UNIT 4
GASOLINE FUEL INJECTION
TEXT A
Gasoline Direct Injection (GDI) and
Throttle-by-wire
PROFESSIONAL ENGLISH
UNIT 3
GASOLINE FUEL INJECTION
TEXT A
Gasoline Direct Injection (GDI) and
Throttle-by-wire
Gasoline Direct Injection
Mitsubishi GDI
Volkswagen AG's direct-injection (FSI)
Toyota DI engine
Electronic Throttle—Throttle-By-Wire
本次课学习内容本次课学习目标
掌握 GDI系统的特点
掌握 GDI系统的原理
掌握电子节气门原理
NEW WORDS
drastic ['dr?stik] a,激烈的，猛烈的
GDI=gasoline direct injection(汽油直接喷射 )
forerunner ['f?:r?n?] n.先驱（者），先锋，祖先
CVT=continuously variable transmission（无级变速器）
characteristics [k?rikt?'ristiks] n.特性（曲线）
exotic [ig'z?tik] n.奇异的，外来的，异国情调的
FSI=fuel straight injection燃油直接喷射
layout ['leiaut] n.规划，设计（图案），布置
stick [stik] n.棒，棍； v.粘住，粘铁
estate [i'steit] n.状态，时期，不动产
signature ['sign?t∫?] n.签名，署名，信号
acronym ['?kr?nim] n.只取首字母的缩写
linchpin [‘lint∫pin] n.关键
justice ['stis] n.正义，正当，公平，欣赏，审判
effervescent [ef?'ves?nt] a.冒泡的，兴奋的
superb [sju:'p?:b] n.壮丽的，华美的，最上等的，无比的
drawback ['dr?:b?k] n.缺点，障碍
brilliant ['brili?nt] a.灿烂的，闪耀的
DI=direct injected,direct injection 直接喷射
crucial ['kru:∫(?)l] a.至关紧要的
nitrogen ['naitr(?)n] n.氮
lean-burn ['li:n-b?:n] a.稀薄燃烧
incorporate[in'k?:p?reit] v.合并，混合，组成公司； a.合并的，一体化的
lip [lip] n.嘴唇，唇缘
helical ['helik(?)l] a.螺旋状的
quintessential [kwinti'sen∫?l] a.精髓的，精萃的，典范的，
本质的
stratify ['str?tifai] v.使成层
promote [pr?'mout] v.促进，加速，激励，提升
vicinity [vi'siniti] n.附近，临近，接近
coincidental [kouinsi'dent(?)l] a.一致的，符合的，巧合的
purify [‘pju?rifai] v.净化，使纯净
occlude [?‘klu:d] v.使闭塞，吸收
stoichiometric [st?iki?‘metrik] a.化学当量的，理想配比的
homogeneous [?h?m?'?i:nj?s] a.相似的，均匀的
crossover ['kr?souv?] n.跨越，交叉，交迭，穿过
throttle-by-wire ['?r?tl-bai-'wai?] 线控节气门
servomotor ['s?:voumout?] n.
伺服电动机，辅助电动机，伺服传动装置
ASR =anti-slip regulator或 acceleration slip regulation
防滑调节装置
ABS =anti-lock braking system防抱死制动系统
takeoff ['teik?f] n.起飞，开始
beat [bi:t] n.敲打，拍子 ; v.打，打败
trust [tr?st] v,& n.信任，信赖
limp-home [limp-'houm] n.跛行回家
make up 补充，修理，整理，形成
all but 几乎，差不多
turbo lag 增压滞后
in conjunction with 连同 … 一起
volumetric efficiency 容积效率
VVT-i (Variable Valve Timing,intelligent)
智能型可变气门定时
cruise control 巡航控制
traction control 牵引控制
lay down 设计，制定，主张
PHRASES AND EXPRESSIONS
Gasoline Direct Injection (GDI)
and Throttle-by-wire
Gasoline Direct Injection
Conventional gasoline engines are designed to use an
electronic fuel injection system,replacing the traditional
mechanical carburetion system,Multi-point injection (MPI),
where the fuel is injected through each intake port,is currently
one of the most widely used systems [1],Although MPI
provides a drastic improvement in response and combustion
quality,it is still limited due to fuel and air mixing prior to
entering the cylinder.
