Vehicle airbag device and method for manufacturing the same

Abstract

The present invention provides a vehicle airbag device and a manufacturing method thereof, which can avoid a stitching portion and insert a stud for installation and fixing to a vehicle body, and does not generate unbalanced stress on a panel portion when expanding and unfolding. The airbag cushion includes: a pair of panel portions (2a, 2b) facing each other by folding or overlapping; a pair of expansion portions (3a, 3b) integrally arranged on the pair of panel portions and in a form of protruding outward from the panel portions respectively; an overlapping portion (10) in which the expansion portion of one panel portion is overlapped on the other panel portion, and the expansion portion of the other panel portion is overlapped on the one panel portion, and each expansion portion is respectively joined to each panel portion at a stitching portion (S1) along the edge portion (9) of the expansion portions; an outer peripheral stitching portion in which the outer peripheral edge portions (11) of a pair of panel portions facing each other are joined to form a hollow bag body; an inflator insertion hole (4) and a bolt insertion hole (5) which are arranged to penetrate the overlapping portion.

Description

Technical Field

[0001] The present invention relates to a vehicle airbag device and a method for manufacturing the same, which can avoid a sewn portion and insert a stud for mounting and fixing to a vehicle body, and does not generate unbalanced stress in a panel portion when expanding and deploying. Background Art

[0002] Patent Document 1 discloses a vehicle airbag cushion in which a stud for mounting an inflator to a vehicle body penetrates a sewn portion of an airbag body.

[0003] In the "side collision airbag device" of Patent Document 1, the airbag is formed into a bag shape by forming a sheet material such as a cloth or a resin sheet, and the interior is divided into a lower chamber on the lower side and an upper chamber on the upper side by a seam. The upper chamber is provided with an exhaust hole. The rear end of the seam is slightly separated from the rear edge of the airbag, and a check valve is provided at the separation portion between the seam and the rear edge of the airbag. The check valve is cylindrical and has a rod-shaped gas generator therein. The gas generator is configured so that its length direction is in the up-and-down direction. The check valve is formed by overlapping two sheets of sheet material and sewing both side edges by a seam, thereby preventing gas from flowing from the lower chamber to the upper chamber.

[0004] In Patent Document 1, Figure 2 and Figure 4 As shown, a stud for mounting the gas generator to a housing, that is, a vehicle body, passes through a seam position at the rear end of the airbag where a pair of left and right panel parts are joined.

[0005] Prior art literature

[0006] Patent Document 1: Japanese Patent Laid-Open No. 2004-256017 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] In the background art, a through hole is formed at a sewing portion or seam position of an airbag cushion or airbag having a pair of left and right panel parts, and a stud of an inflator or gas generator is passed through the through hole from the inside of the airbag cushion to the outside, and the inflator is mounted on a vehicle body using the stud protruding from the sewing portion.

[0009] The position of the sewing part is a complicated part where the airbag base materials constituting the airbag cushion are overlapped for sewing and the sewing lines constituting the sewing part are sewn therein, so it has thickness and hardness. If the stud is firmly tightened in order to attach the inflator to the vehicle body at the position of the sewing part having thickness and hardness, the complicated part will rebound against the tightening, and as a result, the stud cannot be tightened accurately and sufficiently.

[0010] If the studs are not sufficiently tightened, they may loosen over time after the airbag cushion is secured to the vehicle body, and there is a possibility that when the airbag device is deployed, the stable occupant protection performance as originally designed may not be ensured.

[0011] In order to prevent this from happening, it is possible to consider setting the through hole of the stud at a position away from the stitching of the airbag cushion. That is, a through hole is formed on one of the pair of left and right panels of the airbag cushion, so that the panel portion with a smaller thickness and hardness and less rebound when the stud is tightened is mounted on the vehicle body with the stud.

[0012] However, if the position of the stitching portion is avoided, in other words, if one of the pair of panel portions is installed to the vehicle body through studs, when the airbag cushion expands and deploys, the force acting on one of the pair of panel portions and the force acting on the other panel portion will be different and differ greatly, which will cause different stresses between the pair of panel portions, resulting in cracks on one of the panel portions that cannot withstand the stress, etc., which may cause the airbag cushion to rupture.

[0013] The present invention is invented in view of the above-mentioned conventional problems, and its object is to provide a vehicle airbag device and a manufacturing method thereof, which can avoid the stitching part and insert the stud for installation and fixing to the vehicle body, and does not generate unbalanced stress in the panel part when inflating and deploying.

