The life of a car depends largely on the life of its heart engine. Overload, high speed driving, bad driving habits of starting and stopping, etc. may reduce the performance and life of the engine. However, the most harmful factors to engine performance and life are dirt and pollution, which are the first killer of engines. The filter is the only way to avoid dirt and contamination. Therefore, in a sense, as one of the 60 key components of the automobile, the filter is the protector of the automobile engine.
Since the engine came out, people have gradually realized from practice that the engine must have a filter device. If the filter is not installed, the engine will wear abnormally fast. In particular, modern high-speed engines wear faster. With the progress of engine technology, the requirements for filters are getting higher and higher. The importance of filters for engine performance and life is also increasingly recognized. Many automotive engineers believe that one of the main reasons why modern engines have a long life is that they have effective
Filter system.
[Type of filter]
The engine has three kinds of filters: air filter, oil filter and fuel filter, which are generally called "three filters". They are respectively responsible for filtering the medium in the engine air intake system, lubrication system and combustion system. The air filter is located in the engine air intake system. It is an assembly composed of one or several clean air filter components. Its main function is to filter the harmful impurities in the air that will enter the cylinder, so as to reduce the early wear of the cylinder, piston, piston ring, valve and valve seat. There are different types of air filters, namely, dry type and wet type.
The dry air filter is a filter that separates impurities in the air through a dry filter element (such as a paper filter element). The air filter used in light vehicles (including sedans and minicars) is generally single-stage. Its shapes are oblate or elliptical and flat. The filter material is filter paper or non-woven cloth. If the filter element end cover is made of metal or polyurethane, the shell material is metal or plastic. Under the rated air volume flow, the original filtering efficiency of the filter element shall not be less than 99.5%. Due to the harsh working environment of heavy vehicles, their air filters must be majority. The first stage is a swirling pre filter (such as a blade ring, a swirling tube, etc.), which is used to filter out coarse particles and impurities. The filtering efficiency is above 0. The second stage is a microporous paper filter element (commonly referred to as the main filter element), which has a filtering efficiency of more than 9954.
There is also a safety filter element behind the main filter element, which is used to prevent dust from entering the engine when installing and replacing the main filter element, or when the main filter element is accidentally damaged. The material of the safety core is mostly nonwoven, and filter paper is also used.
Wet air filter includes oil immersed type and oil bath type. Oil immersed filter element is used to separate impurities in the air through an oil immersed filter element. The filter element materials include metal wire fabric and foam materials. The oil bath type is to introduce the inhaled dusty air into the oil pool to remove most of the dust, and then further filter when the air with oil mist flows upward through a filter element composed of metal wires. The oil droplets and trapped dust return to the oil pool. Oil bath air filters are now commonly used in agricultural institutions and ships
Power.
The oil filter is located in the engine lubrication system. Its upstream is the oil pump, and its downstream is the parts of the engine that need lubrication. Its function is to filter the harmful impurities in the oil from the oil pan, and provide clean oil to the crankshaft, connecting rod, camshaft, supercharger, piston ring and other motion pairs to lubricate, cool, and clean, thus extending the life of these parts. The oil filters are divided into replaceable, spin on, and centrifugal types according to the structure: they can be divided into full flow and split flow types according to the arrangement in the system. The filter materials used for the oil filter include filter paper, felt, metal mesh, non-woven cloth, etc. Before the 1980s, most of the oil filters used by domestic engines were interchangeable. The filter with this structure puts the filter element and other parts, such as spring, sealing ring, etc., into a metal housing, and connects and fixes the housing filter element, etc. with a metal filter seat through a pull rod. The advantage of the utility model is that the use cost is low, and the filter element only needs regular maintenance and replacement. The disadvantage is that there are too many sealing points. The maintenance and replacement of the filter element may miss the installation of parts, which is easy to cause leaks, and the replacement is time-consuming.
Since the early 1980s, Bengbu Filter Factory was the first domestic spin on filter production line introduced from Italy, the spin on filter has gradually been approved and selected by domestic main engine manufacturers. This filter is characterized by that it is internally equipped with a check valve, a bypass valve, and only one sealing point. It is replaced as a whole, which greatly improves the sealing performance and is easy to replace. The filter element material is mostly imported filter paper, so the filter efficiency is high, the flow resistance is small, and the service life is long. At present, all domestic cars use oil filters of this structure. Most minicars, large, medium and small buses, light and medium trucks, and some heavy trucks and agricultural vehicles use spin on oil filters.
The centrifugal oil filter has a rotor sleeved on a branch shaft and two nozzles with opposite injection directions. When the oil enters the rotor and comes out of the nozzle, the rotor will rotate rapidly, so that the oil in the rotor body is cleaned. The impurities in the oil are centrifugally thrown onto the inner wall of the rotor, and the oil from the nozzle flows back to the oil pan. The centrifugal oil filter is characterized by stable performance and reliable structure. There is no filter element that needs to be replaced. As long as the rotor is disassembled regularly, the dirt deposited on the rotor wall can be cleaned and reused. Its service life can be equivalent to that of the engine. Its disadvantage lies in its complex structure, high price, heavy weight, etc., and high technical requirements for users.
[Domestic filter market situation]
At present, there are about 16 million cars in the whole society, with an annual demand of 2 million cars. With the addition of four wheeled agricultural vehicles, the number of cars and the demand for them exceed 19 million and 2.5 million respectively. The annual demand for filters (including filter elements) of these vehicles exceeds 120 million. So many filters are mostly produced by domestic filter manufacturers. There are more than 1000 filter manufacturers in China. The production scale, production conditions, testing methods and product quality of these enterprises are uneven. There are excellent enterprises with good production equipment, perfect testing means, large production scale and reliable product quality; there are also enterprises with basic production conditions, certain testing equipment
General enterprises whose product quality can be basically guaranteed: but most of them are manual workshops with simple production equipment and no testing equipment. Most of these enterprises did not carry out the final test of products.
Due to the intermingled good and bad filter enterprises and the chaotic auto parts market, the market is flooded with fake and inferior filters. The filter was originally used to filter out harmful impurities, so that the engine can work normally under various working conditions and reach the specified service life. However, these fake filters, especially the inferior filters, can not achieve the above functions at all, thus bringing various hazards to the engine. The following are common: First, low price filter paper is used to make the filter element. Because of its large aperture, poor uniformity and low filtering efficiency, the impurities harmful to the engine cannot be effectively filtered, causing early engine wear.
First, low-quality adhesive is used with very little amount, which is neither oil resistant nor firmly bonded, resulting in short circuit at the bonding part of the filter element; or staples are used at the joint of the filter element, which can not be sealed and short circuit, so that a large number of harmful impurities enter the engine, reducing the service life of the engine.
First, replace the oil resistant rubber parts with ordinary rubber parts. During the use process or due to the internal short circuit of the filter caused by the sealing failure of the internal sealing parts, the engine is worn early, the service life is reduced, or due to the expansion and deformation of the external sealing parts, the external sealing ring of the oil filter is squeezed out, and a large amount of oil is drained in a short time, causing the engine to burn tiles, hold shafts, and suffer serious damage.
A welding part of the air filter housing is spot welded instead of seam welded, which can not ensure the sealing, resulting in a short circuit. The central tube of an oil filter is made of thin material instead of thick material, which is not strong enough. During the use, the central tube is shrunk, the filter element is damaged and blocks the oil path, resulting in insufficient lubrication of the engine. Or the reliability of the bite is poor, and the bite is pulled open during the use, resulting in a large amount of oil leakage in a short time, resulting in tile burning and axle seizure.
