JP2008222111A - Knee protecting airbag device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a knee protecting airbag device in which an airbag when its inflating is completed can make tight attachment to an instrument panel smoothly and receive the knees while it secures the cushion effect quickly. <P>SOLUTION: The knee protecting airbag device M is structured so that the airbag 47 is accommodated in and held by an accommodation part 35 on the side with the lower part 16a inside a column cover 16. The peripheral wall 48 when inflation of the airbag 47 is completed, consists of a driver side wall part 49 and a column side wall part 50. When inflation of the airbag 47 is completed, the column side wall part 50 covers the undersurface 18ab of the peripheral edge of the accommodation part of the column cover and the areas 12 and 14 of the panel surface 11 positioned on the left and right sides of the column cover from below the column cover. The front part 53 and the rear part 57 of the column side wall part 50 are set so that the mutual interseting angle on the sides with the front faces 53a and 57a is made approximately the same as the intersecting angle θ0 formed between the panel surface 11 and the undersurface 18a of the column cover 16 protruded from the panel surface 11 when inflation of the airbag in single piece is completed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a knee protection airbag device that protects a driver's knee with an inflated airbag in the event of a vehicle collision, and in particular, a column that covers a steering column and projects rearward from an instrument panel. The present invention relates to a knee protecting airbag device with a steering column that houses a folded airbag in a cover.

  Conventionally, a knee protection airbag device with a steering column has a folded airbag stored in the lower side of the column cover, and when activated, inflation gas is supplied to the airbag and the airbag is deployed. It was set as the structure which protrudes from a column cover so that it may arrange | position to the front side of a driver | operator's knee, expanding (for example, refer patent document 1).

In the conventional knee protection airbag device, when activated, the inflator disposed in the airbag discharges the inflation gas in a diagonally downward direction on both the left and right sides, and the airbag radiates from the approximate center of the column cover. The airbag was inflated and then inflated to actuate the driver's knees from the column cover by spreading the driver's knees.
JP 2002-37003 A

  However, when protecting the driver's knee, it is desirable to protect not only the column cover but also the instrument panels on the left and right sides of the column cover. However, since the column cover itself protrudes from the instrument panel and the airbag protrudes from the lower surface side of the protruding part, the airbag completes expansion so that it floats away from the rear surface of the instrument panel to the rear side. Easy to do.

  Therefore, even if the knee that moves forward hits the part of the airbag away from the rear surface of the instrument panel to the rear side, the part is not supported by the instrument panel, so it is not pushed until it hits the instrument panel. The reaction force cannot be secured because it is not supported, and it is difficult to quickly catch the knee with a cushioning effect as far as it is away from the instrument panel.

  SUMMARY OF THE INVENTION The present invention solves the above-described problem, and an airbag device for protecting a knee capable of receiving a knee while promptly securing a cushioning action when an airbag at the time of completion of inflation is in close contact with an instrument panel. The purpose is to provide.

The knee protection airbag device according to the present invention covers the steering column and is mounted on the lower side of the column cover that protrudes obliquely upward and rearward from the instrument panel.
The folded airbag is stored and attached to the lower storage part in the column cover,
During operation, inflation gas is supplied to the airbag, and the airbag protrudes from the storage portion in the column cover while being expanded and inflated obliquely rearward and downward, and the column cover is stored on the front side of the driver's knee. A knee protecting airbag device configured to cover the lower surface of the peripheral edge of the region and the rear surface of the instrument panel at the peripheral edge of the column cover,
Panel surfaces located on the left and right sides of the column cover from the lower side of the column cover on the rear surface of the instrument panel that the airbag covers when the inflation is completed are arranged as a substantially flat surface extending in the left-right direction with the upper side protruding rearward. ,
The column cover is disengaged from the panel surface to the rear side in the vicinity of the front end of the airbag opening at the time of deployment and expansion in the storage part, and the lower surface viewed from the side extends obliquely upward and rearward, It is arranged as a substantially flat surface with an angle intersecting the panel surface closer to the horizontal plane,
The outer peripheral wall when the airbag is completely inflated is arranged so that the driver side wall portion arranged on the driver side and the attachment portion attached to the storage part are arranged in the vicinity of the center of the front, rear, left and right, and the entire periphery of the outer peripheral edge A column side wall portion connected to the outer peripheral edge of the side wall portion, and
The column side wall of the airbag is configured to cover the lower surface of the peripheral edge of the storage portion of the column cover and the panel surfaces located on the left and right sides of the column cover from below the column cover when the airbag is completely inflated.
When the inflation of the airbag alone is completed, the front side and the rear side of the column side wall located near the center in the front-rear direction protrude from the panel surface and the panel surface. The airbag is configured to be substantially equal to an intersection angle with the lower surface of the column cover.

  In the knee protection airbag device according to the present invention, when the inflation gas is supplied to the airbag during operation, the airbag is expanded and inflated obliquely rearward and downward from the projection opening of the storage portion in the column cover. Projecting to cover the lower surface of the peripheral edge of the storage area of the column cover and the panel surfaces located on the left and right sides of the column cover from the lower side of the column cover on the rear surface of the instrument panel on the front side of the driver's knee. Placed in. At this time, in the vicinity of the mounting portion located near the front, rear, left, and right center of the column side wall portion of the airbag, the peripheral edge of the storage portion that has entered the storage portion of the column cover but is separated from the protruding opening of the storage portion The rear side part of the column side wall part located on the rear side of the storage part, for example, is in close contact with the lower surface of the column cover. Then, if the rear side portion of the column side wall portion is in close contact with the lower surface on the rear side of the peripheral edge of the projection opening of the storage portion in the column cover, the front side portion of the column side wall portion is connected to the front surface and the front surface of the rear side portion. Is arranged so that the crossing angle is substantially equal to the crossing angle between the panel surface and the bottom surface of the column cover protruding from the panel surface when the airbag is inflated, the front side portion of the column side wall portion is The part of the storage part that is separated from the projection opening can easily adhere to the panel surfaces located on the left and right sides of the column cover from below the column cover. That is, the front center part in the vicinity of the center in the left-right direction at the front side part of the column side wall part located on the lower side of the column cover, and the front left part on both the left and right sides in the front side part of the column side wall part located on the left and right sides of the column cover In addition, the front right part is in close contact with the panel surfaces located on the left and right sides of the column cover from below the column cover.

