JPH0392452A - Air bag device - Google Patents

Abstract

PURPOSE:To prevent scatter in sensitivity by respective sensor members by arranging a plurality of sensor members sensing abrupt deceleration in car speed in such a way as to be symmetrical side to side to a vertical face which is intersected with the rotation center of a steering wheel while being extended to the longitudinal direction of a car. CONSTITUTION:A plurality of sensor members (ball) 44 is arranged in such a way as to be symmetrical side to side to a vertical face which is intersected with the rotation center of a steering wheel 22 while being extended to the longitudinal direction of a car. This therefore causes scatter in acceleration to be elinimated, which is transmitted from the axial center section of a steering wheel 22 to the respective sensor members 44 at the time of abrupt deceleration in car speed, thereby making it possible to make sensitivity by the respective sensor members 44 identical.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an airbag device that is attached to a steering wheel and inflates a bag when a vehicle suddenly decelerates.

[Conventional technology]

Some airbag devices have a structure that is attached to the steering wheel and inflates the bag when the vehicle suddenly decelerates.
4 8 4 5 7>.

This type of airbag device is provided with a base plate that is attached to a steering wheel, a cover is attached to the base plate, and a bag is stored in a folded state between the cover and the base plate.

Furthermore, an inflator is attached to the base plate when inserted into the bag, and the bag is inflated by the inflator. Inflake has
A starting device is attached to the shaft center and is activated by the starting device. The activation device is equipped with a ball that moves with the acceleration when the vehicle suddenly decelerates, and the movement of the ball detects the sudden deceleration of the vehicle and can activate the inflation flake when the vehicle suddenly decelerates. At times, the bag can be inflated by activating an inflation valve.

By the way, in order to be able to accurately sense sudden vehicle deceleration, it is desirable to provide a plurality of balls in the starting device.

However, if a plurality of balls are provided in the starting device, the center of rotation of the steering wheel 10, as shown in FIG.
That is, the distances from the shaft center portion 10A1 to the balls 14 are not equal, and there is a possibility that the sensitivity to sudden deceleration of the vehicle may vary. That is, the center point 12A of each ball 14 is an extension of the center axis of the steering wheel 10.
If it is attached to the steering wheel 10 in a state where it is not aligned with 0A and is biased, for example, the starting device 16 that accommodates each ball 14 will rotate around the axis (aligned with the midpoint 12A of each ball 14). When assembled, as shown in FIG. 6, the distances from the axial center 10A of the steering wheel 10 to each pole 14 are not equal to each other, and the distance between the axial center 10A of the steering wheel 10 and each ball 14 is not equal. There may be variations in the acceleration of the vehicle, which may cause variations in the ability to sense sudden deceleration of the vehicle.

[Problem to be solved by the invention]

The present invention has been made in consideration of the above facts, and an object of the present invention is to provide an airbag device that can prevent variations in the sensitivity of each sensor member even when a plurality of sensor members such as balls for sensing sudden deceleration of a vehicle are provided.

[Means for Solving the Problems] The airbag device according to the present invention is an airbag device that is attached to a steering wheel and inflates the bag when the vehicle suddenly decelerates, and the airbag device includes a plurality of airbag devices that sense when the vehicle suddenly decelerates. The sensor member is characterized in that it is arranged symmetrically with respect to a vertical plane that intersects with the center of rotation of the steering wheel and extends in the longitudinal direction of the vehicle.

[Effect]

In the present invention as described above, the plurality of sensor members are arranged symmetrically with respect to a vertical plane extending in the longitudinal direction of the vehicle and intersecting the center of rotation of the steering wheel.

Therefore, each sensor member can be arranged at a position equidistant from the center of rotation of the steering wheel. Thereby, when the vehicle suddenly decelerates, it is possible to eliminate variations in the acceleration transmitted from the shaft center of the steering wheel to each sensor member, and to equalize the sensitivity of each sensor member.

〔Example〕

1 to 5 show an airbag device 20 according to a first embodiment of the present invention.

In the airbag device 20, as shown in FIG. 5, a base plate 24 is attached to the hub 22A of the steering wheel 22.
are supported substantially parallel. The base plate 24 includes
A bag 26, a cover 28, and an inflator 30 are attached.

