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 may lead to the reduction of engine performance and life. But the most harmful to engine performance and life should be dirty and pollution, they are the first killer of the engine. Filters are the only way to avoid dirt and contamination. Therefore, in a sense, as one of the 60 key parts of automobile, the filter is the God of automobile engine protection.

Since the advent of the engine, people have gradually realized from practice that the engine must have a filter device. If the filter is not installed, the engine wear will be extremely fast. In particular, modern high-speed engines wear faster. With the development of engine technology, the requirement of filter is higher and higher. The importance of filter to engine performance and life is more and more recognized by people. Many automotive engineers believe that one of the main reasons why modern engines have a long life is to have effective over life

Filtration system.

[type of filter]

The engine has three kinds of filters: air, oil and fuel, which are generally called "three filters". They are respectively responsible for the filtration of the medium in the engine intake system, lubrication system and combustion system. The air filter is located in the engine intake system. It is composed of one or several clean air filter components. Its main function is to filter out harmful impurities in the air that will enter the cylinder, so as to reduce the early wear of cylinder, piston, piston ring, valve and valve seat. There are different types of air filters, namely dry type and wet type.

Dry air filter is a kind of filter which can separate impurities from air through a dry filter element (such as paper filter element). Light vehicles (including cars, mini cars) used by the air filter - generally single-stage. Its shape has flat circle or ellipse and flat plate type. The filter material is filter paper or nonwovens. If the end cover of the filter element is metal or polyurethane, the shell material is metal or plastic. Under the rated air volume flow, the original filtration efficiency of the filter element should not be less than 99.5%. Due to the harsh working environment of heavy vehicles, its air filters must be majority. The first stage is cyclone type pre filter (such as blade ring, cyclone tube, etc.), which is used to filter out coarse particles with filtration efficiency above 0. The second stage fine filtration is microporous paper filter element (generally called main filter element), with filtration efficiency of over 99 54.

There is also a safety filter element after the main filter element, which is used to prevent dust from entering the engine when the main filter element is installed and replaced, or when the main filter element is accidentally damaged. The material of safety core is mostly nonwovens, and filter paper is also used.

The wet air filter includes oil immersion type and oil bath type. The oil immersed filter element is used to separate the impurities in the air through an oil immersed filter element. The filter element materials include metal wire fabric and foam material. The oil bath type is to introduce the inhaled dust-bearing air into the oil pool and remove most of the dust, and then further filter when the air with oil mist flows upward through a filter element made of metal wire. The oil droplets and the blocked dust will return to the oil pool. Oil bath air filter is now commonly used in agricultural institutions and ships

Motivation.

The oil filter is located in the engine lubrication system. Its upstream is the oil pump, the downstream is the engine parts that need lubrication. Its function is to filter out the harmful impurities in the oil from the oil pan, and supply clean oil to the crankshaft, connecting rod, camshaft, supercharger, piston ring and other motion pairs, so as to play the role of lubrication, cooling and cleaning, so as to prolong the service life of these parts, According to the structure, the oil filter can be divided into replaceable type, rotary type and centrifugal type; according to the arrangement in the system, it can be divided into full flow type and split type. The filter materials used in oil filter include filter paper, felt, metal mesh, nonwovens, etc. Before the 1980s, most of the oil filters used in Chinese engines were replaceable. The filter element and other parts, such as spring and sealing ring, are put into a metal shell, and the shell filter element and a metal filter seat are connected and fixed by a pull rod. It has the advantage of low cost and only needs regular maintenance and replacement of filter element. The disadvantage is that there are too many sealing points, and the replacement of filter element may miss the installation of parts, which is easy to cause loopholes, and the replacement is laborious.

Since the early 1980s, Bengbu General filter factory introduced the first rotary filter production line from Italy in China. Since then, the rotary filter has been gradually approved by domestic main engine manufacturers. This kind of filter is characterized by one check valve, by-pass valve and only one sealing point. The overall replacement greatly improves the sealing performance and is easy to replace. The filter element material mostly adopts imported filter paper, so it has high filtration efficiency, small flow resistance and long service life. At present, all domestic cars use this type of oil filter. Most of the mini cars, large, medium and small buses, light and medium-sized trucks, and some heavy-duty trucks and agricultural vehicles all use spin on oil filters.

Centrifugal oil filter has a rotor sleeve on a shaft, and there are two nozzles with opposite injection direction. When the oil enters the rotor and comes out from the nozzle, the rotor will rotate rapidly to clean the oil in the rotor body. 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. 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 removed regularly and the dirt deposited on the rotor wall is cleaned, it can be reused. Its life can be equal to that of engine. Its disadvantages lie in its complex structure, high price, bulky and so on. It has higher technical requirements for users.

[domestic filter market situation]

At present, there are about 16 million automobiles in China, and the annual demand for automobiles is up to 2 million. With the addition of four-wheel agricultural vehicles, the number and demand of these vehicles are more than 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 means and product quality of these enterprises are uneven. There are not only excellent enterprises with good production equipment, perfect testing means, large production scale and reliable product quality, but also some enterprises with basic production conditions and certain testing equipment

The quality of products can be basically guaranteed by the general enterprises: but more are some simple production equipment, no testing equipment of the manual workshop type enterprises. Most of these enterprises have not carried out the final test of products.

Due to the uneven quality of filter enterprises, the auto parts market is in chaos, and even fake and shoddy filters are flooding the market. The filter is originally through the filter of harmful impurities, so that the engine can work normally under various conditions, and can reach the specified service life. However, these fake filters, especially the inferior ones, can not achieve the above-mentioned functions at all, thus bringing various hazards to the engine. Common are the following: 1. Using low-cost filter paper to make filter element, because of its large diameter, poor uniformity, low filtration efficiency, can not effectively filter out harmful impurities on the engine, resulting in early engine wear.

First, the use of low-quality adhesives, and the amount is very small, neither oil-resistant, nor can be firmly bonded, resulting in a short-circuit at the bonding part of the filter element; or the seam of the filter element is connected with staples, which can not be sealed and short-circuit, so that a large number of harmful impurities enter the engine and reduce the service life of the engine.

One is to replace the oil resistant rubber parts with ordinary rubber parts. In the process of use or due to the sealing failure of the internal sealing element, the internal short circuit of the filter is formed, resulting in early wear of the engine, reduction of the service life, or expansion and deformation of the external seal, resulting in the extrusion of the outer sealing ring of the oil filter, and a large amount of oil is discharged in a short time, which causes the engine to burn the Bush and hold the shaft and suffer serious damage.

Spot welding instead of seam welding is used to weld the shell parts of an air filter, which can not guarantee the sealing performance and form a short circuit. The material of the center tube of an oil filter is thin instead of thick, and the strength is not enough. In the process of use, the central tube is sucked down, the filter element is damaged and the oil circuit is blocked, resulting in insufficient lubrication of the engine or poor reliability at the bite point. In the process of use, the bite is opened, resulting in a large amount of oil leakage in a short period of time, resulting in Bush burning and axle holding.