JP6779666B2 - How to fold the airbag device and airbag - Google Patents

Description

The present invention relates to an airbag device including an airbag deployed between the lower limbs of an occupant and a vehicle body, and a method of folding the airbag.

Conventionally, a so-called knee airbag device, which is a knee-protecting airbag device that deploys an airbag facing the knees of an occupant seated in an automobile seat, is known. This knee airbag device is arranged, for example, below the glove box in front of the passenger seat or below the steering wheel in front of the driver's seat on the instrument panel, and a bag-shaped airbag is placed inside the case body. It is folded into a small size and stored. Then, when the control device detects an impact such as a frontal collision of the vehicle, gas is supplied to the airbag from the inflator, the airbag is projected from the case body, and this airbag is further displayed on the dash panel below the instrument panel. It is designed to inflate and deploy between the occupant's knees and the occupant's lower limbs to restrain and protect them.

In such an airbag device, the airbag is folded inward on both the left and right sides in a roll shape, and then rolled from the tip side to the base end side, which is the inflator side, to the surface side, which is the vehicle body side. It is known that the airbag is folded into a shape to improve the expansion / deployment speed of the airbag (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2009-101758 (pages 7-10, FIGS. 3 and 4)

In the knee airbag device as described above, it is required to reliably deploy the airbag main body upward in a narrow gap between the lower limbs of the occupant and the dash panel.

The present invention has been made in view of such a point, and provides an airbag device capable of reliably deploying an airbag between the lower limbs of an occupant and a vehicle body, and a method for folding the airbag. The purpose.

The airbag device according to claim 1 includes a container portion provided on a vehicle body located in front of an occupant, an airbag formed in a bag shape and stored in the container portion, and an inflator that supplies gas to the airbag. The airbag device is an airbag device that projects the tip end side of the airbag from the container portion by the gas from the inflator and deploys the airbag between the lower limbs of the occupant and the vehicle body. In the folded state, the first folded portion folded from the tip side toward the base end side and the first folded portion are folded so as to wrap in a U shape that opens toward the base end side. A second folded portion that is overlapped with the upper part on the base end side, and a third folded portion that is folded so that at least a part thereof faces the opening side of the second folded portion. wherein the container portion, deployable and front Symbol lid positioned on the opposite side position to the opening of the second folding portion, the lid portion is cleaved by deployment of the airbag on the passenger side It is equipped with a weak part .

The airbag device according to claim 2 is the airbag device according to claim 1. In the airbag device according to claim 1, the first folded portion is folded in a roll shape toward the surface side where the tip side is the vehicle body side and toward the base end side. It is in a state.

The airbag device according to claim 3 is the airbag device according to claim 1 or 2, so that the third folding portion wraps the second folding portion in a U shape that opens toward the tip side. It is folded.

The airbag device according to claim 4 is the airbag device according to any one of claims 1 to 3, wherein the container portion is a container portion main body for accommodating an airbag and an occupant at one end of the container portion main body. further and an opening which is closed by a cover portion located opposite the lower extremity, the weak portion is to a position corresponding to the upper edge of the front Symbol opening.

The airbag device according to claim 5 is the airbag device according to any one of claims 1 to 4, wherein the thickness of the airbag between the vehicle body and the lower limbs of the occupant in the deployed state is larger than that on the proximal end side. It is larger on the tip side.

Folding method of the airbag according to claim 6, the lid portion by being formed in a bag shape by inflation with a gas from the inflator while being accommodated in the container portion comprising a lid portion cleaves the weak portion of the container portion This is a method of folding an airbag in which the tip side protrudes from the container portion and expands between the occupant's lower limbs and the vehicle body, and the tip side is folded toward the base end side. The first folding step of forming the folding portion and the first folding portion so as to wrap the first folding portion in a U shape that opens toward the base end side and opposite to the lid portion. A second folding step of forming a second folding portion by overlapping the periphery of the lid on the upper side of the folding base end side, and at least a part of the second folding portion is located so as to face the opening side of the second folding portion. It is provided with a third folding step of folding the periphery of the second folding portion to form a third folding portion.

The method for folding the airbag according to claim 7 is the method for folding the airbag according to claim 6, wherein the first folding portion is rolled toward the surface side where the tip side is the vehicle body side and toward the base end side. It is in a folded state.

