airbag cover

Abstract

An airbag cover that can suppress the decline in appearance of the skin layer bonded to the substrate and reliably break to smoothly form the protruding opening of the airbag. The airbag cover (29) has a skin layer (60) bonded to the surface side of the substrate (30). When the airbag is inflated, the door portion (31, 32) provided on the substrate is pressed by the inflated airbag, causing the surrounding fracture pre-break portion (34) to break and the skin layer portion around the door portion to break, thus forming the protruding opening of the airbag. The fracture pre-break portion is configured to have: a strip-shaped fracture opening (40) that runs through both sides and is disposed at the edge of the door portion; and a fracture connecting portion (44) between the fracture openings. The fracture pre-break portion breaks at the point near the center of the front end side of the door portion away from the hinge portion when opened, which is the starting point of the fracture (38). The width dimension of the fracture connecting portion at the starting point area is smaller at the front end (44b) than at the base (44a) on the door portion side.

Description

Technical Field

[0001] The present invention relates to an airbag cover with a structure that covers a folded airbag and forms a protruding opening when the airbag is inflated to protect occupants, etc., so that the airbag protrudes. Background Technology

[0002] Currently, airbag covers for vehicle dashboards are structured as follows: they include a substrate made of a synthetic resin such as polypropylene; and a skin layer bonded to the surface of the substrate, covering the top of a folded airbag. When the airbag inflates, the door portion provided on the substrate is pressed by the inflated airbag, causing the surrounding pre-break portion to break and the skin layer at the periphery of the door portion to break, forming an opening for the airbag to protrude and open (see, for example, Patent Document 1). The door portion is structured such that a door retaining portion extending from the side housing the folded airbag is connected to the back side, and is held in the door retaining portion in a way that allows it to be opened.

[0003] Furthermore, as an airbag cover, there is a structure in which multiple holes penetrating both sides are arranged along the fracture line of the skin layer to allow the door portion with the adhesive skin layer to open smoothly. Moreover, the holes provided in the skin layer are inconspicuously sealed by protrusions protruding from the substrate during substrate molding (for example, see Patent Document 2). Alternatively, there is a structure in which a protruding strip is provided on the substrate to the skin layer side so that the skin layer can easily break when the airbag inflates. When the door portion is opened, the protruding strip is pressed against the skin layer like a cutter, which easily causes the skin layer to break (for example, see Patent Document 3).

[0004] Patent Document 1: Japanese Patent Application Publication No. 2017-210230

[0005] Patent Document 2: Japanese Patent Application Publication No. 2004-114738

[0006] Patent Document 3: Japanese Patent Application Publication No. 2004-352179 Summary of the Invention

[0007] However, regarding the current airbag cover, in the structures described in Patent Documents 2 and 3, holes are provided in the skin layer in a way that makes the skin layer easy to break, or protrusions protruding from the substrate are arranged on the back side of the skin layer. Compared with the structure described in Patent Document 1, the skin layer bonded to the surface side of the substrate can be reliably broken, and protrusions for the airbag to protrude smoothly can be formed. However, the presence of holes and protrusions on the surface side of the skin layer may reduce the aesthetic appearance of the skin layer.

[0008] In order to solve the above problems, the present invention aims to provide an airbag cover that reliably breaks the skin layer bonded to the surface side of the substrate to suppress the decline in appearance and can smoothly form a protruding opening that allows the airbag to bulge out.

[0009] The airbag cover of the present invention is formed with a structure that includes a substrate and a skin layer adhered to the surface of the substrate, covering the top of a folded airbag, and...

[0010] The structure is configured such that, when the airbag inflates, the door portion located on the substrate is pressed by the inflated airbag, causing the surrounding pre-fractured portion to break, and the skin layer at the periphery of the door portion to break, thus forming a protrusion of the airbag that opens into an opening.

[0011] The door is configured such that a door retaining portion extending from the outer shell side that houses the folded airbag is connected to the rear side and is held in place in a way that allows it to be opened.

[0012] The airbag cover is characterized in that...

[0013] The predetermined fracture portion of the substrate is configured to have: a plurality of strip-shaped fracture openings that penetrate both sides of the substrate and are arranged along the edge of the door portion; and a plurality of fracture connecting portions that are arranged to close the gaps between the fracture openings and fracture upon inflation of the airbag.

[0014] The fracture pre-construction portion is structured such that the portion near the center of the front end of the door, away from the hinge portion on the rotation center side when the door is open, serves as the fracture starting point.

[0015] The connecting portion for breaking at the starting point is configured such that, when viewed from above, the width of the front end portion of the adjacent breaking openings away from the hinge portion is smaller than the width of the base portion of the hinge portion near the door portion.

[0016] Regarding the airbag cover according to the present invention, when the airbag inflates, the door is pressed by the inflated airbag, causing the connecting part for breakage to break at the starting point of the breakage at the predetermined breakage portion. The connecting part for breakage breaks due to stress concentration on the side with the smaller width dimension. At this time, the connecting part for breakage leaves the base side, which has a larger width dimension, near the hinge portion of the door, remaining intact, while the front end side, which has a smaller width dimension, breaks away from the door. Therefore, as the door opens, this front end side, with the hinge as its rotation center, contacts the back side of the skin layer, pressing the skin layer upwards. That is, while maintaining the connecting part for breakage with the front edge of the door, this front end side, with a smaller width dimension, cuts into the skin layer like a cutting tool protruding from the front edge of the door, thereby smoothly breaking the skin layer. As a result, as the door of the base material opens, the skin layer rapidly breaks from the front edge side of the door and the breakage propagates towards the periphery of the door, smoothly forming the protruding opening of the airbag together with the door. Furthermore, the door portion does not have any protrusions or other features relative to the skin layer, thus not affecting the aesthetic appearance of the skin layer's surface. Additionally, the door portion is held in place by a door retainer on the outer casing of the airbag device in an openable manner, allowing for smooth opening and the formation of the airbag's protruding opening without splashing during airbag inflation. Similarly, the skin layer is configured to be bonded to the substrate, so that the airbag's protruding opening can be smoothly formed during airbag inflation without splashing simply by breaking it.

[0017] Therefore, regarding the airbag cover of the present invention, the skin layer bonded to the surface side of the substrate can suppress the decline in appearance and ensure reliable breakage, and can smoothly form a protruding opening that allows the airbag to protrude.

