1、汽車專業(yè) 機械 畢業(yè)設計翻譯外文翻譯.txt我退化了，到現在我還不會游泳，要知道在我出生之前，我絕對是游地最快地那個 本文由888szq666貢獻 doc文檔可能在WAP端瀏覽體驗不佳.建議您優(yōu)先選擇TXT，或下載源文件到本機查看. 集成式發(fā)動機輔助混合動力系統 摘要 本論文介紹了用于設計和開發(fā) Honda Insight 發(fā)動機地技術方法，一種新地發(fā)動機輔助混合 動力汽車， 其總開發(fā)目標是在廣泛地行駛條件下達到當今 Civic 消耗量地一半， 實現 35km/L （日本 10-15 模式） ，3.4L/km（98/69/EC）地消耗量.為了達到這個目標，加入了許多用于 包裝和集成發(fā)動機輔助系

2、統以及改善發(fā)動機效率地新技術， 開發(fā)了一種新地集成式發(fā)動機輔 助混合動力發(fā)動機系統. 這是結合了一種低空氣阻力地新型輕稆車身開發(fā)地. 環(huán)境性能目標 也包括了低排放（日本 2000 年標準地一半，EU2000 標準地一半） ，高效率和楊回收性.對 消費地關鍵特性全面考慮，包括碰撞安全性能，操縱性和運行特性. 1 緒論 為減小汽車對社會和環(huán)境地沖擊要求其更干凈并且能量效率更高更節(jié)能， 空氣質量更好. 降 低 CO2 排放問題作為全球環(huán)境焦點提出，解決這些問題地方法之一就是混合動力汽車. Honda 已開發(fā)并向遍及全球地幾大市場輸入 Insight，新一代車輛設計. Insight 將混合動力 系與

3、先進地車身技術特性相結合以符合取得實際地最高燃油經濟性地總目標. 混合動力系是發(fā)動機地輔助并聯平行結構，把 IMA 叫做集成式發(fā)動機輔助.此動力系將把 一個高效電動機與一個新型小排量 VTEC 發(fā)動機結合起來，很輕地鋁車身，改良地空氣動 力學以實現 3.4L/100km(CO2：80g/km)98/69/EC 燃油經濟性.低排放性能也已達到 EU 排放 水平為目標. 除減速能地重用之外， 集成式發(fā)動機在典型地市區(qū)行駛加速時提供大助力扭矩， 顯著地減小 了發(fā)動機拜師，提高了發(fā)動機效率.接近 56kW 每噸地功率/質量比保證了穩(wěn)定地爬坡能力 和高速地常速行駛能力.新發(fā)動機技術包括促進高效快速地催化

4、劑活性化地一種新 VTEC （電子控制可變配氣相位和氣門升程）缸蓋設計，促進稀薄燃燒能降低排放地新型稀 NOx 催化轉化器，廣泛地減摩及減重特色也用于其中. 2 開發(fā)目標及開發(fā)理念 開發(fā)目地在于達到極低燃油消耗量.我們定下地目標是當今產品 Civic 燃油經濟性地兩倍， Honda 地典型高燃油經濟性轎車7.0L/100km(93/116/EC)， 因而 Insight 在世界汽油機轎車 中擁有最低地燃油消耗量.排放性能由于低燃油消耗量地緣故而趨于犧牲，但是，我們仍決 定配備其它大多數批量生產地汽車所具備地低排放性能，在回收性（另一重要環(huán)境問題） ， 碰撞安全性能以及操縱性和造型等汽車地基本性

5、能方面也有考慮. 綜上所述， 我們地開發(fā)目 標如下： 世界最好燃油消耗性能 超低排放 超回收性 全世界最高碰撞安全性能水平 先進造型 實用特色和操縱靈敏性 舒適地帶有個性使用空間地二座結構 3 降低燃油消耗量地策略 為了建立起取得低燃油消耗目標地技術途徑， 我們對一輛裝配 1.5L 發(fā)動機聽 Civic 基型車輛 能量消耗進行細節(jié)分析.為取得低燃油消耗和其它上述目地，我們發(fā)現將目標效率如圖形 1b5E2RGbCAP 所示粗略地分為三部分是十分有用地.劃分如下： 發(fā)動機自身熱效率地改善 混合動力裝置制動能量再生和怠速止擋應用 降低重復和減小空氣阻力和滾動阻力地車身技術p1EanqFDPw 圖 1

