JP2005206067A - Air bag device for front passenger seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air bag device for a front passenger seat capable of positively protecting the head of an occupant by suppressing reacting force when the head of the occupant is interfered with the air bag completed in inflation. <P>SOLUTION: The air bag device for the front passenger seat is provided with the air bag 10 folded/stored in a case 49 arranged on an instrument panel 1 at a front side of the front passenger seat and capable of being projected from the case 49 to the occupant P side on flowing-in of inflation gas. In the air bag 10, a central hole 11 penetrated in an approximately vertical direction is arranged. The air bag 10 is an annular body completing inflation such that the central hole 11 is closed by the base cloth inflated at a periphery. The air bag 10 is provided with a high pressure part 13; and a low pressure part 14 in which internal pressure on completion of inflation is set lower than the high pressure part 13. In the low pressure part 14, the internal pressure on completion of inflation is set higher than the atmospheric pressure and the low pressure part 14 is arranged at a position approximately opposed to the head part H of the occupant P seated at the front passenger seat on completion of inflation of the air bag 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention includes an airbag that is folded and housed in a case disposed in an instrument panel in front of a passenger seat and that can protrude from the case to the rear side of the vehicle on the passenger side when inflating gas flows. The present invention relates to an airbag device for a passenger seat.

Conventionally, in an airbag device for a passenger seat, during deployment and inflating, the airbag is protruded to the occupant side with the surface on the occupant side wide open so that partial pressing force does not act on the occupant side. It was folded and stored (see, for example, Patent Document 1).
JP 2002-255004 A

  However, in the conventional airbag device for the passenger seat, the internal pressure of the inflated airbag is high, and when the inflated airbag interferes with the occupant, the reaction force applied to the occupant is suppressed, so There was room for improvement in terms of protection. In particular, the occupant's head has a small mass, and there is room for further improvement in terms of protection by suppressing the reaction force during interference.

  The present invention solves the above-described problem, and when the occupant's head interferes with an airbag that has been inflated, the reaction force can be suppressed to accurately protect the occupant's head. An object of the present invention is to provide a passenger airbag device.

The airbag device for a passenger seat according to the present invention is folded and housed in a case disposed in an instrument panel in front of the passenger seat, and from the case to the vehicle rear side on the passenger side when inflating gas flows in. An airbag device for a passenger seat equipped with a projecting airbag,
Airbag
It is configured as an annular body that arranges a central hole penetrating in a substantially vertical direction and completes expansion so that the central hole is closed by a surrounding swelling base cloth,
A high-pressure part that is set to have a high internal pressure at the time of completion of expansion, and a low-pressure part that is set to have a low internal pressure at the time of completion of expansion than the high-pressure part.
The low pressure portion is set to have an internal pressure higher than the atmospheric pressure when the inflation is completed, and is disposed at least at a position substantially opposite to the head of the passenger seated in the passenger seat when the inflation of the airbag is completed. It is characterized by that.

  In the passenger seat airbag device according to the present invention, the airbag includes a high-pressure portion in which an internal pressure at the time of completion of inflation is set higher, and a low-pressure portion in which the internal pressure at the time of completion of inflation is set lower than the high-pressure portion. Thus, the low-pressure portion is disposed at least at a position substantially opposite to the head of the occupant seated in the passenger seat when the inflation of the airbag is completed. That is, in the passenger seat airbag device of the present invention, the head of the occupant interferes with the low-pressure portion of the airbag. In this low pressure part, the internal pressure at the completion of expansion is set higher than the atmospheric pressure and lower than the internal pressure of the high pressure part. Therefore, when the occupant's head interferes, the low-pressure portion can suppress the reaction force applied to the occupant's head and enhance the cushion effect and restrain it softly. Further, in the passenger seat airbag device of the present invention, the entire airbag is not composed of a low-pressure part, and has a high-pressure part, so when an occupant interferes with an airbag that has been inflated, It is possible to prevent bottoming or the like and to restrain the occupant with certainty.

  Therefore, in the passenger seat airbag device of the present invention, when the occupant's head interferes with the airbag that has been inflated, the reaction force can be suppressed and the occupant's head can be protected accurately.

