JP7306358B2 - Airbag folded body and its folding method - Google Patents

Description

The present invention relates to a fully folded body of an airbag used in a knee protection airbag device that is mounted on the lower front side of a driver's seat and a passenger's seat in a vehicle to protect the knees of an occupant, and a folding method thereof. Regarding.

Conventionally, knee-protecting airbag devices have been configured to include an airbag, a case, an inflator, and an airbag cover (see Patent Documents 1 and 2, for example). The airbag is stored as a fully folded body in the storage area in front of and below the knees of the seated occupant. The expansion was completed by pushing it open and protruding obliquely upward from the storage part to the rear. The case, together with the airbag cover, constitutes a storage portion for the folded airbag, and has a bottom wall portion disposed on the front end side and a substantially rectangular cylindrical side wall portion extending rearward from the outer peripheral edge of the bottom wall portion. , and an opening for projecting an inflating airbag is provided on the rear end side. The inflator is housed in the airbag so as to be able to supply inflation gas to the airbag, and is provided with mounting bolts attached together with the airbag to the bottom wall side of the case. The airbag cover has a door portion that opens when the airbag is inflated, covers the rear side of the projecting opening of the case, and is mounted with the lower end side positioned forward from the upper end side. and an arrangement wall. Further, the outer peripheral wall of the airbag at the time of completion of inflation has a width dimension in the left-right direction of the upper edge side larger than that of the lower edge side, and the knee side receiving side wall portion and the vehicle body are configured to have substantially the same external shape. and a side wall portion of the vehicle body. The folding of the airbag is carried out by laying the receiving side wall and the vehicle body side wall on top of each other and unfolding them flat. , respectively, are stored in a case as a folded body folded to the central side (see Patent Document 1), or the end portions extending to the left and right sides from the central portion are folded into mountain folds and valley folds, respectively. In some cases, the two folding parts folded with creases along the front-rear direction are stored in a case as a folded body (see Patent Document 2) in which the two folding parts are folded in order toward the lower side of the central part. The reason why the door mounting wall portion of the airbag cover is inclined so that the lower end side is positioned forward from the upper end side is that the floor in front of the knees of the occupants in the vehicle may not be able to reach their feet. This is to ensure a space for free movement.

JP-A-2009-56980 Japanese Patent Application Laid-Open No. 2003-170801 (see C in FIG. 18)

However, when an attempt is made to accommodate the folded body of Patent Document 2 in the conventional knee protection airbag device described in Patent Document 1, two folding portions are formed below the central portion of the folded body. Overlapping, that is, when the central parts of the folded parts are put together, the three folded parts overlap vertically with the same width dimension in the front-rear direction, so that the lower end side is positioned forward from the upper end side. A large gap is left in front of the upper end of the door installation wall portion of the inclined airbag cover, resulting in wasted storage space. Conversely, if the upper end sides of the three folding portions are brought closer to the front side of the upper end side of the door installation wall portion of the airbag cover so as not to cause waste, the two folding portions below them, In particular, the folded portion on the lower end side pushes the lower end side of the door-mounted wall portion rearward, deforming the airbag cover.

An airbag folding completion body and a method for folding the same according to the present invention solve the above-described problems. The object is to provide a body and its folding method.

In the airbag folded body according to the present invention, the airbag is
The airbag cover is folded and stored in a storage portion on the front and lower side of the knees of a seated occupant, and when inflation gas flows in, the door portion of the airbag cover in the storage portion is pushed open and protrudes obliquely upward and rearward. , configured for knee protection to complete inflation,
As an outer peripheral wall at the completion of inflation, a receiving side wall portion on the knee side and a vehicle body side wall portion on the vehicle body side, which have substantially the same external shape, are provided, and
A folded portion is formed by folding the receiving side wall portion and the vehicle body side wall portion in a flat unfolded state so that the upper edge side approaches the lower edge side, and left and right sides from the center portion of the folded portion. a plurality of folded portions are arranged on the lower side of the central portion, with folds along the front-rear direction of mountain folds and valley folds, respectively, on the end portions extending in the direction of An airbag folded body,
a plurality of the folded portions arranged below the central portion,
Viewed from the left and right,
The front end side is roughly along the vertical direction,
The width dimension in the front-rear direction is made smaller than the central portion of the folded portion.

In the airbag folded body according to the present invention, the plurality of vertically overlapping folded portions below the central portion of the folded portion has a width dimension in the front-rear direction smaller than that of the central portion of the folded portion. As a result, the rear end of the folded portion can be displaced forward from the central portion of the upper folded portion, and the lower end of the airbag cover can be inclined forward. A plurality of vertically overlapping folding parts can be arranged without interfering with each other on the front surface side of the door arrangement wall part arranged in the same manner. Of course, since the plurality of vertically overlapping folded portions are arranged such that the front ends thereof are substantially along the vertical direction, an airbag device such as an inflator that supplies inflation gas to the airbag is placed on the front side thereof. Components can be efficiently arranged in a space-saving manner.

