A ship medium and small straight pipe flow line manufacturing method based on MES cooperation

Abstract

The application discloses a kind of before welding after bending ship medium and small straight pipe flow line manufacturing method and production line based on MES cooperation, belong to ship pipeline digitization manufacturing technical field.The method is received by manufacturing execution system model data issued by design system and is parsed as structured task package, in flange assembly station, semi-automatic welding station and numerical control elbow station respectively according to the point welding parameter instruction, welding process parameter instruction and elbow parameter of pipe diameter grading grading, process is promoted, and after flange spot welding and elbow are completed, realize the automatic mistake-proof check of key node by the entry of measured value, finally by manufacturing execution system, form the digitization process record bound with unique pipe identification code.The application deeply couples information cooperation and before welding after bending process, realizes process parameter standardization issue, key node mistake-proof check and whole-process digitization traceability under the premise of not relying on high-cost automatic equipment, and is suitable for the flow line batch production of DN15 to DN150 ship medium and small diameter straight pipe.

Description

Technical Field

[0001] This invention relates to the field of digital manufacturing technology for ship pipelines, specifically to a manufacturing method for small and medium-sized straight pipes in ships based on MES collaboration, which involves welding before bending. Background Technology

[0002] The prefabrication of small-diameter pipes in ships has long employed a process of bending before welding. This involves first bending straight pipes to the required length on a pipe bending machine according to design parameters, and then assembling flanges at both ends of the bent pipes and welding them. This process has several inherent and unavoidable drawbacks.

[0003] Firstly, the bent pipe fittings are irregular in shape due to springback and plastic deformation, and the flange end face is often difficult to align directly with the designed installation surface. Before assembly, the pipe alignment worker must repeatedly compare the position with the drawings for positioning and correction. Moreover, the quality of pipe alignment is highly dependent on the operator's spatial imagination and drawing reading experience, resulting in low efficiency and poor quality stability in the alignment process. The training process for high-level pipe alignment workers is lengthy, and there is a general shortage of pipe alignment workers in the industry.

[0004] Secondly, the shape of the bent spatial tubes varies from piece to piece, making them essentially "non-standard parts." This makes it difficult to use standardized chemical fixtures for assembly and welding in a streamlined manner, which hinders the stable application of automated production lines in this scenario. As a result, the tube processing workshop relies heavily on manual labor in squatting positions.

[0005] Third, design drawings, process flow cards, equipment execution parameters, and quality records are fragmented. Key control information such as flange angles, spot welding positions, welding parameters, and pipe bend angles requires workers to repeatedly read, copy, input, and memorize drawings, resulting in a high error rate and making it difficult to provide a structured data foundation for subsequent quality traceability and digital shipbuilding. Once a quality dispute occurs, it is often necessary to review paper process cards and inspection sheets across shifts and processes, resulting in a slow traceability response.

[0006] Fourth, key control points such as flange angle, spot weld distribution, welding parameters, and pipe bend angle rely entirely on workers' memory and experience, lacking a systematic verification and early warning mechanism. Out-of-tolerance workpieces are often only discovered in subsequent assembly processes, resulting in high rework costs.

[0007] Several improvements to address the aforementioned problems already exist in the existing technology. Chinese invention patent application CN111375994A discloses an intelligent production process for medium-diameter pipes that involves welding before bending. This process connects steps such as material preparation, flange assembly, spot welding, welding, bending, and correction to implement the welding-bending process. However, it focuses little on information coordination between design data and execution equipment, relying primarily on operator experience and lacking automatic error-proofing mechanisms for key nodes. Chinese invention patent application CN111531363A discloses an intelligent control method for welding-bending pipes. This method introduces heavy-duty automated equipment such as integrated welding and assembly machines, fully automated logistics roller conveyors, and automatic pipe bending machines, building upon the welding-bending process. While achieving a high degree of automation, it requires significant space, equipment investment, and production line modification, making parallel deployment difficult in existing workshops. Chinese invention patent application CN112288150A discloses an integrated system for the control and management of pipe fittings processing in the shipbuilding industry. It has built an overall information architecture from the business modules such as project management, data management, planning management, process management and quality management. However, it does not elaborate on the specific collaborative control process of physical processes such as flange assembly, welding and pipe bending.

[0008] In summary, current technologies have not yet solved the problems of standardizing the physical process path of welding before bending, providing information-based guidance for issuing process parameters according to pipe diameter, and ensuring error prevention verification and full-process digital traceability while maintaining the existing semi-automated equipment in the workshop. Therefore, there is an urgent need for a manufacturing solution for small and medium-sized straight pipe production lines that can deeply integrate information collaboration with the welding before bending process.

[0009] This invention solves the problems of difficult separation of the tube straightening process, difficulty in connecting process information, difficulty in preventing errors at key nodes, and difficulty in tracing process data in the existing small and medium-sized straight tube manufacturing process by deeply coupling the information collaboration of the manufacturing execution system with the pre-welding and post-bending process path. In this way, it realizes low-cost, easy-to-implement, and traceable small and medium-sized straight tube production line manufacturing. Summary of the Invention

[0010] To address the aforementioned issues, a method for manufacturing small and medium-sized straight pipes for ships based on MES collaboration, which involves welding before bending, is proposed. By deeply coupling the information collaboration capabilities of the Manufacturing Execution System with the welding-bending process path, this method solves the problems in existing technologies, such as heavy reliance on highly skilled pipe straighteners, gaps in process information, lack of error prevention measures at key nodes, and difficulty in tracing process data. This achieves the technical effects of standardized distribution of process parameters, automatic error prevention verification at key nodes, and full-process digital traceability without relying on high-cost automated equipment.

