Passenger airbag device

Abstract

To provide an airbag device for a front passenger seat which enables two door parts arranged parallel to each other in a vertical direction to smoothly open at substantially the same time in an initial stage of expansion of an airbag even if the airbag device is a mid-mount type.SOLUTION: An airbag is disposed at an area near a center in a vertical direction of an instrument panel 1. An airbag cover 25 covering the folded airbag 10 has a ceiling wall part 27 disposed so as to be substantially along the instrument panel. The ceiling wall part is disposed at an area including an inversion part forming a protruding end protruding rearward in the instrument panel. An upper door part 30U and a lower door part 30D are located adjacent to each other so that a center side breakage planning part formed near the inversion part 28a is disposed therebetween. Abutting ribs 37 for facilitating opening during deployment / inflation of the airbag are formed at the front surface 30b side of the upper door part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a mid-mount type passenger airbag device that is disposed in an area near the vertical center of an instrument panel in front of a passenger seat. [Background technology]

[0002] Typically, a passenger airbag device is mounted in a vehicle such that the ceiling wall of the airbag cover, which covers the airbag folded and stored in the storage area, is connected to the instrument panel in the area of ​​the instrument panel. A mid-mount passenger airbag device is configured to be located in the vertical center of the instrument panel, and is therefore mounted such that the ceiling wall of the airbag cover is located in a significantly curved area of ​​the instrument panel (see, for example, Patent Document 1). In addition, in this conventional passenger airbag device, the airbag cover has two door portions disposed on the vertical sides in the ceiling wall portion in an area covering the protrusion opening of the storage area, and the inflating airbag is protruded by opening the two door portions vertically. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-111424 A Summary of the Invention [Problem to be solved by the invention]

[0004] When the ceiling wall portion of the airbag cover is disposed in a region of the instrument panel that is significantly curved, the upper and lower door portions formed in the region of the ceiling wall portion may be configured to have significantly different external shapes (curvature) and distances from the folded airbag, depending on the external shape of the instrument panel. When the external shapes of the upper and lower door portions are significantly different in this way, differences arise in the opening between the upper and lower door portions (opening start timing, opening speed, etc.), making it difficult to open the projection opening quickly and widely, and preventing the airbag from inflating quickly and stably.

[0005] The present invention solves the above-mentioned problems and aims to provide a passenger seat airbag device that is capable of smoothly opening two door sections arranged side by side above and below at approximately the same time during the initial stage of airbag inflation, even if the airbag device is a mid-mount type that is arranged in an area near the center of the top and bottom of the instrument panel. [Means for solving the problem]

[0006] The passenger seat airbag device according to the present invention is arranged in an area near the vertical center of an instrument panel in front of the passenger seat, and is configured to include an airbag that is inflated by an inflow of inflation gas therein, a storage portion for folding and storing the airbag, and an airbag cover for covering the folded airbag, The storage portion has a protrusion opening formed by opening the rear side so that the folded airbag protrudes rearward, The airbag cover has a ceiling wall portion disposed so as to be substantially aligned with the instrument panel, and a door portion covering the projection opening and a breakable portion formed on the periphery of the door portion are disposed on the ceiling wall portion, and is configured so that when the airbag is deployed and inflated, the breakable portion breaks and the door portion opens, A passenger seat airbag device having two door portions arranged side by side, one above the other, The ceiling wall portion is configured to be disposed in a region including an inverted portion that forms a rearward protruding end of the instrument panel, The upper door portion and the lower door portion are arranged side by side in the vertical direction and are adjacent to each other with a central breakable portion formed near the reversal portion interposed therebetween, A contact rib for promoting the opening of the airbag when it is deployed and inflated is disposed on the front side of at least one of the upper door part and the lower door part so as to protrude forward.

[0007] The passenger airbag device of the present invention is a mid-mount type that is disposed near the vertical center of the instrument panel, and the ceiling wall portion of the airbag cover, which is disposed so as to substantially conform to the instrument panel, is disposed in an area including an inverted portion that constitutes the rearward protruding end of the instrument panel, and the doors that can be opened when the airbag is deployed and inflated are disposed side by side above and below and adjacent to each other with a central planned rupture portion formed near the inverted portion interposed therebetween. That is, in the passenger airbag device of the present invention, the upper and lower doors that are disposed side by side above and below are disposed in an area of ​​the instrument panel that is greatly curved. However, in the passenger seat airbag device of the present invention, a contact rib that protrudes forward is provided on the front side of at least one of the upper door portion and the lower door portion. By appropriately arranging this contact rib and appropriately adjusting the outer shape and protrusion amount of the contact rib, it is possible to adjust the timing at which the airbag pushes open the upper door portion or the lower door portion in the initial stage of inflation, so that the upper door portion and the lower door portion can start opening approximately simultaneously. Therefore, the upper door portion and the lower door portion can be opened approximately simultaneously in the initial stage of airbag inflation, and the protrusion opening of the storage portion can be opened quickly and widely. This allows the inflating airbag to quickly protrude rearward from the protrusion opening. As a result, the airbag can be quickly and stably completed.