[0014] Solutions to the problem

[0015] The vehicle airbag device involved in the present invention is a vehicle airbag device having a vehicle airbag cushion that is expanded and deployed by an inflator gas from an inflator, characterized in that the airbag cushion includes: a pair of panel parts that are opposite to each other by folding or overlapping; a pair of expansion parts that are integrally provided on the pair of panel parts and are in a state of protruding outward from the pair of panel parts respectively; an overlapping part that overlaps the expansion part of the one panel part on the other panel part, and overlaps the expansion part of the other panel part on the one panel part, and each expansion part is respectively joined to each panel part at a stitching part along the edge parts of the expansion parts; an outer peripheral stitching part that joins the outer peripheral edge parts of the pair of panel parts that are opposite to each other to form a hollow bag body; an inflator insertion hole that is provided through the overlapping part and is used to insert the inflator having a stud into the inside of the bag body; and a bolt insertion hole that is provided through the overlapping part and is used to insert the stud of the inflator to protrude to the outside of the bag body.

[0016] The peripheral sewing portion preferably has a pair of sewing end portions reaching the overlapping portion, and these sewing end portions are arranged to intersect with the sewing portion. Alternatively, these sewing end portions are preferably arranged to avoid the sewing portion.

[0017] The inflator insertion hole and the bolt insertion hole are preferably provided on a virtual straight line passing through the overlapping portion and connecting the pair of sewn end portions of the outer peripheral sewn portion.

[0018] The sewn portion along the edge portion of the expansion portion forming the overlapped portion is preferably closed in a ring shape.

[0019] The inflator insertion hole and the bolt insertion hole are respectively formed in the pair of expansion parts. Preferably, the inflator insertion holes and the bolt insertion holes of the pair of expansion parts overlap and communicate with each other in the overlapping part.

[0020] The outer peripheral stitching portion is preferably formed to reach the edge portion of each expansion portion.

[0021] The overlapping portion preferably forms a surrounding stitching portion that joins the panel portion and the expansion portion that overlap each other, surrounding at least one of the inflator insertion hole and the bolt insertion hole.

[0022] The inflator is preferably a cylinder type having a plurality of studs spaced apart in a longitudinal direction, and the studs are inserted into the inflator insertion hole.

[0023] The pair of panel portions preferably have the same outer shape.

[0024] In the bag body, an overhanging portion protruding from the overlapping portion is formed at a position adjacent to the overlapping portion, and the overhanging portion is preferably arranged so that a pair of protrusions protruding from the pair of panel portions respectively along the protruding directions of the expansion portions are opposite to each other and joined at the peripheral stitching portion.

[0025] The inflator having a stud protruding from the bolt insertion hole is provided at the overlapping portion inside the bag body, and the bag body is preferably mounted and fixed to the vehicle body via the stud.

[0026] The manufacturing method of the vehicle airbag device involved in the present invention is the above-mentioned vehicle airbag device manufacturing method, which is characterized in that when manufacturing the airbag cushion, it includes: a panel part forming process, on the pair of panel parts that are opposite to each other by folding or overlapping, the pair of expansion parts are respectively provided, and the inflator insertion hole and the bolt insertion hole are respectively formed on the expansion parts; a pre-sewing process, which is to overlap these panels, and overlap and communicate the inflator insertion holes and the bolt insertion holes of the above-mentioned expansion parts with each other, overlap the expansion part of one panel part with the other panel part, and overlap the expansion part of the other panel part with the one panel part; a sewing process, which is to join each expansion part with each panel part at the sewing part along the edge part of these expansion parts to form the overlapping part; a bag body forming process, which is to join the above-mentioned peripheral edge parts of the above-mentioned pair of panel parts that are opposite to each other at the peripheral sewing part to form the bag body.

[0027] Effects of the Invention

[0028] The vehicle airbag device and the manufacturing method thereof according to the present invention can avoid the sewing portion and insert the studs for mounting and fixing to the vehicle body, and can prevent the panel portion from generating unbalanced stress during inflation and deployment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is an explanatory diagram for explaining a panel portion forming step in a method for manufacturing a vehicle airbag device according to a preferred embodiment of the present invention.

[0030] Figure 2 It is an explanatory diagram for explaining a sewing step in a method for manufacturing a vehicle airbag device according to a preferred embodiment of the present invention.

[0031] Figure 3 It is an explanatory diagram for explaining a bag body forming step in a method for manufacturing a vehicle airbag device according to a preferred embodiment of the present invention.

[0032] Figure 4 yes Figure 3 An enlarged view of the main part in the B direction.

[0033] Figure 5 It is a side view illustrating a vehicle airbag device according to a preferred embodiment of the present invention.

[0034] Figure 6 yes Figure 5 The illustrated diagram is an enlarged perspective view of a main part of a vehicle airbag device.

[0035] Figure 7FIG. 1 is a perspective view showing an example of a mounted state of a vehicle airbag device according to the present invention, and is a rear side airbag device. DETAILED DESCRIPTION

[0036] Hereinafter, preferred embodiments of a vehicle safety device and a method for manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

[0037] The vehicle airbag cushion, which is a vehicle safety device, is inflated and deployed by the inflator gas ejected from the inflator in an emergency such as a collision, thereby protecting passengers and pedestrians.

