JPH1148895A - Air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce manufacture costs of an air bag device by mounting a cover body on a base plate easily and firmly. SOLUTION: An air bag device is constituted by mounting a cover body 12, an air bag 15 and an inflator 16 to a base plate 11. The base plate 11 is integrally formed by die-cast forming. A cover body mounting part 22 is formed at the outer periphery of a base part 21 of the base plate 11. On the cover body mounting part 22, an inner piece part 26 and an outer piece part 27 are formed for holding a mounting wall part 52 of the air bag 15 between them. The inner piece part 26 and the outer piece part 27 are connected together by a connecting piece part 28. A lock part 29 is protruded from the inner piece part 26. On the mounting wall part 52, a connection part insertion groove 55 to which the connecting piece part 28 is inserted and a lock receiving part 56 to be engaged with the lock part 29 are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device in which an inflating and deploying airbag is covered with a cover.

[0002]

2. Description of the Related Art Conventionally, for example, an airbag device provided in a boss portion of a steering wheel or the like to protect a driver of an automobile from a collision impact or the like is known. The airbag device includes an inflator that injects gas, a bag-shaped airbag folded and stored, a cover body that covers the airbag, and the inflator, the airbag, and the cover body. And a base plate. Then, when detecting the collision of the vehicle, that is, when detecting the sudden deceleration of the vehicle or more, the airbag device rapidly injects gas from the inflator to inflate and deploy the airbag,
Due to the pressure of the bulging, the cover body is broken at a predetermined tear line and is deployed in a door shape, and the airbag is projected from the cover body and then inflated and deployed in front of the occupant.

[0003] The cover body is provided with a covering portion for covering the folded airbag, and a mounting wall portion projecting downward from the covering portion. Also, the base plate,
A substrate section to which an inflator or airbag is attached,
And a support piece projecting downward or upward from the substrate. Then, with the mounting wall portion fitted to the outer peripheral portion of the support piece portion, the mounting wall portion, the support piece portion, and the like are fixed with a plurality of rivets, and the cover body is fixed to the base plate. However, the configuration in which the airbag is attached to the base plate using a plurality of rivets has a problem that the number of components is large and the manufacturing process is complicated.

In this respect, for example, Japanese Patent Application Laid-Open No. 8-230593
As described in the publication, the tip of the support piece portion of the base plate is bent along the longitudinal direction, that is, a direction perpendicular to the direction of inflation of the airbag is bent along a folding line to form a mounting wall portion of the airbag. A configuration is known in which the engaging portion is engaged with the groove portion, and if necessary, the engaging portion is reinforced with a bracket. However, when the airbag is inflated and deployed, stress toward the outer peripheral side is applied to each of the support pieces and the bracket of the base plate, and acts to deform the bent portion in the return direction, and
Since stress is concentrated on the groove portion of the cover body, in order to hold the airbag firmly, it is necessary to increase the plate thickness of the base plate and the bracket or to increase the tear strength of the cover body. Therefore, there is a problem that it is difficult to reduce the manufacturing cost and the range of selection of the material of the cover body is narrowed.

[0005]

As described above, the supporting piece of the base plate is bent along the direction perpendicular to the direction in which the airbag inflates, and is engaged with the groove formed in the mounting wall of the airbag. In the configuration in which the engagement portion is reinforced with the bracket, when the airbag is inflated and deployed, stress toward the outer peripheral side is applied to the support piece portion and the bracket of the base plate, and the bent portion is returned in the return direction. It acts to deform and concentrates stress on the groove of the cover, so to firmly hold the airbag, increase the thickness of the base plate and bracket or tear the cover. It is necessary to increase the strength, and it is difficult to reduce the manufacturing cost, and there is a problem that the range of material selection of the cover body is narrowed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an airbag device capable of holding a cover body firmly and reducing manufacturing costs.

