JPH085074Y2 - Car airbag structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an airbag structure of an automobile, more specifically, to an improvement of a bag cover for covering an occupant side of the airbag.

[Prior Art] Conventionally, as a vehicle airbag device, an occupant side of the airbag is covered with a cover body (bag cover), and when the airbag is inflated at the time of a vehicle collision, the inflation pressure of the airbag is used. It is generally well known that the above-mentioned bag cover is opened and the airbag is inflated and deployed from the inside of the cover toward the occupant.

In such an airbag device, usually, a groove is provided in the bag cover, and when the airbag is inflated, the bag cover is broken and opened along the groove by the inflation pressure of the airbag. Sho 63-184546
In the publication, a substantially H-shaped groove is formed in the bag cover by a lateral groove extending in the lateral direction and two vertical grooves provided at both ends of the lateral groove, and when the airbag is inflated, the bag cover is It is disclosed that it is divided into upper and lower parts along the lateral groove and is opened vertically along the vertical groove.

By the way, as is well known, when the vehicle collides head-on and the occupant is moved forward, the upper body of the occupant usually moves forward with a large forward movement of the head centered on the waist seated on the seat. A larger moment load is applied to the upper part of the airbag than to the lower part thereof.

[Problems to be Solved by the Invention] However, in the conventional airbag device, the airbag is uniformly deployed in the vertical direction, and the upper portion and the lower portion thereof are set to have the same impact absorbing ability. Therefore, as described above, when the moment loads acting on the upper portion and the lower portion are different, there is a problem that it is difficult to absorb the impact energy sufficiently effectively.

The present invention has been made in view of the above problems, and an automobile capable of absorbing impact energy more effectively by increasing the impact absorption capacity of the upper portion of the airbag as compared with the lower portion. It is an object of the present invention to provide an airbag structure of.

[Means for Solving the Problems] Therefore, according to the present invention, in the airbag apparatus for a vehicle, the airbag cover is provided on the occupant side of the airbag. The bag cover expands vertically when the airbag is inflated. The opening rigidity of the part is lower than that of the lower part.
It is set to be low from the start of the breakage of the bag cover due to the inflation of the airbag to the full opening of the airbag.

[Advantage of Invention] According to this invention, since the opening rigidity of the upper portion of the bag cover is set lower than the opening rigidity of the lower portion,
When the airbag is inflated during a vehicle collision, the upper part of the bag cover is always stable and is opened more easily to the front side of the vehicle than the lower part, so that the upper part of the airbag is always stable and lower. As compared with the side portion, the opening rigidity of the bag cover does not become a resistance, and the bag cover can be smoothly moved to the front side.

As a result, the upper part of the airbag, on which a larger moment load acts than the lower part, absorbs the shock load while being moved to the front side of the vehicle body, so that it is possible to improve the shock absorbing ability, and at the time of a vehicle collision, The impact energy can be absorbed more effectively.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 5, the automobile 1 according to the present embodiment includes a plurality of front sensors 11 arranged near the front bumper 2 at the front end of the vehicle body as a collision detection unit for detecting a collision of the vehicle, and a vehicle interior. The front sensor is equipped with a dash sensor 12 attached to the front dash panel 3.
The 11 and each dash sensor 12 are both electrically connected to a control unit 13 arranged in the instrument panel 4. Each of the front sensor 11 and the dash sensor 12 is composed of, for example, a well-known G sensor, and the sensitivity of each of the front sensors 11, ..., 11 is set to be relatively low, and a collision occurs in the automobile 1. When this happens, it senses this and turns on. On the other hand, the dash sensors 12, ..., 12 are set to have relatively high sensitivity, and turn on when the impact force due to a collision is above a predetermined value. It has become.

On the other hand, as shown in FIG. 4, the steering wheel 5
As will be described in detail later, an airbag module 20 in which the main components of the airbag device, such as an airbag, a gas generator and an ignition device, are unitized as one assembly is attached to the approximate center of the. The airbag module 20 is electrically connected to the control unit 13, and the ignition device is activated by a command signal from the control unit 20.

In the above configuration, when a collision occurs in the automobile 1, at least one of the front sensors 11 is turned on.
When the dash sensor 12 is activated and the dash sensor 12 is activated, the ignition device is activated by the command signal from the control unit 13 to instantly generate gas in the gas generator. As shown by the chain line, the gas causes the airbag 21 to inflate and deploy toward the occupant M side.

 Hereinafter, the airbag module will be described.

