JP2013006589A - Airbag folding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an airbag folding method that enhances deployment performance of an airbag without using a separate component.SOLUTION: This method has: a planar deployment process of planarly deploying an airbag 2; a first folding process in which a planar part 26 is formed on a base part 22 to fold in such a manner that a restraint part 21 is arranged on the planar part 26 so that the contact surface with an occupant becomes the upper surface; a second folding process in which both ends of the planar part 26 and those of the restraint part 21 are folded inward to have substantially the same size as the width of a retainer 4, and the restraint part 21 and the planar part 26 are formed into a flap part 25 folded into a belt-like shape; a third folding process in which a part on the bottom part 24 side of the flap part 25 is folded to put it between the folded parts of the base part 22 from the vehicle rear side; and a fourth folding process in which the remaining part of the flap part 25 is bellows-folded on the base part 22, and then, a part on the top part 23 side is folded to cover the base part 22 from the vehicle front side.

Description

The present invention relates to an airbag folding method , and more particularly to an airbag folding method capable of improving the deployment performance of an airbag .

  It has become common for vehicles such as automobiles to be equipped with an airbag device for inflating and deploying an airbag in the vehicle in the event of an emergency such as a collision or sudden deceleration to absorb the impact generated on the passenger. Yes. Such an airbag apparatus generally includes an airbag that is normally folded and inflated and deployed in an emergency, an inflator that supplies gas to the airbag, a retainer that fixes the airbag and the inflator, and the retainer And an airbag cover that forms an opening of the airbag.

  When the vehicle collides or suddenly decelerates, gas is supplied from the inflator to the airbag, the airbag is inflated, the airbag cover is opened, the airbag is released into the vehicle, and is inflated and deployed. In particular, in the case of a passenger seat airbag device, the airbag is inflated and deployed in a space surrounded by an instrument panel, a windshield (front glass), and an occupant.

  By the way, as described above, since the airbag breaks the fragile portion of the airbag cover and is released into the vehicle in the process of inflation and deployment, the airbag suddenly jumps out into the vehicle at the moment when the airbag cover is broken. May end up. In this case, when the occupant is approaching the instrument panel, the airbag that is inflated and deployed at high speed interferes with the occupant, and there is a problem that it is difficult to restrain the occupant softly. Therefore, in general, the airbag folding method is devised so that the airbag is inflated upward as much as possible in the initial stage of deployment to avoid interference with an occupant approaching the instrument panel. However, in such a conventional method, there is a problem that the inflation direction is not stable due to a slight difference in how the airbag is folded. As described in Patent Document 1, an airbag that is inflated at a high speed in the initial stage of deployment is an occupant. Inventions aimed at making interference difficult have already been proposed.

  In the invention described in Patent Document 1, the airbag is folded between the airbag and the inner surface of the lid, one end of which is fixed to the retainer and folded, and the belt is folded by a belt-shaped development regulating sheet whose overall length is larger than the reference length. The bag is covered from the rear side of the vehicle body to the front side of the vehicle body, and the reference length is centered immediately above the first reference point at the rear end in the longitudinal direction of the vehicle body of the lid and passes through the first reference point to the windshield. It is defined by the arc length on the rear side of the vehicle body between the first and second reference points of a circle that is in contact with two reference points. According to such a configuration, it is possible to restrict the expansion of the airbag in the initial stage of deployment toward the rear of the vehicle body by the deployment restriction sheet, and it is possible to avoid early interference between the airbag and the occupant.

JP 2001-334900 A

  However, since the invention described in Patent Document 1 adds a deployment regulation sheet that is a separate component from the airbag, the weight of the airbag device that requires a separate manufacturing process from the airbag increases. There is a problem that the folding capacity of the airbag becomes large. Further, in order to avoid early interference between the airbag and the occupant, the airbag is inflated as upward as possible and then inflated and deployed downward or toward the occupant. The air bag easily fluctuates up and down, and the air bag also swings up and down accordingly.

The present invention has been devised in view of such problems, and an object of the present invention is to provide an airbag folding method capable of improving the deployment performance of an airbag without using a separate part.

