Tesla’s integrated die-casting crash cost is high, and users shout that they can’t afford to repair it.

After entering 2022, you should still have the impression that major insurance companies have increased the premiums of pure electric vehicles, and the insurance companies have their own difficulties. It is really not profitable to provide pure electric insurance. So, what exactly is the all-in-one die-casting that Tesla is proud of? Many car companies have begun to follow suit. Who should pay for the cost of a “crash” in the future?

Tesla's integrated die-casting crash cost is high, and users shout that they can't afford to repair it.
Model Y hitting a wall

Model Y hits it, and the repair price is $30,000?

Recently, the maintenance cost of a Model Y hitting a wall is 30,000 dollars, and the new car is only how much. If you don’t charge more, you have to pay for your shorts. Everyone always has to eat. In fact, in the case of rising premiums, the ones who benefited did not appear in the closed-loop circle of users; insurance companies, 4S stores, and car companies were the ones who lay down and saved money. In fact, the reason why Tesla’s maintenance costs are so high has nothing to do with the popular battery cost. The one-piece die-casting body needs to be “mainly responsible” in this matter, of course, including the 200,000 Model Y mentioned above. Repair quote.

As the name suggests, the so-called one-piece die-casting body, the rear body of the Tesla Model Y, is one piece. The metal solution is pressed into the mold through a 6,000-ton die-casting machine. And the body that was initially spliced ​​with dozens of parts is concentrated in a single piece. Production. Tesla’s efficiency and cost improvement is simply a lever without welding or final assembly. However, success is also tiny, and failure is also small. The one-piece body must be replaced as a whole after the deformation of critical positions. For example, with a maintenance cost of 200,000 yuan for the Model Y, the entire rear body is removed and replaced. The reason is that the deformed shock absorber package cannot be provided separately. If you want to ensure the original performance, you can only replace it. This way, it is not a loss for Tesla to complain about this time, and it will transfer its reduced car manufacturing costs to users. Anyone who sees this transaction will call it a good deal.

What is integrated die casting?

The application of integrated die-casting in electric vehicles is a trend. Electric cars are subject to range anxiety and high battery material costs, and the desire for lightweight is apparent. Taking Tesla Model Y as an example, the integrated die-casting rear floor assembly reduces the weight of the lower body assembly by 30% and the manufacturing cost by 40%. The back floor structure of the car is welded by about 70 stamped steel plates. Tesla uses a 6,000-ton die-casting machine Giga Press to integrally die-cast the above 70 parts into 1-2 large aluminum castings, and the number of connection points is 700-800. Reduce to 50, the manufacturing time has been shortened from 1-2 hours to 3-5 minutes.

Compared with the traditional body manufacturing process (stamping-welding-painting-final assembly), integrated die-casting has all the supply chain links of traditional stamping-welding been canceled. And it also has the advantages of a lightweight, reduced number of parts and process steps. The benefits of saving personnel and land can significantly reduce the cost of vehicle manufacturing. It can be said to be a disruptive technology. However, to do an excellent job of integrated die casting, the main difficulties are in three aspects: large tonnage die casting equipment, heat treatment-free materials, die casting process.

The die-casting equipment needs to be equipped with a super-large 6000T or more. The domestic Lijin (Technology) die-casting machines are the most ordered and the best after-sales. The 6600-ton and more than 7,000-ton die-casting machines have been installed and debugged. Mass production, other competitors like Haitian, Yizumi can produce but not in batches. The top one is the Swiss Bühler die-casting machine in the international die-casting industry, which can have 9,000 tons now. The performance and price of the entire device are also excellent. The second brand is Italy’s Indra, wholly owned by LK. . The efficiency of Idra’s 6000-ton die casting machine is about 4%-5% higher than that of Lijin. At present, the 6,000-ton equipment of Lijin (Technology) die-casting machines is less than 40 million, and the 7,000-ton equipment is less than 50 million. As for the yield rate, the yield rate of Tesla’s floor after production has reached 80%-90%, and most die-casting plants basically report a pass rate of 80%-85% to customers.