  Further, in the passenger seat airbag device of the present invention, since the airbag is configured as an annular body provided with a central hole penetrating substantially in the vertical direction, the airbag can be used when the airbag is deployed and inflated. The inflation gas that has flowed into the interior does not flow directly toward the passenger, but once flows so as to spread in the left-right direction along the shape of the airbag. Therefore, the airbag is inflated so as to spread widely in the left-right direction in a state in which the airbag is prevented from projecting greatly to the rear side.

Furthermore, in the airbag device for a passenger seat according to the present invention, the low-pressure portion is disposed over substantially the entire area along the vertical direction on the rear side of the central hole in the airbag when the inflation is completed,
It is preferable that the high pressure part is arranged on the front side of the low pressure part.

  If the airbag device for the passenger seat is configured as described above, the low-pressure part is disposed over substantially the entire area along the vertical direction on the rear side of the central hole, so that not only the head of the passenger but also the chest part interferes. The reaction force of time can be suppressed and protected. In the passenger seat airbag device having the above-described configuration, the high-pressure section is disposed on the front side of the low-pressure section. Even if the inertial force toward the front side of the occupant is large, the occupant can be reliably restrained by the high pressure portion.

  Further, in the passenger seat airbag device having the above-described configuration, the width dimension in the left-right direction when the airbag is completely inflated in the low-pressure portion can be protected, and the head of the occupant can be protected. It is preferable that the configuration is set to a size smaller than the width size.

  When the passenger airbag device has the above-described configuration, when the passenger interferes with the airbag that has been inflated, the passenger's shoulder that can withstand a large reaction force compared to the head interferes with the high-pressure portion. It will be. That is, by restraining the shoulder portion of the occupant to the high-pressure portion, the moving speed of the occupant toward the airbag side (front side) at the time of interference can be suppressed. Therefore, the movement speed of the occupant's head when the airbag interferes can be suppressed, and the occupant's head can be protected by the low-pressure portion while further suppressing the reaction force during the interference.

Furthermore, in the passenger seat airbag device having the above-described configuration, the low-pressure portion is disposed over the entire circumference of the upper side periphery of the central hole in the airbag when the inflation is completed,
It is good also as a structure which arrange | positions a high voltage | pressure part in the lower part side of a low voltage | pressure part.

  Even when the passenger airbag device is configured as described above, when the occupant interferes with the airbag that has been inflated, the occupant's head is protected by the low-pressure part by suppressing the reaction force at the time of interference. be able to. Further, in the passenger seat airbag device configured as described above, the occupant's chest that can withstand a large reaction force compared to the head interferes with the high-pressure portion disposed on the lower side of the low-pressure portion. The moving speed of the passenger to the airbag side (front side) can be suppressed. Therefore, the movement speed of the occupant's head when the airbag interferes can be suppressed, and the occupant's head can be protected by the low-pressure portion while further suppressing the reaction force during the interference.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The vertical / front / rear / left / right relationship in this specification is based on the state in which the passenger seat airbag device M is mounted on the vehicle, and is consistent with the vertical / front / rear / left / right relationship of the vehicle when mounted. It is.

  The airbag device M for the passenger seat according to the embodiment is a top mount type disposed inside the upper panel 1a of the instrument panel (instrument panel) 1 as shown in FIGS. The airbag apparatus M includes a folded airbag 10, an inflator 47 that supplies inflation gas to the airbag 10, a case 49 that stores and holds the airbag 10 and the inflator 47, and the airbag 10 in the case 49. A retainer 45 for attachment and an airbag cover 57 covering the folded airbag 10 are provided.

  In the embodiment, the airbag cover 57 is formed integrally with the instrument panel 1 as shown in FIGS. The instrument panel 1 includes a base portion 2 made of a hard synthetic resin such as polypropylene on the back surface side, and a covering layer 3 having a foam layer such as polyurethane foam and a skin layer covering the outer surface side of the base portion 2. Configured. A soft portion 4 made of a soft synthetic resin such as an olefin-based thermoplastic elastomer is disposed in place of the base portion 2 at a portion of the airbag cover 57. The airbag cover 57 is configured by disposing two door portions 58 (58F and 58B) each having a thin portion to be broken 60 disposed therein. The planned fracture portion 60 is arranged in a substantially H shape when viewed from above the instrument panel 1, and the two door portions 58 </ b> F and 58 </ b> B are hinged portions 59 on the front end side and the rear end side, respectively. Configured to open.

