JP2008114662A - Airbag device for driver's seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an airbag device for a driver's seat, which can accurately prevent such a forward movement as to raise the driver's hips. <P>SOLUTION: In the activation, the airbag device M for the driver's seat comprises an airbag 10 having the periphery of an inflation gas flowing-in opening 11, which is mounted to a boss portion B of a steering wheel W, inflating to cover the upper surface side of a ring portion R. The airbag 10 comprises an outer bag 15 and an inner bag 20. The inner bag 20 comprises a flowing-out port 27 to make the inflation gas flow from the flowing-in opening 11 into an outer bag 15 side. While the form in which the inflation is completed is maintained, the inner bag 20 comprises a front side arm portion 23F and a rear side arm portion 23B to press both sides of a front and a rear of the ring portion downwards, and to be able to maintain the pressed state. At the completion of inflation, the outer bag 15 comprises a presser 18 arranged in the upper surface side of a femoral region DT of the seated driver D, capable of restricting the upward movement of the femoral region DT in a rear edge 15d side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an airbag device for a driver's seat that is mounted on a steering wheel disposed in front of a seated driver, and more specifically, includes an outer bag and an inner bag disposed in the outer bag. The present invention relates to an airbag device for a driver's seat.

  Conventionally, as an airbag of a driver's seat airbag device, the periphery of an inflow opening for inflation gas is attached to a boss portion of a steering wheel, an outer bag that constitutes an outer peripheral wall of the airbag, and an inflow And an inner bag disposed in the outer bag so as to cover the opening (see, for example, Patent Documents 1 and 2). The inner bag has an outlet that allows the inflation gas flowing in through the inflow opening to flow out to the outer bag side.

  Then, the outlet of the inner bag is controlled, for example, to the abdomen of the driver so that the direction of the inflation gas flowing out to the outer bag can be controlled and the inflated shape of the outer bag can be adjusted from the beginning of inflation to the completion of inflation. In order to adjust the shape to a shape that can be quickly arranged, etc., it has been arranged.

Further, although it is not a driver seat airbag device, the passenger seat airbag device is configured so that the inner bag of the airbag is longer than the length in the front-rear direction when the outer bag is completely inflated. In the initial stage of inflation, the inner bag is inflated long in the front-rear direction to reduce the moving speed of the outer bag toward the occupant, thereby reducing the unnecessary pressing force on the occupant in the early stage of inflation of the airbag. Some have adjusted the expansion form of a bag (for example, refer patent document 3).
Japanese Patent Laid-Open No. 9-220995 JP 2001-80440 A JP 2002-254999 A

  However, in the event of a vehicle collision, if the driver does not wear a seat belt and the kinetic energy of the forward movement is increased, the driver will lift his / her waist from the seat he was sitting on. In such a case, the air bag may hit an airbag that has been inflated, and in this case, the driver may move to the windshield without being received by the air bag.

  The present invention solves the above-described problems, and an object of the present invention is to provide a driver-seat airbag apparatus capable of accurately suppressing forward movement that lifts the driver's waist.

An airbag device for a driver's seat according to the present invention includes a ring portion that is gripped during steering and a boss portion that is disposed at the center of the ring portion, and is provided on an upper portion of a boss portion of a steering wheel that is disposed on the front side of the driver. Installed,
In operation, it is configured to include an airbag that inflates so as to cover the upper surface side of the ring portion by flowing in the inflation gas,
The airbag has a configuration in which the periphery of the inflow opening for inflating gas is attached to the boss portion, an outer bag constituting the outer peripheral wall of the airbag, and an inner disposed in the outer bag so as to cover the inflow opening. And a bag,
The inner bag is an airbag device for a driver's seat that is configured to include an outflow port that causes the inflation gas flowing in through the inflow opening to flow out to the outer bag side,
When the inflating gas is introduced, the inner bag of the airbag extends to the front and rear sides beyond the upper surfaces of the front and rear portions of the ring portion, and the inflation gas is introduced to maintain the inflated complete shape. In between, the front and rear arms of the ring part are pressed downward, and the front arm part and the rear arm part that can maintain the pressed state are provided,
The air bag outer bag is disposed on the upper surface side of the seated driver's thigh when inflation is completed, and the presser portion that can regulate the upward movement of the seated driver's thigh is arranged on the rear edge side. , And comprising.

  In the driver airbag device according to the present invention, during operation, the inflation gas flows into the inner bag from the inflow opening, the inflation of the inner bag is completed, and the inflation gas flows from the outlet of the inner bag to the outer bag. It will flow into the bag and the outer bag will complete the expansion.

