Tire is one of the important parts of the car. It directly touches the road surface and cooperates with the car suspension to alleviate the impact of the car when driving. It ensures the car has good ride comfort and ride comfort. Tires ensure good adhesion between the wheel and the road surface. It improves the traction, braking performance. With the weight of the car, the important role of the tire in the car has received more and more attention.
Long ago, the tires were made of wood, iron, etc. The British pioneer Robert Thomson, who invented the first hollow wheel in 1845, proposed to use compressed air to fill the elastic bladder to mitigate vibration and shock during exercise. Although the tires at the time were made of leather and rubberized canvas, such tires have shown the advantage of low rolling resistance. In 1888, John Dunlop made a rubber hollow tire based on this principle. Then Thomas made a rubber hollow tire with a valve switch. Unfortunately, because the inner layer has no canvas, it cannot maintain a certain section shape and section width.
In 1895, with the advent of automobiles, pneumatic tires were widely developed. The first batch of automobile tire samples were single-tube tires made of plain canvas in France in 1895, although there were tread rubbers and no patterns. It was not until 1908-1912 that the tires had a significant change, that is, the tread rubber had a pattern that improved the performance of the tires, thereby opening up the history of the tire tread pattern and increasing the section width of the tire, allowing lower adoption. Internal pressure to ensure better cushioning performance.
In 1892, Bury Mill in the United Kingdom invented the curtain, which was used for production in 1910. This achievement not only improved the quality of the tires, but also expanded the tires, and made the tires have the possibility of molding. With the improvement of the quality requirements of the tires, the quality of the curtains has also been improved, and the cotton cord fabrics have been replaced by rayon. In the late 1950s, the rayon was replaced by nylon and polyester cords with better strength and higher heat resistance. With the development of radial tires, steel cords are more competitive.
In1904, Matt created carbon black reinforced rubber, and large-scale use of reinforcing tread rubber was after the tires were used, because before that, the canvas was damaged more quickly than the tread in the tires. The amount of carbon black used in the rubber compound increased rapidly. In the 1930s, the carbon black used in every 100 parts of raw rubber was only about 20 parts. At this time, carbon black was mainly used on the tread, and the carcass was not used. It has now reached more than 50. Before the carbon black is blended in the tread, the tire can be polished only after driving for about 6000km. After the carbon black is blended, the mileage of the tire is significantly improved. Now a group of truck tires can drive about 100,000km. They can run up to 200,000km on a good road condition.
In 1913-1926, the invention of cord and carbon black tire technology laid the foundation for the development of the tire industry. The outer edge of the tire is standardized, the manufacturing process is gradually improved, the production speed is higher than before, and the output of the tire is increasing day by day.
With the development of the automotive industry, tire technology has been continuously improved and improved, such as the transition from low-pressure tires to ultra-low-pressure tires in the early 1920s to the mid-1930s; the tires gradually transitioned to wide rims in the 1940s; Tubeless Tires appeared by the end of 1940s; low-profile tires came out in the late 1950s and so on. Many new technologies have emerged as the meridian structure tires pioneered by Michelin in France in 1948. This type of tire is known as the revolution of the tire industry due to the significant improvement in service life and performance, especially in running fuel.
Here is a brief introduction to the main types of tires developed today:
Radial tires: This type of tire is characterized in that the direction of the ply cords is aligned with the meridian section of the tire (ie, the crown angle is zero degrees). Due to the arrangement of the cords, the strength of the wire can be fully utilized, and the radial tires are fully utilized. The number of plies is generally about 40-50% less than that of ordinary bias tires. The cords are only connected by rubber in the circumferential direction. Compared with ordinary bias tires, radial tires have high elasticity, good wear resistance, 30-50% increase in tire service life, small rolling resistance, can reduce vehicle fuel consumption by 8%, good adhesion performance, good cushioning performance and large bearing capacity. It is not easy to puncture. The disadvantage is that the sidewall is easy to crack, due to the large side deformation, resulting in poor lateral stability of the vehicle, manufacturing technical requirements and high cost.
Tubeless tires: Tubeless tires differ from normal tires in that they have no inner tube and the air is pressed directly into the tire., so there is a good seal between the tire and the rim. The tubeless tire is similar in appearance and structure to the tube tire, except that a rubber seal layer special sealed for sealing is attached to the inner wall of the tubeless tire by a thickness of about 2-3mm, which is vulcanized. Adhesive, when the tire is perforated, because it is in a compressed state and tightly wrapped around the puncture, it can not leak for a long time, and even if the puncture is pulled out, the intra-fetal pressure can be temporarily maintained. There are a number of concentric annular grooves on the tube of the tubeless tire. Under the pressure of the tire, the groove can reliably press the bead against the edge of the rim to ensure sealing. The rim on which the tubeless tire is mounted is airtight and has a sloping bottom and a smooth paint layer. The valve is directly fixed to the rim with a rubber gasket for sealing. Tubeless tires have the advantages of good air tightness, good hear dissipation, simple structure and light weight. The disadvantage is that it is more difficult to repair on the way.
Wide-section tires: As the speed of the car increased, it is required to lower the center of gravity of the vehicle and improve the handling performance. This requires improving the lateral stability of the tire and the adhesion to the road surface to ensure safe driving at high speeds. The appearance of tires becomes inevitable. The ratio of the section height(H) to the section width(B) of the tire (H/B) is an important parameter representing the structural characteristics of the tire, and is referred to as the aspect ratio of the tire, that is , the flatness ratio. Since the 1920s, the outer diameter of car tires has been reduced by 25%, the diameter of rims has been reduced by 35%, the width of tires and rims has nearly doubled, the aspect ratio of tires has been reduced, and cars have reached 0.5. The car is up to 0.4, especially the wide tires match the limousine, which is more beautiful.
The history of tire production development shows that the first 50 years are mainly to solve the problem of how to improve the service life of tires. In recent years, due to the increasingly demanding tire in the automobile manufacturing and transportation departments, the focus of tire research has shifted to tire driving performance ,safety comfort and economic performance.
