:brick uncle has seen an interesting thing on the internet recently.it's about buying a car.
see this dialogue, you don't laugh, because this also reflects the present a very real problem:a lot of people have a heart that cross-country, suv fire now, but hot these urban suv to high strength cross-country, really can do it?the answer is no, and the next brick uncle will tell you why the city suv doesn't have high intensity off-road.
many people may think that is not a suv, seems nothing but is not the same size, shape is not the same, what's the difference?it's really different, and it's big.
professional off-road vehicles, also known as hard suv, representative models have harvard h9, prado, wrangler, g.and there are too many suvs in the city, such as the road view, hav h6, bmw x5, audi q7 and so on.they have one of the most essential differences, which is the body structure.
professional hardcore off-road vehicles, is a monocoque body structure, also known as the girder body.as the name implies, it has a special force girder to install the mechanical structures such as suspension, engine and transmission.the car shell is another part of the car, which is a little bit more.take it off the shell, and the car can go on.in the case of the non-load-carrying body, it is the bearing body, while the load-bearing body has no single stressed girder, and the whole vehicle needs to be fully stressed.to put it bluntly, a car shell can't be deducted.it's a whole.
so it is easy to understand, the monocoque body, because of the girder, so cross-country, vehicles under the condition of the high strength of twisted, pulling, body force, almost no girder stress.such vehicles are not easily deformed.and if it is a carrier body, playing on the bad road, the body is easy to deform, possibly the final result is structural deformation, the door is not strict, the vehicle is different.
looks like a non-carrying body?of course not, the car of the unloaded body, the center of gravity is high, the weight is large, the control is poor, it is only suitable for the bad road, most people are on the road, or the carrying capacity is more suitable.so there's no one who's better and who's the better one.
about 4 x4 interpretation, there are too many repeated data, but dry brick uncle had always said, is known by friends.in fact, no matter what four drive, can cross country.strong not strong, the key to look at 2 indicators, whether there is an inter-wheel electronic skid device(differential lock) and cross-country low gear.
auto turn, asked about the wheel speed is not the same, then you need a gadget called"differential".as the saying goes, there are pros and cons to all things, and the disadvantages of the differential are reflected in off-road.when a wheel is spinning and idling, another wheel can't move even if it has adhesion.the same is true with four-wheel drive system of the central differential, this means that if the central differential between wheel and differential are open, without any limited slip, as long as there is an idler wheel, the other three wheels will run out of steam.
(below the automobile chassis, in the middle of the round part, limited slip differential in the)
in order to save themselves, so we must limit the effect of differential.this gave birth to two things:a slip differential and a differential lock.both of these devices are designed to overcome the disadvantages of the differential, but there is a difference.the speed limit differential can only limit the function of a part of the differential, and the differential lock is a complete failure of the differential.
(this picture is the front wheels have adhesion, the rear wheels skid, through the limited slip, implements to erase)
(open differential, there is no differential lock, all by auxiliary electronic system, so the rear single wheel have adhesion, unable to save themselves)
, for example, if the differential is 100 idle, idle limited slip differential is 10-90 points, and differential lock is 0 idling, good understanding.therefore, to cope with high intensity off-road, the four-drive system must have a differential lock or differential speed limit slip function.otherwise strong motivation also useless!now city suvs are generally not equipped with differential lock, even though some urban suv is equipped with electronic differential lock based on abs(by the way of differential locking wheels), often locking strength, durability, not quite enough to save themselves.
("4"l"is the meaning of low-speed four-wheel drive, can magnify the torque, let the car more strength)
cross-country climbing, many suv is often because of lack of wheel torque(power) and failure.to improve the force on the wheel, the simplest and most effective method is to set a low-speed four-drive mode.if the power transmission ratio is 3, then the transmission output torque can be magnified 3 times!as a result, many off-road vehicles can climb the slope easily with engine idling after they have been put into low speed.
in addition, how many times the torque amplification, the speed of the car at the same time also can reduce many times, so the low-speed four-wheel drive sometimes also called"slow climb out".people who have played cross-country know that in the face of complicated road conditions, slow crawling is not only powerful, but also safer!obviously, the city suv has not set a low speed four drive.
based on the above, i believe you can understand why urban suv can't heavy off-road.as the saying goes, the fish and the bear are not able to have both, the city suv is controlled, the oil consumption is low, suitable for the road.hard suvs, rugged and durable, are good for bad road play.people should be aware of their needs when buying suvs, and buy the friends of the city suv, and don't think that the four drive is invincible.