Airbag device and method of manufacturing airbag module

Abstract

To provide an airbag device and the like that can efficiently reduce a size of an airbag module, does not require expensive equipment, and exhibits a high economical effect.SOLUTION: An airbag module 11 includes: an inflator 20 that ejects gas to inflate and deploy an airbag cushion 12; an airbag cushion 12 that incorporates the inflator 20 and is folded bellows-like into a single mass; a plate 30 that is disposed on one side face of the airbag cushion 12 along the folded, mass-like airbag cushion; and a resin package 40. The resin package 40 is provided so as to be wrapped around an entire circumference of the airbag cushion 12 together with the plate 30, with the plate 30 in contact with the airbag cushion 12.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an airbag device that protects an occupant from an impact applied to a vehicle due to a collision or the like, and to a method for manufacturing an airbag module. [Background technology]

[0002] In an airbag device, an airbag cushion containing an inflator is stored in a required position in a vehicle in a folded accordion-like state, for example.

[0003] 13, Patent Document 1 discloses an airbag device 100 including 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 state where it is folded like an accordion, and the outside of the airbag case 101 is covered with a film 104.

[0004] Patent Document 1 describes the reasons for covering the outside of airbag case 101 with film 104 as follows: the folded state of airbag body 103 can be reliably maintained; there is no risk of rust or oil adhering to airbag body 103, or of damage to airbag body 103 due to press burrs or welding burrs on the side frame, making assembly easier and improving work efficiency. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-181493 Summary of the Invention [Problem to be solved by the invention]

[0006] Airbag modules, which consist of an inflator and an airbag cushion, are required to be even more compact when stored. For example, one trend in vehicle seats is thin seats, where the thickness of the side support section of the backrest in the vehicle width direction is reduced. With thin seats, the space for locating the airbag module on the outer side of the seat frame is narrow, so a thin and compact airbag module is required.

[0007] Conventionally, a method for miniaturizing a side airbag module has been known in which, for example, heat-melting felt is used as a cover material and the following steps are carried out before the module is attached to the side frame.

[0008] 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 miniaturized by applying pressure to harden the felt into the desired shape.

[0009] 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 itself thick and bulky, so although it can reduce the size of the airbag module to a certain extent, the effectiveness of these methods is limited.

[0010] In Patent Document 1, since the film 104 covers the outside of the airbag case 101, even if the film 104 is heat-shrinkable, it can only shrink when heated to a shape that fits the outer shape of the airbag case 101. Therefore, the configuration of Patent Document 1 cannot be used for the purpose of miniaturizing the airbag module.

[0011] The present invention has been made in consideration of the above circumstances, and aims to realize an airbag device etc. that can efficiently downsize the airbag module before assembling it in a predetermined position in a vehicle, does not require expensive equipment, and is highly economical. [Means for solving the problem]

[0012] 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:

[0013] 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.

[0014] In the present invention, the airbag cushion may be formed in a rod shape, and the resin package may be wound around the outer periphery of the rod-shaped airbag cushion.

[0015] In the present invention, the resin package may be a heat-shrinkable resin that shrinks when heat is applied.

[0016] In the present invention, the plate may be provided with a through-hole through which the stud bolt of the inflator can pass.

[0017] In the present invention, the resin package may be formed in a tubular shape.

[0018] 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 shape into a single unit before assembling the airbag module to the side frame of the 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:

[0019] The method for producing an airbag module of the present invention may further include a fifth step of removing the plate after the fourth step. [Effects of the Invention]

[0020] The airbag device of the present invention includes an inflator that injects gas to inflate and deploy the airbag cushion, an airbag cushion that incorporates 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.

[0021] The present invention further includes a plate disposed on one side of the folded, massive airbag cushion, and 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.

[0022] In the present invention, before assembling an airbag module consisting of an inflator and an airbag cushion to a side frame, heat is applied to the resin package wrapped around the entire periphery of the airbag cushion to shrink the resin package, thereby further compressing the folded airbag cushion due to the contraction force of the resin package.