To further increase response time and combustion efficiency,
while lowering fuel consumption and increasing output,
systems may use direct injection,Gasoline direct injection
engines are engineered to inject the gasoline directly into the
cylinder in a manner similar to diesel direct injection engines.
Direct injection is designed to allow greater control and
precision,resulting in better fuel economy,This is
accomplished by enabling combustion of an ultra-lean
mixture under many operating conditions,Direct
injection is also designed to allow higher compression
ratios,delivering higher performance with lower fuel
consumption,Currently,direct injection gasoline
engines are being deployed throughout the world in
passenger cars.
Mitsubishi GDI
Mitsubishi Motors is aiming to achieve both low fuel
consumption and high output,MMC is a world forerunner in
the development of direct cylinder injection gasoline engines,
known as "GDI",which were first introduced in the 1996
Galant,GDI supplies fuel directly to the inside of the cylinder.
A variety of air-fuel mixtures can be created according to
changes in the fuel injection timing,Using methods and
technologies unique to Mitsubishi,the GDI engine provides
both lower fuel consumption and higher output,This
seemingly contradictory and difficult feat is achieved with the
use of two combustion modes,Put another way,injection
timings change to match engine load.
Ultra-lean Combustion Mode
Under most normal driving conditions,up to speeds of 120
km/h,the Mitsubishi GDI engine operates in ultra-lean
combustion mode,resulting in less fuel consumption,In this
mode,fuel injection occurs at the latter stage of the
compression stroke and ignition occurs at an ultra-lean air-fuel
ratio of 30,40 (35:55,including EGR).
Superior Output Mode
When the GDI engine is operating with higher loads or at
higher speeds,fuel injection takes place during the intake
stroke,This optimizes combustion by ensuring a homogeneous,
cooler air-fuel mixture which minimizes the possibility of engine
knocking.
These two modes are represented in Figure 4-1,The piston
of the GDI engine is shown in Figure 4-2.
Fig,4-1 Two combustion modes of the GDI
Fig.4-2 A piston of Mitsubishi GDI engine
In addition,the GDI-CVT introduced in the 2000 Lancer
significantly reduces energy loss by integrated control that
makes the most of GDI characteristics [3],High-precision
torque control and large range for low fuel consumption as well
as the CVT characteristics of quick and continuous control of
the large gear change ratios enable top class level fuel
economy and an exceptionally smooth ride [4].
Volkswagen AG's direct-injection
The Audi's new 2L I-4 improves greatly on the high
standards set by the 1.8T it replaces,While the Audi misses
the exotic 5-valve-per-cylinder configuration of the 1.8T,the 2L
FSI makes up for its more-conventional 4-valve layout by
sticking a fuel injector into the combustion-chamber,real
estate that used to be occupied by Audi's signature fifth valve.
Direct injection gasoline (DIG) technology is the fastest-
emerging power and economy enhancing innovation in the
powertrain sector and with the 2L FSI (Volkswagen AG’s
direct-injection acronym for Fuel Straight Injection),Audi
and its VW parent is leading the pack.
Audi says FSI will be its gasoline-engine linchpin going
into the future,Soon,every Audi-brand engine will feature
the FSI system.
FSI adds new levels of power and torque,yet also
delivers fuel-economy gains that,at the least,offset what
typically would be lost in generating increased power,For
example,although the 2L FSI develops 30 hp and 40-plus
lb-ft,(41 Nm) more torque than the smaller 1.8T (as used
by Audi),a continuously variable transmission-equipped A4
with the new engine gets 20% better fuel economy in city
driving and does 10% better on the highway.
