Weld joint cutting and groove machining device and method for limited space

Abstract

The invention provides a welding seam cutting and groove machining device and method for a limited space, and the welding seam cutting and groove machining device comprises a main rack, a locking mechanism, a cutterhead rotating mechanism, a cutterhead feeding mechanism and a cutterhead assembly which are sequentially and adjacently arranged in the first direction and form an integrated structure. The size of the formed integrated structure is smaller than the minimum section size of the limited space in the second direction; the first direction of the integrated structure is the axial direction corresponding to the length direction of the integrated structure, and the second direction of the integrated structure is the radial direction corresponding to the outer diameter size of the integrated structure. Infinite rotation of the cutting device is achieved through the power supply mode of the conducting ring, the accumulated error influence of the transmission distance is reduced, and through the modular design of the cutterhead assembly, the cutting tool is rapidly switched to conduct welding seam cutting and the back digging tool is rapidly switched to conduct groove machining; the problems of welding seam cutting and groove machining of a welding seam in a limited space are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of weld removal, and in particular, to a weld cutting and beveling processing device and method for a confined space. Background Art

[0002] The control rod drive mechanism (CRDM) is one of the core equipment of a pressurized water reactor nuclear power plant. Its function is to precisely control the insertion and extraction of control rods, regulate the reactor power, and achieve emergency shutdown, which is directly related to the operation safety and efficiency of the nuclear power plant. The CRDM is composed of components such as a drive shaft, a pressure-resistant shell, and electromagnetic coils. Among them, a full-sealed connection is achieved between the pressure-resistant shell and the reactor pressure vessel top cover through a middle Ω weld. This weld needs to serve for a long time under high temperature (≥300 °C), high pressure (≥15.5 MPa), and strong irradiation environments. Its integrity is the key barrier to preventing radioactive material leakage. International nuclear safety regulations (such as ASME III, RCC-M) clearly stipulate that the defect tolerance of the CRDM weld is extremely low. Once leakage occurs, it will cause the reactor to be forced to shut down, resulting in huge economic losses and even possibly triggering a nuclear safety accident. Therefore, the reliability of the middle Ω weld of the CRDM is regarded as the "lifeline" in the field of nuclear power safety.

[0003] Due to the special-shaped curved surface structure (Ω-shaped cross-section) and harsh service environment of the middle Ω weld of the CRDM, the welding process requirements are very strict. During the welding process, micro thermal cracks, pores (caused by the disturbance of the shielding gas), and lack of fusion are likely to occur, resulting in unqualified weld quality. In addition, during the long-term operation of the middle weld, cracks or other defects may occur due to construction errors, stress, corrosion, and other factors, and in-service repair is required. According to statistics, about 12% of the CRDMs globally have weld defects after 10 years of operation and need in-service repair.

[0004] When defects occur in the middle Ω weld of the CRDM, the first choice is to remedy them by manual welding. If the defects cannot be remedied, the weld must be completely removed and re-welded. At this time, the cutting and beveling processing quality directly determines the success rate of re-welding: if the cutting surface is uneven or the bevel angle deviates, problems such as lack of fusion and stress concentration will occur in the new weld, and in severe cases, secondary failure will be triggered. However, the existing repair technologies face severe challenges:

[0005] Space limitation: The CRDM is located at the top of the reactor pressure vessel, and the surrounding space is narrow. Moreover, the CRDM has 69 travel sleeves, which are distributed in a forest shape. Therefore, the cutting operation space diameter of the middle weld of the CRDM is usually less than 420 mm, and the volume of traditional cutting equipment is relatively large, making it difficult to enter and operate.

[0006] Conductive wire winding: The rotary cutting tool disc needs to be connected to an external power supply. During rotation, the conductive wire is prone to winding, affecting operation safety and rotation efficiency.

[0007] In addition, the radiation environment in nuclear power plants requires equipment to have remote control capabilities, further increasing the technical difficulty. To solve the above problems, the present invention proposes a device and method for integrated cutting and back gouging of the middle Ω weld of CRDM in a confined space of a nuclear power plant, aiming to achieve safe, efficient, and precise cutting and repair.

[0008] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present invention and does not constitute any limitation to the present invention. Summary of the Invention

[0009] In view of the above-mentioned disadvantages of the prior art, the present invention provides a device and method for weld cutting and bevel processing in a confined space. The power supply mode of the slip ring is used to achieve infinite rotation of the cutting device, reduce the cumulative error influence of the transmission distance, and cooperate with the modular design of the tool disc assembly to achieve rapid switching of cutting tools for weld cutting and back gouging tools for bevel processing, so as to solve the problem of weld cutting and bevel processing of welds in a confined space.

