JP5051181B2 - Air bag device for knee protection - Google Patents

Description

  The present invention relates to a knee protection comprising an airbag that is disposed in front of a knee of an occupant seated in a seat and is folded and stored in a storage portion, and an inflator that supplies inflation gas to the airbag. The present invention relates to an airbag device.

  Conventionally, as an airbag device for knee protection, when the inflation is completed, the airbag is disposed on the upper end side to protect the occupant's knee, and disposed below the knee protection area to protect the occupant's shin. There is a structure in which the thickness of the shin protection area at the time of completion of expansion is made thinner than that of the knee protection area (see, for example, Patent Document 1).

  In addition, as a knee protection airbag device using an airbag having a knee protection area and a shin protection area, an inflation gas discharged from an inflator is used using an inner tube provided in the airbag, There is a configuration in which the knee protection area is first flown into the knee protection area, the knee protection area is expanded first, and then the shin protection area is expanded (for example, see Patent Document 2).

JP-A-2005-96576 JP 2005-96625 A

  However, in all of the conventional knee protection airbag devices, the airbag is configured to flow the inflation gas discharged from the inflator into the inside from the lower end side. In some cases, when the airbag is inflated with the occupant's knees in proximity, the occupant's knees cannot be protected properly.

  When the airbag is inflated with the occupant's knees in close proximity, if the knee and shin are pushed backwards almost simultaneously by the inflating airbag, the amount of rearward movement of the shin from the knee that will damage the knee joint In order to suppress the occurrence of such a knee slide phenomenon, in a state where the thickness of the shin protection area is regulated at the initial stage of inflation of the airbag, the so-called knee slide phenomenon occurs. It is desirable to inflate only the knee protection area. In the knee protection airbag device described in Patent Document 2, the knee protection area is first inflated using the inner tube, and then the shin protection area is inflated. However, only the flow of the inflation gas is used. The only difference is in the time of inflation between the two, and it does not regulate the thickness of the shin protection area at the initial stage of inflation of the airbag. There was room for improvement.

  The present invention solves the above-mentioned problems, and even if the occupant's knees are arranged close to each other, the occurrence of the knee slide phenomenon can be accurately suppressed, and the occupant's knees can be protected quickly. An object of the present invention is to provide a possible knee protection airbag device.

An airbag device for knee protection according to the present invention includes an airbag that is disposed in front of an occupant's knee seated in a seat and is folded and stored in a storage portion, and an inflator that supplies inflation gas to the airbag. And comprising
The airbag has a knee protection area that is disposed on the upper end side to protect the occupant's knee when inflated, and a shin protection area that is disposed below the knee protection area to protect the occupant's shin. A knee protection airbag device comprising:
As the upstream side of the inflation gas discharged from the inflator, the knee protection area is configured to flow the inflation gas into the interior earlier than the shin protection area,
The airbag has a deployment inhibitor that regulates the thickness of the shin protection area in the initial stage of inflation of the airbag,
The deployment suppressing member is configured to be able to release the thickness regulation of the shin protection area before the airbag is completely inflated.

  In the knee protection airbag device of the present invention, the knee protection area that is disposed on the upper end side of the airbag when the inflation is completed and protects the occupant's knee is the upstream side of the inflation gas discharged from the inflator. Therefore, in the initial stage of inflation of the airbag, the inflation gas discharged from the inflator first flows into the knee protection area to inflate the knee protection area. Therefore, the knee protection area can be quickly inflated, and even when the airbag is inflated with the occupant's knees in close proximity, the inflated knee protection area can be quickly arranged in front of the occupant's knees. It is possible to protect the occupant's knee smoothly.

  Further, in the knee protection airbag device of the present invention, since the airbag has a deployment suppressing material that regulates the thickness of the shin protection area in the initial stage of inflation of the airbag, In the initial stage of inflation of the airbag, the airbag is deployed in a state in which the thickness is regulated by the deployment restraining material, so that it is possible to suppress the inflation of the airbag. Therefore, in the knee protection airbag device of the present invention, the knee protection area and the shin protection area can accurately prevent the knee and the shin from being pushed backward substantially simultaneously, and the knee slide phenomenon can be accurately caused. Can be suppressed.

  Therefore, in the knee protection airbag device of the present invention, even if the occupant's knees are arranged close to each other, the knee slide phenomenon can be accurately suppressed and the occupant's knees can be protected quickly. be able to.

  Further, in the knee protection airbag device of the present invention, the deployment restraining material that regulates the thickness of the shin protection area at the initial stage of inflation releases the regulation of the thickness of the shin protection area before the airbag is completely inflated. Therefore, when protecting the occupant's knees seated in the normal seating position, the occupant's knees can be received by a wide area above and below the shin protection area and the knee protection area in a thickly expanded state. Thus, the occupant's knee can be protected stably and softly.

Further, in the knee protection airbag device of the present invention, the airbag is configured to include an occupant side wall portion disposed on the occupant side upon completion of inflation, and a vehicle body side wall portion disposed on the vehicle body side upon completion of inflation,
The deployment suppressing material is configured from an inner tether that connects the occupant side wall portion and the vehicle body side wall portion in the airbag,
The inner tether is preferably configured such that the thickness of the shin protection area is regulated at the initial stage of inflation of the airbag and that the regulation of the thickness of the shin protection area can be released before the inflation of the airbag is completed.

  In the knee protection airbag device having the above configuration, since the deployment suppressing material is configured from the inner tether disposed inside the airbag, it is not exposed to the outside when the airbag is completely inflated, and when the inflation is completed. The surface for receiving the occupant's knee (the surface of the occupant side wall) can be made smooth.

  In the above knee protection airbag device, the inner tether is configured as a thickness regulating tether that can connect the occupant side wall portion and the vehicle body side wall portion when the inflation of the airbag is completed to regulate the thickness when the inflation is completed. The occupant side wall portion so that the thickness of the shin protection area can be shifted from the state where the thickness of the shin protection area is regulated to the state where the thickness when the airbag is inflated is regulated. If the length of the connecting part that connects the vehicle body side wall part can be changed, it is not necessary to separately provide a thickness control tether for controlling the thickness dimension when the airbag is completely inflated. This is preferable because it can be reduced.

  Further, in the knee protection airbag device having the above-described configuration, the inner tether is configured as a substantially band shape that divides the knee protection area and the shin protection area, and is opened when the thickness restriction is released before the airbag is completely inflated. If the gas outlet hole that allows the inflation gas flowing into the knee protection area to flow out to the shin protection area side is provided, when the thickness of the shin protection area is regulated by the inner tether, Since the inflow of gas can be suppressed, the thickness of the shin protection area can be stably regulated, and the shin protection area can accurately prevent the shin protection area from pressing the occupant's shin at the initial stage of inflation of the airbag. Can do.

Further, in the airbag device for knee protection of the present invention, the deployment suppressing member covers the outer peripheral side of the lower folding portion formed by folding the shin protection area when the airbag is folded and stored. Consists of an outer tether that can suppress the cancellation of folding of the lower folding part in the early stage of expansion,
The outer tether is connected at one end to the vicinity of the boundary between the knee protection area and the shin protection area on the occupant side wall and to the other end near the boundary between the knee protection area and the shin protection area on the vehicle body side wall. The lower folding part is configured to cover the outer peripheral side from the vehicle body side to the occupant side, and before the airbag is completely inflated, from the connection part with the vehicle body side wall part to the connection part with the occupant side wall part. In this part, the connection state to the airbag may be released.

  In the knee protection airbag device having such a configuration, the outer tether constituting the deployment suppressing member is exposed to the outside when the inflation of the airbag is completed, but is not a configuration arranged in the airbag. If an outer tether is connected to the outer peripheral side, a conventionally used airbag can be used, and an increase in manufacturing steps and costs can be suppressed. In addition, since the thickness restriction of the shin protection area is released by the timing of releasing the connection of the outer tether, the design deformation is facilitated, and the timing of releasing the thickness restriction of the shin protection area is adjusted for each vehicle. It is also easy.

