A piston-type aircraft engine wiring harness assembly line

Abstract

This invention discloses a piston-type aero-engine wiring harness assembly line, belonging to the field of aero-engine wiring harness assembly technology. The assembly line includes a cable cutting machine for precise length cutting, a cable marking machine for identifying cable parameter information, a wire stripping machine for high-precision layer stripping, a terminal pressing machine for precise pressing of cables and terminals, a wiring harness mounting plate for standardized wiring and shaping, a wiring harness testing platform for comprehensive testing of wiring harness electrical performance and airtightness, and a MES server for data acquisition, storage, and traceability management of production and quality throughout the entire process. The assembly line adopts standardized assembly line operations, with quality inspection nodes set at each process to achieve isolation and control of non-conforming products. This assembly line achieves standardized, automated, and traceable production of wiring harness assemblies, improving production efficiency and product quality.

Description

Technical Field

[0001] This invention relates to the field of aircraft engine wiring harness assembly technology, specifically to an assembly line for a piston-type aircraft engine wiring harness assembly. Background Technology

[0002] An aircraft engine is a highly complex thermodynamic machine. It not only provides speed to the aircraft but also generates lift. An aircraft piston engine is a mechanical device that mixes aviation kerosene with air, which is then burned and expanded within a closed cylinder to produce power. This type of engine must work in conjunction with a propeller, using the thrust generated by the propeller to propel the aircraft forward. The main components of a piston engine include cylinders, pistons, connecting rods, crankshafts, valve mechanisms, propeller reducers, and controllers; it is a four-stroke engine. The engine wiring harness assembly is the neural network and vascular system of the aircraft piston engine, responsible for power supply, signal transmission, and safety control; it is a core component ensuring the stable and safe operation of the engine.

[0003] For example, patent CN120914590A discloses a wiring harness assembly method and a vehicle wiring harness assembly. The assembly method includes obtaining the model information of the vehicle wiring harness assembly to be processed; distributing multiple first mounting wiring harnesses, multiple second mounting wiring harnesses, and multiple junction boxes to multiple pre-assembly stations; simultaneously performing the following steps at multiple pre-assembly stations: inserting both first ends of the first mounting wiring harnesses into the corresponding junction boxes, and inserting at least one second end of the second mounting wiring harnesses into the corresponding junction boxes, until pre-assembly is completed; then assembling the pre-assembled semi-finished products formed at multiple pre-assembly stations to the final assembly station, so that the multiple junction boxes are arranged and positioned according to a preset path; based on the completion of the assembly of the pre-assembled semi-finished products at the final assembly station, inserting the second ends of the pre-assembled semi-finished products that are in a free state into the corresponding junction boxes; and bundling the pre-assembled semi-finished products at the final assembly station.

[0004] However, some existing piston-type aircraft engine wiring harness assemblies are assembled manually. The assembly efficiency is highly dependent on the skill level of the workers, resulting in low production efficiency. The assembly accuracy is limited by the experience level of the technicians, leading to poor consistency in the quality of the wiring harness assemblies. Furthermore, the sampling inspection rate for quality control is low, and defective products are easily transferred to downstream processes, resulting in high rework costs. In addition, the production process uses paper records, which has weak data traceability capabilities and makes it difficult to accurately locate the root cause of problems, which is not conducive to continuous improvement of product quality.

[0005] To address the aforementioned issues, there is an urgent need for innovative design based on the existing aircraft engine wiring harness assembly line. Summary of the Invention

[0006] The purpose of this invention is to provide a piston-type aircraft engine wiring harness assembly line to address the problems mentioned in the background art. Existing piston-type aircraft engine wiring harness assemblies are assembled manually, resulting in low production efficiency due to the high dependence on worker skill, assembly accuracy limited by technician experience, poor consistency in wiring harness assembly quality, low sampling rate for quality control, and the easy transfer of defective products to downstream processes, leading to high rework costs. Furthermore, the use of paper records in the production process results in weak data traceability, making it difficult to accurately pinpoint the root cause of problems and hindering continuous product quality improvement.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a piston-type aero-engine wiring harness assembly line, comprising a cable cutting machine for precise length cutting of cables, a cable marking machine for marking cable parameter information, a wire stripping machine for high-precision layer stripping, a terminal pressing machine for precision pressing of cables and terminals, a wiring harness mounting plate for standardized wiring harness shaping, a wiring harness testing bench for comprehensive testing of wiring harness electrical performance and airtightness, and an MES server for full-process production and quality data acquisition, storage, and traceability control; simultaneously, after the cables complete raw material inspection, the wiring harness assembly line sequentially performs cutting, marking, stripping, terminal pressing, wiring fixing, and testing processes. The testing process includes overall line performance testing and appearance re-inspection. After testing, the finished products are packaged and stored.

[0008] Preferably, the wire harness assembly line is also equipped with an enterprise resource planning system server. The enterprise resource planning system server is connected to the cable cutting machine, cable marking machine, wire stripping machine, terminal crimping machine, wire harness testing station and MES server respectively. It is used to coordinate and manage production plans, order allocation and raw material information, and issue process parameters, cable specifications and batch operation instructions that match the wire harness production to each process equipment.

[0009] Preferably, the cutting process of the cable cutting machine includes: adjusting the parameters of the cutting machine, including cutting length and cutting speed; fixing the cable on the machine, with aviation cables placed stably on the feed rack and fed into the feeding end of the equipment; automatic cutting, where the equipment completes fixed-length feeding, precise cutting, and automatic discharge according to preset parameters; first piece length detection, where the length accuracy and cut quality of the first piece of cut cable are fully verified; batch cutting, where continuous automatic cutting is started after the first piece is qualified, maintaining constant parameters; and sorting and placing the cut cables according to specifications and batches, and affixing labels.

[0010] Preferably, the cable marking machine is used to print cable identification and process parameter information on the surface of the cable, and the spacing of the markings on the cable is controlled within the process requirements to maintain a neat arrangement and uniform spacing of the markings.

[0011] Preferably, the wire stripping machine adopts a layered wire stripping process, and the stripping requirements include: the stripping length error is controlled within ±0.2mm; the insulation layer is completely stripped without any residual insulation; the conductor copper wire is free from scratches, broken wires, and loose wires; the conductors of multi-strand cables remain regular, without missing strands or broken strands; and the shielded cable retains a specified length of shielding layer without damaging the shielding mesh and the inner insulation layer.

[0012] Preferably, the crimping process of the terminal crimping machine includes: installing the corresponding crimping mold, matching the mold according to the cable diameter and terminal specifications; adjusting the crimping pressure and stroke, and setting process parameters that match the terminal material and cable conductor cross-sectional area; after stripping the wire, aligning the cable and terminal, feeding the processed wire core into the terminal crimping cylinder and positioning it precisely; starting the crimping process, with the equipment completing the precision crimping of the terminal and cable according to preset parameters; performing a tensile test and visual inspection on the first piece to verify whether the crimping strength and forming state meet the process standards; batch crimping, starting continuous crimping operations after the first piece is qualified, maintaining constant parameters; classifying and sorting the crimped terminals, grouping them by specification and batch; performing tensile tests and cross-sectional analysis on batch products to check the crimping density and conducting a full visual inspection.

