JP2022018373A - Airbag and airbag device - Google Patents

Abstract

To provide an airbag which can be made into a proper expansion completed shape regardless of a steering angle of a steering with a simple structure.SOLUTION: An airbag 10 includes: a first tuck part 15 formed by folding a front panel 11 and including a pair of tucks 16, 17 arranged parallel to each other at both sides sandwiching a center C1 of the front panel 11; a second tuck part 18 formed so as to extend in a direction intersecting with the first tuck part 15 by folding the front panel 11, the second tuck part 18 including a pair of tucks 19, 20 arranged parallel to each other at both sides sandwiching the center C1 of the front panel 11; and four tethers 14A to 14D which are disposed within the airbag 10 and connect the front panel 11 with a rear panel 12.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to airbags and airbag devices.

The driver's airbag is generally stored in the center of the steering wheel. It is preferable that the inflatable shape of the airbag is formed so as to have an appropriate shape depending on the contact portion, such as a relatively thick surface in contact with the head and a relatively thin portion in contact with the chest. However, depending on the steering angle of the steering wheel, the shape suitable for the head and chest may not hit the corresponding portion of the occupant.

Patent Document 1 includes a plurality of tethers in an airbag and locking means for adjusting the length of each tether, and by appropriately selecting a locking means that operates according to the rotation of the steering, the steering angle. Regardless of this, a configuration is disclosed in which the shape of the completed expansion of the airbag can be set to a fixed position.

JP-A-2007-302192

However, in Patent Document 1, a length adjusting mechanism is provided for each of a plurality of tethers, and the control device operates one of the length adjusting mechanisms according to the steering angle. Is required.

It is an object of the present disclosure to provide an airbag and an airbag device that can have an appropriate expansion complete shape regardless of the steering angle of the steering with a simple configuration.

In the airbag according to one aspect of the embodiment of the present invention, the front panel installed on the steering device of the vehicle and arranged on the occupant side at the time of installation and the rear panel arranged on the opposite side to the occupant are the outer circumferences of both panels. A first airbag formed by being joined to each other over the same direction, including a pair of tacks formed by folding the front panel and arranged in parallel on both sides of the center of the front panel. A first tack portion including a pair of tacks formed by folding the front panel so as to extend in a direction intersecting the first tack portion and arranged in parallel on both sides of the center of the front panel. The tack portion of 2 and a plurality of tethers arranged inside the airbag and connecting the front panel and the rear panel are provided, and the plurality of tethers are the first tack portion of the front panel. At a position on the outer peripheral side of the central portion where the second tack portion intersects with the second tack portion, and at positions arranged at predetermined intervals along the circumferential direction of the front panel, each of the front panels. The plurality of tethers have a breaking portion that breaks depending on the magnitude of the tension generated between the connecting portion with the front panel and the connecting portion with the rear panel.

According to the present disclosure, it is possible to provide an airbag and an airbag device that can have an appropriate expansion complete shape regardless of the steering angle of the steering with a simple configuration.

A side view showing a schematic configuration of an airbag device according to an embodiment. An exploded perspective view of the airbag according to the embodiment. Floor plan of the unfolded state of the front panel Diagram showing the first stage of the front panel folding procedure Diagram showing the second stage of the front panel folding procedure Plan view showing the schematic configuration of the tether Diagram showing the connection status between the tether and the front panel The figure which shows the first stage of the expansion process of an airbag The figure which shows the 2nd stage of the expansion process of an airbag The figure which shows the 3rd stage of the expansion process of an airbag

Hereinafter, embodiments will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components are designated by the same reference numerals as possible in the drawings, and duplicate description is omitted.

In the following description, the X direction, the Y direction, and the Z direction are perpendicular to each other. The X and Z directions are horizontal, and the Y direction is vertical. The X direction is the left-right width direction of the vehicle. The Z direction is the front-rear direction of the vehicle. Further, in the following, for convenience of explanation, the Y positive direction side may be expressed as the upper side and the Y negative direction side may be expressed as the lower side.

