| 摘要 |
PROBLEM TO BE SOLVED: To surely prevent an occupant from suffering from a whiplash injury at the occurrence of a collision of a vehicle, and to prevent the deterioration of a riding comfort by an inexpensive and simple constitution.SOLUTION: A substantially-rectangular recess 5 having a magnitude covering a vertical range from below up to above a breast of an occupant, and also covering a right-and-left range having a breast width degree is formed at a side opposite to a design surface of a seatback 3 which contacts with a back of the seated occupant, and a depth of the recess 5 is made deeper as progressing toward a lower side. By this constitution, when a body portion of the occupant is pressed backward of a vehicle by an impact of a rear collision, a portion which is thinned in thickness by the recess 5 of the seatback 3 becomes easier to move backwardly more than the other portion of the seatback 3, a deeper sink of the occupant is thereby allowed, the timing of the forward bouncing of the occupant can be delayed, a burden on a neck of the occupant is alleviated, and thus, a whiplash injury can be prevented without causing the deterioration of a riding comfort by an inexpensive and simple constitution. |
