JP2005029101A - Air bag for knee protection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air bag for knee protection which can complete the expansion of the air bag for knee protection which is housed on the front side of the knees of a passenger sitting on the seat of a vehicle while being folded, and develop-expands by making a gas for expansion flow in so that the knees of the passenger can be protected at the time of a collision of the vehicle. <P>SOLUTION: This air bag 46 for knee protection is housed on the front side of the knees of a sitting passenger while being folded, in a manner to be able to protect the knees of the passenger. When the development-expansion is completed, the shape of the air bag 46 is made into an approximately rectangular plate-form by develop-expanding while fixing the lower end 46b side to a car body side and forming the upper end 46a side into a free end. When the expansion is completed an upper edge 49a is made into an approximately linear shape in the lateral direction, and at the same time, the air bag 46 is formed by bonding the outer peripheral edges of a passenger side base fabric 50 on the passenger side made of a woven fabric and a car body side base fabric 51 on the car body side having approximately the same shape, to each other. For one of the woven fabrics of the base fabrics 50 and 51, a weft HS is arranged in approximately the lateral direction in a manner to go along the upper edge 49a of the air bag 46 when the development-expansion is completed. For the other woven fabric, a warp VS or the weft HS is arranged in a manner to cross the upper edge 49a of the air bag 46 when the development-expansion is completed at a crossing angle θ of approximate 45°. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a knee protection air that is folded and stored on the front side of a knee of an occupant seated on a vehicle seat, and that expands and inflates by inflowing an inflation gas so that the occupant's knee can be protected in the event of a vehicle collision. Regarding the bag.

  Conventionally, in knee protection airbags, the upper edge when inflating is made substantially straight along the left-right direction, and the occupant-side occupant-side base fabric and the vehicle-body-side base body made of woven fabric made into the same shape It was set as the structure formed by sewing the outer periphery with cloth mutually (for example, refer patent document 1).

In addition, as an airbag formed by stitching the outer peripheral edges of a base fabric made of two woven fabrics, the two base fabrics can be maintained so that a disk-shaped expansion completion shape can be maintained without being twisted or inclined. There were some which shifted the thread angles of 45 ° from each other (for example, see Patent Document 2).
International Publication No. 02/04261 Pamphlet JP-A-52-5126

  However, in the conventional knee protection airbag, the shape at the time of completion of deployment and inflation is a substantially rectangular plate shape, and further, the lower end side is fixed to the vehicle body side, and the upper end side is deployed and inflated with the free end. In order to prevent the upper end side from being twisted or inclined to complete the expansion, it is necessary to set in consideration of interference with surrounding members.

  An airbag formed by stitching the outer peripheral edges of two base fabrics can be deployed and inflated while preventing twisting and tilting, but is for a steering wheel and stitches circular base fabrics together. It was a thing. For this reason, it is difficult to immediately apply the setting for shifting the yarns of the two circular base fabrics by 45 ° to a knee protection airbag that has a free end and expands and expands into a substantially rectangular plate shape.

  The present invention solves the above-described problems, and an object of the present invention is to provide a knee protection airbag capable of completing inflation while suppressing unnecessary twisting and inclination.

The airbag for knee protection according to the present invention is folded and stored on the front side of a seated occupant's knee so as to be able to protect the occupant's knee, and has a substantially rectangular plate shape at the time of completion of expansion and inflating. Is a knee protection airbag that expands and inflates with the upper end side as a free end,
The upper edge when the inflation is completed is made substantially straight along the left-right direction, and the outer peripheral edges of the occupant-side base fabric and the vehicle-side base fabric made of woven fabric having the same shape are joined to each other. As a structure formed by
The warp or weft of one woven fabric of the occupant side base fabric and the vehicle body side base fabric is arranged along substantially the left-right direction so as to be substantially along the upper edge of the airbag at the time of completion of deployment,
The warp or weft of the other woven fabric of the occupant side fabric and the vehicle body side fabric is arranged so as to intersect the upper edge of the airbag at the completion of deployment at a crossing angle of approximately 45 °. It is characterized by.