[0018] Furthermore, regarding the airbag cover of the present invention, preferably, the connecting portion for breaking at the starting point region is such that the edge of the front end side, after reducing the width dimension of at least one of the two edges in the width direction, is connected at an acute angle relative to the edge of the connecting opening side for breaking when viewed from above.

[0019] Regarding this structure, if the fracture connector at the starting point is connected at an acute angle to the edge of the adjacent fracture opening on the front end side with a reduced width, stress concentration will smoothly occur at this location when subjected to tensile force during airbag expansion, making fracture easy. Furthermore, if the edge of the fracture opening side extending from the front end of the fracture is formed at an acute angle relative to the edge of the fracture opening side before fracture, then during fracture, as the front end of the fracture connector is pressed upwards, it continuously presses and cuts into the dorsal side of the epidermis from the edge angle of the fracture end face side of the front end, easily propagating the fracture caused by the upward pressing of the front end from the fracture point, allowing the epidermis to smoothly fracture from the fracture starting point along the predetermined fracture portion.

[0020] In this case, if the fracture connector at the starting point region connects the front end edge (after reducing the width of the two edges in the width direction) with the edge of the fracture opening side (when viewed from above) at an acute angle, stress concentration occurs more smoothly at the two edges of the front end edge (after reducing the width of the fracture connector), making it easier for the fracture connector at the starting point to fracture. Of course, since the fracture opening sides extending from the front end of the fracture enter the back side of the epidermis by continuously pressing and cutting into the edge angle of the fracture end face side of the front end of the fracture connector upwards, the epidermis can fracture more smoothly from the starting point along the predetermined fracture portion.

[0021] Furthermore, regarding the airbag cover of the present invention, preferably, the door portion is approximately square in shape, and has a front edge on the front end side when open, a hinge portion on the rotation center side when open, and two side edges between the two ends of the front edge and the two ends of the hinge portion.

[0022] The fracture pre-determined portion is disposed on the front edge side and the two side edges sides.

[0023] The hinge portion is provided with a groove that is recessed from the back side of the substrate toward the surface side.

[0024] The fracture opening of the fracture pre-construction portion and the groove of the hinge portion are simultaneously shaped during the molding of the substrate.

[0025] Regarding this structure, when the base material of the airbag is formed by molding, the fracture opening for the fracture pre-part and the groove for the hinge part are formed simultaneously, thus the base material can be formed easily. In addition, even if the connection between the edge of the front end side with a smaller width dimension of the fracture connection part and the edge of the corresponding fracture opening is formed at an acute angle, it can be formed more easily by molding than by cutting processes such as vertical milling.

[0026] Furthermore, regarding the airbag cover of the present invention, the pre-break portion on the front edge side of the door can be placed in the middle, and the pre-break portion on the front edge side is shared, and a second door portion that opens during inflation is symmetrically arranged including the side edge and the hinge portion.

[0027] That is, this structure allows for the placement of double-door-style doors within the airbag cover.

[0028] In this case, the second door portion is located on the rear side of the door portion and can be configured as an airbag cover for the dashboard located in front of the front seats of the vehicle.

[0029] Regarding this structure, the airbag cover located on the dashboard is formed by configuring a front door (first door) and a rear door (second door). Furthermore, when the first and second doors open with the inflation of the airbag, the breakage connector on the front edge side of the first door breaks off on the side with the smaller width. Therefore, the first and second doors open with the breakage connector engaged with the first door side but not with the second door side. The second door, located near the rear of the occupant, opens without the breakage connector engaged with its open front edge side. Thus, even when the second door comes into contact with the occupant when open, the less concave / convex front edge side can still contact the occupant. Attached Figure Description

[0030] Figure 1 This is a schematic perspective view of an airbag device using an airbag cover according to one embodiment of the present invention.

[0031] Figure 2 This is a schematic longitudinal sectional view of the airbag device according to the embodiment.

[0032] Figure 3 This is a bottom view of the base material of the airbag cover in the embodiment, near the door portion.

[0033] Figure 4 This is a schematic enlarged bottom view showing the vicinity of the fracture initiation point of the predetermined fracture portion of the substrate in the embodiment, and... Figure 3 Corresponding to part IV, a rough cross-sectional view of the vicinity of that part is also shown.

[0034] Figure 5 This is a schematic enlarged bottom view showing the vicinity of the side edge of the door portion of the substrate in the embodiment, and... Figure 3 Corresponding to the V-shaped part, a rough cross-sectional view of the vicinity of that part is also shown.

[0035] Figure 6 This is a schematic enlarged bottom view showing the area near the hinge portion of the door of the substrate in the embodiment, and... Figure 3 Corresponding to part VI, a rough cross-sectional view of the vicinity of that part is also shown.

[0036] Figure 7 This is a schematic enlarged longitudinal cross-sectional view illustrating the opening of the door of the airbag cover in the embodiment.

[0037] Figure 8 This is a schematic partial enlarged bottom view of the fracture pre-determined portion on the front edge side of the door portion of the airbag cover according to the embodiment.

[0038] Figure 9 This is a schematic enlarged bottom view of an airbag cover showing a deformation example of the predetermined fracture point.

[0039] Figure 10 This is a diagram illustrating the substrate molding process of the embodiment.

[0040] Figure 11 This is a schematic enlarged bottom view and a schematic cross-sectional view of the fracture connection portion of a modified example of the starting point of the fracture predetermined portion in the embodiment.

[0041] Figure 12 This is a schematic partial bottom view showing various deformations of the connecting part for fracture of the fracture pre-construction part in the embodiment.

[0042] Figure 13 This is a schematic partial cross-sectional view showing various variations of the hinge portion of the door in the embodiment.

[0043] Figure 14 This is a schematic perspective view of the airbag device of the airbag cover according to a modified embodiment.

[0044] Figure 15 Is using Figure 14 A schematic longitudinal sectional view of the airbag device of the modified airbag cover shown.