It is a perspective view which shows the vehicle mounting state of the glove door which incorporated the airbag apparatus for knee protection which is 1st Embodiment of this invention. It is a schematic longitudinal cross-sectional view along the front-back direction of the vehicle of the instrument panel vicinity of the state which mounted the airbag apparatus for knee protection of 1st Embodiment. It is a schematic longitudinal cross-sectional view of the vehicle mounting state of the grab door incorporating the knee protection airbag device of the first embodiment. It is a general | schematic expanded longitudinal cross-sectional view of the vehicle mounting state of the grab door incorporating the airbag apparatus for knee protection of 1st Embodiment. It is a schematic cross-sectional view which shows the fixing | fixed part and case of an inflator in the airbag apparatus for knee protection of 1st Embodiment. It is a front view of the state which developed the air bag used for the air bag apparatus for knee protection of a 1st embodiment flat. It is a longitudinal cross-sectional view of the airbag of FIG. 6, and respond | corresponds to the VII-VII site | part of FIG. It is a longitudinal cross-sectional view of the airbag of FIG. 6, and respond | corresponds to the VIII-VIII site | part of FIG. It is the top view which expand | deployed the inner tether arrange | positioned in the airbag of FIG. 6 flatly. It is a longitudinal cross-sectional view of the state which inflated the airbag of FIG. 6 alone, and shows the initial stage of inflation of the airbag and the completion of inflation. FIG. 2 is a schematic longitudinal sectional view showing an initial state of inflation of the airbag in the knee protecting airbag device of the first embodiment. In the knee protection airbag device of the first embodiment, it is a schematic longitudinal sectional view showing an airbag inflated completion state. It is a front view of the state which developed the air bag which is a modification flat. It is a rear view of the state which unfolded the air bag of Drawing 13 flat. It is a longitudinal cross-sectional view of the airbag of FIG. 13, and respond | corresponds to the XV-XV site | part of FIG. It is a longitudinal cross-sectional view of the airbag of FIG. 13, and respond | corresponds to the XVI-XVI site | part of FIG. It is the top view which expand | deployed flat the inner tether arrange | positioned in the airbag of FIG. FIG. 14 is a schematic partially enlarged perspective view showing a state in which the inner tether disposed in the airbag of FIG. 13 breaks the portion of the longitudinal stitching portion before completion of the inflation of the airbag. It is a longitudinal cross-sectional view of the state in which the airbag of FIG. 13 is inflated alone, and shows the initial stage of inflation and the completion of inflation. It is a general | schematic expanded longitudinal cross-sectional view of the vehicle mounting state of the grab door incorporating the airbag apparatus for knee protection which is 2nd Embodiment of this invention. It is a front view of the state where the air bag used for the air bag device for knee protection of a 2nd embodiment and the outside tether were developed flat and arranged. It is a schematic longitudinal cross-sectional view of the state which made the outer tether sewn on the airbag of FIG. It is the schematic explaining the folding process of the airbag of FIG. It is the schematic explaining the folding process of the airbag of FIG. 21, and is a figure explaining the process after FIG. In the knee protection airbag device of the second embodiment, it is a schematic longitudinal sectional view showing an initial state of inflation of the airbag. In the knee protection airbag device of the second embodiment, it is a schematic longitudinal cross-sectional view showing a state of completion of inflation of the airbag.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the embodiment, as shown in FIGS. 1 and 2, the instrument panel (hereinafter abbreviated as “instrument panel”) 4 is mounted in the grab door 20 of the grab box 13 mounted on the lower side of the instrument panel (hereinafter referred to as “instrument panel”) and is seated in the passenger seat. The knee protecting airbag device S1 disposed on the front side of the occupant M will be described as an example.

  In this specification, unless otherwise specified, the grab door 20 on which the knee protection airbag device S1 is mounted is in an inclined state in which the opening 14a of the grab box 13 is closed (upper end). 20a side is located on the front side along the horizontal direction from the lower end 20b side, see FIG. 2), the left-right direction corresponds to the left-right direction of the vehicle when traveling straight, and the front-rear direction is The vertical direction VD is the vertical direction of the vehicle when traveling straight, and is the thickness direction TD of the grab door 20 when the vehicle is traveling straight, based on the direction along the thickness direction TD of the grab door 20. Is based on the direction orthogonal to (see FIG. 3).

  The glove box 13 in which the knee protection airbag device S1 of the first embodiment is disposed includes a box body 14 formed of a hard synthetic resin such as polypropylene as a box type (or door type), and a box body 14. And a grab door 20 that closes and opens the rear side opening 14a. As shown in FIG. 2, the box body 14 has a lower wall 15, an upper wall 16 disposed above the lower wall 15 so as to face the lower wall 15, and left and right ends of the lower wall 15 and the upper wall 16. It is provided with left and right side walls 17, 17 and a front wall 18 that are connected to each other in the left-right direction, and have a substantially rectangular parallelepiped box shape having a rectangular opening 14 a on the rear side. The front wall 18 is connected to the front wall side of the lower wall 15, the upper wall 16, and the left and right side walls 17, 17, and is disposed along the substantially vertical direction so as to face the opening 14 a. The left and right side walls 17, 17 are provided with hinge pins 19 constituting a hinge portion when the grab door 20 is opened and closed on the rear end side of the lower end, and a bracket portion (not shown) fixed to the body 1 side. It is arranged. The left and right side walls 17 are also formed with locking recesses (not shown) for locking latches protruding from the grab door 20 when the grab door 20 is closed on the rear end side of the upper end.

  The upper wall 16 is provided with a connecting piece 16 a that is bolted to the connecting portion 4 a of the instrument panel 4. This bolt 5 stop portion is covered with a decorative panel 6. An under cover 11 is disposed below the grab box 13.

  When the grab door 20 closes the opening 14a of the box body 14, the latch (not shown) is inserted into the locking recesses of the left and right side walls 17 and 17 by a biasing means such as a spring, so that the grab door 20 extends substantially in the vertical direction. Thus, the state of closing the opening 14a is maintained. Then, by pulling the lever 36 (see FIG. 1) and pulling the latch away from the locking recess, the upper end 20a side of the grab door 20 is centered on the lower end 20b pivotally supported by the hinge pin 19 as the center of rotation. The grab door 20 can be opened and the opening 14a can be opened (see the two-dot chain line in FIG. 2). When the grab door 20 is opened, a protrusion (not shown) provided near the lower end 20b abuts against a stopper provided on the box body 14 so that the front surface 20c side before opening is substantially horizontal. , Will be placed. A damper mechanism that restricts the sudden opening of the grab door 20 is disposed around the hinge pin 19.

  Incidentally, the hinge pin 19, the lever 36, the latch (not shown), the projecting piece, the stopper, the damper mechanism, and the like are known configurations in this type of grab box.

  As shown in FIGS. 2 to 4, the grab door 20 of the embodiment is between the outer panel portion 21 on the rear surface 20 d side and the inner panel portion 27 on the front surface 20 c side when closed so as to close the opening 14 a. A knee protecting airbag device S1 is provided. In the case of the embodiment, the outer panel portion 21 and the inner panel portion 27 are disposed so as to face each other in the front-rear direction substantially along the vertical direction so that the ends of the outer peripheral edges abut each other. The outer skins 37 and 38 made of non-woven fabric or fabric are attached to each outer surface side in consideration of design properties so as to cover sink marks and parting lines (see FIG. 4).

  As shown in FIG. 4, the outer panel portion 21 is disposed on the outer surface side on the rear surface 20d side of the grab door 20, and is made of a hard synthetic resin such as polypropylene containing filler. A large number of plate-like or rod-like reinforcing ribs 22 extending to the inner panel portion 27 side and fixed to the inner panel portion 27 side are disposed at the upper and lower portions of the knee protection airbag device S1 in the outer panel portion 21. (See FIG. 4). Further, an upper door portion 23 and a lower door portion 24 each having a rectangular plate shape are disposed in a region on the rear side of the knee protection airbag device S1 in the outer panel portion 21. The upper door portion 23 and the lower door portion 24 are formed with a thin planned break portion 25 that is pushed by the inflating airbag 66 and is broken. The planned fracture portion 25 is constituted by a groove formed continuously or intermittently on the front surface side of the outer panel portion 21 and is formed in a substantially “day” shape when viewed from the rear ( (See FIG. 1). The upper door portion 23 is welded to the upper door portion 33 of the housing portion 31 to be described later, and when the upper door portion 23 is pushed by the inflating airbag 66, it breaks the breakable portion 25 and is separated from the surroundings. Along with the upper door portion 33, the upper door portion 33 is configured to be opened upward. The lower door portion 24 is disposed below the upper door portion 23, and when the front door is welded to the lower door portion 34 of the housing portion 31 and pushed by the inflating airbag 66, the planned break portion 25 is broken. Thus, it is separated from the surroundings and, together with the lower door portion 34, is configured to open by being opened downward.

  As shown in FIG. 4, the inner panel portion 27 includes a cover panel 29 disposed on the front side of the knee protecting airbag device S1, a front wall portion 28 disposed on the front side of the surrounding grab door 20, It is configured with. The cover panel 29 is made of a hard synthetic resin such as polypropylene containing filler, and the front wall portion 28 is made of an olefin-based thermoplastic elastomer. In the case of the embodiment, the outer panel portion 21 and the inner panel portion 27 are coupled by vibration welding using the portions of the reinforcing rib 22, the upper door portion 23, and the lower door portion 24, and the cover panel 29 is protected by knee protection. When the air bag device S1 is mounted in the grab door 20, it is fitted into the coupling groove 28a of the front wall portion 28 by using an adhesive, a fastener structure or the like as appropriate, and coupled to the front wall portion 28. Yes. The cover panel 29 is set to be flush with the front wall 20 c of the grab door 20 together with the front wall 28 when coupled to the front wall 28.

