JP7744326B2 - Airbag device and method of manufacturing airbag module - Google Patents

Description

The present invention relates to an airbag device that protects occupants from impacts to the vehicle due to a collision or other event, and a method for manufacturing an airbag module.

In an airbag device, an airbag cushion containing an inflator is stored in a required position in the vehicle, for example, in a folded accordion-like state.

As shown in Figure 13, Patent Document 1 discloses an airbag device 100 that includes an airbag case 101, a gas generator 102, and an airbag body 103 into which gas ejected from the gas generator 102 flows. In this airbag device 100, the airbag body 103 is stored in the airbag case 101 in a bellows-like folded state, and the outside of the airbag case 101 is covered with a film 104.

Patent Document 1 explains that the reasons for covering the outside of the airbag case 101 with film 104 are that it reliably maintains the folded state of the airbag body 103, eliminates the risk of rust or oil adhering to the airbag body 103, and eliminates the risk of damage to the airbag body 103 from press burrs or welding burrs on the side frame, making assembly easier and improving work efficiency.

Japanese Patent Application Publication No. 10-181493

Airbag modules, which consist of an inflator and airbag cushion, are required to be even smaller when stored. For example, one trend in vehicle seats is thin seats, in which the thickness of the side support section of the backrest in the vehicle width direction is reduced. With thin seats, the space available for placing the airbag module on the outer side of the seat frame is narrower, so a thinner, more compact airbag module is required.

A conventional method for miniaturizing a side airbag module is known, for example, by using heat-melting felt as a cover material and carrying out the following process before assembling it to the side frame.

Step 1: Wrap the airbag module with heat-melting felt.
Step 2: The airbag module with the felt wrapped around it is heated in an IR oven to melt the felt.
Step 3: The airbag module with the melted felt is placed in a mold and pressed using a press.
- Step 4: The airbag module is made smaller by applying pressure to harden the felt into the desired shape.

However, the above-mentioned conventional methods have been criticized for the following problems: 1) they require equipment such as an IR oven, molds, and presses, resulting in high equipment costs; 2) when the felt is heated to its melting point and melted, it expands, easily causing the external shape of the airbag module to collapse; and 3) the felt used as the cover material is thick and bulky, so although it can reduce the size of the airbag module to a certain extent, the effect is limited.

In addition, in Patent Document 1, the film 104 covers the outside of the airbag case 101, so even if the film 104 is heat-shrinkable, it can only shrink to a shape that fits the outer shape of the airbag case 101 when heated. Therefore, the configuration of Patent Document 1 cannot be used for the purpose of miniaturizing airbag modules.

The present invention was made in light of these circumstances, and aims to realize an airbag device that can efficiently downsize the airbag module before assembling it in the designated position in the vehicle, does not require expensive equipment, and is highly economical.

The airbag device of the present invention comprises:
an inflator that injects gas;
an airbag cushion containing an inflator and folded into a roll or accordion-like shape to form a single mass;
a resin package provided so as to be wrapped around the entire periphery of the airbag cushion;
It is equipped with:

The airbag device of the present invention comprises:
a plate disposed on one side of the folded mass of the airbag cushion along the cushion;
The resin package may be configured to be wrapped around the entire periphery of the airbag cushion together with the plate, with the plate in contact with the airbag cushion.

In the present invention, the airbag cushion may be formed in a rod shape, and the resin package may be wrapped around the outer periphery of the rod-shaped airbag cushion.

In the present invention, the resin package may be a heat-shrinkable resin that shrinks when heat is applied.

In the present invention, the plate may be provided with a through-hole through which the stud bolt of the inflator can pass.

In the present invention, the resin package may be formed in a tubular shape.

The method for manufacturing an airbag module of the present invention includes the steps of:
A method for manufacturing an airbag module comprising an inflator that injects gas and an airbag cushion that houses the inflator, comprising the steps of:
a first step of folding the airbag module into a roll or accordion-like shape to form a single mass before assembling the airbag module to a side frame of a seat;
a second step of placing a plate on one side of the airbag cushion along the folded mass of the airbag cushion;
a third step of wrapping a resin package made of a heat-shrinkable resin around the entire periphery of the airbag cushion together with the plate while the plate is in contact with the airbag cushion;
a fourth step of heating the airbag module with the resin package wrapped around it to shrink the resin package;
Contains:

The method for manufacturing an airbag module of the present invention may further include a fifth step of removing the plate after the fourth step.

