JPH0660560U - Airbag device - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the manufacturing cost and improve the flexibility of the cover design. [Structure] One end side of a cover 14 for accommodating the bag body 16 is fixed to a right side of a base plate 22 by a bolt 50. On the left side of the base plate 22, a locking plate 52, which is made of metal and has a plate-like shape, is fixed at its base end side with a bolt 50. The front end side of the locking plate 52 is a curved locking portion 54. A protrusion 56 is provided on the other end of the cover 14.
Are formed and are engaged with the locking portion 54. Therefore, when the bag body 16 expands, the cover 14 is spread by the pressure of the bag body 16, and this pressure is applied to the projecting portion 56 via the other end side of the cover 14 and locked with the other end side of the cover 14. The engagement with the plate 52 is released.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an airbag device that protects an occupant during sudden vehicle deceleration.

[0002]

[Prior art]

 BACKGROUND ART An airbag device is known as a vehicle occupant protection device. 2. Description of the Related Art As a conventional airbag device, there is a device in which a bag body that is inflated by a gas generating substance is attached to a hub side of a steering wheel, and a synthetic resin cover covers the bag body. Further, a groove is provided on the back surface side of the cover to facilitate the deployment of the bag body from the inside of the cover.

Therefore, at the time of sudden deceleration of the vehicle, the bag attached to the hub of the steering wheel expands due to the supply of gas into the bag due to the combustion of the gas generating substance, and the cover breaks along the groove and expands. However, the occupants are protected.

[0004]

[Problems to be solved by the device]

 By the way, injection molding is generally used when manufacturing the cover of the conventional airbag device described above, but the cover is owing to the low processing precision of the mold for injection molding and variations in molding conditions during injection molding. The thickness of the groove was not constant. Therefore, there is a possibility that the pressure at the time of deploying the bag and the timing of deploying the bag may change.

In order to solve such a defect, if the working accuracy of the die is improved or the variation of the molding condition at the time of injection molding is reduced, the manufacturing cost of the airbag device is inevitably increased. It will be.

When the groove portion of the cover becomes thicker, the cover is less likely to break and the pressure at the time of unfolding the bag increases, but this pressure is also applied to the mounting portion of the cover. , It is necessary to increase the mounting strength when mounting the cover on the steering wheel. Therefore, it becomes necessary to reinforce this portion, which increases the manufacturing cost of the air bag device as described above.

Further, the wall thickness of the groove portion becomes smaller than the thickness of the other portion of the cover, and sink marks occur on the surface side corresponding to the groove portion of the cover. Therefore, in order to hide the sink mark, unevenness or a pattern is previously formed at a position corresponding to the groove portion on the surface side of the cover. For this reason, there is a limitation in the design of the cover surface side that can be seen from the passenger side.

In view of the above facts, it is an object of the present invention to provide an airbag device that reduces manufacturing cost and improves the degree of freedom in designing a cover.

[0009]

[Means for Solving the Problems]

 The airbag device according to the present invention includes a metal locking plate whose base end is supported by the vehicle body and whose front end is a deformable bent portion, and an air bag body which covers the air bag body and the locking plate is curved. And a cover which is formed with a protruding portion which engages with the tip side and which deforms the locking plate when the airbag bag is inflated to release the engagement with the locking plate. And

[0010]

[Action]

 The base end side of the metal locking plate is supported by the vehicle body, and the protruding portion of the cover that covers the airbag bag engages with the curved front end side of the locking plate.

At the time of sudden deceleration of the vehicle, the engagement between the cover and the locking plate is released by the deformation of the locking plate due to the inflation of the airbag bag, and the cover is released. The airbag bag is deployed by the gas.

Therefore, it is not necessary to form a groove for breaking on the back surface side of the cover, and as a result, it is not necessary to increase the machining accuracy of the mold more than necessary or to stabilize the molding condition more than necessary. Further, the pressure when the bag is deployed is stabilized, and it is not necessary to increase the mounting strength when the cover is mounted on the vehicle body side such as the steering wheel.

Furthermore, as a result of not forming a groove for breaking on the back surface side of the cover, it is not necessary to form an unevenness or a pattern at a position corresponding to the groove portion on the front surface side of the cover, and the degree of freedom in the design of the cover is improved. It became possible to do.