  As shown in FIG. 4, the front wall portion 28 is configured to include a housing portion 31 that covers the upper, lower, left, and right sides and the rear side of the knee protecting airbag device S1. The housing portion 31 includes a cylindrical peripheral wall portion 32 that covers the upper, lower, left, and right sides of the knee protecting airbag device S1, and the upper wall portion 32a and the lower wall portion 32b that are opposed to each other at the upper and lower sides of the peripheral wall portion 32 are arranged in the vertical direction. A plurality of penetrating locking holes 32c are juxtaposed along the left-right direction. The latching claws 49a and 50a of the case 46 of the knee protecting airbag device S1 are inserted into the latching holes 32c, and the peripheral edges are latched by the latching claws 49a and 50a.

  Like the upper door part 23 and the lower door part 24, an upper door part 33 and a lower door part 34 each having a rectangular plate shape are disposed on the rear side of the knee protection airbag device S1 in the housing part 31. ing. The upper door portion 33 is configured to be provided with a U-shaped curved portion serving as a hinge portion 33a at the time of opening at the upper end side, and opened by opening upward. The lower door portion 34 is disposed below the upper door portion 33, and is configured to open at a lower opening by providing a U-shaped curved portion that becomes a hinge portion 34a when opened at the lower end side. ing. The planned fracture portion 35 is formed in a single character when viewed from the rear. The left and right sides of the upper door portion 33 and the lower door portion 34 are separated from the peripheral wall portion 32 of the housing portion 31. It should be noted that a gap may be provided in advance between the lower end of the upper door portion 33 and the upper end of the lower door portion 34 so as to be separated in the vertical direction.

  As shown in FIGS. 3 to 5, the knee protection airbag device S <b> 1 includes an airbag 66, an inflator 54, a case 46, and an airbag cover 40. In the case of the embodiment, the knee protecting airbag device S1 is mounted at a position facing the kneecap in front of the knee K of the occupant M seated in the passenger seat.

  The airbag cover 40 includes a door disposition portion 41 disposed on the rear surface 20 d side of the grab door 20 and a peripheral wall portion 44 disposed around the peripheral wall portion 48 of the case 46. The door arrangement portion 41 includes upper door portions 23 and 33 and lower door portions 24 and 34 of the outer panel portion 21 and the housing portion 31 of the inner panel portion 27, and planned fracture portions 25 and 35 and hinge portions 33a at the periphery thereof. , 34a. And the door arrangement | positioning part 41 of this airbag cover 40 is the upper door part 42 which consists of the upper door parts 23 and 33 integrally couple | bonded by vibration welding, and the lower door integrally couple | bonded by vibration welding. And a lower door portion 43 composed of the portions 24 and 34. Then, when pushed by the inflating airbag 66, as shown by the two-dot chain line in FIG. 4, the upper door portion 42 breaks the breakable portions 25 and 35 around the upper door portions 23 and 33, The upper door portion 33 is opened with the hinge portion 33a of the upper door portion 33 as the center of rotation, and the lower door portion 43 breaks the breakable portions 25 and 35 around the lower door portions 24 and 34, thereby the hinge of the lower door portion 34 being opened. With the part 34a as the center of rotation, it is opened downward. The peripheral wall portion 44 of the airbag cover 40 is composed of the peripheral wall portion 32 of the housing portion 31.

  The case 46 constitutes a storage part of the airbag 66. The case 46 stores the folded airbag 66 and the inflator 54, is attached to the grab door 20, and has a protruding opening 46a for the airbag 66 on the rear side. The box shape is provided. In the case of the embodiment, the case 46 has a long rectangular shape along the left-right direction and is formed into a flat rectangular parallelepiped shape with a reduced thickness, and is formed by pressing a sheet metal material, and has a substantially rectangular shape. A cylindrical peripheral wall portion 48 and a front wall 47 arranged so as to close the front side of the peripheral wall portion 48 are provided.

  The front wall 47 is disposed substantially along the vertical direction. In the case of the embodiment, the front wall 47 has a substantially “<” shape toward the rear side in the vicinity of the upper end near the upper wall 49 of the peripheral wall portion 48. The inflator 54 is configured to have a protruding portion 47a that protrudes, and the lower wall portion of the protruding portion 47a is the mounting wall portion 47b. The protruding portion 47 a is formed over the entire left and right regions of the front wall 47 and is disposed for reinforcing the strength of the case 46. Further, a plurality of insertion holes 47c into which the fixing bolts 63 of the inflator 54 can be inserted are formed in the mounting wall portion 47b. The upper wall 49 and the lower wall 50 that are vertically opposed to each other in the peripheral wall portion 48 are inserted into locking holes 32 c provided in the upper wall portion 32 a and the lower wall portion 32 b of the housing portion 31 in the inner panel portion 27, Locking claws 49a and 50a for locking the periphery of the locking hole 32c are formed. In addition, although not shown, attachment pieces for fixing the case 46 to the outer panel portion 21 are formed at predetermined positions of the left wall 51 and the right wall 52 that are opposed to each other on the left and right sides of the peripheral wall portion 48. Further, the right wall 52 is formed with an insertion hole 52a for projecting an end portion (original portion end 56a) of the main body portion 55 of the inflator 54 from the case 46 (see FIG. 5).

  As shown in FIGS. 4 and 5, the inflator 54 for supplying the inflation gas to the airbag 66 is disposed in the airbag 66 so that the outer shape is substantially cylindrical and the axial direction is along the left-right direction. ing. In the case of the embodiment, the inflator 54 is disposed in a region of a knee protection area 68 described later in the airbag 66. The inflator 54 includes a substantially cylindrical main body portion 55 and a fixing portion 59 that fixes the main body portion 55 to the case 46. The main body 55 includes a substantially cylindrical large-diameter portion 56 and a small-diameter portion 57 formed on the distal end side of the large-diameter portion 56 and having a smaller diameter than the large-diameter portion 56. A plurality of gas discharge ports 57a for discharging the expansion gas when the inflator 54 is operated are provided. As shown in FIG. 5, a terminal (not shown) to which a connector C of a lead wire R extending from a predetermined airbag operating circuit is coupled to the end surface of the base end 56a away from the small diameter portion 57 in the large diameter portion 56, It is arranged.

  In the case of the embodiment, the fixing portion 59 has a substantially rectangular plate-like base portion 60 extending in the left-right direction as a length slightly less than twice that of the main body portion 55, and an outer peripheral side in the vicinity of the base end 56 a of the main body portion 55 And a cylindrical cover portion 62 disposed so as to cover the outer peripheral side of the small diameter portion 57 in the main body portion 55. The base portion 60 includes a plurality of A fixing bolt 63 is provided. In the case of the embodiment, the base portion 60 is configured such that the width dimension in the left-right direction is slightly smaller than the width dimension in the left-right direction of the case 46, and the fixing bolt 63 is near the left and right ends of the base portion 60. And three locations near the center in the left-right direction. In the case of the embodiment, the inflator 54 and the airbag 66 include the airbag 66 in which the inflator 54 is disposed inside the knee protection area 68, and the fixing bolt 63 protruding from the airbag 66 through the insertion hole 47c. The fixing bolt 63 is accommodated in the case 46 so as to protrude from the insertion hole 47c and fastened to each fixing bolt 63 protruding from the insertion hole 47c.

  In the embodiment, the airbag 66 includes a bag-shaped bag body 67 that can be inflated by inflating an inflating gas therein, and an inner tether 76 as a deployment restraining material EC disposed in the bag body 67. I have.

  When the bag body 67 is inflated, as shown by a two-dot chain line in FIGS. 1 and 3, an opening for protrusion formed by opening the upper door portion 42 and the lower door portion 43 provided on the rear surface 20 d side of the grab door 20. 46a, which projects rearward from 46a and completes the inflating along the rear surface 20d of the grab door 20. As shown in FIG. 6, the inflating completed shape can protect the left and right knees K of the occupant M in the left-right direction. It is configured as a horizontally long, substantially rectangular plate with an increased width dimension. Specifically, the bag body 67 has a substantially trapezoidal shape in which the expansion completion shape is wide on the upper side. Further, as shown in FIGS. 6 to 8, the bag body 67 is disposed on the upper end 67 a side when the inflation is completed, and is disposed below the knee protection area 68 and protects the knee K of the occupant M. And a shin protection area 69 for protecting the shin L of the occupant M. In the case of the embodiment, the knee protection area 68 and the shin protection area 69 are partitioned by an inner tether 76, and the inner tether 76 is slightly below the center in the vertical direction when the bag body 67 is flatly deployed. It is arranged at the position. That is, the knee protection area 68 is configured such that the width dimension in the up / down / left / right direction is larger than the width dimension in the top / bottom / left / right direction of the shin protection area 69 in a flatly deployed state.

  6-8, the bag main body 67 is disposed so as to oppose each other, and the occupant side wall portion 71 that becomes the occupant M side when the inflation is completed, and the vehicle body side wall that becomes the grab door 20 side when the inflation is completed. Part 72. In the case of the embodiment, the bag body 67 is formed of a woven fabric made of polyamide yarn, polyester yarn, or the like, and the outer peripheral edges of the passenger side wall portion 71 and the vehicle body side wall portion 72 having substantially the same outer shape are sewn together. (Combined). In the vehicle body side wall portion 72, an insertion hole that can project the base end 56 a of the main body portion 55 of the inflator 54 is located in the vicinity of the upper and lower centers, which are regions constituting the knee protection area 68, and in the vicinity of the right edge. 73 is formed, and a plurality of insertion holes 74 (three in the case of the embodiment) through which the fixing bolts 63 of the fixing portion 59 of the inflator 54 can protrude are provided in the left region of the insertion hole 73 along the left-right direction. Side by side. That is, the bag body 67 of the embodiment has the inflator 54 accommodated in the knee protection area 68, and the knee protection area 68 is located upstream of the shin protection area 69 as the upstream side of the inflation gas discharged from the inflator 54. First, the expansion gas is introduced into the interior.

