JP7718342B2 - Airbag device for vehicle - Google Patents

Description

The present invention relates to an airbag device for a vehicle.

2. Description of the Related Art An airbag device for a passenger seat is provided in front of the passenger seat of an automobile (see, for example, Patent Document 1).
The airbag device includes an airbag door and an airbag module.

The airbag door is formed in a portion of the upper surface of an instrument panel located in front of the driver's seat and passenger seat, the portion being located in front of the passenger seat.
The airbag module is provided below the airbag door, i.e., inside the instrument panel, and includes an airbag and a retainer having a cylindrical wall with an airbag opening through which the airbag passes when deployed and inflated.

A pair of door portions are provided on the periphery of the airbag opening in the retainer, and are pressed by the airbag to open the airbag opening.
The instrument panel has a base material made of hard resin, a cushion layer laminated on the base material, and a skin laminated on the cushion layer.

The airbag door has a tear line that acts as the starting point for tearing when pressed by the pair of door sections. The tear line has three horizontal lines and two vertical lines.

The lateral line portions are spaced apart from one another in the front-rear direction of the vehicle and extend in the vehicle width direction.
The vertical line portions extend in the front-to-rear direction of the vehicle at both end positions of the horizontal line portions.
In such an airbag device, when a vehicle crashes, the airbag deploys and inflates due to gas from the inflator, and the pair of door sections are pressed upward by the airbag. The pair of door sections then press the airbag door upward, causing the central horizontal line section to rupture. The vertical line sections located at both ends of the horizontal line section also rupture. The airbag door then opens, opening the airbag opening, causing the airbag to deploy above the instrument panel.

JP 2016-210218 A

The conventional airbag module described above is disposed inside the instrument panel between the reinforcement member extending in the vehicle width direction and the airbag door.
In recent years, it has become desirable to set the upper surface of the instrument panel lower from the viewpoint of design, etc. However, when the upper surface of the instrument panel is set lower, the vertical space between the reinforcement and the airbag door becomes smaller, making it difficult to arrange the airbag module.

Various aspects of a vehicle airbag device for solving the above problems will be described below.
[Aspect 1] An airbag device for a vehicle comprising an airbag door and an airbag module, wherein, when the front and rear in the longitudinal direction of the vehicle are defined as the front and rear, the airbag door is provided on the rear portion of the vehicle's instrument panel, the airbag module comprises an airbag that deploys and inflates when gas is supplied to it, and a retainer having a tubular portion that houses the airbag, and is positioned in front of the airbag door, the tubular portion having an airbag opening that opens toward the rear and through which the airbag passes when deploying and inflating, the airbag door is configured to move in the vehicle width direction or downward while being pressed by the deploying and inflating airbag, thereby opening the airbag opening.

With the above configuration, when gas is supplied to the airbag, the airbag passes through the airbag opening, which opens toward the rear, while deploying and inflating. The airbag then presses rearward against the airbag door, which is located on the rear surface of the instrument panel. The airbag door then moves in the vehicle width direction or downward to open the airbag opening. At this time, the airbag door does not move upward, so it is less likely to interfere with the upward deployment and inflation of the airbag. Therefore, even if the top surface of the instrument panel is set low, the airbag can be deployed and inflated appropriately upward.

[Aspect 2] The instrument panel includes the airbag door and a panel main body that surrounds the airbag door and is formed continuous with the airbag door, and the peripheral edge of the airbag opening has upper and lower edge portions that extend in the vehicle width direction and are spaced apart in the up-down direction, and a pair of side edge portions that extend in the up-down direction, and tear lines are provided on the front surfaces of the airbag door and the panel main body, which serve as starting points for breaking the airbag door when pressed by the airbag, and the tear lines include an upper tear line that overlaps the upper edge portion in the fore-and-aft direction and extends in the vehicle width direction.

With the above configuration, when the airbag door is pressed rearward by the airbag, the airbag door breaks along the upper tear line. This causes the airbag door to move laterally or downwardly, opening the airbag opening.

Furthermore, because tear lines are provided on the front surfaces of the airbag door and panel body, the addition of tear lines can be prevented from impairing the aesthetic appeal of the instrument panel's design surface.

