The winter maintenance of construction machinery is of great significance. Especially in the northern regions where winters are long and the temperature remains low for extended periods. When construction machinery is used in winter, the cold climate can easily lead to difficulties in starting internal combustion engines, freezing of cooling water and electrolyte, intensified wear of parts, and a significant increase in fuel consumption. したがって, corresponding protective measures must be taken before winter arrives, and maintenance should be strengthened to ensure the safe and normal use of the equipment.
- Pay Attention to Maintaining the Cooling System of the Internal Combustion Engine
(1) Add antifreeze. When the temperature is extremely low and conditions permit, antifreeze can be used. Before use, the cooling system should be thoroughly cleaned, and high-quality, low-corrosive antifreeze should be selected to avoid corroding the engine parts due to poor-quality antifreeze. For equipment that does not use antifreeze in winter, hot water at around 80 °C can be added with the drain valve open every day before use. Close the drain valve when hot water starts to flow out to raise the engine body temperature. After daily operations, all drain valves should be opened to drain the cooling water completely. Leave the valves open after draining to prevent incomplete drainage.
In extremely cold environments, the choice of antifreeze becomes crucial. Antifreeze not only prevents water from freezing but also contains additives that protect the metal components of the cooling system from corrosion. Inferior antifreeze may lack these essential additives, gradually eroding the radiator, water pump, and engine block. When adding hot water, it serves as a temporary measure to warm up the engine, making it easier to start. しかし, this method requires strict adherence to the drainage process, as any remaining water can freeze overnight and cause severe damage, like cracked engine blocks.
(2) Insulate the internal combustion engine. 冬には, the water temperature of the internal combustion engine rises slowly, especially for diesel engines. To ensure the reliable operation of the internal combustion engine, reduce fuel consumption, and minimize mechanical wear, proper insulation is necessary. 一般的に, a cloth curtain can be placed in front of the engine water tank to block heat dissipation, maintain the engine temperature, and prevent it from getting too low.
The insulation measure is a simple yet effective way to conserve heat. Heat loss from the engine can slow down the warm-up process, leading to increased fuel consumption during the initial start-up phase. By covering the water tank, the engine can reach its optimal operating temperature more quickly, which is beneficial for the overall performance and lifespan of the engine.
(3) Remove scale from the water jacket and inspect and maintain the drain valve. Clean the water jacket of the internal combustion engine to eliminate scale deposits. Excessive scale can impede heat dissipation, causing the engine temperature to rise too high. At the same time, maintain the drain valve. If it is clogged with scale, malfunctioning, or damaged, it should be repaired or replaced according to the specific situation. Never use bolts or rags as substitutes, as this may affect drainage and lead to accidents such as cracked engine parts due to freezing.
Scale accumulation is a common issue over time. It forms due to the minerals present in the cooling water. If left unaddressed, scale can act as an insulator, preventing efficient heat transfer between the engine and the cooling water. The inspection and maintenance of the drain valve are equally important, as a malfunctioning valve can trap water in the system, setting the stage for freeze damage.
(4) Check the working condition of the thermostat in the water-cooled internal combustion engine. Ensure that the thermostat works properly to prevent the engine water temperature from being too low or too high, thus reducing part wear. Constantly running the engine at low temperatures can double the wear of engine components. To enable the engine to warm up quickly in winter, the thermostat can be removed, but it must be reinstalled before summer.
The thermostat plays a vital role in regulating the engine’s operating temperature. It controls the flow of coolant between the engine and the radiator, maintaining an optimal temperature range. 冬には, removing it can speed up the warm-up process, but during warmer months, it is essential for preventing overheating.
- Pay Attention to Replacing Various Fluids
(1) Replace hydraulic or hydrodynamic transmission fluid. Before winter arrives, the hydraulic system and hydrodynamic transmission system of the equipment’s working device should be replaced with winter-grade hydraulic and hydrodynamic transmission fluids. This prevents issues such as poor operation of the hydraulic system and transmission system of the working device, or even malfunctions where the working device fails to move and the equipment cannot travel, due to increased fluid viscosity in winter.
Hydraulic and hydrodynamic transmission systems rely on the proper flow of fluids. In cold weather, the thickening of the fluid can impede the movement of pistons, valves, and gears within these systems. By switching to winter-grade fluids with lower viscosities, the systems can maintain smooth operation, ensuring the normal functioning of the equipment’s working mechanisms.
(2) Replace fuel. Select fuel with a low pour point and good low-temperature fluidity. At low temperatures, the viscosity of fuel increases, its fluidity deteriorates, and atomization becomes poor, resulting in a worsened combustion process and significant declines in the starting performance, power, and economy of the internal combustion engine. したがって, fuel with a lower pour point should be selected if possible. The general selection principle is that the pour point of the fuel should be 6 °C lower than the ambient temperature.
The properties of fuel change dramatically with temperature. Inadequate fuel selection can lead to hard starting, rough idling, and reduced power output. Diesel engines, in particular, are sensitive to cold fuel, as poor atomization can cause incomplete combustion, wasting fuel and emitting more pollutants.
(3) Replace gear oil and grease. When construction machinery enters winter operation, the transmission, reducer, and steering gear should be switched to winter gear oil, and the hub bearings should be replaced with low-drop-point grease.
Gear oil and grease are essential for reducing friction between moving parts. In cold weather, regular gear oil and grease can become too thick, hindering the smooth rotation of gears and bearings. Winter-grade lubricants have lower viscosities at low temperatures, ensuring that the power transmission and steering systems operate without excessive resistance.
(4) Replace engine oil. Select internal combustion engine oil with low viscosity. In low-temperature conditions, the viscosity of engine oil increases as the temperature drops, its fluidity worsens, and the friction resistance rises, which can lead to difficulties in starting the internal combustion engine. したがって, this adverse effect can be compensated for or eliminated by promptly replacing the engine oil with lower viscosity.