[0013] Preferably, the wiring fixing process of the wire harness mounting plate includes: placing the crimped terminal cables onto the tooling plate, and placing the crimped terminal cables sequentially at the marked cable paths, branch points, and fixing points according to the drawing requirements; sorting out the branch cables, straightening the routing posture and spacing of each branch cable; fixing and protecting accessories, installing and fixing protective accessories on the cables; overall shaping, adjusting the overall shape of the completed wire harness to maintain a neat wire harness outline and straight routing; visual inspection, checking the wiring path, fixing firmness, and protective integrity, and verifying the branch length and terminal position.

[0014] Preferably, the testing process of the wire harness testing bench includes: preset test parameters, setting voltage, resistance thresholds and test item parameters, including continuity resistance, short circuit, open circuit, misalignment, insulation resistance, withstand voltage and airtightness testing; starting automatic testing, using preset parameters to complete comprehensive testing of the wire harness's electrical performance and airtightness; generating test data reports, recording test results and storing data in real time to ensure data traceability; marking and isolating defective products, analyzing the causes of defects, reworking and retesting, and scrapping wire harnesses that fail twice; and visually inspecting qualified products to confirm that the wire harness is undamaged and undeformed.

[0015] Preferably, the cable cutting machine, terminal crimping machine and wire harness testing station all adopt first-piece inspection control. Batch operation is started after the first piece inspection is qualified, and the equipment parameters are readjusted if the first piece inspection fails.

[0016] Preferably, the cable cutting machine, cable marking machine, wire stripping machine, terminal crimping machine, and wire harness testing station are all equipped with scanning guns. The quality data of each single machine is scanned and bound and stored independently. The data acquisition interface is opened so that the MES server can collect the production data and quality data of each process, thereby realizing full-process data traceability and production control.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention adopts a standardized assembly line operation mode, replacing repetitive manual operations with automated equipment such as cable cutting machines, terminal crimping machines, and wire harness testing benches. It transforms non-standard processes that rely on worker skill into standardized operation processes with controllable parameters, reducing the reliance on human experience in the production process, effectively improving the overall assembly efficiency of wire harness assemblies, and ensuring the stability and controllability of the production process.

[0018] Standardized control of parameters for each process is implemented on the assembly line. For example, the wire stripping length error is controlled within ±0.2mm, and the terminal crimping parameters are precisely adjusted. Through equipment-based and standardized process control, individual errors caused by manual operation are avoided, ensuring that the key dimensions, crimping quality, and conductivity of each batch of wire harness assemblies remain highly consistent, thereby improving the overall stability and consistency of product quality.

[0019] Quality inspection points were set up along the entire assembly line. From cable cutting and terminal crimping to line-wide testing, each process was equipped with quality control links, realizing the detection method of first article inspection and full inspection within the process. Defective products can be identified and isolated in this process, preventing defective products from flowing into downstream processes and reducing subsequent rework costs.

[0020] By establishing communication connections between the MES server and the equipment in each process, production and quality data of each process are collected, stored, and linked in real time, realizing digital quality traceability throughout the entire process. When quality problems occur, they can be accurately located to specific processes, equipment, operators, and batches. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the assembly line equipment of the present invention.

[0022] Figure 2 This is a flowchart of the assembly line of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see Figure 1 This application provides a piston-type aircraft engine wiring harness assembly line. The core of the assembly line includes a cable cutting machine 2 for precise length cutting, a cable marking machine 3 for identifying cable parameter information, a wire stripping machine 4 for high-precision layer stripping, a terminal pressing machine 5 for precise pressing of cables and terminals, a wiring harness mounting plate 6 for standardized wiring harness design, a wiring harness testing bench 7 for comprehensive testing of wiring harness electrical performance and airtightness, and an MES server 8 for collecting, storing, and tracing production and quality data throughout the entire process. Simultaneously, after the cables complete raw material inspection, the wiring harness assembly line sequentially performs cutting, marking, stripping, terminal pressing, wiring fixation, and testing processes. The testing processes include overall line performance testing and visual re-inspection. After testing, the finished products are packaged and stored.

[0025] Example 1, please refer to Figure 2 To better understand the above technical solution, the following will provide a detailed explanation of the technical solution in conjunction with the accompanying drawings and specific implementation methods. The piston-type aircraft engine wiring harness assembly line adopts standardized assembly line operations. The process flow is as follows: raw material inspection, cable cutting, cable marking, wire stripping, terminal crimping, wiring fixing, overall line performance testing, visual inspection, and finished product packaging and warehousing. Quality inspection nodes are set up in each process to achieve isolation and control of non-conforming products. The specific operation of each process is as follows: S1. Raw Material Inspection: Each incoming material, such as aviation cables, terminals, connectors, and protective sleeves, is inspected. The material model, specifications, batch number, and factory certificate of conformity are verified. The cable insulation layer is checked for damage, aging, and cracking. The conductor is free from oxidation, broken strands, and loose wires. The plating of the terminals and connectors is intact and free from deformation and corrosion. After passing the inspection, the information is entered into the system ledger. Unqualified materials are directly isolated and returned and are prohibited from being put into production.

[0026] The engine wiring harness assembly is the neural network and blood vessel system of an aircraft piston engine, responsible for power supply, signal transmission, and safety control. It is a core component for the stable and safe operation of the engine, providing stable power to all electrical components such as the ignition system, sensors, actuators, solenoid valves, and instruments. It transmits real-time operating condition data such as speed, temperature, pressure, throttle position, knock, and cylinder temperature to the engine controller and instruments, and sends instructions from the ECU control box to the ignition coil, fuel injectors, starter motor, fuel pump, throttle actuator, etc., to realize ignition, fuel supply, speed regulation, and protection. The wiring harness assembly includes shielded wires, anti-interference design, high temperature and oil resistant insulation, and wear-resistant sheaths to ensure no interference or malfunction in strong electromagnetic environments.

[0027] The insulation layer of aviation cables requires meticulous appearance and performance verification. In addition to being free from damage, aging, and cracks, it must also ensure that the surface is smooth and flat, free from pinholes, indentations, bulges, peeling, delamination, discoloration, swelling, and oil contamination. The thickness must be uniform and without eccentricity. After bending, there should be no cracks or whitening. The insulation resistance and withstand voltage performance must meet the requirements for aviation-grade use to adapt to harsh working conditions such as high temperature, vibration, and oil immersion in the engine compartment.

