| What are the maintenance components of the cold extrusion three-way machine? A comprehensive analysis of the core guarantees for the efficient operation of the equipment. In the industrial pipeline processing fields such as petroleum, chemical engineering, power, and shipbuilding, the cold extrusion three-way machine plays an indispensable key role. As a specialized hydraulic forming equipment that precisely processes straight pipe blanks into various three-way pipe fittings through the principle of metal plastic deformation, the cold extrusion three-way machine, with its efficient and high-quality material forming capabilities, has become the main production force in modern manufacturing. However, the high-intensity continuous operation of the equipment also exposes it to risks such as hydraulic component wear, sealing component aging, electrical component fatigue, and mold wear. Only through systematic and scientific maintenance and repair can the equipment be kept in a stable operating state for a long time. So, what are the specific contents of the maintenance of the cold extrusion three-way machine? This article will focus on the five core sections of mechanical structure, hydraulic system, electrical control, mold tooling, and lubrication system, combined with safety maintenance and operation norms, to provide a comprehensive analysis of the maintenance key points of the cold extrusion three-way machine. 1. Overview of the basic structure and maintenance system of the cold extrusion three-way machine To fully grasp the maintenance work of the cold extrusion three-way machine, one must first have a clear understanding of its core structure. The cold extrusion three-way machine usually includes the hydraulic power system, worktable and guiding device, electrical control system, and mold tooling as the four core parts. The hydraulic power system is the "heart" of the entire equipment, providing a high-pressure power source for the three-way forming; the electrical control system, with the PLC controller playing the role of the "brain", is responsible for the entire automated operation, ensuring the accuracy and stability of the forming process. A scientific and efficient maintenance system is to ensure that the equipment's heart beats strongly, the brain issues accurate instructions, and all mechanical transmission components are smooth, lubricated, and have good sealing conditions. According to the equipment's usage intensity, the maintenance of the cold extrusion three-way machine is usually divided into three levels: daily inspection, regular (weekly/monthly/quarterly/yearly) maintenance, and medium-term major repair. Daily inspection mainly focuses on the status confirmation before starting the machine and the cleaning and maintenance after stopping; regular maintenance deepens according to the equipment's operating time, involving the replacement of sealing components, filter cleaning, hydraulic oil replacement, and electrical system dust removal, etc.; major repair is carried out for key components such as sliders and main cylinder copper sleeves that have reached a certain degree of wear. Each level of maintenance has its own emphasis content. The following will break down each section item by item. 2. Mechanical structure maintenance: Maintenance of the "skeleton" of the cold extrusion three-way machine The mechanical structure of the cold extrusion three-way machine is the basic framework, including the main body of the machine, guiding rails, sliders and columns, fasteners and transmission components, etc. Under the long-term bearing of high pressure and alternating stress, if the mechanical maintenance is ignored, the equipment may suffer from reduced precision, or even structural failure, resulting in safety hazards. 1. Inspection and maintenance of the main body and base frame. The main body serves as the main load-bearing structure of the machine. During maintenance, it is necessary to carefully check for cracks, weld seam cracking or obvious deformation, especially the key stressed areas that are subject to impact. At the same time, check whether the connecting bolts are tightened and whether there are any signs of loosening. According to the operation norms, before starting the machine, a visual inspection around the main body should be conducted to confirm that all fasteners are normal before starting the equipment. 2. Inspection and maintenance of the guiding device and moving parts. The guiding device (including columns, rails and sliders) is related to the concentricity and stability of the pressing process. During maintenance, it is necessary to focus on checking for scratches, dents on the columns and rails, and wear marks on the slider surface. Long-term operation will make the columns rough and accumulate metal debris and oil stains, accelerating wear. Maintenance methods include using a dial indicator or special tools to detect the straightness and flatness of the guide rail surface. If the wear is severe, it needs to be repaired by scraping or grinding. At the same time, check the flexibility of the slider adjustment thread and add lubricating grease or oil as per regulations to reduce friction and maintain motion accuracy. 