[0011] To address the problems of existing technologies, this invention provides a method for manufacturing small and medium-sized straight pipes in ships using a MES-based collaborative welding and bending process, comprising the following:

[0012] S1. Task Issuance and Information Structuring: The Manufacturing Execution System receives model data issued by the Design System, parses the fitting numbers, flange angle information and bend parameters into structured task packages, and generates unique fitting identification codes.

[0013] S2. Material Patching and Barcode Scanning for Online Delivery: Patch straight pipes, flanges, and accessories according to the structured task package, and verify the consistency between the online materials and the structured task package by scanning the unique pipe fitting identification code;

[0014] S3. Flange assembly: Place the straight pipe on the tooling, and rotate, position and spot weld the flange according to the flange assembly parameters displayed on the manufacturing execution system terminal. After spot welding, record the measured angle value into the manufacturing execution system terminal. The manufacturing execution system will determine whether it falls within the preset allowable deviation range. If it exceeds the range, an out-of-tolerance alarm will be triggered.

[0015] S4. Semi-automatic welding: The components that have been fixed by spot welding are brought into the welding station, and the fillet weld between the flange and the straight pipe is completed according to the welding process parameters displayed on the manufacturing execution system terminal. The welding completion status is then fed back to the manufacturing execution system.

[0016] S5. CNC pipe bending: The flanged straight pipe assembly is sent to the CNC pipe bending station. The manufacturing execution system generates a CNC machining program based on the pipe bending parameters and sends it to the CNC pipe bending machine to perform cold bending. After the pipe bending is completed, the measured bending angle is recorded, and the manufacturing execution system determines whether the measured bending angle falls within the design tolerance range.

[0017] S6. Data Recording: Bind the structured task package, work report data of each workstation and equipment parameters according to the unique pipe fitting identification code and write them into the digital process record.

[0018] In some examples of the present invention, the structured task package includes a header field and a fitting list field, wherein,

[0019] The header fields must include at least the batch number, ship number, system code, task issuance time, and source design system identifier;

[0020] The pipe fitting list fields shall include at least the unique pipe fitting identifier, material, pipe diameter, wall thickness, total cutting length, flange assembly parameters, and bend parameters.

[0021] The flange assembly parameters include at least the flange model, flange standard, first port flange lug angle, second port flange lug angle, and angle tolerance.

[0022] The bending parameters include at least the bending radius, bending angle, spatial rotation angle, and bending angle tolerance;

[0023] The manufacturing execution system and the design system communicate through a combination of intermediate file exchange and service interface triggering. The intermediate file adopts the Extensible Markup Language format and carries the structured task package. The service interface is used to send a task package import notification to the manufacturing execution system after the intermediate file is generated.

[0024] In some examples of the present invention, in step S3, the spot welding parameters in the flange assembly parameter guide are divided into multiple grades according to the nominal diameter DN value, and the spot welding parameters under each grade include at least the number of spot welds, the length of spot welds, and the distribution direction of spot welds.

[0025] In some examples of the present invention, in step S3, the flange assembly parameter guide further includes the spot welding arc initiation position and the spot welding sequence; the spot welding arc initiation position is defined according to the clock position with the center of the flange end face as a reference, and the spot welding sequence is symmetrical alternating welding.

[0026] In some examples of the present invention, in step S4, the welding process parameter guidelines include at least the welding method, welding wire or electrode grade and specifications, welding current range, welding voltage range, welding speed, gas flow rate, wire feed speed, layer distribution, welding sequence strategy, upper limit of single-pass continuous welding time, and upper limit of interpass temperature control.

[0027] In some examples of the present invention, the allowable deviation range in step S3 is preset by the process engineer in the background of the manufacturing execution system according to the ship repair quality standard; the design tolerance in step S5 includes bending angle tolerance and flange rotation angle tolerance.

[0028] In some examples of the present invention, in step S5, the bending parameters are sent to the CNC bending machine through the manufacturing execution system by calling the host computer interface of the CNC bending machine. The message of the host computer interface includes at least the batch number, ship number, pipe fitting number, outer diameter, wall thickness, wheel mold radius, blanking length, and bending data represented by three components.

[0029] In some examples of the present invention, the manufacturing execution system has a built-in process rule library, which includes at least:

[0030] A flange spot welding parameter mapping table divided according to the nominal diameter DN value is used to issue spot welding parameters according to pipe diameter in step S3.

[0031] The pipe diameter threshold determination rule includes a main condition and an auxiliary condition. The main condition is the pipe diameter determination. When the pipe wall thickness falls between the set lower wall thickness limit and the upper wall thickness limit, the process path of welding before bending is determined to be activated. Otherwise, the traditional process path of bending before welding is switched to or the process engineer manually reviews the process.

[0032] In some examples of the present invention, the process rule library also includes a bend springback compensation coefficient table divided by pipe material. The bend springback compensation coefficient table provides springback angle compensation coefficient and springback angle intercept for multiple material categories, including at least carbon steel and austenitic stainless steel, for use in the calculation of bend parameters in step S5.

[0033] In some examples of the present invention, the method is applied to the mass production of small-diameter straight pipes for ships with diameters from DN15 to DN150; in step S6, the manufacturing execution system automatically summarizes the digital process records by ship number, system or batch to generate a digital delivery list.

[0034] The advantages of this invention compared to the prior art are:

[0035] This invention employs a pre-welding, post-bending process, completing flange assembly and welding operations within a straight pipe configuration. This transforms the workpiece from a bent, spatial pipe into a regular, straight pipe, fundamentally eliminating the cumbersome pipe alignment step inherent in traditional pre-bending, post-welding processes. The Manufacturing Execution System (MES) displays process parameters piece-by-piece at key workstations, shifting the information input from individual experience to system guidance and systematically suppressing quality fluctuations caused by differences in worker experience. Information-based error prevention and verification are embedded at critical nodes in flange spot welding and pipe bending, instantly alarming and halting the flow of out-of-tolerance workpieces, thus resolving deviations at the process node level. All process data is bound to a unique pipe fitting identifier to form a digital process record, providing a complete data foundation for quality traceability and continuous process optimization. Attached Figure Description

[0036] Figure 1 This is a process flow diagram of a manufacturing method for small straight pipes in ships based on MES collaboration, which involves welding before bending.

