Method for manufacturing airbag module

Abstract

An airbag module for use in a motor vehicle is manufactured by first to third steps. In the first step, the airbag is folded into a predetermined configuration, and in the second step, an entire external surface of the airbag, in an initially folded condition obtained in the first step, is wrapped in a bag-shaped film forming member. The bag-shaped film forming member includes a plurality of resin layers formed in a layer-stack manner with regard to a film cross-sectional direction. In the third step, the initially folded airbag is housed in the airbag-housing member in a condition wherein the airbag has an airbag volume reduced to less than the airbag volume at a time of being initially folded, by a compression force applied to the bag-shaped film forming member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a cross-sectional structure of an airbag apparatus of the present invention.

FIG. 2 is a view showing a condition in which an airbag in a folded condition in the present embodiment is held by an airbag-holding member.

FIG. 3 is a view showing a cross-sectional structure taken along line 3-3 in the airbag-holding member in FIG. 2.

FIG. 4 is a view showing a cross-sectional structure taken along line 4-4 in the airbag-holding member in FIG. 2.

FIG. 5 is a flowchart of an airbag module-forming process in the first embodiment.

FIG. 6 is a view showing a schematic construction of a first processing device used for forming a lower film sheet in the first embodiment.

FIG. 7 is a view showing a condition of a heat-processing for the lower film sheet in the first embodiment.

FIG. 8 is a view showing a schematic construction of a second processing device used in a vacuuming processing in the first embodiment.

FIG. 9 is a view showing a condition in which an upper film sheet is heat-welded to the lower film sheet in the first embodiment.

FIG. 10 is a view showing a condition of a vacuum-releasing processing in an inside of a chamber of a metallic mold in the first embodiment.

FIG. 11 is a view showing a condition in which an airbag module product in the present embodiment is housed and attached to a housing space in a retainer.

FIG. 12 is a view showing a housing method different from that shown in FIG. 11, with regard to the housing method for the airbag module product in the present embodiment.

FIG. 13 is a view showing a housing method different from that shown in FIG. 11, with regard to the housing method for the airbag module product in the present embodiment.

FIG. 14 is a flowchart of an airbag module-forming process in the second embodiment.

FIG. 15 is a view showing a condition of a process stage corresponding to FIG. 14.

FIG. 16 is a view showing a condition of a process stage corresponding to FIG. 14.

Claims

1. A method for manufacturing an airbag module for use in a motor vehicle, comprising: a first step of folding an airbag into a predetermined configuration;a second step of wrapping an entire external surface of the airbag in an initially folded condition obtained in the first step by a bag-shaped film forming member, wherein the bag-shaped film forming member comprises a plurality of resin layers formed in a layer-stack manner with regard to a film cross-sectional direction; anda third step of housing the initially folded airbag in an airbag-housing member in a condition wherein the airbag has an airbag volume reduced to less than that at a time of being initially folded, by a compression force applied to the bag-shaped film forming member.

2. The method for manufacturing the airbag module according to claim 1, wherein the bag-shaped film forming member comprises a heat-contractive resin layer, and in the third step, the initially folded airbag is compressed via the film forming member by performing a heat-contraction process on the bag-shaped film forming member thereby reducing the airbag volume to a volume less than that at the time of being initially folded.

3. The method for manufacturing the airbag module according to claim 1, wherein the bag-shaped film forming member comprises a film sheet including a heat-welding resin layer; and in the second step, two pieces of the film sheets are arranged such that the heat-welding resin layers are disposed to face one other, and the initially folded airbag is sandwiched between the film sheets.

4. The method for manufacturing the airbag module according to claim 3, wherein in the second step, after sandwiching the initially folded airbag, each of outer edge portions of the film sheets is joined and formed into a bag shape in a tightly sealed condition by heat-welding the heat-welding resin layer.

5. The method for manufacturing the airbag module according to claim 4, wherein in the third step, the initially folded airbag is compressed via the film forming member by performing an evacuation process on the bag-shaped film forming member in a tightly sealed condition so that the airbag volume is reduced less than that at the time being initially folded.

6. The method for manufacturing the airbag module according to claim 5, wherein the bag-shaped film forming member for compressing the initially folded airbag is used as the airbag-housing member.

7. The method for manufacturing the airbag module according to claim 2, wherein the bag-shaped film forming member for compressing the initially folded airbag is used as the airbag-housing member.

8. The method for manufacturing the airbag module according to claim 2, wherein the bag-shaped film forming member for compressing the initially folded airbag is used as an airbag-holding member for holding a folded shape of the airbag.

9. The method for manufacturing the airbag module according to claim 5, wherein the bag-shaped film forming member for compressing the initially folded airbag is used as an airbag-holding member for holding a folded shape of the airbag.

10. The method for manufacturing the airbag module according to claim 5, wherein any of the plurality of resin layers of the film forming member comprises a translucent resin layer, and the method further comprises a fourth step of confirming a condition of the airbag obtained in the third step via observation of the airbag through the bag-shaped film forming member.

11. The method for manufacturing the airbag module according to claim 10, further comprising: a fifth step of housing the film forming member in an airbag-housing member having a housing space larger than the film forming member and smaller than the initially folded airbag; anda sixth step of expanding the airbag along the housing space of the airbag-housing member while weakening the compression force applied to the airbag by weakening an evacuation performed in the third step.

12. The method for manufacturing the airbag module according to claim 11, wherein the film forming member comprises a communication portion for allowing an inside and an outside of the film forming member to communicate with each other, and a cover member capable of forming a covering condition of covering the communication portion and a releasing condition for releasing the covering operation, and wherein the communication portion is set in a condition covered by the cover member when the evacuation processing for the film forming member is performed in the third step while the communication portion is set to the releasing condition by the cover member when the decompression processing for the film forming member is weakened in the sixth step,