How long does it take to produce a Xiaomi car?
The answer is 76 seconds.
Walking into the Xiaomi Automobile Factory in Yizhuang, Beijing, you will be shocked by the size of the workshop and the high degree of automation. "A robotic arm that wields an arm that automatically assembles, an intelligent quality inspection system that replaces human eye recognition, and an AMR robot that pulls medium and large items all over the ground...... More than 700 robots are busy installing, inspecting, and transporting them. Here, the overall automation rate is more than 91%, and the automation rate of key processes reaches 100%. Outside the workshop, rows of Xiaomi cars that have been produced and tested are ready to go.
On the eve of the Xiaomi car press conference, a reporter from Beijing Youth Daily visited the Xiaomi car factory, which was a raw land three years ago, and now the factory covers an area of 718,000 square meters, which is equivalent to the size of a Forbidden City, and the adjacent Mercedes-Benz and BAIC factories form the largest automobile manufacturing base in the area. The newly released Xiaomi SU7 is rolling off the assembly line here, and after the production capacity is full, the factory can produce 40 Xiaomi SU7s per hour, which is equivalent to a new car coming off the assembly line every 76 seconds.
According to reports, outside the Xiaomi car factory, there is also a large store, providing product showrooms, delivery centers and driving experience areas, etc., where consumers can experience the fun of Xiaomi car autonomous driving technology, and can also drive the new car home. As a representative of China's intelligent manufacturing, in the future, Xiaomi Auto Factory will also be built into a 4A-level scenic spot, which is open to the public.
Large die-casting: 72 parts in one Three-section structure reduces maintenance costs
Walking into the Xiaomi car factory, you can see that the factory currently has six major workshops, including: stamping, large die-casting, body, painting, final assembly and battery. In the most central location of some workshops, there are also engineers' offices, which are designed for R&D personnel to improve products faster.
Large die-casting is one of Xiaomi's five core self-developed technologies. At the Xiaomi automotive technology release on December 28 last year, Lei Jun, founder, chairman and CEO of Xiaomi, introduced Xiaomi's five core self-developed technologies in the fields of electric drive, battery, large die-casting, intelligent cockpit, and intelligent driving, which have become the key to Xiaomi's success in the new track.
Walking into the large die-casting workshop, you can see a "industrial monster" constantly running, a single die-casting machine has 718t, the die-casting island covers an area of 840 square meters, the size of two basketball courts. The total number of 9,100t integrated large die-casting equipment clusters here can generate a die-casting part every 120 seconds, giving people a sense of the ingenious combination of industrial design's largeness and sophistication.
In fact, traditional car companies do not have this workshop link. More than three years ago, Tesla introduced the concept of "integrated die-casting" to China, and the rear frame of the Model Y, which was originally stamped and welded by more than 70 parts, was die-cast in less than 2 minutes. At present, only in advanced factories such as Tesla and Xiaomi, there will be special die-casting workshops.
Die-casting can be said to be the first link in the production and manufacturing of Xiaomi's automobile factory. The process of die-casting is similar to making candles of various shapes - first melted, and then molded to create a complete shape at once - the "wax liquid" used by Xiaomi is Xiaomi's self-developed titan alloy, where liquid aluminum at a high temperature of 700 degrees is injected into the mold in 100 milliseconds with 25 times the gravitational acceleration through a pressure of 340 times the standard atmosphere.
According to engineers, a large die casting of Xiaomi Auto is made of 72 parts in one, and the die casting produced by this process can reduce the number of solder joints by 840 and reduce weight by 17%, and the production efficiency is 10 times higher than the traditional floor welding process.
Tesla previously announced that "if 370 parts are replaced with 2-3 large die-casting parts to form the lower body assembly, the manufacturing cost will be reduced by 40%." Industry insiders said that this account cannot be calculated in this way, because once the integrated die casting parts need to be repaired later, the cost will be greatly increased. This is also why many Tesla owners often need 20 or 300,000 yuan in maintenance fees, which is almost worth the price of a car, and the insurance price remains high.
So how does Xiaomi solve this problem? According to reports, Xiaomi car will be divided into three sections of die-casting, greatly reducing maintenance costs, setting up multiple buffers, significantly improving the structural rigidity, low-speed rear collision does not affect the die-casting, high-speed rear collision to ensure the safety of the driver. It not only reduces the maintenance cost, but also makes the safety factor higher.
Body and final assembly: The robot cooperates to complete the body installation The accuracy is less than the thickness of 1 piece of paper
In Xiaomi's body shop, you can intuitively see how a car is installed. The 381 robots in the entire workshop, plus more than 20 employees, completed all the work of the workshop, which is three times more efficient than the workshop of the same level, which can be called a model of automation.
