Method for setting inner pressure of vehicular external airbag, and vehicular external airbag system

• US 20060163852A1
• Filed: 01/24/2006
• Published: 07/27/2006
• Est. Priority Date: 01/26/2005
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Kamiji, Koichi, Okamoto, Yutaka, Kikuchi, Yuji
• Granted Patent: US 7,211,752 B2
• Time in Patent Office: Days
• US Class Current: 280/742
• CPC Class Codes: B60R 2021/01231 control of expansion timing or sequence
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/01508 detecting forces or pressure in bags or modules
• CPC Class Codes: B60R 21/2165 characterised by a tear line for defining a deployment opening
• CPC Class Codes: B60R 21/2171 specially adapted for elongated cylindrical or bottle-like inflators with a symmetry axis perpendicular to the main direction of bag deployment, e.g. extruded reaction canisters B60R21/2176 takes precedence
• CPC Class Codes: B60R 21/36 using airbags

Abstract

When a small-size dummy has collided against a vehicle and once the head of the small-size dummy hits the deployed external airbag at a pre-determined velocity, the inner pressure of the deployed external airbag is set to a characteristic such that the inner pressure takes a predetermined maximum level value capable of not only preventing the dummy from bouncing off the airbag but also preventing the head of the dummy from hitting the bottom of the airbag. When a medium-size dummy has collided against the vehicle, the inner pressure of the deployed external airbag is set to a characteristic such that the inner pressure decreases away from the maximum level value at a predetermined decrease rate to prevent the medium-size dummy from bouncing off the airbag.

Claims

1. A method for setting, by use of a plurality of dummies of different sizes, an inner pressure of a vehicular external airbag deployed along an outer surface of at least a front windshield of a vehicle, said method comprising:

a first step of, when a small-size dummy of the plurality of dummies has collided against the vehicle and once a head of the small-size dummy hits the deployed airbag at a predetermined velocity, setting the inner pressure of the deployed external airbag to a characteristic such that the inner pressure takes a predetermined maximum level value capable of not only preventing the small-size dummy from bouncing off said external airbag but also preventing the head of the small-size dummy from hitting a bottom of said external airbag; and

a second step of, when a medium-size dummy of the plurality of dummies collided against the vehicle, setting the inner pressure of the deployed external airbag to a characteristic such that the inner pressure decreases away from the predetermined maximum level value at a pre-determined decrease rate to prevent the medium-size dummy from bouncing off said external airbag.

2. A method according to claim 1, further comprising a third step of, when a large-size dummy of the plurality of dummies, greater in size than the small- and medium-size dummies, collided against the vehicle and once a head of the large-size dummy hits the deployed external airbag at a predetermined velocity, setting the inner pressure of the deployed external airbag to a characteristics such that the inner pressure is kept, for a predetermined time period, at a predetermined level value smaller than the predetermined maximum level value and capable of not only preventing the large-size dummy from bouncing off the external airbag but also preventing the head of the large-size dummy from hitting the bottom of said external airbag.

3. A vehicular external airbag system comprising:

an inner pressure control characteristic setting unit storing therein predetermined inner pressure control characteristics to control an inner pressure of a vehicular external airbag deployed along an outer surface of at least a front windshield of a vehicle; and

a vehicular external airbag apparatus comprising;

said external airbag;

an inflator for inflating and deploying said external airbag upon detection of a collision of an external object against the vehicle; and

a control section,

wherein, when a small-size external object collided against the vehicle and once a part of the small-size external object hits the deployed external airbag at a predetermined velocity, said control section performs first control, in accordance with the inner pressure control characteristics stored in said inner pressure control characteristic setting unit, such that said inflator is ignited at predetermined first timing and the inner pressure of the deployed external airbag takes a predetermined maximum level value capable of not only preventing the small-size external object from bouncing off said external airbag but also preventing the part of the small-size external object from hitting a bottom of said external airbag, and

when a large-size external object, greater in size than the small-size external object, collided against the vehicle and once a part of the large-size external object hits the deployed external airbag at a predetermined velocity, said control section performs second control, in accordance with the inner pressure control characteristics stored in said inner pressure control characteristic setting unit, such that said inflator is ignited at predetermined second timing later than said first timing and the inner pressure is kept, for a predetermined time period, at a predetermined level value smaller than the maximum level value and capable of not only preventing the large-size external object from bouncing off said external airbag but also preventing the part of the large-size external object hitting the bottom of said external airbag.

4. A vehicular external airbag system according to claim 3 wherein, when a traveling velocity of the vehicle detected when the external object collided against the vehicle is lower than a predetermined reference velocity, said control section controls said second timing to be delayed by a predetermined time as compared to when said traveling velocity of the vehicle detected is not lower than the predetermined reference velocity.