在維修汽車發(fā)動(dòng)機(jī)這么多年，但對(duì)于發(fā)動(dòng)機(jī)上的很多孔要是不知道是干什么的，下面帶你一起去看看這些孔的作用和原理！
I have been repairing the automobile engine for so many years, but if I don't know what many holes on the engine are for, let's take you to see the function and principle of these holes!
曲軸箱上的排氣孔
Exhaust hole on crankcase
發(fā)動(dòng)機(jī)工作時(shí)，一部分可燃?xì)怏w和廢氣總會(huì)通過活塞環(huán)與氣缸壁之間的間隙進(jìn)入曲軸箱。曲軸箱內(nèi)冷凝的燃油蒸氣會(huì)稀釋機(jī)油，廢氣中的酸性物質(zhì)和水蒸氣會(huì)腐蝕零件，使機(jī)油性能惡化（稀釋、老化和結(jié)焦）。
When the engine is working, some combustible gases and exhaust gases always enter the crankcase through the gap between the piston ring and the cylinder wall. The fuel vapor condensed in the crankcase will dilute the engine oil, and the acidic substances and water vapor in the exhaust gas will corrode the parts and deteriorate the performance of the engine oil (dilution, aging and coking).
此外，進(jìn)入曲軸箱的氣體會(huì)使箱內(nèi)溫度和壓力升高，導(dǎo)致油從油封、墊片等處滲出；由于活塞的往復(fù)運(yùn)動(dòng)，曲軸箱內(nèi)的氣體壓力周期性變化，影響發(fā)動(dòng)機(jī)的正常運(yùn)轉(zhuǎn)，嚴(yán)重時(shí)會(huì)導(dǎo)致曲軸箱內(nèi)的機(jī)油向上跑到燃燒室和氣缸蓋罩內(nèi)。
In addition, the gas entering the crankcase will increase the temperature and pressure in the box, resulting in oil leakage from oil seals, gaskets, etc; Due to the reciprocating motion of the piston, the gas pressure in the crankcase changes periodically, affecting the normal operation of the engine. In serious cases, the oil in the crankcase will run up to the combustion chamber and cylinder head cover.
為了避免上述現(xiàn)象，發(fā)動(dòng)機(jī)配備了通風(fēng)裝置，以平衡曲軸箱內(nèi)外的氣壓。如果在使用過程中出現(xiàn)燒機(jī)油、沿結(jié)合面漏油、機(jī)油過早變質(zhì)、發(fā)動(dòng)機(jī)怠速運(yùn)轉(zhuǎn)不穩(wěn)定等現(xiàn)象，檢查曲軸箱通風(fēng)裝置是否有效；確保通風(fēng)孔通暢，負(fù)壓閥板不得變形、粘連或安裝錯(cuò)誤，呼吸管不得彎曲或堵塞，單向閥不得裝反，堵頭不得用木塞代替。
In order to avoid the above phenomenon, the engine is equipped with ventilation device to balance the air pressure inside and outside the crankcase. In case of oil burning, oil leakage along the joint surface, premature deterioration of oil, unstable idle running of engine and other phenomena during use, check whether the crankcase ventilation device is effective; Ensure that the ventilation hole is unobstructed, the negative pressure valve plate shall not be deformed, adhered or installed incorrectly, the breathing tube shall not be bent or blocked, the one-way valve shall not be installed reversely, and the plug shall not be replaced by a wooden plug.
油箱蓋上的排氣孔
Vent on tank cap
為防止油箱內(nèi)的燃油因振動(dòng)而飛濺、油蒸氣逸出和外部灰塵進(jìn)入，應(yīng)將油箱蓋好并密封。但當(dāng)因油耗降低油位時(shí)，油箱內(nèi)會(huì)形成一定程度的真空，使油泵失去吸油能力；另外，當(dāng)溫度高時(shí)，燃油會(huì)蒸發(fā)，油蒸氣會(huì)導(dǎo)致油箱內(nèi)壓力過大。
In order to prevent the splashing of fuel oil in the oil tank due to vibration, the escape of oil vapor and the entry of external dust, the oil tank shall be covered and sealed. However, when the oil level is reduced due to oil consumption, a certain degree of vacuum will be formed in the oil tank, resulting in the loss of oil absorption capacity of the oil pump; In addition, when the temperature is high, the fuel will evaporate, and the oil vapor will lead to excessive pressure in the fuel tank.