  When the airbag is inflated, the presser portion on the rear edge side of the outer bag is arranged on the upper surface side of the thigh of the seated driver so that the seated driver can lift the waist. However, since the upward movement of the driver's thigh is restricted, the forward movement that lifts the driver's waist can be suppressed.

  Further, since the inner bag is configured to hold the front and rear sides of the ring portion downward while the inflation gas is introduced to maintain the inflation completion shape, the outer bag is When the bag is completely inflated, the presser part is easily deployed between the rear part of the ring part and the abdomen of the driver, and further, the outer bag itself is inflated to stabilize the thigh of the driver. The upper thigh can be placed in a state in which the movement of the thigh is swollen in a restrictable manner. And the deployment arrangement | positioning state of the press part between such a rear part of a ring part and a driver | operator's abdomen is when providing an inner bag like the baffle cloth which regulates the flow of the gas for expansion in an outer bag. Compared to the upper part of the driver's thigh by the outer bag presser portion, the inner bag of the present invention can be reliably and stably pushed out by directly supporting and guiding the presser portion of the outer bag. A state that restricts movement can be secured.

  Furthermore, the inner bag presses the upper surface side of the front portion side of the ring portion not only in the rear arm portion, but also in the front arm portion, so the outer bag suppresses the expansion to the left and right by the inner bag, While reducing the pressure on the driver's arm during straight-ahead steering, the front edge side and the rear edge side are well balanced and expanded and inflated. It is stably and smoothly arranged between the abdomen.

  Therefore, in the airbag device for a driver's seat according to the present invention, the forward movement that lifts the driver's waist can be accurately suppressed, and the driver's movement toward the windshield can be prevented.

  If the rear arm portion of the inner bag is configured to dispose the rear end side when the inflation is completed to an area where the upward movement of the thigh of the driver can be restricted, an airbag ( When the inner bag is completely inflated at the initial stage of the expansion of the outer bag, the presser portion of the outer bag can regulate the upward movement of the thigh of the driver while being pressed against the inner bag. Even if the inner bag is completely inflated even before the completion, the airbag uses the rear end side of the inner bag to restrict the upper movement of the driver's thigh by the outer bag presser. Can be secured.

  In this case, if the inner bag is configured so that the length dimension in the front-rear direction when the expansion is completed is substantially equal to the length dimension in the front-rear direction when the outer bag is expanded, the outer bag after the inner bag has been expanded. When the inner bag is inflated, the front side arm and the rear side arm of the inner bag are pressed against the ring side so that the front side and the rear side of the outer bag are inflated in a well-balanced manner. Protrusion can be suppressed.

  The inner bag has a front arm portion and a rear side at a position lower than the opening surface of the inflow opening when the inflating gas is introduced from the inflow opening having a fixed peripheral edge to complete the expansion of the inner bag alone. It is desirable that the tip of the arm is arranged.

  With such a configuration, the front arm portion and the rear arm portion of the inner bag when the inflation is completed can be strongly pressed against the ring portion side, and the presser portion on the rear edge side of the outer bag can be The development state and the balance on the front edge side can be improved, and it can be deployed more quickly and easily between the rear part of the ring part and the abdomen of the driver.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A driver's seat airbag device (hereinafter simply referred to as an airbag device) M according to an embodiment includes a steering wheel W as shown in FIGS. The steering wheel W includes a steering wheel main body 1 and an airbag device M disposed on an upper portion of a boss B at the center of the steering wheel main body 1. The steering wheel body 1 connects an annular ring portion R that is gripped during steering, a boss portion B that is disposed at the center of the ring portion R and fastened to the steering shaft SS, and the boss portion B and the ring portion R. And four spoke portions S.

  In the embodiment of the present specification, unless otherwise specified, the vertical direction corresponds to the vertical direction along the axial direction of the steering shaft SS, and the front-rear direction is the axial direction of the steering shaft SS during straight-ahead steering of the vehicle. The left-right direction corresponds to the left-right direction orthogonal to the axial direction of the steering shaft SS during straight-ahead steering of the vehicle.

  As shown in FIG. 2, the steering wheel body 1 is arranged to connect the ring part R, the boss part B, and the spoke part S, and includes a metal core 2 such as an aluminum alloy. ing. A portion of the ring portion R of the core metal 2 and a portion of each spoke portion S on the ring portion R side are covered with a synthetic resin coating layer 5. A steel boss 3 for inserting the steering shaft SS and fixing the nut N is disposed at the boss portion B of the core metal 2. A lower cover 7 made of synthetic resin is provided below the steering wheel body 1 so as to cover the lower part of the boss B.