Therefore, in the folded airbag body according to the present invention, it can be stored efficiently and smoothly in front of the inclined airbag cover, and a sufficient space can be secured under the feet of the occupant.

Then, the plurality of folding parts arranged on the lower side of the central part,
It is desirable that the width dimension in the front-rear direction is decreased sequentially from the central portion toward the folded portion downward.

With such a configuration, the rear ends of the plurality of folding parts can be shifted downward and forward in order, so that when the folded body is mounted, the lower end side of the airbag cover can be positioned. The rear ends of a plurality of folding parts can be arranged in substantially equal proximity to the front side of a door arrangement wall part inclined so as to be arranged forward, and wasteful space can be saved. Since it does not occur, the plurality of folded portions of the airbag can be arranged more efficiently and smoothly.

Further, in the folding method of the airbag folded body according to the present invention, the airbag is
The airbag cover is folded and stored in a storage portion on the front and lower side of the knees of a seated occupant, and when inflation gas flows in, the door portion of the airbag cover in the storage portion is pushed open and protrudes obliquely upward and rearward. , configured for knee protection to complete inflation,
As an outer peripheral wall at the completion of inflation, a receiving side wall portion on the knee side and a vehicle body side wall portion on the vehicle body side, which have substantially the same external shape, are provided, and
From a state in which the receiving side wall portion and the vehicle body side wall portion are overlapped and unfolded flat, the upper edge side is folded to approach the lower edge side to form a folded portion, and left and right sides are formed from the center portion of the folded portion. The airbag is formed by stacking a plurality of folded portions in order on the lower side of the central portion, each of which is folded with creases along the front-rear direction, i.e., mountain folds and valley folds. A method for folding the folded body of
After the receiving side wall portion and the vehicle body side wall portion are laid flat and unfolded, the upper edge side is folded to approach the lower edge side to form the folded portion,
The upper edge of the lateral edge side of the folded portion is folded to the lower edge side with a diagonal crease so that the folding width of the lateral edge side is wider than that of the central portion side,
Next, creases along the front-rear direction of a mountain fold and a valley fold are made on the end portions extending from the center portion of the folded portion to the left and right sides, respectively, and the folded portion is placed on the lower side of the center portion. It is characterized in that it is folded so as to arrange the

In the folding method according to the present invention, the first folding step of forming a folded portion in which the receiving side wall portion and the vehicle body side wall portion are laid flat and are folded so that the upper edge side approaches the lower edge side from the flat unfolded state. After that, before the third folding step of folding the folded portions in order downward from the central portion by making creases along the front-back direction of mountain folds and valley folds on the left and right end portions from the central portion Then, the upper edges of the left and right edge sides of the folded portion formed in the first folding step are each folded diagonally so that the width of the left and right edge sides is wider than that of the central portion. Then, a second folding step is provided for folding to the lower edge side. That is, after the second folding step, the upper edge itself extending from the central portion of the folded portion in the first folding step toward the left and right end portions approaches the lower edge side toward the left and right direction edge sides. In addition, the width dimension in the front-rear direction of the folded portion itself extending from the central portion to the end portions in the left-right direction after the first folding step is made so that the upper edge side approaches the lower edge side in order as it goes toward the edge side. , make it smaller. Therefore, in the subsequent third folding step, folds along the front-rear direction of mountain folds and valley folds are made on the left and right end portions from the center portion, respectively, and are stacked in order below the center portion. When folding, the folded part itself going downward from the central part is folded in a state in which the upper edge side (which is the rear end side when mounted) is brought closer to the lower edge side (front end side), and the lower edge side ( When mounted, the front end side) is to be folded along the vertical direction.

Therefore, in the method for folding the completed airbag folding body according to the present invention, even if the width dimensions of the plurality of folded portions in the front-rear direction of the folded body gradually decrease downward, that is, Even in a shape in which a plurality of folding parts are vertically folded while shifting the rear end sides forward in order, simply by adding a second folding step of folding so as to make an oblique crease, the folding part can be easily folded. can be formed.

In this folding method, the width dimension in the left-right direction when the end portions extending to the left and right sides from the central portion are mountain-folded is equal to the width in the left-right direction of the storage portion for storing the folded body. Equivalent to the width dimension,
The diagonal creases when the left and right edge sides of the folded portion are folded toward the lower edge side so that the fold width of the left and right edge sides is wider than that of the central side. It is desirable that the starting point of is near the crease of the mountain fold.

