Impact energy absorber for vehicle and method for forming the same

摘要

The resin impact energy absorber for vehicle includes a peripheral wall, a planar portion surrounded by the peripheral wall, and a plurality of first protrusions. The first protrusions are parallel to one another at a predetermined interval in the planar portion. The first protrusion includes a pair of inclined vertical walls and a top wall. The pair of inclined vertical walls projects from the planar portion. The inclined vertical walls face one another. The top wall couples tops of the inclined vertical walls with one another at approximately the same height as the peripheral wall. The inclined vertical walls are inclined at a predetermined inclination angle such that the inclined vertical walls come close to one another as approaching from the planar portion to the top wall. The planar portion includes one plate surface and another plate surface. At least one of them includes an impact load receiving surface.

主权项

1. A method for forming a resin impact energy absorber for vehicle, the method comprising:
providing a pair of split mold blocks, one of which having a mold cavity and either one or both of which having a pinch-off portion, the mold cavity being provided, on a surface of the mold cavity, with a plurality of either first long grooves or first slender protrusions to form first protrusions of the resin impact energy absorber, and a plurality of either second long grooves or second slender protrusions to form second protrusions of the resin impact energy absorber, perpendicularly intersecting with the plurality of either the first long grooves or the first slender protrusions; forming the pinch-off portion either or both around the mold cavity in a circular pattern, projecting the pinch-off portion toward another one of the pair of split mold blocks, when the pinch-off portion is provided with the one of the pair of split mold blocks having the mold cavity, and in a circular pattern in relation to the mold cavity, projecting the pinch-off portion toward the one of the pair of split mold blocks having the mold cavity, when the pinch-off portion is provided with the another one of the pair of split mold blocks without the mold cavity; locating a molten thermoplastic resin sheet extruded through an extrusion slit and introduced downward while pressed with a pair of rollers provided at a predetermined distance, the molten thermoplastic sheet provided to face the mold cavity such that the molten thermoplastic resin sheet has an outer border outside the mold cavity; forming a hermetic space between the mold cavity and a surface of the thermoplastic resin sheet that faces the mold cavity; forming by vacuuming the thermoplastic resin sheet through the hermetic space so as to press the thermoplastic resin sheet against the mold cavity, clamping the thermoplastic resin sheet by the pair of split mold blocks by either or both bringing the pinch-off portion of the one of the pair of split mold blocks in contact with the another one of the pair of split mold blocks when the pinch-off portion is provided with the one of the pair of split mold blocks having the mold cavity, and bringing the pinch-off portion of the another one of the pair of split mold blocks in contact with the one of the pair of split mold blocks when the pinch-off portion is provided with the another one of the pair of split mold blocks without the mold cavity, wherein the method forms the first and second protrusions of the resin impact energy absorber having complementary shapes to either the first and second long grooves, or the first and second slender protrusions, respectively, by having the thermoplastic resin sheet sucked to the first and second protrusions of the mold cavity to form the thermoplastic resin sheet in a shape along the surface of the mold cavity, the second protrusions of the resin impact energy absorber extend in a straight line parallel to a pair of opposing sides of the resin impact energy absorber so as to couple another pair of opposing sides of the resin impact energy absorber with one another, the first protrusions of the resin impact energy absorber extend parallel to the another pair of opposing sides without coupling the pair of opposing sides, and the method forms the first protrusion of the resin impact energy absorber having a height higher than a height of the second protrusion of the resin impact energy absorber, a length longer than a length of the second protrusion of the resin impact energy absorber, and a width wider that a width of the second protrusion of the resin impact energy absorber.