The method for folding the airbag according to claim 8 is the method for folding the airbag according to claim 6 or 7, wherein the third folding step is a U-shape that opens the second folding portion toward the tip side. The third folded portion is formed by folding the periphery of the second folded portion so as to wrap it around the second folded portion.

According to the airbag device according to claim 1, the air bag device capable of protecting the lower limbs of an occupant is formed by folding the tip end side of the airbag toward the proximal end side to form a first folded portion. first the second folding portion overlapping the upper side of the mat seen proximal side folding wrap in a U-shape opening on the opposite side of the lid portion of Ikatsu container portion suited to the proximal end side of the folded portion By forming and folding so that at least a part thereof faces the opening side of the second folding portion to form the third folding portion, the gas supplied from the inflator first causes the third folding portion. By rapidly expanding and expanding the folded portion of the above, the first folded portion is stably pushed out from the container portion together with the second folded portion, and then the second folded portion expands and expands. By pushing up the first folded portion upward and then deploying the first folded portion, the airbag can be reliably deployed in the narrow gap between the lower limbs of the occupant and the vehicle body.

According to the airbag device according to claim 2, in addition to the effect of the airbag device according to claim 1, the first folding portion is rolled toward the surface side where the tip side is the vehicle body side and toward the base end side. By folding in a shape, the second folded portion expands and unfolds so that the first folded portion pushed up can be unfolded along the vehicle body, so that the space between the lower limbs of the occupant and the vehicle body is narrow. The airbag can be deployed more reliably in the gap.

According to the airbag device according to claim 3, in addition to the effect of the airbag device according to claim 1 or 2, the third folding portion is opened toward the tip side of the second folding portion. By folding so as to wrap it in a U-shape, the amount of wrapping of the second folding portion by the third folding portion and the size of the third folding portion are changed to change the first and second folding portions. The angle at which the airbag is pushed up can be controlled, and the airbag can be more reliably deployed between the lower limbs of the occupant and the vehicle body.

According to the airbag device according to claim 4, in addition to the effect of the airbag device according to any one of claims 1 to 3, the upper edge portion of the opening of the lid that closes the opening of the container portion is supported. By providing a weak portion that opens when the airbag is deployed at the position where the airbag is deployed, the lid portion that has been cleaved when the airbag is deployed expands downward with respect to the opening, so that the airbag expands upward. It is difficult for the lid to interfere with the airbag, and the airbag can be more reliably deployed between the occupant's lower limbs and the vehicle body.

According to the airbag device according to claim 5, in addition to the effect of the airbag device according to any one of claims 1 to 4, the thickness between the vehicle body and the lower limbs of the occupant in the deployed state of the airbag is determined. Since the size is larger on the tip side than on the base end side, it is possible to secure a stroke at the knee of the lower limb that wants to absorb the most energy while reliably deploying the airbag between the lower limbs of the occupant and the vehicle body.

According to the folding method of the airbag according to claim 6, the first folding step of folding the tip end side of the airbag toward the proximal end side to form the first folding portion, and the first folding. part of unsuitable proximally Ikatsu container portion second overlapping the first upper peripheral folding tatami seen proximal end side of the folded portion so as to wrap in a U-shape opening on the opposite side of the lid portion of the The second folding step of forming the folding portion and the third folding by folding the periphery of the second folding portion so that at least a part of the folding portion is located opposite to the opening side of the second folding portion. By providing a third folding step for forming the tatami mat portion, the gas supplied from the inflator causes the third folding portion to rapidly expand and expand, so that the first folding portion together with the second folding portion is provided. After the folded portion is stably pushed out from the container portion, the second folded portion is subsequently expanded and expanded to push up the first folded portion upward, and then the first folded portion is expanded. By doing so, the airbag can be reliably deployed in the narrow gap between the lower limbs of the occupant and the vehicle body.

According to the method of folding the airbag according to claim 7, in addition to the effect of the method of folding the airbag according to claim 6, in the first folding step, the first folding portion is placed on the vehicle body side at the tip side. By folding in a roll shape toward the surface side to be the base end side, the second folded portion expands and unfolds so that the first folded portion pushed up can be unwound along the vehicle body. Therefore, the airbag can be more reliably deployed in the narrow gap between the lower limbs of the occupant and the vehicle body.