  Further, a connecting wall portion 61 having a substantially rectangular tube shape that protrudes downward from the back surface side is disposed at a portion of the airbag cover 57 so as to surround the arrangement positions of the door portions 58F and 58B. A plurality of locking holes 62 are penetrated at predetermined positions of the wall portions 61 a and 61 b facing each other in the front-rear direction in the connecting wall portion 61. The locking claw 55 formed in the case 49 is inserted into the locking holes 62, and the connecting wall portion 61 is locked to the locking claw 55.

  In the case of the embodiment, the soft portion 4 includes the back surface side of the door portions 58F and 58B of the airbag cover 57, the connecting wall portion 61 itself, and the instrument panel 1 near the hinge portions 59 of the door portions 58F and 58B. It arrange | positions in the back-and-front site | part which exceeded the connection wall part 61 in the back surface side.

  As shown in FIGS. 1 and 2, the case 49 is formed in a substantially rectangular parallelepiped shape made of a sheet metal having a substantially rectangular opening 49 a on the upper end side. And a side wall 54 extending upward from the outer peripheral edge to the airbag cover 57 side in a substantially rectangular tube shape. The bottom wall portion 50 has a rectangular plate shape extending long in the left-right direction, and an insertion hole 51 that is open in a substantially circular shape in the center so that the upper side of the inflator 47 can be inserted from the lower side to the upper side on the airbag cover 57 side. I have. An attachment hole 52 through which each bolt 45 b of the retainer 45 can be inserted is formed at the periphery of the insertion hole 51 of the bottom wall portion 50. In addition, brackets 53 for connecting the case 49 to the vehicle body 6 side are fixed to the bottom wall portion 50 on the lower surface sides of the left and right side portions of the bottom wall portion 50, respectively. A nut 53 a for screwing the bolt 7 is fixed to each bracket 53. A bracket 6b extending from the reinforcement 6a is disposed on the body 6 side, and the bolt 7 passes through the mounting seat 6c of the bracket 6b and is screwed into the nut 53a. By tightening each bolt 7 to the nut 53a, the case 49, that is, the airbag apparatus M, is attached and fixed to the body 6 side.

  In addition, a plurality of locking claws 55 are formed on the side wall portion 54 of the case 49 at the upper ends of the front and rear portions of the vehicle so as to be reversed outward and downward from the case 49. As described above, each locking claw 55 is inserted into the locking hole 62 of the connecting wall portion 61 of the airbag cover 57 to lock the connecting wall portion 61.

  The inflator 47 is of a disc type provided with a substantially cylindrical main body 47a having a plurality of gas discharge ports 47b on the upper outer peripheral surface. A flange portion 47 c for attaching the inflator 47 to the case 49 is provided on the outer peripheral surface of the main body portion 47 a. The flange portion 47c is formed in a substantially quadrangular ring shape (substantially square plate shape) protruding from the outer peripheral surface of the main body portion 47a, and the attachment holes 47d are respectively passed through the four corners. Each mounting hole 47 d is disposed at a position corresponding to each mounting hole 52 of the bottom wall portion 50 of the case 49 and has an inner diameter dimension substantially the same as the inner diameter dimension of the mounting hole 52.

  The retainer 45 is formed of a sheet metal, and has a base portion 45a provided with a hole that opens substantially in the same shape as the insertion hole 51 of the case 49, and a substantially rectangular tube shape extending upward from the outer peripheral edge of the base portion 45a to the airbag cover 57 side. And a guide wall portion 45c. The base 45a has an outer peripheral edge formed in a substantially square shape (substantially square shape), and bolts 45b extending downward are fixed to the four corner portions. Each bolt 45b is provided with the retainer 45 disposed in the airbag 10, and the mounting hole 23 of the airbag 10, the mounting hole 52 of the bottom wall 50 of the case 49, and the mounting hole of the flange 47c of the inflator 47. The airbag 10 and the inflator 47 are attached to the bottom wall portion 50 of the case 49 by being inserted into 47 d and tightening the nut 46. That is, when the nut 46 is tightened to each bolt 45b, the peripheral edge 21 of the gas inlet 22 of the airbag 10 is pressed against the bottom wall portion 50 by the base portion 45a, and the airbag 10 is attached to the bottom wall portion 50. The flange portion 47 c of 47 is pressed against the peripheral edge of the insertion hole 51, and the inflator 47 is attached to the bottom wall portion 50.