  In the knee protection airbag according to the present invention, one warp or weft of the occupant side base fabric and the vehicle body side base fabric is substantially parallel to the upper edge that is substantially linear in the left-right direction of the airbag when inflation is completed. It is set to be. Therefore, the occupant-side base fabric or the vehicle body-side base fabric (referred to as the parallel-side base fabric) whose thread line is substantially parallel to the upper edge of the airbag is difficult to be deformed so as to be twisted or tilted. The vehicle body-side base fabric or the occupant-side base fabric (referred to as the cross-side base fabric) intersects the warp or weft with the upper edge of the airbag at an intersection angle of approximately 45 °, It is easy to stretch without affecting the outer peripheral edge of the parallel-side base fabric as a bias direction with respect to the yarn. As a result, when the knee protection airbag is deployed and inflated with the lower end side as a fixed end and the upper end side as a free end, the upper edge side of the occupant side base fabric and the vehicle body side base fabric does not twist or incline. It becomes possible to deploy and inflate substantially along the direction, and to deploy and inflate following the upper edge side without twisting or inclining even from the upper part to the lower part of the airbag connected to the upper edge side.

  Therefore, in the knee protection airbag according to the present invention, unnecessary torsion and inclination can be suppressed and inflation can be completed.

  If the base fabric in which the warp or weft intersects the upper edge at an intersection angle of about 45 ° is used as the occupant side base fabric, the occupant side base fabric intersects each side of the substantially rectangular shape in the bias direction. Thus, the warp and the weft are arranged so that it is easy to stretch, and conversely, the vehicle body side base fabric is arranged with the warp and the weft so that it is substantially parallel to each side of the substantially rectangular shape. It is difficult to grow. That is, when the airbag is deployed and inflated, the occupant side base fabric does not extend, but the occupant side base fabric expands. Therefore, the occupant side base fabric is inflated and the vehicle body side base fabric can easily approach the vehicle body side. Thus, unnecessary protrusion of the occupant to the knee side is suppressed, and it is easy to expand and expand upward along the vehicle body side member, and the gap between the occupant's knee and the vehicle body side member positioned in front of the knee is narrow. In both cases, the airbag that is deployed and inflated can be easily intruded into the gap.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A knee protection airbag 46 according to an embodiment is used in a knee protection airbag device S, and a knee protection airbag device according to an embodiment. As shown in FIGS. 1 and 4, S is disposed below the steering column 9 on the front side of the vehicle of the driver MD so as to protect the knee K (KL / KR) of the driver MD as an occupant. ing.

  The vertical / front / rear / left / right relationship in this specification is based on the state in which the airbag device S is mounted on the vehicle, and is consistent with the vertical / front / rear / left / right relationship of the vehicle when mounted. It is.

  As shown in FIG. 1, the steering column 9 includes a column main body 10 connected to the steering wheel 8 and a column cover 13 disposed so as to cover the column main body 10 below the steering wheel 8. Has been. The column body 10 includes a main shaft 11 and a column tube 12 that covers the periphery of the main shaft 11.

  The column cover 13 is made of a synthetic resin having a substantially rectangular tube shape, and is disposed along the axial direction of the column main body 10 so as to cover the column main body 10. A rear surface 13a of a portion of the column cover 13 that protrudes from an instrument panel (hereinafter abbreviated as “instrument panel”) 14 has a substantially rectangular shape, and is formed in a curved shape that rises rearward in the vehicle front-rear direction.

  The knee protection airbag device S stores a folded airbag 46, an inflator 38 that supplies inflation gas to the airbag 46, the folded airbag 46 and the inflator 38, and opens the vehicle rear side. The case 17 and an airbag cover 27 that covers the vehicle rear side of the opening 18a in the case 17 are provided.

  As shown in FIGS. 2 to 4, the case 17 is made of sheet metal and is disposed on the lower side of the steering column 9, and has a box-shaped main body 18 and a panel extending outward from the rear end of the main body 18. Part 24. The main body 18 includes a substantially square cylindrical peripheral wall 19 and a bottom wall 22 that closes the vehicle front side of the peripheral wall 19, and a substantially rectangular opening 18 a on the vehicle rear side. ing. On the outer surface side of the wall portions 19a and 19b facing each other in the vertical direction of the peripheral wall portion 19, a plurality of locking portions 20 (for attaching the upper and lower connecting wall portions 30 and 31 of the airbag cover 27 to the case 17, respectively. 20U and 20D) are provided.

