Abstract: Using as a vehicle body reinforcing member a bent tube with mixed bends of inward and outward projection according to the present invention makes it possible, during a vehicle body collision, to absorb more energy than and exhibit better impact resistance than a vehicle body reinforcing member that uses one of a known straight tube and a curved tube of radius R entirely. Thus the dimensions (outside diameter, wall thickness) of the steel tube that is used as the vehicle body reinforcing member can be reduced, and the tube shape can be modified, while impact resistance is maintained. Modifying the shape in this manner makes it possible to provide the ever higher required level of vehicle body impact resistance at the same time that it reduces the weight of the vehicle body and lowers the cost. The present invention can therefore be widely used as an occupant protection technology.

Abstract: Using as a vehicle body reinforcing member a bent tube with mixed bends of inward and outward projection according to the present invention makes it possible, during a vehicle body collision, to absorb more energy than and exhibit better impact resistance than a vehicle body reinforcing member that uses one of a known straight tube and a curved tube of radius R entirely. Thus the dimensions (outside diameter, wall thickness) of the steel tube that is used as the vehicle body reinforcing member can be reduced, and the tube shape can be modified, while impact resistance is maintained. Modifying the shape in this manner makes it possible to provide the ever higher required level of vehicle body impact resistance at the same time that it reduces the weight of the vehicle body and lowers the cost. The present invention can therefore be widely used as an occupant protection technology.

Abstract: Using as a vehicle body reinforcing member any one of a bent tube with a partial bend of radius R, a tube with a plurality of portions that are bent at radius R, and a bent tube with mixed bends of inward and outward projection according to the present invention makes it possible, during a vehicle body collision, to absorb more energy than and exhibit better impact resistance than a vehicle body reinforcing member that uses one of a known straight tube and a curved tube of radius R entirely. Thus the dimensions (outside diameter, wall thickness) of the metal tube that is used as the vehicle body reinforcing member can be reduced, and the tube shape can be modified, while impact resistance is maintained. Modifying the shape in this manner makes it possible to provide the ever higher required level of vehicle body impact resistance at the same time that it reduces the weight of the vehicle body and lowers the cost. The present invention can therefore be widely used as an occupant protection technology.

Abstract: A metal tube for reinforcing car body, and a car body reinforcement according to the invention have a curved portion extending over the entire longitudinal length or a local longitudinal length, wherein, when the reinforcement is assembled such that the outer periphery of the curved portion is aligned substantially in the direction of impact applied to the car body, the load ramp gradient, the maximum load and the absorbed energy are all enhanced in case of a car body collision. Particularly, an increase in the load ramp gradient as for the load property at the start of deformation provides an excellent crash capacity in reinforcing the car body. Moreover, the metal tube and the reinforcement according to the invention are capable of satisfying the current requirements for much more crash capacity of the car body, along with both a weight reduction of the car body and a reduced manufacturing cost, and therefore they are applicable in a wide field for protecting occupants in an automobile.

Abstract: A metal tube for reinforcing car body, and a car body reinforcement according to the invention have a curved portion extending over the entire longitudinal length or a local longitudinal length, wherein, when the reinforcement is assembled such that the outer periphery of the curved portion is aligned substantially in the direction of impact applied to the car body, the load ramp gradient, the maximum load and the absorbed energy are all enhanced in case of a car body collision. Particularly, an increase in the load ramp gradient as for the load property at the start of deformation provides an excellent crash capacity in reinforcing the car body. Moreover, the metal tube and the reinforcement according to the invention are capable of satisfying the current requirements for much more crash capacity of the car body, along with both a weight reduction of the car body and a reduced manufacturing cost, and therefore they are applicable in a wide field for protecting occupants in an automobile.