[Aspect 3] The vehicle airbag device described in [Aspect 2], wherein the retainer includes a pair of hinge portions provided on each of the pair of side edges and a pair of door portions rotatably connected via the pair of hinge portions, the pair of door portions overlapping the front surface of the airbag door, and the tear line overlapping the boundary line between the pair of door portions in the fore-and-aft direction and including a central tear line extending downward from the upper tear line.

With the above configuration, when the pair of door sections are pressed rearward by the airbag, the airbag doors are broken along the upper tear line and central tear line. As a result, the pair of door sections and the airbag door that overlaps the pair of door sections rotate around the pair of hinge sections and move in the vehicle width direction, opening the airbag opening.

[Aspect 4] The airbag device for a vehicle described in [Aspect 3], wherein the retainer includes a lower hinge portion provided on the lower edge portion and a lower door portion adjacent to and rotatably connected to the pair of door portions via the lower hinge portion, and the tear line overlaps with the boundary line between the pair of door portions and the lower door portion in the fore-and-aft direction and includes a lower tear line extending in the vehicle width direction.

With the above configuration, when the pair of door sections and the lower door section are pressed rearward by the airbag, the airbag door breaks along the upper tear line, central tear line, and lower tear line. As a result, the pair of door sections and the airbag door overlapping the pair of door sections rotate around the pair of hinge sections and move in the vehicle width direction. Additionally, the lower door section and the airbag door overlapping the lower door section rotate around the lower hinge section and move downward, opening the airbag opening.

In addition, the airbag that deploys and inflates receives an upward reaction force from the lower door section, allowing the airbag to deploy and inflate more optimally in an upward direction.

[Aspect 5] The instrument panel includes a panel main body having an opening that overlaps with the airbag opening in the fore-and-aft direction, and an airbag door that is provided in the opening and opens and closes the airbag opening and the opening. The opening has upper and lower edge portions that extend in the vehicle width direction and are spaced apart in the up-down direction, and a pair of side edge portions that also extend in the up-down direction. The airbag door includes a pair of door portions that are adjacent to each other in the vehicle width direction. The door portions are configured to be deformable between an unfolded state in which the door portions are unfolded to close the opening, and a folded state in which the door portions are folded to open the opening. The upper and lower edge portions of the opening are provided with guide portions that guide the deformation of the door portion between the unfolded state and the folded state.

With the above configuration, when the pair of door sections are pressed rearward by the airbag, each door section is guided by the guide section and deforms into a folded state, thereby opening the airbag opening. Because the pair of door sections are in a folded state in this way, the rearward protrusion length of the door sections can be shortened when the airbag is deployed and inflated.

[Aspect 6] The instrument panel includes a panel main body having an opening that overlaps with the airbag opening in the fore-and-aft direction, and an airbag door provided in the opening that opens and closes the airbag opening and the opening. The opening has upper and lower edge portions that extend in the vehicle width direction and are spaced apart in the up-down direction, and a pair of side edge portions that extend in the up-down direction. A pair of protrusions that protrude in the vehicle width direction are provided at upper ends of the airbag door in the vehicle width direction. The pair of side edge portions of the opening are provided with guide portions that extend in the up-down direction and have a pair of guide grooves into which the pair of protrusions are loosely fitted. The airbag door has an engagement portion that engages with the edge of the opening when the airbag door is in a closed state, thereby maintaining the closed state. The engagement portion is configured to be disengaged from the panel main body when pressed by the airbag.

With the above configuration, when the airbag door is pressed rearward by the airbag, the engagement between the engaging portion and the opening is released. As a result, the pair of protrusions of the airbag door move downward under their own weight while being guided by the guide groove, opening the airbag opening. Because the airbag door moves downward along the guide groove that extends in the vertical direction in this way, the rearward protrusion length of the airbag door can be shortened when the airbag is deployed and inflated.

[Aspect 7] The vehicle airbag device described in [Aspect 6], wherein a pair of engaging protrusions that protrude in the vehicle width direction and fit loosely into the pair of guide grooves are provided on the lower ends of the airbag door in the vehicle width direction, and the engaging portions are the pair of engaging protrusions.

With the above configuration, the engagement portion can be easily realized by a pair of engagement protrusions that fit loosely into a pair of guide grooves.

According to the present invention, even when the upper surface of the instrument panel is set low, the airbag can be deployed and inflated appropriately upward.