  As shown in FIG. 2, the airbag device M includes an airbag 10 that is folded and stored, an inflator 43 that supplies an inflation gas to the airbag 10, an airbag cover 49 that covers the folded airbag 10, The air bag 10 and the inflator 43 are housed and held, and a case 45 for holding the air bag cover 49 and a retainer 41 for attaching the air bag 10 to the case 45 together with the inflator 43 are configured.

  As shown in FIGS. 2 to 4, the retainer 41 has a cylindrical main body 43 a of the inflator 43 as a quadrangular ring that can be inserted from below, and bolts 41 a that protrude downward at the four corners as shown in FIGS. It is prepared for. The retainer 41 is housed in the airbag 10 with the bolt 41a protruding, and when being attached to the case 45, each bolt 41a is connected to the through hole 46b (see FIG. 1) of the bottom wall portion 46 of the case 45. The airbag 10 and the inflator 43 are attached and fixed to the bottom wall portion 46 of the case 45 by passing through the flange portion 43c of the inflator 43 and fastening a nut (not shown) to each bolt 41a.

  As shown in FIGS. 2 to 4, the inflator 43 includes a columnar main body 43 a having a plurality of gas discharge ports 43 b at the top, and a flange 43 c that protrudes from the outer peripheral surface of the main body 43 a. Has been. A through-hole (not shown) through which each bolt 41a of the retainer 41 passes is formed in the flange portion 43c.

  As shown in FIGS. 1 and 2, the case 45 is made of sheet metal including a rectangular plate-like bottom wall portion 46 and a side wall portion 47 extending vertically from the outer peripheral edge of the bottom wall portion 46. Arranged at the top of the boss B, the folded airbag 10 is stored. The bottom wall portion 46 is formed with a circular opening 46a that allows the body portion 43a of the inflator 43 to be inserted from below, and four through holes 46b that allow the bolts 41a of the retainer 41 to pass therethrough. Is formed. A mounting piece 47a extending outward is formed at the upper end of the side wall 47, and a mounting board for a horn switch mechanism (not shown) is attached to the mounting piece 47a, and the case 45 is steered using the mounting board (not shown). The airbag device M is mounted and fixed to the core metal 2 of the wheel W, and is mounted on the upper portion of the boss portion B of the steering wheel body 1 that is already attached to the steering shaft SS. A side wall 51 of an airbag cover 49 is attached to the side wall 47 of the case 45 using a rivet 48 or the like.

  The airbag cover 49 is made of synthetic resin, and includes a ceiling wall portion 50 that covers the upper portion of the stored airbag 10, and a substantially rectangular tubular side wall portion 51 that extends downward from the vicinity of the outer peripheral edge of the ceiling wall portion 50. Configured. The ceiling wall portion 50 is formed with two door portions 50a that are pushed by the inflating airbag 10 and open to both the front and rear sides.

  The airbag 10 is configured so that the inflation completion shape is circular when viewed from above and substantially elliptic when viewed from the side, as shown by the two-dot chain line in FIGS. As shown in FIG. 3, an inflow opening 11 that opens in a circular shape so as to allow the inflation gas to flow in is provided on the lower side. At the periphery of the inflow opening 11, an attachment hole 13 is formed through which each bolt 41 a of the retainer 41 for attaching the airbag 10 to the bottom wall portion 46 of the case 45 (see FIG. 5). Therefore, in the airbag 10, the peripheral edge of the inflow opening 11 is attached and fixed to the boss portion B of the steering wheel body 1 with the bottom wall portion 46 of the case 45 interposed as the attachment portion 12 of the airbag 10. In addition, the inflow opening 11, each attachment hole 13, and the attachment portion 12 are respectively disposed in respective portions where an outer bag 15, an inner bag 20, and a tether cloth 33 described later overlap. . The overlapping state is the outer bag 15, the tether cloth 33, and the inner bag 20 from the outer peripheral side to the inner peripheral side of the airbag 10.