According to the present invention, an airbag having an airbag that is normally folded and inflated and deployed in an emergency, an inflator that supplies gas to the airbag, and a retainer that fixes the airbag and the inflator. In the airbag folding method of the apparatus, the airbag includes a restraint portion disposed in front of an occupant during inflation and deployment, a root portion connected to the inflator, and a top disposed on the windshield side during inflation and deployment. And a bottom portion disposed between the occupant and the instrument panel during inflating and deploying the airbag in a plane so that the bottom portion, the top portion, and the restraining portion are stacked in this order. A flat surface unfolding step, folding the root portion so as to be folded over the retainer, and the top portion and the top portion on the root portion. A first folding step of forming a flat portion with the tom portion and folding the flat plate portion so that the constraining portion is disposed so that a contact surface with the occupant is an upper surface on the flat portion; A second folding step in which both end portions of the portion are folded inward so as to have a size substantially equal to the width of the retainer, and the flat portion and the restraining portion are formed in a belt-folded flap portion; and A third folding step of folding the bottom portion side portion from the vehicle rear side so as to be sandwiched between the root portions, and the remaining portion of the flap portion is bellows folded on the root portion; And a fourth folding step of folding the portion from the front side of the vehicle so as to cover the root portion. A method for folding an airbag is provided.

In the third folding step, the bottom portion side portion of the flap portion may be roll-folded toward the inflator side. Moreover, you may make it pinch | interpose the front-end | tip part of the said flap part between the said base parts in the said 4th folding process. In the fourth folding step, the bellows-folded portion of the flap portion may be sandwiched between the root portions. Moreover, you may have the wrapping process which wraps the folded said airbag with a wrapping member and hold | maintains a shape after the said 4th folding process.

According to the airbag folding method of the present invention described above, the flap portion including the restraining portion that comes into contact with the occupant is formed, and the flap portion is moved so as to move while rotating toward the occupant during inflation and deployment of the airbag. Since the airbag is folded, the airbag released into the vehicle when the airbag is inflated and deployed moves while the flap part rotates toward the occupant, and the top part is pulled out and inflated and deployed. In addition, the bottom portion can be inflated and deployed to complete the inflation and deployment of the airbag. By moving the flap portion while rotating the flap portion in this way, the flap portion can play a role of regulating the inflation and deployment of the airbag, and suppressing the upward inflation of the airbag during the initial deployment. And early interference with the occupant can be suppressed. Therefore, according to the airbag folding method of the present invention, the deployment performance of the airbag can be improved without using a separate part.

  In addition, by folding the bottom portion of the flap portion toward the inflator side, a time difference can be given to the expansion and expansion of the roll-folded portion. The vehicle interior structure (for example, an airbag cover) can be temporarily pressed, and a base point when the flap portion rotates can be formed.

  In addition, since the tip of the flap portion is sandwiched between the root portions, the shape when the airbag is folded can be easily maintained, and in particular, the folded shape of the flap portion can be stabilized. .

  In addition, the bellows-folded portion of the flap portion is sandwiched between the root portions, so that the shape of the bellows-folded portion can be stabilized.

  Moreover, by wrapping the folded airbag with a wrapping member, the folded shape can be stabilized, and the handling of the airbag module in the manufacturing process of the airbag apparatus can be facilitated.

It is sectional drawing which shows the airbag apparatus which has the airbag folded by the folding method of the airbag which concerns on 1st embodiment of this invention. It is a figure which shows the expansion | deployment deployment behavior of the airbag shown in FIG. 1, (A) is a normal state, (B) has shown the 1st step, (C) has shown the 2nd step. It is a figure which shows the expansion | deployment deployment behavior of the airbag shown in FIG. 1, (A) is a 3rd step, (B) is a 4th step, (C) has shown the completion state of expansion | deployment. It is a figure which shows the airbag shown in FIG. 1, (A) is a front view, (B) has shown the horizontal sectional view. It is a figure which shows the folding method of the airbag which concerns on 1st embodiment of this invention , (A) has shown the plane expansion | deployment process, (B) has shown the 1st folding process. It is a figure which shows the 2nd folding process in the folding method of the airbag which concerns on 1st embodiment of this invention , (A) is a 1st step, (B) is a 2nd step, (C) is a 3rd step, ( D) shows the fourth stage. It is a figure which shows the folding method of the airbag which concerns on 1st embodiment of this invention , (A) is the 3rd folding process, (B) is the 1st step of the 4th folding process, and (C) is the 4th folding. 2 shows the second stage of the process. It is sectional drawing which shows the airbag apparatus which has the airbag folded by the folding method of the airbag which concerns on 2nd embodiment of this invention. It is a figure which shows the folding method of the airbag which concerns on 2nd embodiment of this invention , (A) is a 3rd folding process, (B) is the 1st step of the 4th folding process, and (C) is the 4th folding. 2 shows the second stage of the process.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is a cross-sectional view showing an airbag apparatus having an airbag folded by the airbag folding method according to the first embodiment of the present invention. 2A and 2B are diagrams showing the inflation and deployment behavior of the airbag shown in FIG. 1, wherein FIG. 2A shows the normal state, FIG. 2B shows the first stage, and FIG. 2C shows the second stage. 3A and 3B are diagrams showing the inflation and deployment behavior of the airbag shown in FIG. 1, in which FIG. 3A shows a third stage, FIG. 3B shows a fourth stage, and FIG. 3C shows a deployment completion state. 4A and 4B are diagrams showing the airbag shown in FIG. 1, wherein FIG. 4A is a front view, and FIG. 4B is a horizontal sectional view.