  As a result, in the column side wall portion of the airbag, the front side portion and the rear side portion can be in close contact with each other without floating away from the panel surface and the lower surface of the column cover, respectively, and the support is good. Even if the driver side wall, which is the rear part of the front side and the rear side of the airbag, receives the driver's knees moving forward or obliquely upward, the panel surface and the lower surface of the column cover It can be supported quickly and smoothly, ensuring cushioning and receiving the knee.

  Therefore, in the knee protection airbag device according to the present invention, the airbag when inflated is smoothly in close contact with the rear surface of the instrument panel or the lower surface of the column cover, and promptly secures a cushioning action to receive the knee. be able to.

  Further, in such an airbag, the front side portion and the rear side portion of the column side wall portion are not bent by the surrounding members, and the bent shape is secured as the inflation completion shape of the airbag itself. Since there is no unnecessary pressing force applied to the outer peripheral wall of the airbag when the inflation is completed, it is difficult to cause damage due to interference with surrounding members that may cause gas leakage.

  And the crossing angle of the front side part of the front side part and the rear side part in the column side wall part of the airbag is arranged in the airbag, and extends from the front side part and the rear side part respectively to the driver side wall part. It is desirable to set by a front tether and a rear tether that are connected and regulate the thickness of the airbag when inflation is completed.

  That is, in such a configuration, the airbag base fabric is stitched and bonded as compared with the case where the airbag is draped and the crossing angle between the front side portion and the rear side portion of the column side wall portion is set. Thus, when manufacturing the airbag, the front tether and the rear tether need only be coupled to the driver side wall and the column side wall, rather than three-dimensionally, such as stitching. It can be manufactured easily.

  In this case, the airbag is configured as a planar airbag type in which the outer shape of the driver side wall portion and the column side wall portion are substantially equal, and the front tether and the rear tether are based on the span between the connecting portions to the column side wall portion. The span between the connecting portions to the driver side wall may be shortened.

  That is, in such a configuration, with respect to the two tethers arranged on the front and rear (upper and lower) sides of the airbag, the span between the connecting portions to be connected to the column side wall and the driver side wall is set from the side of the column side wall to the driver. Connect both ends of each of the two front and rear tethers to the column side wall and the driver side wall so as to shorten the side of the side wall, and then expand the column side wall and the driver side wall flatly. If the outer peripheral edges of the column side wall portion and the driver side wall portion are joined together by stitching or the like, the airbag can be manufactured very easily by a joining operation such as planar stitching.

  In addition, the column cover is configured by arranging the opening for projecting the airbag during inflation from the lower surface of the column cover to the left and right side surfaces so as to extend from the lower side of the storage site to the left and right sides of the storage site. Is desirable.

  In such a configuration, the airbag can be protruded from both the left and right side surfaces of the column cover approaching the panel surface, and the right and left panel surfaces in the vicinity of the column cover approaching the column cover can be It becomes possible to make the column side wall part at the time of completion of expansion more closely contact the part.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 2 to 4, the knee protection airbag device M according to the embodiment includes a folded airbag 47 and a lower portion 16 a in a column cover 16. It is configured to be housed on the side. The column cover 16 covers the steering column 3 and protrudes obliquely upward and rearward from an instrument panel (hereinafter referred to as instrument panel) 7 (see FIGS. 1 and 2). 2 to 4, the knee protection airbag apparatus M includes a folded airbag 47, an inflator 41 that supplies inflation gas to the airbag 47, and the airbag 47 and the inflator 41. And a case 36 constituting a storage part 35 to be stored, and an airbag 47 when inflated pushes open the door portion 26 provided on the column cover 16 to open both knees K ( (KL, KR) so as to be arranged on the front side (see FIGS. 1, 10, and 11).

  In this specification, the front / rear, left / right, and up / down directions are the same as the front / rear, left / right, up / down directions of the vehicle during straight steering unless otherwise specified.

  As shown in FIGS. 1 and 4, the instrument panel 7 includes an upper panel 8 on the upper side and a lower panel 9 on the lower side. The protruding portion of the column cover 16 in the instrument panel 7 is configured in the vicinity of the boundary portion between the upper panel 8 and the lower panel 9 by opening a storage opening 10 through which the column cover 16 protrudes. The airbag 47 that has been inflated covers the peripheral edge of the storage opening 10 on the rear surface 7 a of the instrument panel 7, specifically, the peripheral edge of the storage opening 10 in the portion of the lower panel 9. The panel surface 11 of the lower panel 9 covered by the airbag 47 when the inflation is completed includes a left area 12 and a right area 13 on both the left and right sides of the column cover 16, and a lower area 14 below the column cover 16. It is configured (see FIG. 4). And this panel surface 11 is arrange | positioned as the inclined surface of the overhanging state which protruded the upper part 11a side back, and as a substantially plane along the left-right direction.