  And the airbag 10 of embodiment is formed from flexible woven fabrics, such as polyester and polyamide, and as shown in FIGS. 3-5, the outer bag 15 which comprises the outer peripheral wall of the airbag 10, And an inner bag 20 disposed in the outer bag 15 so as to cover the inflow opening 11. The inner bag 20 has a plurality of (four in the embodiment) so that the inflation gas G (see FIG. 2) that has flowed in through the inflow opening 11 flows out to the outer bag 15 to inflate the outer bag 15. An outlet 27 is provided.

  As shown in FIG. 5, the outer bag 15 is composed of two pieces of a vehicle body side wall portion 16 and a driver side wall portion 17 that are both circular when flattened, and are joined together by stitching the outer peripheral edges together. By this, it is comprised so that it may expand | swell to elliptical spherical bag shape. The vehicle body side wall portion 16 is located on the ring portion R side when the outer bag 15 is inflated, and the driver side wall portion 17 is located on the driver side when the outer bag 15 is inflated. An inflow opening 11 is opened at the center of the vehicle body side wall 16, and a mounting hole 13 is formed at the periphery thereof.

  Further, two tethers 32 for restricting the separation distance from the attachment portion 12 in the vicinity of the center 17a of the driver side wall portion 17 when the outer bag 15 is completely inflated are disposed on the attachment portion 12 at the periphery of the inflow opening 11. Has been. Each tether 32 is formed by connecting the band portions 33b and 34b of the tether cloths 33 and 34 to each other. The tether cloth 33 includes an annular main body portion 33a coupled to the periphery of the inflow opening 11 of the vehicle body side wall portion 16 by stitching or the like, and a belt portion 33b extending from both left and right edges of the main body portion 33a. Has been. The tether cloth 34 includes a circular main body 34a coupled to the center 17a of the driver side wall 17 by sewing or the like, and a band 34b extending from both left and right edges of the main body 34a. . The main body portion 33 a of the tether cloth 33 also serves as a reinforcing cloth for the attachment portion 12.

  The outer bag 15 has a tether 32, 32 that regulates the separation distance from the attachment site 12 to the vicinity of the center 17 a of the driver side wall portion 17, covers the upper surface side of the ring portion R, and It expands into a disk shape having an outer diameter larger than the diameter (see the two-dot chain line in FIG. 2 and B in FIG. 10). Further, the outer bag 15 of the embodiment is formed to have an outer diameter dimension such that the rear edge side lower surface 15e side can come into contact with the upper surface side of the thigh DT of the driver D seated on the driver seat DS when the inflation is completed. Yes.

  As shown in FIGS. 5, 7, and 8, the inner bag 20 has a center portion 21 having an inflow opening 11 and four attachment holes 13 disposed on the periphery thereof, as shown in FIGS. And arm portions 23 (front arm portion 23F and rear arm portion 23B) extending in the front and rear sides along the diameter direction of the inflow opening 11, and the length dimension IL in the front and rear direction when the expansion is completed is When the expansion is completed, the outer bag 15 is stored in a state in which generation of wrinkles is suppressed, and is set to be substantially equal to the length dimension OL in the front-rear direction when the outer bag 15 is expanded (see B in FIG. 11). . That is, when the inner bag 20 completes the expansion, the top portions 26a (26af, 26ab) of the front end portions 26 of the front arm portion 23F and the rear arm portion 23B are respectively within the outer bag 15 when the expansion is completed. It will be arranged near the front edge 15b and the rear edge 15d near the peripheral surface 15a.

  The inner bag 20 is attached to the bottom wall portion 46 of the case 45 by being fixed so that the peripheral edge of the inflow opening 11 in the center portion 21 is fastened together with the retainer 41 together with the outer bag 15. However, in the case of the embodiment, each arm portion 23 is disposed so as to be separated from the inner peripheral surface 15a except for the attachment portion 12 in the outer bag 15. In addition, each arm portion 23 is configured to have a quadrangular prism shape with a reduced thickness from the base portion 24 in the vicinity of the central portion 21 to the apex portion 26 a at the tip end of the tip end portion 26.

  The outflow port 27 of the inner bag 20 can inflate the entire peripheral wall from the central portion 21 of the inner bag 20 to the top portion 26a of the tip portion 26 of each arm portion 23 when the inflation gas flows in from the inflow opening 11. The arm portion 23 is set so as to be disposed at a position closer to the inflow opening 11 than the distal end portion 26 of the arm portion 23 and the opening area is not excessively large. In the case of the embodiment, each outlet 27 is formed in a substantially circular opening on the front and back side surfaces of the intermediate portion 25 between the base portion 24 and the tip portion 26 in each arm portion 23. In each arm portion 23, two pieces are arranged, for a total of four pieces.

