JP3484950B2 - Vehicle airbag device - Google Patents

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, and more particularly to a vehicle capable of variably controlling the airbag to a low pressure deployment, a medium pressure deployment and a high pressure deployment according to a running state of the vehicle and a restrained state of an occupant. In regard to the airbag device of (1), it relates to a device in which the deployment threshold values of three types of deployment of low, middle and high are appropriately set.

[0002]

2. Description of the Related Art An air bag device mounted on a vehicle detects an air bag accommodated inside a steering pad at a central portion of a steering wheel, an inflator for rapidly deploying the air bag at the time of a collision, and a collision of the vehicle. It is equipped with a plurality of collision detection sensors and a control unit that controls the deployment of the airbag by receiving various detection signals.
When a vehicle collides, the inflator is actuated to rapidly deploy the airbag, and the occupant is caught by the deployed airbag to prevent a secondary collision of the occupant with the steering wheel or the like.

In the conventional air bag device, the inflation pressure of the air bag is set to one, and the air bag is inflated and driven when a plurality of collision detection sensors detect a collision.
However, recently, various types of improved airbag devices have been proposed, which are capable of inflating a low pressure or a high pressure depending on a running state of a vehicle or a restraint state of an occupant to a seat.

On the other hand, Japanese Patent No. 2507796 discloses that
A first exhaust valve that maintains the internal pressure of the airbag when the occupant receives the airbag at a first operation start pressure, and a second exhaust valve that maintains the internal pressure of the airbag while the occupant is restrained by the airbag.
A second exhaust valve that maintains the internal pressure at the start of operation, whether or not a seat belt is worn during a vehicle collision, the weight of an occupant, the vehicle speed, etc.
An improved airbag device is provided which includes drive control means for driving and controlling the first and second exhaust valves. In this airbag device, when the internal pressure of the airbag reaches the first operation start pressure after the airbag is deployed, the first operation start pressure is maintained through the exhaust by the first exhaust valve, and the occupant in this state maintains the air pressure. Even if the internal pressure of the airbag is suddenly increased after being received by the bag, the second operation start pressure is maintained through the exhaust by the second exhaust valve, and the occupant is appropriately protected.

Further, in Japanese Patent Laid-Open No. 7-277123, a heater for heating the gas generated by an inflator to increase the gas pressure is provided, and when a collision occurs while wearing a seat belt, the air is kept at normal pressure. Unfold the bag,
There is described an airbag device in which a deployment pressure is increased through heating by a heater when a collision occurs without wearing a seat belt.

[0006] On the other hand, a general improved airbag device usually has a pair of inflators having the same capacity so that one inflator is activated to deploy at a low pressure and two inflators are activated to deploy at a high pressure. The inflator configured as described above (hereinafter referred to as a composite type inflator) is provided.

[0007]

Problems to be Solved by the Invention Patent No. 2507796
In the airbag device disclosed in the publication, the internal pressure of the airbag can be controlled in two ways, a low pressure state and a high pressure state. Therefore, depending on the collision state, the restraint state of the occupant on the seat, the occupant's weight, etc. The internal pressure cannot be set in three or more stages, and the shock absorption performance cannot be ideally set. Also in the airbag device disclosed in Japanese Patent Laid-Open No. 7-277123, the airbag can be inflated at a low pressure or at a high pressure, so that there is a limit to enhancing the impact absorbing performance in the same manner as described above.

In addition, even in the improved airbag apparatus having the conventional composite type inflator, the airbag can be deployed in two ways, low pressure deployment and high pressure deployment. Has a limit. Further, no technology has been proposed that rationally sets the low pressure and high pressure development thresholds in relation to the shock absorption performance. Since the airbag can only be deployed in two ways, low pressure and high pressure, the deployment pressure for low pressure deployment cannot be set low enough to suit a mild collision without wearing the seat belt, and with the seat belt worn The deployment pressure for high pressure deployment cannot be set high enough to accommodate the severe collision of.