  Each locking portion 20U disposed on the outer surface side of the upper wall portion 19a has a substantially Z-shaped cross section and is inserted into the locking hole portion 30a of the upper side wall portion 30 in the airbag cover 27 and locked. The peripheral edge of the hole 30a is a locking hook that can be locked. A plurality of these hooks 20U are arranged on the wall portion 19a along the left-right direction of the vehicle.

  The locking portion 20D disposed on the outer surface side of the lower wall portion 19b is formed in a substantially U-shaped cross section and can be inserted into the locking hole portion 31a of the lower side wall portion 31 in the airbag cover 27. It is a locking projection. A plurality of these locking projections 20D are arranged on the wall portion 19b along the left-right direction of the vehicle. In addition, a saddle member 21 is inserted into each locking projection 20D so as to prevent the locking hole portion 31a from coming off after being inserted into each locking hole portion 31a. This saddle member 21 includes a plurality of insertion portions 21a to be inserted between the outer surface of the lower wall portion 31 and the inner peripheral surface of each locking projection 20D, and is integrated on the vehicle front side. It is fixed to the case 17. Note that the anchoring material 21 is fixed to the case 17 by being fastened together with the nut 41 of the bolt 40 c for fixing the inflator 38 to the case 17 and being fixed to the bottom wall portion 22 of the case 17.

  Furthermore, an insertion hole 19d through which the main body 39 of the inflator 38 can be inserted is formed in the side wall portion 19c of the peripheral wall portion 19 (see FIG. 3). Further, two insertion holes 22 a for inserting the bolts 40 c of the inflator 38 are formed in the bottom wall portion 22.

  The panel part 24 is formed so as to surround the periphery of the opening 18 a of the case 17. Further, as shown in FIG. 4, connecting portions 25 (25 </ b> A, 25 </ b> B, 25 </ b> C) for connecting and fixing the case 17 to the body 1 side are disposed on the panel portion 24. Brackets 4, 5, 6 are arranged on the body (vehicle body) 1 side to which the respective connecting portions 25 are connected. The brackets 4 and 4 for connecting the upper connecting portion 25A are connected to the instrument panel reinforcement 2 on the body 1 side. The brackets 5 and 6 for connecting the connecting portions 25B and 25C on the lower side are connected to a center brace, a front body pillar, etc. (not shown) on the body 1 side. Further, as shown in FIG. 2, the panel portion 24 is formed with an insertion hole 24 a through which the upper wall portion 30 of the airbag cover 27 is inserted.

  The airbag cover 27 is formed of a thermoplastic elastomer such as polyolefin, and is configured to be able to cover the vehicle rear side of the opening 18 a in the case 17 and is assembled to the case 17. The airbag cover 27 is disposed on the lower panel 14b side of the instrument panel 14 including the upper panel 14a and the lower panel 14b. The airbag cover 27 includes a door disposition portion 29 disposed near the opening 18a of the case 17 and a door arrangement. And a general portion 28 disposed around the installation portion 29.

  A lower panel 14 b is disposed around the door arrangement portion 29 adjacent to the door arrangement portion 29. In the case of the embodiment, the door arrangement portion 29 and the lower panel 14b are arranged so that the surface on the vehicle rear side is substantially flush (see FIG. 3). And the door arrangement | positioning part 29 is provided with the door part 36, and the upper, lower, left, right side wall part 30,31,32,33 arrange | positioned in the site | part used as the periphery of the door part 36, and is comprised. Has been.

  The door portion 36 is formed slightly larger than the opening 18a of the case 17 and has a substantially rectangular plate shape covering the opening 18a. The door part 36 is comprised from the two door parts opened to an up-down direction in embodiment. And each door part 36 arrange | positions the hinge part 35 used as the rotation center at the time of opening to an upper end or a lower end, and the site | part used as a substantially H shape seeing from the vehicle rear side around the door part 36, A thin rupture scheduled portion 34 is arranged.

  The upper side wall part 30, the lower side wall part 31, the left side wall part 32, and the right side wall part 33 are adjacent to the outer peripheral side of the peripheral wall part 19 in the case main body part 18 so as to protrude to the vehicle front side. It is arranged. In the case of the embodiment, the upper side wall portion 30 disposed in the vicinity of the upper wall portion 19a of the peripheral wall portion 19 and the lower side wall portion 31 disposed in the vicinity of the lower wall portion 19b form the airbag cover 27. The upper wall portion 30 includes a plurality of locking holes 30a for locking the locking portion 20U, and the lower wall portion 31 engages the locking portion 20D. A plurality of locking holes 31a for stopping are provided.

