Tire is one of the important parts of the automobile, which is in direct contact with the road surface and together with the automobile suspension, can reduce the impact of the automobile when driving, and the automobile tire ensures the automobile to have good ride comfort and ride comfort; Ensure the good adhesion between the wheels and the road surface, and improve the traction, braking and passability of the car; Bearing the weight of the car, people pay more and more attention to the important role of tires in the car. A long time ago, tires were made of wood, iron and other materials. 1845, an Englishman Robert Thomson invented the first hollow wheel. He proposed to fill the elastic airbag with compressed air to reduce the vibration and impact during exercise. Although the tires at that time were made of leather and coated canvas, they had already shown the advantages of low rolling resistance. According to this principle, john dunlop made a rubber hollow tire at 1888, and then Thomas made a rubber hollow tire with a valve switch. Unfortunately, because there is no canvas in the inner layer, it is impossible to maintain a certain cross-sectional shape and cross-sectional width. With the appearance of 1895 automobile, pneumatic tires have been widely developed. The first batch of automobile tire samples appeared in France on 1895. This is a plain canvas tire with a single inner tube. Although there is tread rubber, there is no pattern. It was not until 1908 to 19 12 that obvious changes took place in the tire, that is, patterns appeared on the tread rubber to improve the service performance, which opened the history of tire tread patterns, increased the cross-sectional width of the tire and allowed lower internal pressure to ensure better cushioning performance. 1892, Burrimier of Britain invented the curtain cloth, and 19 10 was used for production. This achievement not only improves tire quality and expands tire varieties, but also makes tire molding possible. With the improvement of tire quality requirements, the quality of cord fabric has also been improved. Cotton cord fabric was replaced by rayon, which was replaced by nylon and polyester cord with better strength and heat resistance in the late 1950s. With the development of radial tire, steel cord has strong competitiveness. Matt created carbon black reinforced rubber in 1904, and used it to reinforce tread compound on a large scale after using cord fabric in tires, because before that, canvas was damaged faster than tread in tire use, and the amount of carbon black in the compound increased rapidly. In 1930s, only about 20 parts of carbon black were used in every 100 part of raw rubber. At this time, carbon black was mainly used on the tread, and the carcass was not used. Now it has reached more than 50 copies. Before carbon black was added to the tread, the tire was polished after driving about 6000km, and the mileage of the tire was greatly improved after carbon black was added. At present, a set of truck tires can travel about 65,438+million kilometers, and even 200,000 kilometers on good roads. 19 13- 1926, because the invention of tire technology of cord and carbon black laid the foundation for the development of tire industry. With the standardization of tire outer edge and the gradual improvement of automobile tire manufacturing technology, the production speed is higher than before and the tire output is increasing day by day. With the development of automobile industry, tire technology is constantly improving and perfecting, such as the transition from low-pressure tires to ultra-low-pressure tires from the early 1920s to the mid-1930s; In the 1940 s, tires gradually transitioned to wide rims; The emergence of tubeless tires in the late 1940s; In the late 1950s, low-profile tires came out and so on. The emergence of many new technologies is nothing more than the radial tire pioneered by French company Mixilin in 1948. This kind of tire is known as the revolution of tire industry because of the remarkable improvement of service life and performance, especially the fuel saving during driving. Here is a brief introduction to the main characteristics of several kinds of tires developed today. Radial tire: The characteristic of this tire is that the arrangement direction of cords is consistent with the radial section of the tire (that is, the crown angle is zero). Due to this arrangement of cords, the strength of tire cords can be fully utilized, and the number of cord layers of radial tires can generally be reduced by about 40-50% compared with ordinary bias tires. The ropes are connected in the circumferential direction only by rubber. Compared with ordinary bias tires, radial tires have the advantages of high elasticity, good wear resistance, long service life of 30-50%, low rolling resistance, reduced automobile fuel consumption by about 8%, good adhesion, good cushioning performance, large load-bearing capacity and non-explosive tires. The disadvantages are: the side wall is easy to crack, and the large lateral deformation leads to poor lateral stability of the automobile, and the manufacturing technical requirements and cost