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🚗 | [Land Rover Defender Snow Test Drive] Akihiko Nakaya notices the significance of the existence of the "Crocan SUV"


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[Land Rover Defender Snow Test Drive] Akihiko Nakaya notices the significance of the existence of "Kurokan SUV"

 
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No matter how good a 4WD car is, its turning ability is almost the same as that of two-wheel drive.
 

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Four-wheel drive

Four-wheel driveWhat is "Yonrinkudo"?AutomobileA type of driving method such as. There are fourWheelA method of transmitting driving force to all and using all four wheels as driving wheels.

Designation

Four wheel drive carFour-wheel drive vehicle(Yonrinkudosha), abbreviated asXNUMXWD(Yonku).EnglishStands for four-wheel drive4WD, Or all-wheel drive (also called all-wheel drive/so-ring drive, all-wheel drive/zenryodo)AWD.EuropeSo, of the four wheels, all four wheels are drive wheels.4x4Also known as (four-by-four). Since a typical car has four wheels, it is called four-wheel drive, and cars equipped with five or more wheels are often called all-wheel drive or all-wheel drive (AWD). Become.AmericaSince the "Four Wheel Drive" company once existed in Japan and was registered as a trademark, it is often referred to as "AWD" mainly in Europe and the United States. In addition, in Japanese, words such as "4WD", "4x4", "XNUMXWD" not only mean AWD as a drive system, but alsoCross countryCars andSUVIt is sometimes used to refer to the vehicle itself as an alternative to the "Jeep" in the generation of people who have not penetrated.

Overview

There are two main purposes for adopting four-wheel drive in automobiles. To drive over rough roads such as snowy roads and mud, where stalls tend to occur, and to transmit the high torque of the high power engine to the road surface. General passenger cars, commercial vehicles, military vehicles, civil engineering and construction machinery, etc. are the former reason. In Japan, there is a densely populated area in the heavy snow region, and the snow quality is also moist and heavy, so there is a demand for four-wheel drive. Manufacturers have four-wheel drivesedan,andMinivan,Small car,Light passenger carWidely set to meet the demand for snowy areas (cold areas). On the other hand, overseas, there are few major cities in areas with heavy snowfall, the snow quality is dry and dry, and there are many movements on flat roads. In addition, spiked tires are approved in Northern Europe, and the demand for 4WD vehicles is limited compared to Japan.[1].

The second reason for adopting four-wheel drive is increasing in recent years when it is installed in high-power vehicle models that emphasize sportiness.Audi QuattroAsk the world atManufacturerWill follow the currentNissan GT-R,LamborghiniThe idea is to reach each model. The "SPYKER" described below is one of the first four-wheel drive vehicles that emphasized this sportiness.

The braking performance is equal to or less than that of the two-wheel drive, and the weight is rather heavy and the braking distance is extended.

Most of the engine is mounted on the front engine, and the front axle is behind the center of gravity of the engine. Some of theRear engine4WD ThePorsche 911,Subaru Sambar(3rd generation-6th generation), and exists in Hafflinger of Steyr Puff. AlsoMidship4WDIt is,Mitsubishi Pajero,Toyota Estima(First generation),Honda acty,Suzuki Every(3th generation),LamborghiniEach model,Bugatti Veyron,Audi R8 (production car)There are examples such as.

General strengths and weaknesses

As an advantageTwo-wheel driveCompared with, the traction force is greatly improved. In particular, the driving force is the grip force of the tire (Friction) On the road surface where slipping is likely to occur,treadIt is possible to disperse the driving force applied to the. For this reason, it is excellent in escapeability on a rough road and high-speed running performance. Similarly,Engine brakeSince the braking force due to is distributed to the four wheels, the wheel lock (タ イ ヤ OfGliding) Is high, there is an advantage that the recovery from the lock is fast.

As a disadvantage, compared with the two-wheel drive, since a drive system is added, the structure is complicated and the manufacturing and maintenance costs are high. Also weight andresistanceWill increaseFuel efficiencyWill get worse. In a live axle with a built-in diff, the unsprung weight also increases, which causes disadvantages in road surface followability and riding comfort. furtherDrive shaft,gearIs addednoiseIt is also disadvantageous.