As shown in FIGS. 1 to 4, the airbag device 1 having an airbag folded by the airbag folding method according to the first embodiment of the present invention is normally folded and inflated and deployed in an emergency. And the retainer 4 that fixes the airbag 2 and the inflator 3. The airbag 2 is disposed in front of the occupant when inflated and deployed. A restraint portion 21, a root portion 22 connected to the inflator 3, a top portion 23 disposed on the windshield W side during inflation and deployment, and a bottom disposed between the occupant and the instrument panel I during inflation and deployment Part 24, and at least the restraint part 21 is folded in a band shape with the contact surface 21a with the occupant as the upper surface to form a flap part 25, and the flap part 2 It is folded to move while rotating toward the occupant during inflation and deployment of the airbag 2.

  The airbag apparatus 1 is an airbag apparatus for a passenger seat, and is attached to an instrument panel I disposed on the front surface of the passenger seat as shown in FIG. Specifically, as shown in FIG. 1, the airbag apparatus 1 includes an airbag cover 5 that houses the airbag 2, the inflator 3, and the retainer 4. The retainer 4 is fixed to a holding case 6, and the holding case 6 is locked to the airbag cover 5. As shown in FIG. 1, a bracket 62 for fixing the airbag device 1 to the vehicle interior structure 7 is attached to the holding case 6. In FIG. 1, the left side shows the back side (windshield side), and the right side shows the front side (occupant side).

  As shown in FIG. 1, the airbag cover 5 is obtained by integrally molding a plate-like portion 51 and an inner case 52. The plate-like portion 51 and the inner case 52 may be integrally formed by injection molding, or may be configured integrally by welding the inner case 52 to the back surface of the plate-like portion 51. Note that the airbag cover 5 is not limited to the illustrated structure and shape. For example, the airbag cover 5 may be formed integrally with the instrument panel I, the plate-like portion 51 may be inclined, etc. Those conventionally used can be used as appropriate.

  The plate-like portion 51 is a member that constitutes a part of the vehicle interior surface of the instrument panel I, for example. A thin tear line 51a is formed in a region located inside the inner case 52 of the plate-like portion 51 in accordance with a shape to be cleaved when the airbag 2 is inflated and deployed. The tear line 51a is formed, for example, in a substantially H-shape, and the plate-like portion 51 is split into a pair of door portions 51b and is opened with the hinge portion 54 as a center. For example, the tear line 51a may be formed in a substantially U-shape so that one door portion is open.

  The inner case 52 is configured by a cylindrical wall surface standing in a rectangular shape on the back surface of the plate-like portion 51. The inner case 52 has a plurality of holding holes 53 for locking the holding case 6 and a hinge portion 54 that rotates the door portion 51b. A hook 61 that can be locked in the holding hole 53 is formed in the holding case 6. The hinge portion 54 is constituted by a connecting portion between the plate-like portion 51 and the inner case 52. For example, as shown in FIG. 1, the hinge portion 54 is constituted by a portion in which a part of the inner case 52 is formed thin.

  The inflator 3 is a gas generator that generates gas to be supplied to the airbag 2 and has, for example, a substantially cylindrical outer shape (cylinder type). The inflator 3 is connected to an ECU (electronic control unit) (not shown), and is controlled based on measurement values from an acceleration sensor or the like. When the ECU senses or predicts a vehicle collision or sudden deceleration, the inflator 3 is ignited by the ignition current from the ECU, burns the chemical stored in the inflator 3 to generate gas, and the gas is supplied to the airbag 2. Supply. The inflator 3 is not limited to the illustrated shape, and may be a disk type.