[0007]

According to a first aspect of the present invention, there is provided an airbag apparatus comprising: an inflating and deploying airbag; a covering portion for covering the airbag; and a mounting wall portion located on an outer peripheral side of the airbag. A cover body, and a support member having a cover body mounting portion that is inserted in a predetermined direction and to which the mounting wall portion is mounted, wherein the cover body mounting portion includes at least one of inner circumferential sides of the mounting wall portion. An inner piece disposed along the portion, an outer piece disposed along at least a part of the outer peripheral side of the mounting wall portion, and at least one of the inner piece and the outer piece toward the other. A protruding locking portion and a connecting piece for connecting the inner piece and the outer piece along the predetermined direction are integrally formed, and the mounting wall is The locking receiving part to be stopped and the connecting piece part are Those having a connecting portion insertion groove to be inserted along.

In this configuration, the mounting wall is fixed to the cover mounting portion by the engagement between the locking portion and the locking receiving portion and the engagement between the connecting piece and the connecting portion insertion groove. The inner piece and the outer piece arranged along at least a part of the mounting wall prevent stress from being concentrated on a part of the mounting wall, and a locking part and a locking receiving part. And the engagement between the connecting piece and the connecting portion insertion groove are firmly held. Therefore, the mounting wall portion is firmly fixed to the cover body mounting portion, and the cover body is firmly mounted to the support member. In addition, since the inner piece, the outer piece, the locking section, and the connecting piece that constitute the cover body attaching section are integrally formed, the number of parts is reduced, and the manufacturing cost is reduced.

According to a second aspect of the present invention, in the airbag apparatus according to the first aspect, the support member is formed by integral die-casting.

[0010] In this configuration, the inner piece, the outer piece, the locking portion, and the connecting piece constituting the cover body attaching portion can be formed firmly and easily integrally, so that the manufacturing cost is reduced. .

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the airbag device of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes an airbag device, which is mounted on a steering wheel of an automobile. The steering wheel includes a steering wheel body, an airbag device 1 attached to the occupant side of the steering wheel body, that is, the front side. The steering wheel is mounted on a steering shaft that is tilted so as to be adjustable as appropriate, and is normally used in a tilted state. Hereinafter, the occupant side on which the airbag device is mounted will be referred to as the upper side or the front side, and Is described as the lower side or the back side. The steering wheel body includes an annular rim, a boss located inside the rim, and a plurality of spokes connecting the rim and the boss, and in this embodiment, four spokes. And so on. At the lower portion of the boss portion, a cylindrical boss fitted to the steering shaft and a boss plate separately or integrally fixed to the boss are provided,
A pair of mounting brackets on both sides are fixed to the boss plate via a horn switch mechanism or the like as necessary, and the airbag device 1 is mounted to these mounting brackets using cap bolts. further,
The lower part of the boss is covered by a lower cover.

The airbag device (airbag module) 1 includes a base plate 11 as a support member, a cover (airbag cover) 12 attached to the base plate 11, an airbag 15, an inflator 16, a retainer 17, and the like. It is composed of

As shown in FIG. 2 and the like, the base plate 11 has a substantially symmetrical shape and a substantially hexagonal flat board portion 21 and a cover body connected to the outer peripheral portion of the board portion 21. The mounting portion (insertion portion) 22 is formed integrally with a die such as die casting by using an aluminum alloy, a magnesium alloy, or the like. That is, the board section 21
In the figure, a circular inflator insertion hole 23 is formed substantially at the center, and a plurality of bolt through holes 24 are formed around the inflator insertion hole 23.

The cover mounting portion 22 includes a polygonal, substantially cylindrical inner piece 26 serving as a first peripheral wall integrally extending downward from substantially the entire periphery of the substrate portion 21. An outer piece 27 serving as a second peripheral wall formed along the inner piece 26 at a predetermined interval on the outer peripheral side of the inner piece 26, and the inner piece 26 and the outer piece 27 A connecting piece 28 to be connected and a locking portion (standing piece) 29 protruding from the inner piece 26 to the outer piece 27 side, that is, the outer peripheral side are integrally formed.