[0038] In the present embodiment, as the airbag cushion of the vehicle airbag device according to the present invention, an airbag cushion applied to a rear side airbag device will be described as an example.

[0039] The airbag cushion of the rear side airbag unit is fixed to the vehicle body parts such as the wheel arch of the rear wheel by studs.

[0040] The airbag cushion inflates and deploys from the wheel arch through the gap between the rear seat cushion and the rear door, diagonally upward along the trim surface of the rear door.

[0041] However, the present invention is applicable to all airbag devices installed on the vehicle body, for example, a pedestrian protection airbag device that inflates and deploys between the engine hood and the front windshield, a so-called curtain airbag device, a driver airbag device for the driver, a side airbag device for the front passenger seat, a far side airbag device that inflates and deploys between the driver's seat and the front passenger seat, etc.

[0042] Hereinafter, the structure of the vehicle airbag cushion of the vehicle airbag device will be described while explaining the steps of the manufacturing method.

[0043] As is well known, a vehicle airbag cushion is formed into a hollow bag shape by folding a sheet-like bag base material made of a cloth or resin sheet, or by overlapping and sewing two sheet-like bag base materials 1, 1.

[0044] The vehicle airbag cushion includes a pair of panel portions 2a and 2b which face and overlap each other by such folding or overlapping.

[0045] In the embodiment shown in Figure 1 , a case where two sheet-like bag base materials 1, 1 are used is shown.

[0046] By stacking these bag base materials 1, 1, a vehicle airbag cushion in which a pair of panel portions 2a, 2b are stacked and opposed to each other is manufactured.

[0047] First, refer to Figure 1 The panel portion forming step will be described.

[0048] The panel portions 2a, 2b of the two bag base materials 1, 1 used for production are respectively formed into outer contours matching the outer shape of the final product vehicle airbag cushion.

[0049] The bag base materials 1 and 1 are respectively provided with expansion parts 3 a and 3 b integrally therewith, and the expansion parts 3 a and 3 b protrude outward from the panel parts 2 a and 2 b , respectively.

[0050] This embodiment shows a case where, in each bag base material 1, 1, each panel portion 2a, 2b is connected to the expansion portion 3a, 3b, respectively, to form an integral body.

[0051] Of course, the expansion parts 3a and 3b may be prepared as separate parts from the panel parts 2a and 2b formed on the bag base materials 1 and 1, and the expansion parts 3a and 3b may be joined to the panel parts 2a and 2b to form an integral body.

[0052] When the pair of panel portions 2a and 2b are aligned with their outer contours and overlapped to face each other, the expanded portions 3a and 3b formed in the bag base materials 1 and 1 are in a positional relationship facing each other.

[0053] Such a positional relationship means that the pair of expansion portions 3 a and 3 b are formed at the same position in relation to the outer contours of the panel portions 2 a and 2 b.

[0054] Preferably, in the two bag base materials 1, 1, the pair of panel portions 2a, 2b and the pair of expansion portions 3a, 3b are formed in the same shape as each other. The expansion portions 3a, 3b may be formed in different shapes from each other.

[0055] An inflator insertion hole 4 is formed through each of the expansion portions 3 a and 3 b , and the inflator insertion hole 4 has a hole diameter through which the inflator can be inserted.

[0056] Furthermore, bolt insertion holes 5 are formed through each of the expansion portions 3 a and 3 b , respectively. The bolt insertion holes 5 have a hole diameter through which a stud for mounting the inflator on a vehicle body can be inserted.

[0057] In the vehicle airbag device according to the present embodiment, a well-known cylinder inflator is incorporated.

[0058] The inflator 6 has a plurality of studs 7 spaced apart in the longitudinal direction. Figure 5 and Figure 6 .

[0059] The vehicle airbag device is configured by assembling an inflator 7 to an airbag cushion, which corresponds to a bag body 8 described later.

[0060] The inflator 6 is not limited to a cylinder type, and may be a disc type inflator in which the stud 7 is arranged in a ring shape.

[0061] The inflator insertion hole 4 and the bolt insertion hole 5 of one expansion portion 3a and the inflator insertion hole 4 and the bolt insertion hole 5 of the other expansion portion 3b are arranged to communicate with each other when the sewn portion is joined in the pre-sewing step and the sewing step described later.

[0062] Specifically, the inflator insertion holes 4 and the bolt insertion holes 5 formed in the respective expansion portions 3 a , 3 b are formed at the same positions with reference to the outer contours of the panel portions 2 a , 2 b .

[0063] Next, the process before suturing will be described.

[0064] like Figure 1 As shown, in the pre-sewing step, the two bag base materials 1, 1 are arranged so that the pair of expanded portions 3a, 3b face each other.