[0037] Figure 2 This is a schematic diagram illustrating the data interaction between the manufacturing execution system, design system, workstation terminal, and CNC equipment in a pre-welding and post-bending ship small straight pipe assembly line manufacturing method based on MES collaboration according to the present invention.

[0038] Figure 3 This is a schematic diagram comparing the pre-welding and post-bending process flow of the MES-based collaborative manufacturing method for small straight pipes in ships with the traditional pre-bending and post-welding process flow.

[0039] Figure 4 The present invention relates to a method for manufacturing small and medium-sized straight pipes in ships based on MES collaboration, which involves welding before bending. The diagram illustrates the workstation layout and information flow of the production line for small and medium-sized straight pipes in ships.

[0040] In the diagram: 100, Manufacturing Execution System; 200, Design System; 300, Workstation Terminal; 400, CNC Equipment; 500, SAP System; 600, QMS System; 10, Blanking Station; 20, Flange Assembly Station; 30, Semi-automatic Welding Station; 40, CNC Pipe Bending Station; 50, Inspection Station; 60, Conveying System; 70, Manufacturing Execution System Terminal. Detailed Implementation

[0041] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0042] The Manufacturing Execution System (MES) described in this invention refers to an information platform deployed in the pipe processing workshop to undertake functions such as plan issuance, process guidance, process reporting, quality verification, and data traceability. The design system described in this invention refers to an information platform used to undertake 3D modeling of ship piping systems, generation of bills of materials, and compilation of process flow cards. Its common specific forms include AM, Tribon, and SPD. The small and medium-sized straight pipes for ships described in this invention specifically refer to marine straight pipes with diameters from DN15 to DN150. The selection criteria for this pipe diameter range will be explained in detail later.

[0043] See Figure 1 This invention provides a method for manufacturing small straight pipes in ships using a collaborative MES-based assembly line, which involves welding before bending. The method includes the following steps: S1, Task Issuance and Information Structuring: The manufacturing execution system receives model data issued by the design system, parses the pipe fitting number, flange angle information, and bending parameters into a structured task package, and generates a unique pipe fitting identifier. The subsequent steps, such as S2 material allocation and barcode scanning, S3 flange assembly, S4 semi-automatic welding, S5 CNC bending, and S6 data recording, will be detailed in subsequent sections.

[0044] See Figure 2 The Manufacturing Execution System 100 establishes data communication channels with the Design System 200, several workstation terminals 300, several CNC machines 400, the SAP System 500, and the QMS System 600, thereby forming the physical basis for the information collaboration of this invention. See also Figure 3The pre-welding-then-bending process flow L1 of this invention differs significantly from the traditional pre-bending-then-welding process flow L2 in both process sequence and information flow pattern. See also... Figure 4 The production line implementing the present invention is provided with a material unloading station 10, a flange assembly station 20, a semi-automatic welding station 30, a CNC pipe bending station 40, an inspection station 50 and a conveying system 60 running through the entire line in sequence along the material flow direction, and each station is equipped with a manufacturing execution system terminal 70.

[0045] The following will elaborate on each of steps S1 to S6.

[0046] Step S1: Task assignment and information structuring:

[0047] See Figure 1 and Figure 2 In this step, the manufacturing execution system 100 first receives model data from the design system 200. This model data, exported by the design system 200 after completing the 3D modeling of the piping system, is generated through a secondary development program and contains the geometric and process information of all pipe fittings within a single batch.

[0048] In one specific embodiment of the present invention, the Manufacturing Execution System (MES) and the Design System communicate through a combination of intermediate file exchange and service interface triggering. The intermediate file adopts Extensible Markup Language (XML) format and carries the structured task package. The service interface is used to send a task package import notification to the MES after the intermediate file is generated. Specifically, after completing the piping system modeling, the Design System 200 exports the pipe fitting bill of materials and key information such as flange angles and bend parameters into an intermediate file in Extensible Markup Language (XML) format through a secondary development program. It then calls the service interface provided by the MES 100 to send a task package import notification to the MES 100. Upon receiving the task package import notification, the MES 100 actively reads and parses the intermediate file, thereby completing the loading of the task package. The technical advantage of this hybrid communication mode is that the intermediate file serves as a transmission carrier with complete fields, a clear structure, and easy cross-system parsing, while the service interface serves as a low-latency notification and online triggering function. The combination of the two can reduce the coupling between the two systems while ensuring interface stability.

[0049] In one specific embodiment of the present invention, the structured task package includes a header field and a fitting list field. The header field includes at least the batch number, ship number, system code, task issuance time, and source design system identifier. The fitting list field includes at least the unique fitting identifier, material, pipe diameter, wall thickness, total cutting length, flange assembly parameters, and bend parameters. The flange assembly parameters include at least the flange model, flange standard, first port flange lug angle, second port flange lug angle, and angle tolerance. The bend parameters include at least the bending radius, bending angle, spatial angle, and bending angle tolerance.

[0050] After completing the task package parsing, the Manufacturing Execution System 100 generates a unique pipe fitting identification code for each pipe fitting. In this embodiment, the unique pipe fitting identification code is carried in the physical form of a one-dimensional barcode or a two-dimensional barcode and is bound to the batch number, ship number, and system code. The unique pipe fitting identification code is used as an identity label for the pipe fitting in subsequent processes. Operators at each workstation only need to scan the label to retrieve all process parameters and historical records of the pipe fitting from the Manufacturing Execution System 100.

