JPH11278196A - Air bag system for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the sinkage of a steering wheel due to a frontal collision, and to reduce any effect of deformation in and around the steering on an occupant. SOLUTION: A column air bag 1a is expanded in the frontal direction of a seat 7 when clashed, whereby any displacement of a steering wheel 3 to the lower part due to deformation of a body 8 is suppressed. The column air bag 1a regulates such a sinking phenomenon that the steering wheel 3 and a steering shaft 4 are sunk toward the leg parts of an occupant due to deformation of a car body at the time of a frontal collision of a vehicle being short in its nose portion, and thereby the sinkage of the steering wheel 3 and the steering shaft 4 is suppressed, and thus such a fear of having the driver's legs held between the steering wheel 3 and the steering shaft 4 is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle airbag device.

[0002]

2. Description of the Related Art Conventionally, in addition to protection by an airbag provided on a steering wheel, a knee protector that protects an occupant's knees and the like by an airbag at the time of a frontal collision, and protects an occupant from a lateral impact at a side collision Side airbags have been developed.

[0003]

However, in an automobile having a short nose (or no cab) called a one-box type (or cab over), the steering wheel or the steering shaft is directed toward the occupant due to deformation of the vehicle body at the time of a front collision. May sink excessively.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to suppress deformation near a steering wheel due to a front collision in an automobile having a short nose portion, and to reduce the influence on the occupant due to deformation near the steering wheel. It is an object of the present invention to provide a vehicle airbag device that reduces the amount of airbag.

[0005]

In order to solve the above-mentioned problems and achieve the object, an automobile airbag device according to the present invention has the following arrangement. That is, in a vehicle airbag device that deploys an airbag when a predetermined deployment condition is satisfied, a first airbag that deploys so as to suppress downward displacement of a steering wheel due to vehicle deformation at the time of a collision is provided.

[0006] Preferably, the airbag is provided at a lower portion of a steering column and is deployed in a seat direction at the time of a collision.

Preferably, the airbag is provided at a lower portion of a steering column, and is deployed toward a door or a front panel when a collision occurs.

Preferably, the vehicle further comprises a second airbag which is deployed between the occupant and the steering wheel at the time of a collision, wherein the first airbag is deployed later than the second airbag.

Preferably, the first airbag is deployed at a lower speed than the second airbag.

Preferably, the first airbag is deployed with a larger filling pressure than the second airbag.

[0011] Preferably, the first airbag is evacuated at a higher speed than the second airbag.

Preferably, the first airbag is deployed only at the time of a frontal collision.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing an airbag device for a vehicle according to an embodiment of the present invention.

As shown in FIG. 1, the vehicle airbag device of the present embodiment includes a column airbag unit 1 and a steering airbag unit 2 which are deployed in response to a sudden deceleration generated at the time of a vehicle collision.

The column airbag unit 1 is disposed below the steering column 6 that supports the steering shaft 4 so as to face the front of the seat 7 (near the legs 9 of the occupant). The steering shaft 4 and the steering column 6 are fixed to a body 8 and supported by a panel member 5 that supports an instrument panel. The steering airbag unit 2 is provided at the center of the steering wheel 3.

FIG. 4 is a sectional view taken along the line AA of FIG.

As shown in FIG. 4, the column airbag unit 1 has an airbag 1a and an inflator 25.
The airbag 1a is stored in a folded state in a storage case 24 provided below the steering column 6,
When the vehicle collides, the protective pad 44a covering the surface of the storage case 24 is broken and expanded to expand between the steering column 6 and the front portion of the seat 7 on which the occupant sits.

The inflator 25 has a gas generating agent 26 and a squib 27 for burning the gas generating agent 26. Then, at the time of a vehicle collision, the squib 27 is detonated at a predetermined operation timing in accordance with a control signal output from the controller 30.

FIG. 5 is a sectional view taken along the line BB of FIG.

As shown in FIG. 5, the steering airbag unit 2 has an airbag 2a and an inflator 13. The airbag 2a is stored in a folded state in a storage case 14 provided at a central portion of the steering wheel 3, and is inflated by breaking a protective pad 14a covering a surface of the storage case 14 at the time of a collision of the vehicle. It is configured to deploy between the steering wheel 3 and the occupant seated in the driver's seat.

The inflator 13 includes a pair of gas generating agents 16 and 17 which are divided and housed in a left and right direction by a partition wall 15.
And a pair of squibs 18 and 19 for burning the gas generating agents 16 and 17 individually. Then, at the time of a vehicle collision, one or both of the squibs 18 and 19 are detonated at a predetermined operation timing in accordance with a control signal output from the controller 30.

The control unit 30 includes the G sensor 3
1 to determine whether or not the vehicle is in a collision state based on the average value of the acceleration / deceleration detected by the column airbag 1.
a and / or the steering airbag 2a is deployed at a predetermined timing.

FIG. 2 is a view showing a state in which the column airbag unit and the steering airbag unit shown in FIG. 1 are operated. FIG. 3 is a front view of FIG. 2, with the steering airbag omitted.

As shown in FIG. 2, the steering airbag 2a receives a driver who is blown forward (to the side of the windshield) in the vehicle compartment by inertial force.

