①Under certain load and driving conditions, the tire of the manual hydraulic pallet truck has a suitable tire pressure. When the tire pressure is lower than the standard value, the radial deformation of the tire increases, and excessive deflection occurs on both sides, resulting in the crown The two sides are grounded, the inner wall of the sidewall is compressed, and the outer wall of the sidewall is stretched, and the cords in the carcass produce greater deformation and alternating stress. Periodic compression deformation will speed up the fatigue damage of the cord, increase the relative slip between the tire ply and the tire and the ground, increase the heat generated by friction, and increase the tire temperature sharply, reducing the tensile strength of the rubber , The cord is loose and partially delamination, and the tire will burst when encountering obstacles and being impacted. The uneven pressure on the tread causes serious wear on the shoulders and produces a "bridge effect". The tread is toothed or wavy. Tire tread recesses are easy to be embedded in road nails and stones, causing mechanical damage. The rolling resistance of the carcass increases and fuel consumption increases. Tests have shown that when tire pressure is lower than 20%-25% of the standard value, fuel consumption will increase by 20%. When the tire pressure is higher than the standard value, the center of the tire crown is grounded, the contact area between the tire and the road surface is reduced, the load per unit area is increased, and the wear of the center of the tire crown increases. The tire cord is over-stretched, the carcass cord stress increases, and the cord fatigue process accelerates, causing the cord to break and causing the tire to burst early.
②Under a certain load and tire pressure, the speed of manual hydraulic transport increases, the deformation frequency of the tire, the vibration of the carcass, and the twisting and deformation of the tire circumference and lateral direction (the formation of static waves) increase accordingly, which is caused by friction per unit time. As the heat increases, the working performance of the tire decreases, and even the ply rupture and tread peeling phenomenon occur, which accelerates the wear and destruction of the tire.