[0051] The technical effect of the above-mentioned structured processing is that the three-dimensional model data output by the design end is effectively decoupled into executable task information oriented towards process nodes. The workstation terminal 300 no longer relies on the operator's ability to read drawings and spatial imagination. The process information is solidified by the system in a field-based and item-based manner, which establishes the necessary data foundation for parameter guidance and error prevention verification in subsequent steps.

[0052] Step S2, Material tray preparation and barcode scanning online:

[0053] See Figure 1 and Figure 4 In this step, the Manufacturing Execution System 100 automatically generates a palletizing list based on the structured task package. The warehouse, according to the palletizing list, categorizes and pallets straight pipes, flanges, and accessories by pipe diameter and material. In one specific embodiment of the invention, small accessories such as bolts, gaskets, and ferrules are delivered using enclosed pallets, with the pallet attached to a task list and labeled with the corresponding batch number, thereby preventing the loss or confusion of small parts during transit.

[0054] After the trays are assembled, they are delivered to the unloading station 10 at the beginning of the production line. Operators scan the barcodes on the trays and the unique pipe identification codes on each straight pipe using a barcode scanner. The Manufacturing Execution System 100 verifies the consistency between the materials being assembled and the information registered in the structured task package, including material, pipe diameter, wall thickness, and total unloading length. If any discrepancy occurs, the Manufacturing Execution System 100 triggers a warning and prevents the assembly from proceeding. Once the verification is successful, the Manufacturing Execution System 100 automatically records the assembly time, operator, and material batch.

[0055] The technical effect of the above-mentioned barcode verification mechanism is that it strongly binds the design data, the warehouse materials, and the workstation actions as soon as the materials enter the production line, thus avoiding quality accidents of the entire batch of workpieces caused by material mixing or incorrect materials.

[0056] Step S3, Flange Assembly:

[0057] See Figure 1 and Figure 4 In this step, the straight pipe is transported to the flange assembly station 20 by the conveying system 60 after being connected to the line. In a specific embodiment of the present invention, the tooling of the flange assembly station 20 includes a V-block or a roller frame, and the inspection tools include a square or a spirit level, all of which are conventional low-cost equipment.

[0058] After the operator clicks "Start Assembly" on the manufacturing execution system terminal 70 at the flange assembly station 20, the manufacturing execution system 100 pushes the flange assembly parameter guide corresponding to the current pipe fitting to the manufacturing execution system terminal 70 for display, based on the unique pipe fitting identification code. The flange assembly parameter guide includes at least the flange model, flange angle requirements, allowable deviation range, and spot welding parameters categorized by pipe diameter.

[0059] The operator places the straight pipe on a V-shaped iron or roller frame, manually inserts the two flanges into the pipe end, and uses a square or spirit level to ensure the perpendicularity of the flange end face to the pipe axis. Then, according to the flange rotation angle requirements displayed on the manufacturing execution system terminal 70, the flange is rotated to the target angle position, and then spot welded and fixed according to the spot welding parameters classified by pipe diameter.

[0060] Regarding the spot welding parameters categorized by pipe diameter, in a specific embodiment of the present invention, in step S3, the spot welding parameters categorized by pipe diameter are divided into multiple grades according to the nominal diameter DN value. The spot welding parameters under each grade include at least the number of spot welds, the spot weld length, and the spot weld distribution orientation. Specifically, the first grade is for pipe diameters from DN15 to DN40, and its corresponding spot welding parameters are three spot welds, a spot weld length of 3mm to 5mm, and a three-point evenly distributed spot weld distribution. The second grade is for pipe diameters greater than DN40 and not greater than DN65, and its corresponding spot welding parameters are four spot welds, a spot weld length of 5mm, and a four-point evenly distributed spot weld distribution with each pair staggered by 90°. The third grade... For pipe diameters greater than DN65 and not greater than DN100, the corresponding spot welding parameters are: four spot welds, spot weld length of 8mm to 10mm, and spot welds distributed evenly at four points with each pair staggered by 90°. For pipe diameters greater than DN100 and not greater than DN125, the corresponding spot welding parameters are: four spot welds, spot weld length of 10mm to 12mm, and spot welds distributed evenly at four points with each pair staggered by 90°. For pipe diameters greater than DN125 and not greater than DN150, the corresponding spot welding parameters are: four to six spot welds, spot weld length of 12mm to 15mm, and spot welds distributed evenly at four or six points with staggered angles.

[0061] The technical benefits of the above five tiers of refinement are as follows: Flanges of different pipe diameters exhibit significant differences in the degree of welding heat deformation. Larger pipe diameters require a greater number and length of spot welds, and a more even distribution of spot welds is necessary to ensure sufficient positioning rigidity during the spot welding stage and to avoid angular deformation caused by localized overheating. Integrating these empirical parameters into the Manufacturing Execution System 100 can prevent operators from using inappropriate spot welding parameters for different pipe diameters due to differences in experience.

[0062] As a further preferred embodiment of the present invention, in step S3, the flange assembly parameter guidance further includes the spot welding arc initiation position and the spot welding sequence; the spot welding arc initiation position is based on the center of the flange end face, with the flange ear plate centerline direction as the 12 o'clock position mark, and the clock positions of 3 o'clock, 6 o'clock, and 9 o'clock are defined clockwise in sequence; the spot welding sequence is symmetrical alternating welding, when using four-point spot welding, the welding is alternately performed at the 12 o'clock, 6 o'clock, 3 o'clock, and 9 o'clock positions, and when using six-point spot welding, the welding is alternately performed at the 12 o'clock, 6 o'clock, 2 o'clock, 8 o'clock, 4 o'clock, and 10 o'clock positions. The technical effect of this symmetrical alternating welding sequence is that: always using the diametrical direction of the current weld point as the next welding position, it can effectively reduce the angular deformation caused by the accumulation of unidirectional thermal stress, and further improve the relative positional accuracy of the flange assembly.