  As shown in FIGS. 2 and 3, the general portion 28 has a thickness equal to the thickness of the lower panel 14 b from the door disposition portion 29 so as not to interfere with the lower panel 14 b disposed around the door disposition portion 29. It is formed so as to be recessed to the side. Note that the lower panel 14b and the general portion 28 are fixed by a clip or the like at a predetermined location (not shown).

  As shown in FIGS. 2 and 3, the inflator 38 is configured as a cylinder type whose axial direction is disposed along the left-right direction of the vehicle, and includes a substantially cylindrical main body 39 and a diffuser 40. . A plurality of gas discharge ports 39 a are disposed on one end side of the main body 39. A connector 42 in which an operation signal input lead wire 43 is connected is connected to the other end side of the main body 39. The diffuser 40 includes a substantially cylindrical sheet-metal holding cylinder portion 40a that can cover the main body 39, and a plurality (two in the embodiment) of bolts 40c protruding from the holding cylinder portion 40a. . The holding cylinder part 40a opens a plurality of gas outlets 40b through which the expansion gas G discharged from the gas discharge port 39a of the main body 39 can flow out to a surface on the vehicle rear side of the holding cylinder part 40a mounted in the vehicle. I am letting.

  When the airbag operation circuit mounted on the vehicle detects a frontal collision of the vehicle, an operation signal is sent to the inflator 38 via the lead wire 43 together with an airbag device (not shown) mounted on the steering wheel 8. Will be entered.

  The airbag 46 restricts the inflation-completed shape of the airbag body 49 by applying a tensile force when the airbag body 49 is inflated, and a bag-like airbag body 49 that can be inflated by inflating the inflation gas G. And tethers 53 and 54. As shown in FIGS. 1, 4, and 5, the airbag 46 is formed into a substantially rectangular plate when deployed and inflated, and includes an attachment portion 48 that houses the inflator 38 on the lower end 46 b side, and an upper side of the attachment portion 48. And a protective part 47 that is disposed and has a width dimension in the left-right direction larger than that of the attachment part 48. The attachment portion 48 is housed in the case main body portion 18 when the airbag 46 is completely inflated and inflated, and is a portion held by the case main body portion 18 using the inflator 38. Therefore, two insertion holes 48a and 48a and one insertion hole 48b are formed in the attachment portion 48 (see FIGS. 3 and 8). The insertion holes 48a and 48a are for inserting the bolts 40c of the inflator 38, and the insertion hole 48b is for inserting the main body 39 of the inflator 38. Then, the attachment portion 48 projects the main body 39 of the inflator 38 from the insertion hole 48b, and the peripheral edge of each insertion hole 48a is sandwiched between the holding cylinder portion 40a and the bottom wall portion 22 of the case main body portion 18, thereby It is attached to the part 18. Therefore, in the airbag 46, the lower end 46b side is a fixed end, and the upper end 46a side is a free end, so that the airbag 46 is deployed and inflated.

  As shown in FIGS. 5 to 8, the bag-shaped airbag body 49 is formed by bonding the outer peripheral edges of two base fabrics 50 and 51 made of woven fabric such as flexible polyester or polyamide yarn. The reinforcing cloth 52 (52F / 52B) is disposed at a predetermined position while being formed. The two base fabrics 50 and 51 constituting the bag-shaped airbag main body 49 are a passenger side base fabric 50 located on the driver MD side and a vehicle body side base fabric 51 located on the column cover 13 side when deployed and inflated. is there. The occupant side base fabric 50 and the vehicle body side base fabric 51 have a substantially rectangular shape with substantially the same outer shape.

  However, the occupant-side base fabric 50 is configured to include a reinforcing portion 50a for reinforcing the attachment portion 48, which is an installation site of the inflator 38. Strictly speaking, the occupant-side base fabric 50 has the same shape as the vehicle body-side base fabric 51. Not in. However, on the upper edge 49a side of the airbag body 49, the base fabrics 50 and 51 are arranged such that the mutual coupling portion 49c is linearly arranged along the left-right direction at the center of the airbag upper end 46a in the front-rear direction. It is formed symmetrically in the front-rear direction around 49c.

