JP2003335214A - Head protective air bag device of automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head protective air bag device of an automobile formed so as not to unfold a curtain air bag to an indoor side from the head position of an occupant when unfolding the curtain air bag. <P>SOLUTION: This head protective air bag device of the automobile has the air bag 2 for folding up and housing an upper end in a state of being fixed to a car body upper part existing in a position higher than the occupant head, and unfolded in a curtain shape toward the lower side at the overturn of the automobile. The curtain air bag 2 detects a distance D between the occupant head and an indoor side wall immediately before unfolding, and prohibits the inflation-unfolding of the curtain air bag 2 when the distance D is smaller than the width of the unfolded curtain air bag 2 in the car width direction. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device for protecting a head of an automobile.

[0002]

2. Description of the Related Art A side roof rail is arranged at a position higher than an occupant's head in the body of an automobile, and an airbag device is provided along the side roof rail for protecting the occupant's head during overturning. (For a similar technique, refer to Japanese Patent Laid-Open No. 2001-260802).

In this type of airbag device, the upper end portion is fixed to the side roof rail, and the entire airbag device is folded and stored in the vertical direction. The airbag device is located at a position corresponding to an occupant seated on a seat. Is a structure that descends like a curtain while expanding from the upper side to the lower side by the gas ejected from the inflator.

[0004]

However, in such a conventional technique, acceleration is applied in the lateral direction of the vehicle so that the occupant approaches the interior side wall of the vehicle and the occupant is deployed in the airbag deployment area. When the curtain airbag is deployed when there is a small gap between the occupant's head and the side wall of the passenger compartment, such as the door glass or pillar trim, for example, when the curtain airbag is deployed, the deployed curtain airbag is deployed closer to the interior than the occupant's head. There is a risk that the passengers will feel discomfort.

The present invention was made by paying attention to such a conventional technique, and when the curtain airbag is deployed, the head portion of the automobile is arranged so that the curtain airbag is prevented from deploying toward the inside of the passenger's head. A protective airbag device is provided.

[0006]

According to a first aspect of the present invention, the upper end portion is folded and stored while being fixed to the upper portion of the vehicle body at a position higher than the occupant's head.
A head protection airbag device for a vehicle, comprising an airbag that deploys downward in a curtain shape when the vehicle rolls over, wherein the curtain airbag includes an occupant's head and an interior side wall immediately before deployment. Is detected, and when the distance is smaller than the width in the vehicle width direction when the curtain airbag is deployed, the inflation and deployment of the curtain airbag is prohibited.

According to the curtain airbag of the first aspect of the invention, when the distance between the occupant's head and the indoor side wall is smaller than the width of the curtain airbag in the vehicle width direction immediately before the curtain airbag is deployed. In addition, since the expansion and deployment of the curtain airbag is prohibited, it is possible to prevent the occupant from feeling uncomfortable due to the deployment to the indoor side. In other words, since the curtain airbag enters between the occupant's head to be protected and the side wall of the vehicle interior, it is possible to absorb the impact force such as the secondary collision of the occupant.

According to the second aspect of the present invention, the lateral acceleration applied to the automobile is integrated to estimate the movement locus of the occupant's head, and the distance between the occupant's head and the indoor side wall is detected from the movement locus.

According to the second aspect of the present invention, since the movement locus of the head of the occupant is estimated, the distance between the occupant and the indoor side wall can be detected more accurately, and the curtain airbag can be used for the occupant's head and the indoor side wall. It can be surely expanded and deployed between and.

According to the third aspect of the present invention, the roll angle of the automobile is estimated from the roll angular velocity of the automobile, and the distance between the occupant's head and the indoor side wall is detected from the magnitude of the roll angle.

According to the third aspect of the present invention, since the roll angle of the automobile is estimated from the roll angular velocity of the automobile, the distance between the occupant and the side wall of the passenger compartment can be detected more accurately, and the curtain airbag can detect the occupant's head. It is possible to surely inflate and deploy between it and the indoor side wall.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a diagram for explaining the relationship between the roll angle θ and the roll angular velocity ω and the rollability of the automobile 1. The automobile 1 is rolled as shown in FIG. The static rollover limit (SSA) is the state in which the roll is lifted to a point on the vertical line passing through the tire 8 on the outside of the roll (FIG. 1B), and even if the roll angular velocity ω is almost zero, this static When the roll angle θ is made larger than the rollover limit (SSA), the automobile 1 rolls over due to gravity.