are high. Tubeless tire: The difference between tubeless tire and ordinary tire is that there is no inner tube, and air is directly pressed into the outer tire, so there needs to be a good seal between the tire and the rim. The tubeless tire is similar to the tubeless tire in appearance and structure, but the difference is that a rubber sealing layer with a thickness of about 2-3 mm is attached to the inner wall of the tubeless tire and bonded by vulcanization. When the tire has a puncture, it is tightly wrapped with the puncture, so it can not leak for a long time, and even if the puncture is pulled out, the air pressure in the tire can be temporarily maintained. There is an annular groove on the bead of tubeless tire, which is concentric with the main road. Under the action of air pressure in the tire, the groove can reliably press the bead on the rim edge to ensure sealing. The rim on which the tubeless tire is mounted is airtight, with an inclined bottom and a flat paint layer. The valve is directly fixed on the rim and sealed with rubber gasket. Tubeless tires have the advantages of good air tightness, good heat dissipation, simple structure and light weight. The disadvantage is that it is more difficult to repair on the way. Wide-section wheel tire: With the increase of vehicle speed, it is required to lower the center of gravity of the whole vehicle and improve the handling performance, which requires improving the lateral stability and adhesion to the road to ensure the safety of high-speed driving, so the appearance of low-section tires has become an inevitable trend. The ratio (H/B) of tire cross-sectional height (H) to cross-sectional width (B) is an important parameter representing tire structural characteristics, which is called tire height-width ratio, and some people also call it flattening ratio. Since the 1920s, the outer diameter of automobile tires has decreased by 25%, the rim diameter has decreased by 35%, the width of tires and rims has nearly doubled, and the aspect ratio of tires has been decreasing, reaching 0.5 for cars and 0.4 for racing cars. In particular, wide tires are more beautiful and elegant with luxury cars. The history of automobile tire production and development shows that the first 50 years are mainly about how to improve the service life of tires. In recent years, due to the increasing requirements of automobile manufacturing and transportation departments for tires, the focus of tire research has shifted to the driving performance, safety performance, comfort performance and economic performance of tires. In short, the general development trend of tires is "three-oriented", that is, meridian, tubeless and low profile. At present, car tires have achieved this "three-oriented", and truck tires are also developing in this direction.

Tire is one of the important parts of automobile, which directly contacts the road surface and works with automobile suspension to alleviate the impact of automobile driving and ensure good riding comfort of automobile. Ensure good adhesion between wheels and road surface, and improve the traction, braking and passing capacity of vehicles; Bearing the weight of the car, the important role of tires in the car has been paid more and more attention. Long before tires were made of wood, iron and other materials, the first hollow wheel was invented by the British inventor Robert Thomson 1845, and his elastic bag was filled with compressed air to reduce the vibration and impact in sports. Although the tires at that time were canvas made of leather and glue, the benefits of tire rolling resistance have been shown. According to this theory, john dunlop made a hollow rubber tire in 1888, and then Thomas made a valve switch with a hollow rubber tire. Unfortunately, because there is no inner canvas, it cannot maintain a certain cross-sectional shape and cross-sectional width. With the appearance of motor vehicles in 1895, the development of pneumatic tires is extensive. The first tire sample appeared in France in 1895. It is a single-tube tire made of plain canvas, although there is no tread pattern. From 1908 to 19 12, the tire changed significantly, that is, the performance of tread pattern was improved, which opened up the history of tire tread, increased the cross-section width of tire, and allowed lower internal pressure to ensure good cushioning. 1892 The British invented the cord rib rolling mill, and 19 10 was used in production. This achievement not only improved the tire quality and expanded the tire variety, but also made it possible to form the tire. With the improvement of tire quality requirements and cord quality, cotton cord was replaced by rayon, and rayon was replaced by nylon and polyester cord with better performance and higher heat resistance in the late 1950s. With the development of radial tire steel cord, it is very competitive. 