  The reinforcing cloth 52F is an area from the attachment portion of the tethers 53 and 54 to the lower end 46b of the airbag 46 including the attachment portion 48 on the inner side surface of the vehicle body-side base cloth 51 and to both left and right edges of the base cloth 51. Are combined and arranged in the area. The reinforcing cloth 52 </ b> B is coupled and arranged on the inner side surface of the occupant-side base cloth 50 in a substantially rectangular area apart from the outer peripheral edge of the base cloth 50 in the vicinity of the attachment site of the tethers 53 and 54.

  The insertion holes 48a and 48b of the attachment portion 48 are integrally disposed on the vehicle body side base fabric 51, the reinforcing portion 50a extending from the passenger side base fabric 50, and the reinforcing fabric 52F.

  Further, the cloth materials 57A and 57B of the reinforcing cloths 52F and 52B and the tethers 53 and 54 are made by weaving a warp VS and a weft HS such as flexible polyester or polyamide yarn, like the base cloths 50 and 51. It is formed from the formed woven fabric.

  The upper edge 49a of the airbag main body 49 when the inflation is completed is arranged in a straight line along the left-right direction, and the warp VS or the weft HS of the base fabrics 50 and 51 (the direction of the yarn) When the inflation is completed, the vehicle body-side base fabric 51 is a parallel-side base fabric in which the stitches (yarn direction) of the warp VS or the weft HS (weft HS in the embodiment) are parallel to the upper edge 49a of the airbag body 49. The occupant-side base fabric 50 is arranged so that the warp VS or weft HS stitches (yarn direction) intersect with the upper edge 49a at a crossing angle θ of 45 °. .

  When the expansion of the main body 49 is completed, the reinforcing cloths 52F and 52B have warps VS or wefts HS (wet thread HS in the embodiment) with the stitches (yarn direction) parallel to the upper edge 49a of the airbag main body 49. Further, the fabric materials 57A and 57B are arranged so that the warp VS or the weft HS (the direction of the yarn) intersects the upper edge 49a at 45 °.

  Furthermore, in the case of the embodiment, the base fabrics 50 and 51, the reinforcing fabrics 52F and 52B, and the fabric materials 57A and 57B of the tethers 53 and 54 are joined by stitching using the suture thread 58. In addition, adhesion, welding, or the like may be used.

  The tethers 53 and 54 are disposed in the region of the protective portion 47 in the airbag body 49 and regulate the separation distance between the occupant side base fabric 50 and the vehicle body side base fabric 51 when the airbag 46 is deployed and inflated. Thus, the protective portion 47 is disposed so as to smoothly enter between the knee K of the driver MD and the column cover 13. In the case of the embodiment, the tethers 53 and 54 are arranged in two upper and lower stages along the left-right direction. Each of the tethers 53 and 54 is composed of two cloth materials 57A and 57B. That is, the two cloth materials 57A and 57A are joined at one end side to the base cloth 50 and 51, respectively, and are joined at the other end side to form a tether 53 to form two cloth materials 57B and 57B. The tether 54 is formed by joining one end side to the base fabrics 50 and 51 and joining the other end side to each other.

  In the case of the embodiment, each of the cloth materials 57A and 57B is used in a double-folded two-ply form, and is further formed in a trapezoidal shape that becomes wider on the base cloth 50/51 side.

  Further, the tether 54 disposed on the lower side (the inflator side) has two cloth materials 57B and 57B on the end portions close to each other, as shown in FIGS. A gas flow hole 55 through which the expansion gas G can flow is opened so as to be cut out into a substantially rectangular shape. In the case of the embodiment, the gas flow hole 55 is formed to be shifted from the center in the left-right direction of the tether 54 to the right side, and the edges of the cloth materials 57B and 57B are cut out into a substantially rectangular shape. It is comprised from the notch recessed part 54a which was made.