  As shown in FIGS. 3 to 5, the airbag 10 has a substantially quadrangular pyramid shape as an inflation completion shape, and a central hole 11 that penetrates is disposed so as to be substantially along the vertical direction near the center at the time of inflation completion. Thus, it is configured as an annular body that completes the expansion so that the central hole 11 is closed by the surrounding base cloths 26 and 30. That is, in the airbag 10, the annular main body portion 12 that is inflated and inflated includes the front inflating portion 16, the rear inflating portion 17, the left inflating portion 18, and the right inflating portion 19 around the central hole 11. Let it be configured.

  Further, the airbag 10 of the embodiment has a high pressure portion 13 in which the internal pressure at the time of completion of inflation is set higher by the partition portions 15 and 15 and a low pressure in which the internal pressure at the time of completion of inflation is set lower than the high pressure portion 13. The section 14 is divided into two parts. The low-pressure part 14 is disposed at a position substantially opposite to the head H of the occupant P seated in the passenger seat when the airbag 10 is completely inflated. In the embodiment, the low-pressure part 14 is an area of the rear inflating part 17. In the inside, it is arrange | positioned over the substantially whole area along the up-down direction in the position used as the center vicinity of the left-right direction. The high-pressure part 13 includes the vicinity of the left and right ends of the rear expansion part 17 that is the left and right sides of the low-pressure part 14, and the entire front side, left side, and right expansion parts 16, 18, and 19 that are the front side of the low-pressure part 14. , Are arranged.

  The low-pressure part 14 is configured so that the internal pressure at the completion of the expansion is higher than the atmospheric pressure. In the embodiment, the width dimension w1 in the left-right direction at the completion of the expansion is set as shown in FIG. The width is set to be smaller than the width in the left-right direction of the shoulder S at P. Of course, the width dimension w1 in the left-right direction of the low-pressure part 14 is set to a dimension that can protect the head H of the seated passenger P when the airbag 10 is completely inflated.

  A gas inflow port 22 that is opened in a circular shape so as to allow the inflating gas G to flow in and attaches the peripheral edge 21 to the case 49 is disposed in the front side expansion portion 16 that constitutes the high pressure portion 13. A plurality of mounting holes 23 are formed in the peripheral edge of the gas inlet 22 to allow the bolt 45 b of the retainer 45 to pass through and attach the inlet peripheral edge 21 to the bottom wall 50 of the case 49. Two reinforcing cloths 36 and 37 are sewn and arranged on the inflow port peripheral edge 21 on the inner peripheral surface side of the airbag 10, and further, the stitched portion is protected on the upper surface side of the reinforcing cloth 37. The reinforcing cloth 38 is arranged without being sewn. Further, vent holes 24 for exhausting excess inflation gas G are opened in a substantially circular shape at the left and right inflating portions 18 and 19 constituting the high-pressure portion 13.

  In the embodiment, the partition wall 15 that divides the low-pressure part 14 and the high-pressure part 13 is arranged along the vertical direction so as to partition the rear expansion part 17 on both the left and right sides of the low-pressure part 14. . Each partition wall 15 is formed with a gas outflow hole 15 a that allows the inflation gas G that has flowed into the high pressure portion 13 to flow out to the low pressure portion 14 side when the airbag 10 is deployed and inflated. The gas outflow holes 15a are provided in the low-pressure portion 14 so that the internal pressure of the low-pressure portion 14 is higher than the atmospheric pressure and lower than the internal pressure of the high-pressure portion 13 when the inflation of the airbag 10 is completed. It is set so that G can flow in. That is, in the airbag 10 of the embodiment, the gas outflow holes 15a of the partition wall portion 15 are arranged in consideration of the outflow of the inflation gas G from the vent hole 24 arranged on the high pressure portion 13 side. Thus, when the inflation of the airbag 10 is completed, the internal pressure of the low pressure portion 14 is set to be higher than the atmospheric pressure and lower than the internal pressure of the high pressure portion 13. In the illustrated example, the gas outflow hole 15a is disposed at one location near the center of the partition wall 15 (see FIGS. 4 to 6).