[0045] Figure 16 yes Figure 14 A schematic bottom view of the base material of the airbag cover near the door. Detailed Implementation

[0046] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings, such as... Figure 1 , Figure 2 As shown, the airbag cover 29 of the embodiment is disposed on the instrument panel (instrument panel) 2 of the vehicle 1 for the airbag device 10 for the passenger seat. The instrument panel 2 is disposed below the windshield 1a on the front side of the front seat of the vehicle 1, and is configured to have a driver's side portion 2a on the front side of the driver's seat, a passenger side portion 2b in front of the passenger seat, and a central portion 2c on the front side of the center console (not shown), such that the portion of the passenger side portion 2b is configured such that the airbag 11 (see reference) is positioned such that the airbag 10 is positioned below the passenger seat. Figure 2 The portion of the airbag cover 29 with the opening 65 is formed in such a way that the airbag 11 protrudes smoothly when inflated.

[0047] like Figure 2As shown, the airbag device 10 is configured to include: an airbag 11 that inflates from the housing 15 (which serves as a storage area) and protrudes through a protrusion opening 65, allowing inflation gas G to flow in and in order to protect the front passenger; an inflator 14 that supplies inflation gas G to the airbag 11; an airbag cover 29 that covers the folded and stored airbag 11; a housing 15 that stores and holds the airbag 11 and the inflator 14; and a connecting member 20 that connects the door portions 31 and 32 (described later) on the airbag cover 29 side to the housing 15 side. The housing 15 is connected to the vehicle body side of the vehicle 1 by a bracket (not shown), and the dashboard 2, where the airbag cover 29 is provided, is held near its outer periphery on the vehicle body side of the vehicle 1, and is connected to the side wall portion 17 of the housing 15 at the airbag cover 29 by the connecting member 20.

[0048] The airbag 11 is made of a textile such as polyester, and when inflated, it is shaped like a truncated pyramid with a support surface at the rear end to support the passenger seat and a tapering shape at the front end. The lower surface of the front end has an inlet opening 11a for the inflating gas G to flow in. The inlet opening 11a is circular, and its periphery is pressed against the bottom wall 16 of the outer casing 15 by a roughly square ring-shaped retainer 12 disposed within the airbag 11. Bolts 12a protrude downwards from the four corners of the roughly square ring-shaped retainer 12. Each bolt 12a passes through the periphery of the inlet opening 11a of the airbag 11, the bottom wall 16 of the outer casing 15 (described later), and the flange 14c of the inflator 14 (described later). Nuts 13 are tightened to secure the airbag 11 and the inflator 14 to the bottom wall 16 of the outer casing 15.

[0049] The inflator 14 is configured to have: a main body 14a, which is approximately cylindrical and has a gas outlet 14b at the top for discharging expansion gas G; and a flange 14c, which protrudes from the outer peripheral surface of the main body 14a, through which each bolt 12a of the retainer 12 passes.

[0050] The outer casing 15 is made of sheet metal and is configured to have a bottom wall portion 16 that is approximately rectangular in shape and a side wall portion 17 that is approximately square in shape and extends upward from the outer periphery of the bottom wall portion 16. The bottom wall portion 16 has an opening for inserting the main body portion 14a of the inflator 14 from below. Around the periphery of the insertion hole 16a are through holes (not shown in the reference numerals) through which the bolts 12a of the retainer 12 pass. The periphery of the airbag 11 inlet opening 11a and the flange portion 14c of the inflator 14 are mounted and fixed to the bottom wall portion 16 of the outer casing 15 using the bolts 12a and nuts 13 of the retainer 12. The side wall portion 17 has locking hooks 17a that engage with locking holes 22 in the outer casing side portion 21 (described later) of the connecting member 20. The locking hooks 17a are located at the front and rear of the side wall portion 17 and are arranged in multiples along the left-right direction.

[0051] The connecting component 20 is made of a synthetic resin such as an olefin thermoplastic resin and is configured to have: an outer shell side portion 21 in an approximately square cylindrical shape, which is configured to surround the side wall portion 17 of the outer shell 15; and a door retaining portion 24 (F, B) which is joined to the back side of the airbag cover 29. On the outer shell side portion 21, locking holes 22 are formed in the front wall portion 21a and the rear wall portion 21b for inserting the locking hooks 17a of the outer shell 15. The door retaining portions 24 (F, B) are separated in the front-rear direction and fused to the back side 31d, 32d of the door portions 31, 32 of the airbag cover 29. Multiple raised weld portions 24a are formed on the upper surface of each door retaining portion 24, and the door retaining portions 24 are fused to the back side 31d, 32d of the door portions 31, 32 by vibration welding using the weld portions 24a. In addition, near the front wall portion 21a and rear wall portion 21b of the outer casing side portion 21 of the door retainer 24 (F, B), the door retainer 24 is provided with a thin-walled hinge portion 25 in a manner that allows it to be easily flexibly opened while holding the door portions 31 and 32.

[0052] like Figures 1-6 As shown, the airbag cover 29 is configured to have a substrate 30 and a skin layer 60 bonded to the surface of the substrate 30 using an adhesive. The substrate 30 is formed from a synthetic resin such as polypropylene by molding (more specifically, injection molding). The substrate 30 and the skin layer 60 are disposed not only on the passenger side 2b, which is the location of the airbag cover 29, but also on the driver side 2a and the central part 2c of the instrument panel 2. At the airbag cover 29 location on the passenger side 2b, the door retaining portion 24 (F, B) of the connecting member 20 is connected to the substrate 30.

[0053] The outer skin layer 60 is configured to include: a fabric 61 serving as the outer skin, disposed on the surface 60a side; and a sheet-like cushioning layer 62 that bonds the fabric 61 together. The fabric 61 is configured to be a fabric woven from yarns such as polyester as warp and weft. The cushioning layer 62 is formed of a cushioning material such as polypropylene.

[0054] Furthermore, door portions 31 and 32 are provided at the mounting location of the connecting member 20 of the base material 30, such that they are opened by means of an opening 65 that covers the folded airbag 11 and is formed by the inflated airbag 11 pressing against it, causing the airbag 11 to protrude towards the passenger side. Door portion 31 is provided as a first door portion located on the front side, and door portion 32 is provided as a second door portion located on the rear side.

[0055] The aforementioned door portions 31 and 32 are configured such that the surrounding fracture pre-fracture portion 34 breaks, and the skin layer 60 at the periphery of the door portions 31 and 32 breaks, forming a protruding opening 65 for the airbag 11. Furthermore, each door portion 31 and 32 is configured such that the door retaining portion 24 (F, B) of the connecting member 20 is connected to the back surface 31d and 32d, and together with the door retaining portion 24 (F, B), it forms a protruding opening 65 for opening.

