1.1 nvh overview nvh 概論,ford motor company vehicle attributes engineering 福特汽車公司整車設(shè)計部門,vehicle nvh awareness,j.juan/m.haffey,1,what is nvh? 什么是nvh呢？,noise-what the customer hears 噪聲- 指的是顧客所能聽到的聲音 sound mainly in the 20hz10000hz frequency range. 聲音的頻率大體上在20赫茲到10000赫茲之間。 characterized by frequency,level and quality. 通過頻率、級別和音質(zhì)來描述。 vibration-what the customer fells and sees. 振動-指的是顧客所感覺到的和看到的。 motion sensed by the body mainly in the 0.5hz50hz frequency range. 身體所能感知運動的頻率范圍通常在0.5赫茲到50赫茲之間。 characterized by frequency,level and direction. 通過頻率、振幅和方向來描述。 harshness-combined effects of noise and vibration 不舒適性-指的是噪聲和振動的綜合影響。 rough,grating or discordant sensations. 粗野的，刺耳的或不和諧的感覺。,vehicle nvh awareness,1.1 nvh overview,2,nvh must fulfill legal requirements. nvh必須滿足法定的要求。 nvh should provide the acoustical/tactile feedback for safe and confident driving. nvh應(yīng)該使乘員在駕駛方面有安全和自信的感覺。 link to operating conditions. 在各種操作環(huán)境。 connection to earth. 在各種路面。 nvh should avoid any negative perception. nvh應(yīng)該避免任何不好的感覺。 unpleasant ,unrefined ,unexpected ,and annoying events. 令人不愉快的，粗俗的，意料之外的和令人討厭的事情。 nvh can exceed customer expectations. nvh應(yīng)該能超過顧客的期望值。,vehicle nvh awareness,1.1 nvh overview,3,nvh link to customer satisfaction nvh反映了消費者滿意的程度,tgrpress review(examples) tgr媒體評論（例如） “fiesta has a surprisingly quiet & well refined engine” “ fiesta有一臺令人驚訝的安靜而且舒適的發(fā)動機(jī)” “f150 ride is smooth quiet with the 4.6 l” “f150乘坐舒適安靜的4.6升發(fā)動機(jī)汽車” tgrthings gone wrong 20%30% of tgw is nvh related. tgr所抱怨的事情 20%30%抱怨的產(chǎn)生都是與nvh有關(guān)系的。,vehicle nvh awareness,1.1 nvh overview,4,vehicle nvh awareness,1.1 nvh overview,5,nvh links to company profit nvh關(guān)系著公司的利益,1529% of warranty cost has noise as a condition code. 1529%的保修的費用是花費在與噪聲有關(guān)的。 1994 model year,36mis,warranty cost associated with all noise was $346 million 18% of total warranty. 94年型車，3年的在用車，在噪聲方面的保修費用 是3.46億美元占總費用的18%。,vehicle nvh awareness,1.1 nvh overview,6,nvh links to company profit nvh關(guān)系著公司的利益,nvh prototype cost reduction opportunity. combined cost breakdown prototype cost contribution 綜合成本明細(xì) 樣機(jī)花費的組成 (tase+safety+nvh) （tase+安全設(shè)備+nvh）,total cost=$303m (base on tase,safety,nvh cost of attribute studies 總支出=3.03億美元 （基于tase，安全，nvh的研究費用）,vehicle nvh awareness,1.1 nvh overview,7,sound generation mechanism 產(chǎn)生噪聲的原理,multiple mechanisms generate a variability of vehicle sound. 汽車所產(chǎn)生噪聲的原理是多種多樣的。 combustion airflow,pumping 燃燒 氣流，進(jìn)排氣 impacts between components airflow,turbulences 零件之間的撞擊 氣流，(液體或氣體的)紊亂 friction contact of components surface roughness 構(gòu)件之間的摩擦 粗糙的表面 rotating parts unbalance masses 旋轉(zhuǎn)的部件 不平衡塊 flow in pipes tire force variation 在管中的流動 輪胎壓力的變化,vehicle nvh awareness,1.1 nvh overview,8,vehicle sounds 汽車的噪聲,combustion noise wind noise gear rattle bearing knock 燃燒的噪聲 風(fēng)的噪聲 齒輪傳動的聲音 軸承的敲擊聲 diesel knocking sunroof noise gear whine electric windows 柴油機(jī)的敲擊聲 遮陽頂棚的噪聲 齒輪的聲音 電動窗的噪聲 valve train door slam gear lever tizz tire noise 氣閥機(jī)構(gòu)的噪聲 門的砰的聲音 變速桿換檔的噪聲 輪胎的噪聲 fead noise central locking driveline clonk exhaust noise fead噪聲 中央門鎖的噪聲 動力傳動系統(tǒng)的噪聲 排氣噪聲 pas noise switch noise driveline thrash squeaks and rattles 動力轉(zhuǎn)向系統(tǒng)的聲音 開關(guān)的噪聲 動力傳動系統(tǒng)的噪聲 吱吱聲和喀嚓聲 fuel pump noise indicator ticking road noise water splash noise 燃油泵的噪聲 指示器的滴答聲 道路的噪聲 水濺的噪聲 alternator whine windscreen wipe noise impact harshness intake noise 交流發(fā)電機(jī)的噪聲 擋風(fēng)玻璃的噪聲 撞擊振動聲 通風(fēng)口的噪聲,vehicle nvh awareness,1.1 nvh overview,9,nvh phenomena nvh現(xiàn)象,operating condition 操作環(huán)境,description 描述,source 資源,pass-by deceleration cruise acceleration idle staring,boom rumble growl whine rattle squeal hiss,engine transmission exhaust/intake road wind tire,vehicle nvh awareness,1.1 nvh overview,10,vehicle noise examples 汽車的噪聲舉例,wind noise(80 mph hst)-1/12th octave spectrum. 