3. Regular pre-tightening and inspection of important fasteners. During the long-term operation of the equipment, high-strength fasteners at various parts may become loose due to vibration and impact, especially the main cylinder fixing bolts, mold fastening bolts, hydraulic pipeline support bolts, and other key parts. During maintenance, use a torque wrench to check and tighten each bolt to the specified torque value. This work is recommended to be carried out once a month or every quarter. Poor tightening can not only increase the risk of hydraulic oil leakage but may even lead to major safety accidents. Do not take it lightly. III. Maintenance of the hydraulic system: "Blood" health management of the cold extrusion three-way machine The hydraulic system is the power source of the cold extrusion three-way machine, consisting of oil pumps, motors, cartridge valves, oil tanks, oil pump valve groups, and various devices for oil filtration, cooling, oil temperature and level display. At the same time, the hydraulic system is also a key area prone to faults, and the adequacy of its maintenance directly determines whether the equipment can operate normally. Based on experience, the common faults of the hydraulic system mainly include hydraulic oil contamination, unstable system pressure, excessive noise, and oil leakage. 1. Control of hydraulic oil contamination and replacement. After using the hydraulic oil for a period of time, impurities, moisture, or oxidation and blackening are inevitable. Impurities mainly enter the system through wear debris of the oil pump, aging seals, or external dust, causing valves, pumps, and cylinder bodies to jam, resulting in abnormal pressure and increased wear. During maintenance, it is necessary to strictly follow the following measures: use anti-wear hydraulic oil that meets requirements, maintain the oil temperature between 15 and 60 degrees Celsius, replace the oil annually, and when replacing the hydraulic oil, thoroughly clean the oil tank and drain the old oil to prevent residual impurities from contaminating the new oil. 2. Maintenance of oil pumps and oil circuit seals. Gears, pistons, and blades inside the oil pump will naturally wear out after long-term operation, causing a decrease in output pressure, fluctuation in flow, and even output instability. During maintenance, check whether the working current and output pressure of the oil pump are stable, and listen for any abnormal noises. If it is confirmed that the oil pump is damaged internally, it should be replaced immediately. At the same time, the seals of the entire hydraulic system (such as O-rings, piston sealing rings, and cylinder dust-proof seals) are all wear-prone parts. Their aging or wear will cause internal leakage or external leakage, resulting in pressure loss. During maintenance, carefully check whether there is external leakage at the piston rod of the hydraulic cylinder and whether there is leakage at the sealing area of the oil cylinder end cover. 3. Maintenance of hydraulic pipelines, valves, and cooling systems. High-pressure oil pipes have the risk of aging and cracking, and pipe joints are high-risk areas for oil leakage. During maintenance, visually and by hand confirm whether all pipeline connections are firm. Loose connections need to be tightened, and damaged oil pipes need to be replaced. Valves such as electromagnetic directional valves and overflow valves also need to be inspected regularly for any impurities blocking the valve core, the sensitivity of the valve core action, and the failure of the spring. For the radiator or air-cooling device of the hydraulic system, during maintenance, clean the surface attached dust to ensure the smoothness of the heat dissipation channel and prevent the oil temperature from being too high, which can lead to a decrease in viscosity and accelerated aging of the seals. 4. Maintenance of oil filters and oil tanks. Oil tank return oil filters and suction oil filters need to be disassembled and cleaned or replaced after a certain period of use. The common practice is to conduct deep cleaning of the filter elements of the cold extrusion three-way machine's filter every month to ensure that the cleanliness of the hydraulic oil meets the standard. During maintenance, do not ignore the sediment, metal shavings, etc. attached to the interior of the oil tank. Use a magnet bar to adsorb impurities, and if necessary, use cleaning oil to sweep. After maintenance, replenish or replace the new hydraulic oil according to the standard model. IV. Maintenance of electrical and control systems: "Nervous system" diagnosis of the cold extrusion three-way machine The intelligent operation of the cold extrusion three-way machine relies on an independent electrical control cabinet, PLC controller, pressure sensors, displacement sensors, limit switches, and various operation button stations. The maintenance work of the electrical system mainly focuses on three aspects: circuit safety, component reliability, and the integrity of control programs. 1. Daily inspection of electrical circuits. Before starting the machine, it is necessary to check for any damage, aging, open circuits, or poor contact in the electrical circuits, especially for the cables in movable parts, to ensure that the insulation layer is not cracked. At the same time, check whether the emergency stop button, safety light curtains, limit switches, and other safety protection devices are functioning properly and operating reliably. Failure of the safety feedback means that the main barrier for personal protection has been lost, which is the top priority in maintenance. 