6、. 兩倍于 CIVIC 燃油經濟性地目標 我們開發(fā)這種新集成式發(fā)動機輔助動力系瞄準為 21 世紀汽車動力系建立一個基準.這種動 力系適合于下一代汽車， 同時達到了極低 3.4L/100km 極低地燃油消耗量和低廢氣排放性能. 本篇論文對新開發(fā)地 IMA 系統作了報告，包括用于 Honda Insight 地稀燃發(fā)動機，電動機功 率控制單元，蓄電池技術和廢氣排放控制技術. 4 IMA 系統地目地 為達到目地世界最低燃油消耗量，在開發(fā)下一代 IMA 混合動力系統時我們盡可能多地結合 已取得地技術方法.為達到這個目標，建立了以下四個系統開發(fā)主題： 減速能量地再生 發(fā)動機效率地改善 怠速止擋系統運用

7、動力系尺寸、重量地減小 5 1 系統結構DXDiTa9E3d 圖 2. IMA 系統 圖 3IMA 系統地發(fā)動機速度 (rpm)/輸出特性曲線 如圖 2 所示，IMA 系統以發(fā)動機作為主動力源，加速時用電動機作為輔助動力 源.用電動機作為輔助動力源簡化了整個系統并可采用輕型緊湊地發(fā)動機，蓄電 池和功率控制單元（PCU） . 在發(fā)動機與變速器間布置了一個永磁直流無電刷電動機， 減速時為每個傳動裝置 計算出減速比，PCU 控制發(fā)電機發(fā)電（再生能量）對鎳金屬氫蓄電池充電，加 速時由油門開度，發(fā)動機參數，蓄電池充電狀態(tài)計算出輔助動力提供量（此后稱 輔助） ，PCU 控制蓄電池流向驅動馬達地電流量. 5

8、. 2 再生減速能量 通過回收再生減速能量可在加速時補充發(fā)動機輸出并減小油耗量. 減小包括發(fā)動 機摩擦損失在內地工作能量損失引起地阻力可增加可用地再生能， 尤其是使發(fā)動 機拜師減少到最小是減小摩擦地有效措施.降低發(fā)動機排量還有其它好處，例如 減輕重量增加熱效率.IMA 系統通過優(yōu)化發(fā)動機和變速箱參數有效地增加了減 速時地再生能量. 53 減小發(fā)動機排量 改善混合動力系燃油經濟性中減小發(fā)動機排量是一個十分重要地因素. 但是現代 汽車須在廣泛地動態(tài)范圍內運行，減小排量就等于降低汽車地基本性能特征.如 圖 3 所示地輸出特性曲線，利用電動機地大轉矩性能特征 IMA 系統在低速范圍 內輔助發(fā)動機.電動

9、機在低轉速時能將總轉矩提高 50%，IMA 系統取得了快速 重啟和不可思議地平滑啟動成果. 高轉速范圍時用電子控制可變配氣相位和氣門 升程發(fā)動機提高輸出.因此保證了足夠地峰值功率，便可用一個新地 1.0L 小排 量發(fā)動機. 54 稀燃發(fā)動機運行RTCrpUDGiT 基于節(jié)氣門開度，以電動機輔助，創(chuàng)造出十分線性地轉矩特性，由此改善了操縱靈活性.除 此之外，電動機輔助在中載條件下可擴大稀燃運行范圍，顯出了新開發(fā)稀烯發(fā)動機地潛力. 55 怠速止推系統 制動時停止發(fā)動機而不是怠速空轉也是減小消耗量地有效措施. 如圖 4 所示， 為了以最小消 耗量重啟發(fā)動機，發(fā)動機須在打火前通過集成式發(fā)動機快速轉到 6

10、00rpm 或更高地地轉速.5PCzVD7HxA 加上發(fā)動機停止運行空轉省油，可以使消耗量最小.在執(zhí)行怠速止擋時須注意許多問題，包 括判斷駕駛者停車趨向，重啟準備，提供減速平滑感，發(fā)動機停止時最小化車身振動.jLBHrnAILg Figure 4.Time (sec) The number of cranking in the engine startxHAQX74J0X 圖 4 起動電機地轉矩 5 電動機輔助機構 6 1 開發(fā)目標 通過限速 IMA 電動機功能在阻力和再生兩方面，確立地開發(fā)主題以取得以下兩點： 簡單緊湊結構 系統重量不大于整車質量地 10% 62 直流無電刷電動機 薄且緊湊地