A reporter from Beiqing Daily saw a production line at the scene, after the body was suspended and sent to the station, 8 robots on a station began to work, the camera robot was responsible for positioning, and the automatic feeding robot was responsible for grabbing the door and building, and the mechanical arms on both sides would carry the tightening gun at the same time, come to tighten the bolts and hinge, so there are 4 robots on one side, and the door of a car can be installed in a few seconds.
This is the customized development of the 100% "four doors and two covers + fenders" automatic assembly system in the Xiaomi workshop, such a system can achieve extremely narrow body clearance, which is currently only possible with Tesla and Xiaomi in China. In the Xiaomi body shop, there are many such stations.
And how are stamped parts such as car doors transported? This depends on "unmanned" AMR vision robots. Entering the factory, you will see AMR trolleys everywhere, and the biggest difference between it and traditional logistics AGVs is that they do not need electromagnetic guidance lines. There are 181 AMR cars in the whole factory, all of which use lidar perception scheme, which is equivalent to "unmanned driving" in the workshop, and they can freely adjust the route according to the production situation of each workshop, and when they encounter people, they will also avoid or stop.
In the paint shop, the body that was previously silver will be changed to color one after another. At present, Xiaomi Auto has released 9 colors, so how to change the color of such a multi-color order?
According to reports, the rapid color change system of Xiaomi car can be applied to the rapid filling, cleaning and quantitative supply of various colors of paint, and realize the stepless switching of the color of the model, and the switching time is only 40 minutes. Through the flexible color sorting system, it can not only intelligently group the colors of the order library, reduce the frequency of painting color change, but also establish a new "order pull" generation method to reduce the order delivery time by 25%.
Finally, in the assembly workshop, the reporter of Beiqing Daily saw that the front and rear windshields and panoramic canopies are automatically assembled by the robotic arm, and the positioning accuracy of the battery assembly of the body reaches 0.1mm, and the gap is so small that it is impossible to stuff an A4 paper. Here, the whole process from parts to body assembly takes less than 30 seconds, which is twice as fast as that of traditional car companies.
"This is the same model as the F1 team, not only with high precision, but also with a record of 'screwing' for 10 years, and any subsequent problems can be traced," the engineer said.
Detection: The self-developed equipment replaces the human eye with light, with an accuracy rate of over 99.9%
"Using X-ray flaw detection technology, you can take 28 photos of the equipment in 84 seconds, and determine whether the completed part meets the standard within 1 second," the engineer said, "This technology is developed by Xiaomi, and the efficiency is more than 100 times that of manual labor."
Walking into the Xiaomi factory, there are almost no workers to be seen, in the inspection process, it is also the machine that is working, in the large die-casting workshop, the parts that have just been manufactured are sent to the X-Eye intelligent quality inspection system. It can replace human eye recognition and point out defects with an accuracy rate of more than 99.9%.
In the body shop, you can also see automated equipment instead of manual inspection. In terms of the appearance of the whole vehicle, Xiaomi uses 100% fully automated ultraviolet light detection, and the measurement accuracy reaches ±0.05mm.
In the assembly workshop of many factories, workers are still used to measure the body clearance with a feeler gauge, but in Xiaomi, the error of one-twentieth of a millimeter can be detected by the machine, and it can also detect whether transparent parts such as the canopy and headlights are installed in place.
Only in the body shop of the Xiaomi car factory, there are currently 207 key inspection points in the Xiaomi factory, which are completed by automatic detection, and the industry is in a leading position.
Battery: Developed in collaboration with CATL for the Max version with a range of 800 km
Battery is also one of Xiaomi's key self-developed technologies. It is understood that the batteries carried by Xiaomi cars are provided by two brands, CATL and BYD. Among them, Xiaomi's high-end models will be equipped with CATL's Kirin battery, which uses a module-less battery structure. The technical highlight is that the battery cells are directly integrated into the battery pack without the module, so that the overall energy density of the battery pack can be increased, thereby improving the cruising range.
According to engineers, Xiaomi and CATL will also reshape the structure of the battery pack, unlike other brands of cars, the battery pack of Xiaomi cars is "upside down", in extreme cases, the direction of battery liquid injection will not be towards the car, which is safer than other "forward" batteries. In order to solve the problem of the electrode being soaked during inverted playing, the two parties also developed their own electrolyte composition, which effectively avoided the problems caused by the electrode being soaked for a long time.
In the battery workshop, the reporter of Beiqing Daily saw that the welded battery is passing the OCT test, which is an advanced method of using the beam to detect the internal welding quality of the battery, "because in the laser welding process, due to the vibration of the equipment itself, the external working conditions are changing at all times, so the penetration depth of the welding parameters may have an impact, but the penetration data can not be directly observed, and the internal situation of the weld cannot be known, and the use of OCT can be 100% automatic measurement, once there is a problem, it will alarm." The engineer said.