  As shown in FIGS. 3 to 6, the airbag 10 of the embodiment is opposed to the inner peripheral base fabric 26 located on the inner peripheral surface side of the central hole 11 and the inner peripheral base fabric 26 when the inflation is completed. The outer peripheral side fabric 30 positioned on the outer peripheral surface side of the airbag 10 and the two partition wall portion base fabrics 34 constituting the partition wall portion 15 that partitions the high pressure portion 13 and the low pressure portion 14. ing. As shown in FIG. 6, the inner peripheral base fabric 26 includes a curved first inner base fabric 27 on the front side and a rectangular plate-shaped second inner base fabric 28 on the rear side. The outer peripheral base fabric 30 is composed of a curved first outer base fabric 31 on the front side, and a second outer base fabric 32 that becomes the occupant side surface 25 on the rear side. These base fabrics 27, 28, 31, 32, and 34 are formed from flexible woven fabrics such as polyester yarns and polyamide yarns together with reinforcing fabrics 36, 37, and 38 to be described later. It is configured as a non-coated cloth to which a coating agent is not applied.

  The first inner base fabric 27 is bent from the portion constituting the rear surface 16b side of the front side expansion portion 16 and extends to both sides on the rear side so that the inner side surfaces 18b and 19b of the left side expansion portion 18 and the right side expansion portion 19 are extended. The part which comprises is arrange | positioned and it is comprised. The outer surface 18a / 19a side of the left side expansion part 18 and the right side expansion part 19 is curved so as to bend and extend from the part constituting the front surface 16a side of the front side expansion part 16 to both sides on the rear side. The part which comprises is arrange | positioned and it is comprised. The second inner base fabric 28 becomes a part constituting the front surface 17a of the rear side expansion part 17, and the second outer base cloth 33 becomes a part constituting the rear surface 17b of the rear side expansion part 17. In the case of the embodiment, the rear surface 17b of the rear inflating portion 17 constitutes a surface 25 that becomes the occupant side when the airbag 10 is deployed and inflated. A gas inflow port 22 and a mounting hole 23 are disposed in a portion of the first outer base fabric 31 on the front side (front surface 16a side).

  The partition wall fabric 34 constituting the partition wall 15 that partitions the high pressure section 13 and the low pressure section 14 is disposed along the vertical direction in the vicinity of the left and right edges of the rear inflating section 17. Are sewn to the second inner base fabric 28 and the second outer base fabric 32 over the entire circumference. A portion of the rear surface 17b (occupant side surface 25) of the rear inflatable portion 17 that is surrounded by the left and right partition walls 15 (the surface on the rear surface side of the low pressure portion 14) is the occupant P when the inflation of the airbag 10 is completed. The head restraint surface 25a is opposite to the head H of the head. Further, in the occupant side surface 25, a portion (a surface on the rear surface side of the high pressure portion 13) disposed on the outer side of the left and right partition walls 15 is the shoulder S of the occupant P when the airbag 10 is completely inflated. The shoulder portion restraining surfaces 25b and 25b are restrained.

  Next, manufacture of the airbag 10 of embodiment is demonstrated. In the case of the embodiment, the airbag 10 (annular main body portion 12) is formed by stitching using a suture thread 40 such as a polyester thread. First, the lower edges 27d and 32d of the first inner base fabric 27 and the first outer base fabric 32 are stitched together. Next, the left edge 28b of the second inner base fabric 28 and the left edge 27b of the first inner base fabric 27 are stitched together, and the right edge 28c of the second inner base fabric 28 and the right end of the first inner base fabric 27 are sewn. The side edge 27c is sewn to form an annular inner peripheral base fabric 26. Further, the left edge 33b of the second outer base cloth 33 and the left end edge 32b of the first outer base cloth 32 are sewn together, and the right edge 33c of the second outer base cloth 33 and the right end of the first outer base cloth 32 are sewn. The edge 32c on the side is sewn to form an annular outer peripheral base fabric 30. The reinforcing cloths 36 and 37 are sewn to the first outer base cloth 31 in advance. The gas inlet 22 and the mounting hole 23 may be formed in the base cloth 31 and the reinforcing cloths 36, 37, and 38, respectively, or the base cloth 31 and the reinforcing cloths 36 and 37 are sewn and reinforced. After placing the cloth 38, the gas inlet 22 and the mounting hole 23 may be integrally formed by drilling.