[0008] Therefore, in the passenger seat airbag device of the present invention, even if it is a mid-mount type that is arranged in an area near the center of the top and bottom of the instrument panel, the two door sections that are arranged side by side above and below can be opened quickly and smoothly at the initial stage of airbag inflation.

[0009] Specifically, in the passenger seat airbag device of the present invention, if the substantial length dimension of the upper door section in a cross section generally along the vertical direction is set to be smaller than the substantial length dimension of the lower door section in a cross section generally along the vertical direction, or if a decorative member is provided on the rear surface of the upper door section, or if the inclination angle of the upper door section with respect to the central axis of the storage area in a cross section generally along the vertical direction is set to be larger than the inclination angle of the lower door section with respect to the central axis of the storage area in a cross section generally along the vertical direction, the upper door section will be more difficult to open than the lower door section. In such a configuration, if a contact rib is formed only on the front side of the upper door section, the upper door section can be opened approximately simultaneously with the lower door section at the initial stage of airbag inflation.

[0010] Furthermore, when forming a contact rib only on the upper door portion side, it is preferable to set the upper hinge portion formed on the base side of the upper door portion to a lower strength than the lower hinge portion formed on the base side of the lower door portion, as this makes it possible to adjust the upper door portion to make it even easier to open.

[0011] Furthermore, when the contact rib is formed only on the upper door portion side, the upper breakable portions formed on the left and right edge sides of the upper door portion may be set to have a lower breaking strength than the lower breakable portions formed on the left and right edge sides of the lower door portion. Even in this configuration, it is possible to adjust the upper door portion to be even easier to open, which is preferable. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic perspective view showing an instrument panel of a vehicle in which a passenger airbag device according to an embodiment of the present invention is mounted. [Figure 2]1 is a schematic vertical cross-sectional view of a passenger seat airbag device according to an embodiment of the present invention, taken along the vertical direction; [Figure 3] 1 is a schematic enlarged vertical cross-sectional view of a passenger seat airbag device according to an embodiment of the present invention; [Figure 4] 4 is a schematic cross-sectional view of the passenger seat airbag device according to the embodiment taken along the left-right direction, and corresponds to the section IV-IV in FIG. 3. FIG. [Figure 5] 1 is a schematic rear view of an airbag cover and a surrounding instrument panel in an airbag device for a passenger's seat according to an embodiment, as viewed from the front side of a vehicle. FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 5. [Figure 7] FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 5. [Figure 8] FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 5. [Figure 9] 1 is a schematic vertical cross-sectional view of a passenger seat airbag device according to an embodiment, showing an airbag in an inflated state; [Figure 10] FIG. 10 is a schematic vertical cross-sectional view of a passenger airbag device according to another embodiment of the present invention. [Figure 11] FIG. 10 is a schematic vertical cross-sectional view of a passenger airbag device according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described below with reference to the drawings. A passenger airbag device (hereinafter referred to as "airbag device") M according to the present embodiment is a mid-mount type device that is disposed in a region near the vertical center of an instrument panel (hereinafter referred to as "instrument panel") 1 in front of the passenger seat of a vehicle, as shown in FIGS. 1 and 2. Specifically, the instrument panel 1 of a vehicle equipped with the airbag device M according to the present embodiment includes an upper panel 2 and a lower panel 3, as shown in FIGS. 1 and 2. The airbag device M is mounted in the region of the lower panel 3. More specifically, the airbag device M is disposed in a region of the lower panel 3 that protrudes most rearward (toward the passenger seat) and that includes an inverted portion 3c that forms the rearward protruding end. Specifically, the lower panel 3 has a region that protrudes rearward, curved in a generally inverted "L" shape in a cross section along the vertical direction, and this protruding region 3a has an opening 3b for mounting the airbag device M. In the present embodiment, a decorative member is provided on the rear side (front surface) of the upper portion 3d of the protruding region 3a of the lower panel 3 of the instrument panel 1, above the inverted portion 3c. The decorative member is a plate-shaped decorative body 5 (specifically, a transparent plate-shaped body made of polypropylene (PP) in this embodiment) made of a synthetic resin with higher rigidity than the airbag cover 25 (described later). The decorative member 5 is provided over substantially the entire left and right area, including the area where the airbag cover 25 is disposed (the area of ​​the opening 3b of the lower panel 3 of the instrument panel 1) (see FIGS. 1 and 2). The decorative body 5 has a groove-shaped breakable portion 5a formed continuously from the front side at a position corresponding to an upper breakable portion 35U and an upper hinge portion 32U (described later) of the airbag cover 25. The breakable portion 5a is breakable when an upper door portion 30U (described later) is opened (see FIGS. 2 and 6). The decorative body 5 is attached to the lower panel 3 using an adhesive, a predetermined attachment member (not shown), or the like.