The bag 26 is arranged in a folded state on the passenger side of the base plate 24 (upper side in FIG. 5). The opening edge of the bag 26 is attached to the approximate center of the base plate 24 via a ring plate 32. The ring plate 32 is tightened and fixed to the base plate 24 with bolts (not shown), and the bag 26 is attached between the ring plate 32 and the base plate 24.
The edges of the opening side are held in place.

As shown in FIG. 1, the cover 28 is shown in FIG. 5 in a state in which the center portion 28A is offset by a length L relative to the axial center portion 22B, which is an extension of the axial center of the steering wheel 22, when viewed from the axial direction of the steering wheel 22. As shown, the bag 26 is disposed on the passenger side of the base plate 24 (upper side in FIG. 5), and a bag 26 is stored between the base plate 24 and the passenger side. A mandrel (not shown) is embedded around the cover 28 and is fixed to the peripheral edge of the base plate 24 with rivets or the like via the mandrel. This cover 28 has a base plate 24
A thin-walled portion 36 is formed in a portion facing the holder, so that it is easy to break at this portion.

As shown in FIG. 1, the inflator 30 is also in a state where its axial center is offset by a length L with respect to the axial center 22B of the steering wheel 22, that is, at the center 28A of the cover 28.
As shown in FIG. 5, the base plate 24 is coaxially penetrated through substantially the center of the base plate 24 and inserted into the bag 26. As shown in FIG.
B and the lower case 30 welded to the Atsuba case 30B.
The outer circumference is formed by C and is fixed to the surface of the base plate 24 on the side opposite to the passenger (bottom side in FIG. 5) with bolts (not shown) via the flange 30A.

This inflation flake 30 has a gas generating substance 38 sealed therein and a starter 40 built therein. The gas generating material 38 is decomposed by combustion and releases a large amount of gas, which can inflate the bag 26.

The starting device 40 is housed in a cylindrical portion 30D formed in the lower case 30C of the inflator 30.
It is arranged coaxially with 0. This starting device 40 includes
As shown in FIG. 3, a spherical ball 44 is placed inside the case 42.
is provided so as to be movable while housed in the cylinder 46.

As shown in Fig. 4, two balls 44 are provided, and these are configured to move forward of the vehicle (in the eight directions of arrows) with acceleration when the vehicle suddenly decelerates. 47 are supported.

The drive shaft 47 is connected to the pin 48 as shown in FIG.
The ball 44 is rotatably supported via the
When the ball 44 moves in the direction of arrow A, the ball 44 rotates counterclockwise in FIG. 3 due to the movement of the ball 44 at this time. A compression coil spring 52 is engaged with the drive shaft 47 via a retainer 50, and a claw 5
The ignition bottle 56 is engaged via the ignition pin 56.

The compression coil spring 52 biases the drive shaft 47 clockwise in FIG. 3 via the retainer 5G, and the ball 44 moves forward of the vehicle (in the eight directions of arrows) due to vibrations during normal vehicle running via the drive shaft 47. I try not to.

The ignition bottle 56 is disengaged from the pawl 54 when the drive shaft 47 rotates counterclockwise in FIG. 3. The ignition pin 56 is biased toward the rear of the vehicle (in the direction of arrow B) via a compression coil spring 58, and when the engagement with the pawl 54 is released, the biasing force of the compression coil spring 58 forces the ignition pin 56 toward the rear of the vehicle (in the direction of arrow B). direction> and collides with a detonator 60 (also shown in FIG. 5) on the outside of the case 42.The detonator 60 collides with the ignition pin 56, causing the gas generating substance 3 in the inflation flake 30 to explode.
It is designed to burn 8.

Therefore, when the vehicle suddenly decelerates, the starting device 40 senses the sudden deceleration of the vehicle by moving the ball 44 with the acceleration at this time, and can burn the gas generating substance 38 in the inflation flake 30.

This starting device 40 is connected to each ball 44 as shown in FIG.
are assembled so that they are positioned equidistant from the axis 22B of the steering wheel 22, respectively.

