Maintenance of dry inertial filtration
Dry inertial air filter is composed of dust hood, guide vane, dust outlet and vacuum cup. During maintenance, attention should be paid to:
1. Regularly check and clean the dust discharge hole on the centrifugal dust removal cover, remove the dust attached to the guide vane, and pour out the dust in the dust collection cup (the amount of dust collected in the container shall not exceed 1/3 of its volume). When installing, the rubber gasket at the joint should be sealed, and there should be no air leakage, otherwise it will cause short circuit of air flow, reduce the speed of air and greatly reduce the dust removal effect.
2, dust cover, deflector should keep the correct shape, if there is any bump should be timely plastic, so as not to make the airflow change the original design direction and reduce the filtering effect.
3. Some drivers are not allowed to refuel the dust cup (or dust tray). Because oil is easy to splash to dust outlet, guide vane and other parts, this part absorbs dust, which will eventually reduce the filtration and separation ability.
Maintenance of wet inertial filtration
The wet inertial air filtering device consists of a central pipe and an oil tank. In the process of use, attention should be paid to:
1. Clean the oil pan regularly and change the oil. When changing oil, the viscosity of the oil should be moderate. The viscosity is too high, which is easy to block the filter screen of the filter device and increase the intake resistance; If the viscosity is too small, the ability of oil to adhere to dust will be reduced, and the splashed oil will be easily sucked into the cylinder to participate in combustion, resulting in carbon deposition.
2. The oil level in the oil pool should be moderate. Oil should be added between the upper and lower score lines of the oil pan or at the arrow mark. The oil level is too low, the oil quantity is insufficient, and the filtering effect is poor; If the oil level is too high and there is too much oil, it is easy to be sucked into the cylinder and burned, which will lead to a "out of control" accident.
Maintenance of dry filtration
Dry air filtration device is composed of paper filter element and sealing washer. In the process of use, attention should be paid to:
1, check regularly and clean correctly. When cleaning the dust on the paper filter, brush the dust and dirt on the surface of the filter along the folding direction with a soft brush, and gently pat the end face to make the dust fall off. During the above operation, clean cotton cloth or rubber plugs should be used to block both ends of the filter element, and air should be blown out from the inside of the filter element with a compressed air machine or pump (the air pressure should not exceed 0.2-0.3MPA to prevent the filter paper from being damaged) to blow away the dust adhering to the outer surface of the filter element.
2. Do not clean the paper filter with water, diesel oil or gasoline, otherwise it will block the pores of the filter and increase the air resistance; At the same time, diesel oil is easily sucked into the cylinder, which leads to "out of control" after loading.
3. When the filter element is found to be damaged, or the upper and lower end faces of the filter element are uneven, or the rubber sealing ring is aged, deformed or damaged, it should be replaced with a new one.
4. Pay attention to the gasket or sealing ring at each joint during installation, and don't miss or misplace it to avoid air short circuit. Do not tighten the butterfly nut of the filter element too tightly to avoid crushing the filter element.
Maintenance of wet filtration
This device is mainly composed of a metal filter screen soaked with engine oil. Attention should be paid to:
1. Wash the dust on the filter screen regularly with diesel oil or gasoline.
2. When assembling, first soak the filter screen with engine oil, and then assemble after the excess engine oil drips out. During installation, the cross skeleton on the filter plate of the filter cake filter should be overlapped and aligned, and the inner and outer aprons of the filter should be well sealed to prevent short circuit of air intake. It is more and more common to use paper-core air filters in modern automobile engines, but some drivers still have prejudice against paper-core air filters and think that the filtering effect of paper-core air filters is not good. In fact, the paper core air filter has many advantages compared with the oil bath air filter:
1, the filtration efficiency is as high as 99.5% (oil bath air filter is 98%), and the dust permeability is only 0.1%-0.3%;
2. Compact structure, can be installed in any direction, and is not limited by the layout of vehicle parts;
3, maintenance does not consume oil, but also saves a lot of cotton yarn, felt and metal materials;
4. Small mass and low cost.
It is very important to use paper core when sealing the air filter, so as not to let unfiltered air enter the engine cylinder from the bypass.
1. During installation, whether flange, rubber tube or direct connection is adopted between the air filter and the engine intake pipe, it must be tight and reliable to prevent air leakage, and rubber washers must be installed at both ends of the filter element; Don't tighten the wing nut for fixing the air cleaner cover too tightly to avoid crushing the paper filter element.
2. When maintaining, never clean the paper filter element in oil, otherwise the paper filter element will fail and it will easily cause flight accidents. During maintenance, dust and dirt attached to the surface of paper filter element can only be removed by vibration method, soft brushing method (brushing along its folds) or compressed air backwashing method. For the coarse filter, the dust in the dust collecting parts, blades and cyclone tubes should be removed in time. Even if it can be carefully maintained every time, the paper filter element can not completely restore its original performance, and the air intake resistance will increase. Therefore, when the paper filter needs to be maintained for the fourth time, it should be replaced with a new filter. If the paper filter element is damaged, perforated or the filter paper and end cover are degummed, it should be replaced immediately.
3. When using, it is necessary to prevent the paper core air filter from getting wet by rain, because once the paper core absorbs a lot of water, it will greatly increase the air intake resistance and shorten the service life. In addition, the paper core air filter can't touch oil and fire.