In such a folding method, the folded body has a width dimension in the lateral direction equal to the width dimension in the lateral direction of the storage portion, so that it can be easily stored in the storage portion. can. In addition, since the starting position of the fold in the diagonal direction is near the fold of the mountain fold, the rear end side of the folded portion below the central portion of the folded portion is brought closer to the rear end side of the central portion. In this state, it can be shifted forward in order, and the folded body can be arranged closer to the front side of the door installation wall part of the airbag cover, and the door can be arranged. The storage space on the front side of the installation wall can be effectively used.

1 is a schematic vertical cross-sectional view showing a state in which a knee-protecting airbag device in which a fully folded airbag body according to one embodiment of the present invention is used is mounted on a vehicle; FIG. FIG. 5 is an enlarged schematic vertical cross-sectional view of an airbag device in which the folded airbag body of the same embodiment is used, and corresponds to the vicinity of the II-II portion of D in FIGS. 3 and 5. FIG. FIG. 3 is a schematic cross-sectional view of an airbag device in which the folded airbag body of the same embodiment is used. It is a figure explaining the folding process of the airbag of the same embodiment in order. It is a figure explaining the folding process of the airbag of the same embodiment in order, and shows the process after FIG. FIG. 10 is a schematic vertical cross-sectional view of a knee-protecting airbag device in which a folded body of a comparative example is used;

An embodiment of the present invention will be described below. A knee-protecting airbag device 10 using the folded body 63 of the airbag 40 of the embodiment is mounted on a steering column in front of the driver's seat, as shown in FIG. It is mounted under 1. The steering column 1 includes a steering shaft (not shown) having a steering wheel 4 steered by a driver M as a passenger, and a column tube 2 covering the steering shaft. covered with The column cover 3 protrudes rearward from an instrument panel (hereinafter, abbreviated as instrument panel as appropriate) 5 , and the knee-protecting airbag device 10 is installed at a lower portion 6 of the instrument panel 5 below the column cover 3 . , is installed.

The knee-protecting airbag device 10 comprises a case 13, an airbag cover 20, an inflator 30, and an airbag 40, as shown in FIGS.

The case 13, together with the airbag cover 20, constitutes the storage portion 11 for the folded airbag 40 (folding completion body 63). It is composed of a wall portion 14 and a substantially rectangular cylindrical side wall portion 15 extending rearward from the outer peripheral edge of the bottom wall portion 14, and an opening 18 for projecting an inflating airbag 40 is arranged on the rear end side. I have it set up. The bottom wall portion 14 is provided with a through hole 14a through which a mounting bolt 33 extending from the inflator 30 is passed. A plurality of locking hooks 16 projecting in an inverted manner are provided. Each locking hook 16 is inserted into a locking hole 26 provided in a side wall portion 25 (described later) of the airbag cover 20 to lock the side wall portion 25 .

The bottom wall portion 14 and the side wall portion 15 are provided with a plurality of mounting brackets (not shown) for mounting the airbag device 10 to brackets extending from the instrument panel hose.

The airbag cover 20 is made of a synthetic resin such as polyolefin, and is provided with a door portion 22 (U, D) that opens when pushed by the airbag 40 when inflated, so that the rear side of the projecting opening 18 of the case 13 is provided. It includes a door installation wall portion 21 for covering, and a side wall portion 25 having a substantially square tubular shape extending forward from the periphery of the door portion 22 (U, D) of the door installation wall portion 21 . The door installation wall portion 21 is mounted on the rear side with an inclination so that the lower end 21b side is arranged forward from the upper end 21a side so as to secure a space on the floor side under the feet of the driver M. be. The door installation wall portion 21 is surrounded by the lower portion 6 of the instrument panel 5 on the upper side and the left and right sides of the rear surface 21d, and is surrounded by the undercover 7 on the lower side.

Each of the door portions 22U and 22D has a substantially square plate shape, and when pushed by the inflating airbag 40, breaks the surrounding thin portion to be broken 24, and hinges are arranged on the edges in the vertical direction. It is configured to open vertically with the portion 23 as the center of rotation.

Locking holes 26 into which the locking hooks 16 of the case 13 are inserted are provided in the upper and lower wall portions 25a and the lower wall portions 25b of the side wall portion 25, respectively. When the upper wall portion 25a and the lower wall portion 25b of the side wall portion 25 are locked by the locking hooks 16 of the case 13, the left wall portion 25c and the right wall portion 25d of the side wall portion 25 are locked to the case 13. It is arranged so as to cover the outer sides of the left wall portion 15 c and the right wall portion 15 d of the side wall portion 15 .

