JP5414174B2 - Airbag device for passenger seat - Google Patents

Description

  The present invention relates to an airbag device that is disposed inside an instrument panel (instrument panel) of a vehicle and protects an occupant seated in a passenger seat.

  In the passenger airbag device, the folded airbag is accommodated in a container, and a cover is attached to the upper portion of the container so as to cover the airbag. In the event of a vehicle collision, the inflator is actuated and the airbag is greatly deployed toward the interior, thereby protecting the occupant.

  Regarding the instrument panel, the laws and regulations stipulate that the characteristics of the instrument panel are deformed so that it can absorb the impact (instrument panel impact) when the occupant collides in a collision at a low speed such that the airbag does not deploy ( Instrument panel impact regulation).

  The container of the passenger seat airbag device is required to have a deformable characteristic so as to satisfy the instrument panel impact regulation, but also required to have a strength that does not greatly deform even when the airbag is being pushed from the inside. Therefore, if the container is made fragile simply to satisfy the instrument panel impact regulation, it is not suitable as an airbag device.

  JP-A-8-225049 discloses a box-shaped container (container) having an open front surface, a rear half part to which an inflator is attached, and a front half part that is attached to the rear half part so as to be movable rearward by instrument panel impact. The airbag apparatus comprised by this is shown. When the instrument panel and the lid (cover) are pressed by the instrument panel impact, the front half of the container moves rearward, so that the deformation of the instrument panel is not affected by the container. In other words, it is possible to provide an airbag device for a passenger seat that has a sufficient resistance to deploying an airbag and has a rapid deformation when a large instrument panel impact is applied.

JP-A-8-225049

  However, in the invention disclosed in JP-A-8-225049, the airbag container is divided into a rear half part to which an inflator is attached and a front half part that is attached to the rear part so as to be movable rearward by an instrument panel impact. There is a problem that the structure becomes complicated, such as separate configuration.

  The present invention has been made in view of the above situation, and an object of the present invention is to provide an airbag device for a passenger seat that can sufficiently absorb external force applied to an instrument panel while having a simple configuration.

  To achieve the above object, an airbag device for a passenger seat according to the present invention includes an airbag accommodated in an inflatable and deployable state, and an airbag container that is fixed to the vehicle and accommodates the airbag. And a cover that covers an upper portion of the airbag container, and a gas supply unit that supplies inflation gas for inflating and deploying the airbag. The cover includes a cover surface portion that is substantially flush with the instrument panel, and a cover extension portion that extends substantially vertically from the cover surface portion toward the inside of the airbag container. In the cover extension portion, a plurality of elongated holes are formed. A side surface of the airbag container is provided with a plurality of hooks that extend substantially perpendicularly from the side surface and are slidable through the locking holes.

  Here, “the airbag container is fixed to the vehicle” means not only the case where it is directly fixed but also the case where it is mechanically fixed via another member. The cover can be regarded as a part of the instrument panel at least in the assembled state. The outer end portions of the plurality of hooks formed on the side surface of the airbag container can be key-like or U-shaped bent upward or downward. The locking hole formed in the cover extension can be, for example, rectangular or elliptical. Further, the number of locking holes is not particularly limited.

  Preferably, the length of the locking hole is larger than a reference stroke required as an impact absorbing performance of the instrument panel. The “required reference stroke” is a stroke amount for satisfying safety standards and the like. In other words, the amount of energy (acceleration) to be absorbed by the instrument panel is defined by safety standards, and from the amount of energy to be absorbed to the instrument panel material, strength, shape, and other holding member positions, methods, and shapes. Taking into account all the energy absorption conditions in the surrounding area, reverse calculation is performed to determine the amount of deformation stroke necessary for the instrument panel itself to sufficiently absorb the remaining energy. The value of the obtained deformation stroke amount is set as a “reference stroke amount”. Therefore, this reference stroke amount varies depending on the vehicle type.

The airbag cover can be formed of a resin that can be elastically deformed to some extent. The locking hole is formed with a projecting portion facing inward. When no external force is applied, the position of the hook is restricted by the projecting portion, and when the external force exceeds a certain level, the hook gets over the projecting portion. It is preferable to adopt a configuration that allows sliding. When an external force of a certain level or more is applied and the hook comes into contact with the protrusion, the locking hole elastically spreads outward or the protrusion itself breaks (plastic deformation), so that the hook protrudes. Go over and slide up. In addition, when other shock absorbing means including a protruding portion provided inside the locking hole, or an impact absorbing function is provided in the airbag device or its peripheral portion, the shock absorbing stroke in the locking hole is necessary. It may be shorter than the stroke to be performed, or may be half or less. Moreover, the protrusion part formed in the latching hole can be made into a pair or single.

  Hereinafter, the present invention will be described in detail with reference to examples.