1904, Matt created carbon black reinforced rubber, which was used for tire cord after reinforcing tread rubber on a large scale, because before that, canvas was damaged much faster than tread rubber in tires, and the amount of carbon black increased rapidly. In 30 years, carbon black was used in every1000 parts of raw rubber, and at this time, carbon black was mainly used on tread, and the matrix was not used, and now it has reached more than 50 parts. Before adding carbon black, the tread mileage of the tire was only about 6000 kilometers, but after adding carbon black, the tire mileage was greatly improved. Now a set of truck tires can travel about 100 000 km, and even 200 000 km in good road conditions. 19 13- 1926, the invention of cord and carbon black laid the foundation for the development of tire technology and tire industry. After the standardization of tire outer edge, the system of tire manufacturing technology is gradually improved, and the output is increased faster than before, which increases the output of tire. With the development of automobile industry, tire technology is constantly improving and improving, such as the transition from low-pressure tires to ultra-low tires in passenger cars from the early 1920s to the mid-1930s; In the 1940 s, tires gradually began to transition to wide rims; The emergence of tubeless tires in the late 1940s; 50 low-profile tires are late and so on. Many new technologies are none other than France's 1948. Mi Xilin pioneered the radial tire structure. The life and performance of this kind of tire have been greatly improved, especially in driving, which can save fuel. At the same time, it is regarded as a revolution in the tire industry. The main characteristics of several kinds of tires currently developed are briefly introduced. Radial tire: The characteristic of this tire is that the cord arrangement direction of the ply tire is the same as the radial section (that is, the crown angle is zero). This cord arrangement makes full use of the strength of the divine cord, and the number of cord layers of radial tire is generally 40-50% higher than that of ordinary bias tire, which can be reduced. The cord contacts the rubber alone in the circumferential direction. Compared with ordinary bias tire, radial tire has the advantages of high elasticity, good wear resistance, 30-50% longer tire life, low rolling resistance, 8% lower automobile fuel consumption, good adhesion, good cushioning performance, strong bearing capacity and explosive tire. The disadvantages are: the side wall is easy to tear, and the lateral stability of the vehicle is poor due to the distortion of the side surface, which has high manufacturing requirements and high cost. Tubeless tire: The difference between tubeless tire and ordinary tire is that there is no inner tube, and the air pressure directly enters the tire, so there needs to be a good seal between the tire and the rim. The tubeless tire is similar to the tubeless tire in appearance and structure. The difference is that a special rubber sealing layer with a thickness of 2-3 mm is attached to the inner wall of the tubeless tire to seal the air layer, which is bonded by vulcanization. When the tire is punctured, because it is in a compressed state, once the golden fruit pierces something, it will not leak for a long time, and even if the punctured object is pulled out, the air pressure in the tire can be temporarily maintained. There are many concentric annular grooves on the tubeless tire. Under the internal pressure of the tire, the grooves can be reliably pressed to the bead edge to ensure sealing. The rim with tubeless tire is airtight, and its inclined bottom absorbs paint smoothly. The valve is directly fixed on the rim, and it is sealed with rubber gasket. The tubeless tire has the characteristics of good air tightness, good heat dissipation, simple structure and light weight. It is a more difficult way to correct shortcomings. Section width of wheeled vehicle tires: With the increase of vehicle speed, in order to reduce the center of gravity of the vehicle and improve the handling performance, it is required to improve the stability and lateral adhesion of the tires on the road to ensure the traffic safety at high speed. The appearance of this low-profile tire has become an inevitable trend. The ratio (H/B) of tire cross-section (H) to cross-section width (B) represents an important parameter of tire structure, which is called the length-width ratio of tire, and some people also call it the flatness ratio. Since the 1920s, the outer diameter of automobile tires has decreased by 25%, the diameter of rims has decreased by 35%, the width of tires and rims has nearly doubled, and the aspect ratio of tires has been declining, reaching 0. 5, the car is as high as 0.4, especially the wider the tires, the more beautiful the match with the advanced car. The development history of automobile tire production shows that the first 50 years are mainly about how to improve the tire life. In recent years, the requirements of automobile and transportation departments for tires are getting higher and higher, and tires should improve the key driving performance, safety performance, comfort and economic performance of tires. In short, the general trend of tire development is "three-oriented", that is, radial, tubeless and low-profile. At present, car tires have achieved this "C", and truck tires are developing in this field.