FIG. 1 is a cross-sectional view of a first embodiment of an airbag device for a vehicle, focusing on the airbag device. FIG. 2 is a front view of the airbag door shown in FIG. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. FIG. 5 is a cross-sectional view corresponding to FIG. 3, showing the airbag in a deployed state. FIG. 6 is a cross-sectional view corresponding to FIG. 4, showing the airbag in a deployed state. FIG. 7 is a front view of an instrument panel with an airbag door in the center according to the second embodiment. 8(a) to 8(c) are cross-sectional views taken along line 8-8 in FIG. 7, where FIG. 8(a) is a cross-sectional view of the unfolded state, FIG. 8(b) is a cross-sectional view of the state in the middle of transitioning from the unfolded state to the folded state, and FIG. 8(c) is a cross-sectional view of the folded state. FIG. 9 is a front view of an instrument panel with an airbag door in the center according to the third embodiment. FIG. 10 is a cross-sectional view taken along line 10A-10A in FIG. FIG. 11 is a cross-sectional view taken along line 11A-11A in FIG. FIG. 12 is a cross-sectional view taken along line 12A-12A in FIG. FIG. 13 is a cross-sectional view taken along line 13A-13A in FIG. 14(a) and 14(b) are views corresponding to FIG. 11 and are cross-sectional views showing the procedure for attaching the air bag door of FIG. 9 to the guide portion. FIG. 15 is a view corresponding to FIG. 11 and is a cross-sectional view showing a state in which the air bag door is open.

First Embodiment
A first embodiment of an airbag device 10 for a vehicle will be described below with reference to FIGS.

In the following description, the fore-and-aft direction of the vehicle, the vehicle width direction, and the up-and-down direction when the vehicle is positioned on a horizontal plane will be referred to as the fore-and-aft direction L, the vehicle width direction W, and the up-and-down direction Z, respectively. Furthermore, the front and rear in the fore-and-aft direction L will be referred to as the front and rear, and the top and bottom in the up-and-down direction Z will be referred to as the top and bottom.

As shown in FIGS. 1 and 2, an instrument panel 30 is provided in front of the passenger seat of the vehicle.
The instrument panel 30 includes an upper surface portion 30a extending in the front-rear direction L and the vehicle width direction W, and a rear surface portion 30b extending downward from the rear end of the upper surface portion 30a.

A reinforcement 60 extending in the vehicle width direction W is provided inside the instrument panel 30 .
A windshield 70 is disposed above the instrument panel 30. The windshield 70 is inclined so that the upper part of the windshield 70 is positioned further rearward.

As shown in FIGS. 1, 3, and 4, the airbag device 10 includes an airbag module 12 and an airbag door 11.
<Airbag module 12>
As shown in FIGS. 1, 3, and 4, the airbag module 12 is provided inside an instrument panel 30.

The airbag module 12 includes a retainer 14 , an airbag 13 , and an inflator 15 .
The airbag module 12 is preferably provided at the same position as the reinforcement 60 or below the reinforcement 60 in the vertical direction Z.

<Retainer 14>
As shown in FIGS. 1, 3, and 4, the retainer 14 has a cylindrical portion 20.
The cylindrical portion 20 has an airbag opening 21 that opens toward the rear and through which the airbag 13 passes when it deploys and inflates. The front end of the cylindrical portion 20 is closed. The cylindrical portion 20 has a rectangular cross-sectional shape.

As shown in Figure 3, the peripheral edge 22 of the airbag opening 21 extends in the vehicle width direction W and has an upper edge 23 and a lower edge 24 that are spaced apart in the vertical direction Z.

A lower hinge portion 18 is provided on the lower edge portion 24. The lower hinge portion 18 extends in the vehicle width direction W. A lower door portion 19 is rotatably connected to the lower hinge portion 18. The lower door portion 19 is adjacent to and below the pair of door portions 17. The lower door portion 19 is in the shape of a rectangular plate.

As shown in FIG. 4 , the peripheral edge 22 of the airbag opening 21 has a pair of side edges 25 extending in the up-down direction Z. A pair of hinge portions 16 are provided on the pair of side edges 25. The pair of hinge portions 16 extend in the up-down direction Z. A pair of door portions 17 are rotatably connected to the pair of hinge portions 16, respectively. The pair of door portions 17 are adjacent in the vehicle width direction W.

2, the pair of door portions 17 are rectangular plate-shaped. The length of the door portion 17 in the vehicle width direction W is half that of the lower door portion 19 in the vehicle width direction W.
As shown in FIGS. 3 and 4, the pair of door portions 17 and the lower door portion 19 close the airbag opening 21.