[0063] In preferred scenarios, the Manufacturing Execution System (MES) terminal 70, while providing spot welding parameter guidance, can also provide matching spot welding process electrical parameters and duration ranges. For example: Category 1 spot welding current 60A to 90A, voltage 22V to 25V, duration 2s to 3s; Category 2 spot welding current 80A to 120A, voltage 18V to 22V, duration 1.5s to 2.5s; Category 3 spot welding current 90A to 130A, voltage 24V to 28V, duration 3s to 4s; Category 4 spot welding current 130A to 180A, voltage 20V to 24V, duration 2s to 3s; Category 5 spot welding current 180A to 240A, voltage 22V to 26V, duration 3s to 5s. These electrical parameters are recommended ranges based on experience and can be adjusted by the process engineer in the MES 100 backend according to the actual welding materials.

[0064] After spot welding is completed, the operator uses a protractor to measure the actual flange lug angle value and enters the measured angle value into the manufacturing execution system terminal 70. The manufacturing execution system 100 automatically determines whether the measured angle value falls within the allowable deviation range. If it falls within the allowable deviation range, it is deemed qualified and released to the next workstation; if it exceeds the allowable deviation range, an out-of-tolerance alarm is triggered. As an example, the allowable deviation range in step S3 is ±2°, which is preset by the process engineer in the background of the manufacturing execution system according to the ship repair quality standards. The design tolerance in step S5 includes the bending angle tolerance and the flange angle tolerance, and the bending angle tolerance is not greater than ±0.5°. The allowable deviation range can be set with reference to the Chinese ship repair quality standards (such as GB / T 34001—2016, abbreviated as CSQS). Those skilled in the art will understand that it can also be adjusted according to the specific classification society standards or customer agreements, and this invention does not limit this.

[0065] The technical effects of the above-mentioned corner measurement and automatic judgment are as follows: the corner qualification judgment is moved to the workstation before the physical welding process is completed, avoiding the transfer of unqualified workpieces across workstations, and solidifying the corner qualification inspection, which originally only existed in the operator's experience judgment, into a system-level, traceable, one-time automatic judgment.

[0066] Step S4, Semi-automatic welding:

[0067] See Figure 1 and Figure 4 In this step, the straight pipe and flange assembly, fixed by spot welding, enters the semi-automatic welding station 30 via a roller frame or conveyor chain. In one specific embodiment of the invention, the semi-automatic welding station 30 is equipped with a welding wire supply system, a semi-automatic welding machine, and a welding terminal.

[0068] The operator scans the unique fitting identification code of the component on the welding terminal. The manufacturing execution system 100 pushes the welding process parameter guidance corresponding to the component to the welding terminal for display. In step S4, the welding process parameter guidance includes at least the welding method, welding wire or electrode grade and specifications, welding current range, welding voltage range, welding speed, gas flow rate, wire feed speed, layer distribution, welding sequence strategy, upper limit of single-pass continuous welding time, and upper limit of interpass temperature control.

[0069] As a specific example, in the scenario of a DN80 fire-fighting pipe fitting with material 20# and a wall thickness of 6mm, the welding process parameters can be set as follows: welding method: gas metal arc welding; welding wire: ER50-6, specification φ1.2mm; welding current range: 160A to 200A; welding voltage range: 20V to 24V; welding speed: 30cm / min to 50cm / min; CO2 gas flow rate: 10L / min to 15L / min; wire feed speed: 3.5m / min to 6.0m / min; pass distribution: 1 root pass, 1 to 2 filler passes, and 1 capping pass, for a total of 2 to 4 passes; welding sequence strategy: symmetrical alternating welding; maximum continuous welding time per pass: 120 seconds; maximum interpass temperature control: 150℃. These parameters can also be adjusted by the process engineer in the process rule library of the Manufacturing Execution System 100 backend, based on the welding material, pipe diameter, and wall thickness.

[0070] Operators, guided by the welding process parameters displayed on the welding terminal, complete the fillet weld between the flange and the straight pipe manually or semi-automatically. In one specific embodiment of the invention, to accommodate welding machine models with different data acquisition capabilities, the Manufacturing Execution System 100 sets separate acquisition strategies for two scenarios: if the welding station equipment has a data acquisition interface, the Manufacturing Execution System 100 automatically acquires current, voltage, and welding time data during the welding process through the data acquisition interface; if the welding station equipment does not have the data acquisition interface, the Manufacturing Execution System 100 forces the operator to enter the set values ​​of the welding parameters or instrument readings on the welding terminal after welding is completed, as part of the quality record. After welding is completed, the operator confirms "welding completed" on the welding terminal, and the Manufacturing Execution System 100 records the welding completion time and operator information.

[0071] The technical effect of the above compatibility design is that, under the current conditions where the models of welding machines in the existing workshop are of varying quality, it can still ensure that the welding process of each pipe fitting has traceable parameter records, and does not force the workshop to carry out large-scale modifications to the existing welding machines.

[0072] Step S5, CNC pipe bending:

[0073] See Figure 1 and Figure 4In this step, the welded components are conveyed by the conveying system 60 to the CNC pipe bending station 40. In one specific embodiment of the present invention, the CNC pipe bending station 40 is equipped with a CNC pipe bending machine and a pipe bending terminal, and the CNC system of the CNC pipe bending machine communicates with the manufacturing execution system 100 through an interface.

[0074] The operator scans the unique pipe fitting identification code of the component at the pipe bending terminal. Based on this, the manufacturing execution system 100 retrieves the corresponding pipe bending parameters of the component from the structured task package and pushes them to the pipe bending terminal for display. The pipe bending parameters include at least three parameter components: bending radius R, bending angle θ, and spatial rotation angle α.

