一般來說，同等排量情況下，氣門越多，進(jìn)排氣效率越好，就像一個(gè)人跑步，累得氣喘吁吁時(shí)，需要張大嘴巴呼吸。傳統(tǒng)的發(fā)動(dòng)機(jī)多是每個(gè)氣缸一個(gè)進(jìn)氣門和一個(gè)排氣門，這種二氣門配氣機(jī)構(gòu)相對(duì)比較簡(jiǎn)單，制造成本低，維修起來也相對(duì)容易。對(duì)于輸出功率要求不太高的普通發(fā)動(dòng)機(jī)來說，兩氣門就能獲得較為滿意的發(fā)動(dòng)機(jī)輸出功率與扭矩性能。
Generally speaking, the same displacement situations, the more the valve, inlet and exhaust efficiency, the better, like a man running, tired panting, need to open mouth breathing. More than the traditional engine is an inlet valve for each cylinder and an exhaust valve, the two valve distribution mechanism is relatively simple, low manufacturing cost, maintenance is also relatively easy. For ordinary engine output power requirement is too high, the valve can get more satisfactory engine power output and torque performance.
排量較大、功率較大的發(fā)動(dòng)機(jī)要采用多氣門技術(shù)。最簡(jiǎn)單的多氣門技術(shù)是三氣門結(jié)構(gòu)，即在一進(jìn)一排的二氣門結(jié)構(gòu)基礎(chǔ)上再加上一個(gè)進(jìn)氣門。世界各大汽車公司新開發(fā)的轎車大多采用四氣門結(jié)構(gòu)。四氣門配氣機(jī)構(gòu)中，每個(gè)氣缸各有兩個(gè)進(jìn)氣門和兩個(gè)排氣門。
Displacement is larger, the power of the larger engine more valve technology must be used. The simplest valve technology is more three valve structure, namely the one into a row of two valve structure based on coupled with an inlet valve. The world's largest car company newly developed cars mostly adopted four valve structure. Four valve of valve-train, each cylinder has two inlet valve and the exhaust valve.
四氣門結(jié)構(gòu)能大幅度提高發(fā)動(dòng)機(jī)的吸氣、排氣效率，新款轎車大都采用四氣門技術(shù)。當(dāng)然，大眾汽車多采用五氣門技術(shù)，如老款捷達(dá)王的20V發(fā)動(dòng)機(jī)，寶來1.8T發(fā)動(dòng)機(jī)也是五氣門。
Four valve structure can greatly improve the efficiency of the suction, exhaust of engine, the new cars are mostly adopted four valve technology. Volkswagen more, of course, take five valve technology, such as old 20 v engine, jetta baolai 1.8 T engine is five valve.
不過，達(dá)到或超過六氣門不僅使配氣結(jié)構(gòu)過于復(fù)雜，還會(huì)導(dǎo)致發(fā)動(dòng)機(jī)壽命縮短，氣門開啟的空間簾區(qū)(氣門的圓周和氣門的升程)也較小，效率下降。因此，四氣門技術(shù)目前使用最為普遍。
However, reach or exceed six valve not only makes the distribution structure is too complex, can also lead to shorten the life engine, the valve open space of the shade area (the circumference of the valve and valve lift) is small, efficiency is decreased. Therefore, four valve technology currently in use is most common.
需要指出的是，氣缸和氣門數(shù)可以作為判斷發(fā)動(dòng)機(jī)優(yōu)劣的標(biāo)準(zhǔn)之一，但不是唯一標(biāo)準(zhǔn)。比如，寶馬公司的直列4氣缸2.0升發(fā)動(dòng)機(jī)，由于其獨(dú)特的可變氣門技術(shù)，在功率和扭矩輸出上絲毫不遜于普通的6缸機(jī)，這也是寶馬318轎車動(dòng)力性廣受好評(píng)的原因。奔馳公司長(zhǎng)期采用每個(gè)氣缸3氣門技術(shù)，也達(dá)到了很好的功率、扭矩和環(huán)保水平。此外，配備渦輪增壓技術(shù)后，寶來1.8T4缸機(jī)的功率和扭矩也能達(dá)到普通6缸機(jī)的水平。
It should be pointed out that, number of cylinders and valves can be used as one of the advantages and disadvantages of standard judgment of engine, but it is not the only standard. For instance, BMW's 2.0 -liter inline 4 cylinder engine, because of its unique variable valve technology, on the power and torque output is no worse than the ordinary 6 cylinder machine, this is why BMW 318 sedan performance critically acclaimed. Mercedes with 3 valves per cylinder technique for a long time, also reached the good power, torque and the environmental protection level. In addition, equipped with a turbo technology, baolai 1.8 T4 cylinder machine power and torque can reach common six-cylinder machine level.