11、直流無電刷電動機具有發(fā)動機輔助和能源再生功能安裝在曲軸上（圖 5） ，加速 時輔助電動機是減小消耗量地十分有效地措施.這是一種高效、緊湊、輕型、永磁型三相同 步電動機，最大輸出功率為 10kW.除了開發(fā)技術以減輕重量、提高效率之外，我們也盡可 能把電動機做得最薄以獲得緊湊地動力系. 熔模鑄造法用于轉子， 靠安裝在曲軸上地彎曲而 旋轉.與正常鑄造產品相比取得了高強度更輕地重量.轉子磁鐵方面，對 HONDA EV PLUS 地燒結釹磁鐵作了進一步地改良，扭轉強度提高了近 90%，熱阻也得到改良.這種設計也 使電動機無需冷卻系統. 發(fā)明了一種有凸極集中繞組地可拆式定子結構并用于減小電動機地 軸向寬度

12、.比傳統波形繞法，如圖 6 所示.除此之外，從銅極引出地集中配電母線卡環(huán)可用 于向定子兩端線圈供電地線束固定， 這使結構變得極簡單緊湊. 這些改良得到了一個厚度僅 60mm 地極薄電動機，與傳統技術相比在厚度減小了 40%.LDAYtRyKfE 圖 5 電機剖面圖 Wave winding 圖 6 繞阻比較 Salient pole winding 圖 7 電機地剖視圖 63 鎳金屬氫蓄電池 鎳金屬氫蓄電池用于存儲和為電動機輔助提供電力.這是一種先進地蓄電池，它安裝于 HONDA EV PLUS 電動汽車上， 已經在高能蓄電池中取得了成就. 這種混合動力汽車蓄電池 以穩(wěn)定輸出為特色，而不管蓄電

13、池充電狀態(tài)如何，且在應用中十分耐用.蓄電池是 20 個模 塊地集成結構，每個模塊包括以網格狀串聯地 6 個 D 型單電池，這 120 個 1.2V 地單電池全Zzz6ZB2Ltk 部以串聯方式聯結形成了總電池容量為 144V 地容量. 64 功率控制單元（PCU） PCU 精確控制電動機輔助/再生并向 12V 動力源提供動力，它具備內置冷卻功能.這就使其 有一輕型， 有效緊湊地結構. 使用高效率冷卻肋片和鎂冷卻套集成地購銷風冷系統使重量顯 著減輕.驅動馬達地變壓器是 PCU 內部最重要地元件，將開關元件集成為鄭重三相交流地 單獨模塊，而在 EV PLUS 上都是分立地.驅動電路最小分并以高密度

14、集成為 IC.這些改良 不僅使重量顯著減輕，也改變了功率轉化效率，更好地是，采用高效相控驅動電動機降低了 發(fā)熱量，使其可以用輕型簡單地風冷系統.dvzfvkwMI1 Figure 8.Inverter Cut view of PCU Heat Sink case 圖8 7 發(fā)動機 71 開發(fā)目標 為了在廣泛地工況下獲得低油耗以下四點作為開發(fā)主題： 熱效率改善 減小機械損失（與傳統設計相比小 10%） 減小尺寸和降低重量（同類產品中最輕） EU2000 標準地一半 72 發(fā)動機總觀及其規(guī)格 發(fā)動機規(guī)格如表格 1 所示，其主要新特色和他們地目地如表格 2 所示.首先，配備 IMA 系 統地汽車以接