[0075] Regarding the method of sending the bending parameters to the CNC pipe bending machine, in one specific embodiment of the present invention, in step S5, the bending parameters are sent to the CNC pipe bending machine through the manufacturing execution system calling the host computer interface of the CNC pipe bending machine. The message of the host computer interface includes at least the batch number, ship number, pipe fitting number, outer diameter, wall thickness, die radius, blanking length, and bending data represented in three components. Another alternative solution is that when the CNC pipe bending machine does not have an open interface, the operator manually inputs the bending parameters displayed on the bending terminal into the control panel of the CNC pipe bending machine. Both solutions can minimize the risk of incorrect angle input by manual reading of drawings.

[0076] As a specific example, under the preferred interface distribution scheme, the manufacturing execution system 100 sends a message to the interface address of the CNC pipe bending machine's host computer via an HTTP POST request.

[0077] Upon receiving the message, the CNC pipe bending machine interface returns a response message to the manufacturing execution system 100. Those skilled in the art will understand that the above message fields and values ​​are merely examples, and the actual list of fields can be expanded according to the specific device interface protocol; this invention does not impose any limitations on this.

[0078] After receiving the bending parameters, the CNC pipe bending machine initiates the cold bending process. After bending is completed, the manufacturing execution system (MES) determines whether the measured bending angle falls within the design tolerance range. Specifically, the operator uses an angle gauge to measure the actual bending angle and a protractor to measure the actual rotation angle of the flange lugs after bending, recording these measured bending parameters into the bending terminal. The MES automatically compares the measured values ​​with the design tolerances: the design tolerances include the bending angle tolerance and the flange rotation angle tolerance, where the bending angle tolerance is preferably no greater than ±0.5°, and the flange rotation angle tolerance is preferably ±2°. If the comparison result falls within the tolerance range, the component status is updated to "Bending Completed"; if it exceeds the tolerance range, the component is marked as pending processing and prompted for re-inspection or rework.

[0079] As further support for the pipe bending step, in one specific embodiment of the present invention, the manufacturing execution system has a built-in process rule library, which includes at least: a flange spot welding parameter mapping table divided according to the nominal diameter DN value, used to issue spot welding parameters according to pipe diameter in step S3; and a pipe diameter threshold determination rule, which includes a main condition and an auxiliary condition. The main condition is pipe diameter determination. When the pipe wall thickness falls between the set lower wall thickness limit and the upper wall thickness limit, it is determined that the pre-welding-then-bending process path is activated; otherwise, it switches to the traditional pre-bending-then-welding process path or manual review by the process engineer.

[0080] As an example, the yield strength reference range for 20# carbon steel is 245MPa to 410MPa, the springback angle compensation coefficient K is 1.05 to 1.12, the springback angle intercept C is 1.0° to 2.5°, and the applicable bending angle range is 30° to 120°; the yield strength reference range for Q235B carbon steel is 235MPa to 375MPa, the springback angle compensation coefficient K is 1.04 to 1.10, and the springback angle intercept C is 1.0° to 2.5°. The springback angle range is 1.0° to 2.0°; the lower reference limit for the yield strength of SS304 austenitic stainless steel is 205 MPa, the springback angle compensation coefficient K has a reference range of 1.12 to 1.20, and the springback angle intercept C has a reference range of 2.0° to 3.5°; the lower reference limit for the yield strength of SS316L austenitic stainless steel is 177 MPa, the springback angle compensation coefficient K has a reference range of 1.15 to 1.25, and the springback angle intercept C has a reference range of 2.5° to 4.0°. Based on this, the Manufacturing Execution System 100 performs springback compensation calculations on the designed bending angle during the task package analysis phase and sends the compensated actual execution angle to the bend end.

[0081] Regarding the selection criteria for the pipe diameter range of DN15 to DN150, those skilled in the art will understand that: the upper limit of DN150 is mainly determined by the physical boundary of the rated load of existing medium-diameter CNC pipe bending machines. When the pipe diameter exceeds DN150, the bending torque of the pipe bending machine is difficult to stabilize and form, at which point elbow connections or hot bending processes are usually used instead; the lower limit of DN15 is mainly determined by the workshop practice of manually bending small-diameter pipe fittings without producing drawings. Therefore, the method described is applied to the assembly line mass production of small-diameter straight pipes for ships with diameters of DN15 to DN150; in step S6, the manufacturing execution system automatically summarizes the digital process records by ship number, system, or batch to generate a digital delivery list. The pipe diameter range of DN15 to DN150 is both the physical boundary of the bending equipment's capacity and the applicable boundary of the assembly line prefabrication.

[0082] Step S6, Data Recording:

[0083] See Figure 1 and Figure 2In this step, the Manufacturing Execution System 100 summarizes and stores the entire process data of each pipe fitting from the blanking station 10 to the CNC bending station 40, forming a digital process record bound to a unique pipe fitting identification code. The digital process record includes at least: the original design parameters in the structured task package, the batch number of the material upon arrival, the measured angle values ​​and judgment results during the flange assembly stage, the welding parameter settings or collected values ​​during the semi-automatic welding stage, the measured bending parameters and judgment results during the CNC bending stage, and the operators, operation times, and equipment numbers at each station.

[0084] In one specific embodiment of the present invention, the Manufacturing Execution System 100 automatically summarizes the digitized process records by ship number, system, or batch to generate a digitized delivery list. The digitized delivery list can be interfaced with the Outfitting Management System in the form of spreadsheets or structured data, thereby forming a complete data link from the design end through the manufacturing end to the outfitting end. Simultaneously, the Manufacturing Execution System 100 maintains data communication with the SAP system 500 and the QMS system 600, synchronizing the pipe fitting completion status, material consumption information, and quality inspection conclusions to the corresponding enterprise-level systems.