[0065] Next, the expanded portion 3a of one panel portion 2a is overlapped with the other panel portion 2b, and the expanded portion 3b of the other panel portion 2b is overlapped with the one panel portion 2a.

[0066] Specifically, if Figure 2 As shown, an expansion portion 3a of one panel portion 2a overlaps on either the front surface or the rear surface of another panel portion 2b, and at the same time, another expansion portion 3b of another panel portion 2b overlaps on either the front surface or the rear surface of one panel portion 2a.

[0067] At this time, the inflator insertion holes 4 and the bolt insertion holes 5 of the pair of expansion portions 3 a and 3 b overlap with each other and communicate with each other.

[0068] For example, an expansion portion 3a below is also called a first expansion portion, and is overlapped on the rear surface of another panel portion 2b below is also called a second panel portion, and another expansion portion 3b below is also called a second expansion portion, and is overlapped on the front surface of a panel portion 2a also called the first panel portion.

[0069] As described above, the pair of first and second expansion portions 3a and 3b formed at the same position in association with the outer contours of the panel portions 2a and 2b overlap each other on the panel portions 2a and 2b, and are thus arranged adjacent to each other between the first panel portion 2a and the second panel portion 2b.

[0070] In the pre-sewing process, the two bag base materials 1, 1 only need to be overlapped so that the expansion parts 3a, 3b overlap the panel parts 2a, 2b.

[0071] Figure 1The arrangement of the two bag base plates 1.1 in FIG. 1 is for illustration purposes only, and it is not necessary to make the expansion parts 3a and 3b face each other as described above. It is sufficient to make the expansion parts 3a and 3b overlap with the panel parts 2a and 2b as described above.

[0072] When a bag base material 1 is folded to form a pair of panel parts 2a, 2b, at this stage, the expansion parts 3a, 3b appear on the side opposite to the folded portion and are folded and overlapped along the rear and front surfaces of the panel parts 2a, 2b, respectively.

[0073] Next, we will refer to Figure 2 The suturing process is described.

[0074] In the sewing step, the expansion portions 3a and 3b and the panel portions 2a and 2b overlapped in the pre-sewing step are joined and sewn.

[0075] Sewing is to join the first expansion portion 3a to the second panel portion 2b, and to join the second expansion portion 3b to the first panel portion 2a.

[0076] As described above, the first expansion portion 3 a and the second expansion portion 3 b are arranged adjacent to each other and side by side.

[0077] A continuous connection between the sewing line joining the first expansion portion 3a to the second panel portion 2b and the sewing line joining the second expansion portion 3b to the first panel portion 2a is ensured.

[0078] In the present embodiment, these sewing lines are provided as sewing portions S1 surrounding both the inflator insertion hole 4 and the bolt insertion hole 5 .

[0079] The sewing portion S1 is in the form of a closed ring between the first expansion portion 3a and the second expansion portion 3b and along the edge portion 9 of the first expansion portion 3a and the second expansion portion 3b.

[0080] In short, each expansion portion 3a, 3b is joined to each panel portion 2a, 2b at the sewn portion S1 along the edge portion 9 of the expansion portions 3a, 3b, respectively.

[0081] The sewn portion S1 does not need to be annular, and may be formed along the edge portions 9 of the expansion portions 3 a , 3 b , such as both sides of the inflator insertion hole 4 and the bolt insertion hole 5 .

[0082] The pair of expansion parts 3a and 3b are joined to the panel parts 2a and 2b through the sewn part S1, which is hereinafter referred to as the annular sewn part S1. The pair of panel parts 2a and 2b are partially connected through the annular sewn part S1.

[0083] When one bag base material 1 is folded to form a pair of panel parts 2a and 2b, if the annular sewn part S1 is formed, the bag base material 1 has a cylindrical shape.

[0084] By joining each expansion part 3a, 3b to each panel part 2a, 2b at the annular sewn part S1, portions with increased thickness due to overlapping of the expansion parts 3a, 3b and portions where the expansion parts 3a, 3b do not overlap are formed on the panel parts 2a, 2b.

[0085] Since the two parts overlap, an overlapping portion 10 is partially formed on the panel portions 2a and 2b.

[0086] As will be described later, when the bag body 8 , that is, the airbag cushion, is completed, the overlapping portion 10 becomes a portion of the bag body 8 that is thicker than other portions.

[0087] The inflator insertion hole 4 and the bolt insertion hole 5 are both provided through the overlapping portion 10 .

[0088] The overlapping portion 10 is formed with a surrounding stitching portion S2 surrounding the inflator insertion hole 4 and joining the overlapping panel portions 2a, 2b and the expansion portions 3a, 3b.