When the car body turns, a difference in rotation occurs between the outer and inner tires, but a typical carDifferential gearIt is equipped with (differential), which divides the engine output into two different rotational speeds and prevents the drive wheels from slipping. Two-wheel drive vehicles have one differential for the left and right pair of drive wheels, whereas four-wheel drive vehicles require at least two for the front wheel pair and the rear wheel pair. Even between the front and rear wheelsInner ring differenceTherefore, before the engine output goes to the front and rear differentials, it is necessary to absorb the rotation difference between the front and rear wheels.Center differentialSome are equipped with. In this case, one output is distributed to four different rotation speeds.

In a vehicle model without a center differential, either of the front and rear wheels forcibly slips when turning,brakeI was hit by a phenomenon likeManual transmissionWhen driving at low speedengine stallThere are also things to do. This is called the tight corner braking phenomenon. Further, when a small turn is made at a low speed, small slips occur, which may cause unpleasant vibration of the entire vehicle body. Widely knownジ ー プThere is also a part-time four-wheel drive vehicle that normally uses two-wheel drive and switches to four-wheel drive only when necessary, such as on a slippery road surface. Since this system does not have a center differential, it is premised that four-wheel drive runs on slippery roads.

History

The first four-wheel drive vehicle1805In americaMarylandIt is said to be a dredging ship manufactured by Nono. Wheels are attached to the ship to transport it overland from the factory that produced the dredger,Steam enginePower ofBeltI ran by telling the front and rear wheels. After thatSteam engineA four-wheel drive vehicle using was manufactured.1824ToThe United KingdomUKMade by William Henry James inSteam carFor each of the four wheelscylinderIt was designed to absorb the rotation difference of each wheel without using a differential.

Electric motorFour-wheel drive vehicles using1900AroundFerdinand PorscheIs made by. This car will laterIn-wheel motorCalled of each wheelHubIt had a four-wheel drive with a built-in drive motor.

gasoline engineA four-wheel drive vehicle using1902To NetherlandsMade by the Spyker brothers ofSPYKERIs the first. This car has 3 forward speeds and 1 reverse speedト ラ ン ス ミ ッ シ ョ ンAnd the second speedtransferIt is designed to drive four wheels via a center differential, and has basically the same mechanism as a modern full-time four-wheel drive vehicle.

1903Has four-wheel drive at Daimler GmbH, AustriaArmored carWas developed. This carArmorAnd 37 mmMachine gunEquipped withTurretIt has four gears and has four gears, a forward gear and a reverse gear. Also,Ford Model TAlso in1910 eraThe four-wheel drive kit was sold after that, and there were vehicles that were made into four-wheel drive, but this is an engine that works only for the rear wheels, which are drive wheels, rather than for improving running performance.brakeIt was to make the front wheels also act.

World War IMiddle and American car companyJeffrey Motor Company(Rambler car company name at the time) is a four-wheel driveTrackAre designed and manufactured. This is known as (Quad Truck or Jeffrey Quad, Nash Quad). Fight in europeAllied ForcesProvided toJohn PershingUnder command, used for heavy duty military applications.

JapanIn1935(Showa10 years ago, in the previous yearImperial ArmyRequested byJapanese Internal Combustion MachineDeveloped byType XNUMX small passenger car(Kurogane Shiki) has appeared. Type XNUMX small passenger carU.S. Forces Ofジ ー プJapan's first practical four-wheel drive vehicle that was developed and mass-produced prior to1936From (Showa 11)1944A total of 19 units were produced until (Showa 4,775),Sino-Japanese war-Nomonhan case-Pacific WarWidely used for reconnaissance, messenger, and transportation.

1941, Jeep appeared in America.German army OfCubelwagen(Two-wheel drive vehicle.1940Appeared around)Military vehicleFrom the prototypes of each company to the specifications of the US Army,bantam(English edition)The company's plan was adopted. Bantam naturally wanted to make it in-house, but in reality most of it depends on the scale and quality of its production equipment.Willis(English edition)CompanyFordIt was ordered and manufactured by the company. Jeep can be useful as a car to drive through rough roads on the battlefieldSecond World WarProven in, through mass productionAllied ForcesWas supplied to and ran across the world. Jeep's success therefore attracted attention all over the world. Even in Japan, the Army is on the Southern FrontCatchingBring back the bantam jeep to Japan and make it with the order that "the body should not be similar"Toyota, But soon it was defeated.