  As shown in FIGS. 1 to 4, the column cover 16 is made of synthetic resin having a substantially rectangular tube shape, and is attached to the column tube 5 of the steering column 3 at a portion not shown, and from the storage opening 10 of the instrument panel 7 to the rear side. It protrudes and is tilted so that the front end side is positioned downward and the rear end side is positioned upward along the axial direction O1 (see FIG. 2) of the steering column 3, and in front of the seated driver D. It is arranged. The steering column 3 includes a main shaft 4 and a column tube 5 disposed around the main shaft 4, and a steering wheel 1 is connected to the main shaft 4 (see FIG. 2). The column cover 16 is viewed from the side as an arrangement position in which the vicinity of the front end 22a (see FIG. 1) of the projection opening 22 of the airbag 47 at the time of deployment and inflation in the storage portion 35 is separated from the panel surface 11 to the rear side. The lower surface 18a is extended from the front lower surface 18aa side to the rear end 18ae side obliquely upward and rearward, and is brought closer to the horizontal plane HP from the panel surface 11 and arranged as a substantially flat surface intersecting the panel surface 11 with an intersection angle θ0. It is installed. In the embodiment, the lower surface 18a of the column cover 16 is disposed along the axial direction O1 of the steering column 3. Further, in the embodiment, the front end 22a of the projection opening 22 of the storage part 35 is a part of the hinge parts 32a and 33a of the auxiliary left door part 32 and the auxiliary right door part 33 (see FIG. 5).

  Further, as shown in FIGS. 5, 10, and 11, the column cover 16 has one protrusion for protruding the airbag 47 in an area extending from the lower surface 18 a side to the left side surface 18 b and the right side surface 18 c of the outer peripheral surface 18. A door portion 26 that is pushed and opened by the airbag 47 is disposed so that the opening 22 can be formed. The door portion 26 is disposed on the rear side of the panel surface 11 of the instrument panel 7 (see FIG. 1), and is disposed on the lower door portion 27 disposed on the lower surface 18a side of the column cover 16 and on the left side surface 18b side of the column cover 16. The left door portion 28 arranged and the right door portion 29 arranged on the right side surface 18c side of the column cover 16, and surrounding portions to be broken that can be broken by being pushed by the inflating airbag 47 24 is formed. The planned fracture portion 24 is configured by providing a linear concave groove on the inner peripheral surface side of the column cover 16 so as to reduce the thickness of the column cover 16.

  The door portion 26 is opened by rotating the front edge 26b side to the rear side with the hinge portion 26a formed of an integral hinge arranged on the rear edge side of the lower door portion 27 as the rotation center when opening, and the left door portion. At that time, as shown in FIG. 5, the door 28 and the right door portion 29 are opened rearward together with the lower door portion 27 in a state where the lower edge side before opening is connected to the left and right edges of the lower door portion 27, respectively. Furthermore, it is arranged so as to be reversed and to contact the left side surface 18b and the right side surface 18c of the column cover 16.

  In the case of the embodiment, as shown in FIGS. 3, 5, and 11, the column cover 16 has a door portion so that the area of the protrusion opening 22 of the airbag 47 can be increased on the front side of the door portion 26. 26 is provided with an auxiliary door portion 30 that is pushed and spread on the airbag 47. The auxiliary door portions 30 are each provided with a portion 24 to be broken around the auxiliary door portion 30, the auxiliary lower door portion 31 arranged on the lower surface 18 a side of the column cover 16, and the auxiliary arranged on the left side surface 18 b side of the column cover 16. The left door portion 32 and the auxiliary right door portion 33 disposed on the right side 18c side of the column cover 16 are configured. The auxiliary lower door portion 31, the auxiliary left door portion 32, and the auxiliary right door portion 33 are respectively provided with hinge portions 31a, 32a, 33a made of integral hinges on the front edge side, and rear edges 31b, 32b, 33b. It is arrange | positioned so that it may rotate and open to the front side.

  In the column cover 16, as shown in FIGS. 2 and 3, the left and right edges are connected to the left side wall 17b and the right side wall 17c, respectively, at the front and rear edges of the area where the projection opening 22 is formed. Mounting walls 19 and 20 extending upward from the lower wall 17a are formed. In the column cover 16, the mounting walls 19, 20 form a storage portion 35 that stores the folded airbag 47 and the inflator 41 together with the case 36. Further, these mounting walls 19 and 20 also serve as mounting walls for the case 36, which will be described later. The locking pieces 38a and 39a of the case 36 are inserted, and the peripheral edges are locked to the locking pieces 38a and 39a. A plurality of locking holes 19a and 20a are formed.

  The storage portion 35 of the folded airbag 47 and the inflator 41 in the column cover 16 has a left door portion 28, a right door portion 29, an auxiliary left door portion 32, and an auxiliary left and right sides on the left and right sides. Surrounded by the right door 33, both front and rear sides are surrounded by the side walls 38, 39 of the case 36 and the mounting walls 19, 20 of the column cover 16, the upper side is surrounded by the ceiling wall 37 of the case 36, and the lower side is the lower door It is constituted by being surrounded by the portion 27 and the auxiliary lower door portion 31.

  As shown in FIGS. 2 to 4, the case 36 is made of sheet metal having an inverted U-shaped cross section, and includes a ceiling wall 37 and side walls 38 and 39 extending downward from front and rear edges of the ceiling wall 37. The side walls 38 and 39 are inserted into the locking holes 19a and 20a provided in the mounting walls 19 and 20 of the column cover 16 and connected to the mounting walls 19 and 20, respectively. Stop pieces 38a and 39a are formed. The ceiling wall 37 is formed with a plurality of (two in the embodiment) through-holes 37a through which the mounting bolts 44 of the inflator 41 are passed.

  The case 36 constitutes the upper side of the storage portion 35 that stores and holds the inflator 41 and the airbag 47 and the upper sides of the front and rear sides, and is attached and fixed to the column tube 5 of the steering column 3. In the case of the embodiment, the case 36 is configured to be attached and fixed to the bracket 5 a of the column tube 5 using the attachment bolt 44 of the inflator 41 that attaches and fixes the airbag 47 to the case 36. Furthermore, in the case of the embodiment, the case 36 has two through holes 37a and 37a arranged on the rear edge side of the ceiling wall 37 so that the inflator 41 is attached to the rear side, and is arranged side by side. (Refer to FIG. 4).