<Airbag 13>
1, the airbag 13 has a well-known structure that is deployed and inflated by supplying gas. The airbag 13 is housed in a tubular portion 20 in a folded state.

As shown by the two-dot chain lines in Figures 1 and 2, the airbag 13 has an upper inflatable portion 13a and a lower inflatable portion 13b. The upper inflatable portion 13a is sized to be able to deploy and inflate between the instrument panel 30 and the upper body of the occupant P, particularly the area from the head PH to the chest PT. The lower inflatable portion 13b is sized to be able to deploy and inflate between the instrument panel 30 and the knees PK of the occupant P.

<Inflator 15>
1, the inflator 15 generates gas for inflation and is attached to the front end of the retainer 14. A gas supply unit is provided at the rear of the inflator 15. The portion including the gas supply unit is housed inside the airbag 13 in a folded state.

<Airbag door 11>
As shown in FIG. 1, the airbag door 11 is provided on a rear surface portion 30 b of an instrument panel 30 .

As shown in Figures 2 to 4, the instrument panel 30 has an airbag door 11 and a panel main body 31 that surrounds the airbag door 11 and is formed continuous with the airbag door 11.

As shown in Figures 1, 2, and 4, the airbag door 11 is located behind the airbag module 12. The front surface of the airbag door 11 overlaps the pair of door sections 17 and the lower door section 19. The airbag door 11, together with the pair of door sections 17 and the lower door section 19, closes the airbag opening 21.

The airbag door 11 and panel body 31 are formed from a hard resin base material. Examples of resin materials that make up the base material include thermoplastic olefin (TPO) and polypropylene.

As shown in Figures 2 to 4, a tear line 33 is provided on the front surface of the airbag door 11 and the panel body 31, which serves as the starting point for tearing of the airbag door 11 when pressed by the airbag 13. The tear line 33 is, for example, a groove with a V-shaped cross section.

The tear line 33 includes an upper tear line 34 , a central tear line 35 , a lower tear line 36 , a pair of side edge tear lines 37 , and a lowermost tear line 38 .
As shown in FIG. 3 , the upper tear line 34 overlaps the upper edge 23 of the airbag opening 21 in the front-rear direction L and extends in the vehicle width direction W.

The lower tear line 36 overlaps a boundary line B1 between the pair of door portions 17 and the lower door portion 19 in the front-rear direction L and extends in the vehicle width direction W.
The lowermost tear line 38 overlaps with the lower hinge portion 18 in the front-rear direction L and extends in the vehicle width direction W.

As shown in FIG. 4 , the central tear line 35 overlaps the boundary line B2 between the pair of door sections 17 in the front-to-rear direction L and extends downward from the upper tear line 34. The pair of side edge tear lines 37 overlap the pair of hinge sections 16 in the front-to-rear direction L, respectively, and extend in the up-down direction Z.

The operation of the first embodiment will be described.
5 and 6 , when a sensor detects an impact force associated with a frontal collision of the vehicle, a control device (not shown) controls the operation of the inflator 15, causing the inflator 15 to supply gas into the airbag 13. As a result, the airbag 13 passes through the airbag opening 21 while deploying and inflating. When the pair of door sections 17 and the lower door section 19 are pressed rearward by the airbag 13, the airbag door 11 is pressed rearward via the pair of door sections 17 and the lower door section 19. As a result, the airbag door 11 is broken along the upper tear line 34, the central tear line 35, the lower tear line 36, the side edge tear lines 37, and the lowermost tear line 38. Furthermore, the pair of door sections 17 rotate about the pair of hinge sections 16 and move in the vehicle width direction W, and the lower door section 19 rotates about the lower hinge section 18 and moves downward, thereby opening the airbag opening 21.

As shown by the two-dot chain lines in Figures 1 and 2, the airbag 13 that passes through the airbag opening 21 deploys and inflates rearward and upward. When the vehicle crashes head-on, the occupant P tends to move forward. At this time, the upper body of the occupant P is supported by the upper inflatable portion 13a of the airbag 13, and the lower body of the occupant P is supported by the lower inflatable portion 13b.

The effects of the first embodiment will be described.
(1-1) The airbag door 11 is configured to open the airbag opening 21 by moving in the vehicle width direction W or downward while being pressed by the deployed and inflated airbag 13.

