Abstract:
An airbag apparatus for a vehicle may include an inflator, and an airbag cushion having a depressed head support portion formed in a rear portion of the airbag cushion so that when the airbag cushion may be deployed by gas supplied from the inflator, the head support portion receives a head of a passenger, and shoulder support portions protruding from lateral sides of the head support portion in a rearward direction and forming a space between the shoulder support portions to have the head support portion therebetween when the airbag cushion may be deployed, and a support tether provided in the airbag cushion and extending in a transverse direction across the shoulder support portions such that a gas path may be defined in a front portion of the airbag cushion below the support tether, the gas path guiding the gas downwards.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to Korean Patent Application No. 10-2010-0083881 filed on Aug. 30, 2010, the entire contents of which is incorporated herein for all purposes by this reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to airbag apparatuses for vehicles and, more particularly, to an airbag apparatus which is installed in a roof of a vehicle so that when a vehicle collision occurs, an airbag is deployed to protect a passenger. 
     2. Description of Related Art 
     Hitherto, development of airbag apparatuses for vehicles has been focused on protecting front seat passengers. 
     However, when a vehicle is involved in a frontal collision, a rear seat passenger that is not wearing a safety belt may injure his/her head as a result of colliding with the head of a passenger in the front seat or with the back of the front seat. Taking into account the fact that the percentage of rear seat passengers who wear safety belts is much lower than that of front seat passengers, the development of airbag apparatuses that protect rear seat passengers is more aggressively required. 
     As shown in  FIG. 5 , in consideration of the above facts, an airbag apparatus of a vehicle for protecting a rear seat passenger was proposed. This conventional airbag apparatus is installed in space between a roof panel  10  and a headliner  20  of the vehicle. When a vehicle collision occurs, a cushion  30  tears the headliner  20 , protrudes outs of the headliner  20 , and then is deployed into the space between the front seat and the rear seat passenger. 
     However, in the conventional airbag apparatus, the cushion  30  is instantaneously inflated just in front of the face of a passenger  40 . As a result, the head or neck of the passenger  40  may be injured by the cushion  30  that is inflated at high pressure. 
     The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
     BRIEF SUMMARY OF THE INVENTION 
     Various aspects of the present invention are directed to provide an airbag apparatus for a vehicle which is configured such that gas smoothly flows in an airbag cushion so that when a vehicle collision occurs, the airbag cushion can effectively protect a passenger. 
     In an aspect of the present invention, the airbag apparatus for a vehicle may include an inflator, and an airbag cushion having a depressed head support portion formed in a rear portion of the airbag cushion so that when the airbag cushion may be deployed by gas supplied from the inflator, the head support portion receives a head of a passenger, and shoulder support portions protruding from lateral sides of the head support portion in a rearward direction and forming a space between the shoulder support portions to have the head support portion therebetween when the airbag cushion may be deployed, and a support tether provided in the airbag cushion and extending in a transverse direction across the shoulder support portions such that a gas path may be defined in a front portion of the airbag cushion below the support tether, the gas path guiding the gas downwards. 
     An airbag screen may be attached to the shoulder support portions, the airbag screen covering the head support portion. 
     The support tether connects the head support portion and inner surface of the airbag cushion, wherein the support tether may include an upper support tether and a lower support tether spaced apart from each other by a predetermined distance in a vertical direction of the airbag cushion. 
     Rear and side edges of the support tether may be respectively connected to a rear surface of the head support portion and sidewalls of the airbag cushion by sewing so that the support tether encloses the head support portion, wherein a front edge of the support tether may be not connected to the inner surface of the airbag cushion and may have a round shape. 
     The front edge of the support tether may have a convex shape protruding along gas passage of the inflator. 
     The airbag apparatus may further include a housing provided in a space between a roof panel and a headliner of the vehicle, the housing containing the airbag cushion, wherein the airbag cushion may include a roof support panel supported by the headliner and receiving the gas through a gas inlet formed thereon, a vertical support panel perpendicularly connected at an upper end line thereof to a rear end line of the roof support panel, a ramp support panel connecting a front end line of the roof support panel to a lower end line of the vertical support panel at an inclined angle, and side support panels connecting side edge lines of the roof support panel, the vertical support panel, the ramp support panel, and the support tether. 
     The present invention has the following effects. 
     First, gas can smoothly flow in the front portion of an airbag cushion. Therefore, the time it takes the airbag cushion to be completely deployed is shortened, which makes the deployment of the airbag smooth and reliable. 
     Second, the airbag cushion is supported by a headliner in a reverse right-triangular shape. Therefore, the cushion can effectively absorb impact applied to the passenger and thus maintain the passenger in a stable position. 