  As shown in FIGS. 2 to 4, the inflator 41 includes a cylinder-type columnar main body 42 having a plurality of gas discharge ports 42 a for discharging inflation gas, a main body 42, and an airbag 47 as a case. And a retainer 43 made of a sheet metal to be fixedly attached to 36. The main body 42 is configured such that when the vehicle is mounted, a plurality of gas discharge ports 42a are arranged in the center in the left-right direction along the axial direction O2 (see FIG. 3) in the left-right direction. The retainer 43 has a substantially cylindrical shape having an axial direction O2 along the left-right direction that coincides with the axial direction O2 of the main body 42, and extends upward and is arranged in parallel along the left-right direction (two in the embodiment). Mounting bolts 44 (see FIG. 4). The attachment bolt 44 constitutes attachment means for attaching the main body 42 of the inflator 41 to the case 36 as the storage portion 35. The left and right ends of the retainer 43 are openings 43a for allowing the inflation gas discharged from the gas discharge ports 42a to flow outward on both the left and right sides, and the lower surface side is notched so as to have a half-cylindrical shape. Yes. Further, near the center in the left-right direction of the retainer 43, a pinched portion 43b having a reduced diameter is formed so as to be held when the main body 42 is inserted.

  In the case of the embodiment, as described above, each mounting bolt 44 of the retainer 43 constitutes a mounting means for mounting the inflator 41 to the case 36, and the airbag 47 is fastened together to be mounted to the case 36. The case 36 itself is attached to the bracket 5a of the column tube 5 of the steering column 3 with a nut 45 attached thereto.

  As shown in FIGS. 6 to 11, the airbag 47 has a horizontally elongated substantially rectangular plate shape in which the length when the inflation is completed is longer in the left-right direction than in the front-rear direction and protrudes to the left and right sides of the column cover 16. The outer peripheral wall 48 is configured by a driver side wall portion 49 disposed on the driver D side when expansion is completed, and a column side wall portion 50 disposed on the column cover 16 side. The driver side wall portion 49 and the column side wall portion 50 are made of a flexible woven fabric such as polyester or polyamide, and are cut into a substantially rectangular shape having an outer shape extending in the left-right direction. To form a flat airbag type airbag 47.

  Further, as shown in FIG. 6, two mounting holes 51 a through which the mounting bolts 44 of the inflator 41 are inserted are provided side by side along the left-right direction in the column side wall portion 50, as shown in FIG. 6. In the case of the embodiment, since the airbag 47 is attached to the case 36 and further to the column tube 5 using the inflator 41, the arrangement region of the inflator 41 around the attachment holes 51a and 51a is the attachment bolt. When the nut 45 is fixed, the mounting portion 51 is attached to the case 36 by being sandwiched between the ceiling wall 37 of the case 36 and the retainer 43 of the inflator 41.

  Therefore, in the case of the embodiment, the vicinity of the attachment portion 51 of the column side wall portion 50 is stored in the storage portion 35 when the inflation of the airbag 47 is completed, as shown in FIGS. Further, the column side wall portion 50 is constituted by a front side portion 53 and a rear side portion 57 that are located forward and backward from the vicinity of the center in the front-rear direction (near the attachment portion 51), as shown by the two-dot chain line in FIG. ing. Further, as shown in FIG. 7, the front side portion 53 is composed of a front left portion 54 and a front right portion 55 on both right and left sides, and a front center portion 56 in the center in the left and right direction, and the rear side portion 57 is on both left and right sides. The rear left portion 58 and the rear right portion 59, and the rear central portion 60 in the center in the left-right direction.

  In the case of the embodiment, when the airbag 47 is completely deployed and inflated in the vehicle mounted state, as shown in FIG. 10, the rear part 56 b of the front central part 56 of the front side part 53 and the rear side of the rear side part 57. The front portion 60a of the central portion 60 is located in the storage portion 35, and the front portion 56a of the front central portion 56 is the front edge (hinge portion 31a) of the opening 22 for protrusion of the column cover 16 on the lower surface 18a of the column cover 16. ) From the front front lower surface 18aa (in the case of the embodiment, more specifically, the opened auxiliary lower door portion 31 hits the peripheral edge of the storage opening 10 so as to close the storage opening 10, so that the auxiliary lower door 18aa is not the front lower surface 18aa. The rear portion 60b of the rear cover 60 is in close contact with the lower area 14 of the panel surface 11 and the rear portion 60b of the column cover 16 on the lower surface 18a of the column cover 16. Close contact with the rear lower surface 18ab from the rear edge (hinge portion 26a) (specifically, the rear lower surface 18ab with the lower door portion 27 of the opened door portion 26 interposed) and the lower surface 2a of the lower cover 2; Become. Further, when the inflation of the airbag 47 in the vehicle mounted state is completed, as shown in FIG. 11, the front left portion 54 and the front right portion 55 of the front side portion 53 are respectively left and right side panel surfaces 11 of the column cover 16. In the left area 12 and the right area 13, a part of the opened auxiliary left door portion 32 and the auxiliary right door portion 33 are interposed and are in close contact with each other. Since the rear left portion 58 and the rear right portion 59 are disposed on the rear side of the front left portion 54 and the front right portion 55 when the airbag 47 is completely inflated in the vehicle mounted state, the column cover 16 The left and right sides of the panel surface 11 are arranged away from the left area 12 and the right area 13 of the panel surface 11.

