Patent ID: 8596903

Claim:
A method for absorbing a vehicle's impact using a kinetic frictional force produced by dragging a surface of a rolled tube, the method comprising: absorbing impact energy of the vehicle primarily by a dragging action of a front barrier and a first dragging kinetic frictional force inducing member with a kinetic friction inducing bolt inserted therein, the first dragging kinetic frictional rolling force inducing member being sequentially installed on a front end portion of a kinetic frictional force inducing tube made of a soft material, with respect to the friction force inducing tube, so that a maximum deceleration of the vehicle slows to 20 g (g=9.8 m/sec 2 ) or less; while dragging the front barrier and the first dragging kinetic frictional rolling force inducing member, dragging a second dragging kinetic frictional force inducing member having a kinetic friction inducing bolt inserted therein and a kinetic friction coefficient larger than that of the first dragging kinetic frictional rolling force inducing member and installed at an intermediate portion of the kinetic frictional force tube, to secondarily absorb and reduce kinetic energy; and while dragging the front barrier, the first dragging kinetic frictional rolling force inducing member and the second dragging kinetic frictional force inducing member, with the kinetic friction inducing bolts and inserted therein, dragging a rear barrier and a third dragging kinetic frictional force inducing member having a kinetic friction inducing bolt inserted therein, the rear barrier being installed at a distance S from a stopper installed rearward on the tube, so that a kinetic frictional force of the vehicle becomes a maximum stop frictional force in a state in which kinetic friction coefficients of the first dragging kinetic frictional force inducing member and the second and third dragging kinetic frictional force inducing members all increase.