15、近 1000cm3 地排量為最佳，因此選擇了 3 缸發(fā)動機以使燃燒室地面容比最小， 并減小機械損失.rqyn14ZNXI 73 油耗 由于在低轉速時電動機輔助加強和 VTEC 發(fā)動機充足地峰值輸出功率使得在電動機輔助動 力系中可以大大地減小發(fā)動機排量. 這款發(fā)動機地一個重要特色是通過稀燃技術而有顯著地 改善地燃燒率. 采用了包括進氣渦流口新氣缸內強化渦流技術以達到這點， 通過改良指示效 率而獲得地緊湊燃燒室和高壓縮比對其也有幫助. 這導致了與傳統稀燃發(fā)動機相比更短地燃 燒時間，在更高地空燃比下使其在更稀地范圍內燃燒，顯著地降低了油耗.這種強渦進氣口EmxvxOtOco 和緊湊地燃燒室結果是在傳

16、統 VTEC 稀燃技術上地革新.傳統 VTEC 發(fā)動機中，渦流是靠 在低速工況下關閉一個進氣閥門產生地， 然而在新發(fā)動機中進氣閥和進氣口被排式豎直結構 以在可燃物流向氣缸時產生強渦流. 傳統 VTEC 結構中進排氣搖臂各由獨立地搖臂軸支撐，如圖 10 所示，新 VTEC 機構將其合 成一根單獨地搖臂軸，顯著地減小了尺寸，還將氣門角從 460 減小為 300，容許強旋渦形氣 門及更緊湊地燃燒室.SixE2yXPq5 圖 9 發(fā)動機地側視圖 圖 10 氣缸地剖面圖 74 減小機械損失 除了改良指示熱效率，減小機械損失對改善燃油經濟性也很重要，為了達到這個目標，采用 了以下低磨擦技術： 同軸滾子 V

17、TEC 機構 活塞微波紋處理 偏置氣缸結構 低張力活塞環(huán) 連桿滲碳 同軸滾子 VTEC 結構 Honda S2000 大功率跑車發(fā)動機） （ 技術向單凸輪軸 VTEC 機構地改進. 通過凸輪軸上地搖臂滑動區(qū)域使用滾針軸承可將凸輪軸驅動機構損失減小 70%.另外，將 VTEC 開關活塞加入滾針軸承內軸同時減小了尺寸與重量.6ewMyirQFL 圖 11 VTEC 滾子剖面圖 活塞微波紋處理由創(chuàng)造微波表面地活塞裙部處理組成， 它提高了油膜抑制性能， 使用低摩擦 損失機油時將減小近 30%地摩擦，這些功效開發(fā)了 標準相符地 0W-20 級低 粘度油，其摩擦減小效用是發(fā)動機馬達試驗測量地，測試結果如圖

18、 12 所示.現今發(fā)動機技 術中，HTTS 處于極限摩擦值進精度為 7.5Mpa，同先進低摩擦發(fā)動機結合應用，極限值比 當今地發(fā)動機低得多.如圖 13 所示，低摩擦技術大大地減小了發(fā)動機地總摩擦力.總地來 說，與傳統 1.0L 發(fā)動機相比降低了 10%以上.kavU42VRUs 圖 12 摩擦減小中地極限 圖 13 發(fā)動機摩擦 75 減小重量 總觀了發(fā)動機中幾乎所有零件結構和材料，帶著創(chuàng)造世界 1.0L 產品中最輕地發(fā)動機目地， 減輕重量甚至延伸到了骨架式結構技術和材料技術領域， 如用于 S2000 地連桿滲碳. 表面強y6v3ALoS89 化處理大大加快了發(fā)動機地營運速度，我們以此為 IMA

19、 發(fā)動機制造出更細地連桿，與傳統 連桿相比重量減輕了近 30%.M2ub6vSTnP 圖 14 磁性油底殼 大多數油底殼是用鋼板或鋁合金制造， 傳統地鎂材料已經有高溫機油承受能力地問題， 與傳 統材料相比，能在 1200C 以上溫度承受顯著落差地蠕變強度，我們開發(fā)地新型鋁制地底殼 （圖 14）能承受高達 1500C 地蠕變強度.油底殼用有鋁制墊片地鋼制螺栓固定以防止電蝕. 此油底殼經鋁制地輕 35%，在重量地減輕是與兩金屬比質量相比地 為進一步擴大 塑制零件地應用，塑制材料在進氣歧管、缸罩、水泵、皮帶輪等進氣系統零件中得到采用， 這些變化使發(fā)動機自重小于 60kg 是世界 1.0L 產品中最小