[0010] The present invention provides a device for weld cutting and bevel processing in a confined space, including a main frame, a locking mechanism, a tool disc rotation mechanism, a tool disc feeding mechanism, and a tool disc assembly that are arranged adjacent to each other in sequence along a first direction and form an integrated structure, and the formed integrated structure is smaller than the minimum cross-sectional size of the confined space in a second direction;

[0011] Among them, the first direction of the integrated structure is the axial direction corresponding to its length direction, and the second direction of the integrated structure is the radial direction corresponding to its outer diameter size.

[0012] In an embodiment of the present invention, the locking mechanism is a pneumatic structure, and a sensor for monitoring the locking state is provided on the locking mechanism.

[0013] In an embodiment of the present invention, the tool disc rotation mechanism includes a rotation driving part, a rotary bearing, and a slip ring assembly. The rotation driving part drives the tool disc assembly to rotate. The rotary bearing is arranged between the rotation driving part and the tool disc feeding mechanism, and the slip ring assembly is electrically connected to the tool disc assembly.

[0014] In an embodiment of the present invention, the slip ring assembly includes:

[0015] A first slip ring, which is installed on the rotation driving part;

[0016] A second slip ring, which is sleeved on the first slip ring;

[0017] A conductive brush body is installed on a conductive brush support, is in sliding contact with a first conductive rod, and the conductive brush support is respectively connected to a second conductive ring and a cutter head assembly.

[0018] In an embodiment of the present invention, the cutter head feeding mechanism includes an axial displacement assembly. The axial displacement assembly adopts a structure of a stepping motor driving a lead screw pair, and a tension spring is also installed on the axial displacement assembly.

[0019] In an embodiment of the present invention, the cutter head assembly includes:

[0020] A mounting tool rest is installed on a rotary driving part and is connected to the conductive brush support;

[0021] A cutting cutter head or a back gouging cutter head is installed on the mounting bracket, and weld seam cutting is performed through the cutting cutter head or groove machining is performed through the back gouging cutter head.

[0022] In an embodiment of the present invention, the mounting tool rest is provided with a radial stroke and an outward displacement amount, and the outward displacement amount is greater than the radial stroke.

[0023] In an embodiment of the present invention, multiple groups of cutting tool rests are arranged on the cutting cutter head, and the axial clearance of the cutting cutter head is compensated by the tension spring on the cutter head feeding mechanism.

[0024] In an embodiment of the present invention, the back gouging cutter head is provided with a back gouging motor for driving the back gouging tool to perform axial feeding, and the back gouging motor is powered through a conductive ring assembly.

[0025] The present invention also provides a method for weld seam cutting and groove machining in a confined space, including the following steps:

[0026] According to the set cutting process parameters, the weld seam cutting and groove machining equipment is locked and fixed with the weld seam part through axial positioning;

[0027] Install the cutting cutter head or the back gouging cutter head on the cutter head assembly. The cutting tools of the cutting cutter head perform feeding cutting through the cutter head feeding mechanism, and the back gouging tools of the back gouging cutter head perform feeding back gouging through the back gouging motor;

[0028] Based on the cutter head rotary mechanism and the cutter head feeding mechanism, the cutting tools or the back gouging tools are pulled to align with the weld seam part for cutting operation or back gouging operation.

[0029] The beneficial effects of the present invention at least include the following:

[0030] 1. The welding seam cutting and bevel processing device and method for a confined space provided by the present invention adopt a clamping method of cylinder clamping. Compared with the existing motor-driven expansion block clamping, the clamping force applied by pneumatic clamping is more uniform and is not affected by the mechanical transmission accuracy. Therefore, the clamping of the pneumatic clamping device is more firm and reliable, reducing possible looseness and misalignment of the equipment, thereby ensuring the cutting and back gouging quality of the equipment.

[0031] 2. The integrated design of cutting and back gouging in the present invention reduces the number of on-site cutting operation equipment, enabling a larger operating space for operations in a confined space. The replacement of the cutting tool disc and the back gouging tool disc achieves high-efficiency and high-precision operations of weld cutting and bevel processing by replacing the actuator.

[0032] 3. Through the design of the slip ring assembly, the integrated design of cutting and back gouging in the present invention is more reasonable. The power supply of the slip ring assembly avoids the problem of wire entanglement as the rotating tool disc rotates during the operation of the back gouging tool disc, thereby further ensuring the safety and processing quality of on-site cutting and back gouging operations.

