汽車檢測站設(shè)計(jì)外文翻譯

1、原文一2.1 Common System ConfigurationsAll chassis dynamometers have several key features in common. Most importantly, a means of absorbing the power output from the test vehicles engine is needed toallow different loads to be applied for a variety of testing procedures. Energy istransmitted to this pow

2、er absorber via a direct connection to the vehicles wheelhubs, or through a set of rollers, which are rotated by the wheels of the test vehicle.Flywheels and/or a motoring capability may also be included if vehicle inertia is tobe simulated. Descriptions of inertia simulation and the modelling of va

3、rious vehicleforces are included in Chapter 3. Systems that incorporate a set of large rollers (oneroller for each driven wheel) are more common in applications requiring long termrunning of the vehicle, in which tyre overheating can occur. Hub dynamometers arebest suited to engine tuning applicatio

4、ns which demand rapid response and minimalset-up time between tests. A common and versatile dynamometer layout consists of asingle DC or AC machine mounted outside the rollers and on the same axis, as shownin Figure 2.1.Output power is most commonly absorbed by hydraulic or electric machinesalsoknow

5、n as dynamometerswhich dissipate power either as heat or electrical energy.A single unit that can perform both motoring (power output) and generating (powerabsorption) functions is a common feature in commercially available chassisdynamometers.All but the simplest of garage tuning dynamometers inclu

6、de the capacity to measure the equivalent road speed and tractive force applied at the vehicles wheels. Chassis dynamometers for in-depth driving cycle and vehicle mapping tests customarily incorporate many different measuring devices, which are sampled and recorded by a computer-controlled data acq

7、uisition system. Common features of interest during a dynamometer test include the exhaust emissions (such as CO, CO2, NOX and unburnt hydrocarbons), vehicle cooling water and oil temperatures, and of course tractive force and power output. Fuel consumption and air inlet flowrates may also be record

8、ed for combustion powered vehicles, and these often require adjustment to the standard engine intake equipment. Where the system is controlled by a computer, processing power and user interfaces vary greatly. The simplest forms may consist only of a data logging function which saves information for

9、later viewing, while more sophisticated systems incorporate digital control of the dynamometer, prompts and feedback to the operator, as well as the recording and graphical display of data. Rates of screen update, data sampling, and control signal output are dependent mostly upon the processing spee

10、d of the control computer and its associated electronics.譯文一2.1常用的系統(tǒng)配置所有的底盤測功機(jī)有幾個關(guān)鍵的共同特點(diǎn)。最重要的是，吸收從測試車輛的發(fā)動機(jī)的功率輸出的手段是必要的，以允許不同的負(fù)載為測試程序的各種應(yīng)用。通過直接連接到車輛的輪轂，或通過一組滾子，這是由該測試車的車輪轉(zhuǎn)動能量被傳輸?shù)皆摴β饰?。飛輪和/或駕駛能力也可以包括，如果車輛的慣性是要模擬的。說明慣量模擬和建模的各種車輛的力，包括在第3章中。系統(tǒng)，納入了一套大型輥（每一組滾子對應(yīng)一從動輪）是較常見的在應(yīng)用程序中，需要長期運(yùn)行的車輛，輪胎過熱發(fā)生。集線器測功機(jī)最適合于要

11、求快速響應(yīng)和最小建立時間測試之間的引擎調(diào)校應(yīng)用。一個常見的和多功能的測力計(jì)的布局由一個直流或交流電機(jī)安裝在室外的滾筒和在同一軸線上，如圖2.1所示。輸出功率是最常用的吸收液動或電動機(jī)也稱為測功機(jī)的消耗功率為熱能或電能。一個單一的的執(zhí)行駕駛（輸出功率）和發(fā)電機(jī)（功率吸收）功能的單位，可以是市售的底盤測功機(jī)的一個共同特點(diǎn)。但簡單的車庫調(diào)整測功機(jī)，包括能力衡量相當(dāng)于車速和車輛的車輪施加牽引力。底盤測功機(jī)在深度駕駛周期和車輛映射的測試習(xí)慣包括許多不同的測量設(shè)備，這是由計(jì)算機(jī)控制的數(shù)據(jù)采集系統(tǒng)采樣和記錄。測試期間的共同特點(diǎn)，功率機(jī)測試包括排放廢氣（如一氧化碳，二氧化碳，氮氧化物和未燃燒的碳?xì)浠衔铮?，?/p>