[0014]

【Example】

 An airbag device according to an embodiment of the present invention is shown in FIGS. 1 to 3, and this embodiment will be described with reference to these drawings.

FIG. 1 (arrow FR indicates the front of the vehicle) shows an airbag device 10. The airbag device 10 includes an inflator 12, a cover 14, and an airbag bag 16 (hereinafter simply referred to as a bag body 16), and is supported by a hub 20 of a steering wheel 18 and constitutes a part of a vehicle body. It is attached to 22.

The inflator 12 has a cylindrical shape that is coaxial with the rotation axis of the steering wheel 18, and one side along the rotation axis of the inflator 12 penetrates the mounting hole 23 of the base plate 22 and projects toward the occupant side. It is fixed to 22 via a mounting flange 24.

The bag body 16 is arranged in a folded state on the occupant side of the base plate 22 and is fixed by a mounting ring 28 fixed by screwing a bolt (not shown) into a screw hole 29 (see FIG. 2) of the base plate 22. The periphery of the opening 26 of the bag body 16 is fixed to the base plate 22. The one side of the inflator 12 is inserted into the bag body 16, and a gas hole 40 of the inflator 12 is opened facing the inside of the bag body 16.

Further, one end side of the cover 14 made of a synthetic resin formed in a bowl shape is fixed to the right side of the base plate 22 in FIG. 1 by screwing with a bolt 50, and the base plate 22 shown in FIG. On the upper and left sides, a base end side of a metal-made plate-like locking plate 52 is fixed by screwing with bolts 50. The tip end side of the locking plate 52 is a locking portion 54 that is curved, for example, in a substantially U shape.

A projecting portion 56 is formed on the other end side of the cover 14 so as to project toward the inside of the cover 14, and the projecting portion 56 projects so as to engage with the locking portion 54 of the locking plate 52. The upper side of the portion 56 has a curved shape corresponding to the locking portion 54. Therefore, as shown in FIG. 1, the other end side of the cover 14 is fixed to the left side of the base plate 22 in the drawing by engaging the protruding portion 56 of the cover 14 with the locking portion 54. Then, a stopper 58 is attached to the base plate 22 so as to be adjacent to the locking portion 54, and the stopper 58 abuts on the lower side of the protruding portion 56 to prevent rattling of the other end side of the cover 14. There is.

As described above, the cover 14 in which both ends of the opening edge are fixed to the base plate 22 stores the bag body 16 between itself and the base plate 22.

Therefore, when the bag body 16 expands, the cover 14 is spread by the pressure of the bag body 16, and this pressure is applied to the projecting portion 56 via the other end side of the cover 14 to project the projecting portion of the cover 14. The engagement between 56 and the locking portion 54 of the locking plate 52 is released, the cover 14 is pushed up by the bag body 16 toward the occupant (upper side in FIG. 1), and the bag body 16 is expanded. It is supposed to be.

In addition, the inflator 12 houses an enhancer 30, a detonator 32, a gas generating substance 34, and an acceleration sensor 36. When the vehicle suddenly decelerates, an ignition pin 38 on the acceleration sensor 36 side collides with the detonator 32 and the detonator 32. Is ignited, the gas generating substance 34 is ignited based on the ignition, and gas is generated, and the gas is supplied into the bag body 16 through the gas holes 40.

Next, the operation of this embodiment will be described. In normal vehicle operation, the bag body 16 is covered by the cover 14 as shown in FIG. 1, but when the vehicle is to be decelerated suddenly to protect the occupant, the acceleration sensor 36 measures the acceleration acting during the sudden deceleration. Is detected and gas is generated from the gas generating substance 34 as described above, and the gas is supplied into the bag body 16 through the gas holes 40.

As a result, from the state shown in FIG. 3A, which is an enlarged view of the main part of FIG. 1 and FIG. 1, the bag body 16 expands and the inner wall surface of the cover 14 is spread left and right by the bag body 16. To be Therefore, the one end side of the cover 14 firmly fixed by the bolt 50 is not deformed, but the other end side of the cover 14 is slightly moved to the left side as shown in FIG. 3B. Along with this, the amount of bending of the locking portion 54 decreases, and the amount of engagement of the protruding portion 56 with the locking portion 54 decreases, so that the other end side of the cover 14 easily separates from the base plate 22.