FIG. 2 is a two-dimensional map showing the possibility of rollover of the automobile 1. The roll angle θ on the vertical axis has a positive value (above the origin) corresponding to the right roll angle, and the roll angular velocity ω on the horizontal axis. Is
A positive value (right side of the origin) corresponds to the right roll angular velocity. In this two-dimensional map, a threshold line S consisting of a straight line descending to the right is set, and the origin side of the threshold line S, that is, the region where the roll angle θ and the roll angular velocity ω are small is set as the non-overturn region, and the threshold is set. The side opposite to the origin of the value line S, that is, the region where the roll angle θ and the roll angular velocity ω are large is set as the rollover region. When the history lines H1 to H3 of the actual roll angle θ and the roll angular velocity ω of the automobile 1 cross the threshold value line S from the non-overturn region on the origin side to the overturn region on the anti-origin side, there is a possibility of the vehicle 1 overturning. It is determined that there is.

The history line H1 is a case where the roll angle θ and the roll angular velocity ω are both zero (origin), and only the roll angle θ is slowly increased while the roll angular velocity ω is kept substantially zero. When the roll angle θ reaches the critical roll angle θ CRIT at the point where the threshold line S intersects the vertical axis, it is determined that the vehicle 1 may roll over. At this time, the position of the center of gravity Mg of the automobile is on the vertical line passing through the tire 8 on the outer side in the roll direction, which is the fulcrum of rolling, and this state becomes the static stability limit for the rollover of the automobile 1. The value of the critical roll angle θCRIT varies depending on the shape of the automobile and the loading state, but is generally about 50 degrees.

Even if the roll angle θ is zero, the automobile 1 may roll over if a large roll angular velocity ω is applied. The roll angular velocity ω at this time is defined as the critical roll angular velocity SSA.

When the vehicle 1 has a roll angular velocity ω in the same direction as the roll angle θ, rollover tends to be promoted by this roll angular velocity ω, so that the roll angle θ is smaller than the critical roll angle θCRIT. Even so, it would roll over. For example, when the history line of the roll angle θ and the roll angular velocity ω is indicated by H2 or H3, the vehicle 1 may roll over at the point where the history line H2 or H3 crosses the threshold line S from the origin side to the anti-origin side. It is determined that there is. At this time, the roll angle θ is smaller than the critical roll angle θCRIT.

FIG. 3 is a diagram showing the behavioral relationship between the automobile 1 and the head 7a of the occupant 7 over time, and FIG.
3 (b) shows the relationship with the roll angle θ, FIG. 3 (b) shows the relationship with the roll angular velocity ω, and FIG. 3 (c) shows the relationship with the lateral acceleration Y-G applied to the automobile 1. (D) shows the clearance between the head 7 a of the occupant 7 and the indoor side wall of the automobile 1. That is, when the lateral acceleration Y-G is applied to the occupant, the head 7a of the occupant 7 is initially separated from the indoor side wall 9 of the automobile 1 (primary collision), and a secondary collision load is applied, whereby the head of the occupant 7 is added. This means that 7a approaches the indoor side wall 9 of the automobile 1 and leaves again.

FIG. 4 shows a curtain-shaped airbag 2 (hereinafter simply referred to as a curtain airbag) 2 that protects a head 7a of an occupant 7 when the vehicle 1 rolls over.
FIG. 3 shows an example of a control system for expanding along the line. The curtain airbag 2 is folded and housed in the vertical direction with the upper end fixed to the upper part of the side roof rail at a position higher than the head 7a of the occupant 7, and the vehicle 1 rolls over. At times, the gas of the inflator is introduced so as to expand in a curtain shape downward.

An example of the control system will be described. The automobile 1
The electronic control unit 3 determines whether or not there is a possibility of rollover and whether or not the operation of the curtain airbag 2 is appropriate.
Is a lateral acceleration of the vehicle body, that is, a lateral acceleration Y-
A signal from the lateral acceleration sensor 4 that detects G and a roll angular velocity sensor 5 that detects the roll angular velocity ω of the automobile 1.
And the signal from. First, the lateral acceleration sensor 4 fixed to the vehicle body turns on the ignition switch.
Then, the lateral acceleration Y-G is output. When the ignition switch is turned on, the automobile 1 is in a stopped state, and therefore the lateral acceleration Y-G caused by the centrifugal force accompanying the turning of the automobile 1 is not detected, and the gravitational acceleration G =
Only the lateral component of the vehicle body 1 is detected as the lateral acceleration Y-G. Therefore, by using the lateral acceleration Y-G, the initial value θi of the roll angle θ of the automobile 1 is θi = sin.
It can be calculated by ^-1 Y-G.

As described above, when the initial value θi of the roll angle θ of the automobile 1 is calculated based on the output of the lateral acceleration sensor 4 when the ignition switch is turned on, the roll angle θ is set to this initial value θi. The roll angle θ of the automobile 1 is calculated by adding the fluctuation amount of That is,
From the time when the ignition switch is turned on, the integrated value ∫ωdt of the roll angular velocity ω of the automobile 1 output from the roll angular velocity sensor 5 is taken as the variation of the roll angle θ and the initial value θ
The roll angle θ of the automobile 1 is calculated by adding it to i.