     Third, when the airbag cushion is deployed, a depressed head support portion of the airbag cushion can maintain the head of the passenger in a stable position. Hence, the cushion can more effectively absorb the impact applied to the passenger when the cushion is deploying. 
     Fourth, the present invention can reduce impact applied to the head of the passenger when the airbag cushion is supporting the position of the passenger, thus minimizing injury to the passenger, and fundamentally preventing the neck of the passenger from being bent by the inflation pressure of the airbag cushion. 
     The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view showing the structure of an airbag apparatus for vehicles, according to an exemplary embodiment of the present invention. 
         FIG. 2  is a view showing the structure of an airbag cushion of the airbag apparatus, according to an exemplary embodiment of the present invention. 
         FIG. 3  is a longitudinal sectional view taken along the line A-A of  FIG. 2 . 
         FIG. 4  is a cross-sectional view taken along the line B-B of  FIG. 2 . 
         FIG. 5  is a view showing an airbag apparatus for vehicles, according to a conventional technique. 
     
    
    
     It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
     In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
     Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the attached drawings. 
     As shown in  FIGS. 1 and 2 , in an airbag apparatus according to an exemplary embodiment of the present invention, a gas path  230  is formed in a front portion of an airbag cushion  200  such that the flow of gas is smooth. A depressed head support portion  210  is formed in a rear portion of the airbag cushion  200  to effectively absorb impact applied to the head of a passenger  630 . 
     To achieve these purposes, the airbag apparatus includes an inflator  100 , the airbag cushion  200  and a support tether  300 . 
     The inflator  100  supplies gas into the airbag cushion  200  when a vehicle collision occurs. Preferably, the inflator  100  is installed in a housing  500  provided in space between a roof panel  610  and a headliner  620 . 
     The housing  500  is a casing which contains the airbag cushion  200  therein. The inflator  100  is installed in a predetermined portion of the housing  500  to supply gas into the airbag cushion  200 . Particularly, a lower surface of the housing  500  may be covered with the headliner  620  or, alternatively, it may be exposed out of the headliner  620  to the passenger compartment. In the case where the housing  500  is covered with the headliner  620 , a tear line is provided on the headliner  620  to ensure deployment of the airbag cushion  200 . In the case where the housing  500  is exposed to the passenger compartment through the headliner  620 , an airbag door is provided in the lower surface of the housing  500  to ensure deployment of the airbag cushion  200 . 
     In this embodiment, although the inflator  100  and the airbag cushion  200  have been illustrated as being installed in the housing  500  provided in the space between the roof panel  610  and the headliner  620 , the inflator  100  and the airbag cushion  200  may be directly installed in the space between the roof panel  610  and the headliner  620  without a separate housing being used. 
     As shown in  FIGS. 3 and 4 , when a vehicle collision occurs, the airbag cushion  200  is deployed downwards by gas supplied from the inflator  100  so as to protect the passenger  630 . The airbag cushion  200  includes a roof support panel  201 , a vertical support panel  202 , a ramp support panel and side support panels  204  such that a gas inlet  250 , the head support portion  210 , the gas path  230  and shoulder support portions  220  are formed. Thereby, the airbag cushion  200  can minimize the impact applied to the head of the passenger  630  when it is deployed. 
     In detail, the roof support panel  201  is a support panel which is in contact with the headliner  620 . The gas inlet  250  is formed in a predetermined portion of the roof support panel  201 . When a vehicle collision occurs, gas is supplied from the inflator  100  into the entire space of the airbag cushion  200  through the gas inlet  250 . 
     Furthermore, front and rear end lines of the roof support panel  201  are respectively connected to an upper end line  216  of the vertical support panel  202  and an upper end line  214  of the ramp support panel  203 . Both side lines of the roof support panel  201  are connected to respective upper end lines of the side support panels  204 . 
     The vertical support panel  202  forms the rear surface of the airbag cushion  200 . The upper end line  216  of the vertical support panel  202  is connected to the rear end line of the roof support panel  201  such that the vertical support panel  202  is perpendicular to the roof support panel  201 . 
     The ramp support panel  203  connects a front end line of the roof support panel to a lower end line  218  of the vertical support panel  201 . 
     The vertical support panel  202  forms the head support portions  210  and the head support portion  210  is provided between the shoulder support portions  220 . 
     The depressed head support portion  210  holds the head of the passenger  630  when a vehicle collision occurs. The head support portion  210  is formed in the rear portion of the airbag cushion  200  and has a depressed shape corresponding to the head of the passenger  630 . Thus, when the airbag cushion  200  is deployed, the head of the passenger  630  is inserted into the head support portion  210 , so that impact force applied to the head of the passenger  630  can be effectively absorbed by inflation force of the airbag cushion  200 . 
