Shulou(Shulou.com)11/24 Report--

There are three most difficult things to buy a car: down payment, monthly payment, and parking.

In first-and second-tier cities where land is more expensive than human skin, parking is an annoying equality for all living beings. Whether you are a hundred or eighty thousand vegetable shopping cars or millions of luxury cars overtaking, you don't care about upside-down ducks and concrete walls. Drivers who have had a painful experience of kneading the library will pay more or less attention to the width of the car when changing cars.

Unfortunately, at first glance, it only changes the powertrain. In terms of the ability to move around in a small area, electric cars actually have a natural disadvantage. This disadvantage can be made up by technical means, or it may be more or less revealed. For some pure electric models, it may not be an illusion that it is difficult to stop.

I'm getting stronger and bigger, and today's cars are getting bigger and bigger, which is not strange, as it has been since the birth of cars. Whenever long-standing models such as the Porsche 911 and the MINI are placed with their grandparents, the size expansion of the car has been clear for half a century.

In the direction of the increase in size, especially in the direction of lateral width, pure electric vehicles as a whole, compared with fuel vehicles, presents a more positive and active attitude and status quo. When the length of the body is similar, electric cars tend to have a relatively larger width.

For example, for medium-sized cars, the typical BBA three intermediate cars have a range of external dimensions, with the length in 4728~4762mm and the corresponding body width in 1820~1827mm (only A4 for 1847mm). All take the standard axle data, excluding the width of the rearview mirror.

Compared with the three BBA competitors, the Model 3 has the shortest 4694mm and significantly smaller than the three fuel vehicles, but the width 1850mm is the maximum of the four. Or looking down from the roof, the Model 3 is the most square.

The picture is marked with rearview mirror width if the Model 3 is not obvious, relax the length range a little bit, slightly longer than the BBA axle medium-sized seals and ET5 (4800mm, 4790mm), the car width reached 1875mm and amazing 1960mm respectively. This is flat or even more than BBA medium-sized and large cars.

When it comes to medium and large cars, the Weilai ET7, Zhiji L7, Polar Krypton 001, Nezha S is as wide as 1960~1999mm, and the narrowest Mercedes-Benz EQE and Zero C01 are also above 1900mm. In the fuel truck world, the typical width of the E-Class, 5-Series and A6 is still "retained" in the 1860~1880mm.

For the new primary pure electric platform, the internal combustion engine can push the four wheels to the four corners of the body as far as possible, and the ratio of wheelbase to length, that is, the axle length ratio, is usually larger. This is clearly reflected in Mercedes-Benz EQS / EQE and smart # 1. Compared with fuel vehicles of the same length, the wheelbase can be more 100~200mm.

Of course, it is not that any electric car has the characteristics of wider and longer wheelbase than any fuel car. And fuel cars are likely to continue to widen over the next few years as they are updated iteratively, and as in the example of 911 above, things have been dynamic.

However, as a whole, the more newly launched and high-end electric vehicles are, the more obvious the tendency of large width and large axle length ratio; compared with the fuel vehicles of the same era, electric vehicles tend to seek wider body width. at the same time, it is easier to choose a relatively larger wheelbase length.

And we know that under the premise of the same body length-discussing flexibility obviously needs to control the size level variable, the pure electric car (as a whole) has a wider body and a longer wheelbase. All these are not conducive to reducing the turning radius and improving flexibility.

For example, a large sedan of a newly built brand without rear wheel steering has a minimum turning radius of 6.3 meters with a width of nearly 2 meters and a wheelbase of 3.1 meters. This means that in most urban areas where the width is less than 3 meters, it is almost inevitable to make a U-turn in two lanes.

Bigger and more expensive, so the larger shaft length ratio of krypton is the benefit of electric cars abandoning the internal combustion engine, but it is not necessary. Then in the case of making use of the advantage of the axle-length ratio of electric vehicles to achieve a long wheelbase, which is bound to damage flexibility, the choice of a larger width can only be caused by other aspects.

Security is easy to think of. The importance of battery safety needless to say, the car has a certain buffer space in front and rear, only the impact from the side is closest to the battery. In fact, this is the same as crew safety, the lack of cushioning side collisions are always the most likely to cause injury. In order to prevent side collisions, electric vehicles generally adopt a wide side sill beam structure.