[0089] The overlapping portion 10 is provided with a surrounding stitching portion S3 surrounding the bolt insertion hole 5 to join the overlapping panel portions 2 a and 2 b and the expansion portions 3 a and 3 b.

[0090] These surrounding sewn portions S2 , S3 suppress leakage of the inflator gas to the outside of the bag body 8 , ie, the airbag cushion.

[0091] The inflator gas flows into the gap of the overlapping portion 10 where the panel portions 2a, 2b and the expansion portions 3a, 3b overlap through the joined and sewn annular sewn portion S1.

[0092] Therefore, there is a possibility that the inflator gas may leak from the overlapping portion 10 to the outside of the bag body 8 through the inflator insertion hole 4 or the bolt insertion hole 5 .

[0093] In this embodiment, the leakage is suppressed by the surrounding stitching parts S2 and S3. In addition, the surrounding stitching parts S2 and S3 also contribute to strengthening the periphery of the insertion holes 4 and 5.

[0094] Next, we will refer to Figure 3 and Figure 4 The bag forming process is described.

[0095] exist Figure 2 In FIG. 1 , a dotted line indicates an overlapping folding line A where a pair of bag base materials 1 , 1 formed into the same shape, that is, the same outline, are folded so that a pair of panel portions 2 a , 2 b overlap and face each other.

[0096] The folding line A is substantially located at a position that connects the inflator insertion hole 4 and the bolt insertion hole 5 that pass through the overlapping portion 10 .

[0097] Figure 3 The figure shows a state where a pair of bag base materials 1 and 1 are overlapped via the folding line A. At this time, a pair of panel parts 2a and 2b are overlapped facing each other.

[0098] The outer peripheral edge portion 11 of the pair of panel portions 2a and 2b is provided with an outer peripheral sewn portion S4 which is formed along the outer peripheral edge portion 11 and surrounds the panel portions 2a and 2b to join the first and second panel portions 2a and 2b.

[0099] In the present embodiment, the outer peripheral sewn portion S4 is formed avoiding the overlapping portion 10. Specifically, the outer peripheral sewn portion S4 is formed so as not to intersect with the annular sewn portion S1 of the overlapping portion 10.

[0100] As shown in the figure, the peripheral sewn portion S4 has a sewn end portion S4t reaching the overlapping portion 10, and the sewn end portion S4t is provided to avoid the annular sewn portion S1.

[0101] The sewing end portion S4t refers to the peripheral sewing portion S4 within a predetermined length ranging from a terminal end of sewing to and including the terminal end.

[0102] Regardless of whether the two bag base materials 1, 1 are connected by the annular sewing portion S1 or the one bag base material 1 is folded, the outer peripheral sewing portion S4 forms a hollow bag body 8 having a pair of panel portions 2a, 2b.

[0103] That is, the pair of panel parts 2a and 2b are joined by annular sewing parts S1 at the overlapping parts of the expansion parts 3a and 3b, and are joined by peripheral sewing parts S4 at the non-overlapping parts of the expansion parts 3a and 3b to form an integrated bag shape.

[0104] The peripheral sewn portion S4 is preferably formed as the edge portion 9 of the expansion portion 3a, 3b extending to the outside of the annular sewn portion S1 as described above, and does not intersect with the annular sewn portion S that has already been sewn.

[0105] This ensures that the sewing line is formed continuously and uninterruptedly over the entire outer contour of the pair of panel portions 2a, 2b. This forms a bag body 8 with high sealing properties that does not leak the inflator gas.

[0106] However, regarding the relationship between the peripheral suture portion S4 and the annular suture portion S1, the suture end portion S4t of the peripheral suture portion S4 reaching the overlapping portion 10 can be set to intersect with the annular suture portion S1 according to various needs, such as increasing the strength around the overlapping portion 10.

[0107] In this case, the sewn end portion S4t does not avoid the annular sewn portion S1 of the overlapping portion 10, but intersects with the annular sewn portion S1 and is sewn.

[0108] When a pair of panel parts 2a, 2b are joined at the peripheral stitching part S4 to form the bag body 8, the inflator insertion hole 4 and the bolt insertion hole 5 of the overlapping part 10 are arranged to be located on the virtual straight line X connecting the stitching end parts S4, referring to Figure 4 .

[0109] That is, the peripheral sewing portion S4 is interrupted at each sewing end portion S4t. The pair of sewing end portions S4t are separated from each other. The virtual straight line X is a straight line that can be imagined in the overlapping portion 10, and is a straight line connecting the pair of sewing end portions S4t through the overlapping portion 10. The inflator insertion hole 4 and the bolt insertion hole 5 are provided on the virtual straight line X.

[0110] In this embodiment, if Figures 1 to 3 As shown, in the panel portion forming step, a pair of protrusions 12, 12 are integrally formed on each bag base material 1, 1.