With this configuration, the airbag door 11 does not move upward due to the above-mentioned effect. As a result, it is less likely to interfere with the upward deployment and inflation of the airbag 13. Therefore, even if the upper surface portion 30a of the instrument panel 30 is set low, the airbag 13 can be deployed and inflated upward appropriately.

(1-2) An upper tear line 34 extending in the vehicle width direction W is provided on the front surface of the airbag door 11 and the panel main body 31 at a position that overlaps with the upper edge portion 23 in the front-rear direction L.

With this configuration, when the airbag door 11 is pressed rearward by the airbag 13, the airbag door 11 breaks along the upper tear line 34. As a result, the airbag door 11 moves in the vehicle width direction W or downward, opening the airbag opening 21.

Furthermore, because a tear line 33 is provided on the front surface of the airbag door 11 and the panel body 31, the addition of the tear line 33 can be prevented from impairing the aesthetic appeal of the design surface of the instrument panel 30.

(1-3) The tear line 33 overlaps the boundary line B2 between the pair of door sections 17 in the front-rear direction L and includes a central tear line 35 that extends downward from the upper tear line 34.
According to this configuration, when the pair of door portions 17 are pressed rearward by the airbag 13, the airbag door 11 is broken along the upper tear line 34 and the central tear line 35. As a result, the pair of door portions 17 rotate about the pair of hinge portions 16, thereby opening the airbag opening 21.

(1-4) The tear line 33 includes a lower tear line 36 that overlaps the boundary line B1 between the pair of door portions 17 and the lower door portion 19 in the front-rear direction L and extends in the vehicle width direction W.
According to this configuration, when the pair of door portions 17 and the lower door portion 19 are pressed rearward by the airbag 13, the airbag door 11 is broken along the upper tear line 34, the central tear line 35, and the lower tear line 36. As a result, the pair of door portions 17 rotate about the pair of hinge portions 16, and the lower door portion 19 rotates about the lower hinge portion 18, thereby opening the airbag opening 21.

In addition, the airbag 13 that deploys and inflates receives an upward reaction force from the lower door portion 19, allowing the airbag 13 to deploy and inflate more optimally in an upward direction.

Second Embodiment
The second embodiment will be described below, focusing on the differences from the first embodiment, with reference to Figures 7 and 8. Note that in the second embodiment, the same or corresponding components as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIGS. 7 and 8A, the instrument panel 30 includes a panel body 31 and an airbag door 11.
The panel body 31 has an opening 40 that overlaps with the airbag opening 21 of the retainer 14 in the front-rear direction L.

The airbag door 11 is provided at the opening 40 and is configured to open and close the airbag opening 21 and the opening 40 .
The opening 40 has a rectangular shape and includes an upper edge 41 and a lower edge 42 that extend in the vehicle width direction W and are spaced apart from each other in the up-down direction Z, and a pair of side edges 43 that extend in the up-down direction Z.

The airbag door 11 includes a pair of door portions 45 adjacent to each other in the vehicle width direction W.
The door section 45 is configured to be deformable between an unfolded state (see FIG. 8(a)) in which the door section 45 is unfolded to close the opening 40, and a folded state (see FIG. 8(c)) in which the door section 45 is folded to open the opening 40.

The door portion 45 includes a first door portion 46 and a second door portion 47. The first door portion 46 and the second door portion 47 are both rectangular plate-shaped and adjacent to each other in the vehicle width direction W. The second door portion 47 is adjacent to the side edge portion 43 in the vehicle width direction W.

The upper edge 41 and lower edge 42 are provided with guide portions 44 that guide the deformation of the door portion 45 between the unfolded state and the folded state. The guide portions 44 have grooves 44a that extend in the vehicle width direction W.

As shown in FIGS. 8( a ) to 8 ( c ), the first door section 46 and the second door section 47 are connected via a hinge section 48 .
First shaft portions 46a that protrude in the up-down direction Z are provided on the upper and lower edge portions of the first door portion 46. The first shaft portions 46a are provided on the ends of the upper and lower edge portions of the first door portion 46 that are opposite the ends where the hinge portion 48 is located in the vehicle width direction W.