Especially when the seat belt is not worn,
At the time of a collision, the occupant is likely to move forward due to inertial force, and the moving occupant may be impacted by the airbag being deployed. Therefore, the deployment threshold value for high-pressure deployment needs to be set appropriately. An object of the present invention is to allow an airbag to be deployed in three ways: low pressure deployment, medium pressure deployment, and high pressure deployment; to lower the deployment pressure for low pressure deployment and to set the deployment pressure for high pressure deployment high; Set the deployment thresholds for the three types of deployment appropriately according to the restraint state and weight of the occupant,
Etc.

[0010]

According to a first aspect of the present invention, an airbag device for a vehicle is capable of variably controlling a deployed state of the airbag according to a running state of the vehicle and a restrained state of an occupant, and lowers the airbag pressure. deployment, development medium pressure, and deployable configured as 3 of the high pressure expansion, the impact velocity or collision acceleration during a collision
As parameters, low pressure expansion threshold and medium pressure expansion threshold
The value and the high pressure deployment threshold are
It is preset depending on whether or not the seat belt is worn,
Threshold for medium pressure deployment without occupant seatbelts
The value is the low pressure deployment threshold when seat belts are used.
Is set smaller than the
Medium pressure when high pressure deployment threshold is without seat belt
Characterized by being set sufficiently larger than the expansion threshold
It is what Therefore, when the collision degree (collision speed or collision acceleration) at the time of collision occurs is low, the airbag is inflated at a low pressure, when the collision degree is moderate, the airbag is expanded at an intermediate pressure, and when the collision degree is heavy, the airbag is inflated. Can be inflated at a high pressure, and the airbag can be inflated at an inflating pressure suitable for the degree of collision to enhance safety.

Moreover, since the airbag can be deployed in three ways, the deployment pressure for low-pressure deployment can be set low so as to suit a slight collision when the seat belt is not worn, and when the seat belt is worn. The deployment pressure for high pressure deployment can be set high to accommodate severe collisions .

[0012]

[0013]

[0014]

Further, the impact velocity or collision acceleration during collision as a parameter, since the set low pressure expansion thresholds and medium pressure expansion threshold and the high pressure expansion thresholds previously, the 3
The two deployment thresholds are set depending on whether or not the occupant wears a seat belt at the time of a collision, and are set so as to be most advantageous in terms of impact absorption performance.

As shown in FIG. 3 of the embodiment, assuming that the low pressure deployment threshold value α1, the medium pressure deployment threshold value α2, and the high pressure deployment threshold value α3 when the seat belt is not worn, α1 <α
2 <α3. As shown in FIG. 4 of the embodiment, assuming that the low-pressure deployment threshold β1, the medium-pressure deployment threshold β2, and the high-pressure deployment threshold β3 when the seat belt is worn are β1.
<Β2 <β3. Further, at least α1 is sufficiently smaller than β1, α2 is sufficiently smaller than β2, and
3 is set smaller than β3.

[0017]

When the seat belt is not worn, the occupant is likely to move forward due to the inertial force at the time of a collision, so the airbag is deployed to absorb the impact from a stage where the degree of collision (collision speed or collision acceleration) is small. Is desirable. Therefore, the medium pressure deployment threshold value when the seatbelt is not worn by the occupant is set smaller than the low pressure deployment threshold value when the seatbelt is worn.

On the other hand, when the airbag is deployed toward the occupant moving forward due to inertial force at the time of a collision, the impact of the airbag on the occupant is likely to be large. It is desirable to limit the development to medium pressure and not to develop high pressure. However, if the degree of collision is severe, shock absorption may be insufficient in medium pressure deployment, so the high pressure deployment threshold without seat belts should be adjusted to the medium pressure deployment threshold without seat belts. Is set sufficiently larger than As described above, it is possible to enhance the safety of the occupant against a mild to severe collision without wearing the seat belt.

