On October 25, 2022, SDGC Automotive Chassis System Corporation, China's leading manufacturer of air springs and elastic hinges, invested in a new production base project of new nano composite elastic components for lightweight automotive chassis (suspension).
The air spring and elastic hinge have been monopolized by foreign technologies for many years. The core technical team led by Academician Zhang Liqun of the Chinese Academy of Engineering used the key material technology of "super polymer natural rubber+Gutta Percha (Eucommia ulmoides) mode" to break the technical barriers of foreign air springs and hinges at one stroke and successfully achieve import substitution.
As the core components of air suspension, air spring and elastic hinge are the "crown" of air suspension. They have always become short plate components due to their vulnerability, which is the core difficulty of independent research, development and production of new energy vehicles in China.
"Elastic hinges, like human knee joints, will be damaged if they are used frequently.
For a long time, we have used rubber imported from abroad as the material of elastic hinges, which is still easy to wear. Generally, the service life of elastic hinges is 3 years and 100000 kilometers, and the service life of some special elastic hinges is shorter. For example, the ball joint of the thrust bar of commercial vehicles will have problems during 30000 to 50000 kilometers, which will affect the safety of the vehicle body. "
The elastic hinge using gutta percha succeeded in replacing the one made in China
In order to find a kind of anti fatigue colloid, the research and development team of SDGC searched for thousands of materials and conducted tens of thousands of tests. Finally, Gutta Percha (Eucommia ulmoides), which is not easy to damage and improves the service life of elastic hinges, was extracted from Eucommia ulmoides.
Through experiments, it is found that Gutta Percha (Eucommia ulmoides) presents typical plastic properties of crystalline polymers at room temperature and typical rubber properties after heating and melting, which has the characteristics of significantly improving the fatigue resistance of natural rubber.
If Gutta Percha (Eucommia ulmoides) is added to super polymer natural rubber, what effect will it produce?
Han Dongli and members of the technical research and development team have made many tests, and they are surprised to find that under the tensile fatigue test conditions, compared with the pure natural rubber nanocomposite system, the fatigue resistance can be improved by more than 40% – 200%.
The perfect combination of the two can give full play to the performance of the materials, and produce high fatigue resistance, high-performance air springs and elastic hinges.
At present, the project team has completed the pilot development stage of air spring products. The interlaminar peel strength of the air spring products prepared in the pilot scale is about 1.5 times that of the foreign brand benchmarking products;
The fatigue times of the prepared air spring under 9bar (bar: pressure unit) have exceeded 4 million times, far exceeding 3 million times under 7bar pressure as required by the national standard GB/T13061-2017 and 2 million times under 9bar as required by the main engine manufacturer. The air spring has excellent fatigue performance and load bearing performance, fully meeting the load requirements of the air suspension with 8 airbags;
The bursting pressure exceeds 25bar, which is much higher than the 21bar required by the national standard GB/T13061-2017 (3 times of the normal service pressure of 7bar), fully meeting the requirements of impact and bursting resistance, and equivalent to the performance of Contitech, Firestone and other first-line brands;
The trial produced air spring products have been tested and verified in many well-known automobile OEMs in China, and no rubber cracking, air leakage and other failures have occurred after 4 million times of operation. The products fully meet the requirements of OEMs.