[0023] In addition, in the present invention, before assembling the airbag module consisting of the inflator and the airbag cushion to the side frame, the resin package wrapped around the entire circumference of the airbag cushion together with a plate placed on one side of the airbag cushion may be heated to shrink the resin package.

[0024] When a plate is used, by applying the plate to 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 airbag cushion, which allows the airbag cushion to be compressed efficiently and the airbag module to be made smaller.

[0025] The present invention does not require expensive equipment such as an IR oven, a press, a mold, etc. The present invention is highly economical because it can efficiently compress the airbag cushion by heating the resin package during the mass production process of the airbag module, thereby reducing the size of the airbag module. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a view of an airbag device according to an embodiment (plates and a resin package are not shown) in a state where an airbag cushion is inflated and deployed, as viewed from the side of a vehicle. [Figure 2] 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. [Figure 3]Regarding the airbag device according to the embodiment, FIG. 3(a) is a diagram showing a longitudinal cross section of a state in which a resin package is wrapped around one end of a folded airbag cushion with a plate aligned therearound, and FIG. 3(b) is a diagram showing a longitudinal cross section of a state in which the resin package has shrunk after heating and the airbag cushion has been compressed. [Figure 4] 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. [Figure 5] 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 multiple holes is used. [Figure 6] 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. [Figure 7] 7(a) to 7(d) 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. [Figure 8] 8(a) and 8(b) are views showing the same states as those of FIGS. 3(a) and 3(b), respectively, for an airbag device according to a second modified example of the embodiment. [Figure 9] 9(a) and 9(b) are diagrams showing the same states as those of FIGS. 3(a) and 3(b), respectively, for airbag devices according to other modified examples. [Figure 10] 10(a) and 10(b) are diagrams showing the same states as those of FIGS. 3(a) and 3(b), respectively, for airbag devices according to other modified examples. [Figure 11] 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. [Figure 12]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. [Figure 13] 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. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present invention will be described in detail 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.

[0028] In the present invention, an "occupant" refers to, for example, a person with a physique equivalent to that of an average American man, conforming to a frontal collision test dummy (Hybrid III AM50 / frontal collision 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.

[0029] In this specification, "upper" and "upper side" may refer to the head direction of an occupant 5 seated in the normal position on the seat 1, and "lower" and "lower side" may refer to the foot direction of the occupant 5. Here, the "normal 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 makes contact with the backrest 3 from top to bottom. Furthermore, "front" and "front side" may refer to the front direction of the occupant 5 seated in the normal position on the seat 1, and "rear" and "rear side" may refer to the back direction of the occupant 5. Furthermore, "left" and "left side" may refer to the left hand direction of the occupant 5 seated in the normal position on the seat 1, and "right" and "right side" may refer to the right hand direction of the occupant 5.

[0030] In this specification, the term "folded airbag cushion" may refer to any of an airbag cushion that has been wound into a roll by a winding operation, an airbag cushion that has been folded like accordion by a folding operation, and an airbag cushion that has been folded by a combination of a winding operation and a folding operation.

[0031] 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. An 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 width direction of the vehicle inside the vehicle. 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.

[0032] [Seat configuration] As shown in Fig. 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.

[0033] 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 the seating frame 8 are connected via a reclining mechanism 9, forming the framework of the seat 1.

[0034] The seat frame 4 includes a pair of side frames 4a extending in the up-down direction of the seat at the right and left ends in the seat width direction within the backrest portion 3, 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 into a frame shape by the side frames 4a, the upper frame 4b, and the lower frame 4c. The side frames 4a are molded from, for example, metal or resin.

[0035] In the seat cushion 2, a pad made of, for example, urethane foam 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.

[0036] [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 4a, 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 placed on one side of the airbag cushion 12 along the folded, mass-like airbag cushion, and a resin package 40.