The inner piece 26 extends downward from substantially the entire periphery of the substrate 21 and is integrally formed in a polygonal substantially cylindrical shape. A bracket portion 31 is provided which protrudes to the side, and a square nut to which a cap bolt is screwed is fixed by caulking or the like inside a bolt through hole (mounting through hole) 32 formed in the bracket portion 31. .

The outer piece portion 27 has openings 33 formed at predetermined intervals in the circumferential direction, and is formed in a state of being separated from each other in a flat plate shape or a curved plate shape.
Each is formed so as to face the locking portion 29 or the bracket portion 31 or the like.

The connecting piece 28 extends substantially in the radial direction, connects the inner piece 26 and the outer piece 27, and is formed in a plate shape having a longitudinal direction in a predetermined direction, that is, a vertical direction. ing. Each connecting piece 28 is connected to the center or one end of each outer piece 27, and the connecting piece 28 and the outer piece 27 form a substantially T-shaped cross section or a substantially L-shaped cross section. It constitutes a reinforcing member. The upper ends of the connecting piece 28 and the outer piece 27 are formed so as to protrude above the upper surface of the substrate 21. For example, in FIG.
May be adjusted to the height of the upper surface of the substrate portion 21 or, as shown by a broken line 44b, from the upper end of the outer piece 27, Reinforcing ribs inclined toward the upper surface of the first member. Further, the outer piece may be formed to have a height so as to cover the outer peripheral side surface of the accommodation space of the cover body 12 over substantially the entire height.

Further, the locking portion 29 projects substantially radially from the inner piece 26 and has a substantially horizontal locking surface on the lower surface and an inclined surface on the upper surface.

As shown in FIG. 5, a die-casting mold 35, which is a manufacturing apparatus for forming the base plate 11 by die-casting, comprises only dies 36 and 37 which are divided in the vertical direction. The portion 29 can be formed, and there is no need to provide a divided piece in the left-right direction, except for the portion of the bracket portion 31 where the bolt through-hole 32 is formed. Also, in FIG.
Form the substrate part 21, the cavity 42 forms the inner piece 26, the cavity 43 forms the outer piece 27, the cavity 44 indicated by the broken line forms the connecting piece 28, and the cavity 45 forms the locking part. Form 29. FIG. 5 shows an embodiment in which the connecting piece 28 is adjusted to the height of the upper surface of the substrate 21.

On the other hand, as shown in FIG. 1 and the like, the cover body 12 is integrally formed of a synthetic resin, for example, formed by injection-molding an olefin-based thermoplastic elastomer using a mold, and includes four It has an outer shape as a center pad combined with a steering wheel body having a spoke portion. That is, the cover body 12 includes a covering portion 51 that covers a part of the surface side of the boss portion and the spoke portion of the steering wheel body, and a mounting wall portion that protrudes vertically downward from the lower surface of the covering portion 51 ( The side wall portion 52 is integrally formed, and a portion surrounded between the covering portion 51 and the inside of the mounting wall portion 52 is an airbag storage portion (container portion) for storing the airbag 15. At the same time, a fragile tear line having a substantially H-shaped plane is formed on the lower surface of the covering portion 51 so as to be concave and thin so as to face the airbag storage portion.

The mounting wall portion 52 of the cover body 12 has a polygonal cylindrical shape, and the inner surface thereof has a shape corresponding to the substrate portion of the base plate 11.
In other words, the outer shape of the outer piece 27 substantially matches the outer shape of the inner piece 26, and the outer shape of the inner piece 26 substantially matches the inner shape of the outer piece 27. Are adapted.

Further, the mounting wall 52 of the cover 12 is aligned with the bracket 31 of the base plate 11,
A notch 54 for the bracket is formed, and a groove-shaped connecting portion insertion groove 55 is formed which is aligned with the connecting piece 28 and is opened at the lower end. A lock receiving portion 56, which is a rectangular through hole penetrating in the direction, is formed.