[0028] Meanwhile, a special quality inspection is conducted on the cable conductors. In addition to ensuring the absence of oxidation, broken strands, and loose wires, it is also necessary to confirm that the multi-strand copper wires are tightly twisted and neatly arranged, without any skipped wires, missing strands, burrs, impurities, or loose misalignment. The cross-sectional dimensions, twisting pitch, and DC resistance must all meet the design standards to ensure stable conductivity and reliable current carrying capacity, and to eliminate risks such as poor contact, localized overheating, and open circuits. For the terminals and connectors, the plating and structural quality are carefully checked to ensure that the plating is uniform and dense, without peeling, rust, or discoloration, and that the body is free from deformation, cracks, burrs, and looseness. The terminals should be easy to insert and remove, and the contact should be reliable, meeting the high vibration and high reliability requirements of aerospace products.

[0029] S2. Cable Cutting: Adjust the length and speed parameters of the cable cutting machine, fix the cable on the machine and start automatic cutting. The length of the first piece is checked. After passing the test, the first piece is cut in batches. After cutting, the cables are sorted and labeled with specifications. During quality inspection, 10% of the cables in each batch are randomly selected for inspection. The length is measured and the cut quality is checked. The equipment is readjusted for the batches that do not pass the test.

[0030] Cable cutting requires controllable length precision, clean cuts, and no damage to the wire core and insulation layer. High efficiency and automation are crucial, with automatic wire feeding, stable quality, and good length consistency, reducing manual labor and rework. Automatic cutting employs automated feeding and fixed-length cutting, eliminating the need for manual intervention in wire feeding and cutting. This effectively avoids length deviations and uneven cuts caused by manual operation, ensuring a highly efficient and stable cutting process, suitable for the high-precision, high-volume cutting needs of aviation wire harnesses.

[0031] First piece length inspection is a key verification step before mass production. It comprehensively verifies the actual length, cut flatness, and core integrity of the first piece of cable, confirms that the wire cutting machine parameters are accurate and the cutting quality meets the standards, and prevents the generation of batch defective products from the source, thus building a solid first line of defense for quality.

[0032] Batch cutting starts after the first piece passes inspection. The equipment continuously and automatically completes cable feeding, fixed-length cutting, and unloading according to preset parameters. The cutting process parameters are constant and the actions are consistent, ensuring that the length of the cables in the whole batch is uniform and the cut quality is consistent, which greatly improves production efficiency and batch consistency. After cutting, the cables are sorted and labeled with specifications. They are stored in separate areas according to cable model, specifications, batch and other information, and clear labels are affixed at the same time to achieve material traceability and differentiation, avoid mixing and misuse of cables of different specifications, and ensure the accurate flow of subsequent processes.

[0033] Sampling 10% of each batch of cables is the core sampling inspection mechanism for quality control. This covers the entire batch of production samples and allows for the timely detection of potential quality fluctuations in mass production. It balances testing efficiency and quality coverage, meeting the high reliability quality control requirements of aviation products. The sampling inspection process focuses on measuring the actual length of the cables and verifying the deviation from the design standard to ensure that the length accuracy meets the requirements of aviation wire harness assembly. At the same time, the quality of the cut is carefully checked to confirm that the cut is flat, burr-free, flattened, and without damage to the wire core and insulation layer, ensuring that the quality of subsequent cable processing is not affected.

[0034] For non-conforming batches, the equipment should be readjusted. If the length or cut quality is found to be substandard during random inspection, production should be immediately suspended. The parameters such as the length, speed, and blade pressure of the wire cutting machine should be recalibrated and adjusted. After the adjustment is completed, the first piece verification should be carried out again. Mass production can only be resumed after the first piece is qualified to avoid the continuous production of non-conforming products.

[0035] S3. Cable Marking: According to the drawing requirements, print the cable number, wire number, specifications, polarity, batch number and other information on the surface of the cable. The markings must be clear, permanent and wear-resistant, and will not fade or fall off, so as to facilitate later maintenance and traceability.

[0036] Automatic marking requires aviation cables to retain permanent markings, and the marking spacing must be within the required range. Information such as cable number, wire number, specifications, polarity, and batch number are printed on the cable surface, giving each cable a unique identification code and key parameter label. The information content fully covers the key data required throughout the entire production, assembly, and maintenance cycle, ensuring that each cable segment can be accurately located, distinguished, and traced.

[0037] The markings must be clear, using high-resolution marking technology, with sharp, unblurred, ghosted, and unmissable character edges. Font size and spacing must be uniform and standardized, allowing for rapid identification under both natural and artificial light to prevent misassembly and misdiagnosis during maintenance due to blurry markings. The markings must be permanently wear-resistant, employing a specialized marking method adapted to aviation cable materials. The markings must adhere firmly to the cable surface, exhibiting excellent resistance to friction, bending, oil, and high / low temperatures. They must remain undamaged and clear even after long-term use in environments with engine compartment vibration, oil contamination, and fluctuating temperatures. The markings must be colorfast and resistant to peeling. The marking material must have good chemical compatibility with the cable insulation layer, eliminating the risk of corrosion and peeling. Even after bending, pulling, and wiping, the markings must remain intact and clear, without fading, peeling, or detachment due to time or environmental factors.

[0038] The identification system is compatible with post-maintenance and traceability. Complete identification information can be quickly matched with design drawings, production batches, assembly locations, and historical maintenance records. During the maintenance, repair, and troubleshooting of aero-engines, it can quickly locate target cables, trace the production process, and identify quality problems, significantly improving maintenance efficiency and operational reliability.

[0039] Permanent markings are required for aviation cables, which is a core requirement for the high reliability and long service life of aviation products. Unlike the temporary markings on ordinary industrial cables, aviation cable harness markings must have the same lifespan as the product, be traceable and identifiable throughout the entire process, and ensure the safe and reliable operation of the engine throughout its entire life cycle. The marking spacing of the cables must be within the required range, and the markings must be applied strictly according to the fixed spacing set in the process documents. The spacing must be uniform and the error controllable to ensure that the markings are neatly arranged and the spacing is consistent after the cable harness is bundled, which facilitates quick identification and verification and avoids identification difficulties caused by chaotic marking spacing.

[0040] S4. Wire Stripping Process: The stripping length is strictly controlled according to terminal specifications and design requirements, with an error within ±0.2mm. The insulation layer is completely stripped without residue, and the conductor copper wires are free of scratches, broken wires, and loose strands. Multi-strand cables have neat conductors without missing or broken strands. Multi-layer insulated cables and shielded cables use a layered stripping process, first stripping the outer sheath, then the inner insulation layer. Shielded cables retain a specified length of shielding layer without damaging the shielding mesh or the inner insulation layer.

