Abstract:
An automotive air bag device has a panel, a folded bag installed in a deeper portion behind the panel, a cover provided in the panel and a connecting member that connects a vehicle body side with the cover. The air bag is inflated by virtue of a gas pressure to push open the cover provided so that the air bag deploy into a passenger compartment, the cover is mounted in the panel so as to be separated from the panel when the air bag is inflated and the connecting member controls a protrusion of the air bag into a passenger compartment.

Description:
[0001]     The present invention claims foreign priority to Japanese patent application No. JP-2003-205389, filed on Aug. 1, 2003, the contents of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to an improved automotive air bag device.  
         [0004]     2. Description of the Related Art  
         [0005]     Conventionally, there has been known, as an automotive air bag device, an air bag device installed in a part of a steering wheel (for example, See Japanese Utility Model Examined Publication JP-UM-Y-54-1711 pages 2 to 3,  FIG. 1 ).  
         [0006]      FIG. 6  is incorporated herein to show  FIG. 1  of the JP-UM-Y-54-1711. However, reference numerals are changed.  
         [0007]     Reference numeral  101  denotes a gas bag, reference numeral  102  denoting a bag housing case, reference numeral  103  denoting a lid, reference numeral  104  denoting a gas bag protruding opening, reference numeral  106  denoting a lining, reference numeral  107  denoting an elongate convex portion, and reference numeral  108  denoting an elongate concave portion.  
         [0008]      FIG. 7A and 7B  are drawings showing a drawback caused when the gas bag shown in  FIG. 6  deploys.  
         [0009]      FIG. 7A  shows an initial stage of the deployment of the gas bag. When a vehicle detects an object with which it would collide, a signal activating the gas bag is transmitted to the gas generator  105  by the action of the sensor. The gas bag  101  is inflated by a gas and is introduced thereinto. The gas bag  101  dislocates the elongate convex portions  107  that fit in the elongate concave portions  108  so as to push up the lid  103  and starts to deploy into the passenger compartment from the gas bag protruding opening  104 .  
         [0010]      FIG. 7B  is a drawing showing a drawback caused in an intermediate stage of the deployment of the gas bag. When the gas bag  101  fills with the gas from the gas generator  105 , the lid  3  opens like a door that opens on one side thereof or in a cantilever-like fashion. The deployment direction of a gas bag distal end portion  110  is caused to deviate (for example, to the diagonally left front), whereby there may be caused a risk that the deployment of the gas bag becomes incomplete.  
         [0011]     Thus, in the patent literature JP-UM-Y-54-1711, the gas bag  101  is subject to the resistance of the lid  103  and the deployment direction thereof is caused to deviate. Thereby there may be caused a risk that the gas bag  101  cannot deploy into a uniform parabola.  
       SUMMARY OF THE INVENTION  
       [0012]     Then, an object of the invention is to provide an automotive air bag device which can deploy an air bag more uniformly.  
         [0013]     With a view to attaining the object, according to a first aspect of the invention, there is provided an automotive air bag device has a panel, a folded bag installed behind the panel, a cover provided in the panel, and a connecting member that connects a vehicle body side with the cover. Wherein the air bag is inflated by virtue of a gas pressure to push open the cover so that the air bag deploy into a passenger compartment, the cover is mounted in the panel so as to be separated from the panel when the air bag is inflated, and the connecting member controls a protrusion of the air bag into a passenger compartment.  
         [0014]     According to a second aspect of the present invention as set forth in the first aspect of the present invention, wherein the connecting body comprises at least two parallel pieces so that the cover moves in a substantially parallel posture to a surface of the panel.  
         [0015]     According to a third aspect of the present invention as set forth in the first aspect of the present invention, the automotive air bag device further has a thinned portion provided between the cover and the panel. Wherein the cover is provided in the panel via a thinned portion.  
         [0016]     According to a fourth aspect of the present invention as set forth in the first aspect of the present invention, wherein the panel is an instrument panel.  
         [0017]     According to a fifth aspect of the present invention as set forth in the first aspect of the present invention, wherein the connecting member is string-like shape.  
         [0018]     According to a sixth aspect of the present invention as set forth in the first aspect of the present invention, wherein the connecting member is ribbon-like shape.  