[0056] The fracture pre-determined portion 34 is configured to have: a plurality of strip-shaped fracture openings 40 that penetrate the front and back surfaces of the substrate 30 and are arranged along the edges of the door portions 31 and 32; and a plurality of fracture connecting portions 44 and 48 that are arranged to close the gaps between the fracture openings 40 and fracture when the airbag 11 inflates. Moreover, the fracture pre-determined portion 34 is structured such that the portion near the center of the front edge 31a and 32a of the door portions 31 and 32, which is separated from the hinge portions 31c and 32c on the rotation center side of the door portions 31 and 32 when opened, is used as the fracture starting point portion 38 for fracture.

[0057] In the embodiment, the first door portion 31 and the second door portion 32 are each formed into an approximately rectangular plate extending in the left-right direction. Viewed from above, the fracture pre-determined portion 34 is provided with: a horizontal bar portion 35 extending in the left-right direction; and left and right vertical bars 36 (L, R) extending from the left and right ends of the horizontal bar portion 35 to the front and rear sides, forming an approximately H-shape when viewed from above. Furthermore, a fracture connecting portion 44 (see reference) is provided at the horizontal bar portion 35 in a manner that closes the fracture opening 40. Figure 4 At the longitudinal bar portion 36 (L, R), a break-connecting portion 48 is provided in such a way as to close the break-connecting opening 40 (see reference). Figure 5 ).

[0058] In the implementation, the central portion 35a of the crossbar portion 35 in the left-right direction is set as the starting point of the breakage 38 shared by the front edge 31a and 32a sides of the first door portion 31 and the second door portion 32.

[0059] Furthermore, regarding the break-off connecting portions 44 (A, B) disposed on the crossbar portion 35, the width dimension when viewed from above between adjacent break-off openings 40, 40 is configured such that the front end portion 44b side away from the hinge portion 31c is smaller than the base portion 44a side near the hinge portion 31c (see reference). Figure 4 , 8That is, if the first door portion 31 on the front side of the airbag cover 29 is taken as a reference, the width dimension W11 of the base portion 44a on the hinge portion 31c side of the breakage connection portion 44A in the top view is set to be greater than the width dimension W12 of the front end portion 44b away from the hinge portion 31c.

[0060] Furthermore, in the embodiment, 14 rupture connection parts 44 are arranged on the crossbar portion 35, 4 rupture connection parts 44A are arranged in the area of ​​the starting point portion 38, and 5 rupture connection parts 44B are arranged on the left and right sides respectively, which are offset from the starting point portion 38.

[0061] Regarding the intersection angle between the side edges 45 and 46 of the adjacent fracture openings 40 and 40 on the width direction (left-right direction) of the fracture connection 44A at the starting point 38 and the opposing edges 41 and 42 on the front-rear direction of the fracture openings 40, the intersection angle θA on the front end portion 44b side of the hinge portion 31c is set to an acute angle (approximately 60° in the embodiment) (see reference). Figure 4 ).

[0062] Furthermore, regarding the breakage connection 44B that deviates to the left or right from the central portion 35a of the horizontal bar portion 35 in the left-right direction towards the longitudinal bar portion 36 (L, R), such as Figure 8 As shown, the intersection angle between the side edges 45 and 46 of the adjacent fracture openings 40 and 40 sides in the width direction (left-right direction) and the opposing edges 41 and 42 in the front-back direction of the fracture openings 40 will be the intersection angle θB of the front end portion 44b side of the hinge portion 31c side, which is set to an acute angle, but is larger than that of the fracture connection portion 44A (approximately 75° in the case of the embodiment).

[0063] In addition, the thickness t0 of the substrate 30 is set to approximately 3 mm, the opening width H0 of the fracture opening 40 is set to approximately 1 mm, the width W11 of the base 44a of the fracture connector 44A is set to approximately 4.2 mm, the width W12 of the front end 44b is set to approximately 3 mm, the width W21 of the base 44a of the fracture connector 44A is set to approximately 4.54 mm, and the width W22 of the front end 44b is set to approximately 4 mm.

[0064] Furthermore, the fracture connection portion 48 disposed on the longitudinal bar portion 36 (L, R) is configured to close the gap between adjacent fracture openings 40, but is drum-shaped when viewed from above, such that the side edges 49, 50 on the fracture opening 40 side are formed into a semi-circular arc shape, and the base portion 48a on the door portion 31, 32 side and the front end portion 48b on the non-door portion (general portion) 52 side around the door portion 31, 32 are formed into a symmetrical shape (see reference). Figure 5When the drum-shaped fracture occurs during the expansion of the airbag 11, the connecting portion 48 fractures near the middle portion 48c between the base 48a (which has a smaller width) and the front end portion 48b.

[0065] Furthermore, the longitudinal bar portion 36 (L, R) is formed such that the front portion 36a is disposed on the side edge 31b of the first gate portion 31, and the rear portion 36b is disposed on the side edge 32b of the second gate portion 32. In the central portion 36c in the front-rear direction, the breaking opening 40 extends from the breaking connecting portion 44 on the side of the cross bar portion 35 in a Y-shaped two-strand shape to the front and rear sides, and the breaking opening 40 extends forward and backward through the breaking connecting portion 48 respectively.

[0066] The hinge portions 31c and 32c of each door portion 31 and 32 are formed by intermittently provided grooves 55 that are recessed from the back side 30b side of the substrate 30 towards the surface 30a side in the left-right direction. The grooves 55 are formed by providing side surfaces 57 and 57 that extend from the bottom surface 56, which has an approximately semi-circular cross-section. Figure 6 Furthermore, it is structured such that when the doors 31 and 32 are opened, the bottom wall 58 flexes or breaks, so as to form a protruding opening 65 that allows the doors 31 and 32 to rotate.

[0067] In the implementation, the opening width H1 of the groove 55 is set to approximately 1 mm, and the thickness t1 of the bottom wall portion 58 is set to approximately 0.4 mm.