  Next, the lower edge 28d of the second inner base fabric 28 in the inner peripheral base fabric 26 and the lower edge 32d of the second outer base fabric 32 in the outer peripheral base fabric 30 are sewn, so that the seam allowance of the stitched portion is air. The base fabrics 26 and 30 are inverted so as not to be exposed on the outer peripheral surface of the bag 10. Then, the peripheral edge of each partition wall base fabric 34 is sewn to a predetermined position of the base fabrics 26 and 30. Thereafter, the upper edges 27a and 31a of the first inner base cloth 27 and the first outer base cloth 31 are stitched together, and the upper edges 28a and 32a of the second inner base cloth 28 and the second outer base cloth 32 are connected to each other. If it sews, the cyclic | annular main-body part 12 (airbag 10) of embodiment can be formed.

  The mounting of the airbag 10 manufactured as described above on the vehicle will be described. First, the airbag 10 is folded with the retainer 45 disposed therein so that the bolts 45b protrude from the mounting holes 23. Further, the folded airbag 10 is wrapped with a breakable wrapping sheet 42 (see FIG. 2) so as not to collapse. Then, the folded airbag 10 is placed on the bottom wall portion 50 of the case 49 from the opening 49 a while the bolts 45 b are inserted through the attachment holes 52 from above. Next, the upper part of the main body 47a of the inflator 47 is inserted from below into the insertion hole 51, the gas inlet 22, and the base 45a of the retainer 45, and each bolt 45b protruding downward from the bottom wall 50 is inserted. The flange 47c of the inflator 47 is inserted into the mounting hole 47d. Thereafter, when the nut 46 is fastened to each bolt 45 b protruding from the flange portion 47 c of the inflator 47, the folded airbag 10 and the inflator 47 can be attached to the bottom wall portion 50 of the case 49.

  Thereafter, the side wall portion 54 of the case 49 is inserted into the connecting wall portion 61 of the airbag cover 57 in the instrument panel 1 mounted on the vehicle, and the locking claws 55 of the case 49 are inserted into the locking holes 62 of the connecting wall portion 61. The locking claws 55 are locked to the connecting wall portion 61. Further, if the bolt 7 is fastened to the nut 53a of each bracket 53 via the mounting seat 6c, the passenger seat airbag device M can be mounted on the vehicle.

  In addition, when the airbag apparatus M is mounted on a vehicle, when the instrument panel 1 is attached to the airbag cover 57 of the instrument panel 1 by attaching the case 49 to which the airbag 10 and the inflator 47 are attached in advance, the bolt 7 The airbag device M may be mounted on the vehicle by connecting and fixing the airbag device M to the body 1 side.

  If the inflation gas G is discharged from the gas discharge port 47b of the inflator 47 after the airbag device M is mounted on the vehicle, the airbag 10 expands to break the wrapping sheet 42 and the airbag cover 57. Then, the door 60 F and 58 B are opened as shown by two-dot chain lines in FIGS. The airbag 10 projects greatly from the opening 63 formed by opening the door portions 58B and 58F of the airbag cover 57, completes the expansion, and discharges the excess inflation gas G from the vent hole 24. It will be. 1 and 8 is a windshield.

  In the passenger seat airbag apparatus M according to the embodiment, the airbag 10 includes a high pressure portion 13 in which an internal pressure at the time of completion of inflation is set high, and a low pressure portion in which the internal pressure at the time of completion of inflation is set lower than the high pressure portion 13. 14 and the low pressure portion 14 is disposed at least at a position substantially opposite to the head H of the occupant P seated in the passenger seat when the airbag 10 is completely inflated. It becomes. That is, in the airbag apparatus M of the embodiment, the head H of the occupant P interferes with the portion of the low-pressure part 14 in the airbag 10. The low pressure portion 14 is set so that the internal pressure at the completion of expansion is higher than the atmospheric pressure and lower than the internal pressure of the high pressure portion 13. For this reason, when the head H of the occupant P interferes, the low-pressure portion 14 can suppress the reaction force applied to the head H of the occupant P, thereby enhancing the cushion effect and restraining it softly. Further, in the airbag apparatus M of the embodiment, since the entire airbag 10 is not composed of the low-pressure part 14 and includes the high-pressure part 13, the occupant P interferes with the airbag 10 that has completed the inflation. In this case, it is possible to prevent bottoming and the like, and the occupant P can be reliably restrained.