The airbag device of the present invention comprises an inflator that sprays gas to inflate and deploy the airbag cushion, an airbag cushion that houses the inflator and is folded into a roll or accordion-like shape to form a single mass, and a resin package that is wrapped around the entire periphery of the airbag cushion.

The present invention further includes a plate that is placed on one side of the folded, bulky airbag cushion. In this case, the resin package is arranged to wrap around the entire periphery of the airbag cushion together with the plate, with the plate in contact with the airbag cushion.

In this invention, before assembling the airbag module consisting of the inflator and airbag cushion to the side frame, heat is applied to the resin package wrapped around the entire circumference of the airbag cushion, causing the resin package to shrink. As a result, the folded airbag cushion is subjected to the contraction force of the resin package, which further compresses it.

In addition, in the present invention, before assembling the airbag module consisting of the inflator and the airbag cushion to the side frame, heat may be applied to the resin package wrapped around the entire periphery of the airbag cushion together with a plate placed on one side of the airbag cushion to shrink the resin package.

When a plate is used, by placing the plate on one side of the folded airbag cushion, it is possible to control the direction in which the contraction force of the resin package is exerted and the shape of the contracted cushion. This allows the airbag cushion to be compressed efficiently and the airbag module to be made smaller.

The present invention does not require expensive equipment such as IR ovens, presses, or molds. By heating the resin package during the mass production process of airbag modules, the present invention can efficiently compress the airbag cushion and reduce the size of the airbag module, resulting in a highly economical effect.

FIG. 1 is a view of an airbag device (plates and a resin package are not shown) according to an embodiment, viewed from the side of a vehicle, with an airbag cushion inflated and deployed. FIG. 2 is a perspective view of the airbag device according to the embodiment, showing a seat frame that forms the framework of the seat, as viewed obliquely. Regarding the airbag device according to the embodiment, FIG. 3(a) is a diagram showing a vertical cross section of a state in which a resin package is wrapped around one end of a folded airbag cushion with a plate aligned therebetween, and FIG. 3(b) is a diagram showing a vertical cross section of a state in which the resin package has shrunk after heating and the airbag cushion has been compressed. Regarding the resin package, FIG. 4(a) is a diagram showing an example in which a cylindrical shrink tube is used, and FIG. 4(b) is a diagram showing an example in which a sheet-like shrink film is used. Regarding the through-holes in the plate, FIG. 5( a) is a diagram showing an example in which a slit-shaped through-hole is used, and FIG. 5( b) is a diagram showing an example in which a through-hole consisting of a plurality of holes is used. 6(a) and 6(b) are diagrams showing the airbag device according to the first modified example of the embodiment in the same states as those shown in FIGS. 3(a) and 3(b), respectively. 7A to 7D are diagrams illustrating a procedure for winding an airbag cushion into a roll in an airbag device according to a second modified example of the embodiment. 8(a) and 8(b) are views showing the same states as those shown in FIGS. 3(a) and 3(b), respectively, for an airbag device according to a second modified example of the embodiment. 9(a) and 9(b) are views showing the same states as those shown in FIGS. 3(a) and 3(b), respectively, for airbag devices according to other modified examples. 10(a) and 10(b) are views showing the same states as those shown in FIGS. 3(a) and 3(b), respectively, for airbag devices according to other modified examples. FIG. 11 is a view of an airbag device according to another modified example (the plate and resin package are not shown) with the airbag cushion inflated and deployed, as viewed from the side of the vehicle. FIG. 12 is a view of an airbag device according to another modified example, in which the airbag cushion is inflated and deployed, as viewed from above the vehicle. FIG. 13 is a cross-sectional view showing a state in which a gas generator and an airbag body are assembled inside an airbag case in a conventional airbag device.

