Shield cutter ring and remanufacturing method thereof

Abstract

The invention discloses a shield hob cutter ring and a remanufacturing method thereof, comprising a cutter ring, an alloy deposition layer, a hard alloy cutter tooth and a wear-resistant layer. The cutter ring is a failed cutter ring recycled and remanufactured from a failed shield disc cutter. The alloy deposition layer material is FeNiCrBSi series iron-based alloy powder, which is generated on the outer surface of the cutter ring by 3D printing. The hard alloy wedge-shaped cutter teeth are embedded between the alloy deposition layers, and the side of the cutter ring is clad with a wear-resistant layer. The repaired cutter ring printed with the alloy deposition layer does not need to disassemble the cutter ring or the hob, and the cutter teeth can be quickly replaced at the construction site, saving maintenance time. The alloy deposition layer has good toughness and low rigidity, can withstand the load from the cutter teeth, there is a certain interval between the cutter teeth, can increase the cutter ring torque, reduce eccentric wear, the hard alloy cutter teeth and the wear-resistant layer can improve the wear resistance of the cutter ring, and the use of the failed cutter ring can significantly improve the utilization rate of the cutter ring, extend the service life, save construction costs, and has good economic benefits and promotion value.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel boring tools, and in particular relates to a shield cutter ring and a remanufacturing method thereof. Background Art

[0002] The shield machine is a tunnel boring machine that uses the shield method. It is the core equipment in infrastructure and a symbol of the manufacturing level of a country's underground construction equipment. The shield cutter ring is a key part for the shield machine to perform rock breaking tasks. It is often in extreme service conditions of huge extrusion, bending and twisting, impact, wear and local high temperature. Therefore, after a period of use, it will show normal wear, eccentric wear, fracture, peeling, deformation and other failures. The failed cutter must be removed from the cutter head and replaced with a new one. It takes 2 people 2 to 4 hours to remove the cutter, repair it and reinstall it. It takes at least half a day for the shield machine to stop and replace the cutter each time, which reduces the efficiency of shield excavation. According to statistics, the cost of cutter consumption in shield machine construction accounts for about 1 / 5 to 1 / 4 of the project cost, and it is as high as about 1 / 3 when the geological conditions are bad; the time consumed by the cutter replacement accounts for about 1 / 3 of the construction time. At the same time, the cutter rings that are cut off cannot be reused, resulting in a waste of resources and increased excavation costs. However, most of the failure forms of cutter rings are normal wear, and most of the structures are still intact, so remanufacturing of failed cutter rings is of great significance and value.

[0003] Since the mechanical properties and integrity of the cutter ring decrease after serving under extreme working conditions, during the remanufacturing process of the cutter ring, excessive stress should be avoided and structures that cause unbalanced stress distribution should be avoided to avoid secondary damage to the cutter ring. Only under this premise can the cutter ring be strengthened to maintain or even exceed the original performance.

[0004] Currently, the main method for remanufacturing failed cutter rings is surfacing, but the heat input of surfacing is large, which can easily lead to cracks in the cutter ring and cause cracking and peeling of the additive manufacturing coating. It also has the disadvantages of long surfacing time and excessive heat input, which causes coarse grains and reduces performance.

[0005] There is also a method of installing the cutter teeth in the industry, which involves drilling holes, slotting and installing the cutter teeth on the cutter ring. There is also a method of installing the cutter teeth on the cutter ring using threaded connections, which also requires drilling holes on the cutter ring. There is also a method of connecting the cutter teeth and the cutter ring by welding. In addition, except for some processes for strengthening the cutter ring, which describe the use of cutter ring blanks, other processes do not mention whether the cutter rings used are recycled from failed cutter rings.

[0006] In summary, the use of surfacing for remanufacturing may cause defects such as cracks and coarse grains; if the method of installing cutter teeth is used for remanufacturing, the above-mentioned shield cutter ring with cutter teeth needs to have cutter tooth installation holes on the cutter ring, which is not suitable for failed cutter rings to be remanufactured.