  The airbag 47 has two front and rear (upper and lower) front tethers 61 and rear tethers 62 that connect the column side wall 50 and the driver side wall 49 on both front and rear sides of the mounting portion 51. The front tether 61 and the rear tether 62 are formed in a strip shape extending in the left-right direction, and the crossing angle of the front side portion 53 and the rear side portion 57 between the front side portion 53 and the rear side portion 57 when the inflation of the single airbag 47 is completed. The arrangement position and the length dimension are set so that θ1 is substantially equal to the intersection angle θ0 between the panel surface 11 and the lower surface 18a of the column cover 16 protruding from the panel surface 11 (see FIG. 9). In the embodiment, the front surface 53a of the front side portion 53 that defines the crossing angle θ1 has a coupling portion 61b of the front tether 61 to the column side wall portion 50 in the vicinity of the center in the left-right direction of the column side wall portion 50. The front side 57a of the rear side portion 57 is also connected to the column side wall portion 50 of the rear tether 62 in the vicinity of the center in the left-right direction of the column side wall portion 50. Both surfaces are in contact with the swelled portions 57b and 57c on both the front and rear sides with the portion 62b in between.

  The arrangement of the front tether 61 and the rear tether 62 is such that the front tether 61 disengages the coupling portion 61b to the column side wall portion 50 from the storage portion 35 to the front side when the airbag 47 is completely inflated. 53, and the rear tether 62 connects the connecting portion 62b to the column side wall portion 50 to the rear side portion 57 of the region separated from the storage portion 35 rearward when the inflation of the airbag 47 is completed (see FIG. 10). The front tether 61 and the rear tether 62 are connected to the column side wall portion 50 (connection portion) 61b, 62b from the mutual column side span 65 and connected to the driver side wall portion 49 (connection portion) 61a, 62a The driver-side spans 64 of each other are shortened (see FIG. 8).

  Further, the length dimensions LV1 and LV2 (see FIG. 9) for connecting the driver side wall portion 49 and the column side wall portion 50 of the front tether 61 and the rear tether 62 are the plates in which the airbag 47 at the completion of the inflation is a rectangular plate. The lengths LL1 and LL2 (refer to FIG. 6) in the left-right direction of the front tether 61 and the rear tether 62 are set to dimensions that can secure the shape of the shape. The dimension is set so that it can flow on both sides.

  The front tether 61 and the rear tether 62 are each formed of a flexible woven fabric such as polyester or polyamide, similarly to the driver side wall portion 49 and the column side wall portion 50. In the case of the embodiment, the front tether 61 and the rear tether 62 are configured such that when the driver side span 64 is shorter than the column side span 65 and the driver side wall portion 49 and the column side wall portion 50 are coupled to each other, 61, the positions of the connecting portions 61a and 61b to the driver side wall portion 49 and the column side wall portion 50 are defined as the front edge (lower edge) 47b of the airbag 47 (the boundary portion between the driver side wall portion 49 and the column side wall portion 50). And the position of the connecting portion 62a of the rear tether 62 to the driver side wall portion 49 of the airbag 47 from the connecting portion 62b to the column side wall portion 50. In other words, the position of the connecting portion 62a of the rear tether 62 to the driver side wall portion 49 is moved from the connecting portion 62b to the column side wall portion 50 to the rear edge 47a of the airbag 47. Away from And it is disposed.

  When the airbag 47 is deployed and inflated, the airbag 47 has a front side and a rear side of the projection opening 22 on the lower surface 18a of the column cover 16 projecting rearward from the instrument panel 7 with respect to the knees KL and KR of the driver D. The back surface 31c of the auxiliary lower door portion 31, the rear lower surface 18ab, and the left area 12, the right area 13, and the lower area 14 of the panel surface 11 that are the periphery of the storage opening 10 on the rear surface 7a of the instrument panel 7 can be covered. It is configured with dimensions of the front, rear, left and right (see FIGS. 10 and 11). Further, the vicinity of the rear edge (upper edge) 47a of the airbag 47 when the inflation is completed is disposed at a position covering the lower surface 2a of the lower cover 2 covering the lower side of the steering wheel 1. Incidentally, in the case of the embodiment, the length dimension LL0 in the left-right direction of the airbag 47 deployed flat is about 600 mm, which is about twice the length dimension LV0 in the front-rear direction (see FIG. 6). Further, the length dimension LV1 between the coupling portions 61a and 61b of the front tether 61 is about 50 mm, the length dimension LV2 between the coupling portions 62a and 62b of the rear tether 62 is about 75 mm, and the front tether 61 and the rear tether 62 are. The length dimensions LL1 and LL2 in the left-right direction are about 400 mm.

  The airbag 47 is manufactured by flattening a single airbag base fabric having a shape in which the driver side wall portion 49 and the column side wall portion 50 are connected with each other at the rear edge 47a of the airbag 47 as a fold. In this state, the airbag 47 is folded in half at the rear edge 47a of the airbag 47 and joined together by sewing or the like on the outer peripheral edges of the airbag 47. At this time, the connecting portions 61a, 61b of the front tethers 61, 62 are connected. , 62a, 62b are coupled to the driver side wall 49 and the column side wall 50, and at that time, the mounting bolts 44 are protruded from the mounting holes 51a provided in the column side wall 50 in advance. Let me store. The operation signal input lead wire extending from the inflator 41 is projected from an insertion hole (not shown) near the attachment hole 51a.

  The airbag fabric constituting the airbag 47 may be composed of two sheets in which the driver side wall portion 49 and the column side wall portion 50 are separated.

  Then, the mounting operation of the knee protection airbag apparatus M of the embodiment on the vehicle will be described. First, the airbag 47 in which the inflator 41 is housed is folded. In the case of the embodiment, the inflator 41 is disposed so as to be offset toward the rear end side of the storage portion 35 so that the left edge 47c side and the right edge 47d side of the airbag 47 are directed forward. In that state, narrow the left and right width dimensions so as to correspond to the width dimensions of the storage portion 35 in the left and right directions and the front and rear directions, and narrow the front and rear width dimensions by roll-folding the front edge side. Then, the folding of the airbag 47 is completed.

  When the folding of the airbag 47 is completed, the airbag 47 is wrapped with a predetermined unillustrated wrapping material for preventing collapse so as not to collapse. Next, the folded airbag 47 and the inflator 41 are accommodated between the side walls 38 and 39 of the case 36 on the lower surface side of the ceiling wall 37 while the mounting bolts 44 of the inflator 41 are passed through the through holes 37a. A spring nut (not shown) is attached, and the airbag 47 and the inflator 41 are assembled to the case 36 to form the airbag assembly SA.