The airbag device for a vehicle according to claim 2 is a vehicle
Deployment of airbags depending on the running condition of the vehicle and restraint of the occupants
In a vehicle airbag device that can variably control the state,
3 deployment of low pressure, medium pressure deployment and high pressure deployment of the airbag
It is configured so that it can be deployed in a cage, and the collision speed or collision
Low pressure deployment threshold and medium pressure deployment with velocity as parameter
The threshold and high pressure deployment threshold are preset and
If the weight is less than the specified value, the threshold value
The body is set smaller than the low pressure deployment threshold above.
High pressure deployment threshold is less than the specified value when the weight is less than the specified value
Is set sufficiently higher than the medium pressure expansion threshold for
It is characterized by that. See paragraph [0015]
In addition to the same effects as those described above, the following effects are exhibited. Immediately
However, since the occupant with a light weight is not robust, the degree of collision is small.
Deploying the airbag from the initial stage to absorb the shock
Is desirable. Therefore, if the weight of the occupant is less than the specified value
Low pressure expansion threshold when the medium pressure expansion threshold is above a specified value
It is set smaller than a certain value.

On the other hand, when the airbag expands toward the occupant moving forward due to inertial force at the time of a collision, the impact of the airbag on the occupant is likely to be large. Therefore, when the weight of the occupant is less than a predetermined value, It is desirable that the airbag be inflated at medium pressure and not inflated at high pressure. However, if the degree of collision is severe, shock absorption may be insufficient in medium pressure deployment, so if the weight of the occupant is less than a predetermined value, the high pressure deployment threshold is set to the medium pressure without seat belts. It is set sufficiently higher than the expansion threshold. As described above, it is possible to improve the safety of the occupant against a mild to severe collision when the weight of the occupant is less than the predetermined value.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is an example in which the present invention is applied to an airbag device installed in a vehicle equipped with a seatbelt. The airbag device 1 has a collision speed, a weight of an occupant, and whether or not a seatbelt is worn. It is an airbag device capable of inflating an airbag at low pressure, at medium pressure, or at high pressure.

As shown in FIGS. 1 and 2, the airbag device 1 mounted on the automobile C includes a steering wheel 10 and a steering wheel 10.
Of the steering pad 11a and the airbag 2 folded and stored in the case 11, the inflator unit 3 provided in the case 11 for rapidly deploying the airbag 2 by generating gas at the time of a collision, and the longitudinal acceleration acting on the vehicle body. A pair of acceleration sensors 4 and 5 for detecting the vehicle speed, a vehicle speed sensor 6 for detecting the vehicle speed V, a weight sensor 7 for detecting the weight W of the occupant in the driver's seat, and a seat belt switch 8 for detecting whether or not the seat belt 25 is worn, The control unit 9 and the like are provided.

As shown in FIG. 2, a steering pad 11a and a case 11 connected to the front side of the steering pad 11a are provided at the center of the steering wheel 10, and the airbag 2 has a base end portion inside the case 11 and a rear end portion thereof. The airbag 2 is fixedly attached to the end portion and stored in a folded state, and at the time of a collision, the airbag 2 ruptures the broken portion of the steering pad 11a and inflates, and is deployed between the steering wheel and the occupant B to protect the occupant B. .

The inflator unit 3 has a pair of inflators 15 and 16 having different capacities, and electric heaters 15a and 16a for igniting the flammable liquid (gas generating agent) of the inflators 15 and 16, and the case 11 It is fixed to the bottom on the back side. When the small capacity inflator 15 operates, the airbag 2 deploys at a low pressure, and when the large capacity inflator 16 operates, the airbag 2 deploys at an intermediate pressure.
When both inflators 15 and 16 are activated, the airbag 2 is inflated at a high pressure. The pair of acceleration sensors 4 and 5 are fixedly attached to, for example, the bumper frame of the vehicle body and the cross member of the cowl portion, and detect the longitudinal acceleration acting on the vehicle body of the automobile C.

The vehicle speed sensor 6 is a sensor for detecting the rotational speed of the output shaft of the transmission of the engine 18, and the vehicle speed V is calculated from the detection signal. The weight sensor 7 is composed of a load cell embedded in the seat cushion of the driver's seat, and detects the weight W of the occupant in the driver's seat. The seatbelt switch 8 is provided inside a buckle member 27 that releasably connects the tongue plate 26 of the seatbelt 25 in the driver's seat. However, the weight sensor 7 may be provided on the four seats and the seat belt switch may be provided on the four seat belts. Detection signals from the acceleration sensors 4, 5, the vehicle speed sensor 6, the weight sensor 7, and the seat belt switch 8 are supplied to the control unit 9, and the control unit 9 causes the inflator unit 3 to operate.
The electric heaters 15a and 16a are driven and controlled.