  The retainer 4 includes a lower retainer 41 that supports the inflator 3, and an upper retainer 42 that is disposed on the top of the inflator 3. The inflator 3 is disposed between the lower retainer 41 and the upper retainer 42, and the lower retainer 41 and the upper retainer 42 are connected by a fastener such as a bolt to sandwich the inflator 3. In addition, the connection part of the airbag 2 and the inflator 3 can be sealed by clamping a part of the airbag 2 together between the lower retainer 41 and the upper retainer 42.

  As shown in FIGS. 4A and 4B, the airbag 2 is, for example, a twin bag in which a pair of inflating portions 2a and 2a are arranged in the vehicle left-right direction. As shown in FIG. 4B, the airbag 2 has an opening 2c connected to the retainer 4 on the base end 2b side, and the vicinity of the opening 2c communicates with the inflating portions 2a and 2a. The root portion 22 is configured. A pair of expansion | swelling parts 2a and 2a are connected by the sewing part 2d, and it is comprised so that the shape as one expansion body can be hold | maintained. A tether 2e that restricts the shape in the width direction may be connected to each inflatable portion 2a.

  The front surface of the airbag 2 constitutes a contact surface 21 a that comes into contact with an occupant, and the distal ends of the inflating portions 2 a and 2 a constitute a restraining portion 21. Further, as shown in FIG. 3C, the airbag 2 includes a top portion 23 disposed on the windshield W side, an occupant, an instrument panel I, and an intermediate portion between the restraint portion 21 and the root portion 22. And a bottom portion 24 disposed between the two. The airbag 2 is not limited to the illustrated shape, and may have a vent hole that adjusts the internal pressure, or may be a single bag configured by one inflating portion.

  In addition, as shown in FIG. 1, the airbag 2 is folded so that the flap portion 25 covers the folded airbag 2 from the vehicle front side (windshield side) toward the vehicle rear side (passenger side). ing. More specifically, the bottom portion 24 is wrapped by the top portion 23 so as to be sandwiched from the vehicle front side (wind shield side), and the top portion 23 is flapped so as to be sandwiched from the vehicle front side (wind shield side). It is wrapped in part 25.

Here, the folding method of the airbag 2 , that is, the folding method of the airbag according to the first embodiment of the present invention will be described with reference to FIGS. FIGS. 5A and 5B are diagrams showing a method of folding an airbag according to the first embodiment of the present invention, wherein FIG. 5A shows a flat surface deployment step and FIG. 5B shows a first folding step. FIG. 6 is a diagram showing a second folding step in the airbag folding method according to the first embodiment of the present invention, in which (A) is the first stage, (B) is the second stage, and (C) is the first stage. Three stages, (D) shows the fourth stage. FIG. 7 is a view showing a method of folding an airbag according to the first embodiment of the present invention, in which (A) is a third folding step, (B) is a first stage of a fourth folding step, and (C). Shows the second stage of the fourth folding step.

  In the folding method of the airbag 2 according to the present embodiment, as shown in FIGS. 5 to 7, the airbag 2 is planarly deployed so that the bottom portion 24, the top portion 23, and the restraining portion 21 are stacked in this order. In the flat surface development step, the root portion 22 is folded so as to be folded on the retainer 4, and the flat portion 26 is formed on the root portion 22 by the top portion 23 and the bottom portion 24. A first folding step of folding so that the restraining portion 21 is disposed so that the contact surface is the upper surface, and both the flat portion 26 and both ends of the restraining portion 21 are inward so as to have a size substantially equal to the width of the retainer 4. Folding, the second folding process of forming the restraining part 21 and the flat part 26 in the folded flap part 25, and the bottom part 24 side part of the flap part 25 from the vehicle rear side (occupant side) of the root part 22 In between A third folding step of folding the flap portion 25 so that the remaining portion of the flap portion 25 is bellows folded on the root portion 22, and then covering the root portion 22 from the vehicle front side (windshield side) to the top portion 23 side portion. And a fourth folding step of folding into the fourth.

