JP2003267178A - Airbag device for knee protection - Google Patents

Abstract

(57) [Problem] To provide a knee-protecting airbag device in which a seated occupant's shin can be prevented from being pressed against the shin, and the deployed and inflated airbag can accurately protect the occupant's kneecap. An airbag of a knee protection airbag device is provided.
When the inflation is completed, it is disposed on the front side from the vicinity of the shin to the vicinity of the kneecap of the seated occupant. The airbag is provided with upper and lower tethers 45 and 49 for regulating the thickness, which interconnect the occupant side wall 41 and the vehicle body side wall 42 with each other. The upper and lower tethers
A vertical distance h1 between the connecting portions 48 and 52 to the occupant side wall and the connecting portions 47 and 51 to the vehicle body side wall.
A shorter separation distance h2 is provided above and below the front of the shin when the inflation is completed. The width in the left-right direction when the inflation of the airbag 35 is completed is such that the portion 36 above the connecting portion 52 to the occupant side wall of the lower tether is wide enough to protect the vicinity of both kneecaps of the occupant, and The part 37 below the part 52 is narrowed downward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knee protection airbag device in which an airbag that inflates by inflating an inflation gas can protect the knees of an occupant such as a seated driver or passenger. .

[0002]

2. Description of the Related Art Conventionally, as a device for protecting the knees of an occupant such as a driver, there is WO 02/04261 A1 (see FIGS. 35-40).
The information described in (see reference) was known.

In the knee protection airbag device of the above publication,
The airbag is folded and stored below the front side of both knees of the occupant and attached, and the upper side at the time of completion of inflation is the downstream side of the inflation gas, and the lower side is the inflation gas. As an upstream side portion of the vehicle, when inflated, it is configured so as to project from the storage portion to the vehicle rear side, expand and inflate upward, and be disposed on the front side from near the occupant's shin to near the kneecap. Further, the airbag is provided with a tether for thickness control, which connects the occupant side wall portion arranged on the occupant side at the time of completion of inflation and the vehicle body side wall portion arranged on the vehicle body side to each other in upper and lower stages. It was arranged in.

The upper tether (upper tether) is
The connection portion to the occupant side wall portion is arranged downstream of the inflation gas from the position of the occupant side wall portion facing in the thickness direction of the airbag at that position with reference to the connection portion to the vehicle body side wall portion. It was

Further, the lower tether (lower tether) is located at the position of the side wall portion of the occupant, which is opposed to the side wall portion of the vehicle body in the thickness direction of the airbag, based on the connecting portion to the side wall portion of the vehicle body.
The connection portion to the passenger side wall portion was arranged.

Therefore, the upper tether displaces the connecting portion to the passenger side wall portion to the downstream side of the inflation gas from the connecting portion to the vehicle body side wall portion, so that the connecting portion to the passenger side wall portion of the upper tether is changed. The portion of the airbag on the upper side is configured as a thick portion that can be inflated as thick as possible so as to enhance the cushioning effect at the time of interference with the knee.

Further, since the connecting portions of the upper and lower two-stage tethers to the occupant side wall portion are arranged below the thick portion, the thin portion having a reduced thickness when inflated as compared with the thick portion. The parts are arranged so that the airbag at the time of completion of inflation can prevent unnecessary compression of the lower shin of the kneecap of the occupant.

However, in this airbag, the connecting portions of the upper and lower two-stage tethers with the passenger side wall portions are separated from each other by a distance shorter than the vertical distance between the connecting portions of the upper and lower two-step tethers with the vehicle body side wall portions. It is a structure that becomes a distance.
That is, the portion of the airbag on the lower side of the connecting portion of the lower tether to the occupant side wall portion is likely to be thickly inflated similarly to the portion of the airbag on the upper side of the connecting portion to the occupant sidewall portion of the upper tether. .

Therefore, even if the compression of the upper side of the shin can be prevented, the airbag at the time of completion of the inflation may cause the compression of the lower side of the shin. In particular, when the upstream side portion of the inflation gas is arranged to the vehicle front side less than the downstream side portion at the time of completion of the inflation of the airbag, that is, the vehicle from the upstream side portion to the downstream side portion of the airbag. The above problem is promoted when the airbag is inclined to the rear side at a shallow angle and the inflation is completed so that the airbag approaches the vertical plane.

In view of the above, the present invention provides a knee protection airbag device capable of preventing the seated occupant from pressing down on the shin, and the airbag inflated to protect the occupant's kneecap appropriately. The purpose is to provide.

[0011]

SUMMARY OF THE INVENTION A knee protecting airbag device according to the present invention is provided below a front side of a seated occupant's knee.
The airbag, which is attached and folded and stored, expands and inflates upward while projecting from the storage portion to the vehicle rear side when inflated, and is arranged on the front side from near the occupant's shin to near the kneecap, At least two upper and lower tethers for thickness control, which connect the occupant side wall portion disposed on the occupant side when the inflation is completed and the vehicle body side wall portion disposed on the vehicle body side to each other, are configured. In the knee protection airbag device, the airbag is connected to the passenger side wall portion of the upper and lower two-tier tethers and to the vehicle body side wall portion of the upper and lower two-tier tethers. As a separation distance shorter than the mutual separation distance in the vertical direction,
It is arranged above and below the front of the shin at the time of completion of expansion, and as the width dimension in the left-right direction at the time of completion of expansion,
The upper side of the lower tether in the upper and lower two-tier tethers connected to the occupant side wall is a wide width that can protect the vicinity of the kneecaps of both knees of the occupant, and the lower tether It is characterized in that it is configured such that a portion below the connection portion to the passenger side wall portion is narrowed downward.

