Tire knowledge

tire
　　tireAscarThe performance of the support and transmission part of the force between the road and the road has a great influence on the driving performance of the car. The performance of a tire is related to its structure, material, air pressure, pattern and other factors.
The tire assembly is mounted on the rim and directly contacts the road surface. Its function is to withstand the gravity of the car; when the car is running, the uneven road surface causes impact and vibration, requiring the tire and suspension to alleviate the impact; to ensure good adhesion between the wheels and the road surface, and transmit driving force and braking force. , To maintain the stability of the car.
Structural tires are mainly composed of crowns, shoulders, sidewalls, carcass and beads.
1. Tire crown refers to the middle part of the two shoulder clamps of the tire. Including tread, buffer layer (or belt layer) and ply, etc.
Tread refers to the tread rubber layer with a pattern on the outermost layer of the crown and the road surface. The role is to protect the carcass and prevent its early wear and damage.
The buffer layer refers to the tape layer between the bias tire tread and the carcass. The function is to alleviate and partially absorb the impact of the road on the tire.
The belt layer refers to the material layer that clamps the carcass in the circumferential direction of the tread centerline under the tread base of the radial tire and the bias tire. The function is to enhance the circumferential rigidity and inclined rigidity of the tire, and bear most of the stress of the tread.
The ply layer refers to the cloth layer composed of rubber-coated parallel cords in the carcass. It is the skeleton of the carcass and supports various parts of the carcass.
2. The sidewall refers to the rubber layer on the sidewall of the carcass between the shoulder and the bead, which protects the carcass and bears lateral forces.
3. The carcass is the force-bearing structure of a pneumatic tire composed of one or more layers of cords and beads. The carcass cords of the bias tire are arranged to cross each other, and the carcass cords of the radial tire are parallel to each other.
4. The bead refers to the part of the tire installed on the rim. It is composed of a bead core and chafer cloth. The function is to prevent the tire from falling off the rim.

type
According to different carcass structures, automobile tires can be divided into pneumatic tires and solid tires. Car tires commonly used in automobiles are pneumatic tires. Solid tires are currently only used on low-pressure cars or heavy-duty trailers running on arterial roads on asphalt concrete roads.
Pneumatic tires can be divided intoInner tubeAnd tubeless.
According to the cord material, it can be divided into cotton cord tires, artificial thread tires, nylon tires, steel wire tires, polyester tires, glass fiber tires, and cordless tires.
According to the tread pattern, it can be divided into ordinary tread tires, off-road tread tires, and mixed tread tires.
According to the air pressure, it can be divided into high pressure tires, low pressure tires, and ultra low pressure tires.
According to the ply structure, it can be divided into bias tires, belt bias tires and radial tires.
1. The pneumatic tire with inner tube is mainly composed of outer tube, inner tube and cushion belt. The inner tube is filled with compressed air, and the outer tube is used to protect the inner tube from damage and has a certain degree of elasticity; the cushion belt is placed under the inner tube to prevent the inner tube from being damaged by hard contact with the rim.
2. Ordinary bias tires
Its characteristic is that the cords of each adjacent layer of the ply and the buffer layer are arranged crosswise, and each ply and the center line of the crown form an angle of 35o to 40o, so it is called a bias tire.
3. Radial tires
The carcass ply of this tire is arranged at an angle of 90 degrees or close to 90 degrees with the center line of the tread, and the cords are distributed like the earth's meridian, so it is called a radial tire. The cord strength of radial tires is fully utilized, and the number of plies is less than that of ordinary bias tires, so that the weight of the tire can be reduced and the carcass is softer. The radial tire adopts a multi-layer buffer layer with a small angle (10o to 20o) to the center line of the tread. It is made of structural cords or steel cords with high strength and low tensile force, which can bear the large cuts generated during driving. Xiangli. The belt layer is like a steel belt, tightly boxed on the carcass, which greatly improves the rigidity, driveability and wear resistance of the tread.
Due to the structure of the radial tire, when it rotates at a high speed, the deformation wheel has a low temperature and the critical speed for generating a standing wave is higher than that of the bias tire, which improves the safety in driving.
4. Tubeless tires
In appearance, it is similar to ordinary tires. The difference is that the inner wall of the tubeless tire is attached with a layer of about 2 to 3mm thick rubber sealing layer specially used for sealing air, which is adhered to by the method of vulcanization, and the sealing layer is facing the tread surface. Below, a self-adhesive layer made of a special mixture of unvulcanized rubber is attached. When the tire is pierced, the self-adhesive layer can bond the pierced holes by itself, so there are also tubeless tires with self-adhesive layers.
When a tubeless tire is pierced, the pressure will not drop sharply, which is conducive to safe driving. The tubeless tire has no friction and jams between the inner and outer tires. It has good air tightness and can directly dissipate heat through the rim with low temperature rise. , Long service life, simple structure and light weight. The disadvantage is that it is difficult to repair when it is broken on the way.
Tire pressure
Pneumatic tires can be divided into high pressure tires, low pressure tires and ultra low pressure tires according to the air pressure inside the tires. High pressure tires (air pressure 0.49～0.69MPa), low pressure tires (air pressure 0.147～0.49MPa), ultra low pressure tires pressure below 0.147Mpa).
Nowadays, low-pressure tires are mostly used in trucks and cars, because low-pressure tires have good elasticity, wide cross-section, large contact area with the road surface, and thin tire walls and good heat dissipation.These properties extend tire life