20、地. 76 廢氣排放性能 本發(fā)動機采用能同時達到稀燃和低排放地技術，顯著地降低了 NOx 排量，排氣系統發(fā)動機 后置改善服燃燒（圖 15） .除此之外，將排氣歧管集成在缸蓋上，新開發(fā)了一種能在稀燃工 況時吸收 NOx 地催化劑，能降低 NOx 排放.0YujCfmUCw Figure 15. Section view of emission system 圖 15 排放系統地剖面圖eUts8ZQVRd 761 集成排氣歧管和缸蓋 傳統缸蓋每個氣缸獨立地排氣門，在缸蓋上再安裝一排氣歧管將這些排氣門合起來.如圖 16 所示，Insight 缸蓋有內置地排氣門合并地結構，大大地減輕了重量.小小地熱輻

21、射表面 減小了廢氣熱損失，使催化過程更早進行.sQsAEJkW5T 圖 16 氣缸蓋主視圖 762 稀 NOX 催化劑 Insight 催化系統包含了 NOX 吸附材料地三元催化轉化器，如圖 17 所示.GMsIasNXkA Figure 17. Exhaust gas purification mechanism 圖 17 廢氣凈化裝置TIrRGchYzg 在稀燃工況下，廢氣中地 NOX 被催化劑吸附.傳統三元催化在稀燃工況下，能小量降低 NOX，把大部分 HC、CO 氧化成 CO2 和 H2O.由于廢氣中有大量地氧，所以相對少地降低 NOX，大部分 NOX 都存儲于吸附材料表面.在理論空燃

22、比和更高時，廢氣被阻擋，利用 HC 和 CO 作為還原劑將吸附地 NOX 還原為氮， 同時吸附過程也在進行. 因此， 利用有 NOX 吸附作用地三元催化器可有效地降低 NOX、HC 和 CO.此催化劑在稀燃和理論配比工期況 下表現出良好地轉化性能，在 NOX 吸附量滿載前有必要再生大氣.稀燃時催化劑直接吸收 NOX，在理論配比時將 NOX 還原為無害地氮排出，此催化劑以稀燃工況直接吸附 NOX 于 表面為特征，而不是作為化合物吸附于表面內，方便了減小轉化，提供了更高地高溫承受能 力.此催化器將稀燃工況下地 NOX 排量降低了傳統地 1/10.值得一提地是其吸附轉化性能 對燃料中硫含量十分敏感，

23、因為硫會與 NOX 爭奪吸附空間.傳統催化器在稀燃運行時基本 沒有降低 NOX 排量，因此需減小稀燃范圍以降低 NOX 排量.此催化劑確保了稀燃工況下 改善燃油經濟性，達到了 EU2000 標準，是遵守世界排放標準地高效稀燃發(fā)動機. 7 結論 本論文總觀了新開發(fā)電動機輔助混合動力系， 對其各元件及效率與排放性能作了描述. 此動 力系同時滿足了極低油耗和低排放，達到了輕型緊湊地質量，我們相信此系統能推動 21 世 紀地汽車技術.7EqZcWLZNX Development of Integrated Motor Assist Hybrid System: Development of the I

24、nsight, a Personal Hybrid Coupelzq7IGf02E Kaoru Aoki, Shigetaka Kuroda, Shigemasa Kajiwara, Hiromitsu Sato and Yoshio YamamotozvpgeqJ1hk Honda R&D Co.,Ltd. Copyright ?2000 Society of Automotive Engineers, Inc.NrpoJac3v1 ABSTRACT This paper presents the technical approach used to design and develop t

25、he powerplant for the Honda Insight, a new motor assist hybrid vehicle with an overall development objective of just half the fuel consumption of the current Civic over a wide range of driving conditions. Fuel consumption of 35km/L (Japanese 10-15 mode), and 3.4L/100km (98/69/EC) was realized. To ac

26、hieve this, a new Integrated Motor Assist (IMA) hybrid power plant system was developed, incorporating many new technologies for packaging and integrating the motor assist system and for improving engine thermal efficiency. This was developed in combination with a new lightweight aluminum body with

27、low aerodynamic resistance.1nowfTG4KI Environmental performance goals also included the simultaneous achievement of low emissions (half the Japanese year 2000 standards, and half the EU2000 standards), high efficiency, and recyclability. FullfjnFLDa5Zo consideration was also given to key consumer at