Embodiments of the present invention will be described in detail below with reference to the drawings. Note that the following embodiments are merely examples of the present invention and are not intended to limit the scope of the present invention, its applications, or its uses.

In this invention, the term "occupant" refers to, for example, a person with a physique equivalent to that of an average American male, conforming to a frontal crash test dummy (Hybrid III AM50/frontal crash test dummy established by the NHTSA [National Highway Traffic Safety Administration] standard [49 CFR Part 572 Subparts E and O]), with approximate dimensions of 175 cm in height, 88 cm in seated height, and 78 kg in weight. However, the present invention is also applicable to other anthropomorphic dummies.

In this specification, "above" and "upper side" may refer to the direction of the head of an occupant 5 seated in the correct position on the seat 1, and "below" and "lower side" may refer to the direction of the feet of the occupant 5. Here, "correct position" refers to the center position of the seat cushion 2 in the left-right direction on the seat 1, where the back of the occupant 5 touches the backrest 3 from top to bottom. Also, "front" and "front side" may refer to the direction in front of the occupant 5 seated in the correct position on the seat 1, and "rear" and "rear side" may refer to the direction behind the occupant 5. Also, "left" and "left side" may refer to the direction to the left of the occupant 5 seated in the correct position on the seat 1, and "right" and "right side" may refer to the direction to the right of the occupant 5.

In this specification, the term "folded airbag cushion" can refer to an airbag cushion that has been wound into a roll by a winding operation, an airbag cushion that has been folded into an accordion-like shape by a folding operation, or an airbag cushion that has been folded by a combination of a winding operation and a folding operation.

The airbag device 10 of this embodiment is a side airbag device that restrains the side of an occupant 5 who attempts to move toward the door in the event of a side collision or the like of the vehicle. The airbag module 11 that constitutes the airbag device 10 is installed inside the side of the seat back 3 of one of two seats arranged side by side in the vehicle width direction. In this embodiment, the airbag module 11 is installed in the driver's seat 1. The airbag module 11 includes an airbag cushion 12 and an inflator 20.

[Seat configuration]
As shown in Figure 1, the seat 1 includes a seat cushion 2 that supports the buttocks and thighs of an occupant 5, and a backrest 3 that supports the back of the occupant 5. The backrest 3 is attached to the rear end of the seat cushion 2 so as to be able to tilt. A headrest 6 is attached to the upper end of the backrest 3 via a rod-shaped support member 7. The seat 1 may be one in which the backrest 3 and the headrest 6 are integrally formed.

As an example, as shown in Figure 2, a seat frame 4 is provided inside the backrest 3, and a seating frame 8 is disposed on the bottom side of the seat cushion 2. The seat frame 4 and seating frame 8 are connected via a reclining mechanism 9, forming the framework of the seat 1.

The seat frame 4 comprises a pair of side frames 4a extending in the up-down direction of the seat at the right and left ends of the seat back 3 in the seat width direction, an upper frame 4b connecting the upper ends of the pair of side frames 4a in the seat width direction, and a lower frame 4c connecting the lower ends of the pair of side frames 4a in the seat width direction. The seat frame 4 is configured in a frame shape by the side frames 4a, upper frame 4b, and lower frame 4c. The side frames 4a are molded from, for example, metal or resin.

In the seat cushion 2, a pad made of, for example, urethane foam material is disposed above the seat frame 8. In the backrest 3, a pad is provided in front of the seat frame 4a. These pads are covered with a skin material. The skin material is made of elastic fabric or leather.

[Configuration of Airbag Device and Manufacturing Method of Airbag Module]
As shown in FIG. 3( a), the airbag module 11 constituting the airbag device 10 of this embodiment includes, before being assembled to the side frame 4 a, an inflator 20 that sprays gas to inflate and deploy the airbag cushion 12, the airbag cushion 12 that has the inflator 20 built in and is folded accordion-like so as to form a single mass, a plate 30 that is arranged on one side of the airbag cushion 12 along the folded, mass-like airbag cushion, and a resin package 40.