The airbag 15 is formed, for example, in a flat bag shape by sewing two base cloths together, and has a circular bottom gas inlet 15a through which an inflator 16 is inserted.
Are formed, and a plurality of bolt holes (mounting holes) 15b are formed around the gas inlet 15a.

Further, the inflator 16 includes a substantially cylindrical main body 16a, and a mounting flange 16b protrudes from an outer peripheral portion of the main body 16a. A plurality of gas injection ports 16c for injecting gas into the main body 16a are formed above the mounting flange 16b, and a plurality of bolt holes (mounting holes) are formed in the mounting flange 16b. 16
d is formed. Also, from the lower surface of the main body 16a,
A lead wire (not shown) is led out, and an inflator cover made of synthetic resin or the like is fitted and attached as needed.

The retainer 17 has a substantially annular retainer body 17a. And this retainer body 17
a has a substantially U-shaped cross section having upper and lower flange portions on the inner and outer peripheral sides, and four stud bolts 17b are fixed to the retainer body 17a downward. . A nut (fixed nut) 59 is screwed into each of the stud bolts 17b from the lower end side.

Next, the steps of assembling the airbag device 1 of the present embodiment will be described.

First, the base plate 11 and the cover body
12 and the like are formed in a predetermined shape using a mold in advance.

Then, the retainer 17 is inserted into the airbag 15 from the gas inlet 15a by deforming the gas inlet 15a of the airbag 15 into an oblong shape, and the stud bolts 17b are used for bolts. The stud bolt 17b is pulled out from the through hole 15b, and further, these stud bolts 17b are inserted into the bolt through holes 24 of the base plate 11 from above, and the peripheral edge of the gas inlet 15a is pressed onto the substrate 21 of the base plate 11. Subsequently, the airbag 15 is folded into a petal shape or the like by an airbag folding machine so that the airbag 15 fits within the outer shape of the substrate portion 21 of the base plate 11.

Then, from this state, for example, by an automatic assembling machine driven by air pressure or the like, the airbag is used.
15 from the upper side to the lower side of the base plate 11 where the cover 15 is folded, the cover body 12 is covered by automatic supply or the like and press-fitted, and the airbag 15 is stored between the base plate 11 and the cover body 12, and The mounting wall portion 52 is inserted into the mounting portion 22 and fitted. In this state, as shown in FIG. 3 and the like, the mounting wall 52 of the cover body 12 is sandwiched between the inner piece 26 and the outer piece 27, and the connecting part insertion groove is formed.
The connecting piece 28 is inserted into the notch portion 55 or the bracket notch 54, the locking portion 29 is further engaged with the locking receiving portion 56, and the mounting wall portion 52 is retained and held by the cover body mounting portion 22, The cover body 12 is attached to the base plate 11. In addition, since the portion of the base plate 11 facing the locking portion 29 is the opening portion 33, deformation to the outside of the mounting wall portion 52 is allowed,
The locking portion 29 easily engages with the locking receiving portion 56.

Subsequently, the upper part of the main body 16a of the inflator 16 is pushed into the inflator insertion hole 23 and the gas inlet 15a from below the base plate 11, and
Insert stud bolt 17 of retainer 17 into bolt through hole 16d of b.
b, and by screwing and tightening nuts 59 under these stud bolts 17b, respectively.
The base plate 11 and the airbag 15 are fastened together between the retainer body 17a and the mounting flange 16b, and the assembly of the airbag device 1 is completed.

The airbag device 1 assembled as described above is mounted on the boss of the steering wheel body, and a cap bolt is inserted from outside the pair of mounting brackets on both sides standing upright on the boss. The base plate 11 is fixed by being screwed into a square nut through a bolt through hole 32 of a bracket portion 31 of the base plate 11.