The inflator 30 includes a substantially cylindrical main body 31 having a gas discharge portion 31a for discharging inflation gas G disposed on the right end thereof, and a substantially square cylinder-shaped sheet metal retainer 32 that holds the main body 31. configured as follows. The retainer 32 has two mounting bolts 33 projecting forward. These mounting bolts 33 protrude from through holes 45a of the airbag 40, which will be described later, in a state in which the retainer 32 is housed in the airbag 40, and further penetrate through holes 14a of the bottom wall portion 14 of the case 13. By fastening the nut 34, the airbag 40 is attached and fixed to the bottom wall portion 14 of the case 13, and the inflator 30 is attached and fixed to the bottom wall portion 14 of the case 13. As shown in FIG.

When the nuts 34 are fastened to the respective mounting bolts 33, the main body 31 accommodated in the retainer 32 is pushed by the convex portion 14b provided on the bottom wall portion 14 of the case 13, and is pushed backward from the retainer 32. Since the main body 31 is also pressed against the inner peripheral surface of the retainer 32, the main body 31 is also firmly held by the retainer 32. As shown in FIG.

A lead wire 36 for inputting an actuation signal of the inflator 30 is connected to the main body 31 on the end face away from the gas discharge portion 31a.

The airbag 40 is stored as a folded folded body 63 in the storage portion 11 on the front and lower side of the knees K of the driver M who is seated. The door portions 22 (U, D) of the airbag cover 20 are pushed open to project obliquely upward and rearward from the storage portion 11 to complete the inflation, and the upper portion 41 is made wider than the lower portion 42 in the horizontal direction. It is configured to spread out and protect the knee K (see FIGS. 1 and 4). The outer peripheral wall 43 of the airbag 40 at the time of completion of inflation has a width dimension in the left-right direction larger on the side of the upper edge 41a than on the side of the lower edge 42a (WU>WD), and is configured to have substantially the same external shape. It is configured to include a knee-side receiving side wall portion 44 and a vehicle body side wall portion 45 . When the airbag 40 is mounted on the vehicle, the airbag 40 protrudes obliquely upward and rearward from the housing portion 11 to complete the inflation. , is also the leading edge.

The airbag 40 is made of a woven fabric such as polyester or polyamide, and the receiving side wall portion 44 and the vehicle body side wall portion 45 are connected to each other on the upper edge 41a side. It is formed by folding on the 41a side and sewing the overlapped outer peripheral edges. A through hole 45a through which the two mounting bolts 33 pass and an insertion hole 45b through which the body 31 of the inflator 30 is inserted are formed on the side of the lower edge 42a of the vehicle body side wall portion 45 (see FIGS. 2 to 4). ).

When folding the airbag 40 to form the folded body 63, first, as shown in FIG. A bag 47 is formed. Next, as a first folding step, as shown in FIGS. 4A and 4B, horizontal creases H1 and H2 are made so that the upper edge 47a (41a) side approaches the lower edge 47b (42a) side. Then, a first folded body 50 provided with a folded portion 51 folded by roll folding is formed. In the case of the embodiment, the upper edge 47a side is arranged on the side of the vehicle body side wall portion 45 and folded, and the folding portion 51 is formed from the folding area 48 on the upper edge 47a side of the initially deployed airbag 47. Since the inflator 30 is arranged in the non-folding area 49 provided with the through hole 45a, it is not folded so as to narrow the dimension in the front-rear direction.

Next, as shown in FIGS. 4B and 4C, as a second folding step, the upper edge (rear edge) of the folded portion 51 of the first folded body 50, which is separated from the lower edge 47b side of the initially deployed airbag 47, is folded. At the left and right edges 51c and 51d on the side of 51a, diagonal creases CL and CR are made so as to widen the folding width BW of the edges 51c and 51d in the left and right direction from the central side, and the upper edge 51a is folded. The second folded body 55 is formed by providing obliquely folded portions 60 (L, R) folded on the side of the vehicle body side wall portion 45 while bringing the side closer to the lower edge 51b side. In this case, the left side portion 53 and the right side portion 54 extending left and right from the center portion 52 in the left-right direction of the folded portion 51 of the first folded body 50 are on the lower edge (front edge) 51b side of the folds CL and CR. Folded portions 53b, 54b (diagonally folded portions 60L, 60R) of the upper edges (rear edges) 51a of the folds CL, CR are superimposed on the side of the body portions 53a, 54a of the second folded body 55. A tatami mat portion 56 is formed.