  The inner tether 76 constituting the development suppressing material EC is formed of a woven fabric made of polyamide yarn, polyester yarn or the like, like the bag body 67. In the case of the embodiment, the inner tether 76 is arranged along the left-right direction so as to partition the knee protection area 68 and the shin protection area 69 in the bag body 67 as shown in FIGS. Thus, the knee protection area 68 and the shin protection area 69 are configured as a belt-like shape set to a length dimension that can be divided over substantially the entire left and right regions. In the case of the embodiment, the inner tether 76 is disposed below the insertion hole 73 and the insertion hole 74. Specifically, the inner tether 76 is set so that the length in the left-right direction is slightly smaller than the width of the bag body 67 that is flatly deployed, so that the inner tether 76 can be disposed in the bag body 67. Only the front and rear edges (the connecting edges 76b and 76c) are sewn (coupled) to the bag body 67 (the passenger side wall 71 and the vehicle body side wall 72). Further, as shown in FIG. 9, the inner tether 76 is opened in a substantially oval shape in the vicinity of the center in the left-right direction (length direction) and in the vicinity of the center in the width direction with the longitudinal direction extending in the left-right direction. The gas outlet hole 77 is provided. Further, in the vicinity of the left and right ends of the inner tether 76 and in the vicinity of the center in the width direction, auxiliary circulation holes 78 each having a circular opening are formed. Each auxiliary circulation hole 78 has an opening area smaller than that of the gas outflow hole 77.

  In the case of the embodiment, the inner tether 76 is connected to the vicinity of the connecting edges 76b and 76c in a state in which the connecting edges 76b and 76c coincide with each other and is folded in two along the longitudinal direction. This portion is placed in the bag body 67 in a state where the portion is sewn using the suture thread T1. As shown in FIGS. 6 and 9, the temporary joining portion 80 for sewing the base fabrics 76a and 76a constituting the inner tether 76 is in the vicinity of the connecting edges 76b and 76c over substantially the entire region in the left-right direction (length direction). In addition to being arranged, both ends are curved in a straight line along the left-right direction (length direction) so as to be directed toward the connecting edges 76b and 76c. The temporary coupling portion 80 includes the ends 80b and 80b of the curved portions 80a and 80a provided at both ends, the left edge 67c and the right edge 67d of the bag body 67, and the connecting edges 76b and 76c of the inner tether 76. It is formed so as to be slightly separated from the stitched portions 81 and 81 sewn to the side wall 71 and the vehicle body side wall 72. The suture T1 constituting the temporary coupling site 80 is broken before the inflation of the bag body 67 is completed by the inflating gas flowing into the bag body 67, and the base T constituting the inner tether 76 formed by the temporary coupling site 80 is formed. The strength is set such that the cloth 76a and the cloth 76a can be released from each other. Specifically, when the bag body 67 is deployed and inflated, if tension is applied to the inner tether 76 to separate the connecting edges 76b and 76c, the distal ends 80b of the curved portions 80a and 80a in the temporary coupling portion 80 are Stress concentration occurs in the vicinity of 80b, the suture thread T1 constituting the distal ends 80b, 80b side is broken, and the temporary binding site 80 is replaced with the broken suture thread T1 as the bag body 67 expands. The base cloths 76a and 76a constituting the inner tether 76 are released from the sewn state by sequentially pulling toward the center in the left-right direction or breaking a plurality of locations at once.

  That is, the inner tether 76 of the embodiment has the occupant side wall portion 71 and the vehicle body side wall portion 72 connected to each other at the initial stage of expansion of the bag body 67 because the base fabrics 76a and 76a are sewn together by the temporary coupling portion 80. Before the expansion of the bag body 67 is completed, the length of the connecting portion to be connected (the separation distance D1 between the connecting edges 76b and 76c) is shortened to regulate the thickness of the shin protection area 69 (see FIG. 10A). Since the suture thread T1 constituting the temporary joining portion 80 is broken and the sewing state between the base fabrics 76a and 76a is released, the length of the connecting portion for connecting the occupant side wall portion 71 and the vehicle body side wall portion 72 is increased. This increases the distance (the separation distance D2 between the connecting edges 76b and 76c), thereby releasing the thickness restriction of the shin protection area 69 (see B in FIG. 10). That is, the inner tether 76 of the embodiment regulates the thickness when the inflation is completed by connecting the occupant side wall 71 and the vehicle body side wall 72 even when the airbag 66 (bag body 67) is completely inflated ( The thickness dimension of the shin protection area 69 near the boundary with the knee protection area 68 is regulated to the separation distance D2), which also serves as a thickness regulation tether.

  Further, the inner tether 76 of the embodiment is set so that the length dimension in the left-right direction is slightly smaller than the width dimension in the left-right direction of the flatly deployed bag body 67, and the knee protection area 68 and the shin protection area 69 are left and right. It is the structure divided over the substantially whole area. In the embodiment, the gas outflow hole 77 formed in the inner tether 76 is closed below the temporary coupling portion 80 and closed before the suture T1 is broken. In the initial stage, the inflation gas hardly flows into the shin protection area 69 before the suture thread T1 is broken. If the suture thread T1 is broken before the bag body 67 is inflated and the sewing state of the base fabrics 76a and 76a is released, the gas outflow hole 77 is opened and the knee protection area 68 is filled. The expansion gas G flows out into the shin protection area 69 through the gas outflow hole 77. In addition, since the auxiliary | assistant circulation hole 78 arrange | positioned in the right-and-left both ends vicinity of the inner tether 76 is formed in the vicinity of the curved part 80a in the temporary coupling | bond part 80, it is hard to be obstruct | occluded before the suture T1 breaks. Since the opening area is set to be small, the inflation gas G that has flowed into the knee protection area 68 flows into the shin protection area 69 through the auxiliary circulation hole 78 before the suture T1 is broken. Even if this happens, the amount is very small, and the shin protection area 69 is not greatly expanded.

  Next, the mounting of the knee protecting airbag device S1 of the first embodiment on a vehicle will be described. First, the fixing bolt 63 is protruded outside the airbag 66, the fixing portion 59 of the inflator 54 is accommodated in the airbag 66, and the airbag 66 is folded. The airbag 66 is folded in such a way that the upper end 67a side and the lower end 67b side are wound toward the vehicle body side wall 72 side from the state where the vehicle body side wall portion 72 and the passenger side wall portion 71 are overlapped and flattened. Folding is performed by folding the left and right edges to the center so as to reduce the width in the vertical direction and further reduce the width in the horizontal direction. Then, after the folding of the airbag 66 is completed, a wrapping material (not shown) is wound around the airbag 66 so as to prevent the airbag 66 from collapsing.

  Thereafter, the folded airbag 66 is accommodated in the case 46 while causing the fixing bolts 63 to protrude from the insertion holes 47 c of the mounting wall portion 47 b in the case 46. Further, the main body portion 55 of the inflator 54 is inserted into the belt portion 61 and the cover portion 62 of the fixing portion 59 disposed in the airbag 66 through the insertion hole 52a of the case 46, and each fixing bolt 63 is inserted. If the nut 64 is fastened, the inflator 54 and the airbag 66 can be attached to the case 46.

  Next, the case 46 is inserted into the peripheral wall portion 32 (the peripheral wall portion 44 of the airbag cover 40) of the housing portion 31 of the grab door 20 in a state where the cover panel 29 is removed, and the locking claws 49a, 50a is inserted into each locking hole 32c in the peripheral wall portion 44 of the airbag cover 40 (the peripheral wall portion 32 of the housing portion 31), and locked to the periphery thereof. Next, if a mounting piece (not shown) formed at a predetermined position of the case 46 is fixed to the outer panel portion 21, the knee protecting airbag device S1 can be assembled to the grab door 20. In the grab door 20, the outer panel portion 21, the housing portion 31 of the inner panel portion 27, and the front wall portion 28 are coupled in advance by vibration welding.

  After the knee protection airbag device S1 is assembled to the grab door 20, the cover panel 29 is fitted into the coupling groove 28a so as to cover the front side of the knee protection airbag device S1, and the inner panel portion 27 If it connects with the front wall part 28 and the skins 37 and 38 are stuck, the glove door 20 which incorporated the airbag apparatus S1 for knee protection can be manufactured. The skin 38 may be attached to the outer panel portion 21 before the vibration welding between the outer panel portion 21 and the inner panel portion 27 or before the cover panel 29 is joined to the inner panel portion 27 after the vibration welding. .