As shown in FIG. 2 and FIG. 3, the air bag module 20 is, for example, energized with a gas generator 22 (inflator) that instantaneously generates gas due to the reaction between the gas generating agent and the flame intensifier. An igniter 23 (igniter) that causes heat to be generated and causes a reaction between the gas generating agent and the flame intensifier.
And an airbag 21 that is instantly inflated by being filled with the gas generated in the inflator 22, and the airbag 21, the inflator 22, the igniter 23, and the like,
A main assembly portion of the airbag device is fixed to the base plate 24, and the occupant side thereof is covered with a case 25 (bag cover) to form one assembly unit, which is fixed to the lower surface of the base plate 24. The four mounting bolts 31 are also fastened and fixed to the central hub of the steering wheel 5.

The inflator 22 includes a plurality of bolts (for example, four pairs).
The base plate 24 is fastened and fixed to the base plate 24 by a nut 32a and a nut 32b, and an igniter 23 is disposed in the center of the base plate 24, and a large number of gas holes 22a are formed in the side surface of the igniter 23 for discharging generated gas into the airbag 21. Is provided. In addition, the airbag 21 has a retainer ring at its peripheral portion.
It is sandwiched between 33 and the base plate 24, fixed with a large number of rivets 34, and folded and stored in the bag cover 25. In addition, the above igniter 23
A harness 26 having a connector 27 attached to its tip is connected to the harness 26, and the harness 26 is adapted to be connected to a harness (not shown) on the control unit 13 side through the connector 27. There is.

The bag cover 25 is formed in a box shape having a substantially U-shaped cross section, and is fixed to the base plate 24.
22, after storing the igniter 23 and the airbag 21, etc.,
The lower end of the periphery is the base plate 24 and the upper and lower reinforcing plates 3
It is sandwiched between 5, 35 and the left and right reinforcing plates 36, 36, and is fixed to the base plate 24 by a large number of rivets 37.

Further, as shown in FIG. 1, on the surface side of the bag cover 25, there are lateral grooves 41a extending in the lateral direction and loop-shaped vertical grooves 42a, 43a provided at both left and right ends of the lateral groove 41a. On the other hand, on the back surface of the bag cover 25, as shown by the broken line in FIG. 1, it is located immediately below the lateral groove 41a on the front surface side and the vertical grooves 42a, 43a of the loop shape are formed.
A lateral groove 41b extending right below an outer portion of the lateral groove 41b, and the lateral groove 41b.
The vertical grooves 42a, 43 on the front surface side are respectively provided at both ends of the
Left and right vertical grooves 42b, 43b located directly below the outer portion of a are provided. That is, in the bag cover 25, the lateral groove 41 composed of the front and back grooves 41a and 41b and the front and rear grooves 42a and 42b.
A substantially H-shaped groove portion 40 formed by a left-side vertical groove 42 configured by and a right-side vertical groove 43 configured by front and back grooves 43a and 43b is provided.

The bag cover 25 is embedded with a sheet-like reinforcing agent 25r, which is knitted in a mesh shape with synthetic fibers, along the curved surface thereof (see FIG. 3), and the reinforcing agent 25r is formed in the groove portion 40. It is arranged so as not to interfere with, and acts as a core material that holds the shape of the bag cover 25,
When the bag cover 25 is opened, the cover 25 is prevented from being shattered and scattered.

In addition, the vertical walls 25e, 25f on the left and right sides of the bag cover 25 described above.
The outer shape of the bag cover is set so that the rigidity is increased by forming the upper and lower ends in a substantially concave shape projecting outward (see FIG. 1).
When the bag 25 is opened, the bag cover 25 is easily pushed and spread in the left-right direction to prevent a problem such as partial disengagement from the base plate 24. Further, the cross-sectional shape of the vertical wall of the bag cover is formed so as to widen toward the attachment side to the base plate 24 (see FIG. 3), and the airbag 21 and the inflator 22 are provided.
It is possible to secure a predetermined rigidity after sufficiently securing a storage space for storing the above.

Then, when a collision occurs in the automobile 1 and the airbag device is activated and the airbag 21 is inflated, the inflation pressure of the airbag 21 causes the lateral grooves 41a, 41 on the front and back sides to be inflated.
The thin portion 41c formed between b (see FIG. 3) is broken to divide the bag cover 25 into upper and lower portions, and the thin portion formed between the front and back vertical grooves 42a, 42b and 43a, 43b. Are broken and the bag cover 25 is opened up and down. In the present embodiment, the vertical grooves 42a, 43 on the front surface side
Since a is formed in a loop shape, and this loop portion is opened to the left and right, the bag cover 25 is opened slightly not only in the vertical direction but also in the horizontal direction, and the airbag 21
Can be deployed smoothly.