[0007] Therefore, it is urgent to improve the remanufacturing technology of failed cutter rings, develop a remanufactured cutter ring with performance no less than that of a new cutter ring, improve the utilization rate of the cutter ring, save construction costs, and expand the remanufacturing channels of the cutter ring. Summary of the invention

[0008] The object of the present invention is to provide a shield cutter ring and a remanufacturing method thereof to solve the problems raised in the above-mentioned background technology.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] A shield cutter ring remanufacturing method comprises the following steps:

[0011] 1) Remove the failed cutter ring from the hob and smooth it;

[0012] 2) Printing a plurality of alloy deposition layers on the outer surface of the cutter ring by 3D printing, wherein the plurality of alloy deposition layers are arranged at intervals to form a plurality of mounting grooves;

[0013] 3) Cladding a wear-resistant layer on the side of the cutter ring;

[0014] 4) Push multiple carbide cutting teeth into multiple mounting grooves.

[0015] Furthermore, the leveling process in step 1) includes:

[0016] Clean the knife ring;

[0017] Use wire cutting to cut the cutter ring to the position with the lowest outer diameter wear and remove the worn part;

[0018] Turn the outer surface of the cutter ring until it is flat.

[0019] Furthermore, in step 2), FeNiCrBSi iron-based alloy powder is used for 3D printing, and the mass percentage of each element in the FeNiCrBSi iron-based alloy powder is as follows: 7.3% Ni, 12.2% Cr, 1.0% B, 2.3% Si, 2.0% Mo, 0.3% Mn, 2.0% C, 0.1% V, 1.2% W, and the rest is Fe.

[0020] Furthermore, in step 2), it includes:

[0021] (1) Printing the first alloy deposition layer;

[0022] (2) Rotate the cutter ring 90° to print the next alloy deposition layer;

[0023] (3) Repeat step (2) twice to complete the printing of a set of four alloy deposition layers;

[0024] (4) rotating the cutter ring to a position adjacent to the first alloy deposition layer and executing steps (1) to (3) to complete the printing of the next set of four alloy deposition layers;

[0025] (5) Repeat step (4) until all alloy deposition layers are printed.

[0026] The present invention also provides a shield cutter ring, comprising:

[0027] Knife ring;

[0028] A plurality of alloy deposition layers are arranged at intervals on the outer surface of the cutter ring to form a plurality of mounting grooves;

[0029] Wear-resistant layer, provided on the side of the knife ring;

[0030] A plurality of carbide cutting teeth are respectively embedded in a plurality of mounting grooves.

[0031] Furthermore, along the opposite direction of the hob's revolution, the front side of the alloy deposition layer is a convex structure with an inclined arc surface, and the rear side is a dovetail-shaped concave structure with an inclined arc surface, and the intersection line of the front and rear arc surfaces on the symmetry plane of the cemented carbide tooth is an involute.

[0032] Furthermore, the carbide tooth comprises a tooth seat and a tooth head arranged on the tooth seat, the tooth seat is adapted to the mounting groove, the tooth seat is self-locking after being embedded in the mounting groove, and can be pulled out in the reverse direction of the embedding direction, and edges are arranged on both sides of the tooth seat.

[0033] Furthermore, the blade tooth head is wedge-shaped or spherical.

[0034] Furthermore, the cutter head and the insert seat are integrally formed.

[0035] Furthermore, the material of the alloy deposition layer is FeNiCrBSi iron-based alloy powder, and the mass percentage of each element is as follows: 7.3% Ni, 12.2% Cr, 1.0% B, 2.3% Si, 2.0% Mo, 0.3% Mn, 2.0% C, 0.1% V, 1.2% W, and the rest is Fe.

[0036] Beneficial Effects

[0037] The present invention provides a shield cutter ring and a remanufacturing method thereof, which uses a laser cladding technology with low heat input and good formability for 3D printing remanufacturing; the printed alloy deposition layer is wear-resistant and impact-resistant, and can withstand the load from the cemented carbide teeth; the cemented carbide teeth are tightly embedded between the alloy deposition layers, and the failed teeth can be conveniently disassembled and replaced without removing the roller or the cutter ring, which can shorten the maintenance time and reduce the construction time; the alloy deposition layers are staggered and clad during the 3D printing process, which can reduce local thermal stress; reusing the failed cutter ring with remanufacturing value can save the excavation construction cost, and has good economic significance and promotion value.