[0068] Furthermore, the fracture opening 40 of the fracture pre-fracture portion 34 of the substrate 30 and the groove 55 of the hinge portions 31c and 32c are simultaneously formed during the molding of the substrate 30. That is, as Figure 10 As shown in A, B, and C, the substrate 30 is formed using a molding die (specifically, an injection molding die) 70 having parting molds 71 ​​and 72. The parting molds 71 ​​and 72 have mold surfaces 71a and 72a capable of molding the surface 30a and back surface 30b of the substrate 30. The mold surface 72a molding the back surface 30b is provided with ribs 73 for forming a fracture opening 40 and ribs 74 for forming grooves 55 for forming hinge portions 31c and 32c. Therefore, if the molding material M of the substrate 30 is injected into the cavity 70a when the parting molds 71 ​​and 72 of the molding die 70 are closed, and then cured, and the mold is opened and demolded, the substrate 30 can be manufactured. As a result, the fracture opening 40 of the fracture predetermined portion 34 and the grooves 55 of the hinge portions 31c and 32c of the substrate 30 are shaped by the ribs 73 and 74 during the molding of the substrate 30.

[0069] Furthermore, regarding the airbag cover 29 of the embodiment, if an adhesive is applied to the substrate 30 formed by molding and the skin layer 60 is pressed together, the airbag cover 29 is formed. In addition, if the fabric 61 is adsorbed onto the buffer layer 62 coated with adhesive by vacuum forming, the skin layer 60 is formed.

[0070] In this way, the airbag cover 29 is manufactured by pre-welding the door retaining portion 24 (F, B) of the connecting member 20 to the back surfaces 31d and 32d of the corresponding first door portion 31 and second door portion 32.

[0071] Furthermore, with the retainer 12 housed within the airbag 11, the airbag 11 is folded, and the folded airbag 11 is covered with packaging material (not shown) and housed within the outer casing 15. At this time, each bolt 12a of the retainer 12 protrudes downward from the bottom wall portion 16 of the outer casing 15. Next, if the main body portion 14a of the inflator 14 is inserted into the through hole 16a of the outer casing 15 from below, and each bolt 12a of the retainer 12 passes through the flange portion 14c of the inflator 14, and the nut 13 is tightened to each bolt 12a, the folded airbag 11 and the inflator 14 can be mounted and fixed to the outer casing 15.

[0072] Then, the dashboard 2 is fixed to the side of the vehicle body 1, and the locking hook 17a of the housing 15 is inserted into the locking hole 22 of the housing side 21 of the connecting member 20 fused to the airbag cover 29. The lead wire (not shown) for input of the working signal extending from the specified control device is connected to the inflator 14. If the housing 15 is fixed to the side of the vehicle body 1 using the specified bracket, the airbag device 10 can be mounted on the vehicle 1.

[0073] Regarding the airbag device 10 mounted on the vehicle 1, if the inflator 14 operates in a manner that discharges the inflation gas G, the inflation gas G flows in and the airbag 11 inflates. Moreover, when the airbag 11 inflates, the base material 30 causes the fracture connecting portions 44 and 48 of the fracture pre-fracture portion 34 to break, the first door portion 31 and the second door portion 32 cause the hinge portions 31c and 32c to flex, causing the peripheral skin layer 60 to break, and together with the door holding portion 24 (F, B) of the connecting member 20, it is pressed open, so that the protrusion opening 65 opens, and the airbag 11 protrudes from the protrusion opening 65.

[0074] Furthermore, regarding the airbag cover 29 of the embodiment, when the airbag 11 inflates, for example, at the front door 31, the door 31 is pressed by the inflated airbag 11, causing the fracture connection 44A to break at the fracture starting point 38 of the fracture predetermined portion 34. This fracture connection 44A breaks due to stress concentration on the side with a smaller width dimension W12. At this time, the fracture connection 44A leaves the base portion 44a side, which has a larger width dimension W11, near the hinge portion 31c, remaining, while the front end portion 44b side, which has a smaller width dimension W12, breaks away from the door 31. Therefore, the edge corner 44bb of the surface 30a of the substrate 30 at the fracture surface 44ba side of the front end portion 44b side, which has a smaller width dimension W12, contacts the back surface 60b side of the skin layer 60 with the hinge portion 31c as the door 31 opens, pressing the skin layer 60 upwards. That is, as... Figure 7 As shown in A, B, and C, with the rupture connector 44A engaged with the front edge 31a of the door portion 31, the edge corner 44bb on the side of the front end portion 44b, which has a smaller width dimension W12, cuts into the skin layer 60 like a cutting tool protruding from the front edge 31a of the door portion 31, thereby enabling the skin layer 60 to rupture smoothly. As a result, as the door portion 31 of the substrate 30 opens, the skin layer 60 rapidly ruptures from the front edge 31a side of the door portion 31, and the rupture propagates along the periphery of the door portion 31, smoothly forming the protruding opening 65 of the airbag 11 together with the door portion 31 (see reference). Figure 2 (The double-dotted line). Furthermore, since the door portion 31 does not have protrusions or the like relative to the skin layer 60, it does not affect the aesthetic appearance of the surface 60a side of the skin layer 60. Also, the door portion 31 is held in place by the door retaining portion 24 on the outer casing 15 side of the airbag device 10 in an openable manner, so it will not splash when the airbag 11 inflates, but can be smoothly opened to form the protruding opening 65 of the airbag 11. Similarly, the skin layer 60 is also bonded to the substrate 30, so it will not splash when the airbag 11 inflates, but can be smoothly formed to form the protruding opening 65 of the airbag 11 only by breaking. Furthermore, in the embodiment, as the starting portion 38 breaks, the entire range of the crossbar portion 35 breaks, and due to the propagation of the breakage, the longitudinal bar portion 36 (L, R) also breaks, so the door portion 32 also allows the hinge portion 32c to flex and open smoothly.

[0075] Therefore, regarding the airbag cover 29 of the embodiment, the skin layer 60 bonded to the surface 30a side of the substrate 30 can suppress the decline in appearance aesthetics and can reliably break and smoothly form the protruding opening 65 that allows the airbag 11 to protrude.

[0076] Furthermore, regarding the airbag cover 29 of the embodiment, the break connection portion 44A at the region of the starting point 38 causes the end edge 45a on the front end 44b side, after the width dimension W12 of at least one of the two edges 45, 46 in the width direction is reduced, to be connected at an acute angle relative to the edge 42 on the side of the break opening 40 of the connection when viewed from above.