(Airbag device)
FIG. 1 is a side view showing a schematic configuration of the airbag device 2 according to the embodiment. FIG. 1 illustrates a state in which the airbag device 2 is applied to a driver's seat airbag and the airbag 10 is completely expanded and expanded.

As shown in FIG. 1, the steering device 1 is arranged in front of the occupant P seated in the driver's seat (in front of the vehicle), and the airbag device 2 is provided inside the steering device 1. The steering device 1 includes an annular steering wheel 3 and a hub 4 located at the center thereof.

The airbag device 2 is provided inside the hub 4, and includes an airbag 10, a case 5 for accommodating the entire airbag 10, and an inflator (gas generator) 6 provided at the bottom of the case 5. ing.

The airbag 10 is housed in the case 5 in a folded state before expansion and deployment. In the event of a vehicle collision or the like, the airbag 10 is folded by supplying gas from the inflator 6 to the inside of the airbag 10 stored in the case 5 in a state of being folded to a size that can be accommodated in the case 5. It expands and expands from the state of being inflated.

(Airbag)
The configuration of the airbag 10 according to the embodiment will be described with reference to FIGS. 2 to 7. FIG. 2 is an exploded perspective view of the airbag 10 according to the embodiment.

As shown in FIGS. 1 and 2, the airbag 10 includes a front panel 11 and a circular rear panel 12, and the front panel 11 and the rear panel 12 are formed by being joined to each other over the outer periphery 13 of both panels. , It is a part that can be expanded and expanded. As the airbag 10 expands and expands, the movement of the occupant P in the vehicle is restrained.

The rear panel 12 is provided with an opening 12A for supplying gas from the inflator 6 and a vent hole 12B for discharging the gas in the airbag 10 on the side opposite to the occupant P with respect to the maximum expansion width portion. Be done. The opening 12A is provided at the center including the center point C2 of the circular rear panel 12, for example. Around the opening 12A, a bolt insertion hole 12C through which a bolt for fixing the rear panel 12 to the retainer such as the case 5 together with the inflator 6 is inserted is provided.

Inside the airbag 10, four tethers 14A, 14B, 14C, 14D connecting the outer peripheral side of the front panel 11 and the rear panel 12 so as to regulate the separation distance between the front panel 11 and the rear panel 12 during expansion. Are arranged.

As shown in FIG. 2, the shape of the front panel 11 in a state where the rear panel 12 and the outer periphery are sewn is the same circular shape as the rear panel 12. In this state, the front panel 11 is formed with a first tack portion 15 and a second tack portion 18 by folding the front panel 11. The first tack portion 15 includes a pair of tacks 16 and 17 arranged in parallel on both sides of the center C1 of the front panel 11. The second tack portion 18 includes a pair of tacks 19 and 20 extending in a direction intersecting the first tack portion 15 and arranged in parallel on both sides of the center C1 of the front panel 11.

The front panel 11, the rear panel 12, the tethers 14A, 14B, 14C, and 14D constituting the airbag 10 are formed of a cloth material woven with a yarn such as polyamide or polyester.

FIG. 3 is a plan view of the front panel 11 in an expanded state. As shown in FIG. 3, the front panel 11 has a substantially circular shape, but has overhanging portions 40A to 40D at four points on the peripheral portion.

Of the outer peripheral edge of the front panel 11, the arc portion 30A is formed between the overhanging portion 40A and the overhanging portion 40D. An arc portion 30B is formed between the overhanging portion 40A and the overhanging portion 40B. An arc portion 30C is formed between the overhanging portion 40B and the overhanging portion 40C. An arc portion 30D is formed between the overhanging portion 40C and the overhanging portion 40D.

The overhanging portion 40A is located on the lower edge of the front panel 11, the overhanging portion 40B is located on the left edge of the front panel 11, the overhanging portion 40C is located on the upper edge of the front panel 11, and the overhanging portion 40D is located. It is located on the right edge of the front panel 11. The perimeters of the overhanging portions 40A to 40D are the same. The radius of curvature of the overhanging portions 40A to 40D is equal to the radius of curvature of the outer peripheral edge of the arc portions 30A to 30D.