[0038] A common method in 3D printing is to add WC powder. The online remanufacturing process of 3D printing knife rings with WC powder has the following shortcomings: The melting point and thermal expansion coefficient of WC powder are too different from those of 3D printing alloy powder, and the WC content is high. Cracks will inevitably appear between WC particles and 3D printing alloys, and there is also a lack of a process to eliminate cracks. The iron-based alloy powder provided by the present invention can effectively solve the above problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of a self-locking 3D printed toothed remanufactured shield cutter ring in specific embodiment 1 of the present invention;

[0040] Figure 2 It is a structural schematic diagram of a self-locking 3D printed inlaid tooth type remanufactured shield cutter ring wedge tooth in specific embodiment 1 of the present invention;

[0041] Figure 3 It is an isometric view of a self-locking 3D printed inlaid tooth type remanufactured shield hob cutter ring wedge tooth in specific embodiment 1 of the present invention;

[0042] Figure 4 It is a structural schematic diagram of an alloy deposition layer of a self-locking 3D printed toothed remanufactured shield cutter ring in a specific embodiment of the present invention;

[0043] Figure 5 It is a structural schematic diagram of a cut cutter ring of a self-locking 3D printed toothed remanufactured shield hob cutter ring in a specific embodiment of the present invention.

[0044] Figure 6 It is an implementation flow chart of a self-locking 3D printed toothed remanufactured shield cutter ring in a specific embodiment of the present invention.

[0045] Figure 7 It is a structural schematic diagram of a self-locking 3D printed toothed remanufactured shield cutter ring in specific embodiment 2 of the present invention;

[0046] Figure 8It is a structural schematic diagram of an integral wedge tooth of a self-locking 3D printed inlaid tooth type remanufactured shield cutter ring in a specific embodiment 2 of the present invention;

[0047] Fig. 9 It is an isometric view of an integral wedge tooth of a self-locking 3D printed inlaid tooth type remanufactured shield hob cutter ring in specific embodiment 2 of the present invention;

[0048] Fig.10 It is a structural schematic diagram of a self-locking 3D printed toothed remanufactured shield cutter ring in specific embodiment 3 of the present invention;

[0049] Fig.11 It is a structural schematic diagram of an integral wedge tooth of a self-locking 3D printed inlaid tooth type remanufactured shield cutter ring in a specific embodiment 3 of the present invention;

[0050] Fig.12 It is an isometric view of an integral wedge tooth of a self-locking 3D printed inlaid tooth type remanufactured shield hob cutter ring in specific embodiment 3 of the present invention;

[0051] The reference numerals in the drawings are: 1, cutter ring; 2, carbide cutter teeth; 3, alloy deposition layer; 4, wear-resistant layer; 101, outer surface of cutter ring; 102, side surface of cutter ring; 201, cutter tooth head; 202, insert seat; 203, edge. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making creative work should all fall within the scope of protection of this application. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", "inside", "outside", etc., are only reference to the directions of the accompanying drawings. Therefore, the directional words used are used to illustrate rather than limit the invention.

[0053] The present invention provides a self-locking 3D printed toothed remanufacturing shield hob cutter ring and a remanufacturing method thereof. The shield hob cutter ring comprises a cutter ring, a hard alloy cutter tooth, an alloy deposition layer and a wear-resistant layer.

[0054] The cutter ring is recovered from the failed shield disc cutter and has remanufacturing value. It undergoes pre-processing steps such as cleaning, cutting, rust removal, and turning to facilitate the subsequent 3D printing work.

[0055] The alloy deposition layer is made of an iron-based FeNiCrBSi alloy, which is generated on the outer surface of the cutter ring by 3D printing. The front side is a convex structure of an inclined arc surface, and the rear side is a dovetail-shaped concave structure of an inclined arc surface. The intersection of the front and rear arc surfaces on the symmetry plane of the cutter teeth is an involute. The direction of the alloy deposition layer is opposite to the revolution direction of the hob, and it bears the pressure from the cutter teeth.

[0056] The carbide tooth is embedded between two alloy deposition layers, and a tooth seat is arranged at the bottom. The front and rear sides of the tooth seat are frosted, and the shapes of the front and rear sides are consistent with the front and rear sides of the alloy deposition layer. It can fit tightly with the front and rear sides of the alloy deposition layer. The tooth can be self-locked after being embedded, and can be pulled out by pulling in the opposite direction of the embedding direction, so as to realize the rapid replacement of broken teeth.

[0057] The left and right sides of the insert seat are provided with edges, which can promote the rolling of the cutter ring and alleviate eccentric wear.