As shown in FIGS. 2 and 3, the column airbag 1a is deployed in the front direction of the seat 7 at the time of a collision, so that the column airbag 1a is below the steering wheel 3 due to the deformation of the body 8 at the time of the collision. The displacement to the leg 9) is suppressed.

The column airbag 1a is designed to prevent the steering wheel 3 and the steering shaft 4 from sinking toward the occupant's legs due to deformation of the vehicle body at the time of a front collision of a vehicle having a short (or no) nose portion. The sinking of the steering wheel 3 and the steering shaft 4 is suppressed, and the legs of the occupant are prevented from being pinched by the steering wheel 3 and the steering shaft 4.

Since the column airbag 1a is deployed while the legs 9 of the occupant are opened, the legs 9 can be protected even when the steering column 6 sinks.

Incidentally, in order to suppress the sinking of the steering column 6 by the column airbag 1a, the steering column 6 can be expanded from the lower part of the seat toward the front panel, or expanded toward the door and the center console box. The downward displacement of the wheel 3 can be suppressed.

FIG. 7 is a flowchart for explaining airbag deployment control by the vehicle airbag apparatus of the present embodiment.

As shown in FIG. 7, when the processing is started,
In step S2, the control unit 30 inputs a sensor detection value g from the G sensor 31. In step S4, the control unit 30 determines whether or not the sensor detection value g is equal to or greater than a first threshold value g1. If the sensor detection value g is equal to or greater than the first threshold value g1 in step S4, the process proceeds to step S6, and if not, the process proceeds to step S10.

In step S6, the control unit 30 determines whether the sensor detection value g is equal to or greater than a second threshold value g2. In step S6, the sensor detection value g is set to the second threshold value g2.
If so, the process proceeds to step S8. If not, the process returns to step S2.

Here, the relationship of first threshold value g1> second threshold value g2 is satisfied. This is because the column airbag 1a may be deployed at a deceleration at which the steering column 6 sinks, and the deployment of the steering airbag 2a is sufficient in other states.

In step S8, the control unit 30 initiates one or both of the squibs 18 and 19 of the steering airbag unit 2 at a predetermined operation timing.

In step S10, the control unit 30 determines whether or not the vehicle is in a front collision state. The determination as to whether the vehicle is in the front collision state is made according to whether the sensor detection value g of the G sensor 31 is in the deceleration direction or the acceleration direction. Step S10
If it is a front collision, the process proceeds to step S12, and if it is a rear collision or side collision that is not a front collision, the process proceeds to step S6.

In step S12, the control unit 30 activates one or both of the squibs 18 and 19 of the steering airbag unit 2 at a predetermined operation timing.

In step S14, the control unit 30 sets the delay time T of the deployment of the column airbag 1a with respect to the deployment timing of the steering airbag 2a according to the collision speed V of the vehicle. Here, the collision speed V of the vehicle is calculated from the sensor detection value g of the G sensor 31, and the deployment delay time T of the column airbag 1a is set from a map shown in FIG.

As shown in the map of FIG. 8, as the collision speed V becomes higher, the delay time T is made shorter, so that the deployment of the column airbag 1a after the deployment of the steering airbag 2a is made faster. This is because the sinking of the steering column 6 is faster as the collision speed V is higher, and it is necessary to suppress the sinking immediately.

The reason for setting the delay time in this way is that, in the initial stage of a front collision, the occupant is thrown forward by inertia before the steering column or the like sinks, and the column airbag is deployed before the steering column sinks. This is because the steering column moves upward from a normal position before sinking, and the steering airbag 2a deployed from the steering wheel does not normally hit the occupant.

In step S16, the column airbag 1a is deployed with a delay time T with respect to the steering airbag 2a in accordance with the delay time T set in step S14.

The control unit 30 sets the deployment speed v1 of the column airbag 1a to a speed lower than the deployment speed v2 of the steering airbag 2a in the deployment control of the column airbag 1a and the steering airbag 2a. Deployment speed v1 of column airbag 1a
The reason is that if the deployment speed of the column airbag 1a is too high, the leg of the occupant may be affected. In addition, the leg portion is opened by slowly inflating the column airbag 1a at the initial stage of deployment, and thereafter the column airbag 1a is inflated to a filling pressure sufficient to support the steering column 6.

As shown in FIG. 9, the filling pressure p1 of the air into the column airbag 1a is set to be larger than the filling pressure p2 of the steering airbag 2a.
The reason why the filling pressure p1 of the column airbag 1a is increased is that the column airbag 1a needs a pressure sufficient to suppress the sinking of the steering column 6. At the initial stage of deployment of the column airbag 1a, the charging pressure p
The reason why 1 is made small is to protect the occupant's legs and increase the filling pressure to support the steering column 6 in the late stage of deployment.

Further, as shown in FIG. 10, the air exhaust speed w1 of the column airbag 1a is set to be exhausted at an exhaust speed higher than the exhaust speed w2 of the steering airbag 2a. The deployment speed w2 of the steering airbag 2a is reduced because it is necessary to protect the occupant in preparation for a secondary collision. The reason why the exhaust speed w1 of the column airbag 1a is increased is to make it easier for the occupant to escape from the passenger compartment after the collision.