[0033] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings herein are incorporated into the specification and form a part of this specification, showing embodiments in accordance with the present invention, and are used together with the specification to explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. In the drawings:

[0035] Figure 1 is a schematic structural diagram of the welding seam cutting and bevel processing device of the present invention;

[0036] Figure 2 is a sectional view of the welding seam cutting and bevel processing device of the present invention.

[0037] In the figure: 10, main frame; 20, locking mechanism; 30, tool disc slewing mechanism; 31, slewing drive part; 32, slewing bearing; 33, slip ring assembly; 331, first slip ring; 332, second slip ring; 333, brush body; 334, brush support; 40, tool disc feeding mechanism; 50, tool disc assembly; 51, mounting tool holder; 52, cutting tool disc; 521, cutting tool holder; 53, back gouging tool disc; 531, back gouging motor; 100, welded part. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. It should also be understood that the terms used in the embodiments of the present invention are for describing specific implementation manners and are not intended to limit the protection scope of the present invention.

[0039] Please refer to Figures 1 to 2 . It should be noted that the structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not intended to limit the limiting conditions under which the present invention can be implemented. Therefore, they do not have a substantial technical meaning. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, the terms used in this specification to refer to positions, quantitative relationships, etc. are only for the convenience of clear description and are not intended to limit the scope under which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present invention can be implemented.

[0040] Please refer to Figure 1 , the present invention provides a weld cutting and bevel processing device for a confined space, including a main frame 10, a locking mechanism 20, a cutter head rotation mechanism 30, a cutter head feeding mechanism 40, and a cutter head assembly 50 that are arranged adjacent to each other in sequence along a first direction and form an integral structure, and the formed integral structure is smaller than the minimum cross-sectional size of the confined space in a second direction;

[0041] Among them, the first direction of the integral structure is the axial direction corresponding to its length direction, and the second direction of the integral structure is the radial direction corresponding to its outer diameter dimension.

[0042] Specifically, in the embodiment of the present invention, the weld cutting and beveling device for the welded part 100 adopts an integrated design. The main frame 10, the locking mechanism 20, the cutter head slewing mechanism 30, the cutter head feeding mechanism 40 and the cutter head assembly 50 are compactly arranged in sequence along the first direction, i.e., its axial direction. This modular layout makes the whole device form a tightly structured whole, and at the same time ensures that its dimension in the second direction, i.e., the radial dimension, is controlled within the range allowed by the limited space. Each mechanism realizes the minimum space occupation through optimized design, retaining the complete weld repair welding function and meeting the requirements for the equipment dimension in special environments such as nuclear power plants, e.g., within the limited space of CRDM (Control Rod Drive Mechanisms).

[0043] It should be noted that the limited space can correspond to the welding processing operation space where the control rod drive mechanism CRDM is located in this embodiment. According to the position of the specific welding processing operation, the size of the limited space where corresponding operation can be performed also varies. However, generally, it can be understood as the minimum space size within the limited space. Therefore, specifically in the limited space where CRDM is located, generally, the radial dimension of the weld cutting and beveling device for performing the welding processing operation can be limited within 400 mm to meet the space requirements of the corresponding welding operation. Similarly, when the integrated structure of the weld cutting and beveling device used in the embodiment of the present invention is applied to other operation environments, the size requirements for performing operations within the corresponding limited space can be met based on the stacking mode of each component in the integrated structure.

[0044] In one embodiment, the main frame 10 may include components such as lifting lugs, guide sleeves, control cable interfaces and connectors, which are mainly used for the hoisting and installation of the integrated structure of the weld cutting and beveling device and the installation and fixation of each component in its integrated structure.

[0045] More specifically, to adapt to the narrow working environment within the limited space, the mechanism modules of the weld cutting and beveling device can adopt a coaxial nested layout to avoid structural expansion. The volume can also be reduced by selecting special miniaturized components to replace traditional components, configuring quick disassembly and assembly interfaces, and simplifying the installation process. And it can be ensured through calculation that each mechanism component operates without interference within the limited space and maintains the operating performance of the weld cutting and beveling device under the conditions of the limited space.

[0046] Thus, compared with traditional split-type weld cutting and beveling equipment, its overall size is significantly reduced, enabling it to enter narrow areas such as restricted spaces where conventional equipment cannot operate. And it can maintain its operational convenience and control precision. To achieve efficient and precise cutting of the middle weld of CRDM and beveling processing. The effective clamping of the equipment is achieved through the clamping method of the locking mechanism 20 such as a pneumatic chuck, and the effective alignment of the equipment with the weld is ensured. The corresponding weld cutting and beveling processes are realized through the cutter head rotation mechanism 30, the cutter head feeding mechanism 40 and the cutter head assembly 50. The formed integral structure can be switched through the cutter head assembly 50 in the corresponding mechanism to achieve weld cutting based on the cutting cutter head 52 or beveling processing based on the back gouging cutter head 53, so as to achieve the effect of independent selection of weld cutting process and beveling processing process.