The control unit 9 includes an input / output interface, a microcomputer, and electric heaters 15a, 1
6a, a drive circuit for 6a, a ROM of a microcomputer, which stores in advance a deployment threshold value, a control program for airbag deployment control, and a map and a table associated therewith, and RAM Various memories are provided for controlling bag deployment.

Here, FIG. 3 shows four characteristics of the shock absorbing performance of the airbag 2 when the seat belt is not worn when a collision occurs. These four characteristic curves include a characteristic curve a when the airbag 2 is not inflated, a characteristic curve b when inflated at a low pressure, a characteristic curve c when inflated at an intermediate pressure, and a characteristic curve d when inflated at a high pressure. Figure 4
4 shows four characteristics of the impact absorption performance of the airbag 2 when a seat belt is worn when a collision occurs. These four
The one characteristic curve includes a characteristic curve e when the airbag 2 is not deployed, a characteristic curve f when the airbag 2 is deployed at a low pressure, a characteristic curve g when the airbag 2 is deployed at an intermediate pressure, and a characteristic curve h when the airbag 2 is deployed at a high pressure. The eight characteristics of impact absorption performance shown in FIGS. 3 and 4 are unique to the present application obtained through various collision experiments.

By the way, in the airbag apparatus 1, the collision speed E of the vehicle is used as a parameter, as shown in FIG. 3, when the seat belt 25 is not worn.
Low pressure deployment threshold α1 for deploying the airbag 2 at low pressure,
Medium pressure deployment threshold value α2 for deploying the airbag 2 at medium pressure,
High pressure deployment threshold value α3 for deploying the airbag 2 at high pressure,
As shown in FIG. 4, when the seat belt 25 is worn, the low pressure deployment threshold β1 for deploying the airbag 2 at a low pressure, the intermediate pressure deployment threshold β2 for deploying the airbag 2 at an intermediate pressure, the airbag 2 are shown. A high-pressure expansion threshold value β3 for high-pressure expansion is set. In addition, in the example of FIG. 3 and FIG.
Expansion thresholds α1, α using the collision velocity E as a parameter
Although 2, α3, β1, β2, and β3 are set, the expansion thresholds of these may be set using the collision acceleration as a parameter.

The scales on the horizontal and vertical axes of FIGS. 3 and 4 are set to be equal, and as can be seen from these figures, α1 <α2 <α3, β1 <β2 <β3, α2 <β.
1 and α3 are set sufficiently larger than α2 and are set to values close to β2.

As can be seen from FIG. 3, in the case where the seat belt is not worn, the low pressure deployment threshold value α1 is substantially the minimum value in the region where it is desirable to deploy the low pressure as compared with the case where the airbag 2 is not deployed. The intermediate pressure expansion threshold value α2 is set to a substantially minimum value in the region where it is desirable to perform the intermediate pressure expansion compared with the case where the low pressure expansion is performed, and the high pressure expansion threshold value α3 is set to the intermediate pressure value. It is set to a substantially minimum value in a region in which it is desirable to deploy high pressure as compared with the case of deploying. The "area" means an area at the collision speed E.

As can be seen from FIG. 4, when the seat belt is worn, the low pressure deployment threshold value β1 is substantially the minimum value in the region where it is desirable to deploy the low pressure as compared with the case where the airbag 2 is not deployed. The intermediate pressure expansion threshold β2 is set to a substantially minimum value in the region where it is desirable to expand the intermediate pressure as compared with the case where the low pressure expansion is performed, and the high pressure expansion threshold β3 is set to the intermediate pressure. It is set to a substantially minimum value in a region in which it is desirable to deploy high pressure as compared with the case of deploying. The "area" means an area at the collision speed E.