         [0019]     According to a seventh aspect of the present invention as set forth in the first aspect of the present invention, wherein the cover has a protrusion portion, and the panel has a recessed portion that engages with the protrusion portion of the cover.  
         [0020]     According to an eighth aspect of the present invention as set forth in the first aspect of the present invention, wherein a distal end of the air bag is a parabola-like pattern while a central portion thereof is restrained from the deployment by the cover.  
         [0021]     According to a ninth aspect of the present invention as set forth in the first aspect of the present invention, wherein the material of the panel is different from a material of the cover.  
         [0022]     According to a tenth aspect of the present invention as set forth in the first aspect of the present invention, wherein the cover is formed separately from the cover.  
         [0023]     According to an eleventh aspect of the present invention as set forth in the first aspect of the present invention, wherein the connecting body is made of an elastic rubber or a synthetic resin.  
         [0024]     According to a twelfth aspect of the present invention as set forth in the first aspect of the present invention, wherein the automotive air bag device is provided on a lower portion of an instrument panel.  
         [0025]     According to a thirteenth aspect of the present invention as set forth in the first aspect of the present invention, wherein the automotive air bag device is provided so as to be opposed to a knee portion of an occupant.  
         [0026]     According to a fourteenth aspect of the present invention as set forth in the third aspect of the present invention, wherein the thinned portion, the cover and the panel are integrally formed.  
         [0027]     According to a fifteenth aspect of the present invention as set forth in the first aspect of the present invention, wherein the connecting member is provided in an inner side of the air bag.  
         [0028]     According to a sixteenth aspect of the present invention according to the first aspect of the present invention, wherein the connecting member has a first fixing portion that fixes to the cover, the first fixing portion controls a protrusion of the air bag into a passenger compartment when the air bag is inflated.  
         [0029]     According to a seventeenth aspect of the present invention as set forth in the first aspect of the present invention, wherein the connecting member has a second fixing portion that fixes to the vehicle body side, the second fixing portion is provided on a surface of the vehicle body side so as to oppose to the cover. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]      FIG. 1  is a drawing of an automobile air bag system into which an air bag device according to the invention is incorporated.  
         [0031]      FIG. 2  is a drawing showing a mounting example of the air bag device according to the invention.  
         [0032]      FIG. 3  is a cross-sectional view of a main part of the air bag device when the air bag is not inflated.  
         [0033]      FIG. 4A  is a first explanatory drawing for explaining a function of the air bag device when the device is deployed.  
         [0034]      FIG. 4B  is a second explanatory drawing for explaining a function of the air bag device when the device is deployed.  
         [0035]      FIG. 4C  is a third explanatory drawing for explaining a function of the air bag device when the device is deployed.  
         [0036]      FIG. 5A  is a drawing another embodiment which differs from the embodiment illustrated in  FIG. 3 .  
         [0037]      FIG. 5B  is a drawing another embodiment which differs from the embodiment illustrated in  FIG. 5A .  
         [0038]      FIG. 6  is a drawing incorporated herein to show FIG. 1 of JP-UM-Y-54-1711.  
         [0039]      FIG. 7A  is a first drawing illustrating a drawback of a gas bag illustrated in  FIG. 6  which results when the gas bag is deployed.  
         [0040]      FIG. 7B  is a second drawing illustrating a drawback of a gas bag illustrated in  FIG. 6  which results when the gas bag is deployed. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0041]     Embodiments of the invention will be described based on the accompanying drawings. Note that the drawings are to be seen in a direction in which reference numerals stand properly.  
         [0042]      FIG. 1  shows an automotive air bag system into which an air bag device according to the invention is incorporated, in which reference numeral  10  denotes an automobile, reference numeral  11  denoting a vehicle body, reference numeral denoting a front wheel, reference numeral  13  denoting a front bumper, reference numeral  14  denoting a headlamp, reference numeral  15  denoting a bonnet, reference numeral  16  denoting a windscreen, reference numeral  17  denoting a door, and reference numeral  18  denoting a front pillar.  
         [0043]     An air bag system  20  includes a primary driver air bag device  21  and a secondary driver air bag device  22  which are both designed to protect the driver, a front seat passenger air bag device  23  for protecting a front seat passenger, an acceleration sensor  24  for detecting an impact given to the automobile  10 , a detection sensor  25  for detecting that the front bumper  13  hits an object, and a control unit  26  for inflating and deploying the primary driver air bag device  21 , the secondary driver air bag device  22  and the front seat passenger air bag device  23  based on information received from the acceleration sensor  24  and the detection sensor  25 .  