After that, as a third folding step, as shown in FIGS. A left side portion 58 and a right side portion 59 on the end portion side extending to both left and right sides from 57 are formed by mountain folds CM (L, R) and valley folds CV (L, R) along the front-rear direction, respectively. and folded so as to provide folding portions 65 (L, R) and 66 (L, R) so as to overlap in order on the lower side of the central portion 57, a third folded body, that is, a folded A complete body 63 can be formed (see FIGS. 2 and 5D).

Note that the lateral width WM (see D in FIG. 5) of the folded body 63 folded at the mountain fold lines CM (L, R) is the width WS of the storage portion 11, that is, the storage portion 11 and the width dimension WS (see FIG. 3) between the left wall portion 15c and the right wall portion 15d of the side wall portion 15 of the case 13 of FIG.

Further, the fold lines CM (L, R) of the mountain fold substantially coincide with the points of intersection with the respective upper edges 51a of the oblique fold lines CL and CR, that is, the origin positions CL0 and CR0 of the fold lines CL and CR. is set to

In this folded body 63, the central part 57 of the folded part 56 of the second folded body 55 in the left-right direction constitutes the central part 64 of the folded body 63, and the right and left sides of the central part 64 are right and left. , base-side folded portions 65L, 65R consisting of the base portions 58a, 59a of the left side portion 58 and the right side portion 59 of the folded portion 56 of the second folded body 55 are folded, and the base side folded portion 65L is further folded. , 65R, end-side folded portions 66L and 66R consisting of tip portions 58b and 59b of the left side portion 58 and the right side portion 59 of the folded portion 56 of the second folded body 55 are folded.

Then, after the second folding process before the third folding process, the folded portion 51 in the first folding process is diagonally folded at the folds CL and CR so that the center portion 52 of the folded portion 51 and the edges 51c and 51d in the left and right direction are folded. The upper edge 51a itself extending in the horizontal direction approaches the lower edge 51b as it goes toward the edges 51c and 51d in the left-right direction. The width dimension of the folded portion 56 itself in the front-rear direction is set so that the upper edge 51a side approaches the lower edge 51b side in order toward the end portion side, and the width dimension LF on the central portion 57 side to the edge 51c. , 51d side so as to be the width dimension LB. Therefore, in the subsequent third folding step, the ends in the left-right direction from the central portion 57 are simply folded along the front-rear direction by mountain folds and valley folds CM (L, R) and CV (L, L, respectively). R) is attached, and the folded portions 65 and 66 extending downward from the central portion 57 extend from the central portion 57 to the front and rear width dimensions LM1 and LM2 of the central portion 64, respectively. (See FIG. 2), and the upper edges 65a and 66a (which will be the rear end when mounted) are brought closer to the lower edges 65b and 66b (the front end). , and the lower edges 65b, 66b (the front end when mounted) are folded in the vertical direction.

In folding the airbag 40 as described above, the mounting bolts 33 are protruded from the through holes 45a and the retainer 32 is inserted into the airbag 40 in advance to form the folded body 63. As shown in FIG. After forming the folded body 63, the folded body 63 is wrapped with a wrapping sheet 70 for preventing collapse of the folded body (see FIG. 2).

Before housing in the case 13, the main body 31 of the inflator 30 is inserted into the retainer 32 through the insertion hole 45b, the lead wire 36 is connected to the main body 31, and the mounting bolt 33 protrudes from the through hole 14a. The folded body 63 is placed on the side of the bottom wall portion 14 in the case 13, and the nut 34 is fastened to the mounting bolt 33. As shown in FIG. The terminal end of the lead wire 36 is ejected outside the case 13 from an extraction recess provided in the side wall portion 15 of the case 13 .

Then, the terminal side (not shown) of the lead wire 36 is connected to a lead wire (not shown) on the vehicle body side for inputting the actuation signal of the airbag device 10, and the mounting bracket (not shown) of the case 13 is connected to a predetermined bracket on the vehicle body side. Along with the attachment, the side wall portion 25 of the airbag cover 20 is arranged on the outer peripheral side of the side wall portion 15 of the case 13, and the locking hooks 16 are inserted into the locking holes 26 to connect the upper wall portion 25a and the lower wall portion 25b. After connecting them, the undercover 7 is assembled to the vehicle body, so that the airbag device 10 can be mounted on the lower front side of the knees K of the driver M of the vehicle.

Thereafter, when an actuation signal is input to the main body 31 of the inflator 30, the inflation gas G is discharged from the gas discharge portion 31a of the inflator 30, and the airbag 40 is inflated by the flow of the inflation gas G. The door portions 22U and 22D of the door-arranged wall portion 21 of the cover 20 are pushed open upward and downward to protrude obliquely upward and rearward from the protrusion opening 18 of the case 13 to complete the expansion.

