高端汽車制造商的頂級(jí)車型正在遭遇大滑坡，因此在推出新車的時(shí)候，各大制造商都想方設(shè)法賦予車輛更奢華的配置和更尖端的科技。
在2015年法蘭克福車展上，寶馬揭開了全新7系的面紗，直接對(duì)戰(zhàn)梅賽德斯奔馳S級(jí)與奧迪A8等車型。盡管使用在跑車上的碳纖維材料還未在轎車中普及使用，但2016年的寶馬7系向人們展示了這一方向，7系的底盤使用了強(qiáng)化碳纖維制作，堅(jiān)固程度堪比鋼結(jié)構(gòu)。寶馬將這一混合材料稱為“碳內(nèi)核”。
車門、行李廂蓋、懸架、制動(dòng)和車輪部件都是用鋁合金制作，為車身結(jié)構(gòu)減輕了15%的重量。
“這種將碳纖維結(jié)構(gòu)與鋼材、鋁材、鎂和塑料相結(jié)合的做法使750i xDrive比舊版車型輕了130 kg (287 磅)，”寶馬研發(fā)委員會(huì)成員Klaus Frolich指出。“輕量化設(shè)計(jì)總共實(shí)現(xiàn)了200 kg (440 磅)的減重，這樣我們可以為車輛添加更多的舒適與安全配置。這讓7系成為了該級(jí)別中最輕的豪華轎車。”
從外部來(lái)看，7系新添的一系列主動(dòng)設(shè)計(jì)使車身外殼的形狀與空氣流動(dòng)更為流暢。其中包括格柵百葉窗和前翼子板上的垂直進(jìn)氣口。前者的作用相當(dāng)于一塊“空氣擋幕”，可將氣流導(dǎo)向輪罩拱的外側(cè)，而后者則是一個(gè)“呼吸器”，可將空氣直接吸入前輪罩拱。這些主動(dòng)設(shè)計(jì)加上密封的車身底座一共可減少15%的氣動(dòng)阻力。
7系的前方與后方都安裝了自調(diào)平空氣懸架。在上陡坡的時(shí)候，駕駛員可以手動(dòng)將車輛抬升20 mm (0.8 英寸)，而在高速行駛時(shí)，車輛會(huì)自動(dòng)降低10 mm (0.4 英寸)以減小阻力。
主動(dòng)防傾桿是一個(gè)在SUV上越來(lái)越常見(jiàn)的裝置，它的作用是車輛轉(zhuǎn)彎時(shí)先松開車輪，再減少車身傾斜。新7系上使用的防傾桿可在車輛直線行駛時(shí)，讓每個(gè)角落的懸架對(duì)路面磕碰實(shí)現(xiàn)獨(dú)立反應(yīng)，不會(huì)互相干涉。只有在轉(zhuǎn)彎時(shí)，防傾桿才會(huì)發(fā)揮它的本來(lái)作用——減少車身傾斜。
此外，7系還有一個(gè)可變速率轉(zhuǎn)向架和主動(dòng)后轉(zhuǎn)向系統(tǒng)，它們也為操縱性能的提升做出了貢獻(xiàn)。
其他技術(shù)呢？比如遠(yuǎn)程控制自動(dòng)泊車技術(shù)？“這一技術(shù)可以讓汽車自動(dòng)進(jìn)出車庫(kù)或停車場(chǎng)，而駕駛員無(wú)需用方向盤操縱” ，F(xiàn)rolich解釋道。駕駛員則使用寶馬新推出的“顯示鑰匙”（Display Key），它的外觀是一個(gè)小型的智能手機(jī)。駕駛員可以用它來(lái)啟動(dòng)車輛，查看鎖門狀態(tài)和服務(wù)通知等信息。新7系將于今年秋天登陸經(jīng)銷商，屆時(shí)還不會(huì)帶有遠(yuǎn)程控制泊車系統(tǒng)。但他補(bǔ)充道，這一技術(shù)不用等多久便會(huì)推出。
Frolich自信地邀請(qǐng)客戶試用7系上全新推出的姿勢(shì)控制系統(tǒng)。這是車載信息娛樂(lè)系統(tǒng)中的一個(gè)界面，可讀取該方向上的駕駛員的各種姿勢(shì)，并判斷駕駛員是否試圖控制某個(gè)功能，如聽(tīng)收音機(jī)和使用電話等?？紤]到寶馬語(yǔ)音控制系統(tǒng)和iDrive界面在過(guò)去的市場(chǎng)反應(yīng)褒貶不一，這個(gè)新的姿勢(shì)識(shí)別電腦系統(tǒng)性能如何，還需進(jìn)一步觀察。
寶馬對(duì)其標(biāo)志性的iDrive信息娛樂(lè)系統(tǒng)界面進(jìn)行了進(jìn)一步升級(jí)。10年來(lái)，寶馬一直堅(jiān)稱指紋會(huì)弄臟觸屏，但今年它終于在控制旋鈕之外加上了觸屏輸入。