  In addition, the inner bag 20 has the retainer 41 inserted into the inner bag 20 with the bolts 41a protruding from the mounting holes 13, and the mounting portion 12 at the periphery of the inflow opening 11 in the central portion 21 is fixed. In the state in which the inner bag 20 is inflated alone, as shown in FIGS. 7 and 8, it is viewed from the left-right direction perpendicular to the front-rear direction in which the two front arm portions 23F and the rear arm portion 23B extend. The top portions 26a (26af, 26ab) of the front end portions 26 of the front and rear arm portions 23 are arranged at positions lower than the opening surface OP of the inflow opening 11.

  Furthermore, in the inner bag 20 of the embodiment, when the inflation is completed, the outline that connects between the front end portions 26 of the two front arm portions 23F and the rear arm portion 23B on the upper peripheral wall 29 on the side facing the inflow opening 11 is provided. 29a has a convex shape, and a membrane length (upper membrane length) LU connecting the front end portions 26 of the two front arm portions 23F and the rear arm portion 23B of the upper peripheral wall 29 is set to the lower side on the inflow opening 11 side. It is configured to be longer than a film length (lower film length) LD connecting the two front arm portions 23F and the front end portions 26 of the rear arm portions 23B on the peripheral wall 30. The upper peripheral wall 29 extends from the top portion 26a of the front arm portion 23F to the top portion 26a of the rear arm portion 23B through the upper surface 23a of the front arm portion 23F, the upper surface 21a of the central portion 21, and the upper surface 23a of the rear arm portion 23B. It is a part. The lower peripheral wall 30 extends from the top portion 26a of the front arm portion 23F, the lower surface 23b of the front arm portion 23F, the lower surface 21b of the central portion 21 (this portion becomes the attachment portion 12 fixed by the retainer 41), the rear arm It is a part from the lower surface 23b of the part 23B to the top part 26a of the rear arm part 23B.

  This inner bag 20 is formed by bending a flat sheet material 36 shown in FIG. 6A and stitching predetermined portions together to form a three-dimensional shape. The sheet material 36 is a main body that extends in a belt shape long in the front-rear direction. A portion 37 and four triangular side walls 38 that are continuous with the left and right edges of the main body 37 are provided. The main body portion 37 includes an upper wall portion 37a that constitutes the upper peripheral wall 29, and a lower wall portion 37b that constitutes the lower peripheral wall 30, and the lower wall portion 37b includes the inflow opening 11 and the attachment hole 13. Is formed. An outlet 27 is disposed on each side wall 38. The four side wall portions 38 are arranged symmetrically in the left and right sides of the upper wall portion 37a in the main body portion 37 and symmetrically in the front-rear direction. The adjacent edge portions 38a are sewn together in the front-rear direction, and the remaining edges As shown in FIG. 6B, the inner bag 20 is formed by stitching the portion 38b to the lower wall portion 37b.

  As described above, the inner bag 20 is disposed in the outer bag 15, and the length dimension IL in the front-rear direction when the expansion of the outer bag 15 is completed is changed to the length dimension OL in the front-rear direction when the expansion of the outer bag 15 is completed. When the expansion is completed, the top portions 26a of the front end portions 26 of the front arm portion 23F and the rear arm portion 23B connect the front edge side lower surface 15c and the rear edge side lower surface 15e to the ring portion R. The front edge 15b and the rear edge 15d of the outer bag 15 are pressed downward so as to be brought into contact with the upper surface PR side of the front part RF and the rear part RB (see FIGS. 9 and 10).

  The sheet material 36, the tether cloths 33 and 34 described above, and the vehicle body side wall portion 16 and the driver side wall portion 17 constituting the outer bag 15 are flexible woven fabrics such as polyester and polyamide. Formed from. The sheet material 36 is provided with a coating layer made of silicon rubber or the like on the inner peripheral surface side of the inner bag 20 in order to improve heat resistance.

  In addition, the outer bag 15 fixes the main body portion 33a of the tether cloth 33 to the vehicle body side wall portion 16 and fixes the main body portion 34a of the tether cloth 34 to the driver side wall portion 17 in advance. After the vehicle body side wall portion 16 and the driver side wall portion 17 are overlapped with each other to be brought into contact with each other and the outer peripheral edges are joined together, the inflow opening 11 is prevented so that the joining margin (sewing margin) is not exposed to the outer peripheral surface side. The outer bag 15 can be manufactured by turning over and joining the corresponding band portions 33b, 34b of the tether cloths 33, 34 together.

