Why is there an urgent need for cars to be lightweight?

What's the point?

Among all parts of a car, the chassis has become the one with the greatest room for aluminum alloy materials.

For new energy vehicles, in order to replace part of the fuel vehicle market, the demand for lightweight is more urgent. As a new lightweight market, battery packs, the weight reduction of the casing is particularly important.

"Technical Roadmap for Energy Saving and New Energy Vehicles 2.0" puts forward clear requirements for the fuel consumption of fuel vehicles. In the three stages of 2025, 2030 and 2035, the average fuel consumption of new passenger cars (excluding new energy vehicles) needs to reach 100 kilometers respectively.

5.6, 4.8 and 4.0L.

For fuel vehicles, reducing fuel consumption is inevitable, but as fuel consumption standards become increasingly tighter, the space for reduction is getting smaller and smaller, and it is becoming more and more difficult to reduce consumption by relying on traditional power modules.

On the other hand, subsidy policies are also raising the threshold for new energy vehicles' battery life. As a new component, power batteries also have a greater impact on the vehicle's battery life.

Therefore, whether it is due to factors such as fuel consumption, battery life, cost, etc., lightweighting is undoubtedly a very urgent matter.

SAIC Volkswagen engineer Shen Weidong made it clear at the "2021 China Automotive Aluminum Alloy Developers Forum" that experiments have proven that for every 10% reduction in the weight of a traditional vehicle, fuel consumption is reduced by 6%-8%, and the vehicle weight is reduced by 100kg, CO2 emissions

The weight can be reduced by about 5g/km; the weight of new energy vehicles can be reduced by 100kg, and the battery life can be increased by 10%-11%. It can also reduce battery costs by 20% and daily wear and tear costs by 20%.

The positive impact of lightweighting is obvious.

Compared with lightweight methods of design and craftsmanship, the lightweight effect brought by materials is the most immediate.

Aluminum alloy has become a key material for lightweight automobiles, and the chassis has a lot of room to play. "Aluminum has become a key alternative material for lightweight design of automobiles in recent years." said Shen Weidong, an engineer at SAIC Volkswagen.

It is expected that by 2025, hot-formed high-strength steel and aluminum alloys will account for about 75% of the automotive lightweight market, of which aluminum alloys will account for 60%.

Automobile lightweighting mainly focuses on four parts: body, chassis, power system and interior and exterior trim parts.

From the perspective of components, the body in white, powertrain and chassis assembly basically account for more than 80% of the weight of the entire car.

In powertrains, there are two main ways to reduce weight. One is to use topology optimization analysis to optimize the size and shape of components. The second is to reduce weight through the combination of different parts to improve module versatility. The third is to

Increase the use of aluminum alloys. Fuel vehicles include engines, cylinder heads, brake calipers, etc., and new energy vehicles include battery cases.

In the body panel, since some components need to consider factors such as strength and safety, such as being used in core safety structural parts such as A-pillars, B-pillars, C-pillars, door anti-collision beams, front and rear bumpers, etc., the main lightweight components

The material is hot-formed high-strength steel.

The chassis should be the sector where aluminum alloy materials have the greatest potential. The penetration rate of lightweight products made of aluminum control arms, subframes, steering knuckles, and brake calipers is increasing significantly.

According to predictions from West China Securities and the China Banking and Insurance Regulatory Commission, the penetration rates of aluminum alloys in these four parts will reach 40%, 25%, 60% and 20% respectively in 2025.

Taken together, the lightweight consumables of the car body are large and the cost is high. It is difficult to significantly increase the penetration rate of aluminum alloy in a short period of time. The power system started to use aluminum alloy relatively early, and the penetration rate is already very high. The lightweight interior and exterior decoration is due to the material and environmental protection.

Limitations still require further development, so the chassis is currently considered to be the most cost-effective part of lightweighting made of aluminum alloy.

According to predictions from Soochow Securities, the penetration rate of aluminum alloy chassis will be about 35.3% by 2025, and the market space will be about 33.24 billion yuan. In 2019, this amount was only about 13.8 billion yuan. The market space is very worth looking forward to.

Of course, in addition to lightweight materials, technology and design can also help cars achieve lightweighting.

Lightweight design is to use various optimization analysis, simulation calculations and other methods to optimize the weight, structure and quantity of parts while ensuring performance and safety.

In terms of process lightweighting, the current mainstream process technologies include thermoforming stamping manufacturing process, laser tailor-welded blank process, roll forming process, laser welding, hydraulic pressure, etc. Among them, thermoforming technology has begun to be widely used.

The demand for lightweighting of new energy vehicles is more urgent. The market space for battery pack casings is expected. Compared with fuel vehicles, new energy vehicles are generally more focused. If new energy vehicles are to replace part of the fuel vehicle market, they must have more advantages in various factors such as cost and battery life.

, so the need for lightweighting is more urgent.