[0111] These protrusions 12 and 12 are formed in a form protruding from the panel portions 2a and 2b in the same direction as the protruding direction of the expansion portions 3a and 3b at positions adjacent to the expansion portions 3a and 3b.

[0112] The pair of protruding portions 12 , 12 are formed in the same shape.

[0113] The pair of protrusions 12, 12, like the pair of expansion portions 3a, 3b, face and overlap each other when the pair of panel portions 2a, 2b are aligned with each other in outer contour and overlap each other.

[0114] The pair of protrusions 12, 12 can be said to be a part of each panel part 2a, 2b. The edge parts of these protrusions 12, 12 are a part of the outer peripheral edge 11 of the panel part 2a, 2b, and are joined by the outer peripheral sewing part S4.

[0115] A pair of protrusions 12, 12 joined by the peripheral stitching portion S4 is formed as a part of the bag body 8. The protrusions 12, 12 form an overhang 13 on the bag body 8. When the bag body 8 is inflated by the inflator gas, the overhang 13 appears as a protrusion that expands outward near the overlapping portion 1 formed on the expansion portions 3a, 3b.

[0116] That is, the hanging portion 13 is provided by making a pair of protruding portions 12 and 12 that protrude from the pair of panel portions 2a and 2b in the protruding directions of the expansion portions 3a and 3b face each other and join them at the peripheral sewn portion S4.

[0117] exist Figure 5 and Figure 6 In the vehicle airbag device shown in FIG. 1 , the inflator 6 is inserted into the bag body 8 of the completed airbag cushion, so that the inflator 6 can be mounted on the vehicle body using the stud 7 thereof.

[0118] The inflator 6 is inserted from the outside of the bag body 8 into the inside of the bag body 8 through the inflator insertion hole 4 of the overlapping portion 10 .

[0119] In the inflator 6 inside the bag body 8 , the stud 7 thereof protrudes from the inside of the bag body 8 to the outside of the bag body 8 through the bolt insertion hole 5 of the overlapping portion 10 .

[0120] An example of the vehicle airbag device of the present embodiment is the rear side airbag device as described above. Figure 7 As shown, it is arranged on the wheel housing 14 of the rear wheel of the vehicle body.

[0121] The stud 7 protruding from the bag body 8 is fixed to the wheel house 14 with a nut, and the bag body 8 is mounted and fixed to the wheel house 14 together with the inflator via the stud 7 .

[0122] like Figure 6 As shown, the stud 7 of the inflator 6 has no sewing portion on the inner side of the annular sewing portion S1 (1), (2) at least the bag base material 1, 1 overlaps the two expansion portions 3a, 3b and the panel portions 2a, 2b to form a wall thickness, and (3) on the virtual straight line X (refer to FIG. 1 ) which is assumed to be the sewing line of the pair of panel portions 2a, 2b having the same outer contour shape, that is, the peripheral sewing portion S4. Figure 4 ) on the vehicle body, the bag body 8, i.e. the airbag cushion, is installed and fixed on the vehicle body.

[0123] In the illustrated example, any one of the studs 7 of the inflator 6 protrudes from the inside of the bag body 8 to the outside through the inflator insertion hole 4 , and is fastened to the wheel house 14 .

[0124] In the rear side airbag device, the inflated and deployed bag body 8, that is, the airbag cushion, inflates and deploys obliquely upward from the wheel house 14 region toward the interior of the vehicle compartment.

[0125] The bag body 8 is expanded and deployed through a gap Z between the seat cushion 15 a of the rear seat 15 and the rear door trim 16 .

[0126] The bag body 8 has an overhang portion 13 at a position adjacent to the overlapping portion 10 where the inflator 6 is provided. The overhang portion 13 extends outward from the bag body 8 beyond the overlapping portion 10 , and specifically protrudes toward the same side as the inflator 6 .

[0127] The overhang portion 13 is a portion where, when the bag body 8 is inflated and deployed, a portion of the inflated bag body 8 passes over a virtual mounting line extending in the longitudinal direction of the mounting portion of the inflator 6 and enters the mounting side direction.

[0128] The overhang portion 13 expands downward toward the inflator 6 in the opposite direction to the upward expansion and deployment direction of the bag body 8 , thereby closing the gap Z between the rear seat cushion 15 a and the rear door trim 16 , thereby ensuring the support function of the bag body 8 at the gap Z position.

[0129] Therefore, even if there is no supporting portion on the rear seat cushion 15 side, the posture of the bag body 8 is stable.

