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發(fā)動機出現(xiàn)出現(xiàn)異響的原因與排除
摘要 發(fā)動機發(fā)生故障時,時常伴隨著異常聲音出現(xiàn)。分析了幾種故障產生的原因及異響特征,并提出了排除方法,以供參考。
關鍵詞發(fā)動機 異響 原因 排除
發(fā)動機發(fā)生故障時,時常伴隨著異常的聲音出現(xiàn),發(fā)動機出現(xiàn)異響,首先要根據(jù)聲響的類別辨別是由于正常爆發(fā)聲而產生的敲擊聲,還是由于不正常運動而產生的撞擊聲,然后再根據(jù)異響特征,結合構造原理找出原因,進行排除[1-4]。現(xiàn)將幾種故障產生的原因、異響特征及其排除方法分析如下。
(1)柴油機工作粗暴引起的異響,俗稱“敲缸聲”;低速運轉時,聲音強,在距發(fā)動機十幾米遠處聽得比較真切;同時伴隨著起動困難,發(fā)動機著火后,運轉不平穩(wěn),冷卻水消耗較快。這種異響是由噴油時間太早引起的,應當重新調整供油提前角。
(2)異響有一定規(guī)律,有時敲缸,有時放炮,同時伴隨著柴油機轉速不穩(wěn)定及間斷排放黑煙等現(xiàn)象。這種不均勻的異響是由于噴油器滴漏柴油引起的,當出現(xiàn)這種現(xiàn)象時,應對噴油器進行保養(yǎng)。
(3)排氣管在排氣時伴隨著連續(xù)放炮聲,同時排黑煙,排氣管過熱,起動較困難。當?shù)退贂r,放炮聲有所減輕。這種異響是噴油時間過遲引起的,應及時調整供油提前角。
(4)發(fā)動機發(fā)出“空咚”、“空咚”的敲擊聲,在發(fā)動機低速運轉或轉速突然變化時特別明顯,同時伴有燒機油的現(xiàn)象。這種異響聲是由于活塞與氣缸壁間隙過大,當柴油機工作時增加了活塞對氣缸壁的撞擊而引起的。為了進一步證實,可在柴油機溫度正常時停車,向氣缸套內加入少許機油,待1 min后重新啟動,若響聲減弱或消失,則證明是活塞撞擊氣缸壁。這是因為加入的機油產生油膜補償了活塞裙部與氣缸之間的間隙,但待加入的機油耗盡時撞擊聲又出現(xiàn),消除的辦法是換氣缸套或活塞。
(5)在氣缸體全長部位都能聽到似小錘輕輕敲擊鐵砧的“當當”響聲,當發(fā)動機轉速突然變化時聲響更明顯。這是因為活塞環(huán)側間隙太大引起的,應更換活塞環(huán),必要時活塞環(huán)一起更換。
(6)氣缸罩蓋周圍發(fā)出“咯嗒”、“咯嗒”的敲擊聲,熱機時聲音小,冷機時聲音大,低速停止供油時聲音不消失。主要原因是因為氣門間隙太大,造成氣門桿頭與搖臂撞擊,應調整氣門間隙。
(7)發(fā)動機工作時,在其氣缸體中部可聽到沉重的敲擊聲,工作時響聲更大,同時有機油門壓力下降的現(xiàn)象。這種響聲是由于主軸承間隙過大而引起的,應及時修理曲軸主軸頸或更換主軸瓦。
(8)在發(fā)動機轉速突然變化或負荷加大時,在氣缸蓋處可聽到“嘶嘶”異響聲,伴隨有起動困難,功率降低,有時會燒壞噴油咀,這是因為噴油器安裝孔處漏氣,漏氣的原因有未裝噴油器密封墊圈或墊圈損壞、安裝孔內的平面不平、噴油器的壓板螺栓未上緊或扭力不均勻、噴油器的壓板裝反等,使噴油器不能壓緊。
(9)定時齒輪室響,在定時齒輪室處可聽到齒輪撞擊聲,改變柴油機轉速時,聲音更明顯。主要原因是齒輪軸套等零件磨損嚴重,使齒輪的齒側間隙變大,應更換磨損嚴重的齒輪和軸套。 轉貼于 中國論文下載中心 http://www.studa.net
(10)在氣門室罩處能聽到“嚓嚓”聲,或發(fā)出2根彈簧撞擊聲,同時柴油機間斷爆發(fā),工作不穩(wěn)定。這是氣門彈簧折斷所致,應停車檢查,以免鎖夾脫落,氣門掉入氣缸,搗壞活塞及氣缸蓋。
(11)當齒輪磨損后,嚙合間隙過大時柴油機工作起來會發(fā)出“咯拉”、“咯拉”的噪音,停車時,晃動曲軸,也會聽到齒輪相撞的聲音。應用鉛片測量其齒側間隙,超過規(guī)定尺寸應更換,如齒輪有剝落、缺損現(xiàn)象也應更換。某一個齒輪的襯套與軸配合松曠或齒輪軸軸承磨損過甚,也會發(fā)出很大噪音,如果因裝有齒輪的某兩根軸軸線不平行,使兩軸上的齒輪嚙合不正常,則發(fā)出“嘶啦,嘶啦”聲音,應修復或更換有關零件。如有的齒輪因軸向間隙大,發(fā)生軸向竄動,會發(fā)出間歇性敲擊聲,應恢復標準間隙。
(12)柴油機工作時發(fā)出沉重有力的“咯咯”聲。大小油門均有,改變油門時尤甚。主要原因:一是飛輪螺母松動,應擰緊螺母并鎖定;二是飛輪鍵槽與曲軸平衡配合松動;三是曲軸軸頸錐面與軸孔錐面損傷,應修復之。柴油機震動厲害,并發(fā)出“空空”聲。主要原因是:一是平衡軸定時齒輪裝錯,應按要求重裝;二是兩平衡軸重量不匹配(S195),應重新選配平衡軸;三是平衡軸承損壞,應更換損壞的軸承。