2. Dust removal and heat dissipation maintenance of control cabinets. Precision electronic components such as PLC controllers, intermediate relays, and servo drives are sensitive to dust and high temperatures. After long-term operation, the control cabinet will accumulate a large amount of dust, which may lead to short circuits, poor heat dissipation, and severe overheating. During maintenance, disconnect the main power supply and gently blow the surface of the electrical components using a vacuum cleaner or compressed air. At the same time, check whether the cooling fans are operating normally to ensure that the temperature inside the cabinet is within a reasonable range. It is recommended to conduct dust removal and heat dissipation checks of the electrical control system once a month. 3. Calibration of sensors and limit switches. The feedback signals of displacement sensors and pressure sensors are crucial for accurately controlling the pressure and position in the forming process. During maintenance, confirm whether the sensor zero point is accurate and the feedback value is within a reasonable range. If there is a deviation, it is necessary to re-calibrate. In particular, the reliability of the side cylinder travel limit switch directly affects whether the equipment will have an over-travel accident, and it must be ensured that it triggers at the specified position reliably. 4. PLC program inspection and operation panel maintenance. During each maintenance process, it is recommended to check the alarm records of the PLC control module to determine if there are frequent and unresolved fault warnings. At the same time, check whether all function buttons on the main operation button station are sensitive, and whether the point motion function and semi-automatic mode are in a normal state. These "minor" control functions that fail can seriously affect production efficiency and cause safety hazards. 5. Maintenance of molds and tooling systems: The cornerstone for ensuring the accuracy of three-way forming Molds are the key to determining the shape, size accuracy, and surface quality of three-way parts. Molds include pipe blank clamping molds, impact heads, core shafts, and upper molds, etc. During cold extrusion, the huge deformation pressure of the metal material constantly impacts the working surface of the mold cavity, so wear, cracking, cavitation erosion, and other problems are inevitable. 1. Daily visual and tactile inspection of molds. Before each shift starts or after the processing of a batch of products, carefully observe the surface of the mold cavity for cracks, chipped areas, or abnormal bright bands, and touch to feel for burrs and raised grooves. Especially when extruding hard materials such as stainless steel, the tolerance of the mold material is lower, and small cracks are prone to rapidly expand, leading to the complete failure of the mold. 2. Inspection and grinding repair of the parting surface accuracy. The mating surfaces of the upper and lower molds may develop local deformation or pits after a large number of extrusions, causing the mold to not fit properly and resulting in uneven wall thickness of the three-way parts, excessive burrs, or even pipe breakage. During maintenance, apply red lead powder or marking oil to the parting surface to check if the contact marks are uniform. For worn or pitted parting surfaces, use oil stones or precision grinding machines to gently grind to restore flatness. Be careful not to use hard tools such as steel to clean the mold surface and sealing areas, as this may cause new damage. 3. Maintenance of core shafts, impact heads, and spring accessories. Impact heads used for a long time are prone to breakage, bending, and wear. During maintenance, measure the outer diameter and inner diameter of the impact head and core shaft to ensure they are within the tolerance range. If they exceed the tolerance, they must be replaced. At the same time, check if the mold spring is broken or deformed. When replacing the spring, pay attention to the consistency of specifications and models, and verify through the three parameters of outer diameter, length, and color mark before replacement. 4. Regular rust prevention treatment and spare parts management for molds. For molds that have been out of use for a long time, thorough cleaning, oil removal, and application of anti-rust oil should be carried out. They should then be placed in a dry and ventilated area. Maintenance records should include the cumulative number of extrusion operations for each set of molds, which will be used to schedule repair or scrapping cycles. If the enterprise uses brands such as Cangzhou Aoguang Machinery Equipment Co., Ltd. for three-way machines, during maintenance, the compatibility of the molds with the machine models should also be checked to avoid loss of precision due to mismatch between the molds and the equipment. Six. Maintenance of lubrication and sealing systems: Maintenance of the "joints" of cold extrusion three-way machines The lubrication system may seem trivial, but it is actually a key factor in significantly extending the mechanical lifespan of cold extrusion three-way machines. If the moving parts such as the guide rails, columns, bearings, and slider screw rods do not receive sufficient lubrication and continue to operate, they will experience excessive wear, abrasion, and even erosion within a short period of time, resulting in irreparable severe losses. 