To explain in detail, as shown in FIG. 1, a notch 64 is formed on the outer periphery of the flange 30A of the inflator 30, and is engaged with the notch 64 on the surface of the base plate 24 on the side opposite to the passenger (lower side in FIG. 3). A bracket 66 is fixed thereto, and engagement of the bracket 66 with the notch 64 positions the inflation flake 30 at a predetermined position around the central portion 28A of the cover 28.

Furthermore, two bottle-shaped protrusions 68 are formed on the outer periphery of the case 42 of the starting device 40 at equal intervals from the axis of the case 42 . Each ball 4 is placed on an extension line of the axis of these convex portions 68.
4 axes are arranged. Further, an engagement hole 70 that engages with the protrusion 68 is formed in the bulge case 30B of the inflator 30, and the engagement of the protrusion 68 with the engagement hole 70 causes the activation device 40 to move to the axial center of the inflator 30. It is designed to be positioned at a fixed position around the surroundings.

As a result, the starting device 40 is positioned around the axial center of the inflator 30 and the center 28A of the cover 28, and each ball 44 of the starting device 40 is arranged at an equal distance from the axial center 22B of the steering wheel 22. It is designed to be positioned.

Next, the operation of this embodiment will be explained.

When the vehicle suddenly decelerates, the acceleration causes the ball 44 of the starting device 40 to
The sudden deceleration of the vehicle is sensed by the movement of the ball 44 toward the front of the vehicle (in the eight directions of arrows), and the movement of the ball 44 at this time causes the drive shaft 47 to rotate counterclockwise in FIG. With this rotation, the engagement between the pawl 54 and the ignition pin 56 is released, and the ignition pin 56 is moved toward the rear of the vehicle (in the direction of arrow B) by the biasing force of the compression coil spring 58, and the detonator 6 is placed outside the case 42.
0, and this collision causes the gas generating substance 38 in the inflation flake 30 to burn. The gas generating material 38 is decomposed by combustion and releases a large amount of gas, which inflates the bag 26. This expansion pressurizes the cover 28 from the inside, and this pressure breaks the thin wall portion 36 of the cover 28 so that the bag 26 is interposed between the occupant and the steering wheel 22.

Here, each ball 44 of the starting device 40 is positioned at the same distance from the axial center 22B of the steering wheel 22 when assembled, so that the acceleration transmitted from the axial center 22B of the steering wheel 22 There is no variation, and sudden vehicle deceleration can be accurately detected.

That is, during assembly, the flange 3 of the inflator 30
The bracket 66 is engaged with the notch 64 at 0A, and the inflation flake 30 is positioned around the center portion 28A of the cover 28. Further, the protrusion 68 of the case 42 of the activation device 40 is engaged with the engagement hole 70 of the bulge case 30B of the inflator 30, and the activation device 40 is positioned around the axis of the inflake 30. As a result, the starting device 40 is positioned around the axial center of the inflator 30 and the center 28A of the cover 28, and each ball 44 of the starting device 40 is positioned at an equal distance from the axial center 22B of the steering wheel 22. be done.

Therefore, when the vehicle suddenly decelerates, the steering wheel 2
The acceleration transmitted from the second axis 22B to each ball 44 does not vary, and the sensitivity of each ball 44 of the starting device 40 becomes equal.

In the above embodiment, the upper case 30B and the lower case 30C of the inflator 30 are welded together, but the protrusion 68 of the case 42 of the starting device 40 is engaged with the engagement hole 70 of the upper case 30B of the inflator 30. Any structure that allows positioning around the axial center of the inflator 30 may be used, and the lower case 30C may be fixed to the upper case 30B with bolts, rivets, or the like.

Next, a second embodiment of the present invention will be described with reference to FIG.

This embodiment differs from the first embodiment only in the structure and assembly of the inflator, and other structural functions are the same. In addition, in the description of this embodiment, the same members and the like as those of the first embodiment in the drawings will be designated by the reference numerals of the first embodiment, and the explanation will be omitted.

In this embodiment as well, the inflator 130 is composed of an upper case 130B, a lower case 130C welded to the upper case 130B, and a starting device 1140.

The structure and operation of the starting device 140 are the same as those in the first embodiment, so a description thereof will be omitted.