In the folding completion body 63 of the airbag 40 of the embodiment, below the central portion 64 of the folded portion, the two folded portions 65 (L, R) and 66 (L, R) are vertically overlapped. Since the width dimensions LM1 and LM2 in the front-rear direction are smaller than the width dimension LF in the front-rear direction of the central portion 64 (LF>LM1, LM2), the rear ends 65a and 66a of the folded portions 65 and 66 are A door mounting wall which can be displaced forward from the rear end 64a of the upper central portion 64 and which is tilted so as to position the lower end 21b of the airbag cover 20 forward. The two folded parts 65 and 66, which overlap vertically, can be arranged on the front surface 21c side of the part 21 without interfering with each other. Of course, the two vertically overlapping folded portions 65 and 66 are arranged such that the front ends 65b and 66b of the folded portions 65b and 66b are substantially along the vertical direction, so that the inflation gas G is supplied to the airbag 40 on the front side thereof. The components of the airbag device 10 such as the inflator 30 can be efficiently arranged in a space-saving manner.

Therefore, the folded body 63 of the airbag 40 of the embodiment can be stored efficiently and smoothly in front of the tilted airbag cover 20, and a sufficient space under the occupant M can be secured.

Furthermore, in the folding completion body 63 of the airbag 40 of the embodiment, the two folding portions 65 and 66 arranged on the lower side of the central portion 64 extend from the central portion 64 toward the folding portions 65 and 66 below. Then, the width dimensions LM1 and LM2 in the front-rear direction are decreased in order (LF>LM1>LM2).

Therefore, in the embodiment, the rear ends 65a and 66a of the two folding parts 65 and 66 can be shifted downward and forward in order. The rear ends 65a and 66a of the two folding portions 65 and 66 are placed on the front surface 21c side of the door installation wall portion 21 which is inclined so that the lower end 21b side of the airbag cover 20 is arranged forward. To arrange the two folding parts 65, 66 of the airbag 40 more efficiently and smoothly since they can be arranged in a substantially evenly approached manner and no useless space is generated. can be done.

Note that the folded body 103 folded without the second folding step is stored as shown in FIG. The folded body 103 is roll-folded so that the upper edge 47a of the initially deployed airbag 47 shown in FIGS. 4A and 4B approaches the lower edge 47b. It is folded at the folds of the mountain fold and the valley fold along the direction, and the two folded portions 101 and 102 on the tip side of each fold are overlapped under the center portion 100 in the left-right direction of the roll folded portion. It is what I did. Further, when forming the roll-folded portion, in the case of the illustrated example, the folds H1, H2, and H3 along the left-right direction are made one more time than in the case of the embodiment.

In the folded body 103 of this comparative example, the three folded portions 100, 101, and 102 overlap in the vertical direction when the center portion 100 of the roll-folded portion is aligned, with the width dimension L0 in the front-rear direction being equal. Finally, when the folded body 103 is mounted on a vehicle, the upper end 21a of the door installation wall portion 21 of the airbag cover 20 is inclined so that the lower end 21b side is located forward from the upper end 21a side. There is a large gap 104 on the front side of the side, which wastes the storage space.

Further, in the folded body 103 of this comparative example, there are three folds H1, H2, and H3 as folds of roll folding that bring the upper edge 47a of the initially deployed airbag 47 closer to the lower edge 47b. On the other hand, in the folding completion body 63 of the embodiment, the folding portion 51 for roll folding has two folding folds H1 and H2 as folds for roll folding. When the airbag is inflated, the number of folds of the roll folds is small, so the roll folds can be quickly eliminated, and as a result, the time from the start of the inflation of the airbag to the completion of the inflation can be shortened. In addition, the knees K of the occupant M can be protected.

In the method of folding the folded body 63 of the airbag 40 according to the embodiment, the receiving side wall portion 44 of the airbag 40 and the vehicle body side wall portion 45 are overlapped and unfolded flat. After forming the folded portion 51 by folding so as to approach the lower edge 47b side, the upper edge 51a on the side of the left and right edges 51c and 51d of the folded portion 51 are respectively folded in the left and right direction from the central portion 52 side. In order to widen the folding width BW of the edges 51c and 51d of the folded portion 56, make diagonal creases CL and CR and fold the folded portion 56 toward the lower edge 47b. Extending ends 58 and 59 are folded to the lower side of the central portion 57 with creases CM (L, R) and CV (L, R) along the front-rear direction of mountain folds and valley folds, respectively. It is folded so that the portions 65 (L, R) and 66 (L, R) are arranged.

