In 1946, the French tire company Michelin pilot production of the world’s first radial tire. Invention radial tire is the a revolution in the industry, it has become a new direction of development of automobile tires.
radial tire international code is “R”, because its structure is different from the bias tire carcass, some countries called radial tires, X tires.
radial tire carcass cord arrangement is different from the bias tire, radial tire cords are not arranged to intersect each other, but with the tire section close to parallel, radial arrangement like the earth, a small cord angle, generally between the carcass cords does not maintain 0deg ;, intersection, when the tire during running, the stress around the crown portion is increased, circumferential stretching will cause fetal body into a radial gap. Thus the use of radial tires the buffer layer close to the circumferential cord layer arranged in contact with the carcass cord angle to 90deg; intersect, usually 70deg; 78deg ;, to form a rigid annular band hardly extendable, fixed to the entire tire , limits the circumferential deformation of the tire, the buffer layer 60 to withstand the entire tire stress percentage to 70 percent, a major force receiving member of the radial tire, so called belt layer of a radial tire. Main bias tire force receiving member is not on the buffer layer, the internal stress 80 percentage to 90 percentage borne by the carcass ply. Thus, with a radial tire belt layer design is very important, must have good rigidity, large angle can be multilayer, high tensile strength and not easily fibrous material such as steel or glass fibers.
The radial tires of different materials can be divided into all steel radial tire, PCR TIRESAnd all-fiber three types of radial tires. all-steel radial tires
all steel radial tire belt layers are used steel cord, it is generally used for load vehicles and construction machinery. PCR TIRES
steel radial tire carcass half using rayon or other fibers, the belt layer is a steel cord, radial tires of this type are generally used on a car or light truck, such as buses and the like.
fiber full radial tire carcass and the belt layer or other wide use of rayon fiber cords, belt cords with a low-elongation cords, which are generally used for low-speed radial tire for a passenger car or a tractor.
radial tire reasonable structure, superior to bias tires performance, there are many excellent characteristics: good wear resistance and puncture resistance; good cushioning properties, low running temperature; good stability and safety, economic efficiency and mileage high.
4, the advantages
1) ground contact area, good adhesion properties, a small slip of the tread on the ground unit pressure is small, and thus rolling resistance, long service life.
2) has a crown thick and stiff belt layer, easy piercing; small deformation during running can be reduced by 3 ~ 8 Percentage Percentage consumption.
3) Because the low-rise ply, sidewall is thin, its radial elasticity, cushioning property, a large load capacity. Good
4) heat radiation performance, can be adapted to high temperature, high speed.
5) tax: Since January 1, 2001, radial tires are exempt from consumption tax.
5, the advantages and disadvantages
due to the thinner sidewall, a crown thick, which is easy to produce cracks in the transition zone of the sidewall. Side deformation, resulting in poor lateral stability of the vehicle, the high requirements of manufacturing technology, the cost is high.
Since the tire having a radial wear, fuel economy, ride comfort and traction, the high-speed stability and good performance characteristics, so as to obtain a fast development. EyeOn the international front radial tire market share of 80 percentage, car and truck radial tires were 90 and 63 percentage percentage.
1) The tire assembly: a radial tire can not be mixed with other tire on the same vehicle, in particular with all other tires mounted on the same shaft used .
2) Tire pressure: standard pneumatic radial tire according to the provisions. When it’s a normal tire inflation pressure and the same, it will become under-inflated.
3) Toe vehicle: when the vehicle front modified by one of ordinary tire radial tire, the toe to be reduced accordingly.
4) driving operation: Driving a vehicle fitted with radial tires, started to slow, steady brake to, cornering, the car will slow down or when traveling on uneven roads, overtaking should be selected in a wide section of the ground, do not turn too hard plate.
5) protecting the carcass: radial tire side of the thin, large deformation, it can easily be scratched.
7, the development of
China’s huge demand for cars contributed to the rapid growth of the tire industry in 2007 January-August Chinese tire production was 3.3836 million, an increase of 23 percentage, radial tire production was 153 million, an increase of 36.7 percentage. Radial tire reached 45 percentage of the total tire. It indicates that China’s tire architecture is changing to the pursuit of high quality and high value-added direction.
From the point of view of listed companies, three quarters of 2007 vehicle tires were the main business income 19,932,910,000, an increase of 30.10 percentage, total profit of 608.82 million, an increase of 243.74 percentage. Profit growth were higher than revenue growth, the overall development of the industry in good condition.
car tire industry, the percentage of net profit growth of 146.2, profitability significantly more than the detergent industry, as China’s huge car ownership and the continued growth of automobile consumptionAnd ushered in another stage of development, brought a car tire business development opportunities.
competitive situation: China’s tire business is divided into state-owned, joint ventures / wholly-owned, private and other three categories, strengths and weaknesses in the mechanisms for enterprises, technology, products, capital and marketing. State-owned enterprises on the basis of the company, but except for a few companies, most of faltering, institutional constraints by the slow development; joint ventures / wholly-owned enterprises have advantages in capital, management, technology and so on, but most of them focus on high-end products, in addition to cars, light load and other semi-steel radial tire, other varieties do not possess the scale advantages; private enterprises rely on flexible mechanisms, rapid progress, but the strength of the technical and marketing aspects of the rival network.
industry trends and forecast: 2010 is expected to total demand of automobile tires to more than 240 million, of which the radial tire demand will exceed 200 million. Experts predict that in 2010 car ownership in China is about 62 million, of which 31 million cars. By then, the domestic market demand for automobile tires will be 164.8 million, an average annual increase of 9.2 percentage; exports of about 78.7 million, an average annual increase of 3.9 percentage; total 243.5 million, an average annual increase of 7.3 percentage.
By 2010, the projected domestic demand for radial passenger car tires is about 81 million, exports of about 45 million, adding up to 126 million; domestic market demand for light truck radial tires of about 28.3 million, exported about 17.4 million, for a total of 45.7 million; domestic demand for radial truck tire is about 32.1 million, 6 million exports, adding up to 38.1 million. Radial tire demand in 2010 is expected to total 209.8 million, an increase of 1 times more than in 2004, one hundred million, compared with negative growth bias tires.