When an impact such as a collision is applied to the automobile, a control unit (not shown) activates the inflator 16 and rapidly supplies an inert gas such as nitrogen gas to the inside of the airbag 15 from the gas injection port 16c. Then, the gas inflates and deploys the airbag 15 rapidly, and the pressure of the inflation causes the covering portion 51 of the cover body 12 to break along the tear line and protrude above the cover body 12. Further, the airbag 15 is inflated and deployed widely in front of the occupant to absorb and reduce the impact applied to the occupant.

According to the present embodiment, when the airbag 15 is inflated, a force is applied to the cover body 12 to expand the mounting wall portion 52 in the circumferential direction. Mounting wall
The cover body 12 can be firmly held on the base plate 11 by being received by the cover body mounting portion 22 for fixing the 52.

That is, the inner piece 26 of the cover body mounting portion 22
And the outer wall 27 sandwiches the mounting wall 52 and
The engagement between the engagement portion 29 and the engagement receiving portion 56 and the engagement between the coupling piece portion 28 and the coupling portion insertion groove portion 55 can be maintained. The outer piece 27 and the connecting piece 28 serve as a reinforcing member for locking with respect to the locking portion 29 to be engaged, and can maintain the engagement between the locking portion 29 and the lock receiving portion 56. At this time, the locking portion 29 has a shape swelling out of the inner piece portion 26, that is, a shape in which the entire periphery is in close contact with a planar portion,
Because it does not rely on cutting and bending, it is difficult to deform (retreat) in response to a force that tries to expand in the circumferential direction.
There is a large shape holding force against a load inward (in the direction of arrow B shown in FIG. 4), and the cover body 12 can be held firmly. In addition, the connecting piece 28 is also integrally formed in a plate shape having the longitudinal direction as the longitudinal direction, and is not cut and raised, and does not depend on bending. The cover body 12 can be held firmly.

Further, since the inner piece 26 and the outer piece 27 are arranged along at least a part of the mounting wall 52, the concentration of stress on a part of the mounting wall 52 can be suppressed. The cover body 12 can be held firmly and the cover body
It is not necessary to increase the tear strength of the twelfth embodiment, and the degree of freedom in selecting the material of the cover body that smoothly breaks at the tear line can be increased.

The base plate 11 has a locking portion 29
And a part serving as a reinforcing member are integrally formed to form a cover body.
12 can be press-fitted into the base plate 11 and fixed, so that the number of parts and the number of assembling steps can be reduced more easily than the configuration using a plurality of rivets.
Can be assembled, and the manufacturing cost can be reduced.

Further, since the base plate 11 is integrally formed by die-casting of an aluminum alloy, a magnesium alloy or the like, the inner piece 26, the outer piece 27, the connecting piece 28, the locking piece 28 constituting the cover body mounting portion 22 are formed. 29 can be formed integrally, the number of parts can be reduced, the manufacturing cost can be reduced, and the weight can be reduced.

In the above-described embodiment, the outer piece 27 of the base plate 11 is formed intermittently, and the locking part 29 is protruded from the inner piece 26 to the outer peripheral side. Can be taken.

For example, as shown in FIGS. 6 and 7, the outer piece 27 may be formed continuously, and may be formed in a substantially annular shape except for the bracket 31 and the like.

As shown in FIGS. 6 and 7, the locking portion 29 can also be provided so as to protrude from the outer piece portion 27 toward the inner peripheral side. In this configuration, in order to facilitate engagement of the locking receiving portion 56 with the locking portion 29, the inner piece portion 26 is formed with a recessed portion 61 recessed toward the inner peripheral side. I have. Further, in this configuration, as shown in FIG. 7, an opening 63 into which a die piece is inserted is formed adjacent to the locking portion 29, so that molding can be facilitated. Further, although not shown, the concave portion
As for 61, a cover plate portion that covers the upper end may be formed.

Further, in each of the above embodiments, for example, as shown in FIG. 8, a bottom plate portion 65 for connecting the lower end portions (tip portions) of the inner piece portion 26 and the outer piece portion 27 is formed. The strength of the cover body mounting portion 22 can be further increased.