[0077] Therefore, in the embodiment, if the fracture connection 44A of the starting point 38 is connected at an acute angle to the edge 45 of the adjacent fracture opening on the front end 44b side where the width dimension W12 decreases, stress concentration will smoothly occur at this location when subjected to the tensile force accompanying the expansion of the airbag 11, making it easy to fracture. In addition, if the end edge 45a of the fracture opening 40 side extending from the fracture front end 44b is formed at an acute angle to the edge 42 of the fracture opening 40 side before fracture, then during fracture, with the upward pressing of the front end 44b of the fracture connection 44A, the fracture will enter the back surface 60b side of the epidermal layer 60 in a manner that continuously presses and cuts into the edge corner 44bb on the fracture end face (fracture surface) 44ba side of the front end 44b, making it easy to propagate the fracture starting from the fracture portion based on the upward pressing of the front end 44b, and the epidermal layer 60 can be smoothly fractured from the fracture starting point 38 along the fracture predetermined portion 34.

[0078] In the embodiment, the fracture connection 44A at the starting point 38 further connects the end edges 45a and 46a on the front end 44b side (after reducing the width dimension W12 of the two edges 45 and 46 in the width direction) at acute angles relative to the edge 42 on the fracture opening 40 side when viewed from above. Therefore, stress concentration is more smoothly generated on the two end edges 45a and 46a on the front end 44b side (after reducing the width dimension W12 of the fracture connection 44A), making the fracture connection 44A at the starting point 38 more prone to fracture. Of course, the end edges 45a and 46a on the sides of the fracture opening 40 extending from the front end 44b of the fracture are pressed upward by the front end 44b of the fracture connection 44A and continuously pressed into the back side 60b of the epidermal layer 60 in a manner that cuts into the edge corner 44bb on the fracture surface 44ba side of the front end 44b of the fracture. Therefore, the epidermal layer 60 can be fractured more smoothly from the fracture starting point 38 along the fracture predetermined part 34.

[0079] Furthermore, regarding the airbag cover 29 of the embodiment, the front door portion (first door portion) 31 is formed into an approximately square plate shape, with a front edge 31a on the front end side when opened, a hinge portion 31c on the rotation center side when opened, and two side edges 31b, 31b between the two ends of the front edge 31a and the two ends of the hinge portion 31c arranged around it. Moreover, a fracture pre-cut portion 34 is arranged on the front edge 31a side and the two side edges 31b sides. A groove 55 is provided in the hinge portion 31c, which is recessed from the back surface 30b side of the substrate 30 towards the surface 30a side. The fracture opening 40 of the fracture pre-cut portion 34 and the groove 55 of the hinge portion 31c are formed simultaneously during the molding of the substrate 30.

[0080] Therefore, in this embodiment, when the base material 30 of the airbag cover 29 is formed by molding, the fracture opening 40 of the fracture pre-fracture portion 34 and the groove 55 of the hinge portion 31c are formed simultaneously, thus the base material 30 can be formed easily. In addition, even if the end edge 45a on the front end 44b side with a smaller width dimension W12 of the fracture connection portion 44A forms an acute angle with the edge 42 of the corresponding fracture opening 40, molding can be performed more easily than cutting processes such as vertical milling.

[0081] Furthermore, regarding the airbag cover 29 of the embodiment, the fracture pre-determined portion 34 (crossbar portion 35) on the front edge 31a side of the door portion 31 is placed in the middle, and the fracture pre-determined portion 34 (crossbar portion 35) on the front edge 31a side is shared. A second door portion 32, which opens during inflation, is symmetrically arranged including the side edges 31b, 31b and the hinge portion 31c. The second door portion 32 shares the crossbar portion 35, which is the fracture pre-determined portion 34 on the front edge 32a side. The side edges 32b, 32b and the hinge portion 32c are symmetrically arranged relative to the side edges 31b and the hinge portion 31c of the first door portion 31 with reference to the crossbar portion 35 of the fracture pre-determined portion 34.

[0082] Therefore, the airbag cover 29 in the embodiment is provided with double-leaf door portions 31 and 32. That is, when the airbag 11 inflates, the crossbar portion 35 and the longitudinal bar portion 36 (L, R) of the breakage pre-break portion 34 break, and the first door portion 31 and the second door portion 32 are pressed open with the hinge portions 31c and 32c as the rotation center, so that they can be opened like double-leaf doors, and a protruding opening 65 with a large opening area can be formed.

[0083] Furthermore, the airbag cover 29 of the embodiment is configured such that the second door portion 32 is disposed on the rear side of the first door portion 31, and is configured as an airbag cover 29 disposed on the dashboard 2 in front of the front seat of the vehicle 1.

[0084] Therefore, in this embodiment, the airbag cover 29 disposed on the dashboard 2 is configured to have a front door portion (first door portion) 31 and a rear door portion (second door portion) 32. Furthermore, as the airbag 11 inflates, when the first door portion 31 and the second door portion 32 open, the breakage connecting portions 44A and 44B on the front edge 31a side of the first door portion 31 cause the front end portion 44b side, which has smaller width dimensions W12 and W22, to break. Therefore, the first door portion 31 and the second door portion 32 open when the breakage connecting portions 44A and 44B are engaged with the first door portion 31 side and not engaged with the second door portion 32 side (see reference). Figure 2 The second door portion 32, located near the rear of the occupant (with double-dotted lines), opens without engaging the break-off connecting portions 44A and 44B with the front edge 32a side when open. Therefore, even when the second door portion 32 contacts the occupant when open, the less concave / convex front edge 32a side can still contact the occupant.

[0085] Additionally, regarding the airbag cover 29 in the implementation method, as... Figure 8 As shown, near the fracture starting point 38 of the fracture pre-fracture portion 34, regarding the fracture connecting portion 44A of the central portion 35a of the crossbar portion 35 of the fracture pre-fracture portion 344, the intersection angle θA between the end edge 45a, 46a of the front end portion 44b with the smaller width dimension W12 of the side edges 45, 46 and the edge 42 of the fracture opening 40 is set to approximately 60°, and the intersection angle θB between the end edge 45a, 46a of the front end portion 44b with the smaller width dimension W22 of the side edges 45, 46 of the fracture connecting portion 44B away from the starting point 38 and the edge 42 of the fracture opening 40 is set to approximately 75°, which can improve the degree of acute angle near the starting point 38. Therefore, when the airbag 11 inflates, the crossbar portion 35 of the rupture link 44A, which is configured to improve the acute angle state of the cross angle θA, reliably breaks near the central part 35a in the left and right direction as the starting point 38 of the breakage, and the door portions 31 and 32 can smoothly rotate and open with the front edge 31a and 32a side as the rotation center with the hinge portions 31c and 32c as the rotation center.

