Jinyu is a brand of domestic tires produced by Shandong Jinyu Factory. The factory is located in Guangrao County, Dongying City, Shandong Province. The "Jinyu" trademark was recognized as a "China Famous Trademark" and the "Jinyu" brand tire products were recognized as "Shandong Famous Brand" products. The following are: 1. The functions of tires: Tires are ground-rolling elastic rubber products assembled on vehicles or machinery. They are installed on metal wheel steel to support the body weight and buffer external impacts to achieve contact with the road and ensure the driving performance of the vehicle. 2. Tire maintenance methods: (1) Check tire pressure regularly. (2) Regularly check the tires for bulges, cracks, cuts, nails and abnormal wear. (3) Clean up stones, iron blocks and nails in the tire tread. (4) Carry out four-wheel alignment or tire dynamic balancing.