12、輛冷卻水和油的溫度，當(dāng)然還有牽引力和功率輸出。耗油量和進(jìn)氣口的流速也可以是記錄，可用于燃燒的動力的車輛，而這些往往需要調(diào)整的是標(biāo)準(zhǔn)的發(fā)動機(jī)的進(jìn)氣設(shè)備。其中系統(tǒng)是由計(jì)算機(jī)控制的，處理能力和用戶接口差異很大。最簡單的形式，可能只包含數(shù)據(jù)記錄功能，將信息保存供日后查看，而更復(fù)雜的系統(tǒng)，包括數(shù)字控制測功機(jī)，提示和反饋的操作，以及記錄和數(shù)據(jù)的圖形顯示。畫面更新率，數(shù)據(jù)采集和控制信號輸出，主要是依賴于控制計(jì)算機(jī)的處理速度和相聯(lián)電子。 滾輪 功率吸收裝置 正視圖 側(cè)視圖 圖2.1滾筒式底盤測功機(jī)的典型配置原文二2.2 System Configuration at the University of Can

13、terburyAs mentioned in Chapter 1, the entire chassis dynamometer was transplanted into anew laboratory in 1994. The new layout of the laboratory and the desire to reuse thepresent equipment dictated that the power absorbing shaft be mounted at right anglesto the roller drums. The overall dynamometer

14、 system is shown in Figure 2.2 and Plate2.1. The roller drums are carried on a trunnion-mounted Ford 15C truck axle, with itsdifferential locked and a ratio of 43:7 (6.14:1). The axle assembly is located laterallyby a Watt linkage lying in a horizontal plane beneath the axle, as shown in Figure2.3.

15、Figure 2.2 University of Canterbury chassis dynamometer schematic diagramThe use of trunnion bearings means that forces applied at the surface of the drumscan be detected by a strain-gauge load cell recording the reaction force of theassembly on the rigid support stand. To determine the actual force

16、 at the drumsurface, the friction and inertia of the drum axle assembly must be taken in toaccount. This tractive effort correction is detailed in Section 5.5.Power is absorbed by a Froude EC50TA Eddy-Current Dynamometer. The suppliedtorque and speed measuring equipment of this instrument are used f

17、or controlpurposes. Originally, the design included a 166 kw D.C. motor-generator set whichcould motor and absorb in both directions. However, this compact regenerativesystem was not practical due to a lack of sufficient A.C. mains current capacity. Thewater-cooled, disc-type dynamometer was chosen

18、in preference to a hydrokineticabsorber on the grounds of a superior low-speed torque capacity and a lesserrequirement on the water supply for a given maximum torque rating. The gearingincorporated in the axle assembly means that the dynamometer operates at a higherspeed and lower torque than if it

19、were connected in a direct fashion to the rollerdrums.A set of flywheels is mounted between the axle and dynamometer to allow inertiasimulation of vehicle masses between 664 kg and 1794 kg. Running through thecentre of the flywheel set is a hollow shaft, which can be rigidly coupled to the mainshaft

20、, or allowed to rotate independently on bearings. Each of the four flywheels sitson bearings on the outside of the hollow shaft. Flywheels may be engaged to spinwith this shaftand therefore, with the main shaftby bolting on the respectiveflanges. The discrete inertia intervals that can be achieved b

21、y including or omittingindividual flywheels are listed in Appendix A and provide steps of not more than120 kg over the entire range. While the inertial loads present during acceleration anddeceleration of the roller drums may be accommodated by the eddy-currentdynamometer, the inclusion of flywheels

22、 lessens the overall power absorptionrequirement. Figure 2.4 shows a schematic of the flywheel assembly.During calibration and warming up of the system, it is useful to be able to motor thedynamometer and rollers without the presence of a vehicle. A 26 kW ASEA LAK180LA D.C. motor has been installed,

23、 which is controlled by a 3 phase thyristorconverter with polarity reversing switch gear to enable motoring in both directions. Itwas intended that this machine perform additional inertia simulationparticularlyduring decelerationin the original configuration. However, it was found that theresponse t

24、ime and control accuracy were insufficient for this task (see Section )and that the power absorber and flywheels offered superior inertia approximationwithout the use of the electric motor. As shown in Figure 2.2, the components of thesystem are connected via universal shafts to accommodate any misalignment.譯文二2.2 底盤測功機(jī)的系統(tǒng)配置如第1章中提到的，整個底盤測功機(jī)移植到在1994年的新的實(shí)驗(yàn)室。實(shí)驗(yàn)室和重復(fù)使用本設(shè)備的愿望的新的布局決定了功率吸收軸成直角安裝到輥鼓。顯示在圖2.2和整體測功機(jī)系統(tǒng)配置圖2.1中。滾子鼓耳軸安裝式福特15C卡車的車軸上，而其鎖定差的比