         [0044]     Namely, when the acceleration sensor  24  detects an impact which exceeds a predetermined value and when the detection sensor  25  detects that the automobile  10  has hit an object, the control unit  26  detects the impact that has been transmitted thereto as indicated by an arrow  1  and an arrow  2  and sends out signals as indicated by arrows  3 , so that the primary driver air bag device  21 , the secondary driver air bag device  22  and the front seat passenger air bag device  23  are caused to expand to deploy, whereby the air bag system  20  is activated.  
         [0045]      FIG. 2  is a drawing illustrating an example of mounting an air bag device according to the invention, and, for example, the secondary driver air bag device  22  is installed in a deeper portion behind a panel lower  32  of an instrument panel  31 , the installation place largely differing from a conventional one in which the air bag device is installed in a part of a steering wheel  33 . Note that reference numeral  34  denotes the knee of the driver.  
         [0046]      FIG. 3  is a cross-sectional view of a main part of the air bag device when the air bag device is not inflated. The secondary driver air bag device  22  is a structure including an accommodating container main body  41 , main body fixing portions  42 ,  42  which fit in panel connecting portions  36 ,  36 , respectively, in a deeper portion  35  behind the panel lower  32  of the instrument panel  31  (refer to  FIG. 2 ) , a bag  43  compressed and folded in the interior of the accommodating container main body  41 , a cover  44  for pressing down the air bag  43 , strings or similar connecting bodies  45  connected to the cover  44 , strings or similar connecting bodies connecting portions  46  for connecting the cover  44  and the strings or similar connecting bodies  45 , a vehicle body side strings or similar connecting bodies connecting portion  47  for connecting the other ends of the strings or similar connecting bodies  45  to the vehicle body side, thinned portions  48 ,  48  disposed on upper and lower sides of the cover  44  and located between the instrument panel lowers  32 ,  32  and gas introducing ports  49 ,  49  through which gas is blown into the air bag  43  for deployment thereof.  
         [0047]      FIG. 4A  to  FIG. 4C  are explanatory drawings explaining the function of the air bag device when it deploys.  
         [0048]      FIG. 4A  shows the air bag device when it is not inflated, and the air bag device remains exactly the same as the structure illustrated in  FIG. 3 , wherein the air bag  43  is accommodated in the interior of the accommodating container main body  41  in a compressed and folded state.  
         [0049]      FIG. 4B  shows an initial stage of the inflation and deployment of the air bag. When an impact detected by the acceleration sensor  24  and the detection sensor  25 , which are shown in  FIG. 1 , is transmitted to the control unit  26 , a signal sent out from the control unit  26  is then transmitted to the gas generator, whereby a gas (mainly, air is used) enters the interior of the air bag  43  through the gas introducing ports  49  as indicated by arrows  4 . The air bag  43  that is so inflated pushes out the cover  44  and breaks the thinned portions  48 ,  48  (refer to  FIG. 4A ), and a bag distal end  51  of the air bag  43  that has started to deploy dashes out from the thinned portions so broken.  
         [0050]      FIG. 4C  shows a final stage of the inflation and deployment of the air bag. The distal end  52  of the air bag that has been completely inflated and deployed then dashes out into the passenger compartment side. As this occurs, since the cover  44  is connected to the vehicle body side strings or similar connecting bodies connecting portion  47  via the strings or similar connecting bodies connecting portions  46  and the strings or similar connecting bodies  45 , a fly-out distance of the cover  44  is controlled by the strings or similar connecting bodies  45  which extend to a certain length when the air bag  43  is inflated and deployed at the final stage of the inflation and deployment thereof.  
         [0051]     Consequently, the distal end  52  of the air bag that has completed its inflation and deployment is formed into a parabola-like pattern while a central portion thereof is being restrained from the deployment by the cover  44 , and the inflation and deployment of the air bag is thus completed.  