[0014] 2 to 4, the airbag device M is configured to include an airbag 10 that inflates when inflation gas flows into the airbag 10, an inflator 15 that supplies inflation gas to the airbag 10, a case 17 that serves as a storage area for storing the folded airbag 10 and the inflator 15, a retainer 12 for attaching the airbag 10 and the inflator 15 to the case 17, and an airbag cover 25 that covers the folded airbag 10. The case 17 is connected to the vehicle body side by a bracket (not shown).

[0015] Although not shown in detail, the airbag 10 has a shape that, when fully inflated, covers a wide area in front of the passenger seat and converges toward the front end, and has an inlet opening 10a (see FIGS. 3 and 4) at the front end for allowing inflation gas G to flow into the interior. Although not shown in detail, the inlet opening 10a is formed as a circular opening, and its periphery is held down by a retainer 12 disposed within the airbag 10, and the retainer 12 is attached to a bottom wall portion 18 (described below) of the case 17. The retainer 12 is formed in a substantially rectangular ring shape, and bolts 12a extending downward and forward are disposed at the four corners. Each bolt 12a passes through the periphery of the inlet opening 10a in the airbag 10, the bottom wall portion 18 of the case 17, and the flange portion 15c of the inflator 15 (described later), and is fastened with a nut 13. The retainer 12 secures the airbag 10 and the inflator 15 to the bottom wall portion 18 of the case 17 using these bolts 12a and nuts 13.

[0016] The inflator 15 is approximately cylindrical and comprises a main body 15a having a gas discharge port 15b for discharging inflation gas G into an area located within the case 17, and a flange portion 15c having an approximately square plate shape that protrudes from the outer peripheral surface of the main body 15a.

[0017] The case 17 serving as the storage portion is generally box-shaped with an opening at the rear side, and is configured to include a bottom wall portion 18 in the shape of a generally rectangular plate, and a peripheral wall portion 19 in the shape of a generally square tube extending rearward (specifically, rearward and upward) from the outer periphery of the bottom wall portion 18, with a projection opening 17a at the rear end of the peripheral wall portion 19 for projecting the airbag 10. The bottom wall portion 18 is formed with an insertion hole (reference numeral omitted) for inserting the main body portion 15a of the inflator 15 and through-holes (reference numeral omitted) for passing the bolts 12a of the retainer 12 therethrough, and as described above, the periphery of the inlet opening 10a of the airbag 10 and the flange portion 15c of the inflator 15 are attached and fixed by the bolts 12a of the retainer 12 and the nuts 13. 2 and 3, a plurality of locking hooks (reference numerals omitted) are formed along the left-right direction at the rear ends of the upper wall portion 19a and the lower wall portion 19b that face each other in the vertical direction of the peripheral wall portion 19 for locking onto a side wall portion 42 (described later) of the airbag cover 25. In this embodiment, the case 17 is mounted on the vehicle with its axial direction (center axis C1, see FIG. 3) tilted slightly upward and rearward from the horizontal direction. The axial direction of this case 17 substantially coincides with the protruding direction of the folded airbag 10.

[0018] The airbag cover 25 is made of a soft thermoplastic resin (specifically, in the case of the embodiment, polyolefin-based thermoplastic elastomer (TPO) or the like), and as shown in FIGS. 2 to 5, includes a ceiling wall portion 27 that closes the opening 1b of the instrument panel 1, and a side wall portion 42 that extends forward from the front (rear) side of the ceiling wall portion 27. The side wall portion 42 is disposed on the outer periphery of the peripheral wall portion 19 of the case 17 so as to generally follow the peripheral wall portion 19. In the side wall portion 42, an upper wall portion 42a and a lower wall portion 42b that face each other in the vertical direction are formed with a plurality of locking holes (reference numerals omitted) for locking the periphery to lock hooks formed in the upper wall portion 19a and the lower wall portion 19b of the case 17.

[0019] The ceiling wall portion 27 is disposed so as to substantially follow the lower panel 3 of the instrument panel 1, and includes a door mounting portion 28 formed by an area surrounded by a side wall portion 42, and a peripheral edge portion 40 extending around the door mounting portion 28. As shown in FIGS. 3 and 4, the peripheral edge portion 40 is disposed on the front side of the peripheral edge of the opening 3b of the lower panel 3.