Heat treatment-free materials refer to aluminum alloys. At present, this alloy is mainly produced by overseas enterprises, such as Alcoa, Reinfeld, etc. It is only developed by Lizhong Group in China, has applied for a patent, and is available in batches.

Manufacturing Revolution: How does one-piece die casting take the world by storm?

The artillery fire has sounded, and cost, quality, and cycle, as the frontal battlefield of this manufacturing revolution, will face the most violent attack from Tesla:

1. Cost aspect

Manufacturing cost: If the application range of die-casting parts is further expanded in the future, and the body-in-white is all manufactured by an integrated die-casting process, the weight of the all-aluminum die-casting body-in-white will be 200-250kg. According to the public calculation of Wencan Co., Ltd., a die-casting aluminum alloy auto parts supplier, the current aluminum alloy supply price is about 35 yuan/kg, so the theoretical die-casting cost of the body-in-white is about 7000~8750 yuan/set.

The weight of the steel body of the same level is 350-450kg, the steel supply price is calculated at 18 yuan/kg, and the welding manufacturing cost is about 6300-8100 yuan/unit.

This shows that the manufacturing cost of the all-aluminum die-casting body and the steel body is not much different, but the weight can be reduced by about 170kg, which has a massive advantage in the body’s lightweight.

The cost of a steel-aluminum hybrid body is around 15,000~20,000 yuan/unit, and the manufacturing cost of an all-aluminum welded body-in-white is about 30,000 yuan/unit.

The cost of the all-aluminum die-casting body is 7000~8750 yuan per unit, which can be completely rolled out of the steel-aluminum hybrid body and the all-aluminum welded body-in-white.

Equipment input cost: Calculate the equipment input for one-piece die-casting and traditional punching and welding processes based on an annual output of 100,000 vehicles. If the whole vehicle adopts the integrated die-casting approach, the total investment of die-casting machine + auxiliary machine + mold is about 710 million yuan. The amortization cost of the bicycle is 7100 yuan.

In traditional crafts:

The whole vehicle stamping factory needs to purchase large-scale press units to continuously stamp the outer cover, and the loading and unloading links are realized by automated robots. Equipment investment needs about 190 million yuan.

Suppliers stamp and manufacture body internal components, generally purchasing small presses and small and medium-sized machines. Equipment investment needs about 130 million yuan.

The body-in-white welding line of the vehicle welding plant is multi-station continuous welding of more than 300 large-scale industrial robots, and the equipment investment requires about 170 million yuan.

The supplier’s welding factory mainly welds the small parts of the stamped body structure into components or sub-assemblies, and the equipment investment costs about 30 million yuan. Then the total investment of the traditional stamping and welding process OEMs and parts factories is about 520 million yuan. The bicycle amortization cost is 5,200 yuan.

total cost

Using integrated die-casting technology, the cost per vehicle (manufacturing cost + equipment amortization cost) is about 14,100~15,850 yuan;

Using traditional stamping and welding technology, the cost per vehicle (manufacturing cost + equipment amortization cost) is about 12,000~13,300 yuan.

According to the calculation, at the current market price, the cost of a bicycle using the integrated die-casting technology is about 2,350 yuan higher than that using the traditional punching and welding technology. However, the weight of the one-piece die-casting body can be reduced by about 170kg, the material utilization rate and material recycling rate of the die-casting all-aluminum body can reach more than 95%, and the factory floor area is reduced by 30%. Technology has a more significant technical advantage.

2. In terms of body accuracy and quality

In the traditional body precision control system, the “2mm project” is considered to measure whether the car body size control has reached the advanced international level. That is to say, the dimensional accuracy of the traditional body needs to get the tolerance range of ±1mm, which can be regarded as the advanced international level.

Tesla's integrated die-casting crash cost is high, and users shout that they can't afford to repair it.
model 3 rear underbody 70 pieces

In the field of autonomous driving[1], vehicles can detect and perceive road conditions through high-precision measurement equipment such as lidar, millimeter-wave radar, and high-definition cameras. Installation accuracy has highly stringent requirements. The 2mm tolerance emphasized by the traditional body cannot meet the installation requirements of autonomous driving equipment.