[0130] In the vehicle airbag device manufactured by the manufacturing method involved in this embodiment, there are: (1) a pair of expansion parts 3a, 3b, which are respectively integrally arranged on a pair of panel parts 2a, 2b and overlap these panel parts 2a, 2b; (2) an overlapping part 10, which is partially formed on the panel parts 2a, 2b by joining these expansion parts 3a, 3b and the panel parts 2a, 2b at an annular stitching part S1, and the annular stitching part S1 surrounds both the inflator insertion hole 4 and the bolt insertion hole 5 along the edge part 9 of the expansion parts 3a, 3b; (3) a peripheral stitching part S4, which avoids the annular stitching part S1 of the overlapping part 10, joins the peripheral edge parts 11 of the pair of panel parts 2a, 2b, and forms a hollow bag body.

[0131] Thus, the stud 7 of the inflator 6 can be inserted while avoiding the sewn portions S1 and S2.

[0132] Therefore, when the inflator 6 and the bag body 8 are mounted to the vehicle body, the stud 7 can be accurately and securely tightened.

[0133] Therefore, the stud 7 can be prevented from loosening due to the passage of time, and the airbag device can be made to exert stable occupant protection performance as designed.

[0134] Furthermore, the bolt insertion hole 5 for the stud 7 is formed in the overlapping portion 10 where the expansion portions 3 a and 3 b and the two panel portions 2 a and 2 b are overlapped to increase the strength of the bag body 8 .

[0135] The overlapping portion 10 is not a complicated portion formed by overlapping and sewing as described in the background art, and therefore will not cause springback when the stud 7 is tightened.

[0136] On the contrary, the overlapping portion 10 serves as a mounting location for mounting the bag body 8 on the vehicle body, and can disperse stress caused by tightening the stud 7 and the expansion of the bag body 8 by the inflator gas, thereby providing excellent mounting fixation.

[0137] Furthermore, since the overlapping portion 10 is formed by overlapping the pair of panel portions 2a, 2b and the pair of expansion portions 3a, 3b, when the bag body 8 is expanded and unfolded, equal stress can be generated on both panels 2a, 2b, thereby preventing the bag body 8 from rupturing.

[0138] The outer peripheral sewn portion S4 is formed to reach the edge portion 9 of each expansion portion 3a, 3b, so that the continuity of the joining between the overlapping portion 10 and the annular sewn portion S1 can be ensured. Thus, the bag body 8 can have a high strength.

[0139] The overlapping portion 10 is formed with surrounding sewn portions S2 , S3 which surround the inflator insertion hole 4 and the bolt insertion hole 5 and join the panel portions 2 a , 2 b and the expansion portions 3 a , 3 b which overlap each other.

[0140] This can prevent the inflator gas from leaking to the outside of the bag body 8 through the insertion holes 4 and 5 from between the two overlapping expansion portions 3 a and 3 b and the panel portions 2 a and 2 b.

[0141] The bag body 8 is formed with an overhanging portion 13 at a position adjacent to the expansion portions 3 a and 3 b.

[0142] The hanging portion 13 is formed by joining a pair of protruding portions 12 , 12 formed by protruding from the pair of panel portions 2 a , 2 b facing each other at an outer peripheral sewn portion S4 .

[0143] The overhang portion 13 expands toward the inflator 6 side and closes a gap around the inflator 6 , for example, a gap between the rear seat cushion 15 a and the rear door trim 16 .

[0144] As a result, the supporting function of the bag body 8 can be ensured at the position of the gap Z, and the posture of the bag body 8 can be stabilized to improve the occupant protection performance.

[0145] In the bag body 8 , ie, the airbag cushion, having the overhanging portion 13 , it is difficult to provide the inflator 6 at a position where the outer peripheral sewn portion S4 for joining the panel portions 2 a and 2 b passes.

[0146] By providing the expansion portions 3 a and 3 b and overlapping them, the outer peripheral sewn portion S4 can be ensured even in a structure having the overhang portion 13 , and the strength of the mounting portion of the inflator 6 can be sufficiently ensured.

[0147] The present invention is applicable to all airbag devices installed in a vehicle body, for example, a side airbag for a rear seat installed in a vehicle body panel on a wheel housing of a vehicle body; a side airbag installed on the side of a vehicle seat and installed on a frame of a seat frame facing the front side of the passenger side; a pedestrian protection airbag installed on the front outer side of the vehicle body of a windshield to protect pedestrians; a curtain airbag installed on a longitudinal beam of a vehicle roof, etc. It can be mainly used for a vehicle airbag device using a cylinder inflator.

[0148] The vehicle airbag device and its manufacturing method described above are preferred embodiments of the present invention, and other embodiments can also be implemented or practiced in various ways. Unless there is a special record of the subject matter in this specification, the present invention is not restricted by the shape, size and structural configuration of the detailed components shown in the drawings. In addition, the expressions and terms used in this specification are for the purpose of explanation, and are not limited to this unless there is a special record of the subject matter.