[0041] The stripped insulation layer should be flush, without being flattened or damaged, and there should be no roughening. The stripping length error should be controlled within ±0.2mm, which falls within the scope of high-precision processing for aviation wire harnesses. This ensures precise matching of the crimping depth and contact area for terminals of different specifications, avoiding short circuit hazards caused by excessively long stripping and weak crimping or poor contact caused by excessively short stripping, thus guaranteeing the quality of terminal crimping and the reliability of electrical connections.

[0042] Multi-layer insulated and shielded cables employ a layered stripping process. A dedicated processing procedure is designed for the multi-layer protective structure of aviation cables, peeling off the outer sheath and inner insulation layer step by step to avoid damage to the inner insulation layer, deformation or breakage of the shielding mesh caused by one-time forceful stripping, thus meeting the precision processing requirements of complex cable structures.

[0043] The insulation layer is completely stripped without any residue, ensuring that the insulation layer in the stripped area is completely removed without any loose fragments or adhesive residue. This prevents residual insulation from mixing into the crimping area, causing poor crimping, increased contact resistance, or insulation hazards, and ensures that the terminals and conductors fit tightly and the electrical connection is stable. The conductor copper wires are free of scratches, broken wires, and loose strands. During the stripping process, the pressure and stroke of the cutting tool are precisely controlled to avoid scratching the copper wires due to excessive cutting or pulling that could cause broken or loose strands. This ensures the integrity of the conductor structure, no loss of conductive cross-section, and maintains excellent conductivity and mechanical strength. The multi-strand cable conductors are neat and without missing or broken strands. After stripping, the multi-strand copper wires are arranged tightly and neatly, without any missing, broken, or misaligned strands. This ensures that the overall conductive cross-section of the conductor meets the standards and the stranded structure is stable, preventing the risk of local current concentration, overheating, or open circuit.

[0044] The shielded cable retains a specified length of shielding layer, strictly adhering to design requirements to ensure reliable connection between the shielding layer and terminals or connectors, maintain the electromagnetic shielding performance of the harness, resist strong electromagnetic interference from the engine compartment, and guarantee stable signal transmission without crosstalk. The shielding mesh and inner insulation layer are not damaged; the cutting depth of the cutting tool is precisely controlled during the layered stripping process, stripping only the target insulation layer without touching the shielding mesh and inner insulation layer. This protects the integrity and continuity of the shielding mesh and the inner insulation layer, ensuring that the shielding effectiveness and insulation performance are not affected.

[0045] The stripped insulation layer should be flush, with a smooth and even cut surface and uniform edges, free from tilting, unevenness, or irregularities. This ensures uniform force and tight contact during terminal crimping, improving the appearance quality and structural stability of the crimp. The stripping tool should not flatten or damage the insulation layer of the unstripped portion. The opening and closing angle and pressure of the stripping tool should be precisely matched to the cable's outer diameter, acting only on the section to be stripped. Avoid squeezing or damaging the insulation layer in non-stripped areas to prevent deformation, cracking, or internal damage, ensuring the overall insulation protection capability of the cable. There should be no burr or roughening. The edges of the stripped cut should be smooth, clean, and free of burrs, streaks, or roughness. Avoid sharp burrs that could scratch operators, puncture subsequent protective sleeves, or affect terminal assembly, ensuring the safety and appearance quality of the wire harness processing.

[0046] S5. Terminal crimping: Install the corresponding crimping mold, adjust the crimping pressure and stroke, align the stripped cable with the terminal, start crimping, conduct a crimping tensile test and visual inspection on the first piece, and crimp in batches after passing the inspection. After crimping, the terminals are sorted and organized. During quality inspection, tensile test and cross-sectional analysis are performed on each batch to check the crimping tightness and visual inspection. Deformed, poorly crimped, or leaky crimped terminals are re-crimped or scrapped.

[0047] Terminal crimping requirements: Select terminals or connectors that are compatible with the cross-section of the wires and cables according to the drawings; strip the wires and cables before crimping them with terminals or connectors, and put the stripped wire cores into the crimping cylinder; after crimping, in addition to the pre-installed insulating sleeve on the crimping cylinder, heat shrink tubing should be used for insulation protection of terminals and connectors.

[0048] Match the specifications and models of the crimping molds and select appropriate mold cavities based on the cable diameter and terminal structure to ensure standard crimping profiles. This avoids crimping misalignment and abnormal forming from a hardware perspective, conforming to aviation wire harness crimping standards. Before crimping, accurately adjust the crimping pressure and stroke parameters, and set process values ​​based on the terminal material and cable conductor cross-sectional area. Proper parameter adjustment can effectively control the crimping compression, preventing conductor damage from excessive pressure and poor adhesion from insufficient pressure.

[0049] The first piece undergoes a crimping tensile test and visual inspection as a pre-production verification process. This simultaneously verifies the mechanical connection strength and appearance, determines the compatibility of process parameters, and prevents systematic crimping defects in the entire batch. Only after the first piece passes inspection can batch crimping operations commence. The equipment operates stably according to predetermined parameters, and the operation process is standardized to ensure that the crimping shape and bonding strength of terminals in the same batch remain highly consistent. After crimping, the terminals are classified and organized according to terminal model, cable specification, and production batch, ensuring orderly material arrangement, avoiding material mixing or mismatch, and facilitating subsequent wiring processes.

[0050] Tensile testing and cross-sectional analysis are conducted on each batch to test the crimping quality from both mechanical properties and internal structure perspectives. This accurately determines the firmness of the connection between the conductor and the terminal, and thoroughly investigates internal crimping hazards that cannot be detected by the naked eye. In addition, the crimping tightness is strictly checked, and the compression and bonding state of the conductor bundle is observed to ensure that there are no gaps or looseness between the wire core and the inner wall of the terminal. This ensures smooth electrical conduction, reduces contact resistance, and improves the long-term operational stability of the wire harness.

[0051] A full inspection of the terminal appearance is conducted, checking the shape and appearance of each crimped part, comprehensively screening for various molding defects, and controlling the product appearance quality standards. Terminals with deformation, incomplete crimping, or missing crimping issues are reworked or scrapped according to quality handling specifications to prevent unqualified parts from entering the next process and ensure the overall assembly quality of the finished wire harness. Connecting terminals and mating joints that match the cable cross-section are selected according to the drawings to ensure that the structural dimensions are compatible and lay the foundation for reliable crimping assembly. The processed wire core is carefully fed into the crimping cylinder to ensure that the wire core is placed in place without deviation or exposure, and to ensure that the crimping action area completely covers the effective contact area.

[0052] After crimping, heat shrink tubing is added as needed to implement insulation protection, fill the protective gaps of exposed conductive parts, enhance the insulation protection capability of the wire harness, and avoid the safety risks of short circuit leakage.