  Thereafter, the grab door 20 is assembled to the box body 14, the box body 14 is attached to the vehicle, and an air bag is operated on the body portion 55 of the inflator 54 through an insertion hole (not shown) provided in the box body 14 and the inner panel portion 27. If the lead wire R extending from the circuit is connected, the airbag device S1 for knee protection can be mounted on the vehicle together with the grab box 13.

  In the knee protection airbag device S1 according to the first embodiment, if an actuation signal from a predetermined airbag actuation circuit is input to the main body 55 of the inflator 54 via the lead wire R after being mounted on the vehicle, the inflator 54 discharges the expansion gas from the gas discharge port 57 a of the main body 55. Then, the airbag 66 is inflated by infusing an inflating gas into the interior, and pushes the upper door portion 42 and the lower door portion 43 of the airbag cover 40 so as to open both sides in the vertical direction. It protrudes rearward from the opening 46a, further expands and inflates while eliminating folding, and completes inflating on the front side of the knee K of the occupant M (see the two-dot chain line in FIGS. 1 and 3 and FIG. 12).

  In the knee protection airbag device S1 of the first embodiment, the knee protection area 68 that is disposed on the upper end 67a side of the airbag 66 at the completion of inflation and protects the knee K of the occupant M is discharged from the inflator 54. In the initial stage of inflation of the airbag 66, the inflation gas G discharged from the inflator 54 first flows into the knee protection area 68, and then the knee protection area 68. Will be expanded. Therefore, the knee protection area 68 can be quickly inflated, and even when the airbag 66 is inflated in a state where the knee K of the occupant M is close, the knee protection area 68 inflated in front of the knee K of the occupant M. Can be arranged quickly, and the knee K of the occupant M can be protected smoothly.

  Further, in the knee protection airbag device S1 of the first embodiment, the airbag 66 is deployed so as to regulate the thickness of the shin protection area 69 disposed below the knee protection area 68 in the initial stage of inflation of the airbag 66. Since the inner tether 76 as the restraining material EC is provided, the shin protection area 69 is deployed in a state where the thickness is regulated by the inner tether 76 as the deployment restraining material EC at the initial stage of the inflation of the airbag 66. Therefore, it is possible to suppress the expansion of the thickness.

  More specifically, in the knee protection airbag device S1 of the first embodiment, the inner tether 76 arranged so as to partition the knee protection area 68 and the shin protection area 69 in the bag body 67 is a base fabric. The distance D1 between the connecting edges 76b and 76c connected to the bag body 67 (the occupant side wall portion 71 and the vehicle body side wall portion 72) is reduced in a state where the 76a and 76a are sewn together by the temporary coupling portion 80. . Therefore, first, in the initial stage of inflation of the airbag 66, the inflation gas G discharged from the inflator 54 flows into the knee protection area 68, and when the knee protection area 68 is inflated, the knee protection area 68 and the shin In a state where the inner tether 76 that divides the protective area 69 is shortened in the separation distance D1 between the connecting edges 76b and 76c (the length of the connecting portion that connects the occupant side wall 71 and the vehicle body side wall 72). Since the occupant side wall 71 and the vehicle body side wall 72 are connected to each other, only the upstream knee protection area 68 is inflated thickly, and the shin protection area 69 is thin and the folding is eliminated. It will be developed (see FIG. 11). Then, if the knee protection area 68 expands thickly so that the vertical cross section is substantially circular, and tension is applied to the inner tether 76 to separate the connecting edges 76b, 76c, the base cloth 76a, 76a, stress concentration occurs in the vicinity of the distal ends 80b and 80b of the curved portions 80a and 80a in the temporary joint portion 80 sewn together, and the suture thread T1 constituting the distal ends 80b and 80b is broken, Along with the expansion of the bag body 67, the broken suture T1 is sequentially pulled out toward the central side in the left-right direction, or a plurality of places are broken at a time to form a base cloth 76a constituting the inner tether 76. 76a, the mutual sewing state is released. Then, the inner tether 76 increases the length of the connecting portion connecting the occupant side wall portion 71 and the vehicle body side wall portion 72 (the separation distance D2 between the connecting edges 76b and 76c), so that the shin protection area 69 is formed. Simultaneously with the release of the thickness restriction, the gas outflow hole 77 and the auxiliary circulation holes 78 and 78 formed in the inner tether 76 are opened, and the expansion gas G flows into the shin protection area 69, so that the shin protection area 69 will expand (see FIG. 12).

  That is, in the knee protection airbag device S1 of the embodiment, the knee protection area 68 is first inflated thickly at the initial stage of the inflation of the airbag 66, and then the shin protection area 69 is inflated before the inflation of the airbag 66 is completed. Therefore, the knee protection area 68 and the shin protection area 69 can accurately prevent the knee K and the shin L from being pushed backwards substantially simultaneously, and the knee slide phenomenon can be accurately suppressed. can do.

  Therefore, in the knee protecting airbag device S1 of the first embodiment, even if the knee K of the occupant M is disposed in close proximity, the occurrence of the knee slide phenomenon can be accurately suppressed, and the occupant M The knee K can be protected quickly.

  Further, in the knee protection airbag device S1 of the first embodiment, the inner tether 76 as the deployment restraining material EC that regulates the thickness of the shin protection area 69 is in the initial stage of inflation before the airbag 66 is completely inflated. Therefore, when the knee K of the occupant M seated at the normal seating position is to be protected, the shin protection area 69 and the knee protection area in a thickly inflated state are protected. It is possible to receive the knee K of the occupant M by the wide area above and below 68, and the occupant's knee can be stably and softly protected.

  Furthermore, in the knee protection airbag device S1 of the first embodiment, the deployment suppressing material EC is composed of the inner tether 76 disposed inside the airbag 66, so that when the inflation of the airbag 66 is completed, The surface (the surface of the occupant side wall 71) that receives the knee K of the occupant M when the inflation is completed can be made smooth without being exposed to the outside.

  Furthermore, in the knee protecting airbag device S1 of the first embodiment, the inner tether 76 connects the occupant side wall portion 71 and the vehicle body side wall portion 72 when the airbag 66 is completely inflated to increase the thickness when the inflation is completed. Since it also acts as a restrictable thickness restricting tether, it is not necessary to separately provide a thickness restricting tether for restricting the thickness dimension when the airbag 66 is completely inflated, and the manufacturing cost can be reduced. Of course, if such a point is not taken into account, the inner tether is configured to release the regulation of the thickness of the shin protection area by releasing the connection between the occupant side wall and the vehicle body side wall before the airbag is completely inflated. It is good also as a structure which separately arrange | positions the thickness-controlling tether in an airbag.

  Furthermore, in the knee protection airbag device S1 of the first embodiment, the inner tether 76 is configured as a substantially belt-like shape that divides the knee protection area 68 and the shin protection area 69, and the airbag is attached to the inner tether 76. 66 is opened when the thickness restriction is released before the expansion of 66 is completed (when the suture thread T1 constituting the temporary coupling portion 80 is broken), and the inflation gas G flowing into the knee protection area 68 is supplied to the shin protection area 69 side. A gas outflow hole 77 that can be outflowed is provided. For this reason, in the knee protection airbag device S1 of the embodiment, when the thickness of the shin protection area 69 is regulated by the inner tether 76, the inflow of the inflation gas G into the shin protection area 69 can be suppressed. The area 69 can be deployed in a thin state, and the thickness of the shin protection area 69 can be stably regulated. The shin protection area 69 presses the shin L of the occupant M at the initial stage of inflation of the airbag 66. This can be accurately prevented. Of course, if such a point is not taken into consideration, an inner tether that intermittently partitions the shin protection area and the knee protection area may be used. Further, the arrangement position of the inner tether is not limited to the boundary part between the shin protection area and the knee protection area, and if the thickness of the shin protection area can be regulated, It is good also as a structure to arrange.

  In the embodiment, the inner tether 76 has a configuration in which the separation distance D1 of the connection edges 76b and 76c at the time of thickness regulation is reduced by sewing the base fabrics 76a and 76a to each other at the temporary coupling portion 80. However, an inner tether 86 such as the airbag 84 shown in FIGS. 13 to 16 may be used as the deployment suppressing material EC. In the airbag 84 shown in FIGS. 13 to 16, the bag main body 67 </ b> A that is a member other than the inner tether 86 has the same configuration as the bag main body 67 in the airbag 66, so A detailed description is omitted with “A” at the end.

  The inner tether 86 used in the airbag 84 is formed from a woven fabric made of polyamide yarn, polyester yarn or the like, similar to the inner tether 76 used in the airbag 66 described above. The knee protection area 68 </ b> A and the shin protection area 69 </ b> A have a strip shape arranged along the left-right direction so as to divide the entire area in the left-right direction. In the case of the embodiment, the inner tether 86 includes a reinforcing cloth portion 87 that reinforces the periphery of the insertion hole 73A and the periphery of the insertion hole 74A in the bag body 67A, and the tether body that connects the occupant side wall 71A and the vehicle body side wall 72A. 88 (see FIGS. 15 to 17).