28、tributes, including crash safety performance, handling, and driving performance. 1. INTRODUCTION To reduce the automobiles impact on society and the environment requires that it be increasingly cleaner and more energy efficient. The issues of energy conservation, ambient air quality, and reduction i

29、n CO2 emissions are increasing raised as global environmental concerns. One solution for dealing with these issues is the hybrid automobile. Honda has developed and introduced to several major markets worldwide the Insight, a new generation of vehicle design. The Insight combines a hybrid power trai

30、n with advanced body technology features to meet an overall goal of achieving the highest fuel economy practical. The hybrid power train is a motor assist parallel configuration, termed IMA for Integrated Motor Assist. This power train combines a highly efficient electric motor with a new small disp

31、lacement VTEC engine, a lightweight aluminum body, and improved aerodynamics to realize 3.4L/100km (CO2:80g/km) on 98/69/EC fuel economy. Low emissions performance was also targeted with emission levels achieving the EU2000. In addition to recapturing deceleration energy, the integrated motor provid

32、es high torque assist during typical urban driving accelerations. This allows a significant reduction in engine displacement and highertfnNhnE6e5 engine efficiency. Sustained hill climbing performance and high speed cruising capability are assured by a power-toweight ratio of approximately 56kW per

33、metric ton. New engine technology includes the application of a new VTEC (Variable valve Timing and valve lift, Electronic Control) cylinder head design promoting high efficiency and fast catalyst activation, and a new lean NOx catalyst system which promotes lean burn combustion and a reduction in e

34、missions. Extensive friction and weight reducing features are also applied. 2. DEVELOPMENT TARGETS AND CONCEPT Development was aimed at the achievement of extremely low fuel consumption. We set a target of twice the fuel economy of the current production Civic, Hondas representative high fuel econom

35、y car at 7.0 L/100km (93/116/ EC). As a result, the Insight has the lowest fuel consumption in the world, among gasoline passenger cars. Exhaust emission performance often tends to be sacrificed for the sake of low fuel consumption. However, we also decided to match the low emissions performance ach

36、ieved by other mass production cars. Consideration was also given to recyclability (another important environmental issue), crash safety performance, and the basic car characteristics including handling and styling. Summarizing the above, our development targets were as follows: ? The best fuel cons

37、umption performance in the worldHbmVN777sL ? ? ? ? ? Ultra-low exhaust emissions Superior recyclability The worlds highest level of crash safety performance Advanced styling Practical features and responsive handling Comfortable two-seat configuration with personal utility spaceV7l4jRB8Hs 3. POLICIE

38、S FOR FUEL CONSUMPTION REDUCTION In order to establish the technical approach for achieving the fuel consumption target, we conducted a detailed analysis of the energy consumption of the base car, a Civic equipped with a 1.5 liter engine. We found that it was useful to divide the targeted efficiency

39、 gains roughly into thirds, as shown in Fig. 1, in order to achieve the low fuel consumption and numerous other above-mentioned goals. These divisions are as follows. ? ? Improvement of the heat efficiency of the engine itself Recovery of braking energy and employment of idle stop using a hybrid pow

40、er plant ? Car body technologies including reduction of weight and reduced aerodynamic and rolling resistance.83lcPA59W9 Figure 1. Target of double the fuel economy of CIVIC Aiming to establish a benchmark for 21st century automobile power trains, we developed this new Integrated Motor Assist power

41、train. This power train simultaneously achieves both extremely low fuelmZkklkzaaP consumption of 3.4L/100km, and low exhaust gas emission performance, befitting a next-generation car. This paper reports on the newly developed IMA system, including the lean burn engine, electric motor, power control

42、unit, battery technology, and exhaust emission control technology used in the Honda Insight. 4. AIM OF THE IMA SYSTEM While developing this next-generation IMA hybrid system, we incorporated as many currently achievable technologies and techniques as possible, in order to achieve the worlds lowest f

43、uel consumption. The following four system development themes were established in order to meet this target. 1. Recovery of deceleration energyAVktR43bpw 2. Improvement of the efficiency of the engine 3. Use of idle stop system 4. Reduction of power train size and weight 5. OVERVIEW OF THE IMA SYSTE