If the collision speed E at the time of collision is Ec,
As will be described later, when the seat belt is not worn at the time of collision, the airbag 2 is not deployed when Ec <α1 and α
When 1 ≦ Ec <α2, the airbag 2 is inflated at a low pressure,
When α2 ≦ Ec <α3, the airbag 2 is inflated at a medium pressure, and when α3 ≦ Ec, the airbag 2 is inflated at a high pressure. Ec <β if seat belt is worn at the time of collision
When 1, the airbag 2 is not deployed and β1 ≦ Ec <β
When 2, the airbag 2 is inflated at a low pressure and β2 ≦ Ec <
When β3, the airbag 2 is inflated to a medium pressure, and β3 ≦ Ec
At this time, the airbag 2 is deployed at high pressure.

The microcomputer of the control unit 9 uses the expansion thresholds α1 to α3, β1 to β3, the expansion thresholds, the collision speed Ec, the weight W of the occupant B, and whether or not the seat belt is worn. An airbag deployment control program for controlling deployment of the airbag 2 is stored in advance.

Next, the airbag deployment control will be described with reference to FIG.
This will be described with reference to the flowchart of FIG. However, this control is repeatedly executed at every predetermined minute time (for example, 1 msec), and Si (i = 1, 2, 3, ...
・) Indicates each step. When this control is started at the same time as the traveling of the automobile C is started, an initial setting (not shown) is first executed, and then various signals (collision accelerations A1, A2, weight W, seat belt SW signal SS) are read. It is stored in the register (S1), and when both the collision accelerations A1 and A2 are equal to or higher than the predetermined acceleration C0 (S2: Yes), it is determined that a collision has occurred, and the timer T is reset and then started (S3).

Next, the collision accelerations A1 and A2 for obtaining the collision speed Ec are read (S4), the average value (A1 + A2) / 2 of A1 and A2 is calculated, and the average value is stored in the register as A. (S5). Next, when the measured time T of the timer T is less than the minute time τ (for example, 8 msec) (S
6: No) and S4 to S6 are repeated, and the data of the collision acceleration A is accumulated in the register. When the measured time T becomes a minute time τ or more (S6: Yes), the collision acceleration A is integrated by using the data of the plurality of accelerations A stored in the register while the timer T is between 0 and τ. Ec is calculated (S7), and then the weight W immediately before the collision and the seat belt SW signal SS are calculated using the data read in S1 and stored in the register (S8).

Next, in S9, it is determined whether or not the seat belt 25 (abbreviated as S / B) is worn or the weight is W ≧ W0 (predetermined value). If the determination is No, that is, the seat belt is worn If there is none or if the weight is W <W0,
If S10 to S15 are executed and the determination in S9 is Yes,
That is, if the seat belt is worn or the weight is W ≧ W0, S16 to S21 are executed.

In S10, it is determined whether or not α1 ≦ Ec <α2. If the determination is Yes, the airbag 2 is inflated at a low pressure (S11), and this control ends. No in S10
In the case of, it is determined whether or not α2 ≦ Ec <α3 (S12),
If the determination is Yes, the airbag 2 is inflated to intermediate pressure (S13), and this control ends. If the determination in S12 is No, it is determined whether or not α3 ≦ Ec (S14), and the determination is
If Yes, the airbag 2 is inflated to a high pressure (S15).
When this control ends and the determination in S14 is No, the process returns.

In S16, it is determined whether or not β1 ≦ Ec <β2. If the determination is Yes, the airbag 2 is inflated to a low pressure (S17), and this control ends. No in S16
In the case of, it is determined whether or not β2 ≦ Ec <β3 (S18),
If the determination is Yes, the airbag 2 is inflated to intermediate pressure (S19), and this control ends. If the determination in S18 is No, it is determined whether β3 ≦ Ec (S20), and the determination is
If Yes, the airbag 2 is deployed at high pressure (S21).
When this control ends and the determination in S20 is No, the process returns.