On May 18, 2021, Musk tweeted that “the accuracy of the next-generation Model Y model will be measured in microns, not millimeters.” According to the precision level of machining, the precision of CNC machining processes such as turning, milling, planing, and grinding is within IT11, which is all micron level. In addition, after the general parts are die-cast, they will be precisely machined. Therefore, we can speculate that the manufacture of Model Y will be manufactured using an integrated die-casting + CNC machining solution in the future.

The one-piece die-casting parts shorten the size chain matching the body to two or three rings, which is like the difference between taking a high-speed rail and taking a green train for the accuracy of the car body. The fewer the size links, the fewer the factors affecting the accuracy of the body, the easier it is to achieve the accuracy of the body, and the easier it is to maintain the stability of the accuracy. With the blessing of CNC machining technology, the precision of the whole vehicle has been improved to the micron level. Tesla’s solution provides an efficient solution for installing high-precision measurement equipment such as lidar, millimeter-wave radar, and high-definition cameras. This means that the accuracy of the 2mm tolerance in the traditional automobile manufacturing industry has been rewritten by Tesla.

3. Cycle aspects

In traditional automobile manufacturing, for professional appearance parts such as body, interior and exterior decoration, and electrical appliances, it is necessary to go through three rounds of MB1, MB2, and MB3 matching to stabilize the parts within the tolerance requirements. This work takes nearly 6 months in the vehicle development process, which is a long cycle, heavy workload, and high repetitive work. Taking the matching of the body MB stage as an example, the traditional body engineer needs to carry out the whole process of the design process route of each part of BIW. the supplier’s production process route, equipment conditions, part materials, part accuracy, packaging logistics, and factory acceptance and rectification. Control. Complicated tasks and lengthy process quality control cycles increase the difficulty for engineers to control parts.

To manufacture one-piece die-casting parts, a die-casting island the size of a badminton court replaces all the stamping and welding workshops in the original OEM and the production sites of suppliers’ claims outside the OEM the logistics process is ultimately canceled. To the extreme, a single die-casting part compresses the cumbersome supply chain management cycle. From upstream procurement subcontracting, supplier designation, midstream tooling equipment development, whole-process quality control of functions, downstream welding matching, loading verification, all businesses are replaced by die-casting single-piece rule. In this way, the difficulty of matching the body-in-white is significantly reduced.

The cycle required for the body in MB matching will be shortened to 1~2 rounds. Based on the precision curing of the body, it is expected to save 3~4 months. If the interior and exterior trims, electrical appliances, and other parts can be matched in advance, the speed of model iteration will also be rapidly improved. In the field of intelligent driving, the iteration speed of hardware is often faster than the iteration speed of the whole vehicle. For example, when the chip is installed, there will be such a phenomenon: the most advanced computing chip is used to plan an entire car, which can be used as a whole vehicle. At the time of production, the chip with this computing power was outdated. The iteration of autonomous driving chips means the expansion of car functions. Corresponding to the body, the installation points and installation surfaces of the hardware requirements change, resulting in changes in the body structure. This involves many aspects, such as styling, collision, and NVH. Therefore, there is little room for high-frequency oscillations in the later stage once the body structure is determined. This is one of the primary reasons that hinder the speed of model iteration.

It is difficult for model development to keep up with the iterative speed of hardware such as chips, and the competitiveness of model products in the market is challenging to play. The application of integrated die-casting technology is expected to further improve the iteration speed of models, which will bring more significant market influence to Tesla. The integrated die-casting technology set up by Tesla has formed an effective blow to traditional car companies in critical areas such as cost, quality, and cycle. If there is no more significant advantage of the same class of models, then every action of Tesla in the future, traditional car companies will not be able to dodge.

In conclusion

As the saying goes, the wool comes out of the sheep. The integrated body die-casting can indeed be regarded as a significant innovation in the automobile manufacturing process, significantly improving the production efficiency of car companies and at the same time providing consumers with better models. But from the perspective of consumers, users still have to pay for technological innovation to some extent. As an automobile manufacturer, we must see the benefits of integrated die casting and stand in the position of consumers, improve the reliability and stability of vehicles as much as possible, and ultimately eliminate users’ anxiety about pure electric cars.

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