     Particularly, the head support portion  210  is inclined downwards and rearwards such that the depth thereof is reduced from the top towards the bottom of the airbag cushion. The reason for this is to make the shape of the head support portion  210  correspond to the outline of the head and the neck of the passenger  630 . 
     Thereby, the head support portion  210  can reliably protect the head and the neck of the passenger  630 . The shoulder support portions  220  are disposed on opposite sides of the head support portion  210  and configured such that when the airbag cushion  200  is deployed, they protrude from the head support portion  210  towards the shoulders of the passenger  630 . Thus, when the head of the passenger  630  is supported by the head support portion  210 , the shoulders of the passenger  630  can be stably supported by the shoulder support portions  220 . 
     The ramp support panel  203  forms the front surface of the airbag cushion  200 . The upper end line of the ramp support panel  203  is connected to the front end line of the roof support panel  201  such that the ramp support panel  203  forms a predetermined angle with the roof support panel  201 . The gas path  230  is defined in the airbag cushion  200  at a position adjacent to the ramp support panel  203 . The gas path  230  forms a path between the ramp support panel  203  and the support tether  300  along which gas flows. Thereby, the flow of gas becomes smooth, and the time it takes for the airbag cushion  200  to be completely deployed is reduced, thus making it possible to deploy the airbag cushion  200  reliably and smoothly. 
     The side support panels  204  form the opposite sidewalls of the airbag cushion  200  and connect side edge lines of the roof support panel  201 , the vertical support panel  202  and the ramp support panel  203  to each other. 
     The support tether  300  is provided in the airbag cushion  200  to maintain the entire shape of the airbag cushion  200 . 
     The support tether  300  has a “U” shape. Rear and side edges of the support tether  300  are respectively connected to the rear surface and the sidewalls of the airbag cushion  200 , in other words, the vertical support panel  202  and the side support panels  204 , by sewing. 
     The support tether  300  includes an upper support tether  300   a  and a lower support tether  300   b  which are spaced apart from each other by a predetermined distance with respect to the vertical direction of the airbag cushion  200 . Front edges of the upper and lower support tethers  300   a  and  300   b  have a round shape (R) to form the gas path  230  along which gas flows. 
     The airbag cushion  200  having the above-mentioned structure generally has a reverse right-triangular shape. The airbag cushion  200  having this shape can effectively absorb impact applied to the passenger  630  when a vehicle collision occurs. 
     Particularly, the front surface of the airbag cushion  200  is inclined and curved downwards and rearwards to prevent it from being impeded by the front seat when the airbag cushion  200  is being deployed. In detail, the front surface of the airbag cushion  200  has a shape corresponding to a track along which a head rest of the front seat moves when the front seat back is tilted forwards or rearwards. Thus, the airbag cushion  200  can be smoothly deployed without interruption. 
     Meanwhile, an airbag screen  400  is attached to the shoulder support portions  220  of the airbag cushion  200 . The airbag screen  400  covers the head support portion  210 . For example, for the case where the airbag screen  400  is attached to the shoulder support portions  220 , the shoulder support portions  220  are supported relative to each other by the airbag screen  400 . Thereby, the space between the shoulder support portions  220  can be prevented from widening to the left and the right. On the other hand, if no airbag screen is attached to the shoulder support portions  220 , when the airbag cushion  200  is deployed, the space between the shoulder support portions  220  widens to the left and the right based on the head support portion  210 , because the shoulder support portions  220  cannot be supported relative to each other. 
     Therefore, in an exemplary embodiment of the present invention, when the airbag cushion  200  is deployed by a vehicle collision, the face of the passenger  630  is covered by the airbag screen  400  and stably supported by the head support portion  210 . Thereby, impact applied to the head of the passenger  630  can be effectively absorbed by the airbag cushion  200  while it is deploying. 
     As described above, in an exemplary embodiment of the present invention, when the airbag cushion  200  is deployed in the case of a vehicle collision, gas can smoothly flow in the front portion of the airbag cushion  200 . Therefore, the time it takes the airbag cushion  200  to be completely deployed is reduced, thus making the deployment of the airbag smooth and reliable. Furthermore, the depressed head support portion  210  of the airbag cushion  200  holds the head of the passenger  630  at the initial stage of the deployment of the airbag cushion  200 . Hence, the airbag cushion  200  can effectively absorb impact applied to the passenger  630 . 
     For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. 
     The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.