In this embodiment, the resin package 40 is made of a heat-shrinkable resin film whose volume shrinks when heated to a certain temperature. The resin film that makes up the resin package 40 can be made of any desired material, such as PS (polystyrene), PET (polyethylene terephthalate), PVC (vinyl chloride), PP (polypropylene), or PO (polyolefin), and can be a single-layer or multi-layer film.

Specifically, an example of the physical property data of the resin package 40 used in this embodiment is shown below. Note that the following physical property data is only an example, and may be modified as appropriate according to the required specifications.

The airbag cushion 12 is folded accordion-like when laid flat, to assume the storage configuration when stored inside the seat 1. The airbag cushion 12 folded accordion-like forms a single mass. This single mass may be spherical, oval-shaped, or the like, but in this embodiment, the airbag cushion 12 is folded so that it has an elongated overall shape, specifically, a rod shape.

In this embodiment, the longitudinal direction of the folded, rod-shaped airbag cushion 12 and the longitudinal direction of the plate 30 that is aligned with the airbag cushion 12 are aligned in the same direction. Furthermore, when the airbag module 11 is installed inside the side support portion of the backrest 3 of the seat 1, the longitudinal direction of the plate 30 is aligned with the fore-and-aft direction of the vehicle.

In this embodiment, the resin package 40 is wrapped around the entire circumference of the airbag cushion 12 together with the plate 30, with the plate 30 in contact with one of the sides of the rod-shaped airbag cushion 12.

The resin package 40 has holes 41 through which the stud bolts 21 of the inflator 20 pass. By passing the stud bolts 21 through the holes 41, the resin package 40 can be positioned relative to the folded airbag cushion 12.

Because the resin package 40 is heat-shrinkable, when the airbag module 11 is heated from the state shown in Figure 3(a), the resin package 40 shrinks in both the radial and longitudinal directions. Heat is applied to a temperature at which heat shrinkage preferably begins, which is predetermined depending on the physical properties of the resin that makes up the resin package 40. Specifically, the resin package 40 of this embodiment has a radial shrinkage rate of 45±4% and a longitudinal shrinkage rate of 5±4%. As shown in Figure 3(b), when the resin package 40 shrinks, the contraction force compresses the folded airbag cushion 12, reducing the size of the airbag module 11. The resin package 40 breaks when the airbag cushion 12 inflates and deploys.

In this embodiment, the airbag cushion is pre-formed into a long, thin rod shape, which makes it easier to take advantage of the characteristics of the resin package 40, which has a high radial shrinkage rate of 45±4%, thereby increasing the compression effect of the airbag cushion 12.

In this embodiment, by placing a plate 30 along one side of the accordion-folded airbag cushion 12, it is possible to control the direction in which the contraction force of the resin package is exerted, as well as the shape of the package when contracted. The plate 30 is a flat, plate-shaped member made of steel.

As described above, the manufacturing method for the airbag module 11 of this embodiment is a method for manufacturing an airbag module 11 comprising an inflator 20 that injects gas and an airbag cushion 12 that incorporates the inflator 20, and includes the following steps: a first step of folding the airbag cushion 12 into a single accordion-like mass before assembling the airbag module 11 to the side frame 4a of the seat 1; a second step of placing a plate 30 on one side of the airbag cushion 12 along the folded, mass-like mass; a third step of wrapping a resin package 40 made of heat-shrinkable resin around the entire periphery of the airbag cushion 12 together with the plate 30 while the plate 30 is in contact with the airbag cushion 12; and a fourth step of heating the airbag module 11 with the resin package 40 wrapped around it to shrink the resin package 40.

The airbag cushion 12 used in this embodiment is a cloth bag constructed by preparing the required number of base fabrics of the required shape in advance and sewing the periphery and other predetermined locations of these base fabrics. The airbag cushion 12 may also be formed using the so-called "one-piece weaving" technique.