  This gas flow hole 55 controls the flow of the inflation gas G in the protection part 47, and in order to allow the inflation gas G to quickly flow between the tethers 53 and 54 when the airbag 46 is deployed and inflated. Arranged. The reason why the airbag 46 is displaced in the left-right direction is that the airbag 46 at the time of completion of inflation in the embodiment is seated at the center C0 in the left-right direction due to the arrangement of members on the surrounding body 1 side and the like. It is slightly shifted to the left from the center C1 in the left-right direction of the driver MD (which can also be said to be the center in the left-right direction of the seat on which the driver MD as the occupant sits). In relation, the gas flow hole 55 is positioned at the center C1 so that the gas flow hole 55 is not blocked by the left knee KL when it is already positioned on the front side before the operation of the airbag device S. It is to make it. That is, even when the center C0 of the airbag 46 and the center C1 of the seated occupant MD are shifted from side to side, even when there is a knee KL that has already been positioned before the operation of the device S, This is because the inflation gas G flows smoothly between the gas flow hole 55 and the tethers 53 and 54, and the knees KR and KL are accurately protected between the tethers 53 and 54.

  Further, as shown in FIGS. 7 and 9, a notch portion 56 formed by making a notch in the inner edge 54 b of the notch recess 54 a so as to be arranged on the inner side of the tether 54, as shown in FIGS. Is disposed. In the case of the embodiment, the cut portion 56 is formed at a position near the edge in the front-rear direction on the inner peripheral edge 54b of the notch recess 54a.

  In manufacturing the airbag 46, the reinforcing portion 50a of the occupant side base fabric 50 and the portion of the attachment portion 48 of the vehicle body side base fabric 51 are overlapped and stitched with the suture thread 58, and further, the portion of the attachment portion 48 is reinforced. The cloth 52F is overlapped, and the reinforcing cloth 52B is overlapped on the occupant side base cloth 50, and each is sutured using the suture thread 58. Next, the fabric materials 57B and 57B are sewn to the base fabrics 50 and 51, and are sewn together to form the tether 54. Further, the fabric materials 57A and 57A are sewn to the base fabrics 50 and 51, and The tethers 53 are formed by stitching together. And if the outer periphery of base fabric 50 * 51 is stitched | sutured together, the airbag 46 can be manufactured.

  Before sewing the outer peripheries of the base fabrics 50 and 51, the bolt 40c and the end of the inflator body 39 protrude from the insertion holes 48a and 48b so that the inflator 38 is placed in the airbag 46. Store and then sew.

  And if the mounting of the airbag apparatus S to a vehicle is demonstrated, the manufactured airbag 46 will be folded first. Specifically, as shown in FIG. 10A, from the state where the occupant side base fabric 50 and the vehicle body side base fabric 51 are overlapped and flattened, the left and right edges 46c and 46d are connected to the occupant side base fabric 50. Fold it to the side. Next, as shown in FIGS. 10B and 10C, the upper end 46a side of the airbag 46 is rolled around a fold along the left-right direction so as to be wound around the vehicle body-side base fabric 51, and D in FIG. As shown in FIG. 4, the right and left edges 60a and 60b of the roll-folded portion 60 are folded on the occupant-side base fabric 50 side so as to have a width dimension that can be stored in the case body 18, and the airbag 46 is folded. To complete. Thereafter, the airbag 46 is wrapped with a breakable wrapping material (not shown) for preventing collapse. At this time, the bolt 40c of the inflator 38 protruding from the insertion holes 48a and 48b and the end of the main body 39 are protruded from the wrapping material.

  Next, the bolt 40c of the inflator 38 is protruded from the insertion hole 22a, and the end of the inflator main body 39 is protruded from the insertion hole 19d, so that the inflator 38 is folded together with the folded airbag 46 to the case main body 18. Store inside.

  Thereafter, the airbag cover 27 is assembled to the case 17. At this time, first, the upper wall portion 30 is inserted into the insertion holes 24a of the panel portion 24, and the respective locking hooks 20U are inserted into the respective locking hole portions 30a. Lock to the periphery of the portion 30a. Next, the respective locking projections 20D are inserted into the respective locking hole portions 31a of the lower side wall portion 31, and between the outer surface of the lower side wall portion 31 and the inner peripheral surface of each locking projection 20D, The airbag cover 27 can be assembled to the case 17 by inserting the insertion portion 21a, inserting the bolts 40c into the collar member 21, and screwing the nuts 41 into the bolts 40c.

  Then, each connecting portion 25 of the case 17 is attached and fixed to the body 1 side using the brackets 4, 5, and 6, and at the same time, the connector 42 to which the lead wire 43 is connected is connected to the inflator body 39. After that, if the instrument panel 14 and the under cover 15 (see FIGS. 1 and 2) are attached, the airbag device S can be mounted on the vehicle.