Further, in each of the above embodiments, for example, as shown in FIG. 9, a guide portion (bent portion) 67 which is inclined upward and outward is formed at the upper end of the outer piece portion 27.
The assemblability of the cover body 12 can be improved. Note that such a guide portion 67 can be provided on the inner piece portion 26 or the like.

The base plate 11 is formed by die-casting using an aluminum alloy, a magnesium alloy or the like.
30% glass fiber in PS (polyphenylene sulfide), unsaturated polyester resin and their resins
It can also be formed by injecting a material containing a certain amount into a mold.

Further, when assembling the base plate 11 and the cover body 12, in addition to the engagement between the locking portion 29 and the locking receiving portion 56, a fixing tool such as a rivet can be used.

The airbag device according to the present invention is mounted on a steering wheel of an automobile, and is provided on an instrument panel in front of a passenger seat, for an occupant in a passenger seat, or on a seat or door. The present invention can be applied to an airbag device, and further to an object requiring protection from impact, such as a moving body other than a vehicle such as an automobile.

[0047]

According to the airbag device of the first aspect, the stress is concentrated on a part of the mounting wall by the inner piece and the outer piece arranged along at least a part of the mounting wall. And the engagement between the locking portion and the locking receiving portion and the engagement between the connecting piece and the connecting portion insertion groove can be firmly held, so that the mounting wall portion is firmly attached to the cover body mounting portion. It can be fixed, and the cover body can be firmly attached to the support member. Further, since the inner piece, the outer piece, the locking section, and the connecting piece that constitute the cover body attaching section can be integrally formed, the number of parts can be reduced, and the manufacturing cost can be reduced.

According to the airbag device of the second aspect,
In addition to the effects of the first aspect, since the inner piece, the outer piece, the locking portion, and the connecting piece that constitute the cover body attaching portion can be firmly and easily formed integrally, the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of an airbag device of the present invention.

FIG. 2 is a perspective view showing a base plate of the airbag device.

FIG. 3 is a partial perspective view showing a state where the cover body and the base plate of the airbag apparatus are combined with each other.

FIG. 4 is a sectional view of the airbag device, taken along the line AA in FIG. 3;

FIG. 5 is a cross-sectional view of a part of an apparatus for manufacturing a base plate of the airbag apparatus.

FIG. 6 is a cross-sectional view taken along the line CC of FIG. 7, showing a state in which a cover body is combined with a base plate of an airbag apparatus according to another embodiment of the present invention.

FIG. 7 is a perspective view of a base plate of the airbag device.

FIG. 8 is a partial cross-sectional view of a state where a cover body is combined with a base plate according to still another embodiment of the present invention.

FIG. 9 is a partial cross-sectional view of a state where a cover body is combined with a base plate according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Airbag device 11 Base plate as a support member 12 Cover body 15 Airbag 22 Cover body attaching part 26 Inner piece 27 Outer piece 28 Connecting piece 29 Locking part 51 Covering part 52 Mounting wall part 55 Connecting part insertion groove 56 Lock receiving part

Claims (2)

[Claims] An airbag that inflates and deploys, a cover that covers the airbag, and a cover body that has a mounting wall located on the outer peripheral side of the airbag; A support member provided with a cover body mounting part to which the part is mounted, wherein the cover body mounting part is an inner piece arranged along at least a part of an inner peripheral side of the mounting wall part; An outer piece disposed along at least a part of an outer peripheral side of the wall; a locking part protruding from at least one of the inner piece and the outer piece toward the other; A connecting piece for connecting the inner piece and the outer piece is integrally formed, wherein the mounting wall includes a locking receiving portion to which the locking portion is locked, and the connecting piece. A connecting portion insertion groove portion inserted along the predetermined direction. Airbag device, characterized in that the. 2. The airbag device according to claim 1, wherein the support member is integrally formed by die casting.