The numbers don't do justice to the effervescent nature of
the new I-4,The throttle response is the last word in
immediate,and this is one of those rare 4-cyls,That
continually hits the fuel cutoff long before noise and vibration
suggest a gear change is in order,Twin balance shafts
certainly help in that regard.
The 2L mill has a variable-length intake manifold and a
superb BorgWarner Turbo Systems variable-turbine
turbocharger that,when combined with FSI,all but
eliminates turbo lag,just about the last remaining drawback
of turbocharging.
The 2L I-4 is claimed to be the world's first automotive
engine to combine DIG technology and turbocharging,If
Audi's brilliant new 4-cyl,engine is typical of what happens
when direct injection and turbocharging get together,we
expect to see much of the auto industry follow in Audi's
innovative footsteps.
Toyota DI engine
Toyota Motor Corp,has developed a 4-stroke,direct-
injected (DI) gasoline engine,In conjunction with the new DI
engine is another crucial item,a production-ready 3-way
exhaust catalyst capable of oxidizing the oxides of nitrogen
(NOX)-rich exhaust inherent to lean-burn engines.
The new engine,designated D-4 by Toyota,is a 2L DOHC
inline 4-cyl,Compression ratio is 10:1,and the engine
operates efficiently on regular unleaded gasoline.
The D-4 incorporates a highly optimized combustion
chamber,The piston crowns are fitted with a lipped,cup-like
formation that focuses the injected air/fuel mixture tightly
around the spark plug for maximum burn.
Intake air is drawn through helical ports that create a high
degree of horizontal swirl,which Toyota says combines with
the lipped combustion chamber to not only maintain highly
stable combustion— a quintessential problem for lean-
burners— but also to stratify the air/fuel mixture,
Additional swirl is promoted with special swirl-inducing high-
pressure injectors,The end result is a fuel-rich mixture in
the direct vicinity of the spark plug,with extremely lean
air/fuel ratios near the cylinder walls.
The D-4 can operate stably with air/fuel ratios as high as
50:1,compared with the company's existing indirect-
injected lean-burn engine that operates with maximum
air/fuel ratios of roughly 24:1.
Toyota says a coincidental advantage of the highly
stratified charge employed in the new engine is a cooler air
charge,due to increased fuel vaporization,The cooler
charge increases volumetric efficiency,and the engine also
is fitted with the company's VVT-i (Variable Valve Timing,
intelligent) system to precisely control each cylinder's intake
event.
Lean-burn engines are known for their characteristic high
levels of NOX emissions,The company says the new D-4
uses a high degree of exhaust gas recirculation (EGR)--as
much as 40% when the engine operates in the lean-
combustion mode--and the natural EGR-like operation of the
VVT-i system to drastically reduce NOX production.
The new 3-way catalyst uses a storage/reduction design to
purify occluded NOX at the stoichiometric level -- when the
engine operates in lean modes,excess NOX is stored until it
can be combined/purified with exhaust gases produced
during stoichiometric operation.
The new engine relies on powerful,precise engine-
management software to accurately tailor fuel-injection timing
and duration,At high loads,such as during heavy
acceleration,fuel is injected earlier in the compression stroke,
creating a homogeneous mixture and optimum power,
Crossover points between homogeneous and stratified
mixtures produce semi-stratified air/fuel mixture for
"smooth torque transition."
Torque production in the low- and middle-speed
ranges is improved by 10% over conventional engines,
while fuel economy in the Japanese 10-15 urban fuel
economy test is improved by a significant 30% or better,
Moreover,Toyota claims the quicker response
presented by the DI design improves 0 to 62 mph (0-100
km/h) and passing acceleration times by 10%.