After the warIn Japan, there was a growing demand for cars to drive on rough roads even in the private sector, but at the beginning, there were only options such as discontinuing military cars and making domestically produced jeep-type cars that were made similar. Still,Prewar(1930 eraFor the Japanese at that time, who only knew the (old) car, the power and technology of the jeep were to convey the technological progress of the United States.1953(Showa 28) New Mitsubishi Heavy Industries (→ Mitsubishi Heavy Industries →Mitsubishi Motors) Is a Willis Overland JeepPolice reserveForKnockdown productiondid. Self-developedToyota Jeep (later renamed Land Cruiser)とNissan PatrolOf the police reservebidBecause I was defeated by Mitsubishi atNational local policePioneered a path for private and private demand. The Mitsubishi Jeep will then add models developed in Japan,Defense AgencyIn addition to expanding sales channels, while achieving unique evolution1998It was produced until (10). The "Jeep" has come to be used as a synonym for all small four-wheel drive vehicles.

1970 eraA turning point came one after another.1967(Showa 42),Hope car Light car(At that time 360cc) Full-scale four-wheel drive vehicle with a frame "Hope star ON type 4WDWas released. This vehicle isSuzuki JimnyIt was the predecessor of "," and put a stone in the form of a four-wheel drive vehicle = a large displacement vehicle.Fuji Heavy Industries(CurrentSUBARU) Is called "a field patrol vehicle that is more comfortable than a Jeep and can be used all year round"Tohoku Electric PowerIn response to the requestSubaru ff-1 1300GTo the van,Nissan BluebirdPart-time 4WD "Subaru ff-1 1300G Van 4WD" with rear axle is manufactured.1972(Showa 47)Leone 1400 Estate Van 4WDWas launched as a new category of passenger 4WD.

1970 eraIn the USCounter cultureIn Japan, which was influenced byOutdoorThere was a boom,Cross countryThe car became popular. At this point, laterRVThe concept of Japanese-specific leisure vehicles has begun to form. In 1984, it was a pioneer of passenger cross-country vehicles, maintaining both easy-to-use as a passenger car while maintaining the rough road running performance as a cross-country car.Mitsubishi PajeroWas released and caused a big boom. In 1985, the third generation equipped with the world's first full-time four-wheel drive in a horizontal engineMazda FamiliaAppeared[2], Full-time four-wheel drive technology with center differential began to become popular in passenger cars as well. As a result of these trends, four-wheel drive vehicles are now set for all types of vehicles.

Four-wheel drive type and mechanism

Permanent type (narrow sense)

The most primitive four-wheel drive system, also called permanent direct drive type. A prototype four-wheel drive vehicle in the early days,Military vehicle,Agricultural vehicleFound only in part of. This method is not adopted as modern passenger car technology.

Of course, it does not have a center differential that absorbs the difference in rotation between the front and rear,transferIt is not suitable for use on normal roads or for high-speed driving because you can't choose the two-wheel drive condition even if you don't even have it, or if you have it.

In addition,Construction machineryFor example, steering the rear wheels in the opposite phase at the same steering angle as the front wheels (Four-wheel steeringHowever, there is an example of avoiding the tight corner braking phenomenon by matching the trajectories of the front and rear wheels, but in extreme casesUndersteerDue to the characteristics, it is not possible to cope with the speed improvement.

Full-time type (center differential type)

Permanent type (broadly defined), also called constant type. A differential gear called a center differential (differential gear) is placed between the drive shafts connecting the front and rear wheels to absorb the rotation difference between the front and rear wheels when turning. Since the torque is distributed properly to all the wheels at all times, it excels in stability when traveling at high speeds or in rainy weather.

The early four-wheel drive vehicles that adopted this method were simple with no differential limitation.Differential gearWas using. In that case, when one wheel starts to spin on a bad road, the driving force is hardly transmitted to the other wheels. In order to avoid this, a direct connection mechanism ((Diff lock) And those that use limited slip diff. However, these names do not have a uniform definition among manufacturers, and those that use a fluid clutch (coupling) instead of differential gear or transfer for the front and rear connections, such as the standby method described later, are generally full-time type ( It is called (in a broad sense). Even in the field of service such as maintenance, the front and rear connecting parts, whether they are gears or clutches, are sometimes called center differentials, but there is a big difference in running performance, as described later.

Incidentally,Military vehicleAnd off-road orientedCross countryCar orSUVIn part of, in order to improve running performance, not only the center diff, but also the front and rear diffs (axle diff) can be differentially limited or directly connected.