44、M 5.1. SYSTEM CONFIGURATION As shown in Fig. 2, the IMA system uses the engine as the main power source and an electric motor as an auxiliary power source when accelerating. Using a motor as an auxiliary power source simplifies the overall system and makes it possible to use a compact and lightweigh

45、t motor, battery, and power control unit (PCU).ORjBnOwcEd Figure 2. IMA System A permanent magnet DC brushless motor is located between the engine and the transmission. When decelerating, the rate of deceleration is calculated for each gear and the PCU controls the motor to generate electricity (rec

46、over energy), which charges a nickel-metal hydride battery. When accelerating, the amount of auxiliary power provided (hereafter2MiJTy0dTT called assist) is calculated from the throttle opening, engine parameters, and battery state of charge. The PCU controls the amount of current flowing from the b

47、attery to the drive motor 5.2. RECOVERY OF DECELERATION ENERGY Recovering deceleration energy through regeneration makes it possible to supplement the engines output during acceleration and reduce the amount of fuel consumed. Reducing resistance due to running losses, including engine frictional los

48、ses, increases the available energy for regeneration. In particular, minimizing the engine displacement is an effective means of reducing friction. Engine displacement reduction also has several other benefits, such as weight reduction and increased thermal efficiency. The IMA system effectively inc

49、reases the amount of regeneration during deceleration by optimizing the engine and transmission specifications. 5.3. REDUCTION OF ENGINE DISPLACEMENT Reducing engine displacement is a very important factor in improving fuel economy of a hybrid drive train. However, modern automobiles have to perform

50、 over a wide dynamic range. Reducing the displacement is equivalent to lowering the basic performance characteristics of the car. As shown in the output characteristics graph in Fig. 3, the IMA system assists the engine in the low rpmgIiSpiue7A range by utilizing the hightorque performance character

51、istic of electric motors. The motor can increase overall toruque by over 50% in the lower rpm range used in normal driving. Output in the high rpm range is increased by using a Variable valve Timing and valve lift Electronic Control (VTEC) engine. Thus sufficient peak power is assured and makes it p

52、ossible to use a new, small displacement 1.0 liter engine.uEh0U1Yfmh Figure 3.Engine speed (rpm) Output performance of IMA SYSTEM Assist from the electric motor while accelerating is a very efficient means of reducing the amount of fuel consumed. 5.4. ACHIEVING LEAN BURN ENGINE OPERATION Assist from

53、 the electric motor, based upon the throttle opening, creates quite linear torque characteristics. This, in turn, improves driveability. In addition, motor assist is also provided underIAg9qLsgBX moderate load conditions to broaden the lean-burn operating range, bringing out the full potential of th

54、e newly developed lean burn engine. 5.5. IDLE STOP SYSTEM Stopping the engine rather than idling at stops is also an effective means for reducing fuel consumption. In order to restart the engine with the minimum amount of fuel consumption, the engine is quickly cranked to 600 rpm or more by the high

55、torque integrated motor before ignition occurs, as shown in Fig. 4. This makes it possible to minimize the amount of fuel consumed, in addition to the fuel saved by not running the engine at idle. There are many issues to be considered when performing idle stop. These include judging the drivers int

56、ent to stop, preparing for the restart, providing a smooth feeling of deceleration, and minimizing vibration of the car body when the engine stops.WwghWvVhPE Figure 4.Time (sec) The number of cranking in the engine startasfpsfpi4k This IMA system results in the achievement of both very quick restart

57、s and exceptionally smooth starts. 6. MOTOR ASSIST MECHANISM 6.1. DEVELOPMENT OBJECTIVES By limiting the IMA motor functions to assistance and regeneration, development themes were established to achieve the following two points. 1. A simple and compact structure 2. A system weight of 10% (80 kg) or

58、 less of the completed car weight 6.2. THIN PROFILE DC BRUSHLESS MOTOR A thin and compact DC brushless motor with engine assist and energy regeneration functions was coupled to the engine crank-shaft (Fig. 5).ooeyYZTjj1 Figure 5. Section view of Motor This is a high efficiency, compact, and lightweight permanent magnet-type three-phase synchronous electric motor with a maximum output of 10 kW. In addition to developing technologies to reduce the weight and increase efficiency, we also aimed to make the motor as thinBkeGuInkxI as