[0058] The self-locking 3D printed toothed remanufacturing shield hob cutter ring and the remanufacturing method thereof are characterized in that the remanufacturing method comprises the following steps:

[0059] 1) Remove the failed cutter ring with remanufacturing value from the hob; carefully wash off the oil, dirt, etc. on the cutter ring, use wire cutting to cut the cutter ring to remove the uneven wear, cracking, and peeling parts, use acid to remove the rust on the cutter ring, turn the outer surface of the cutter ring to the lowest position of outer diameter wear, and polish it flat to facilitate the subsequent 3D printing work;

[0060] 2) Using 3D printing to print alloy deposition layers on the outer surface of the cutter ring in a certain order;

[0061] 3) Grind and correct the dimensions of the front and rear sides of the alloy deposit layer to retain a suitable interference fit, so as to facilitate the embedding of the carbide teeth without generating excessive prestress on the alloy deposit layer;

[0062] 4) Cladding a wear-resistant layer on the side of the cutter ring;

[0063] 5) Pushing the carbide cutting teeth (2) to be embedded between the two alloy deposit layers (3).

[0064] The side of the cutter ring is clad with a wear-resistant layer to improve the overall performance of the cutter ring;

[0065] To avoid excessive local heat input, an alloy deposition layer is printed every 90°. After printing 4 alloy deposition layers, the printing is continued in the above manner by deflecting an angle, and so on.

[0066] The advantages of the present invention are:

[0067] (1) Compared with cladding and 3D printing of the entire cutter ring, partial 3D printing has lower heat input and no crack defects;

[0068] (2) Compared with cladding and 3D printing of the entire cutter ring, the cutter ring with a printed alloy deposition layer does not need to be disassembled after the cutter teeth fail. The cutter teeth can be quickly replaced at the construction site, saving maintenance time. Example 1

[0069] See also Figure 1-6 , a self-locking 3D printed toothed remanufactured shield hob cutter ring, comprising a cutter ring 1, an alloy deposition layer 3, a carbide cutter tooth 2 and a wear-resistant layer 4, characterized in that: the cutter ring 1 is recovered from a failed shield disc hob, has remanufacturing value, and has undergone pre-treatment steps such as cleaning, cutting, rust removal, and turning;

[0070] The alloy deposition layer 3 is made of FeNiCrBSi iron-based alloy powder, and the mass percentage of each element is as follows: 7.3% Ni, 12.2% Cr, 1.0% B, 2.3% Si, 2.0% Mo, 0.3% Mn, 2.0% C, 0.1% V, 1.2% W, and the rest is Fe. It is generated on the outer surface 101 of the cutter ring by 3D printing, with a convex structure of an inclined arc surface on the front side and a dovetail-shaped concave structure of an inclined arc surface on the rear side. The intersection of the front and rear arc surfaces on the symmetry plane of the cutter tooth 2 is an involute. The direction of the alloy deposition layer 3 is opposite to the revolution direction of the hob, and it bears the pressure from the cutter tooth 2;

[0071] The cutter head 201 of the cemented carbide cutter tooth 2 of the embodiment 1 is wedge-shaped, the cemented carbide cutter tooth 2 is embedded between two alloy deposition layers 3, and a tooth insert seat 202 is provided at the bottom. The front and rear sides of the tooth insert seat 202 are frosted, and the front and rear side shapes are consistent with the front and rear side shapes of the alloy deposition layer 3, and can fit tightly with the front and rear side surfaces of the alloy deposition layer 3. The cutter tooth 2 can be self-locked after being embedded, and can be pulled out by pulling in the opposite direction of the embedding direction, so as to realize the rapid replacement of the broken cutter tooth. There are edges 203 on the left and right sides of the tooth insert seat 202, which can promote the rolling of the cutter ring and reduce eccentric wear.

[0072] The self-locking 3D printed toothed remanufacturing shield hob cutter ring remanufacturing method comprises the following steps:

[0073] 1) Remove the failed cutter ring 1 with remanufacturing value from the hob; carefully wash away the oil, dirt, etc. on the cutter ring 1, use wire cutting to cut the cutter ring 1 to the lowest position of outer diameter wear, remove the eccentric wear, cracking, and peeling parts, use acid to remove the rust on the cutter ring 1, and turn the outer surface 101 of the cutter ring to be flat, so as to facilitate the subsequent 3D printing work;

[0074] 2) using FeNiCrBSi iron-based alloy powder, printing an alloy deposition layer 3 on the outer surface 101 of the cutter ring in a certain order by 3D printing;

[0075] 3) Grinding and correcting the dimensions of the front and rear sides of the alloy deposit layer 3, retaining a suitable interference, so as to facilitate the embedding of the carbide cutter teeth 2 without generating excessive prestress on the alloy deposit layer 3;

[0076] 4) cladding the wear-resistant layer 4 on the side surface 102 of the cutter ring;

[0077] 5) Pushing the carbide cutting teeth (2) to be embedded between the two alloy deposit layers (3).

