=1, wear of the hobbing cutter ring =20mm. The design method for multi-tooth disc hobs is as follows:

[0047] (1) Based on the tunneling parameters and cutter geometry parameters, the vertical force on the cutter during tunneling is calculated as follows:

[0048] ≈ N

[0049] (2) Determine the tooth height of the cutting teeth in the involute hobbing structure as follows:

[0050]

[0051] Where h is 50mm.

[0052] (3) With a vertical force F v The product of the tooth height h and the tooth root bending moment is used as the tooth root bending moment. Combined with the allowable bending stress of the hob cutter ring material, the minimum tooth thickness of the cutting tooth in an involute hobbing structure that meets the strength requirements is calculated using the tooth root bending strength check formula:

[0053] σ F ≤750Mpa

[0054]

[0055] ≤750Mpa

[0056] The minimum tooth thickness S is set at 28.26 mm;

[0057] (5) Determine the tooth groove width based on the minimum tooth thickness and the rock compressive strength grade;

[0058]

[0059] (6) Finally, based on the radius R of the cutter ring, the wear amount t of the cutter ring, the minimum tooth thickness s, and the tooth groove width e, the number of teeth of the cutter ring is determined as follows:

[0060] 24.56

[0061] The number of teeth on the cutter ring is set to 25.

[0062] (II) Based on the critical shear buckling stress of honeycomb structures =4667MPa; Shear buckling coefficient =5.35; Elastic modulus of the honeycomb structure material itself =72000MPa; Poisson's ratio of honeycomb structure material =0.33; honeycomb wall thickness =1mm; the width of the cutter shaft C=483mm, and the design method of the honeycomb porous structure hob cutter shaft is as follows:

[0063] (1) Calculate the geometric dimensions of the honeycomb structure by using the critical shear buckling stress;

[0064]

[0065]

[0066] The connection width between the honeycomb structures is determined to be J = 2.91 mm, and the width of the honeycomb structure is... =5.82mm;

[0067] (2) Finally, the number of cells in the cutter shaft honeycomb structure was determined to be:

[0068]

[0069] The number of cells in the cutter shaft honeycomb structure was determined to be 56.

Claims

1. A design method for multi-tooth rock-breaking cutters on a honeycomb tunnel boring machine cutterhead, characterized in that, A multi-tooth disc hob is formed by creating involute hobbing teeth on the cutting edge of the hob ring, and a honeycomb structure is added to the cutter shaft to form a honeycomb-shaped porous hob shaft; the steps are as follows: (1) Design method of multi-tooth disc hob; (1.1) Based on the tunneling parameters and cutter geometry parameters, the vertical force acting on the cutter during tunneling is calculated as follows: (1) in, F v Vertical force, unit: N; Rock compressive strength, in MPa; θ The blade angle is expressed in degrees (°). R The radius of the hob is in mm. A Blade width, in mm; k The elastic limit coefficient is between 1 and 2. L The depth of the intrusion into the rock, in mm; (1.2) The tooth height of the cutting teeth in the involute hobbing structure is determined as follows: (2) in: h Tooth height, in mm; t This represents the wear amount of the hob cutter ring; g The minimum vertical distance between the hob cutter rings, in mm; (1.3) With vertical force F v With tooth height h The product is used as the root bending moment. Combined with the allowable bending stress of the hob ring material, the minimum tooth thickness of the cutting tooth of the involute hobbing structure that meets the strength requirements is calculated using the tooth root bending strength check formula: (3) (4) σ F ≤[ σ FP ] (5) in, σ F This represents the tooth root stress, measured in MPa. σ FP is the allowable bending stress of the hob cutter ring material, and is the ultimate strength of the hob cutter ring, not exceeding 750 MPa; F M B is the tooth root bending moment, in N; B is the tooth width, i.e., the thickness of the hob cutter ring, in mm. S f The safety factor is between 2 and 3; S is the tooth thickness in mm. (1.4) Based on the minimum tooth thickness The tooth groove width is determined based on the rock compressive strength grade; (6) Where e is the tooth groove width, in mm; K e The surrounding rock coefficient is used for both Class I and Class II rocks. K e The value ranges from 0.5 to 0.75; for Class III, Class IV, and Class V rocks, K e The value range is 1-1.25; (1.5) Based on the hob cutter ring radius R, the hob cutter ring wear amount t, and the minimum tooth thickness Given the tooth groove width e, the number of teeth on the hob cutter ring is determined as follows: (7) Where Z represents the number of teeth on the cutter ring, in units of teeth; (2) Design method for hobbing cutter shaft with honeycomb porous structure; The cutter shaft is replaced with a hob cutter shaft with a honeycomb porous structure; the honeycomb porous structure is composed of a series of polygonal hole units arranged regularly inside the hob cutter shaft, forming a continuous and uniform periodic topological structure. (2.1) Calculate the honeycomb geometry using the critical shear buckling stress: (8) (9) in, The critical shear buckling stress of the honeycomb structure is expressed in MPa. The shear buckling coefficient is taken as 5.35; This represents the elastic modulus of the honeycomb structure material itself, expressed in MPa. Poisson's ratio for honeycomb structure materials; The cell wall thickness is expressed in mm and ranges from 1 mm to 2 mm. J This represents the connection width between the honeycomb structures, in mm. The width of the honeycomb structure is in mm. (2.2) Finally, the number of cells in the cutter shaft honeycomb structure was determined to be: (10) in, The number of cellular structures, expressed in units. C This represents the width of the cutter shaft, in mm.

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