聽診異響的難度較大,能否正確判斷異響聲源,主要與聽診者的實際經驗及聽覺靈敏有關,各種異響很難用文字確切描述,要靠機手平時多鍛煉,不斷積累經驗,特別是對機車的正常運轉聲音要極為熟悉,以便出現(xiàn)異響時能立即識別。當異響嚴重時不要在運轉較長時間后進行聽診,應立刻停機,在靜態(tài)下仔細檢查分析;另外,當發(fā)動機突然出現(xiàn)破壞性異響時,必須立即熄火檢查,以免造成重大事故。
The engine and eliminate the causes abnormal sound occurs
Summary of engine failure, often accompanied with the abnormal sound appears. Analysis of several causes for the failure and abnormal sound characteristics, and proposed exclusion method for reference.
Keywords engine abnormal sound reason excluded
Engine failure, often accompanied with the exception of the voices, the engine appeared abnormal sound, first of all to distinguish according to the type of sound is due to the outbreak of the normal percussion sound generated, or the abnormal movement resulting crash, and then According to abnormal sound characteristics, combined with structural principles determine the cause, the exclusion [1-4]. Now several causes for the failure, abnormal sound analysis of characteristics of excluded methods as follows.
(1) diesel crude caused by abnormal sound, called "Knocking sound"; at low speed, sound strong, ten meters away from the engine hear the real comparison; accompanied difficult start, the engine caught fire, the operation is not smooth cooling water consumption faster. The abnormal sound is caused by the injection time is too early, should be re-adjust the fuel supply advance angle.
(2) abnormal sound a certain regularity, and sometimes knock, sometimes shooting, accompanied by intermittent emissions of diesel engine speed instability, and smoke and so on. This is due to uneven abnormal sound caused by diesel fuel injector leakage, when this phenomenon, the response to the injector maintenance.
(3) when the exhaust pipe in the exhaust along with the continuous discharge of guns, the same row of black smoke, exhaust heat, starting more difficult. When the low speed, put the guns have reduced. The abnormal sound is caused by injection too late, should adjust the fuel supply advance angle.
