JPH08119052A - Air bag for air bag device - Google Patents

Abstract

PURPOSE: To reduce production man-hour and production cost by maintaining the effect to suppress the amount of projection of an air bag when it is inflated. CONSTITUTION: An air bag 1 is formed in a bag shape by seaming a bottom side sheet 2 provided with a gas inlet port 3 and a gas outlet port 4 with a roof side sheet 6 opposed to the gas inlet port 3 around the outer periphery of them. Also the bottom side sheet 2 is seamed with the roof side sheet 6 inside the exhaust port 4 around the gas inlet port 3 using form control seaming thread 9 weaker in tensile strength than outer periphery seaming thread 8 which seams the outer peripheries to each other. Then the form control seaming thread 9 is provided with corner parts 10a facing toward the gas inlet port 3 and seams the sheets 2 and 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bag-shaped airbag which is used in an airbag device mounted on a vehicle and inflates at a predetermined time.

[0002]

2. Description of the Related Art In an air bag of a conventional air bag device, as is known from Japanese Utility Model Laid-Open No. 61-85549, a bottom sheet having a gas inlet and a gas inlet are provided. The opposing ceiling-side sheets have a bag shape in which the outer peripheral edges are sewn together, and are normally folded and stored in the airbag device.

Inside the airbag, a plurality of belt-shaped tethers for connecting the bottom side sheet and the ceiling side sheet are arranged in order to suppress the amount of protrusion when the airbag is inflated.

When manufacturing an air bag while arranging these tethers, first, attach one end of the tether to the back side of the bottom sheet or the ceiling side sheet (the inner peripheral surface side when the air bag is manufactured). Sew on.

Next, the back side peripheral edges of the sheet to which one end of the tether is sewn and the other sheet of the ceiling side sheet or the bottom side sheet are sewn to each other.

[0006] Then, turn over using the gas inlet,
The other end of the tether disposed inside is sewn to the inner peripheral surface side of the ceiling side sheet or the bottom side sheet to manufacture an airbag.

That is, in the conventional tether, when the other end is sewn, it is necessary to sew the inner side of the bag-shaped air bag while confirming the arrangement position thereof. This is time-consuming and increases man-hours and manufacturing cost of the airbag.

The present invention solves the above-mentioned problems, and provides an airbag for an airbag device, which maintains the effect of suppressing the amount of protrusion at the time of inflation and can reduce the number of manufacturing steps and the manufacturing cost. The purpose is to

[0009]

In an airbag according to the present invention, a bottom side sheet having a gas inlet port and an exhaust port, and a ceiling side sheet facing the gas inlet port are sewn together at their outer peripheral edges. An airbag of a bag-shaped airbag device comprising: a bottom side sheet and a ceiling side sheet, wherein the outer peripheral edges are sewn to each other at a portion inside the exhaust port around the gas inlet port. The suturing thread for shape regulation having a lower tensile strength than the suture thread for outer peripheral edge is sutured, and the suture thread for shape regulation has a corner portion toward the gas inlet side and is sutured. It is characterized by

[0010]

With the airbag according to the present invention,
At the time of expansion, first, the area around the gas inflow port that has been sewn with the shape-regulating suture expands, and the amount of protrusion is suppressed.

After that, the internal pressure increases, the shape-regulating suture stitching the bottom sheet and the ceiling sheet has a lower tensile strength than the outer peripheral suture thread, and the stress is concentrated on the stitched locus. Since the corners that are apt to occur are arranged to break, in order to smoothly connect the expansion part and the exhaust port,
The airbag can effectively exhaust the inflation gas and prevent an unnecessary increase in internal pressure.

Since the shape-regulating suture thread is thin, unlike the conventional band-shaped tether, after forming an air bag in the shape of a bag, the suture thread is penetrated from the front side of the bottom side sheet or the ceiling side sheet. Since the stitches can be sewn, the shape-regulating suture thread can be arranged without much trouble.

Therefore, in the airbag according to the present invention, the effect of suppressing the amount of protrusion at the time of inflation can be maintained, and the number of manufacturing steps and the manufacturing cost can be reduced.

Further, in the airbag according to the present invention, since the exhaust port is closed at the beginning of inflation, it takes a short time to inflate the occupant into a shape capable of restraining the occupant. can do.

Further, in the airbag according to the present invention,
After restraining the occupant, the shape-regulating suture breaks, and the exhaust port can be opened to suppress the rise in internal pressure, thus preventing unnecessary rise in internal pressure and improving the restraint performance of the occupant. be able to.

Furthermore, in the airbag according to the present invention, when the airbag is folded and stored, unlike the conventional band-shaped tether, only a thin thread is arranged inside.
It is not bulky and can be stored easily.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 4, the airbag 1 of the embodiment is used in an airbag device M arranged in a steering wheel of an automobile, and has a gas inlet 3 and an exhaust port 4. A bottom sheet 2 having a substantially disc shape and a ceiling sheet 6 having a substantially disc shape facing the gas inflow port 3, and their outer peripheral edges are sewn with a suture thread 8 for the outer peripheral edge. Formed into a bag shape.

The sheets 2 and 6 are made of a woven fabric such as nylon or polyester, and the suture thread 8 is made of a nylon thread or the like.