The upper case 130B has a flange 130A formed into a substantially hat shape. At the center of the top of this Atsupa case 130B is a through hole 132 through which a bolt 160 is inserted.
is in great shape. Note that the shape of the flange portion 130A and the notch 164 provided on the outer periphery of the flange portion 130A
The structure and function are the same as those of the flange portion 30A and the notch 64 of the first embodiment, so a description thereof will be omitted.

The lower case 130C is provided with a protrusion 140 in the center, and a cylindrical side wall 14 forming the protrusion 140.
2 and the top wall 144, a housing portion 145 for housing the activation device 40 is provided. A protrusion 146 protrudes from the center of the top wall 144 in the same direction as the aforementioned protrusion 140, and a through hole 148 in which a threaded groove is formed is provided at the center of the protrusion 146. . Further, the diameter of this protrusion 146 is set to a size that allows it to fit into the through hole 132 of the above-mentioned upper case 130B. Furthermore, the inner surface of the top wall 142 has a convex portion 68 provided on the activation device 40.
An engagement hole 170 into which the holder is inserted and engaged is formed. Therefore, the activation device 40 is positioned at a certain position around the axial center of the inflator 30 by engaging the protrusion 68 with the engagement hole 170. In addition, lower case 130
The outer periphery of C is provided with an annular flange 180 that protrudes in the same direction as the above-mentioned protrusion 144.
It is used for welding with C.

The assembly of each member configured as described above will be explained.

Atsuba case 130
It fits into the through hole 132 of B. At that time, lower case 13
A gas generating substance and a detonator are arranged at predetermined positions in the annular space between OC and the upper case 130B. The fitted lower case 130C and upper case 130B are positioned relative to each other, and the bolt 160 is inserted into the through hole 148.
At the same time, the flange 1 of the lower case 130C
The end face of 80 and the hot case 130 that this end face abuts
B side is welded. Next, the activation device 40 operates in the accommodating portion 145 of the protrusion 140 provided in the lower case 130C.
At the same time, the convex portion 68 is inserted into and engaged with the engagement hole 170, and is positioned and fixed to the lower case 130C.

The flake 130 assembled in this manner is assembled to the base plate 24 in the same manner as in the first embodiment.

The operation of this embodiment is similar to that of the first embodiment, so the explanation will be omitted.

In the first and second embodiments described above, the airbag device is rotated together with the steering wheel, but the present invention is not limited to such a case; even if the steering wheel is rotated, the airbag device is not rotated. Of course, it can also be applied to things that are not.

〔Effect of the invention〕

As described above, the airbag device according to the present invention has an excellent effect of preventing variations in the sensitivity of each sensor member even when a plurality of sensor members for sensing sudden vehicle deceleration are provided.

[Brief explanation of drawings]

1 to 5 show an airbag device according to a first embodiment to which the present invention is applied, and FIG. 1 is a front view of the arrangement of the balls of the activation device shown in FIG. 5 as seen from above the steering wheel; Figure 2 is an exploded perspective view of the main parts of Figure 5, and Figure 3 is an exploded perspective view of the main parts of Figure 5.
4 is a sectional view taken along line rV-IV in FIG. 3, FIG. 5 is a schematic sectional view showing the overall structure, and FIG. An example is shown, and the second
FIG. 7 is an exploded perspective view of essential parts corresponding to the figure, and FIG. 7 is a front view of the arrangement of balls of an activation device in a conventional airbag device as seen from above the steering wheel. 20... Airbag device, 22... Steering wheel, 24... Base plate, 26... Bag, 28... Cover 30, 130... Inflator, 40... Starting device, 44... - Ball (sensor member), 64... Notched first positioning means>, 66... Bracket (first positioning means), 68... Convex portion (second positioning means), 70... - Engagement hole (second positioning means). No. 22 22... Steering wheel 28... Cover 30-. - Inflake 40. ．． ．． Starting device 44... ball (sensor member)

Claims (1)

[Claims] (1) An airbag device that is attached to a steering wheel and inflates the bag when the vehicle suddenly decelerates, in which a plurality of sensor members that detect when the vehicle suddenly decelerates intersects with the center of rotation of the steering wheel and extends in the longitudinal direction of the vehicle. An airbag device characterized by being arranged symmetrically with respect to a vertical plane.