  If an operation signal is input to the inflator body 39 through the lead wire 43 after the airbag device S is mounted on the vehicle, the inflation gas G is discharged from the gas discharge port 39a of the inflator 38, and the inflation gas G is The air flows into the airbag 46 through the gas outlet 40 b of the diffuser 40. The airbag 46 is inflated to break a wrapping material (not shown), presses the door portion 36 of the airbag cover 27, breaks the planned break portion 34, and the door portion 36 rotates the hinge portion 35. The airbag 46 opens up and down as the center, and the airbag 46 is inflated and inflated as shown by a two-dot chain line in FIGS.

  When the inflation of the airbag 46 having a substantially rectangular plate shape is completed, the weft HS of the vehicle body-side base fabric 51 is parallel to the upper edge 49a that is linear in the left-right direction of the airbag 46 when the inflation is completed. Therefore, the vehicle body side base fabric 51 having a substantially rectangular shape is difficult to be deformed so as to be twisted or inclined, and conversely, the passenger side base fabric 50 having a substantially rectangular shape has the warp VS or the weft HS. The upper edge 49a intersects with the crossing angle θ of 45 ° and extends as a bias direction with respect to the thread of the base fabric 51 without affecting the outer peripheral edge of the base fabric 51. As a result, when the knee protection airbag 46 is deployed and inflated with the lower end 46b side as a fixed end and the upper end 46a side as a free end, the upper edge 49a side of the occupant side base fabric 50 and the vehicle body side base fabric 51 is twisted. It is possible to expand and inflate substantially along the left-right direction without inclining, and follow the upper edge 49a side without twisting or inclining even from the upper part to the lower part of the airbag 46 connected to the upper edge 49a side. It becomes possible to expand and expand.

  Therefore, in the knee protection airbag 46 according to the embodiment, unnecessary torsion and inclination can be suppressed and the inflation can be completed.

  In the embodiment, the warp VS or the weft HS of the vehicle body-side base fabric 51 is set so as to be parallel to the upper edge 49a that is linear in the left-right direction in the airbag 46 when the inflation is completed. Further, the occupant-side base fabric 50 is parallel to the parallel-side base so that the warp VS or the weft HS of the occupant-side base fabric 50 is parallel to the upper edge 49a that is linear in the left-right direction in the airbag 46 when inflation is completed. Even if the vehicle body-side base fabric 51 is used as the cross-side base fabric so that the warp VS or the weft HS of the vehicle-body-side base fabric 51 intersects the upper edge 49a at 45 °, the airbag is useless. Inflating can be completed while suppressing twisting and tilting.

  However, in the embodiment, the occupant-side base fabric 50 is the cross-side base fabric that crosses the warp VS or the weft HS with the upper edge 49a at the crossing angle θ of about 45 °. Therefore, the occupant-side base fabric 50 that is the cross-side base fabric is provided with the warp VS and the weft HS so as to cross each side of the substantially rectangular shape in the bias direction. The vehicle body-side base fabric 51 is difficult to stretch because the warp VS and the weft HS are disposed so as to be substantially parallel to the sides of the substantially rectangular shape. That is, when the airbag 46 is deployed and inflated, the occupant side base fabric 50 does not extend but the occupant side base fabric 50 extends, so that the occupant side base fabric 50 is inflated from the vehicle body side base fabric 51. Thus, the vehicle body side base fabric 51 can be easily approached to the column cover 13 as the vehicle body side member, and unnecessary protrusion of the occupant MD to the knee K side is suppressed, along the rear surface 13a of the vehicle body side member 13, and upward. Even if the gap between the knee K of the occupant MD and the vehicle body-side member 13 located in front of the knee K is narrow, the airbag 46 that is easily deployed and inflated can enter the gap. Can be arranged.

  Incidentally, the occupant-side base fabric 50 is placed on the parallel side so that the warp VS or the weft HS of the occupant-side base fabric 50 is substantially parallel to the upper edge 49a that is linear in the left-right direction in the airbag 46 when the inflation is completed. When the vehicle body side base fabric 51 is set to the cross side base fabric so that the warp VS or the weft HS of the vehicle body side base fabric 51 intersects the upper edge 49a at an intersection angle θ of about 45 °. The occupant-side base fabric 50 side, which is composed of a single piece except for the reinforcing fabric 52B, is difficult to stretch, and it is easy to prevent misalignment of the sutured portions by the sutures 58 on the left and right edges 46c and 46d side. it can.