Around the gas inlet port 3 of the bottom sheet 2 of the airbag 1, a plurality of mounting holes 5 for mounting the airbag 1 in a bag holder 13 described later are formed, and these gas flows Inlet 3, exhaust port 4, mounting hole 5
Before the suturing of the sheet 2 and the sheet 6, the bottom sheet 2 is preliminarily perforated and formed.

The airbag device M in which the airbag 1 is used will be described.
As shown in FIG. 4, a pad 11 for covering the folded airbag 1, an inflator 12 for supplying inflation gas to the airbag 1, an airbag 1, a pad 11 ,.
And bag holder 13 for holding the inflator 12
It consists of and. 14 is an annular retainer arranged around the gas inlet 3 of the airbag 1,
A predetermined number of bolts 14a fixed to the retainer 14
Through the mounting holes 5 of the airbag 1 and through holes (not shown) of the bag holder 13 and the inflator 12, and fixing the nuts 15 to hold the airbag 1 and the inflator 12 in the bag holder 13. The Rukoto. Further, the pad 11 has a side wall 11a extending downward.
Is fixed to the peripheral edge of the bag holder 13 by the rivets 16 so that the bag is held by the bag holder 13. In addition, 17 is a contact plate.

In the airbag 1 of the embodiment, as shown in FIG.
As shown in FIGS. 3 to 3, the bottom sheet 2 and the ceiling sheet 6 are sewn together with a breakable suture 9 for shape regulation.
The suture thread 9 is formed of a nylon thread or the like having a lower tensile strength than the suture thread 8. In the case of the embodiment, the suture 8 is
The suture 8 comprises 1260 denier upper thread and 8 lower thread.
The suture thread 40 has a denier of 40, and the suture thread 9 has an upper thread of 1260 denier and a lower thread of 630 denier, and is adjusted by the thickness of the suture threads 8 and 9.

As shown in FIG. 1, the locus 10 of the suture thread 9 of the embodiment has a four-petal shape when the airbag 1 is in a deployed state, and the seat is located inside the exhaust port 4 around the gas inlet port 3. Corners 10a that are sewn to 2.6 and are recessed in the inner part
Are arranged.

In manufacturing the airbag 1, first, a bottom side sheet 2 and a ceiling side sheet 6 each having a predetermined gas inflow port 3, an exhaust port 4, and a mounting hole 5 are formed on an inner peripheral surface of the airbag 1. The outer peripheral edges are sewn together with the outer peripheral edge suture thread 8 in a state where the parts arranged on the side are in close contact with each other.

Thereafter, using the gas inlet 3, the inside is turned over,
The sheets 2 and 6 can be manufactured by stitching them with the shape regulating suture thread 9.

In such an airbag 1, the airbag device M is folded and stored, and after the airbag device M is mounted on the vehicle, the inflation gas G is supplied from the inflator 12 to the pad. As shown in FIG. 2, the area 11 sewn by the shape regulating suture thread 9 expands around the gas inflow port 3 and the amount of protrusion is suppressed.

After that, the internal pressure rises, and as shown in FIG. 3, the shape-regulating suture thread 9 for sewing the bottom sheet 2 and the ceiling sheet 6 has a tensile strength higher than that of the outer peripheral suture thread 8. Since the corner portion 10a is weakened and the corner portion 10a where stress concentration is likely to occur is arranged on the sewn track 10, the airbag 1 is broken to smoothly connect the initial inflated portion 1a and the exhaust port 4 to each other. The expansion gas G can be effectively exhausted, and an unnecessary increase in internal pressure can be prevented.

Since the shape regulating suture thread 9 is thin, unlike the conventional band-shaped tether, after the airbag 1 is formed into a bag shape, the surface side of the bottom side sheet 2 and the ceiling side sheet 6 is formed. Since it can be sewn through from the bottom, the shape-regulating suture thread 9 can be disposed without any trouble, and the same effect as described in the section of the action and effect of the invention described above can be obtained. You can

[Brief description of drawings]

FIG. 1 is a bottom view of an airbag according to an embodiment of the present invention in a deployed state.

FIG. 2 is an initial sectional view of the same embodiment at the time of expansion.

FIG. 3 is a cross-sectional view showing a state after the state shown in FIG. 2 of the same embodiment.

FIG. 4 is a schematic sectional view of an airbag device in which the airbag of the embodiment is used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Airbag, 2 ... Bottom side sheet, 3 ... Gas inflow port, 4 ... Exhaust port, 6 ... Ceiling side sheet, 8 ... Outer peripheral suture thread, 9 ... Shape regulation suture thread, 10a ... Corner part, M ... airbag device.

Claims (1)

[Claims] 1. An airbag for a bag-shaped airbag device, wherein a bottom sheet having a gas inlet and an exhaust outlet and a ceiling sheet facing the gas inlet are sewn together at their outer peripheral edges. Wherein, the bottom side sheet and the ceiling side sheet, the inner portion of the exhaust port in the vicinity of the gas inlet, the shape of the tensile strength is weaker than the outer peripheral suture thread which is sewn to each other An airbag for an airbag device, which is sewn with a restricting suture, and the shape restricting suture has a corner portion toward the gas inflow side and is sutured.