[0020] The door mounting portion 28 has a generally inverted V-shaped cross section in the vertical direction so that the portion near the vertical center protrudes furthest rearward along the curved shape (protruding shape) of the lower panel 3, and has an inverted portion 28a at approximately the vertical center (see FIGS. 2 and 3). In the embodiment, the inverted portion 28a has a linear portion 28b that generally follows the bottom wall portion 18 of the case 17 (generally perpendicular to the axial direction (center axis C1) of the case 17, i.e., the protruding direction of the airbag 10), as shown in FIG. The door arrangement section 28 includes two door sections 30U, 30D arranged side by side, one above the other, that can open when the airbag 10 is deployed and inflated, hinge sections (upper hinge section 32U, lower hinge section 32D) that serve as the rotation center when the door sections 30U, 30D are opened, and breakable sections 35C, 35U, 35D that are formed on the periphery of the door sections 30U, 30D and that are broken when the door sections 30U, 30D are opened.

[0021] Specifically, the upper door section 30U and the lower door section 30D, which are arranged side by side vertically, are adjacent to each other with a central breakable portion 35C formed near the reversing portion 28a interposed therebetween. Specifically, the central breakable portion 35C, which separates the upper door section 30U from the lower door section 30D, is disposed at a position that is approximately the center of the vertical direction of the linear portion 28b of the reversing portion 28a (see FIG. 3). The decorative body 5, which serves as a decorative member disposed on the rear surface (front surface) of the lower panel 3 of the instrument panel 1, is disposed so that its lower end 5b coincides with the position of the central breakable portion 35C (see FIGS. 2 and 3), and so as to completely cover the rear surface of the upper door section 30U. The upper door section 30U and the lower door section 30D have breakable portions 35C, 35U, 35D arranged in a generally H-shape when viewed from the front-to-rear direction, and have generally the same width dimension in the left-to-right direction (see FIGS. 1 and 5). The upper door section 30U and the lower door section 30D also have generally the same thickness (see FIGS. 2 and 3).

[0022] In this embodiment, the upper door portion 30U and the lower door portion 30D have the same width and thickness on the left and right sides, but are configured with different inclination relative to the case 17 (the inclination angle relative to the central axis C1 of the case 17 (the protruding direction of the airbag 10)) and different effective length dimensions (the distance from the upper hinge portion 32U or the lower hinge portion 32D to the central breakable portion 35C in a cross section along the vertical direction). In detail, in the case of the embodiment, the upper door section 30U has the upper hinge section 32U arranged on the base side (front end side) located rearward of the lower hinge section 32D arranged on the base side (front end side) of the lower door section 30D, and the substantial length dimension L1 (the distance from the upper hinge section 32U to the central planned breaking section 35C, see FIG. 3) is set to be smaller than the substantial length dimension L2 (the distance from the lower hinge section 32D to the central planned breaking section 35C, see FIG. 3) of the lower door section 30D. Furthermore, in the case of the embodiment, the upper door section 30U has an inclination angle α of about 40° with respect to the central axis C1 of the case 17 in a cross section generally along the vertical direction, and the lower door section 30D has an inclination angle β of about 25° with respect to the central axis C1 of the case 17 in a cross section generally along the vertical direction (see FIG. 3). Furthermore, as described above, the decorative body 5 as a decorative member is disposed over the entire rear surface of the upper door section 30U. Furthermore, a contact rib 37 is disposed on the front surface 30b of the upper door section 30U so as to protrude forward to facilitate opening of the upper door section 30U when the airbag 10 is deployed and inflated. Specifically, the contact rib 37 is disposed over substantially the entire length of the front and rear of the upper door section 30U, and has an outline shape, as viewed from the left and right sides, with its edges formed in a substantially arc-like shape (see FIGS. 2 and 3). The contact rib 37 is formed at multiple locations (five locations in this embodiment) on the left and right sides (see FIGS. 4 and 5), and as shown in FIG. 8, the front surface of the contact rib 37 serves as a contact surface 37a that can come into contact with the inflating airbag 10. Such a contact rib 37 is provided to bring the surface (front surface (rear surface)) of the upper door portion 30U that is pressed by the expanding airbag 10 relatively closer to the airbag 10 when the upper door portion 30U is opened in the early stage of inflation of the airbag 10, compared to when the contact rib is not provided, thereby accelerating the timing at which the pressure starts.The outer shape, forward protrusion amount, and number of the contact ribs 37 are set so that the timing at which the upper door portion 30U starts to open can be approximately the same as the timing at which the lower door portion 30D starts to open at the initial stage of inflation of the airbag 10.