By the way, in the present embodiment, with respect to the outer shape of the vertical wall 25d of the lower portion 25b of the bag cover 25, the left and right ends thereof are formed in a substantially arcuate shape in which the left and right ends thereof are lowered downward and the central portion thereof is raised slightly upward. Vertical wall 25c of upper part 25a
Are extended in a substantially straight line (see FIG. 1). Therefore,
The vertical wall 25c of the upper portion 25a has a lower rigidity than the vertical wall 25d of the lower portion 25b, and the inflation pressure of the airbag 21 acts on the inner surface portion of the bag cover 25 to deploy the bag cover 25 up and down. When the air bag 21 is inflated, the bag cover
From the start of the rupture of 25 to the full opening of the airbag 21, the upper portion 25a of the bag cover 25 is easier to open than the lower portion 25b.

As described above, according to the present embodiment, the vertical wall 25d of the lower portion 25b of the bag cover 25 is formed into a substantially arcuate shape, while the vertical wall 25c of the upper portion 25a is formed into a substantially linear shape. As a result, the opening rigidity of the upper portion 25a of the bag cover 25 is lower than the opening rigidity of the lower portion 25b from the start of rupture of the bag cover 25 accompanying the inflation of the airbag 21 to the full opening of the airbag 21. Since the setting is made, when the airbag 21 is inflated at the time of a vehicle collision, the upper portion 25a of the bag cover 25 is always stably opened to the front side of the vehicle body more easily than the lower portion 25b. The upper portion of 21 is always stable and can move smoothly to the front side of the vehicle body without the opening rigidity of the bag cover 25 becoming a resistance as compared with the lower portion.

As a result, the airbag 21 on which a larger moment load acts than that of the lower portion absorbs the impact load while being moved to the front side of the vehicle body, so that the impact absorbing capacity of the upper portion can be improved and the vehicle collision can be achieved. At this time, the impact energy can be absorbed more effectively.

In the above embodiment, the rigidity of the vertical wall 25c of the upper portion 25a of the bag cover 25 is made lower than the rigidity of the vertical wall of the lower portion 25b, 25d, so that the opening rigidity of the upper portion 25a of the bag cover 25 is increased. Although it was set to be low, the same effect as that of the above embodiment can be obtained by other methods.

That is, as shown in FIG. 6, by setting the thickness Ta of the upper portion 55a of the bag cover 55 smaller than the thickness Tb of the lower portion 55b, the opening rigidity of the upper portion 55a is reduced. It can be set lower than.

Further, as shown in FIG. 7, the vertical position C ₂ of the lateral groove 60 that divides the bag cover 65 into upper and lower parts is offset below the vertical center line C ₁ of the bag cover 65, so that the bag cover 65 is separated. The opening rigidity of the upper part 65a can be set lower than that of the lower part 65b.

Further, although not specifically shown, the opening rigidity of the upper part can be changed by changing the embedding amount and material of the reinforcing material embedded in the bag cover between the upper part and the lower part of the bag cover. Can be set lower than the lower part.

[Brief description of drawings]

The drawings are all for explaining the embodiments of the present invention. FIG. 1 is a plan view of a bag cover, FIG. 2 is a plan view of the back side of an airbag module, and FIG. 3 is A of FIG. −
FIG. 4 is a cross-sectional view of the direction A, FIG. 4 is a plan view of a steering wheel equipped with an airbag module, FIG. 5 is a side view of a front portion of an automobile, and FIGS. It is a section explanatory view of a bag cover concerning an example. 1 ... Car, 21 ... Airbag, 25, 55, 65 ... Bag cover, 25a, 55a, 65a ... Upper part of the bag cover, 25b, 55b, 6
5b… The lower part of the bag cover.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masafumi Sakaki 3-3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (56) References JP 63-212147 (JP, A) JP 63- 184544 (JP, A) Japanese Patent Sho 57-20177 (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. An airbag device for an automobile, wherein a bag cover that expands vertically when the airbag is inflated is provided on the occupant side of the airbag. The opening rigidity of the upper part of the bag cover is lower than the opening rigidity of the lower part. Compared to, the airbag structure for an automobile is characterized in that it is set to a low value from the start of the breakage of the bag cover due to the inflation of the airbag to the full opening of the airbag.