Views: 1000 Author: Site Editor Publish Time: 2022-06-20 Origin: Site
One 6T loader equipped with 23.5-25-20pr-l3 bias tire often had air leakage in the front wheel inner tube during use. Just after the left wheel inner tube was repaired, the right wheel inner tube leaked again a few days later. The main engine manufacturer and the tire manufacturer went to the site for inspection, and found that the damaged parts of the inner tube were located at the edge of the outer tire pad belt, and the outer tire pad belt was wrinkled at the toe.
1. troubleshooting
The tire rim curve of the loader was tested on site and met the requirements of the national standard. The machine has just been sold for one month, and the contact parts between the rim and the tire heel are worn to varying degrees.
The on-site inspection found that the loader was often overloaded. The density of nickel iron ore loaded by the loader is relatively high. When the bucket is full, it can shovel 7 ~ 7.5t of nickel iron ore, and the tire overload rate reaches 16.7% ~ 25%.
In addition, in order to ensure that the tire deformation will not be too large when the loader is overloaded, the driver inflated the tire pressure to 550kpa, resulting in abnormal tire pattern wear, and the steel wire pricking phenomenon occurs when the new tire is used for 200H.
According to the technical data, the overall weight of the loader is 20900kg, the rated load of 23.5-25-20pr-l3 tire is 10950kg, the tire pressure range is 375 ~ 487.5kpa, and the rated overload rate of the tire is 14.47%. It can be seen that the loader often exceeds the rated loading mass and the tire pressure is too high.
According to the tire manufacturer, the steel ring in the outer tire was not fully treated before the outer tire was vulcanized, resulting in premature degumming of individual steel ring lap and rubber under the effect of tire overload and frequent rolling. Individual bead laps lose restraint after degumming, and the bead laps eventually puncture the inner tube under the repeated action of the outer tube grounding pressure and air pressure.
2. improvement measures
(1) Improved tire structure
In view of tire quality problems, it is suggested that tire manufacturers improve tire structure from the following three aspects: first, increase the number of steel rings and rubber core size of 23.5-25-20p bias ply tire; The second is to redesign the structure of the tire bead lap to ensure that the part has sufficient friction and prevent the bead lap from warping; The third is to add a layer of reinforcing structure to the outer surface of the pressed steel ring.
(2) Improve production process
In view of the tire production process, it is suggested that the tire manufacturer improve the tire production process from the following two aspects: first, the tire bead shall be treated in strict accordance with the process flow before the tire is vulcanized; The second is to improve the ability of the steel ring to adhere to the rubber material.
(3) Carry out technical training
For the use of loaders, the manufacturer should provide technical training to customers and Loaders' drivers from the following three aspects: first, drivers should change their bad operating habits to avoid forced operation in case of serious overload; Second, the loader can choose 26- 25-20pr, 26.5-25-24pr and even 23.5r25 radial tyres can greatly improve the overload capacity of tyres; The third is to correctly select the tire model, level and pattern according to the main materials loaded by the loader. After the tire manufacturer implemented the above improvement measures and the loader host manufacturer carried out technical training for customers and loader drivers, the tire failure of the 6T loader basically disappeared.