  FIG. 1 is a schematic diagram showing a use state of an airbag apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view illustrating a configuration of a main part of the airbag apparatus according to the embodiment. FIG. 3 is an enlarged perspective view (partially cross-sectional view) illustrating a structure of a main part of the airbag apparatus according to the embodiment. A passenger seat airbag device according to this embodiment is a passenger seat airbag device disposed inside an instrument panel (instrument) 10 of a vehicle, and includes an airbag 20 accommodated in an inflatable and deployable state. An airbag container 12 that is fixed to the vehicle and accommodates the airbag 20, a cover 18 that covers an upper portion of the airbag container 12, and an inflator as a gas supply unit that supplies inflation gas for inflating and deploying the airbag 20 14.

  The cover 18 includes a slightly curved cover surface portion 18a that is substantially flush with the instrument panel 10, and a cover extension portion (leg portion) 18b that extends substantially perpendicularly from the cover surface portion 18a toward the airbag container 12 (inner side). Have. A plurality of elongated hole-like locking holes 22 are formed in the cover extension 18b. On the side surface of the airbag container 12, a plurality of hooks 16 that extend substantially perpendicularly from the side surface and are slidable through the locking holes 22 are provided. The position of the hook 16 can be set in the left-right direction instead of the front-rear direction with respect to the occupant M on the outer surface of the airbag container 12. A constant gap for absorbing shock is formed between the airbag container 12 and the cover 18. The airbag container 12 is fixed to the vehicle via the inflator 14 and / or other members.

  In the present embodiment, the airbag container 12 is formed in a rectangular box shape, but may have other shapes such as a rounded corner. The inflator 14 may be structured to be accommodated inside the airbag container 12. The airbag 20 is molded into a bag shape and accommodated inside the airbag container 12 in a folded state. Although the upper part of the airbag container 12 is open and the airbag 20 is exposed, any weak restricting member that does not hinder the favorable expansion and deployment of the airbag 20 can be arranged.

  As shown in FIG. 3, the length H in the vertical direction (stroke direction) of the locking hole 22 is set to be larger than the reference stroke required for the impact absorbing performance of the instrument panel. For example, when the amount of deformation stroke required for deformation of the instrument panel upon energy absorption is 50 mm, it can be about 60 mm, which is larger than that. The width of the locking hole 22 is slightly larger than the width of the hook 16 and is devised so as not to disturb the relative stroke with the hook 16.

  When assembling the airbag apparatus having the above-described configuration, first, as shown in FIG. 2, the airbag container 12 containing the airbag 20 and the cover 18 separated from the instrument panel 10 are prepared. Next, in order to attach the airbag container 12 to the cover 18, the hook 16 is inserted into the corresponding locking hole 22 while the extension 18 b is pushed and expanded in the width direction. Thereafter, the cover 18 combined with the airbag container 12 is attached to the instrument panel 10.

  4A and 4B are explanatory views showing the operation of the airbag apparatus according to the embodiment, in which FIG. 4A shows a state where an external force is not applied to the instrument panel 10 and FIG. 4B shows an external force applied to the instrument panel 10. Indicates the state. As shown in (A), in a normal state where no external force is applied to the instrument panel 10 (cover 18), the hook 16 of the airbag container 12 is positioned below the locking hole 22 of the cover extension 18b. As shown in (B), when an external force is applied by the occupant M hitting the head of the instrument panel 10 (cover 18) or the like, the cover 18 is pushed down and the hook 16 of the airbag container 12 extends along the locking hole 22. Rise relatively. Thus, the impact force on the occupant M is mitigated by the deformation of the instrument panel 10 (cover 18) itself.

  FIG. 5 is an explanatory view showing another example of the shape of the locking hole, which is a main part of the airbag apparatus according to the present invention. In the example of FIG. 5, the locking hole 122 formed in the cover extension 18 b is formed with a protruding portion 122 c facing inward, and the locking hole 122 is formed on the upper side of the first area 122 a on the lower side by the protruding portion 122 c. And the second area 122b. In a state where no external force is applied to the instrument panel 10, the hooks 16 are restricted by the protrusions 122c so as to be positioned in the first area 122a. As a result, the air bag container 12 can be attached to the vehicle in an improved manner, and there are other advantages such as less play. On the other hand, when an external force of a certain level or more is applied to the instrument panel 10, the hook 16 slides beyond the protrusion 122c and reaches the upper second area 122b. That is, when an external force of a certain level or more is applied and the hook 16 comes into contact with the projecting portion 122c, the locking hole 122 elastically expands outward or the projecting portion 122c breaks, so that the hook 16 projects. Slide over the part 122c. As in this example, by making the locking hole 122 have a two-stage structure, it is possible to absorb a large amount of energy in the initial stage and further reduce the impact force.