Electronic Throttle— Throttle-By-Wire
Some of the newest Motronic systems have an
electronic throttle (also known as a throttle-by-wire
system),The electronic throttle has no mechanical
link between the accelerator pedal and the throttle
valve,Instead,as shown in Fig.4-3,an accelerator
sensor picks up your movement or position of the
accelerator pedal,It signals the control unit about
pedal movement,and the control unit signals the
servomotor on the throttle shaft to open,The
electronic throttle (Bosch calls it EGAS) may
sound like something none of us needs,but it has
many benefits.
Fig,4-3 Electronic throttle sends accelerator signal to
Motronic control unit DC motor moves throttle valve,
modified by engine temperature,idle rpm,and
maximum rpm
The throttle opening signal may be modified according to
engine rpm and engine temperature,It can provide
simplified cruise control,It can also control minimum rpm,
replacing the idle-speed stabilizer,and control maximum
rpm,replacing the alternate-injector cut-out,
But there's more,For traction control,the electronic
throttle links with the ABS (Anti-lock Braking System),The
same wheel-speed sensors of ABS also feed the ASR (Anti-
Slip Regulator).
When any driving wheel starts to slip,a slight brake
application prevents that wheel from slipping so much that
the differential delivers no power to the other driving wheel,
If both driving wheels show signs of slipping,the electronic
throttle cuts back power for maximum traction,Traction
control gives the car the max acceleration the tires can
deliver to the road,If laying down tire smoke is your thing,
avoid ASR,But for making the fastest takeoff,you cannot
beat it,
Can you trust the electronic throttle? Will it provide
unintended acceleration? The system checks its safety
circuits before start-off,and reports defects to the driver,
If a defect is found,a limp-home circuit may disable
some of the functions,but it will allow you to get to the
house or the shop,It may well be more reliable than
some cable actuated throttles.
小结
Gasoline Direct Injection
Advantages
Mitsubishi GDI
Volkswagen AG's direct-injection(FSI)
Toyota DI engine
Electronic Throttle— Throttle-By-Wire
作业
熟记相关专业词汇
P84 EXERCIES Ⅰ & Ⅱ
GASOLINE FUEL INJECTION
TEXT A
Gasoline Direct Injection (GDI) and
Throttle-by-wire
PROFESSIONAL ENGLISH
UNIT 3
GASOLINE FUEL INJECTION
TEXT A
Gasoline Direct Injection (GDI) and
Throttle-by-wire
Gasoline Direct Injection
Mitsubishi GDI
Volkswagen AG's direct-injection (FSI)
Toyota DI engine
Electronic Throttle—Throttle-By-Wire
本次课学习内容本次课学习目标
掌握 GDI系统的特点
掌握 GDI系统的原理
掌握电子节气门原理
NEW WORDS
drastic ['dr?stik] a,激烈的，猛烈的
GDI=gasoline direct injection(汽油直接喷射 )
forerunner ['f?:r?n?] n.先驱（者），先锋，祖先
CVT=continuously variable transmission（无级变速器）
characteristics [k?rikt?'ristiks] n.特性（曲线）
exotic [ig'z?tik] n.奇异的，外来的，异国情调的
FSI=fuel straight injection燃油直接喷射
layout ['leiaut] n.规划，设计（图案），布置
stick [stik] n.棒，棍； v.粘住，粘铁
estate [i'steit] n.状态，时期，不动产
signature ['sign?t∫?] n.签名，署名，信号
acronym ['?kr?nim] n.只取首字母的缩写
linchpin [‘lint∫pin] n.关键
justice ['stis] n.正义，正当，公平，欣赏，审判
effervescent [ef?'ves?nt] a.冒泡的，兴奋的
superb [sju:'p?:b] n.壮丽的，华美的，最上等的，无比的
drawback ['dr?:b?k] n.缺点，障碍
brilliant ['brili?nt] a.灿烂的，闪耀的
DI=direct injected,direct injection 直接喷射
crucial ['kru:∫(?)l] a.至关紧要的
nitrogen ['naitr(?)n] n.氮
lean-burn ['li:n-b?:n] a.稀薄燃烧
incorporate[in'k?:p?reit] v.合并，混合，组成公司； a.合并的，一体化的
lip [lip] n.嘴唇，唇缘
helical ['helik(?)l] a.螺旋状的
quintessential [kwinti'sen∫?l] a.精髓的，精萃的，典范的，
本质的
stratify ['str?tifai] v.使成层
promote [pr?'mout] v.促进，加速，激励，提升
vicinity [vi'siniti] n.附近，临近，接近
coincidental [kouinsi'dent(?)l] a.一致的，符合的，巧合的
purify [‘pju?rifai] v.净化，使纯净
occlude [?‘klu:d] v.使闭塞，吸收
stoichiometric [st?iki?‘metrik] a.化学当量的，理想配比的
homogeneous [?h?m?'?i:nj?s] a.相似的，均匀的
crossover ['kr?souv?] n.跨越，交叉，交迭，穿过
throttle-by-wire ['?r?tl-bai-'wai?] 线控节气门
servomotor ['s?:voumout?] n.
