CN-121988976-A - Maintenance method of shield composite cutterhead

CN121988976ACN 121988976 ACN121988976 ACN 121988976ACN-121988976-A

Abstract

The invention discloses a maintenance method of a shield composite cutter head, and relates to the technical field of shield manufacturing technology and cutter head maintenance. The method is implemented according to the logic of integral detection, main body maintenance, component repair, stress relief and coating protection, firstly, the diameter and the flatness of the cutter head excavation are detected, correction and leveling are carried out according to the requirement, then main body structures such as a large circular ring, a torsion leg, a main beam and the like are maintained, defects are detected and standardized through UT, MT and PT, then a cutter, a pipeline fitting, a wear-resistant component and an accessory component are overhauled, repair welding or replacement is carried out according to the requirement, after the main body maintenance, the welding residual stress is removed by adopting aging vibration, and finally integral coating is carried out. The invention realizes the cooperative maintenance of all parts of the cutterhead, solves the problems of long period and high cost of the newly manufactured cutterhead, and has the advantages of standard intensity of the cutterhead after maintenance, low risk of secondary cracking, capability of adapting to complex ground quality, convenience in operation, strong universality and guarantee of shield construction continuity and reliability.

Inventors

LIU ZHISHENG
Zhu Musen
WANG LONG
LU GUANGPU
LI XIANGYU
LI XIAOWEI
LI LI
ZHANG MING
ZHAO QIAN

Assignees

深圳地铁建设集团有限公司
中铁工程装备集团(天津)有限公司

Dates

Publication Date: 20260508
Application Date: 20260209

Claims (10)

1. The maintenance method of the shield composite cutterhead is characterized by comprising the following steps of: Firstly, carrying out integral abrasion detection comprising excavation diameter and flatness on a shield composite cutter disc, and determining correction or leveling requirements based on detection results; Then the main structure is used as maintenance priority, and structural repair, deformation correction and weld joint flaw detection treatment are carried out on the cutter head large ring, the torsion legs, the main beam, the auxiliary beam and the cutter box tool apron; Then sequentially completing detection and repair welding or replacement of the cutter, functional test and maintenance of the pipeline fittings and the wear-resistant parts, overhaul and precision adjustment of the accessory parts, and removing welding residual stress by adopting an aging vibration mode after the main body structure and the parts are maintained; And finally, carrying out integral coating protection on the maintained cutterhead, and realizing cooperative maintenance of main beams, auxiliary beams, panels and accessories of the cutterhead.
2. The method for repairing a shield composite cutter head according to claim 1, wherein the integral wear detection criteria are: The error of the excavation diameter is 0-8mm without correction, the correction is carried out when the error exceeds 8mm, the flatness out-of-tolerance is controlled within 8mm, and the cutter head leveling is carried out when the error exceeds 8 mm.
3. The method for repairing a shield composite cutter head according to claim 1, wherein the weld flaw detection specifically comprises: carrying out UT flaw detection on the torsion leg and the welding line of the main beam, carrying out visual inspection on the welding line of the auxiliary beam of the tool box tool apron, and carrying out MT and PT flaw detection when the defect exists; If cracks are found after the weld joint flaw detection, a carbon arc gouging method is adopted to eliminate the defects, two ends of the crack length are respectively extended for 30mm to gouge, the surface is polished after gouging, MT/PT detection is carried out again to confirm that the defects are completely eliminated, and then welding is carried out again; And after all defects are repaired, UT and MT detection are carried out on relevant welding seams of the torsion leg base and the girder and a detection report is provided.
4. The method for repairing a shield composite cutter head according to claim 1, wherein the maintenance standard of the cutter box cutter seat is: the theoretical design height exceeds 15mm of the panel, the abrasion loss is less than or equal to 5mm, no treatment is needed, the abrasion loss is 5-15mm, the surfacing is carried out, and the replacement is carried out when the abrasion loss exceeds 15 mm.
5. The method for repairing a shield composite cutter head according to claim 1, wherein the cutter comprises a scraper, a tearing cutter, a gauge cutter and a hob cutter, and the detection indexes comprise the integrity of an alloy block, the abrasion loss and the condition of cracks; The detection standard is that the integrity of the alloy block with the alloy cutter is more than or equal to 80 percent, the abrasion loss of the alloy block is less than or equal to 10mm and no crack exists, and when the abrasion loss of the abrasion-resistant alloy block is more than or equal to 1/3 of the thickness of the abrasion-resistant alloy block, the abrasion loss or fragmentation of the abrasion-resistant alloy block is carried out, and the abrasion loss of the abrasion-resistant alloy block matrix is more than or equal to 1/3 of the thickness of the original design matrix, the cutter is replaced.
6. The method for repairing the shield composite cutter head according to claim 1, wherein the repairing and welding adopts a combination of melting and welding and brazing, the repair welding is performed after the repair welding is performed on the part with the large damaged area of the cutter matrix, and the brazing is performed when the abrasion of the cutter abrasion-resistant alloy is excessive; The welding process follows the following specifications: preheating at 100-150deg.C before welding, and slowly cooling with heat-insulating cotton after welding; Adopting phi 1.2 welding wire, carbon dioxide gas shielded welding, direct current reverse polarity, welding current 180-270A during flat welding and transverse welding, arc voltage 18-25V, and gas flow 15-25L/min; Welding current 140-170A, arc voltage 16-26V and gas flow 15-25L/min during vertical welding, welding current 120-150A, arc voltage 15-18V and gas flow 15-25L/min during overhead welding.
7. The method for maintaining the shield composite cutter head according to claim 1, wherein the layout, the number and the foam injection proportion of the nozzles are optimized during maintenance of the pipeline fittings, the nozzle device is required to ensure no blockage and no leakage of the nozzle holes of the pipeline, the pressure maintaining test pressure is 5bar, and the pressure maintaining is 15min without pressure drop.
8. The method for repairing a shield composite cutter head according to claim 1, wherein the wear-resistant component comprises a wear-resistant plate and a wear-resistant layer, and the detection standard is: The abrasion loss of the abrasion-resistant grids exceeds 2mm for repair welding, the abrasion loss of the panel alloy abrasion-resistant plate with the specification of 6+6mm exceeds 3mm and is replaced, the abrasion loss is smaller than 3mm, the abrasion loss is repaired welding is performed in a 50X 50mm abrasion-resistant grid mode, and the abrasion of the cutter head structural base material is repaired welding to restore the original design size.
9. The method for repairing the shield composite cutter head according to claim 1, wherein the specific standard of accessory repair is: The oil cylinder and the pipeline of the super-digging device are maintained for 15min under 20MPa, the pressure drop is qualified within 20bar, the parallelism between the L-shaped beam/U-shaped beam and the cutter head flange is controlled to be 4mm, and the adjusting precision is 0.01mm when the parallelism exceeds the standard.
10. The method for repairing a shield composite cutter head according to claim 1, further comprising the step of cleaning the shield composite cutter head integrally, wherein the integral cleaning is performed by adopting a high-pressure cleaning machine to clean and remove rust; In the whole abrasion detection process, damaged parts are replaced after the L-shaped blocks, the clamping blocks, the tensioning blocks and the wedge blocks in the tool box accessory are detected according to the standard.