[0086] Furthermore, in the embodiment, regarding the intersection angle between the end edges 45a and 46a on the front end portion 44b side of the fracture connection portion 44 and the edge 42 of the fracture opening 40, there are two types: intersection angle θA (approximately 60°) and intersection angle θB (approximately 75°). It is shown that a smaller intersection angle θA is provided at the fracture starting point 38. If the central portion 35a of the crossbar portion 35 is structured as the fracture starting point 38, the entire range of the crossbar portion 35 can be configured with the same acute-angled intersection angle at the front end portion 44b of the fracture connection portion 44. Additionally, regarding the intersection angles θA and θB between the end edges 45a and 46a of the side edges 45 and 46 of the fracture connection portion 44 and the edge 42 of the fracture opening 40, if at least one is formed as an acute angle, even if they are not equal, the other can be set as an obtuse angle around 90°. Furthermore, if both intersection angles θA and θB are acute angles, they can also be unequal.

[0087] Furthermore, as in the embodiment, when the acute-angled intersection angle increases sequentially with respect to the side farther from the fracture origin 38, as in the embodiment, except that it is set to two stages, as in the embodiment... Figure 9 As shown, the intersection angle θC near the fracture starting point 38 is set to approximately 45°, and is increased in three stages, or further subdivided, as intersection angle θA (approximately 60°) and intersection angle θB (approximately 75°), or is set to increase sequentially.

[0088] Furthermore, as a connecting part for breakage, such as Figure 11 As shown in the fracture connection 44D, the front end 44b side with a smaller width dimension may have a notch recess 44bc that reduces the cross-sectional area in a way that further concentrates stress and causes fracture when the airbag inflates.

[0089] Furthermore, at least one edge 46 in the width direction of the connecting portion 44 for breaking, such as Figure 12 As shown in embodiment A, in addition to the edge 46 extending in a straight line from the base 44a side toward the front end 44b side in a manner that reduces in width, it can also be as shown in the embodiment A. Figure 12 The fracture shown in B is designed with a concave edge 46E, as in the case of the connecting portion 44E, where the width dimension decreases from the base portion 44a side toward the front end portion 44b side. Alternatively, it can be as follows: Figure 12 The fracture shown in C is designed as a convex edge 46F, with the width decreasing from the base 44a side towards the front end 44b side, as the connecting portion 44F. Furthermore, it can be as follows: Figure 12 The fracture shown in D is designed as a series of straight edges 46G with the angle changing in such a way that the width dimension decreases from the base 44a side toward the front end 44b side.

[0090] In addition, as a connecting part 48 for breaking, the width of the base 48a on the side of the door 31 and 32 can be increased, the width on the front end 48b side can be decreased, or the width dimensions of the base 48a and the front end 48b can be set to be the same.

[0091] Furthermore, as a hinged part, the door only needs to open smoothly, except for things like... Figure 13 In the embodiment shown in A, the cross-sectional shape is set such that, except for the groove 55 which has sides 57, 57 parallel to each other from the semi-circular bottom surface 56, it can be as follows: Figure 13 As shown in Figure B, the groove 55H is designed with a cross-sectional shape resembling a parabola. Additionally, as... Figure 13 As shown in C, it can be set as a V-shaped groove 55I. Furthermore, as... Figure 13 As shown in D, it can be configured to have grooves 55J with side surfaces 57, 57 parallel to each other from the V-shaped bottom surface 56.

[0092] Additionally, in this embodiment, an airbag cover 29 with door sections 31 and 32 that open outwards is shown, but it can also be as follows: Figures 14-16 The shown is an airbag cover 29K with a door-like door section 33.

[0093] The airbag cover 29K is also located on the passenger side 2b of the instrument panel 2. Furthermore, the airbag cover 29F is configured to have a base material 30K formed by injection molding from polypropylene or the like, and a skin layer 60 identical to that in embodiments where the base material 30K is bonded to its surface using an adhesive. Moreover, at the location of the airbag cover 29K on the passenger side 2b, the door retaining portion 24K of the connecting member 20K is fused to the base material 30K. The connecting member 20K is configured to have a rectangular cylindrical outer shell side 21 and a door retaining portion 24K.

[0094] Furthermore, the door portion 33 of the airbag cover 29K is approximately rectangular in shape, with the hinge portion 33c positioned on the rear edge side. The front edge side is designated as the front end 33a when open, and the side edges 33b extend rearward from both ends of the front edge 33a. The door retaining portion 24K of the connecting member 20K is fused to the back surface 33d side. The door retaining portion 24K has a thin-walled hinge portion 25 positioned on the rear edge side.

[0095] The door portion 33 is configured such that the surrounding U-shaped fracture pre-fracture portion 34K is fractured, and the skin layer 60 at the periphery of the door portion 33 is fractured to open it in a way that forms a protruding opening 65 for the airbag 11. Of course, similar to the embodiment, the door portion 33 connects the door retaining portion 24K of the connecting member 20K to the back surface 33d side, and together with the door retaining portion 24K, forms a protruding opening 65 to open it.

[0096] The fracture pre-determined portion 34K is configured to have: a plurality of strip-shaped fracture openings 40, which are arranged to penetrate the front and back surfaces of the substrate 30K along the edge of the door portion 33; and a plurality of fracture connecting portions 44 (A, B) and 48, which are arranged to close the gaps between the fracture openings 40 and fracture when the airbag 11 inflates. Furthermore, the fracture pre-determined portion 34K is configured such that the portion near the center of the front edge 33a side of the door portion 33, which is away from the hinge portion 33c on the rotation center side of the door portion 33 when it is open, serves as the fracture starting point portion 38 for fracture.

[0097] The fracture pre-connection portion 34K is configured to include: a crossbar portion 35K, which has a starting point portion 38 disposed at the central portion 35a and is arranged in the left-right direction; and a longitudinal bar portion 36K (L, R), which extends from both ends of the crossbar portion 35K toward the rear of the hinge portion 33c. The fracture connection portion 44 disposed on the crossbar portion 35K is configured such that the fracture connection portion 44A of the embodiment is disposed near the starting point portion 38K, and the fracture connection portion 44B of the embodiment is disposed on the longitudinal bar portion 36K side. The fracture connection portion 48 of the embodiment is disposed on the longitudinal bar portion 36K. The fracture connection portion 44 (A, B) connects the wider base portion 44a to the front edge 33a side of the door portion 33, and connects the narrower front end portion 44b side to the general portion 52 side of the rear side of the door portion 33.