[0047] In one embodiment, by defining the orientation in the spatial layout of the integral structure, that is, the first direction refers to the axial direction extending along the length of the equipment, and the second direction corresponds to the radial dimension perpendicular to the axis. This directional design can directly serve the restricted space limitation requirements in maintenance scenarios such as nuclear power plant control rod drive mechanisms. In the radial dimension, the overall outer diameter size of the device is limited within a corresponding size range, such as not exceeding 400 millimeters, which can be based on the measured data of the actual available operating space at the top of the nuclear reactor pressure vessel.

[0048] More specifically, to meet the radial dimension requirements, a coaxial nested structure layout can be adopted, so that the core components such as motors and reduction mechanisms in the weld cutting and beveling device share the central axis. Cooperate with the development of small functional components, such as the drive motors and bearings involved in the cutter head rotation mechanism 30 and the cutter head feeding mechanism 40. The mechanical transmission path can also be optimized, such as direct meshing of gear pairs instead of traditional pulley drives, and a miniaturized pneumatic locking mechanism 20 is adopted to control the size of the locking mechanism 20 within the minimum range to ensure the requirements of the welding device in terms of radial dimension.

[0049] Furthermore, while ensuring that its radial dimension meets the standard, the axial layout can also be correspondingly optimized. For example, flange-type docking is adopted for each mechanism module to eliminate redundant connection structures. A common installation reference surface is set to reduce the cumulative assembly error. The refitted components are arranged in an overlapping manner, the welding cable gas path is optimized, and an axial centralized wiring scheme is adopted. These space control designs enable the weld cutting and beveling device to be smoothly used in the dense equipment array in the nuclear power plant structure and reach the restricted space maintenance positions where conventional equipment is difficult to apply.

[0050] Please refer to Figure 1 , in one embodiment, the locking mechanism 20 is a pneumatic structure, and a sensor for monitoring the locking state is provided on the locking mechanism 20.

[0051] Specifically, in the embodiments of the present invention, its pneumatic locking mechanism 20 includes components such as a cylinder, a pressing connecting rod, a hoop, and a positioning chuck. To ensure that the equipment for fixing the weld repair welding device does not move relative to each other during operation and to ensure the fixation between the equipment and the workpiece during the operation process. The clamping and loosening actions are achieved quickly and reliably through pneumatic drive. The locking mechanism 20 is equipped with a corresponding state monitoring system, which can work in coordination with a displacement sensor and a pressure sensor to provide real-time feedback on the clamping state. These sensor signals are directly connected to the control system of the equipment and are displayed in an intuitive manner on the operation interface to show the current locking state. The system has a perfect safety interlock function. For example, when it is detected that the preset clamping force is not reached or the position is abnormal, all actions will be automatically locked to effectively prevent equipment damage caused by misoperation. When the machine head does not clamp the workpiece at the weld position, the actions are locked to avoid damage to the machine head caused by misoperation. During the installation and removal of the machine head, the operator can use the sensor to know the position of the machine head and can remotely control the locking and unlocking of the machine head to achieve convenient and precise operation.

[0052] Please refer to Figure 1 and Figure 2 , in one embodiment, the cutter head slewing mechanism 30 includes a slewing drive part 31, a slewing bearing 32, and a slip ring assembly 33. The slewing drive part 31 drives the cutter head assembly 50 to slewing, the slewing bearing 32 is arranged between the slewing drive part 31 and the cutter head feeding mechanism 40, and the slip ring assembly 33 forms an electrical connection with the cutter head assembly 50.

[0053] Specifically, in the embodiments of the present invention, the cutter head slewing mechanism 30 may include components such as a slip ring assembly 33, an AC motor, a gear reducer, and a cutter head slewing bearing 32, which can realize the wireless slewing of the cutting cutter head 52 and perform high-precision cutting operations according to the set cutting slewing speed. Its slewing drive part 31 serves as a power source and can convert the high-speed rotation of the motor into the low-speed and high-torque motion required by the cutter head through a multi-stage reduction device. It can be connected to the cutter head assembly 50 by a rigid coupling to ensure accurate power transmission. Its multi-stage reduction device can be a gear reducer. And a high-resolution encoder can be integrated at the power output end of the slewing drive part 31, such as its main shaft part, to form a speed closed-loop control, so that the cutter head can still maintain stable slewing under complex load conditions.