The first shaft portion 46a is configured to be movable in the vehicle width direction W by being loosely fitted in the groove 44a.
Second shaft portions 47a that protrude in the up-down direction Z are provided on the upper and lower edge portions of the second door portion 47. The second shaft portions 47a are provided on the ends of the upper and lower edge portions of the second door portion 47 that are opposite the ends where the hinge portion 48 is located in the vehicle width direction W. The second shaft portions 47a are attached to the grooves 44a so as to be rotatable about the axis of the second shaft portions 47a but not movable in the vehicle width direction W.

The retainer 14 of this embodiment does not have the pair of door portions 17 and the lower door portion 19 .
The operation of the second embodiment will be described.

As shown in FIG. 8(b), the airbag 13 presses the pair of door sections 45 rearward. This causes the hinge section 48 to move rearward, causing the first door section 46 to rotate around the axis of the first shaft section 46a, and the second door section 47 to rotate around the axis of the second shaft section 47a. The first shaft sections 46a of the pair of first door sections 46 then move along the groove 44a away from each other in the vehicle width direction W, causing the first door section 46 and the second door section 47 to fold. At this time, the second shaft section 47a does not move in the vehicle width direction W, so as shown in FIG. 8(c), the door sections 45 fold and open the opening 40. The airbag 13 then deploys and inflates rearward and upward after passing through the opening 40.

The effects of the second embodiment will be described.
(2-1) The door section 45 is configured to be deformable between an unfolded state in which the door section 45 is unfolded to close the opening 40, and a folded state in which the door section 45 is folded to open the opening 40.

Additionally, grooves 44a are provided at the upper edge 41 and the lower edge 42 of the opening 40 as guide portions 44 that guide the deformation of the door portion 45 between the unfolded state and the folded state.
According to this configuration, the above-mentioned effect is achieved, and the pair of door portions 45 are in a folded state, so that the rearward protrusion length of the door portions 45 when the airbag 13 is deployed and inflated can be shortened.

Third Embodiment
9 to 15, the third embodiment will be described, focusing on the differences from the second embodiment. Note that in the third embodiment, the same reference numerals are used to designate the same or corresponding components as those in the first and second embodiments, and redundant description will be omitted.

As shown in FIGS. 9 and 11, the instrument panel 30 includes a panel body 31 having an opening 40 and an airbag door 11.
10, the rear portion of the upper edge 41 of the opening 40 protrudes downward more than the front portion, and the front portion of the lower edge 42 of the opening 40 protrudes upward more than the rear portion.

As shown in Figures 9 and 11, a pair of guide portions 50 are provided on a pair of side edge portions 43. The guide portions 50 extend in the vertical direction Z. The guide portions 50 are provided with guide grooves 50a extending in the vertical direction Z. The lower portions of the guide portions 50 are provided with communication openings 51 that open forward and communicate with the guide grooves 50a.

As shown in FIG. 9, the airbag door 11 has a rectangular plate shape.
10, the front portion of the upper edge of the airbag door 11 protrudes upward more than the rear portion, and the rear portion of the lower edge of the airbag door 11 protrudes downward more than the front portion.

As shown in Figures 9 and 11, a pair of protrusions 52 that protrude in the vehicle width direction W are provided on the upper portion of each end of the airbag door 11. The protrusions 52 are, for example, cylindrical. The pair of protrusions 52 are loosely fitted into the pair of guide grooves 50a, respectively.

A pair of engagement protrusions 54 protruding in the vehicle width direction W are provided at the bottom of both ends of the airbag door 11. The engagement protrusions 54 are, for example, cylindrical. The pair of engagement protrusions 54 are loosely fitted into the pair of guide grooves 50a.

The pair of engaging protrusions 54 function as engaging portions 53 that engage with the opening 40 when the airbag door 11 is in a closed state, thereby maintaining the closed state. The engaging portions 53 are configured to be released from engagement with the panel main body 31 when pressed by the airbag 13.

As shown in Figures 12 and 13, the length L1 of the engaging protrusion 54 is shorter than the length L2 of the protrusion 52 (L1 < L2). The diameter R1 of the engaging protrusion 54 is smaller than the diameter R2 of the protrusion 52 (R1 < R2). In addition, the tip of the engaging protrusion 54 is chamfered.

Next, a procedure for attaching the air bag door 11 to the pair of guide portions 50 will be described.
First, as shown in FIG. 14A, the upper end of the airbag door 11 is inserted into the opening 40 from behind, so that the protrusion 52 is positioned in front of the communication opening 51.