According to the method of folding the airbag according to claim 8, in addition to the effect of the method of folding the airbag according to claim 6 or 7, in the third folding step, the third folding portion is formed into a second. By folding the folded portion so as to cover it in a U-shape that opens toward the tip side, the amount of wrapping of the second folded portion by the third folded portion and the size of the third folded portion. By changing the above, the angle at which the first and second folding portions are pushed up can be controlled, and the airbag can be more reliably deployed between the lower limbs of the occupant and the vehicle body.

It is explanatory drawing of the cross section of the state attached to the vehicle body which shows the airbag device of one Embodiment of this invention. It is explanatory drawing which shows the deployment process following FIG. 1 of the airbag of the above-mentioned airbag device. It is explanatory drawing which shows the unfolding process following FIG. 2 of the above-mentioned airbag. It is explanatory drawing which shows the unfolding process following FIG. 3 of the above-mentioned airbag. It is explanatory drawing which shows the unfolding process following FIG. 4 of the above-mentioned airbag. It is explanatory drawing which shows the deployed state of the airbag as above. (A) is a plan view showing a folding process of the same airbag, and (b) is a cross-sectional view of (a). (A) is a plan view showing a first folding step following FIG. 7 (a) of the same airbag folding step, and (b) is a cross-sectional view of (a). (A) is a plan view showing a part of a second folding step following FIG. 8 (a) of the same airbag folding step, and (b) is a cross-sectional view of (a). (A) is a plan view showing a part of a second folding step following FIG. 9 (a) of the same airbag folding step, and (b) is a cross-sectional view of (a). (A) is a plan view showing a part of a second folding step following FIG. 10 (a) of the same airbag folding step, and (b) is a cross-sectional view of (a). (A) is a plan view showing a third folding step following FIG. 11 (a) of the same airbag folding step, and (b) is a cross-sectional view of (a).

Hereinafter, the configuration of the airbag device and the method of folding the airbag according to the embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 10 denotes an airbag, and the airbag device 11 provided with the airbag 10 is a mounting surface portion as a vehicle body facing the passenger compartment 12 as an interior portion of an automobile as a vehicle to be mounted. It is located on panel 14. The airbag device 11 is also called a knee airbag device, that is, an airbag device for protecting the knee. When an impact such as a frontal collision is received, as shown in FIG. 6, the foot of the occupant, that is, the knee A1 is moved. It is deployed so as to face the lower limb part A including the lower limb part A, and restrains the lower limb part A including the occupant's knee A1 to protect the occupant. Hereinafter, the directions such as the front-rear direction are based on the straight-ahead direction of the vehicle body, that is, as shown in FIG. 1, the front side of the vehicle (direction of arrow F) is the base end side of the airbag 10 and the rear side of the vehicle ( (Arrow R direction) is the tip side and the occupant side of the airbag 10, and the upper and lower sides will be described with reference to the vehicle. Further, as shown in FIG. 7A and the like, the width direction which is the left-right direction of the vehicle is the width direction (arrow W direction) which is both sides of the airbag 10, that is, the left-right direction.

As shown in FIGS. 1 to 6, this vehicle body is provided with a pair of seats on both sides on which passengers can sit in the passenger compartment 12, and in front of these seats, a windshield and an instrument panel ( (Not shown) and are arranged. Further, a panel 14 called a dash panel or the like constituting the instrument panel is arranged in the lower lower part or the middle part below the instrument panel, and the airbag device 11 is placed on the panel 14 facing each seat. It is installed. Further, one seat (not shown) is a driver's seat, and a steering wheel is arranged between the instrument panel and the panel 14. The other seat is a passenger seat, and a glove box or the like is arranged between the instrument panel and the panel 14. In addition to the above-mentioned airbag device 11, the passenger compartment 12 is provided with an airbag device (not shown) on the steering wheel, the instrument panel, the side of the seat, the roof side rail, and the like.

