Land vehicles – Wheeled – Attachment
Utility Patent
1998-01-02
2001-01-02
English, Peter C. (Department: 3619)
Land vehicles
Wheeled
Attachment
C280S741000
Utility Patent
active
06168201
ABSTRACT:
TECHNICAL FILED
The present invention relates to a gas generating apparatus for an air bag apparatus mounted in a vehicle or the like for charging a gas, at the time of collision of the vehicle, into an air bag interposed between a passenger and an interior member of the vehicle chamber so as to inflate the air bag, thereby protecting the passenger of the vehicle.
BACKGROUND ART
Conventionally, in the gas generating apparatus for the air bag apparatus, an inert gas such as a compressed nitrogen gas or argon gas is used. Japanese Patent Application Laid-open No. 5-278554 discloses an apparatus which uses a combustible gas mixture. In this apparatus, the combustible gas mixture accommodated in a pressure container is ignited from its one end surface, and when the gas pressure is increased due to a rise of the temperature by combustion, the other end surface of the pressure container is broken by such a pressure, which allows the combustion gas to flow therefrom into the air bag to inflate the same.
However, in the initial state in which the combustible gas mixture is ignited in the conventional apparatus as disclosed in this Japanese Patent Application Laid-open No. 5-278554, among the entire gas in the pressure container, only gas at the side of the ignition is burnt, and gas at the side of the other end surface is prone not to be burnt. Therefore, it is difficult to effectively utilize the entire combustible gas mixture, or it takes a long time to increase the pressure within the pressure container. As a result, a problem is brought about that the initial responding time period is elongated.
Further, in such a gas generating apparatus for the air bag apparatus, it is necessary that the initial responding speed of the air bag apparatus at the time of operation is high, and it is also necessary that a time period required for completing the inflation of the air bag can variously be varied in accordance with a volume of the air bag and speed which are determined for the type of a vehicle in view of a size and a shape of the vehicle.
Furthermore, in the conventional apparatus as disclosed in the above mentioned publication, the air bag is inflated by ignition of the gas mixture, and an inflating characteristic up to the completion of inflating operation follows a previously designed characteristic. Therefore, such a characteristic is fixed at the designing stage. However, the inflating characteristic should not necessarily be limited to only one value in view of various conditions such as a degree of a collision, a position of a sitting passenger, a difference in physique of passengers and the like. For this reason, it is required to provide an air bag apparatus in which a degree of freedom at the time of operation of the air bag apparatus is ensured so that the inflating characteristic can appropriately be varied in accordance with the above mentioned various conditions.
Therefore, a major object of the present invention is to provide a gas generating apparatus for an air bag apparatus in which a fluid mixture (which will be called as “combustion fluid mixture” hereinafter) which is generated after a combustible fluid mixture is sufficiently burnt is effectively and swiftly fed into the air bag, and in which a time period required for completing the inflation of the air bag can variously be changed by means of a simple structure.
Further, another object of the invention is to realize an inflating characteristic which corresponds to various conditions at the time of operation of the air bag apparatus.
Further, another object of the invention is to realize a reliable gas generating apparatus for an air bag apparatus with a simple structure in which the combustible fluid mixture can be burnt swiftly, and only the combustion fluid mixture can swiftly be fed into the air bag and hence, responding speed is high, by dividing a combustion chamber into a first chamber and a second chamber.
A further object of this invention is to control the direction of the fluid flowing through a third vent opening from a first chamber into a second chamber, when the combustible fluid mixture in the first chamber is ignited and the ignited combustion fluid mixture is introduced into the second chamber.
A still further object of the invention is to control the communication state between the first chamber and the second chamber in accordance with a given condition, and to control the inflating state of the air bag.
A still further object of the invention is to control an amount of the combustion fluid mixture introduced into the air bag with respect to the given condition so as to control the inflating state of the air bag.
DISCLOSURE OF THE INVENTION
According to claim
1
, there is provided a gas generating apparatus for an air bag apparatus, comprising:
a first chamber accommodating a combustible fluid and provided with a first vent opening which is in communication with an air bag; a second chamber which is larger than the first chamber and which accommodates a combustible fluid and/or an inert fluid; a first occluding member for occluding the first vent opening; and ignition means for igniting the combustible fluid in the first chamber; wherein at least a portion of the combustible fluid in the first chamber is burnt, thereby discharging the fluid in the first and second chambers through the first vent opening to inflate the air bag.
With the above arrangement, the chamber for accommodating the combustible is fluid divided into first and second chambers, and the combustible fluid is ignited in the first chamber provided with the first vent opening which is in communication with the air bag. Therefore, it is possible to break the first occluding member swiftly, and to discharge the combustion fluid mixture within this first chamber. Thus, the initial responding time period in which the air bag starts inflating can be shortened.
Because the first chamber is smaller than the second chamber, this effect is further enhanced.
According to claim
2
, in addition to claim
1
, the gas generating apparatus for the air bag apparatus further includes a second vent opening for bringing the first and second chambers into communication with each other, and a second occluding member for occluding the second vent opening, wherein when the combustible fluid in the first chamber is burnt, the first chamber is substantially closed.
With this arrangement, when the combustible fluid in the first chamber is burnt, because the first chamber is substantially closed, a pressure within the first chamber can reliably be increased by the combustion. Therefore, the first occluding member can reliably and swiftly be broken, and the initial responding time period in which the air bag starts inflating can be shortened. Here, it should be noted that the expression that the first chamber is “substantially closed” means that the first chamber is closed to such an extent that a pressure rise which is necessary to break the first occluding member is not prevented.
According to claim
3
, in addition to claim
2
, the second occluding member is provided outside the first chamber.
With such an arrangement, it is possible to easily mount the second occluding member.
According to claim
4
, in addition to claim
2
, the second occluding member is provided inside the first chamber.
With this arrangement, it is possible to control a direction of the pressure for breaking the second occluding member.
According to claim
5
, in addition to claim
2
, the second occluding member is formed to be broken easier by a pressure from the second chamber than by a pressure from the first chamber.
With this arrangement, when the fluid in the second chamber is burnt or expanded after the discharge of the fluid in the first chamber into the air bag is started, the second occluding member is broken. Therefore, the first occluding member is reliably and swiftly broken to shorten the initial responding time period in which the air bag starts inflating. Further, because the fluid in the second chamber is discharged later than the fluid in the first chamber, i
Eto Norimasa
Kawauchi Yoshikazu
Ono Takuhiro
Takahashi Hiroyuki
Takeyama Shigeru
Armstrong, Westerman Hattori, McLeland & Naughton
English Peter C.
Matsushita Electric Industrial
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