The inflator 20 is connected to a connector provided inside the airbag cushion 12. The inflator 20 is a gas generator formed in a roughly cylindrical shape, and when assembled, its axial direction is aligned with the longitudinal direction of the side frame 4a of the backrest 3. The upper end 22a and lower end 22b of the inflator 20 each have an ejection hole. Two stud bolts 21 are provided on the outer surface of the inflator, protruding in the longitudinal direction at an appropriate interval. The stud bolts 21 are inserted through the through-holes 31 in the plate 30 and the holes 41 in the resin package 40.

The inflator 20 is attached to the side frame 4a of the backrest 3 with a stud bolt 21 and a nut 22. The stud bolt 21 is passed through an insertion hole in the inflator 20 storage section and fixed to the side frame 4a, thereby also fixing the airbag cushion 12 to the side frame 4a.

The inflator 20 is electrically connected to a control unit 51 such as an ECU (Electronic Control Unit). When a side collision of the vehicle is detected or predicted based on signals from sensors 52, such as a side collision detection sensor that detects a side collision of the vehicle and a side collision prediction sensor that predicts a side collision, the inflator 20 is activated by a signal from the ECU. When the inflator 20 is activated, gas is sprayed from the nozzle holes at the upper end 22a and lower end 22b of the inflator 20.

The airbag cushion 12 is stored inside the side support section on the near side of the backrest 3 of the seat 1. It is inflated by gas generated by the inflator 20, and the inflation pressure of the airbag cushion 12 ruptures the covering material of the backrest 3, causing the airbag cushion 12 to inflate and deploy laterally outward in the width direction of the seat 1 relative to the occupant 5.

The airbag cushion 12 includes an upper chamber 14, a lower chamber 15, and a baffle 16 that separates the upper and lower chambers 14 and 15. The upper chamber 14 is long enough in the vertical and front-to-rear directions to receive the sides of the occupant's 5 torso, such as the shoulders 5s, chest 5c, and upper arms 5ua. It also has a length in the vertical and front-to-rear directions to receive the occupant's 5 head 5h in addition to the sides of the torso. The lower chamber 15 has a length in the vertical and front-to-rear directions to receive the occupant's 5 sides of the torso, such as the abdomen 5a and waist 5w. In the event of a side collision, the inflated and deployed airbag cushion 12 restrains the sides of the occupant 5 that tend to move in the direction of the impact, restricting the occupant's 5 movement.

[Effects of this embodiment]
In this embodiment, the airbag device 10 includes an inflator 20 that injects gas, an airbag cushion 12 that houses the inflator 20 and is folded accordion-like so as to form a single mass, a plate 30 that is placed on one side of the airbag cushion 12 along the folded mass of the airbag cushion 12, and a resin package 40 made of heat-shrinkable resin. In this embodiment, the resin package 40 is provided so as to wrap around the entire periphery of the airbag cushion 12 together with the plate 30 with the plate 30 in contact with the airbag cushion 12.

In this embodiment, before the airbag module 11, consisting of the inflator 20 and the airbag cushion 12, is assembled to the side frame 4a, heat is applied to the resin package 40, which is wrapped around the entire circumference of the airbag cushion 12 together with the plate 30 placed on one side of the airbag cushion 12, to shrink the resin package 40. As a result, the folded airbag cushion 12 is further compressed by the contraction force of the resin package 40.

In this embodiment, by aligning the plate 30 along one side of the folded airbag cushion 12, it is possible to control the direction in which the contraction force of the resin package 40 is exerted and the shape of the airbag cushion 12 when it is contracted. As a result, in this embodiment, the airbag cushion 12 can be compressed efficiently, and the airbag module 11 can be made smaller.

The resin package 40 of this embodiment is heat-shrinkable and is a thin film with a thickness of 0.10±0.03 mm, eliminating the problems found in conventional technology: 1) the felt expands when thermally melted, easily causing the external shape of the airbag module to collapse, and 2) the felt itself is bulky, so even if it can be made smaller, the effect is limited.

In addition, this embodiment uses a plate 30 and a resin package 40, and although a small heater is used to heat the resin package 40, expensive equipment such as an IR oven, press, or mold, as in conventional technology, is not required. The cost of the heater used to heat the resin package 40 in this embodiment is approximately 55% of the cost of the IR oven used in conventional technology.