Therefore, in the folding method of the embodiment, the folding portion is folded so that the upper edge 47a side approaches the lower edge 47b side from a state in which the receiving side wall portion 44 and the vehicle body side wall portion 45 are overlapped and unfolded flat. After the first folding step of forming 51, the ends 58 and 59 in the left and right direction from the central portion 57 are folded along the front-rear direction by mountain folds and valley folds CM (L, R) and CV (L, R), and before the third folding step in which the folded portions 65 and 66 are sequentially folded over the lower side of the central portion 57, the left and right edges 51c of the folded portion 51 formed in the first folding step, The upper edge 51a on the side of 51d is formed with diagonal folds CL and CR (in other words, from the side of the upper edge 51a) so that the folding widths BW on the left and right edges 51c and 51d are wider than the center side. A second folding step is provided in which linear creases CL and CR are formed so as to expand each other toward the lower edge 51b side and intersect with the edges 51c and 51d, and are folded toward the lower edge 51b side. That is, after the second folding step, the upper edge 51a itself extending from the central portion 52 of the folded portion 51 in the first folding step toward the lateral ends 53 and 54 extends toward the lateral ends 51c and 51d. As it goes, it approaches the lower edge 51b side, and the folded portion 56 itself from the center portion 52 after the first folding step toward the left and right ends 53 and 54 has a width dimension in the front-rear direction that is equal to the end. As it approaches the edges 51c and 51d, the upper edge 51a side is brought closer to the lower edge 51b side in order (so that the width dimension LF>the width dimension LB) and is made smaller. Therefore, in the subsequent third folding process, the ends 58 and 59 in the left and right direction from the central portion 57 are respectively attached with creases CM and CV along the front-rear direction of the mountain fold and the valley fold, and the central portion 57 is folded. When folded so as to overlap in order on the lower side of the , the folded portions 65 and 66 themselves directed downward from the central portion 57 ( 64 ) are in order, the upper edges 65 a and 66 a side (which will be the rear end side when mounted) are folded downward. The bottom edges 65b and 66b (the front end when mounted) are folded in the vertical direction.

Therefore, in the method of folding the folded body 63 of the embodiment, the width dimensions LM1 and LM2 of the two folded parts 65 and 66 in the front-rear direction of the folded body 63 decrease in order downward. In other words, even if the two folded portions 65 and 66 are vertically folded while shifting the rear ends 65a and 66a forward in order, the diagonal folds CM and CV are formed. It can be easily formed only by adding a second folding process.

In addition, in the embodiment, the width dimension WM in the left-right direction when the ends 58 and 59 extending from the central portion 57 to the left and right sides are respectively folded in a mountain is the left-right width of the storage portion 11 in which the folded body 63 is stored. It is equivalent to the width dimension WS in the direction. Furthermore, diagonal creases CL and CR are added to the left and right edge sides of the folded portion so that the folding width BW of the left and right edges 51c and 51d is wider than that of the central side, and the lower edge 51b is folded. The origin positions CL0 and CR0 of the oblique creases CL and CR when folding to the side are near the crease CM of the mountain fold.

Therefore, in the folding method of the embodiment, since the folded completed body 63 has a lateral width WM equivalent to the lateral width of the storage portion 11, it can be stored in the storage portion 11. can be easily performed. In addition, since the starting positions CL0 and CR0 of the diagonal folds CL and CR are near the fold CM of the mountain fold, the folded portions 65 and 66 below the central portion 57 (64) of the folded portion 56 With the rear ends 65a and 66a close to the rear end 64a of the central portion 64, the door mounting wall portion of the airbag cover 20 can be shifted forward in turn. The folding completion body 63 can be arranged close to the front surface 21c side of the door 21, and the storage space on the front surface 21c side of the door installation wall portion 21 can be effectively utilized.

Incidentally, if the starting positions CL0 and CR0 of the diagonal folds CL and CR are positioned closer to the center in the left-right direction than the mountain folds CM (L and R), the rear end 64a of the central portion 64 The forward displacement of the rear ends 65a, 66a of the folding portions 65, 66 becomes large, and the distance between the rear ends 65a, 66a of the folding portions 65, 66 and the front surface 21c of the door installation wall portion 21 increases. It gets bigger. In addition, if the starting positions CL0 and CR0 of the diagonal folds CL and CR are positioned closer to the left and right edges 51c and 51d than the mountain folds CM (L and R), then The forward deviation of the rear ends 65a, 66a of the folded portions 65, 66 from the end 64a becomes small, and the rear ends 65a, 66a of the folded portions 65, 66 move toward the front surface 21c of the door installation wall portion 21. There is a risk that it will come too close to the

In addition, in the folding completion body 63 of the embodiment, the two folding parts 65 and 66 are arranged below the left and right sides of the central part 64. In addition, the lateral end portions 58 and 59 of the folded portion 56 in the second folding step may be folded to arrange three or more folded portions below the central portion 64 .