  The plane deployment process shown in FIG. 5A is a process of planarly deploying the airbag 2 sewn as a bag body on the work table. In order to make it easy to maintain the folded state of the airbag 2, the retainer 4 may be connected to the airbag 2 in advance. In FIG. 5A, a front view, a central sectional view, and a back view are shown from the left side of the drawing. In this flat surface deployment step, the airbag 2 is flattened into a shape in which the airbag 2 is crushed from above while pressing the contact surface 21 a of the restraining portion 21. Therefore, the airbag 2 is laminated | stacked in order of the bottom part 24, the top part 23, and the restraint part 21 toward the surface side from the back surface side. Further, the root portion 22 is located between the top portion 23 and the bottom portion 24 in the planar development state. In the surface view, a vent hole 23a and a sewing portion 23b of the tether 2e are arranged on the side surface of the top portion 23. In the rear view, a part of the root portion 22 is folded inside the airbag 2 to form a tongue portion 22 a protruding into the airbag 2.

  The first folding step shown in FIG. 5 (B) is a step of folding the airbag 2 along the folding lines L1 and L2 from the airbag 2 in the flat deployed state shown in FIG. 5 (A). Specifically, as shown in the central sectional view of FIG. 5A, the restraint portion 21 is rotated from the front surface side to the back surface side along the fold line L1, and the retainer 4 is moved along the fold line L2. Rotate on top of root 22. As a result, as shown in FIG. 5B, the airbag 2 is folded so as to have a substantially diamond-shaped outer shape. In FIG. 5B, a front view, a central sectional view, and a back view are shown from the left side of the drawing. As shown in the central cross-sectional view, the base portion 22 is in a bellows-folded state below the retainer 4, and a flat portion 26 is formed under the bellows-folded root portion 22. The surface of the flat part 26 is constituted by the restraining part 21 (contact surface 21 a), the upper part on the back side (base part 22 side) is constituted by part of the bottom part 24, and the lower part is constituted by part of the top part 23. Has been. Further, as shown in the rear view, the surface of the flat portion 26 is configured such that the restraining portion 21 (contact surface 21a) and a part of the top portion 23 are folded.

  In the following steps, the state in which the retainer 4 and the base portion 22 are down and the flat portion 26 is up (the state in which the front and back are reversed), and the top portion 23 side of the flat portion 26 is up and the bottom portion 24 side is up. Assume that the airbag 2 is folded in a state of being lowered (upside down).

  The second folding step shown in FIGS. 6A to 6D is a step of shortening the lateral width so that the airbag 2 can be accommodated in the airbag cover 5. Specifically, as in the first stage shown in FIG. 6 (A), the top part 23 and the bottom part 24 constituting the flat part 26 are roll-folded upward and shown in FIG. 6 (B). As in the second stage, the flat portion 26 is hidden under the restraint portion 21. Similarly, the opposite side is also rolled and the top part 23 and the bottom part constituting the flat part 26 are formed below the restraining part 21 constituting the flat part 26 as in the third stage shown in FIG. Fold 24 in a folded state.

  Next, as in the fourth stage shown in FIG. 6D, the constraining portion 21 constituting the flat portion 26 is folded downward (inflator side), and the same width as the roll-folded portion of the flat portion 26 is obtained. To be. At this time, when the width of the restraining portion 21 constituting the flat portion 26 is large, it may be roll-folded downward (inflator side). Thus, by shortening the lateral width of the flat portion 26 and the restraining portion 21 and folding the flat portion 26 and the restraining portion 21 in a band shape by folding the flat portion 26 and the restraining portion 21 so as to be approximately the same as the width of the retainer 4, Form.

  The third folding step shown in FIG. 7A is a step of folding the flap portion 25 so that the bottom portion 24 side portion can be accommodated in the airbag cover 5. A portion of the flap portion 25 on the bottom portion 24 side is roll-folded downward (on the inflator side) toward the root portion 22 where the bellows is folded. At this time, a part of the root portion 22 that has been folded in the bellows is pulled out, and the roll-folded portion of the flap portion 25 is supported by about half the area.

  The fourth folding step shown in FIGS. 7B and 7C is a step of folding the flap portion 25 so that the portion on the top portion 23 side can be accommodated in the airbag cover 5. Specifically, by folding the portion on the top portion 23 side of the flap portion 25 shown in FIG. 7A once in the direction indicated by the arrow in the drawing, as shown in FIG. The remaining part of 25 is accordion-folded on the root part 22. At the same time, folding is performed so as to cover the bellows-folded portion of the flap portion 25 with a part of the bellows-folded root portion 22 pulled out in the third folding step. That is, the bellows-folded portion of the flap portion 25 is sandwiched between the root portions 22.