The airbag device 11 includes a case body 21 as a container portion, an inflator 22, a retainer 24, an airbag 10 and the like attached to the case body 21. The case body 21 is also called a housing, and is integrated with the panel 14 separately from the main body 21b as a container main body having a substantially box-like rear surface with an opening 21a and the main body 21b. The inside of the main body 21b is the airbag storage 28. Further, the opening 21a has a quadrangular shape with both sides in the longitudinal direction, and is opened rearward toward the lower part of the occupant's lower limb A (below the knee A1). Further, a plurality of mounting holes (not shown) are formed on the front surface of the main body portion 21b.

The lid portion 21c is a cover body also called a lid or the like, and is integrally formed of, for example, a synthetic resin, and is formed in a flat plate shape flush with, for example, the panel 14. The lid portion 21c is formed of one synthetic resin or a plurality of synthetic resins stacked on top of each other. Further, the lid portion 21c is attached to the main body portion 21b so as to close the opening portion 21a, and at a position corresponding to the upper edge portion of the opening portion 21a, that is, at the upper edge portion of the lid portion 21c. On the occupant side (rear side), a tear line 21d, which is a weak part that can be broken by the unfolding pressure of the airbag 10, is provided in a groove shape. Therefore, the lid portion 21c is configured to open downward toward the rear on the occupant side with the position on the lower edge portion side of the opening 21a as the hinge portion.

The inflator 22 includes an inflator main body 22a having a substantially cylindrical shape, and a gas injection portion is provided near one end of the inflator main body 22a, and a connection portion is provided at the other end. Then, the inflator 22 is connected to the control device via a harness (not shown) connected to the connection portion, and injects gas from the gas injection unit based on the start signal supplied from the control device via the harness.

The retainer 24 is attached to the main body 21b (mounting hole) of the case body 21 via a mounting bolt 24a.

Further, the airbag 10 is formed into a bag shape by sewing one base cloth or sewing a plurality of base cloths, and is folded into a predetermined shape and stored in the airbag storage portion 28 of the case body 21. .. Then, in the present embodiment, the airbag 10 has an airbag main body 30 constituting a bag-shaped outer shell and, for example, first to third partition walls arranged inside the airbag main body 30. The partition walls 31, 32, 33 and a single or a plurality of reinforcing cloths (not shown) arranged inside the airbag main body 30 are joined to each other by sewing or the like.

Then, the airbag main body 30 is used as a first surface portion located on the panel 14 side in the unfolded state by joining one or a plurality of base fabrics cut into a predetermined shape by sewing or the like at appropriate positions. An opening (not shown) in which an upper side surface portion 35 and a lower side surface portion 36 as a second surface portion located on the lower limb portion A side of the occupant in the deployed state are configured, and the inflator 22 is inserted into the base end portion 38 on the front end side. Is provided, and the inside is configured in a bag shape with an air chamber 39. Further, the airbag main body 30 is configured such that the width dimension is the smallest on the base end portion 38 side and the width dimension increases toward the tip end portion 40. The airbag main body 30 includes the base end 38, and a base 41 to be attached to the airbag storage portion 28 is formed in the vicinity of the base end 38, and the airbag main body 30 is folded to the tip end side of the base 41. A protective portion 42, which is a occupant restraint portion that is stored in the airbag storage portion 28 in the state and protrudes from the case body 21 from the opening 21a to the rear side that is the occupant side in the deployed state, is formed.

Further, the partition walls 31, 32, and 33 are each composed of a strip-shaped base cloth, the second partition wall 32 is arranged on the tip portion 40 side of the first partition wall 31, and the partition wall 32 is arranged on the tip portion 40 side of the second partition wall 32. A third partition 33 is arranged. Then, due to the first partition wall 31, the second partition wall 32, and the third partition wall 33, in the present embodiment, the air chamber 39 inside the airbag main body 30 is replaced with the base side air chamber 44, the first partition wall 33. It is divided into four air chambers: an intermediate air chamber 45, a second intermediate air chamber 46, and a distal air chamber 47. The first partition wall 31, the second partition wall 32, and the third partition wall 33 have a length dimension for partitioning the entire length of the airbag main body 30 in the width direction of at least the air chamber 39, and the outer edge portion thereof. It is joined to the airbag body 30 by sewing or the like. Further, the partition walls 31, 32, and 33 are formed with circulation portions (not shown), which are holes as ventilation portions through which gas can flow, at predetermined intervals. As for the four air chambers 44, 45, 46, 47 partitioned by these partition walls 31, 32, 33, the air chambers 44, 45, 46, 47 adjacent to each other are in the partition walls 31, 32, 33, respectively. It is partitioned over the entire width in both sides, that is, in the width direction, and each is configured to communicate only with the distribution section. Further, when the airbag 10 is deployed, the base side air chamber 44 is changed to the first intermediate air chamber 45, the second intermediate air chamber 46, and the distal end side air chamber 47, in other words, the base end portion 38. The volume is set to increase from the side to the tip 40 side. Therefore, the thickness (front-rear stroke) between the panel 14 and the occupant's lower limbs A in the deployed state of the airbag 10 (airbag main body 30) is larger on the tip side than on the base end side. Further, the base 41 is configured in the base side air chamber 44, and a gas introduction portion in which the inflator 22 is arranged is set in the base 41 of the base side air chamber 44.