具有1個(gè)10頻道、1400 W擴(kuò)音器與16個(gè)揚(yáng)聲器的Bowers & Wilkins鉆石環(huán)繞式音響系統(tǒng)，可讓車內(nèi)乘客充分沉浸在音樂(lè)中。此外，7系還采用了一個(gè)全新的平視顯示儀。該設(shè)備可將信息以圖像的方式投射在擋風(fēng)玻璃上，投射畫面比舊系統(tǒng)大75%，圖像質(zhì)量與呈現(xiàn)細(xì)節(jié)也更加完善。
寶馬公布了美國(guó)市場(chǎng)上7系的三種傳動(dòng)系統(tǒng)：750i將使用一臺(tái)445馬力(332-kW)的雙渦輪4.4 L V8發(fā)動(dòng)機(jī)，740i將使用一臺(tái)320馬力(239-kW) 的3.0 L雙渦輪直列式6缸發(fā)動(dòng)機(jī)，而740e將采用由一臺(tái)258馬力(192-kW)2.0 L雙渦輪直列式4缸發(fā)動(dòng)機(jī)與83 kW電機(jī)組成的插電式混合動(dòng)力系統(tǒng)。混動(dòng)系統(tǒng)的總輸出功率為243 kW。三輛車都搭載了八速自動(dòng)變速箱。
V8發(fā)動(dòng)機(jī)采用“熱V”設(shè)計(jì)，意味著一對(duì)霍尼韋爾雙渦輪增壓器位于V字中間。新一代發(fā)動(dòng)機(jī)的壓縮率為10.5:1，比舊款高了0.5。冷卻系統(tǒng)也得到了優(yōu)化，一個(gè)由地圖控制的水泵讓水流朝著氣缸蓋和氣缸組兩個(gè)方向流動(dòng)。冷啟動(dòng)時(shí)，系統(tǒng)流量被限制在正常水平的10%，這樣可使機(jī)身更快地升溫。
直列式6缸發(fā)動(dòng)機(jī)為全鋁材結(jié)構(gòu)，具備可變閥門正時(shí)和汽油直接噴射等功能，運(yùn)行順暢且功率強(qiáng)大。
插電式混合動(dòng)力版740e的鋰離子電池組可在不使用燃油的情況下確保75 mph (120 km/h)的駕駛速度，純電動(dòng)行駛里程高達(dá)23英里(37 km)?？刹捎玫某潆姺绞桨?biāo)準(zhǔn)家用電源、公共充電樁，和寶馬的i Wallbox。寶馬聲稱該車的最大效率為112 mpg。
此外，寶馬還將在全球市場(chǎng)推出730d，它將搭載一臺(tái)265馬力(198-kW)、52 mpg的3.0 L直列式6缸柴油發(fā)動(dòng)機(jī)。
作者：Dan Carney
來(lái)源：SAE《汽車工程雜志》
翻譯：SAE 上海辦公室
BMW lightens 7 Series, but bulks up on tech
Prestige car manufacturers are trading body blows among their top-segment models, with each ladling on more lavish content and more cutting-edge technology with each new introduction.
So it was for BMW at the 2015 Frankfurt Motor Show, where it pulled the cover off its 7 Series and released it to take on the Mercedes-Benz S-Class and Audi A8. We may not have yet reached the day when carbon-fiber chassis seen in sports cars have proliferated among these sedans, but the 2016 7 Series offers a step in that direction with a chassis featuring significant carbon-fiber reinforcement to a mostly steel structure. BMW terms this hybrid materials approach “carbon core.”
The car’s doors and trunk lid are aluminum, and use of that metal in the suspension, brakes, and wheels slashes unsprung weight by 15%.
