What exactly is inside the Tesla Gigafactory has been a mystery to many. Just this week, Tesla brought a miniature version of the factory into the Tesla Delivery Center in Xidao, Beijing, showing the interior of the Shanghai Gigafactory with real scenes and objects in the factory.

The production process of traditional auto factories is divided into stamping, welding, painting, and final assembly. Tesla Shanghai Super Factory has two more, which are one-piece die-casting before stamping and battery/motor workshop . In the Tesla factory, these two additional workshops are also the most mysterious.

The die-casting force includes 6,000 tons of integrated die-casting technology for the underbody, high-speed stamping with an accuracy of 0.01 mm, martensitic steel that can withstand a maximum pressure of 1,700 MPa on the bottom of the welded car, five coats of paint, and the power of CATL The battery module and AC induction motor system were all displayed in the Tesla delivery center, which is really eye-opening.

In 2021, the annual output of Tesla’s Shanghai factory will exceed 450,000 vehicles , and the production capacity is still climbing. For a factory with an area of ​​only about 120 acres, how to use the limited land to build more vehicles is particularly important. Therefore, what Tesla is doing at this stage is not only increasing the production capacity per unit area, but even increasing the production capacity per unit volume.

So, what secrets have not been discovered in Tesla’s Shanghai Gigafactory, and how strong is its craftsmanship? On the first day that the miniature version of the factory was launched, Che Dong came to the scene to find the secret behind the factory.

1.One hand can lift the underbody castings to develop new cars in China

At the beginning of 2019, the construction of Tesla’s Shanghai factory started, and it took less than a year for the factory to be completed and put into production. Hundreds of thousands of cars have been born on this 120-acre land.

Entering the “GIGA Museum” at the Tesla Delivery Center in Beijing Crab Island, the structure of the Shanghai Super Factory comes into view. The factory also has a vehicle shipping center and a research and development center.

According to the introduction, the area of ​​the Shanghai Super Factory is actually not large, which requires higher land utilization. Among the many vehicle factories visited by Chedongxi before, the major workshops basically have spacious transportation roads and green belts, and the land utilization rate is relatively low. But the Tesla Shanghai factory is different. There is only one transportation road between different workshops, and even some workshops are in the same factory building, and there is only one wall to distinguish the process .

In order to increase production capacity, Tesla has also divided floors inside the factory, with large machinery running on the upper and lower floors at the same time.

There is also a Tesla R&D center in the factory, which has the same status as the R&D center in the US headquarters . According to the introduction, this center is currently developing new models , hoping to attract more consumers with a model that is more in line with the daily use of Chinese people.

At the beginning of 2021, the second phase of the super factory, which was expanded in less than a year, was completed, and the production of Tesla Model Y models began. Compared with the Model 3 model, one of the biggest innovations of the Tesla Model Y is the introduction of a one-piece die-casting process.

The rear bottom plate of the Model Y model is made of one-piece die-casting, which has been reduced from 70 parts to one. And this casting is very light, with a single weight of 60kg, one person can lift a corner with one hand, and two people can directly lift it away.

According to the introduction, there are a total of 4 6,000-ton die-casting machines from Lijin in the Tesla Super Factory , and 8,000-ton and 12,000-ton larger die-casting machines may be used in the future.

In fact, the die-casting process in the industry is relatively mature, but what is more difficult is what material to use. Due to the properties of the metal, the larger the single aluminum metal, the easier it is to crack during use. In a car, there is a major safety hazard if major components crack. At the same time, this single material is still very thin, only 1mm at the thinnest point, which makes it more difficult not to crack.

Therefore, Tesla engineers developed a new type of aluminum alloy material, which added bromine to create a special aluminum alloy material to enhance the overall strength. And, within Tesla, the team developing the body materials and the SpaceX rocket materials team share, and various materials are developed by this team.

In addition, Tesla is not the first in the automotive industry to use the die-casting process. The engine block of traditional automobiles and some components of the transmission can be completed by casting. However, the traditional process usually requires secondary tempering and heating to ensure the rigidity of the casting. And Tesla’s one-piece casting only needs one processing, and this huge single body can be completed in just 180 seconds.