當(dāng)罐的內(nèi)部和外部之間發(fā)生壓力差時(shí)，這兩種情況都需要與大氣自動(dòng)連通。為此，在油箱蓋上設(shè)有通氣孔，以平衡油箱內(nèi)外的氣壓。使用過程中，確保油箱蓋上的通風(fēng)孔暢通無阻。油箱蓋丟失后，如果通風(fēng)口堵塞或用塑料片堵住油箱，發(fā)動(dòng)機(jī)工作時(shí)油位下降，油箱內(nèi)部會(huì)形成負(fù)壓，導(dǎo)致在發(fā)動(dòng)機(jī)運(yùn)行不穩(wěn)定、功率下降、自動(dòng)熄火和發(fā)動(dòng)機(jī)故障時(shí)，在暖機(jī)狀態(tài)等情況下難以啟動(dòng)。
When there is a pressure difference between the inside and outside of the tank, both cases need to be automatically connected to the atmosphere. Therefore, a vent hole is arranged on the oil tank cover to balance the air pressure inside and outside the oil tank. During use, ensure that the ventilation hole on the fuel tank cover is unobstructed. After the fuel tank cover is lost, if the vent is blocked or the fuel tank is blocked with plastic sheet, the oil level will drop when the engine is working, and a negative pressure will be formed inside the fuel tank, which will make it difficult to start under the condition of warm-up in case of unstable engine operation, power decline, automatic flameout and engine failure.
散熱器箱上的進(jìn)排氣孔
Air inlet and exhaust holes on radiator box
濟(jì)南哪里有寶馬汽車維修的人員認(rèn)為發(fā)動(dòng)機(jī)工作時(shí)，封閉式冷卻系統(tǒng)中水溫的升高會(huì)導(dǎo)致冷卻水汽化并產(chǎn)生高壓，從而導(dǎo)致散熱器芯管因膨脹開裂而泄漏。當(dāng)發(fā)動(dòng)機(jī)負(fù)荷降低或停止運(yùn)轉(zhuǎn)時(shí)，冷卻系統(tǒng)中的水蒸氣會(huì)凝結(jié)成水，其壓力會(huì)下降。壓力差可能導(dǎo)致芯管被壓扁，阻礙冷卻水的正常循環(huán)。
Jinan where BMW car maintenance personnel believe that when the engine is working, the rise of water temperature in the closed cooling system will lead to the vaporization of cooling water and high pressure, resulting in the leakage of radiator core pipe due to expansion and cracking. When the engine load decreases or stops running, the water vapor in the cooling system will condense into water and its pressure will drop. The pressure difference may cause the core tube to be flattened and hinder the normal circulation of cooling water.
為此，在散熱器蓋上設(shè)置了一個(gè)空氣蒸汽閥，并有一個(gè)與大氣相通的公共氣孔。當(dāng)水溫升高時(shí)，散熱器內(nèi)產(chǎn)生水蒸氣，打開蒸汽閥，水蒸氣從該孔排出；當(dāng)水溫下降時(shí)，壓力下降，空氣閥打開，外界空氣將從這個(gè)孔進(jìn)入散熱器，從而保證散熱器。內(nèi)壓穩(wěn)定。在使用過程中，一定要確保這個(gè)孔是暢通的，不能被堵塞，否則會(huì)影響散熱器和發(fā)動(dòng)機(jī)的散熱性能。
Therefore, an air steam valve is set on the radiator cap, and there is a public air hole connected with the atmosphere. When the water temperature rises, water vapor is generated in the radiator. Open the steam valve and the water vapor is discharged from the hole; When the water temperature drops, the pressure drops, the air valve opens, and the outside air will enter the radiator from this hole, so as to ensure the radiator. The internal pressure is stable. During use, make sure that the hole is unblocked and cannot be blocked, otherwise it will affect the heat dissipation performance of radiator and engine.
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