  When the airbag apparatus M of the embodiment is assembled and mounted on a vehicle, the retainer 41 is inserted into the inner bag 20 so that each bolt 41a protrudes from the mounting hole 13, and the inner bag 20 is inserted into the outer bag 15. At the same time, the bolts 41a are projected from the mounting holes 13 of the outer bag 15, and the airbag 10 is assembled. Next, the airbag 10 is folded and wrapped with a predetermined collapse preventing material so as not to collapse. Next, the airbag 10 is housed on the bottom wall portion 46 in the case 45 so that each bolt 41a protrudes from the through hole 46b. Further, the main body portion 43a of the inflator 43 is inserted into the insertion hole of the bottom wall portion 46 from below. 46a, the bolts 41a are passed through the flange portions 43c, and nuts (not shown) are fastened to the bolts 41a, so that the airbag 10 and the inflator 43 are accommodated in the case 45, and the retainer 41 is Utilizing this, the airbag 10 and the inflator 43 can be attached. Further, the case 45 is covered with an airbag cover 49 and the side wall portions 47 and 51 are connected to each other by using a rivet 48 or the like, and the airbag cover 49 is attached to the case 45. If the horn switch mechanism (not shown) is assembled, the airbag apparatus M can be assembled. And the mounting of the airbag apparatus M on the vehicle is performed by attaching the airbag apparatus M to the steering wheel body 1 fastened to the steering shaft SS in advance using an attachment board (not shown) of the horn switch mechanism. The airbag apparatus M can be mounted on a vehicle.

  In the airbag apparatus M, as shown in FIG. 2, when the inflation gas G flows into the airbag 10 through the inflow opening 11 during operation, the airbag 10 is inflated and the door portion 50a of the airbag cover 49 is inflated. , 50a are pushed open, and the airbag 10 projects from the case 45 as a housing part as shown by the two-dot chain line in FIG.

  At that time, in the initial stage of inflation of the airbag 10, as shown in FIGS. 9A and 9B and FIG. 11A, the inflation gas G flows into the inner bag 20 from the inflow opening 11, and the inner bag 20 is inflated. Further, as shown in FIGS. 10A and 10B and FIG. 11B, the inflation gas G flows into the outer bag 15 from the outlet 27 of the inner bag 20, and the outer bag 15 completes the inflation. It will be.

  When the airbag 10 is inflated, the presser portion 18 on the side of the rear edge 15d of the outer bag 15 is disposed on the upper surface side of the thigh DT of the seated driver D, as shown in FIG. Even if the driver D who is seated tries to move so as to lift his / her waist, the upper movement of the thigh DT of the driver D is restricted, so that the driver D moves forward so as to lift his / her waist. Can be suppressed.

  Further, as shown in FIG. 9B and FIG. 10A, the inner bag 20 has the front portion RF and the rear portion RB of the ring portion R while the inflation gas G is introduced and the expansion completion shape is maintained. Since the outer bag 15 is configured to press both sides of the inner bag 20 downward, the outer bag 15 can easily hold the presser 18 when the inner bag 20 is completely inflated, and the rear part RB of the ring part R and the abdomen DB of the driver D. Further, as shown in FIGS. 10A and 10B, the thigh part is stabilized at the position on the upper surface side of the thigh part DT of the driver D by the expansion of the outer bag 15 itself. The upward movement of the DT can be placed in a swellable state. And the deployment arrangement | positioning state of the press part 18 between the rear part RB of such a ring part R and the driver | operator's D abdomen DB is like the rectification | straightening cloth which regulates the flow of the gas G for expansion in the outer bag 15. Compared to the case where an inner bag is provided, the inner bag 20 of the embodiment can be reliably and stably performed by the pushing operation in which the pressing portion 18 of the outer bag 15 is directly supported and guided. It is possible to secure a state in which the upward movement of the thigh DT of the driver D by the presser portion 18 is restricted.

  Furthermore, the inner bag 20 presses the upper surface PR side on the front RF side of the ring portion R not only in the rear arm portion 23B but also in the front arm portion 23F. The outer bag 15 is expanded and inflated with the balance between the front edge 15b side and the rear edge 15d side being improved while suppressing the left and right expansion and reducing the pressure on the arm portion DA of the driver D during straight-ahead steering. The presser portion 18 on the rear edge 15d side is stably and smoothly disposed between the rear portion RB of the ring portion R and the abdomen DB of the driver D.