伺服电动机，辅助电动机，伺服传动装置
ASR =anti-slip regulator或 acceleration slip regulation
防滑调节装置
ABS =anti-lock braking system防抱死制动系统
takeoff ['teik?f] n.起飞，开始
beat [bi:t] n.敲打，拍子 ; v.打，打败
trust [tr?st] v,& n.信任，信赖
limp-home [limp-'houm] n.跛行回家
make up 补充，修理，整理，形成
all but 几乎，差不多
turbo lag 增压滞后
in conjunction with 连同 … 一起
volumetric efficiency 容积效率
VVT-i (Variable Valve Timing,intelligent)
智能型可变气门定时
cruise control 巡航控制
traction control 牵引控制
lay down 设计，制定，主张
PHRASES AND EXPRESSIONS
Gasoline Direct Injection (GDI)
and Throttle-by-wire
Gasoline Direct Injection
Conventional gasoline engines are designed to use an
electronic fuel injection system,replacing the traditional
mechanical carburetion system,Multi-point injection (MPI),
where the fuel is injected through each intake port,is currently
one of the most widely used systems [1],Although MPI
provides a drastic improvement in response and combustion
quality,it is still limited due to fuel and air mixing prior to
entering the cylinder.
To further increase response time and combustion efficiency,
while lowering fuel consumption and increasing output,
systems may use direct injection,Gasoline direct injection
engines are engineered to inject the gasoline directly into the
cylinder in a manner similar to diesel direct injection engines.
Direct injection is designed to allow greater control and
precision,resulting in better fuel economy,This is
accomplished by enabling combustion of an ultra-lean
mixture under many operating conditions,Direct
injection is also designed to allow higher compression
ratios,delivering higher performance with lower fuel
consumption,Currently,direct injection gasoline
engines are being deployed throughout the world in
passenger cars.
Mitsubishi GDI
Mitsubishi Motors is aiming to achieve both low fuel
consumption and high output,MMC is a world forerunner in
the development of direct cylinder injection gasoline engines,
known as "GDI",which were first introduced in the 1996
Galant,GDI supplies fuel directly to the inside of the cylinder.
A variety of air-fuel mixtures can be created according to
changes in the fuel injection timing,Using methods and
technologies unique to Mitsubishi,the GDI engine provides
both lower fuel consumption and higher output,This
seemingly contradictory and difficult feat is achieved with the
use of two combustion modes,Put another way,injection
timings change to match engine load.
Ultra-lean Combustion Mode
Under most normal driving conditions,up to speeds of 120
km/h,the Mitsubishi GDI engine operates in ultra-lean
combustion mode,resulting in less fuel consumption,In this
mode,fuel injection occurs at the latter stage of the
compression stroke and ignition occurs at an ultra-lean air-fuel
ratio of 30,40 (35:55,including EGR).