The operation and effect of the above airbag device 1 will be described. The airbag 2 can be deployed in three ways: low pressure deployment, medium pressure deployment, and high pressure deployment, and the deployment threshold α
Since 1 to α3 and β1 to β3 are set as described above, when the seat belt is not worn or the weight W of the occupant B is <W0, the airbag 2 is inflated at a low pressure when α1 ≦ Ec <α2. , Α2 ≦ Ec <α3, the airbag can be inflated at a medium pressure, and α3 ≦ Ec can be inflated at a high pressure.

Similarly, when the seat belt is worn or the weight W ≧ W0 of the occupant B, when β1 ≦ Ec <β2, the airbag 2 is inflated to a low pressure, and β2 ≦ Ec <β3.
In the case of, the airbag can be inflated at an intermediate pressure, and in the case of β3 ≦ Ec, the airbag can be inflated at a high pressure. In this manner, the safety can be enhanced by deploying the airbag 2 with an appropriate deployment pressure according to whether or not the seat belt is worn and the collision speed Ec. Moreover, since the airbag 2 can be deployed in three ways, the deployment pressure for low-pressure deployment can be set low so as to suit a slight collision when the seatbelt is not worn, and the serious pressure when the seatbelt is worn can be set. The deployment pressure of the high-pressure deployment can be set high to suit the collision.

The inflator unit 3 includes inflators 15 and 16 having different capacities, the airbag 2 is inflated at a low pressure by the operation of the inflator 15 having a small capacity, and the airbag 2 is operated by the operation of the inflator 16 having a large capacity.
Is inflated at a medium pressure and the airbag 2 is inflated at a high pressure by actuation of both inflators 15, 16. Therefore, the inflator unit 3 having a relatively simple configuration is used to inflate the airbag 2 at low pressure and at medium pressure. High pressure deployment 3
Can be deployed as The inflator unit 3 does not become so large, which is advantageous in terms of manufacturing cost.

Since the expansion threshold values α1 to α3 and β1 to β3 are preset with the collision speed Ec at the time of collision occurring as a parameter, the airbag 2 has a expansion pressure suitable for the collision speed Ec.
Can be deployed. Since the intermediate pressure expansion threshold value α2 when the seat belt is not worn is set to be smaller than the low pressure expansion threshold value β1 when the seat belt is worn, the collision velocity E
The impact can be absorbed by deploying the airbag 2 at a low pressure when c is small.

Moreover, the high pressure deployment threshold value α3 when the seat belt is not worn is set to be sufficiently larger than the medium pressure deployment threshold value α2 when the seat belt is not worn. Does not deploy high pressure,
It is possible to prevent a large impact from the airbag 2 on the occupant B, and to protect the occupant B by deploying the airbag 2 at a high pressure in a severe collision. As described above, it is possible to enhance the safety of the occupant B in a mild to severe collision without wearing the seat belt.

Considering that the occupant B having a light weight W is not robust and is vulnerable to impact, the medium pressure expansion threshold value α2 when the occupant B has a weight W less than a predetermined value W0 is inflated to a low pressure when the occupant B has a predetermined value or more. Since the threshold value β1 is set to be smaller than the threshold value β1, the airbag 2 can be deployed at a low pressure to absorb impact when the seat belt is not worn, from a stage where the collision speed Ec is small.

Moreover, the high pressure deployment threshold value α3 when the weight W is less than the predetermined value W0 is set to be sufficiently larger than the intermediate pressure deployment threshold value α2 when the seat belt is not worn. The airbag 2 does not deploy high pressure,
It is possible to prevent a large impact from the airbag 2 on the occupant B, and to protect the occupant by deploying the airbag 2 at a high pressure in a severe collision. As described above, the safety of the occupant B in a mild to severe collision when the weight W is less than the predetermined value W0 can be improved.

The airbag device 1 described above can be partially modified as follows. 1) The expansion thresholds α1 to α3 and β1 to β3 are corrected so as to decrease as the vehicle speed Vc at the time of collision increases, or decrease as the steering angle at the time of collision increases, There is also a case where the larger the deceleration at time, the smaller the correction.

2) Development thresholds α1 to α3, β1 to β3
In addition to the collision speed E, the collision acceleration of the automobile may be applied as a parameter for setting. 3) The characteristics shown in FIGS. 3 and 4 may be stored in the ROM, and the expansion thresholds α1 to α3 and β1 to β3 may be calculated from the characteristics.