In this way, in this embodiment, by heating the resin package 40 during the mass production process of the airbag module 11, the airbag cushion 12 can be efficiently compressed and the airbag module 11 can be made smaller, resulting in a high economic effect.

Here, the resin package 40 may be a cylindrical shrink tube as shown in Figure 4(a), or a sheet-like shrink film as shown in Figure 4(b).

The resin package 40, made of a sheet-like shrink film, can accommodate a wide range of thicknesses, shapes, and sizes of the folded airbag cushion 12, depending on how the shrink film is folded, thereby increasing the versatility of the resin package 40.

On the other hand, the resin package 40 made of a cylindrical shrink tube is somewhat limited in the types of airbag cushion 12 that can be used, but the resin package 40 can be attached to the outer periphery of the airbag cushion 12 and plate 30 simply by inserting them into the tube, making the wrapping of the resin package 40 easier.

Whether the resin package 40 is tubular or sheet-shaped, the plate 30 is placed along one end of the folded airbag cushion 12, and the package is wrapped around the entire circumference together with the plate 30. Heat is then applied, causing the side where the plate 30 is not present to shrink. In this embodiment, by applying a plate to one side of the airbag cushion 12, the airbag cushion 12 can be compressed while controlling the direction in which the contraction force is generated and the shape of the airbag cushion when contracted.

The plate 30 has a through-hole 31 through which the stud bolt 21 of the inflator 20 can pass. The through-hole 31 may be a slit-shaped through-hole 31, as shown in Figure 5(a), or may be a through-hole 31 consisting of multiple holes provided at required positions, as shown in Figure 5(b).

The plate 30, which has a slit-shaped through-hole 31, can accommodate variations in the distance between the multiple stud bolts 21, 21 spaced at a fixed distance along the length of the cylindrical inflator 20, within the range of the slit length, thereby increasing the versatility of the plate 30.

On the other hand, a plate 30 having a through-hole 31 consisting of multiple holes can fixably position the plate 30 relative to the folded airbag cushion 12.

Whether the through-hole 31 of the plate 30 is slit-shaped or hole-shaped, the amount of shrinkage of the resin package 40 on the side where the plate 30 is placed is suppressed, and the amount of shrinkage on the side where the plate 30 is not present is increased. This makes it possible to control the direction of shrinkage of the airbag cushion 12 and its shape after shrinkage.

In this embodiment, as shown in Figure 3, a plate 30 with a linear cross section is used. The plate 30 is composed only of a linear portion 32. The plate 30 is positioned so as not to interfere with the deployment of the airbag cushion 12, so the airbag module 11 can be assembled to the side frame 4a with the plate 30 included. If necessary, the plate 30 may be removed after heat shrinkage, taking care not to distort the shape of the compressed airbag cushion 12.

In other words, the manufacturing method for the airbag module 11 of this embodiment may include the following steps before assembling the airbag module 11 to the side frame 4a of the seat 1: a first step of folding the airbag cushion 12 accordion-like into a single mass; a second step of arranging the plate 30 on one side of the airbag cushion 12 along the folded mass of the airbag cushion 12; a third step of wrapping a resin package 40 made of heat-shrinkable resin around the entire periphery of the airbag cushion 12 together with the plate 30 while the plate 30 is in contact with the airbag cushion 12; a fourth step of heating the airbag module 11 with the resin package 40 wrapped around it to shrink the resin package 40; and a fifth step of removing the plate 30.

In this case, in the fifth step, a slit slightly longer than the width of the plate 30 in the short direction is made in the resin package 40 near the tip of the plate 30, and the plate 30 is removed through this slit. In this embodiment, since the entire resin package 40 is sufficiently shrunk in the fourth step, even when a slit for removing the slit 30 is made in the fifth step, the compressed state of the airbag cushion 12 is maintained and the shape of the airbag cushion 12 is not distorted.