Xiaopeng G9, grey threshold beam using extruded aluminum profile stronger threshold beam is also one of the typical features of electric vehicle body-in-white structure, threshold beam and battery side buffer structure occupy a certain width, but also to ensure the internal ride space and battery pack width-the latter determines power and battery life. As a result, the overall width of the electric vehicle tends to go straight to the maximum possible.

The width increases and the wheelbase increases, but if the maximum deflection angle of the front wheel can be increased, the turning radius may not increase and the low-speed flexibility level can be maintained. However, the innate structure of electric vehicles determines that they are not easy or suitable to do so.

In the past, it was generally believed that due to the removal of the internal combustion engine from the electric car, the space in the front engine room was liberated, and the left and right deflection space of the front wheel should be greater. However, in some electric vehicles, the front longitudinal beam moves further to both sides, and the central motor does not make full use of the space between the longitudinal beams, while the deflection space left on both sides of the front wheel is reduced.

Lucid Air, there is still a lot of space on both sides of the front motor in order to improve the collision safety, the front longitudinal member of the front of the fuel truck era can directly transmit energy to the multi-channel longitudinal structure arranged at the bottom of the car. In an electric vehicle, because a large area in the center of the chassis is occupied by a tiled battery pack at the bottom, the forward collision energy needs to be transmitted backward.

For example, with already stronger side threshold beams, some electric cars direct collision energy from the front longitudinal beam to the threshold on both sides. For the energy transmission under this path to be as efficient as possible, the front longitudinal beam at the front of the car needs to be as close to both sides as possible, but this will naturally compress the space left and right for the front wheel to deflect.

Weilai ES7

The energy transmission path of fuel-fueled vehicles is more common in high-end electric vehicles. In addition to collision energy transmission, high-end cars need to pursue high body stiffness in order to pursue better NVH and driving quality. Between the front longitudinal beam and the side sill beam, a large anti-torsion box (torque-box) made of cast aluminum is used to make the side sill beam share the load from the front wheel together with the front longitudinal beam.

ES6

I-PACE pushes the front longitudinal beam to both sides for body performance, and the large size of the high-end car makes the flexibility even worse, so the front wheel deflection angle can not be increased or even limited, so the rear wheel steering system RWS has almost become the standard and symbol of large-size high-end electric vehicles. Although fuel vehicles are also being large-scale and use RWS, the demand for electric vehicles is particularly urgent.

The Mercedes-Benz EQE has achieved a significant improvement in only the minimum turning diameter from 12.5m to 10.7m with a rear wheel steering capacity of up to 10 °in the case of 3120mm wheelbase. The Zhiji L7 wheelbase is similar, but the width of the car is larger. The 6 °rear wheel steering (12 °left and right) reduces the turning diameter by 1.3 meters.

It can also be seen that the width of EQE's 1906mm is narrow in the same class of electric vehicles, and it still depends on the existing 4.5 °rear wheel steering before the upgrade to achieve a turning diameter of 12.5m / radius of 6.25m, which shows that only the front wheel steering has to face the pressure. Because of the structural characteristics of electric vehicles, RWS is likely to become an indispensable business card configuration for high-end electric vehicles in the future.

The car is a systematic project, one link after another, leading the whole body. High-end cars with less scruples about cost can rely on krypton gold to get rid of some of the weakening tendencies caused by the structure of electric cars, thus leaving the tendency to stay in the tendency. Rear wheel steering is the hardware foundation, and there is bound to be thought of a lifesaver, automatic parking.

Only the width of the car body exists, it still needs to be rescued by the standard infrastructure. The narrow parking spaces that are not uncommon in some first-and second-tier cities, not counting the rearview mirror, are nearly two meters wide, probably only partially compensated by functions such as automatic summoning.

Small and medium-sized cars that do not pursue space are inherently flexible and may not be easy to sense the difference. But there will also be some unlucky people who, because of necessity or coincidence, such as being large but unable to use RWS, may become the one trapped in the parking space by electrification. If you encounter an electric car that is surprisingly difficult to stop, it may not be your problem.

This article comes from the official account of Wechat: autocarweekly (ID:autocarweekly), author: ao'hu

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