Further, in this state, when the bag body 16 expands and a force for pushing up the inner wall surface of the cover 14 is applied to the locking portion 54, the other end side of the cover 14 moves to the left side and the locking portion 54. Since the contact position of the protruding portion 56 with respect to the left side is moved to the left, the bending moment applied to the locking portion 54 becomes larger than that when the hanging margin of the protruding portion 56 is large. Therefore, as shown in FIG. 3C, the locking portion 54 is plastically deformed, the engagement between the protruding portion 56 of the cover 14 and the locking portion 54 is released, and the other end side of the cover 14 is released. It rises due to the deployment pressure of the bag body 16.

After that, since the cover 14 is fixed to the base plate 22 only at one end side, the cover 14 rotates around the one end side, and the bag body 16 expands from the steering wheel 18 side. It will protect the occupants.

As described above, it is not necessary to form the groove on the back surface side of the cover 14, and as a result, it is possible to improve the processing accuracy of the mold for molding the cover more than necessary and to stabilize the molding conditions more than necessary. Got better Further, when the bag body 16 is deployed, instead of breaking the groove on the cover 14, the metal locking plate 52 whose strength is easily calculated is plastically deformed to release the engagement with the protruding portion 56 of the cover 14. Therefore, the pressure when the bag body 16 is deployed is stabilized, and the mounting strength when the cover 14 is mounted on the steering wheel 18 side can be reduced.

Further, as a result of not forming the groove on the back surface side of the cover 14, there is no need to form unevenness or a pattern or the like at the position corresponding to the groove portion on the front surface side of the cover 14, so that the degree of freedom in designing the cover surface can be increased. It has become possible to improve.

On the other hand, according to the structure of this embodiment, when an external force is applied to the cover 14 except when the vehicle is rapidly decelerated, as shown in FIG. Has a large bending force, the bending moment becomes small even when the same force is applied, and the cover 14 does not easily come off the base plate 22.

Although a metal plate such as a steel plate or a copper plate can be considered as a material of the locking plate 52, the locking plate 52 is not limited to this, and any material that can plastically deform under a constant load may be used.

Further, in this embodiment, the cover 14 is integrally formed by injection molding. However, the protruding portion 56 to which a particularly strong force is applied is made of, for example, a metal material, and the protruding portion 56 made of metal is attached to the cover 14. Alternatively, a metal material may be embedded in the cover 14 to improve the strength of the protrusion 56.

As another embodiment, as shown in FIG. 4, a locking plate 62 having a concave locking portion 64 on the tip side is used, and a shape that engages with the concave locking portion 64 is used. Alternatively, the protrusion 66 of the cover 14 may be formed.

Also in this embodiment, when the vehicle is rapidly decelerated, the thinned portion is deformed due to the existence of the locking portion 64, and the engagement of the protrusion 66 with the locking portion 64 is released.

[0034]

[Effect of device]

 The airbag device according to the present invention has an excellent effect that the manufacturing cost can be reduced and the degree of freedom in the cover design can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an airbag device according to an embodiment of the present invention taken along the vehicle front-rear direction.

FIG. 2 is a perspective view of a base plate and a locking plate of an airbag device according to an embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view of an essential part showing a state in which the engagement between the cover and the locking plate of the airbag device according to the embodiment of the present invention is released.

FIG. 4 is an enlarged sectional view of an essential part of an airbag device according to another embodiment of the present invention.

[Explanation of symbols]

 10 Airbag Device 14 Cover 16 Airbag Bag 18 Steering Wheel 22 Base Plate 26 Gas Supply Port 52 Locking Plate 54 Locking Part 56 Projection Part 62 Locking Plate 64 Locking Part 66 Projection Part

Claims (1)

[Scope of utility model registration request] 1. A metal locking plate having a base end side supported by a vehicle body and a distal end side being a deformable bent portion, and an air bag body covering the curved front end side of the locking plate. An airbag device, comprising: a protrusion that engages with the cover; and a cover that deforms the locking plate when the airbag bag is inflated to release the engagement with the locking plate.