[0023] As described above, the planned rupture portions 35C, 35U, 35D are arranged in a substantially H-shape when the airbag cover 25 is viewed from the front-rear direction (see FIG. 5). The central planned rupture portion 35C is arranged substantially along the left-right direction between the upper door portion 30U and the lower door portion 30D. The upper planned rupture portions 35U extend upward from both ends of the central planned rupture portion 35C and are arranged on the left and right edges of the upper door portion 30U. The lower planned rupture portions 35D extend downward from both ends of the central planned rupture portion 35C and are arranged on the left and right edges of the lower door portion 30D. The central breakable portion 35C is recessed from the rear surface (front surface) in a generally groove-like shape and is disposed continuously in the left-right direction, while the upper breakable portion 35U and the lower breakable portion 35D are recessed from the front surface (rear surface) in a generally groove-like shape and are each formed continuously in the up-down direction (see FIGS. 2, 6, and 7). In the airbag cover 25 of the embodiment, the upper breakable portion 35U is set to have a lower breaking strength than the lower breakable portion 35D. Specifically, in the case of the embodiment, the upper breakable portion 35U is set to have a larger width than the lower breakable portion 35D, as shown in FIGS. 6 and 7, thereby setting the breaking strength lower. More specifically, in this embodiment, the lower breakable portion 35D has a recess shape that is substantially the same as that of the central breakable portion 35C (see Figures 2 and 6), and the breaking strength is set to be substantially the same as that of the central breakable portion 35C, while the upper breakable portion 35U has a width dimension that is larger than that of the central breakable portion 35C.

[0024] The upper hinge portion 32U and the lower hinge portion 32D, which serve as rotation centers when the upper door portion 30U and the lower door portion 30D are opened, are disposed on the base side (front end 30a side) of the upper door portion 30U and the base side (front end 30a side) of the lower door portion 30D, respectively, and in the embodiment, the upper hinge portion 32U disposed on the upper door portion 30U side is set to have lower strength than the lower hinge portion 32D disposed on the lower door portion 30D side. Specifically, in the embodiment, as shown in Fig. 2, the upper hinge portion 32U is configured to be curved so as to protrude significantly forward as a whole while continuing from the upper door portion 30U, and the lower hinge portion 32D is configured as a groove recessed from the front side in the base side (front end 30a side) region of the lower door portion 30D.

[0025] The airbag device M of this embodiment is mounted on a vehicle as follows. First, the airbag 10 is folded with the retainer 12 housed inside and stored in the case 17. The inflator 15 is inserted into the case 17 with the main body 15a from below the bottom wall 18, and the bolts 12a of the retainer 12 protruding downward from the bottom wall 18 are inserted into the flanges 15c of the inflator 15. Then, nuts 13 are fastened to the bolts 12a protruding from the flanges 15c, thereby attaching the folded airbag 10 and the inflator to the case 17. Next, the airbag cover 25 is attached to the case 17, thereby assembling the airbag device M. The airbag device M is then fixed to the vehicle body using a bracket (not shown) attached to the case 17, and lead wires (not shown) for transmitting activation signals extending from a predetermined control device are connected to the inflator 15, thereby mounting the airbag device M on the vehicle.

[0026] In the airbag device M of the embodiment, when the inflator 15 is activated after installation in the vehicle, the airbag 10 is inflated by flowing inflation gas therein. The inflating airbag 10 presses against the upper door portion 30U and the lower door portion 30D of the airbag cover 25, causing the upper door portion 30U and the lower door portion 30D to break the surrounding central break portion 35C, upper break portion 35U, and lower break portion 35D, and is pushed open vertically around the upper hinge portion 32U and the lower hinge portion 32D as shown in FIG. 9 . The airbag 10 then protrudes rearward from the protrusion opening 17a of the case 17, which is formed when the upper door portion 30U and the lower door portion 30D are opened, thereby completing the inflation.

[0027] In the airbag device M of the embodiment, the upper door portion 30U and the lower door portion 30D, which are arranged side by side vertically in the airbag cover 25, are arranged in a greatly curved region (protruding region 3a) of the lower panel 3 of the instrument panel 1, but a contact rib 37 that protrudes forward is arranged on the front surface side of at least one of the upper door portion 30U and the lower door portion 30D (in the case of the embodiment, on the front surface 30b side of the upper door portion 30U). This contact rib 37 is intended to promote opening of the airbag 10 when it is deployed and inflated, and in the case of the embodiment, by providing this contact rib 37 on the upper door portion 30U, it is possible to adjust the timing at which the upper door portion 30U starts to open so that it is approximately simultaneous with the timing at which the lower door portion 30D starts to open. Therefore, in the initial stage of inflation of the airbag 10, the upper door portion 30U and the lower door portion 30D can be opened substantially simultaneously, and the projection opening 17a of the case 17 can be opened quickly and widely, so that the inflating airbag 10 can be quickly projected rearward from the projection opening 17a. As a result, the airbag 10 can be quickly and stably completed in inflation.

