【正文】
電氣系統(tǒng)有幾項作用:啟動發(fā)電機;提供高壓電脈沖點燃燃燒室中空氣和燃油的高壓混合氣,電氣系統(tǒng)包括電池、發(fā)電機、啟動系統(tǒng)、點火系統(tǒng)、照明系統(tǒng)、喇叭,收音機以及其他裝置。 在制造蓄電池時,幾塊相似的極板以適合的間隔焊在一起成極板組。隔板材料可以是木片、玻璃纖維片或聚乙烯化合物等。 發(fā)電機 發(fā)電機是把發(fā)動機產(chǎn)生的機械能轉(zhuǎn)化為電能的裝置。直流電流僅向一個方向流動,而交流電流則先向一個方向流動,繼而又向另一個方向流動。電流表一般可顯示充電過程中充入蓄電池被充入的電流量,以及在發(fā)電機不充電時從蓄電池流出的電流量。 許多充電電路用一指示燈來顯示發(fā)電機是否在給蓄電池供電。 多年來所有的汽車發(fā)電機都是直流發(fā)電機。當(dāng)硫酸放入 極板組之間,就會發(fā)生化學(xué)反應(yīng),把一塊極板中所含的電子聚結(jié)到另一極板。一塊陽極板組被一組陰極板組所包圍,隔板放在兩組極板之間形成單元。同時在發(fā)電機的轉(zhuǎn)速尚未達(dá)到可以提供 足夠的負(fù)荷時,蓄電池也向電燈、收音機和其他用電設(shè)備提供電流。散熱器芯為分離和間隔交錯的兩部分。冬季在水中須加入防凍劑?,F(xiàn)在大多數(shù)汽車發(fā)動機都采用液體冷卻系。冷卻后的水又重新進入發(fā)動機,再把發(fā)動機中的熱量傳導(dǎo)出去。在發(fā)動機運行中水被加熱,并以水循環(huán)方式把熱量從發(fā)動機中帶走。但是,殘留在發(fā)動機這的預(yù)熱仍足以使發(fā)動機手到嚴(yán)重?fù)p壞,除非用其他的方法排除這些余熱的。因此,潤滑油廠家在制第 7 頁 共 9 頁 造潤滑油的過程中,加入了許多添加劑。 5, 在活塞環(huán)和汽缸壁之間形成良好的密封。潤滑油在發(fā)動機的所有活動部件之間循環(huán)流動,其作用是: 1, 潤滑運動零件,減少磨損。飛濺上來的油形成油滴或油霧,使氣門機構(gòu)、活塞銷、汽缸壁和活塞環(huán)得到充分的潤滑。要保護這些零件就必須進行潤滑,這樣可以避免金屬零件之間的直接接觸。 (7) detergentdispersants。 (3) oxidation inhibitors。 (2) pourpoint depressants。 (6) foam inhibitor s。 the others are discussed in the follow ing pages . Battery The purpose of battery is to supply current for operation of the cranking motor and the ignition sys tem w hen the engine is being cranked for starting . It also supplies current for light , radio , and other electrical accessories at times w hen the generator is not operating fast enough to handle the electrical load . The amount of current the battery can supply is strictly limited by the “capacity” of the battery , w hich in turn depends on the amount of chemicals it contains . In making the battery , several similar plates are properly spaced and welded to a strap to form a plate group . Plates of two ty pes are used , one for the positive plate group , the other for the negative plate group . A positive plate is nested with a negative plate group , with separators placed between the plates to from an element . Separators are designed to hold the plates apart so that they do not touch , and at the same time they must be porous enough to sheets , spun glass matted into sheets , and polyvinyl chloride have been used as separators . The liquid , called the electrolyte , is made up of about 40 percent sulfuric acid and about 60 percent w ater . When sulfuric acid is placed between the plates , chemical actions take place that remov