Superior Output Mode
When the GDI engine is operating with higher loads or at
higher speeds,fuel injection takes place during the intake
stroke,This optimizes combustion by ensuring a homogeneous,
cooler air-fuel mixture which minimizes the possibility of engine
knocking.
These two modes are represented in Figure 4-1,The piston
of the GDI engine is shown in Figure 4-2.
Fig,4-1 Two combustion modes of the GDI
Fig.4-2 A piston of Mitsubishi GDI engine
In addition,the GDI-CVT introduced in the 2000 Lancer
significantly reduces energy loss by integrated control that
makes the most of GDI characteristics [3],High-precision
torque control and large range for low fuel consumption as well
as the CVT characteristics of quick and continuous control of
the large gear change ratios enable top class level fuel
economy and an exceptionally smooth ride [4].
Volkswagen AG's direct-injection
The Audi's new 2L I-4 improves greatly on the high
standards set by the 1.8T it replaces,While the Audi misses
the exotic 5-valve-per-cylinder configuration of the 1.8T,the 2L
FSI makes up for its more-conventional 4-valve layout by
sticking a fuel injector into the combustion-chamber,real
estate that used to be occupied by Audi's signature fifth valve.
Direct injection gasoline (DIG) technology is the fastest-
emerging power and economy enhancing innovation in the
powertrain sector and with the 2L FSI (Volkswagen AG’s
direct-injection acronym for Fuel Straight Injection),Audi
and its VW parent is leading the pack.
Audi says FSI will be its gasoline-engine linchpin going
into the future,Soon,every Audi-brand engine will feature
the FSI system.
FSI adds new levels of power and torque,yet also
delivers fuel-economy gains that,at the least,offset what
typically would be lost in generating increased power,For
example,although the 2L FSI develops 30 hp and 40-plus
lb-ft,(41 Nm) more torque than the smaller 1.8T (as used
by Audi),a continuously variable transmission-equipped A4
with the new engine gets 20% better fuel economy in city
driving and does 10% better on the highway.
The numbers don't do justice to the effervescent nature of
the new I-4,The throttle response is the last word in
immediate,and this is one of those rare 4-cyls,That
continually hits the fuel cutoff long before noise and vibration
suggest a gear change is in order,Twin balance shafts
certainly help in that regard.
The 2L mill has a variable-length intake manifold and a
superb BorgWarner Turbo Systems variable-turbine
turbocharger that,when combined with FSI,all but
eliminates turbo lag,just about the last remaining drawback
of turbocharging.
The 2L I-4 is claimed to be the world's first automotive
engine to combine DIG technology and turbocharging,If
Audi's brilliant new 4-cyl,engine is typical of what happens
when direct injection and turbocharging get together,we
expect to see much of the auto industry follow in Audi's
innovative footsteps.
Toyota DI engine
Toyota Motor Corp,has developed a 4-stroke,direct-
injected (DI) gasoline engine,In conjunction with the new DI
engine is another crucial item,a production-ready 3-way
exhaust catalyst capable of oxidizing the oxides of nitrogen
(NOX)-rich exhaust inherent to lean-burn engines.
The new engine,designated D-4 by Toyota,is a 2L DOHC
inline 4-cyl,Compression ratio is 10:1,and the engine
operates efficiently on regular unleaded gasoline.
The D-4 incorporates a highly optimized combustion
chamber,The piston crowns are fitted with a lipped,cup-like
formation that focuses the injected air/fuel mixture tightly
around the spark plug for maximum burn.
Intake air is drawn through helical ports that create a high
degree of horizontal swirl,which Toyota says combines with
the lipped combustion chamber to not only maintain highly
stable combustion— a quintessential problem for lean-
burners— but also to stratify the air/fuel mixture,
Additional swirl is promoted with special swirl-inducing high-
pressure injectors,The end result is a fuel-rich mixture in
the direct vicinity of the spark plug,with extremely lean
air/fuel ratios near the cylinder walls.