1. Regular addition and replacement of lubricating oil. Maintenance personnel should follow the equipment lubrication chart and regularly add the specified brand of lubricating oil or grease to each lubrication point (especially the guide rail surface, exposed surfaces of the columns, oil cups of the bearing seats, and the adjusting screw positions of the sliders). During continuous operation, it is usually recommended to replenish the main moving parts every 4 hours. At the same time, the oil tank cover plate should be removed, and the impurities and sediment at the bottom of the oil pool should be cleared to ensure that the lubricant is clean and free of foreign substances. 2. Inspection of drying devices. If the sealing devices in mechanical transmission (such as the sealing of the piston rod guide sleeve and the circumferential stopper sealing ring) are damaged or have insufficient pre-compression, it will cause hydraulic oil leakage and waste of lubricant. During maintenance, the lips of the sealing parts and the obvious wear and abrasion on the mating surfaces should be carefully inspected. If any abnormalities are found, they should be replaced and the initial torque of the fastening screws or covers checked to ensure it is appropriate. Seven. Safety maintenance and operation norms for cold extrusion three-way machines During maintenance, safety is an unbreakable red line. Before conducting any electrical maintenance, hydraulic pipe disassembly, or mechanical structure adjustment, the power supply of the equipment must be cut off and reliably locked, and residual pressure and energy must be released. A "prohibition of closing" warning sign should be set. Maintenance personnel should also correctly wear protective equipment, including compliant protective glasses, safety helmets, and anti-slip gloves. The following are several key safety points in the maintenance operation: · Shutdown and pressure relief: Before disassembling hydraulic components, the pressure must be released - let the equipment run unloaded for a few seconds and then turn off the oil pump motor, and then release the accumulated pressure through the manual valve. · Hoisting and transportation: When disassembling and maintaining large components, qualified lifting equipment should be used and safety checks should be conducted. It is strictly prohibited to use bent or damaged steel wire ropes for lifting. · Standardized records: Every maintenance operation should be recorded in detail, including personnel, time, content, and the model of replaced parts, and saved as part of the equipment's history file to facilitate tracking changes in equipment status. · No overheating, overpressure, over-speed, or overloading: Operators and maintenance personnel must operate according to the equipment's specified parameters and must not exceed temperature, pressure, speed, or load limits to avoid "illness"-stricken cold extrusion three-way machines working under high pressure. Eight. Summary and suggestions Overall, the maintenance part of cold extrusion three-way machines is a comprehensive and well-structured system project. From the maintenance of the "bones" of the mechanical structure, the management of the "blood" of the hydraulic system, the diagnosis of the "nerves" of electrical and control systems, to the reproduction of the accuracy of molds and the meticulous care of lubrication and sealing, the five sections are interrelated and indispensable. Scientific and systematic maintenance can effectively prevent sudden failures of cold extrusion three-way machines under high pressure and significantly reduce the impact of unexpected shutdowns on production plans, while controlling the quality deviations in the metal processing process within the lowest range. For the long-term safe operation of the equipment, regular routine checks and periodic maintenance are more economical and efficient than post-failure repairs. Therefore, both the operators and the maintenance team should adhere to the principle of "prevention first, maintenance foremost", and strictly implement the daily inspection打卡system. They should meticulously cooperate with a series of core maintenance operations such as adding lubricating oil， inspecting seals, cooling electrical components, and preventing rust and damage to molds. A well-functioning cold extrusion three-way machine can bring more than just a reduction in single failure time or a decrease in spare parts costs to pipeline processing enterprises； it also reshapes and consolidates their market competitiveness. Regularly inviting professional maintenance teams to conduct in-depth maintenance can effectively identify the hidden defects of old components， and promptly arrange for replacement and repair， thereby ensuring that the equipment maintains peak performance for a long time and providing the most reliable equipment guarantee for enterprises to manufacture three-way pipe fittings efficiently， precisely and safely. |