“Its innovative combination of carbon-fiber structures with steel, aluminum, magnesium, and plastic means that the 750i xDrive is 130 kg (287 lb) lighter than the previous model,” noted Klaus Frolich, BMW Board Member for Research and Development. “Lightweight design measures adding up to roughly 200 kg (440 lb) have enabled us to integrate additional comfort and safety features,” he said. “This ensures that the 7 Series is the lightest luxury sedan in its segment.”
Outside, the body shell is smoothed and airflowed aided by active measures such as grille shutters, an “air curtain” that steers airflow past the side of the wheel arch, while “air breathers” direct air into the front wheel arches through vertical intakes in the front fenders. These measures, along with a sealed underbody, contribute to a 15% reduction in aerodynamic drag.
Front and rear self-leveling air suspension lets drivers manually raise the car by 20 mm (0.8 in) when approaching steep entrances and automatically lowers is by 10 mm (0.4 in) when driving at highway speeds for reduced drag.
An active anti-roll bar is a feature increasingly seen on SUVs because it permits disconnection for wheel articulation when driving off road, then returns to its normal function of reducing body lean in turns on road. The new 7 Series uses one so it can disconnect the bar when the car is driving in a straight line to let each corner’s suspension respond to bumps individually, without affecting the others. When turning, the anti-roll bar returns to its normal function.
The 7 Series also has a variable ratio steering rack and active rear steering, which combine to provide improved maneuverability.
What else? How about remote control self-parking? “This means the vehicle can maneuver itself in and out of a garage or parking spot without the driver behind the wheel,” Frolich explained. The driver will use BMW’s new Display Key, which appears to combine the appearance of a small smartphone with functions such as starting, the car’s lock status, and even service notifications. Remote-control parking will not be available when cars reach dealers this fall, but is scheduled to follow soon afterward, he added.
Frolich boldly invited customers to try the 7 Series’ new gesture-control system, an interface for the car’s infotainment systems that reads the driver’s gesticulating in its direction and interprets that to control functions like radio and phone. Considering the mixed record of voice command systems and BMW’s iDrive interface, it is worrisome to consider what gestures the computer system might induce.
BMW continues to refine its signature iDrive infotainment interface, finally combining touch screen inputs with its control knob despite a decade of insisting that fingerprints make touch screens undesirable.
A Bowers & Wilkins Diamond surround sound system features a 10-channel, 1400-W amplifier and 16 speakers to immerse occupants in sound. Meanwhile a new headup display projects information for the driver with an image on the windshield that is 75% larger than the previous system, with improved image quality and detail.
BMW has announced three U.S. gasoline drivetrains for the 7 Series; a 445-hp (332-kW) twin-turbo 4.4-L V8 for the 750i, a 320-hp (239-kW) 3.0-L twin-turbo inline six for the 740i, and a 258-hp (192-kW) 2.0-L twin-turbo inline four and 83 kW electric motor plug-in hybrid-electric combination in the 740e. The hybrid's total system output is 243 kW. All three cars use eight-speed automatic transmission.
The V8 is a hot-vee design, nesting a pair of Honeywell twin scroll turbos in the valley of its vee. Compression for this iteration of the engine climbs a half-point to 10.5:1, with cooling optimized with separate flow to the heads and cylinder liners determined by a map-controlled water pump. System flow can be restricted to 10% of normal for faster warmup on cold starts.
BMW is debuting a new inline-six for 2016 featuring all-aluminum construction, variable valve timing, and direct gasoline fuel injection for a good combination of smoothness and power.
The plug-in hybrid 740e has a lithium-ion battery pack that can propel the car with no fuel consumption at speeds as high as 75 mph (120 km/h) or for distances as far as 23 mi (37 km). Charging is via standard household current, public charging station or BMW’s i Wallbox. BMW claims maximum efficiency of 112 mpg for the plug-in hybrid
Global markets will also enjoy the 730d, a 265-hp (198-kW) 3.0-L, 52-mpg fuel-sipping 3.0-L inline six-cylinder diesel.
2016年寶馬7系的光滑外形，使得新車型比舊款降低了15%的氣動(dòng)阻力。
位于7系儀表板中央的高精度信息娛樂(lè)系統(tǒng)顯示器換成了觸屏，使駕駛員可以更方便地使用某些功能。
插電式混合動(dòng)力版7系的鋰離子電池組的純電動(dòng)里程為23英里。
4.4 L V8發(fā)動(dòng)機(jī)將一對(duì)霍尼韋爾渦輪增壓器置于V形的中間。