4. Some vehicle engines are equipped with cyclone air filters. The plastic cover at the end of the paper filter element is a guide cover. The blades on the cover make the air rotate, and 80% of the dust is separated by centrifugal force and collected in the dust bag. The dust reaching the paper filter element is 20% of the inhaled dust, and the total filtration efficiency is about 99.7%. Therefore, when maintaining the cyclone air filter, be careful not to miss the nutrient guide cover on the filter element. The function of the air filter is to filter out suspended particles in the air entering the cylinder, thus reducing the wear of the cylinder, piston and piston ring. Of the three media required for engine operation, the air consumption is the largest, which comes from the atmosphere. If the air filter can't effectively filter out the suspended particles in the air, it will accelerate the wear of the cylinder, piston and piston ring, even cause cylinder strain and shorten the service life of the engine.
abuse
Don't pursue quality when buying.
Because a few maintenance personnel didn't realize the importance of air filter, they just bought it at will for the sake of cheapness, not for the sake of quality, so that the engine was abnormal soon after installation. Especially in the current market, there are many fake and shoddy products, so we should shop around carefully and always adhere to the principle of quality first.
(2) Dismantle at will during use.
The engine must use air filter, which has scientific basis. However, some drivers will remove the air filter at will and let the engine directly inhale unfiltered air to work. The test of truck air filter shows that the wear of engine cylinder, piston and piston ring increases 8 times, 3 times and 9 times respectively after air filter is removed.
(3) Maintenance and replacement cannot proceed from reality.
Although the operating instructions for air filters stipulate mileage or working hours as data for maintenance or replacement. But in fact, the maintenance and replacement cycle of air filters is also related to environmental factors. The maintenance or replacement cycle of air filter should be shorter for cars that often drive in dusty environment; For cars with less dust, the maintenance or replacement cycle of air filter can be extended appropriately. In practical work, many drivers and maintenance personnel do things according to the regulations mechanically, instead of grasping flexibly according to different factors such as the environment, and insisting on waiting until the mileage reaches the standard, the working state of the engine is obviously abnormal. It should be noted that the maintenance at this time can not only recover the losses already caused, but also cause greater harm. What's more, individual drivers simply don't know that the air filter will fail. As long as the outside is not damaged, they will continue to use it.
Identification method
The working principle of the air filter and when it needs maintenance or replacement can be identified by the following methods:
Theoretically speaking, the service life and maintenance cycle of air filter should be measured by the ratio of gas flow through filter element to gas flow required by engine. When the flow rate is greater than the flow rate, the filter works normally; When the flow is equal to the flow, the filter should be maintained; When the flow rate is less than the flow rate, the filter can no longer be used, otherwise the working condition of the engine will get worse and worse, or even it will not work.
In practical work, when the filter element of the air filter is blocked by suspended particles and cannot meet the air flow required by the engine, the working state of the engine will be abnormal, such as roaring and muffled sound, slow acceleration (insufficient air intake and insufficient cylinder pressure); Incomplete work (incomplete combustion due to too much mixed gas); The water temperature is relatively high (combustion continues when entering the exhaust stroke); And the exhaust smoke becomes thicker during acceleration.
When these symptoms appear, it can be judged that the air filter is blocked, and the filter element should be taken out in time for maintenance or replacement. When maintaining the air filter element, pay attention to the color change of the inner and outer surfaces of the filter element. After dust removal, if the outer surface of the filter paper is clear and the inner surface is bright, the filter element can continue to be used; If the outer surface of the filter paper has lost its true color or the inner surface is dark, it must be replaced! Customers are usually advised to replace it every 654.38+0.5 million kilometers. Vehicles that often work in harsh environments should be replaced once (desert, construction site, etc.). ) at a distance of no more than 65,438+00,000 kilometers. The service life of air filters is 30,000 kilometers for cars and 80,000 kilometers for commercial vehicles.
The filter requires high filtering accuracy: all larger particles are filtered out (>: 1-2 μm). High filtration efficiency: reduce the number of particles passing through the filter. Prevent premature engine wear. Prevent the air flowmeter from being damaged! The low pressure difference ensures that the engine has the best air-fuel ratio. Reduce the fluid loss. Large filtering area, high ash content and long service life. Reduce operating expenses. Small installation space and compact structure. High wet stiffness, preventing the filter element from cracking due to the shrinkage of the filter element. Flame retardant. Reliable sealing performance. Good cost performance. No metal structure, which is beneficial to environmental protection, reuse and storage. The first step is to open the engine compartment cover and confirm the position of the air filter. The air filter is generally located on the left side of the engine compartment, that is, above the left front wheel. You can see a square plastic black box with a filter inside. We only need to gently lift the two metal clips upwards to lift the entire air cleaner upper cover. There are also some models that use screws to fix the air filter. At this time, it is necessary to select a suitable screwdriver to unscrew the screws on the air cleaner box. Take out the air filter
Step 2: Take out the air filter element and check whether there is too much dust. You can tap the end face of the filter element gently, or use compressed air to clean the dust on the filter element from the inside out. Don't rinse with tap water. If the air filter is seriously blocked, it needs to be replaced with a new filter (we can go to 4S shop or auto parts city to buy the same model).
The third step is to thoroughly clean the empty filter box after the air filtration treatment. Generally, a lot of dust will accumulate under the air filter, which is the chief culprit leading to the decline of engine power. The location of the filter, the air filter is generally located on the left side of the engine compartment, that is, above the left front wheel. You can see a square plastic black box with a filter installed in it. We only need to gently lift the two metal clips upwards to lift the entire air cleaner upper cover. There are also some models that use screws to fix the air filter. At this time, it is necessary to select a suitable screwdriver to unscrew the screws on the air cleaner box. Take out the air filter