[0053] S6. Wiring Fixing: Use a dedicated wiring fixture plate, marked with cable paths, branch points, and fixing point locations. Arrange the cables with crimped terminals onto the fixture plate according to the drawings, organize the branch cables, fix the accessories and provide protection, and perform an overall appearance inspection after shaping. During quality inspection, check the wiring path, fixing firmness, and protection integrity, and verify the branch length and terminal position. If it does not meet the requirements, reorganize the wiring.

[0054] Wiring must follow the wiring harness routing specified on the wire and cable labels and diagrams. Wires and cables should be placed straight between the pins on both sides of the wiring harness shown in the diagram. Wiring should be completed one harness at a time. The beginnings should be flush, the wires straight, and crossings should be avoided. If the diagram specifies that the wiring harness has various protective sleeves, the sleeves should be installed first, and then the wiring should be done. To ensure smooth installation into the sleeves, the wiring can be secured with binding ropes first.

[0055] The dedicated wiring fixture board is a standardized tooling for piston-type aircraft engine wiring harness assemblies. It serves as the core tooling carrier for achieving standardized and consistent wiring, completely replacing the traditional manual wiring method based on experience. The fixture board's structural dimensions are fully aligned with the overall aircraft assembly drawings, strictly constraining the overall shape, branch angles, and arrangement of the wiring harness. This ensures that the wiring shape, bending curvature, and branch position height of each wiring harness are uniform, eliminating differences from manual assembly at the tooling level and significantly improving the consistency of finished wiring harnesses and the accuracy of overall aircraft compatibility.

[0056] The fixture plate marks the cable path, branch points, and fixing points. All marked points are precisely calibrated and correspond one-to-one with aerospace design drawings, ensuring clear, high-precision, and error-free positioning. Operators can directly complete cable routing, branch separation, and fixing based on the marked points on the fixture, eliminating the need for repeated subjective judgment by referring to drawings. This effectively reduces problems such as incorrect wiring, omissions, and cable misalignment, achieving standardization, visualization, and normalization of wiring operations.

[0057] During the process of sorting out branch cables, all main and branch cables must be straightened one by one, and the bending angle, slack, and spacing of the cables must be precisely adjusted to prevent undesirable conditions such as cable twisting, tangling, hard bending, and compression. Considering the characteristics of the confined space and frequent vibration of the aircraft engine nacelle, reasonable allowances should be reserved for cable expansion to ensure that the cable harness is evenly stressed and the wiring is neatly arranged after assembly, avoiding potential problems such as cable damage and insulation wear caused by stress concentration, compression, and friction after installation.

[0058] When inspecting the wiring path, it is necessary to align the entire process with the design drawings and tooling references, and comprehensively verify the direction, layout, and detour of each cable to prevent wiring deviations, bypasses, reverse wiring, and other violations. Ensure that the overall wiring harness route perfectly conforms to the reserved wiring space in the engine compartment to avoid the risks of interference, compression, and scratches during later installation, and to meet the compact and standardized assembly requirements of aviation equipment.

[0059] When checking the secure fastening, focus on verifying the installation status of all cable clips, cable ties, fixing buckles, and limit accessories to ensure that all fixing accessories are locked in place, without looseness, misalignment, or displacement. For operating environments with high-frequency engine vibration and alternating operating conditions, ensure the wiring harness as a whole remains stable without shifting, shaking, or displacement. This prevents long-term vibration from causing cable wear, loose terminals, poor contact, and other quality issues, thus improving the long-term reliability of the wiring harness.

[0060] When inspecting the integrity of the protection, check the wrapping condition of protective accessories such as corrugated pipes, wear-resistant sleeves, insulating sheaths, and protective tape item by item, paying special attention to covering key vulnerable areas such as cable bends, branch points, exposed and easily worn locations, and connector roots. Ensure that the protection is fully covered, without omissions or gaps, and that the protective sleeves are properly fitted and tightly wrapped to effectively resist damage to the cables caused by harsh working conditions such as high temperatures, oil contamination, friction, and impacts in the engine compartment.

[0061] When verifying the branch length and terminal position, strictly check the effective length, extension allowance and terminal installation position of each branch cable against the standard dimensions in the drawings. Accurately control the branch size tolerance and terminal alignment accuracy to ensure that the length of each branch cable is suitable for the overall assembly spacing, the terminals are neatly arranged and aligned to standard, and there are no length deviations or position offsets. This ensures that the subsequent assembly of the whole machine is accurate and smooth, avoiding assembly difficulties and terminal tension problems caused by size deviations.

[0062] S7. Overall Line Performance Test: Connect the wire harness to the tester interface, preset the voltage, resistance threshold, and test parameters, start the automatic test, generate a test data report, mark and isolate unqualified products, and re-inspect qualified products visually; the wire harness test bench can perform wire harness continuity resistance, short circuit, open circuit, misalignment, insulation resistance, and withstand voltage tests, and can be used with an airtightness tester to complete the airtightness test of connectors and accurately measure leakage values.

[0063] The engine wiring harness assembly test bench fully meets the continuity testing requirements of cables and components, enabling the measurement of continuity resistance between any channels. It integrates a PC, supports barcode printers, barcode scanners, and MES system integration, and can meet testing requirements for wiring harness continuity resistance, short circuits, open circuits, misalignment detection, insulation resistance, and withstand voltage. When paired with an airtightness tester, it can perform connector airtightness testing and accurately measure leakage values.

[0064] Before testing, voltage and resistance thresholds and test parameters are preset. The parameters are set strictly according to the design conditions, electrical standards and aviation inspection specifications of piston aircraft engine wiring harnesses. Different models and functional branches of wiring harnesses are matched with exclusive test thresholds, covering all operating condition parameters such as low-voltage power supply, signal transmission and control circuits. Unified and standardized parameter thresholds can eliminate the bias of human subjective judgment, so that the test standards of each wiring harness are completely consistent, ensuring that the test results are accurate, authoritative and comparable to industry aviation quality standards.

[0065] After starting the automatic test, the test bench automatically executes multi-dimensional test items in sequence according to the built-in standardized test process, without the need for manual point-by-point verification and level adjustment; the equipment test sequence is stable, the output voltage and excitation signal are precise and controllable, and the entire process is automated closed-loop test, which effectively avoids test errors caused by manual omissions, mistests and non-standard operations, greatly improves test efficiency and test coverage, and achieves 100% full-item performance testing.

[0066] The system generates test data reports. It can automatically collect, statistically analyze, and summarize the measured data, standard thresholds, deviation values, test times, equipment numbers, and batch information for all test channels, and automatically generate standardized electronic test reports. The report data is authentic, complete, and tamper-proof, and can be synchronously stored in the MES system, realizing one file per wire harness and one ledger per batch, providing complete data support for product quality traceability, factory acceptance, and subsequent quality review.

