The present invention relates to an airbag device in which an airbag is inflated to protect a vehicle occupant in the event of a vehicle collision. More particularly, an airbag device with an improved airbag configuration for protecting an occupant more efficiently.
An airbag for protecting a vehicle occupant is normally stored in a folded state in a cavity disposed in the middle section of a steering wheel or within an instrument panel of a vehicle. In the event of a vehicle collision, the airbag is deployed and inflated in the vehicle interior by gas produced by an inflator. The inflated airbag receives and restrains the occupant.
In conventional airbag devices, the airbag when deployed does not leave a sufficiently safe distance between the airbag contact surface and the vehicle occupant, Thus, in a vehicle emergency the kinetic energy of the occupant is not efficiently absorbed by the airbag, which may result in injury to the occupant. In addition, when the occupant has a small build, the seat is often pulled forward to the front-most position. Such an occupant is plunged into a conventional airbag before the seatbelt has sufficient time to absorb impact energy. As a result, some passengers, especially children, have been fatally injured.
Another disadvantage of conventional airbags is that the restraint force of the airbag is not focused on the mass point of the occupant's head. Thus, the kinetic energy of the occupant's head is not efficiently absorbed.
Because the energy absorption effect of conventional airbags is not optimized, such airbags require increased volume and an inflator with increased output.
According to an embodiment, an airbag device includes an airbag; wherein the airbag includes an inside airbag member, an outside airbag member, a recess formed between the inside airbag member and the outside airbag member, and a tether; wherein the tether is connected to at least one of the inside airbag member and the outside airbag member; and a winding devices wherein the winding device is connected to the tether, wherein the winding device is arranged to control the size and shape of the airbag when the airbag is in a deployed state.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory.
These and other features, aspects, and advantages of the present invention will become apparent from the following description, appended claims, and the accompanying exemplary embodiments shown in the drawings, which are described briefly below.
Embodiments will be described with reference to the attached drawings.
In the description below, the longitudinal direction is identical to that of a vehicle in which the head-protecting airbag is mounted. Although the following embodiments are directed to an airbag device for a passenger seat mounted in the upper part of a vehicle dashboard, the airbag device can be applied to an airbag other than for a passenger seat.
According to an embodiment, an airbag device is provided. The airbag device includes an airbag that is normally stored in an upper part of an instrument panel. The airbag can be inflated and deployed into a space in front of a vehicle occupant in the event of an emergency, such as a vehicle collision. In a top view, the airbag upon completion of deployment has a right side portion, a left side portion, and a recess formed between the right and left side portions. The recess can maintain a recessed shape when pressure is applied to the right and left side portions.
According to another embodiment, an airbag device is provided. The airbag device includes an airbag that is normally stored in an upper part of an instrument panel. The airbag can be inflated and deployed into a space in front of a vehicle occupant in the event of an emergency, such as a vehicle collision. When the airbag makes contact with the occupant's head during an emergency, the contact surface extends from the deepest section of the recess to the right side end of the recess (right contact surface) and from the deepest section of the recess to the left side end of the recess (left contact surface). The left and right contact surfaces can be disposed at an angle of about 15 to 90 degrees (preferably 30 to 60 degrees) relative to the line extending through the deepest section of the recess in the longitudinal direction of the vehicle (the airbag centerline).
Thus, by projecting the front surface of the airbag toward an occupant, the area of the occupant's head corresponding to the mass point (center of gravity) of the occupant's head can come in contact with the front surface of the airbag, which enables more efficient restraint of the occupant's head during the initial stage of impact. If the angle between the contact surface and the airbag centerline exceeds about 90 degrees, the efficiency is lost, If the angle is less than about 15 degrees, the recess doesn't cover the occupant's head.
According to another embodiment, an airbag device is provided. The airbag device includes an airbag that is normally stored in an upper part of an instrument panel. The airbag can be inflated and deployed into a space in front of a vehicle occupant in the event of an emergency, such as a vehicle collision. In a top view, the airbag upon completion of deployment has a right side portion, a left side portion, and a recess formed between the right and left side portions. The front surface of the airbag projects toward an occupant. The front surface is formed to project so that the area corresponding to the mass point (center of gravity) of the heads of occupants of different sizes/builds comes in contact with the area of the front surface of the airbag extending from the deepest section of the recess to the right and left side ends of the recess.
