| 摘要 |
PURPOSE:To reinforce the rigidity of a back rest part by providing in parallel in the vertical direction plural spot-like beads formed by joining like a spot the front frame wall and the back frame wall in the vicinity of a hinge knuckle mechanism provided part of the back rest part of a seat back frame. CONSTITUTION:In the vicinity of a hinge knuckle mechanism 5 provided part of a back rest part 5a of a seat back frame 5, plural spot-like beads 12 obtained by joining like a spot the front frame wall 8 and the back frame wall 9 are provided in parallel in the vertical direction. In such a state, in the case a front load or a rear load works on the back rest part 5a of the seat back frame 5 and the back rest part 5a is deformed, it is obstructed that tensile force which follows its deformation is propagated to a rise part 5b of a hinge knuckle mechanism 3 attached side by a spot-like bead 12 formed part whose rigidity is reinforced. In such a way, a section modulus of the seat back frame 5 can be maintained roughly in an initial state, and the rigidity of the back rest part 5a is improved. |
