TtaMake all the curves ofthevehicleinfigurenTractiveForce (N)300250200ConstantPowerEngine1501 st Geor1002nd3rd504th0080100601202040Ua(km/h)Tractiveforce-speed characteristicsfor a manual transmission11Chapter1AccelerationPerformance
Chapter 1 Acceleration Performance Tractive force-speed characteristics for a manual transmission Make all the curves of the vehicle in figure. 11
GraphofTractiveForceforAudi-A4800070006000Ft1Ft25000Ft3ZFt44000EFt53000Ft6200010000O102030405060108090100110120130140150160170180190200210220230240250260270280290300310320ua/ (km/h)12Chapter1 AccelerationPerformance
Chapter 1 Acceleration Performance 0 1000 2000 3000 4000 5000 6000 7000 8000 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 ua/(km/h) F t/N Ft1 Ft2 Ft3 Ft4 Ft5 Ft6 Graph of Tractive Force for Audi-A4 12
3) Conclusions from the graph of tractive force."Constant Power Engine" curve is equal to the maximumpower of the engine; which is the upper limit of tractiveforceavailable,less anylosses inthedriveline.(等功率发动机最大动力线是可获得的驱动力的极限，该线和驱动力线的差为传动系统中损失的部分。）The curvesillustratevisually theneedtoprovidea numberof gear ratios for operation of the vehicle(low gearing forstart-up, and high gearing for high-speed driving). (驱动力图直观表明汽车需要变速器来提供不同传动比，低挡用于起步，高挡用于高速行驶。）Formaximumaccelerationperformancetheoptimumshiftpoint between gears is the point where the line cross.(最佳的换挡时刻在各挡驱动力线的交点处。）13Chapter1AccelerationPerformance
Chapter 1 Acceleration Performance 3) Conclusions from the graph of tractive force • “Constant Power Engine” curve is equal to the maximum power of the engine; which is the upper limit of tractive force available, less any losses in the driveline.(等功率发 动机最大动力线是可获得的驱动力的极限，该线和驱动 力线的差为传动系统中损失的部分。) • The curves illustrate visually the need to provide a number of gear ratios for operation of the vehicle ( low gearing for start-up, and high gearing for high-speed driving).(驱动力 图直观表明汽车需要变速器来提供不同传动比，低挡用 于起步，高挡用于高速行驶。) • For maximum acceleration performance the optimum shift point between gears is the point where the line cross.(最佳 的换挡时刻在各挡驱动力线的交点处。) 13
Inquiries after-classWhat else representation method is for thetire model? Why tractive force curve is transformed bythe full characteristic curve?14Chapter1AccelerationPerformance
Chapter 1 Acceleration Performance Inquiries after-class • What else representation method is for the tire model? • Why tractive force curve is transformed by the full characteristic curve? 14
2.Driving Resistance行驶阻力ZF=F,+F,+F+F滚动阻力ResistanceF:Rolling空气阻力Fw:Air Resistance坡度阻力1 GradeResistanceF:Uphill加速阻力F:Accelaration Resistance15Chapter1AccelerationPerformance
Chapter 1 Acceleration Performance 2. Driving Resistance 行驶阻力 F F F F F f w i j :Rolling Resistance Ff 滚动阻力 :Air Resistance FW 空气阻力 :Uphill Grade Resistance Fi 坡度阻力 :Accelaration Resistance Fj 加速阻力 15