Thus, because the front surface of the airbag projects toward an occupant, the mass point of the occupant's head can be restrained in an earlier stage of the impact. And since the energy absorption effect of the airbag is raised, the occupant's head can be restrained more efficiently during the earlier stage of the impact.
In a vehicle emergency, the shoulder portions of the occupant first press the airbag and are the first part of the occupant to receive a reaction force of the airbag. In particular, the shoulders of an occupant can make contact with the right and left side portions of the airbag before the head of the occupant contacts a recess in the airbag. Due to such contact between the shoulders of an occupant and the right and left side portions of the airbag, the pressure in the right and left side portions increases and is supplied to the recess so as to increase the inner pressure of the recess. Thus, the energy absorption effect of the right and left side portions and of the recess is increased.
When the shoulders of the occupant press the airbag, the inner pressure of the airbag increases. Even when the inner pressure increases, the airbag is constructed such that the recessed shape of the airbag is maintained. Because the recessed configuration of the airbag is maintained, it is difficult for gas pressure to leak out, which enhances the efficiency of the restraint of the occupant's shoulders at the initial stage of restraint. Thus, in such an airbag, the airbag is first compressed by the occupant's shoulders, which causes the inner pressure (reaction force) of the airbag to rise. The increased inner pressure enhances the initial restraint of the occupant's shoulders. Next, because the airbag has a recess and the area where the recess is formed does not deform much, gas is supplied into the airbag without a substantial deformation of the recess and without lowering the inner pressure. As a result, the inner pressure of the airbag, including the recess, is raised higher than that of a conventional airbag. Occupant restraint capability is thus improved. Because the energy absorption effect of the recess is improved, the moving distance of the occupant (stroke of the occupant) before the occupant stops is reduced. Therefore, the need for increasing the output of the inflator is eliminated and initial restraint of the occupant is safely achieved. The increased energy absorption effect also allows a reduction in the volume of the airbag so that a compactly constructed airbag may be used.
According to an embodiment, an angled surface of the airbag's recess, which extends from the deepest section of the recess to a right side end of the airbag (the right contact portion) and from the deepest section of the recess to a left side end of the airbag (the left contact portion), is adapted so that the area of the occupant's face opposite the center of gravity (mass point) of the occupant's head (i.e., the area between the eyebrows of the occupant) will always come into contact with the contact surface of the airbag. The angled surface extends such that the contact surfaces extending from the deepest section of the recess to the right and left side ends of the contact surface (the right and left contact portions) form an angle of about 15 to 90 degrees (preferably 30 to 60 degrees) relative to the line extending through the deepest section of the recess in the longitudinal direction of the vehicle (the airbag centerline). In such an airbag, the restraint force of the recess is focused on the area of the occupant's head corresponding to the mass point thereby absorbing the kinetic energy of the occupant's head in a most efficient manner. In addition, when the occupant has a small build, the seat is often pulled forward to the front-most position. When such an occupant is plunged into the airbag during a vehicle collision, the recess allows frontward movement of the occupant. Thus, the recess provides an extra distance (stroke) for the occupant's head to move frontward and allows the occupant to be sufficiently decelerated by a seat belt before the occupant's head makes contact with the airbag.
A recess 11b is provided in the vicinity of the center area of the contact surface 11a of the airbag 11. The recess 11b may be in the form of, for example, a constriction, a hollow, or a valley in the airbag. The recess 11b preferably extends from the top of the airbag 11 to the bottom of the airbag 11 so that the recess 11b is visible in a top view of the airbag. In the preferred embodiment, the fully deployed airbag 11 has a configuration in its top view showing a right side portion, a left side portion, and a recess formed between the left side portion and the right side portion.