  Regarding the locking hole 122, it is preferable that the first area 122a is smaller than the second area 122b. For example, the height of the first area 122a can be made slightly larger than the height of the hook 116. As a result, it is possible to greatly absorb an impact at an early stage in the first area while securing a sufficient stroke length in the second area 122b. The width W0 of the narrowest portion of the locking hole 122 regulated by the protruding portion 122c is smaller than the width W1 of the hook 116, and specifically, it is preferably determined in consideration of the absorbed energy of the cover 18. In addition, the protrusion part 122c can also be set as the structure formed only in one side besides forming a pair of right and left.

  FIG. 6 is a graph showing the action (relationship between load stroke and impact force) of the airbag apparatus according to the present invention. In the figure, (1) is the data of the comparative example in which the shape of the locking hole is substantially square and the stroke length of the hook is shortened, (2) is the data of the embodiment shown in FIG. 3, etc., (3) is the data in FIG. It is the data of the Example shown. As is apparent from the graph, when a square (narrow stroke width) locking hole is employed, a large impact force is applied to the occupant M at a time. In the case of (2), the impact force is considerably reduced by the relative movement (stroke) of the instrument panel 10 and the airbag container 12.

  In the case of (3), due to the action of the gourd-shaped locking hole 122, when the hook 16 gets over the protruding portion 122c, a large energy absorption occurs once, and then the instrument panel within the range of the second area 122b. By the relative movement of 10 and the airbag container 12, the impact force is effectively mitigated.

  FIG. 7 is an explanatory view showing another example of the shape of the hook, which is a main part of the airbag device according to the present invention. The outer end portions of the plurality of hooks formed on the side surface of the airbag container 12 can adopt a shape 116 bent upward as shown in FIG. It is preferable that the shape 216 bends. When the shape shown in (B) is adopted, the instrument panel is released from the locking hole with respect to the instrument panel impact, but there is an advantage that it is caught when the airbag is deployed and the effect of preventing the release is exhibited.

As mentioned above, although the Example of this invention was described, this invention is not limited to these Examples at all, It can change in the category of the technical idea shown by the claim.

FIG. 1 is a schematic diagram showing a use state of an airbag apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view illustrating a configuration of a main part of the airbag apparatus according to the embodiment. FIG. 3 is an enlarged perspective view (partially cross-sectional view) illustrating a structure of a main part of the airbag apparatus according to the embodiment. FIG. 4 is an explanatory view showing the operation of the airbag apparatus according to the embodiment, in which (A) shows a state where no external force is applied to the instrument panel, and (B) shows a state where an external force is applied to the instrument panel. Show. FIG. 5 is an explanatory view showing another example of the shape of the locking hole, which is a main part of the airbag apparatus according to the present invention. FIG. 6 is a graph showing the action (relationship between load stroke and impact force) of the airbag apparatus according to the present invention. FIG. 7 is an explanatory view showing another example of the shape of the hook, which is a main part of the airbag device according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Instrument panel 12 Air bag container 14 Inflator 16, 116, 216 Hook 18 Cover surface part 18b Cover extension part 20 Airbag 22, 122 Locking hole 122a 1st area 122b 2nd area

Claims (3)

In an airbag device for a passenger seat arranged inside an instrument panel of a vehicle,
An airbag accommodated in an inflatable and deployable state;
An airbag container fixed to the vehicle and containing the airbag;
A cover covering an upper portion of the airbag container;
A gas supply unit for supplying an inflation gas for inflating and deploying the airbag,
The cover has a cover surface portion that is substantially flush with the instrument panel, and a cover extension portion that extends substantially vertically from the cover surface portion toward the inside of the airbag container,
The cover extension is formed with a plurality of elongated locking holes,
The side surface of the airbag container is provided with a plurality of hooks that extend substantially perpendicularly from the side surface and are relatively slidable through the locking holes.
In a situation where the airbag is not deployed, when the external force is applied to the cover surface portion and the cover surface portion is deformed downward, the plurality of hooks of the airbag container are attached to the cover extension portion. Ri structures der to absorb the impact by sliding in said locking hole,
The locking hole is formed with an inward protruding portion, and the protruding portion divides the locking hole into a first area and a second area larger than the first area, and an external force is applied to the instrument panel. Is not applied, the protrusion is restricted so that the hook is positioned in the first area, and when a certain external force is applied to the instrument panel, the restriction is released, and the hook is An airbag device, wherein the airbag device is configured to slide beyond the protrusion and reach the second area .   The airbag device according to claim 1, wherein the length of the locking hole is larger than a reference stroke required as an impact absorbing performance of the instrument panel.   The airbag device according to claim 2, wherein the release of the hook position restriction by the protrusion is realized by elastic deformation or plastic deformation of the locking hole including the protrusion.

Images