Patent Publication Number: US-2005127647-A1

Title: Side curtain airbag system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      The present application is based on, and claims priority from, Korean Application Number 10-2003-0089528, filed on Dec. 10, 2003, the disclosure of which is hereby incorporated by reference herein in its entirety.  
     FIELD OF THE INVENTION  
      The present invention relates to a side curtain airbag system. More particularly, the present invention relates to a rapidly and evenly deploying side curtain airbag in the event of a vehicular crash.  
     BACKGROUND OF THE INVENTION  
      Generally, vehicles are equipped with various safety devices to protect occupants in vehicle collisions. As one of the safety devices for a vehicle, an air bag protects against injury to a passenger&#39;s chest and head region, whether the passenger is a child or adult, in a head-on or side collision.  
      Typically, the driver&#39;s air bag is stored in the middle of a steering wheel while the air bag for a front passenger is stored inside a crash pad. In order to optimize protection to a passenger, an additional air bag is installed beside within the left or right side of seats, or along a roof side rail, thereby protecting the passengers even against impact in a side collision.  
      The air bag arranged along the roof side rail is called the side curtain airbag. The side curtain airbag system provides gas generated from an inflator to an air bag via a gas pipe. When the air bag inflates from the roof side rail into the passenger compartment completely, the curtain airbag covers the side window.  
      There is a drawback in the conventional curtain airbag in that it is configured so that gas flows into the curtain airbag from the rear pillar, which is near the inflator, to the middle pillar, and then to the front pillar. This configuration causes a deployment time difference for the curtain airbag between the rear pillar and front pillar.  
      In order to safely protect the passengers from a side collision impact, the pillars for the side curtain airbag should be inflated at the same time. The deployment time of the side curtain airbags should also be decreased.  
     SUMMARY OF THE INVENTION  
      The present invention is adapted to simultaneously deploy all positions of the curtain airbag and reduce their deployment time, resulting in a rapid response to a vehicle collision. The present invention includes a side curtain airbag, an inflator, and a gas pipe formed with a plurality of gas injection films that become detached or dangle from the gas pipe by the pressure of the gas generated when the inflator inflates. The interior of the gas pipe is filled with gas having a predetermined pressure. The curtain airbag is connected to the gas pipe at the points on the gas pipe where the gas injection films are disposed, and becomes inflated by gas injected from the gas pipe when the gas injection films detach or rupture from the gas pipe. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      For a better understanding of the nature and objects of the present invention, reference should be made to the following detailed description, read in conjunction with the accompanying drawings, in which:  
       FIG. 1  illustrates a front view of a side curtain airbag according to an embodiment of the present invention;  
       FIG. 2  is a detailed front view of a gas pipe according to an embodiment of the present invention;  
       FIG. 3  is a side sectional view of the gas pipe taken along line A-A of  FIG. 2 ; and  
       FIG. 4  is a perspective view illustrating the operation of the gas pipe of  FIG. 2 . 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT  
      With reference to  FIGS. 1 and 2 , a side curtain airbag system of a vehicle comprises a gas pipe  112  for providing gas generated from an inflator  110  to a curtain formed with a plurality of gas injection films  112   a  for supplying gas to curtain airbag  114 . Gas injection films  112   a  are formed where gas pipe  112  connects to curtain airbag  114 .  
      As shown in  FIGS. 3 and 4 , gas injection film  112   a  is disposed on gas pipe  112  and may be composed of material identical to that of gas pipe  112 . Gas injection film  112   a  may be formed by a thin film that is relatively thinner than the thickness of gas pipe  112  (i.e., the difference between the thickness of the outer diameter and the inner diameter of gas pipe  112 ). Gas injection film  112   a  is circular in the figure, but an elliptical, polygonal, or other shape may be used instead. A groove  112   b  may be formed on gas pipe  112  at the boundary of gas injection film  112   a . Groove  112   b  is formed to facilitate the detachment or rupture of gas injection film  112   a  from gas pipe  112  by gas generated when inflator  110  inflates.  
      Gas injection film  112   a  may be manufactured in various ways based on the material. The methods include but are not limited to core casting, compressively forging, or punching. For the core casting method, gas injection film  112   a  and gas pipe  112  are formed simultaneously by using a frame that is pre-manufactured with the shape of gas injection film  112   a . In the compressively forging method, the section where gas injection film  112   a  will be formed is compressed when gas pipe  112  is manufactured. The punching method forms a crack on gas pipe  112  in the shape of gas injection film  112   a.    
      The operation of the side curtain airbag according to the embodiment of the present invention will now be described.  
      Gas pipe  112  is initially filled with gas under a predetermined pressure such that gas injection films  112   a  do not detach or rupture. When inflator  110  inflates, additional gas enters gas pipe  112 , resulting in a pressure increase in gas pipe  112 . Then, as shown in  FIG. 4 , the pressure increase causes the plurality of gas injection films  112   a  to detach or dangle from (or become blown off of) gas pipe  112 , and gas is injected into curtain airbag  114  instantaneously.  
      One of ordinary skill in the art will appreciate that a gas pipe is formed with a plurality of gas injection films configured to easily be detached or ruptured by a high pressure blast of gas generated when the inflator inflates. As a result, when the inflator inflates and the high pressure gas is injected into the gas pipe, the plurality of gas injection films are detached or ruptured at the same time by the increased pressure. Thus, the deployment time of the curtain airbag is effectively reduced and the gas is simultaneously delivered to all portions of the curtain airbag. Accordingly, the curtain airbags of a vehicle are able to rapidly inflate, contributing to a prompt response to a vehicle crash.  
      In one embodiment of the invention, multiple inflators are attached to the gas pipe to inflate each portion of the curtain airbag simultaneously. In another embodiment of the invention, gas injection films  112   a  are different sizes, with the smallest size being closest to inflator  110 , and the a largest size being farthest away from inflator  110 . The smaller sized gas injection films  112   a  and the larger sized gas injection films  112   a  thus compensate for any difference in inflation time between the portion of curtain airbag closest to inflator  110  and the portion of curtain airbag farthest from inflator  110 .  
      The technical concept of the present invention is not limited to the embodiment of the present invention but may be embodied in various methods in the scope of the present invention. Even though the present invention is described in detail with reference to the foregoing embodiments, it is not intended to limit the scope of the present invention thereto. It is evident from the foregoing that many variations and modifications may be made by a person having an ordinary skill in the present field without departing from the essential concept of the present invention.