Multiple screw springs combined independent suspension device

The utility model relates to a multi-helical spring combined independent suspension device for high mobility off-road vehicles. The helical spring group of the device comprises a large-travel linear (rigidity-variable) primary helical spring and an auxiliary helical spring with smaller wire diameter and pitch diameter. When the wheels are in such condition that the vehicle is unloaded, the primary helical spring as elastic element in the suspension device works alone. When wheels are in such condition that the vehicle is full-loaded, the auxiliary helical spring and the primary helical spring in the suspension device corporate, thereby increasing the rigidity of the suspension device. The combination of multiple helical springs can change the rigidity and overcome the problems of high difficulty in manufacturing rigidity-variable helical spring, high manufacturing cost and short service life. Therefore, the manufacturing cost of the suspension system is reduced and the reliability of the suspension system and the whole vehicle is improved.