Next, the protruding portion 52 is moved rearward to be inserted into the guide groove 50a through the communication opening 51.
Next, as shown in FIG. 14(b), the protrusion 52 is moved upward along the guide groove 50a.

Next, as shown by the arrow in Figure 14(b), the lower portion of the airbag door 11 is rotated forward around the axis of the protrusion 52. At this time, the engaging protrusion 54 is pressed against the edge of the opening 40 and the guide portion 50, causing the engaging protrusion 54, or the panel body 31 and the guide portion 50, to bend and deform. As a result, the engaging protrusion 54 is loosely fitted into the pair of guide grooves 50a. In this way, the airbag door 11 is attached to the opening 40.

The operation of the third embodiment will be described.
15 , when the airbag door 11 is pressed rearward by the airbag 13, the engaging projection 54, which is shorter and thinner than the protrusion 52, disengages rearward from the guide groove 50a. As a result, the airbag door 11 moves downward under its own weight while being guided by the guide groove 50a, thereby opening the airbag opening 21 (open state). Then, the airbag 13 deploys and inflates rearward and upward.

The effects of the third embodiment will be described.
(3-1) The airbag door 11 is configured to transition from a closed state in which it closes the opening 40 to an open state in which the airbag door 11 moves downward along the guide groove 50a due to its own weight, thereby opening the airbag opening 21.

According to this configuration, the rearward protrusion length of the airbag door 11 when the airbag 13 is deployed and inflated can be shortened.
(3-2) The engaging portions 53 are a pair of engaging protrusions 54 provided on the lower portion of each end of the airbag door 11 in the vehicle width direction W. The engaging protrusions 54 protrude in the vehicle width direction W and are loosely fitted into the pair of guide grooves 50a.

According to this configuration, the engaging portion 53 can be easily realized by the pair of engaging protrusions 54 loosely fitted into the pair of guide grooves 50a.
(3-3) The tip of the engaging protrusion 54 is chamfered.

With this configuration, when attaching the airbag door 11 to the opening 40, the tip of the chamfered engaging protrusion 54 comes into contact with the opening 40, making it easier for the engaging protrusion 54 to pass through the opening 40. Therefore, the airbag door 11 can be easily attached to the opening 40.

In addition, when the airbag door 11 is pressed rearward by the airbag 13, the chamfered tip of the engaging protrusion 54 comes into contact with the guide groove 50a, making it easier for the engaging protrusion 54 to disengage rearward from the guide groove 50a. This allows for an easy transition from the closed state to the open state.

<Example of change>
The first to third embodiments can be modified as follows: The first to third embodiments and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

In the third embodiment, the tip portion of the engaging protrusion 54 does not have to be chamfered.
In the third embodiment, the engaging portion 53 is not limited to the engaging protrusion 54. For example, a recess may be provided in the lower edge portion 42 of the opening 40, and a claw portion that fits into the recess may be provided in the lower edge portion of the airbag door 11.

In the second embodiment, the configuration of the airbag door 11 is not limited to the one described above. For example, the second axis portion 47a may be omitted, and the side edge portion 43 of the opening 40 of the panel main body 31 and the edge of the second door portion 47 adjacent to the side edge portion 43 may be integrally formed by a hinge. Alternatively, the hinge portion 48 may be omitted, and a notch extending in the vertical direction Z may be provided on the rear surface of the door portion 45, so that the pair of door portions 45 can be folded starting from the notch. In either case, the above-described effect (2-1) can be achieved.

- In the first to third embodiments, a skin may be provided on the rear surface of the base material of the instrument panel 30. The skin may be made of synthetic leather, for example. In the second embodiment, it is preferable to provide tear lines on the front surface of the skin in the longitudinal direction L at portions that overlap the boundary between the airbag door 11 and the opening 40, the boundary between the pair of door sections 45, and the boundary between the first door section 46 and the second door section 47. In the third embodiment, it is preferable to provide tear lines on the front surface of the skin in the longitudinal direction L at portions that overlap the boundary between the airbag door 11 and the opening 40.

- In the first embodiment, the lower door portion 19 may be omitted, and the pair of door portions 17 may be adjacent to the lower edge portion 24. Alternatively, the pair of door portions 17 may be omitted, and the lower door portion 19 may be adjacent to the upper edge portion 23.

In the first embodiment, the airbag door 11 and the panel body 31 may be formed separately. In this case, the upper tear line 34, side edge tear lines 37, and lowermost tear line 38 are omitted.