[0078] The side surface 102 of the cutter ring is clad with a wear-resistant layer 4, which can improve the overall performance of the cutter ring;

[0079] In order to avoid excessive local heat input, an alloy deposition layer 3 is printed every 90°. After printing four alloy deposition layers 3, the printing is continued in the above manner by deflecting an angle, and so on. Example 2

[0080] See also Figure 4-9 The shape of the tooth head 201 of the cemented carbide tooth 2 of the second embodiment is spherical, and the rest is the same as that of the first embodiment. Example 3

[0081] See also Figure 4-6 , 10-12, the tooth head and the tooth seat of the cemented carbide tooth 2 of Example 3 are designed as one body, and its force distribution is more reasonable, and the rest is the same as Example 1.

[0082] Only the preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention, and various changes should be included in the protection scope of the present invention.

Claims

1. A shield cutter ring remanufacturing method, characterized in that: Includes steps: 1) Remove the failed cutter ring from the hob and smooth it; 2) Printing a plurality of alloy deposition layers on the outer surface of the cutter ring by 3D printing, wherein the plurality of alloy deposition layers are arranged at intervals to form a plurality of mounting grooves; 3) Cladding a wear-resistant layer on the side of the cutter ring; 4) Pushing multiple carbide cutting teeth into multiple mounting grooves; In step 2), include: (1) Printing the first alloy deposition layer; (2) Rotate the cutter ring 90° to print the next alloy deposition layer; (3) Repeat step (2) twice to complete the printing of a set of four alloy deposition layers; (4) rotating the cutter ring to a position adjacent to the first alloy deposition layer and executing steps (1) to (3) to complete the printing of the next set of four alloy deposition layers; (5) Repeat step (4) until all alloy deposition layers are printed.

2. The shield cutter ring remanufacturing method according to claim 1, characterized in that: The leveling process in step 1) includes: Clean the knife ring; Use wire cutting to cut the cutter ring to the position with the lowest outer diameter wear and remove the worn part; Turn the outer surface of the cutter ring until it is flat.

3. The shield cutter ring remanufacturing method according to claim 1, characterized in that: In step 2), FeNiCrBSi iron-based alloy powder is used for 3D printing. The mass percentage of each element in the FeNiCrBSi iron-based alloy powder is as follows: 7.3%Ni, 12.2%Cr, 1.0%B, 2.3%Si, 2.0%Mo, 0.3%Mn, 2.0%C, 0.1%V, 1.2%W, and the rest is Fe.

4. The shield cutter ring manufactured by the shield cutter ring remanufacturing method according to claim 1 is characterized in that: include; Knife ring; A plurality of alloy deposition layers are arranged at intervals on the outer surface of the cutter ring to form a plurality of mounting grooves; Wear-resistant layer, provided on the side of the knife ring; A plurality of carbide cutting teeth are respectively embedded in a plurality of mounting grooves.

5. The shield cutter ring according to claim 4, characterized in that: Along the opposite direction of the hob revolution, the front side of the alloy deposition layer is a convex structure of an inclined arc surface, and the rear side is a dovetail-shaped concave structure of an inclined arc surface, and the intersection line of the front and rear arc surfaces on the symmetry plane of the cemented carbide cutter teeth is an involute.

6. The shield cutter ring according to claim 5, characterized in that: The carbide cutter tooth comprises a tooth seat and a tooth head arranged on the tooth seat. The tooth seat is adapted to the mounting groove. The tooth seat is self-locking after being embedded in the mounting groove and can be pulled out in the reverse direction of the embedding direction. Edges are arranged on both sides of the tooth seat.

7. The shield cutter ring according to claim 6, characterized in that: The cutter tooth head is wedge-shaped or spherical.

8. The shield cutter ring according to claim 6, characterized in that: The cutter tooth head and the insert seat are integrally formed.

9. The shield cutter ring according to claim 4, characterized in that: The alloy deposition layer is made of FeNiCrBSi iron-based alloy powder, and the mass percentage of each element is as follows: 7.3% Ni, 12.2% Cr, 1.0% B, 2.3% Si, 2.0% Mo, 0.3% Mn, 2.0% C, 0.1% V, 1.2% W, and the rest is Fe.

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