The arc portion 30A is located diagonally downward to the right when viewed from the center C1 of the front panel 11. The arc portion 30B is located diagonally downward to the left when viewed from the center C1 of the front panel 11. The arc portion 30C is located diagonally upward to the left when viewed from the center C1 of the front panel 11. The arc portion 30D is located at a position diagonally upward to the right when viewed from the center C1 of the front panel 11. The outer peripheral edges of the arc portions 30A to 30D are arcuate with the same radius of curvature. The circumferences of the outer peripheral edges of the arc portions 30A to 30D are the same.

In the present embodiment, a pair of tacks 16 and 17 constituting the first tack portion 15 are provided so as to be inclined at 45 degrees with respect to the vertical direction and the horizontal direction from diagonally upper left to diagonally lower right. There is. Similarly, a pair of tacks 19 and 20 constituting the second tack portion 18 are provided so as to be inclined at 45 degrees with respect to the vertical direction and the left-right direction from diagonally upper right to diagonally lower left. That is, the extending directions of the first tack portion 15 and the second tack portion 18 are orthogonal to each other.

The tacks 16 and 17 of the first tack portion 15 are formed by folding the front panel 11 along the valley fold lines 16a and 17a and folding the front panel 11 along the mountain fold lines 16b and 17b. To. That is, the tacks 16 and 17 are folded so that the valley fold lines 16a and 17a are inserted into the center side of the front panel 11 with respect to the mountain fold lines 16b and 17b.

The tacks 19 and 20 of the second tack portion 18 are formed by folding the front panel 11 along the valley fold lines 19a and 20a and folding the front panel 11 along the mountain fold lines 19b and 20b. To. That is, the tacks 19 and 20 are folded so that the valley fold lines 19a and 20a are inserted into the center side of the front panel 11 with respect to the mountain fold lines 19b and 20b.

The valley fold line 16a is a straight line connecting the right end of the outer peripheral edge of the overhanging portion 40A and the upper end of the outer peripheral edge of the overhanging portion 40B. The mountain fold line 16b is a straight line connecting the lower ends of the arc portions 30A and 30C. The valley fold line 17a is a straight line connecting the left end of the outer peripheral edge of the overhanging portion 40C and the lower end of the outer peripheral edge of the overhanging portion 40D. The mountain fold line 17b is a straight line connecting the upper ends of the arc portions 30A and 30C.

Similarly, the valley fold line 19a is a straight line connecting the lower end of the outer peripheral edge of the overhanging portion 40B and the right end of the outer peripheral edge of the overhanging portion 40C. The mountain fold line 19b is a straight line connecting the upper ends of the arc portions 30B and 30D. The valley fold line 20a is a straight line connecting the left end of the outer peripheral edge of the overhanging portion 40A and the upper end of the outer peripheral edge of the overhanging portion 40D. The mountain fold line 20b is a straight line connecting the lower ends of the arc portions 30B and 30D.

FIG. 4 is a diagram showing a first stage of the folding procedure of the front panel 11. FIG. 5 is a diagram showing a second stage of the folding procedure of the front panel 11.

In the present embodiment, from the unfolded state shown in FIG. 3, the front panel 11 is first folded along the valley fold lines 16a and 17a and the mountain fold lines 16b and 17b, so that the first tack portion is as shown in FIG. A pair of 15 tacks 16 and 17 are formed.

Then, from the state of FIG. 4, by folding the front panel 11 along the valley fold lines 19a and 20a and the mountain fold lines 19b and 20b, as shown in FIG. 5, a pair of tacks 19 of the second tack portion 18 , 20 are formed. The tacks 19 and 20 of the second tack portion may be formed first, and then the tacks 16 and 17 of the first tack portion 15 may be formed.

As a result, as shown in FIG. 5, the front panel 11 becomes circular. That is, the outer peripheral edges of the overhanging portions 40A to 40D and the arc portions 30A to 30D form a circle having an equal radius from the center C1 of the front panel 11. Further, at the intersection of the first tack portion 15 and the second tack portion 18, a substantially rectangular central portion 23 including the center C1 of the front panel 11 is formed.