(4) The engine is "empty boom", "empty boom" of the percussion sound, the engine speed low speed or a sudden change is particularly evident when, accompanied by the phenomenon of burning oil. This difference is due to the sound of the piston and cylinder wall clearance is too large, when the diesel engine when the piston of the cylinder wall to increase the impact caused. To further confirm that the temperature in the normal diesel engine stop cylinder kit to add a little oil, until 1 min after the restart, if the noise reduced or lost, then the proof is the piston hit the cylinder walls. This is because the added compensation for oil produced film cylinder piston skirt and the gap between, but to be depleted by adding the oil crash appeared to eliminate the way is breath cylinder or piston.
(5) full part in the cylinder block can be heard like the anvil hammer lightly tap the "Dangdang" sound, when a sudden change in engine speed is more obvious when the noise. This is because the piston side of the gap caused by too much, replace the piston rings, piston rings with the necessary replacement.
(6) cylinder covers around the issue "slightly despair", "slightly despair," the percussion sound, the sound of small heat machine, cold machine loud, low-speed stop oil supply when the sound does not disappear. Mainly due to valve clearance is too large, causing the valve head and arm impact, should adjust valve clearance.
(7) engine, in the middle of the cylinder block can hear the sound of heavy percussion, the sound of a larger work, while the phenomenon of organic throttle pressure drop. This noise is due to the main bearings caused by the gap is too large, it is timely repair or replacement of the main crankshaft main journal bearing.
(8) The sudden change in engine speed or load increase, in the cylinder head can be heard at the "hissing" sound different, with a difficult start, power down, sometimes burn fuel injection nozzle, because the injector Installation hole leakage, due to a leak injector gasket is not installed or the washer is damaged, uneven surface hole installation, injector plate bolt tightening or torque is not uniform, anti-loaded injector plate , so that the injector can not be compressed.
(9) timing gear room sound, timing gears in the gear room at the crash can be heard, change the engine speed, the sound is more pronounced. Mainly due to severe wear and tear parts such as gear sleeve, so that gear backlash larger, should be replaced badly worn gears and bushings. Links in the paper for download http://www.studa.net
(10) in the valve chamber cover at hear "Cha Cha" sound, or the issue of two spring crash, while diesel intermittent outbreak of job insecurity. This is due to broken valve spring, should stop checks, so as not to clip off the lock, fall into the cylinder valve, piston and cylinder head disturbed.
(11) when the gear wear, the engagement gap is too large it will be issued when the diesel engine, "slightly pull", "slightly pull" of the noise, stop, shake crankshaft gear will hear the voice of the collision. Application of lead sheet to measure the backlash, more than the required size should be replaced, such as gears are falling off, the defect of the phenomenon should be replaced. One bush and the shaft with the gear or gear shaft bearing wear Songkuang been very, loud noise will be, if the result of a two-axis with the axis of gear are not parallel, so that the two axes of the gear mesh is not normal, then issued a "hiss you, cries of friends" sound, should repair or replacement of the parts. If the gear due to the axial gap, axial movement occurs, will be issued intermittent percussion, should restore the standard gap.
(12) issued when heavy diesel engine powerful "giggle" sound. Both the size of the throttle, particularly when changing the throttle. Main reasons: First, loose wheel nuts, and lock nut should be tightened; Second, balance the flywheel and crankshaft keyway with the loose; third crankshaft cone and the shaft hole cone damage, should fix it. Powerful engine vibration, and issued "empty" sound. Main reasons are: First balance shaft timing gears installed wrong, should be required to reinstall; Second, the weight of the two balance shafts do not match (S195), should be re-matching balance shaft; third balance bearing damage, replace the damaged bearings.
Abnormal sound auscultation difficult, can correctly judge the different noise sources, mainly with the practical experience of auscultation and Tingjuelingmin related to a variety of abnormal sound is difficult to describe in words exactly, to rely more than usual exercise machine hand, the accumulation of experience , in particular, the normal operation of the locomotive to be very familiar sound to immediately recognize when there abnormal sound. When the abnormal sound serious, do not run after a long time auscultation, should be immediately shut down, check carefully in the static analysis; In addition, the sudden appearance of destructive abnormal sound when the engine when the flame must be checked immediately to avoid a major accident.
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