DESCRIPTION OF SYMBOLS 10...Airbag device 11...Airbag door 12...Airbag module 13...Airbag 13a...Upper inflation portion 13b...Lower inflation portion 14...Retainer 15...Inflator 16...Hinge portion 17...Door portion 18...Lower hinge portion 19...Lower door portion 20...Cylindrical portion 21...Airbag opening 22...Peripheral edge portion 23...Upper edge portion 24...Lower edge portion 25...Side edge portion 30...Instrument panel 30a...Upper surface portion 30b...Rear surface portion 31...Panel body 33...Tear line 34...Upper tear line 35...Central tear line 36...Lower tear line 37...Side edge tear line 38...Lowermost tear line 40...Opening 41...Upper edge portion 42...Lower edge portion 43...Side edge portion 44...Guide portion 44a...Groove 45...Door portion 46...First door portion 46a...First shaft portion 47...Second door portion 47a...Second shaft portion 48...Hinge portion 50...Guide portion 50a...Guide groove 51...Communication port 52...Protrusion portion 53...Engagement portion 54...Engagement protrusion 60...Reinforcement 70...Windshield B1, B2...Boundary line P...Occupant PH...Head PT...Chest PK...Knee portion

Claims (3)

An airbag device for a vehicle including an airbag door and an airbag module,
When the front and rear in the longitudinal direction of the vehicle are defined as the front and rear,
The airbag door is provided at the rear portion of the instrument panel of the vehicle,
the airbag module includes an airbag that deploys and inflates when gas is supplied thereto, and a retainer having a cylindrical portion that houses the airbag, and is disposed in front of the airbag door;
the cylindrical portion has an airbag opening that opens rearward and through which the airbag passes when deployed and inflated,
The airbag door is configured to move in a vehicle width direction or downward while being pressed by the deployed and inflated airbag, thereby opening the airbag opening ,
The instrument panel includes:
a panel body having an opening that overlaps with the airbag opening in the front-rear direction;
an airbag door provided at the opening and configured to open and close the airbag opening and the opening,
the opening has an upper edge portion and a lower edge portion extending in the vehicle width direction and positioned at an interval from each other in the up-down direction, and a pair of side edge portions extending in the up-down direction,
The airbag door includes a pair of door portions adjacent to each other in the vehicle width direction,
the door portion is configured to be deformable between an unfolded state in which the door portion is unfolded to close the opening and a folded state in which the door portion is folded to open the opening,
The upper edge and the lower edge of the opening are provided with guide portions that guide the deformation of the door portion between the unfolded state and the folded state.
An airbag device for a vehicle. An airbag device for a vehicle including an airbag door and an airbag module,
When the front and rear in the longitudinal direction of the vehicle are defined as the front and rear,
The airbag door is provided at the rear portion of the instrument panel of the vehicle,
the airbag module includes an airbag that deploys and inflates when gas is supplied thereto, and a retainer having a cylindrical portion that houses the airbag, and is disposed in front of the airbag door;
the cylindrical portion has an airbag opening that opens rearward and through which the airbag passes when deployed and inflated,
The airbag door is configured to move in a vehicle width direction or downward while being pressed by the deployed and inflated airbag, thereby opening the airbag opening ,
The instrument panel includes:
a panel body having an opening that overlaps with the airbag opening in the front-rear direction;
an airbag door provided at the opening and configured to open and close the airbag opening and the opening,
the opening has an upper edge portion and a lower edge portion extending in the vehicle width direction and positioned at an interval from each other in the up-down direction, and a pair of side edge portions extending in the up-down direction,
a pair of protrusions protruding in the vehicle width direction are provided on upper portions of both ends of the airbag door in the vehicle width direction,
a pair of guide portions each having a pair of guide grooves extending in the vertical direction and into which the pair of protrusions are loosely fitted, and
the airbag door has an engaging portion that engages with an edge of the opening to maintain the closed state when the airbag door closes the opening,
The engaging portion is configured to be released from engagement with the panel main body when pressed by the airbag.
An airbag device for a vehicle. a pair of engaging protrusions that protrude in the vehicle width direction and are loosely fitted into the pair of guide grooves are provided at lower portions of both ends of the airbag door in the vehicle width direction,
The engaging portions are the pair of engaging protrusions.
3. The airbag device for a vehicle according to claim 2 .