Battery life is also one of the most critical user experiences for electric vehicles. According to Lei Jun, at the beginning of the project, he asked the R&D team: "Long battery life for the whole system!" Xiaomi SU7 standard version starts with CLTC 700 kilometers, and in the case of the same 19-inch wheels, the battery life of Xiaomi SU7 standard version directly exceeds that of Model 3 long battery life. The Xiaomi SU7 Max reaches 800 kilometers, becoming the only tram in China to achieve both 2-second acceleration and 800-kilometer range.
The industry uses the cruising range, and the CLTC working condition is adopted. CLTC is a very professional standardized test and is a universal endurance evaluation standard. However, in fact, each user's driving habits and driving environment are very different, resulting in some discrepancies between everyone's actual mileage and the nominal CLTC mileage of the vehicle. Xiaomi said that "the measured Xiaomi SU7 standard version has achieved a range of 495 kilometers".
Testing: Each vehicle is tested on 18 "bad roads".
After all the cars are installed, Xiaomi cars cannot be delivered immediately, but have to go through a "bad road" first. The reporter of Beiqing Daily saw that outside the whole workshop, there is a "bad road" about 1 km long, which is set up: twisted road, concave and convex manhole cover road, cobblestone road, speed bump road, deviation acceleration road and other more than 18 special road conditions, including most of the difficult road conditions that can be encountered on the daily road surface.
Every Xiaomi SU7 that rolls off the factory line must first complete a vehicle test and verification track with a total length of 2.5 kilometers, a design speed of 120 km/h, and 18 road conditions here before it can be delivered to users.
In addition, during the development period, Xiaomi cars completed many tests. Xiaomi invested 576 vehicles and conducted large-scale tests in 300 cities across the country, from the ultra-low temperature of -40 °C in Heihe to the high temperature of 60 °C in Turpan, across the temperature difference of 100 °C, and then to the plateau test of Kunlun Mountain at an altitude of 4,768 meters. The scale of the tests is quite large. It is worth noting that since the test car is in the early stage of research and development, the cost of the first batch is very high, about more than 2 million per car, and the closer it is to the cost of the production car.
Lei Jun revealed that all Xiaomi executives have participated in the actual test of Xiaomi SU7 road surface, which has accumulated more than 100,000 kilometers. Lei Jun himself participated in more than 10 tests, with a mileage of more than 3,000 kilometers. "The longest one was on January 5 this year, from Beijing to Shanghai, the whole journey was 1,276 kilometers, I drove alone, the whole high-speed NOA, plus charging and resting, the total time was more than 15 hours. He said, "This test is very challenging for battery life, four-wheel drive, winter + high-speed (there are not many cars on the road, most of the time the speed is above 100km/h), a total of 2 times on the road, the experience is quite good." ”
Xiaomi's automobile factory provides a strong guarantee for exquisite craftsmanship and high-quality delivery.
Xiaomi Auto's R&D investment in 2023 will reach 5.9 billion yuan Lei Jun: "Delivery is the volume"
Every Xiaomi car is changed from a self-developed alloy material to a car here. "The Xiaomi SU7 will be delivered when it is released, and the delivery will be on the scale", Lei Jun said. A reporter from Beiqing Daily saw that at present, a large number of new cars made of various colors have been parked in the park.
Behind Xiaomi's car factory is Xiaomi's continuous R&D investment. According to the financial report, in 2023, Xiaomi's R&D expenditure will be 19.1 billion yuan, a year-on-year increase of 19.2%, and it has achieved outstanding results in many related fields such as new energy vehicles, artificial intelligence, and robots. With the official debut of Xiaomi's first vehicle, the Xiaomi SU7 series, Xiaomi's innovative business expenses such as smart cars increased to RMB6.7 billion (excluding RMB0.8 billion of stock-based compensation expenses related to innovative businesses such as smart electric vehicles) for the year, of which RMB2.4 billion (excluding RMB200 million of share-based compensation expenses related to innovative businesses such as smart electric vehicles) increased to RMB6.7 billion for the year, of which RMB2.4 billion (excluding RMB200 million of share-based compensation expenses related to innovative businesses such as smart electric vehicles) in the fourth quarter. According to this calculation, the annual R&D cost of Xiaomi's automobile business is 5.9 billion yuan, which is enough to see Xiaomi's high investment in the field of smart cars.
On March 28, the price of Xiaomi car SU7 has been announced, and the price of 215,900 yuan was called "loss" by Lei Jun, which also made more rice fans say "unexpected". Market data shows that after Dading opened that night, it exceeded 10,000 units in 4 minutes and 50,000 units in 27 minutes.
Lei Jun reiterated, "Xiaomi's long-term goal is to become one of the top five car companies in the world through 15 to 20 years of hard work, and strive for the comprehensive rise of China's automobile industry." ”
Text/Beijing Youth Daily reporter Wen Jing
Photographer/Beijing Youth Daily reporter Guo Qian
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