  The reinforcing cloth portion 87 is configured to cover the inner peripheral side of the vehicle body side wall portion 72A in the bag body 67A, and can cover the lower half region of the knee protection area 68A over substantially the entire region in the left-right direction. As a belt shape, both edge sides (upper edge side and lower edge side) in the width direction are sewn to the vehicle body side wall portion 72A to reinforce the periphery of the insertion hole 73A and the periphery of the insertion hole 74A. In the reinforcing cloth portion 87, openings (not shown) corresponding to the insertion hole 73A and the insertion hole 74A are formed. A stitching part 90 for sewing the lower edge side of the reinforcing cloth part 87 to the vehicle body side wall part 72A constitutes a connection part for connecting the tether body 88 to the car body side wall part 72A. It is continuously formed over substantially the entire region in the left-right direction.

  The tether main body 88 is configured to be continuous from the reinforcing cloth portion 87, and can be divided into a knee protection area 68A and a shin protection area 69A, and a lateral dimension of the bag main body 67A in a lateral direction is flattened. The edge part (the connecting edge 88a) that is set slightly smaller than the width dimension and is away from the reinforcing cloth part 87 is sewn (coupled) to the passenger side wall part 71A of the bag body 67A. In addition, a gas outflow hole 89 that is opened in a circular shape is disposed in a portion of the tether body 88 in the vicinity of the stitched portion 90 (a portion on the side of the vehicle body side wall portion 72A). In the case of the embodiment, two gas outflow holes 89 are formed in the vicinity of both left and right ends. The tether body 88 is sewn to the side wall 72A of the vehicle body by a temporary coupling portion 91 that is formed so as to extend from the stitching portion 90 in the left and right direction inside of each gas outflow hole 89. . The temporary coupling portion 91 is formed in a double line shape inside the gas outflow hole 89 located on the inner side in the left-right direction. Each temporary coupling part 91 is formed so as to be substantially perpendicular to the stitching part 90 and along the vertical direction (front-rear direction), and the tip 91 a away from the stitching part 90 is set below the lower edge of the gas outflow hole 89. It is comprised so that it may arrange at the position which becomes. That is, in the tether main body 88 of the embodiment, the gas outflow hole 89 is closed by being surrounded by the sutured portion 90 and the temporary coupling portion 91 (see A in FIGS. 14, 15, and 18). . Further, the suture thread T2 constituting the temporary coupling portion 91 is set to a strength that can be broken before the bag body 67A is completely inflated. Specifically, when the bag body 67A is deployed and inflated, if tension is applied to the tether body 88 to separate the temporary coupling portion 91 and the connecting edge 88a, stress concentration is concentrated on the tip 91a side of each temporary coupling portion 91. As a result, the suture T2 constituting the distal end 91a is broken, and each temporary coupling portion 91 sequentially moves the broken suture T2 toward the suture portion 90 as the bag body 67A expands. The sewn state between the tether main body 88 and the vehicle body side wall portion 72A by the temporary coupling portion 91 is released by removing a plurality of locations at a time (see B in FIG. 18).

  That is, since the inner tether 86 in the airbag 84 is partially sewn to the vehicle body side wall portion 72A by the temporary coupling portion 91 in the initial stage of inflation of the bag body 67A, the passenger side wall portion 71A and the vehicle body The length of the connecting portion that connects the side wall portion 72A (the separation distance D3 from the tip 91a of the temporary connecting portion 91 to the connecting edge 88a) is shortened to regulate the thickness of the shin protection area 69A (A in FIG. 19). Reference), before the completion of the expansion of the bag body 67A, the suture T2 constituting the temporary coupling portion 91 is broken, and the sewn state between the tether body 88 and the vehicle body side wall portion 72A by the temporary coupling portion 91 is released. From this, the length of the connecting portion connecting the occupant side wall portion 71A and the vehicle body side wall portion 72A (the separation distance D4 from the stitching portion 90 to the connecting edge 88a) is increased, so that the shin protection area 6 is increased. And thus it is lifted thickness regulation A (see B in FIG. 19). The inner tether 86 also connects the occupant side wall portion 71A and the vehicle body side wall portion 72A even when the airbag 84 (bag body 67A) is completely inflated, and regulates the thickness when the inflation is completed (the shin protection area). The thickness dimension of the boundary portion with the knee protection area 68A in 69A is restricted to the separation distance D4).

  In the inner tether 86, before the suture thread T2 is broken, the gas outflow hole 89 formed in the tether main body 88 is surrounded by a suture part 90 and a temporary joint part 91 as shown in FIG. The outer peripheral side is covered with the vehicle body side wall 72A, and the peripheral portion is closed by receiving the internal pressure of the inflation gas flowing into the knee protection area 68A and being pressed against the vehicle side wall 72A. Therefore, in the initial stage of inflation of the bag body 67A, the inflation gas hardly flows into the shin protection area 69A before the suture T2 is broken. If the suture T2 is broken before the expansion of the bag body 67A is completed, and the sewn state between the tether body 88 and the vehicle body side wall portion 72A by the temporary coupling portion 91 is released, B in FIG. 18 and B in FIG. As shown, the gas outflow hole 89 is opened, and the inflation gas G filled in the knee protection area 68A flows out into the shin protection area 69A through the gas outflow hole 89.

  Even in the knee protection airbag device using such an airbag 84, the knee protection area 68A is on the upstream side of the inflation gas discharged from the inflator. The knee protection area 68A can be quickly inflated, and the inflated knee protection area 68A can be quickly placed in front of the occupant's knee even when the airbag 84 is inflated in a state where the occupant's knees are close to each other. And can protect the passenger's knee smoothly.

  Further, in the knee protection airbag device using the airbag 84 having the above-described configuration, the inner tether 86 arranged so as to partition the knee protection area 68A and the shin protection area 69A in the bag body 67A is the bag body 67A. In the initial stage of expansion, the tip of the temporary coupling portion 91 connected to the bag main body 67 (the passenger side wall portion 71A, the vehicle body side wall portion 72A) as being partially sewn to the vehicle body side wall portion 72A by the temporary coupling portion 91. The separation distance D3 from 91a to the connecting edge 88a is shortened (see A in FIG. 19). Therefore, first, in the initial stage of inflation of the airbag 84 (bag body 67A), the inflation gas G discharged from the inflator flows into the knee protection area 68A, and the knee protection area 68A is inflated. The tether body 88 that divides the area 68A and the shin protection area 69A is connected to the length of the connecting portion that connects the occupant side wall portion 71A and the vehicle body side wall portion 72A (from the tip 91a of the temporary connecting portion 91 to the connecting edge 88a). Since the occupant side wall portion 71A and the vehicle body side wall portion 72A are connected in a state where the separation distance D3) is reduced, only the upstream knee protection area 68A expands thickly, and the shin protection area 69A In a thin state, it will be unfolded to eliminate folding. After that, the knee protection area 68A expands thickly so that the vertical cross section is substantially circular, and tension is applied to the tether body 88 of the inner tether 86 so as to separate the temporary coupling portion 91 and the connecting edge 88a. In this case, stress concentration occurs in the vicinity of the tip 91a of each temporary coupling portion 91 that sews the tether body 88 and the vehicle body side wall portion 72A, and the suture thread T2 constituting the tip 91a side is broken, and the bag As the main body 67A expands, the broken suture thread T2 is sequentially pulled out toward the suture site 90, or a plurality of locations are broken at a time so that the tether body 88 and the vehicle body side wall by the temporary coupling site 91 are removed. The sewing state with the portion 72A is released (see B in FIG. 18). And as shown to B of FIG. 19, the tether main body 88 lengthens the length (separation distance D4 from the stitching site | part 90 to the connection edge 88a) of the connection part which connects 71 A of passenger | crew side wall parts and 72 A of vehicle body side wall parts. Thus, at the same time that the thickness regulation of the shin protection area 69A is released, the gas outflow hole 89 formed in the tether body 88 is opened, and the inflation gas G flows into the timber protection area 69A. The shin protection area 69A will expand.

  That is, even when the airbag 84 configured as described above is used, the knee protection area 68A is first inflated thickly at the initial stage of inflation of the airbag 84, and then the shin protection area 69A is Since the knees are inflated, the knee protection area 68A and the shin protection area 69A can accurately prevent the knee and the shin from being pushed backward substantially simultaneously, and can accurately prevent the knee slide phenomenon from occurring. be able to.

  Further, even when the airbag 84 having the above-described configuration is used, the inner tether 86 is configured as a substantially band shape that divides the knee protection area 68A and the shin protection area 69A, and the airbag 84 is attached to the inner tether 86. Opened when the thickness restriction is released before the expansion is completed (when the suture thread T2 constituting the temporary coupling portion 91 is broken), and the inflation gas G flowing into the knee protection area 68A flows out to the shin protection area 69A side. Since the possible gas outflow holes 89 are provided, it is possible to prevent the inflation gas G from flowing into the shin protection area 69A when the thickness of the shin protection area 69A is regulated by the inner tether 86. The shin protection area 69A can be deployed in a thin state, and the shin protection area 69A can be accurately prevented from pressing the occupant's shin in the initial stage of inflation of the airbag 84.