It is desirable that the lower tether is disposed so as to be connected to the side wall portion of the occupant and the side wall portion of the vehicle body in a substantially horizontal direction when the inflation of the airbag is completed.

It should be noted that the terms "upper", "left", "right", "front" and "back" in this specification correspond to the "vertical", "lateral", "front-back" of the vehicle when the knee protection airbag device is mounted on the vehicle.

[0014]

In the airbag device for knee protection according to the present invention, the airbag has a portion below the connecting portion of the lower tether to the side wall portion of the lower tether (lower side portion) to the side wall of the lower tether passenger. The width of the occupant side in the lower side is shorter than the width of the upper side (upper side) of the connecting part to the lower part so that the width in the left and right direction is narrower. .

Therefore, the distance between the connecting portions of the upper and lower two-tiered tethers to the passenger side wall portions is lower than the vertical distance between the connecting portions of the upper and lower two-tiered tethers to the vehicle body side wall portions. Even if the vertical film length on the occupant side in the region becomes long, the film length in the horizontal direction on the occupant side in the lower region is short, so that when the airbag is inflated, the lower region itself does not project to the occupant side. It is possible to prevent the seated occupant from pressing down on the lower side of the shin.

Of course, the connecting parts of the upper and lower two-tiered tethers above and below the lower part are connected to the occupant side wall parts, and are located above the lower part and above and below the front part of the shin when the inflation is completed. As a result, the pressure on the upper side of the occupant's shin can be prevented when the airbag is completely inflated.

A portion of the lower tether above the connecting portion to the side wall portion of the occupant (upper side portion) is formed wide so that the width dimension in the left-right direction can protect the vicinity of the kneecaps of both knees of the occupant. Therefore, if the airbag is inflated, both knees (knee caps) of the occupant can be protected appropriately.

Therefore, in the knee protecting airbag device according to the present invention, the seat occupant's shin is prevented from being pressed,
The expanded and inflated airbag can protect the occupant's kneecaps accurately.

Further, in the case of the second aspect, when the inflation of the airbag is completed, the lower tether regulates the thickness of the airbag along the substantially horizontal direction. Therefore, the vicinity of the connection portion of the lower tether to the side wall portion of the occupant can be prevented from protruding to the shin of the occupant in a wide area. By the way, when the lower tether is inflated,
When the connection portion to the passenger side wall portion is located much higher than the connection portion to the vehicle body side wall portion, the vertical film length on the passenger side of the lower side portion becomes too long, and the passenger of the lower side portion becomes too long. It becomes difficult to suppress the protrusion of the shin on the shin, and the effect of the present invention is reduced. Further, when the lower tether positions the connecting portion to the passenger side wall portion much lower than the connecting portion to the vehicle body side wall portion when the airbag is completely inflated, the lower tether is attached to the passenger side wall portion in the upper and lower tethers. The distance between the connecting parts is increased, and the connecting parts of the upper and lower tethers to the side wall of the occupant are likely to protrude to the shin of the occupant, which also reduces the effect of the present invention.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 4, the knee protection airbag device S according to the embodiment of the present invention has a steering column 2.
A folded airbag 35 disposed below the
An inflator 28 that supplies inflation gas to the airbag 35, a case 11 that houses the airbag 35 and the inflator 28, and an airbag cover 16 that covers the vehicle rear side of the case 11 are configured. The airbag 35 has a knee (knee head) K (K) of the driver M as an occupant.
L · KR) is attached and folded and stored in the case 11 as a storage portion below the front side of L / KR), and an inflating gas is made to flow into the case 11 so as to project from the case 11 to the vehicle rear side and expand upward. However, it is configured to protect both kneecaps KL and KR of the driver M.

The steering column 2 comprises a column body 3 and a column cover 7. The column cover 7 is made of a synthetic resin having a substantially rectangular tube shape, and is arranged along the axial direction of the column body 3 so as to cover the column body 3 below the steering wheel 1. That is,
The column cover 7 is arranged so as to be inclined rearward. Further, the lower surface 7a of the column cover 7 has a substantially rectangular shape, and is formed in a curved shape that rises rearward in the vehicle front-rear direction. As shown in FIG. 1, the column main body 3 includes a main shaft 4 connected to the steering wheel 1 and a column tube 5 that covers the periphery of the main shaft 4, and the main shaft 4 and the column tube 5 are connected to each other. A tilt mechanism (not shown) that can adjust the angle of the ring surface of the steering wheel 1, a telescopic mechanism (not shown) that can move the steering wheel 1 in the axial direction of the shaft to stop the steering mechanism, and the like are provided between them. .