Further, an attachment (not shown) for inserting, for example, the attachment bolt 24a of the retainer 24 through the base cloth (and the reinforcing cloth) constituting the airbag main body 30 through the gas introduction portion of the airbag 10. A hole is formed.

Next, a method of folding the airbag 10 will be described.

First, the airbag 10, the inflator 22, the retainer 24, and the like are combined to form an assembly. In this step, the inflator 22 is first inserted and fixed inside the retainer 24. Then, the retainer 24 to which the inflator 22 is attached is inserted into the gas introduction portion inside the airbag 10 through the opening of the base end portion 38, and the attachment bolt 24a of the retainer 24 is pulled out from the attachment hole.

Next, as a flattening step, as shown in FIGS. 7A and 7B, the airbag 10 is spread out in a plane so that the upper side surface portion 35 is on the upper side and the lower side surface portion 36 is on the lower side. It is in a flat plate state with a regular shape.

Next, from this flat plate state, as a first folding step, as shown in FIGS. 8 (a) and 8 (b), the tip end side (tip portion 40) of the protective portion 42 of the airbag 10 is placed on the base end side. The first folded portion 51 is formed by folding in a roll shape toward a certain base portion 41 (base end portion 38). At this time, the tip end side of the protective portion 42 is folded so as to be wound around the upper side surface portion 35, which is the surface on the panel 14 (FIG. 1) side in the unfolded state, that is, upward.

After that, as a part of the second folding step, as shown in FIGS. 9A and 9B, the portion of the protective portion 42 of the airbag 10 including the first folding portion 51 is included in the base 41. The overlapping portion 52 is formed by valley folding so as to overlap the upper side surface portion 35 toward (base end portion 38).

Further, as a part of the second folding step, as shown in FIGS. 10A and 10B, the tip portion of the overlapping portion 52 including the first folding portion 51 is attached to the overlapping portion 52. Fold it in a valley so that it overlaps.

Next, as a part of the second folding step, as shown in FIGS. 11A and 11B, the surplus portion of the overlapping portion 52 that does not include the first folding portion 51 is subjected to the second folding portion. The second folding portion 53 is formed by the overlapping portion 52 by bending so as to cover the upper side of the folding portion 51 of 1 and superimposing it on the first folding portion 51. That is, the second folding portion 53 is formed by folding the airbag main body portion 30 (protecting portion 42) around the first folding portion 51. At this time, the second folded portion 53 is formed so as to wrap the first folded portion 51 in a U shape that opens toward the base end side. Therefore, the second folding portion 53 is folded in a so-called alligator shape in which the first folding portion 51 is held up and down.