The lateral acceleration sensor 4 cannot detect the lateral acceleration Y-G when the vehicle 1 is free falling, and the lateral acceleration Y-G caused by the centrifugal force accompanying the turning of the vehicle 1.
Has a demerit that it cannot be distinguished from the lateral acceleration Y-G which is a component of the gravitational acceleration G in the left-right direction of the vehicle body and is erroneously detected. However, the lateral acceleration Y-G output by the lateral acceleration sensor 4 is detected. Turn on the ignition switch
It is used only for calculating the initial value θi of the roll angle θ of the vehicle 1 at that time, and for the subsequent calculation of the roll angle θ of the vehicle 1, the integrated value of the roll angular velocity ω of the vehicle 1 output by the roll angular velocity sensor 5 is used. By using ∫ωdt, the above demerit can be eliminated and an accurate roll angle θ can be calculated.

The above operation will be described with reference to the flow chart shown in FIG. In step 1, the roll angular velocity ω and the lateral acceleration Y-G of the automobile 1 are read, and in step 2, the threshold line S, S on the map is determined according to the lateral acceleration Y-G. The threshold lines S, S are determined when the critical roll angle θCRIT intersecting the vertical axis of the map and the critical roll angular velocity ωCRIT intersecting the horizontal axis are determined. In this embodiment, when lateral rollover of the vehicle 1 is promoted by the lateral acceleration Y-G, the critical roll angle θCRIT and the critical roll angular velocity ωCRIT.
Both decrease and the threshold value lines S, S move toward the origin, and when the lateral acceleration Y-G suppresses the rollover of the automobile 1, both the critical roll angle θCRIT and the critical roll angular velocity ωCRIT increase. The threshold lines S, S move in a direction away from the origin. Accordingly, it is possible to set an appropriate rollover region and non-rollover region according to the lateral acceleration Y-G of the automobile 1.

Subsequently, it is determined whether the coordinate point formed by the current roll angle θ1 and roll angular velocity ω1 is in the rollover region or the non-rollover region. That is, in step 3, the judgment value ωS is calculated by substituting the current value of the roll angular velocity ω1 for the roll angular velocity ω in the equation of the threshold value line S. Step 4
Then, the judgment value ωS is compared with the current roll angle θ1, and if the roll angular velocity ω is larger than the judgment value ωS, the routine proceeds to step 5, where it is judged that the vehicle is in the rollover region. From the detected lateral position of the head 7a of the occupant 7, a lateral distance (D in FIG. 8) between the head 7a of the occupant 7 and the indoor side wall 9 such as the roof lining or the door window panel is calculated, and this distance D Threshold value D set in advance
Compare with min. The threshold value Dmin is set as a vehicle width direction width (minimum distance) so that the curtain airbag does not interfere with the head 7a of the occupant 7 even when the curtain airbag is deployed.

Thus, in step 6, if the distance D in the left-right direction between the head 7a of the occupant 7 and the indoor side wall 9 such as the roof lining or the door window panel is the threshold value Dmin or more, the process proceeds to step 7. Thus, the curtain airbag 2 can be inflated and deployed so that the head portion 7a of the occupant 7 does not interfere with the indoor side wall 9 when the vehicle 1 rolls over. On the other hand, in step 4, the determination value ωS is compared with the current roll angle θ1, and if the roll angular velocity ω is smaller than the determination value ωS, the process proceeds to step 8 and it is determined that the non-rollover region is present. Supplying gas to the curtain airbag 2 is prohibited, and the curtain airbag 2 is disabled. Further, in step 6, if the distance D in the left-right direction between the occupant's head and the indoor side wall 9 such as the roof lining or the door window panel is less than the threshold value Dmin, when the curtain airbag 2 is deployed, the curtain air It is estimated that the bag 2 is equal to or less than the width (minimum distance) in the vehicle width direction that does not interfere with the head 7a of the occupant 7, and the process proceeds to step 9,
Prohibiting the supply of gas to the curtain airbag 2,
It is made inoperative to prevent the occupant's head from interfering with the curtain airbag 2.