The column airbag 1a is particularly effective at the time of a frontal collision where the steering column or steering wheel sinks into the occupant's leg. [Other Embodiment] FIG. 6 is a cross-sectional view showing an automobile airbag device according to another embodiment.

As shown in FIG. 6, the difference from the air bag apparatus for a car shown in FIG. 1 is that the column air bag 1a also has the function of the steering air bag 2a. Therefore, no steering airbag is mounted on the steering wheel 3. According to this example, since the column airbag 1a is deployed from the occupant's leg toward the head, the sinking of the steering column 6 can be prevented and the occupant's head can be protected.

Further, if the filling pressure of the column airbag 1a is appropriately increased in order to deploy to the head of the occupant, the steering shaft is bent from the center line l1 to the line l2 to suppress the sinking of the steering wheel 3. it can.

The present invention can be applied to modifications or variations of the above embodiment without departing from the spirit thereof.

[0048]

As described above, according to the first aspect of the present invention, by providing the first airbag which is deployed to suppress the downward displacement of the steering wheel due to the deformation of the vehicle body at the time of a collision, for example, In a car having a short nose portion, the sinking of the steering wheel due to a front collision can be suppressed, and the influence on the occupant due to deformation near the steering can be reduced.

According to the second aspect of the present invention, the airbag is provided at the lower portion of the steering column, and when the airbag is deployed in the seat direction at the time of collision, the leg of the occupant is opened. While protecting the occupant's legs.

According to the third aspect of the present invention, the airbag is provided at the lower part of the steering column, and is deployed toward the door or the front panel at the time of collision, so that the sinking of the steering wheel can be suppressed at the lower part of the seat.

According to the fourth aspect of the present invention, there is further provided a second airbag which is deployed between the occupant and the steering wheel in the event of a collision, wherein the first airbag is deployed later than the second airbag, The second airbag can be normally deployed toward the occupant.

According to the fifth aspect of the present invention, the first airbag is deployed at a lower speed than the second airbag, so that the occupant's legs are protected from the first airbag while the steering wheel sinks. Can be suppressed.

According to the sixth aspect of the present invention, the first airbag is deployed with a larger filling pressure than the second airbag, so that a pressure sufficient to suppress the sinking of the steering wheel can be secured.

According to the seventh aspect of the present invention, the first airbag is evacuated at a higher speed than the second airbag, so that the occupant can quickly escape from the cabin.

According to the eighth aspect of the present invention, the first airbag is deployed only at the time of a front collision, so that the first airbag can be deployed only in a state in which the steering wheel is sunk. Deployment control becomes possible.

[0056]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an automobile airbag device according to an embodiment of the present invention.

FIG. 2 is a view showing a state in which a column airbag unit and a steering airbag unit shown in FIG. 1 are operated.

FIG. 3 is a front view of FIG. 2;

FIG. 4 is a sectional view taken along the line AA of FIG. 1;

FIG. 5 is a sectional view taken along line BB of FIG. 1;

FIG. 6 is a cross-sectional view illustrating an automobile airbag device according to another embodiment.

FIG. 7 is a flowchart illustrating airbag deployment control by the vehicle airbag device of the present embodiment.

FIG. 8 is a diagram showing a relationship between a collision speed and a delay time when the column airbag is deployed.

FIG. 9 is a diagram showing a relationship between a filling pressure of a column airbag and a filling pressure of a steering airbag.

FIG. 10 is a diagram showing the relationship between the exhaust speeds of a column airbag and a steering airbag.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Column airbag unit 2 ... Steering airbag unit 3 ... Steering wheel 4 ... Steering shaft 5 ... Panel member 6 ... Steering column 7 ... Seat 8 ... Body 13, 25 ... Inflator 30 ... Control unit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Sachiko Ishizuka 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd.

Claims (8)

[Claims] An automobile airbag device for deploying an airbag when a predetermined deployment condition is satisfied, wherein a first airbag is provided for deploying so as to suppress a downward displacement of a steering wheel due to a deformation of a vehicle body in a collision. An airbag device for a vehicle, comprising: 2. The vehicle airbag device according to claim 1, wherein the airbag is provided at a lower portion of a steering column and expands in a seat direction at the time of a collision. 3. The vehicle airbag device according to claim 1, wherein the airbag is provided at a lower portion of a steering column, and is deployed toward a door or a front panel when a collision occurs. 4. The vehicle according to claim 1, further comprising a second airbag that is deployed between the occupant and the steering wheel in a collision, wherein the first airbag is deployed later than the second airbag. An automobile airbag device according to claim 3. 5. The vehicle airbag device according to claim 4, wherein the first airbag is deployed at a lower speed than the second airbag. 6. The airbag device for an automobile according to claim 4, wherein the first airbag is deployed with a larger filling pressure than the second airbag. 7. The vehicle airbag device according to claim 4, wherein the first airbag is exhausted at a higher speed than the second airbag. 8. The vehicle airbag device according to claim 1, wherein the first airbag is deployed only at the time of a frontal collision.