  Therefore, in the airbag apparatus M of the embodiment, it is possible to accurately suppress the forward movement that causes the waist of the driver D to rise, and to prevent the driver D from moving toward the windshield WS.

  In the embodiment, the rear arm portion 23B of the inner bag 20 is arranged so that the rear end 26ab side when the inflation is completed is arranged to an area where the upward movement of the thigh DT of the driver D can be restricted. It is configured. Therefore, when the inner bag 20 is completely inflated at the initial stage of inflation of the airbag (outer bag 15) 10, the outer bag 15 is pressed against the inner bag 20 as shown in FIGS. 9B and 10A. The presser part 18 can regulate the upward movement of the thigh part DT of the driver D, and even if the inner bag 20 completes expansion even before the outer bag 15 is completely inflated, the airbag 10 is By using the rear end 26ab side of the inner bag 20, it is possible to ensure a state in which the upward movement of the thigh DT of the driver D by the presser portion 18 of the outer bag 15 is restricted.

  If this point is not taken into consideration, the rear arm portion 23B of the inner bag 20 does not extend to an area where the upward movement of the thigh DT of the driver D can be restricted, but the two-dot chain line in FIG. As shown, when the inner bag 20 is inflated, the presser 18 of the outer bag 15 is connected to the rear RB of the ring R when the inner bag 20 is inflated as long as the upper surface PR side of the rear RB of the ring R can be pressed. It can be supported and guided directly to the abdomen DB of the driver D.

  Incidentally, in the case of the embodiment, the inner bag 20 extends so as to be disposed up to an area where the upward movement of the thigh DT of the driver D can be restricted when the inflation is completed, and the length dimension IL in the front-rear direction is Since the outer bag 15 is configured to be approximately equal to the length dimension OL when the outer bag 15 is inflated, when the outer bag 15 is inflated after the inner bag 20 is inflated, the front arm portion 23F and the rear side of the inner bag 20 are inflated. By pressing the arm portion 23B toward the ring portion R side, as shown in FIGS. 10A and 10B and FIGS. 11A and 11B, the front portion (front edge) 15b side and the rear portion (rear edge) of the outer bag 15 15d side expands in a well-balanced state while bringing the front edge side lower surface 15c and the rear edge side lower surface 15e into contact with the upper surface PR side of the front portion RF and the rear portion RB of the ring portion R so as not to be lifted. To driver D It is possible to suppress.

  Furthermore, in the case of the embodiment, the inner bag 20 has an opening surface OP of the inflow opening 11 when the inflating gas G is introduced from the inflow opening 11 having a fixed peripheral edge to complete the expansion of the inner bag 20 alone. The top portions 26a of the front end portions 26 of the front arm portion 23F and the rear arm portion 23B are arranged at lower positions. Therefore, the inner bag 20 at the time of completion of inflation can strongly press the front arm portion 23F and the rear arm portion 23B toward the ring portion R side, and the presser portion 18 on the rear edge 15d side of the outer bag 15 can be The outer bag 15 can be deployed between the rear portion RB of the ring portion R and the abdomen DB of the driver D more quickly and easily by improving the balance and balance of the outer bag 15 on the front edge 15b side.

  In the embodiment, the inner bag 20 is three-dimensionally formed by stitching a predetermined portion of the sheet material 36. However, as shown in FIGS. The inner bag 20 </ b> A may be formed by folding the oval sheet material 36 </ b> A in half so that both edges in the lateral direction are overlapped, and the folded outer peripheral edge is stitched. Even in such an inner bag 20A, since the outlet 27 is not disposed in the vicinity of the distal end portion 26 when the expansion of the single bag is completed, the two front arm portions 23F and the rear arm portion 23B are tapered. It smoothly swells to the tip portion 26 having the shape as described above, and the peripheral edge of the inflow opening 11 is fixed by the retainer 41 as the attachment portion 12 having a substantially square area and does not swell. Therefore, the outer circumferential line 29a of the upper peripheral wall 29 is convex, and the upper film length LU of the upper peripheral wall 29 is expanded so as to be longer than the lower film length LD of the lower peripheral wall 30. As a result, each front end portion 26 of the inner bag 20A is bent from the vicinity of the central portion 21 where the inflow opening 11 is disposed so that the two front arm portions 23F and the rear arm portion 23B of the inner bag 20A are bent. The inner bag 20A may be used as it can be disposed at a position lower than the opening surface OP.