[0054] The slewing bearing 32 can adopt a preloaded design of a non-raceway closely arranged steel ball structure. Its inner ring is in interference fit with the drive main shaft of the slewing drive part 31 to transmit torque, and the outer ring is linked with the feeding mechanism to bear the axial thrust. This decouples the rotational motion and the linear feed mechanically, ensuring both the effective transmission of the cutting force and the avoidance of interference between the two motions.

[0055] The conductive ring assembly 33 may include a conductive ring fixed to the main shaft and a conductive brush on the rotary tool rest to form a sliding contact pair, thus forming an electrical path. During the cutting operation, there is no power demand on the cutting tool disc 52, and its conductive ring assembly 33 is not in use. When switched to the back-milling mode, the conductive ring assembly 33 can supply power to the back-milling motor 531 on the back-milling tool disc 53, enabling the back-milling motor 531 to rotate on the tool disc. There is no entanglement between the conductive wires, thus enabling the normal operation of the back-milling motor 531.

[0056] In this way, the design of the tool disc slewing mechanism 30, especially the conductive ring assembly 33, in the integrated structure design of the cutting and back-milling equipment enables the control of the back-milling motor 531 to be free from wire transmission, thus avoiding wire entanglement during the back-milling operation and effectively integrating the cutting tool disc 52 and the back-milling tool disc 53.

[0057] Please refer to Figure 2 , in an embodiment, the conductive ring assembly 33 includes:

[0058] A first conductive ring 331, which is installed on the slewing drive part 31;

[0059] A second conductive ring 332, which is sleeved on the first conductive ring 331;

[0060] A conductive brush body 333, which is installed on the conductive brush support 334 and is in sliding contact with the first conductive rod. The conductive brush support 334 is respectively connected to the second conductive ring 332 and the tool disc assembly 50.

[0061] Specifically, in the embodiment of the present invention, the first conductive ring 331 of the conductive ring assembly 33 serves as static power supply. The second conductive ring 332 is nested outside the first conductive ring 331, and a corresponding pre-tightening mechanism such as a wave spring is provided between the two to ensure stability during the slewing state. The conductive brush support 334 is fixed to the second conductive ring 332 through an insulating connector, and the end is rigidly connected to the slewing frame of the tool disc assembly 50 to form a complete mechanical-electrical connection.

[0062] More specifically, the conductive brush body 333 is installed on the conductive brush support 334, in cooperation with the fixation of the second conductive ring 332, and also utilizes the constant pressure provided by the disc spring of the pre-tightening mechanism of the second conductive ring 332 to keep the conductive brush body 333 in stable contact with the first conductive ring 331, ensuring power supply continuity. That is to say, the conductive ring assembly 33 is fixed to the main shaft, and the conductive brush body 333 and its conductive brush support 334 are installed on the rotating tool disc assembly 50. Through the contact of the two groups of conductive rings of the first conductive ring 331 and the second conductive ring 332, the wire assembly is conducted to supply power to the back-milling motor 531 on the back-milling tool disc 53. And the working circuit of the conductive ring assembly 33 can be composed of multiple groups of evenly distributed conductive brushes to form a stable redundant power supply.

[0063] Please refer to Figure 1 , in one embodiment, the cutter head feeding mechanism 40 includes an axial displacement component. The axial displacement component adopts a structure of a stepping motor driving a lead screw pair, and a tension spring is further installed on the axial displacement component.

[0064] Specifically, in the embodiment of the present invention, the cutter head feeding mechanism 40 mainly includes components such as a stepping motor, a lead screw transmission pair, a guide post, and a tension spring, which can realize the axial movement of the cutter head end face. The cutter head end face is 70 ± 10 mm away, which is convenient for observation. It can also realize the feeding movement of the cutter head, accurately control the feeding amount and feeding speed of the cutting cutter head 52, so as to ensure the quality of weld cutting and back gouging.

[0065] Furthermore, the control system of the axial displacement component can adopt a closed-loop feedback mechanism to monitor the actual displacement in real time and compensate for mechanical errors. When the cutter head moves to the observation position, the holding mode can be triggered to ensure the stable and reliable safety distance of 70 ± 10 mm, and ensure that the operator obtains the best observation field of view.

[0066] More specifically, the multi-condition motion control of the cutter head is realized through the axial displacement component. The stepping motor is used as the power source and is rigidly connected to the lead screw transmission pair to convert the rotational motion into linear feeding. The lead screw pair can adopt a pre-tightened ball structure and cooperate with the linear guide post to form a stable motion guiding system to ensure the trajectory accuracy of the cutter head during axial movement. The two ends of its tension spring are respectively fixed between the lead screw nut and the frame to form a constant tension system. And the axial clearance of the cutter head assembly 50 can be eliminated by the tension spring to avoid tool jamming. And during forward feeding, the tension spring is in a stretched state to store elastic potential energy; when it needs to retract, the tension spring releases energy to assist the motor to quickly reset. It not only improves the dynamic response speed but also realizes the automatic safe retraction in the case of power failure.