Then, as a third folding step, as shown in FIGS. 12A and 12B, the base 41 (base end 38) is more than the second folding 53 that wraps the first folding 51. ) Side portion, that is, the airbag main body portion 30 (protection portion 42 and base portion 41) around the second folding portion 53 is folded, and the third folding portion 54 wrapping the second folding portion 53. To form. At this time, the third folded portion 54 is a portion closer to the base portion 41 (base end portion 38) than the second folded portion 53 that encloses the first folded portion 51, and the upper side surface portion 35 and the lower side surface. The tack portions 54a and 54b obtained by picking the portions 36 in a tack shape are formed so as to be overlapped on the upper side and the lower side of the second folded portion 53, respectively. Therefore, the third folding portion 54 is folded in a so-called alligator shape so as to hold the second folding portion 53 that encloses the first folding portion 51 up and down. As a result, in the third folded portion 54, the tack portion 54a, which is a part of the third folded portion 54, faces the front side (base 41 (base end 38) side) which is the opening side of the second folded portion 53. The second folded portion 53 is wrapped in a U shape that opens toward the rear side, that is, the unfolding tip side, which is opposite to the front side which is the opening side of the second folded portion 53. It is formed like a tatami mat. That is, the third folded portion 54 is formed so as to be branched into upper and lower tack portions 54a and 54b. Therefore, the upper tack portion 54a is formed so as to bend from the upper side to the rear side, and the lower tack portion 54b is formed so as to extend linearly toward the rear side.

When the size of the airbag main body 30 in the width direction is larger than that of the opening 21a of the case body 21, both ends of the airbag main body 30 in the width direction are folded into a Z shape or a roll shape.

Then, if necessary, the airbag 10 is covered with a wrapping (not shown), and as shown in FIG. 1, an assembly in which the airbag 10 is folded into a predetermined shape is held, and the case body 21 is held through the opening 21a. Insert the mounting bolt 24a of the retainer 24 through the mounting hole of the case body 21 and screw the nut into the mounting bolt 24a from the outside of the case body 21, so that the assembly, that is, the airbag 10, the inflator 22, retainer 24, etc. are fixed to the case body 21. Next, the airbag device 11 is configured by attaching the lid 21c to the main body 21b of the case body 21 so that the lid 21c covers the opening 21a, that is, the airbag 10.

Then, the case body 21 was fixed to the vehicle body mounting member using an appropriate mounting tool, and the airbag device 11 was attached to the vehicle body so that the lid 21c was flush with the panel 14, and was connected to the inflator 22. The harness is electrically connected to the control device, and the airbag device 11 is installed on the vehicle body as shown in FIG.

Next, the operation of the airbag device 11 will be described.

When the control device detects an impact such as a head-on collision of an automobile from the state shown in FIG. 1, the control device supplies electric power as a start signal through a harness to operate the inflator 22. Then, when gas is supplied from the inflator 22 into the airbag 10, the airbag 10 expands inside the case body 21, first breaking the wrapping, and then the tack portion of the third folding portion 54. The 54a and 54b are expanded, the second folding portion 53 that encloses the first folding portion 51 is moved rearward, and the lid portion 21c is pushed rearward as shown in FIG. 2 to break at the tear line 21d. .. More specifically, first, the gas supplied from the inflator 22 is supplied to the gas supply unit of the base 41 of the airbag 10 while being diffused by the retainer 24. Then, first, the base 41 of the airbag 10 starts to expand and expand, but in particular, it directly communicates with this gas supply part and the gas flow path is linear, that is, it is not a roll or a bellows. Gas is quickly supplied to the lower tack portion 54b and the upper tack portion 54a of the third folding portion 54, and the third folding portion 54 expands to move the second folding portion 53 backward. The tear line 21d is cleaved and the lid portion 21c is expanded so as to rotate toward the passenger compartment 12 side with the lower edge portion as a hinge portion. As a result, as shown in FIG. 3, the second folding portion 53 that encloses the first folding portion 51 is stably pushed out into the vehicle interior 12.

At this time, gas is supplied to the second folding portion 53 following the third folding portion 54, so that the second folding portion 53 that wraps the first folding portion 51 in a U shape is formed. As it expands and unfolds, the second folding portion 53 pushes the first folding portion 51 upward and forward and upward toward the panel 14.