In addition, in the embodiment, the folded body 63 of the airbag 40 of the knee protection airbag device 10 mounted on the front lower side of the driver's seat has been described, but the present invention is mounted on the front lower side of the passenger seat. It can also be applied to the folded body of the airbag of the knee protection airbag device.

DESCRIPTION OF SYMBOLS 10... Airbag apparatus for knee protection, 11... (airbag) storage part, 13... Case, 20... Airbag cover, 22 (U, D)... Door part, 40... Airbag, 41a, 47a, 51a... (Rear edge) upper edge 42a, 47b, 51b... (front edge) lower edge 43...peripheral wall 44...receiving side wall part 45...vehicle body side wall part 51...folding part 51c, 51d...end edge , 52, 57, 64... Central part 53, 58... Left part 54, 59... Right part 63... Folded body 64a, 65a, 66a... Rear end 64b, 65b, 66b... Front end 65 ( L, R), 66 (L, R)... folding section,
LF, LM1, LM2... Width dimension (in the front-rear direction of the folded portion), BW... Fold width (of the diagonal fold), CL, CR... Fold (in the diagonal direction), CL0, CR0... Starting point position, CM (L, R): Fold (mountain fold), CV (L, R): Fold (valley fold), WU: Width (upper edge side of airbag), WD: (under airbag) width), M... (passenger) driver, K... knee, G... inflation gas.

Claims (4)

the air bag
The airbag cover is folded and stored in a storage portion on the front and lower side of the knees of a seated occupant, and when inflation gas flows in, the door portion of the airbag cover in the storage portion is pushed open and protrudes obliquely upward to the rear side. , configured for knee protection to complete inflation,
As an outer peripheral wall at the completion of inflation, a receiving side wall portion on the knee side and a vehicle body side wall portion on the vehicle body side, which have substantially the same outer shape as each other, are provided, and
A folded portion is formed by folding the receiving side wall portion and the vehicle body side wall portion in a flat unfolded state so that the upper edge side approaches the lower edge side, and left and right sides from the center portion of the folded portion. a plurality of folded portions are arranged on the lower side of the central portion, with folds along the front-rear direction of mountain folds and valley folds, respectively, on the end portions extending in the direction of An airbag folded body,
a plurality of the folded portions arranged below the central portion,
Viewed from the left and right,
The front end side is roughly along the vertical direction,
A folded body of an airbag, wherein the width dimension in the front-rear direction is smaller than that of the central portion of the folded portion. a plurality of the folded portions disposed below the central portion,
2. The folded body of an airbag according to claim 1, wherein the width dimension in the front-rear direction is gradually decreased from the central portion toward the folded portion downward. the air bag
The airbag cover is folded and stored in a storage portion on the front and lower side of the knees of a seated occupant, and when inflation gas flows in, the door portion of the airbag cover in the storage portion is pushed open and protrudes obliquely upward and rearward. , configured for knee protection to complete inflation,
As an outer peripheral wall at the completion of inflation, a receiving side wall portion on the knee side and a vehicle body side wall portion on the vehicle body side, which have substantially the same external shape, are provided, and
From a state in which the receiving side wall portion and the vehicle body side wall portion are overlapped and unfolded flat, the upper edge side is folded to approach the lower edge side to form a folded portion, and left and right sides are formed from the center portion of the folded portion. The airbag is formed by stacking a plurality of folded portions in order on the lower side of the central portion, each of which is folded with creases along the front-rear direction, i.e., mountain folds and valley folds. A method for folding the folded body of
After the receiving side wall portion and the vehicle body side wall portion are laid flat and unfolded, the upper edge side is folded to approach the lower edge side to form the folded portion,
The upper edge of the lateral edge side of the folded portion is folded to the lower edge side with a diagonal crease so that the folding width of the lateral edge side is wider than that of the central portion side,
Next, creases along the front-rear direction of a mountain fold and a valley fold are made on the end portions extending from the center portion of the folded portion to the left and right sides, respectively, and the folded portion is placed on the lower side of the center portion. A method for folding a folded body of an airbag, characterized in that the airbag is folded so as to place the The width dimension in the left-right direction when each of the end portions extending from the central portion to the left and right sides is mountain-folded is equal to the width dimension in the left-right direction of the storage portion for storing the folded body,
The diagonal creases when the left and right edge sides of the folded portion are folded toward the lower edge side so that the fold width of the left and right edge sides is wider than that of the central side. 4. The method for folding a completely folded airbag body according to claim 3, wherein the starting point of is near the crease of the mountain fold.

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