[0037] In this embodiment, the resin package 40 is made of a heat-shrinkable resin film whose volume shrinks when heat is applied up to a certain temperature. The resin film constituting the resin package 40 can be made of a desired material such as PS (polystyrene), PET (polyethylene terephthalate), PVC (vinyl chloride), PP (polypropylene), or PO (polyolefin), and a single-layer or multi-layer film can be used.

[0038] 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 just an example, and may be modified as appropriate according to the required specifications. [Table 1]

[0039] The airbag cushion 12 is folded into an accordion-like shape when laid flat, to assume the storage configuration when stored inside the seat 1. The airbag cushion 12 folded into an accordion-like shape forms a single mass. The single mass may be spherical, oval-spherical, or the like, but in this embodiment, the airbag cushion 12 is folded so that the entire airbag cushion 12 has an elongated shape, specifically, a rod shape.

[0040] In this embodiment, the longitudinal direction of the airbag cushion 12 that is folded into a rod shape and the longitudinal direction of the plate 30 that is placed along the airbag cushion 12 are oriented 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 oriented in the same direction as the front-to-rear direction of the vehicle.

[0041] 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 being in contact with one of the sides of the airbag cushion 12, which is formed in a rod shape.

[0042] 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.

[0043] Because the resin package 40 is heat-shrinkable, when the airbag module 11 is heated from the state shown in FIG. 3(a), the resin package 40 shrinks in the radial and longitudinal directions. This heating is performed to a temperature at which heat shrinkage preferably begins, which is predetermined depending on the physical properties of the resin constituting 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 FIG. 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 is broken when the airbag cushion 12 is inflated and deployed.

[0044] In this embodiment, the airbag cushion is formed in advance 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%, and the compression effect of the airbag cushion 12 is improved.

[0045] In this embodiment, the direction in which the contraction force of the resin package is obtained and the shape of the contracted package can be controlled by placing the plate 30 along one side of the accordion-folded airbag cushion 12. The plate 30 is a flat, plate-like member made of steel.

[0046] As described above, the manufacturing method of the airbag module 11 of this embodiment is a method of manufacturing the airbag module 11 consisting of the inflator 20 that injects gas and the airbag cushion 12 with the inflator 20 built in, and includes the following steps: a first step of folding the airbag cushion 12 accordion-like into a single mass before assembling the airbag module 11 to the side frame 4a of the seat 1; 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 the resin package 40 made of heat-shrinkable resin around the entire periphery of the airbag cushion 12 together with the plate 30 in a state where 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.

[0047] The airbag cushion 12 used in this embodiment is a cloth bag constructed by preparing a required number of base fabrics of a required shape in advance and sewing predetermined locations such as the periphery of these base fabrics. The airbag cushion 12 may be formed using the so-called "one-piece weaving" technique.

[0048] The inflator 20 is connected to a connection portion provided inside the airbag cushion 12. The inflator 20 is a gas generator formed in a substantially cylindrical shape, and when assembled, its axial direction is aligned with the longitudinal direction of the side frame 4a of the backrest 3. An upper end 22a and a 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 so as to protrude at an appropriate interval in the longitudinal direction. The stud bolts 21 are inserted through the through-holes 31 of the plate 30 and the holes 41 of the resin package 40.

[0049] 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 storage section of the inflator 20 and fixed to the side frame 4a, whereby the airbag cushion 12 is also fixed to the side frame 4a.

[0050] 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 the lower end 22b of the inflator 20.

[0051] The airbag cushion 12 is stored inside the side support part on the near side of the backrest part 3 of the seat 1, and is inflated by gas generated by the inflator 20. The inflation pressure of the airbag cushion 12 causes the covering material of the backrest part 3 to break, and the airbag cushion 12 is inflated and deployed laterally on the outer side of the width direction of the seat 1 relative to the occupant 5.