[0067] The visual re-inspection of qualified products is the final manual verification process after electrical performance testing. A comprehensive visual re-inspection is carried out on wire harnesses that have passed the electrical test, focusing on checking for problems that may have occurred during the testing process, such as cable pulling, loose terminals, sheath displacement, and connector damage. This achieves dual quality control of electrical performance and visual compliance, preventing products with hidden defects from entering the finished product stage.

[0068] The wiring harness continuity resistance test can collect high-precision resistance values ​​for each line channel, accurately identify hidden quality problems such as conductor core damage, improper terminal crimping, poor line contact, and loose joints; by comparing the measured resistance value with the standard resistance value, it can effectively determine whether the wiring harness conductivity is stable, avoid faults such as signal attenuation, unstable power supply, and localized overheating after installation, and ensure the stable operation of the engine electrical system.

[0069] Short circuit, open circuit, and misalignment detection can comprehensively investigate wiring harness continuity faults, accurately locate wiring break points, abnormal short circuits between wires, incorrect pin connections, and misaligned circuits, among other assembly defects. This detection item can avoid assembly errors left over from manual wiring, prevent serious faults such as circuit disorder, signal disorder, malfunction of electrical components, and failure to work after wiring harness assembly, and ensure the accuracy of the overall electrical system logic.

[0070] Insulation resistance testing is used to inspect the overall protective performance of the cable insulation layer. By applying a standard test voltage, the overall insulation resistance of the wire harness is measured to identify potential problems such as insulation layer damage, aging, pinholes, scratches, moisture leakage, etc. This ensures reliable insulation isolation between the wire harness lines and between the lines and the housing, and avoids safety risks such as leakage, cross-current, and short circuit to ground.

[0071] The withstand voltage test simulates the extreme operating conditions of an aircraft engine, such as high altitude, high temperature, and high load, by applying the rated withstand voltage test voltage. It examines the breakdown resistance and electrical safety margin of the wiring harness insulation layer, screens out defective products with weak insulation and insufficient withstand voltage, effectively avoids major safety hazards such as insulation breakdown, arcing, and short circuits during the operation of the whole machine, and meets the high safety redundancy requirements of aviation products.

[0072] The airtightness test of the connector is specifically designed for the performance of aviation-grade sealed connectors. It is adapted to the complex operating conditions of high humidity, oil and gas adhesion, and air pressure changes in the engine compartment. The test focuses on verifying the sealing performance of the internal sealing ring and sealing structure of the connector to prevent moisture, oil, and dust from entering the connector and causing faults such as pin oxidation, corrosion, poor contact, and signal interruption.

[0073] Precise measurement of leakage values ​​enables quantitative detection of airtightness data, eliminating reliance on manual qualitative judgment. Real-time leakage data is collected by precision instruments and accurately compared with standard leakage thresholds to objectively determine the sealing performance. It can accurately identify subtle leaks, poor hidden sealing, and other hard-to-detect defects, ensuring long-term stable sealing performance of connectors and significantly improving the service life and environmental adaptability of the entire wiring harness.

[0074] S8. Visual Re-inspection: Conduct a full inspection of the qualified wire harnesses, check that the cable markings are clear and complete, there is no deformation or cracking at the terminal crimping, the sheath and binding are firm and reliable, the cable outer sheath is free of scratches and damage, and the connectors are intact and undamaged. Confirm that the overall appearance and dimensions of the wire harness meet the requirements of the drawings. Minor defects are reworked, and serious defects are scrapped.

[0075] Check that the terminal crimping area is free from deformation and cracking. Focus on observing the forming condition of all terminal crimping areas, and check for various defects such as terminal body deformation, cracking of crimping area, edge warping, exposed copper wire, and crimping misalignment. The terminal crimping area is the core point of electrical connection of the wiring harness. The absence of deformation and cracking can ensure that the terminal structural strength meets the standard and avoid safety hazards such as terminal breakage, contact failure, and circuit breakage under long-term engine vibration conditions.

[0076] Inspect the cable sheath for scratches and damage, and examine the overall condition of the cable insulation sheath section by section. Check for minor scratches, bumps, dents, tears, aging and whitening, oil stains and corrosion, etc. Aviation wiring harnesses are exposed to the harsh environment of engine compartment with high temperature, oil, vibration and friction for a long time. The intact and undamaged sheath is the basis for ensuring the insulation and protection performance of the cable, and can effectively avoid the risk of failure such as leakage, short circuit and core damage.

[0077] Inspect the connectors to ensure they are intact and undamaged. Carefully check the structure of the housing, latches, pins, and sealing rings of all types of aviation connectors. Confirm that the housing is free from cracks, deformation, and dents; that the latches open and close smoothly and lock reliably; that the pins are free from bending, oxidation, rust, and deformation; and that the sealing rings are free from detachment, damage, and aging. Ensure that the connectors are precisely aligned, have stable contact, and provide a good seal, meeting the high reliability requirements of aviation equipment.

[0078] S9. Finished Product Packaging and Warehousing: Wire harnesses that pass the re-inspection are individually packaged with anti-static materials, affixed with traceability labels containing model, batch, production date, and inspection number, and scanned to bind quality data in the MES system. They are then categorized, boxed, and clearly labeled. After verification, they are processed for warehousing and included in the enterprise resource planning system for unified management.

[0079] Individually packaged with anti-static materials, the aero-engine wiring harness contains precision electrical connection structures and shielding components, making it highly sensitive to electrostatic environments. Specialized anti-static packaging materials effectively isolate the harness from external static electricity, dust, moisture, and air oxidation, preventing issues such as static electricity attracting dust, pin oxidation, and insulation moisture absorption during storage, transportation, and delivery. This provides comprehensive protection for the finished wiring harness's electrical performance and appearance integrity, meeting the packaging protection standards for precision aerospace components.

[0080] By attaching traceability labels containing model number, batch number, production date, and inspection number to the products, a unique identity is established for each finished wire harness. The label information comprehensively covers key information throughout the entire product production cycle. The labels are clear, firmly attached, wear-resistant, and not easy to fall off, enabling rapid identification of product models, accurate differentiation of production batches, traceability of production time, and location of inspection responsibility, thus building a complete product quality traceability system.

[0081] By scanning barcodes to bind quality data to the MES system, all production process data, testing data, quality inspection results, equipment parameters, and operator information of the finished wire harness are bound and archived with the product entity through barcode identification of label information. This enables interconnection and interoperability of production, testing, and quality data, completely changing the drawbacks of traditional paper records that make traceability difficult. The entire production file of a single wire harness can be retrieved at any time, providing accurate data support for quality traceability, problem review, and quality improvement.

[0082] After verification, the goods are put into storage. Before storage, a dedicated person will conduct a second verification of the packaging integrity, label information accuracy, packing quantity, and product model. Only after confirming that all information is correct, packaging protection is intact, and product condition is qualified can the storage operation be carried out. This will prevent management problems such as incorrect storage, omissions, and mixed batch storage, and ensure that the data of stored materials is completely consistent with the actual goods.