4) In the above embodiment, the expansion thresholds α1 to α3 and β1 to β1 are divided into cases depending on whether the seat belt is worn or not.
Although β3 is set, two expansion thresholds are set in advance with or without the seatbelt and the seatbelt with the collision speed E or the collision acceleration as a parameter. The bag may be unfolded and controlled. That is, as the two common development thresholds, the development threshold γ1 having a value approximate to the development threshold α1 or α2.
Then, the expansion threshold γ2 having a value approximate to the expansion threshold α3 is set in advance.

In the case where the seat belt is not worn, the airbag 2 is inflated at a low pressure in the first low pressure side deployment mode in which the airbag 2 is deployed under the condition of γ1≤Ec <γ2. In the second deployment mode on the high pressure side where the airbag 2 is deployed under the conditions, the airbag 2 is deployed at an intermediate pressure. In addition, in the case where the seat belt is worn, the airbag 2 is deployed under the condition of γ1 ≦ Ec <γ2. In the first deployment mode on the low pressure side, the airbag 2 is deployed at an intermediate pressure, and γ2 ≦ Ec is satisfied. In the second high-pressure side deployment mode in which the airbag 2 is deployed, the airbag 2 is deployed at high pressure.

As described above, since the two expansion threshold values γ1 and γ2 are set commonly for the case where the seat belt is not worn and the case where the seat belt is worn, the expansion control is simplified. When the seat belt is not worn, only the low pressure deployment and the intermediate pressure deployment are allowed, and the airbag 2 is not deployed at a high pressure. Therefore, the impact of the airbag 2 on the occupant B does not become too large. When the seatbelt is worn, the occupant B is restrained by the seatbelt 25, so that the airbag 2 is allowed to be deployed only at medium and high pressures.

5) With respect to the inflator unit 3 of the airbag apparatus 1, the inflator unit 3 is composed of three inflators having the same capacity, and one inflator is actuated to deploy the airbag 2 at a low pressure to actuate the two inflators. The airbag 2 may be inflated at a medium pressure, and the three inflators may be operated to inflate the airbag 2 at a high pressure. Alternatively, one inflator capable of high-pressure deployment is provided, the internal pressure of the airbag is controlled to a low pressure to deploy at a low pressure, the internal pressure is controlled to an intermediate pressure to deploy at an intermediate pressure, and the internal pressure is controlled to a high pressure. It is also possible to apply an inflator of the type in which high pressure deployment is performed.

[0053]

According to the invention of claim 1, since the airbag can be deployed in three ways: low pressure deployment, medium pressure deployment, and high pressure deployment, the degree of collision (collision speed or collision acceleration) at the time of collision occurrence. When the impact is light, the airbag can be deployed at a low pressure, when the degree of collision is medium, the airbag can be deployed at a medium pressure, and when the degree of collision is heavy, the airbag can be deployed at a high pressure. The airbag can be deployed with the deployment pressure to enhance safety. Moreover, since the airbag can be deployed in three ways, the deployment pressure for low-pressure deployment can be set low so as to suit a mild collision when the seat belt is not worn, and a serious collision when the seat belt is worn is also possible. The deployment pressure of the high pressure deployment can be set high so that

[0054]

[0055]

[0056]

Further, since the low pressure expansion threshold value, the intermediate pressure expansion threshold value and the high pressure expansion threshold value are set in advance using the collision speed or the collision acceleration at the time of the open angle collision as a parameter, the collision speed or the collision acceleration is set. The airbag can be deployed at a suitable deployment pressure .

Furthermore, since the threshold value for intermediate pressure deployment when the seat belt of the occupant is not worn is set to be smaller than the low pressure deployment threshold value when the seat belt is worn, a collision occurs when the seat belt is not worn. The impact can be absorbed by deploying the airbag at a low pressure when the degree (collision velocity or collision acceleration) is low. And, since the high-pressure deployment threshold value without wearing the seatbelt was set to be sufficiently larger than the medium-pressure deployment threshold value without wearing the seatbelt, the airbag does not deploy at high pressure except in a severe collision, It is possible to prevent the impact of the airbag from acting on the occupant, and to protect the occupant by deploying the airbag at a high pressure in a severe collision. As described above, it is possible to enhance the safety of the occupant in a mild to severe collision without wearing the seat belt .