[0052] 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 has a length in the vertical and front-to-rear directions sufficient to receive the sides of the torso of the occupant 5, such as the shoulders 5s, chest 5c, and upper arms 5ua. The upper chamber 14 also has a length in the vertical and front-to-rear directions sufficient to receive the head 5h in addition to the sides of the torso of the occupant 5. The lower chamber 15 has a length in the vertical and front-to-rear directions sufficient to receive the sides of the torso of the occupant 5, such as the abdomen 5a and waist 5w. In the event of a side collision or the like, the inflated and deployed airbag cushion 12 restrains the sides of the occupant 5 that tend to move in the direction of the impact, thereby restricting the movement of the occupant 5.

[0053] [Effects of this embodiment] In this embodiment, the airbag device 10 includes an inflator 20 that injects gas, an 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 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.

[0054] In this embodiment, before the airbag module 11, which is composed 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 periphery of the airbag cushion 12 together with the plate 30, which is arranged on one side of the airbag cushion 12, to shrink the resin package 40. As a result, the airbag cushion 12 in the folded state is further compressed by the contraction force of the resin package 40.

[0055] In this embodiment, by arranging 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 obtained and the shape of the contracted airbag cushion 12. As a result, in this embodiment, the airbag cushion 12 can be compressed efficiently and the airbag module 11 can be made smaller.

[0056] The resin package 40 of this embodiment has heat-shrinkable properties and is a thin film with a thickness of 0.10±0.03 mm, which solves the problems seen 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 small.

[0057] Furthermore, in this embodiment, the plate 30 and the resin package 40 are used, and a small heater is used to heat the resin package 40, but expensive equipment such as an IR oven, a press, and a mold, as in the prior art, 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 the prior art.

[0058] In this manner, in this embodiment, by heating the resin package 40 in 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, which is highly economical.

[0059] Here, the resin package 40 may be a cylindrical shrink tube as shown in FIG. 4(a), or a sheet-like shrink film as shown in FIG. 4(b).

[0060] 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.

[0061] 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 work of the resin package 40 easy.

[0062] 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 resin package 40 is wrapped around the entire circumference together with the plate 30, and then heat is 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 when contracted.

[0063] The plate 30 is provided with 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 Fig. 5(a), or may be a through-hole 31 consisting of a plurality of holes provided at required positions as shown in Fig. 5(b).

[0064] The plate 30 having the slit-shaped through-hole 31 can accommodate variations in the distance between the multiple stud bolts 21, 21 spaced at a fixed distance in the longitudinal direction of the cylindrical inflator 20 within the range of the slit length, thereby increasing the versatility of the plate 30.

[0065] On the other hand, the plate 30 having the through-holes 31 can fixably position the plate 30 relative to the folded airbag cushion 12 .

[0066] Whether the shape of the through-hole 31 of the plate 30 is slit-shaped or hole-shaped, the amount of shrinkage of the resin package 40 is suppressed on the side where the plate 30 is placed and the amount of shrinkage is increased on the side where the plate 30 is not present. This makes it possible to control the shrinkage direction of the airbag cushion 12 and the shape after shrinkage.

[0067] In this embodiment, as shown in Fig. 3, a plate 30 having 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.

[0068] That is, the manufacturing method of 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-wise 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 the 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, followed by a fifth step of removing the plate 30.

[0069] 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 end of the plate 30, and the plate 30 is removed through this slit. In this embodiment, since the entire resin package 40 has been sufficiently shrunk in the fourth step, even if 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.

[0070] [First Modification of the Embodiment] In this modification, a plate 30 having an L-shaped cross section is used, as shown in Fig. 6. The plate 30 of this modification includes 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.

[0071] In this modified example, heat shrinking is performed with the L-shaped plate aligned, so it is possible to control not only the longitudinal direction of the folded rod-shaped airbag cushion 12, but also the lateral direction shape of the airbag cushion 12. The plate 30 of 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.

[0072] In this modification, too, by aligning the plate 30 along 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 obtained and the shape of the contracted airbag cushion 12. This allows the airbag cushion 12 to be compressed efficiently, and the airbag module 11 to be made smaller.

[0073] [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 of the inflator 20, as shown in Fig. 7(b).