  Subsequently, the front end portion of the flap portion 25 that protrudes from the folded airbag 2 is folded so as to cover the portion of the root portion 22 that is accordion-folded, as indicated by an arrow shown in FIG. At this time, if the leading end portion of the flap portion 25 is sandwiched between the bellows-folded root portion 22, the shape of the folded airbag 2 can be stably maintained. As a result, as shown in FIG. 7C, the entire airbag 2 can be folded on the retainer 4 to a size that can be accommodated in the airbag cover 5.

  Finally, after the fourth folding step, a wrapping step of wrapping the folded airbag 2 with the wrapping member 27 shown in FIG. 7C and maintaining the shape may be added. Specifically, one end of the wrapping member 27 is locked to a fastener such as a bolt attached to the retainer 4, and the other end of the wrapping member 27 is attached to the other side fastener so as to wrap the folded airbag 2. Lock. Further, the entire side surface of the airbag 2 may be covered with the wrapping member 27 by wrapping the side surface portion of the airbag with the side surface portion 27a of the wrapping member 27 and engaging the fastener with a fastener. By wrapping the airbag 2 in this way, the handling of the airbag module in the manufacturing process of the airbag device 1 can be facilitated. The wrapping member 27 is formed of the same material as the base fabric that constitutes the airbag 2, for example. In addition, a tear line 27 b that is torn when the airbag 2 is inflated and deployed is formed at an intermediate portion of the wrapping member 27.

  By folding the airbag 2 by the above-described folding method, the bottom portion 24 is wrapped in the root portion 22 so as to be sandwiched from the vehicle front side (windshield side), and the root portion 22 is placed on the vehicle front side (windshield side). ) And the top portion 23 is wrapped by the flap portion 25 so as to be sandwiched from the vehicle front side (windshield side). That is, the flap portion 25 is folded so as to cover the folded airbag 2 from the vehicle front side (windshield side) toward the vehicle rear side (occupant side).

  Finally, the airbag device 1 connects the inflator 3 to the retainer 4, fixes the airbag 2, the inflator 3 and the retainer 4 folded on the holding case 6, and holds the holding case 6 to the airbag cover 5. By being engaged with the hole 53, it is formed in the state shown in FIG.

  Next, the inflating and deploying behavior of the airbag 2 folded by the above-described folding method will be described with reference to FIGS. In addition, the shape shown with the dashed-two dotted line in FIG.2 (C)-FIG.3 (B) illustrates the expansion | deployment deployment behavior in the airbag 200 of a prior art as a comparative example.

  The normal state shown in FIG. 2 (A) is a state in which the vehicle has not collided or suddenly decelerated. The airbag 2 is fixed by fitting an airbag cover 5 on the instrument panel I, and windshields W are disposed in front of and above the instrument panel I.

  In an emergency such as a collision or a sudden deceleration, the inflator 3 is operated and gas is ejected into the airbag 2 based on a command from an ECU (electronic control unit). The gas ejected into the airbag 2 first inflates the root portion 22 and moves the flap portion 25 folded on the root portion 22 upward, as in the first stage shown in FIG. And the airbag cover 5 is cleaved.

  Further, when the gas is supplied into the airbag 2, the top portion 23 side portion of the flap portion 25 can be pushed upward and released into the vehicle as in the second stage shown in FIG. It becomes a state. Moreover, since the part by the side of the bottom part 24 of the flap part 25 is roll-folded, it is difficult to unravel, it can give a time difference to expansion | deployment, and it is extruded with the roll-folded state, and is an airbag. The cover 5 is temporarily pressed near the outlet. On the other hand, in the prior art airbag 200 at the same time, generally, since it is easily folded upward from the airbag cover 5, it is folded upward from the airbag 2 according to the present embodiment. It has become.

  Further, when gas is supplied into the airbag 2, a roll in which the portion on the top portion 23 side of the flap portion 25 is pressed against the airbag cover 5 as in the third stage shown in FIG. It moves while turning toward the occupant with the folded portion as a base point. On the other hand, since the airbag 200 of the prior art at the same time is easily folded upward and is folded, the airbag 2 protrudes upward from the airbag 2 according to the present embodiment and extends along the windshield W. Is in an expanded state.