Part-time

Also called the selective formula. Usually, it is based on two-wheel drive, and is a system that switches to four-wheel drive by connecting a transfer that takes out power only when necessary. This was also essential for avoiding many problems such as the occurrence of tight corner braking phenomenon, deterioration of handling and fuel consumption, and making the vehicle usable on paved road surfaces. Also, in terms of automobile manufacturing, it is still practical and has been adopted by many models as a method that allows the original 2WD vehicle to be retrofitted to 4WD.

Part-time vehicles do not have a center differential, and four-wheel drive does not absorb the front-rear rotation difference at all, but absorbs the rotation difference by generating a forced slip between the tire and the road surface. That is, four-wheel drive traveling is premised on a slippery bad road.

If you drive on a dry paved road with part-time four-wheel drive, the tires and road surfacefrictionThe force is so great that tire slip cannot occur, causing tight corner braking and torque circulation. The drive system may be damaged or burned out, so caution is required. Torque circulation occurs even when the front and rear tire diameters are different. It happens even if the tire size in the catalog is the same, the model name is different (tread pattern or slight difference in diameter), or the degree of wear of the tire is visible. Further, it has a very high straightness regardless of the steering angle of the steering wheel. It is important to note that the maneuverability and stability of the vehicle will be greatly impaired. It is recommended to switch between XNUMXWD and XNUMXWD at low speed with the steering in neutral, or at a stopped state. A caution plate is attached to the inside of such a vehicle type, and these facts are noted.

Assuming that it is used on rough roads, the mechanism is relatively simple and reliable, and the advantage of permanent type or center differential type differential lock state can be obtained, so it is possible to drive on harsh off-road such as sandy land, mud, rocky mountain etc.Cross country,stackIt is effective to use for recovery from Since there are few merits unless such a full-scale off-road driving is premised, there was an example of adoption in passenger cars in the past, but it is almost obsolete now.

In addition, it is also common to mechanically disconnect the driven wheels using a freehub, etc. Many vehicles have a manual hub or an AUTO freehub.Land roverLike Series I,One way clutchAs a result, there is also a system in which four-wheel drive is used only when moving forward.

Part-time 4WD is for jeep andSuzuki JimnyIn a traditional cross-country car likeAt least for Japanese cars, most of the existing vehicles are based on FF.[3][4].. On the other hand, most of the original FR cars do not have a space for the front axle (there is the space for the engine), so it is difficult to use 4WD. MR layout mechanical part-time 4WD vehicle is a Japanese cabover style minivan[5]Among them, almost all cars except RR's Sambar and Domingo are adopted. The so-called "center midship" isHonda actyOnly the old model of. For RR layoutSubaru SambarAnd its expanded typeSubaru Domingo[6]There is no other example.

Full-time/part-time compound formula

It is equipped with both a part-time switchable transfer and a full-time center differential, and can be used as a full-time or part-time type. Fuel economy in two-wheel drive, stable running by distributing the driving force by the center differential, running on bad roads with direct front and rear connections, all of which can be added.

There are differences in the differential absorption method, drive distribution method, etc.Selec truckThen, we adopted a non-differential method of changing the distribution by viscous immediately after the transmission and having a transfer.Mitsubishi Motors OfSuper select 4WDThen, a method that has a differential immediately after the transmission, and then a viscous bypass with a chain and a transfer.ToyotaIn the multi-mode 4WD of, the order is the same as that of the super select XNUMXWD, but they are placed without bypassing. Both are full-scale cross-country vehicles equipped with a rudder frame and a rigid axle, but they are used for RVs that have passenger car taste for passenger comfort and decoration by diverting passenger car parts.

It has double and triple equipment, and it has a drawback that it is heavy, but in the case of a large country cross-country vehicle, it is originally responsible for low range switching for transfer.Sub transmission(* It has a low range for running on rough roads, not for improving CVT fuel economy.)Driving performanceIt has been adopted for vehicle models that are not so disadvantageous.