FIG. 6 is a plan view showing a schematic configuration of the tethers 14A to 14D. As shown in FIG. 6, the tethers 14A to 14D include a first end 51 connected to the front panel 11 and a second end 52 connected to the rear panel 12.

The first end 51 is sutured to the front panel 11 by the suture line 54. The stitching position with the front panel 11 is different for each of the four tethers 14A to 14D. The tether 14A is sewn at the position of the suture line 22A arranged on the overhanging portion 40A of the front panel 11. The tether 14B is sutured at the position of the suture line 22B arranged on the overhanging portion 40B of the front panel 11. The tether 14C is sewn at the position of the suture line 22C arranged on the overhanging portion 40C of the front panel 11. The tether 14D is sutured at the position of the suture line 22D located on the overhanging portion 40D of the front panel 11.

The second end portion 52 has a substantially circular shape, for example, as shown in FIG. 6, and has an opening portion 55 and an insertion hole 59. In the second end 52, the opening 55 and the insertion hole 59 are arranged so as to overlap with the opening 12A and the bolt insertion hole 12C of the rear panel 12, for example, the case of the airbag device 2 together with the rear panel 12 via the insertion hole 59. By being fixed to 5 or the like, it is connected to the rear panel 12.

A widening portion 53 is formed in the intermediate portion between the first end portion 51 and the second end portion 52. The widening portion 53 is a portion that extends widely in a direction substantially perpendicular to the center line connecting the first end portion 51 and the second end portion 52 (left-right direction). The widened portion 53 has a symmetrical outer shape, and a broken portion 56 is formed at a substantially central portion in the extending direction.

The broken portion 56 includes, for example, a slit 57 formed in a direction substantially perpendicular to the tension generated between the first end portion 51 and the second end portion 52, and a tear portion 58. The slit 57 is arranged at the center of the widening portion 53 in the extending direction, and the tear portions 58 are arranged on both sides thereof. The slit 57 is a portion that gives a trigger (starting point) for the tethers 14A to 14D to break at the breaking portion 56. In particular, in the initial stage of expansion and deployment of the airbag 10, since a large impact force is likely to be applied to the tethers 14A to 14D, first, the slit 57 is widened to widen the distance between the first end portion 51 and the second end portion 52. , It is configured to evenly transmit tension to the left and right tether portions 58. The presence / absence and length of the slit 57 are appropriately changed depending on conditions such as the type and capacity of the airbag 10 and the gas pressure of the inflator 6.

In the tear portion 58, a plurality of cuts (teas) are arranged linearly or curvedly at predetermined intervals. Here, the cut may be a simple notch or a narrow slit. When the tension exceeds a predetermined value, the tear portion 58 begins to break from the cut on the central side, and thereafter, the expansion of the airbag 10 progresses, the distance between the first end portion 51 and the second end portion 52 gradually increases, and the tension increases. Every time the amount exceeds a predetermined value again, the outer cut is repeatedly broken.

FIG. 7 is a diagram showing a connection state between the tethers 14A to 14D and the front panel 11. In FIG. 7, as shown in FIG. 5, the front panel 11 is in a state of being folded into a circular shape, and shows the back surface side of FIG. As shown in FIG. 7, the four tethers 14A to 14D are laminated and sequentially sewn to each suture line 22A to 22D of the front panel 11. After that, the front panel 11 folded in a circle and sutured with the tethers 14A to 14D and the rear panel 12 are overlapped as shown in FIG. 2, and the suture line 21 on the outer peripheral edge of the front panel 11 and the outside of the rear panel 12 are overlapped. The airbag 10 is formed by suturing the suture lines 12D on the peripheral edge. The procedure may be performed in which the four tethers 14A to 14D are sewn to the front panel 11 in the deployed state shown in FIG. 3, and then the front panel 11 is folded into the state shown in FIG.

The expansion process of the airbag 10 of the present embodiment will be described with reference to FIGS. 8 to 10. Here, as illustrated in FIG. 7, the case where the tether 14A is arranged below among the four tethers 14A to 14D and this portion abuts on the chest of the occupant P will be described. 8 and 9 show a case where the seating position of the occupant P is relatively close to the steering device 1, and FIG. 10 shows that the seating position of the occupant P is from the steering device 1 as compared with the cases of FIGS. 8 and 9. Indicates a distant case.