  Then, the airbag assembly SA assembled in this way is fixed to the bracket 5a of the column tube 5 of the steering column 3 by fixing the mounting bolts 44 to the nuts 45, and extends from the inflator 41 to the airbag operating circuit. If the column cover 16 is attached to the steering column 3 while the lead wires are not connected and the locking pieces 38a and 39a are inserted into the locking holes 19a and 20a and locked to the mounting walls 19 and 20, the knee protection is achieved. The air bag device M can be mounted on a vehicle.

  In the knee protection airbag device M according to the embodiment, during operation, the inflation gas G is discharged from the gas discharge port 42 a of the main body 42 of the inflator 41, and the inflation gas G is opened at the left and right ends 43 a of the retainer 43. To the airbag 47. When the inflation gas G is supplied to the airbag 47, the airbag 47 pushes and opens the door portion 26 and the auxiliary door portion 30 to open the projection opening 22, and from the storage portion 35 in the column cover 16. While projecting and expanding obliquely rearward and downward, it protrudes to the left and right sides, and on the front side of the knees KL and KR of the driver D, the auxiliary lower door portion 31 and the lower door portion 27 on the lower surface 18a of the column cover 16 are provided. The front lower surface 18aa, the rear lower surface 18ab, and the left area 12, the right area 13, and the lower area 14 of the panel surface 11, which are the rear surfaces 7a of the instrument panel 7 on both the left and right sides of the column cover 16, are disposed. The

  At this time, in the vicinity of the attachment portion 51 located in the vicinity of the center of the column side wall portion 50 of the airbag 47 in the front, rear, left, and right, it has entered the storage portion 35 of the column cover 16, but is detached from the projection opening 22 of the storage portion 35. The rear portion 60b of the rear central portion 60 of the rear side portion 57 of the column side wall portion 50 located on the rear side of the storage portion 35 is located under the opened door portion 26. The door portion 27 is interposed so as to be in close contact with the rear lower surface 18ab of the lower surface 18a of the column cover 6, and in close contact with the lower surface 2a of the lower cover 2. At this time, the front side portion 53 and the rear side portion 57 positioned in the front-rear direction from the vicinity of the center in the front-rear direction of the column side wall portion 50 intersect each other at the crossing angle between the front surfaces 53a and 57a when the airbag 47 is completely inflated. θ1 is configured to be substantially equal to the intersection angle θ0 between the panel surface 11 and the lower surface 18a of the column cover 16 protruding from the panel surface 11.

  Therefore, the rear portion 60b of the rear center portion 60 in the rear side portion 57 of the column side wall portion 50 is disposed on the rear lower surface 18ab of the rear side periphery of the projection opening 22 of the column cover 16 with the lower door portion 27 interposed therebetween. If they are in close contact with each other, the front side portion 53 of the column side wall portion 50 is easily positioned at the left and right sides of the column cover 16 from the lower side of the column cover 16 so that the portion separated from the protruding opening 22 of the storage portion 35 is easily removed. 11 can adhere. That is, the front portion 56a of the front center portion 56 in the front side portion 53 of the column side wall portion 50 located on the lower side of the column cover 16 is in close contact with the lower area 14 below the column cover 16 on the panel surface 11 (see FIG. 10). In addition, the front left part 54 and the front right part 55 on the left and right sides of the front side part 53 of the column side wall part 50 located on both the left and right sides of the column cover 16 are the left side of the panel surface 11 located on the left and right sides of the column cover 16. A part of the auxiliary left door part 32 and the auxiliary right door part 33 are interposed between the area 12 and the right area 13 (see FIG. 11).

  In the case of the embodiment, the front portion 56a of the front central portion 56 is such that the rear portion 56b of the front central portion 56 is drawn into the storage portion 35, and the front edge (hinge portion 31a) of the protruding opening 22 of the column cover 16 is provided. ) To the front lower surface 18aa (specifically, the back surface 31c of the auxiliary lower door portion 31) located on the front side.

  In the case of the embodiment, in the column side wall portion 50 of the airbag 47, the front side portion 53 and the rear side portion 57 are appropriately opened to form the protruding openings 22, respectively (of the door portion 26). The lower area 27 of the panel surface 11, the right area 13, the lower area 14, and the column cover 16 are interposed with the lower door 27, the auxiliary lower door 31, the auxiliary left door 32, and the auxiliary right door 33. The lower surface 18a can be in close contact with the rear lower surface 18ab without being lifted away from the rear surface 18ab, thereby providing good support. Therefore, the driver's knees KL and KR that move forward or move diagonally forward are received by the driver side wall portion 49 that is the rear portion of the front side portion 53 and the rear side portion 57 of the airbag 47. However, it is quickly supported by the left area 12, the right area 13, the lower area 14 of the panel surface 11, and the rear lower surface 18ab of the lower surface 18a of the column cover 16, and the cushioning property is ensured smoothly. KL and KR can be received.

  Therefore, in the knee protection airbag device M of the embodiment, the airbag 47 at the completion of the inflation smoothly adheres to the rear surface 7a of the instrument panel 7 and the lower surface 18a of the column cover 16 to quickly secure a cushioning action. The knees KL and KR can be received.

  Further, in the airbag 47 of the embodiment, the front side portion 53 and the rear side portion 57 of the column side wall portion 50 are not bent by the surrounding members, but the bent shape is used as the inflation completion shape of the airbag 47 itself. Since there is no unnecessary pressing force applied to the outer peripheral wall 48 of the airbag 47 when the inflation is completed, it is difficult to cause damage due to interference with surrounding members that may cause gas leakage.