As shown in FIGS. 1 to 3, the inflator 28 is constructed as a cylinder type in which the axial direction is arranged along the left-right direction of the vehicle, and is provided with a substantially cylindrical main body 29 and a diffuser 30. ing.

The main body 29 has a cylindrical general portion 29a, and a small diameter portion 29b having a small diameter protruding from the end surface of the general portion 29a.
And a plurality of gas discharge ports 29 on the outer peripheral surface of the small diameter portion 29b.
It is configured by arranging c. And the general section 29
The connector 32 to which the lead wire 33 for inputting the operation signal is connected is connected to the end surface of the a located away from the small diameter portion 29b.

The diffuser 30 includes a holding cylinder portion 30a made of a substantially cylindrical sheet metal capable of covering the main body 29, and a holding cylinder portion 3.
A plurality of (two in the embodiment) bolts 3 protruding from 0a
0f, and are configured. The holding cylinder portion 30a is
A bottom portion 30b that covers the small diameter portion 29b of the exterior body 29 is provided on the tip surface side, and the body 29 is provided on the other end surface side.
Of the holding cylinder portion 30a in the vehicle mounted state. The holding cylinder portion 30a is equipped with a plurality of gas outlets 30d through which the expansion gas discharged from the gas discharge port 29c of the main body 29 can be discharged. It is opened on the surface on the rear side of the vehicle. Further, a plurality of holding portions 30e for holding the main body 29 are arranged in the holding cylinder portion 30a.
Each of the holding portions 30e is notched on both sides along the axial direction of the holding cylinder portion 30a, and is plastically deformed so as to be curved inside the holding cylinder portion 30a. And the main body 29
The main body 29 can be fixed to the holding cylinder portion 30a by inserting the main body 29 from the insertion hole 30c with the small diameter portion 29b at the front and further pressing the holding portions 30e toward the outer peripheral surface side of the general portion 29a. Can be fixed in the holding cylinder portion 30a.

The inflator 28 is provided with a lead wire 33 together with an airbag device (not shown) mounted on the steering wheel 1 when an airbag operating circuit mounted on the vehicle detects a frontal collision of the vehicle. ,
The operation signal will be input.

As shown in FIGS. 1 to 3, the case 11 has a substantially rectangular parallelepiped box shape having an opening 11a on the rear side of the vehicle, and has a peripheral wall portion 12 having a substantially rectangular tube shape at the periphery of the opening 11a. A bottom wall portion 14 that closes the vehicle front side of the peripheral wall portion 12
And are provided. The opening 11a is formed in a rectangular shape having a longer side on the side extending in the vehicle left-right direction.

On the upper wall 12a and the lower wall 12b of the peripheral wall portion 12, a plurality of hooks 13 having a substantially J-shaped cross section, whose tips are inverted to the side of the bottom wall portion 14 so as to be separated from the opening 11a, are fixed. . Four hooks 13 are provided on each of an upper wall 12a of the airbag cover 16 on the front end 25a side of a door portion 25 described later and a lower wall 12b of the airbag cover 16 on the hinge portion 24 side described later. It is installed (see Figure 4). A circular insertion hole 12d for inserting the main body 29 of the inflator 28 is formed in one side wall 12c of the peripheral wall portion 12 which faces in the left-right direction.

The bottom wall 14 has an insertion hole 14a through which the bolt 30f of the inflator 28 is inserted. In addition, the case 1 is provided on the upper surface side of the peripheral wall portion 12.
A bracket (not shown) for mounting and fixing 1 to the vehicle body is provided, and the bracket (not shown) is fixed to the instrument panel reinforcement by using bolts or the like, so that the case 11 is mounted on the body side. It will be fixed.

The airbag cover 16 is made of a thermoplastic elastomer such as polyolefin, and is shown in FIGS.
As shown in, the outer shape of the case 11 is larger than that of the case 11 so as to cover the vehicle rear side of the case 11.

The airbag cover 16 is disposed on the lower panel 9b side of the peripheral edge of the column cover 7 in the instrument panel (hereinafter abbreviated as instrument panel) 9 including the upper panel 9a and the lower panel 9b, and projects from the instrument panel 9. It covers the lower peripheral edge of the column cover 7. Therefore, when viewed from the vehicle rear side, the airbag cover 16 is recessed downward near the center of the upper edge so as to project the column cover 7 rearward, and the upper edge side below the recess is the lower surface of the column cover. It is configured to be raised so as to be curved toward the vehicle rear side corresponding to the curved surface on the 7a side. The airbag cover 16 includes a door portion 25 that covers the opening 11a of the case 11 and a general portion 17 around the door portion 25.
And are provided.

The door portion 25 is formed in a plate shape that is substantially the same as the opening 11a, and the door portion 2 is provided in the inverted U-shaped portion of the outer peripheral edge thereof.
A thin portion 23 to be broken, which is connected to the general portion 17, is formed so that 5 is opened downward. Expected break part 23
Is formed by forming a continuous or intermittent groove on the front surface of the vehicle so that the door 25 is easily broken when pushed by the inflating airbag 35.