[0067] Please refer to Figure 1 , in one embodiment, the cutter head assembly 50 includes:

[0068] An installation tool rest 51, which is installed on the rotary drive part 31 and is connected to the conductive brush bracket 334;

[0069] A cutting cutter head 52 or a back gouging cutter head 53, which is installed on the installation bracket, and weld cutting is performed through the cutting cutter head 52 or groove processing is performed through the back gouging cutter head 53.

[0070] Specifically, in the embodiment of the present invention, the cutter head assembly 50 includes components such as a cutting cutter head 52, a back gouging cutter head 53, an installation tool rest, cutting tools (pointed tools, cutters, forming tools), back gouging tools, etc. Its structural form is as Figure 1As shown, it can realize the cutting and bevel processing operations of the Ω weld in the middle of the CRDM. The cutter head assembly 50 adopts a modular integrated design and realizes various processing functions through replaceable special tools. The installation tool rest serves as the load-bearing structure and is fixed on the rotary drive part 31 through corresponding connecting parts. Its tool rest can be integrally designed with the brush holder 334 to form a stable electrical path and provide a reliable power supply for the back-cutting tool. The cutter head assembly 50 adopts a modular design concept and realizes cutting and back-cutting operations by replacing the cutting or back-cutting cutter head 53, thus realizing the integrated design of the cutting and back-cutting machine. The integrated equipment meets the cutting and bevel processing operation requirements under limited working space.

[0071] Furthermore, the cutting cutter head 52 and the back-cutting cutter head 53 can adopt a quick-change interface, such as realizing quick replacement through a special positioning pin and a locking mechanism 20. The cutting cutter head 52 is equipped with a variety of special tools, including pointed tools for rough machining, cutting tools for finish machining, and forming tools with special profiles. These tools can be combined and configured according to the weld characteristics. The back-cutting cutter head 53 integrates bevel processing tools, and its geometric parameters are optimized to accurately control the bevel angle and surface quality.

[0072] As shown in the Figure 1 attachment, both the cutting cutter head 52 and the back-cutting cutter head 53 are shown. The back-cutting cutter head 53 is located on the weld cutting and bevel processing device, and the illustration of the cutting cutter head 52 is separately located on one side of the device and can be replaced with the corresponding part of the back-cutting cutter head 53 on the device.

[0073] In this way, the weld cutting and bevel processing device with an integrated structure avoids the limitation of the single function of traditional equipment and realizes the conversion between cutting and back-cutting functions by quickly replacing the cutter head. The compact layout adapts to the narrow working space of the CRDM equipment, and the integrated design simplifies the maintenance process and improves the operation efficiency.

[0074] In one embodiment, the installation tool rest is provided with a radial stroke and an outward displacement amount, and the outward displacement amount is greater than the radial stroke.

[0075] Specifically, in the embodiments of the present invention, the radial movement of the mounting tool holder can adopt a corresponding guiding mechanism, such as realizing the two-way fine adjustment function through a crossed roller guide. The outward displacement mechanism can adopt an independent drive design, for example, realizing the corresponding linear movement range through a lead screw and nut transmission. For example, the maximum outward displacement of the mounting tool holder is set to 12 mm. When the tool needs to completely withdraw from the machining area, the tool holder can be quickly moved to a safe position to provide sufficient space for observation and measurement. In the fine machining stage, the mounting tool holder preferentially uses a radial stroke of ±4 mm for micro adjustment; when rapid tool retraction or tool change is required, the 12-mm outward displacement function is activated. The guide rail mechanism of the mounting tool holder adopts a fully enclosed dust-proof design, effectively blocking the intrusion of impurities in the working environment. In this way, the mounting tool holder can perform precise radial displacement in two directions, meeting the fine adjustment requirements for the tool position in weld processing.

[0076] Please refer to Figure 1 , in one embodiment, a plurality of cutting tool holders 521 are provided on the cutting tool disc 52, and the axial clearance of the cutting tool disc 52 is compensated by a tension spring on the tool disc feed mechanism 40.