[0098] Regarding the airbag cover 29K, when the airbag 11 mounted behind the vehicle 1 inflates, the door portion 33 is also pressed by the inflated airbag 11. At the fracture initiation point 38 of the fracture predetermined portion 34K, the fracture connector 44A breaks. At this time, similar to the embodiment, the fracture connector 44A remains engaged with the front edge 33a of the door portion 33. The edge corner 44bb on the side of the smaller front end portion 44b (refer to...) Figure 7 A tool protruding from the front edge 33a of the door portion 33 can cut into the skin layer 60, causing the skin layer 60 to break smoothly. Moreover, as the door portion 33 of the substrate 30K opens, the skin layer 60 breaks rapidly from the front edge 33a side of the door portion 33, and the break propagates towards the periphery of the door portion 33, smoothly forming the protruding opening 65 of the airbag 11 together with the door portion 33, thus achieving the same function / effect as in the embodiment.

[0099] Furthermore, as the door of the airbag cover, the breakage pre-connection part is shaped such that the two ends of the crossbar part open in a Y-shape. As a four-door structure, such as the two doors on the front and rear sides of the crossbar part and the two doors on the left and right sides surrounded by the Y-shaped breakage pre-connection parts on both sides of the crossbar part, the present invention can also be applied to the breakage connection part of the breakage pre-connection part.

[0100] Explanation of the label

[0101] 2…(Instrument panel)Instrument panel, 2b…Passenger side, 10…Airbag assembly, 11…Airbag, 20, 20G…Connecting parts, 24(F, B), 24K…Door retainer, 29, 29K…Airbag cover, 30, 30K…Base material, 30a…Surface, 30b…Back side, 31…First door section, 31a…Front end edge, 31b…Side edge, 31c…Hinge, 31d…Back side, 32…Second door section, 32a…Front end edge, 32b…Side edge, 32c…Hinge, 3 2d…back side, 33…door section, 33a…front edge, 33b…side edge, 33c…hinge section, 33d…back side, 34, 34K…breakage pre-determined section, 35, 35K…crossbar section, 35a…central section, 36, 36K(L, R)…vertical bar section, 38, 38K…(breakage) starting point section, 40…breakage opening, 41…(front) opposite edge, 42…(rear) opposite edge, 44(A, B), 44C, 44D, 44E, 44F, 44G…(crossbar)…(horizontal)…(breakage ... 44a… (Wide side) for connecting parts in case of breakage, 44b… (Wide side) base, 44ba… (Narrow side) front end, 44bb… (Front end face) fracture surface, 45… (Left) side edge, 45a… (End edge), 46, 46E, 46F, 46G… (Right) side edge, 46a… (End edge), 48… (General part side) for connecting parts in case of breakage, 48a… (Door side) base, 48b… (Non-door side) front end, 48c… (Middle part), 49… (Front) side edge, 50 …(Rear) Side edge, 52…(Non-door) General part, 55, 55H, 55I, 55J…(Hinge part) Groove, 60…Skin layer, 60a…Surface, 60b…Back side, 65…Protruding opening, 70…Mold, 70a…Cavity, 71…Parting mold, 72…Parting mold, W(01, 11, 21)…(Wide dimension of the wider part), W(02, 12, 22)…(Wide dimension of the narrower part), θA, θB, θC…Intersection angle.

Claims

1. An airbag cover, formed in the following structure: having a substrate and a skin layer adhered to the surface side of the substrate, covering the top of a folded airbag, and... The structure is configured such that, when the airbag inflates, the door portion disposed on the substrate is pressed by the inflated airbag, causing a pre-fractured portion around the door portion to fracture, and causing a portion of the skin layer at the periphery of the door portion to fracture, thus forming a protrusion of the airbag that opens in an opening manner. The door is configured such that a door retaining portion extending from the outer shell side that houses the folded airbag is connected to the rear side, and is held in place by the door retaining portion in a manner that allows it to be opened. The airbag cover is characterized in that... The predetermined fracture portion of the substrate is configured to have: a plurality of strip-shaped fracture openings that penetrate both sides of the substrate and are arranged along the edge of the door portion; and a plurality of fracture connecting portions that are arranged to close the gaps between the fracture openings and fracture upon inflation of the airbag. The fracture pre-construction portion is structured such that the portion near the center of the front end of the door, away from the hinge portion on the rotation center side when the door is open, serves as the fracture starting point. The connecting portion for breaking at the starting point is configured such that, when viewed from above, the width of the front end portion of the adjacent breaking openings away from the hinge portion is smaller than the width of the base portion of the hinge portion near the door portion.

2. The airbag cover according to claim 1, characterized in that, The connecting portion for breaking at the starting point region such that the edge of the front end side, after reducing the width dimension of at least one of the two edges in the width direction, is connected at an acute angle relative to the edge of the connecting opening side for breaking when viewed from above.

3. The airbag cover according to claim 2, characterized in that, The connecting portion for breaking at the starting point region causes the edge of the front end side, after reducing the width dimension of the two edges in the width direction, to be connected at an acute angle relative to the edge of the connecting opening side for breaking when viewed from above.

4. The airbag cover according to any one of claims 1 to 3, characterized in that, The door is approximately square in shape, with a front edge on the front side when open, a hinge on the rotation center side when open, and two side edges between the two ends of the front edge and the two ends of the hinge. The fracture pre-determined portion is disposed on the front edge side and the two side edges sides. The hinge portion is provided with a groove that is recessed from the back side of the substrate toward the surface side. The fracture opening of the fracture pre-construction portion and the groove of the hinge portion are simultaneously shaped during the molding of the substrate.

5. The airbag cover according to claim 4, characterized in that, The second door portion, which opens during expansion, is symmetrically arranged including the side edge and the hinge portion, with the fracture pre-prepared portion on the front edge side of the door portion placed in the middle and sharing the fracture pre-prepared portion on the front edge side.

6. The airbag cover according to claim 5, characterized in that, The second door is configured such that it is a dashboard located on the rear side of the door and in front of the front seats of the vehicle.

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