On the lower edge side of the door portion 25, there is formed a hinge portion 24 which serves as a rotation center of the door portion 25 when the scheduled breaking portion 23 is broken and the door portion 25 is opened. The hinge portion 24 is an integral hinge and has a wall thickness within a range that does not break and is thinner than the general portion 17 and the door portion 25.

Then, the case opening 1 in the general portion 17
Around the peripheral edge of the la 1a, four substantially rectangular tubular wall portions 19, 20, 21, 22 are provided so as to surround the peripheral wall portion 12 so as to project toward the front side of the vehicle. The upper and lower wall portions 19 and 20 are connecting wall portions 19 and 20 that connect the airbag cover 16 to the case 11 in order to smoothly break the planned breaking portion 23 when the airbag 35 is deployed and inflated. -A plurality of locking holes 19a, 20a opened in a rectangular shape for locking the periphery of the lower connecting wall portion 19, 20 with the hook 13
Are formed corresponding to the hooks 13.

A plurality of (in the embodiment, three) mounting legs 18 are formed on the left and right sides of the door portion 25 of the general portion 17, each extending toward the front side of the vehicle.
These mounting legs 18 are engaged with the locking holes 9e of the lower panel 9b.
Will be locked to the periphery of. The lower panel 9b is provided with a housing recess 9c for the case 11, and a locking hole 9e is formed in a flange 9d at the peripheral edge of the housing recess 9c (see FIGS. 3 and 4). The rib 18 is provided at the base of the mounting leg portion 18.
When a is formed and the mounting leg 18 is locked in the locking hole 9e, the rib 18a abuts the flange 9d of the lower panel 9b to support the general part 17.

As shown in FIGS. 4 to 6, the airbag 35 has a shape at the time of completion of deployment and expansion, and has a lower end 35 on the upper end 35a side.
As a substantially home-based plate wider than b, the upper and lower tethers 45 and 49 are arranged inside the peripheral wall 40.

The peripheral wall 40 is formed of one piece of flexible woven fabric such as polyester or polyamide, and is folded back at the portion which will be the lower end 35b of the airbag 35, and the peripheral edges of the opposing portions are sewn together. , Formed. Perimeter wall 40
Includes a passenger side wall portion 41 on the driver M side and a vehicle body side wall portion 42 on the column cover 7 side and the lower panel 9b side. Then, the passenger side wall portion 41 and the vehicle body side wall portion 4
2 is a flat airbag type because the flat shape that is flattened out is substantially the same.

Two insertion holes 42a, 42a and one insertion hole 42b are formed in the side wall portion 42 of the vehicle body near the lower end 35b of the airbag 35 (see FIGS. 3 and 5). The insertion holes 42a and 42a are used for the bolts 3 of the inflator 28.
The insertion hole 42b allows the main body 29 of the inflator 28 to pass therethrough. Then, in the airbag 35, the main body 29 of the inflator 28 is projected from the insertion hole 42b, and the peripheral edge of each insertion hole 42a is fitted to the holding cylinder portion 30a of the diffuser 30 and the case 11.
It is attached to the case 11 by being sandwiched between the bottom wall portion 14 and the bottom wall portion 14. That is, the peripheral edges of the holes 42a and 42b serve as the attachment portions 43 of the airbag 35 to the case 11.

When the airbag 35 housed in the case 11 is inflated, it is expanded and inflated while projecting to the rear side of the vehicle while the mounting portion 43 is mounted and fixed in the case 11, and is seated on the seat. The driver M is provided on the front side from the vicinity of the shin L of the driver M to the vicinity of the kneecap K, and covers the lower surface 7a of the column cover 7 and the lower panel 9b on both left and right sides of the column cover 7.

The upper tether 45 and the lower tether 49 in the upper and lower stages connect the passenger side wall portion 41 and the vehicle body side wall portion 42 so that the thickness of the airbag 35 at the time of completion of inflation can be regulated.
The substantially plate shape of the airbag 35 is maintained. Each tether 4
The parts 5 and 49 are arranged in a strip shape along the left-right direction of the vehicle, and are also arranged in the vicinity of the center 35e in the left-right direction of the airbag 35 when the expansion and inflation are completed.

Further, these tethers 45 and 49 are rear connecting portions 48 and 52 which are connecting portions with the passenger side wall portion 41.
Is a front connecting portion 47 that serves as a connecting portion with the vehicle body side wall portion 42.
51 is provided above and below the front of the shin L of the driver M when the inflation of the airbag 35 is completed, as a separation distance h2 shorter than the vertical separation distance h1 (FIG. 1).
・ See 8). Specifically, as shown in FIG. 6, in the upper tether 45, the airbag 3 at the position where the rear connecting portion 48 with the passenger side wall portion 41 and the front connecting portion 47 with the vehicle body side wall portion 42 are located.
5 is disposed below a position Ha facing each other in the thickness direction, and in the lower tether 49, the rear connecting portion 5 with the occupant side wall portion 41.
2 is disposed above the position Hb facing the side wall portion 42 of the vehicle body in the front connecting portion 51 in the thickness direction of the airbag 35.