When it comes to why single-body casting is used, the staff of the Tesla factory gave two explanations. One is to improve the rigidity of the body and ensure that the vehicle does not twist under the limit state, and the other is to reduce the number of parts. It will reduce the abnormal noise in the car.

2. Adopt steel-aluminum hybrid body with 5 layers of paint

Enter the stamping workshop, which mainly produces body panels, such as doors, front hoods, trunk lids, fenders, etc.

There are 4 fully automatic steel and aluminum hybrid servo stamping production lines in the Shanghai factory. After tens of thousands of tons of stamping, the accuracy is still 0.01mm , which is more than twice as fine as a hair.

At the scene, the engineer of the Tesla factory also revealed to us that among so many parts of the whole vehicle, the most difficult stamping process is the trunk cover, because its shape is the most complicated.

Coming to the welding workshop, there is a Model 3 body-in-white. After the processing in the two workshops of die-casting and stamping, in the welding workshop, workers have to “joint” various parts together by welding, riveting and bonding.

What is more attractive is that there are several pieces of red material on the white body of this Model 3. According to the presentation, these are ultra-high-strength steels.

Among them, the ultra-high-strength steel of the roof beam has a load-bearing capacity of 1300 MPa, which is approximately equivalent to 1 square centimeter area (the size of a fingernail) to withstand 10 tons of pressure. On the whole, the roof of the Tesla Model 3 can withstand 6 times the weight of the body, more than 90,000 Newtons of pressure .

In addition to the top of the car, the bottom of the car is also made of ultra-high-strength steel. The steel at the bottom of the car is stronger and is martensitic steel with a load-bearing capacity of 1700 MPa, which can protect the safety of the occupants in the event of a side collision.

In the United States, Tesla has also established its own crash laboratory, which can simulate large vehicle crashes such as pickups and meet crash test standards in more countries and regions.

The paint shop shows a half-painted side fender. According to the introduction, the Tesla body has a total of five layers of paint, from the lower layer to the upper layer are the anti-corrosion layer, the electrophoresis layer, the primer, the topcoat, and the varnish.

At the same time, Tesla bakes the paint longer, which allows longer curing time, so that the paint surface is smoother and harder.

3. All battery motors have been exposed with silicon carbide controller

In China, there are two battery suppliers for Tesla Gigafactory, namely CATL and LG . On display this time is a lithium iron phosphate battery module from the Ningde era.

According to the introduction, there are 4 such modules in Tesla models equipped with lithium iron phosphate batteries, with a total capacity of 60kWh.

In this module, the cells are connected by cables, similar to the cables used in mobile phones and computers. In the early Tesla models, traditional wires were used to connect the cells, and the manufacturing level has been greatly improved in recent years.

At the same time, the battery module is also getting bigger and bigger. In the Model S and X, a battery module was about the size of a pillow, and now it’s significantly larger. At present, Tesla is still exploring battery-chassis integration technology, and may cancel the concept of modules in the future and directly integrate the battery cells into the chassis.

Tesla also showed an AC asynchronous induction motor. The overall volume of this motor is not large, and its internal structure is very delicate. According to the introduction, Tesla Motors has adopted a silicon carbide (SiC) controller, not the IGBT controller that is more commonly used in the industry today.

In terms of motor efficiency, Tesla can achieve a motor efficiency of 90% to 95%, and finally can achieve 7km per 1kWh of power consumption, and the energy consumption is relatively low.

After all the above production steps are completed, the final assembly shop will produce Teslas one by one and finally deliver them to users.

In fact, the GIGA Museum also has the latest achievements in Tesla energy, autonomous driving, AI, and charging. If you happen to be going to see the car in the store or pick up the car at the delivery center, it is strongly recommended to visit the GIGA Museum, which can really enhance your understanding of Tesla and have a deeper understanding of smart electric vehicles.

Conclusion: Tesla’s black technology leads the industry’s progress

Tesla has triggered revolution after revolution in the auto industry. From electric vehicles, assisted driving functions, to innovations in factory production processes, every revolution seems to be telling traditional car companies to seize the electrified future. .

Although the technology in Tesla’s factory is not an industry innovation, it has completely changed the thinking of traditional car companies to build cars. These black technologies are also leading the rapid progress of the entire electric vehicle industry.