  In the embodiment, a notch 56 is provided in the inner peripheral edge 54b of the notch recess 54a in the tether 54. When a tensile force acts on the tether 54 as the airbag 46 is inflated, the inner peripheral edge 54b. On the side, the stress concentrates on a portion of the tether 54 near the tip 56a of the cut portion 56. Then, in the stitched portion 61 of the cloth material 57B of the tether 54, as shown in FIG. 9, a line extending along the direction of application of the tensile force from the tip 56a of the cut portion 56 (substantially orthogonal to the stitched portion 61). However, the tip 56a of the cut portion 56 is more distant from the recessed portion 54a than the end portion 61a of the sutured portion 61. Therefore, the largest force is applied to a position on the inner side of the end portion 61a in the suture site 61. That is, when a tensile force is applied to the tether 54, the force applied to the vicinity of the end 61a of the suture site 61 can be reduced, and the stress concentration acting on the suture thread 58 near the end 61a of the suture site 61 can be reduced. Even if the recess 54a that forms the gas flow hole 55 is provided, the stitching strength between the cloth materials 57B and 57B in the tether 54 can be improved.

  In the embodiment, the knee protection airbag 46 for the driver has been described, but the present invention may of course be applied to a knee protection airbag for the passenger seat.

It is a schematic longitudinal cross-sectional view of the vehicle front-back direction which shows the use condition of the knee protection airbag apparatus in which the airbag of embodiment of this invention is used. It is a general | schematic expanded longitudinal cross-sectional view of the vehicle front-back direction of the airbag apparatus for knee protection of embodiment. It is a general | schematic expanded cross-sectional view of the vehicle front-back direction in the airbag apparatus for knee protection of embodiment, and respond | corresponds to the III-III site | part of FIG. It is a schematic front view of the airbag apparatus for knee protection of embodiment. It is a front view of an air bag in the state where an inflator in an embodiment was built, and shows a state showing a tether. It is a longitudinal cross-sectional view of the airbag of embodiment, and respond | corresponds to the VI-VI site | part of FIG. It is a cross-sectional view of the airbag of the embodiment and corresponds to the VII-VII portion of FIG. It is the front view and back view of the airbag of embodiment, and each shows the state showing the reinforcement cloth. It is a front view which shows the cloth material which comprises the tether of the lower part side of the airbag of embodiment. It is a figure explaining the folding process of the airbag of an embodiment.

Explanation of symbols

1 ... (Body) Body,
13 ... (vehicle body side) column cover,
46 ... Knee protection airbag,
46a ... (top of the airbag),
46b ... the lower end of the airbag
49a ... upper edge of the airbag body,
50 ... passenger side fabric,
51 ... body side fabric,
VS ... warp,
HS ... weft,
θ ... crossing angle,
MD ... (Driver) Crew,
K (KL / KR) ... Knee,
S: Air bag device for knee protection.

Claims (2)

Folded on the front side of the seated occupant's knee so that the occupant's knee can be protected, the unfolded and expanded shape is a substantially rectangular plate, the lower end is fixed to the vehicle body, and the upper end is free A knee protecting airbag that deploys and inflates as an end,
The upper edge when the inflation is completed is made substantially straight along the left-right direction, and the outer peripheral edges of the occupant-side base fabric and the vehicle-side base fabric made of woven fabric having the same shape are joined to each other. As a structure formed by
The warp or weft of one woven fabric of the occupant side base fabric and the vehicle body side base fabric is disposed along substantially the left-right direction so as to be substantially along the upper edge of the airbag when deployment is completed,
The warp or weft of the other woven fabric of the occupant side base fabric and the vehicle body side base fabric is arranged so as to intersect the upper edge of the airbag at the completion of deployment at an intersection angle of approximately 45 °. An air bag for protecting the knee.   The knee protection airbag according to claim 1, wherein a base fabric in which warps or wefts intersect with an upper edge at an intersection angle of about 45 ° is used as the occupant side base fabric.

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