  Further, when the gas is supplied into the airbag 2, the top portion 23 is moved along with the rotation of the portion on the top portion 23 side of the flap portion 25 as in the fourth stage shown in FIG. Inflated and deployed, the back surface (surface on the vehicle front side) of the flap portion 25 is inflated and deployed toward the windshield W. At this time, the roll folded portion pressed against the airbag cover 5 is gradually unrolled as the airbag 2 is inflated and deployed. On the other hand, in the prior art airbag 200 at the same time, the airbag 200 is inflated and deployed upward along the windshield W, and the entire airbag 200 is pulled out into the vehicle and then inflated and deployed downward. It has become.

  Further, when the gas is supplied into the airbag 2, the flap portion 25 is inflated and deployed toward the occupant to form the contact surface 21a as shown in the deployed state shown in FIG. The portion of the roll fold pressed against the cover 5 is completely unwound, and the bottom portion 24 is inflated and deployed between the occupant and the instrument panel I. On the other hand, the conventional airbag 200 at the same time is also inflated and deployed in substantially the same shape. In FIG. 3C, the alternate long and short dash line that divides the restraining portion 21, the root portion 22, the top portion 23, and the bottom portion 24 is merely a virtual boundary line.

  By the way, in the conventional airbag 200, since the airbag 200 is inflated and deployed upward after being inflated and deployed along the windshield W, the vertical fluctuation of the gas in the airbag 200 is large. The airbag 200 is easy to swing up and down. On the other hand, in the airbag 2 according to this embodiment, since the top portion 23 is inflated and deployed as the flap portion 25 rotates, the vertical fluctuation of the gas during the inflation process of the airbag 2 can be reduced. It is possible to suppress the vertical swing of the airbag 2.

  In addition, as described above, in the present embodiment, the flap portion 25 plays a role of regulating the inflation and deployment of the airbag 2 by moving the flap portion 25 formed by the restraining portion 21 while rotating. It is possible to suppress the upward expansion of the airbag 2 at the time of initial deployment, and early interference with the occupant can be suppressed. In particular, since the flap portion 25 is formed by folding a part of the airbag 2, it is not necessary to use a separate part, and it is not necessary to add an extra manufacturing process. An increase in the folding capacity of the bag 2 can also be suppressed.

  Further, as described above, in the present embodiment, the bottom portion 24 is wrapped with the top portion 23 so as to be sandwiched from the vehicle front side (windshield W side), and the top portion 23 is sandwiched from the vehicle front side (windshield W side). Thus, the airbag 2 can be inflated and deployed in the order of the flap portion 25, the top portion 23, and the bottom portion 24.

Next, an airbag folding method and an airbag apparatus provided with the airbag according to the second embodiment of the present invention will be described with reference to FIGS. 8 and 9. Here, FIG. 8 is a sectional view showing an airbag apparatus having an airbag folded by the airbag folding method according to the second embodiment of the present invention. FIG. 9 is a view showing a method of folding an airbag according to the second embodiment of the present invention, in which (A) is a third folding step, (B) is a first stage of a fourth folding step, and (C). Shows the second stage of the fourth folding step. In addition, about the folding method of the airbag 2 which concerns on 1st embodiment mentioned above, and the airbag apparatus 1 provided with the airbag 2, and the same component, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  The airbag apparatus 1 shown in FIG. 8 has the same configuration as that of the airbag apparatus 1 shown in FIG. 1, and only the folding method of the airbag 2 is different. In the airbag 2 shown in FIG. 8, the portion sandwiched between the bellows-folded root portions 22 is only the portion of the flap portion 25 on the bottom portion 24 side that is roll-folded. In other words, the portion of the flap portion 25 that is accordion folded on the root portion 22 is not sandwiched between the root portions 22 that are folded accordion. Even with this configuration, like the airbag 2 according to the first embodiment, the flap portion 25 can be folded so as to move while rotating toward the occupant when the airbag 2 is inflated and deployed. The airbag 2 can be inflated and deployed with substantially the same behavior as the inflating and deploying behavior shown in FIG.

  The folding method of the airbag 2 according to the second embodiment described above is the same as the folding method of the airbag 2 according to the first embodiment in the plane deployment process to the second folding process and the wrapping process illustrated in FIGS. 5 and 6. The same. Hereinafter, based on FIG. 9 (A)-(C), a 3rd folding process and a 4th folding process are demonstrated.