Description

Maintenance method of shield composite cutterhead Technical Field The invention relates to the technical field of shield manufacturing technology and cutter head structural member maintenance, in particular to a maintenance method of a shield composite cutter head. Background The shield cutterhead is used as a core bearing and cutting component for tunneling operation of a shield machine, directly contacts and collides with stratum rock mass and dregs, and bears impact load, friction abrasion and alternating stress for a long time under complex geological conditions. Especially, special combined type blade disc in hard rock stratum, its structure contains key atress parts such as girder, auxiliary girder, turn round leg rest, tool box blade holder, and the in-process of tunneling is liable to lead to quotation deformation, welding seam fracture, damage such as cutter wearing and tearing because of the rock mass impact, can cause to turn round the fault such as leg rest fracture, tool box inefficacy when serious, directly reduces the tunneling efficiency, causes construction safety risk even. Therefore, the damage repair and performance recovery of the cutterhead are key links for guaranteeing the continuity of shield construction. Along with the expansion of the tunnel engineering construction scale and the popularization of the green manufacturing concept, the cutterhead maintenance and reutilization has the remarkable advantages of low cost, short period and high resource utilization rate compared with a new cutterhead, and becomes an important technical direction in the field of shield construction. The existing cutterhead repairing technology mostly adopts a local targeted maintenance mode, such as a shield machine cutterhead repairing method disclosed in patent CN113634983A, mainly focuses on repair welding and cutter replacement of specific damaged parts, and focuses on defect treatment of a single structural member. The technology has obvious limitations that firstly, the maintenance lacks systematicness, only aims at local part repair, does not consider the cooperative working characteristics of a cutter head main body structure and accessory parts, is easy to cause uneven overall stress after maintenance and higher secondary cracking risk, secondly, the maintenance standard is not uniform, the control of core indexes such as cutter head excavation diameter, flatness and the like lacks clear specification, the consistency of the cutter head performance after maintenance and a new machine is difficult to ensure, thirdly, the active protection design is insufficient, key parts such as pipeline layout and wear-resisting structures are not combined, and the wear resistance and the adaptability of the cutter head after maintenance are limited. In addition, the prior art does not form a complete technical system from integral detection, layered maintenance to stress relief and protective coating, and the problems of long period, high cost, insufficient strength of the maintained cutterhead and the like of a new cutterhead cannot be effectively solved, so that the economical efficiency and the reliability of shield construction are restricted. Disclosure of Invention Therefore, the invention provides a maintenance method of a shield composite cutterhead, which aims to solve the problems that the period of a new cutterhead is long, the cost is high, the strength of the cutterhead after maintenance is insufficient and the like in the traditional technology. In order to achieve the purpose, the embodiment of the invention provides the following technical scheme that the maintenance method of the shield composite cutterhead is characterized by being implemented according to the following logic sequence: Firstly, carrying out integral abrasion detection comprising excavation diameter and flatness on a shield composite cutter disc, and determining correction or leveling requirements based on detection results; Then the main structure is used as maintenance priority, and structural repair, deformation correction and weld joint flaw detection treatment are carried out on the cutter head large ring, the torsion legs, the main beam, the auxiliary beam and the cutter box tool apron; Then sequentially completing detection and repair welding or replacement of the cutter, functional test and maintenance of the pipeline fittings and the wear-resistant parts, overhaul and precision adjustment of the accessory parts, and removing welding residual stress by adopting an aging vibration mode after the main body structure and the parts are maintained; And finally, carrying out integral coating protection on the maintained cutterhead, and realizing cooperative maintenance of main beams, auxiliary beams, panels and accessories of the cutterhead. As a maintenance method preferred scheme of the shield composite cutterhead, the integral abrasion detection standard is as follows: The error of the excavation diameter is 0-8mm without