Xiaomi can produce an SU7 every 76 seconds thanks to new production processes

Just days after reports claim that Tesla is abandoning ambitious plans to cast the underbody of its cars as a single piece, Xiaomi has given details of the innovations it is using as part of its production process. Tesla’s process is known as gigacasting and Xiaomi uses both this and stamping to produce the SU7.

Xiaomi claims to be the only domestic automobile company that uses the two technologies of self-developed die cast alloy materials and self-developed large die casting equipment cluster system.

Tesla pioneered the use of large scale die casting, the use of which can replace many individual components that would be assembled into a larger component with a single casting. From a manufacturing perspective it means that the factory needs less floor space while for the car there is better safety as the car now has increased rigidity. Furthermore, usually die-cast parts are lighter which helps increase the car’s range. A number of Chinese producers including XPeng and Nio have subsequently started using die casting technology.

Xiaomi’s system was self-developed in conjunction with Haitian. Covering an area about the size of two basketball courts the machine is marked with the name 9100t, which refers to the clamping force of the machine.

The machine creates the rear floor assembly of the Xiaomi SU7 and reduces 72 parts that previously required stamping and welding down to just one die cast part which can be produced in 100 seconds. For production this means 840 fewer welding points and a 45% reduction in production time. Whereas for the car it means the component is 17% lighter and also results in 2 dB reduction in road noise. Furthermore it increases the life expectancy of the integrated floor panel meaning it can easily achieve mileage of over 2 million kilometers, over 10 times the life expectancy of a traditional floor panel.

One major criticism for such manufacturing has been the expense in replacing the part if it is damaged. Xiaomi, however, has reportedly implemented a three-stage anti-collision design. This means that in the event of a low-medium speed collision only the anti-collision beam and crumple zone needs to be replaced.

Xiaomi has developed an entire die casting machine group system consisting of 60 devices and 433 processes, of which the Xiaomi Super Die Casting 9100T is only one of them. R&D from Xiaomi’s team resulted in 11 patent design innovations and improvements to the industry’s existing die casting technology including an AI active injection optimization parameter system.

The factory producing Xiaomi cars has a high degree of automation and when it ramps up to capacity will be able to produce 40 cars an hour, or one every 76 seconds. There are over 700 robots in the factory and 181 autonomous mobile robot (AMR) units delivering stamped parts. Each AMR uses Lidar to find its way around the factory floor. Machines are also used for quality inspection, the X-Eye inspection system has an accuracy of 99.9% with pointing out defects instead of the human eye.

Sources: Autohome, Medium, LinkedIn