[0149] Explanation of symbols

[0150] 1.1 Sheet bag substrate

[0151] 2a, 2b a pair of panel parts

[0152] 3a, 3b a pair of expansion parts

[0153] 4Inflator insertion hole

[0154] 5 Bolt insertion holes

[0155] 6. Inflator

[0156] 7 studs

[0157] 8 bags

[0158] 9 Edge of expansion part

[0159] 10 Overlapping

[0160] 11 Outer edge of panel

[0161] 12, 12 protrusion

[0162] 13 Overhang

[0163] S1 annular suture

[0164] S2, S3 surrounding suture

[0165] S4 peripheral suture

[0166] S4t The sewing end portion of the peripheral sewing part

Claims

1. A vehicle airbag device, comprising a vehicle airbag cushion that is expanded and deployed by inflator gas ejected from an inflator, characterized in that: The airbag cushion comprises: a pair of panel portions which are opposed to each other by being folded or overlapped; a pair of expansion parts, which are integrally provided on the pair of panel parts and are in a form of protruding outwards from the panel parts respectively; an overlapping portion, wherein the expansion portion of one of the panel portions is overlapped on the other panel portion, and the expansion portion of the other panel portion is overlapped on the one panel portion, and each expansion portion is joined to each panel portion at a stitching portion along the edge portion of these expansion portions; A peripheral stitching portion that joins the peripheral edge portions of the pair of panel portions facing each other to form a hollow bag body; an inflator insertion hole, which is provided through the overlapping portion and is used to insert the inflator having the stud into the interior of the bag body; a bolt insertion hole, which is provided through the overlapping portion and is used to insert the stud of the inflator and protrude to the outside of the bag body, In the bag body, an overhanging portion is formed at a position adjacent to the overlapping portion and protrudes beyond the overlapping portion, and The hanging portion is configured such that a pair of protrusions protruding from the pair of panel portions in the protruding directions of the expansion portions face each other and are joined at the peripheral stitching portion. The pair of protrusions are formed at positions adjacent to the expansion portion.

2. The vehicle airbag device according to claim 1, wherein: The peripheral sewn portion has a pair of sewn end portions reaching the overlapped portion, and the sewn end portions are arranged to intersect the sewn portion.

3. The vehicle airbag device according to claim 1, wherein: The peripheral sewn portion has a pair of sewn end portions reaching the overlapped portion, and the sewn end portions are arranged avoiding the sewn portion.

4. The vehicle airbag device according to claim 2 or 3, characterized in that: The inflator insertion hole and the bolt insertion hole are provided on a virtual straight line passing through the overlapping portion and connecting the pair of sewn end portions of the outer peripheral sewn portion.

5. The vehicle airbag device according to any one of claims 1 to 3, characterized in that: The sewn portion along the edge portion of the expansion portion forming the overlapped portion is closed in a ring shape.

6. The vehicle airbag device according to any one of claims 1 to 3, characterized in that: The inflator insertion hole and the bolt insertion hole are respectively formed in the pair of expansion parts, and the inflator insertion holes and the bolt insertion holes of the pair of expansion parts overlap and communicate with each other at the overlapping part.

7. The vehicle airbag device according to any one of claims 1 to 3, characterized in that: The outer peripheral stitched portion is formed to reach the edge portion of each expansion portion.

8. The vehicle airbag device according to any one of claims 1 to 3, characterized in that: The overlapping portion surrounds at least one of the inflator insertion hole and the bolt insertion hole to form a surrounding stitching portion that joins the panel portion and the expansion portion that overlap each other.

9. The vehicle airbag device according to any one of claims 1 to 3, characterized in that: The inflator is a cylinder type having a plurality of studs spaced apart in a length direction, and the studs are inserted into the inflator insertion hole.

10. The vehicle airbag device according to any one of claims 1 to 3, characterized in that: The pair of panel parts have the same outer shape.

11. The vehicle airbag device according to any one of claims 1 to 3, characterized in that: Inside the bag body, the inflator in which a stud protrudes from the bolt insertion hole is provided at the overlapping portion, and the bag body is mounted and fixed to the vehicle body by the stud.

12. A method for manufacturing a vehicle airbag device, which is the method for manufacturing a vehicle airbag device according to any one of claims 1 to 11, characterized in that: The production of the airbag cushion includes: a panel portion forming step of providing the pair of expansion portions respectively on the pair of panel portions opposed to each other by folding or overlapping, and forming the inflator insertion hole and the bolt insertion hole respectively on the expansion portions; a pre-sewing step of overlapping the panels, overlapping and communicating the inflator insertion holes and the bolt insertion holes of the expansion parts, overlapping the expansion part of the one panel part with the other panel part, and overlapping the expansion part of the other panel part with the one panel part; a sewing step of joining each expansion part to each panel part at the sewing part along the edge part of these expansion parts to form the overlapping part; The bag body forming step is to join the outer peripheral edge portions of the pair of panel portions facing each other at the outer peripheral sewn portion to form the bag body.

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