[0085] The technical effect of the above data recording steps is that the process data, which was originally scattered in paper process cards, equipment logs and inspection sheets, is centrally carried in the Manufacturing Execution System 100, forming a "one item, one file" full-process digital archive, which establishes a data foundation for quality traceability and continuous process optimization.

[0086] Regarding the specific implementation of the production line:

[0087] See Figure 4Another aspect of the present invention provides a production line for small and medium-sized straight pipes in ships, used to implement the manufacturing method for small and medium-sized straight pipes in ships based on MES collaboration as described in any one of claims 1 to 10, which involves welding before bending. The production line is arranged sequentially along the material flow direction as follows: a material unloading station equipped with an industrial control computer connected to the manufacturing execution system (MES) for scanning codes to obtain unloading tasks and reporting work to the MES; a flange assembly station equipped with tooling and testing tools, wherein the tooling supports the straight pipe in its straight pipe state and is equipped with a flange assembly terminal, which is communicatively connected to the MES for displaying spot welding parameter guidance according to pipe diameter and flange rotation requirements, as well as receiving measured rotation values ​​entered by the operator; and a semi-automatic welding station equipped with a welding wire supply system, a semi-automatic welding machine, and a welding terminal, wherein the welding terminal is communicatively connected to the MES for displaying welding process parameter guidance and reporting to the MES. The system provides feedback on welding completion status; a CNC pipe bending station equipped with a CNC pipe bending machine and a pipe bending terminal, wherein the CNC system of the CNC pipe bending machine communicates with the manufacturing execution system via an interface, and is used to perform cold bending processing according to the pipe bending parameters issued by the manufacturing execution system; a conveying system for conveying pipe fittings between the blanking station, the flange assembly station, the semi-automatic welding station, and the CNC pipe bending station; a manufacturing execution system management platform, which communicates with the blanking station, the flange assembly station, the semi-automatic welding station, the CNC pipe bending station, the SAP system, and the QMS system respectively, and is used to execute the information collaboration and quality closed-loop control of the method described in any one of claims 1 to 10; the manufacturing execution system management platform has a built-in process rule library, which includes at least a flange spot welding parameter mapping table classified by pipe diameter, a pipe bending springback compensation coefficient table classified by material, and pipe diameter threshold determination rules.

[0088] The tooling at flange assembly station 20 can be V-blocks or roller frames, and the inspection tools can be squares or spirit levels. The semi-automatic welding machine at semi-automatic welding station 30 uses a carbon dioxide gas shielded welding machine. The section of the conveyor system 60 between flange assembly station 20 and semi-automatic welding station 30 can use roller frames or conveyor chains to form a continuous, rhythmic transmission. Inspection station 50 is equipped with conventional inspection tools, and the inspection results are entered into manufacturing execution system 100. Furthermore, the manufacturing execution system 100 can also have a built-in production progress dashboard at the software level, dynamically updating the pipe fitting ledger status based on real-time work reports from each station and generating a pipe fitting production progress dashboard for workshop managers to perform rhythm balancing and anomaly handling.

[0089] A comparison of the process path of this invention with that of traditional processes:

[0090] See Figure 3The core difference between the pre-welding-then-bending process L1 and the traditional pre-bending-then-welding process L2 lies in the relative order of the bending and welding processes. In the traditional pre-bending-then-welding process L2, the pipe fitting is bent into a spatial shape before flange assembly and welding are performed. The assembly object is an irregularly shaped spatial component, requiring repeated pipe alignment and heavily relying on the operator's spatial judgment ability. In the pre-welding-then-bending process L1 of this invention, the flange assembly and welding are completed while the pipe fitting is in a straight pipe state. The assembly object is a regular straight pipe, which can be stably positioned with the help of tooling. Then, a CNC cold bending is performed to obtain the final spatial shape.

[0091] Regarding the verification of this invention during in-workshop trial production:

[0092] As a verification of the feasibility of the process path of the present invention, under the trial production conditions in the workshop, a batch of 20 DN80 fire protection pipe fittings (material 20#, wall thickness 6mm, design bend angle 90°, bending radius R=250mm) were selected as a comparison sample and processed using the traditional first-bend-then-weld process and the first-weld-then-bend process based on MES collaboration described in the present invention. Trial production results show that, after adopting the process path of this invention, the average working time per pipe was reduced from approximately 52 minutes to approximately 26 minutes, the total working time for 20 batches was reduced from approximately 17.3 hours to approximately 9.2 hours, the rework rate was reduced from approximately 15% to the range of 0 to 5%, the flange angle deviation rate was reduced from approximately 10% to 0%, the bend angle qualification rate was increased from approximately 90% to 95% to nearly 100%, the standard deviation σ of flange angle dispersion was narrowed from approximately 1.5° to approximately 0.7°, the standard deviation σ of bend angle dispersion was narrowed from approximately 0.65° to approximately 0.28°, the batch traceability response time was shortened from approximately 45 minutes to approximately 8 seconds, and the single-pipe traceability response time was shortened from approximately 5 minutes to approximately 3 seconds. The above data are only sample comparison results from the workshop trial production stage. Specific values ​​may vary depending on pipe diameter, material, wall thickness, welding materials, and specific equipment conditions. This invention does not impose any limitations on these variations. During longer-term workshop trial production tracking, the rework rate of pipe fittings of various specifications from DN50 to DN150 processed using the process path of this invention can remain stable at a low level for a long period of time.