  In the embodiment, the airbag 10 is inflated in a circular shape when viewed from above. However, like the outer bag 15A of the airbag 10A shown in FIG. 14, the width of the outer bag 15 in the lateral direction is reduced. Alternatively, an oval shape that is long in the front-rear direction may be used. Also in the outer bag 15A, the presser portion 18 is disposed on the rear edge 15d side when the inflation is completed so that the upward movement of the thigh DT of the driver D can be regulated.

1 is a schematic plan view showing a driver's seat airbag device according to an embodiment of the present invention. It is a longitudinal cross-sectional view of the vehicle mounted state in the airbag apparatus of embodiment. It is a schematic longitudinal cross-sectional view along the left-right direction of the inner bag deflated at the time of completion of inflation of the airbag used in the airbag device of the embodiment. It is a schematic longitudinal cross-sectional view along the front-back direction of the inner bag deflated at the time of completion of inflation of the airbag used in the airbag device of the embodiment. It is a disassembled perspective view which shows the structural member of the airbag used for the airbag apparatus of embodiment. It is a figure explaining the process of manufacturing the inner bag of the airbag apparatus of embodiment. It is a schematic front view which shows the state which expanded the inner bag of embodiment alone. It is a schematic bottom view which shows the state which expanded the inner bag of embodiment alone. It is a schematic longitudinal cross-sectional view which shows the time of the action | operation of the airbag apparatus of embodiment in order. It is a schematic longitudinal cross-sectional view which shows the time of the action | operation of the airbag apparatus of embodiment in order, and shows the state after FIG. It is a top view which shows the inflated state of the outer bag at the time of the action | operation of the airbag apparatus of embodiment sequentially. It is the top view which unfolded flat the sheet material used at the time of manufacture of the modification of the inner bag of an embodiment. It is the schematic front view and schematic bottom view which show the state which expanded the inner bag manufactured combining the sheet | seat material shown in FIG. 12 alone. It is a top view which shows the inflated state in the modification of the airbag of embodiment.

Explanation of symbols

10 ... Airbag,
11 ... inflow opening,
15.15A ... Outer bag,
15d ... Rear edge (outer bag)
18: Presser part,
20.20A ... Inner bag,
23F ... front arm,
23B: Rear arm,
26ab ... rear end (of rear arm),
27 ... Outlet,
W ... Steering wheel,
B ... Boss
R ... Ring part,
PR: top surface,
D ... Driver,
DT ... thigh,
DS ... Driver seat,
M: An airbag device for a driver's seat.

Claims (4)

It is mounted on the upper part of the boss part of the steering wheel provided with a ring part to be gripped at the time of steering and a boss part arranged at the center of the ring part and arranged on the front side of the driver,
In operation, it is configured to include an airbag that inflates so as to cover the upper surface side of the ring portion by flowing in the inflation gas,
The airbag has a configuration in which a periphery of an inflow opening for inflating gas is attached to the boss portion, an outer bag constituting an outer peripheral wall of the airbag, and an inside of the outer bag so as to cover the inflow opening. And an inner bag disposed on the
The inner bag is an airbag device for a driver's seat configured to include an outflow port through which inflation gas flowing in through the inflow opening flows out to the outer bag side,
When the inflation gas flows in, the inner bag of the airbag extends to the front and rear sides beyond the upper surface of the front and rear portions of the ring portion, and maintains the completed inflation shape by flowing the inflation gas. While holding the front and rear sides of the ring portion downward, and comprising a front arm portion and a rear arm portion capable of maintaining the pressed state,
The outer bag of the airbag is disposed on the upper surface side of the thigh of the seated driver when the inflation is completed, and a presser portion that can regulate the upward movement of the seated driver's thigh An airbag device for a driver's seat that is provided on the edge side.   The rear arm portion of the inner bag is configured to dispose the rear end side when the inflation is completed to an area where the upward movement of the driver's thigh can be restricted. Item 2. A driver's seat airbag device according to Item 1.   The operation according to claim 2, wherein the inner bag is configured so that a length dimension in a front-rear direction at the time of completion of inflation is substantially equal to a length dimension in a front-rear direction at the time of completion of inflation of the outer bag. Seat airbag device.   When the inner bag is inflated with an inflating gas from the inflow opening having a fixed peripheral edge to complete the expansion of the inner bag alone, the front arm portion is positioned below the opening surface of the inflow opening. The driver seat airbag device according to any one of claims 1 to 3, wherein a tip of the rear arm portion is arranged.

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