According to the invention of claim 2 , when an open angle collision occurs
Using the collision speed or collision acceleration of the
Open threshold, medium pressure expansion threshold and high pressure expansion threshold are predicted.
Is set so that it is suitable for collision speed or collision acceleration.
The airbag can be deployed by pressure. When the weight of the occupant is less than the predetermined value, the intermediate pressure deployment threshold is set to be smaller than the low pressure deployment threshold when the weight is more than the predetermined value. The impact can be absorbed by deploying the airbag at a low pressure from the stage when the acceleration) is small.

Since the high pressure deployment threshold when the weight is less than the predetermined value is set to be sufficiently larger than the medium pressure deployment threshold when the seat belt is not worn, the high pressure deployment of the airbag is performed except for a severe collision. Therefore, it is possible to prevent the impact of the airbag from acting on the occupant from increasing, and to protect the occupant by deploying the airbag at a high pressure in a severe collision. As described above, weight Ru can increase passenger safety in mild from severe collisions when less than the predetermined value.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an automobile airbag device according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a main part of the airbag device.

FIG. 3 is a diagram showing characteristics of impact absorption performance with respect to collision speed.

FIG. 4 is a diagram showing characteristics of impact absorption performance with respect to collision speed.

FIG. 5 is a part of a flowchart of airbag deployment control.

FIG. 6 is the rest of the flowchart of airbag deployment control.

[Explanation of symbols]

C car 1 Airbag device 2 airbags 3 Inflator unit 4, 5 Acceleration sensor 7 Weight sensor 8 seat belt switch 9 Control unit 10 steering wheel 25 seat belts

Continuation of front page (56) Reference JP-A-9-183359 (JP, A) JP-A-49-94030 (JP, A) JP-A-49-33320 (JP, A) JP-A-11-20607 (JP , A) JP 10-175503 (JP, A) JP 8-318814 (JP, A) JP 6-206514 (JP, A) JP 8-332912 (JP, A) JP 7-277123 (JP, A) JP-A-9-240406 (JP, A) Actual exploitation Sho 49-47326 (JP, U) Registered utility model 3029326 (JP, U) International publication 96/009942 (WO, A1) Patent 2507796 (JP, B2) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60R 21/32

Claims (2)

(57) [Claims] 1. A vehicle airbag device capable of variably controlling the deployment state of an airbag in accordance with the running state of a vehicle and the restraint state of an occupant. The airbag has three types of low pressure deployment, medium pressure deployment, and high pressure deployment. It is configured to be expandable to , and the collision speed or collision acceleration at the time of collision is used as a parameter,
Low pressure expansion threshold, medium pressure expansion threshold and high pressure expansion threshold
The value of the seat belt of the occupant at the time of a collision
It is set in advance depending on the presence / absence of the vehicle, and the threshold for the expansion of the medium pressure when the seat belt of the passenger is not worn
The value is the low pressure deployment threshold when seat belts are used.
Is set smaller than the
Medium pressure when high pressure deployment threshold is without seat belt
Characterized by being set sufficiently larger than the expansion threshold
The vehicle airbag device. 2. Depending on the running condition of the vehicle and the restraint condition of the occupant.
A vehicle airbag that can variably control the deployment state of the airbag
In the air bag device, the airbag is divided into three types: low pressure deployment, medium pressure deployment, and high pressure deployment.
It is configured so that it can be deployed in a cage , with the collision speed or collision acceleration at the time of collision as a parameter,
Low pressure expansion threshold, medium pressure expansion threshold and high pressure expansion threshold
Value is set in advance, and the intermediate pressure expansion threshold is set when the weight of the occupant is less than the predetermined value.
Set smaller than the low pressure deployment threshold when the value is above a certain value.
If the weight is less than the predetermined value,
If the value is less than
An airbag device for a vehicle, characterized by being specified.