FIG. 8 is a diagram showing a first stage of the expansion process of the airbag 10. FIG. 8 shows the initial deployment of the airbag 10 in the case of the occupant P near the steering device 1. As shown in FIG. 8, in the first stage, the tethers 14A to 14D suppress the protrusion of the central portion 23 of the front panel 11, thereby suppressing the protrusion of the airbag 10 to the head of the occupant P, and the occupant. It is possible to suppress a feeling of oppression and an impact force against P.

FIG. 9 is a diagram showing a second stage of the expansion process of the airbag 10. FIG. 9 shows a state at the time of contact of the airbag 10 in the case of the occupant P near the steering device 1. As shown in FIG. 9, in the second stage, the tethers 14A to 14D receive a tension equal to or higher than a predetermined value, the fractured portion 56 begins to break in stages, and the tethers 14A to 14D begin to stretch (note that the occupant P). In the case of the tether 14A arranged in front of the chest, if the broken portion 56 comes into contact with the chest before the broken portion starts to break, the broken portion 56 is not broken and the connection portion between the front panel 11 and the rear panel 12 is connected. The length between them may not extend from the dimensions before expansion). The tether 14A in front of the chest, which has a short distance from the occupant P, is short, and the tethers 14B to 14D near the head are extended, so that the time difference between the head and the chest in contact with the airbag 10 can be reduced.

Further, the first tack portion 15 and the second tack portion 18 provided on the front panel 11 increase the distance of the stroke S1 of the central portion 23 of the front panel 11, that is, the portion in contact with the head of the occupant P. On the other hand, since the tether 14A receives an external force F from the chest due to contact with the chest of the occupant P, no further extension occurs in the stroke of the tether 14A, and the stroke of the portion of the airbag 10 in contact with the chest of the occupant P. S2 is shorter than the stroke S1 to the head. As a result, the difference between the stroke S1 to the head and the stroke S2 to the chest of the airbag 10 can be increased, and the expansion of the airbag 10 can be controlled so as to have an appropriate stroke for the head and the chest.

Then, the stroke S1 to the head, which is relatively far from the steering device 1, can be made longer than the stroke S2 to the chest, which is relatively close to the head, so that the occupant by the airbag 10 is compared with the conventional airbag. The restraint timing of P's head can be accelerated. At that time, since the head restraint surface can be increased by tacking, it is possible to suppress the oppressive force and the impact force on the head of the occupant P.

FIG. 10 is a diagram showing a third stage of the expansion process of the airbag 10. FIG. 10 shows a state at the time of contact of the airbag 10 in the case of the occupant P far from the steering device 1. When the seating position of the occupant P is farther from the steering device 1 as compared with FIGS. 8 and 9, the airbag 10 may not be sufficiently in contact with the occupant P in the expanded state of the airbag 10 shown in FIG. .. As shown in FIG. 10, in the third stage, even if the seating position of the occupant P is different, the tethers 14A to 14D are further extended from the state shown in FIG. Can be made smaller. In the example of FIG. 10, the broken portions 56 of the remaining tethers 14B to 14D other than the tether 14A that came into contact with the chest of the occupant were completely broken, and the stroke of these portions was extended longer than the contact portion with the chest. , The expansion of the airbag 10 is completed.

The effect of the airbag 10 according to the present embodiment will be described. As described above, the airbag 10 has a first tack portion 15 including a pair of tacks 16 and 17 which are formed by folding the front panel 11 and are arranged in parallel on both sides of the center C1 of the front panel 11. A second tack 19 and 20 including a pair of tacks 19 and 20 formed by folding the front panel 11 so as to extend in a direction intersecting the first tack portion 15 and arranged in parallel on both sides of the center C1 of the front panel 11. The tack portion 18 and four tethers 14A to 14D arranged inside the airbag 10 and connecting the front panel 11 and the rear panel 12 are provided. The tethers 14A to 14D are located on the outer peripheral side of the central portion 23 where the first tack portion 15 and the second tack portion 18 of the front panel 11 intersect, and are located along the circumferential direction of the front panel 11. At the positions of the suture lines 22A to 22D arranged at predetermined intervals, each is connected to the front panel 11. The tethers 14A to 14D have the tension generated between the connecting portion with the front panel 11 (the suture line 54 of the first end portion 51) and the connecting portion with the rear panel 12 (the insertion hole 59 of the second end portion 52). It has a broken portion 56 that breaks according to the size.