[0028] Therefore, in the airbag device M of the embodiment, even if it is a mid-mount type arranged in an area near the center of the top and bottom of the instrument panel 1, the two door sections 30U, 30D arranged side by side above and below can be opened quickly and smoothly at the initial stage of inflation of the airbag 10.

[0029] Specifically, in the airbag device M of this embodiment, the contact rib 37 is disposed only on the upper door portion 30U. The difference in timing at which the upper door portion 30U and the lower door portion 30D start to open is thought to be due to the difference in the pressing force acting on the front surfaces 30b of the upper door portion 30U and the lower door portion 30D by the airbag 10 at the initial stage of inflation, the shapes of the upper door portion 30U and the lower door portion 30D, and the presence or absence of decorative members (the weight of the door portion itself to be opened). Because the upper door portion 30U and the lower door portion 30D have substantially the same width dimension in the left-right direction, if the effective length dimension in a cross section substantially along the up-down direction is different, it is presumed that the larger the length dimension, the larger the pressing area pressed by the airbag 10 and the faster the door portion will open. The difference in pressing force also results from the inclination angle of each door portion 30U, 30D relative to the central axis C1 of the case 17 in a cross section generally along the vertical direction. Because the central axis C1 of the case 17 generally coincides with the protruding direction of the airbag 10, it is presumed that a larger inclination angle facilitates application of the pressing force of the airbag 10, resulting in faster opening. In the airbag device M of the embodiment, the upper door portion 30U is disposed at a greater inclination relative to the central axis C1 of the case 17 than the lower door portion 30D. However, since the upper door portion 30U has a smaller effective length and is provided with a decorative body 5 as a decorative member on its rear surface, it is more difficult to open than the lower door portion 30D. Therefore, by providing a contact rib 37 only on the front surface 30b of the upper door portion 30U to promote opening of the airbag 10 upon deployment and inflation, the upper door portion 30U can be opened approximately simultaneously with the lower door portion 30D at the initial stage of inflation of the airbag 10.

[0030] As in the airbag cover 25A shown in FIG. 10 , even when the inclination angle of the upper door portion 30AU relative to the central axis of the case 17 is set smaller than the inclination angle of the lower door portion 30AD, the upper door portion 30AU is more difficult to open than the lower door portion 30AD. Therefore, by providing the contact rib 37A, the upper door portion 30AU and the lower door portion 30AD can be adjusted to open approximately simultaneously. In the embodiment, the contact rib is provided only on the upper door portion. However, the contact rib may be provided only on the lower door portion. Furthermore, in order to accelerate the opening timing of both door portions depending on the outer shape of the ceiling wall of the airbag cover, the contact rib may be provided on both the upper and lower door portions. In the embodiment, the contact rib formed on the upper door portion is configured so that the outer shape when viewed from the left and right directions has an approximately arc-shaped edge. However, the shape of the contact rib is not limited to the embodiment. For example, like a contact rib 37B of an airbag cover 25B shown in FIG. 11, the outer shape as viewed from the left and right direction may be a substantially right-angled triangle.

[0031] In the airbag device M of this embodiment, the upper hinge portion 32U, which serves as the rotation center for the upper door portion 30U when opening, is set to have lower strength than the lower hinge portion 32D, which serves as the rotation center for the lower door portion 30D when opening. Furthermore, the upper breakable portions 35U formed on the left and right edges of the upper door portion 30U are also set to have lower breaking strength than the lower breakable portions 35D formed on the left and right edges of the lower door portion 30D. Therefore, the upper breakable portions 35U, which break in a manner that propagates from the breakable portion 35C in the center, can be quickly broken. Furthermore, the upper hinge portion 32U, which is set to have lower strength, can be adjusted to make the upper door portion 30U easier to open. The strength settings of the hinge portions and breakable portions are merely supplementary and may not be provided if the opening start timing can be adjusted using only the contact rib. In the airbag device M of the embodiment, a decorative body 5 is disposed as a decorative member over the entire rear surface of the upper door portion 30U, and the decorative body 5 is disposed so as to extend upward and to both the left and right beyond the arrangement area of ​​the airbag cover 25. When the airbag 10 is fully inflated, the decorative body 5 is broken at the locations of the breakable portions 5a formed in the arrangement areas of the upper breakable portion 35U and the upper hinge portion 32U, and moves together with the upper door portion 30U being pushed open (see FIG. 9). Therefore, by setting the upper breakable portion 35U and the upper hinge portion 32U to have lower strength than the lower breakable portion 35D and the lower hinge portion 32D provided on the lower door portion 30D side, the upper door portion 30U can be opened substantially simultaneously with the lower door portion 30D, even in a configuration in which the decorative body 5 is disposed over the entire rear surface. [Explanation of symbols]