[First Modification of the Embodiment]
6, a plate 30 having an L-shaped cross section is used. The plate 30 of this modification has a straight portion 32 and a bent portion 33 extending in a direction perpendicular to the straight portion 32. The length of the bent portion 33 is shorter than the length of the straight portion 32.

In this modified example, heat shrinking is performed with the L-shaped plate aligned, making it possible to control the shape of the airbag cushion 12 in the short direction as well as the longitudinal direction of the folded, rod-shaped airbag cushion 12. The plate 30 in this modified example does not interfere with the deployment of the airbag cushion 12, and the airbag module 11 can be assembled to the side frame 4a with the plate 30 included.

In this modified example, by aligning the plate 30 with one of the sides of the folded airbag cushion 12, it is possible to control the direction in which the contraction force of the resin package 40 is exerted and the shape of the airbag cushion 12 when it is contracted. This allows the airbag cushion 12 to be compressed efficiently, making it possible to reduce the size of the airbag module 11.

[Second Modification of the Embodiment]
In this modified example, an airbag cushion 12 that has been wound into a roll by a winding operation is used in the first step of the manufacturing method of the airbag module 11. Specifically, the winding operation in this modified example is as follows: First, the airbag cushion 12 is laid flat as shown in Fig. 7(a), and the rear portion 17 of the airbag cushion 12 is folded back toward the front in the vehicle longitudinal direction so as to overlap the storage portion for the inflator 20, as shown in Fig. 7(b).

Next, the airbag cushion 12 undergoes a folding process. In the folding process, a fold line 18a is set along which the upper portion of the airbag cushion 12 is folded, and the upper region 18b above the fold line 18a is folded over the lower region 18c below the fold line 18b. A rolled region 18d, excluding the inflator 20 storage area, is then set, and the airbag cushion 12 undergoes a winding process. In the winding process, a winding center 18e is set, and the airbag cushion 12 is rolled up around the rolled region 18d using the winding center 18e as a reference, forming a rolled portion 18f, as shown in Figure 7(c). Figure 7(d) is a cross-sectional view taken along line A-A in Figure 7(c).

The winding process for the roll winding region 18d is performed in a cone shape with the winding center 18e at the top and the outer edge of the airbag cushion 12, which spreads out radially from the winding center 18e, at the bottom. The winding process begins at the fold line 18a and terminates toward the inflator 20 storage compartment. The roll portion 18f formed by the winding process is positioned adjacent to the inflator 20 stored in the storage compartment, as shown in Figure 7(d). The airbag cushion 12, including the cone-shaped roll portion 18f, forms a single mass. This mass is rod-shaped overall.

In this modified example, as shown in Figures 8(a) and 8(b), by aligning the plate 30 with one of the sides of the rolled and folded airbag cushion 12, it is possible to control the direction in which the contraction force of the resin package 40 is exerted and the shape of the airbag cushion 12 when it is contracted. This allows the airbag cushion 12 to be compressed efficiently, and the airbag module 11 to be made smaller.

As can be understood from the above description, the first step in the method for manufacturing the airbag module 11 may be a step of winding the airbag cushion 12 into a roll so that it becomes a single mass. Alternatively, the first step may be a step of folding the airbag cushion 12 by combining a winding operation and a folding operation.

[Other Modifications]
In the above-described embodiment, the airbag device may be a curtain airbag. In a curtain airbag, an airbag cushion is wound in a roll and stored in the upper part on the door side of the seat 1. By applying the present invention to a curtain airbag, the roll diameter of the airbag cushion in the stored state can be reduced.

In the above-described embodiment, as shown in Figures 9 and 10, the airbag cushion 12 folded into a roll or bellows shape may be covered with a covering member 13, and then a heat-shrinkable resin package 40 may be wrapped around the outside of the covering member 13. In this modification, the covering member 13 is used to temporarily maintain the roll or bellows folded shape. The covering member 13, together with the resin package 40, is broken when the airbag cushion 12 is inflated and deployed. In this modification, the contraction of the resin package 40 compresses the folded airbag cushion 12 via the covering member 13. The covering member 13 in this modification does not have to be heat-shrinkable.