The D-4 can operate stably with air/fuel ratios as high as
50:1,compared with the company's existing indirect-
injected lean-burn engine that operates with maximum
air/fuel ratios of roughly 24:1.
Toyota says a coincidental advantage of the highly
stratified charge employed in the new engine is a cooler air
charge,due to increased fuel vaporization,The cooler
charge increases volumetric efficiency,and the engine also
is fitted with the company's VVT-i (Variable Valve Timing,
intelligent) system to precisely control each cylinder's intake
event.
Lean-burn engines are known for their characteristic high
levels of NOX emissions,The company says the new D-4
uses a high degree of exhaust gas recirculation (EGR)--as
much as 40% when the engine operates in the lean-
combustion mode--and the natural EGR-like operation of the
VVT-i system to drastically reduce NOX production.
The new 3-way catalyst uses a storage/reduction design to
purify occluded NOX at the stoichiometric level -- when the
engine operates in lean modes,excess NOX is stored until it
can be combined/purified with exhaust gases produced
during stoichiometric operation.
The new engine relies on powerful,precise engine-
management software to accurately tailor fuel-injection timing
and duration,At high loads,such as during heavy
acceleration,fuel is injected earlier in the compression stroke,
creating a homogeneous mixture and optimum power,
Crossover points between homogeneous and stratified
mixtures produce semi-stratified air/fuel mixture for
"smooth torque transition."
Torque production in the low- and middle-speed
ranges is improved by 10% over conventional engines,
while fuel economy in the Japanese 10-15 urban fuel
economy test is improved by a significant 30% or better,
Moreover,Toyota claims the quicker response
presented by the DI design improves 0 to 62 mph (0-100
km/h) and passing acceleration times by 10%.
Electronic Throttle— Throttle-By-Wire
Some of the newest Motronic systems have an
electronic throttle (also known as a throttle-by-wire
system),The electronic throttle has no mechanical
link between the accelerator pedal and the throttle
valve,Instead,as shown in Fig.4-3,an accelerator
sensor picks up your movement or position of the
accelerator pedal,It signals the control unit about
pedal movement,and the control unit signals the
servomotor on the throttle shaft to open,The
electronic throttle (Bosch calls it EGAS) may
sound like something none of us needs,but it has
many benefits.
Fig,4-3 Electronic throttle sends accelerator signal to
Motronic control unit DC motor moves throttle valve,
modified by engine temperature,idle rpm,and
maximum rpm
The throttle opening signal may be modified according to
engine rpm and engine temperature,It can provide
simplified cruise control,It can also control minimum rpm,
replacing the idle-speed stabilizer,and control maximum
rpm,replacing the alternate-injector cut-out,
But there's more,For traction control,the electronic
throttle links with the ABS (Anti-lock Braking System),The
same wheel-speed sensors of ABS also feed the ASR (Anti-
Slip Regulator).
When any driving wheel starts to slip,a slight brake
application prevents that wheel from slipping so much that
the differential delivers no power to the other driving wheel,
If both driving wheels show signs of slipping,the electronic
throttle cuts back power for maximum traction,Traction
control gives the car the max acceleration the tires can
deliver to the road,If laying down tire smoke is your thing,
avoid ASR,But for making the fastest takeoff,you cannot
beat it,
Can you trust the electronic throttle? Will it provide
unintended acceleration? The system checks its safety
circuits before start-off,and reports defects to the driver,
If a defect is found,a limp-home circuit may disable
some of the functions,but it will allow you to get to the
house or the shop,It may well be more reliable than
some cable actuated throttles.
小结
Gasoline Direct Injection
Advantages
Mitsubishi GDI
Volkswagen AG's direct-injection(FSI)
Toyota DI engine
Electronic Throttle— Throttle-By-Wire
作业
熟记相关专业词汇
P84 EXERCIES Ⅰ & Ⅱ