Further, the lower tether 49 is located at a position where the connecting portion 51 to the vehicle body side wall portion 42 is detached rearward from the case 11 when the inflation of the airbag 35 in the vehicle mounted state is completed.
It is set (see Figures 1.8). Then, in the case of the embodiment, the lower tether 49, when the inflation of the airbag 35 is completed,
A main body 50, which will be described later, is arranged so as to extend in a substantially horizontal direction from a connection part 51 to a connection part 52 with the occupant side wall part 41.

The upper and lower tethers 45 and 49 are respectively formed of two cloth materials 44 and 44 having flexibility such as polyester and polyamide.
The side 4a is sewn to the occupant side wall 41 or the vehicle body side wall 42, and the occupant side wall 4 of each tether 45/49 is sewn.
1 and the vehicle body side wall portion 42, at an intermediate portion in the front-rear direction of the body portions 46 and 50, the tip end portion 44d of the cloth material 44 and 44.
They are formed by stitching each other.

At the base portion 44a of each cloth material 44, the cloth material 44 is folded back so as to form two sheets, and the folded portion 44b is formed.
Are sewn to the wall portions 41 and 42 using a suture thread 54. In the front / rear connecting parts 47/48 of the upper tether 45, the folding part 44b is provided in the left / right direction (the connecting wall parts 41/42).
At least one stitching portion 55 extending in the width direction of the tether 45 that is orthogonal to the facing direction between the wall portion 41.
42, and the tip 44c side of the base portion 44a is projected from the folded portion 44b, and the extended portion 44c is formed.
Also sutured to the walls 41, 42 using sutures 54. In the front / rear connecting portions 51/52 of the lower tether 49, at least 2 extending in the left-right direction (the width direction of the tether 49 orthogonal to the facing direction between the connecting wall portions 41 and 42) at the portion of the folded portion 44b itself. The sewn-together portions 55 and 55 are provided and sewn to the wall portions 41 and 42.

With respect to the width dimension in the left-right direction when the airbag 35 is inflated, the airbag 36 has a portion 36 above the connection portion 48 of the lower tether 49 to the passenger side wall portion 41 and both kneecaps of the seated driver M. A wide width W3 that can protect the vicinity of KL / KR, and the side wall portion 41 of the occupant of the lower tether 49
A portion 37 below the connection portion 52 to is set to have a tapered shape that narrows downward.

In the case of the embodiment, the lower end of the lower portion 37,
That is, the lower end 35b of the airbag 35 is formed so as to extend in a substantially straight line in the left-right direction, and the width dimension W1 in the left-right direction near the lower end 35b when inflated is the case 11
The width dimension W0 of the opening 11a is set to be substantially equal to the width dimension W0.

Further, the lateral portion of the mounting portion 43 in a state where the occupant side wall portion 41 and the vehicle body side wall portion 42 are superposed and flattened, when expanded and inflated in a vehicle mounted state, from the width dimension W0 of the opening 11a, It is set to the width dimension W2 which becomes large,
The left and right edges of the occupant side wall portion 41 near the attachment portion 43 at the time of completion of expansion and expansion are set so as to be separated from the case 11 without interfering with the inner peripheral surface of the case 11.

The assembly of the airbag device S will be described. First, the suture thread 48 is used at a predetermined position on the woven fabric forming the peripheral wall 40 to be the occupant side and the vehicle body side wall portions 41 and 42. Each piece of cloth 44 for 45/49
The base portion 44a of each of the fabric pieces 44 is sewn, and then the woven fabric forming the peripheral wall 40 is folded back, and the tip portions 44d of the corresponding cloth pieces 44 are sewn together by using the suture thread 54, and the occupant side and the vehicle body side wall. The airbag 35 is manufactured by stitching the peripheral edges of the portions 41 and 42 together. At this time, leaving the unsewn portion 35f (see FIG. 5), the inflator 28 is housed in the airbag 35 from the portion 35f, and then each bolt 3
0f is projected from the insertion hole 42a, and the main body 29
The end of the base portion of the is protruded from the insertion hole 42b. Then, the unsewn portion 35f of the airbag 35 is sewn.

Then, the airbag 35 is folded. In the folding process of the airbag 35, first, as shown in FIGS. 7A and 7B, the occupant side wall portion 41 and the vehicle body side wall portion 42 are overlapped and flattened, and then the width dimension in the left-right direction is narrowed. The left and right edges 35c and 35d to the airbag 3
Put in 5. At this time, the left and right ends of the tethers 45 and 49 interfere with part of the edges 35c and 35d, but do not interfere with the left and right ends of the tethers 45 and 49.
To the center 35e of the airbag 35 in the left-right direction,
It is put into the airbag 35 as much as possible, and the width of the airbag 35 after being put in the left-right direction is made compact so as to correspond to the width W0 of the opening 11a of the case 11 to be stored in the left-right direction. .

Then, as shown in C and D of FIG. 7, by folding the upper end 35a side of the airbag 35 so as to approach the lower end 35b side, the folding work of the airbag 35 can be completed. In the case of the embodiment, this folding is performed by roll folding in which the upper end 35a side is wound around the vehicle body side wall portion 42 side.