With this configuration, the first tack portion 15 and the second tack portion 18 are provided so as to pass through the center C1 of the front panel 11, so that when the airbag 10 is inflated, the first tack portion 15 and the second tack portion 15 and the second tack portion 18 are provided. The distance of the stroke S1 in the expansion direction of the central portion 23 where the tack portion 18 intersects can be increased. Further, by connecting the four tethers 14A to 14D to the front panel 11 along the circumferential direction from the central portion 23 on the outer peripheral side, the tethers 14A to 14D are predetermined on the outer peripheral side portion of the front panel 11 when the airbag is inflated. Since the tensile load can be applied, the expansion of the outer peripheral portion can be delayed with respect to the central portion 23, and the increasing speed of the stroke S2 can be reduced. As a result, the distance of the stroke S1 of the central portion 23 that contacts the head of the occupant P during expansion and deployment can be increased to ensure the protection of the head, and the stroke S2 of the outer peripheral portion including the portion that contacts the chest of the occupant P. The strokes S1 and S2 in the expansion process of the airbag 10 can be individually controlled so that the increase rate of the airbag 10 can be delayed to alleviate the impact on the chest.

Further, since the four tethers 14A to 14D are arranged along the circumferential direction of the steering wheel 3, the airbag device 2 is operated while the steering wheel 3 is being rotated for the steering operation of the vehicle. Even in this case, any one of the four tethers is always located in the direction of the bottom of the steering wheel 3 or in a portion close to this direction. Therefore, the increasing speed of the stroke S2 of the portion of the occupant P in contact with the chest can be surely reduced by the action of one tether located in front of the chest. That is, it is possible to eliminate the step of the performance difference when the steering is rotated. Therefore, the airbag 10 of the present embodiment has a simple configuration in which a plurality of tethers 14A to 14D are arranged along the circumferential direction of the steering wheel 3, and has an appropriate expansion completion shape regardless of the steering angle of the steering wheel 3. can.

Further, of the four tethers 14A to 14D, one tether that comes into contact with the chest of the occupant P receives a reaction force F from the chest when it comes into contact with the chest of the occupant P, and the tether loosens, so that no further extension is achieved. As described above, since the central portion 23 in contact with the head is provided with a tack, the distance of the stroke S1 is longer than that of other portions other than the central portion 23, but the stroke of the chest is further stopped by stopping the extension of the tether. S2 can be made smaller than other parts other than the central part 23. As a result, in the airbag 10 of the present embodiment, the difference in the distances between the strokes S1 and S2 of the airbag 10 with respect to the head and chest of the occupant P can be further increased. That is, by providing the tacks 15 and 18 on the central portion 23 of the front panel 11 and providing the tethers 14A to 14D on the outer peripheral portion of the front panel 11, the stroke S1 between the portion hitting the head and the portion hitting the chest of the occupant P , The difference in distance of S2 can be further widened.

Further, of the four tethers 14A to 14D, the remaining three tethers that do not come into contact with the chest of the occupant P do not come into contact with the chest and therefore do not receive the reaction force F from the chest, so that the broken portion 56 is finally completely broken. Extend to. That is, the distance of the stroke S2 of the tether 14A in contact with the chest can be made shorter than the stroke amount of the other tethers 14B to 14D. As described above, each of the airbags 10 of the present embodiment depends on only one condition of whether or not each part of the front panel 11 on which the four tethers 14A to 14D are arranged comes into contact with the chest of the occupant P. It is possible to switch whether the break portion 56 of the tethers 14A to 14D is completely broken or the break can be interrupted, and the length between the tether 14A placed in front of the chest and the other tethers 14B to 14D is automatically set. Can be changed. For example, as in Patent Document 1, in order to switch the lengths of a plurality of tethers, it is necessary to provide a special mechanism for adjusting the length of the tethers based on the steering angle of the steering or to execute a special control. do not have. As described above, the airbag 10 of the present embodiment is provided with a plurality of tethers 14A to 14D having the broken portion 56, so that the airbag 10 can be formed into an appropriate expansion complete shape regardless of the steering angle of the steering wheel 3 with a simple configuration.