Then, as shown in FIGS. 4 and 5, the second folding portion 53 expands and expands, and gas is supplied to the first folding portion 51 following the second folding portion 53. , The first folding portion 51 unfolds upward so as to roll along the panel 14, efficiently enters between the panel 14 and the lower limb part A of the occupant, and the lower limb part A is placed on the knee A1. Cover the area including the part to prevent and protect the occupant from slipping downward. At this time, since the protective portion 42 is partitioned by the first partition wall 31, the second partition wall 32, and the third partition wall 33, first, the base side air chamber 44 located below the other portions is formed. Expanded, then the first septal chamber 45 is deployed above the base side air chamber 44, and further located above the first septum 45, the second septum 46 Expands, and the tip side air chamber 47 expands further above the other part. Then, the portion of the tip side air chamber 47 expands and expands toward the occupant's knee A1 moving forward due to inertia, restraining and protecting the occupant's knee A1, and as a result, the occupant's waist. It suppresses the movement of the occupant, effectively suppresses the relative movement of the occupant with respect to the vehicle body, and suppresses and protects the panel 14 and the floor surface entering the passenger compartment 12 directly. Finally, the airbag 10 expands and expands into the shape shown in FIG.

As described above, according to the present embodiment, the air bag device 11 capable of protecting the lower limbs A including the occupant's knee A1 is first folded by folding the tip end side of the air bag 10 toward the base end side. The tatami mat 51 is formed, and the periphery of the first tatami mat 51 is folded so as to wrap the first tatami mat 51 in a U shape that opens toward the base end side to form the second tatami mat 53. By forming the third folding portion 54 by folding the periphery of the second folding portion 53 so that at least a part of the second folding portion 53 is located opposite to the opening side of the second folding portion 53. , The gas supplied from the inflator 22 causes the third folding portion 54 to rapidly expand and expand, so that the first folding portion 51 together with the second folding portion 53 is stably expanded from the case body 21. After pushing out to the passenger compartment 12, the second folding portion 53 expands and expands to push up the first folding portion 51 upward in the passenger compartment 12, and then the first folding portion 51. The air bag 10 can be reliably deployed in the narrow gap between the occupant's lower limb A and the panel 14, and a preferable characteristic of reliably protecting the occupant's lower limb A can be realized.

Further, by folding the first folding portion 51 toward the upper side surface portion 35 side, which is the panel 14 side, from the tip end side of the airbag 10 in a roll shape toward the base end side, the second folding portion 53 The first folding portion 51 pushed up by the expansion and deployment expands so that it can be unwound along the panel 14, so that the airbag 10 is more secure in the narrow gap between the occupant's lower limb A and the panel 14. Can be expanded to.

Further, by folding the third folding portion 54 so as to wrap the second folding portion 53 in a U-shape that opens toward the tip side, the second folding portion 54 is used for the second folding. By changing the wrapping amount (alligator amount) of the part 53 and the size of the third folding part 54, the unfolding timing of the third folding part 54 and the first and second folding parts 51 and 53 are pushed up. You can change the power. As a result, the angles at which the first and second folding portions 51 and 53 are pushed up can be controlled, and the airbag 10 can be more reliably deployed between the lower limb portion A of the occupant and the panel 14. The shape of the third folding portion 54 is changed even for a vehicle model in which the mounting position of the airbag 10 (position of the case body 21) is different, that is, a vehicle model in which the required upward deployment angle of the airbag 10 is different. It can be easily dealt with only by.

Further, by providing a tear line 21d that is torn by the deployment of the airbag 10 at a position corresponding to the upper edge of the opening 21a of the lid portion 21c that closes the opening 21a of the case body 21, the airbag 10 is deployed when the airbag 10 is deployed. Since the lid portion 21c in which the tear line 21d is dissociated expands downward with respect to the opening 21a, not only is it difficult for the lid portion 21c to prevent the airbag 10 from expanding upward, but also the airbag 10 is expanded upward by the lid portion 21c. It also has the effect of guiding toward, and makes it possible to more reliably deploy the airbag 10 between the lower limb portion A of the occupant and the panel 14.

Further, since the thickness between the panel 14 and the occupant's lower limb A in the deployed state of the airbag 10 is made larger on the tip side (upper side) than on the proximal end side (lower side), the occupant's lower limb A and the panel While reliably deploying the airbag 10 between 14 and 14, it is possible to secure a stroke at the knee portion A1 of the lower limb portion A that wants to absorb the most energy. In other words, even if the airbag 10 is thicker on the tip side (upper side) than on the base end side (lower side) so as to secure the stroke of the lower limb part A at the knee part A1, the lower limb part of the occupant It can be reliably deployed in the narrow gap between A and the panel 14.