Claims

1. A method for manufacturing small straight pipes in ships using a pre-welding and post-bending assembly line based on MES collaboration, characterized in that, Including the following: S1. Task Issuance and Information Structuring: The Manufacturing Execution System receives model data issued by the Design System, parses the fitting numbers, flange angle information and bend parameters into structured task packages, and generates unique fitting identification codes. S2. Material Patching and Barcode Scanning for Online Delivery: Patch straight pipes, flanges, and accessories according to the structured task package, and verify the consistency between the online materials and the structured task package by scanning the unique pipe fitting identification code; S3. Flange assembly: Place the straight pipe on the tooling, and rotate, position and spot weld the flange according to the flange assembly parameters displayed on the manufacturing execution system terminal. After spot welding, record the measured angle value into the manufacturing execution system terminal. The manufacturing execution system will determine whether it falls within the preset allowable deviation range. If it exceeds the range, an out-of-tolerance alarm will be triggered. S4. Semi-automatic welding: The components that have been fixed by spot welding are brought into the welding station, and the fillet weld between the flange and the straight pipe is completed according to the welding process parameters displayed on the manufacturing execution system terminal. The welding completion status is then fed back to the manufacturing execution system. S5. CNC pipe bending: The flanged straight pipe assembly is sent to the CNC pipe bending station. The manufacturing execution system generates a CNC machining program based on the pipe bending parameters and sends it to the CNC pipe bending machine to perform cold bending. After the pipe bending is completed, the measured bending angle is recorded, and the manufacturing execution system determines whether the measured bending angle falls within the design tolerance range. S6. Data Recording: Bind the structured task package, work report data of each workstation and equipment parameters according to the unique pipe fitting identification code and write them into the digital process record.

2. The method for manufacturing small and medium-sized straight pipes in a shipbuilding assembly line based on MES collaboration for pre-welding and post-bending as described in claim 1, characterized in that, The structured task package includes header fields and a utility list field, wherein... The header fields must include at least the batch number, ship number, system code, task issuance time, and source design system identifier; The pipe fitting list fields shall include at least the unique pipe fitting identifier, material, pipe diameter, wall thickness, total cutting length, flange assembly parameters, and bend parameters. The flange assembly parameters include at least the flange model, flange standard, first port flange lug angle, second port flange lug angle, and angle tolerance. The bending parameters include at least the bending radius, bending angle, spatial rotation angle, and bending angle tolerance; The manufacturing execution system and the design system communicate through a combination of intermediate file exchange and service interface triggering. The intermediate file adopts the Extensible Markup Language format and carries the structured task package. The service interface is used to send a task package import notification to the manufacturing execution system after the intermediate file is generated.

3. The method for manufacturing small straight pipes in ships using a pre-welding and post-bending assembly line based on MES collaboration as described in claim 1 or 2, characterized in that, In step S3, the spot welding parameters in the flange assembly parameter guide are divided into multiple grades according to the nominal diameter DN value. The spot welding parameters under each grade include at least the number of spot welds, the length of spot welds, and the distribution direction of spot welds.

4. The method for manufacturing small straight pipes in ships using a pre-welding and post-bending assembly line based on MES collaboration as described in claim 3, characterized in that, In step S3, the flange assembly parameter guide also includes the spot welding arc starting position and the spot welding sequence; the spot welding arc starting position is defined according to the clock position with the center of the flange end face as the reference, and the spot welding sequence is symmetrical alternating welding.

5. The method for manufacturing small and medium-sized straight pipes in a shipbuilding assembly line based on MES collaboration for welding before bending, as described in claim 1, is characterized in that... In step S4, the welding process parameter guidelines include at least the welding method, welding wire or electrode grade and specifications, welding current range, welding voltage range, welding speed, gas flow rate, wire feed speed, layer distribution, welding sequence strategy, upper limit of single-pass continuous welding time, and upper limit of interpass temperature control.

6. The method for manufacturing small straight pipes in ships using a pre-welding and post-bending assembly line based on MES collaboration as described in claim 1, characterized in that, The allowable deviation range in step S3 is preset by the process engineer in the background of the manufacturing execution system according to the ship repair quality standards; the design tolerance in step S5 includes bending angle tolerance and flange rotation angle tolerance.

7. The method for manufacturing small and medium-sized straight pipes in a shipbuilding assembly line based on MES collaboration for pre-welding and post-bending as described in claim 1, characterized in that, In step S5, the bending parameters are sent to the CNC bending machine through the manufacturing execution system by calling the host computer interface of the CNC bending machine. The message of the host computer interface includes at least the batch number, ship number, pipe fitting number, outer diameter, wall thickness, wheel mold radius, blanking length, and bending data represented by three components.

8. The method for manufacturing small and medium-sized straight pipes in a shipbuilding assembly line based on MES collaboration for pre-welding and post-bending as described in claim 1, characterized in that, The manufacturing execution system has a built-in process rule library, which includes at least: A flange spot welding parameter mapping table divided according to the nominal diameter DN value is used to issue spot welding parameters according to pipe diameter in step S3. The pipe diameter threshold determination rule includes a main condition and an auxiliary condition. The main condition is the pipe diameter determination. When the pipe wall thickness falls between the set lower wall thickness limit and the upper wall thickness limit, the process path of welding before bending is determined to be activated. Otherwise, the traditional process path of bending before welding is switched to or the process engineer manually reviews the process.

9. The method for manufacturing small and medium-sized straight pipes in a shipbuilding assembly line based on MES collaboration for pre-welding and post-bending as described in claim 8, characterized in that, The process rule library also includes a bend springback compensation coefficient table divided by pipe material. The bend springback compensation coefficient table provides springback angle compensation coefficient and springback angle intercept for multiple material categories, including at least carbon steel and austenitic stainless steel, for use in the calculation of bend parameters in step S5.

10. The method for manufacturing small and medium-sized straight pipes in a shipbuilding assembly line based on MES collaboration for pre-welding and post-bending as described in claim 1, characterized in that, The method is applied to the mass production of small-diameter straight pipes for ships with diameters from DN15 to DN150 on an assembly line. In step S6, the manufacturing execution system automatically summarizes the digital process records by ship number, system, or batch to generate a digital delivery list.

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