Further, in the airbag 10 of the present embodiment, the front panel 11 has a circular shape with the first tack portion 15 and the second tack portion 18 formed, and the front panels 11 of the four tethers 14A to 14D are formed. The connecting portion (sewn lines 22A to 22D) with is an intermediate position (a radial line connecting the center C1 and the outer peripheral 13) between the joint portion between the center C1 and the outer peripheral rear panel 12 in the radial direction of the front panel 11. It is preferably arranged in the range from the center position of the minute to the outer peripheral side.

Further, the airbag 10 is installed in the steering device 1 so that the front panel 11 rotates in the same direction as the steering wheel 3 as the annular steering wheel 3 of the steering device 1 rotates. When the connecting portions (suture lines 22A to 22D) of the plurality of tethers 14A to 14D with the front panel 11 are in the direction of the lowermost portion of the ring of the steering wheel 3, the occupant P is in the expanded state of the airbag 10. It is preferably placed in a position that hits the chest of the wheel.

With these configurations, any one of the plurality of tethers 14A to 14D can be more reliably arranged at a position where the occupant P touches the chest regardless of the steering angle of the steering wheel 3, and the stroke speed of the chest is reduced. The effect can be exhibited more reliably.

Further, in the airbag 10 of the present embodiment, it is preferable that the first tack portion 15 and the second tack portion 18 of the front panel 11 are arranged orthogonally to each other. As a result, the increase in the stroke amount due to the tack can be made more evenly along the circumferential direction, and the increase in the stroke amount in the central portion 23 can be made more stable regardless of the steering angle of the steering wheel 3.

Further, in the airbag 10 of the present embodiment, the connecting portions (suture lines 22A to 22D) of the plurality of tethers 14A to 14D with the front panel 11 are the first tack portion 15 and the second tack portion 15 in the circumferential direction of the front panel 11. It is preferable that it is arranged between the tack portion 18 and the tack portion 18. With this configuration, the tethers 14A to 14D can be sewn to the front panel 11 while avoiding the first tack portion 15 and the second tack portion 18, and the tethers 14A to 14D can be easily sewn to the front panel 11. Further, even when the tack portions 15 and 18 are formed after the tethers 14A to 14D are sewn on the front panel 11, the sewn portions do not overlap the mountain fold lines and valley fold lines of the tacks 16, 17, 19 and 20. The tack can be easily folded. In this way, by arranging the connecting portion of the plurality of tethers 14A to 14D with the front panel 11 between the first tack portion 15 and the second tack portion 18, the airbag 10 can be easily manufactured. ..

Further, in the airbag 10 of the present embodiment, as shown in FIGS. 5 and 7, the connecting portion (sewn lines 22A to 22D) of the plurality of tethers 14A to 14D with the front panel 11 has the diameter of the front panel 11. It is formed so as to extend in a direction orthogonal to the direction (sewing of the stitch lines 22A to 22D is composed of a continuous combination of a pair of R portions at both ends in the extending direction and a straight portion connecting the pair of R portions. The R portion is curved toward the outside of the panel from the connection portion with the straight portion. The straight portion may be formed of a relatively large arc with respect to the R portion, and the R portion may be formed. May consist of circular sewing). As a result, the connecting portion extends horizontally in the portion of the airbag 10 that comes into contact with the chest of the occupant P during expansion and deployment, and the tensile load from the tether is evenly applied in the horizontal direction at the portion in contact with the chest. It will be like. As a result, the contact surface of the airbag 10 with the occupant chest can be flattened, so that the contact area of the airbag 10 with the occupant chest can be increased, and the impact on the chest can be further mitigated (see FIG. 13).