[0074] Next, the airbag cushion 12 is subjected to 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 an upper region 18b above the fold line 18a is folded over a lower region 18c below the fold line 18b. A rolled region 18d excluding the storage section for the inflator 20 is then set, and the airbag cushion 12 is subjected to a winding process. In the winding process, a winding center 18e is set, and the airbag cushion 12 is rolled up by winding around the rolled region 18d based on the winding center 18e, forming a rolled portion 18f as shown in FIG. 7(c). FIG. 7(d) is a cross-sectional view taken along the arrow AA in FIG. 7(c).

[0075] The winding process for the roll winding region 18d is performed in a cone shape with the winding center 18e side at the top and the outer edge side of the airbag cushion 12 that spreads out radially from the winding center 18e at the bottom. The winding process starts at the fold line 18a and ends at the storage section side of the inflator 20. The roll portion 18f formed by the winding process is disposed adjacent to the inflator 20 stored in the storage section, as shown in FIG. 7(d). The airbag cushion 12 including the cone-shaped roll portion 18f forms a single mass. This mass has a rod-like shape as a whole.

[0076] 8(a) and 8(b), by aligning the plate 30 along 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 obtained and the shape of the contracted airbag cushion 12. This allows the airbag cushion 12 to be compressed efficiently and the airbag module 11 to be made smaller.

[0077] 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 as to form a single mass by a winding operation. Alternatively, the first step may be a step of folding the airbag cushion 12 by combining a winding operation and a folding operation.

[0078] [Other variations] 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 of 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.

[0079] In the above-described embodiment, as shown in FIGS. 9 and 10 , the airbag cushion 12 folded in 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 for the purpose of temporarily maintaining the roll or bellows folded shape. The covering member 13 is broken together with the resin package 40 when the airbag cushion 12 is inflated and deployed. In this modification, the resin package 40 contracts, compressing the folded airbag cushion 12 via the covering member 13. The covering member 13 in this modification does not have to be heat-shrinkable.

[0080] 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, and sides of the abdomen 5a and waist 5w of the occupant 5, as shown in FIG. 11.

[0081] In the above-described embodiment, the airbag device 10 may be a far-side airbag device, as shown in Fig. 12, which is stored in a side portion of the backrest 3 of the seat 1 on the center side in the vehicle width direction, and when an impact is applied to the vehicle, an airbag cushion 12 inflates and deploys on the side portion on the far side of the occupant 5 to restrain the occupant 5. Fig. 11 shows a driver's seat 1, and illustrates an example in which the airbag device 10 is provided on the side portion of the backrest 3 on the door D side, and also on the side portion on the center console C side.

[0082] In the above-described embodiment, a fragile portion that is weaker than other portions may be formed at a required position of the resin package 40. The fragile 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 fragile portion may be formed, for example, by a perforation or a 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 a targeted position, stabilizing the operation of the airbag cushion 12 in the initial stage of deployment. [Industrial Applicability]

[0083] The configuration of the present invention is not limited to a side airbag device, but can be applied to any airbag device such as a curtain airbag or a knee airbag. [Explanation of symbols]

[0084] 1 seat 4a Side frame 10 Airbag device 11 Airbag module 12 Airbag cushion 20 Inflator 21 Stud bolt 30 plates 31 Penetration 40 Resin Package

Claims

1. 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, The airbag device is configured such that, when heated after the wrapping, 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. An airbag device as described in claim 1, wherein the airbag cushion is formed in a rod shape, and the resin package is wrapped around the outer periphery of the airbag cushion which is formed in a rod shape.

3. An airbag device as described in claim 1, wherein the plate has a through-hole through which the stud bolt of the inflator can pass.

4. An airbag device as described in claim 1, wherein the resin package is formed in a tubular shape.

5. A method for manufacturing an airbag module comprising an inflator that injects gas and an airbag cushion incorporating the inflator, comprising: 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.

6. A method for manufacturing an airbag module comprising an inflator that injects gas and an airbag cushion incorporating the inflator, comprising: 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:

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