[0032] 1...instrument panel (instrument panel), 3...lower panel, 3a...protruding region, 3c...inverted portion, 5...decorative body (decorative member), 10...airbag, 17...case (storage area), 25, 25A, 25B...airbag cover, 27...ceiling wall portion, 28...door arrangement portion, 28a...inverted portion, 30U, 30AU...upper door portion (door portion), 30D, 30AD...lower door portion (door portion), 32U...upper hinge portion (hinge portion), 32D...lower hinge portion (hinge portion), 35C...center intended fracture portion (intended fracture portion), 35U...upper intended fracture portion (intended fracture portion), 35D...lower intended fracture portion (intended fracture portion), 37, 37A, 37B...contact rib, 37a...contact surface, M...passenger seat airbag device.

Claims

1. The airbag is disposed in a region near the center of the top and bottom of the instrument panel in front of the passenger seat, and is configured to be inflated by the flow of inflation gas therein, a storage portion for folding and storing the airbag, and an airbag cover for covering the folded airbag, The storage portion includes a protrusion opening formed by opening a rear side thereof so as to allow the folded airbag to protrude rearward, the airbag cover has a ceiling wall portion disposed so as to substantially follow the instrument panel, and a door portion covering the projection opening and a breakable portion formed on a periphery of the door portion are disposed on the ceiling wall portion, and when the airbag is deployed and inflated, the breakable portion is broken to open the door portion, The passenger seat airbag device has a configuration in which two door portions are arranged side by side, one above the other, and the ceiling wall portion is configured to be disposed in a region including an inverted portion that forms a rearward protruding end of the instrument panel, The upper door portion and the lower door portion are arranged side by side in the vertical direction and are adjacent to each other with a central breakable portion formed near the reversal portion interposed therebetween, a contact rib for promoting opening of the airbag when deployed and inflated is disposed on a front surface side of at least one of the upper door portion and the lower door portion so as to protrude forward, The upper door portion is configured by disposing a decorative member on the rear surface side, The passenger seat airbag device is characterized in that the contact rib is formed on the front side of the upper door portion.

2. The airbag is disposed in a region near the center of the top and bottom of the instrument panel in front of the passenger seat, and is configured to be inflated by the flow of inflation gas therein, a storage portion for folding and storing the airbag, and an airbag cover for covering the folded airbag, The storage portion includes a protrusion opening formed by opening a rear side thereof so as to allow the folded airbag to protrude rearward, the airbag cover has a ceiling wall portion disposed so as to substantially follow the instrument panel, and a door portion covering the projection opening and a breakable portion formed on a periphery of the door portion are disposed on the ceiling wall portion, and when the airbag is deployed and inflated, the breakable portion is broken to open the door portion, The passenger seat airbag device has a configuration in which two door portions are arranged side by side, one above the other, and the ceiling wall portion is configured to be disposed in a region including an inverted portion that forms a rearward protruding end of the instrument panel, The upper door portion and the lower door portion are arranged side by side in the vertical direction and are adjacent to each other with a central breakable portion formed near the reversal portion interposed therebetween, a contact rib for promoting opening of the airbag when deployed and inflated is disposed on a front surface side of at least one of the upper door portion and the lower door portion so as to protrude forward, The upper door portion has a substantially length dimension in a cross section generally along the vertical direction set to be smaller than the substantially length dimension in a cross section generally along the vertical direction of the lower door portion, The contact rib is formed on the front side of the upper door portion, The upper door portion and the lower door portion are configured such that a hinge portion, which serves as a rotation center when opening, is disposed on the base portion side, An airbag device for a passenger seat, characterized in that an upper hinge portion disposed on the upper door portion side is set to have lower strength than a lower hinge portion disposed on the lower door portion side.