[0077] Specifically, in the embodiments of the present invention, the cutting tool disc 52 adopts a design of multi-tool holder collaborative operation, and realizes efficient processing through annular array arrangement. Each cutting tool holder 521 is installed on the base body of the cutting tool disc 52 through a corresponding adjusting mechanism, forming a tool that can be flexibly configured. Its modular layout allows different tool combinations to be selected according to the weld characteristics, which can not only meet the requirements of straight-line cutting but also complete complex contour processing. By using the linkage between the tension spring mechanism and the tool disc feed mechanism 40, the mechanical clearance in the transmission chain is continuously eliminated by a constant elastic force. While ensuring sufficient pre-tightening force, excessive friction is avoided. The vibration during the processing is suppressed by the dynamic compensation method of the tension spring, improving the surface quality.

[0078] Please refer to Figure 1 , in one embodiment, the back-cutting tool disc 53 is provided with a back-cutting motor 531 for driving the back-cutting tool to perform axial feed, and the back-cutting motor 531 is powered by a slip ring assembly 33.

[0079] Specifically, in the embodiments of the present invention, the back-cutting tool disc 53 adopts an independent drive design, and the axial feed of the tool is realized through an integrated back-cutting motor 531. The layout of the back-cutting motor 531 shortens the power transmission chain, improving the transmission stiffness and response speed of the axial feed. The feed movement of the back-cutting motor 531 can be automatically matched with the rotational speed of the tool disc, and the best cutting parameters are maintained through a closed-loop control algorithm. The force feedback system monitors the axial cutting force in real time and dynamically adjusts the feed rate to avoid overload. The power supply of the back-cutting motor 531 on the back-cutting tool disc 53 adopts the above-mentioned slip ring assembly 33 structure. Stable power supply can still be maintained under high-speed rotation conditions.

[0080] The present invention also provides a method for cutting weld seams and machining bevels in a confined space, comprising the following steps:

[0081] According to the set cutting process parameters, the locking and fixing of the weld seam cutting and bevel machining equipment and the weld seam part are achieved through axial positioning;

[0082] Install the cutting tool disc 52 or the back gouging tool disc 53 onto the tool disc assembly 50. The cutting tool of the cutting tool disc 52 performs feed cutting through the tool disc feed mechanism 40, and the back gouging tool of the back gouging tool disc 53 performs feed back gouging through the back gouging motor 531;

[0083] Based on the tool disc slewing mechanism 30 and the tool disc feed mechanism 40, the cutting tool or the back gouging tool is towed to align with the weld seam part for cutting operation or back gouging operation.

[0084] Specifically, in the embodiment of the present invention, it is fixed on the support column for simulating weld seam cutting and bevel machining through a pneumatic locking device. The cutting tool installed on the tool disc tool rest is driven by an AC motor to drive the tool disc slewing mechanism 30 to realize the cutting motion. The tool disc is driven by a stepping motor to drive the lead screw pair to drive the tool disc to perform axial feed motion, realizing the feed cutting motion of the cutting equipment; The back gouging tool disc 53 is replaced through a modular tool disc design, the axial position of the tool disc is fixed, the feed motion of the back gouging tool is realized through the back gouging motor 531, and the bevel machining of the back gouging operation of the equipment is realized in combination with the slewing motion of the tool disc.

[0085] More specifically, before cutting (back gouging), connect and install the integrated cutting and back gouging equipment, and complete the setting of the cutting process parameters. When the machine head is sleeved onto the workpiece, the middle Ω cutting machine is axially positioned by the step surface of the welding part size. Start the air cylinder, push the lever, and the positioning chuck clamps the stroke housing controlling the rod size. After being locked by the lever, the clamping with the workpiece is completed, and the corresponding pressure of the locking air cylinder is provided for control. When in the locked state, the machine head is not allowed to have relative movement with the seal housing assembly.

[0086] Further, by selecting the cutting tool disc 52 to perform the weld seam cutting operation, determine that the tool execution position is aligned with the middle weld seam, driven by an AC variable frequency speed regulating motor, through a gear reducer, the tool disc is driven to rotate. Three groups of tool rests are installed on the end face of the tool disc, and the cutting tool is installed on the tool rest. The tool disc slewing bearing 32 adopts a non-raceway closely arranged steel ball preloaded bearing, and the tool disc realizes precise rotation. Driven by a stepping motor, the lead screw pair drives the axial positioning disc of the tool disc to perform feed motion. The axial system clearance of the tool disc is eliminated by three tension springs, which can avoid tool jamming. When the cutting is completed, start the release air cylinder. When the lever returns to the starting position, the positioning chuck is released, the workpiece is separated from the cutting machine, and the cutting machine is lifted and the inner ring is unloaded.

[0087] Furthermore, by adjusting the position of the back milling tool and repeating the above operations, the back milling operation can be achieved. It should be noted that the feed motion of the back milling operation is controlled by the back milling motor 531, and the cutting feed motion remains stationary. After the cutting is completed, start the release cylinder. When the lever returns to the starting position, the positioning chuck is released, the workpiece is separated from the cutting machine, and then the cutting machine can be lifted.