         [0052]     Since the cover  44  is connected to the vehicle body side with the strings or similar connecting bodies  45 , the cover is allowed to be separated toward the passenger compartment side to such an extent that the inflation of the air bag  43  is not interrupted, and therefore, there is caused no risk that the cover  43  flies into the passenger compartment. In addition, the deployment pattern of the air bag  43  can be controlled by the cover  44  and the strings or similar connecting bodies  45 .  
         [0053]     As a result, the air bag  43  is allowed to inflate to a size which can stabilize a deploying behavior and absorb earlier energy caused by the collision, whereby a highly efficient occupant protecting performance can be obtained. In addition, an optimized deployment of the air bag  43  can be implemented by controlling the protruding amount of the distal end  52 .  
         [0054]     In addition, since the air bag  43  breaks the thinned portions  48 ,  48 , there is caused less resistance at the broken and opened portions around the cover  44 , and an air bag surface for restraining the body to be protected can be formed earlier.  
         [0055]      FIG. 5A  shows another embodiment, which differs from the embodiment illustrated in  FIG. 3 , in which a secondary driver air bag device  22  is a structure including an accommodating container main body  41 , main body fixing portions  42 ,  42  which fit in panel connecting portions  36 ,  36 , respectively, in a deeper portion  35  behind the panel lower  32  of the instrument panel  31  (refer to  FIG. 2 ), a bag  43  compressed and folded in the interior of the accommodating container main body  41 , a cover  44  for pressing down the air bag  43 , strings or similar connecting bodies  45  connected to the cover  44 , strings or similar connecting bodies connecting portions  46  for connecting the cover  44  and the strings or similar connecting bodies  45 , a vehicle body side strings or similar connecting bodies connecting portion  47  for connecting the other ends of the strings or similar connecting bodies  45  to the vehicle body side, cover convex portions  53 ,  53 , panel concave portions  54 ,  54  which fit on the cover convex portions  53 ,  53 , and gas introducing ports  49 ,  49  through which gas is blown into the air bag  43  for deployment thereof.  
         [0056]     Namely, in this embodiment, the cover  44  is constructed to be mounted in the panel lower  32  by causing the cover convex portions  53 ,  53  to fit in the panel concave portions  54 ,  54 , respectively.  
         [0057]     As a result, the instrument panel  31  (refer to  FIG. 2 ) and the cover  44  can be produced separately. The instrument panel  31  (refer to  FIG. 2 ) and the cover  44  can be freely produced from the same materials in the same color or from different materials in different colors. As a result, the degree of freedom in design can be enhanced.  
         [0058]     Note that there is imposed no particular limitation on kinds of materials for the air bag  43 , provided that flexible fabric or the material coated with rubber or synthetic resin is used.  
         [0059]     In addition, there is imposed no limitation on kinds of materials for the strings or similar connecting bodies  45 , provided that materials of rubber system or synthetic resin system which are superior in resilience and strength are used.  
         [0060]     Furthermore, there is imposed no limitation on shapes of the accommodating container main body  41  for containing the air bag  43 , and any shapes which can allow for the smooth inflation and deployment of the air bag  43  are used.  
         [0061]     While there has been described in connection with the preferred embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modification may be made therein without departing from the present invention, and it is aimed, therefore, to cover in the appended claim all such changes and modifications as fall within the true spirit and scope of the present invention.  
         [0062]     Being constructed as has been described heretofore, the invention exhibits the following advantages.  
         [0063]     According to the first aspect of the invention, since the cover is connected to the vehicle body side with the string or similar connecting body, the cover is separated toward the passenger compartment side to such an extent that the inflation of the air bag is not interrupted, and thus, there is caused no risk that the cover flies into the passenger compartment. In addition, the deployment pattern of the air bag can be controlled by the cover and the string or similar connecting body.  
         [0064]     According to the second aspect of the invention, constituting the string or similar connecting body by a plurality of pieces allows the posture of the air bag when separated to remain as stable as possible. As a result, the air bag is allowed to deploy to any other directions than one blocked by the cover to form a uniform parabolic pattern.  
         [0065]     According to the third aspect of the invention, since the cover is fixed via the thinned portions, the resistance caused by the cover when the air bag breaks the thinned portions for deployment is reduced, and thus the deployment pattern and performance of the air bag can be exhibited in an earlier stage.  
         [0066]     In addition, since the thinned portions and the cover portion can be both formed as integral parts of the panel, it is possible to produce the panel at lower costs.