Further, since the deployment behavior can be controlled by the folding method of the airbag 10, there is no need to complicate the configuration of the airbag 10 or the airbag device 11 or change the shape of the airbag 10, and the manufacturing cost of the airbag device 11 is not required. Can be reduced.

Further, since the protection unit 42 is divided into four air chambers 44, 45, 46, 47 by the partition walls 31, 32, 33, it is possible to realize the behavior of sequentially expanding and expanding each air chamber 44, 45, 46, 47. ..

In this way, the airbag 10 quickly and stably expands and expands between the panel 14 and the lower limb A from the airbag storage 28 in a narrow space provided at a low position, and is seated in the vehicle seat. It is possible to provide an airbag device 11 that can effectively protect the lower limbs A of an occupant.

In the above embodiment, the first folded portion 51 is formed in a roll shape, but the present invention is not limited to this configuration, and the first folded portion 51 can be folded into a bellows shape, for example.

Similarly, the third folding portion 54 is formed in an alligator shape, but the present invention is not limited to this configuration, and for example, it can be folded in a bellows shape.

Further, the air chamber 39 is divided into four air chambers 44 to 47, but the number may be three or less, or five or more.

The present invention can be suitably used as a knee airbag device for a vehicle such as an automobile and a method for folding the airbag.

10 airbags
11 Airbag device
14 Panel as a car body
21 Case body as a container
21a opening
21b Main body of the container
21c lid
21d Weak part, tear line
22 Inflator
51 First folding part
53 Second folding part
54 Third folding part A Lower limb part

Claims (8)

A container portion provided on the vehicle body located in front of the occupant, an airbag formed in a bag shape and stored in the container portion, and an inflator for supplying gas to the airbag are provided, and gas from the inflator is provided. An airbag device that projects the tip end side of the airbag from the container portion and deploys it between the lower limb portion of the occupant and the vehicle body.
The airbag is in the folded state.
The first folding part folded from the tip side to the base end side,
A second folding portion that is folded so as to wrap the first folding portion in a U shape that opens toward the base end side and is overlapped on the upper portion of the base end side.
It is provided with a third folding portion that is folded so that at least a part thereof faces the opening side of the second folding portion.
Weak to deployable said container portion has a front Symbol lid positioned on the opposite side position to the opening of the second folding portion, the lid portion is cleaved by deployment of the airbag on the passenger side An airbag device characterized by having a part and . The airbag device according to claim 1, wherein the first folded portion is in a state of being folded in a roll shape toward the surface side where the tip end side is the vehicle body side and toward the base end side. The airbag according to claim 1 or 2, wherein the third folded portion is in a state of being folded so as to wrap the second folded portion in a U shape that opens toward the tip side. apparatus. The container part
The main body of the container that stores the airbag and
An opening located at one end of the main body of the container facing the lower limbs of the occupant and closed by the lid is further provided.
Weak section, before Symbol airbag apparatus of claims 1, characterized in that a position corresponding to the upper edge of the opening 3 any one described. The airbag device according to any one of claims 1 to 4, wherein the thickness of the airbag between the vehicle body and the lower limbs of the occupant in the deployed state is larger on the tip side than on the base end side. .. Is formed in a bag shape by inflation with a gas from the inflator while being accommodated in the container portion comprising a lid push the said lid by cleaving the weak portion of the container portion on the occupant side, the tip from the container portion It is a method of folding an airbag that projects from the side and deploys between the occupant's lower limbs and the vehicle body.
The first folding step of folding the tip side toward the base end side to form the first folding portion, and
The periphery of the first folded portion is folded and overlapped on the upper side of the base end side so as to wrap the first folded portion toward the base end side and open in a U shape opposite to the lid portion. The second folding step of forming the second folding part, and
A third folding step of folding the periphery of the second folding portion so that at least a part of the second folding portion is located facing the opening side of the second folding portion to form a third folding portion. A method of folding an airbag, which is characterized by being equipped. The method for folding an airbag according to claim 6, wherein the first folded portion is in a state of being folded in a roll shape toward the surface side where the tip end side is the vehicle body side and toward the base end side. .. In the third folding step, the periphery of the second folding portion is folded so as to wrap the second folding portion in a U shape that opens toward the tip side to form the third folding portion. The method for folding an airbag according to claim 6 or 7.

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