  Therefore, in the passenger seat airbag apparatus M of the embodiment, when the head H of the occupant P interferes with the airbag 10 that has been inflated, the reaction force is suppressed and the occupant P's head H is accurately positioned. Can be protected.

  Further, in the passenger seat airbag apparatus M of the embodiment, the airbag 10 is configured as an annular body provided with a central hole 11 penetrating substantially in the vertical direction, and as shown in FIG. When the bag 10 is deployed and inflated, the inflating gas G that has flowed into the airbag 10 does not flow directly toward the occupant side, but temporarily flows in the left-right direction along the shape of the airbag 10. Will be. For this reason, the airbag 10 is inflated so as to spread widely in the left-right direction in a state in which the airbag 10 is prevented from largely projecting backward (see FIG. 7).

  Furthermore, in the airbag apparatus M of the embodiment, as shown in FIG. 8, the low-pressure part 14 is disposed over substantially the entire area along the vertical direction on the rear side of the central hole 11 in the airbag 10 when the inflation is completed, The high pressure part 13 is arranged on the front side of the low pressure part 14. Therefore, not only the head H of the occupant P but also the chest B can be protected by the low-pressure part 14 while suppressing the reaction force at the time of interference. And since the high voltage | pressure part 13 is arrange | positioned in the front part side of the low voltage | pressure part 14, the passenger | crew P who interfered with the airbag 10 which completed the inflation is restrained by the high voltage | pressure part 13 via the low voltage | pressure part 14. Thus, even if the inertial force toward the front side of the occupant P is large, the occupant P can be reliably restrained by the high pressure portion 13.

  Furthermore, in the airbag apparatus M of the embodiment, as shown in FIG. 7, the width dimension w1 in the left-right direction when the airbag 10 is completely inflated in the low-pressure portion 14 can be protected. Thus, the dimension is set to be smaller than the width dimension in the left-right direction of the shoulder S in the occupant P. That is, when the occupant P interferes with the airbag 10 that has been inflated, the shoulder S of the occupant P that can withstand a reaction force larger than that of the head H is the rear surface (shoulder constraining surface 25b ) To be restrained by the high pressure portion 14. Therefore, by restraining the shoulder portion S with the high pressure portion 14, the moving speed of the occupant P toward the airbag 10 (front side) at the time of interference can be suppressed. As a result, the moving speed of the head H of the occupant P to the airbag 10 side (front side) when the airbag 10 interferes can be suppressed, and the occupant P's head H can be moved by the low-pressure unit 14 when the interference occurs. The reaction force can be further suppressed and protected. Of course, if such a point is not taken into consideration, an airbag having a configuration in which the rear inflating portion 17 is the low pressure portion 14 over the entire area may be used.

  Moreover, you may use the thing of the structure shown to FIGS. The airbag 10A has a low-pressure portion 14A disposed over the entire circumference of the upper peripheral edge of the central hole 11 when the inflation is completed so as to substantially face the head H of the occupant P seated in the passenger seat. 13A is arranged on the lower side of the low pressure portion 14A. The airbag 10A has the same configuration as the airbag 10 described above except for the arrangement position of the low-pressure part 14A and the high-pressure part 13A and the arrangement position of the partition wall part 15A that partitions the low-pressure part 14A and the high-pressure part 13A. The same reference numerals are assigned and description thereof is omitted. Also in the airbag 10A, the partition wall 15A is formed with a gas outflow hole 15a that allows the inflation gas G flowing into the high pressure portion 13A to flow out to the low pressure portion 14A side (see FIG. 10). In the case of the embodiment, as shown in FIGS. 10 and 11, the partition wall portion 15A is disposed so that the front side, the rear side, the left side, and the right side expansion portions 16, 17, 18, and 19 are divided into upper and lower parts, respectively. Has been. Also in the airbag 10A of the embodiment, the low pressure portion 14A is set so that the internal pressure at the completion of the inflation is lower than the high pressure portion 13A and higher than the atmospheric pressure.

  Also in the airbag apparatus using the airbag 10A having the above-described configuration, when the occupant P interferes with the airbag 10A that has been inflated, as shown in FIG. Therefore, the reaction force at the time of interference can be suppressed and protected. In the airbag device using the airbag 10A having the above-described configuration, the chest B of the occupant P that can withstand a reaction force larger than that of the head H is provided with the high-pressure portion 13A disposed on the lower side of the low-pressure portion 14A. Therefore, the movement speed of the occupant P toward the airbag 10A (front side) at the time of the interference can be suppressed. Therefore, the moving speed of the head H of the occupant P when the airbag 10A interferes can be suppressed, and the head H of the occupant P can be protected by the low-pressure portion 14A by further suppressing the reaction force at the time of interference. it can.