  In the case of the embodiment, the intersection angle θ1 between the front surfaces 53a and 57a of the front side portion 53 and the rear side portion 57 in the column side wall portion 50 of the airbag 47 is disposed in the airbag 47, and the front side portion. The front tether 61 and the rear tether 62 extend from the rear side portion 57 and the rear side portion 57 and are connected to the driver side wall portion 49 and regulate the thickness of the airbag 47 when inflation is completed. Therefore, as compared with the case where the airbag is three-dimensionally cut and the crossing angle θ1 between the front side portion 53 and the rear side portion 57 of the column side wall portion 50 is set, the airbag base fabric is stitched and bonded, etc. When manufacturing the bag, the connecting portions 61a, 61b, 62a, and 62b of the front tether 61 and the rear tether 62 are simply connected to the driver side wall portion 49 and the column side wall without performing the binding operation such as stitching three-dimensionally. The airbag 47 can be easily manufactured by simply coupling to the portion 50.

  In particular, in the case of the embodiment, the airbag 47 is configured as a planar airbag type in which the outer shapes of the driver side wall portion 49 and the column side wall portion 50 are substantially equal, and the front tether 61 and the rear tether 62 are arranged on the column side wall. The connection part (joint part 61b, 62b) to the part 50 is made shorter than the mutual column side span 65, and the connection part (joint part 61a, 62a) to the driver side wall part 49 is made shorter. It is arranged. Therefore, the span between the connecting portions of the front tether 61 and the rear tether 62 connected to the column side wall portion 50 and the driver side wall portion 49 is closer to the driver side wall portion 49 side than the column side span 65 on the column side wall portion 50 side. The driver side span 64 is shortened so that the connecting portions 61a, 61b, 62a, 62b at both ends of the front tether 61 and the rear tether 62 are connected to the column side wall 50 and the driver side wall 49, respectively. If the column side wall portion 50 and the driver side wall portion 49 are flattened and overlapped, and the outer peripheral edges of the column side wall portion 50 and the driver side wall portion 49 are joined together by sewing or the like, planar sewing or the like Thus, the airbag 47 can be manufactured very easily.

  In the case of the embodiment, the lower surface 18a of the column cover 16 extends so that the column cover 16 extends from the lower side of the storage part 35 to the left and right sides of the storage part 35. To the left and right left side surfaces 18b and the right side surface 18c. Therefore, the airbag 47 can be protruded from the left and right left side surfaces 18b and the right side surface 18c of the column cover 16 approaching the panel surface 11, and the column cover 16 approaching the column cover 16 can be projected. The front side portion 53 of the column side wall portion 50 when the expansion is completed can be further brought into close contact with the left area 12 and the right area 13 of the adjacent left and right panel surfaces 11.

  In the case of the embodiment, the intersection angle θ0 between the panel surface 11 and the lower surface 18a of the column cover 16 projecting from the panel surface 11 is set to about 160 °, and the column side wall portion 50 at the completion of the expansion of the airbag 47 alone is completed. The crossing angle θ1 between the front surfaces 53a and 57a of the front side portion 53 and the rear side portion 57 is about 160 °, and they are configured to be equal to each other. However, the column side wall portion 50 is retracted into the storage portion 35 so that it can be tucked when expansion is completed in the vehicle mounted state, and the portions of the front surfaces 53a and 57a that are detached from the storage portion 35 reduce the area, In addition, since the portion of the driver side wall portion 49 facing in the vertical direction expands in the free space, the portions of the front surfaces 53a and 57a that are separated from the storage portion 35 are the rear lower surface 18ab and the panel surface 11 of the column cover 16. The lower area 14, the left area 12, and the right area 13 are easily pressed. For this reason, the crossing angle θ1 between the front surfaces 53a and 57a of the front side portion 53 and the rear side portion 57 in the column side wall portion 50 when the inflation of the single airbag 47 is completed is the column protruding from the panel surface 11 and the panel surface 11. The crossing angle θ0 with the lower surface 18a of the cover 16 may be about 10 ° or smaller. Of course, when the airbag 47 is completely inflated with the vehicle mounted, if the adhesion to the lower area 14, the left area 12, and the right area 13 of the panel surface 11 is good, the crossing angle θ1 between the front surfaces 53a and 57a is The crossing angle θ0 between the surface 11 and the lower surface 18a of the column cover 16 protruding from the panel surface 11 may be slightly larger (about 5 °). Therefore, the crossing angle θ1 may be appropriately set within the range of about −5 ° to + 10 ° of θ0. However, if the crossing angles θ0 and θ1 are equal to each other, even if the steering column 3 is configured with a telescopic mechanism and the storage portion 35 to which the airbag 47 is attached together with the column cover 16 is shifted in the front-rear direction, etc. When the airbag 47 is completely inflated in the mounted state, the airbag 47 is secured to the rear lower surface 18ab of the column cover 16 with the lower area 14, the left area 12, the right area of the panel surface 11 being secured. It can be easily adhered to the area 13 and is suitable.

  Further, in the embodiment, the front surfaces 53a and 57a of the front side portion 53 and the rear side portion 57 of the column side wall portion 50 when the inflation of the airbag 47 alone is completed are the same as the front side 53a of the front side portion 53. 50, in the vicinity of the center in the left-right direction, the surface is in contact with both the front and rear swelled portions 53b and 53c with the connecting portion 61b to the column side wall portion 50 of the front tether 61 therebetween, and the front surface 57a of the rear side portion 57 However, in the vicinity of the center in the left-right direction of the column side wall portion 50, a case is shown in which both the front and rear swollen portions 57b and 57c are in contact with the column side wall portion 50 coupling portion 62b of the rear tether 62. . However, if the front surfaces 53a and 57a are defined in other words, when the airbag 47 is completely inflated when mounted on the vehicle, the averaged surface of the portion where the front side portion 53 is in wide contact with the panel surface 11 is the front surface. 53a, and an averaged surface of the portion where the rear side portion 57 is in surface contact with the rear edge side periphery of the projection opening 22 may be defined as the front surface 57a, and the front surfaces 53a and 57a may be defined by the airbag 47. The angle formed when the expansion of the single body is completed may be the intersection angle θ1.

