Forklift truck is an industrial handling vehicle, which specifically refers to various wheeled handling vehicles for loading and unloading, stacking and short-distance transportation of palletized goods. Forklifts can realize highly efficient mechanized logistics operations and reduce the labor intensity of workers' handling, and are characterized by strong versatility, flexibility and wide range of activities. According to the World Industrial Vehicle Statistical Association, industrial vehicles are divided into motorized industrial vehicles and non-motorized industrial vehicles, and motorized industrial vehicles are divided into five categories, namely, Class I electric counterbalanced ride-on forklifts, Class II electric ride-on storage forklifts, Class III electric walk-behind storage forklifts, Class III electric walk-behind storage forklifts, Class IV internal combustion counterbalanced ride-on forklifts (solid tires), Class V internal combustion counterbalanced forklifts (pneumatic tires), and Class V internal combustion counterbalanced forklifts (pneumatic tires). Forklift trucks with pneumatic tires. According to the different power sources of forklifts, they can be divided into internal combustion forklifts, electric forklifts and manual forklifts, among which internal combustion forklifts are also divided into ordinary internal combustion forklifts, heavy-duty forklifts, container forklifts and side forklifts, etc. Electric forklifts include electric counterbalanced forklifts and electric warehouse forklifts; according to the structural characteristics of forklifts, they can be divided into forklifts, legged forklifts, pick-and-place forklifts, rough terrain forklifts and other types.