[0088] In summary, a weld cutting and beveling processing device and method for a confined space provided by the present invention, by adopting a clamping method of cylinder clamping, compared with the existing motor-driven expansion block clamping, the clamping force applied by pneumatic clamping is more uniform and will not be affected by the mechanical transmission accuracy. Therefore, the clamping of the pneumatic clamping device is more firm and reliable, reducing the possible loosening and misalignment of the equipment, thereby ensuring the cutting and back milling quality of the equipment. Through the integrated design of cutting and back milling, the number of on-site cutting operation equipment is reduced, enabling a larger operating space for operations in a confined space. The replacement of the cutting tool disc and the back milling tool disc achieves high-efficiency and high-precision operations of the actuator replacement for weld cutting and beveling processing. Through the design of the slip ring assembly, the integrated design of cutting and back milling is more reasonable. The power supply of the slip ring assembly avoids the problem of the wire winding with the rotating tool disc during the operation of the back milling tool disc, thereby further ensuring the safety and processing quality of the on-site cutting and back milling operations.

[0089] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A welding seam cutting and beveling processing device for a confined space, characterized in that, It includes a main frame (10), a locking mechanism (20), a cutter head slewing mechanism (30), a cutter head feeding mechanism (40), and a cutter head assembly (50) that are arranged adjacent to each other in sequence along a first direction and form an integral structure, and the formed integral structure is smaller than the minimum cross-sectional size of the restricted space in a second direction; Wherein, the first direction of the integral structure is the axial direction corresponding to its length direction, and the second direction of the integral structure is the radial direction corresponding to its outer diameter dimension.

2. The device according to claim 1, characterized in that, The locking mechanism (20) is a pneumatic structure, and a sensor for monitoring the locking state is provided on the locking mechanism (20).

3. The device according to claim 1, wherein, The cutter head slewing mechanism (30) includes a slewing drive part (31), a slewing bearing (32), and a slip ring assembly (33). The slewing drive part (31) drives the cutter head assembly (50) to slewing. The slewing bearing (32) is arranged between the slewing drive part (31) and the cutter head feeding mechanism (40), and the slip ring assembly (33) forms an electrical connection with the cutter head assembly (50).

4. The device according to claim 3, wherein The slip ring assembly (33) includes: A first slip ring (331) installed on the slewing drive part (31); A second slip ring (332) sleeved on the first slip ring (331); A slip brush body (333) installed on a slip brush bracket (334) and in sliding contact with the first conductive rod, and the slip brush bracket (334) is respectively connected to the second slip ring (332) and the cutter head assembly (50).

5. The device according to claim 1, wherein The cutter head feeding mechanism (40) includes an axial displacement assembly. The axial displacement assembly adopts a structure of a stepping motor driving a lead screw pair, and a tension spring is also installed on the axial displacement assembly.

6. The device according to claim 4, characterized in that The cutter head assembly (50) includes: A mounting tool holder (51) installed on the slewing drive part (31) and connected to the slip brush bracket (334); A cutting cutter head (52) or a back gouging cutter head (53) installed on the mounting bracket, and the welding seam is cut through the cutting cutter head (52) or the groove is machined through the back gouging cutter head (53).

7. The device according to claim 6, characterized in that, The mounting tool holder is provided with a radial stroke and an outward displacement amount, and the outward displacement amount is greater than the radial stroke.

8. The device according to claim 6, characterized in that, Multiple groups of cutting tool holders (521) are provided on the cutting cutter head (52), and the axial clearance of the cutting cutter head (52) is compensated by the tension spring on the axial displacement assembly.

9. The device according to claim 6, wherein The back gouging cutter head (53) is provided with a back gouging motor (531) for driving the back gouging tool to perform axial feeding, and the back gouging motor (531) is powered through the slip ring assembly (33).

10. A method for cutting weld seams and machining bevels in a confined space, characterized in that, It includes the following steps: According to the set cutting process parameters, the locking and fixing of the welding seam cutting and groove machining equipment and the welding seam part are realized through axial positioning; Install the cutting cutter head (52) or the back gouging cutter head (53) on the cutter head assembly (50). The cutting tool of the cutting cutter head (52) performs feeding cutting through the cutter head feeding mechanism (40), and the back gouging tool of the back gouging cutter head (53) performs feeding back gouging through the back gouging motor (531); Based on the cutter head rotation mechanism (30) and the cutter head feeding mechanism (40), the cutting tool or the back gouging tool is tractioned to align with the weld position for cutting operation or back gouging operation.

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