  In the airbags 10 and 10A of the embodiment, the gas outflow holes 15a are provided in the partition portions 15 and 15A so that the inflation gas flowing into the high pressure portions 13 and 13A flows out to the low pressure portions 14 and 14A side. For example, the partition wall portions 15 and 15A may be made of a base cloth having a predetermined gas permeation performance and the gas outflow holes may not be provided. Furthermore, as a airbag, it is good also as a structure which isolate | separates a high pressure part and a low pressure part completely, and inflate each using another inflator.

It is sectional drawing of the vehicle front-back direction of the airbag apparatus for passenger seats which is one Embodiment of this invention. It is a general | schematic expanded sectional view of the vehicle front-back direction of the airbag apparatus of the embodiment. It is a perspective view of the state where the air bag used for the embodiment was inflated alone. It is sectional drawing of the left-right direction of the state which expanded the airbag used for the embodiment alone. It is sectional drawing of the up-down direction of the state which expanded the airbag used for the embodiment alone. It is a top view which shows the member which comprises the airbag used for the same embodiment. It is a figure explaining the action | operation time of the airbag apparatus of the embodiment, and is the schematic seen from the upper side of the vehicle. It is a figure explaining the time of the action | operation of the airbag apparatus of the embodiment, and is the schematic seen from the side of the vehicle. It is a perspective view of the state where the air bag of other forms was inflated alone. It is sectional drawing of the up-down direction of the state which expanded the airbag of FIG. 9 alone. It is sectional drawing of the left-right direction in the state which expanded the airbag of FIG. 9 alone, and respond | corresponds to the XI-XI site | part of FIG. It is a figure explaining the time of the action | operation of the airbag apparatus using the airbag of another form, and is the schematic seen from the side of a vehicle.

Explanation of symbols

1 ... Instrument panel,
10.10A ... Airbag,
11 ... central hole,
13.13A ... High pressure part,
14.14A ... Low pressure part,
15 ... partition wall,
15a ... Gas outflow hole,
17 ... rear expansion part,
22 ... gas inlet,
24 ... Benthole,
25 ... Crew side,
25a ... head restraint surface,
25b ... Shoulder restraint surface,
47 ... Inflator,
49 ... Case,
57 ... Airbag cover,
B ... Chest,
G ... expansion gas,
H ... head,
P ... Crew,
S ... shoulder,
M ... Airbag device for passenger seat.

Claims (4)

For passenger seats that are folded and housed in a case placed on the instrument panel in front of the passenger seat and that have an airbag that can protrude from the case toward the rear of the vehicle on the passenger side when inflating gas flows An airbag device,
The airbag is
It is configured as an annular body that arranges a central hole penetrating in a substantially vertical direction and completes expansion so that the central hole is closed by a surrounding swelling base cloth,
A high-pressure part that is set to have a high internal pressure at the completion of expansion, and a low-pressure part that is set to have a low internal pressure at the time of completion of expansion than the high-pressure part.
The low-pressure portion is set to have an internal pressure higher than atmospheric pressure at the time of completion of inflation, and is disposed at least at a position substantially opposite to the head of an occupant seated in the passenger seat at the time of completion of inflation of the airbag. An airbag device for a passenger seat, characterized in that The low-pressure portion is disposed over substantially the entire region along the vertical direction on the rear side of the central hole in the airbag when the inflation is completed,
The airbag device for a passenger seat according to claim 1, wherein the high pressure portion is disposed on a front portion side of the low pressure portion.   The low-pressure portion is set to have a width dimension in the left-right direction when the airbag is completely inflated, which can protect the head of the occupant and is smaller than the width dimension in the left-right direction of the shoulder portion of the occupant. The airbag device for a passenger seat according to claim 2, wherein the airbag device is for a passenger seat. The low-pressure portion is disposed over the entire circumference of the upper-side peripheral edge of the central hole in the airbag when inflation is completed,
The airbag device for a passenger seat according to claim 1, wherein the high pressure portion is disposed on a lower side of the low pressure portion.

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