On-demand type/Standby type (passive type)

There are many users who are confused about switching between XNUMXWD and XNUMXWD in the part-time system, and there are not a few troubles such as breaking the car or causing a fire by running at high speed on the paved road without noticing the direct connection state. Therefore, an on-demand system was devised that does not require a switching operation and is automated. Fluid clutch (instead of center differentialFluid fitting, Which is also called a coupling), and normally runs with either the front or rear main drive wheel, and if there is a difference in rotation between the main drive wheel and the remaining two wheels (the sub drive wheels), the drive force is also applied to the sub drive wheels. Automatic transmission method. The driven wheels have an auxiliary function, and are not suitable for a long time or transmission of a strong driving force. It is also called a passive type because drive distribution is performed after it is needed. (Actually, the coupling is a wet clutch filled with high-viscosity oil, so it never completely disengages. Torque is applied). There is no need to disconnect the driven wheels, and there is almost no XNUMXWD selector switch.

It is often confused with the center differential system with viscous LSD, but it shows a completely different operation in terms of long-term durability and driving force distribution, and this standby system without the center differential is mechanically simpler. With a multi-plate clutch in a sturdy cylindrical caseSilicone resinAnd the multi-plate clutch is crimped by expansion of silicon due to stirring heat generated by the difference in rotation between the front and rear wheels to limit the differentialViscous couplingIs the method of inserting into the propeller shaft in front of the rear differential. No electronic control device required, especiallyVolkswagenThe early large ones adopted by were excellent in response and effectiveness. After that, to Visco DrivePatentToraiblade (3 leaves)propeller) Expressions andDual pumpAlthough a fluid clutch of the type appeared, it was lacking in sophistication, such as poor response in general and sudden connection.

In particular, the latter standby type 4WD has a clear lag until the rear wheels are driven by slipping on a bad road, and the driving force is applied to the rear when the front slips at corners etc. It may cause great shaking and spin of the car body. Was often there. There are many situations in which there is no real merit in driving on rough roads, and it is often ridiculed that "no one is better" or "Nanchatte 4WD". At present, it is rare to be adopted in the category of ordinary cars or more, but by taking advantage of the lightness of the system while making improvements such as increasing the pressure inside the case, it is often adopted in compact cars and light cars with a displacement of less than 1500cc. ing.

Although this item distinguishes from the center differential type full-time 4WD,In JapanIt is,Honda Motor Co., Ltd.(Isuzu MotorsToOEM(Including products that were supplied) used the name "Realtime 4WD"Nearly all passenger car manufacturers call the viscous coupling 4WD "full-time 4WD"... In particular, Fuji Heavy Industries (nowSUBARU)When,Mitsubishi MotorsThe implications of the fact that he followed this are great. In addition, as a commercially available base competition carSuzuki Alto Works""Daihatsu Mira The TR-XX” has been adopted and has a great track record.

Torque split type/Active torque split type/Active on demand type

It is an on-demand type developed type and has a clutch mechanism of a fluid coupling on the drive shaft of the same type, but an electronically controlled pump controls increase/decrease in clutch case oil pressure to actively control front/rear drive force distribution. Using the method to do.

While the conventional on-demand (standby) type distributes the driving force to the rear wheels after a mechanical rotation difference occurs, this is the rotation difference of each wheel, steering wheel turning angle, throttle opening, G sensor Since the vehicle driving conditions are electronically calculated to predict slippage and the vehicle is driven, it is possible to obtain driving performance and stability according to actual driving conditions. In addition, the drive control is programmed even when starting or slightly turning the steering wheel, which often contributes to handling and drivability on the pavement. Some of them allow the driver to actively select (mode switching) the tendency of automatic calculation depending on road conditions such as dry roads, rainy roads, and frozen roads.

As typical ones, Toyota's dynamic torque control, Nissan's all mode 4x4, Honda'sIntelligent control system,VTM-4, SUB-4 ACT-XNUMX, Mitsubishi AWC, Suzuki ALL GRIP, BMW xDrive, etc. Alsoスウェーデン OfHaldex Traction CompanyMade active system is highly rated,VWsystem,Volvo,Ford,GMIt is used by overseas manufacturers such as[7].

Even when switching to 2WD, most of them do not use transfer disconnection, etc., but instead switch the distribution using electronically controlled switches. Some models do not have a 2WD selector switch. In addition, released in 2019Toyota RAV4Has adopted a mechanism to prevent the deterioration of fuel efficiency in FF driving by disconnecting the propeller shaft, though it is electronically controlled.[8].

Torque vectoring type

In addition to activating front-rear driving force distribution,Yaw control differentialA sophisticated four-wheel drive system that electronically variably distributes the driving force even between the left and right wheels.