After the airbag 35 is folded, the airbag 35 is wrapped by a breakable wrapping film (not shown) for preventing collapse. The bolt 30f of the inflator 28 and the end of the main body 29 protruding from the insertion holes 42a and 42b are made to protrude from the wrapping film.

Next, each bolt 3 of the inflator 28
0f is projected from the insertion hole 14a, and the main body 29
The inflator 28 housed in the air bag 35 is housed in the case 11 together with the folded air bag 35 so that the end of the inflator protrudes from the insertion hole 12d.
If the nut 31 is fastened to each bolt 30f, the inflator 28 and the airbag 35 can be housed in the case 11 and attached to the case 11.

Thereafter, the bracket (not shown) of the case 11 is attached to the instrument panel reinforcement of the vehicle to which the upper panel 9a and the lower panel 9b have already been attached, and the connector 32 to which the lead wire 33 is connected is connected to the main body 29 of the inflator 28. Then, push the airbag cover 16 toward the front side of the vehicle to remove the mounting leg portions 18
Is inserted and locked in the locking hole 9e of the lower panel 9b, and the locking holes 19a and 20a of the upper and lower connecting wall portions 19 and 20 are locked.
By locking the hook 13 of the case 11, the airbag device S can be mounted on the vehicle.

After the airbag device S is mounted on the vehicle, if an actuation signal is input to the main body 29 of the inflator 28 via the lead wire 33, the inflation gas G is discharged from the gas discharge port 29c of the inflator 28, The expansion gas G
Since the gas flows into the lower portion 36 of the airbag 35 through the gas outlet 30d of the diffuser 30 and further flows into the upper portion 37 of the airbag 35, as shown in FIG.
As shown by the chain double-dashed line of 4 and the solid line of FIG.
5 expands, breaks the wrapping film (not shown), and pushes the door portion 25 of the airbag cover 16,
The part to be broken 23 is broken and the door 25 is opened downward with the hinge 24 as the center of rotation. As a result, the airbag 35 is formed by opening the door 25 from the opening 11a of the case 11. It projects through the opening 26 of the airbag cover 16 toward the vehicle rear side, and further, the column cover lower surface 7
Along the line a and the lower panel 9b, it expands and expands upward to complete the expansion and expansion with a predetermined thickness.

In the knee protecting airbag device S of the embodiment, the airbag 35 is arranged so that the airbag 35 has a lower portion 37 below the connecting portion 52 of the lower tether 49 to the passenger side wall portion 41.
Is narrowed downward so that the width dimension in the left-right direction is narrower than the width dimension W3 of the upper portion 36 above the connecting portion 52, and the film length UH in the left-right direction on the driver M side in the lower portion 37 is set. (See FIG. 10) is shorter than the upper portion 36.

Therefore, the connecting portions 48 and 52 of the upper and lower tethers 45 and 49, which are connected to the passenger side wall portion 41, are
A vertical distance film on the driver M side in the lower side portion 37 is defined as a distance h2 shorter than the vertical distance distance h1 between the connection portions 47, 51 of the upper and lower tethers 45, 49 and the vehicle body side wall portion 42. Even if the long UV (see FIG. 6) becomes long, the driver M side of the lower side portion 37 (passenger side wall portion 41
Since the film length UH in the left-right direction is short, the protrusion of the lower side portion 37 itself to the driver M side is suppressed when the inflation of the airbag 35 is completed, and the shin L of the seated driver M is suppressed. It is possible to prevent pressure on the lower LD side.

Of course, the upper and lower two-tiered tethers 45 and 49, which are located above the lower portion 37, are connected to the occupant side wall portion 41 so that the connecting portions 48 and 52 are located above the lower portion 37 and the expansion is completed. Up and down near the front of the shin L at time,
Since the airbag 35 is provided, when the inflation is completed,
The pressure on the upper LU side of the shin L of the driver M can also be prevented.

The upper side portion 36 of the lower tether 49, which is above the connecting portion 52 to the passenger side wall portion 41, can protect the width dimension W3 in the left-right direction in the vicinity of both kneecaps KL and KR of the driver M. Since the airbag 35 is formed wide and the inflation of the airbag 35 is completed, both kneecaps KL and KR of the driver M can be appropriately protected.

Therefore, in the knee protection airbag device S of the embodiment, the airbag 35 inflated by preventing the driver M as an occupant from compressing the shin L is prevented by the airbag 35 inflated.・ The KR can be protected properly.

Then, in the embodiment, when the inflation of the airbag 35 is completed, the lower tether 49 causes the body portion 50 to extend in a substantially horizontal direction and regulates the thickness of the airbag 35. Therefore, the vicinity of the connecting portion 51 of the lower tether 49 to the occupant side wall portion 41 can prevent the driver M from protruding to the shin L in a wide area.

