Abstract: A method for manufacturing an air bag includes forming a bag portion surrounded by a welded portion extending in an annular shape by pressing at least one welding mold against two sheet materials arranged to be stacked from a stacking direction of the sheet materials. The welding mold is pressed against the sheet materials to form the welded portion including a welding bead portion protruding to an inside of the bag portion between the sheet materials. A pressing surface of the welding mold against the sheet materials is provided with a slope portion facing in the stacking direction of the sheet materials and in a direction of the inside of the bag portion at a position further on an outside of the bag portion than a position at which the welding bead portion is formed.

Abstract: An airbag includes plural bag portions respectively including two sheet members attached to each other, and a welded portion at which the sheet members being in contact with each other are attached to each other. The welded portion includes a communication hole penetrating the sheet members to communicate the bag portions, and a rib portion arranged radially outward of the communication hole, the rib portion protruding in the thickness direction from a welded surface of the welded portion. The rib portion includes an annular rib surrounding the communication hole, and a cutout portion provided at the annular rib. The rib portion includes plural radial ribs arranged radially inward of the annular rib, the plural radial ribs radially surrounding the communication hole and extending in a radial direction of the communication hole. At least one of the radial ribs is arranged at a position radially away from the communication hole.

Abstract: An airbag includes plural bag portions respectively including two sheet members attached to each other, and a welded portion at which the sheet members being in contact with each other are attached to each other. The welded portion includes a communication hole penetrating the sheet members to communicate the bag portions, and a rib portion arranged radially outward of the communication hole, the rib portion protruding in the thickness direction from a welded surface of the welded portion. The rib portion includes an annular rib surrounding the communication hole, and a cutout portion provided at the annular rib. The rib portion includes plural radial ribs arranged radially inward of the annular rib, the plural radial ribs radially surrounding the communication hole and extending in a radial direction of the communication hole. At least one of the radial ribs is arranged at a position radially away from the communication hole.

Abstract: An airbag includes a bag portion including two sheet members which are attached to each other. The bag portion provided with the sheet members which are attached to each other includes a peripheral rim portion having a plurality of bent side portions, the bent side portions which each is bent by filling with air inside the bag portion, the bent side portions, the bent side portions which each is formed with a groove-shaped constriction at a surface of the bag portion which is configured to inflate by filling with air.

Abstract: A method for manufacturing an air bag includes forming a bag portion surrounded by a welded portion extending in an annular shape by pressing at least one welding mold against two sheet materials arranged to be stacked from a stacking direction of the sheet materials. The welding mold is pressed against the sheet materials to form the welded portion including a welding bead portion protruding to an inside of the bag portion between the sheet materials. A pressing surface of the welding mold against the sheet materials is provided with a slope portion facing in the stacking direction of the sheet materials and in a direction of the inside of the bag portion at a position further on an outside of the bag portion than a position at which the welding bead portion is formed.

Abstract: An airbag includes a bag portion including two sheet members which are attached to each other. The bag portion provided with the sheet members which are attached to each other includes a peripheral rim portion having a plurality of bent side portions, the bent side portions which each is bent by filling with air inside the bag portion, the bent side portions, the bent side portions which each is formed with a groove-shaped constriction at a surface of the bag portion which is configured to inflate by filling with air.