By freely and variablely controlling the front, rear, left, and right driving forces, it is possible to forcibly generate a yaw moment (turning force) during turning, which a conventional four-wheel drive system has as a physical barrier. Overcoming the weak point that the stability of driving characteristics during turning was reduced. Furthermore, it becomes possible to positively control the turning characteristics, which is the control of the accelerator amount.Traction control systemFunction or individual brake controlAnti-skid deviceBy performing comprehensive control in combination with the system, we obtained turning performance superior to that of a rear-wheel drive vehicle. Various characteristics can be given by the control program, and it is also possible to exert excellent running performance even on rough terrain traveling such as split mu road.Mitsubishi Motors OfS-AWC (Super All Wheel Control)In 2001Mitsubishi Lancer EvolutionAdopted from the popular Evo 7 of the series, it set a precedent. In Honda, the drive was made active (prior to electronic control depending on the situation) by using front and rear with a fluid joint only without center diff, and using differentials with planetary gears on the left and right.SH-AWDCalled systemlegend,AcuraAdopted in 2004. Manufacturers such as BMW and Audi have also followed and adopted the left and right active differential systems.

Power distribution type

A power source is attached to each driven wheel or front and rear axles.

Internal combustion engine

Internal combustion engineIt was prime20st centuryIt couldn't be mainstream, but it still has a long history,Ferdinand PorscheA motor-driven vehicle prototyped by1900 OfParis World ExpositionIt has been put up for sale.

Since the output becomes the driving force of the tire almost as it is, there is little energy loss, and while the power distribution of the four wheels can be freely decided, the existingdiesel engineIn the case of gasoline engines, there is a limit to miniaturization, the number of parts is large, exhaust treatment is troublesome,throttleDue to the high degree of control required for motion coordination, there were only experimentally built vehicles. HoweverElectric carIn the case of No, there is no exhaust, and since it is only necessary to extend the wiring for electric power, there is little loss and it is advantageous from the point that the room can be taken widely. Mitsubishi MotorsLancer Evolution MIEVOr, although it is an "8-wheel" drive vehicle,ElikaHas adopted this method. After that, the MIEV system was commercializedMitsubishi Outlander PHEVIn the above, the two front and rear motor drives are dynamically controlled, and the left and right rear wheel drive forces are differentially controlled.AYCControlled byS-AWCIt was equipped with a mechanism. For more information,S-AWCSee section.

With an internal combustion engine,Hill climbSuch asCompetition vehicleThere is an example of twin engine in, but in a commercial carCitroen 2CV 4x4, also known as "SaharaIs almost unique. Originally with 2CV engineTransaxleFits in the front, but another same onetrunkIt was crushed and pushed. The cooperation of the two sets is simple,throttleIs a wire,ト ラ ン ス ミ ッ シ ョ ンIs only linked by shift linkage, the other two engines are independent of each other, two main switches are provided, and it is possible to operate with only one engine. ,DesertAtRedundancyIt can be said that the design has a strong implication for securing. on the other hand,Citroen Mary 4x4 istransferとSub transmissionHaving a general part time4WD.

electric motor

Electric 4WDIt is called. In addition to the drive shaft by the engine,motorThis is the method to drive the other axle. In the early days of Nissan, which was adopted as a life 4WD in terms of coste-4WDLike this, it was a simple one with a low output (about 5 ps) aimed mainly at assisting when starting on a low μ road, but hybrid vehicles with a powerful motor and battery have become common, and it is standard equipment It is expected that it will become one of the main methods in the future.

Currently, the "e-4WD" system for vehicles sold in JapanAutomatic transmissionHowever, it is only necessary to control the output of the electric shaft according to the number of revolutions of the engine drive shaft or the torque applied to it.Manual transmissionCombination with is not impossible.

Motor sports

Emphasis is placed on turning and agilityRally,Rally crossIn the 1980s, four-wheel drive became popular in the worldGroup BIs the age of. At the time when the technology was not developed, four-wheel drive was rare,WRCTo participate inSubaru Leone OfSafari RallyIt was first to participate in the spot, but it has become popular in the upper classAudi quattroIt was due to the success of. Both Audi and Subaru are pioneers of four-wheel drive passenger cars, but neitherVertical engine-Front wheel driveSince there was a car with the structure of on the market, take out the drive shaft from the vertical gearbox to the rear.DifferentialWith the addition of a rear-wheel drive shaft and other processing, the structure was relatively easy to drive with four wheels.Group AIn that era, almost all upper entrants adopted four-wheel drive.After that, the management side drastically relaxed the rules for two-wheel drive vehicles in order to increase entrants, and as a result, the two-wheel drive vehicles won the overall victory twice in 1999.[9]However, regulations have been tightened since then, and the top category has been contested only for four-wheel drive until now.