FIG. 6 shows the relationship between the behavior of the vehicle 1 and the head 7a of the occupant 7 and the lateral acceleration Y-G to be integrated. That is, as shown in FIG. 6A, when the lateral acceleration Y-G is equal to or less than a constant value G1 (for example, 0.3 G), neither the automobile 1 nor the head 7a of the occupant 7 moves. Next, FIG.
As shown in (b), the lateral acceleration Y-G has a constant value G1.
In the case of a higher constant value G2 (for example, 1.1 G), the tire 8 does not float in the automobile 1, but the head 7 of the occupant 7
a moves in the direction in which the lateral acceleration Y-G is applied (referred to as secondary collision). Then, as shown in FIG. 6C, when the lateral acceleration Y-G is higher than a constant value G2, the automobile 1
, The head 8a of the occupant 7 is pressed in the direction in which the lateral acceleration Y-G is applied.
The relationship between the lateral acceleration Y-G and the behavior of the head 7a of the occupant 7 is calculated by integrating only the lateral acceleration Y-G in FIG. Was estimated and is shown in FIG. In FIG. 9, the solid line indicates the actual movement trajectory of the head 7a, the thin line indicates the movement trajectory in which the integration range is limited, and the dotted line indicates the movement trajectory in which all are integrated. The distance between the head 7a of the occupant 7 and the indoor side wall 9 is detected from this movement trajectory. Also, in the event that the lateral acceleration Y-G is continuously applied such as steady circular turning, the integrated value accumulates and the error becomes large. Therefore, malfunction is prevented by limiting the integration time (for example, 200 mmsec). You can do it.

FIG. 10 shows another embodiment of the present invention, and is an example in which the roll angular velocity ω of the automobile 1 by the roll angular velocity sensor 5 is used to calculate the movement trajectory of the head 7a of the occupant 7. . According to this embodiment, FIG.
As shown in (b), when a large roll angular velocity ω is generated, the occupant 7 behaves to return to its original position due to inertia, so that the distance D tends to increase, and as shown in FIG. 8 (a). In addition, when a small roll angular velocity ω is generated, the occupant 7 tends to approach the vehicle interior side 9 of the automobile 1 by relying on gravity, and using this tendency, the movement trajectory of the head 7 a of the occupant 7 is estimated. , The head 7 of the occupant 7 from the size of the roll angle
The distance between the passenger a and the indoor side wall 9 is detected. Therefore, the distance between the passenger 7 and the indoor side wall 9 is detected more accurately, and the curtain airbag 2 is reliably positioned between the head 7a of the passenger 7 and the indoor side wall 9. Can be expanded and deployed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a relationship between a roll angle and a roll angular velocity of an automobile.

FIG. 2 is an explanatory view showing a relationship between a roll angle and a roll angular velocity of the automobile in FIG. 1 and a rollability of the automobile.

FIG. 3 is a locus diagram showing the state of the vehicle and occupants until the vehicle rolls over.

FIG. 4 is a system diagram according to an embodiment of the present invention.

FIG. 5 is a flowchart of FIG.

FIG. 6 is an explanatory diagram showing a relationship between a lateral acceleration applied to an automobile and an occupant's head.

7 is an explanatory view showing a range of lateral acceleration to be integrated into the vehicle in FIG.

FIG. 8 is an explanatory diagram showing the relationship between the roll angular velocity of the automobile and the behavior of the occupant's head.

FIG. 9 is a diagram showing a movement trajectory of an occupant's head.

FIG. 10 is a system diagram according to another embodiment of the present invention.

[Explanation of symbols]

1 car 2 Curtain airbag 3 Electronic control unit 4 Lateral acceleration sensor 5 roll angular velocity sensor 7 crew 7a Crew head 8 tires 9 Indoor side wall D Distance between indoor side wall and occupant's head θ roll angle θCRIT Critical roll angle ω Roll angular velocity ωCRIT Critical roll angular velocity ωS judgment value Center of gravity of Mg car SSA car static rollover limit S threshold line Y-G lateral acceleration

Claims (3)

[Claims] 1. An air which is folded and stored while being fixed to an upper part of a vehicle body whose upper end is higher than a passenger's head, and which is expanded downward in a curtain shape when the vehicle rolls over. An airbag device for protecting a head of an automobile equipped with a bag, wherein the curtain airbag detects a distance between an occupant's head and a side wall of a passenger compartment immediately before deployment, and the distance is determined when the curtain airbag is deployed. An airbag device for protecting the head of an automobile, which prohibits the expansion and deployment of the curtain airbag when the width is smaller than the width in the vehicle width direction. 2. The airbag apparatus for protecting a head of a vehicle according to claim 1, wherein the lateral acceleration applied to the vehicle is integrated to infer a movement locus of the occupant's head, and the occupant is estimated from the movement locus. An airbag device for protecting a head of an automobile, which detects a distance between a head and a side wall of a room. 3. The automobile head protection airbag device according to claim 1, wherein the roll angle of the automobile is estimated from the roll angular velocity of the automobile, and the occupant is determined from the size of the roll angle. An airbag device for protecting a head of an automobile, which detects a distance between a head and a side wall of a room.