The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. These specific examples with appropriate design changes by those skilled in the art are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element included in each of the above-mentioned specific examples, its arrangement, conditions, a shape, and the like are not limited to those exemplified, and can be appropriately changed. The combinations of the elements included in each of the above-mentioned specific examples can be appropriately changed as long as there is no technical contradiction.

In the above embodiment, the configuration in which the first tack portion 15 and the second tack portion 18 provided on the front panel 11 are arranged at right angles is exemplified, but the first tack portion 15 and the second tack portion 18 are May be configured to intersect at least at the central portion 23 including the center C1, and the intersection angle may be other than 90 degrees.

In the above embodiment, the configuration in which four tethers 14A to 14D are connected to the front panel 11 is exemplified, but the configuration may be such that a plurality of tethers are arranged along the circumferential direction of the front panel 11, and the number is four. It may be other than. At this time, it is preferable that the front panels are arranged at substantially even intervals along the circumferential direction of the front panel. For example, in a configuration in which three tethers are connected, they can be arranged around the center C1 at intervals of about 120 degrees. In this case, the connecting portion between each tether and the front panel 11 may be arranged so as to overlap with the first tack portion 15 or the second tack portion 18.

In the above embodiment, the connection portions (suture lines 22A to 22D) of the four tethers 14A to 14D with the front panel 11 are exemplified, but at least the configuration in which the connecting portions (suture lines 22A to 22D) are arranged at intermediate positions along the radial direction of the front panel 11 is exemplified. It may be arranged in a portion on the outer peripheral side of the central portion 23 that expands toward the head side of the occupant P.

10 Airbag 11 Front panel 12 Rear panel 15 First tack part 18 Second tack part 14A-14D Tether 56 Broken part

Claims (7)

Air for the driver's seat formed by joining the front panel installed on the steering device of the vehicle and arranged on the occupant side at the time of installation and the rear panel arranged on the opposite side to the occupant to each other over the outer periphery of both panels. It ’s a bag,
A first tack portion including a pair of tacks formed by folding the front panel and arranged in parallel on both sides of the center of the front panel.
A second tack portion including a pair of tacks formed by folding the front panel so as to extend in a direction intersecting the first tack portion and arranged in parallel on both sides of the center of the front panel. ,
A plurality of tethers arranged inside the airbag and connecting the front panel and the rear panel,
Equipped with
The plurality of tethers are located on the outer peripheral side of the central portion of the front panel where the first tack portion and the second tack portion intersect, and are located along the circumferential direction of the front panel. At positions arranged at predetermined intervals, each is connected to the front panel and
The plurality of tethers have a breaking portion that breaks depending on the magnitude of tension generated between the connecting portion with the front panel and the connecting portion with the rear panel.
Airbag. The front panel has a circular shape with the first tack portion and the second tack portion formed.
The connecting portion of the plurality of tethers to the front panel is arranged in a range from the intermediate position between the center and the joint portion of the outer periphery of the rear panel in the radial direction of the front panel to the outer peripheral side.
The airbag according to claim 1. The airbag is installed in the steering device so that the front panel rotates in the same direction as the steering wheel as the annular steering wheel of the steering device rotates.
The connection portion of the plurality of tethers with the front panel is arranged at a position corresponding to the chest of the occupant in the expanded state of the airbag when it is in the direction of the lowermost portion of the ring of the steering wheel.
The airbag according to claim 1 or 2. The first tack portion and the second tack portion are arranged orthogonally to each other.
The airbag according to any one of claims 1 to 3. The connecting portion of the plurality of tethers with the front panel is arranged between the first tack portion and the second tack portion in the circumferential direction of the front panel.
The airbag according to any one of claims 1 to 4. The connecting portion of the plurality of tethers with the front panel is formed so as to extend in a direction orthogonal to the radial direction of the front panel.
The airbag according to any one of claims 1 to 5. Inflator and
The airbag according to any one of claims 1 to 6, which is installed in a steering device of a vehicle and is deployed by a gas supplied from the inflator.
An airbag device equipped with.

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