Engine oil is the lifeblood of the internal combustion engine, lubricating the moving parts to reduce friction and wear. Cold temperatures can turn normal engine oil into a thick, sluggish substance. By choosing the right low-viscosity oil for winter, the engine can start more easily and run more smoothly.
- Pay Attention to Maintaining Electrical Equipment
(1) Maintain the starter. Starting the internal combustion engine is more difficult in winter, and the starter is used frequently. If the starter has insufficient power, it will further increase the difficulty of starting the internal combustion engine. Practice shows that in summer, when the starting power is slightly insufficient, it may not affect the engine start-up, but in winter, starting can become extremely difficult or even impossible. したがって, the starter should be thoroughly maintained before winter. Keep all components of the starter clean and dry, especially ensuring good contact between the brushes and the commutator.
The starter is the key to getting the engine running in cold weather. A dirty or malfunctioning starter can struggle to turn over the engine, especially when the engine is cold and the oil is thick. Regular maintenance, including cleaning and checking the electrical connections, can improve its performance and reliability.
(2) Check and adjust the electrolyte density and pay attention to the insulation of the storage battery. The electrolyte density can be appropriately increased to prevent the storage battery case from cracking due to excessively low electrolyte density. 一般的に, the electrolyte density of the storage battery can be adjusted to 1.28 in winter.
The electrolyte density in a battery affects its freezing point. As the temperature drops, a lower-density electrolyte is more likely to freeze, which can cause the battery case to expand and crack. By increasing the density, the battery can withstand colder temperatures without damage, ensuring reliable power supply for starting the engine.
In addition to the above key maintenance points, there are several other aspects that deserve our attention in winter maintenance of construction machinery:
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Inspect and Maintain the Chassis and Suspension System
- Check the tightness of bolts on the chassis. Low temperatures can cause metal components to contract, which may lead to bolts loosening. Regularly inspect all bolts on the chassis, including those connecting the frame, axles, and suspension components. Any loose bolts should be tightened immediately to maintain the structural integrity of the vehicle. Loose bolts can result in abnormal vibrations during operation, accelerating the wear of other parts and potentially causing safety hazards.
- Lubricate the suspension joints. The suspension system’s joints, such as ball joints and bushings, are subject to greater stress in cold weather due to the stiffening of rubber components. Apply a suitable low-temperature lubricant to these joints to reduce friction and prevent premature wear. Proper lubrication also helps to maintain a smooth ride, improving the operator’s comfort and the overall handling of the machinery.
- Check the condition of tires. 冬には, tire pressure can drop significantly due to the cold. Regularly measure and adjust tire pressure according to the manufacturer’s recommendations. さらに, consider using winter tires if the machinery operates in snowy or icy conditions. Winter tires have deeper treads and softer rubber compounds, providing better traction on slippery surfaces, which is crucial for the safety and mobility of the equipment.
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Maintain the Cab and Operator Compartment
- Check the heating system. Ensure that the heater in the cab works properly. A malfunctioning heating system can make the operator uncomfortable during long hours of work in cold weather, affecting work efficiency. Inspect the heater core, blower fan, and all associated hoses for leaks or blockages. Replace any faulty components promptly to keep the cab warm.
- Inspect the seals around the cab. Cold air can seep into the cab through damaged or worn seals, reducing the effectiveness of the heating system. Check the door seals, window seals, and any other openings for signs of wear or damage. Replace the seals if necessary to keep the cab well-insulated.
- Clean and maintain the interior. Keep the operator compartment clean to prevent the accumulation of dirt and debris, which can be more difficult to clean in cold weather. Wipe down the dashboard, controls, and seats regularly. Also, ensure that all safety equipment, such as fire extinguishers and first aid kits, are in good condition and easily accessible.
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Protect Exposed Components
- Coat exposed metal parts. Use a suitable anti-corrosion spray or grease to coat exposed metal components, such as hydraulic cylinders, linkages, and exposed sections of the frame. This protects them from rust and corrosion caused by snow, ice, and road salt. Rust can weaken the strength of metal parts over time, reducing the lifespan of the machinery.
- Cover exposed cables and hoses. Electrical cables and hydraulic hoses that are exposed to the elements can be damaged in cold weather. Use insulated covers or wraps to protect them from freezing, cracking, or abrasion. Damaged cables and hoses can lead to electrical short circuits or hydraulic fluid leaks, both of which can cause significant malfunctions.
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Perform Regular Pre-Operational Checks
- Before starting the machinery each day, conduct a comprehensive pre-operational check. Check the fluid levels again, including engine oil, coolant, 燃料, and hydraulic fluid, to ensure there are no unexpected leaks overnight. Inspect the tires, brakes, and steering system for any signs of damage or malfunction. Also, test all lights and electrical devices to confirm they are working properly. This pre-check helps to identify and address potential issues before they escalate during operation, ensuring a safe start to the day’s work.
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Store Machinery Properly
- If the construction machinery is not in use for an extended period during winter, proper storage is essential. Park the machinery in a dry, sheltered area, preferably indoors. If indoor storage is not possible, use a high-quality tarp to cover the equipment completely, protecting it from snow, ice, and rain. Before storing, drain all fluids as described earlier, except for the engine oil, which should be left in the engine to prevent rust. Disconnect the battery and store it in a warm, dry place, periodically checking and charging it to maintain its charge level. Proper storage can prevent unnecessary damage during the idle winter months, saving costs on repairs and maintenance when the machinery is put back into use.
By following these comprehensive winter maintenance guidelines, construction machinery such as クレーンs can better withstand the harsh winter conditions, ensuring reliable operation, reducing downtime, and prolonging the lifespan of the equipment.
