Analysis of eight non normal wear of electric forklift truck
In a certain load and driving conditions, forklift tire has a proper tire pressure, when the tire pressure is lower than the standard value when driving, the tire radial deformation increases, both sides have excessive deflection, so that both sides of the tread ground, tire side wall pressure, tire side wall tension, carcass cord in deformation and alternating large stress. Compression deformation periodically, fatigue damage will speed cord, tire cord fabric layer and between the tire and the ground slip increases, the heat generated by the friction increases, the tire temperature rise sharply reduce the tensile strength of the rubber, loose cord and delamination, in case of the impact generated when the obstacle tire. Tread pressure is not uniform, the shoulder part wear, to produce a “bridge” effect, fetal dentate or wavy surface. The tire tread is easy to be embedded in the nail and stone of the road, causing mechanical damage. Tire rolling resistance increased, increased fuel consumption. Experiments show that when the tire pressure is lower than the standard value of 20% – 25%, fuel consumption increase 20%. When the tyre pressure is higher than the standard value, the center of the tire is grounded, the contact area between the tire and the road surface is reduced, the load on the unit area is increased, and the wear of the center of the tire is intensified. Tyre cord by hyperextensible, carcass cord stress increased, the fatigue process of cord is accelerated, caused by cord break, causing early burst tire.
The increase in speed and load tire certain pressure, deformation, frequency, the vibration of the tire carcass and tire circumferential and lateral distortion (the formation of stationary wave) increased, unit time internal friction and heat generated increases, the decline in the performance of the tire, and even the emergence of ply rupture and tread spalling accelerate the tire wear and damage.
In a certain tire pressure, tire overloading the flexural deformation increases, stress increases cord and cord, easilycausing sidewall cord broken, loose and ply delamination, cord force will exceed the allowable design stress and tire ground pressure, the heat generated increased. Body temperature, load capacity decline. At the same time, because of the contact between the shoulder and the ground to wear, especially in the face of obstacles, even if a small stone, it will cause the tire crown blasting. Practice has proved that in the case of turning and rough road, when the tire load of more than 20%, the mileage will be shortened by 35%; more than 50%, 59%; more than 1 times, shorter than 80%.
The service life of the road conditions on the tire has a great impact, it affects the dynamic load and tire friction between the tire and the ground is.
The high temperature will make the rubber tensile strength, elongation and hardness decreased, the adhesive strength between rubber and cord decreased, but also accelerated the aging of rubber. In the high temperature aging tires, especially when tire slip occurred or roll over obstacles, it is easy to make the crown tear pattern. The sidewall rubber aging and cracks and sidewall deformation caused serious separation of carcass ply cord and rubber tire, once the local emergency load is likely to burst.
When the tire is oil, acid-base material corrosion and long time high temperature, physical and chemical properties of the tire will be changed, the bearing capacity is greatly reduced, use it easily. In addition, the corrosion of oil seal gas tire will appear massive spalling, a small area of rubber tyre off, and tire cord and rubber detachment phenomenon. As the patch can not be compatible with the oil and rubber, so even if the tire damage to the wound is small, but also lost the possibility of repair.
And because of the difference of characteristics of front and rear axle load distribution is different, the driving wheel and the steering wheel and different road conditions, the wear condition of the tire is not consistent, if both sides of the same axle without replacement of the same plant, the same size, structure, level and pattern of the tire, the tire wear will accelerate.
In use, if not pay attention to the reasonable collocation and periodic rotation caused by the tire load bear uneven tire wear will accelerate.