FIGS. 1(a) and 1(b) show two occupants H1, H2 of different builds. The occupant H1 has a larger build than the occupant 112. The distance between the jaw area of the occupant H1 and the recess 11b (center of the contact surface 11a) of the deployed airbag is indicated by L1. The distance between the jaw area of the occupant H2 and the recess 11b (center of the contact surface 11a) of the deployed airbag is indicated by L2. For example, L1, L2 may be on the order of 100 mm or the like. For comparison, a contact surface 103a of a conventional airbag is also shown. As can be seen, the distance L102 between the contact surface 103a of a conventional airbag and the jaw area of the occupant H2 is less than the distance L2 between the jaw area of the occupant H2 and the center of the contact surface 11a.
Thus, in the airbag device shown in FIGS. 1(a) and 1(b), the existence of the recess 11b makes the distance L2 between the occupant H2 and the contact surface 11a not so different from the distance L1 between the occupant H1 and the contact surface 11a. This enables the occupant H2 also to be sufficiently decelerated by the seat belt before the head portion of the occupant H2 comes into contact with the airbag 11.
In FIGS. 1(a) and 1(b), the mass points position of center of gravity) of the heads of the occupants H1, H2 are represented by MPL and MPS, respectively. In the airbag device according to this embodiment, a front surface of the airbag is formed so that the portions of the heads of the occupants H1, H2 corresponding to the mass points MPL, MPS will come into contact with the front surface area of the airbag extending (or projecting) from the deepest section of the recess 11b to the right side end (the right contact portion) and from the deepest section of the recess 11b to the left side end (the left contact portion) toward the occupants H1, H2. Thus by projecting the front surface of the airbag in a direction toward the occupant, the occupant can be restrained more safely during the initial stage of the impact than is possible with a conventional airbag.
With reference to
As shown in
Additional embodiments of the airbag 11 will now be described. In the following embodiments and examples, various methods are employed so that the shape of the recess is maintained even when the right and left sides of the airbag are compressed as shown
FIGS. 3(a) and 3(b) show another embodiment.
As shown in
By adding a tether belt 15, the shape of the recess 11b can be maintained when the airbag 11 is inflated.
The tether 210 shown in the example of
According to an embodiment, the airbag device 205 is used to control the area of vent holes. For example, the airbag device 205 can be used to control the area of vent holes by controlling the size and shape of the airbag 200. In a further embodiment, the airbag device includes a size controlling device, such as the device described above, and a vent hole area controlling device.
In an embodiment, the size and shape of an airbag may be controlled in response to signals from detection devices. For example, sensors such as, for example, seat weight sensors (SWS), cameras, proximity devices, and other crash detection devices known in the art may be used. Signals received from the sensors can be used to control the size and shape of the airbag in relation to the conditions detected by the sensors. For example, a signal received from a seat weight sensor can be used to control the size of an inner airbag chamber and/or or outside airbag chamber to accommodate the size and/or position of a vehicle occupant. In another example, signals received from cameras, proximity devices, and/or other crash detection devices can be used to determine a crash condition, as well as a size and shape of the airbag for accommodation of a vehicle occupant.
In a further embodiment, the airbag device can include a controller that receives signals from sensors, such as, for example, seat weight sensors (SWS), cameras, proximity devices, and other crash detection devices known in the art, and controls the winding devices 220 in response to the signals from the sensors.
In an embodiment, an airbag device 205 according to an embodiment described above is used in combination with a seat belt retractor (erg., motorized seat belt retractor MSR) to restrain an occupant. In a further embodiment, an airbag device 205 according to an embodiment described above is used in combination with a knee bolster, a knee bag, and MRS to restrain an occupant.
According to an embodiment, an airbag device is adapted to adjust more than two levels of size for each airbag in the direction of an occupant during deployment.
The present invention in its broader aspects is not limited to the specific airbag devices according to the embodiments shown and described herein with reference to
As described above, by modifying the configuration of the airbag, an occupant can be protected in a more efficient manner.
Given the disclosure of the present invention, one versed in the art would appreciate that there may be other embodiments and modifications within the scope and spirit of the invention. Accordingly, all modifications attainable by one versed in the art from the present disclosure within the scope and spirit of the present invention are to be included as further embodiments.
This application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 60/655,014, filed on Feb. 22, 2005, which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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60655014 | Feb 2005 | US |