Among the various professional companies affiliated to the group, there are companies specializing in the production of various types of air springs. The application of the products covers the following three aspects: (1) suspension of automobiles; (2) suspension of railways and rail vehicles; (3) industrial machinery Vibration isolation. ContiTech was the first company in Europe to develop air springs. In 1955, it began developing air springs for the automotive industry. For over 40 years, its products and technologies have grown rapidly. The following is a list of the development of air spring systems for railway vehicles: in 1956, an air spring for the German railway vehicle VT98 was developed; in 1962, a free diaphragm air spring for a bolsterless bogie was developed; 1968 In the year, a cylindrical air spring for the ET-420 vehicle was developed; in 1985, the first air spring for the NEICO pendulum body was developed; in 1988, the lateral stiffness was very low and the lateral stability was developed. Air spring system; in 1990, developed analytical software for railway vehicle air spring suspension systems; in 1993, developed air springs for high internal pressure; in 1994, developed air spring system for ICE-2 In 1995, an air spring system with high stationarity was developed; in 1997, an air spring for a suspension of bogies was developed; in 2000, an integrated circuit height for an air spring system was developed.

At present, the daily output of ContiTech air springs is more than 11,000 sets, with 3.75 million sets in the whole year. The market share in Germany is the first in Germany, the first in Europe (60%), and the first in the world (accounting for 35%). The product is applied to almost all countries and regions that use air springs except Japan. ContiTech's air spring system has a global leading position because of its high technical level, good quality and complete specifications, which can meet various requirements and competitive prices. They value the development of new technologies and new products, investing 5% to 6% of sales expenses each year for research and development, and collaborating with universities, research institutions and other departments. The test equipment of the ContiTech air spring system is also leading the world. Application on railway vehicles ContiTech air spring systems are widely used in high-speed trains, tilting trains, fast trains and urban rail transit vehicles. Due to space limitations, only the first two will be introduced below. Applications on high-speed trains There are 320 to 330 high-speed trains around the world that use ContiTech's air spring systems, the most famous of which are the TGV series and the ICE series.

In order to eliminate the high-frequency vibration of 10Hz transmitted by the round spring and improve its smoothness, the TGV-PSE adopted the 684N4.10B air spring with high flexibility in the vertical and horizontal directions manufactured by ContiTech in the early 1980s. The 168L large-capacity additional air chamber is used to reduce the vertical and lateral natural vibration frequencies of the vehicle body to 0.7Hz and 0.75Hz respectively. The test results of the two spring devices are as follows: (1) Vertical vibration acceleration: vertical stability The sex index (fatigue time) is: spiral spring 12h, air spring 24h. (2) Lateral vibration acceleration: The lateral stability index (fatigue time) is: spiral steel spring 10h, air spring 15h. That is, the vertical and horizontal stability indexes are increased by 1 time and 0.5 times, respectively. Accordingly, this type of spring is widely used on all TGV-PSE trains. This highly flexible air spring arrangement ensures that the TGV still has excellent running stability when it created the world record 515.3km/h in 1990. Later, the French National Railways SNCF accepted the recommendation of ContiTech. Since 1992, all the air springs of the TGV-PSE trains have been connected in series with a 100.260 cone rubber pile. The advantage is: prolonging the life of the air spring;

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