  The third folding step shown in FIG. 9A is a step of folding the flap portion 25 so that the portion on the bottom portion 24 side can be accommodated in the airbag cover 5. The portion of the flap portion 25 on the bottom portion 24 side is roll-folded downward (inflator side) toward the root portion 22 where the bellows is folded, as indicated by the arrows in the figure.

  The fourth folding step shown in FIGS. 9B and 9C is a step of folding the flap portion 25 so that the portion on the top portion 23 side can be accommodated in the airbag cover 5. Specifically, as shown in FIG. 9 (B), the flap portion 25 shown in FIG. 9 (A) is folded once in the direction indicated by the arrow of the flap portion 25 as shown in FIG. 9 (B). 25 is bellows folded on the root portion 22.

  Subsequently, the front end portion of the flap portion 25 that protrudes from the folded airbag 2 is folded so as to cover the portion of the root portion 22 that is accordion-folded, as indicated by an arrow in FIG. At this time, if the leading end portion of the flap portion 25 is sandwiched between the bellows-folded root portion 22, the shape of the folded airbag 2 can be stably maintained. As a result, as shown in FIG. 9C, the entire airbag 2 can be folded on the retainer 4 to a size that can be accommodated in the airbag cover 5.

  In the above-described embodiment, the case where the present invention is applied to a passenger seat airbag device has been described. However, as long as the airbag device can adopt the same configuration, the driver seat airbag device, the side airbag device, the curtain You may make it apply to an airbag apparatus, a knee airbag apparatus, an airbag apparatus for pedestrians, etc.

  The present invention is not limited to the above-described embodiment, and the air bag 1 may be a single bag formed of a three-piece base fabric, and various modifications can be made without departing from the spirit of the present invention. is there.

DESCRIPTION OF SYMBOLS 1 ... Airbag apparatus 2 ... Airbag 2a ... Expansion | swelling part 2b ... Base end part 2c ... Opening part 2d ... Sewing part 2e ... Tether 3 ... Inflator 4 ... Retainer 5 ... Airbag cover 6 ... Holding case 7 ... Car interior structure 21 ... restraint part 21a ... contact surface 22 ... root part 22a ... tongue part 23 ... top part 23a ... vent hole 23b ... sewing part 24 ... bottom part 25 ... flap part 26 ... flat part 27 ... lapping member 27a ... side part 27b ... tear line DESCRIPTION OF SYMBOLS 41 ... Lower retainer 42 ... Upper retainer 51 ... Plate-like part 51a ... Tear line 51b ... Door part 52 ... Inner case 53 ... Holding hole 54 ... Hinge part 61 ... Hook 62 ... Bracket 200 ... Air bag (prior art)

Claims (5)

An airbag that is normally folded and inflated and deployed in an emergency, an inflator that supplies gas to the airbag, and a retainer that fixes the airbag and the inflator. In the folding method,
The airbag includes a restraint portion disposed in front of an occupant during inflation and deployment, a root portion connected to the inflator, a top portion disposed on a windshield side during inflation and deployment, and an occupant and instrument during inflation and deployment. A bottom portion disposed between the panel and
A plane deployment step of planarly deploying the airbag so as to be laminated in the order of the bottom portion, the top portion and the restraint portion;
The base part is folded so as to be folded on the retainer, a flat part is formed on the base part by the top part and the bottom part, and a contact surface with the occupant is formed on the flat part. A first folding step of folding so that the restraining portion is disposed,
A second folding step in which both ends of the planar portion and the restraining portion are folded inward so as to have a size substantially equal to the width of the retainer, and the planar portion and the restraining portion are formed in a flap portion folded in a band shape. When,
A third folding step of folding the flap portion so that the portion on the bottom portion side is sandwiched between the root portions from the vehicle rear side;
A fourth folding step of folding the remaining portion of the flap portion on the root portion and then folding the top portion side portion from the vehicle front side so as to cover the root portion;
A method of folding an airbag, comprising:   2. The airbag folding method according to claim 1, wherein in the third folding step, a portion of the flap portion on the bottom portion side is roll-folded toward an inflator side.   2. The airbag folding method according to claim 1, wherein, in the fourth folding step, a front end portion of the flap portion is sandwiched between the root portions. 3.   2. The airbag folding method according to claim 1, wherein in the fourth folding step, a bellows-folded portion of the flap portion is sandwiched between the root portions. 3. 2. The airbag folding method according to claim 1, further comprising a wrapping step of holding the shape by wrapping the folded airbag with a wrapping member after the fourth folding step. 3.