In the above-described embodiment, the airbag cushion 12 may be compact in size to support the shoulders 5s, chest 5c, and sides of the upper arms 5ua, as well as the sides of the abdomen 5a and waist 5w of the occupant 5, as shown in FIG. 11.

In the above-described embodiment, the airbag device 10 may be a far-side airbag device, as shown in Figure 12, which is stored in the side of the backrest 3 of the seat 1 toward the center of the vehicle width direction, and inflates and deploys the airbag cushion 12 on the far side of the occupant 5 to restrain the occupant 5 when an impact is applied to the vehicle. Figure 11 shows a driver's seat 1 in which an airbag device 10 is provided on the side of the backrest 3 on the door D side, and also on the side on the center console C side.

In the above-described embodiment, a weak portion that is weaker than other portions may be formed at a required position on the resin package 40. The weak portion may be provided in a portion of the resin package 40 that faces the direction in which the airbag cushion 12 inflates and deploys. The weak portion may be formed, for example, by a perforation or slit. In this case, the resin package 40 begins to tear at the position of the perforation or slit, allowing the airbag cushion 12 to inflate and deploy from the targeted position, stabilizing the operation of the airbag cushion 12 during the initial deployment stage.

The configuration of the present invention is not limited to side airbag devices, but can also be applied to all airbag devices, such as curtain airbags and knee airbags.

REFERENCE SIGNS LIST 1 seat 4a side frame 10 airbag device 11 airbag module 12 airbag cushion 20 inflator 21 stud bolt 30 plate 31 penetration portion 40 resin package

Claims (6)

an inflator that injects gas;
an airbag cushion incorporating the inflator and folded into a roll or accordion-like shape to form a single mass;
a resin package that is wrapped around the entire periphery of the airbag cushion and is made of a heat-shrinkable resin that shrinks when heat is applied ;
a plate disposed on one side of the folded mass of the airbag cushion along the cushion;
Equipped with
the resin package is wrapped around the entire periphery of the airbag cushion together with the plate in a state in which the plate is in contact with the airbag cushion,
When heated after the winding, the amount of shrinkage of the resin package on the side where the plate is arranged is suppressed, and the amount of shrinkage of the resin package on the side where the plate is not present is increased . 2. The airbag device according to claim 1, wherein the airbag cushion is formed in a rod shape, and the resin package is wrapped around an outer periphery of the airbag cushion which is formed in a rod shape . 2. The airbag device according to claim 1, wherein the plate is provided with a through-hole through which a stud bolt of the inflator can pass . The airbag device according to claim 1, wherein the resin package is formed in a tubular shape . A method for manufacturing an airbag module comprising an inflator that injects gas and an airbag cushion that incorporates the inflator, comprising the steps of:
a first step of folding the airbag module into a roll or accordion-like shape to form a single mass before assembling the airbag module to a side frame of a seat;
a second step of placing a plate on one side of the folded, bulky airbag cushion along the cushion;
a third step of wrapping a resin package made of a heat-shrinkable resin around the entire periphery of the airbag cushion together with the plate while the plate is in contact with the airbag cushion;
a fourth step of heating the airbag module with the resin package wrapped around it to shrink the resin package;
Including,
The method for manufacturing an airbag module, wherein the heating causes the resin package to shrink so that the amount of shrinkage of the resin package on the side where the plate is placed is suppressed and the amount of shrinkage of the resin package on the side where the plate is not present is increased. A method for manufacturing an airbag module comprising an inflator that injects gas and an airbag cushion that incorporates the inflator, comprising the steps of:
a first step of folding the airbag module into a roll or accordion-like shape to form a single mass before assembling the airbag module to a side frame of a seat;
a second step of placing a plate on one side of the folded, bulky airbag cushion along the cushion;
a third step of wrapping a resin package made of a heat-shrinkable resin around the entire periphery of the airbag cushion together with the plate while the plate is in contact with the airbag cushion;
a fourth step of heating the airbag module with the resin package wrapped around it to shrink the resin package;
a fifth step of removing the plate after the fourth step;
A method for manufacturing an airbag module, comprising: