JP2001322521A - Air bag for steering wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bag for a steering wheel relatively early enterable between a ring part and an occupant belly part without increasing a bag abutting time load to an occupant trunk when unfolding and inflating a bag. SOLUTION: This air bag is installed in an air bag device for the steering wheel, and is formed of a panel (base cloth). In a bag body of an almost circular shape in a plane outer peripheral shape when viewed from the occupant side at unfolding swelling completed time (hereinafter, the expression of upper and lower, left and right or front and rear side is valid for this view as a reference), the air bag 18 is provided with a bag body 26 having a front panel 22 having a gas inflow port 20 and a rear panel 24 opposed to the front panel 22 and a straightening cloth body 28 arranged in the bag body 26. The straightening cloth body 28 is arranged so that a flow or a main flow of inflow gas from the gas inflow port 20 turns in the left and right obliquely downward direction of the x axis (the lateral axis) from the center in the gas inflow port.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an airbag for a steering wheel in an automobile. In particular, the present invention relates to an airbag for a steering wheel that is excellent in deployment / inflation characteristics of the airbag.

[0002]

2. Description of the Related Art In an airbag device for a steering wheel, when an impact load is applied to a vehicle, a bag expands between an occupant's body and a steering wheel, that is, a ring portion simultaneously with deployment (hereinafter referred to as "deployment / inflation"). (Intrusion) to protect the occupants. At this time, the bag is quickly deployed / expanded, and when the bag enters between the ring portion and the occupant body, the load at which the bag comes into contact with the occupant body (hereinafter referred to as “contact load”). .)
Is preferably as small as possible.

In order to reduce the load at the time of contact, for example, a rectifying cloth is disposed in the vertical direction (y-axis direction) so as to substantially cover the surface of the inflator facing the rear panel, and the rectifying cloth blows out from the inflator. Various techniques for guiding a gas flow from the center of an air inlet (inflator) in the left-right direction (x-axis direction) of the bag and techniques similar thereto have been proposed in the following publications and the like.

[0004] JP-A-1-31930, JP-A-8-1
04196, JP-A-9-30353, JP-A-9-1
18185, JP-A-9-220995, JP-A-10
-100838, JP-A-10-152009, Japanese Patent No. 2677937, International Patent Publication WO97 / 3676
8. The technology based on these rectifying cloths, such as GB-233049-A in the British Patent Specification, is based on the direction in which the gas ejected from the inflator mainly flows first (hereinafter referred to as "primary gas flow").
That. ) Is in the left-right direction (x-axis direction), and the primary gas flow having a large velocity vector is parallel to the front surface of the occupant fuselage (not in the orthogonal direction). The direction of the first deployment / inflation of the bag (hereinafter "primary deployment / inflation") is not the direction directly toward the occupant fuselage. That is, the occupant's body does not abut on the bag at the time of primary deployment / expansion in which the load at the time of abutment (interference) with other members becomes large.

[0005] Then, by the next gas flow having a relatively small velocity vector (hereinafter referred to as "secondary gas flow") following the primary gas flow, the bag expands in the vertical direction, that is, in the vertical axis direction (y-axis). To touch the occupant's torso. The velocity vector of the secondary gas flow is attenuated compared to the primary gas flow,
The load at the time of contact with the occupant torso does not increase.

On the other hand, the distance between the lower part of the ring portion (rim portion) 14 of the steering wheel 12 and the occupant body 116 (more specifically, the occupant body abdomen 16a), that is, the so-called ring portion /
The distance L1 between the abdomen is shorter than the distance L2 between the upper part of the ring portion 14 and the occupant trunk 16 and the distance L3 between both sides of the ring portion and the occupant trunk 16 (FIGS. 1A and 1B). Therefore, when an impact load is applied to the vehicle, the abdomen of the occupant's body tends to interfere earlier than the lower part of the ring and other body parts. In particular, this tendency becomes more remarkable when the occupant sets the seat (seat) position forward.

For this reason, in terms of the bag deployment characteristics, it is desirable that the bag enters the space between the ring and the abdomen as quickly as possible.

However, the timing of bag intrusion between the ring portion and the occupant's abdomen is likely to be delayed. It is presumed that the following two reasons are synergistic.

[0009] The primary gas flow is in the x-axis direction and the secondary gas flow is in the y-axis direction. Therefore, the expansion and inflation of the lower part of the bag comes after the expansion and inflation of the left and right sides.

Since the distance between the ring portion and the occupant's abdomen is shorter than that of the other portions, the bag receives resistance when the bag enters.

For this reason, a technique for guiding the primary gas flow downward in the y-axis has been proposed in Japanese Patent Application Laid-Open No. 7-149199.

However, the load at the time of contact with the occupant trunk tends to be high. This is because the bag tends to enter between the smallest ring part / occupant abdomen from above, where the distance between the ring part / occupant trunk is large at the time of primary deployment / bulging where the load at the time of contact is large, but not in the orthogonal direction. is there.

In view of the above, the present invention allows the bag to be deployed / expanded relatively early between the ring portion and the abdomen of the occupant without increasing the load at the time of bag contact with the occupant trunk when the bag is deployed / inflated. It is an object of the present invention to provide a steering wheel airbag that can be (penetrated).

[0014]

Means for Solving the Problems The present inventors have made intensive efforts to develop the above-mentioned objects, and as a result, have arrived at a steering wheel airbag having the following structure.

An airbag assembled to a steering wheel airbag device and formed of a panel (base cloth), which is viewed from the occupant side when deployment and inflation are completed (hereinafter, referred to as an airbag).
“Up / down, left / right, front / back” is based on this. A) a bag body having a front panel provided with a gas inlet and a rear panel facing the front panel, the bag body having a substantially circular planar outer peripheral shape, and a rectifying cloth provided in the bag body. In the airbag provided with the body, the rectifying cloth body is disposed such that the flow or the main flow of the inflow gas from the gas inflow port is directed obliquely downward from the center of the gas inflow port to the left and right of the x-axis (left-right axis). It is characterized by having.

The primary gas flow from the gas inlet goes obliquely downward from the center of the gas inlet to the left and right of the x-axis (left-right axis). The velocity vector of the primary gas flow has a lower component as well as a left and right component. For this reason, the bag is primarily deployed / expanded toward the left and right sides of the occupant's body, and the abdomen of the occupant is not directly subjected to the load at the time of contact based on the primary deployment / inflation. Further, based on the primary gas flow directed obliquely downward to the left and right, followed by the secondary gas flow directed in the vertical central axis (y-axis) direction, the bag expands / expands (enters), so that the bag extends between the ring portion and the abdomen of the occupant. The invasion time is relatively early.

The inclination angle toward the left and right obliquely downward is approximately 3 with respect to the x axis (left and right axis) at the gas inlet.
Desirably, it is 0 °. The angle is just the direction toward the flank (torso constriction) of the occupant torso of a standard size. The flank position is constricted, so that there is no contact (interference) between the bag and the occupant torso during primary deployment / inflation, and there is no resistance to a position as close as possible to the part between the ring and the occupant abdomen. This is for the purpose of prompt secondary expansion / expansion. Therefore, it is easier to achieve the object of the present invention "to allow the bag to enter relatively early between the ring portion and the abdomen of the occupant without increasing the load of the bag against the occupant torso". Become.

As one embodiment of the rectifying cloth, the rectifying cloth may be configured to also serve as a tether arranged in a planar Y-shape from the periphery of the gas inlet. In the case of this configuration, it is only necessary to change the width and shape of the tether, so that the airbag configuration is simple, there is no need to provide a separate tether, and the amount of increase in bag bulk when folded is small.

As another embodiment of the rectifying cloth, the rectifying cloth is
A gas primary inflow chamber that covers the upper surface of the gas inflow port and is disposed substantially concentrically, and extends partway toward the front panel periphery diagonally below the left and right of the gas primary inflow chamber, and the extending end extends through the gas passage; It can be configured to include a pair of guide cylinders that are scheduled portions. In the case of this configuration, the gas flow can be reliably guided downward, and the object of the present invention "to allow the bag to enter relatively early between the ring portion and the occupant abdomen" is further achieved. Easier to do.

In the above configuration, the above-mentioned object is further easily achieved by setting the extending end of the guide cylinder at a position at least half the distance in the extending direction from the center of the gas inlet to the peripheral edge of the front panel. . This is because the primary gas flow is reliably ensured to the abdomen position, and is guided by the periphery of the bag, so that the secondary gas flow is easily guided in the y-axis (occupant abdomen) direction.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 2 and 3 show a first embodiment of an airbag (hereinafter sometimes abbreviated as "bag") of the present invention.
FIG. 2 is a model plan view of the front panel of the bag,
FIG. 3 is a model sectional view corresponding to the position taken along line 3-3 in FIG. 2 when the bag is inflated.

The bag 18 of the present embodiment has a substantially planar outer peripheral shape viewed from the occupant side at the time of completion of deployment and swelling (hereinafter, unless otherwise noted, "up, down, left, right, front and back" is used as a reference). A front panel 2 which is a circular bag and has a gas inlet 20 (which serves as an attachment port for the inflator 21);
2 and a rear panel 24 facing the front panel 22
And a rectifying cloth body 28 disposed in the bag body 26.

In the present embodiment, the rectifying cloth body 28 is constituted by three tethers 28a, 28b and 28c arranged in a planar Y-shape from the periphery of the gas inlet 20.
That is, the tethers 28a and 28b extend leftward and rightward and extend obliquely upward to the left and right, and the downward tethers 28c extend downward. With this configuration, the gas inlet 22
The main flow of the inflow gas from the gas flows obliquely downward from the center of the gas inlet into the x-axis (left-right axis). Of course,
The length of the straightening cloth 28 corresponds to the regulation value of the amount of bulging of the bag 18 in the occupant direction.

In the present embodiment, the angles of the upper left and upper right tethers 28a and 28b directed obliquely upward and the upper left, upper right and lower tethers 28a, 28b and 28c
Is the width of the main axis of the inflow gas from the gas inlet 20 from the center O at the gas inlet 20 along the x-axis (left-right axis).
The configuration is not particularly limited as long as the configuration is directed diagonally right and left downward. Normally, the angles α of the tethers 28a and 28b facing upward and leftward and obliquely upward are 30 ° to 60 °, respectively.
(45 ° in the illustrated example).

If the angle α is too small, the left and right tethers 28
The upper V space S1 formed between the a and 28b is larger than the lower left and lower right V spaces S2 and S3 formed by the left and right tethers 28a and 28b and the lower tether 28c. Difficult to play. That is, the primary gas flow easily flows from the center to the gas inlet above the y-axis, and the amount of the primary gas flow from the center of the gas inlet to the left and right diagonally below the x-axis (left-right axis) is relatively small. is there.

On the other hand, if the angle α is too large, the function of guiding the gas obliquely downward by the left and right tethers 28a and 28b (more specifically, each lower edge) is weakened.
The operation of the present invention is reduced.

The width of each of the left and right tethers 28a and 28b and the lower tether 28c is larger than the conventional tether width.
This is for rectifying the inflow gas (primary gas flow). Specifically, it is desirable to make the width larger than the width of the gas inlet (that is, the diameter of the gas blowing portion of the inflator) 20.
In particular, it is almost inevitable to make the width of the lower tether 28c larger than the gas inlet 20 so that the primary gas flow is not directed in the y-axis direction (directly below). On the other hand, the upper limit of the tether width is not particularly limited as long as the tether width does not impair the function of the tether itself and the rectification function required for the present invention. The width of the reinforcing cloth at the gas inlet 20 is usually selected from the viewpoints of saving the bag material cost and reducing the bag weight and the bag folding volume. Each tether 28a, 28b, 2
The widths of 8c do not need to be all the same, and can be increased or decreased as appropriate without impairing the effects of the present invention. Also, of course,
The length of the straightening cloth 28 corresponds to the regulation value of the bulging amount of the bag 18 in the occupant direction.

FIGS. 4 and 5 show a second embodiment. FIG. 4 is a model plan view of a front panel of an airbag (bag) according to the present embodiment, and FIG.
5 is a cross-sectional view of the model corresponding to line 5-5 of FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and all or part of the description thereof will be omitted.

The bag 18A of the present embodiment has a rectifying cloth 3
2 is directly connected to the gas inlet 20, that is, the gas inlet 2
A gas primary inflow chamber 34 that covers directly above the gas inlet port 0 and is disposed substantially concentrically with the gas inflow port 20, and extends halfway from the gas primary inflow chamber 34 toward the periphery of the front panel 22 diagonally below left and right, Further, a pair of guide cylinders (left and right guide cylinders 38, 4
0). In the illustrated example, reference numeral 29 denotes a tether that regulates the amount of bulging of the bag 18A in the occupant direction.

The direction in which the guide cylinder 38 extends depends on the flow of the gas flowing in from the gas inlet 20 as in the embodiment.
There is no particular limitation as long as it goes diagonally downward from the center of the gas inlet into the x-axis (left-right axis). Usually, the angle β of the left and right guide cylinders 38 and 40 obliquely downward is usually 1
The angle is set to 0 to 60 °, preferably 15 to 45 °, and more preferably 30 ° (illustrative example).

If the angle β is too small or too large, it is difficult to achieve the working configuration of the present invention.

That is, if it is too small, the deployment / expansion time between the ring portion of the bag and the abdomen of the body tends to be delayed. The velocity vector of the primary gas flow (white arrow) flowing out of the guide cylinders 38 and 40 into the bag main body 26 has a small y-axis (downward) component in the velocity vector, and the force for expanding / expanding the bag downward is weak. As a result, the penetration force of the bag between the ring portion and the abdomen of the torso based on the secondary gas flow of the bag is reduced.

If the angle β is too large, the timing of the deployment / inflation of the bag in the downward direction is advanced, but the bag may approach the occupant torso during primary deployment / inflation and interfere with the occupant torso. That is, the occupant torso may receive a large contact load. The velocity vector in the y-axis direction (downward component) of the primary gas flow flowing out of the guide cylinders 38 and 40 into the bag body 26 increases, and the primary deployment / expansion direction of the bag also goes between the ring portion / body abdomen. It is because it becomes a direction.

In the present embodiment, the gas primary inflow chamber 34 is
The inflated height is formed to be the same as the height of the left and right guide cylinders 38 and 40. The gas primary inflow chamber 34 may have an inner bag body (bag sub-body) with a double bag structure. If you have a double bag structure,
The inner bag body makes it easier for the bag to jump out of the bag storage chamber more quickly.

The extending ends (scheduled gas passage portions) 36 of the guide cylinders 38 and 40 have a distance of 1 from the center O of the gas inlet to the peripheral edge of the front panel 22 in the extending direction.
It is desirable to be located at a position of at least / 3, preferably at least half. This is because it is easy to secure the directionality of the velocity vector of the gas flow.

It is preferable that the left and right guide cylinders 38 and 40 are tapered (tapered) toward the gas passage scheduled portion 36. This is because it is easy to secure the magnitude of the velocity vector of the primary gas flow (white arrow). However, if the squeezing is performed too much, the outflow resistance of the inflow gas may increase, and the deployment / expansion speed of the entire bag may be relatively slowed. Usually, the narrowing amount is the guide cylinder 38,
30 to 80%, desirably 40 to 70%, of the base section area of 40. The taper angle (inclination angle with respect to the axis) is 10 to 30 °, preferably 15 to 25 °.

The gas passage portion 36 is normally open at all times, but may be closed as a fragile joint portion that breaks at a predetermined gas pressure and becomes a gas passage port. The mode of forming the fragile joint portion is usually formed by suturing with a weak suture, but is arbitrary such as adhesion or sack sewing (jacquard). In the case of this configuration, the bag 18A can be more reliably deployed / expanded obliquely downward to the left and right. Since the left and right guide cylinders 38, 40 project rigidly to the left and right diagonally downward, the bag can be more reliably deployed and bulged left and right diagonally downward.

In the illustrated example, the left and right guide cylinders 3
8 and 40, a part of the cross section is formed by the front panel 22 forming the bag body 26. However, the guide cylinder may be formed separately and attached to the front panel later.
Further, the guide cylinder is appropriately provided in the y-axis direction (upward / downward) within a range that does not impair the effects of the present invention, that is, within a range that does not impair the operation of the left and right guide cylinders 38 and 40. You may. Further, the left and right guide cylinders may each have a branch structure.

The bag 18 of each of the first and second embodiments.
The manufacturing method of (18A) will be described. For common parts, both will be described simultaneously.

The bag 18 (18A) is usually made of a woven fabric made of polyester yarn or nylon yarn, a panel body (base fabric),
That is, the front panel 22, the rear panel 24, the straightening cloth 28 (or 32), and in the second embodiment, the tether 29 cloth is further cut into a predetermined shape and sewn to manufacture. In addition, it can also manufacture by adhesion | attachment, bag sewing, etc. instead of or together with suturing.

The panel body may be a woven cloth rubberized. The rectifying cloth 28 of the first embodiment is a Y-shaped panel, and the rectifying cloth 32 of the second embodiment is a V-shaped panel.

Then, the bag main body 26 is
(Or 32) a front panel 22 (bottom panel) and a rear panel 24 to which a panel for a tether 29 is further sewn.
(Ceiling side panel), and then suturing with the inner side outside, and then forming it upside down. Further, the front panel 22 is usually provided with one or more gas vent holes (vents) 23 (two on the left and right in the illustrated example). And the gas inlet 20
Although not shown, the periphery of the gas vent hole 23 is usually sewn together with one or more annular reinforcing cloths.

Next, the usage of the bag 18 (18A) will be described mainly by taking the first embodiment as an example. In the second embodiment, only parts different from the first embodiment will be described.

The bag 18 is folded and used by assembling it with the airbag device M as shown in FIGS. For example, description will be made by taking as an example a case where the wheel body is mounted on a three-spoke type wheel body 46 as shown in FIG.

The wheel body 46 includes a ring portion 14 to be gripped during steering, a boss portion 50 connected to a steering shaft (not shown), and three spokes extending left, right, and downward connecting the boss portion 50 and the ring portion 16. Part 52,
52 and 54.

The wheel main body 46 is formed by covering a wheel core metal 56 made of aluminum die-cast or the like with a molded covering portion 58 made of a synthetic resin such as polyurethane. Further, an airbag device M and a horn switch device S are incorporated in the wheel body 46 (see FIGS. 6 and 7). The outline is as follows.

The airbag device M includes an inflator 62,
The bag 18 and the pad cover 66 are integrated via an apparatus case (bag holder) 68. The mounting of the airbag device M includes the support flange 70a of the support plate 70 screwed to each spoke portion core bar 56a of the wheel core bar 56, and the mounting flange 68a of the device case 68.
The horn switch devices S are arranged at three places between the two and are supported by three points (see FIG. 6). Switch device S
Is a conventional one in which a coil spring 76 is disposed between a fixed contact 72 fixed to the support flange 70a and a movable contact 74 fixed to the mounting flange 68a, and therefore detailed description is omitted. Reference numeral 78 denotes a guide post (stepped bolt) for moving the movable contact in the vertical direction, and reference numeral 80 denotes a pressing rib for operating a switch. Further, a guide (fin) may be formed so that the air outlet of the inflator 62 blows gas obliquely downward to the left and right of the bag. In the above, the folding method of the bag 18 is as follows.
Although not particularly limited, for example, folding by the following method shown in FIGS. 8 to 10 is preferable because it can reduce the increase in the bulk of the folded bag and can easily expand / expand the bag diagonally right and left downward.

Front panel 2 having gas inlet 20
After the rear panel 24 on the side facing the gas inflow port is overlapped on the two sides and unfolded flat, it is folded in the following two steps.

In the first stage, the gas inlet 2 shown in FIG.
From the planar shape (circular shape) with the rear panel 24 side facing up to 0 facing upward, uniform three-parted peripheral edges 82, 84, 86 around the gas inlet 20 are respectively bellowed so as to approach the gas inlet 20 side. Fold and fold to a planar shape as shown in FIG. 8B. Specifically, each peripheral edge 82,
At 84 and 86, respectively, the first mountain fold m1, the first valley fold v1, the second mountain fold m2, and the second valley fold v
2. A bellows fold consisting of a third mountain fold m3 is performed, and folded so that each fold as shown in FIG. The shape shown in FIG. 8B is basically a three-rotation symmetrical shape having three radial projections 88, 90, and 92 surrounded by arcs substantially circumscribing the gas inlet 20 in three directions. is there.

In the second stage, the radial projections 88, 90, 92 having a planar shape shown in FIG. 8B are wound around an outer roll (toward the front panel 22 side) so as to approach the gas inlet 20 side. After forming the masses 94, 96, 98,
It is inverted and placed on the rear panel 24 (see FIG. 10), and folded so as to form a substantially inverted triangular plane as shown in FIG. 8c.

Before folding the bag 18, the retainer 69 is inserted into the bag 18, and although not shown, the above-mentioned folding operation is performed with each bolt of the retainer protruding from the mounting hole on the peripheral edge of the gas inlet. . After the folding is completed, the bag 18 may be wrapped with a film to maintain the shape.

The folded bag 18 is stored in an apparatus case (bag holder) 68. Although not shown, the bolt of the retainer 69 is inserted through the through hole in the bottom wall portion of the bag holder, and is fixed with a nut.

At this time, the bag 18 is placed in the device case so that only one of the three rolls 94, 96, 98 in the bag 18 is located at the upper end of the device case bottom wall 68b. It is placed on the bottom wall 68b.

The airbag device M having the bag housed in the device case 68 is assembled to the steering wheel according to a conventional method.

Thus, the steering wheel 12 incorporating the airbag device or the like is mounted on a vehicle by being incorporated into a steering wheel via a steering shaft (not shown).

The detection signal of the impact load is input to the inflator 62, and the inflation gas ejected from the inflator 62 flows into the bag 18 from the gas inlet 20. Then, the H-shaped tear line 67 of the pad cover 66 is broken and opened by forming / expanding the bag 18 to form an air outlet. Then bag 18
Protrudes from the device case 68 and expands / expands (see FIG. 11).

In the bag 18 of the present embodiment, the following gas flows are generated due to the presence of the rectifying cloth 28 disposed in the bag body 26.

First, the primary gas flow of the inflation gas is guided obliquely downward to the left and right by the rectifying cloth 28. For this reason,
As shown in FIG. 12A, the bag body 26 expands / expands diagonally right and left downward, that is, protrudes to both sides of the abdomen 16 a of the occupant body 16. Therefore, the bag 18
In the initial stage of deployment of the vehicle, the occupant body 16 and the bag do not interfere (contact). And then, as shown in FIG. 12B,
The secondary gas flow following the primary gas flow expanded / inflated downward causes the bag 18 to rapidly deploy / expand between the ring portion 14 / occupant body 16.

At this time, a longitudinal centerline C portion between the lower portion of the ring portion 14 and the abdomen 16 of the occupant's body (see FIG. 1)
Even if the distance in the (y-axis direction) is shorter than the other parts, since the secondary gas flow has a velocity vector directed to the vertical axis, there is a gap between the ring part 14 and the occupant body 16. From the direction, the bag 18 is quickly moved to the ring part 14 / occupant abdomen 1
It can deploy / bulge (enter) between the six. In this way, interference between the occupant body and the ring portion is prevented.

When the bag 18 is deployed / inflated, when the above-mentioned folding system is used, the speed vector of the initial deployment / inflation of the bag 18 can be suppressed, and the load at the time of contact can be reduced when the bag 18 interferes with the torso. it can. That is, the presence of the three rolls 88, 90, and 92 divides the gas amount in each development direction into three and reduces the velocity vector in each direction.

While the first embodiment has been described above, the same applies to the second embodiment. However, in the bag 18A of the second embodiment, the left and right guide cylinders 3
According to 8, 40, all of the primary gas flows are directed to the left and right guide cylinders 38, 40, so that the required deployment characteristics can be more easily obtained.

[Brief description of the drawings]

FIG. 1 is a model diagram showing a positional relationship between an occupant (driver) and a steering wheel (ring).

FIG. 2 is a model plan view of the front panel of the airbag according to the embodiment of the present invention as viewed from the inside.

FIG. 3 is a cross-sectional view of the model at the time of completion of inflation of the airbag in a portion corresponding to line 3-3 in FIG. 2;

FIG. 4 is a model plan view of a front panel of an airbag according to another embodiment of the present invention as viewed from the inside.

FIG. 5 is a model cross-sectional view of a state where an airbag is inflated at a portion corresponding to line 5-5 in FIG. 4;

FIG. 6 is a plan view of a steering wheel equipped with an airbag device accommodating the airbag of the present invention.

FIG. 7 is a schematic sectional view corresponding to a portion taken along line 7-7 of FIG. 6;

FIG. 8 is an explanatory view showing one folding method applicable to the airbag according to the embodiment of the present invention.

9 is a schematic cross-sectional view of a portion corresponding to line 9-9 in FIG. 8 showing a first-stage folded state in the folding method of FIG. 8;

FIG. 10 is a schematic model end view of a portion corresponding to the line 10-10 in FIG. 8 showing the folded state in the second stage.

11 is a schematic model end view corresponding to the line 11-11 in FIG. 6, showing the form of deployment / inflation of the airbag.

FIG. 12 is a plan view showing the positional relationship between the airbag and the occupant torso at the initial stage and at the completion of deployment / inflation of the airbag of the present invention.

[Explanation of symbols]

 12 Steering Wheel 14 Ring (Rim) 16 Passenger Torso (Body Torso) 18 Airbag 20 Gas Inlet 21 Inflator 22 Front Panel (Bottom Panel) 24 Rear Panel (Ceiling Panel) 26 Bag Body 28 Straightening Cloth (Tether) 32 Rectifying cloth (guide cylinder) 34 Primary gas inflow chamber 36 Expected gas outflow section 38 Left guide cylinder 40 Right guide cylinder 68 Device case (device case) x-axis Horizontal (left / right) axis of bag y-axis Bag Vertical (vertical) axis

Continuing from the front page (72) Inventor Masahiro Takimoto 1 Ochiai Nagahata, Kasuga-machi, Nishi-Kasugai-gun, Aichi Prefecture Inside Toyoda Gosei Co., Ltd. (72) Inventor Nao Yamamoto 1 Ochiai-Ochiai, Kasuga-cho, Nishi-Kasugai-gun, Aichi No. 1 Toyoda Gosei Co., Ltd. Company F term (reference) 3D030 DB47 3D054 AA13 CC10 CC11 CC30

Claims (5)

[Claims] 1. An airbag assembled to a steering wheel airbag device and formed of a panel (base cloth), which is viewed from an occupant side at the time of completion of deployment and inflation (hereinafter referred to as "up, down, left, right, front and rear"). Is a basis.) A bag body having a substantially circular planar outer peripheral shape, a front panel having a gas inlet, a bag body having a rear panel facing the front panel, and the bag body. The flow of the inflow gas from the gas inflow port or the main flow is obliquely downward and left and right of the x-axis (left and right axis) from the center of the gas inflow port. The airbag for a steering wheel, wherein the rectifying cloth is disposed so as to face the airbag. 2. The inclination angle toward the left and right obliquely downward,
The airbag for a steering wheel according to claim 1, wherein each of the gas inlets is approximately 30 degrees with respect to an x-axis (left-right axis). 3. The airbag for a steering wheel according to claim 1, wherein the rectifying cloth also serves as a tether arranged in a planar Y-shape from a periphery of the gas inlet. 4. A gas primary inflow chamber which covers the upper surface of a gas inlet and is disposed substantially concentrically with the straightening cloth body, and extends from the gas inflow chamber diagonally downward and rightward toward the peripheral edge of the front panel. The airbag for a steering wheel according to claim 1 or 2, further comprising a pair of guide cylinders extending to the end and having an extension end serving as a gas passage scheduled portion. 5. The steering according to claim 4, wherein an extension end of the guide cylinder is located at a position at least half or more of a distance in an extending direction from a center of the gas inflow port to a peripheral edge of the front panel. Airbag for wheels.