[0083] Example 2: This application provides a piston-type aircraft engine wiring harness assembly line. The assembly line includes a cable cutting machine 2 for precise cutting of cables to a fixed length, a cable marking machine 3 for identifying cable parameter information, a wire stripping machine 4 for high-precision layer stripping, a terminal pressing machine 5 for precision pressing of cables and terminals, a wiring harness mounting plate 6 for standardized wiring harness shaping, a wiring harness testing bench 7 for comprehensive testing of wiring harness electrical performance and airtightness, and an MES server 8 for the collection, storage, and traceability control of production and quality data throughout the entire process. Meanwhile, on the wire harness assembly line, after the raw materials of the cables have been inspected, the following processes are carried out in sequence: S1 cutting, S2 marking, S3 wire stripping, S4 terminal crimping, S5 wiring fixing and S6 testing. The testing process includes overall line performance testing and appearance re-inspection. After testing, the finished products are packaged and put into storage.

[0084] The wire harness assembly line is also equipped with an enterprise resource planning system server 1. The enterprise resource planning system server 1 is connected to the cable cutting machine 2, the cable marking machine 3, the wire stripping machine 4, the terminal crimping machine 5, the wire harness testing station 7, and the MES server 8. It is used to coordinate and manage production plans, order allocation and raw material information, and to issue process parameters, cable specifications and batch operation instructions that match the wire harness production to each process equipment.

[0085] The cutting process of cable cutting machine 2 includes: S11. Adjust the parameters of the wire cutting machine, including cutting length and cutting speed.

[0086] S12. The cable is fixed on the machine. The aviation cable is placed stably on the wire feeding frame and fed into the feed end of the equipment.

[0087] S13. Automatic cutting: The equipment completes fixed-length feeding, precise cutting and automatic material discharge according to preset parameters.

[0088] S14. First piece length inspection: Verify the length accuracy and cut quality of the first piece of cut cable.

[0089] S15. Batch cutting: After the first piece passes inspection, continuous automatic cutting is started, keeping the parameters constant.

[0090] S16. After cutting, the cables are sorted and placed in separate areas according to specifications and batches, and labeled accordingly.

[0091] The cable marking machine 3 is used to print cable identification and process parameter information on the surface of the cable. The spacing of the markings on the cable is controlled within the process requirements to ensure that the markings are neatly arranged and uniformly spaced.

[0092] Wire stripper 4 employs a layered wire stripping process, and the stripping requirements include: S31, the stripping length error is controlled within ±0.2mm.

[0093] S32. The insulation layer is completely peeled off, with no residual insulation.

[0094] S33. The conductor copper wire is free from scratches, broken wires, and loose wires.

[0095] S34. The conductors of multi-strand cables remain regular, with no missing strands or broken strands.

[0096] S35. Shielded cables retain a specified length of shielding layer without damaging the shielding mesh and the inner insulation layer.

[0097] The pressing process of terminal pressing machine 5 includes: S41. Install the corresponding crimping mold and match the mold according to the cable diameter and terminal specifications.

[0098] S42. Adjust the crimping pressure and stroke, and set process parameters that match the terminal material and cable conductor cross-sectional area.

[0099] S43. After stripping the wires, align the cable with the terminals, and send the processed wire cores into the terminal crimping cylinder for precise positioning.

[0100] S44. Start crimping. The equipment completes the precision crimping of the terminal and the cable according to the preset parameters.

[0101] S45. First piece pressing tensile test and appearance inspection to verify whether the pressing strength and forming state meet the process standards.

[0102] S46. Batch pressing: After the first piece passes inspection, start continuous pressing operation and keep parameters constant.

[0103] S47. After pressing, the terminals are sorted and organized, and grouped by specification and batch.

[0104] S48. For each batch of products, tensile tests and cross-sectional slice analysis are performed to check the tightness of the compression and a full visual inspection is conducted.

[0105] The wiring fixing process of the wire harness mounting plate 6 includes: S51. Place the crimped terminal cables onto the tooling plate, and place the crimped terminal cables in sequence at the marked cable paths, branch points and fixing points according to the drawing requirements.

[0106] S52. Branch cable management: straighten out the routing and spacing of each branch cable.

[0107] S53. Accessory Fixing and Protection: Install and secure protective accessories on the cable.

[0108] S54. Overall shaping: Adjust the overall shape of the completed wiring harness to maintain a neat outline and straight routing.

[0109] S55. Visual inspection: Check the wiring path, fixing firmness, and protection integrity; verify branch length and terminal position.

[0110] The testing process of wire harness test bench 7 includes: S61. Preset test parameters, set voltage and resistance thresholds and test item parameters. Test items include continuity resistance, short circuit, open circuit, misalignment, insulation resistance, withstand voltage and airtightness test.

[0111] S62. Start automatic testing and complete the comprehensive testing of the electrical performance and airtightness of the wire harness using preset parameters.

[0112] S63. Generate test data reports, record test results and store data in real time to ensure data traceability.

[0113] S64. Non-conforming products are marked and isolated, the cause of the defect is analyzed, and the product is reworked and retested. Wire harnesses that fail twice are scrapped.

[0114] S65. Visual inspection: Conduct a visual inspection on the qualified products to confirm that the wire harness is undamaged and undeformed.

[0115] The cable cutting machine 2, terminal crimping machine 5, and wire harness testing station 7 all adopt first-piece inspection control. Batch operation is started after the first piece inspection is qualified, and the equipment parameters are readjusted if the first piece inspection is unqualified.

[0116] The cable cutting machine 2, cable marking machine 3, wire stripping machine 4, terminal crimping machine 5, and wire harness testing station 7 are all equipped with scanning guns. The quality data of each single machine is scanned and bound and stored independently. The data acquisition interface is opened for the MES server 8 to collect production data and quality data of each process, so as to realize full-process data traceability and production control.

[0117] This embodiment, through the collaborative deployment of multiple devices and the linkage control of dual systems, fully realizes the automated and standardized production operation of the piston aero-engine wiring harness assembly, from raw material verification, precision cable processing, standardized assembly to fully automated performance testing and digital warehousing. The entire assembly line connects the processing and testing stations in an orderly manner according to the established process flow. The parameters of each special equipment are unified and the process is closely connected, so that every process of wiring harness processing has standards to follow, parameters to control, and records to check, realizing the standardized, orderly, and closed-loop control of the production process.

[0118] The Enterprise Resource Planning (ERP) system server uniformly distributes production process parameters and operation instructions, enabling coordinated scheduling of production planning, material management, and process standards. It unifies the processing standards of each batch of products from the source of production, avoiding parameter deviations and non-standard operation problems caused by differences in human experience. At the same time, it works with the MES server to complete the collection, storage, and binding of data for the entire process. Each individual device independently completes data binding and storage and opens the collection interface, realizing the comprehensive retention of production data, quality inspection data, and equipment operation data. This provides accurate, comprehensive, and practical data support for product quality iteration and optimization, production process improvement, and batch quality traceability.