3. The airbag is disposed in a region near the center of the top and bottom of the instrument panel in front of the passenger seat, and is configured to be inflated by the flow of inflation gas therein, a storage portion for folding and storing the airbag, and an airbag cover for covering the folded airbag, The storage portion includes a protrusion opening formed by opening a rear side thereof so as to allow the folded airbag to protrude rearward, the airbag cover has a ceiling wall portion disposed so as to substantially follow the instrument panel, and a door portion covering the projection opening and a breakable portion formed on a periphery of the door portion are disposed on the ceiling wall portion, and when the airbag is deployed and inflated, the breakable portion is broken to open the door portion, The passenger seat airbag device has a configuration in which two door portions are arranged side by side, one above the other, and the ceiling wall portion is configured to be disposed in a region including an inverted portion that forms a rearward protruding end of the instrument panel, The upper door portion and the lower door portion are arranged side by side in the vertical direction and are adjacent to each other with a central breakable portion formed near the reversal portion interposed therebetween, a contact rib for promoting opening of the airbag when deployed and inflated is disposed on a front surface side of at least one of the upper door portion and the lower door portion so as to protrude forward, The upper door portion has a substantially length dimension in a cross section generally along the vertical direction set to be smaller than the substantially length dimension in a cross section generally along the vertical direction of the lower door portion, The contact rib is formed on the front side of the upper door portion, The upper door portion and the lower door portion are configured to have an upper breakable portion or a lower breakable portion disposed on a left edge side or a right edge side, respectively, which is broken when the upper door portion or the lower door portion is opened, 10. An airbag device for a passenger seat, wherein the upper breakable portion has a lower breaking strength than the lower breakable portion.

4. The airbag is disposed in a region near the center of the top and bottom of the instrument panel in front of the passenger seat, and is configured to be inflated by the flow of inflation gas therein, a storage portion for folding and storing the airbag, and an airbag cover for covering the folded airbag, The storage portion includes a protrusion opening formed by opening a rear side thereof so as to allow the folded airbag to protrude rearward, the airbag cover has a ceiling wall portion disposed so as to substantially follow the instrument panel, and a door portion covering the projection opening and a breakable portion formed on a periphery of the door portion are disposed on the ceiling wall portion, and when the airbag is deployed and inflated, the breakable portion is broken to open the door portion, The passenger seat airbag device has a configuration in which two door portions are arranged side by side, one above the other, and the ceiling wall portion is configured to be disposed in a region including an inverted portion that forms a rearward protruding end of the instrument panel, The upper door portion and the lower door portion are arranged side by side in the vertical direction and are adjacent to each other with a central breakable portion formed near the reversal portion interposed therebetween, a contact rib for promoting opening of the airbag when deployed and inflated is disposed on a front surface side of at least one of the upper door portion and the lower door portion so as to protrude forward, The upper door portion has a cross section substantially along the vertical direction, and the inclination angle with respect to the central axis of the storage area is set to be larger than the inclination angle with respect to the axial direction of the storage area of ​​the lower door portion, The contact rib is formed on the front side of the upper door portion, The upper door portion and the lower door portion are configured such that a hinge portion, which serves as a rotation center when opening, is disposed on the base portion side, An airbag device for a passenger seat, characterized in that an upper hinge portion disposed on the upper door portion side is set to have lower strength than a lower hinge portion disposed on the lower door portion side.

5. The airbag is disposed in a region near the center of the top and bottom of the instrument panel in front of the passenger seat, and is configured to be inflated by the flow of inflation gas therein, a storage portion for folding and storing the airbag, and an airbag cover for covering the folded airbag, The storage portion includes a protrusion opening formed by opening a rear side thereof so as to allow the folded airbag to protrude rearward, the airbag cover has a ceiling wall portion disposed so as to substantially follow the instrument panel, and a door portion covering the projection opening and a breakable portion formed on a periphery of the door portion are disposed on the ceiling wall portion, and when the airbag is deployed and inflated, the breakable portion is broken to open the door portion, The passenger seat airbag device has a configuration in which two door portions are arranged side by side, one above the other, and the ceiling wall portion is configured to be disposed in a region including an inverted portion that forms a rearward protruding end of the instrument panel, The upper door portion and the lower door portion are arranged side by side in the vertical direction and are adjacent to each other with a central breakable portion formed near the reversal portion interposed therebetween, a contact rib for promoting opening of the airbag when deployed and inflated is disposed on a front surface side of at least one of the upper door portion and the lower door portion so as to protrude forward, The upper door portion has a cross section substantially along the vertical direction, and the inclination angle with respect to the central axis of the storage area is set to be larger than the inclination angle with respect to the axial direction of the storage area of ​​the lower door portion, The contact rib is formed on the front side of the upper door portion, The upper door portion and the lower door portion are configured to have an upper breakable portion or a lower breakable portion disposed on a left edge side or a right edge side, respectively, which is broken when the upper door portion or the lower door portion is opened, 10. An airbag device for a passenger seat, wherein the upper breakable portion has a lower breaking strength than the lower breakable portion.

6. The upper door portion and the lower door portion are configured to have an upper breakable portion or a lower breakable portion disposed on a left edge side or a right edge side, respectively, which is broken when the upper door portion or the lower door portion is opened, 5. The passenger seat airbag device according to claim 2, wherein the upper breakable portion has a lower breaking strength than the lower breakable portion.

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