  Next, the knee protecting airbag device S2 of the second embodiment will be described. As shown in FIG. 20, the knee protection airbag device S <b> 2 of the second embodiment includes an airbag 94 and a lower folding portion 102 formed by folding the shin protection area 69 </ b> B in the folded airbag 94. Except for the outer tether 97 as the deployment restraining material EC covering the outer peripheral side, the configuration is the same as the knee protection airbag device S1 of the first embodiment, and the same members are denoted by the same reference numerals. Detailed description is omitted.

  In the case of the embodiment, the airbag 94 has the same configuration as the bag body 67 in the airbag 66 described above except for the tether 95 for regulating the thickness at the time of completion of inflation. , “B” is added to the end of the same figure code, and detailed description is omitted. As shown in FIGS. 21 and 22, the tether (thickness regulating tether) 95 disposed in the airbag 94 is formed in a belt shape along the left-right direction, and the knee protection area is located at the same position as the inner tether 76 described above. The occupant side wall 71B and the vehicle body side wall 72B are connected to each other at the boundary between the 68B and the shin protection area 69B, and the separation distance between the occupant side wall 71B and the vehicle body side wall 72B during inflation is regulated. Specifically, the tether 95 is formed in a belt shape with the longitudinal direction along the left-right direction, and both edges on the short side are sewn (coupled) to the vehicle body side wall portion 72B and the occupant side wall portion 71B, respectively. The vehicle body side wall 72B and the passenger side wall 71A are connected. In the case of the embodiment, the tether 95 is disposed so as to provide a gap between the airbag 94 and the edge on the left and right direction side. That is, in the airbag 94 of the embodiment, the shin protection area 69A is configured to allow the inflation gas to flow into the inside through a gap between the tether 95 and the edge of the airbag 94 on the left-right direction.

  The outer tether 97 as the deployment restraining material EC covers the outer peripheral side of the lower folded portion 102 formed by folding the shin protection area 69B in the folded airbag 94. The end 97a on one end side in the longitudinal direction is connected to the vicinity of the boundary between the knee protection area 68B and the shin protection area 69B (near the tether 95) in the occupant side wall 71B. The end 97b on the other end side in the longitudinal direction is connected (sewn) to the vicinity of the boundary between the knee protection area 68B and the shin protection area 69B (near the tether 95) in the vehicle body side wall 72B. The lower folding portion 102 is configured to cover the outer peripheral side from the vehicle body side to the occupant side. In the case of the embodiment, the outer tethers 97 are disposed at two positions separated in the left-right direction so as to substantially correspond to the position of the shin L of the occupant M. The outer tether 97 is formed of a woven fabric made of polyamide yarn, polyester yarn or the like, like the airbag 94. The outer tether 97 is a portion from the connection portion (end portion 97b) to the vehicle body side wall portion 72B to the connection portion (end portion 97a) to the passenger side wall portion 71B before the inflation of the airbag 94 is completed. It is comprised so that the connection state to 94 can be cancelled | released.

  More specifically, as shown in FIGS. 21 and 22, the outer tether 97 of the embodiment is formed in a belt shape whose longitudinal direction is substantially along the vertical direction, and the vehicle body of the lower folding portion 102. A vehicle body side fabric portion 98 which is arranged so as to cover the side (front side) and is sewn to the vehicle body side wall portion 72B on the upper end 98a (corresponding to the end portion 97b of the outer tether 97), and an occupant of the lower folding portion 102 The upper end 99a (corresponding to the end portion 97a of the outer tether 97) is disposed so as to cover the side (rear side), and the lower end 98b, 99b of the occupant side cloth portion 99 sewn to the occupant side wall portion 71B. The lower folding part 102 is configured to be sewn (coupled) using the suture thread T3 (see B in FIG. 23). The temporary joint portion 100 for sewing the lower ends 98b and 99b of the vehicle body side fabric portion 98 and the occupant side fabric portion 99 to each other is formed linearly over the entire region along the left-right direction (width direction). Further, the suture thread T3 constituting the temporary coupling portion 100 is set to a strength that can be broken before the airbag 94 is completely inflated. Specifically, when the airbag 94 is deployed and inflated, when the lower foldable portion 102 is deployed downward to eliminate folding, the vehicle body side fabric portions 98 and the occupant side fabric portions 99 are moved downward. If tension such as pulling is applied, stress concentration occurs in the vicinity of the end portion of the temporary bonding portion 100, and the suture T3 is broken. As the lower folding portion 102 is deployed, the broken suture T3 is removed. Then, the sewing state between the vehicle body side fabric portion 98 and the occupant side fabric portion 99 by the temporary coupling portion 100 is released by sequentially pulling out or breaking a plurality of locations at a time.

  Next, folding of the airbag 94 will be described. The vehicle body side fabric portion 98 and the occupant side fabric portion 99 constituting the outer tether 97 have their upper ends 98a and 99a side sewn in advance to the occupant side wall portion 71B and the vehicle body side wall portion 72B of the airbag 94, respectively. . Thereafter, the airbag 94 is folded. Specifically, the airbag 94 is vertically reduced to reduce the width dimension in the vertical direction in a state where the fixing portion 59 of the inflator 54 is accommodated in the inside so that the fixing bolt 63 protrudes from the insertion hole 74B and is flattened. The folding is performed through folding and left-right reduced folding for reducing the width in the left-right direction.

  First, in the airbag 94 in a flat deployed state, as shown in FIGS. 23A and 23B, a region of the shin protection area 69B that is below the tether 95 is wound with the lower edge side toward the vehicle body side wall portion 72B. In this way, the lower folding part 102 is formed. Then, the vehicle body side fabric portion 98 and the occupant side fabric portion 99 constituting the outer tether 97 disposed so as to cover the outer peripheral side of the lower folding portion 102 are connected to the lower ends 98b and 99b, and the temporary coupling portion 100 is disposed. It is sewn using the suture thread T3 so as to form. Similarly, the area of the knee protection area 68B above the tether 95 is roll-folded so that the upper edge side is wound toward the vehicle body side wall 72B side to form the upper folding part 103 (B, FIG. 23). 24 A). The upper and lower folding parts 103 and 102 are folded back so as to be placed on the occupant side wall part 71B side, and the vertically reduced folding airbag 104 is shrunk so that the vertical dimension can be stored in the case 46. (See FIG. 24A). Thereafter, as shown in FIGS. 24A and 24B, the left and right edge sides of the vertically contracted folded airbag 104 are folded along the left-right direction so as to be placed on the occupant side wall portion 71B side, and the bellows is folded. In this case, the airbag 94 can be folded.

  The airbag 94 folded in this manner can be mounted on the vehicle in the same manner as the knee protection airbag device S1 of the first embodiment.

  Also in the knee protection airbag device S2 of the second embodiment, the knee protection area 68B that protects the knee K of the occupant M in the airbag 94 at the completion of the inflation is the inflation gas discharged from the inflator 54. Since the upstream side is the upstream side, the inflation gas G discharged from the inflator 54 first flows into the knee protection area 68B to inflate the knee protection area 68B. Become. Therefore, the knee protection area 68B can be quickly inflated, and even when the airbag 94 is inflated in the state where the knee K of the occupant M is in close proximity, the knee protection area 68B inflated in front of the knee K of the occupant M. Can be arranged quickly, and the knee K of the occupant M can be protected smoothly.

  Further, in the knee protecting airbag device S2 of the second embodiment, the airbag 94 regulates the thickness of the shin protecting area 69B disposed below the knee protecting area 68B in the initial stage of inflation of the airbag 94. Since the outer tether 97 serving as the restraining material EC is provided, the shin protection area 69B is deployed in a state where the thickness is regulated by the inner tether 76 serving as the deployment restraining material EC in the initial stage of inflation of the airbag 66. Therefore, it is possible to suppress the expansion of the thickness.

  More specifically, in the knee protection airbag device S2 of the second embodiment, the folded airbag 94 covers the outer peripheral side of the lower folding portion 102 configured by folding the shin protection area 69B. The tether 97 includes a vehicle body side fabric portion 98 and an occupant side fabric portion 99. The vehicle body side fabric portion 98 and the occupant side fabric portion 99 are below the lower folding portion 102 and have lower ends 98b, The 99b side is sewn together by a suture thread T3 that can be broken before the airbag 94 is completely inflated. Therefore, when the airbag 94 is initially inflated, the inflation gas G discharged from the inflator 54 flows into the knee protection area 68B, and when the knee protection area 68B is inflated, the lower folding portion 102 Since the outer tether 97 covers the outer peripheral side of the lower fold portion 102, the folding of the lower folding portion 102 is suppressed by the outer tether 97, and the thickness of the boundary portion between the shin protection area 69B and the knee protection area 68B is reduced. The dimension is regulated by the separation distance D5, and only the upstream knee protection area 68B expands thickly (see FIG. 25). Thereafter, when the inflation gas flows into the shin protection area 69B from the gaps on the left and right sides of the tether 95, and the lower folding portion 102 expands downward in order to cancel the folding, If tension is applied to pull the portion 98 and the occupant side fabric portion 99 downward, stress concentration occurs near the end of the temporary coupling portion 100, the suture T3 is broken, and the lower folding portion 102 is unfolded. As a result, the broken suture thread T3 is sequentially pulled out, or a plurality of places are broken at once, so that the vehicle body side fabric portion 98 and the occupant side fabric portion 99 are sewn together by the temporary joint portion 100. It will be released. Then, the shin protection area 69B is inflated after the thickness restriction is released by setting the thickness dimension of the boundary portion with the knee protection area 68B as the separation distance D6 larger than the separation distance D5 (see FIG. 26). That is, also in the knee protection airbag device S2 of the second embodiment, the knee protection area 68B is first inflated thickly at the initial stage of the inflation of the airbag 94, and then the shin protection area before the airbag 94 is completely inflated. Since 69B is inflated, the knee protection area 68B and the shin protection area 69B can accurately prevent the knee K and the shin L from being pushed backward substantially simultaneously, and the knee slide phenomenon occurs. It can be accurately suppressed.