Incidentally, the lower tether 49 is the airbag 3
When the inflation of 5 is completed, the connecting portion 52 to the passenger side wall portion 41 is
In the case of being positioned above the connection portion 51 to the vehicle body side wall portion 42, the film length of the lower side portion 37 on the driver M side in the vertical direction becomes too long, and the driver M of the lower side portion 37 is It becomes difficult to suppress the protrusion to the shin L, and the effect of the present invention is reduced. Further, the lower tether 49 is attached to the airbag 35.
When the inflation of the vehicle is completed, if the connecting portion 52 to the occupant side wall portion 41 is positioned much lower than the connecting portion 51 to the vehicle body side wall portion 42, to the occupant side wall portion 41 in the two upper and lower tethers 45 and 49. The distance h2 between the connecting portions 48 and 52 of the vehicle is increased, and the distance between the connecting portions 48 and 52 of the upper and lower tethers 45 and 49 to the passenger side wall portion 41 is increased by the driver M.
It becomes easy to project to the shin L of the body, which also reduces the effect of the present invention.

Further, the airbag 35 of the embodiment is a flat airbag in which the outer peripheral edges of the passenger side wall portion 41 and the vehicle body side wall portion 42 having the same shape are coupled to each other, and
As shown in FIG.
A mounting portion 43 is provided at a position distant upward from the lower end 35b of the mounting portion 43, and the mounting portion 43 is mounted on the inner peripheral surface side of the case 11. With such a configuration, the occupant side wall portion 41 of the airbag 35 can be inflated in the free space from the vicinity of the lower end 35b to the upper end 35a without being restrained by the case 11 as much as possible in the cross section in the vehicle front-rear direction. on the other hand,
In the vehicle body side wall portion 42 of the airbag 35, the mounting portion 43 near the lower end 35b is mounted by being pushed into the inner peripheral surface side of the case 11 in a cross section in the vehicle front-rear direction.
As shown in FIG. 9, the tack 59 is inserted near the lower end 35b of the vehicle body side wall portion 42, so that the substantial length in the vertical direction is shorter than that of the passenger side wall portion 41.

Therefore, as shown in FIGS. 8 and 9, the vicinity of the upper end 35a where the passenger side wall portion 41 and the vehicle body side wall portion 42 of the airbag 35 at the time of completion of inflation is connected to the case 11 of the vehicle body side wall portion 42. Upon receiving a force F that rotates around the mounting portion 43, the front side is pulled toward the vehicle body side column cover 7 side, and the upper side portion 36 of the airbag 35 comes into close contact with the lower surface 7a side of the column cover 7. It will be easier.

The airbag 3 shown by the two-dot chain line in FIG. 9 is shown.
5A is a state in which the attachment portion 43 formed by providing the attachment hole 42a and the like at the lower end 35b is attached to the case 11 and expanded.

Especially, in the airbag 35, when the lateral portion of the mounting portion 43 in a state where the occupant side wall portion 41 and the vehicle body side wall portion 42 are superposed and flattened, when the vehicle is mounted on the vehicle, the opening 11a is opened. The width dimension W2 is set to be larger than the width dimension W0 of the occupant side wall portion 41 near the attachment portion 43 at the time of completion of expansion and expansion.
It is set so as to be separated from the case 11 without interfering with the inner peripheral surface of 1. Therefore, the occupant side wall portion 41 of the lower side portion 37 of the airbag 35 at the time of completion of deployment and inflation becomes difficult to be restrained by the case 11 as shown in FIG. Edge 35
Almost the entire surface including the vicinity of c · 35d can be freely inflated, and the airbag 35 can further closely contact the upper side portion 36 with the lower surface 7a side of the column cover 7.

As a result, as the upper portion 36 closely adheres to the lower surface 7a of the column cover, the vicinity of the lower portion 37 where the tether 49 is disposed is a member on the vehicle front side, that is, the airbag cover 16 in general. Opening 2 in part 17
It is possible to further suppress the rearward protrusion of the tethers 45 and 49 near the connecting portions 48 and 52 to the occupant side wall portion 41 to the rim L of the driver M, by closely contacting with the peripheral edge of the upper edge of 6. It is possible to accurately prevent the pressure on.

In the embodiment, each tether 45/49 is used.
Then, the folded portion 44b is provided on the side of the base portion 44a of each cloth material 44, and is sewn to the wall portions 41 and 42. In such suturing, the folded portion 44b also has the function of the reinforcing cloth arranged at the sutured portion, and therefore, the strength of suturing the tethers 45, 49 to the walls 41, 42 can be improved.

By the way, in the stitching mode of the upper tether 45,
When the angle θ1 between the wall portions 41 and 42 on the side of the extending portion 44c and the main body portion 46 is an obtuse angle, the wall portion 41 between the sutured portions 55 and 55
Since the portion 42 can be reinforced by the extended portion 44c and the folded portion 44b, the wall portion 41 of the tether 45
The suture strength to 42 can be improved.

Further, in the stitching mode of the lower tether 49, at least two stitching portions 55, 55 of the folding portion 44b are provided.
Since the seam is formed, if the distance P between the sutured portions 55, 55 is set to about 1 to 3 mm, the sutured portion 55.5
The sutures 54 of No. 5 reinforce each other to increase the strength of the suture, and the suture strength to the walls 41 and 42 of the tether 49 can be improved.