  Furthermore, the panel surface 11 and the lower surface 18a of the column cover 16 may be formed in a slightly curved surface that bulges downward. In these cases, the air when the airbag 47 is completely inflated when mounted on the vehicle is used. The area in contact with the bag 47 may be replaced with an averaged surface, and the angle formed by both of these replacements may be the intersection angle θ0.

1 is a schematic side view of the vicinity of a column cover on which a knee protecting airbag device according to an embodiment of the present invention is mounted. It is a general | schematic expanded longitudinal cross-sectional view along the front-back direction of the column cover vicinity in which the airbag apparatus for knee protection of embodiment is mounted. It is a general | schematic expanded cross-sectional view of the column cover vicinity in which the airbag apparatus for knee protection of embodiment is mounted, and respond | corresponds to the III-III site | part of FIG. It is a general | schematic expanded longitudinal cross-sectional view along the left-right direction of the column cover vicinity where the airbag apparatus for knee protection of embodiment is mounted, and respond | corresponds to the IV-IV site | part of FIG. It is a perspective view which shows the state before opening of the door part of the column cover used for the airbag apparatus for knee protection of embodiment, and the open state. It is a top view in the state where the air bag used for the knee protection air bag device of an embodiment was developed flat. It is the top view which divided roughly the area of the front side part and rear side part of the column side wall part in the airbag used for an embodiment. FIG. 7 is a cross-sectional view of the airbag used for the knee protection airbag device of the embodiment inflated as a single unit immediately before completion of the inflation, corresponding to the VIII-VIII portion of FIG. 6. It is sectional drawing at the time of the completion of the expansion | swelling which inflated the airbag used for the airbag apparatus for knee protection of embodiment alone. It is a general | schematic expanded longitudinal cross-sectional view which shows the time of the action | operation of the airbag apparatus for knee protection of embodiment. It is a schematic longitudinal cross-sectional view along the substantially left-right direction which shows the time of the action | operation of the airbag apparatus for knee protection of embodiment.

Explanation of symbols

3 ... Steering column,
7 ... (Instrument panel) Instrument panel,
7a ... rear side,
11 ... Panel surface,
12 ... Left area,
13 ... Right area,
14 ... Lower area,
16 ... Column cover,
16a ... the lower part of the column cover,
18a ... the lower surface (of the column cover),
22 ... Opening for protrusion,
22a ... front end (of projecting opening),
35. Storage part,
47 ... Airbag,
48 ... outer peripheral wall,
49 ... Driver side wall,
50 ... Column side wall,
51 ... Mounting part,
53 ... front side,
53a, 57a ... front,
57 ... rear side,
61 ... The previous tether,
62 ... Rear tether,
D ... Driver,
K ・ KL ・ KR… Knees,
M: Air bag device for knee protection.

Claims (4)

It is mounted on the lower side of the column cover that covers the steering column and projects diagonally upward and rearward from the instrument panel.
The folded airbag is stored and attached to the lower storage portion in the column cover,
During operation, inflation gas is supplied to the airbag, and the airbag projects while being expanded and inflated obliquely rearward and downward from the storage portion in the column cover, on the front side of the driver's knee, A knee protection airbag device configured to cover a lower surface of a peripheral edge of the storage portion of the column cover and a rear surface of the instrument panel at a peripheral edge of the column cover,
Panel surfaces located on the left and right sides of the column cover from the lower side of the column cover on the rear surface of the instrument panel that the airbag covers when the inflation is completed are substantially flat along the left-right direction by projecting the upper side to the rear side. Arranged,
The column cover disengages the vicinity of the front end of the airbag opening when the airbag is deployed and inflated at the storage site from the panel surface to the rear side, and the lower surface viewed from the side extends obliquely upward and rearward. While being arranged as a substantially flat surface at an angle intersecting the panel surface by approaching the horizontal surface from the panel surface,
The outer peripheral wall at the time of completion of inflation of the airbag has a driver side wall portion arranged on the driver side and an attachment portion attached to the storage part arranged in the vicinity of the center of the front, rear, left and right, and the entire circumference of the outer peripheral edge A column side wall portion connected to the outer peripheral edge of the driver side wall portion, and
The column side wall portion of the airbag when the airbag is completely inflated, the lower surface of the peripheral edge of the storage portion of the column cover, and the panel surfaces positioned on the left and right sides of the column cover from below the column cover , And
When the front side portion and the rear side portion located in the front-rear direction from the vicinity of the center in the front-rear direction of the column side wall portion are completely inflated as a single piece of the airbag, the crossing angle between the front sides is determined by the panel surface and the panel. The knee protection airbag device, wherein the airbag is configured to be substantially equal to an intersection angle with a lower surface of the column cover protruding from a surface.   The intersection angle between the front side and the rear side of the column side wall portion of the airbag is disposed in the airbag and extends from the front side and the rear side, respectively. 2. The knee protection device according to claim 1, wherein the knee protection member is set by a front tether and a rear tether that are connected to the driver side wall portion and regulate the thickness of the airbag when inflation is completed. Airbag device. The airbag is configured as a planar airbag type having substantially the same outer shape of the driver side wall and the column side wall,
The front tether and the rear tether are arranged so that the span between the connection portions to the driver side wall portion is shorter than the span between the connection portions to the column side wall portion. The knee protection airbag device according to claim 2.   The column cover is arranged from the lower surface of the column cover to the left and right side surfaces so that the opening for projecting the airbag when inflated extends from the lower side of the storage part to the left and right sides of the storage part. The knee protection airbag device according to any one of claims 1 to 3, wherein the knee protection airbag device is configured.

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