  Therefore, even in the knee protection airbag device S2 of the second embodiment, even if the knee K of the occupant M is disposed in close proximity, the occurrence of the knee slide phenomenon can be accurately suppressed, and the occupant M The knee K can be quickly protected.

  Also in the knee protection airbag device S2 of the second embodiment, the outer tether 97 serving as a deployment restraining material that regulates the thickness of the shin protection area 69B is in the initial stage of inflation before the airbag 94 is completely inflated. Therefore, when the knee K of the occupant M seated at the normal seating position is to be protected, the timber protection area 69B and the knee protection area in a thickly inflated state are protected. It is possible to catch the occupant M's knee K by the wide area above and below 68B, and the occupant's knee can be stably and softly protected.

  Further, in the knee protection airbag device S2 of the second embodiment, since the outer tether 97 covering the outer peripheral side of the airbag 94 is disposed as the deployment suppressing material EC, the outer tether 97 is an airbag. Although it is configured to be exposed to the outside when the inflation of 94 is completed, it is not configured to be disposed in the airbag 94, so if an outer tether is connected to the outer peripheral side, a conventionally used airbag should be used. And increase in manufacturing man-hours and cost can be suppressed. In addition, since the thickness restriction of the shin protection area is released by the timing of releasing the connection of the outer tether, the design deformation is facilitated, and the timing of releasing the thickness restriction of the shin protection area is adjusted for each vehicle. It is also easy.

  In the embodiment, as the outer tether 97, lower ends 98b and 99b of the vehicle body side fabric portion 98 and the occupant side fabric portion 99 are sewn together using the suture thread T3, and the suture thread T3 is broken. However, the configuration of the outer tether is not limited to this, for example, intermittently at the intermediate portion. It may be composed of a single cloth-like one that is provided with a scheduled break consisting of a perforated cut provided in the, and breaks the planned break to release the thickness restriction of the shin protection area, In addition, as an outer tether, the connection of the end to the vehicle body side wall or the passenger side wall is affixed using an adhesive or the like, and the thickness of the shin protection area is regulated by peeling off the affixed part. Use a configuration that releases It may be. Of course, when the outer tether is formed from two pieces of the vehicle body side fabric portion and the passenger side fabric portion, the lower ends of the vehicle body side fabric portion and the passenger side fabric portion are adhered using an adhesive or the like. A configuration may be adopted.

  Further, in the embodiment, the lower folding portion 102 whose outer peripheral side is covered with the outer tether 97 is formed by roll folding that winds the shin protection area 69B from the lower end side toward the vehicle body side wall portion 72B. However, the folding shape of the lower folding portion is not limited to this, and may be formed by bellows folding or the like.

  In the knee protection airbag devices S1 and S2 of the embodiment, the inflator 54 is stored in the knee protection areas 68, 68A, and 68B in the airbags 66, 84, and 94, and is inflated thickly when the inflation is completed. The knee protection areas 68, 68A and 68B cover the rear of the inflator 54. If the knee protection area is configured to flow the inflation gas on the upstream side of the inflation gas, the arrangement position and configuration of the inflator are as follows. It is not limited to this. For example, as an inflator, an inflator that is disposed in a region away from an airbag storage part (case) and connected to the knee protection area of the airbag using an inflow pipe or the like may be used.

  Further, in the knee protection airbag devices S1 and S2 of the first embodiment, the inner tethers 76 and 86 and the tether 95 regulate the thickness of the airbags 66, 84 and 94 when the inflation is completed. As the airbag, one having a configuration in which a thickness-regulating tether is not disposed inside may be used. However, in order to smoothly deploy to the front of the occupant's knees, it is preferable to have a structure in which a thickness-regulating tether that regulates the thickness dimension when inflation is completed is disposed inside the airbag.

  In the embodiment, the knee protection airbag devices S1 and S2 housed in the grab door 20 of the grab box 13 disposed in front of the passenger seat have been described as an example. However, the knee protection airbag device is mounted. The position is not limited to this, and a knee protection airbag in which a storage part for storing the folded airbag is disposed in front of the occupant's knee so that the knee protection area is an upstream part. The present invention can be applied to any apparatus. For example, the present invention is applied to a knee protection airbag device housed in a column cover disposed in front of a driver's knee seated in a driver's seat and a knee protection airbag device mounted in front of a rear seat. May be applied.

13 ... grab box,
20 ... Grab door,
40 ... Airbag cover,
46: Case (storage part),
54 ... Inflator,
66, 84, 94 ... airbags,
68, 68A, 68B ... Knee protection area,
69, 69A, 69B ... shin protection area,
71, 71A, 71B ... occupant side wall,
72, 72A, 72B ... vehicle body side wall,
76, 86 ... inner tether,
77, 89 ... Gas outflow holes,
80, 91 ... Temporary binding site,
97 ... Outer tether,
100 ... Temporary binding site,
102 ... lower folding part,
EC ... Development restriction material,
K ... knees,
L ... Shin,
M ... Crew,
S1, S2 ... Knee protecting airbag devices.

Claims (5)

An airbag that is disposed in front of a knee of an occupant seated in a seat and is folded and stored in a storage portion; and an inflator that supplies inflation gas to the airbag,
When the airbag is inflated, a knee protection area that is disposed on the upper end side and protects the occupant's knee, and a shin protection area that is disposed below the knee protection area and protects the occupant's shin. A knee protection airbag device comprising:
The knee protection area is configured to allow the inflation gas to flow into the interior earlier than the shin protection area, as the upstream side of the inflation gas discharged from the inflator,
The airbag has a deployment inhibitor that regulates the thickness of the shin protection area in the initial stage of inflation of the airbag,
The knee protection airbag device, wherein the deployment suppressing member is configured to be able to release the thickness restriction of the shin protection area before the airbag is completely inflated. The airbag is configured to include an occupant side wall portion disposed on the occupant side upon completion of inflation, and a vehicle body side wall portion disposed on the vehicle body side upon completion of inflation,
The deployment suppressing member is configured from an inner tether that connects the occupant side wall and the vehicle body side wall in the airbag.
The inner tether is configured to regulate the thickness of the shin protection area at the initial stage of inflation of the airbag and to release the thickness regulation of the shin protection area before the inflation of the airbag is completed. The knee protection airbag device according to claim 1. The inner tether is
It is configured as a thickness regulation tether capable of regulating the thickness at the time of completion of inflation by connecting the occupant side wall and the vehicle body side wall at the time of completion of inflation of the airbag,
The occupant can move from the state where the thickness of the shin protection area is regulated to the state where the thickness regulation of the shin protection area is released and the thickness when the airbag is completely inflated is regulated. The knee protection airbag device according to claim 2, wherein the knee protection airbag device is configured to be capable of changing a length of a connecting portion that connects the side wall portion and the vehicle body side wall portion.   The inner tether is configured as a substantially band shape that divides the knee protection area and the shin protection area, and opens when the thickness restriction is released before the airbag is completely inflated. The knee protection airbag device according to claim 3, further comprising a gas outflow hole through which the inflation gas flowing into the shin protection area can flow out to the shin protection area side. The airbag is configured to include an occupant side wall portion disposed on the occupant side upon completion of inflation, and a vehicle body side wall portion disposed on the vehicle body side upon completion of inflation,
When the airbag is folded and stored, the deployment inhibitor covers an outer peripheral side of a lower folding portion formed by folding the shin protection area, and the lower folding is performed at the initial stage of inflation of the airbag. Consists of an outer tether that can suppress the folding of the part,
The outer tether is connected at one end to the vicinity of a boundary portion between the knee protection area and the shin protection area in the occupant side wall, and at the other end, the knee protection area and the shin protection in the vehicle body side wall. The vehicle body side wall portion is connected to the vicinity of the boundary portion with the area and configured to cover the outer peripheral side from the vehicle body side to the occupant side of the lower folding portion, and before the airbag is completely inflated. The knee protection airbag according to claim 1, wherein the airbag is configured to be able to release a connected state to the airbag at a portion extending from the connecting portion to the connecting portion with the occupant side wall portion. apparatus.

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