Of course, the folded portion 44b of the upper tether 45
Similarly to the lower tether 49, two stitches 55 may be provided. The lower tether 49 may be provided with an extended portion 44c, and the extended portion 44c may be provided with the sutured portion 55 in the same manner as the upper tether 45.
May be provided.

The stitching mode of these tethers is not limited to the airbag 35 of the knee protection airbag device S, but is also applicable to the airbag of the airbag device for steering wheels and the airbag device for side impacts to be arranged on the vehicle seat. It can be applied to airbags and the like.

Further, in the air bag 35 of the embodiment, only the two tethers 45 and 49 in the upper and lower two stages are provided, but at least one of the tethers 45 and 49 in the upper and lower two stages is left and right. You may divide | segment in a direction and may be arrange | positioned. Further, a tether may be additionally provided above the upper tether 45.

Further, in the embodiment, as the lower narrowed shape of the lower portion 37 of the airbag 35, the case where the lower tether 49 is tapered downward from the position of the rear connecting portion 52 is shown. If the lateral membrane length UH of the side portion 37 can be made smaller than that of the upper side portion 36, the side portion 37 can be narrowed downward from the upper portion of the rear connecting portion 52 or can be narrowed downward from the lower portion of the rear connecting portion 52. Good.

Further, in the embodiment, the kneecap K of the driver M is
In order to protect the vehicle, the airbag apparatus S arranged on the vehicle body side of the driver M on the vehicle front side has been described as an example. However, in order to protect both knees of the passenger seated in the passenger seat, The present invention may be implemented in a knee protection airbag device arranged on the vehicle body side (the instrument panel 9 side), which is the vehicle front side of the occupant seated in the passenger seat.

[Brief description of drawings]

FIG. 1 is a schematic longitudinal cross-sectional view in a vehicle front-rear direction showing a usage state of an airbag device for knee protection according to an embodiment of the present invention.

FIG. 2 is a schematic enlarged vertical sectional view in the vehicle front-rear direction of the knee protecting airbag apparatus according to the same embodiment.

3 is a schematic cross-sectional view of a III-III portion of FIG.

FIG. 4 is a schematic front view showing a usage state of the knee protecting airbag apparatus of the same embodiment as seen from the vehicle rear side.

FIG. 5 is a front view of the airbag used in the same embodiment.

6 is a cross-sectional view of the airbag in a completed state of inflation, which corresponds to a VI-VI portion in FIG.

FIG. 7 is a schematic view showing folding of the airbag of the same embodiment.

FIG. 8 is a schematic longitudinal cross-sectional view in the vehicle front-rear direction of the airbag of the knee protecting airbag apparatus of the same embodiment, in a state where the airbag is inflated and inflated.

FIG. 9 is a conceptual vertical cross-sectional view for explaining deployment and inflation of the airbag of the same embodiment.

FIG. 10 is a schematic cross-sectional view for explaining the expansion and inflation of the airbag of the same embodiment.

[Explanation of symbols]

11 ... (storage part) case, 35 ... airbag, 36 ... upper part, 37 ... Lower part, 41 ... Side wall of passenger, 42 ... the side wall of the vehicle body 45 ... Upper tether, 47.51 ... Connection part (to side wall of tether), 48/52 ... Connection part (to side wall of passenger of tether), 49 ... Lower tether, M ... (crew) driver, K (KL / KR) ... kneecap, L ... shin S ... Knee protection airbag device.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Funabashi             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor, Hisaaki Kato             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F term (reference) 3D044 BA07 BA14 BB01 BC02 BC13                       BC15                 3D054 AA02 AA03 AA08 AA12 BB23                       CC11 CC29 CC34 DD15 DD17                       DD40

Claims (2)

[Claims] 1. An airbag, which is attached to a seated occupant and is folded and stored below a knee side of the occupant, is expanded and inflated while projecting from a storage portion toward a vehicle rear side when inflated to expand the occupant. The thickness that connects the occupant's side wall portion, which is arranged on the front side from the vicinity of the shin to the kneecap and is arranged on the occupant side when the inflation is completed, and the vehicle body side wall portion, which is arranged on the vehicle body side, to each other. A knee protection airbag device configured by arranging at least two regulating tethers in upper and lower stages, wherein the airbag includes a connecting portion of the upper and lower two-stage tethers with the passenger side wall portion. Is arranged above and below the front part of the shin at the time of completion of expansion, with a separation distance shorter than the separation distance in the vertical direction between the connecting portions with the vehicle body side wall portion in the upper and lower two-stage tether. As a width dimension in the left-right direction at the time of completion of tensioning, a portion above the connection portion of the lower tether to the occupant side wall portion in the upper and lower two-stage tether is wide enough to protect the vicinity of the kneecaps of both knees of the occupant. A knee protection airbag device, which has a width dimension and is configured such that a portion below a connection portion of the lower tether to the occupant side wall portion is narrowed downward. 2. The lower tether is disposed so as to be connected to the passenger side wall portion and the vehicle body side wall portion along a substantially horizontal direction when the inflation of the airbag is completed. The knee protection airbag device according to claim 1.