Even in the same off-road system, reliable running performance is requiredRally raidThen, the first timeParis-Dakar RallyWon theLand Rover / Range RoverAs is the case, four-wheel drive has been common for a long time.However, in recent years, the operation has been active in promoting two-wheel drive vehicles, and it is no longer rare for two-wheel drive vehicles to defeat four-wheel drive vehicles with significant deregulation.[10].. As of 2021, four of Dakar's last five events have been won by two-wheel drive vehicles.

In circuit racing, in the 1960sF1Four-wheel drive machines have appeared for a while[11]However, due to its immature technology, it could not be used with terrible understeer, and there were many disadvantages such as heavy weight, poor fuel economy, and no matching front tires.It disappeared when the rear wing, which can earn traction without a complicated mechanism, was invented, and in 1983, four-wheel drive was officially banned.[12].Touring carIn the era of Group A in the raceNissan Skyline GT-RHowever, due to the above-mentioned disadvantages and tightening of regulations, conversion to FR became the mainstream.SUPER GTBut special approvalSubaru ImprezaWon the GT300 victory, but withdrew due to the tightening of regulations.Currently extremely popularGroup GT3,TCRAssuming performance adjustment such asTouring carIn racing, it is extremely difficult to adjust the performance with a two-wheel drive vehicle, and there is a clear difference in advantages and disadvantages especially in stormy weather, so if the base vehicle is a four-wheel drive vehicle, it is generally required to replace it with a two-wheel drive vehicle. Is the target.for that reasonSuper endurance,Nürburgring 24 hoursIt is still only recognized in the lower classes of races with strong amateur colors.

But it was the only professional circuit race that started in 2012.WecFour-wheel drive is being actively adopted in. Under LMP1 regulationsAudi R18,Toyota/TS050 HYBRID,Porsche 919 HYBRIDBut modern advanced four-wheel drive technology +hybridWith the packaging of technology, it gained speed approaching F200 which is as light as 1 kg, and temporarily gained immense popularity. Scheduled to come into effect from 2021Hyper carThe regulations also permit the adoption of four-wheel drive.

footnote

[How to use footnotes]
  1. ^ How to choose "4WD" cultivated by Japan's climate with one of the world's most heavy snowfall areas 2016.2.22 Masayuki Moriguchi
  2. ^ Japan's first full-time 2WD was Mazda! Speaking of AWD, two reasons that are likely to become Mazdacliccar January 2016, 1
  3. ^ Is a dawnSubaru LeoneHowever, the FF drive system is extended and the rear wheels are driven via transfer. Fuji Heavy Industries (currentlySUBARU) Was a subsidiary company at that time because there was no rear axle production know-how because FR cars were not produced at the time of the release of the first Leone 4WDNissan MotorからBluebirdHad been OEM supplied. Other companiesToyota Sprinter CaribbeanAnd so on.
  4. ^ IwanyaMitsubishi Minica(Up to the 4th generation)Suzuki Cappuccino, And is manufactured with Suzuki OEM partsCaterhamThere is only Jimny in the light car which has only FR model of FR.
  5. ^ OnceOne box carThe car type called.
  6. ^ Based on a Sambar engine with a 1000cc engine and a 3-row seat for a 7-seater passenger car. When it became 1200cc later, it became a one-way clutch type, but in the subsequent full model change it became a viscous coupling type described later.
  7. ^ What about full-time 4WD for imported cars? Do you have individuality with various controls 2017.10.03 / Entertainment Best Car Web Editor
  8. ^ What is the world's first "dynamic torque vectoring AWD" of the new Toyota RAV4
  9. ^ Citroen KusaraF2 kit car
  10. ^ Dakar's Shlesser Buggy, Peugeot 3008 DKR Maxi, MINI JCW Buggy, etc.
  11. ^ Faggerson P99, BRM / P67,Lotus 63, Matra MS84, McLaren M9A
  12. ^ Four wheel drive prohibited in F1Tochu F1 Express July 2010, 7

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