[0119] Meanwhile, this embodiment sets up dedicated quality inspection nodes in each process step of the entire process, forming a multi-level quality control system of first article verification, batch sampling inspection, full inspection and re-inspection, and full performance testing. It can identify, isolate and handle non-conforming products in advance, effectively prevent defective products from flowing into downstream processes, significantly reduce rework frequency and scrap costs, and improve the finished product qualification rate and production economy of wire harness assemblies. By replacing manual subjective operation with precision equipment, the accuracy of wire cutting, wire stripping tolerance, crimping quality, wiring form, electrical performance and sealing performance are strictly controlled, so that the dimensional accuracy, assembly form, electrical performance and appearance quality of wire harness products in the same batch are highly consistent.

[0120] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An aircraft engine harness assembly line, comprising: include: (2) Cable cutting machine for precise cutting of fixed length of cable, (3) Cable marking machine for marking cable parameter information, (4) Wire stripping machine for high-precision layer stripping, (5) Terminal pressing machine for precision pressing of cable and terminal, (6) Wire harness mounting plate for standardized wiring of wire harness, (7) Wire harness test bench for comprehensive testing of electrical performance and air tightness of wire harness, and (8) MES server for full-process production and quality data collection, storage and traceability control. Meanwhile, the wire harness assembly line performs cutting, marking, stripping, terminal crimping, wiring fixation and testing processes in sequence after the raw materials of the cables are inspected. The testing process includes overall line performance testing and appearance re-inspection. After testing, the finished products are packaged and put into storage.

2. A piston aeroengine wiring harness assembly line according to claim 1, characterized in that: The wire harness assembly line is also equipped with an enterprise resource planning system server (1). The enterprise resource planning system server (1) is connected to the cable cutting machine (2), cable marking machine (3), wire stripping machine (4), terminal crimping machine (5), wire harness testing station (7) and MES server (8) respectively. It is used to coordinate and manage production plans, order allocation and raw material information, and issue process parameters, cable specifications and batch operation instructions that match the wire harness production to each process equipment.

3. A piston aeroengine wiring harness assembly line according to claim 1, characterized in that: The cutting process of the cable cutting machine (2) includes: Adjust the parameters of the thread cutting machine, including cutting length and cutting speed; The cable is fixed on the machine, and the aviation cable is placed stably on the wire feeding frame and fed into the feed end of the equipment. Automatic cutting: The equipment completes fixed-length feeding, precise cutting and automatic unloading according to preset parameters; First piece length inspection: Verify the length accuracy and cut quality of the first piece of cut cable. Batch cutting: After the first piece passes inspection, continuous automatic cutting is started while keeping parameters constant. After cutting, the cables are sorted and arranged, stored in separate areas according to specifications and batches, and labeled.

4. A piston aeroengine wiring harness assembly line according to claim 1, characterized in that: The cable marking machine (3) is used to print cable identity and process parameter information on the surface of the cable. The spacing of the cable markings is controlled within the process requirements to keep the markings neat and the spacing uniform.

5. The piston-type aircraft engine wiring harness assembly line according to claim 1, characterized in that: The wire stripping machine (4) adopts a layered wire stripping process, and the wire stripping requirements include: The stripping length error is controlled within ±0.2mm; The insulation layer was completely peeled off, with no residual insulation. The conductor copper wire is free of scratches, broken wires, and loose wires; The conductors of multi-strand cables remain neat and orderly, with no missing or broken strands. The shielded cable retains a specified length of shielding layer without damaging the shielding mesh and the inner insulation layer.

6. The piston-type aircraft engine wiring harness assembly line according to claim 1, characterized in that: The pressing process of the terminal pressing machine (5) includes: Install the corresponding crimping mold and match the mold according to the cable diameter and terminal specifications; Adjust the crimping pressure and stroke, and set process parameters that match the terminal material and cable conductor cross-sectional area; After stripping the wires, align the cable with the terminals, and then feed the processed wire cores into the terminal crimping cylinder for precise positioning. Once the crimping process is initiated, the equipment will precisely crimp the terminals and cables according to preset parameters. The first piece undergoes a tensile test and visual inspection to verify whether the pressing strength and forming condition meet the process standards. Batch pressing: After the first piece passes the test, continuous pressing operation is started while keeping the parameters constant. After pressing, the terminals are sorted and organized, and grouped by specification and batch. The batch of products undergoes tensile testing and cross-sectional analysis to check the tightness of the compression and performs a full visual inspection.

7. The piston-type aircraft engine wiring harness assembly line according to claim 1, characterized in that: The wiring fixing process of the wire harness mounting plate (6) includes: Place the crimped terminal cables onto the tooling plate, and arrange the crimped terminal cables in sequence at the marked cable paths, branch points, and fixing points according to the drawing requirements; Organize and straighten the routing and spacing of each branch cable; Accessory fixing and protection: Install and fix protective accessories on the cable; Overall shaping involves adjusting the overall shape of the completed wiring harness to maintain a neat outline and straight routing. Visual inspection: check the wiring path, fixing firmness, and protection integrity; verify branch length and terminal position.

8. The piston-type aircraft engine wiring harness assembly line according to claim 1, characterized in that: The testing process of the wire harness testing station (7) includes: Preset test parameters, set voltage and resistance thresholds and test item parameters. Test items include continuity resistance, short circuit, open circuit, misalignment, insulation resistance, withstand voltage and airtightness test. Initiate automatic testing and complete comprehensive testing of the electrical performance and airtightness of the wire harness using preset parameters; Generate test data reports, record test results, and store data in real time to ensure data traceability; Non-conforming products are marked and isolated, the cause of the defect is analyzed, and they are reworked and retested. Harnesses that fail twice are scrapped. Visual inspection: Conduct a visual inspection on the qualified products to confirm that the wire harness is undamaged and undeformed.

9. A piston-type aircraft engine wiring harness assembly line according to claim 1, characterized in that: The cable cutting machine (2), terminal pressing machine (5) and wire harness testing station (7) all adopt first-piece inspection control. After the first piece inspection is qualified, batch operation is started. If the first piece inspection is unqualified, the equipment parameters are readjusted.

10. A piston-type aircraft engine wiring harness assembly line according to claim 1, characterized in that: The cable cutting machine (2), cable marking machine (3), wire stripping machine (4), terminal crimping machine (5) and wire harness testing station (7) are all equipped with scanning guns. The quality data of each single machine is scanned and bound and stored independently. The data acquisition interface is opened so that the MES server (8) can collect the production data and quality data of each process, so as to realize full-process data traceability and production control.

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