風(fēng)的噪聲（80英里每小時的高速試驗）1/12倍頻程,分貝,頻率,vehicle nvh awareness,1.1 nvh overview,11,vehicle noise examples 汽車噪聲舉例,road noise(40mph rough rd.)-narrow spectrum. 道路噪聲（40英里每小時在粗糙路面之上）-窄頻。,vehicle nvh awareness,1.1 nvh overview,12,vehicle noise examples 汽車噪聲舉例,power noise(wot)-loudness&speech intelligibility. 動力系統(tǒng)噪聲（wot）-響度以及說話的清晰度,vehicle nvh awareness,1.1 nvh overview,13,subjective impression 主觀感受,created by the brain based on: 建立在頭腦感覺的基礎(chǔ)之上： database,data analysis “this sounds like an engine” 資料庫，數(shù)據(jù)分析 “這種噪聲如同一臺發(fā)動機(jī)” experience “i have head a variety of engines” 經(jīng)驗 “我聽到了發(fā)動機(jī)的聲音” bias “has never built good engines” 偏見 “從來沒有生產(chǎn)過好的發(fā)動機(jī)” company uses vers to produce consistent ratings. 公司用定額指標(biāo)的方法生產(chǎn)產(chǎn)品。,vehicle nvh awareness,1.1 nvh overview,14,subjective/objective correlation 主觀與客觀的相互關(guān)系,objective measure is required for target setting/cascading. 客觀的方法需要滿足目標(biāo)的設(shè)置和層次。,vehicle nvh awareness,1.1 nvh overview,15,road nvh target cascade 道路nvh目標(biāo)層次,road nvh(1),body acoustic & vibration sensitivities(4),airborne noise(3),structure borne nvh(2),suspension force input in body(5),point mobiles(8),body modes(9),body structure(10),panel damping & noise isolation(11),seat vibration transmissibility(12),seat modes(13),sleeping column vib sensitivity (14),power train modes(15),body/frame/sub frame force transmissibility(16),suspension force transmissibility(19),body/frame/sub frame mounts(17),frame/sub frame modes(18),suspension mounts(20),suspension friction/sticktion(21),shock damping(22),suspension geometry(23),road/tire contact force(26),tire properties(27),tire pressure(28),tire size/aspect ratio(29),tire modes(30),wheel modes(31),strut modes(30),imbalance force(32),sound package noise reduction(6),tire radiated noise(7),barrier transmission loss(33),absorption(42),carpet(43),seat material(44),headliner(45),wheelhouse(38),floor(39),side panel(40),glass(41),lockage (34),area of holes (pass-through) (35),wheel modes(36),vehicle nvh awareness,1.1 nvh overview,16,road nvh design guidelines 道路nvh設(shè)計指導(dǎo),reduce body noise transfer functions(5:1). 增加車身附件剛性/襯套剛性比(5:1)。 assure good modal separation. 保證好的模態(tài)分離。 -separate major body modes and acoustic cavities. 分離主要的車體模態(tài)和有聲音的。 -separate body modes from suspension modes. 分離車體模式中的懸掛部分。 -separate wheel modes from tire modes. 把車輪和車胎分離開來。 reduce tire/wheel unbalance and tire radiated noise. 減少車胎/輪不平衡性和車胎的輻射噪聲。,vehicle nvh awareness,1.1 nvh overview,17,vehicle attributes compatibility 車輛的兼容特性,vehicle nvh awareness,1.1 nvh overview,18,course expected outcomes 課程預(yù)期的結(jié)果,understanding and appreciation of each major systems influence on nvh. 理解和正確評價各個主要系統(tǒng)對nvh的影響。 understanding of design concept and guidelines for nvh and their trade- offs with other vehicle attributes. 理解nvh的設(shè)計觀念和指導(dǎo)方法以及其和車輛其它屬性的協(xié)調(diào)。 understanding of engineering best practices and appropriate nvh t